Circular Polarization-Resolved Raman Optical Activity: A Perspective on Chiral Spectroscopies of Vibrational States

Circular polarization-resolved Raman scattering methods include Raman optical activity (ROA) and its derivative─surface-enhanced Raman optical activity (SEROA). These spectroscopic modalities are rapidly developing due to their high information content, stand-off capabilities, and rapid development of Raman-active chiral nanostructures. These methods enable a direct readout of the vibrational energy levels of chiral molecules, crystals, and nanostructured materials, making it possible to study complex interactions and the dynamic interfaces between them. They were shown to be particularly valuable for nano- and biotechnological fields encompassing complex particles with nanoscale chirality that combine strong scattering and intense polarization rotation. This perspective dives into recent advancements in ROA and SEROA, their distinction from surface-enhanced Raman scattering, and the potential of these information-rich label-free spectroscopies for the detection of chiral biomolecules.

Passive high explosive neutron inspection (PHENIX): a new method to confirm the presence or absence of high explosives for nuclear treaty verification

Advanced instruments and methods need to be developed now to create a technical basis to support the negotiation of future nuclear arms control treaties. One new capability that is anticipated is the ability to confirm either the declared presence or declared absence of high explosive (HE) material in the presence of special nuclear material (SNM). Towards this goal, Passive HE Neutron Inspection (PHENIX) has been developed and demonstrated as a method for confirming the presence or absence of HE in the presence of plutonium. The method exploits the inherent presence of neutrons associated with the decay of plutonium as an internal probe source for performing prompt gamma-ray neutron activation analysis (PGNAA), searching for the presence of HE as revealed by the emission of characteristic gamma rays following neutron absorption in hydrogen and nitrogen which are building blocks of present-day, military-grade HE. Tests using stoichiometrically-correct hemishells of mock HE with plutonium show that a system can be expected to positively confirm the presence or absence of these signatures, supporting determination of HE presence or absence with Pu, in a few hours. To protect other potentially sensitive gamma-ray signatures from a treaty accountable item, an analog information barrier has been conceptualized and tested which physically prevents the collection of gamma-ray spectral data outside of user selected energy windows strategically chosen to view only narrow spectral regions corresponding to the hydrogen (2223.2 keV) and nitrogen (9807.2 keV, 10,318.2 keV, and 10,829.2 keV) PGNAA signatures.

Assessing One Health capacities for transboundary zoonotic diseases at the Libya-Tunisia border

BACKGROUND

The dynamic nature of zoonotic emergence, spillover and spread necessitates multisectoral coordination beyond national borders to encompass cross-boundary and regional cooperation. Designated points of entry (POEs), specifically ground crossings, serve as critical locales for establishing and maintaining robust prevention, detection, notification, coordination, and response mechanisms to transboundary emerging and re-emerging disease threats. In order to better assess One Health capacities for transboundary zoonotic diseases (TZD) prevention, detection and response we adapted an existing tool, One Health Systems Assessment for Priority Zoonoses (OHSAPZ), for a cross-border, POE setting in North Africa.

METHODS

The One Health Transboundary Assessment for Priority Zoonoses (OHTAPZ) tool was used to support prioritization of transboundary zoonoses and analyze operational capacities between national and subnational-level human and animal health stakeholders from Libya and Tunisia. Country partners jointly identified and prioritized five TZDs of concern. Case study scenarios for each priority pathogen were used to elicit current disease operations, as well as multisectoral and bilateral engagement networks. Finally, a gap analysis was performed to determine bilateral strengths and weaknesses to TZDs.

RESULTS

The five priority TZDs jointly confirmed to undergo One Health assessment were avian influenza (low and high pathogenic strains); brucellosis; Rift Valley fever; Crimean-Congo hemorrhagic fever; and rabies. Using the qualitative information collected, a transboundary systems map schematic was developed outlining the movement of human patients, animals, diagnostic samples, and routes of communication and coordination both within and between countries for zoonotic diseases.

CONCLUSIONS

Analysis of current operations (prevention, detection, surveillance, laboratory capacity, quarantine/isolation, and response) and the resulting transboundary systems map schematic helped identify existing capacity strengths for certain priority pathogens, as well as challenges to timely information-sharing and coordination. We developed targeted recommendations to address these limitations for joint action planning between Libya and Tunisia.

Audience Response to COVID Monologues: Research-Based Theater on the Societal Impact of COVID-19

PURPOSE

Research-based theater uses drama to communicate research findings to audiences beyond those that typically read peer-reviewed journals. We applied research-based theater to translate qualitative research findings on the impact of the COVID-19 pandemic on different segments of U.S. society.

APPROACH

Theater artists and public health researchers collaborated to create a collection of eight monologues from systematically sourced, peer-reviewed publications. Following three virtual performances in Spring, 2021, audience members were invited to complete a survey.

SETTING/PARTICIPANTS

Audience survey respondents (n = 120) were mostly U.S.-based and were diverse in terms of age, race/ethnicity, gender, profession, and experience attending theater.

METHOD

We summarized closed-ended responses and explored patterns by demographic characteristics. We synthesized themes of open-ended responses with inductive coding.

RESULTS

Audience members somewhat/strongly agreed that COVID Monologues increased their knowledge (79.4%), represented the reality of the U.S. COVID-19 epidemic (95.7%), and offered new perspectives on what people had been experiencing (87.5%). Most also agreed research-based theater is an effective means of understanding health research (93.5%) and can promote community resilience in times of public health crisis (83.2%). Mann-Whitney U tests suggested less positive reactions from demographics that were not well-represented in monologue characters (cisgender men, Hispanics). Qualitative comments suggested audience members valued monologues that offered self-reflection and validation of their own COVID-19 experiences through relatable characters as well as those that offered insight into the experiences of people different from themselves.

CONCLUSION

This work adds to evidence that research-based theater can help build knowledge and emotional insight around a public health issue. As these elements are foundational to pro-social, preventative health behaviors, research-based theater may have a useful role in promoting collective response to public health crises like COVID-19. Our method of systematically-sourcing research for theater-based dissemination could be extended to target more specific audiences with actionable behaviors.

Corridor-Level Impacts of Battery-Electric Heavy-Duty Trucks and the Effects of Policy in the United States

Electrifying freight trucks will be key to alleviating air pollution burdens on disadvantaged communities and mitigating climate change. The United States plans to pursue this aim by adding vehicle charging infrastructure along specific freight corridors. This study explores the coevolution of the electricity grid and freight trucking landscape using an integrated assessment framework to identify when each interstate and drayage corridor becomes advantageous to electrify from a climate and human health standpoint. Nearly all corridors achieve greenhouse gas emission reductions if electrified now. Most can reduce health impacts from air pollution if electrified by 2040 although some corridors in the Midwest, South, and Mid-Atlantic regions remain unfavorable to electrify from a human health standpoint, absent policy support. Recent policy, namely, the Inflation Reduction Act, accelerates this timeline to 2030 for most corridors and results in net human health benefits on all corridors by 2050, suggesting that near-term investments in truck electrification, particularly drayage corridors, can meaningfully reduce climate and health burdens.

An integrated framework for examining groundwater vulnerability in the Mekong River Delta region

The Mekong River provides water, food security, and many other valuable benefits to the more than 60 million Southeast Asian residents living within its basin. However, the Mekong River Basin is increasingly stressed by changes in climate, land cover, and infrastructure. These changes can affect water quantity and quality and exacerbate related hazards such as land subsidence and saltwater intrusion, resulting in multiple compounding risks for neighboring communities. In this study, we demonstrate the connection between climate change, groundwater availability, and social vulnerability by linking the results of a numerical groundwater model to land cover and socioeconomic data at the Cambodia-Vietnam border in the Mekong River Delta region. We simulated changes in groundwater availability across 20 years and identified areas of potential water stress based on domestic and agriculture-related freshwater demands. We then assessed adaptive capacity to understand how communities may be able to respond to this stress to better understand the growing risk of groundwater scarcity driven by climate change and overextraction. This study offers a novel approach for assessing risk of groundwater scarcity by linking the effects of climate change to the socioeconomic context in which they occur. Increasing our understanding of how changes in groundwater availability may affect local populations can help water managers better plan for the future, leading to more resilient communities.

Caregivers' perspectives on future planning for their adult children with intellectual disabilities in Romania

BACKGROUND

Much of the research and program innovation regarding future planning for adults with intellectual disabilities has occurred in countries with well-developed disability service systems. This study explored how family caregivers planned for their adult children's future caregiving needs in Romania, a country with a limited array of disability services.

METHOD

In this exploratory qualitative study, we conducted 30 face-to-face interviews with caregivers of adults with intellectual disabilities in Romania. We used thematic analysis to analyse the transcribed and translated interview data.

RESULTS

The majority of participants, while believing that future planning was necessary, had not engaged in planning and had no supports for planning. As there were few disability services, the majority of the participants reported that they could not engage in planning, and many avoided thinking about the future.

CONCLUSION

Romania and other countries with fewer disability services likely need alternative models of future planning than those that have been developed and tested previously.

Intimate partner violence victimization during pregnancy increases risk of postpartum depression among urban adolescent mothers in South Africa

BACKGROUND

It is estimated that 38.8% of mothers develop postpartum depression (PPD) in South Africa. While empirical evidence documents an association between intimate partner violence (IPV) victimization in pregnancy and PPD among adult women, the association has been underexamined among adolescent mothers (< 19 years). The study's purpose is to examine whether IPV victimization during pregnancy is associated with PPD among adolescent mothers.

METHODS

Adolescent mothers (14-19 years) were recruited at a regional hospital's maternity ward in KwaZulu Natal, South Africa between July 2017-April 2018. Participants completed behavioral assessments at two visits (n = 90): baseline (up to 4 weeks postpartum) and follow-up (6-9 weeks postpartum, when PPD is typically assessed). The WHO modified conflict tactics scale was used to create a binary measure of any physical and/or psychological IPV victimization that occurred during pregnancy. Participants with scores ≥ 13 on the Edinburgh Postpartum Depression Scale (EPDS) were classified as having symptoms of PPD. We used a modified Poisson regression with robust standard errors to assess PPD in association with IPV victimization during pregnancy, controlling for relevant covariates.

RESULTS

Nearly one-half (47%) of adolescent mothers reported symptoms of PPD by 6-9 weeks post-delivery. Further, IPV victimization during pregnancy was highly prevalent (40%). Adolescent mothers who reported IPV victimization during pregnancy had marginally higher risk of PPD at follow-up (RR: 1.50, 95 CI: 0.97-2.31; p = 0.07). The association was strengthened and significant in covariate-adjusted analysis (RR: 1.62, 95 CI: 1.06-2.49; p = 0.03).

CONCLUSIONS

Poor mental health was common among adolescent mothers, and IPV victimization during pregnancy was associated with PPD risk among adolescent mothers. Implementing IPV and PPD routine screenings during the perinatal period may aid in identifying adolescent mothers for IPV and PPD interventions and treatment. With the high prevalence of IPV and PPD in this vulnerable population and the potential negative impact on maternal and infant outcomes, interventions to reduce IPV and PPD are needed to improve adolescent mothers' well-being and their baby's health.

A new enzymatic assay to quantify inorganic pyrophosphate in plasma

Inorganic pyrophosphate (PPi) is a crucial extracellular mineralization regulator. Low plasma PPi concentrations underlie the soft tissue calcification present in several rare hereditary mineralization disorders as well as in more common conditions like chronic kidney disease and diabetes. Even though deregulated plasma PPi homeostasis is known to be linked to multiple human diseases, there is currently no reliable assay for its quantification. We here describe a PPi assay that employs the enzyme ATP sulfurylase to convert PPi into ATP. Generated ATP is subsequently quantified by firefly luciferase-based bioluminescence. An internal ATP standard was used to correct for sample-specific interference by matrix compounds on firefly luciferase activity. The assay was validated and shows excellent precision (< 3.5%) and accuracy (93-106%) of PPi spiked into human plasma samples. We found that of several anticoagulants tested only EDTA effectively blocked conversion of ATP into PPi in plasma after blood collection. Moreover, filtration over a 300,000-Da molecular weight cut-off membrane reduced variability of plasma PPi and removed ATP present in a membrane-enclosed compartment, possibly platelets. Applied to plasma samples of wild-type and Abcc6-/- rats, an animal model with established low circulating levels of PPi, the new assay showed lower variability than the assay that was previously in routine use in our laboratory. In conclusion, we here report a new and robust assay to determine PPi concentrations in plasma, which outperforms currently available assays because of its high sensitivity, precision, and accuracy.

Organellar microcapture to extract nuclear and plastid DNA from recalcitrant wood specimens and trace evidence

BACKGROUND

Illegal logging is a global crisis with significant environmental, economic, and social consequences. Efforts to combat it call for forensic methods to determine species identity, provenance, and individual identification of wood specimens throughout the forest products supply chain. DNA-based methodologies are the only tools with the potential to answer all three questions and the only ones that can be calibrated "non-destructively" by using leaves or other plant tissue and take advantage of publicly available DNA sequence databases. Despite the potential that DNA-based methods represent for wood forensics, low DNA yield from wood remains a limiting factor because, when compared to other plant tissues, wood has few living DNA-containing cells at functional maturity, it often has PCR-inhibiting extractives, and industrial processing of wood degrades DNA. To overcome these limitations, we developed a technique-organellar microcapture-to mechanically isolate intact nuclei and plastids from wood for subsequent DNA extraction, amplification, and sequencing.

RESULTS

Here we demonstrate organellar microcapture wherein we remove individual nuclei from parenchyma cells in wood (fresh and aged) and leaves of Carya ovata and Tilia americana, amyloplasts from Carya wood, and chloroplasts from kale (Brassica sp.) leaf midribs. ITS (773 bp), ITS1 (350 bp), ITS2 (450 bp), and rbcL (620 bp) were amplified via polymerase chain reaction, sequenced, and heuristic searches against the NCBI database were used to confirm that recovered DNA corresponded to each taxon.

CONCLUSION

Organellar microcapture, while too labor-intensive for routine extraction of many specimens, successfully recovered intact nuclei from wood samples collected more than sixty-five years ago, plastids from fresh sapwood and leaves, and presents great potential for DNA extraction from recalcitrant plant samples such as tissues rich in secondary metabolites, old specimens (archaeological, herbarium, and xylarium specimens), or trace evidence previously considered too small for analysis.

Contraceptive Method Mix and HIV Risk Behaviors Among Kenyan Adolescent Girls and Young Women Seeking Family Planning Services: Implications for Integrating HIV Prevention

Background: Understanding HIV risk behaviors among adolescent girls and young women (AGYW) seeking contraception could help inform integrating HIV prevention services within family planning (FP) clinics. Methods: From 10/2018 to 04/2019, we conducted a survey at 4 FP clinics in Kisumu, Kenya to evaluate risk behaviors among AGYW without HIV infection seeking contraception. All AGYW aged 15-24 were invited to participate following receipt of FP services. Adolescent girls and young women initiating or refilling contraception were included in this analysis. Long-acting reversible contraceptives (LARC) included intrauterine devices, implants, or injectables. Non-LARC methods included oral contraceptive pills (OCP) or condoms. We used an empiric risk score to assess HIV risk behaviors; HIV risk scores of ≥5 (corresponding to 5-15% HIV incidence) defined "high" HIV risk. Results: Overall, 555 AGYW seeking FP were included. Median age was 22 years [interquartile range (IQR) 20-23], median completed education was 12 years (IQR 10-12); 23% of AGYW had HIV risk scores of ≥5. The most frequent form of contraception was injectables (43%), followed by implants (39%). After adjustment for education, prior pregnancy, and marital status, LARC users more frequently engaged in transactional sex than non-LARC users [6 vs. 0%, adjusted prevalence ratio (PR) = 1.17, 95% CI 1.09-1.29, p < 0.001]; LARC use was not associated with HIV risk scores ≥5. Among LARC users, AGYW using injectables more frequently had condomless sex compared to AGYW using other LARC methods (85 vs. 75%, adjusted PR = 1.52, 95% CI 1.09-2.10, p = 0.012); injectable use was not associated with HIV risk scores ≥5. Conclusions: Adolescent girls and young women seeking contraception frequently had high HIV risk, emphasizing the importance of integrating HIV prevention within FP. Multipurpose technologies for contraception and HIV prevention could particularly benefit AGYW.

HIV risk screening and HIV testing among orphans and vulnerable children in community settings in Tanzania: Acceptability and fidelity to lay-cadre administration of the screening tool

INTRODUCTION

HIV risk screening tool validation studies have not typically included process evaluations to understand tool implementation. The study aim was to assess the fidelity to which an HIV risk screening tool was administered by lay workers and acceptability of delivering home-based screening coupled with HIV testing to beneficiaries in an orphans and vulnerable children (OVC) program.

METHODS

This cross-sectional study was conducted March-April 2019 in two regions of Tanzania. Community case workers (CCW) were observed conducting screenings with OVC 2-19 years and participated in focus group discussions. Research staff used structured observation checklists to capture if screening questions were asked or reworded by CCW. In-depth interviews were conducted with older adolescents and caregivers in their homes following screening and testing. A composite score was developed for the checklist. Qualitative data were thematically analyzed to address screening and testing perceptions and experiences.

RESULTS

CCW (n = 32) participated in 166 observations. Commonly skipped items were malnutrition (34% of all observed screenings) and sexual activity and pregnancy (20% and 45% of screenings for adolescents only). Items frequently re-worded included child abuse (22%) and malnutrition (15%). CCW had an average composite observation score of 42/50. CCW in focus groups (n = 34) found the screening process acceptable. However, they described rewording some questions viewed as harsh or socially inappropriate to ask. Overall, adolescent beneficiaries (n = 17) and caregivers (n = 25) were satisfied with home-based screening and testing and reported no negative consequences. Learning one's HIV negative status was seen as an opportunity to discuss or recommit to healthy behaviors. While respondents identified multiple benefits of home testing, they noted the potential for privacy breaches in household settings.

CONCLUSIONS

We found sub-optimal fidelity to the administration of the screening tool by CCW in home environments to children and adolescents enrolled in an OVC program. Improvements to questions and their delivery and ongoing mentorship could strengthen tool performance and HIV case finding using a targeted testing approach. Overall, home-based HIV risk screening and testing were acceptable to beneficiaries and CCW, could improve testing uptake, and serve as a platform to promote healthy behaviors for those with limited health system interactions.

Magnetic aerogel: an advanced material of high importance

Magnetic materials have brought innovations in the field of advanced materials. Their incorporation in aerogels has certainly broadened their application area. Magnetic aerogels can be used for various purposes from adsorbents to developing electromagnetic interference shielding and microwave absorbing materials, high-level diagnostic tools, therapeutic systems, and so on. Considering the final use and cost, these can be fabricated from a variety of materials using different approaches. To date, several studies have been published reporting the fabrication and uses of magnetic aerogels. However, to our knowledge, there is no review that specifically focuses only on magnetic aerogels, so we attempted to overview the main developments in this field and ended our study with the conclusion that magnetic aerogels are one of the emerging and futuristic advanced materials with the potential to offer multiple applications of high value.

The potential impact of COVID-19 in refugee camps in Bangladesh and beyond: A modeling study

BACKGROUND

COVID-19 could have even more dire consequences in refugees camps than in general populations. Bangladesh has confirmed COVID-19 cases and hosts almost 1 million Rohingya refugees from Myanmar, with 600,000 concentrated in the Kutupalong-Balukhali Expansion Site (mean age, 21 years; standard deviation [SD], 18 years; 52% female). Projections of the potential COVID-19 burden, epidemic speed, and healthcare needs in such settings are critical for preparedness planning.

METHODS AND FINDINGS

To explore the potential impact of the introduction of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the Kutupalong-Balukhali Expansion Site, we used a stochastic Susceptible Exposed Infectious Recovered (SEIR) transmission model with parameters derived from emerging literature and age as the primary determinant of infection severity. We considered three scenarios with different assumptions about the transmission potential of SARS-CoV-2. From the simulated infections, we estimated hospitalizations, deaths, and healthcare needs expected, age-adjusted for the Kutupalong-Balukhali Expansion Site age distribution. Our findings suggest that a large-scale outbreak is likely after a single introduction of the virus into the camp, with 61%-92% of simulations leading to at least 1,000 people infected across scenarios. On average, in the first 30 days of the outbreak, we expect 18 (95% prediction interval [PI], 2-65), 54 (95% PI, 3-223), and 370 (95% PI, 4-1,850) people infected in the low, moderate, and high transmission scenarios, respectively. These reach 421,500 (95% PI, 376,300-463,500), 546,800 (95% PI, 499,300-567,000), and 589,800 (95% PI, 578,800-595,600) people infected in 12 months, respectively. Hospitalization needs exceeded the existing hospitalization capacity of 340 beds after 55-136 days, between the low and high transmission scenarios. We estimate 2,040 (95% PI, 1,660-2,500), 2,650 (95% PI, 2,030-3,380), and 2,880 (95% PI, 2,090-3,830) deaths in the low, moderate, and high transmission scenarios, respectively. Due to limited data at the time of analyses, we assumed that age was the primary determinant of infection severity and hospitalization. We expect that comorbidities, limited hospitalization, and intensive care capacity may increase this risk; thus, we may be underestimating the potential burden.

CONCLUSIONS

Our findings suggest that a COVID-19 epidemic in a refugee settlement may have profound consequences, requiring large increases in healthcare capacity and infrastructure that may exceed what is currently feasible in these settings. Detailed and realistic planning for the worst case in Kutupalong-Balukhali and all refugee camps worldwide must begin now. Plans should consider novel and radical strategies to reduce infectious contacts and fill health worker gaps while recognizing that refugees may not have access to national health systems.

Storm impacts on phytoplankton community dynamics in lakes

In many regions across the globe, extreme weather events such as storms have increased in frequency, intensity, and duration due to climate change. Ecological theory predicts that such extreme events should have large impacts on ecosystem structure and function. High winds and precipitation associated with storms can affect lakes via short-term runoff events from watersheds and physical mixing of the water column. In addition, lakes connected to rivers and streams will also experience flushing due to high flow rates. Although we have a well-developed understanding of how wind and precipitation events can alter lake physical processes and some aspects of biogeochemical cycling, our mechanistic understanding of the emergent responses of phytoplankton communities is poor. Here we provide a comprehensive synthesis that identifies how storms interact with lake and watershed attributes and their antecedent conditions to generate changes in lake physical and chemical environments. Such changes can restructure phytoplankton communities and their dynamics, as well as result in altered ecological function (e.g., carbon, nutrient and energy cycling) in the short- and long-term. We summarize the current understanding of storm-induced phytoplankton dynamics, identify knowledge gaps with a systematic review of the literature, and suggest future research directions across a gradient of lake types and environmental conditions.

Carnelian uncovers hidden functional patterns across diverse study populations from whole metagenome sequencing reads

Microbial populations exhibit functional changes in response to different ambient environments. Although whole metagenome sequencing promises enough raw data to study those changes, existing tools are limited in their ability to directly compare microbial metabolic function across samples and studies. We introduce Carnelian, an end-to-end pipeline for metabolic functional profiling uniquely suited to finding functional trends across diverse datasets. Carnelian is able to find shared metabolic pathways, concordant functional dysbioses, and distinguish Enzyme Commission (EC) terms missed by existing methodologies. We demonstrate Carnelian's effectiveness on type 2 diabetes, Crohn's disease, Parkinson's disease, and industrialized and non-industrialized gut microbiome cohorts.

Vaginal microbiota and mucosal pharmacokinetics of tenofovir in healthy women using tenofovir and tenofovir/levonorgestrel vaginal rings

Recent data support that the vaginal microbiota may alter mucosal pharmacokinetics (PK) of topically delivered microbicides. Our team developed an intravaginal ring (IVR) that delivers tenofovir (TFV) (8–10 mg/day) alone or with levonorgestrel (LNG) (20 ug/day). We evaluated the effect of IVRs on the vaginal microbiota, and describe how the vaginal microbiota impacts mucosal PK of TFV. CONRAD A13-128 was a randomized, placebo controlled phase I study. We randomized 51 women to TFV, TFV/LNG or placebo IVR. We assessed the vaginal microbiota by sequencing the V3-V4 regions of 16S rRNA genes prior to IVR insertion and after approximately 15 days of use. We measured the concentration of TFV in the cervicovaginal (CV) aspirate, and TFV and TFV-diphosphate (TFV-DP) in vaginal tissue at the end of IVR use. The change in relative or absolute abundance of vaginal bacterial phylotypes was similar among active and placebo IVR users (all q values >0.13). TFV concentrations in CV aspirate and vaginal tissue, and TFV-DP concentrations in vaginal tissue were not significantly different among users with community state type (CST) 4 versus those with Lactobacillus dominated microbiota (all p values >0.07). The proportions of participants with CV aspirate concentrations of TFV >200,000 ng/mL and those with tissue TFV-DP concentrations >1,000 fmol/mg were similar among women with anaerobe versus Lactobacillus dominated microbiota (p = 0.43, 0.95 respectively). There were no significant correlations between the CV aspirate concentration of TFV and the relative abundances of Gardnerella vaginalis or Prevotella species. Tissue concentrations of TFV-DP did not correlate with any the relative abundances of any species, including Gardnerella vaginalis. In conclusion, active IVRs did not differ from the placebo IVR on the effect on the vaginal microbiota. Local TFV and TFV-DP concentrations were high and similar among IVR users with Lactobacillus dominated microbiota versus CST IV vaginal microbiota.

Trial registration: ClinicalTrials.gov NCT02235662.

Peer-assisted learning after onsite, low-dose, high-frequency training and practice on simulators to prevent and treat postpartum hemorrhage and neonatal asphyxia: A pragmatic trial in 12 districts in Uganda

An urgent need exists to improve and maintain intrapartum skills of providers in sub-Saharan Africa. Peer-assisted learning may address this need, but few rigorous evaluations have been conducted in real-world settings. A pragmatic, cluster-randomized trial in 12 Ugandan districts provided facility-based, team training for prevention and management of postpartum hemorrhage and birth asphyxia at 125 facilities. Three approaches to facilitating simulation-based, peer assisted learning were compared. The primary outcome was the proportion of births with uterotonic given within one minute of birth. Outcomes were evaluated using observation of birth and supplemented by skills assessments and service delivery data. Individual and composite variables were compared across groups, using generalized linear models. Overall, 107, 195, and 199 providers were observed at three time points during 1,716 births across 44 facilities. Uterotonic coverage within one minute increased from: full group: 8% (CI 4%‒12%) to 50% (CI 42%‒59%); partial group: 19% (CI 9%‒30%) to 42% (CI 31%‒53%); and control group: 11% (5%‒7%) to 51% (40%‒61%). Observed care of mother and newborn improved in all groups. Simulated skills maintenance for postpartum hemorrhage prophylaxis remained high across groups 7 to 8 months after the intervention. Simulated skills for newborn bag-and-mask ventilation remained high only in the full group. For all groups combined, incidence of postpartum hemorrhage and retained placenta declined 17% and 47%, respectively, from during the intervention period compared to the 6‒9 month period after the intervention. Fresh stillbirths and newborn deaths before discharge decreased by 34% and 62%, respectively, from baseline to after completion, and remained reduced 6‒9 months post-implementation. Significant improvements in uterotonic coverage remained across groups 6 months after the intervention. Findings suggest that while short, simulation-based training at the facility improves care and is feasible, more complex clinical skills used infrequently such as newborn resuscitation may require more practice to maintain skills. Trial Registration: ClinicalTrials.gov NCT03254628.

Classification of CITES-listed and other neotropical Meliaceae wood images using convolutional neural networks

BACKGROUND

The current state-of-the-art for field wood identification to combat illegal logging relies on experienced practitioners using hand lenses, specialized identification keys, atlases of woods, and field manuals. Accumulation of this expertise is time-consuming and access to training is relatively rare compared to the international demand for field wood identification. A reliable, consistent and cost effective field screening method is necessary for effective global scale enforcement of international treaties such as the Convention on the International Trade in Endagered Species (CITES) or national laws (e.g. the US Lacey Act) governing timber trade and imports.

RESULTS

We present highly effective computer vision classification models, based on deep convolutional neural networks, trained via transfer learning, to identify the woods of 10 neotropical species in the family Meliaceae, including CITES-listed Swietenia macrophylla, Swietenia mahagoni, Cedrela fissilis, and Cedrela odorata. We build and evaluate models to classify the 10 woods at the species and genus levels, with image-level model accuracy ranging from 87.4 to 97.5%, with the strongest performance by the genus-level model. Misclassified images are attributed to classes consistent with traditional wood anatomical results, and our species-level accuracy greatly exceeds the resolution of traditional wood identification.

CONCLUSION

The end-to-end trained image classifiers that we present discriminate the woods based on digital images of the transverse surface of solid wood blocks, which are surfaces and images that can be prepared and captured in the field. Hence this work represents a strong proof-of-concept for using computer vision and convolutional neural networks to develop practical models for field screening timber and wood products to combat illegal logging.

Competitiveness and survival of two strains of Glossina palpalis gambiensis in an urban area of Senegal

Background

In the Niayes area, located in the west of Senegal, only one tsetse species, Glossina palpalis gambiensis Vanderplank (Diptera: Glossinidae) was present. The Government of Senegal initiated and implemented an elimination programme in this area that included a sterile insect technique (SIT) component. The G. p. gambiensis strain (BKF) mass-reared at the Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES) in Burkina Faso was used for the SIT component.

Methodology/principal findings

Studies conducted in 2011 in four localities in the Niayes area (Pout, Sébikotane, Diacksao Peul and the Parc de Hann) showed that the BKF strain demonstrated inferior survival in the ecosystem of the Parc de Hann, a forested area in the city centre of the capital Dakar. Therefore, G. p. gambiensis flies from the Niayes area (SEN strain) were colonized. Here we compared the competitiveness and survival of the two strains (BKF and SEN) in the Parc de Hann. Released sterile males of the SEN colony showed a daily mortality rate of 0.08 (SD 0.08) as compared with 0.14 (SD 0.08) for the BKF flies but the difference was not significant (p-value = 0.14). However, the competitiveness of the SEN males was lower (0.14 (SD 0.10)) as compared with that of the BKF males (0.76 (SD 0.11)) (p-value < 10⁻³).

Conclusions/significance

Based on the results of this study, it can be concluded that the BKF strain will remain the main strain to be used in the elimination programme. Despite the slightly longer survival of the SEN males in the Parc de Hann, the superior competitiveness of the BKF males is deemed more important for the SIT component, as their shorter survival rates can be easily compensated for by more frequent fly releases.

Senegal is one of the many African countries infested by tsetse flies responsible for the transmission of trypanosomes to humans and animals, causing health and economic losses. In the Niayes area, located in the west of Senegal, only one tsetse species, Glossina palpalis gambiensis Vanderplank (Diptera: Glossinidae) is present, which is targeted by an elimination effort including the sterile insect technique (SIT). The quality of the strain used to implement any SIT effort is instrumental for its success. Here we compared the competitiveness and survival of irradiated males of two strains (BKF and SEN) released in the Parc de Hann, to assess their usefulness in eradicating this isolated population, located within the capital city, Dakar. We observed that the mating competitiveness of the SEN males was significantly lower as compared with that of the BKF males. Based on this study, we concluded that the BKF strain will remain the main strain to be used in the elimination programme in the Niayes.

Fluorescent Receptor Binding Assay for Detecting Ciguatoxins in Fish

Ciguatera fish poisoning is an illness suffered by > 50,000 people yearly after consumption of fish containing ciguatoxins (CTXs). One of the current methodologies to detect ciguatoxins in fish is a radiolabeled receptor binding assay (RBA_(R)). However, the license requirements and regulations pertaining to radioisotope utilization can limit the applicability of the RBA_(R) in certain labs. A fluorescence based receptor binding assay (RBA_(F)) was developed to provide an alternative method of screening fish samples for CTXs in facilities not certified to use radioisotopes. The new assay is based on competition binding between CTXs and fluorescently labeled brevetoxin-2 (BODIPY^®- PbTx-2) for voltage-gated sodium channel receptors at site 5 instead of a radiolabeled brevetoxin. Responses were linear in fish tissues spiked from 0.1 to 1.0 ppb with Pacific ciguatoxin-3C (P-CTX-3C) with a detection limit of 0.075 ppb. Carribean ciguatoxins were confirmed in Caribbean fish by LC-MS/MS analysis of the regional biomarker (C-CTX-1). Fish (N = 61) of six different species were screened using the RBA_(F). Results for corresponding samples analyzed using the neuroblastoma cell-based assay (CBA-N2a) correlated well (R² = 0.71) with those of the RBA_(F), given the low levels of CTX present in positive fish. Data analyses also showed the resulting toxicity levels of P-CTX-3C equivalents determined by CBA-N2a were consistently lower than the RBA_(F) affinities expressed as % binding equivalents, indicating that a given amount of toxin bound to the site 5 receptors translates into corresponding lower cytotoxicity. Consequently, the RBA_(F), which takes approximately two hours to perform, provides a generous estimate relative to the widely used CBA-N2a which requires 2.5 days to complete. Other RBA_(F) advantages include the long-term (> 5 years) stability of the BODIPY^®- PbTx-2 and having similar results as the commonly used RBA_(R). The RBA_(F) is cost-effective, allows high sample throughput, and is well-suited for routine CTX monitoring programs.