Fermentable sugars and microbial inhibitors formation from two-stage pretreatment of corn stalk with variation in particle size and severity factor

Microbial inhibitors including weak acids, furan derivatives and phenolic compounds are key problems of cellulosic bio-fuels production by fermentation. Most of these inhibitors are sugars and lignin degradation compounds, which are almost unavoidable during pretreatment processes. While, most of the one stage pretreatment has been conducted at high severity factors of 3.5 or more to get high sugar yield, with increase in severity factor, high concentration of microbial inhibitors were formed and significantly affected downstream biofuel yield. Thus, a two-stage pretreatment of corn stalk, hydrothermal followed by oxalic acid, under low severity factor and its enzymatic degradability was investigated in this study to identify fermentable sugar production and corresponding microbial inhibitors formation. Additionally, effect of equivalent severity factors of 2 to 3.5 and particle sizes of 1 to 35 mm were also studied systematically. Particle size of 15 mm was found as an optimum size at an equivalent severity factor of 2.5. Sugars 61.99 ± 0.03 g and inhibitors 5.12 ± 0.01 g from 100 g of corn stalk were obtained at the optimum particle size and pretreatment condition. The highest glucan conversion and recovery at the optimum conditions were 92.95± 0.08 and 78.42± 0.07%, respectively. Overall, the two-stage pretreatment process with the larger particle size and low equivalent severity factor could be an alternative to reduce microbial inhibitors formation and excessive biomass processing cost.Key words: Bio-fuel, corn stalk, pretreatment, particle size, microbial inhibitors, fermentable sugars

The Nopp140 gene in Drosophila melanogaster displays length polymorphisms in its large repetitive second exon

Nopp140, often called the nucleolar and Cajal body phosphoprotein (NOLC1), is an evolutionarily conserved chaperone for the transcription and processing of rRNA during ribosome subunit assembly. Metazoan Nopp140 contains an amino terminal LisH dimerization domain and a highly conserved carboxyl domain. A large central domain consists of alternating basic and acidic motifs of low sequence complexity. Orthologous versions of Nopp140 contain variable numbers of repeating basic-acidic units. While vertebrate Nopp140 genes use multiple exons to encode the central domain, the Nopp140 gene in Drosophila uses exclusively exon 2 to encode the central domain. Here, we define three overlapping repeat sequence patterns (P, P\u27, and P \u27\u27) within the central domain of D. melanogaster Nopp140. These repeat patterns are poorly conserved in other Drosophila species. We also describe a length polymorphism in exon 2 that pertains specifically to the P\u27 pattern in D. melanogaster. The pattern displays either two or three 96 base pair repeats, respectively, referred to as Nopp140-Short and Nopp140-Long. Fly lines homozygous for one or the other allele, or heterozygous for both alleles, show no discernible phenotypes. PCR characterization of the long and short alleles shows a poorly defined, artifactual bias toward amplifying the long allele over the short allele. The significance of this polymorphism will be in discerning the largely unknown properties of Nopp140\u27s large central domain in rDNA transcription and ribosome biogenesis

A qualitative study of women’s experience and perceptions of using Skilled Birth Attendants in rural Nepal.

Background: Access of health services such as transportation, cost of the services, women’s autonomy, community influences, socio-cultural and gender roles in decision-making are discussed repeatedly. However, women’s own perceptions and experiences are poorly explored during service use and health services development. This study aimed to explore women’s experiences and perceptions in the use of SBA during the pregnancy and childbirth in rural Nepal. Methods: Semi-structured interviews were conducted. The data were analysed using the thematic analysis. The fieldwork was conducted in a village of western Nepal. Interviews were conducted with 24 married women aged 18-49 who had given birth within the three years at the ti me of study. Results: Health service providers’ attitude and behaviour towards women during service use appeared one of the important factors in skilled birth attendants’ use. Positive behaviour from health service providers encouraged women to service use while negative behaviour discouraged. Lack of privacy and confidentiality discouraged women to use skilled delivery care. Women expected friendly and respective care but findings show that women were not happy of the services they received during skilled care used. Conclusion: This study contributes to understanding why women do or do not use Skilled Birth Attendants. Women who had attended hospital in order to receive care by skilled birth attendants generally described this as a negative experience, due to poor quality of services and rude behaviour of female service providers. Many of the participants said that they would prefer to have their babies at home, if they had access to skilled care in their local area

The uptake of skilled birth attendants’ services in rural Nepal: A qualitative study

Aim and objective: The general aim of this research was to explore why women do or do not want to uptake Skilled Birth Attendants’ (SBAs) services during childbirth. The objective was to explore the factors affecting the uptake of SBAs’ services during childbirth in ruralNepal. Methods: Semi-structured interviews were conducted. The data were analysed using thematic analysis. Setting: The fieldwork was conducted in a rural area, in a western hill district of Nepal. Participants: Interviews were conducted with 24 married women aged 18-49, who had given birth during the three years prior to the time of interview. Sixteen women were SBA users and eight were non-SBA users. Eight relatives, such as husbands, and parents-in-law were also interviewed as key informants. Findings: Four themes were identified as affecting the uptake of skilled care during childbirth: (1) Women’s individual characteristics; (2) Choice of, and access to, SBA services; (3) Cultural practice, gender role and decision making; and (4) Attitude and quality of SBAs and the hospital environment. Conclusion: A wide range of factors affect the uttake of SBAs services. These include: lack of SBAs in rural areas; women’s autonomy; difficult terrain; widespread poverty and illiteracy; limited resources and traditional and cultural attitudes; and gender factors. However, to date, women’s experiences and preferences have been overlooked in service design and development. There is a need for specific maternity service development, based on women’s experiences and perceptions. The establishment of a fully trained cadre of midwives, operating according to a professional code of ethics, could improve the quality of care in the existing health care facilities

Giant spontaneous magnetostriction in MnTe driven by a novel magnetostructural coupling mechanism

We present a comprehensive x-ray scattering study of spontaneous magnetostriction in hexagonal MnTe, an antiferromagnetic semiconductor with a Neel temperature of $T_{\mathrm{N}} = 307$ K. We observe the largest spontaneous magnetovolume effect known for an antiferromagnet, reaching a volume contraction of $|\Delta V/V| > 7 \times 10^{-3}$. This can be justified semiquantitatively by considering bulk material properties, the spatial dependence of the superexchange interaction, and the geometrical arrangement of magnetic moments in MnTe. The highly unusual linear scaling of the magnetovolume effect with the short-range magnetic correlations, beginning in the paramagnetic state well above $T_{\mathrm{N}}$, points to a novel physical mechanism, which we explain in terms of a trilinear coupling of the elastic strain with superposed distinct domains of the antiferromagnetic order parameter. This novel mechanism for coupling lattice strain to robust short-range magnetic order casts new light on magnetostrictive phenomena and also provides a template by which the exceptional magnetostrictive properties of MnTe might be realized in a wide range of other functional materials.Comment: Submitted May 11, 202

NMR chemical shift and relaxation measurements provide evidence for the coupled folding and binding of the p53 transactivation domain

The interaction between the acidic transactivation domain of the human tumor suppressor protein p53 (p53TAD) and the 70 kDa subunit of human replication protein A (hRPA70) was investigated using heteronuclear magnetic resonance spectroscopy. A (1)H–(15)N heteronuclear single quantum coherence (HSQC) titration experiment was performed on a (15)N-labeled fragment of hRPA70, containing the N-terminal 168 residues (hRPA70(1–168)) and p53TAD. HRPA70(1–168) residues important for binding were identified and found to be localized to a prominent basic cleft. This binding site overlapped with a previously identified single-stranded DNA-binding site, suggesting that a competitive binding mechanism may regulate the formation of p53TAD–hRPA70 complex. The amide (1)H and (15)N chemical shifts of an uniformly (15)N-labeled sample of p53TAD were also monitored before and after the addition of unlabeled hRPA70(1–168). In the presence of unlabeled hRPA70(1–168), resonance lineshapes increased and corresponding intensity reductions were observed for specific p53TAD residues. The largest intensity reductions were observed for p53TAD residues 42–56. Minimal binding was observed between p53TAD and a mutant form of hRPA70(1–168), where the basic cleft residue R41 was changed to a glutamic acid (R41E), demonstrating that ionic interactions play an important role in specifying the binding interface. The region of p53TAD most affected by binding hRPA70(1–168) was found to have some residual alpha helical and beta strand structure; however, this structure was not stabilized by binding hRPA70(1–168). (15)N relaxation experiments were performed to monitor changes in backbone dynamics of p53TAD when bound to hRPA70(1–168). Large changes in both the transverse (R(2)) and rotating frame (R(1ρ)) relaxation rates were observed for a subset of the p53TAD residues that had (1)H–(15)N HSQC resonance intensity reductions during the complex formation. The folding of p53TAD upon complex formation is suggested by the pattern of changes observed for both R(2) and R(1ρ). A model that couples the formation of a weak encounter complex between p53TAD and hRPA70(1–168) to the folding of p53TAD is discussed in the context of a functional role for the p53–hRPA70 complex in DNA repair

Attribute-Guided Adversarial Training for Robustness to Natural Perturbations

While existing work in robust deep learning has focused on small pixel-level norm-based perturbations, this may not account for perturbations encountered in several real-world settings. In many such cases although test data might not be available, broad specifications about the types of perturbations (such as an unknown degree of rotation) may be known. We consider a setup where robustness is expected over an unseen test domain that is not i.i.d. but deviates from the training domain. While this deviation may not be exactly known, its broad characterization is specified a priori, in terms of attributes. We propose an adversarial training approach which learns to generate new samples so as to maximize exposure of the classifier to the attributes-space, without having access to the data from the test domain. Our adversarial training solves a min-max optimization problem, with the inner maximization generating adversarial perturbations, and the outer minimization finding model parameters by optimizing the loss on adversarial perturbations generated from the inner maximization. We demonstrate the applicability of our approach on three types of naturally occurring perturbations -- object-related shifts, geometric transformations, and common image corruptions. Our approach enables deep neural networks to be robust against a wide range of naturally occurring perturbations. We demonstrate the usefulness of the proposed approach by showing the robustness gains of deep neural networks trained using our adversarial training on MNIST, CIFAR-10, and a new variant of the CLEVR dataset.Comment: AAAI 2021. Camera Ready version + Appendi