bluuebunny/crossref_metadata_2025_split huggingface dataset:
The interplay of polyoxyethylene (40) stearate surfactant concentration and aging time on the Mesoporous γ-alumina synthesis and appraisal of its catalytic activity
Authors: Bello Abdu Muhammad , Yacob Abdul Rahim 
Published: January 2021

AbstractAn economical and environmentally benign synthesis method remains important in industrial processes. In this work, kaolin an abundant and non-toxic precursor is employed for mesoporous gamma-alumina synthesis. The study explored the consequence of varying polyoxyethylene (40) stearate (PS) surfactant concentration and aging time in the synthesis of mesoporous gamma-alumina with enhancing structural properties. The alumina was characterized using X-Ray Powder Diffraction (XRD), Thermogravimetric-Derivative Thermal Gravimetric (TG-DTG), Fourier Transform Infrared (FTIR), N2 Adsorption–Desorption, Field Emission Scanning Electron Microscopy (FESEM), Solid State 27Al MAS NMR, and X-Ray Fluorescence (XRF). Structural properties and morphology of the mesoporous γ-Al2O3 improved with increasing surfactant amount from 0.45 g to 1.8 g and aging time from 1 to 2 days, then dropped afterward. Accordingly, mesoporous γ-Al2O3 synthesized with 1.8 g PS and age for 2 days (Al-1.8-2) possessed the highest surface area of 319.2 m2/g, a narrow average pore diameter of 2.7 nm, and pore volume of 0.42 cm3/g. Thus, Al-1.8-2 was chosen and doped with 15% NaOH to obtained 15-Na/Al-1.8-2 catalyst. After modification, the basic sites increased, the surface area decreased, and the morphology changed, signifying Na incorporation into the alumina. On application in methanolysis reaction, up to 99.46% biodiesel yield was obtained, demonstrating a very high activity for the catalyst. The tremendous activity of the catalyst can be associated with the enhanced structural properties of the mesostructured gamma-alumina.
Concentration and risk assessment of toxic metals in indoor dust in selected schools in Southeast, Nigeria
Authors: Ugwu Kenechukwu E. , Ofomatah Anthony C. 
Published: January 2021

AbstractThe health risk of students’ exposure to some potentially toxic metals in classroom dusts in Southeast, Nigeria was assessed. Dust particles were collected from classrooms in some public high schools and digested with aqua regia before analysis for selected metals by atomic absorption spectrophotometry. The geoaccumulation index, contamination factor and the pollution load index were assessed from the metal concentrations of the dust. Hazard quotient and cancer risk index were used to estimate the potential health risk of students’ exposure to the metals in the dust. The metal concentrations (mg/kg) were in the ranges of 1.57–175.38 (Cr); 0.93–463.28 (Cu); 31.94.76–6623.41 (Fe); 4.96–143.98 (Ni); 2.64–375.27 (Zn); and 2.35–53.96 (Pb).The geo-accumulation index values showed that all the dust samples were polluted with Fe and Cr; and unpolluted with other metals with few exemptions. The contamination factor values showed that all the schools but one had a low contamination status due to Ni and Cu. There was moderate contamination by Pb at all the schools but two. All the schools had high contamination of Cr and Fe. The pollution load index indicated that the quality of all the classrooms was deteriorated. The calculated values of hazard quotient indicated that ingestion of dust at most of the classrooms would have no significant risk of non-carcinogenic effects on the health of the students. Dermal contact with the dust at all the classrooms would expose students to adverse effects of Fe. There will be adverse effect due to Pb for dermal contact with dust at most of the schools. Ingestion of dust particles at classrooms in all the schools would have carcinogenic effect due to Ni. Correlation analysis indicated that the sources of the metals varied. This study provided baseline data for relevant bodies to use in monitoring and controlling pollution so as to protect students from toxic metals.
Building socio-hydrological resilience “improving capacity for building a socio hydrological system resilience”
Authors: Javadinejad Safieh , Hannah David , Krause Stefan , Naseri Mohsen , Dara Rebwar , Jafary Forough 
Published: January 2021

AbstractIn response to the climate change, hydrologic and environmental changes and increased uncertainties, implication of water resilience in a context of water governance is essential for improved management. This study aims to answer the following questions: 1) what are different types of resilience with regard to its several definitions, 2) what is the relationship between resilience, trend and performance in water governance. This research applied literature reviews (as theoretical approach) and interviews with local water managers (as experimental approach) to develop better resilient plan under extreme events. This study compared the results of reviewed articles with results that we obtained from interviews with water managers in a case study area in order to develop a resilience planning under extreme events. The research has analyzed the resilience for water management based on theoretical and empirical knowledge and also provided some helpful recommendations for building system resilience for the future. The analysis of the findings shows that sufficient resilience in each society depends considerably on water resources planning (implied by the government) and also resilience in water supply infrastructure (designed by engineers). In addition, in order to get a high level of resilience, integration of ecological knowledge, water supplies, government’s regulation/legislation, engineering projects and humans’ interaction, is necessary. Moreover, the results indicate that failures and hydrologic catastrophes are mainly as a result of big gaps between these elements and also a lack of integrated approach between water-institutions and the environment in water management.
Attitudes and Preparedness of Non-Frontline Physicians in Saudi Arabia Toward the COVID-19 Pandemic
Authors: Malaekah Haifaa , Aljahany Muna , Alassaf Wajdan , Alotaibi Malak , Alsaffar Mashael 
Published: January 2021

AbstractObjective:This study assesses the attitudes (willingness) and preparedness of non-frontline physicians across different specialties in the Kingdom of Saudi Arabia (KSA) toward the management of hospitalized coronavirus disease (COVID-19) patients.Methods:This cross-sectional study conducted between April 15, 2020, and May 5, 2020, included 6209 physicians working in KSA. An electronic questionnaire was designed and validated for the assessment of 3 categorical outcome variables, namely, attitudes, confidence, and knowledge levels. Pearson’s chi-square test was used for comparing the distribution of the proportions of these 3 categorical variables.Results:Most participants (63.2%) were willing and prepared to treat COVID-19 patients. A significantly large proportion of participants specializing in anesthesiology (78.2%) had higher knowledge levels, followed by those from plastic surgery (71.1%), pediatrics (69.7%), and obstetrics and gynecology (69.1%) (P< 0.0001). Lower confidence levels were found for airway management skills (38.1%), particularly among dermatologists and radiologists.Conclusion:Higher knowledge levels about personal protective equipment (PPE) use and confidence in airway management skills were proportionally related to the level of willingness to participate in COVID-19 patient management. There is an urgent need to train doctors from certain specialties on PPE use and airway management to enable their frontline support of severely ill COVID-19 patients.
Brill-Noether theory for curves of a fixed gonality
Authors: Jensen David , Ranganathan Dhruv 
Published: January 2021

AbstractWe prove a generalisation of the Brill-Noether theorem for the variety of special divisors$W^r_d(C)$on a general curveCof prescribed gonality. Our main theorem gives a closed formula for the dimension of$W^r_d(C)$. We build on previous work of Pflueger, who used an analysis of the tropical divisor theory of special chains of cycles to give upper bounds on the dimensions of Brill-Noether varieties on such curves. We prove his conjecture, that this upper bound is achieved for a general curve. Our methods introduce logarithmic stable maps as a systematic tool in Brill-Noether theory. A precise relation between the divisor theory on chains of cycles and the corresponding tropical maps theory is exploited to prove new regeneration theorems for linear series with negative Brill-Noether number. The strategy involves blending an analysis of obstruction theories for logarithmic stable maps with the geometry of Berkovich curves. To show the utility of these methods, we provide a short new derivation of lifting for special divisors on a chain of cycles with generic edge lengths, proved using different techniques by Cartwright, Jensen, and Payne. A crucial technical result is a new realisability theorem for tropical stable maps in obstructed geometries, generalising a well-known theorem of Speyer on genus$1$curves to arbitrary genus.
Reflecting laser-driven shocks in diamond in the megabar pressure range
Authors: Jakubowska K. , Mancelli D. , Benocci R. , Trela J. , Errea I. , Martynenko A. S. , Neumayer P. , Rosmej O. , Borm B. , Molineri A. , Verona C. , Cannatà D. , Aliverdiev A. , Roman H. E. , Batani D. 
Published: January 2021

AbstractIn this work we present experimental results on the behavior of diamond at megabar pressure. The experiment was performed using the PHELIX facility at GSI in Germany to launch a planar shock into solid multi-layered diamond samples. The target design allows shock velocity in diamond and in two metal layers to be measured as well as the free surface velocity after shock breakout. As diagnostics, we used two velocity interferometry systems for any reflector (VISARs). Our measurements show that for the pressures obtained in diamond (between 3 and 9 Mbar), the propagation of the shock induces a reflecting state of the material. Finally, the experimental results are compared with hydrodynamical simulations in which we used different equations of state, showing compatibility with dedicated SESAME tables for diamond.
SHORTENING CLOPEN GAMES
Authors: AGUILERA JUAN P. 
Published: January 2021

AbstractFor every countable wellordering
$\alpha $
greater than
$\omega $
, it is shown that clopen determinacy for games of length
$\alpha $
with moves in
$\mathbb {N}$
is equivalent to determinacy for a class of shorter games, but with more complicated payoff. In particular, it is shown that clopen determinacy for games of length
$\omega ^2$
is equivalent to
$\sigma $
-projective determinacy for games of length
$\omega $
and that clopen determinacy for games of length
$\omega ^3$
is equivalent to determinacy for games of length
$\omega ^2$
in the smallest
$\sigma $
-algebra on
$\mathbb {R}$
containing all open sets and closed under the real game quantifier.
Dietary acrylamide intake and risk of women’s cancers: a systematic review and meta-analysis of prospective cohort studies
Authors: Benisi-Kohansal Sanaz , Salari-Moghaddam Asma , Seyed Rohani Zahraalsadat , Esmaillzadeh Ahmad 
Published: January 2021

AbstractThis systematic review and meta-analysis was done to review earlier publications on the association between dietary acrylamide intake and risk of breast, endometrial and ovarian cancers. We performed a systematic search in the online databases of PubMed, ISI Web of Science and Scopus for relevant publications up to August 2020. Prospective cohort studies that considered dietary acrylamide as the exposure variable and breast, endometrial or ovarian cancer as the main outcome variable or as one of the outcome variables were included in this systematic review and meta-analysis. A total of fourteen cohort studies were included in the meta-analysis. We found no significant association between dietary acrylamide intake and the risk of breast (relative risk (RR) 0·95; 95 % CI 0·90, 1·01), endometrial (RR 1·03; 95 % CI 0·89, 1·19) and ovarian cancers (RR 1·02; 95 % CI 0·84, 1·24). In addition, we observed no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers in different subgroup analyses by smoking status, menopausal status, BMI status and different types of breast cancer. In conclusion, no significant association was found between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers.
The contribution of provitamin A biofortified cassava to vitamin A intake in Nigerian pre-schoolchildren
Authors: Afolami Ibukun , Samuel Folake , Borgonjen-van den Berg Karin , Mwangi Martin N. , Kalejaiye Olatundun , Sanusi Rasaki A. , Putri Linda Ayu Rizka , Brivio Francesca , Brouwer Inge D. , Melse-Boonstra Alida 
Published: January 2021

AbstractBiofortified yellow cassava has been developed to alleviate vitamin A deficiency. We examined the potential contribution of yellow cassava to total retinol activity equivalent (RAE) intake if replacing white by yellow cassava among pre-school Nigerian children. Dietary intake was assessed as part of a randomised controlled trial. Pre-schoolchildren (n 176) were randomly assigned to receive either white cassava (WC) or yellow cassava (YC) for 17 weeks. Dietary intake assessments were conducted during the intervention and 1 month after, when children had resumed their habitual diet. Differences in RAE intake between groups and time points were compared using a linear mixed model regression analysis. During intervention, median RAE intake was 536 µg/d in the YC group and 301 µg/d in the WC group (P < 0·0001). YC contributed approximately 40 % to total RAE intake. Of the children, 9 % in the YC group and 29 % in the WC group had RAE intake below the Estimated Average Requirement. After intervention, median RAE intake was 300 µg/d and did not differ between intervention groups (P = 0·5). The interaction effect of group and time showed a 37 % decrease in RAE intake in the YC group after the intervention (Exp(β) = 0·63; 95 % CI 0·56, 0·72). If WC was replaced by YC after intervention, the potential contribution of YC to total RAE intake was estimated to be approximately 32 %. YC increased total RAE intake and showed a substantially lower inadequacy of intake. It is therefore recommended as a good source of provitamin A in cassava-consuming regions.
No effect of salmon fish protein on 2-h glucose in adults with increased risk of type 2 diabetes: a randomised controlled trial
Authors: Hustad K. S. , Ottestad I. , Hjorth M. , Dalen K. T. , Sæther T. , Sheikh N. A. , Strømnes M. , Ulven S. M. , Holven K. B. 
Published: January 2021

AbstractThe association between fish consumption and decreased risk of CVD is well documented. However, studies on health effects of fish consumption suggest that other components than n-3 PUFA have beneficial cardiometabolic effects, including effects on glucose metabolism. The aim of the present study was to investigate effects of salmon fish protein on cardiometabolic risk markers in a double-blind, randomised controlled parallel trial. We hypothesised that daily intake of a salmon fish protein supplement for 8 weeks would improve glucose tolerance in persons with increased risk of type 2 diabetes mellitus (T2DM). Our primary outcome measure was serum glucose (s-glucose) 2 h after a standardised oral glucose tolerance test. In total, eighty-eight adults with elevated s-glucose levels were randomised to 7·5 g of salmon fish protein/d or placebo, and seventy-four participants were included in the analysis. We found no significant effect of salmon fish protein supplementation on our primary outcome or other markers related to glucose tolerance, serum lipids, weight or blood pressure compared with placebo. The present study does not support the hypothesis that daily intake of a salmon fish protein supplement for 8 weeks improves glucose tolerance in persons with increased risk of T2DM.
POLYCENTRICITY AND POLYPHONY IN INTERNATIONAL LAW: INTERPRETING THE CORPORATE RESPONSIBILITY TO RESPECT HUMAN RIGHTS
Authors: Partiti Enrico 
Published: January 2021

AbstractComplex multi-actors and multi-level governance structures have emerged in areas that were traditionally exclusively the preserve of the State and treaty-making. The adoption of the United Nations Guiding Principles on Business and Human Rights (UNGP) affirmed a corporate responsibility to respect human rights to be implemented through human rights due diligence (HRDD), ie via management processes. The open-ended character of the UNGP generated the emergence of other soft instruments offering guidance to corporations in structuring HRDD. This contribution conceptualises the UNGP from the perspective of regulation as a principles-based exercise in polycentric governance reliant on regulatory intermediaries for interpretation. It then assesses the role of various sui generis normative instruments in providing interpretation to the UNGP and, how the presence of an additional layer of interpretative material contributes to the institutionalisation of responsible corporate conduct. The analysis of instruments drafted by international, non-governmental and business organisations reveals both a decentralising tension between different intermediaries due to disagreements and divergence concerning the precise extent of corporate human rights responsibilities, as well as attempts to centralise the interpretation of the UNGP. The article concludes by recommending some caution towards the employment of polycentric governance regimes and their lack of centralised interpretive authority in this domain of international law and suggests possible ways to formally establish centralised interpretation.
ACCIDENT AND DESIGN: RECOGNISING VICTIMS OF AGGRESSION IN INTERNATIONAL LAW
Authors: Darcy Shane 
Published: January 2021

AbstractInternational law has not traditionally recognised individuals as victims of the crime of aggression. Recent developments may precipitate a departure from this approach. The activation of the jurisdiction of the International Criminal Court over the crime of aggression opens the way for the future application of the Court's regime of victim participation and reparation in the context of prosecutions for this crime. The determination by the United Nations Human Rights Committee in General Comment No. 36 that any deprivation of life resulting from an act of aggression violates Article 6 of the International Covenant on Civil and Political Rights serves to recognise a previously overlooked class of victims. This article explores these recent developments, by discussing their background, meaning and implications for international law and the rights of victims.
Network Centrality and Managerial Market-Timing Ability
Authors: Evgeniou Theodoros , Peress Joel , Vermaelen Theo , Yue Ling 
Published: January 2021

AbstractWe document that long-run excess returns following announcements of share buyback authorizations and insider purchases are a U-shaped function of firm centrality in the input–output trade-flow network. These results conform to a model of investors endowed with a large but finite capacity for analyzing firms. Additional links weaken insiders’ informational advantage in peripheral firms (simple firms whose cash flows depend on few economic links), provided investors’ capacity is large enough, but eventually amplify that advantage in central firms (firms with many links) as a result of investors’ limited capacity. These findings shed light on the sources of managerial market-timing ability.
Macromolecular room temperature crystallography
Authors: Fischer Marcus 
Published: January 2021

AbstractX-ray crystallography enables detailed structural studies of proteins to understand and modulate their function. Conducting crystallographic experiments at cryogenic temperatures has practical benefits but potentially limits the identification of functionally important alternative protein conformations that can be revealed only at room temperature (RT). This review discusses practical aspects of preparing, acquiring, and analyzing X-ray crystallography data at RT to demystify preconceived impracticalities that freeze progress of routine RT data collection at synchrotron sources. Examples are presented as conceptual and experimental templates to enable the design of RT-inspired studies; they illustrate the diversity and utility of gaining novel insights into protein conformational landscapes. An integrative view of protein conformational dynamics enables opportunities to advance basic and biomedical research.
Setting up and operating a cryo-EM laboratory
Authors: Mills Deryck J. 
Published: January 2021

AbstractCryo-electron microscopy (cryo-EM) has become the technique of choice for structural biology of macromolecular assemblies, after the ‘resolution revolution’ that has occurred in this field since 2012. With a suitable instrument, an appropriate electron detector and, last but not least, a cooperative sample it is now possible to collect images from which macromolecular structures can be determined to better than 2 Å resolution, where reliable atomic models can be built. By electron tomography and sub-tomogram averaging of cryo-samples, it is also possible to reconstruct subcellular structures to sub-nanometre resolution. This review describes the infrastructure that is needed to achieve this goal. Ideally, a cryo-EM lab will have a dedicated 300 kV electron microscope for data recording and a 200 kV instrument for screening cryo-samples, both with direct electron detectors, and at least one 120 kV EM for negative-stain screening at room temperature. Added to this should be ancillary equipment for specimen preparation, including a light microscope, carbon coater, plasma cleaner, glow discharge unit, a device for fast, robotic sample freezing, liquid nitrogen storage Dewars and a ready supply of clean liquid nitrogen. In practice, of course, the available budget will determine the number and types of microscopes and how elaborate the lab can be. The cryo-EM lab should be designed with adequate space for the electron microscopes and ancillary equipment, and should allow for sufficient storage space. Each electron microscope room should be connected to the image-processing computers by fibre-optic cables for the rapid transfer of large datasets. The cryo-EM lab should be overseen by a facility manager whose responsibilities include the day-to-day tasks to ensure that all microscopes are operating perfectly, organising service and repairs to minimise downtime, and controlling the budget. Large facilities will require additional support staff who help to oversee the operation of the facility and instruct new users.
Modeling of Inverse Kinematic of 3-DoF Robot, Using Unit Quaternions and Artificial Neural Network
Authors: Jiménez-López Eusebio , Servín de la Mora-Pulido Daniel , Reyes-Ávila Luis Alfonso , Servín de la Mora-Pulido Raúl , Melendez-Campos Javier , López-Martínez Aldo Augusto 
Published: January 2021

SUMMARYThis paper presents a novel method for modeling a 3-degree of freedom open kinematic chain using quaternions algebra and neural network to solve the inverse kinematic problem. The structure of the network was composed of 3 hidden layers with 25 neurons per layer and 1 output layer. The network was trained using the Bayesian regularization backpropagation. The inverse kinematic problem was modeled as a system of six nonlinear equations and six unknowns. Finally, both models were tested using a straight path to compare the results between the Newton–Raphson method and the network training.