bluuebunny/crossref_metadata_2025 huggingface dataset:
Co-ordination between leaf biomechanical resistance and hydraulic safety across 30 sub-tropical woody species
Authors: Wang Yong-Qiang , Ni Ming-Yuan , Zeng Wen-Hao , Huang Dong-Liu , Xiang Wei , He Peng-Cheng , Ye Qing , Cao Kun-Fang , Zhu Shi-Dan
Published: April 2021

Background and Aims

Leaf biomechanical resistance protects leaves from biotic and abiotic damage. Previous studies have revealed that enhancing leaf biomechanical resistance is costly for plant species and leads to an increase in leaf drought tolerance. We thus predicted that there is a functional correlation between leaf hydraulic safety and biomechanical characteristics.

Methods

We measured leaf morphological and anatomical traits, pressure–volume parameters, maximum leaf hydraulic conductance (Kleaf-max), leaf water potential at 50 % loss of hydraulic conductance (P50leaf), leaf hydraulic safety margin (SMleaf), and leaf force to tear (Ft) and punch (Fp) of 30 co-occurring woody species in a sub-tropical evergreen broadleaved forest. Linear regression analysis was performed to examine the relationships between biomechanical resistance and other leaf hydraulic traits.

Key Results

We found that higher Ft and Fp values were significantly associated with a lower (more negative) P50leaf and a larger SMleaf, thereby confirming the correlation between leaf biomechanical resistance and hydraulic safety. However, leaf biomechanical resistance showed no correlation with Kleaf-max, although it was significantly and negatively correlated with leaf outside-xylem hydraulic conductance. In addition, we also found that there was a significant correlation between biomechanical resistance and the modulus of elasticity by excluding an outlier.

Conclusions

The findings of this study reveal leaf biomechanical–hydraulic safety correlation in sub-tropical woody species.
Age-dependent Immune Response to the Biontech/Pfizer BNT162b2 Coronavirus Disease 2019 Vaccination
Authors: Müller Lisa , Andrée Marcel , Moskorz Wiebke , Drexler Ingo , Walotka Lara , Grothmann Ramona , Ptok Johannes , Hillebrandt Jonas , Ritchie Anastasia , Rabl Denise , Ostermann Philipp Niklas , Robitzsch Rebekka , Hauka Sandra , Walker Andreas , Menne Christopher , Grutza Ralf , Timm Jörg , Adams Ortwin , Schaal Heiner
Published: April 2021

Background

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has led to the development of various vaccines. Real-life data on immune responses elicited in the most vulnerable group of vaccinees older than age 80 years old are still underrepresented despite the prioritization of the elderly in vaccination campaigns.

Methods

We conducted a cohort study with 2 age groups, young vaccinees below the age of 60 years and elderly vaccinees over the age of 80 years, to compare their antibody responses to the first and second dose of the BNT162b2 coronavirus disease 2019 vaccination.

Results

Although the majority of participants in both groups produced specific immunoglobulin G antibody titers against SARS-CoV-2 spike protein, titers were significantly lower in elderly participants. Although the increment of antibody levels after the second immunization was higher in elderly participants, the absolute mean titer of this group remained lower than the <60 years of age group. After the second vaccination, 31.3% of the elderly had no detectable neutralizing antibodies in contrast to the younger group, in which only 2.2% had no detectable neutralizing antibodies.

Conclusions

Our data showed differences between the antibody responses raised after the first and second BNT162b2 vaccination, in particular lower frequencies of neutralizing antibodies in the elderly group. This suggests that this population needs to be closely monitored and may require earlier revaccination and/or an increased vaccine dose to ensure stronger long-lasting immunity and protection against infection.
Prognostic relevance of lymph node regression on survival in esophageal cancer: a systematic review and meta-analysis
Authors: Hagens Eliza , Tukanova Karina , Jamel Sara , van Berge Henegouwen Mark , Hanna George B , Gisbertz Suzanne , Markar Sheraz R
Published: April 2021

Introduction

The prognostic value of histomorphologic regression in primary esophageal cancer has been previously established, however the impact of lymph node (LN) response on survival still remains unclear. The aim of this review was to assess the prognostic significance of LN regression or downstaging following neoadjuvant therapy for esophageal cancer.

Methods

An electronic search was performed to identify articles evaluating LN regression or downstaging after neoadjuvant therapy. Random effects meta-analyses were performed to assess the influence of regression in the LNs and nodal downstaging on overall survival. Histomorphologic tumor regression in LNs was defined by the absence of viable cells or degree of fibrosis on histopathologic examination. Downstaged LNs were defined as pN0 nodes by the tumor, node, and metastasis classification, which were positive prior to treatment neoadjuvant.

Results

Eight articles were included, three of which assessed tumor regression (number of patients = 292) and five assessed downstaging (number of patients = 1368). Complete tumor regression (average rate of 29.1%) in the LNs was associated with improved survival, although not statistically significant (hazard ratio [HR] = 0.52, 95% confidence interval [CI] = 0.26–1.06; P = 0.17). LNs downstaging (average rate of 32.2%) was associated with improved survival compared to node positivity after neoadjuvant treatment (HR = 0.41, 95%CI = 0.22–0.77; P = 0.005).

Discussion

The findings of this meta-analysis have shown a survival benefit in patients with LN downstaging and are suggestive for considering LN downstaging to ypN0 as an additional prognostic marker in staging and in the comparative evaluation of differing neoadjuvant regimens in clinical trials. No statistically significant effect of histopathologic regression in the LNs on long-term survival was seen.
Living costs and welfare ratios in Western Europe: new estimates using a linear programming model
Authors: Zegarra Luis Felipe
Published: April 2021

This study provides new estimates on welfare ratios for London, Amsterdam, Paris, Strasbourg, Munich, and Leipzig for 1600–1850. I use a linear programming model to compute the basket that minimizes the food cost subject to nutrient requirements. For a balanced nutrition, I take into consideration that people should ingest not only calories and proteins, but also fat, iron, and some basic vitamins. The results suggest that living standards in Western Europe were lower than previously thought. However, like previous studies, this article suggests that welfare ratios in London were higher than in other European cities.
Clinical characteristics and prognosis of patients with microvascular angina: an international and prospective cohort study by the Coronary Vasomotor Disorders International Study (COVADIS) Group
Authors: Shimokawa Hiroaki , Suda Akira , Takahashi Jun , Berry Colin , Camici Paolo G , Crea Filippo , Escaned Javier , Ford Tom , Yii Eric , Kaski Juan Carlos , Kiyooka Takahiko , Mehta Puja K , Ong Peter , Ozaki Yukio , Pepine Carl , Rimoldi Ornella , Safdar Basmah , Sechtem Udo , Tsujita Kenichi , Yasuda Satoshi , Beltrame John F , Merz C Noel Bairey
Published: April 2021

Aims

To provide multi-national, multi-ethnic data on the clinical characteristics and prognosis of patients with microvascular angina (MVA).

Methods and results

The Coronary Vasomotor Disorders International Study Group proposed the diagnostic criteria for MVA. We prospectively evaluated the clinical characteristics of patients according to these criteria and their prognosis. The primary endpoint was the composite of major cardiovascular events (MACE), verified by institutional investigators, which included cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization due to heart failure or unstable angina. During the period from 1 July 2015 to 31 December 2018, 686 patients with MVA were registered from 14 institutes in 7 countries from 4 continents. Among them, 64% were female and the main ethnic groups were Caucasians (61%) and Asians (29%). During follow-up of a median of 398 days (IQR 365–744), 78 MACE occurred (6.4% in men vs. 8.6% in women, P = 0.19). Multivariable Cox proportional hazard analysis disclosed that hypertension and previous history of coronary artery disease (CAD), including acute coronary syndrome and stable angina pectoris, were independent predictors of MACE. There was no sex or ethnic difference in prognosis, although women had lower Seattle Angina Questionnaire scores than men (P < 0.05).

Conclusions

This first international study provides novel evidence that MVA is an important health problem regardless of sex or ethnicity that a diagnosis of MVA portends a substantial risk for MACE associated with hypertension and previous history of CAD, and that women have a lower quality of life than men despite the comparable prognosis.
Effectiveness of Companion Robot Care for Dementia: A Systematic Review and Meta-Analysis
Authors: Lu Li-Chin , Lan Shao-Huan , Hsieh Yen-Ping , Lin Long-Yau , Lan Shou-Jen , Chen Jong-Chen
Published: April 2021

Background and Objectives

Dementia and central nervous system degeneration are common problems in aging societies with regard to the number of people affected and total medical expenses. Socially assistive robotic technology has gradually matured; currently, most scholars believe it can be used as companions in long-term care facilities and to work as caregivers alongside staff to improve the social interaction and mental state of older adults and patients with dementia. Therefore, this study measured the effect of the duration of exposure to socially assistive robots in older adults with dementia.

Research Design and Methods

Seven databases were searched up to February 2019 through the consultation of appropriate Internet sites and the use of criteria lists recommended by relevant experts. Randomized controlled trials comparing socially assistive robot use with a control group in older adults with dementia and using at least one of the primary outcomes of agitation, depression, and quality of life were included.

Results

Thirteen randomized controlled trials were identified from 873 articles, 7 of which were included in the meta-analysis. The pooled effect estimate from 3 trials with 214 participants revealed that the pet-type robot improved patients’ agitation level, with a standardized mean difference of −0.37 (95% CI: −0.64 to −0.10, p < .01) and no heterogeneity (I2 = 0%). The results also revealed that length of each session and pet-type robot exposure time per week were associated with reduced depression levels (β = −0.06, Q = 21.213, df = 1, p < .001 and β = −0.019, Q = 7.532, df = 1, p < .01, respectively). However, the results for quality of life were nonsignificant.

Discussion and Implications

Pet-type robot systems seem to be a potential activity in long-term care facilities for dementia care. Further research is warranted to establish a comprehensive intervention plan related to the use of pet-type robots.
Prognostic significance of preoperative haemoglobin A1c level in patients with lung adenocarcinoma
Authors: Ogawa Hiroyuki , Fujibayashi Yusuke , Nishikubo Megumi , Nishioka Yuki , Tane Shinya , Kitamura Yoshitaka , Nishio Wataru
Published: April 2021

OBJECTIVES

We investigated the influence of the preoperative haemoglobin A1c (HbA1c) value on the prognosis and pathology of patients with lung adenocarcinoma who underwent surgery.

METHODS

We reviewed the medical records of 400 lung adenocarcinoma patients who underwent lobectomy with mediastinal lymph node dissection between 2009 and 2013 using a prospectively maintained database. We stratified 400 patients into 4 groups according to the preoperative HbA1c value as follows: HbA1c ≤ 5.9 (n = 296), 6.0 ≤ HbA1c ≤ 6.9 (n = 70), 7.0 ≤ HbA1c ≤ 7.9 (n = 21) and HbA1c ≥ 8.0 (n = 12). We compared the recurrence-free survival and overall survival (OS) among these 4 groups. Univariate and multivariate analyses were performed to identify the risk factors for recurrence.

RESULTS

The median follow-up period was 61.2 months. On comparing the recurrence-free survival and OS rates among these 4 groups, we found that these rates among patients in the HbA1c ≥ 8.0 group were significantly poorer compared with the other 3 groups (5-year recurrence-free survival: HbA1c ≤ 5.9, 70.4%; 6.0 ≤ HbA1c ≤ 6.9, 69.7%; 7.0 ≤ HbA1c ≤ 7.9, 70.7%; ≥8.0 HbA1c, 18.8%; P = 0.002; and 5-year OS: HbA1c ≤ 5.9, 88.7%; 6.0 ≤ HbA1c ≤ 6.9, 80.6%; 7.0 ≤ HbA1c ≤ 7.9, 90.2%; ≥8.0 HbA1c, 66.7%; P = 0.046). Patients in the HbA1c ≥ 8.0 group had significantly more tumours with vascular invasion (P = 0.041) and experienced distant metastasis significantly more often (P = 0.028) than those with other values. A multivariate analysis revealed that preoperative HbA1c ≥ 8.0 [hazard ratio (HR) 2.33; P = 0.026] and lymph node metastasis (HR 3.94; P < 0.001) were significant independent prognostic factors for recurrence.

CONCLUSIONS

Our results revealed that preoperative HbA1c ≥ 8.0 is associated to poor prognosis due to the occurrence of distant metastasis and we should carefully follow these patients after surgery.

Clinical registration number

Hyogo Cancer Center, G-57.
Mechanistic dissection of spatial organization in NF-κB signaling pathways by hybrid simulations
Authors: Wu Yinghao , Dhusia Kalyani , Su Zhaoqian
Published: April 2021

The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is one of the most important transcription factors involved in the regulation of inflammatory signaling pathways. Inappropriate activation of these pathways has been linked to autoimmunity and cancers. Emerging experimental evidences have been showing the existence of elaborate spatial organizations for various molecular components in the pathways. One example is the scaffold protein tumor necrosis factor receptor associated factor (TRAF). While most TRAF proteins form trimeric quaternary structure through their coiled-coil regions, the N-terminal region of some members in the family can further be dimerized. This dimerization of TRAF trimers can drive them into higher-order clusters as a response to receptor stimulation, which functions as a spatial platform to mediate the downstream poly-ubiquitination. However, the molecular mechanism underlying the TRAF protein clustering and its functional impacts are not well-understood. In this article, we developed a hybrid simulation method to tackle this problem. The assembly of TRAF-based signaling platform at the membrane-proximal region is modeled with spatial resolution, while the dynamics of downstream signaling network, including the negative feedbacks through various signaling inhibitors, is simulated as stochastic chemical reactions. These two algorithms are further synchronized under a multiscale simulation framework. Using this computational model, we illustrated that the formation of TRAF signaling platform can trigger an oscillatory NF-κB response. We further demonstrated that the temporal patterns of downstream signal oscillations are closely regulated by the spatial factors of TRAF clustering, such as the geometry and energy of dimerization between TRAF trimers. In general, our study sheds light on the basic mechanism of NF-κB signaling pathway and highlights the functional importance of spatial regulation within the pathway. The simulation framework also showcases its potential of application to other signaling pathways in cells.
Adult Gastroenterology Trainees’ Experience of Receiving Feedback on Their Performance of Endoscopy in the Workplace
Authors: Phaneuf Julien-Carl , Wood Dawn
Published: April 2021

Background

Competency-based gastrointestinal endoscopy training is concerned with outcomes of the learning experience. Feedback allows for trainees to achieve the expected outcomes. However, little is known about trainees’ experience of receiving feedback. Gaining understanding of their experience could help improve feedback practices. The study was conducted to explore what it means for adult gastroenterology trainees to receive feedback on their performance of endoscopy in the workplace.

Methods

An interpretative phenomenological approach was used. Individual semi-structured interviews were conducted with six trainees from three Canadian adult gastroenterology residency programs. Interviews were audio-recorded and transcribed verbatim for analysis. Analysis was conducted to identify the phenomenological themes across participants’ accounts of lived experience to provide an insight into the meaning of experiencing the studied phenomenon.

Findings

Three phenomenological themes of experience were identified: taking pauses, negotiating understandings and accepting asymmetry. Taking pauses allowed for participants to receive feedback on their performance of endoscopy. Participants needed to negotiate attending gastroenterologists’ different understandings of gastrointestinal endoscopy while carrying their own whenever feedback was provided. They had to accept the asymmetry between the roles of care provider and learner as well.

Discussion

The study has captured the uniqueness and the complexity of the lived experience of receiving feedback on the performance of endoscopy in the workplace from the perspective of study participants. The gained understanding of this experience has enabled the authors to suggest how attending gastroenterologists’ feedback practices may be improved.
Overexpression of Janus kinase 2 protein in extramammary Paget’s disease
Authors: Otsuka-Maeda Saki , Mijiddorj Myangat Tselmeg , Kajihara Ikko , Sakamoto Ryoko , Yamada-Kanazawa Saori , Kanemaru Hisashi , Nishimura Yuki , Sawamura Soichiro , Makino Katsunari , Aoi Jun , Makino Takamitsu , Masuguchi Shinichi , Fukushima Satoshi , Ihn Hironobu
Published: April 2021

Extramammary Paget’s disease is a rare malignant tumor of the skin that occurs primarily in the genitocrural region. Although the prognosis of extramammary Paget’s disease with distant metastasis is poor, an effective therapy has not been established. Because Janus kinase 2 has attracted attention as a therapeutic target in several cancers, we investigated the expression of the Janus kinase 2 protein and the relationship between its level of expression and clinical significance in 53 patients with extramammary Paget’s disease in our hospital. Immunohistochemistry showed that most extramammary Paget’s disease tissues were positive for Janus kinase 2 (50/53, 94.3%), and the immunostaining intensity of Janus kinase 2 was correlated with the degree of invasiveness, lymph node metastasis and distant metastasis. Based on these findings, Janus kinase 2 may be a promising therapeutic target in extramammary Paget’s disease.
Field Analysis of Biological Factors Associated With Sites at High and Low to Moderate Risk for Eastern Equine Encephalitis Virus Winter Activity in Florida
Authors: Miley Kristi M , Downs Joni , Burkett-Cadena Nathan D , West Richard G , Hunt Brenda , Deskins George , Kellner Billy , Fisher-Grainger Sandra , Unnasch Robert S , Unnasch Thomas R
Published: April 2021

Eastern equine encephalitis virus (EEEV) is the most pathogenic arbovirus endemic to the United States. Studies have demonstrated Florida’s role as a regional reservoir for the virus and its ability to support year-round transmission. Previous research has developed risk index models for mapping locations most at risk for EEEV transmission. We compared vector abundance, vector feeding behavior, potential host species, and fauna presence at high versus low–moderate risk sites during the winter and spring. Predicted high-risk sites had a significantly greater abundance of mosquitoes overall, including Culiseta melanura (Coquillett) (Diptera: Culicidae), the primary enzootic vector of EEEV. Twenty host species were identified from Cs. melanura bloodmeals, with the majority taken from avian species. Culiseta melanura largely fed upon the Northern Cardinal (Cardinalis cardinalis (Passeriformes: Cardinalidae)), which accounted for 20–24.4% of the bloodmeals obtained from this species in years 1 and 2, respectively. One EEEV-positive mosquito pool (Cs. melanura) and nine EEEV seropositive sentinel chickens were confirmed during winter-spring collections from high-risk sites; no seropositive chickens nor mosquito pools were found at the low–moderate risk sites. These results suggest that high-risk sites for EEEV activity are characterized by habitats that support populations of Cs. melanura and which may also provide ample opportunities to feed upon Northern Cardinals. The overall low level of mosquito populations during the winter also suggests that control of Cs. melanura populations in winter at high-risk sites may prove effective in reducing EEEV transmission during the peak summer season.
Optimal dynamic control for a maglev vehicle moving on multi-span guideway girders
Authors: Liu Linya , Yau J D , Qin Jialiang , Urushadze S
Published: April 2021

An optimal control algorithm using a virtual tuned mass damper called virtual TMD to control the levitation force of a magnetic system is developed for resonance suppression of a maglev vehicle moving on multi-span guideway girders. Since the optimal dynamic parameters of a TMD in vibration control are well developed, the optimal tuning gains required to control the magnetic oscillations of the maglev bogie can be directly used and fed back to the maglev control system. To address the dynamic interaction analysis from the maglev vehicle to the guideway girders and vice versa, the entire coupling system is decomposed into two subsystems, one is the moving vehicle subsystem and another the stationary guideway subsystem. Then, an incremental–iterative procedure associated with the Newmark method is presented to solve the two sets of subsystem equations. Finally, the control effectiveness and parametric studies of the optimal virtual TMD scheme on resonance reduction of the moving maglev vehicle are demonstrated.
Acute abdomen in a 54-year-old COVID-19 patient: a case report
Authors: Holleb Peter , Patel Priya , Saxena Pranay , Beniwal Jagbir , Zuberi Jamshed
Published: April 2021

Although primarily a respiratory virus, coronavirus-19 acts on the gastrointestinal tract to cause symptoms such as anorexia, nausea, vomiting and diarrhea. One possible mechanism involves the ACE2 receptor, which serves as the primary receptor for virus entry into the gastrointestinal epithelium. We describe the case of a 54-year-old-male with recent coronavirus disease 2019 (COVID-19) infection, who later presented with nausea, vomiting, diarrhea and progressively worsening diffuse abdominal pain for 1 week. He was diagnosed to have a small bowel obstruction; however, continued to have progressively worsening pain and failed conservative management. No cause for the obstruction was found in the operating room. Gastrointestinal involvement occurs in at least two-thirds of patients with coronavirus infection. Viral entry into the small bowel, triggering an inflammatory response, and virus-induced microthrombosis of the microcirculation have been postulated as a possible mechanism for paralytic ileus/small bowel obstruction.
Rare, long-term complication after pancreatoduodenectomy—a case report of cecal volvulus
Authors: Nofi Colleen P , Maloney Caroline , Kallis Michelle P , Levy Anna T , Nealon William H , Weiss Matthew J , DePeralta Danielle K
Published: April 2021

Complications after pancreatoduodenectomy are common, and range widely in timing of presentation, relation to pancreatobiliary pathology, and necessity of operative intervention. We present a case of a 74-year-old male with history of pancreatoduodenectomy for pancreatic adenocarcinoma who presented 11 months after index operation with cecal volvulus and required emergent right hemicolectomy. Prior history of pancreatoduodenectomy with mobilization of the right colon likely predisposed him to development of this surgical emergency. Patients have altered gastrointestinal anatomy after pancreatoduodenectomy and special care is necessary to protect the afferent biliopancreatic limb during intraoperative exploration, and particularly if right colectomy is necessary.
Hinge like domain motion facilitates human RBMS1 protein binding to proto-oncogene c-myc promoter
Authors: Aggarwal Priyanka , Bhavesh Neel Sarovar
Published: April 2021

DNA binding proteins recognize DNA specifically or non-specifically using direct and indirect readout mechanisms like sliding, hopping, and diffusion. However, a common difficulty in explicitly elucidating any particular mechanism of site-specific DNA-protein recognition is the lack of knowledge regarding target sequences and inadequate account of non-specific interactions, in general. Here, we decipher the structural basis of target search performed by the key regulator of expression of c-myc proto-oncogene, the human RBMS1 protein. In this study, we have shown the structural reorganization of this multi-domain protein required for recognizing the specific c-myc promoter sequence. The results suggest that a synergy between structural re-organization and thermodynamics is necessary for the recognition of target sequences. The study presents another perspective of looking at the DNA-protein interactions.
Prevalence of Chlamydia trachomatis Among Pregnant Women, Gynecology Clinic Attendees, and Subfertile Women in Guangdong, China: A Cross-sectional Survey
Authors: Li Changchang , Tang Weiming , Ho Hung Chak , Ong Jason J , Zheng Xiaojing , Sun Xuewan , Li Xia , Liu Lijun , Wang Yajie , Zhao Peizhen , Xiong Mingzhou , Zheng Heping , Wang Cheng , Yang Bin
Published: April 2021

Background

Chlamydia trachomatis (CT) is a major cause of infertility and adverse birth outcomes, but its epidemiology among childbearing-age women remains unclear in China. This study investigated the prevalence of CT and associated factors among Chinese women aged 16–44 years who were either (1) pregnant, (2) attending gynecology clinics, or (3) subfertile.

Methods

We conducted a cross-sectional survey and recruited participants from obstetrics, gynecology, and infertility clinics in Guangdong between March and December 2019. We collected information on individuals’ sociodemographic characteristics, previous medical conditions, and sexual behaviors. First-pass urine and cervical swabs were tested using nucleic acid amplification testing. We calculated the prevalence in each population and subgroup by age, education, and age at first sex. Multivariable binomial regression models were used to identify factors associated with CT.

Results

We recruited 881 pregnant women, 595 gynecology clinic attendees, and 254 subfertile women. The prevalence of CT was 6.7% (95% CI, 5.2%–8.5%), 8.2% (95% CI, 6.2%–10.7%), and 5.9% (95% CI, 3.5%–9.3%) for the above 3 populations, respectively. The subgroup-specific prevalence was highest among those who first had sex before age 25 years and older pregnant women (>35 years). The proportion of asymptomatic CT was 84.8%, 40.0%, and 60.0% among pregnant women, gynecology clinic attendees, and subfertile women, respectively. Age at first sex (<25 years), multipara, and ever having more than 1 partner increased the risk of CT.

Conclusions

Childbearing-age women in China have a high prevalence of CT. As most women with CT were asymptomatic, more optimal prevention strategies are urgently needed in China.
Genomic and acoustic differences separate Lilian’s Meadowlark (Sturnella magna lilianae) from Eastern (S. magna) and Western (S. neglecta) meadowlarks
Authors: Beam Johanna K , Funk Erik R , Taylor Scott A
Published: April 2021

Examining differences among recently diverged populations can provide insight into the traits and evolutionary mechanisms that drive or maintain divergence. The genus Sturnella includes 2 recently diverged species, Sturnella magna (Eastern Meadowlark) and S. neglecta (Western Meadowlark), the former of which has a complex of subspecies distributed across the Americas. Of the S. magna subspecies that occur in the United States, S. m. lilianae is the only one with a disjunct range, occurring in the southwestern United States and central Mexico. It also has markedly different song patterns than all other S. magna subspecies. In order to assess population differentiation, we performed whole-genome sequencing of 35 birds and analyzed song characteristics from 85 birds. Songs from each species and S. m. lilianae were diagnosable using linear discriminant function analysis and support divergence in song between all taxa. Phylogenetic analysis and admixture proportions support 3 distinct clades within North American meadowlarks, and tests of introgression failed to detect a significant signal. Overall, our results indicate that S. m. lilianae exhibits high levels of genetic and vocal differentiation from both S. magna and S. neglecta, with no evidence of introgression between any group, and forms a distinct evolutionary lineage. We thus recommend the elevation of S. m. lilianae to species status.
Phloem unloading via the apoplastic pathway is essential for shoot distribution of root-synthesized cytokinins
Authors: Zhao Jiangzhe , Ding Bingli , Zhu Engao , Deng Xiaojuan , Zhang Mengyuan , Zhang Penghong , Wang Lu , Dai Yangshuo , Xiao Shi , Zhang Cankui , Liu Chang-Jun , Zhang Kewei
Published: April 2021

Root-synthesized cytokinins are transported to the shoot and regulate the growth, development, and stress responses of aerial tissues. Previous studies have demonstrated that Arabidopsis (Arabidopsis thaliana) ATP binding cassette (ABC) transporter G family member 14 (AtABCG14) participates in xylem loading of root-synthesized cytokinins. However, the mechanism by which these root-derived cytokinins are distributed in the shoot remains unclear. Here, we revealed that AtABCG14-mediated phloem unloading through the apoplastic pathway is required for the appropriate shoot distribution of root-synthesized cytokinins in Arabidopsis. Wild-type rootstocks grafted to atabcg14 scions successfully restored trans-zeatin xylem loading. However, only low levels of root-synthesized cytokinins and induced shoot signaling were rescued. Reciprocal grafting and tissue-specific genetic complementation demonstrated that AtABCG14 disruption in the shoot considerably increased the retention of root-synthesized cytokinins in the phloem and substantially impaired their distribution in the leaf apoplast. The translocation of root-synthesized cytokinins from the xylem to the phloem and the subsequent unloading from the phloem is required for the shoot distribution and long-distance shootward transport of root-synthesized cytokinins. This study revealed a mechanism by which the phloem regulates systemic signaling of xylem-mediated transport of root-synthesized cytokinins from the root to the shoot.
Clinical and biomechanical factors associated with falls and rheumatoid arthritis: baseline cohort with longitudinal nested case–control study
Authors: Smith Toby O , Clarke Celia , Wells Jacob , Dainty Jack R , Watts Laura , Yates Max , Pomeroy Valerie M , Stanmore Emma , O’Neill Terence W , Macgregor Alexander J
Published: April 2021

Objective

To identify the clinical and biomechanical characteristics associated with falls in people with RA.

Methods

A total of 436 people ≥60 years of age with RA completed a 1 year prospective survey of falls in the UK. At baseline, questionnaires recorded data including personal and medical history, pain and fatigue scores, health-related quality of life (HRQoL), physical activity and medication history. The occurrence of falls wasmonitored prospectively over 12 months by monthly self-reporting. A nested sample of 30 fallers (defined as the report of one or more falls in 12 months) and 30 non-fallers was evaluated to assess joint range of motion (ROM), muscle strength and gait parameters. Multivariate regression analyses were undertaken to determine variables associated with falling.

Results

Compared with non-fallers (n = 236), fallers (n = 200) were older (P = 0.05), less likely to be married (P = 0.03), had higher pain scores (P < 0.01), experienced more frequent dizziness (P < 0.01), were frequently taking psychotropic medications (P = 0.02) and reported lower HRQoL (P = 0.02). Among those who underwent gait laboratory assessments, compared with non-fallers, fallers showed a greater anteroposterior (AP; P = 0.03) and medial-lateral (ML) sway range (P = 0.02) and reduced isokinetic peak torque and isometric strength at 60° knee flexion (P = 0.03). Fallers also showed shorter stride length (P = 0.04), shorter double support time (P = 0.04) and reduced percentage time in swing phase (P = 0.02) and in knee range of motion through the gait cycle (P < 0.01).

Conclusion

People with RA have distinct clinical and biomechanical characteristics that place them at increased risk of falling. Assessment for these factors may be important to offer more targeted rehabilitation interventions.
Recovering “Lay Ignorance” in the Stanford Financial Group Ponzi Scheme
Authors: Leslie Camilo Arturo
Published: April 2021

The Stanford Financial Group’s 2009 collapse devastated more than 20,000 depositors across the Americas. News stories portrayed the $7.2 billion fraud as an elaborate production of ignorance, and its middle-class marks as silent dupes. Media accounts thus differed little from dominant schools of ignorance scholarship, which have emphasized how powerful organizations use their expertise to foist ignorance on passive publics. However, the notion that laypeople are voiceless in such processes is empirically and theoretically untenable. Drawing on interviews with 103 defrauded Stanford clients in the US and Venezuela, this article shows that laypeople play an active interpretive and storytelling role in producing “lay ignorance” in the course of transacting with institutions, personnel, technologies, or products they lack the means to comprehend. Repurposing the concept of “jurisdiction,” I frame “layperson” as a role marked by its distance from the forms of authority that comprise expertise. As my comparison of US and Venezuelan investors reveals, laypeople nonetheless stitch surrogate forms of normative and epistemic authority from inapposite sources to produce their “lay ignorance.” The resulting accounts, I demonstrate, draw opportunistically from laypeople’s institutional, cultural, and political contexts.
Analysis of the Number of Tests, the Positivity Rate, and Their Dependency
Structure during COVID-19 Pandemic
Authors: Jamshidi Babak , Bekrizadeh Hakim , Zargaran Shahriar Jamshidi , Rezaei Mansour
Published: April 2021

Background

Applying recent advances in medical instruments, information technology,
and unprecedented data sharing into COVID-19 research revolutionized medical
sciences, and causes some unprecedented analyses, discussions, and
models.

Methods

Modeling of this dependency is done using four classes of copulas:
Clayton, Frank, Gumbel, and FGM. The estimation of the parameters of the
copulas is obtained using the maximum likelihood method. To evaluate the
goodness of fit of the copulas, we calculate AIC. All computations are
conducted on Matlab R2015b, R 4.0.3, Maple 2018a, and EasyFit 5.6, and the
plots are created on software Matlab R2015b and R 4.0.3.

Results

As time passes, the number of tests increases, and the positivity rate
becomes lower. The epidemic peaks are occasions that violate the stated
general rule –due to the early growth of the number of tests. If we divide
data of each country into peaks and otherwise, about both of them, the
rising number of tests is accompanied by decreasing the positivity
rate.

Conclusion

The positivity rate can be considered a representative of the level of
the spreading. Approaching zero positivity rate is a good criterion to scale
the success of a health care system in fighting against an epidemic. We
expect that if the number of tests is great enough, the positivity rate does
not depend on the number of tests. Accordingly, the number and accuracy of
tests can play a vital role in the quality level of epidemic data.

Key messages

-

In a country, increasing the positivity rate is more
representative than increasing the number of tests to warn about an
epidemic peak.

-

Approaching zero positivity rate is a good criterion to scale
the success of a health care system in fighting against an
epidemic.

-

Except for the first half of the epidemic peaks, in a country,
the higher number of tests is associated with a lower positivity
rate.

-

In countries with high test per million, there is no significant
dependency between the number of tests and positivity rate.
Diagnostic accuracy of a novel SARS-CoV-2 antigen-detecting rapid diagnostic test from standardized self-collected anterior nasal swabs
Authors: Osmanodja Bilgin , Budde Klemens , Zickler Daniel , Naik Marcel G. , Hofmann Jörg , Gertler Maximilian , Hülso Claudia , Rössig Heike , Horn Philipp , Seybold Joachim , Lunow Stephanie , Bothmann Melanie , Barrera-Pesek Astrid , Mayrdorfer Manuel
Published: April 2021

Background

Antigen-detecting rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 offer new opportunities for the quick and laboratory-independent identification of infected individuals for control of the SARS-CoV-2 pandemic. Despite the potential benefits, nasopharyngeal sample collection is frequently perceived as uncomfortable by patients and requires trained healthcare personnel with protective equipment. Therefore, anterior nasal self-sampling is increasingly recognized as a valuable alternative.

Methods

We performed a prospective, single-center, point of care validation of an Ag-RDT using a polypropylene absorbent collector for standardized self-collected anterior nasal swabs. Real-Time Polymerase Chain Reaction (RT-PCR) from combined oropharyngeal/nasopharyngeal swabs served as a comparator. Primary endpoint was sensitivity of the standardized Ag-RDT in symptomatic patients with medium or high viral concentration (≥ 1 million RNA copies on RT-PCR for SARS-CoV-2).

Results

Between February 12 and March 22, 2021, 388 participants were enrolled. After exclusion of 9 patients for which no PCR result could be obtained, the novel Ag-RDT was evaluated based on 379 participants, of which 273 were symptomatic and 106 asymptomatic. In 61 samples from symptomatic patients with medium or high viral load (≥ 1 million RNA copies), the sensitivity of the standardized Ag-RDT was 96.7% (59/61; 95%CI: 88.7-99.6%) for the primary endpoint. In total, 62 positive Ag-RDT results were detected out of 70 RT-PCR positive individuals, yielding an overall sensitivity of 88.6% (95%CI: 78.7-94.9%). Specificity was 99.7% (95%CI: 98.2-100%) in 309 RT-PCR negative individuals.

Conclusion

Here, we present a validation of a novel Ag-RDT with a standardized sampling process for anterior nasal self-collection, which meets WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, this assay could be beneficial due to its rapid results, ease of use, and suitability for standardized self-testing.

(Funded by Drägerwerk AG & Co. KGaA, Lübeck, Germany; ClinicalTrials.gov number NCT04698993)
Convergent evolution of SARS-CoV-2 spike mutations, L452R, E484Q and P681R, in the second wave of COVID-19 in Maharashtra, India
Authors: Cherian Sarah , Potdar Varsha , Jadhav Santosh , Yadav Pragya , Gupta Nivedita , Das Mousmi , Rakshit Partha , Singh Sujeet , Abraham Priya , Panda Samiran ,   NIC team
Published: April 2021

As the global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic expands, genomic epidemiology and whole genome sequencing are being constantly used to investigate its transmissions and evolution. In the backdrop of the global emergence of “variants of concern” (VOCs) during December 2020 and an upsurge in a state in the western part of India since January 2021, whole genome sequencing and analysis of spike protein mutations using sequence and structural approaches was undertaken to identify possible new variants and gauge the fitness of current circulating strains.

Phylogenetic analysis revealed that the predominant clade in circulation was a distinct newly identified lineage B.1.617 possessing common signature mutations D111D, G142D, L452R, E484Q, D614G and P681R, in the spike protein including within the receptor binding domain (RBD). Of these, the mutations at residue positions 452, 484 and 681 have been reported in other globally circulating lineages. The structural analysis of RBD mutations L452R and E484Q along with P681R in the furin cleavage site, revealed that these may possibly result in increased ACE2 binding and rate of S1-S2 cleavage resulting in better transmissibility. The same two RBD mutations indicated decreased binding to select monoclonal antibodies (mAbs) and may affect their neutralization potential. Experimental validation against a wider panel of mAbs, sera from vaccinees and those that recovered from natural infection needs to be studied.

The emergence of such local variants through the accumulation of convergent mutations during the COVID-19 second wave needs to be further investigated for their public health impact in the rest of the country and its possibility of becoming a VOC.
Alprazolam modulates persistence energy during emotion processing in first-degree relatives of individuals with schizophrenia: a network control study
Authors: Mahadevan Arun S. , Cornblath Eli J. , Lydon-Staley David M. , Zhou Dale , Parkes Linden , Larsen Bart , Adebimpe Azeez , Kahn Ari E. , Gur Ruben C. , Gur Raquel E. , Satterthwaite Theodore D. , Wolf Daniel H. , Bassett Danielle S.
Published: April 2021

Schizophrenia is marked by deficits in facial affect processing associated with abnormalities in GABAergic circuitry, deficits also found in first-degree relatives. Facial affect processing involves a distributed network of brain regions including limbic regions like amygdala and visual processing areas like fusiform cortex. Pharmacological modulation of GABAergic circuitry using benzodiazepines like alprazolam can be useful for studying this facial affect processing network and associated GABAergic abnormalities in schizophrenia. Here, we use pharmacological modulation and computational modeling to study the contribution of GABAergic abnormalities toward emotion processing deficits in schizophrenia. Specifically, we apply principles from network control theory to model persistence energy – the control energy required to maintain brain activation states – during emotion identification and recall tasks, with and without administration of alprazolam, in a sample of first-degree relatives and healthy controls. Here, persistence energy quantifies the magnitude of theoretical external inputs during the task. We find that alprazolam increases persistence energy in relatives but not in controls during threatening face processing, suggesting a compensatory mechanism given the relative absence of behavioral abnormalities in this sample of unaffected relatives. Further, we demonstrate that regions in the fusiform and occipital cortices are important for facilitating state transitions during facial affect processing. Finally, we uncover spatial relationships (i) between regional variation in differential control energy (alprazolamversusplacebo) and (ii) both serotonin and dopamine neurotransmitter systems, indicating that alprazolam may exert its effects by altering neuromodulatory systems. Together, these findings reveal differences in emotion-processing circuitry associated with genetic vulnerability to schizophrenia.
SAMBA controls the rate of cell division in maize development through APC/C interaction
Authors: Gong Pan , Bontinck Michiel , Demuynck Kirin , De Block Jolien , Gevaert Kris , Eeckhout Dominique , Persiau Geert , Aesaert Stijn , Coussens Griet , Van Lijsebettens Mieke , Pauwels Laurens , De Jaeger Geert , Inzé Dirk , Nelissen Hilde
Published: April 2021

SAMBA has been identified as a plant-specific regulator of the anaphase-promoting complex (APC/C) which controls unidirectional cell cycle progression in Arabidopsis, but so far its role was not studied in monocots. Here, the association of SAMBA with APC/C was shown to be conserved in maize. TwosambaCRISPR alleles showed growth defects that aggravated with plant age such as dwarfed plants due to shortened upper leaf length, erect leaf architecture, and reduced leaf size due to an altered cell division rate and cell expansion. Despite the fact that in both alleles the frameshift occurred at the same position, the two alleles differed in the severity and developmental onset of the phenotypes, becausesamba-1represented a knock-out allele, while translation re-initiation insamba-3resulted in a truncated protein that was still able to interact with the APC/C and regulate its function, albeit with altered APC/C activity or efficiency. Our data are consistent with a dosage-dependent role forSAMBAto control developmental processes for which a change in growth rate is pivotal.
RAP80 suppresses the vulnerability of R-loops during DNA double-strand break repair
Authors: Yasuhara Takaaki , Kato Reona , Yamauchi Motohiro , Uchihara Yuki , Zou Lee , Miyagawa Kiyoshi , Shibata Atsushi
Published: April 2021

R-loops, consisting of ssDNA and DNA-RNA hybrids, are potentially vulnerable unless they are appropriately processed. Recent evidence suggests that R-loops can form in the proximity of DNA double-strand breaks (DSBs) within transcriptionally active regions. Yet, how the vulnerability of R-loops is overcome during DSB repair remains unclear. Here, we identify RAP80 as a factor suppressing the vulnerability of ssDNA in R-loops and chromosome translocations and deletions during DSB repair. Mechanistically, RAP80 prevents unscheduled nucleolytic processing of ssDNA in R-loops by CtIP. This mechanism promotes efficient DSB repair via transcription-associated end-joining dependent on BRCA1, Polθ, and LIG1/3. Thus, RAP80 suppresses the vulnerability of R-loops during DSB repair, thereby precluding genomic abnormalities in a critical component of the genome caused by deleterious R-loop processing.
Comparative morphology of the dormouse skull
Authors: Hennekam Jesse J.
Published: April 2021

Dormice exhibit both inter- and intrageneric variation in cranial and mandibular morphology. Using geometric morphometrics, the form of eight out of nine extant dormouse genera was analysed, to provide a better understanding of the overall morphological variation present within Gliridae. Three genera representing the subfamilies, were studied in more detail. Species-, genus- and family-specific morphological trends are linked with certain habitats and feeding strategies. Smaller dormice show adaptations to a more arboreal lifestyle such as a relatively enlarged braincase and an inferiorly reoriented foramen magnum. Larger dormice show cranial modifications, including clear flattening of the skull and a more posteriorly positioned foramen magnum, hinting towards a more rupicolous lifestyle. Furthermore, specimens inhabiting arid areas appear to have more inflated auditory bullae, whereas other variable features, such as the length of the incisive foramen, were not associated with either size changes nor climatic variables. Lastly, more robust and horizontally orientated zygomatic arches as well as increased robusticity of the molar row appear to be linked with herbivory in dormice, whereas thinner arches and small concave molars are seen in more insectivorous species. This study results in a better understanding of ecological drivers underpinning the morphological divergence present within Gliridae.