bluuebunny/crossref_metadata_2025 huggingface dataset:
Sine-cosine algorithm for parameters’ estimation in solar cells using datasheet information
Authors: Montoya O D , Gil-González W , Grisales-Noreña L F
Published: November 2020

This paper explores the problem of optimal calculation of electrical parameters in solar cells using three well-known operative points provided by manufacturers considering a single-diode model. These are open circuit, short circuit, and maximum power point; with these points is formulated a nonlinear non-convex optimization problem that deals with the minimization of mean square errors associated with variables evaluated at these points, i.e., open-circuit voltage, short circuit current, and current in the maximum power point, respectively. A sine-cosine algorithm is addressed in this research to solve the resulting optimization problem. Numerical results provided by the sine-cosine algorithm show objective functions lower than 1 × 10−12, which confirms the efficiency and robustness of the proposed approach. All the numerical validations are conducted via MATLAB software.
Engineering education in the development of physical thinking
Authors: Díaz Arenas D , Gallardo Pérez H J , Rojas Suárez J P
Published: November 2020

The present research project seeks to identify an application of didactic engineering in the teaching and learning processes of mathematics and physics through a pedagogical strategy in a group of 24 ninth grade students from a public educational institution located in the municipality of Tibú, Norte de Santander, Colombia, in order to determine the degree of appropriation of the concepts associated with mathematical physical thinking. Three didactic sequences were designed and applied, based on the theories of didactic situations and semiotic representations, to later determine their effect on the learning process, which showed better results in the communication competence, but the reasoning and problem-solving competences still show difficulties in the students. Therefore, it is concluded that the work in the classroom should be strengthened with the implementation of didactic sequences with clear objectives and that enhance these two processes of mathematics and physics.
Effects of root chord movement on thrust generation of oscillatory pectoral fins
Authors: Arastehfar Soheil , Chew Chee-Meng
Published: November 2020

Fin kinematics is the key to thrust generation of oscillatory pectoral fins of manta rays. This could be one of the main reasons that fin designs of robotic manta rays are becoming more complex to simulate the fin kinematics more closely so as to generate high thrusts. However, as the trend suggests, the extent of improvement to thrust generation might not be worth the complexities added to the designs. Out-of-the-box design changes that favour the simplicity and yet improve the fin performance can be a sound replicate for the complicated fin design features. One aspect of manta rays’ pectoral fins that influences the fin kinematics is the constraint imposed on the movement of their particularly long root chord that is entirely attached to the body of manta rays. Hypothetically, reducing such a constraint can promote the angle-of-attack during flapping, which can improve thrust generation. This paper aims to study if the simple idea of disengagement of the fin root chord from the body, which is obviously a deviation from the nature, can improve thrust generation. An experiment was conducted on thrust generation of four basic fin designs, where different portions of their chord was disengaged from the body step-by-step. The disengagement occurred for each quarter of the chord, starting from the trailing edge towards the leading edge. It was found that the fins with free root chord (minimal attachment to the body) could generate thrust slightly less than the fully constrained fins (full attachment). In addition, it was shown that thrust generation efficiency kept increasing while disengaging the chord further, and reached the maximum for free root chord. This may show that a powerful and yet more efficient fin can be produced with such a deviation from the nature.
Effects of the South Asian summer monsoon anomaly on interannual variations in precipitation over the South-Central Tibetan Plateau
Authors: Zhu Yanxin , Sang Yan-Fang , Chen Deliang , Sivakumar Bellie , Li Donghuan
Published: November 2020

An anomalous South Asian summer monsoon (SASM) system could generate a large anomaly in precipitation and hydrological disasters in the SASM-prevailing area, as widely reported for the Indian Peninsula. However, how the SASM system influences the precipitation anomaly over the South-Central Tibetan Plateau (SCTP) is largely unknown. In this study, we (a) analyze the influences of the early and late onset (demise) of the SASM on the interannual variations in precipitation over the SCTP during 1979–2015; and (b) illuminate the underlying mechanisms and asymmetric effects with regard to the onset and demise of the SASM by analyzing the characteristics of water vapor transport and moisture budgets in this region. Results indicate that the precipitation anomaly over the SCTP is dominated by the cyclonic and anticyclonic water vapor transport associated with the anomalous SASM activities, causing moisture convergence and divergence in this region. The topographic effect in the southeastern Tibetan Plateau (SETP) and southwestern Tibetan Plateau (SWTP) further strengthens the anomaly in water vapor transport in vertical direction and contributes to the precipitation anomaly through moisture convergence and divergence. The anomalous SASM and topography exhibit asymmetric effects between the onset and demise as well as between the early and late onset (demise) of the SASM. They cause 23.41%, 15.91%, and 1.96% difference in precipitation between the early and late SASM-onset years, and 13.05%, 21.50%, and 29.86% difference in precipitation between the early and late SASM-demise years in the SETP, central Tibetan Plateau (CETP), and SWTP, by regulating the horizontal and vertical thermodynamic and dynamic processes. The results help improve our understanding of the SASM-precipitation relationship over the SCTP and guide the prediction of precipitation and alleviation of water-related disasters in the region and its surroundings that are home to billions of people in Asia.
Global marine heatwave events using the new CMIP6 multi-model ensemble: from shortcomings in present climate to future projections
Authors: Plecha Sandra M , Soares Pedro M M
Published: November 2020

In recent years, research related to the occurrence of marine heatwave (MHW) events worldwide has been increasing, reporting severe impacts on marine ecosystems which led to losses of marine biodiversity or changes in world fisheries. Many of these studies, based on regional and global coupled models, show relevant biases in the MHW properties when compared with observations. In this study, the MHW frequency of occurrence, the duration and mean intensity over the global oceans are characterized, taking advantage of the new global climate model (GCM) dataset, from the Coupled Model Project Intercomparison Phase 6 (CMIP6). The MHWs result for the historical period are compared with observations, and the future projected changes are characterized under three socioeconomic pathways (SSPs) (SSP1, SSP2 and SSP5), for the middle and end of century (2041–2070 and 2071–2100). The results show a reasonable agreement between the modeled and observed MHW property trends, indicating increases in the frequency, duration and intensity of MHWs along the historical period. For the period 1982–2014, both the ∼2 mean observed events per year and the mean intensity of 0.35 °C above the threshold are underestimated by the multi-model ensemble (MME) mean by 21% and 31%, respectively, while the observed duration of ∼12 d are overestimated by 100%. The future MHWs are expected to increase in duration and intensity, where a near permanent MHW occurs with reference to the historical climate conditions, mainly by the end of the 21st century. The future MHWs intensity, projected by the MME mean, increases in the range of 0.2 °C to 1.5 °C, from the least to the most severe pathways. The GCMs biases obtained with CMIP6 revealed to be in line with the CMIP5 biases, reinforcing the need to use high spatial resolution models to characterize MHW.
Linear gyrokinetic simulations of reversed shear Alfvén eigenmodes and ion temperature gradient modes in DIII-D tokamak
Authors: WANG Hongyu , LIU Pengfei , LIN Zhihong , ZHANG Wenlu
Published: November 2020

Global linear gyrokinetic simulations using realistic DIII-D tokamak geometry and plasma profiles find co-existence of unstable reversed shear Alfvén eigenmodes (RSAE) with low toroidal mode number n and electromagnetic ion temperature gradient (ITG) instabilities with higher toroidal mode number n. For intermediate n = [10, 12], RSAE and ITG co-exist and overlap weakly in the radial domain with similar growth rates but different real frequencies. Both RSAE and ITG growth rates decrease less than 5% when compressible magnetic perturbations are neglected in the simulations. The ITG growth rates increase less than 7% when fast ions are not included in the simulations. Finally, the effects of trapped electrons on the RSAE are negligible.
Optical clocks based on molecular vibrations as probes of variation of the proton-to-electron mass ratio
Authors: Hanneke David , Kuzhan Boran , Lunstad Annika
Published: November 2020

Some new physics models of quantum gravity or dark matter predict drifts or oscillations of the fundamental constants. A relatively simple model relates molecular vibrations to the proton-to-electron mass ratio μ. Many vibrational transitions are at optical frequencies with prospects for use as highly accurate optical clocks. We give a brief summary of new physics models that lead to changes in μ and the current limits on drifts and oscillation amplitudes. After an overview of laboratory procedures, we give examples of molecules with experiments currently in development or underway. These experiments’ projected systematic and statistical uncertainties make them leading candidates in next-generation searches for time-variation of μ.
Inorganic nanomaterials for fighting surface and airborne pathogens and viruses
Authors: Shah Kwok Wei , Huseien Ghasan Fahim
Published: November 2020

Nowadays, the deadly viruses (including the latest coronavirus) and pathogens transmission became the major concern worldwide. Efforts have been made to combat with these fatal germs transmitted by the airborne, human-to-human contacts and contaminated surfaces. Thus, the antibacterial and antiviral materials have been widely researched. Meanwhile, the development of diverse nanomaterials with the antiviral traits provided several benefits to counter the threats from the surface and airborne viruses especially during the Covid-19 pandemic. Based on these facts, this paper overviewed the advantages of various nanomaterials that can disinfect and deactivate different lethal viruses transmitted through the air and surfaces. The past development, recent progress, future trends, environmental impacts, biocidal effects and prospects of these nanomaterials for the antiviral coating applications have been emphasized.
Professional Practices, Beliefs, and Incomes of Postdoctoral Trainees: The AACN, NAN, SCN 2020 Practice and ‘Salary Survey’
Authors: Sweet Jerry J , Klipfel Kristen M , Nelson Nathaniel W , Moberg Paul J
Published: November 2020

Objective

Within a portion of the 2020 professional practice and “salary survey,” to update key information regarding neuropsychology postdoctoral trainees.

Methods

Postdoctoral trainees were contacted via a variety of membership listings, including the listserv used by the program directors of the Association of Postdoctoral Programs in Clinical Neuropsychology (APPCN). Invitations sent in multiple waves to members of numerous neuropsychological organizations via e-messages and physical postcards included the request that postdoctoral trainees participate. The survey website was opened on January 17, 2020 and closed on April 2, 2020, during which time a total of 178 postdoctoral trainees in the USA and 3 in Canada participated.

Results

Response rate was estimated to be 56.4%, which adequately represents the target sample. The modal postdoctoral trainee is a woman whose internship was American Psychological Association (APA)-accredited and whose postdoctoral training is in an APPCN program that adheres to Houston Conference training guidelines. Extensive clinical experiences in neuropsychology in the form of externship practica and during internship were reported by the majority of trainees prior to postdoctoral training. There are few differences between APPCN and non-APPCN trainees and reported training experiences. Job satisfaction is high. Salaries appear to have increased substantially in recent years. There is universal interest in pursuing board certification. Support for the empirical foundations justifying assessment of response validity is high.

Conclusions

Surveys of postdoctoral trainees continue to provide valuable perspectives regarding training background, clinical experiences, practice beliefs, and incomes of individuals who will soon launch their careers in clinical neuropsychology.
Understanding the unimodal distributions of cancer occurrence rates: it takes two factors for a cancer to occur
Authors: Qiu Shuang , An Zheng , Tan Renbo , He Ping-an , Jing Jingjing , Li Hongxia , Wu Shuang , Xu Ying
Published: November 2020

Data from the SEER reports reveal that the occurrence rate of a cancer type generally follows a unimodal distribution over age, peaking at an age that is cancer-type specific and ranges from 30+ through 70+. Previous studies attribute such bell-shaped distributions to the reduced proliferative potential in senior years but fail to explain why some cancers have their occurrence peak at 30+ or 40+. We present a computational model to offer a new explanation to such distributions. The model uses two factors to explain the observed age-dependent cancer occurrence rates: cancer risk of an organ and the availability level of the growth signals in circulation needed by a cancer type, with the former increasing and the latter decreasing with age. Regression analyses were conducted of known occurrence rates against such factors for triple negative breast cancer, testicular cancer and cervical cancer; and all achieved highly tight fitting results, which were also consistent with clinical, gene-expression and cancer-drug data. These reveal a fundamentally important relationship: while cancer is driven by endogenous stressors, it requires sufficient levels of exogenous growth signals to happen, hence suggesting the realistic possibility for treating cancer via cleaning out the growth signals in circulation needed by a cancer.
HDAC1–Smad3–mSin3A complex is required for Smad3-induced transcriptional inhibition of hepatocyte growth factor receptor in human lung cancers
Authors: Gui Hao-Xin , Peng Jun , Yang Ze-Ping , Chen Lu-Yao , Zeng Hong , Shao Yu-Ting , Mu Xi , Hao Qian , Yang Yang , An Su , Guo Xiao-Xi , Xu Tian-Rui , Liu Ying
Published: November 2020

c-Met hyperactivity has been observed in numerous neoplasms. Several researchers have shown that the abnormal activation of c-Met is mainly caused by transcriptional activation. However, the molecular mechanism behind this transcriptional regulation is poorly understood. Here, we suggest that Smad3 negatively regulates the expression and activation of c-Met via a transcriptional mechanism. We explore the molecular mechanisms that underlie Smad3-induced c-Met transcription inhibition. We found in contrast to the high expression of c-Met, Smad3 showed low protein and mRNA levels. Smad3 and c-Met expressions were inconsistent between lung cancer tissues and cell lines. We also found that Smad3 overexpression suppresses whereas Smad3 knockdown significantly promotes Epithelial-Mesenchymal Transition and production of the angiogenic factors VEGF, CTGF and COX-2 through the ERK1/2 pathway. In addition, Smad3 overexpression decreases whereas Smad3 knockdown significantly increases protein and mRNA levels of invasion-related β-catenin and FAK through the PI3K/Akt pathway. Furthermore, using the chromatin immunoprecipitation analysis method, we demonstrate that a transcriptional regulatory complex consisting of HDAC1, Smad3 and mSin3A binds to the promoter of the c-Met gene. By either silencing endogenous mSin3A expression with siRNA or by pretreating cells with a specific HDAC1 inhibitor (MS-275), Smad3-induced transcriptional suppression of c-Met could be effectively attenuated. These results demonstrate that Smad3-induced inhibition of c-Met transcription depends on of a functional transcriptional regulatory complex that includes Smad3, mSin3A and HDAC1 at the c-Met promoter. Collectively, our findings reveal a new regulatory mechanism of c-Met signaling, and suggest a potential molecular target for the development of anticancer drugs.
Social mobilization and tackling the performance of local government in rural Nepal
Authors: Pandeya Ganesh Prasad , Oyama Tatsuo , Acharya Chakrapani
Published: November 2020

Based on extensive fieldwork in two rural villages, this paper qualitatively examines how social mobilization initiatives influence local government (LG) performance in Nepal. LG mobilized community people to empower them for their effective participation in local planning and decision-making processes. Comparing with the prior period of mobilization, evidence demonstrates that mobilization promises to boost LG performance through empowering communities to enhance their agency and entitlements, promoting democratic and effective citizen participation, and strengthening LG responsiveness and social accountability. But these connections are not straightforward, as there appeared discrepancies in parallel in recognizing equal participation rights of disadvantaged groups and equitable distribution of public resources among social groups. The findings imply that mobilization can be an effective strategy for tackling many challenges of participatory institutions, as it tends to create social pressures for making participatory institutions more democratic and changing the local power dynamics in favour of disadvantaged groups.
Limitations of Accelerated Stability Model Based on the Arrhenius Equation for Shelf Life Estimation of In Vitro Diagnostic Products
Authors: Ebrahim Alireza , DeVore Karl , Fischer Tim
Published: November 2020

Background

An accelerated stability model based on the Arrhenius Equation can be used to estimate stability of diagnostic reagents. Here we review 3 examples in which the model does not accurately predict the stability of diagnostic reagents.

Methods

We prepared several pilot lots of quality controls materials containing fructosamine, BNP, and HbA1c in human whole blood and serum matrices and performed accelerated stability studies at increased temperatures (5 °C to 35 °C) and real-time stability studies at the recommended storage temperature (-10 °C to -20 °C) for several analytes in quality control materials.

Results

We observed that the stability predictions obtained from the accelerated stability studies were longer in 2 instances and much shorter in another than those observed from the real-time stability studies.

Conclusions

Due to discrepancies between the stability results from accelerated stability studies and those from the real-time stability studies, we stress the need for caution when reagent manufacturers use the Arrhenius model and recommend that the technical groups and committees assigned to revise CLSI and ISO stability documents highlight the limitations of the accelerated stability model and include more guidance and direction on how and when to use the accelerated stability model.
Metabolomic Analysis in Inflammatory Bowel Disease: A Systematic Review
Authors: Gallagher Kate , Catesson Alexandra , Griffin Julian L , Holmes Elaine , Williams Horace R T
Published: November 2020

Background and Aims

The inflammatory bowel diseases [IBD], Crohn’s disease and ulcerative colitis, are chronic, idiopathic gastrointestinal diseases. Although their precise aetiology is unknown, it is thought to involve a complex interaction between genetic predisposition and an abnormal host immune response to environmental exposures, probably microbial. Microbial dysbiosis has frequently been documented in IBD. Metabolomics [the study of small molecular intermediates and end products of metabolism in biological samples] provides a unique opportunity to characterize disease-associated metabolic changes and may be of particular use in quantifying gut microbial metabolism. Numerous metabolomic studies have been undertaken in IBD populations, identifying consistent alterations in a range of molecules across several biological matrices. This systematic review aims to summarize these findings.

Methods

A comprehensive, systematic search was carried out using Medline and Embase. All studies were reviewed by two authors independently using predefined exclusion criteria. Sixty-four relevant papers were assessed for quality and included in the review.

Results

Consistent metabolic perturbations were identified, including increases in levels of branched chain amino acids and lipid classes across stool, serum, plasma and tissue biopsy samples, and reduced levels of microbially modified metabolites in both urine [such as hippurate] and stool [such as secondary bile acids] samples.

Conclusions

This review provides a summary of metabolomic research in IBD to date, highlighting underlying themes of perturbed gut microbial metabolism and mammalian–microbial co-metabolism associated with disease status.
Host Plant Signal Persistence in the Gut of the Brown Marmorated Stink Bug (Hemiptera: Pentatomidae)
Authors: Hepler James , Cooper Rodney , Beers Elizabeth
Published: November 2020

Determining the host range of an invasive insect in a new environment is a key step in the development of management strategies. As the brown marmorated stink bug, Halyomorpha halys Stål, expands into agricultural regions of North America, efforts to elucidate its dietary habits on a landscape scale rely on intensive sampling of potential host plants. Although this approach yields useful information, results can be biased toward common and easily sampled plant species; important hosts can be missed if sampling them is impractical or limited in scope. Here we lay the groundwork for the application of gut content analysis to the feeding ecology of H. halys by investigating the persistence of host plant DNA in the digestive tracts of insects with known feeding histories. Adult H. halys were fed bean seedlings (Phaseolus lunatus L.) for 7 d, followed by a forced host switch to carrot (Daucus carota L.). Insect guts were dissected out at 0, 1, 3, 7, and 14 d following the switch, and host plant chloroplast genes (trnF and trnL) were amplified via polymerase chain reaction. Amplicons were identified using high-throughput sequencing and analyzed for Phaseolus DNA. The original host remained detectable at 3 d (trnF) and 14 d (trnL) in substantial quantities. The proportion of total reads identified as Phaseolus rapidly decreased with time; a concomitant increase in Daucus reads was observed. Our results indicate that high-throughput sequencing of gut contents has great potential for exploring the dietary histories of field-caught H. halys and other phytophagous insects.
Qualities of good homework activities: teachers’ perceptions
Authors: Moorhouse Benjamin Luke
Published: November 2020

Assigning homework is a common practice of teachers internationally. However, we know little about teachers’ perceptions of the qualities of good homework. This article reports on the findings of a study that investigated teachers’ perceptions of good homework activities and their beliefs about homework’s effectiveness as a teaching and learning tool. Data were collected in two stages: a survey of 279 primary-school teachers; and follow-up interviews with 11 of the participants who completed the survey, including collecting samples of homework they assign. The first data source focused on teachers’ practices and beliefs about homework, while the second source provided more in-depth understanding of teachers’ beliefs in relation to their practices. The article presents the salient findings related to teachers’ perceptions of the qualities of good homework activities, as well as contextual factors that limit teachers’ ability to assign good homework. It includes practical implications for English-language teachers.
Coronary flow velocity reserve predicts adverse prognosis in women with angina and no obstructive coronary artery disease: results from the iPOWER study
Authors: Schroder Jakob , Michelsen Marie M , Mygind Naja D , Suhrs Hannah E , Bove Kira B , Bechsgaard Daria Frestad , Aziz Ahmed , Gustafsson Ida , Kastrup Jens , Prescott Eva
Published: November 2020

Aims 

Many patients with angina, especially women, do not have obstructive coronary artery disease (CAD) yet have impaired prognosis. We investigated whether routine assessment of coronary microvascular dysfunction (CMD) is feasible and predicts adverse outcome in women with angina and no obstructive CAD.

Methods and results 

After screening 7253, we included 1853 women with angina and no obstructive CAD on angiogram who were free of previous CAD, heart failure, or valvular heart disease in the prospective iPOWER (Improving Diagnosis and Treatment of Women with Angina Pectoris and Microvascular Disease) study. CMD was assessed by Doppler echocardiography in the left anterior descending artery as coronary flow velocity reserve (CFVR). Patients were followed for a composite outcome of cardiovascular death, myocardial infarction (MI), heart failure, stroke, and coronary revascularization. CFVR was obtained in 1681 patients (91%) and the median CFVR was 2.33 (quartiles 1–3: 2.00–2.74). During a median follow-up of 4.5 years, 96 events occurred. In univariate Cox regression, CFVR was associated with the composite outcome {hazard ratio (HR) 1.07 [95% confidence interval (CI) 1.03–1.11] per 0.1 unit decrease in CFVR; P < 0.001}, primarily driven by an increased risk of MI and heart failure. Results remained significant in multivariate analysis [HR 1.05 (95% CI 1.01–1.09) per 0.1 unit decrease in CFVR; P = 0.01]. In exploratory analyses, CFVR was also associated with the risk of repeated hospital admission for angina and all-cause mortality.

Conclusion 

Assessment of CFVR by echocardiography is feasible and predictive of adverse outcome in women with angina and no obstructive CAD. Results support a more aggressive preventive management of these patients and underline the need for trials targeting CMD.
Defect in the nuclear pore membrane glycoprotein 210-like gene is associated with extreme uncondensed sperm nuclear chromatin and male infertility: a case report
Authors: Arafah Karim , Lopez Fabrice , Cazin Caroline , Kherraf Zine-Eddine , Tassistro Virginie , Loundou Anderson , Arnoult Christophe , Thierry-Mieg Nicolas , Bulet Philippe , Guichaoua Marie-Roberte , Ray Pierre F
Published: November 2020

After the two meiotic divisions, haploid round spermatids undergo dramatic changes to become mature spermatozoa. One of the main transformations consists of compacting the cell nucleus to confer the sperm its remarkable hydrodynamic property and to protect its DNA from the oxidative stress it will encounter during its reproductive journey. Here, we studied an infertile subject with low sperm count, poor motility and highly abnormal spermatozoa with strikingly large heads due to highly uncondensed nuclear sperm DNA. Whole-exome sequencing was performed on the subject’s DNA to identify the genetic defect responsible for this severe sperm anomaly. Bioinformatics analysis of exome sequence data uncovered a homozygous loss of function variant, ENST00000368559.7:c.718-1G>A, altering a consensus splice site expected to prevent the synthesis of the nucleoporin 210 like (NUP210L) protein. High-resolution mass spectrometry of sperm protein extracts did not reveal any NUP210L peptide sequence in the patient’s sperm, contrary to what was observed in control donors, thus confirming the absence of NUP210L in the patient’s sperm. Interestingly, homozygous Nup210l knock-out mice have been shown to be infertile due to a reduced sperm count, a high proportion of round-headed sperm, other head and flagella defects and a poor motility. NUP210L is almost exclusively expressed in the testis and sequence analogy suggests that it encodes a nuclear pore membrane glycoprotein. The protein might be crucial to regulate nuclear trafficking during and/or before spermiogenesis, its absence potentially impeding adequate nuclear compaction by preventing the entry of histone variants/transition proteins/protamines into the nucleus and/or by preventing the adequate replacement of core histones. This work describes a new gene necessary for male fertility, potentially improving the efficiency of the genetic diagnosis of male infertility. The function of NUP210L still remains to be resolved and its future investigation will help to understand the complex mechanisms necessary for sperm compaction.
Potential 2-Aminoindane Fatality Invalidated by Careful Mass Spectrometric Analysis
Authors: Deville Marine , Dubois Nathalie , Charlier Corinne
Published: November 2020

We describe herewith the case of a patient presenting to the emergency department for worsening ear–nose–throat symptoms. As chemsex was evocated by the family, patient’s serum was submitted to a new psychoactive substances screening. After a simple liquid–liquid extraction, serum was injected on a high-resolution mass spectrometer using quite usual conditions (C18 column, gradient mode with acidic buffer, methanol and acetonitrile). An almost perfect match with 2-aminoindane (2-AI) was observed considering that the precursor ion was present in the sample but absent in the commercial library. Literature concerning 2-AI is sparse, and further investigations were undertaken. After injection of the reference standard, a small retention time shift has been observed (0.3 min) between the standard and the sample. The case was only closed while spiking the sample with the standard, giving rise to two distinct peaks. As a result, 2-AI was then considered as absent from the sample and death was attributed only to infection. Moreover, a rapid liquid chromatography–tandem mass spectrometry method dedicated to 2-AI was developed. It generated the same false-positive result highlighted by significant differences observed in ion ratios (2.37 for the sample versus 6.62 for the neat standard).
Genomic Determination of Reproductive Mode in Facultatively Parthenogenetic Opiliones
Authors: Brown Tyler A , Tsurusaki Nobuo , Burns Mercedes
Published: November 2020

Sexual reproduction may pose myriad short-term costs to females. Despite these costs, sexual reproduction is near ubiquitous. Facultative parthenogenesis is theorized to mitigate some of the costs of sex, as individuals can participate in occasional sex to limit costs while obtaining many benefits. However, most theoretical models assume sexual reproduction is fixed following mating, with no possibility of clutches of mixed reproductive ontogeny. Therefore, we asked: if coercive males are present at high frequency in a population of facultative parthenogens, will their clutches be solely sexually produced, or will there be evidence of sexually and asexually-produced offspring? How will their offspring production compare to conspecifics in low-frequency male populations? We addressed our questions by collecting females and egg clutches of the facultatively parthenogenetic Opiliones species Leiobunum manubriatum and L. globosum. In L. manubriatum, females from populations with few males were not significantly more fecund than females from populations with higher male relative frequency, despite the potential release of the former from sexual conflict. We used 3 genotyping methods along with a custom set of DNA capture probes to reveal that offspring of L. manubriatum from these high male populations were primarily produced via asexual reproduction. This is surprising because sex ratios in these southern populations approach equality, increasing the probability for females to encounter mates and produce offspring sexually. We additionally found evidence for reproductive polymorphisms within populations. Rapid and accurate SNP genotyping data will continue to allow us to address broader evolutionary questions regarding the role of facultative reproductive modes in the maintenance of sex.
Repellency of Novel Catnip Oils Against the Bed Bug (Hemiptera: Cimicidae)
Authors: Shi Xianhui , Wang Changlu , Simon James E , Reichert William , Wu Qingli
Published: November 2020

The common bed bug, Cimex lectularius L., resurged as an important urban pest in the last 20 yr. Yet, there are no commercial repellent products labeled for bed bugs available in the United States. We evaluated the repellency of two catnip oils from newly developed cultivars, CR3 and CR9, and compared each to 10 and 25% N,N-diethyl-meta-toluamide (DEET). CR3 contains 63.4% E,Z-nepatalactone and 27.5% Z,E-nepatalactone, and CR9 contains 94.9% Z,E-nepatalactone. Arena studies showed that CR3 and CR9 oils were more effective than DEET within a 24-h period. At 10% concentration, both CR3 and CR9 oils exhibited a repellency of over 94% during the first 8 h. At 25% concentration, the repellency of CR3 and CR9 oils increased to 100%, and repellency of DEET was 92% during the first 24 h. Repellency of 25% CR3 and CR9 oils became lower than 25% DEET after being aged for 3 d. After 28-d aging, repellency of 25% CR3, CR9, and DEET reduced to 25, 64, and 92%, respectively. Soiled socks were placed above repellent treated bands to determine if the repellent can protect soiled socks from being infested. The 20% CR3 oil prevented 100% of bed bugs from infesting soiled socks showing that it was more effective than DEET. These results indicate that catnip oils from CR3 and CR9 cultivars are more repellent than DEET over a 24-h period following application, but their longevity is shorter than DEET after 72 h.
Variation between rice accessions in photosynthetic induction in flag leaves and underlying mechanisms
Authors: Acevedo-Siaca Liana G , Coe Robert , Quick W Paul , Long Stephen P
Published: November 2020

Several breeding initiatives have sought to improve flag leaf performance as its health and physiology are closely correlated to rice yield. Previous studies have described natural variation of photosynthesis for flag leaves; however, none has examined their performance under the non-steady-state conditions that prevail in crop fields. Photosynthetic induction is the transient response of photosynthesis to a change from low to high light. Rice flag leaf photosynthesis was measured in both steady- and non-steady-state conditions to characterize natural variation. Between the lowest and highest performing accession, there was a 152% difference for average CO2 assimilation during induction (Ā300), a 77% difference for average intrinsic water use efficiency during induction (iWUEavg), and a 185% difference for the speed of induction (IT50), indicating plentiful variation. No significant correlation was found between steady- and non-steady-state photosynthetic traits. Additionally, measures of neither steady-state nor non-steady-state photosynthesis of flag leaves correlated with the same measures of leaves in the vegetative growth stage, with the exception of iWUEavg. Photosynthetic induction was measured at six [CO2], to determine biochemical and diffusive limitations to photosynthesis in vivo. Photosynthetic induction in rice flag leaves was limited primarily by biochemistry.
The fungal-specific subunit i/j of F1FO-ATP synthase stimulates the pathogenicity of Candida albicans independent of oxidative phosphorylation
Authors: Zhao Yajing , Lyu Yan , Zhang Yanli , Li Shuixiu , Zhang Yishan , Liu Yuting , Tang Chuanyan , Zhang Zhanpeng , Li Dongmei , Zhang Hong
Published: November 2020

Invasive fungal infections are a major cause of human mortality due in part to a very limited antifungal drug arsenal. The identification of fungal-specific pathogenic mechanisms is considered a crucial step to current antifungal drug development and represents a significant goal to increase the efficacy and reduce host toxicity. Although the overall architecture of F1FO-ATP synthase is largely conserved in both fungi and mammals, the subunit i/j (Su i/j, Atp18) and subunit k (Su k, Atp19) are proteins not found in mammals and specific to fungi. Here, the role of Su i/j and Su k in Candida albicans was characterized by an in vivo assessment of the virulence and in vitro growth and mitochondrial function. Strikingly, the atp18Δ/Δ mutant showed significantly reduced pathogenicity in systemic murine model. However, this substantial defect in infectivity exists without associated defects in mitochondrial oxidative phosphorylation or proliferation in vitro. Analysis of virulence-related traits reveals normal in both mutants, but shows cell wall defects in composition and architecture in the case of atp18Δ/Δ. We also find that the atp18Δ/Δ mutant is more susceptible to attack by macrophages than wild type, which may correlate well with the abnormal cell wall function and increased sensitivity to oxidative stress. In contrast, no significant changes were observed in any of these studies for the atp19Δ/Δ. These results demonstrate that the fungal-specific Su i/j, but not Su k of F1FO-ATP synthase may play a critical role in C. albicans infectivity and represent another opportunity for new therapeutic target investigation.

Lay Abstract

This study aims to investigate biological functions of fungal-specific subunit i/j and subunit k of ATP synthase in C. albicans oxidative phosphorylation and virulence potential. Our results revealed that subunit i/j, and not subunit k, is critical for C. albicans pathogenicity.
Updating constraints onf(T) teleparallel cosmology and the consistency with big bang nucleosynthesis
Authors: Benetti Micol , Capozziello Salvatore , Lambiase Gaetano
Published: November 2020

We focus on viable f(T) teleparallel cosmological models, namely power law, exponential, and square-root exponential, carrying out a detailed study of their evolution at all scales. Indeed, these models were extensively analysed in the light of late time measurements, while it is possible to find only upper limits looking at the very early time behaviour, i.e. satisfying the big bang nucleosynthesis (BBN) data on primordial abundance of 4He. Starting from these indications, we perform our analysis considering both background and linear perturbations evolution and constrain, beyond the standard six cosmological parameters, the free parameters of f(T) models in both cases whether the BBN consistency relation is considered or not. We use a combination of Cosmic Microwave Background, Baryon Acoustic Oscillation, Supernovae Ia and galaxy clustering measurements, and find that very narrow constraints on the free parameters of specific f(T) cosmology can be obtained, beyond any previous precision. While no degeneration is found between the helium fraction, YP, and the free parameter of f(T), we note that these models constrain the current Hubble parameter, H0, higher extent than the standard model one, fully compatible with the Riess et al. measurement in the case of power-law f(T) model. Moreover, the free parameters are constrained at non-zero values in more than 3-σ, showing a preference of the observations for extended gravity models.
Discovery of new mercury–manganese stars, including a fast rotator
Authors: González J F , Nuñez N E , Saffe C , Alejo A D , Veramendi M E , Collado A
Published: November 2020

The origin of mercury–manganese (HgMn) stars is still poorly understood and the statistical analysis of an extensive sample of well characterized objects would be very valuable. Nevertheless, the compilation of a clean and reliable list of all known HgMn stars, and complete characterization of those objects, is still a pending issue. We report the identification of 13 new HgMn stars from our own spectroscopic observations and from publicly available spectral libraries. In addition, we perform a thorough literature search to give a list of 46 confirmed HgMn stars (plus a further nine suspected HgMn stars) discovered over the last years or neglected by other compilations. When required, we performed specific observations to confirm doubtful cases. For the 13 newly identified HgMn stars we derived photospheric chemical abundances by spectral synthesis. Besides Hg and Mn, which are overabundant in the whole sample, P, Ga, and Xe are overabundant in the hottest stars of the sample, and Sr, Zr, and Pt among the coolest; Y is present in most stars of the sample. Three of these new HgMn stars are members of open clusters: HD 93549 in IC 2602, HD 96473 in NGC 3532, and HD 322659 in NGC 6281. Furthermore, our sample includes HD 145842, an object remarkable for its high rotation. In fact, its projected rotational velocity of ve sin i = 124 km s−1 is the highest measured in any HgMn star and is more than 30 per cent above the theoretical limit predicted by the diffusion theory, which makes HD 145842 a challenging test case for the current models.
Extremely band-limited repetition from a fast radio burst source
Authors: Kumar P , Shannon R M , Flynn C , Osłowski S , Bhandari S , Day C K , Deller A T , Farah W , Kaczmarek J F , Kerr M , Phillips C , Price D C , Qiu H , Thyagarajan N
Published: November 2020

The fast radio burst (FRB) population is observationally divided into sources that have been observed to repeat and those that have not. There is tentative evidence that the bursts from repeating sources have different properties than the non-repeating ones. In order to determine the occurrence rate of repeating sources and characterize the nature of repeat emission, we have been conducting sensitive searches for repetitions from bursts detected with the Australian Square Kilometre Array Pathfinder (ASKAP) with the 64-m Parkes radio telescope, using the recently commissioned Ultra-wideband Low (UWL) receiver system, over a band spanning 0.7–4.0 GHz. We report the detection of a repeat burst from the source of FRB 20190711A. The detected burst is 1 ms wide and has a bandwidth of just 65 MHz. We find no evidence of any emission in the remaining part of the 3.3 GHz UWL band. While the emission bandwidths of the ASKAP and UWL bursts show ν−4 scaling consistent with a propagation effect, the spectral occupancy is inconsistent with diffractive scintillation. This detection rules out models predicting broad-band emission from the FRB 20190711A source and puts stringent constraints on the emission mechanism. The low spectral occupancy highlights the importance of sub-banded search methods in detecting FRBs.
A population of galaxy-scale jets discovered using LOFAR
Authors: Webster B , Croston J H , Mingo B , Baldi R D , Barkus B , Gürkan G , Hardcastle M J , Morganti R , Röttgering H J A , Sabater J , Shimwell T W , Tasse C , White G J
Published: November 2020

The effects of feedback from high luminosity radio-loud active galactic nuclei (AGN) have been extensively discussed in the literature, but feedback from low-luminosity radio-loud AGN is less well understood. The advent of high sensitivity, high angular resolution, large field-of-view telescopes such as LOFAR is now allowing wide-area studies of such faint sources for the first time. Using the first data release of the LOFAR Two Metre Sky Survey (LoTSS) we report on our discovery of a population of 195 radio galaxies with 150-MHz luminosities between 3 × 1022 and 1.5 × 1025 WHz−1 and total radio emission no larger than 80 kpc. These objects, which we term galaxy-scale jets (GSJ), are small enough to be directly influencing the evolution of the host on galaxy scales. We report upon the typical host properties of our sample, finding that 9 per cent are hosted by spirals with the remainder being hosted by elliptical galaxies. Two of the spiral-hosted GSJ are highly unusual with low radio luminosities and FRII-like morphology. The host properties of our GSJ show that they are ordinary AGN observed at a stage in their life shortly after the radio emission has expanded beyond the central regions of the host. Based on our estimates, we find that about half of our GSJ have internal radio lobe energy within an order of magnitude of the ISM energy so that, even ignoring any possible shocks, GSJ are energetically capable of affecting the evolution of the host. The current sample of GSJ will grow in size with future releases of LoTSS and can also form the basis for further studies of feedback from low-luminosity radio sources.
Revisiting the dust destruction efficiency of supernovae
Authors: Priestley F D , Chawner H , Matsuura M , De Looze I , Barlow M J , Gomez H L
Published: November 2020

Dust destruction by supernovae is one of the main processes removing dust from the interstellar medium (ISM). Estimates of the efficiency of this process, both theoretical and observational, typically assume a shock propagating into a homogeneous medium, whereas the ISM possesses significant substructure in reality. We self-consistently model the dust and gas properties of the shocked ISM in three supernova remnants (SNRs), using X-ray and infrared (IR) data combined with corresponding emission models. Collisional heating by gas with properties derived from X-ray observations produces dust temperatures too high to fit the far-IR fluxes from each SNR. An additional colder dust component is required, which has a minimum mass several orders of magnitude larger than that of the warm dust heated by the X-ray emitting gas. Dust-to-gas mass ratios indicate that the majority of the dust in the X-ray emitting material has been destroyed, while the fraction of surviving dust in the cold component is plausibly close to unity. As the cold component makes up virtually all the total dust mass, destruction time-scales based on homogeneous models, which cannot account for multiple phases of shocked gas and dust, may be significantly overestimating actual dust destruction efficiencies, and subsequently underestimating grain lifetimes.
PK-DB: pharmacokinetics database for individualized and stratified computational modeling
Authors: Grzegorzewski Jan , Brandhorst Janosch , Green Kathleen , Eleftheriadou Dimitra , Duport Yannick , Barthorscht Florian , Köller Adrian , Ke Danny Yu Jia , De Angelis Sara , König Matthias
Published: November 2020

A multitude of pharmacokinetics studies have been published. However, due to the lack of an open database, pharmacokinetics data, as well as the corresponding meta-information, have been difficult to access. We present PK-DB (https://pk-db.com), an open database for pharmacokinetics information from clinical trials. PK-DB provides curated information on (i) characteristics of studied patient cohorts and subjects (e.g. age, bodyweight, smoking status, genetic variants); (ii) applied interventions (e.g. dosing, substance, route of application); (iii) pharmacokinetic parameters (e.g. clearance, half-life, area under the curve) and (iv) measured pharmacokinetic time-courses. Key features are the representation of experimental errors, the normalization of measurement units, annotation of information to biological ontologies, calculation of pharmacokinetic parameters from concentration-time profiles, a workflow for collaborative data curation, strong validation rules on the data, computational access via a REST API as well as human access via a web interface. PK-DB enables meta-analysis based on data from multiple studies and data integration with computational models. A special focus lies on meta-data relevant for individualized and stratified computational modeling with methods like physiologically based pharmacokinetic (PBPK), pharmacokinetic/pharmacodynamic (PK/PD), or population pharmacokinetic (pop PK) modeling.