Isochrony in barks of Cape fur seal (Arctocephalus pusillus pusillus) pups and adults

Animal vocal communication often relies on call sequences. The temporal patterns of such sequences can be adjusted to other callers, follow complex rhythmic structures or exhibit a metronome-like pattern (i.e., isochronous). How regular are the temporal patterns in animal signals, and what influences their precision? If present, are rhythms already there early in ontogeny? Here, we describe an exploratory study of Cape fur seal (Arctocephalus pusillus pusillus) barks-a vocalisation type produced across many pinniped species in rhythmic, percussive bouts. This study is the first quantitative description of barking in Cape fur seal pups. We analysed the rhythmic structures of spontaneous barking bouts of pups and adult females from the breeding colony in Cape Cross, Namibia. Barks of adult females exhibited isochrony, that is they were produced at fairly regular points in time. Instead, intervals between pup barks were more variable, that is skipping a bark in the isochronous series occasionally. In both age classes, beat precision, that is how well the barks followed a perfect template, was worse when barking at higher rates. Differences could be explained by physiological factors, such as respiration or arousal. Whether, and how, isochrony develops in this species remains an open question. This study provides evidence towards a rhythmic production of barks in Cape fur seal pups and lays the groundwork for future studies to investigate the development of rhythm using multidimensional metrics.

DNA-metabarcoding supports trophic flexibility and reveals new prey species for the Galapagos sea lion

Tropical ecosystems are challenging for pinnipeds due to fluctuating food availability. According to previous research, the Galapagos sea lion (GSL, Zalophus wollebaeki) adopts trophic flexibility to face such conditions. However, this hypothesis comes from studies using traditional methods (hard-parts analysis of scat and isotopic analysis from tissue). We studied the diet of five rookeries in the southeastern Galapagos bioregion (which harbors the highest GSL density), via DNA-metabarcoding of scat samples. The DNA-metabarcoding approach may identify consumed prey with a higher taxonomic resolution than isotopic analysis, while not depending on hard-parts remaining through digestion. Our study included five different rookeries to look for evidence of trophic flexibility at the bioregional level. We detected 98 prey OTUs (124 scats), mostly assigned to bony-fish taxa; we identified novel prey items, including a shark, rays, and several deep-sea fish. Our data supported the trophic flexibility of GSL throughout the studied bioregion since different individuals from the same rookery consumed prey coming from different habitats and trophic levels. Significant diet differentiations were found among rookeries, particularly between Punta Pitt and Santa Fe. Punta Pitt rookery, with a more pronounced bathymetry and lower productivity, was distinguished by a high trophic level and consumption of a high proportion of deep-sea prey; meanwhile, Santa Fe, located in more productive, shallow waters over the shelf, consumed a high proportion of epipelagic planktivorous fish. Geographic location and heterogeneous bathymetry of El Malecon, Española, and Floreana rookeries would allow the animals therein to access both, epipelagic prey over the shelf, and deep-sea prey out of the shelf; this would lead to a higher prey richness and diet variability there. These findings provide evidence of GSL adopting a trophic flexibility to tune their diets to different ecological contexts. This strategy would be crucial for this endangered species to overcome the challenges faced in a habitat with fluctuating foraging conditions.

Effects of river regulation on aquatic invertebrate community composition: A comparative analysis in two southern African rivers

While natural floods play a crucial role in shaping the composition of aquatic communities, the most rivers worldwide are regulated or dammed for anthropogenic purposes, resulting in alterations to the biological and chemical composition of these ecosystems. Studies have demonstrated various negative effects of river regulation on aquatic invertebrate communities globally. However, there is a scarcity of research in Africa, despite its vulnerability to anthropogenic impacts. This study aimed to compare aquatic invertebrate communities in the Phongolo River, an impacted regulated river, and the Usuthu River, a less impacted unregulated river, in South Africa. It further aimed to ascertain whether Lake Nyamithi, a naturally saline lake receiving water from both of the aforementioned systems, exhibited a stronger similarity to one of the two rivers in terms of its aquatic invertebrate composition. Aquatic invertebrate and water samples were collected from 2012 to 2018 over several surveys. The Usuthu River demonstrated a diverse and sensitive aquatic invertebrate community, emphasising its high conservation value. The Phongolo River demonstrated effects of anthropogenic impact, with taxa more resilient to changes in water quality and flow compared to the Usuthu River. Mismanagement and excessive water use may lead to the loss of any remaining sensitive aquatic invertebrate communities in this river. The presence of invasive molluscan in the Phongolo River and Lake Nyamithi also poses a threat to the native aquatic invertebrate communities. These invasive species are currently absent from the Usuthu River although other invasive species, such as the Australian redclaw crayfish, are found in both river systems. Lake Nyamithi displayed a unique aquatic invertebrate community, distinct from both rivers and their floodplains. This study provides important baseline information on the Usuthu River's aquatic invertebrates and emphasises the need to maintain adequate water flow in rivers and floodplains to protect biodiversity and sensitive species.

Only kosmotrope anions trigger fibrillization of the recombinant core spidroin eADF4(C16) from Araneus diadematus

Recombinant core spidroin eADF4(C16) has received increasing attention due to its ability to form micro- and nano-structured scaffolds, which are based on nanofibrils with great potential for biomedical and biotechnological applications. Phosphate anions have been demonstrated to trigger the eADF4(C16) self-assembly into cross-beta fibrils. In the present work, we systematically addressed the effect of nine sodium anions, namely SO4 2- , HPO4 2- (Pi), F- , Cl- , Br- , NO3 - , I- , SCN- , and ClO4 - from the Hofmeister series on the in vitro self-assembly kinetics of eADF4(C16). We show that besides the phosphate anions, only kosmotropic anions such as sulfate and fluoride can initiate the eADF4(C16) fibril formation. Global analysis of the self-assembly kinetics, utilizing the platform AmyloFit, showed the nucleation-based mechanism with a major role of secondary nucleation, surprisingly independent of the type of the kosmotropic anion. The rate constant of the fibril elongation in mixtures of phosphate anions with other studied anions correlated with their kosmotropic or chaotropic position in the Hofmeister series. Our findings suggest an important role of anion hydration in the eADF4(C16) fibrillization process.

Barriers to and enablers of the promotion of patient and family participation in primary healthcare nursing in Brazil, Germany and Spain: A qualitative study

BACKGROUND

Most health systems are insufficiently prepared to promote the participation of chronically ill patients in their care. Strong primary health care (PHC) strengthens patients' resources and thus promotes their participation. The tasks of providing continuous care to people with chronic diseases and promoting self-management are the responsibility of PHC nurses. Recent research assessing enablers of or barriers to nurses' efforts to support patients' participation has mostly not considered the special situation of patients with chronic diseases or focused on the PHC setting.

OBJECTIVE

To investigate enablers of and barriers to PHC nurses' efforts to promote the participation of chronically ill patients in their care.

METHODS

We interviewed 34 practicing PHC nurses and 23 key informants with advanced knowledge of PHC nursing practice in Brazil, Germany and Spain. The data was analyzed using thematic coding.

RESULTS

We identified four categories of barriers and enablers. (1) Establishing bonds with patients: Interviewees emphasized that understanding patients' views and behaviours is important for PHC nurses. (2) Cooperation with relatives and families: Good relationships with families are fundamental, however conflicts within families could challenge PHC nurses efforts to strengthen participation. (3) Communication and cooperation within PHC teams: PHC nurses see Cooperative team structures as a potential enabler, while the dominance of a 'biomedical' approach to patient care is seen as a barrier. (4) Work environment: Interviewees agreed that increased workload is a barrier to patient participation.

DISCUSSION AND CONCLUSIONS

Supporting patient participation should be acknowledged as an important responsibility for nurses by general practitioners and PHC planners. PHC nurses should be trained in communicative competence when discussing participation with chronically ill patients. Interprofessional education could strengthen other professionals' understanding of patient participation as a nursing task.

PATIENT OR PUBLIC CONTRIBUTION

This study is part of a research project associated with the research network 'forges: User-oriented care: Promotion of health in the context of chronic diseases and care dependency'. The study's focus and provisional results were discussed continuously with partners in health and social care practice and presented to and discussed with the public at two conferences in which patient representatives, professionals and researchers participated.

The K+ transporter NPF7.3/NRT1.5 and the proton pump AHA2 contribute to K+ transport in Arabidopsis thaliana under K+ and NO3- deficiency

Nitrate (NO3 -) and potassium (K+) are distributed in plants via short and long-distance transport. These two pathways jointly regulate NO3 - and K+ levels in all higher plants. The Arabidopsis thaliana transporter NPF7.3/NRT1.5 is responsible for loading NO3 - and K+ from root pericycle cells into the xylem vessels, facilitating the long-distance transport of NO3 - and K+ to shoots. In this study, we demonstrate a protein-protein interaction of NPF7.3/NRT1.5 with the proton pump AHA2 in the plasma membrane by split ubiquitin and bimolecular complementation assays, and we show that a conserved glycine residue in a transmembrane domain of NPF7.3/NRT1.5 is crucial for the interaction. We demonstrate that AHA2 together with NRT1.5 affects the K+ level in shoots, modulates the root architecture, and alters extracellular pH and the plasma membrane potential. We hypothesize that NRT1.5 and AHA2 interaction plays a role in maintaining the pH gradient and membrane potential across the root pericycle cell plasma membrane during K+ and/or NO3 - transport.

Occupancy of the Ethiopian endemic Moorland Francolin in pristine and degraded Afroalpine biome using a camera trap approach

Occupancy modeling is an essential tool for understanding species-habitat associations, thereby helping to plan the conservation of rare and threatened wildlife species. The conservation status and ecology of several avian species, particularly ground-dwelling birds, are poorly known in Ethiopia. We used camera trap-based occupancy modeling to investigate habitat covariate influence on occupancy (Ψ) and detection probability (ρ) estimates of Moorland Francolins Scleroptila psilolaema from spatially replicated surveys across both relatively pristine and disturbed landscapes in the Afroalpine biome of Ethiopia. Model-averaged estimate of ψ ^ across all sites was 0.76 (SD = 0.28) and ρ ^ was 0.77 (SD = 0.13) in the pristine landscape. The ψ ^ of the species in the disturbed landscape was 0.56 (SD = 0.19) and ρ ^ was 0.48 (SD = 0.06). As hypothesized, based on our model-averaged beta coefficient estimates (βmean ± SE), predators significantly negatively influenced the occupancy of Moorland Francolins in pristine habitat. We also found a significant positive association of occupancy with herb species richness. Contrary to our prediction, distance to road significantly negatively influence the occupancy of the species, suggesting that occupancy probability was highest in proximity to roadsides and trails in the pristine habitat. There was no significant influence of habitat covariates on the occupancy of the species in the disturbed habitat. The most important covariates that significantly influence the detectability of the species in pristine habitat included sampling occasion and precipitation. The greater occupancy and detectability of this endemic species in the pristine habitat could be linked with the particular conservation status and management of this biodiversity hotspot in the central highlands of Ethiopia. Our results suggest that strict legal enforcement is required to sustainably preserve Moorland Francolins and the ecological integrity of the entire Afroalpine biome. We recommend using camera traps in order to develop realistic and effective conservation and management strategies for rare, sensitive, cryptic, and ground-dwelling animals in the region.

Differential expression of immunity-related genes in larval Manduca sexta tissues in response to gut and systemic infection

Introduction

The midgut epithelium functions as tissue for nutrient uptake as well as physical barrier against pathogens. Additionally, it responds to pathogen contact by production and release of various factors including antimicrobial peptides, similar to the systemic innate immune response. However, if such a response is restricted to a local stimulus or if it appears in response to a systemic infection, too is a rather underexplored topic in insect immunity. We addressed the role of the midgut and the role of systemic immune tissues in the defense against gut-borne and systemic infections, respectively.

Methods

Manduca sexta larvae were challenged with DAP-type peptidoglycan bacteria - Bacillus thuringiensis for local gut infection and Escherichia coli for systemic stimulation. We compared the immune response to both infection models by measuring mRNA levels of four selected immunity-related genes in midgut, fat body, hematopoietic organs (HOs), and hemocytes, and determined hemolymph antimicrobial activity. Hemocytes and HOs were tested for presence and distribution of lysozyme mRNA and protein.

Results

The midgut and circulating hemocytes exhibited a significantly increased level of lysozyme mRNA in response to gut infection but did not significantly alter expression in response to a systemic infection. Conversely, fat body and HOs responded to both infection models by altered mRNA levels of at least one gene monitored. Most, but not all hemocytes and HO cells contain lysozyme mRNA and protein.

Discussion

These data suggest that the gut recruits immune-related tissues in response to gut infection whereas systemic infections do not induce a response in the midgut. The experimental approach implies a skewed cross-talk: An intestinal infection triggers immune activity in systemic immune organs, while a systemic infection does not elicit any or only a restricted immune response in the midgut. The HOs, which form and release hemocytes in larval M. sexta, i) synthesize lysozyme, and ii) respond to immune challenges by increased immune gene expression. These findings strongly suggest that they not only provide phagocytes for the cellular immune response but also synthesize humoral immune components.

Sex-related patterns in the electroencephalogram and their relevance in machine learning classifiers

Deep learning is increasingly being proposed for detecting neurological and psychiatric diseases from electroencephalogram (EEG) data but the method is prone to inadvertently incorporate biases from training data and exploit illegitimate patterns. The recent demonstration that deep learning can detect the sex from EEG implies potential sex-related biases in deep learning-based disease detectors for the many diseases with unequal prevalence between males and females. In this work, we present the male- and female-typical patterns used by a convolutional neural network that detects the sex from clinical EEG (81% accuracy in a separate test set with 142 patients). We considered neural sources, anatomical differences, and non-neural artifacts as sources of differences in the EEG curves. Using EEGs from 1140 patients, we found electrocardiac artifacts to be leaking into the supposedly brain activity-based classifiers. Nevertheless, the sex remained detectable after rejecting heart-related and other artifacts. In the cleaned data, EEG topographies were critical to detect the sex, but waveforms and frequencies were not. None of the traditional frequency bands was particularly important for sex detection. We were able to determine the sex even from EEGs with shuffled time points and therewith completely destroyed waveforms. Researchers should consider neural and non-neural sources as potential origins of sex differences in their data, they should maintain best practices of artifact rejection, even when datasets are large, and they should test their classifiers for sex biases.

Androgen receptor agonist and antagonist reduce response of cytokine-induced killer cells on prostate cancer cells

Despite many advances, prostate cancer (PCa) is still the second most frequently diagnosed cancer and fifth leading cause of cancer death in men worldwide. So far, the promising field of onco-immunology has not yet provided a satisfactory treatment option for PCa. Here we show that the ex vivo expansion and activation of cytokine-induced killer (CIK) cells isolated from primary peripheral blood mononuclear cells induce immune-mediated apoptosis in both human PCa LNCaP and C4-2 cells. Interestingly, pretreating LNCaP and C4-2 cells with either androgen or the androgen receptor (AR) antagonist enzalutamide mediates resistance to this immunogenic attack. This is associated with a reduction of both total cell loss and apoptosis levels suggesting one possible mechanism blunting onco-immunological activity. The data also suggest that secreted factors from AR ligand-treated PCa cell suppress lymphocyte proliferation. Further, we analysed immune-mediated killing activity using conditioned media from LNCaP and C4-2 treated cells. The obtained data suggest that the conditioned media from PCa treated cells does not influence a measurable lymphocyte-mediated apoptosis. However, analysing clonal expansion of activated lymphocytes, the androgen-derived conditioned media suppresses lymphocyte proliferation/expansion suggesting inhibition of onco-immunological activity by pretreatment of PCa cells with AR ligands.

Dual-targeting peptides@PMO, a mimetic to the pro-apoptotic protein Smac/DIABLO for selective activation of apoptosis in cancer cells

The refractoriness of tumor cells to apoptosis represents the main mechanism of resistance to chemotherapy. Smac/DIABLO mimetics proved to be effective in overcoming cancer-acquired resistance to apoptosis as a consequence of overexpression of the anti-apoptotic proteins XIAP, cIAP1, and cIAP2. In this work, we describe a dual-targeting peptide capable of selectively activating apoptosis in cancer cells. The complex consists of a fluorescent periodic mesoporous organosilica nanoparticle that carries the short sequences of Smac/DIABLO bound to the αvβ3-integrin ligand. The dual-targeting peptide @PMO shows significantly higher toxicity in αvβ3-positive HeLa cells with respect to αvβ3-negative Ht29 cells. @PMO exhibited synergistic effects in combination with oxaliplatin in a panel of αvβ3-positive cancer cells, while its toxicity is overcome by XIAP overexpression or integrin β3 silencing. The successful uptake of the molecule by αvβ3-positive cells makes @PMO promising for the re-sensitization to apoptosis of many cancer types.

The landscape of the immunoglobulin repertoire in endemic pemphigus foliaceus

Introduction

Primarily driven by autoreactive B cells, pemphigus foliaceus (PF) is an uncommon autoimmune blistering skin disease of sporadic occurrence worldwide. However, PF reaches a prevalence of 3% in the endemic areas of Brazil, the highest ever registered for any autoimmune disease, which indicates environmental factors influencing the immune response in susceptible individuals. We aimed to provide insights into the immune repertoire of patients with PF living in the endemic region of the disease, compared to healthy individuals from the endemic region and a non-endemic area.

Methods

We characterized the B-cell repertoire in i) nontreated patients (n=5); ii) patients under immunosuppressive treatment (n=5); iii) patients in remission without treatment (n=6); and two control groups iv) from the endemic (n=6) and v) non-endemic areas in Brazil (n=4). We used total RNA extracted from peripheral blood mononuclear cells and performed a comprehensive characterization of the variable region of immunoglobulin heavy chain (IGH) in IgG and IgM using next-generation sequencing.

Results

Compared to individuals from a different area, we observed remarkably lower clonotype diversity in the B-cell immune repertoire of patients and controls from the endemic area (p < 0.02), suggesting that the immune repertoire in the endemic area is under geographically specific and intense environmental pressure. Moreover, we observed longer CDR3 sequences in patients, and we identified differential disease-specific usage of IGHV segments, including increased IGHV3-30 and decreased IGHV3-23 in patients with active disease (p < 0.04). Finally, our robust network analysis discovered clusters of CDR3 sequences uniquely observed in patients with PF.

Discussion

Our results indicate that environmental factors, in addition to disease state, impact the characteristics of the repertoire. Our findings can be applied to further investigation of the environmental factors that trigger pemphigus and expand the knowledge for identifying new targeted and more effective therapies.

Cell type-specific roles of NLRP3, inflammasome-dependent and -independent, in host defense, sterile necroinflammation, tissue repair, and fibrosis

The NLRP3 inflammasome transforms a wide variety of infectious and non-infectious danger signals that activate pro-inflammatory caspases, which promote the secretion of IL-1β and IL-18, and pyroptosis, a pro-inflammatory form of cell necrosis. Most published evidence documents the presence and importance of the NLRP3 inflammasome in monocytes, macrophages, and neutrophils during host defense and sterile forms of inflammation. In contrast, in numerous unbiased data sets, NLRP3 inflammasome-related transcripts are absent in non-immune cells. However, an increasing number of studies report the presence and functionality of the NLRP3 inflammasome in almost every cell type. Here, we take a closer look at the reported cell type-specific expression of the NLRP3 inflammasome components, review the reported inflammasome-dependent and -independent functions, and discuss possible explanations for this discrepancy.

Nickel Oxide Decorated Halloysite Nanotubes as Sulfur Host Materials for Lithium-Sulfur Batteries

Lithium-sulfur batteries with high energy density still confront many challenges, such as polysulfide dissolution, the large volume change of sulfur, and fast capacity fading in long-term cycling. Herein, a naturally abundant clay material, halloysite, is introduced as a sulfur host material in the cathode of Li-S batteries. Nickel oxide nanoparticles are embedded into the halloysite nanotubes (NiO@Halloysite) by hydrothermal and calcination treatment to improve the affinity of halloysite nanotubes to polysulfides. The NiO@Halloysite composite loaded with sulfur (S/NiO@Halloysite) is employed as the cathode of Li-S batteries, which combines the physical confinements of tubular halloysite particles and good chemical adsorption ability of NiO. The S/NiO@Halloysite electrode exhibits a high discharge capacity of 1205.47 mAh g^-1 at 0.1 C. In addition, it demonstrates enhanced cycling stability, retaining ≈60% of initial capacity after 450 cycles at 0.5 C. The synthesized NiO@Halloysite can provide a promising prospect and valuable insight into applying natural clay materials in Li-S batteries.

Local stochastics and ecoclimatic situation shape phytophagous chafer assemblage composition

Very little is known about factors determining the assemblage structure of megadiverse polyphagous-herbivore scarab chafers in the tropics (Coleoptera: Scarabaeidae). Here, we examined the composition of Sri Lankan chafer assemblages and investigated whether it is influenced more by the general ecoclimatic situation, macrohabitat, or indetermined stochastic biotic and abiotic factors of each locality. We also explored the influence of the latter on separate lineages and general body size. Based on dedicated field surveys conducted during the dry and wet seasons, we examined 4847 chafer individuals of 105 species sampled using multiple UV-light traps in 11 localities covering different forest types and altitudinal zones. Assemblages were assessed for compositional similarity, species diversity, and abundance within four major eco-spatial partitions: forest types, elevational zones, localities, and macrohabitats. Our results revealed that assemblages were shaped mainly by locality stochastics (i.e., multi-factor ensemble of all biotic and abiotic environmental conditions at local scale), and to a minor extent by ecoclimatic conditions. Macrohabitat had little effect on the assemblage composition. This was true for the entire chafer assemblage as well as for all single lineages or different body size classes. However, in medium and large species the contrasts between localities were less pronounced, which was not the case for individual lineages of the assemblage. Contrasts of assemblage similarity between localities were much more evident than those for forest types and elevation zones. Significant correlation between species composition and geographic distance was found only for the assemblage of small-bodied specimens. Seasonal change (dry-wet) in species composition was minor and only measurable in a few localities. The strong turnover between examined localities corroborates with the high degree of endemism in many phytophagous chafers, particularly in Sericini. Connected with their hypothetic poor habitat specificity and polyphagy, this might also explain why so many chafer crop pests in the Asian tropics are endemics.

Differential effects of weather, plant phenology and predators on the seasonal variation of aphids on cabbage

The aphids Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) pose serious threats to the production of cruciferous crops in the tropics. Understanding their population dynamics is important for developing integrated pest management programmes to minimize their damage to crops. This study investigated the effects of climatic factors, natural enemies and plant age on the population dynamics of these pests. The population density of aphids and their natural enemies in 20 cabbage plants, and weather conditions were monitored for five cropping seasons from 2019 to 2021 in two agroecological zones of Ghana (Coastal Savannah and Deciduous Forest zones). The highest population density of L. e pseudobrassicae was recorded in January (dry season) in both agroecological zones, while the highest population density for M. persicae occurred in September (minor rainy season) and August (dry spell) in the Coastal Savannah and Deciduous Forest zones, respectively. The highest aphid densities were noted to occur during periods with low relative humidity and low rainfall. The population density of L. e. pseudobrassicae was significantly negatively related to plant age, air temperature and relative humidity, and positively related to syrphids (Paragus borbonicus) and spiders in the Coastal Savannah zone, while in the Deciduous Forest zone, it was significantly positively related to coccinellids. On the other hand, M. persicae population density was significantly positively related to syrphids and coccinellids in the Deciduous Forest zone. Rainfall negatively affected syrphids in the Coastal Savannah zone, while air temperature positively affected syrphids and negatively affected spiders in the Deciduous Forest zone. Coccinellids had a significant positive relationship with relative humidity in the Deciduous Forest zone. This study provides important insights into the key factors that regulate aphid population densities on cabbage and will support development of timely interventions to manage these pests.

Local and landscape environmental heterogeneity drive ant community structure in temperate seminatural upland grasslands

Environmental heterogeneity is an important driver of ecological communities. Here, we assessed the effects of local and landscape spatial environmental heterogeneity on ant community structure in temperate seminatural upland grasslands of Central Germany. We surveyed 33 grassland sites representing a gradient in elevation and landscape composition. Local environmental heterogeneity was measured in terms of variability of temperature and moisture within and between grasslands sites. Grassland management type (pasture vs. meadows) was additionally included as a local environmental heterogeneity measure. The complexity of habitat types in the surroundings of grassland sites was used as a measure of landscape environmental heterogeneity. As descriptors of ant community structure, we considered species composition in terms of nest density, community evenness, and functional response traits. We found that extensively grazed pastures and within-site heterogeneity in soil moisture at local scale, and a high diversity of land cover types at the landscape scale affected ant species composition by promoting higher nest densities of some species. Ant community evenness was high in wetter grasslands with low within-site variability in soil moisture and surrounded by a less diverse landscape. Fourth-corner models revealed that ant community structure response to environmental heterogeneity was mediated mainly by worker size, colony size, and life history traits related with colony reproduction and foundation. We discuss how within-site local variability in soil moisture and low-intensity grazing promote ant species densities and highlight the role of habitat temperature and humidity affecting community evenness. We hypothesize that a higher diversity of land cover types in a forest-dominated landscape buffers less favorable environmental conditions for ant species establishment and dispersal between grasslands. We conclude that spatial environmental heterogeneity at local and landscape scale plays an important role as deterministic force in filtering ant species and, along with neutral processes (e.g., stochastic colonization), in shaping ant community structure in temperate seminatural upland grasslands.

A Triazolium-Anchored Self-Immolative Linker Enables Self-Assembly-Driven siRNA Binding and Esterase-Induced Release

The increased importance of RNA-based therapeutics comes with a need to develop next-generation stimuli-responsive systems capable of binding, transporting and releasing RNA oligomers. In this work, we describe triazolium-based amphiphiles capable of siRNA binding and enzyme-responsive release of the nucleic acid payload. In aqueous medium, the amphiphile self-assembles into nanocarriers that can disintegrate upon the addition of esterase. Key to the molecular design is a self-immolative linker that is anchored to the triazolium moiety and acts as a positively-charged polar head group. We demonstrate that addition of esterase leads to a degradation cascade of the linker, leaving the neutral triazole compound unable to form complexes and therefore releasing the negatively-charged siRNA. The reported molecular design and overall approach may have broad utility beyond this proof-of-principle study, because the underlying CuAAC "click" chemistry allows bringing together three groups very efficiently as well as cleaving off one of the three groups under the mild action of an esterase enzyme.

The role of proteasome activators PA28αβ and PA200 in brown adipocyte differentiation and function

Introduction

Brown adipocytes produce heat through non shivering thermogenesis (NST). To adapt to temperature cues, they possess a remarkably dynamic metabolism and undergo substantial cellular remodeling. The proteasome plays a central role in proteostasis and adaptive proteasome activity is required for sustained NST. Proteasome activators (PAs) are a class of proteasome regulators but the role of PAs in brown adipocytes is unknown. Here, we studied the roles of PA28α (encoded by Psme1) and PA200 (encoded by Psme4) in brown adipocyte differentiation and function.

Methods

We measured gene expression in mouse brown adipose tissue. In cultured brown adipocytes, we silenced Psme1 and/or Psme4 expression through siRNA transfection. We then assessed impact on the ubiquitin proteasome system, brown adipocyte differentiation and function.

Results

We found that Psme1 and Psme4 are expressed in brown adipocytes in vivo and in vitro. Through silencing of Psme1 and/or Psme4 expression in cultured brown adipocytes, we found that loss of PAs did not impair proteasome assembly or activity, and that PAs were not required for proteostasis in this model. Loss of Psme1 and/or Psme4 did not impair brown adipocyte development or activation, suggesting that PAs are neither required for brown adipogenesis nor NST.

Discussion

In summary, we found no role for Psme1 and Psme4 in brown adipocyte proteostasis, differentiation, or function. These findings contribute to our basic understanding of proteasome biology and the roles of proteasome activators in brown adipocytes.

A trimeric coiled-coil motif binds bacterial lipopolysaccharides with picomolar affinity

α-helical coiled-coils are ubiquitous protein structures in all living organisms. For decades, modified coiled-coils sequences have been used in biotechnology, vaccine development, and biochemical research to induce protein oligomerization, and form self-assembled protein scaffolds. A prominent model for the versatility of coiled-coil sequences is a peptide derived from the yeast transcription factor, GCN4. In this work, we show that its trimeric variant, GCN4-pII, binds bacterial lipopolysaccharides (LPS) from different bacterial species with picomolar affinity. LPS molecules are highly immunogenic, toxic glycolipids that comprise the outer leaflet of the outer membrane of Gram-negative bacteria. Using scattering techniques and electron microscopy, we show how GCN4-pII breaks down LPS micelles in solution. Our findings suggest that the GCN4-pII peptide and derivatives thereof could be used for novel LPS detection and removal solutions with high relevance to the production and quality control of biopharmaceuticals and other biomedical products, where even minuscule amounts of residual LPS can be lethal.

Environmental DNA (eDNA) reveals potential for interoceanic fish invasions across the Panama Canal

Interoceanic canals can facilitate biological invasions as they connect the world's oceans and remove dispersal barriers between bioregions. As a consequence, multiple opportunities for biotic exchange arise and the resulting establishment of migrant species often causes adverse ecological and economic impacts. The Panama Canal is a key region for biotic exchange as it connects the Pacific and Atlantic Oceans in Central America. In this study, we used two complementary methods (environmental DNA (eDNA) metabarcoding and gillnetting) to survey fish communities in this unique waterway. Using COI (cytochrome oxidase subunit I) metabarcoding, we detected a total of 142 fish species, including evidence for the presence of sixteen Atlantic and eight Pacific marine fish in different freshwater sections of the Canal. Of these, nine are potentially new records. Molecular data did not capture all species caught with gillnets, but generally provided a more complete image of the known fish fauna as more small-bodied fish species were detected. Diversity indices based on eDNA surveys revealed significant differences across different sections of the Canal reflecting in part the prevailing environmental conditions. The observed increase in the presence of marine fish species in the Canal indicates a growing potential for interoceanic fish invasions. The potential ecological and evolutionary consequences of this increase in marine fishes are not only restricted to the fish fauna in the Canal as they could also impact adjacent ecosystems in the Pacific and Atlantic Oceans.

Identification of altered miRNAs and their targets in placenta accreta

Placenta accreta spectrum (PAS) is one of the major causes of maternal morbidity and mortality worldwide with increasing incidence. PAS refers to a group of pathological conditions ranging from the abnormal attachment of the placenta to the uterus wall to its perforation and, in extreme cases, invasion into surrounding organs. Among them, placenta accreta is characterized by a direct adhesion of the villi to the myometrium without invasion and remains the most common diagnosis of PAS. Here, we identify the potential regulatory miRNA and target networks contributing to placenta accreta development. Using small RNA-Seq followed by RT-PCR confirmation, altered miRNA expression, including that of members of placenta-specific miRNA clusters (e.g., C19MC and C14MC), was identified in placenta accreta samples compared to normal placental tissues. In situ hybridization (ISH) revealed expression of altered miRNAs mostly in trophoblast but also in endothelial cells and this profile was similar among all evaluated degrees of PAS. Kyoto encyclopedia of genes and genomes (KEGG) analyses showed enriched pathways dysregulated in PAS associated with cell cycle regulation, inflammation, and invasion. mRNAs of genes associated with cell cycle and inflammation were downregulated in PAS. At the protein level, NF-κB was upregulated while PTEN was downregulated in placenta accreta tissue. The identified miRNAs and their targets are associated with signaling pathways relevant to controlling trophoblast function. Therefore, this study provides miRNA:mRNA associations that could be useful for understanding PAS onset and progression.

Chamber-based system for measuring whole-plant transpiration dynamics

Most of our insights on whole-plant transpiration (E) are based on leaf-chamber measurements using water vapor porometers, IRGAs, or flux measurements. Gravimetric methods are integrative, accurate, and a clear differentiation between evaporation and E can be made. Water vapor pressure deficit (VPD) is the driving force for E but assessing its impact has been evasive, due to confounding effects of other climate drivers. We developed a chamber-based gravimetric method, in which whole plant response of E to VPD could be assessed, while keeping other environmental parameters at predetermined values. Stable VPD values (0.5-3.7 kPa) were attained within 5 min after changing flow settings and maintained for at least 45 min. Species differing in life form and photosynthetic metabolism were used. Typical runs covering the range of VPDs lasted up to 4 h, preventing acclimation responses or soilborne water deficit. Species-specific responses of E to VPD could be identified, as well as differences in leaf conductance. The combined gravimetric-chamber-based system presented overcomes several limitations of previous gravimetric set ups in terms of replicability, time, and elucidation of the impact of specific environmental drivers on E, filling a methodological gap and widening our phenotyping capabilities.

Controlling the Formation of Conductive Pathways in Memristive Devices

Resistive random-access memories are promising candidates for novel computer architectures such as in-memory computing, multilevel data storage, and neuromorphics. Their working principle is based on electrically stimulated materials changes that allow access to two (digital), multiple (multilevel), or quasi-continuous (analog) resistive states. However, the stochastic nature of forming and switching the conductive pathway involves complex atomistic defect configurations resulting in considerable variability. This paper reveals that the intricate interplay of 0D and 2D defects can be engineered to achieve reproducible and controlled low-voltage formation of conducting filaments. The author find that the orientation of grain boundaries in polycrystalline HfO_x is directly related to the required forming voltage of the conducting filaments, unravelling a neglected origin of variability. Based on the realistic atomic structure of grain boundaries obtained from ultra-high resolution imaging combined with first-principles calculations including local strain, this paper shows how oxygen vacancy segregation energies and the associated electronic states in the vicinity of the Fermi level govern the formation of conductive pathways in memristive devices. These findings are applicable to non-amorphous valence change filamentary type memristive device. The results demonstrate that a fundamental atomistic understanding of defect chemistry is pivotal to design memristors as key element of future electronics.

Meta-analysis and co-expression analysis revealed stable QTL and candidate genes conferring resistances to Fusarium and Gibberella ear rots while reducing mycotoxin contamination in maize

Fusarium (FER) and Gibberella ear rots (GER) are the two most devastating diseases of maize (Zea mays L.) which reduce yield and affect grain quality worldwide, especially by contamination with mycotoxins. Genetic improvement of host resistance to effectively tackle FER and GER diseases requires the identification of stable quantitative trait loci (QTL) to facilitate the application of genomics-assisted breeding for improving selection efficiency in breeding programs. We applied improved meta-analysis algorithms to re-analyze 224 QTL identified in 15 studies based on dense genome-wide single nucleotide polymorphisms (SNP) in order to identify meta-QTL (MQTL) and colocalized genomic loci for fumonisin (FUM) and deoxynivalenol (DON) accumulation, silk (SR) and kernel (KR) resistances of both FER and GER, kernel dry-down rate (KDD) and husk coverage (HC). A high-resolution genetic consensus map with 36,243 loci was constructed and enabled the projection of 164 of the 224 collected QTL. Candidate genes (CG) mining was performed within the most refined MQTL, and identified CG were cross-validated using publicly available transcriptomic data of maize under Fusarium graminearum infection. The meta-analysis revealed 40 MQTL, of which 29 were associated each with 2-5 FER- and/or GER-related traits. Twenty-eight of the 40 MQTL were common to both FER and GER resistances and 19 MQTL were common to silk and kernel resistances. Fourteen most refined MQTL on chromosomes 1, 2, 3, 4, 7 and 9 harbored a total of 2,272 CG. Cross-validation identified 59 of these CG as responsive to FER and/or GER diseases. MQTL ZmMQTL2.2, ZmMQTL9.2 and ZmMQTL9.4 harbored promising resistance genes, of which GRMZM2G011151 and GRMZM2G093092 were specific to the resistant line for both diseases and encoded "terpene synthase21 (tps21)" and "flavonoid O-methyltransferase2 (fomt2)", respectively. Our findings revealed stable refined MQTL harboring promising candidate genes for use in breeding programs for improving FER and GER resistances with reduced mycotoxin accumulation. These candidate genes can be transferred into elite cultivars by integrating refined MQTL into genomics-assisted backcross breeding strategies.

Phenotypic adaptation of Mycobacterium tuberculosis to host-associated stressors that induce persister formation

Mycobacterium tuberculosis exhibits a remarkable ability to interfere with the host antimicrobial response. The pathogen exploits elaborate strategies to cope with diverse host-induced stressors by modulating its metabolism and physiological state to prolong survival and promote persistence in host tissues. Elucidating the adaptive strategies that M. tuberculosis employs during infection to enhance persistence is crucial to understanding how varying physiological states may differentially drive disease progression for effective management of these populations. To improve our understanding of the phenotypic adaptation of M. tuberculosis, we review the adaptive strategies employed by M. tuberculosis to sense and coordinate a physiological response following exposure to various host-associated stressors. We further highlight the use of animal models that can be exploited to replicate and investigate different aspects of the human response to infection, to elucidate the impact of the host environment and bacterial adaptive strategies contributing to the recalcitrance of infection.

Glycolysis, monocarboxylate transport, and purinergic signaling are key events in Eimeria bovis-induced NETosis

The protozoan parasite Eimeria bovis is the causative agent of bovine coccidiosis, an enteric disease of global importance that significantly affects cattle productivity. Previous studies showed that bovine NETosis—an important early host innate effector mechanism of polymorphonuclear neutrophil (PMN)—is elicited by E. bovis stages. So far, the metabolic requirements of E. bovis-triggered NET formation are unknown. We here studied early glycolytic and mitochondrial responses of PMN as well as the role of pH, distinct metabolic pathways, P2 receptor-mediated purinergic signaling, and monocarboxylate transporters 1 and 2 (MCT1, MCT2) in E. bovis sporozoite-induced NET formation. Seahorse-based experiments revealed a rapid induction of both neutrophil oxygen consumption rate (OCR) and early glycolytic responses, thereby reflecting immediate PMN activation and metabolic changes upon confrontation with sporozoites. The impact of these metabolic changes on NET formation was studied via chemical inhibition experiments targeting glycolysis and energy generation by the use of 2-fluor-2-deoxy-D-glucose (FDG), 6-diazo-5-oxo-L-norleucin (DON), sodium dichloroacetate (DCA), oxythiamine (OT), sodium oxamate (OXA), and oligomycin A (OmA) to block glycolysis, glutaminolysis, pyruvate dehydrogenase kinase, pyruvate dehydrogenase, lactate dehydrogenase, and mitochondrial ATP-synthase, respectively. Overall, sporozoite-induced NET formation was significantly diminished via PMN pretreatments with OmA and OXA, thereby indicating a key role of ATP- and lactate-mediated metabolic pathways. Consequently, we additionally studied the effects of extracellular pH, MCT1, MCT2, and purinergic receptor inhibitors (AR-C141900, AR-C155858, theobromine, and NF449, respectively). Pretreatment with the latter inhibitors led to blockage of sporozoite-triggered DNA release from exposed bovine PMN. This report provides first evidence on the pivotal role of carbohydrate-related metabolic pathways and purinergic receptors being involved in E. bovis sporozoite-induced NETosis.

Bacterial subversion of NLR-mediated immune responses

Members of the mammalian Nod-like receptor (NLR) protein family are important intracellular sensors for bacteria. Bacteria have evolved under the pressure of detection by host immune sensing systems, leading to adaptive subversion strategies to dampen immune responses for their benefits. These include modification of microbe-associated molecular patterns (MAMPs), interception of innate immune pathways by secreted effector proteins and sophisticated instruction of anti-inflammatory adaptive immune responses. Here, we summarise our current understanding of subversion strategies used by bacterial pathogens to manipulate NLR-mediated responses, focusing on the well-studied members NOD1/2, and the inflammasome forming NLRs NLRC4, and NLRP3. We discuss how bacterial pathogens and their products activate these NLRs to promote inflammation and disease and the range of mechanisms used by bacterial pathogens to evade detection by NLRs and to block or dampen NLR activation to ultimately interfere with the generation of host immunity. Moreover, we discuss how bacteria utilise NLRs to facilitate immunotolerance and persistence in the host and outline how various mechanisms used to attenuate innate immune responses towards bacterial pathogens can also aid the host by reducing immunopathologies. Finally, we describe the therapeutic potential of harnessing immune subversion strategies used by bacteria to treat chronic inflammatory conditions.

From Stable PH-Ylides to α-Carbanionic Phosphines as Ligands for Zwitterionic Catalysts

Although ylides are commonly used reagents in organic synthesis, the parent methylphosphine MePH2 only exists in its phosphine form in the condensed phase. Its ylide tautomer H3 P+ -CH2 - is considerably higher in energy. Here, we report on the formation of bis(sulfonyl)methyl-substituted phosphines of the type (RO2 S)2 C(H)-PR2, which form stable PH ylides under ambient conditions, amongst the first examples of an acyclic phosphine which only exists in its PH ylide form. Depending on the exact substitution pattern the phosphines form an equilibrium between the PH ylide and the phosphine form or exist as one of both extremes. These phosphines were found to be ideal starting systems for the facile formation of α-carbanionic phosphines. The carbanion-functionalization leads to a switch from electron-poor to highly electron-rich phosphines with strong donor abilities and high basicities. Thus, the phosphines readily react with different electrophiles exclusively at the phosphorus atom and not at the carbanionic center. Furthermore, the anionic nature of the phosphines allows the formation of zwitterionic complexes as demonstrated by the isolation of a gold(I) complex with a cationic metal center. The cationic gold center allows for catalytic activity in the hydroamination of alkyne without requiring a further activation step.

GARP as a Therapeutic Target for the Modulation of Regulatory T Cells in Cancer and Autoimmunity

Regulatory T cells (Treg) play a critical role in immune homeostasis by suppressing several aspects of the immune response. Herein, Glycoprotein A repetitions predominant (GARP), the docking receptor for latent transforming growth factor (LTGF-β), which promotes its activation, plays a crucial role in maintaining Treg mediated immune tolerance. After activation, Treg uniquely express GARP on their surfaces. Due to its location and function, GARP may represent an important target for immunotherapeutic approaches, including the inhibition of Treg suppression in cancer or the enhancement of suppression in autoimmunity. In the present review, we will clarify the cellular and molecular regulation of GARP expression not only in human Treg but also in other cells present in the tumor microenvironment. We will also examine the overall roles of GARP in the regulation of the immune system. Furthermore, we will explore potential applications of GARP as a predictive and therapeutic biomarker as well as the targeting of GARP itself in immunotherapeutic approaches.

Grassland type and seasonal effects have a bigger influence on plant functional and taxonomical diversity than prairie dog disturbances in semiarid grasslands

Prairie dogs (Cynomys sp.) are considered keystone species and ecosystem engineers for their grazing and burrowing activities (summarized here as disturbances). As climate changes and its variability increases, the mechanisms underlying organisms' interactions with their habitat will likely shift. Understanding the mediating role of prairie dog disturbance on vegetation structure, and its interaction with environmental conditions through time, will increase knowledge on the risks and vulnerability of grasslands.Here, we compared how plant taxonomical diversity, functional diversity metrics, and community-weighted trait means (CWM) respond to prairie dog C. mexicanus disturbance across grassland types and seasons (dry and wet) in a priority conservation semiarid grassland of Northeast Mexico.Our findings suggest that functional metrics and CWM analyses responded to interactions between prairie dog disturbance, grassland type and season, whilst species diversity and cover measures were less sensitive to the role of prairie dog disturbance. We found weak evidence that prairie dog disturbance has a negative effect on vegetation structure, except for minimal effects on C4 and graminoid cover, but which depended mainly on season. Grassland type and season explained most of the effects on plant functional and taxonomic diversity as well as CWM traits. Furthermore, we found that leaf area as well as forb and annual cover increased during the wet season, independent of prairie dog disturbance.Our results provide evidence that grassland type and season have a stronger effect than prairie dog disturbance on the vegetation of this short-grass, water-restricted grassland ecosystem. We argue that focusing solely on disturbance and grazing effects is misleading, and attention is needed on the relationships between vegetation and environmental conditions which will be critical to understand semiarid grassland dynamics under future climate change conditions in the region.

Anti-Inflammatory Potential of Phenolic Compounds Isolated From Entada africana Guill. & Perr. Used in the Republic of Benin

In West African medicine, Entada africana Guill. &amp; Perr. from the family of Fabaceae is used to treat inflammatory conditions in the management of fractures, wounds, and sprains in the northern region of the Republic of Benin. The aim of the present study was to isolate and elucidate phenolic compounds from a hydroalcoholic leaf extract from E. africana and to identify compounds with anti-inflammatory activity in vitro. Eleven compounds were purified from three fractions, which have shown strong to medium anti-inflammatory activity. The isolated compounds were characterized by HRESI-MS and NMR methods as gallic acid (1), ethyl gallate (2), 5,7-dihydroxychromen-4-one (3), 3′,4′,7-trihydroxyflavone (4), dihydrokaempferol-7-O-glucoside (5), catechin (6), quercetin-3-O-[β-apiosyl-(1‴→2″)-β-glucoside] (7), quercetin-3-O-glucoside (8), naringenin-7-O-glucoside (9), aromadendrin (10), and myricetin-3-O-glucoside (11). Nine of the major phenolic compounds were tested using TNF-α stimulated human keratinocytes (HaCaT) as skin inflammation model to identify molecules, which may explain the use of the plant leaves as an anti-inflammatory remedy by assessing the release of proinflammatory cytokines IL-8 and IL-6. The hydroacoholic leaf extract of E. africana exerted a medium inhibitory effect on the release of IL-8. 3′,4′,7-trihydroxyflavone, aromadendrin, dihydrokaempferol-7-O-glucoside and ethyl gallate demonstrated a strong to medium effect on the release of IL-6. For the release of IL-8, 3′,4′,7-trihydroxyflavone demonstrated a medium activity. This study provides for the first time a detailed screening of phenolic compounds occurring in the hydroethanolic leaf extract of E. africana. Additionally, it is shown that E. africana contains active compounds which may justify its traditional medicinal use as an anti-inflammatory remedy to treat inflammatory and pain-related skin conditions in the Republic of Benin.

Strong Antibiotic Activity of the Myxocoumarin Scaffold in vitro and in vivo

The increasing emergence of resistances against established antibiotics is a substantial threat to human health. The discovery of new compounds with potent antibiotic activity is thus of utmost importance. Within this work, we identify strong antibiotic activity of the natural product myxocoumarin B from Stigmatella aurantiaca MYX‐030 against a range of clinically relevant bacterial pathogens, including clinical isolates of MRSA. A focused library of structural analogs was synthesized to explore initial structure‐activity relationships and to identify equipotent myxocoumarin derivatives devoid of the natural nitro substituent to significantly streamline synthetic access. The cytotoxicity of the myxocoumarins as well as their potential to cure bacterial infections in vivo was established using a zebrafish model system. Our results reveal the exceptional antibiotic activity of the myxocoumarin scaffold and hence its potential for the development of novel antibiotics.

Optimization and Kinetic Modeling of a Fed-Batch Fermentation for Mannosylerythritol Lipids (MEL) Production With Moesziomyces aphidis

Mannosylerythritol lipids are glycolipid biosurfactants with many interesting properties. Despite the general interest in those molecules and the need for a robust process, studies on their production in bioreactors are still scarce. In the current study, the fermentative production of MEL in a bioreactor with Moesziomyces aphidis was performed using a defined mineral salt medium. Several kinetic process parameters like substrate consumption rates and product formation rates were evaluated and subsequently enhanced by increasing the biomass concentration through an exponential fed-batch strategy. The fed-batch approaches resulted in two to three fold increased dry biomass concentrations of 10.9–15.5 g/L at the end of the growth phase, compared with 4.2 g/L in the batch process. Consequently, MEL formation rates were increased from 0.1 g/Lh up to around 0.4 g/Lh during the MEL production phase. Thus, a maximum concentration of up to 50.5 g/L MEL was obtained when oil was added in excess, but high concentrations of residual fatty acids were also present in the broth. By adjusting the oil feeding to biomass-specific hydrolysis and MEL production rates, a slightly lower MEL concentration of 34.3 g/L was obtained after 170 h, but at the same time a very pure crude lipid extract with more than 90% MEL and a much lower concentration of remaining fatty acids. With rapeseed oil as substrate, the ideal oil-to-biomass ratio for full substrate conversion was found to be around 10 g_oil/g_biomass. In addition, off-gas analysis and pH trends could be used to assess biomass growth and MEL production. Finally, kinetic models were developed and compared to the experimental data, allowing for a detailed prediction of the process behavior in future experiments.

Machine Learning Models for Classifying High- and Low-Grade Gliomas: A Systematic Review and Quality of Reporting Analysis

Objectives

To systematically review, assess the reporting quality of, and discuss improvement opportunities for studies describing machine learning (ML) models for glioma grade prediction.

Methods

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy (PRISMA-DTA) statement. A systematic search was performed in September 2020, and repeated in January 2021, on four databases: Embase, Medline, CENTRAL, and Web of Science Core Collection. Publications were screened in Covidence, and reporting quality was measured against the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) Statement. Descriptive statistics were calculated using GraphPad Prism 9.

Results

The search identified 11,727 candidate articles with 1,135 articles undergoing full text review and 85 included in analysis. 67 (79%) articles were published between 2018-2021. The mean prediction accuracy of the best performing model in each study was 0.89 ± 0.09. The most common algorithm for conventional machine learning studies was Support Vector Machine (mean accuracy: 0.90 ± 0.07) and for deep learning studies was Convolutional Neural Network (mean accuracy: 0.91 ± 0.10). Only one study used both a large training dataset (n>200) and external validation (accuracy: 0.72) for their model. The mean adherence rate to TRIPOD was 44.5% ± 11.1%, with poor reporting adherence for model performance (0%), abstracts (0%), and titles (0%).

Conclusions

The application of ML to glioma grade prediction has grown substantially, with ML model studies reporting high predictive accuracies but lacking essential metrics and characteristics for assessing model performance. Several domains, including generalizability and reproducibility, warrant further attention to enable translation into clinical practice.

Systematic Review Registration

PROSPERO, identifier CRD42020209938.

The Putative Bromodomain Protein PfBDP7 of the Human Malaria Parasite Plasmodium Falciparum Cooperates With PfBDP1 in the Silencing of Variant Surface Antigen Expression

Epigenetic regulation is a critical mechanism in controlling virulence, differentiation, and survival of the human malaria parasite Plasmodium (P.) falciparum. Bromodomain proteins contribute to this process by binding to acetylated lysine residues of histones and thereby targeting the gene regulatory machinery to gene promoters. A protein complex containing the P. falciparum bromodomain proteins (PfBDP) 1 and PfBDP2 (BDP1/BDP2 core complex) was previously shown to play an essential role for the correct transcription of invasion related genes. Here, we performed a functional characterization of a third component of this complex, which we dubbed PfBDP7, because structural modelling predicted a typical bromodomain fold. We confirmed that PfBDP7 is a nuclear protein that interacts with PfBDP1 at invasion gene promoters in mature schizont stage parasites and contributes to their transcription. Although partial depletion of PfBDP7 showed no significant effect on parasite viability, conditional knock down of either PfBDP7 or PfBDP1 resulted in the de-repression of variant surface antigens (VSA), which are important pathogenicity factors. This de-repression was evident both on mRNA and protein level. To understand the underlying mechanism, we mapped the genome wide binding sites of PfBDP7 by ChIPseq and showed that in early schizonts, PfBDP7 and PfBDP1 are commonly enriched in heterochromatic regions across the gene body of all VSA families, including genes coding for PfEMP1, RIFIN, STEVOR, and PfMC-2TM. This suggests that PfBDP7 and PfBDP1 contribute to the silencing of VSAs by associating with heterochromatin. In conclusion, we identified PfBDP7 as a chromatin binding protein that is a constitutive part of the P. falciparum BDP1/BDP2 core complex and established PfBDP1 and PfBDP7 as novel players in the silencing of heterochromatin regulated virulence gene families of the malaria parasite P. falciparum.

Emerging Roles for Phase Separation of RNA-Binding Proteins in Cellular Pathology of ALS

Liquid-liquid phase separation (LLPS) is emerging as a major principle for the mesoscale organization of proteins, RNAs, and membrane-bound organelles into biomolecular condensates. These condensates allow for rapid cellular responses to changes in metabolic activities and signaling. Nowhere is this regulation more important than in neurons and glia, where cellular physiology occurs simultaneously on a range of time- and length-scales. In a number of neurodegenerative diseases, such as Amyotrophic Lateral Sclerosis (ALS), misregulation of biomolecular condensates leads to the formation of insoluble aggregates—a pathological hallmark of both sporadic and familial ALS. Here, we summarize how the emerging knowledge about the LLPS of ALS-related proteins corroborates with their aggregation. Understanding the mechanisms that lead to protein aggregation in ALS and how cells respond to these aggregates promises to open new directions for drug development.

Destructive Photon Echo Formation in Six-Wave Mixing Signals of a MoSe2 Monolayer

Monolayers of transition metal dichalcogenides display a strong excitonic optical response. Additionally encapsulating the monolayer with hexagonal boron nitride allows to reach the limit of a purely homogeneously broadened exciton system. On such a MoSe2 -based system, ultrafast six-wave mixing spectroscopy is performed and a novel destructive photon echo effect is found. This process manifests as a characteristic depression of the nonlinear signal dynamics when scanning the delay between the applied laser pulses. By theoretically describing the process within a local field model, an excellent agreement with the experiment is reached. An effective Bloch vector representation is developed and thereby it is demonstrated that the destructive photon echo stems from a destructive interference of successive repetitions of the heterodyning experiment.

Emerging Role of PD-1/PD-L1 Inhibitors in Chronic Liver Diseases

Programmed cell death protein 1 (PD-1)/PD-ligand (L)1, the immune checkpoint inhibitors have emerged as a promising strategy for the treatment of various diseases including chronic liver diseases (CLDs) such as hepatitis, liver injury and hepatocellular carcinoma (HCC). The role of PD-1/PD-L1 has been widely inspected in the treatment of viral hepatitis and HCC. PD-1 is known to play a crucial role in inhibiting immunological responses and stimulates self-tolerance by regulating the T-cell activity. Further, it promotes apoptosis of antigen-specific T-cells while preventing apoptosis of Treg cells. PD-L1 is a trans-membrane protein which is recognized as a co-inhibitory factor of immunological responses. Both, PD-1 and PD-L1 function together to downregulate the proliferation of PD-1 positive cells, suppress the expression of cytokines and stimulate apoptosis. Owing to the importance of PD-1/PD-L1 signaling, this review aims to summarize the potential of PD-1/PD-L1 inhibitors in CLDs along with toxicities associated with them. We have enlisted some of the important roles of PD-1/PD-L1 in CLDs, the clinically approved products and the pipelines of drugs under clinical evaluation.

Asymmetric allelic introgression across a hybrid zone of the coal tit (Periparus ater) in the central Himalayas

In the Himalayas, a number of secondary contact zones have been described for vicariant vertebrate taxa. However, analyses of genetic divergence and admixture are missing for most of these examples. In this study, we provide a population genetic analysis for the coal tit (Periparus ater) hybrid zone in Nepal. Intermediate phenotypes between the distinctive western "spot-winged tit" (P. a. melanolophus) and Eastern Himalayan coal tits (P. a. aemodius) occur across a narrow range of <100 km in western Nepal. As a peculiarity, another distinctive cinnamon-bellied form is known from a single population so far. Genetic admixture of western and eastern mitochondrial lineages was restricted to the narrow zone of phenotypically intermediate populations. The cline width was estimated 46 km only with a center close to the population of the cinnamon-bellied phenotype. In contrast, allelic introgression of microsatellite loci was asymmetrical from eastern P. a. aemodius into far western populations of phenotypic P. a. melanolophus but not vice versa. Accordingly, the microsatellite cline was about 3.7 times wider than the mitochondrial one.

A high-density 256-channel cap for dry electroencephalography

High‐density electroencephalography (HD‐EEG) is currently limited to laboratory environments since state‐of‐the‐art electrode caps require skilled staff and extensive preparation. We propose and evaluate a 256‐channel cap with dry multipin electrodes for HD‐EEG. We describe the designs of the dry electrodes made from polyurethane and coated with Ag/AgCl. We compare in a study with 30 volunteers the novel dry HD‐EEG cap to a conventional gel‐based cap for electrode‐skin impedances, resting state EEG, and visual evoked potentials (VEP). We perform wearing tests with eight electrodes mimicking cap applications on real human and artificial skin. Average impedances below 900 kΩ for 252 out of 256 dry electrodes enables recording with state‐of‐the‐art EEG amplifiers. For the dry EEG cap, we obtained a channel reliability of 84% and a reduction of the preparation time of 69%. After exclusion of an average of 16% (dry) and 3% (gel‐based) bad channels, resting state EEG, alpha activity, and pattern reversal VEP can be recorded with less than 5% significant differences in all compared signal characteristics metrics. Volunteers reported wearing comfort of 3.6 ± 1.5 and 4.0 ± 1.8 for the dry and 2.5 ± 1.0 and 3.0 ± 1.1 for the gel‐based cap prior and after the EEG recordings, respectively (scale 1–10). Wearing tests indicated that up to 3,200 applications are possible for the dry electrodes. The 256‐channel HD‐EEG dry electrode cap overcomes the principal limitations of HD‐EEG regarding preparation complexity and allows rapid application by not medically trained persons, enabling new use cases for HD‐EEG.

Unexpectedly High Capacitance of the Metal Nanoparticle/Water Interface: Molecular-Level Insights into the Electrical Double Layer

The electrical double‐layer plays a key role in important interfacial electrochemical processes from catalysis to energy storage and corrosion. Therefore, understanding its structure is crucial for the progress of sustainable technologies. We extract new physico‐chemical information on the capacitance and structure of the electrical double‐layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order‐of‐magnitude than predicted by the traditional mean‐field models of the double‐layer such as the Gouy–Chapman–Stern model. Performing molecular dynamics simulations, we investigate the possible relationship between the measured high capacitance and adsorption strength of the water adlayer formed at the metal surface. These insights may launch the active tuning of solid–solvent and solvent–solvent interactions as an innovative design strategy to transform energy technologies towards superior performance and sustainability.

Seed dispersal by wind decreases when plants are water-stressed, potentially counteracting species coexistence and niche evolution

Hydrology is a major environmental factor determining plant fitness, and hydrological niche segregation (HNS) has been widely used to explain species coexistence. Nevertheless, the distribution of plant species along hydrological gradients does not only depend on their hydrological niches but also depend on their seed dispersal, with dispersal either weakening or reinforcing the effects of HNS on coexistence. However, it is poorly understood how seed dispersal responds to hydrological conditions. To close this gap, we conducted a common-garden experiment exposing five wind-dispersed plant species (Bellis perennis, Chenopodium album, Crepis sancta, Hypochaeris glabra, and Hypochaeris radicata) to different hydrological conditions. We quantified the effects of hydrological conditions on seed production and dispersal traits, and simulated seed dispersal distances with a mechanistic dispersal model. We found species-specific responses of seed production, seed dispersal traits, and predicted dispersal distances to hydrological conditions. Despite these species-specific responses, there was a general positive relationship between seed production and dispersal distance: Plants growing in favorable hydrological conditions not only produce more seeds but also disperse them over longer distances. This arises mostly because plants growing in favorable environments grow taller and thus disperse their seeds over longer distances. We postulate that the positive relationship between seed production and dispersal may reduce the concentration of each species to the environments favorable for it, thus counteracting species coexistence. Moreover, the resulting asymmetrical gene flow from favorable to stressful habitats may slow down the microevolution of hydrological niches, causing evolutionary niche conservatism. Accounting for context-dependent seed dispersal should thus improve ecological and evolutionary models for the spatial dynamics of plant populations and communities.

Size-Controlled Formation of Polymer Janus Discs

A straightforward method is presented for the preparation of nano- to micrometer-sized Janus discs with controlled shape, size, and aspect ratio. The method relies on cross-linkable ABC triblock terpolymers and involves first the preparation of prolate ellipsoidal microparticles by combining Shirasu porous glass (SPG) membrane emulsification with evaporation-induced confinement assembly (EICA). By varying the pore diameter of the SPG membrane, we produce Janus discs with controlled size distributions centered around hundreds of nanometers to several microns. We further transferred the discs to water by mild sulfonation of PS to polystyrene sulfonic acid (PSS) and verified the Janus character by subsequent labelling with cationic nanoparticles. Finally, we show that the sulfonated Janus discs are amphiphilic and can be used as efficient colloidal stabilizers for oil-in-water (O/W) emulsions.

Synthesis and Surface Behaviour of NDI Chromophores Mounted on a Tripodal Scaffold: Towards Self-Decoupled Chromophores for Single-Molecule Electroluminescence

This paper reports the efficient synthesis, absorption and emission spectra, and the electrochemical properties of a series of 2,6-disubstituted naphthalene-1,4,5,8-tetracarboxdiimide (NDI) tripodal molecules with thioacetate anchors for their surface investigations. Our studies showed that, in particular, the pyrrolidinyl group with its strong electron-donating properties enhanced the fluorescence of such core-substituted NDI chromophores and caused a significant bathochromic shift in the absorption spectrum with a correspondingly narrowed bandgap of 1.94 eV. Cyclic voltammetry showed the redox properties of NDIs to be influenced by core substituents. The strong electron-donating character of pyrrolidine substituents results in rather high HOMO and LUMO levels of -5.31 and -3.37 eV when compared with the parental unsubstituted NDI. UHV-STM measurements of a sub-monolayer of the rigid tripodal NDI chromophores spray deposited on Au(111) show that these molecules mainly tend to adsorb flat in a pairwise fashion on the surface and form unordered films. However, the STML experiments also revealed a few molecular clusters, which might consist of upright oriented molecules protruding from the molecular island and show electroluminescence photon spectra with high electroluminescence yields of up to 6×10-3 . These results demonstrate the promising potential of the NDI tripodal chromophores for the fabrication of molecular devices profiting from optical features of the molecular layer.

Total Synthesis and Bioactivity Mapping of Geodiamolide H

The first total synthesis of the actin-stabilizing marine natural product geodiamolide H was achieved. Solid-phase based peptide assembly paired with scalable stereoselective syntheses of polyketide building blocks and an optimized esterification set the stage for investigating the key ring-closing metathesis. Geodiamolide H and synthetic analogues were characterized for their toxicity and for antiproliferative effects in cellulo, by characterising actin polymerization induction in vitro, and by docking on the F-actin target and property computation in silico, for a better understanding of structure-activity relationships (SAR). A non-natural analogue of geodiamolide H was discovered to be most potent in the series, suggesting significant potential for tool compound design.

Multidimensional trophic niche revealed by complementary approaches: Gut content, digestive enzymes, fatty acids and stable isotopes in Collembola

Trophic niche differentiation may explain coexistence and shape functional roles of species. In complex natural food webs, however, trophic niche parameters depicted by single and isolated methods may simplify the multidimensional nature of consumer trophic niches, which includes feeding processes such as food choice, ingestion, digestion, assimilation and retention. Here we explore the correlation and complementarity of trophic niche parameters tackled by four complementary methodological approaches, that is, visual gut content, digestive enzyme, fatty acid and stable isotope analyses-each assessing one or few feeding processes, and demonstrate the power of method combination. Focusing on soil ecosystems, where many omnivore species with cryptic feeding habits coexist, we chose Collembola as an example. We compiled 15 key trophic niche parameters for 125 species from 40 studies. We assessed correlations among trophic niche parameters and described variation of these parameters in different Collembola species, families and across life-forms, which represent microhabitat specialisation. Correlation between trophic niche parameters was weak in 45 out of 64 pairwise comparisons, pointing at complementarity of the four methods. Jointly, the results indicated that fungal- and plant-feeding Collembola assimilate storage, rather than structural polysaccharides, and suggested bacterial feeding as a potential alternative feeding strategy. Gut content and fatty acid analyses suggested alignment between ingestion and assimilation/retention processes in fungal- and plant-feeding Collembola. From the 15 trophic niche parameters, six were related to Collembola family identity, suggesting that not all trophic niche dimensions are phylogenetically structured. Only three parameters were related to the life-forms, suggesting that species use various feeding strategies when living in the same microenvironments. Consumers can meet their nutritional needs by varying their food choices, ingestion and digestion strategies, with the connection among different feeding processes being dependent on the consumed resource and consumer adaptations. Multiple methods reveal different dimensions, together drawing a comprehensive picture of the trophic niche. Future studies applying the multidimensional trophic niche approach will allow us to trace trophic complexity and reveal niche partitioning of omnivorous species and their functional roles, especially in cryptic environments such as soils, caves, deep ocean or benthic ecosystems.

Female and male Eurasian lynx have distinct spatial tactics at different life-history stages in a high-density population

Knowledge regarding the spatial behavior of the Eurasian lynx is mainly inferred from populations in Europe. We used GPS telemetry to record the spatial behavior of nine individuals in northwestern Anatolia obtaining eleven home ranges (HRs). Analyses revealed the smallest mean HR sizes (nHR ♀  = 4) at 57 km2 (95% kernel utilization distribution, KUD) and 56 km2 (95% minimum convex polygon, MCP), ever reported for adult female Eurasian lynx. Adult males either occupied small permanent territories (nHR♂.T = 2), with a mean of 176 km2 (95% KUD) and 150 km2 (95% MCP), or were residents without territories (floaters, nHR♂. F  = 2) roaming across large, stable HRs with a mean size of 2,419 km2 (95% KUD) and 1,888 km2 (95% MCP), comparable to HR sizes of Scandinavian lynx populations. Three disperser subadult males did not hold stable HRs (mean 95% KUD = 203 km2, mean 95% MCP = 272 km2). At 4.9 individuals per 100 km2, population density was one of the highest recorded, suggesting that the presence of adult male floaters was a consequence of a landscape fully occupied by territorials and revealing a flexibility of spatial behavior of Eurasian lynx not previously recognized. Such a high population density, small HRs, and behavioral flexibility may have been aided by the legal protection from and apparent low levels of poaching of this population. The observed spatial tactics are unlikely to be seen in most of the previously studied Eurasian lynx populations, as they either suffer medium to high levels of human-caused mortality or were unlikely to be at carrying capacity. For effective and appropriate conservation planning, data from felid populations in a reasonably natural state such as ours, where space, density, prey, and pathogens are likely to be the key drivers of spatial dynamics, are therefore essential.

Texture Analysis Using CT and Chemical Shift Encoding-Based Water-Fat MRI Can Improve Differentiation Between Patients With and Without Osteoporotic Vertebral Fractures

PURPOSE

Osteoporosis is a highly prevalent skeletal disease that frequently entails vertebral fractures. Areal bone mineral density (BMD) derived from dual-energy X-ray absorptiometry (DXA) is the reference standard, but has well-known limitations. Texture analysis can provide surrogate markers of tissue microstructure based on computed tomography (CT) or magnetic resonance imaging (MRI) data of the spine, thus potentially improving fracture risk estimation beyond areal BMD. However, it is largely unknown whether MRI-derived texture analysis can predict volumetric BMD (vBMD), or whether a model incorporating texture analysis based on CT and MRI may be capable of differentiating between patients with and without osteoporotic vertebral fractures.

MATERIALS AND METHODS

Twenty-six patients (15 females, median age: 73 years, 11 patients showing at least one osteoporotic vertebral fracture) who had CT and 3-Tesla chemical shift encoding-based water-fat MRI (CSE-MRI) available were analyzed. In total, 171 vertebral bodies of the thoracolumbar spine were segmented using an automatic convolutional neural network (CNN)-based framework, followed by extraction of integral and trabecular vBMD using CT data. For CSE-MRI, manual segmentation of vertebral bodies and consecutive extraction of the mean proton density fat fraction (PDFF) and T2* was performed. First-order, second-order, and higher-order texture features were derived from texture analysis using CT and CSE-MRI data. Stepwise multivariate linear regression models were computed using integral vBMD and fracture status as dependent variables.

RESULTS

Patients with osteoporotic vertebral fractures showed significantly lower integral and trabecular vBMD when compared to patients without fractures (p<0.001). For the model with integral vBMD as the dependent variable, T2* combined with three PDFF-based texture features explained 40% of the variance (adjusted R²[Ra2] = 0.40; p<0.001). Furthermore, regarding the differentiation between patients with and without osteoporotic vertebral fractures, a model including texture features from CT and CSE-MRI data showed better performance than a model based on integral vBMD and PDFF only ( Ra2 = 0.47 vs. Ra2  = 0.81; included texture features in the final model: integral vBMD, CT_Short-run_emphasis, CT_Varianceglobal, and PDFF_Variance).

CONCLUSION

Using texture analysis for spine CT and CSE-MRI can facilitate the differentiation between patients with and without osteoporotic vertebral fractures, implicating that future fracture prediction in osteoporosis may be improved.