First report of Fusarium falciforme causing basal rot of onion (Allium cepa) in India

Onion (Allium cepa, L) is a very important vegetable crop in India. India is the second largest producer of onion in the world and the crop is grown on more than 1.22 million hectares. Fusarium Basal Rot (FBR) is an economically important diseasef onion that causes considerable losses in onion production up to 50% in field and 30-40% during post-harvest storage of bulbs (Gupta and Gupta 2013; Rajamohan et al. 2019). Onion plants showing chlorosis, twisting, wilting, necrosis, bulb discoloration, rot in the basal parts of bulb and roots typical to FBR were observed, in a field trial of 36 onion cultivars during October 2020 in Bangalore, Karnataka. FBR incidence varied from 30-100% in this field (Fig 1 a-d). Symptomatic bulbs were washed with water, basal plate and fleshy leaves cut into 0.5 to 1 cm-size, surface disinfected with 1.5% sodium hypochlorite (NaOCl) for 3 min, and rinsed with sterile distilled water. Twenty pieces were placed on potato dextrose agar (PDA) in Petri plates and incubated at 25°C for 7 days. Colonies from single-spore isolates on PDA showed abundant white aerial mycelium. Colonies showed light pink or purple coloration on the reverse side of the culture plate with brown center (Fig 1e-f). Macroconidia were 19.13 to 28.35 (mean= 24.2) × 4.29 to 6.06 (mean= 5.05) µm, hyaline, falcate, with slightly curved apexes, and three to five septa. Microconidia were cylindrical to ellipsoid, aseptate, hyaline 8.20 to 12 (mean=10.0) × 3.55 to 4.79 (mean= 4.29) µm (Fig 1g). Chlamydospores were round, intercalary, hyaline, single or in chains (Fig 1h). Two isolates (IBFF-09 & IBFF-10) were analyzed for internal transcribed spacer-ITS (White et al. 1990) and translation elongation factor 1-α (tef1) gene (O'Donnell et al. 1998) by polymerase chain reaction (PCR) and sequenced. ITS and partial tef1 gene sequences of isolates IBFF-09 and IBFF-10 were submitted to the NCBI database (GenBank accession # ON394614&ON026859; # ON409480, ON093166 respectively). Phylogenetic analysis of tef1 gene placed the isolates with F. falciforme (Fig 1i). A pathogenicity test was performed by dipping roots of 28 days old healthy onion seedlings of a susceptible genotype 16/7Y GR3 into a conidial suspension (1 × 104 conidia/ml) of isolate IBFF-10 for 15 min and then transplanting the plants into pots containing sterilized potting mix. Inoculated plants developed typical symptoms of FBR and were all dead by 20 days post inoculation (Fig 1j) while the non-inoculated controls remained healthy. Pathogen was re-isolated from infected plants and showed the same morphology, ITS and tef1 sequence similarity as the original isolate, thus fulfilling Koch's postulates. Basal rot of onion by F. falciforme is reported from Mexico (Tirado-Ramírez et al. 2021). Till date, only F .oxysporum, F. proliferatum and F. solani have been implicated in onion FBR in India (Lee et al. 2021; Rathore and Patil, 2019). F. falciforme however, i prevalent in India and is reported to infect other crops (Gangaraj et al. 2022; Gupta et al. 2019; Homa et al. 2018). There is a high probability that this pathogen is contributing significantly to basal rot disease but it has not been reported yet. To our knowledge, this is the first report of F. falciforme infecting onions in India. In order to develop FBR resistant onion cultivars it is critical to identify and study the response of onion genotypes to different Fusarium spp causing the disease.

One-step start-up and subsequent operation of CANON process in a fixed-bed reactor by inoculating mixture of partial nitrification and Anammox sludge

The feasibility of one-step start-up of CANON process in a FBR by inoculating mixture of partial nitrification and Anammox sludge as well as its subsequent operation performances were investigated in the present study. The FBR was operated for around 3 months. The CANON process was quickly started up within 21 days. The max total nitrogen (TN) removal rate reached 183.61 g m^-3 d^-1 with the TN removal efficiency of 91.81% on day 95. The CANON process exhibited a good capability for resistance to loading shock and restoration from the unstable state. The mature CANON biofilms displayed a morphology of aggregates and had porous and microporous structure. The structural characteristics of the biofilms were conducive to improve the transferring of substrates and products. AOB and Anammox bacteria absolutely predominated in the mature biofilms and furthermore established a balanced interaction relationship. The microbial community structure contributed to the relatively stable operation performances.

High-rate microbial selenate reduction in an up-flow anaerobic fluidized bed reactor (FBR)

Wastewater contaminated with high concentrations of selenium oxyanions requires treatment prior to discharge. Biological fluidized bed reactors (FBRs) can be an option for removing selenium oxyanions from wastewater by converting them into elemental selenium, which can be separated from the treated effluent. In this study, a lab-scale FBR was constructed with granular activated carbon as biofilm carrier and inoculated with a consortium of selenate reducing bacteria enriched from environmental samples. The FBR was loaded with an influent containing ethanol (10 mM) and selenate (10 mM) as the microbial electron donor and acceptor, respectively. The performance of the FBR in reducing selenate was evaluated under various hydraulic retention times (HRTs) (120 h, 72 h, 48 h, 24 h, 12 h, 6 h, 3 h, 1 h and 20 min). After process acclimatization, selenate was completely removed with no notable selenite produced when the HRT was stepwise decreased from 120 h to 6 h. However, decreasing the HRT to 3 h resulted in selenite accumulation (0.17 ± 0.023 mM) in the effluent although selenate removal efficiency remained at 99.8 ± 0.20%. At 1 h HRT, the FBR removed 90.8 ± 1.4% of the selenate at a rate of 9.6 ± 0.15 mM h^-1, which is the highest selenate reduction rate reported in the literature so far. However, 1 h HRT resulted in notable selenite accumulation (up to 2.4 ± 0.27 mM). Further decreasing the HRT to 20 min resulted in a notable decline in selenate reduction. Selenate reduction recovered from the "shock loading" after the HRT was increased back to 3 h. However, selenite still accumulated until the FBR was operated in batch mode for 6 days. This study affirmed that FBR is a promising treatment option for selenate-rich wastewater, and the process can be efficiently operated at low HRTs.

Immobilized Macrophage Colony-Stimulating Factor (M-CSF) Regulates the Foreign Body Response to Implanted Materials

The functionality and durability of implanted biomaterials are often compromised by an exaggerated foreign body reaction (FBR). M1/M2 polarization of macrophages is a critical regulator of scaffold-induced FBR. Macrophage colony-stimulating factor (M-CSF), a hematopoietic growth factor, induces macrophages into an M2-like polarized state, leading to immunoregulation and promoting tissue repair. In the present study, we explored the immunomodulatory effects of surface bound M-CSF on poly-l-lactic acid (PLLA)-induced FBR. M-CSF was immobilized on the surface of PLLA via plasma immersion ion implantation (PIII). M-CSF functionalized PLLA, PLLA-only, and PLLA+PIII were assessed in an IL-1β luciferase reporter mouse to detect real-time levels of IL-1β expression, reflecting acute inflammation in vivo. Additionally, these different treated scaffolds were implanted subcutaneously into wild-type mice to explore the effect of M-CSF in polarization of M2-like macrophages (CD68⁺/CD206⁺), related cytokines (pro-inflammatory: IL-1β, TNF and MCP-1; anti-inflammatory: IL-10 and TGF-β), and angiogenesis (CD31) by immunofluorescent staining. Our data demonstrated that IL-1β activity in M-CSF functionalized scaffolds was ∼50% reduced compared to PLLA-only at day 1 (p < 0.01) and day 2 (p < 0.05) post-implantation. There were >2.6-fold more CD206+ macrophages in M-CSF functionalized PLLA compared to PLLA-only at day 7 (p < 0.001), along with higher levels of IL-10 at both day 7 (p < 0.05) and day 14 (p < 0.01), and TGF-β at day 3 (p < 0.05), day 7 (p < 0.05), and day 14 (p < 0.001). Lower levels of pro-inflammatory cytokines were also detected in M-CSF functionalized PLLA in the early phase of the immune response compared to PLLA-only: a ∼58% decrease at day 3 in IL-1β; a ∼91% decrease at day 3 and a ∼66% decrease at day 7 in TNF; and a ∼60% decrease at day 7 in MCP-1. Moreover, enhanced angiogenesis inside and on/near the scaffold was observed in M-CSF functionalized PLLA compared to PLLA-only at day 3 (p < 0.05) and day 7 (p < 0.05), respectively. Overall, M-CSF functionalized PLLA enhanced CD206+ macrophage polarization and angiogenesis, consistent with lower levels of pro-inflammatory cytokines and higher levels of anti-inflammatory cytokines in early stages of the host response, indicating potential immunoregulatory functions on the local environment.

Ultrasonic Transducer for Non-Destructive Testing of Structures Immersed in Liquid Sodium at 200 °C

TUCSS transducer (French acronym standing for Transducteur Ultrasonore pour CND Sous Sodium) is designed for performing NDT (Non-Destructive Testing) under liquid sodium. Under sodium, the tests results obtained show that these transducers have sufficiently good acoustic properties to perform basic NDT of a structure immersed under liquid sodium at about 200 °C using conventional immersion ultrasonic technics. Artificial defects were made next to an X-shaped weld and could clearly be detected.

Is Cancer Cachexia Attributed to Impairments in Basal or Postprandial Muscle Protein Metabolism?

Cachexia is a significant clinical problem associated with very poor quality of life, reduced treatment tolerance and outcomes, and a high mortality rate. Mechanistically, any sizeable loss of skeletal muscle mass must be underpinned by a structural imbalance between muscle protein synthesis and breakdown rates. Recent data indicate that the loss of muscle mass with aging is, at least partly, attributed to a blunted muscle protein synthetic response to protein feeding. Whether such anabolic resistance is also evident in conditions where cachexia is present remains to be addressed. Only few data are available on muscle protein synthesis and breakdown rates in vivo in cachectic cancer patients. When calculating the theoretical changes in basal or postprandial fractional muscle protein synthesis and breakdown rates that would be required to lose 5% of body weight within a six-month period, we can define the changes that would need to occur to explain the muscle mass loss observed in cachectic patients. If changes in both post-absorptive and postprandial muscle protein synthesis and breakdown rates contribute to the loss of muscle mass, it would take alterations as small as 1%–2% to induce a more than 5% decline in body weight. Therefore, when trying to define impairments in basal and/or postprandial muscle protein synthesis or breakdown rates using contemporary stable isotope methodology in cancer cachexia, we need to select large homogenous groups of cancer patients (>40 patients) to allow us to measure physiological and clinically relevant differences in muscle protein synthesis and/or breakdown rates. Insight into impairments in basal or postprandial muscle protein synthesis and breakdown rates in cancer cachexia is needed to design more targeted nutritional, pharmaceutical and/or physical activity interventions to preserve skeletal muscle mass and, as such, to reduce the risk of complications, improve quality of life, and lower mortality rates during the various stages of the disease.

The relationship between glial cell mechanosensitivity and foreign body reactions in the central nervous system

Devices implanted into the body become encapsulated due to a foreign body reaction. In the central nervous system (CNS), this can lead to loss of functionality in electrodes used to treat disorders. Around CNS implants, glial cells are activated, undergo gliosis and ultimately encapsulate the electrodes. The primary cause of this reaction is unknown. Here we show that the mechanical mismatch between nervous tissue and electrodes activates glial cells. Both primary rat microglial cells and astrocytes responded to increasing the contact stiffness from physiological values (G' ∼ 100 Pa) to shear moduli G' ≥ 10 kPa by changes in morphology and upregulation of inflammatory genes and proteins. Upon implantation of composite foreign bodies into rat brains, foreign body reactions were significantly enhanced around their stiff portions in vivo. Our results indicate that CNS glial cells respond to mechanical cues, and suggest that adapting the surface stiffness of neural implants to that of nervous tissue could minimize adverse reactions and improve biocompatibility.