Inspiration en pleine crise : l’enseignement en ligne dans une faculté de médecine du Népal pendant la pandémie de la COVID-19

The Coronavirus disease (COVID-19) pandemic continues to shut down colleges and universities including medical schools all over the world, thus pushing medical schools to seek e-learning to maintain continuity of curriculum. Although developed countries are comfortable learning through the internet, low-income countries like Nepal with limited experience in e-learning have used this lockdown as an opportunity to develop online classes. This crisis has clearly revealed the importance of e-learning in for medical educators in Nepal to disseminate knowledge beyond the restrictions of geography and other barriers.La pandémie de la maladie à coronavirus (COVID-19) continue de provoquer la fermeture des collèges et des universités partout dans le monde, incitant les facultés de médecine à recourir à l’enseignement en ligne pour maintenir la continuité des programmes d'études. Tandis que les pays développés s’adaptent bien à l’enseignement en ligne, les pays à faible revenu comme le Népal, qui ont une expérience limitée de cette technologie, ont profité du confinement pour mettre au point des cours en ligne. La crise a mis en évidence l'importance de cette modalité d’enseignement pour les enseignants en médecine au Népal dans la mesure où elle leur permet de surmonter les contraintes géographiques et d’autres barrières à la diffusion des connaissances

Learning from each other: ABC transporter regulation by protein phosphorylation in plant and mammalian systems

The ABC (ATP-binding cassette) transporter family in higher plants is highly expanded compared with those of mammalians. Moreover, some members of the plant ABCB subfamily display very high substrate specificity compared with their mammalian counterparts that are often associated with multidrug resistance (MDR) phenomena. In this review we highlight prominent functions of plant and mammalian ABC transporters and summarize our knowledge on their post-transcriptional regulation with a focus on protein phosphorylation. A deeper comparison of regulatory events of human cystic fibrosis transmembrane conductance regulator (CFTR) and ABCB1 from the model plant Arabidopsis reveals a surprisingly high degree of similarity. Both physically interact with orthologues of the FK506-binding proteins (FKBPs) that chaperon both transporters to the plasma membrane in an action that seems to involve Hsp90. Further both transporters are phosphorylated at regulatory domains that connect both nucleotide-binding folds. Taken together it appears that ABC transporters exhibit an evolutionary conserved but complex regulation by protein phosphorylation, which apparently is, at least in some cases, tightly connected with protein–protein interactions (PPI)

A critical view on abc transporters and their interacting partners in auxin transport

Different subclasses of ATP-binding cassette (ABC) transporters have been implicated in the transport of native variants of the phytohormone auxin. Here, the putative, individual roles of key members belonging to the ABCB, ABCD and ABCG families, respectively, are highlighted and the knowledge of their assumed expression and transport routes is reviewed and compared with their mutant phenotypes. Protein–protein interactions between ABC transporters and regulatory components during auxin transport are summarized and their importance is critically discussed. There is a focus on the functional interaction between members of the ABCB family and the FKBP42, TWISTED DWARF1, acting as a chaperone during plasma membrane trafficking of ABCBs. Further, the mode and relevance of functional ABCB-PIN interactions is diagnostically re-evaluated. A new nomenclature describing precisely the most likely ABCB–PIN interaction scenarios is suggested. Finally, available tools for the detection and prediction of ABC transporter interactomes are summarized and the potential of future ABC transporter interactome maps is highlighted

Accumulation of Poly-hydroxy-butyric Acid (PHB) by Bacillus Strain Isolated from Paddy Field of Kathmandu University Premises

In this study, the effect of applying nutrient limitation on the production of Poly-hydro-oxy-butyric acid (PHB) from soil bacteria was examined. PHB is a biodegradable polymer which provides a reserve of carbon and energy. PHB was extracted by chloroform dispersion method. The amount of synthesized PHB was determined as crotonic acid by spectrophotometry. We found that Nitrogen limiting condition stimulated PHB accumulation. The highest level of PHB accumulation was observed in DNB-6 strain which accumulated 31 % of the dry mass at 20 % glucose concentration. The probabilistic identification of bacteria by PIBwin software version 1.9.2 showed that the strain DNB-6 was close in nature to Bacillus cereus.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 2-

Arabidopsis BTB/POZ protein-dependent PENETRATION3 trafficking and disease susceptibility

The outermost cell layer of plant roots (epidermis) constantly encounters environmental challenges. The epidermal outer plasma membrane domain harbours the PENETRATION3 (PEN3)/ABCG36/PDR8 ATP-binding cassette transporter that confers non-host resistance to several pathogens. Here, we show that the Arabidopsis ENDOPLASMIC RETICULUM-ARRESTED PEN3 (EAP3) BTB/POZ-domain protein specifically mediates PEN3 exit from the endoplasmic reticulum and confers resistance to a root-penetrating fungus, providing prime evidence for BTB/POZ- domain protein-dependent membrane trafficking underlying disease resistance.The PENETRATION3 (PEN3/ABCG36/PDR8) ATP-binding cassette transporter of Arabidopsis thaliana is a crucial component of preinvasive defence against some fungal and bacterial non-host pathogens entering by direct penetration1,2,3,4. In above-ground organs, PEN3 is recruited to sites of pathogen attack at the cell surface3,4. In seedling roots, PEN3 polarly localizes to the epidermal outer membrane domain in the absence of pathogens5,6. Root epidermal cells display four major polar plasma membrane domains: the outer domain facing the environment, the inner domain oriented towards the cortical cell layer, the shootward-oriented, apical, and the root tip-oriented, basal, domain6. Proteins in the outer domain that function in regulating the transport of inorganic compounds include, for example, the NIP5;1 boric acid uptake channel7. Factors required for PEN3 and NIP5;1 trafficking from the trans-Golgi network to the outer domain have been identified8,9,10, and exocyst complex components promote polar tethering of several outer domain proteins9,11. However, factors that specifically mediate trafficking of polar outer membrane cargos involved in responses to root-penetrating pathogens remain to be discovered.In a genetic screen for mislocalization of PEN3 fused to green-fluorescent protein (PEN3- GFP) in the root epidermis of seedlings9, we recovered one recessive mutant in which PEN3-GFP localized to a cytoplasmic structure resembling the endoplasmic reticulum (ER) (Fig. 1a–d). This er-arrested pen3-1 (eap3-1) mutation indistinguishably affected localization of PEN3-GFP from that of PEN3-mCherry (Supplementary Fig. 1a,b), which colocalized with the ER-intrinsic chaperone BIP in the eap3-1 mutant (Supplementary Fig. 1c,d), corroborating an ER arrest of PEN3

Evaluation of Phytochemical, Antioxidant and Antibacterial Activities of Selected Medicinal Plants

Medicinal plants are important reservoirs of bioactive compounds that need to be explored systematically. Because of their chemical diversity, natural products provide limitless possibilities for new drug discovery. This study aimed to investigate the biochemical properties of crude extracts from fifteen Nepalese medicinal plants. The total phenolic contents (TPC), total flavonoid contents (TFC), and antioxidant activity were evaluated through a colorimetric approach while the antibacterial activities were studied through the measurement of the zone of inhibition (ZoI) by agar well diffusion method along with minimum inhibitory concentrations (MIC) by broth dilution method. The methanolic extracts of Acacia catechu and Eupoterium adenophorum showed the highest TPC (55.21 ± 11.09 mg GAE/gm) and TFC (10.23 ± 1.07 mg QE/gm) among the studied plant extracts. Acacia catechu showed effective antioxidant properties with an IC50 value of 1.3 μg/mL, followed by extracts of Myrica esculenta, Syzygium cumini, and Mangifera indica. Morus australis exhibited antibacterial activity against Klebsiella pneumoniae (ZoI: 25mm, MIC: 0.012 mg/mL), Staphylococcus aureus ATCC 25923 (ZoI: 22 mm, MIC: 0.012 mg/mL), Pseudomonas aeruginosa (ZoI; 20 mm, MIC: 0.05 mg/mL), and methicillin-resistant Staphylococcus aureus (MRSA) (ZoI: 19 mm, MIC: 0.19 mg/mL). Morus australis extract showed a broad-spectrum antibacterial activity, followed by Eclipta prostrata, and Hypericum cordifolium. Future study is recommended to explore secondary metabolites of those medicinal plants to uncover further clinical efficacy

Digital learning Initiatives, Challenges and Achievement in Higher Education in Nepal Amidst COVID-19

The COVID-19 pandemic has affected higher education institutions (HEIs) worldwide and reshaped the existing educational system. Due to travel constraints and physical separation, there has been a global shift toward distance learning, and Nepal is no exception. This research intends to assess the practicality of online education by evaluating learners' experiences amidst COVID-19. A cross-sectional study was directed among HEIs students in Nepal using self-structured questionnaires. Our study revealed that 64.6% of the respondents were unsatisfied with online classes. More than half of the respondents (53.4%) use cell phones for online studies. Online education was reported to be unappealing to 28.8% of respondents. Variables such as age group (p = 0.05), enjoying class (p < 0.001), hours spent for an online class in a day (p = 0.05), and period for educational work using an electronic device (p = 0.1) were found significant with satisfaction level using both bivariate test and inferential test of univariate binary logistics regression. The challenges and opportunities encountered among students and faculties are highlighted along with the recommendations for fortifying communication in online-based teaching/learning

ABCG36/PEN3/PDR8 Is an Exporter of the Auxin Precursor, Indole-3-Butyric Acid, and Involved in Auxin-Controlled Development

The PDR-type ABCG transporter, ABCG36/PDR8/PEN3, is thought to be implicated in the export of a few structurally unrelated substrates, including the auxin precursor, indole-3-butyric acid (IBA), although a clear-cut proof of transport is lacking. An outward facing, lateral root (LR) location for ABCG36 fuelled speculations that it might secrete IBA into the rhizosphere. Here, we provide strong evidence that ABCG36 catalyzes the export of IBA – but not of indole-3-acetic acid – through the plasma membrane. ABCG36 seems to function redundantly with the closely related isoform ABCG37/PDR9/PIS1 in a negative control of rootward IBA transport in roots, which might be dampened by concerted, lateral IBA export. Analyses of single and double mutant phenotypes suggest that both ABCG36 and ABCG37 function cooperatively in auxin-controlled plant development. Both seem to possess a dual function in the control of auxin homeostasis in the root tip and long-range transport in the mature root correlating with non-polar and polar expression profiles in the LR cap and epidermis, respectively

A substrate of the ABC transporter PEN3 stimulates bacterial flagellin (flg22)-induced callose deposition in Arabidopsis thaliana

Nonhost resistance of Arabidopsis thaliana against Phytophthora infestans, a filamentous eukaryotic microbe and the causal agent of potato late blight, is based on a multilayered defense system. Arabidopsis thaliana controls pathogen entry through the penetration-resistance genes PEN2 and PEN3, encoding an atypical myrosinase and an ABC transporter, respectively, required for synthesis and export of unknown indole compounds. To identify pathogen-elicited leaf surface metabolites and further unravel nonhost resistance in Arabidopsis, we performed untargeted metabolite profiling by incubating a P. infestans zoospore suspension on leaves of WT or pen3 mutant Arabidopsis plants. Among the plant-secreted metabolites, 4-methoxyindol-3- yl-methanol and S-(4-methoxy-indol-3-yl-methyl) cysteine were detected in spore suspensions recollected from WT plants, but at reduced levels from the pen3 mutant plants. In both whole-cell and microsome-based assays, 4-methoxyindol-3-yl- methanol was transported in a PEN3-dependent manner, suggesting that this compound is a PEN3 substrate. The syntheses of both compounds were dependent on functional PEN2 and phytochelatin synthase 1. None of these compounds inhibited mycelial growth of P. infestans in vitro. Of note, exogenous application of 4- methoxyindol-3-yl methanol slightly elevated cytosolic Ca2+ levels and enhanced callose deposition in hydathodes of seedlings treated with a bacterial pathogen- associated molecular pattern (PAMP), flagellin (flg22). Loss of flg22-induced callose deposition in leaves of pen3 seedlings was partially reverted by the addition of 4- methoxyindol-3-yl methanol. In conclusion, we have identified a specific indole compound that is a substrate for PEN3 and contributes to the plant defense response against microbial pathogens