Discomfort, Pressure Distribution and Safety in Operator's Seat-A Critical Review

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is an Invited Paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 5 (2003): H. Dhingra, V. Tewari, and S. Singh. Discomfort, Pressure Distribution and Safety in Operator's Seat-A Critical Review. Vol. V. July 2003

Comparative chloroplast genomics and phylogenetics of Fagopyrum esculentum ssp. ancestrale – A wild ancestor of cultivated buckwheat

<p>Abstract</p> <p>Background</p> <p>Chloroplast genome sequences are extremely informative about species-interrelationships owing to its non-meiotic and often uniparental inheritance over generations. The subject of our study, <it>Fagopyrum esculentum</it>, is a member of the family Polygonaceae belonging to the order Caryophyllales. An uncertainty remains regarding the affinity of Caryophyllales and the asterids that could be due to undersampling of the taxa. With that background, having access to the complete chloroplast genome sequence for <it>Fagopyrum </it>becomes quite pertinent.</p> <p>Results</p> <p>We report the complete chloroplast genome sequence of a wild ancestor of cultivated buckwheat, <it>Fagopyrum esculentum </it>ssp. <it>ancestrale</it>. The sequence was rapidly determined using a previously described approach that utilized a PCR-based method and employed universal primers, designed on the scaffold of multiple sequence alignment of chloroplast genomes. The gene content and order in buckwheat chloroplast genome is similar to <it>Spinacia oleracea</it>. However, some unique structural differences exist: the presence of an intron in the <it>rpl2 </it>gene, a frameshift mutation in the <it>rpl23 </it>gene and extension of the inverted repeat region to include the <it>ycf1 </it>gene. Phylogenetic analysis of 61 protein-coding gene sequences from 44 complete plastid genomes provided strong support for the sister relationships of Caryophyllales (including Polygonaceae) to asterids. Further, our analysis also provided support for <it>Amborella </it>as sister to all other angiosperms, but interestingly, in the bayesian phylogeny inference based on first two codon positions <it>Amborella </it>united with Nymphaeales.</p> <p>Conclusion</p> <p>Comparative genomics analyses revealed that the <it>Fagopyrum </it>chloroplast genome harbors the characteristic gene content and organization as has been described for several other chloroplast genomes. However, it has some unique structural features distinct from previously reported complete chloroplast genome sequences. Phylogenetic analysis of the dataset, including this new sequence from non-core Caryophyllales supports the sister relationship between Caryophyllales and asterids.</p

InsIghts Into the mechanIsm of natural terpenoIds as NF-κB InhIBItors: an overvIew on theIr antIcancer potentIal

The transcription factor, nuclear factor kappa B (NF-kB) is one of the principal inducible protein in mammals known to control the gene expression in many critical physiological responses such as oxidative stress, inflammation etc. and has been shown to play an important role in the pathogenesis of cancer. Terpenoids are major constituents present in nutritionally used fruits, vegetables and different spices which possess various pharmacological action including anticancer activity. Various terpenoids, viz. monoterpenoids, sesquiterpenoids, diterpenoids, sesterterpenoids, triterpenoids, tetraterpenoids and polyterpenoids inhibit NF-kB signaling pathway through IkB phosphorylation, DNA binding, p65 translocation etc. Keeping in mind these facts, the present review revealed the anti-cancer potential of naturally occurring terpenoids highlighting their mechanism of NF-kB inhibition. This review also focuses on some of the naturally occurring terpenoids belonging to various chemical categories with potential inhibitory effects on NF-kB and their role in the treatment of cancer

RbdB, a Rhomboid Protease Critical for SREBP Activation and Virulence in Aspergillus Fumigatus

SREBP transcription factors play a critical role in fungal virulence; however, the mechanisms of sterol regulatory element binding protein (SREBP) activation in pathogenic fungi remains ill-defined. Screening of the Neurospora crassa whole-genome deletion collection for genes involved in hypoxia responses identified a gene for an uncharacterized rhomboid protease homolog, rbdB, required for growth under hypoxic conditions. Loss of rbdB in Aspergillus fumigatus also inhibited growth under hypoxic conditions. In addition, the A. fumigatus ΔrbdB strain also displayed phenotypes consistent with defective SREBP activity, including increased azole drug susceptibility, reduced siderophore production, and full loss of virulence. Expression of the basic helix-loop-helix (bHLH) DNA binding domain of the SREBP SrbA in ΔrbdB restored all of the phenotypes linking RdbB activity with SrbA function. Furthermore, the N-terminal domain of SrbA containing the bHLH DNA binding region was absent from ΔrbdB under inducing conditions, suggesting that RbdB regulates the protein levels of this important transcription factor. As SrbA controls clinically relevant aspects of fungal pathobiology in A. fumigatus, understanding the mechanisms of SrbA activation provides opportunities to target this pathway for therapeutic development

Effi cacy of chlorhexidine application to umbilical cord on neonatal mortality in Pemba, Tanzania: a community-based randomised controlled trial

Background In low-income countries, including the east African region, a third of neonatal deaths are due to infections. A substantial proportion of these have been attributed to sepsis, which can result from umbilical cord infections. Evidence from Asia suggests that chlorhexidine application to the neonatal umbilical cord reduces mortality, but no data from Africa are available. We aimed to assess the eff ect of umbilical cord cleansing with 4% chlorhexidine solution on neonatal mortality and omphalitis in rural settings of sub-Saharan Africa. Methods We did a community-based randomised controlled trial on Pemba Island, Zanzibar, Tanzania. All eligible babies (aged 1 h to 48 h, without congenital malformations) from hospital-based and community-based deliveries on Pemba Island were enrolled. Participants were randomly assigned to either 4% free chlorhexidine for cord care or to dry cord care using a computer-generated random sequence. For babies allocated to the chlorhexidine group, mothers or caretakers were advised to apply the solution to the cord every day until 3 days after the cord had dropped off . Cord stumps were examined for redness, pus, swelling, and foul odour on day 0, 1, 4, 10, and 28. The primary outcome for this study was mortality until day 28 on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, number NCT01528852. Findings Between May 19, 2011, and Aug 31, 2014, 36 911 newborn babies were enrolled into the chlorhexidine (n=18 015) and dry cord care study (n=18 896) groups. 17 468 (96·9%) of 18 015 neonates in the chlorhexidine group were available for complete follow-up (28 days) compared with 18 384 (97·3%) of 18 896 neonates in the dry cord care group. Mortality rate in the chlorhexidine group (10·5 deaths per 1000 livebirths) was not signifi cantly lower than that in the dry cord care group (11·7 per 1000 livebirths; relative risk 0·90, 0·74–1·09; p=0·27). Interpretation Our fi ndings do not support the use of chlorhexidine for reduction of neonatal mortality in this east African setting, which might not justify a change in the WHO policy. To inform global policy, a detailed meta-analysis and pooled analysis needs to be undertaken using data from both African and Asian settings

In vitro selection of yellow passion fruit genotypes for resistance to Fusarium vascular wilt.

Fusarium vascular wilt (caused by Fusarium oxysporum f. sp. passiflorae) is a limiting factor in the cultivation of yellow passion fruit (Passiflora edulis). Since there is no effective and economically viable control available, development of resistant or at least tolerant cultivars are in demand. A number of procedures have been used for the initial selection of plant genotypes resistant to various fungal pathogens by means of a fungal culture filtrate or purified toxin. In this study, seeds and in vitro-grown plantlets of passion fruit were screened with different concentrations of either Fusarium oxysporum f. sp. passiflorae (FOP) culture filtrate (0, 20, 30, 40 or 50%, v/v) or fusaric acid (0.10, 0.20, 0.30 or 0.40 mM) supplemented in Murashige and Skoog (MS) basal media. Subsequently, selected plants were inoculated with a conidial suspension of FOP to assess correlation between in vivo and in vitro responses. In vitro sensitivity to the selective agents and the resistance response to the pathogen were also compared. Root growth was markedly influenced by FA, culture filtrate, and conidial suspension culture treatments. Observations indicated that roots were primary targets for attack by F. oxysporum. Successful in vitro selection of resistant genotypes by both FA and culture filtrate treatments suggested that this strategy was viable for accelerating breeding of passion fruit for resistance to the Fusarium vascular wilt

Open-Retrieval Conversational Question Answering

Conversational search is one of the ultimate goals of information retrieval. Recent research approaches conversational search by simplified settings of response ranking and conversational question answering, where an answer is either selected from a given candidate set or extracted from a given passage. These simplifications neglect the fundamental role of retrieval in conversational search. To address this limitation, we introduce an open-retrieval conversational question answering (ORConvQA) setting, where we learn to retrieve evidence from a large collection before extracting answers, as a further step towards building functional conversational search systems. We create a dataset, OR-QuAC, to facilitate research on ORConvQA. We build an end-to-end system for ORConvQA, featuring a retriever, a reranker, and a reader that are all based on Transformers. Our extensive experiments on OR-QuAC demonstrate that a learnable retriever is crucial for ORConvQA. We further show that our system can make a substantial improvement when we enable history modeling in all system components. Moreover, we show that the reranker component contributes to the model performance by providing a regularization effect. Finally, further in-depth analyses are performed to provide new insights into ORConvQA.Comment: Accepted to SIGIR'2

Aggregatibacter Actinomycetemcomitans LtxA Hijacks Endocytic Trafficking Pathways in Human Lymphocytes

Leukotoxin (LtxA), from oral pathogen Aggregatibacter actinomycetemcomitans, is a secreted membrane-damaging protein. LtxA is internalized by β2 integrin LFA-1 (CD11a/CD18)-expressing leukocytes and ultimately causes cell death; however, toxin localization in the host cell is poorly understood and these studies fill this void. We investigated LtxA trafficking using multi-fluor confocal imaging, flow cytometry and Rab5a knockdown in human T lymphocyte Jurkat cells. Planar lipid bilayers were used to characterize LtxA pore‐forming activity at different pHs. Our results demonstrate that the LtxA/LFA-1 complex gains access to the cytosol of Jurkat cells without evidence of plasma membrane damage, utilizing dynamin-dependent and presumably clathrin-independent mechanisms. Upon internalization, LtxA follows the LFA‐1 endocytic trafficking pathways, as identified by co-localization experiments with endosomal and lysosomal markers (Rab5, Rab11A, Rab7, and Lamp1) and CD11a. Knockdown of Rab5a resulted in the loss of susceptibility of Jurkat cells to LtxA cytotoxicity, suggesting that late events of LtxA endocytic trafficking are required for toxicity. Toxin trafficking via the degradative endocytic pathway may culminate in the delivery of the protein to lysosomes or its accumulation in Rab11A‐dependent recycling endosomes. The ability of LtxA to form pores at acidic pH may result in permeabilization of the endosomal and lysosomal membranes. © 2020 by the authors. Licensee MDPI, Basel, Switzerland