bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Mechanism of Microvesicle Regulation by the Antiviral Protein Tetherin During HIV Infection
Authors: Weber Emily A. , Singh Meera V. , Singh Vir B. , Jackson Joseph W. , Ture Sara K. , Suwunnakorn Sumanun , Morrell Craig N. , Maggirwar Sanjay B.
Published: August 2020

Background

Microvesicles are cell membrane–derived vesicles that have been shown to augment inflammation. Specifically, monocyte‐derived microvesicles (MDMVs), which can express the coagulation protein tissue factor, contribute to thrombus formation and cardiovascular disease. People living with HIV experience higher prevalence of cardiovascular disease and also exhibit increased levels of plasma microvesicles. The process of microvesicle release has striking similarity to budding of enveloped viruses. The surface protein tetherin inhibits viral budding by physically tethering budding virus particles to cells. Hence, we investigated the role of tetherin in regulating the release of MDMVs during HIV infection.

Methods and Results

The plasma of aviremic HIV‐infected individuals had increased levels of tissue factor + MDMVs, as measured by flow cytometry, and correlated to reduced tetherin expression on monocytes. Superresolution confocal and electron microscopy showed that tetherin localized at the site of budding MDMVs. Mechanistic studies revealed that the exposure of monocytes to HIV‐encoded Tat triggered tetherin loss and subsequent rise in MDMV production. Overexpression of tetherin in monocytes led to morphologic changes in the pseudopodia directly underneath the MDMVs. Further, tetherin knockout mice demonstrated a higher number of circulating MDMVs and less time to bleeding cessation.

Conclusions

Our studies define a novel regulatory mechanism of MDMV release through tetherin and explore its contribution to the procoagulatory state that is frequently observed in people with HIV. Such insights could lead to improved therapies for individuals infected with HIV and also for those with cardiovascular disease.
Placental Mitochondria Therapy for Cerebral Ischemia-Reperfusion Injury in Mice
Authors: Nakamura Yoshihiko , Lo Eng H. , Hayakawa Kazuhide
Published: August 2020

Background and Purpose:

There is an urgent need to develop adjunct therapies that can be added onto reperfusion for acute ischemic stroke. Recently, mitochondrial transplantation has emerged as a promising therapeutic approach for boosting brain tissue protection. In this proof-of-concept study, we investigate the feasibility of using placenta as a source for mitochondrial transplantation in a mouse model of transient focal cerebral ischemia-reperfusion.

Methods:

Mitochondria-enriched fractions were isolated from cryopreserved mouse placenta. Mitochondrial purity and JC1 membrane potentials were assessed by flow cytometry. Adenosine triphosphate and mitochondrial proteins were measured by luminescence intensity and western blot, respectively. Therapeutic efficacy of mitochondrial fractions was assessed in a mouse model of transient focal cerebral ischemia-reperfusion.

Results:

Flow cytometry analysis demonstrated that about 87% of placental mitochondria were viable and maintained JC1 membrane potentials after isolation. Placental mitochondrial fractions contained adenosine triphosphate equivalent to mitochondrial fractions isolated from skeletal muscle and brown fat tissue. Normalized mitochondrial antioxidant enzymes (glutathione reductase, MnSOD [manganese superoxide dismutase]) and HSP70 (heat shock protein 70) were highly preserved in placental mitochondrial fractions. Treatment with placental mitochondrial fractions immediately after reperfusion significantly decreased infarction after focal cerebral ischemia in mice.

Conclusions:

Cryopreserved placenta can be a feasible source for viable mitochondrial isolation. Transplantation with placental mitochondria may amplify beneficial effects of reperfusion in stroke.
Teachers’ Unions, Collective Bargaining, and the Response to COVID-19
Authors: Hemphill Annie A. , Marianno Bradley D.
Published: August 2020

In response to the COVID-19 crisis, school districts worked quickly to roll out distance learning plans in the spring. Sometimes these plans impinged upon or were directly in conflict with provisions found in collective bargaining agreements (CBAs) negotiated between teachers' unions and district administration. In this brief, we unpack how urban school systems changed CBAs to make way for learning under COVID-19 conditions. We review COVID-19–related contract changes in 101 urban school districts around the country. We find that twenty-five urban school districts returned to the bargaining table with teachers’ unions to negotiate short-term fixes to CBAs that allowed for more flexibility to implement distance learning. These contract changes focused on several areas of the CBA, including compensation, workload, non-teaching duties, evaluation, leave, and technology. We argue that the lessons learned in spring contract negotiations have implications for the design and implementation of fall schooling plans, and that how fall schooling plays out will shape teacher morale and labor relations beyond the 2020–21 school year.
Electrical Characteristics of a Chemical Vapor Deposition-Grown MoS2 Monolayer-Based Field Effect Transistor
Authors: Kang Soo-Young , Kim Gil-Sung , Kang Min-Sung , Lee Won-Yong , Park No-Won , Le Chinh Tam , Park Jinjae , Kim Yong Soo , Saitoh Eiji , Koo Sang-Mo , Lee Sang-Kwon
Published: August 2020

Transition metal dichalcogenides (TMDs) are layered two-dimensional (2D) semiconductors and have received significant attention for their potential application in field effect transistors (FETs), owing to their inherent characteristics. Among the various reported 2D TMD materials, monolayer
(ML) molybdenum disulfide (MoS2) is being considered as a promising channel material for the fabrication of future transistors with gate lengths as small as ∼1 nm. In this work, we present chemical vapor deposition-grown triangular ML MoS2 with a lateral size of ∼22
μm and surface coverage of ∼47%, as well as a PMMA-based wet transfer process for depositing the as-grown triangular ML MoS2 flakes onto a SiO2 (∼100 nm)/p++-Si substrate. Additionally, we demonstrate the fabrication of an n-type
MoS2-based FET device and study its electrical characteristics as a function of the gate voltage. Our FET device shows an excellent on/off ratio of ∼106, an off-state leakage current of less than 10– 12 A, and a field effect mobility of ∼10.4
cm2/Vs at 300 K.
Structure Functions and Structure Parameters of Velocity Fluctuations in Numerically Simulated Atmospheric Convective Boundary Layer Flows
Authors: Gibbs Jeremy A. , Fedorovich Evgeni
Published: August 2020

We extend our previous study, which dealt with structure functions of potential temperature fluctuations, and focus on the characteristics of second-order velocity structure functions and corresponding structure parameters in the atmospheric convective boundary layer. We consider the three previously reported methods to compute the structure parameters of turbulent velocity fields: the direct method, the true spectral method, and the approximate spectral method. The methods are evaluated using high-resolution gridded numerical data from large-eddy simulations of shear-free and shear-driven convective boundary layers. Results indicate that the direct and true spectral methods are more suitable than the approximate spectral method, which overestimates the structure parameters of velocity as a result of assuming the inertial-subrange shape of the velocity spectrum for all turbulence scales. Results also suggest that structure parameters of vertical velocity fluctuations are of limited utility because of violations of local isotropy, especially in shear-free convective boundary layers.
Multidecadal Warming and Density Loss in the Deep Weddell Sea, Antarctica
Authors: Strass Volker H. , Rohardt Gerd , Kanzow Torsten , Hoppema Mario , Boebel Olaf
Published: August 2020

The World Ocean is estimated to store more than 90% of the excess energy resulting from man-made greenhouse gas–driven radiative forcing as heat. Uncertainties of this estimate are related to undersampling of the subpolar and polar regions and of the depths below 2000 m. Here we present measurements from the Weddell Sea that cover the whole water column down to the sea floor, taken by the same accurate method at locations revisited every few years since 1989. Our results show widespread warming with similar long-term temperature trends below 700-m depth at all sampling sites. The mean heating rate below 2000 m exceeds that of the global ocean by a factor of about 5. Salinity tends to increase—in contrast to other Southern Ocean regions—at most sites and depths below 700 m, but nowhere strongly enough to fully compensate for the warming effect on seawater density, which hence shows a general decrease. In the top 700 m neither temperature nor salinity shows clear trends. A closer look at the vertical distribution of changes along an approximately zonal and a meridional section across the Weddell Gyre reveals that the strongest vertically coherent warming is observed at the flanks of the gyre over the deep continental slopes and at its northern edge where the gyre connects to the Antarctic Circumpolar Current (ACC). Most likely, the warming of the interior Weddell Sea is driven by changes of the Weddell Gyre strength and its interaction with the ACC.
Book review: Sumit Sarkar, Essays of a Lifetime. Reformers, Nationalists, Subalterns
Authors: Robb Peter
Published: August 2020

Sumit Sarkar, Essays of a Lifetime. Reformers, Nationalists, Subalterns, Delhi and Albany: Permanent Black and University of New York Press, 2017 and 2019, 650 pp.
Multi-objective parametric optimization for high surface quality and process efficiency in micro-grinding
Authors: Wang Jun , Ye Qiang , Zhao Man , Shi Xusheng , Fei Tingwei
Published: August 2020

In this study, for the selection of maximum material removal rate and minimum surface roughness [Formula: see text] in micro-grinding of aluminum alloy through multi-response optimization, two optimization approaches are proposed based on statistical analysis and genetic algorithm. The statistical analysis–based approach applies response surface methodology according to the analysis of variance to propose a mathematical model for [Formula: see text]. In addition, the individual desirability of material removal rate, [Formula: see text], and the global desirability function are calculated, and the inverse analysis is conducted to locate input setting giving maximum desirability function. The genetic algorithm–based approach uses the improved multi-objective particle swarm optimization with the experimental data trained by support vector machine. To demonstrate that the material microstructure is a significant parameter for material removal rate and [Formula: see text], the models with and without Taylor factor consideration are developed and compared. The optimized results achieved from both response surface methodology and improved multi-objective particle swarm optimization demonstrate that the consideration of Taylor factor can significantly improve the optimization process to achieve the maximum material removal rate and minimum [Formula: see text].
COVID pandemic as an opportunity for improving mental health treatments of the homeless people
Authors: Martin Carmen , Andrés Pilar , Bullón Alberto , Villegas José Luis , de la Iglesia-Larrad Javier Ignacio , Bote Berta , Prieto Nieves , Roncero Carlos
Published: August 2020

Background:

Homeless population has been severely affected by the COVID-19 pandemic. Their living conditions, comorbidity with different pathologies and a greater frequency of mental disorders, make this population vulnerable.

Method:

We implemented a program of serial visits in a hostel for confined homeless of the city council social services, for the monitoring and treatment of mental disorders and substance abuse problems. Accompanied by serial phone and email contacts.

Results:

A highly significant percentage (63%) had mental disorders or substance abuse, requiring pharmacological intervention, and 37% began follow-up in resources of the Mental Health and Addiction network of the Psychiatric Service at the end of the program. Hospital emergency service visits were drastically reduced. None of them were infected with COVID-19. An individualized Social plan was drawn up in order to reintegrate them with support in the community.

Conclusions:

The Results have been really positive, meeting all the objectives and opening up developing new programs in the future, in the pandemic outbreak and out of it.
Building administrative capacity under developmental states in Chile and Singapore: a comparative perspective
Authors: Shamsul Haque M. , Puppim de Oliveira Jose A.
Published: August 2020

Administrative capacity depends on the nature of the state of which the administrative system is an integral part. In recent years, there has been a revival of debates on the role of public administration under developmental states in Southeast Asia and Latin America. A major analytical component of developmental states has been their administrative capacity and how to build it. There are significant variations in administrative capacity among developmental states caused by divergences in their historical, economic, political, and cultural contexts. This article compares two cross-continental cases (Singapore and Chile) with regard to the formations of developmental states shaping their administrative systems and capacity-building initiatives. It examines the divergences in their state formations and the contextual factors affecting their administrative capacity. The article concludes by making some generalizations, offering an analytical framework for further research, and suggesting policies needed for building effective administrative capacity.

Points for practitioners

This article highlights the significance of administrative capacity-building for development. It explores how this capacity is shaped by the formation of the state under which public administration functions. In explaining this relationship between state formation and public administration, the article specifically focuses on the “developmental” state, compares two cross-continental cases (Singapore and Chile) as regards how these two developmental states differ and cause variations in their administrative systems, and explains the major contextual factors leading to such variations. This understanding is crucial to designing effective policies for building administrative capacity in any country depending on its state formation and context.
LGBTQIA+ at the Blue Sky Club in Ho Chi Minh City
Authors: Ha Do Xuan , Hien Nguyen Phi , Sinh Bui Mai , Phuong Linh Nguyen Thi
Published: August 2020

The LGBTQIA+ (lesbian, gay, bisexual, transgender, queer, intersex, asexual) community in Vietnam faces discrimination which consequentially increases their risk of HIV infection and sexually transmitted diseases. The question is one of what practical methods might be introduced in Vietnam to strongly support the LGBTQIA+ community in protecting and maintaining health for themselves, their families, and society. How will advice best be delivered? To answer these questions, we conducted research at the Blue Sky Club in Ho Chi Minh City. We evaluate the effectiveness of health education communications and recognize that the LGBTQIA+ community has a different perspective on discrimination to the majority, and they consider discrimination a motivating force in their lives. This research takes account of the diversity of sexual orientation in the LGBTQIA+ community and yet acknowledges their desire is to be equally recognized by society.
Robust output tracking of nonlinear systems with transient improvement via funnel-based sliding mode control
Authors: Zahedi Mehdi , Binazadeh Tahereh
Published: August 2020

This paper studies a new procedure for robust tracking of nonlinear systems. This procedure is based on the combination of the sliding mode control and the funnel control, which in addition to the robust performance of the closed-loop system in the face of model uncertainties and/or external disturbances also leads to improvement of the characteristics of the transient responses. Using funnel control and the appropriate choice of the funnel can affect the convergence rate and overshoot. In this regard, a theorem has been presented and the effective performances of the suggested controller have been guaranteed in various respects based on exact mathematical analysis. Simulations have also been carried out to illustrate the efficiency of the proposed approach and to verify the theoretical achievements of the paper despite model uncertainties and external disturbances.
Clinical outcome of acute thoracic aortic syndrome in nonagenarians
Authors: Arakawa Mamoru , Okamura Homare , Miyagawa Atsushi , Kitada Yuichiro , Adachi Hideo
Published: August 2020

Background

Decision-making regarding the operability of thoracic aortic disease in nonagenarian patients remains controversial because outcomes of open surgical repair of the thoracic aorta are unclear. We investigated the surgical and nonsurgical outcomes of acute thoracic aortic syndrome treatment in nonagenarians.

Methods

After evaluating data in our institute from April 2016 to March 2020, we included 10 nonagenarians who needed surgical intervention on the thoracic aorta via a median sternotomy for acute thoracic aortic syndrome. The mean age of the cohort was 91.9 ± 2.1 years. Five patients underwent open surgical repair of the thoracic aorta (surgical group), and 5 refused surgery (nonsurgical group). All patients in the surgical group performed activities of daily living independently, with a mean clinical frailty scale of 3.2 ± 0.4. The surgical group included 4 patients with type A aortic dissection and one with a ruptured thoracic aortic aneurysm. Hemiarch replacement was performed in 3 patients and total arch replacement in 2. The mean follow-up period was 17.8 ± 5.1 months.

Results

Hospital mortality rates were 0% in the surgical and 80% in the nonsurgical group. The mean length of hospitalization was 28.4 ± 6.7 days in the surgical group. The 1-year survival rates were 100% in the surgical group and 20% in the nonsurgical group.

Conclusion

Open surgical repair for acute thoracic aortic syndrome via median sternotomy is a reasonable treatment option even in nonagenarians. Involvement of family members is important for decision-making to devise the optimal treatment strategy (surgical vs. medical).
Identity formation in music teacher education: The role of the curriculum
Authors: Haning Marshall
Published: August 2020

The purpose of this descriptive quantitative research was to examine undergraduate music teacher education curricula in the context of professional identity formation and in comparison with teacher education curricula in other subjects. Comprehensive course listings for undergraduate degree programs in music teacher education, mathematics teacher education, and English teacher education were gathered from the official course catalogs of 16 higher education institutions. These data were coded and analyzed to determine the amount of coursework in each program devoted to developing pedagogical skills, subject-area content knowledge, and other skills. Results indicated that while the amount of content-focused and pedagogy-focused courses was relatively balanced in English and mathematics teacher education programs, music teacher education programs devoted a significantly larger proportion of the curriculum to content-based courses. While scholars have called on music teacher educators to prioritize the development of a teacher identity in undergraduate music education students, current music teacher education curricula may not be aligned with these recommendations.
The SME paradox? Investigating ill-treatment behaviours in small and medium-sized enterprises in Ireland
Authors: Lewis Duncan , Manolchev Constantine , Pursell Lisa , Hodgins Margaret , Hogan Victoria , Mannix-McNamara Patricia
Published: August 2020

The dynamics of employment relations in small and medium-sized enterprises (SMEs) have attracted academic interest since the 1970s. To date, research debates have converged around two competing perspectives extolling either the opportunities, or the exploitation caused by informal working practices in smaller sized firms. Responding to calls for a more balanced and nuanced view, we analyse n = 1764 responses from a nationally representative study of workplace relations in Ireland, specifically focusing on negative behaviours in SMEs. We contribute to bullying and SME literatures by disaggregating the SME label and showing that certain employee groups in medium-sized firms are likely to report higher incidences of ill-treatment than their counterparts in smaller and larger firms. We conclude by making recommendations on how managers, owners and HRM practitioners can use our study’s findings to improve employee experiences and tackle bullying, harassment and other types of ill-treatment in their respective working environments.
Low cardiac output syndrome requiring extracorporeal membrane oxygenation following pericardiocentesis in an adolescent with Hodgkin Lymphoma: a case report
Authors: Matic Toni , Bakos Matija , Saric Dalibor , Cvitkovic Miran , Salek Zrinko , Mestrovic Daniel , Pavlovic Maja , Bilic Ernest
Published: August 2020

We present a case of a 16-year-old male with large pericardial effusion due to Hodgkin Lymphoma (HL). Shortly after drainage of pericardial effusion he developed a low cardiac output syndrome which had to be treated with extracorporeal membrane oxygenation (ECMO). This 9-day ECMO support helped the patient to recover his cardiac function, and thereafter a remission of his primary disease was successfully achieved with chemotherapy. It is a matter of discussion whether a large pericardial effusion with moderate symptoms in patients with HL should be evacuated or just observed since the effusion should ameliorate with chemotherapy. But based upon our experience in this case of hemodynamic instability due to a large effusion requiring evacuation, we propose that pericardiocentesis procedure should be performed with caution at a slow drainage rate of 0.5-1 ml/kg/hour with a maximum rate of 50 ml/hour, to help avoid the low cardiac output syndrome in patients with similar disease conditions.
Developing a fatigue programme: Protocol for the Nottingham Fatigue After Stroke (NotFAST2) study
Authors: Drummond Avril , Ablewhite Joanne , Condon Laura , Nair Roshan das , Jones Amanda , Jones Fiona , Sprigg Nikola , Thomas Shirley
Published: August 2020

Introduction

Post-stroke fatigue is common and is one of the most distressing symptoms after stroke. It has a negative impact on physical, social and psychological functioning; it is also associated with poor outcomes and increased mortality. The effective management of post-stroke fatigue is therefore regarded as a clinical priority.

Method

This study will use a mixed-methods design with three overlapping phases. Phase 1 will be a survey of existing fatigue management within the United Kingdom. In phase 2, interviews and focus groups will be conducted with stroke survivors with fatigue, carers and clinicians to determine strategies used to manage fatigue successfully. In phase 3, data from phases 1 and 2 will contribute to the co-design of a fatigue management programme with the NotFAST2 study Patient and Public Involvement group. This will be further refined through subsequent focus groups, which will include those with fatigue associated with other health conditions.

Results

Survey data will be analysed using descriptive statistics. Interview and focus group data will be analysed using a framework approach.

Conclusion

Post-stroke fatigue requires a comprehensive management programme necessitating input from key stakeholders. A post-stroke fatigue programme will be developed which will be tested in a future randomised controlled trial.
Commuters’ Assessment of Public Transport as a “Reasonable” Option in Montreal, QC
Authors: DeWeese James , El-Geneidy Ahmed
Published: August 2020

Retaining and increasing public transport ridership is a centerpiece of many strategies to address both the climate crisis and public health challenges. Understanding how and why commuters choose or reject public transport as a viable option or actual mode is, thus, central to policymakers’ efforts. This study makes use of a detailed travel-behavior survey conducted at McGill University in Montreal, Quebec, to answer two key questions: 1) What factors influence travelers’ perception of public transport as a reasonable commuting option? and 2) From among those travelers that do consider public transport to be reasonable, what factors influence their final decision to use it? One important finding is that there is sometimes a disconnect between the factors that influence a person’s initial assessment of reasonableness and subsequent mode choice. For example, car owners were paradoxically more likely to consider public transport a reasonable option but significantly less likely to use it. More generally, another important finding of this study is that there may be a sizeable contingent of travelers who consider public transport to be a reasonable or viable option but nonetheless decline to use it. These travelers may be easier to convert to public transport than those who do not already consider it a reasoanble option, making it important for policymakers to understand their motivations. Ultimately, public transport agencies may be able to use this type of information to develop policies better targeted at bolstering ridership.
Evaluating the Dynamic Accessibility of Metro Systems in Overcrowded Conditions
Authors: Li Wei , Luo Qin , Zephaniah Samwel , Liu Zhaoran
Published: August 2020

Metro accessibility is a concept used to describe the dynamic accessibility index of metro transportation systems. Most studies on accessibility apply a static approach, which overlooks the index fluctuations throughout the day. While it is possible to represent the accessibility using a single index, the ability to capture the dynamic nature of the index is important in understanding the quality of a transportation service and identify actionable aspects for improvement. For example, when the metro system is overcrowded and passengers fail to board the next arriving train, they instead wait for the subsequent train. As a result, the accessibility of the system is deemed to be lower than when its condition is uncrowded. This paper analyzes and integrates two aspects of metro accessibility: the performance of metro networks; and the dynamics of train schedules. An evaluation model in the form of a gravity model is proposed to measure the accessibility between each pair of stations with the dynamic travel time. This allows us to obtain profiles that highlight the daily variations in accessibility in the metro network and to identify the influence of congestion among stations. The effectiveness of the proposed evaluation model is validated using the metro network of Shenzhen in China. Results show that the proposed methodology provides useful information for passengers and travel guides as well as technical reference for the metro operation guidelines that are used to compile train schedules.
Tensile behaviour and damage characteristic of recycled aluminium alloys AA6061 undergoing finite strain deformation
Authors: Ho CS , Mohd Nor MK
Published: August 2020

The effects of temperature and strain rate of hot-forged recycled aluminium alloys AA6061 are examined via uniaxial tensile test implementations in this paper. The tests are conducted at elevated temperatures of 100 °C, 200 °C and 300 °C, at two different strain rates of 10−4 s−1 and 10−3 s−1. The tensile behaviour and damage characteristic are analysed in terms of stress-strain curves and microstructural analysis, respectively. The microstructure and fracture surface of such materials are observed using Scanning Electron Microscope (SEM) and Optical Microscope (OM). The flow stress of recycled AA6061 increases with increasing strain rate and decreases with increasing temperature. ImageJ software is used to quantify void characteristics. It is observed that the quantity and size of the micro-voids are strain-rate sensitive. This is due to the growth and coalescence of the micro-voids. The OM analysis shows the gap between the grain boundaries becomes wider with the increasing temperature that affects the strength of the material. The outcome of this work gives valuable information before the appropriate applications, especially in automotive and aerospace fields, can be established. It can be agreed that there is still a need for improved recycling methods to fulfil the needs in the required applications, as shown by its primary resources. It is a massive challenge and an obvious drawback in such materials due to the degradation of material’s properties related to damage.
Study of the influence of microwave sintering parameters on the mechanical behaviour of magnesium-based metal matrix composite
Authors: Kumar Ajit , Pandey Pulak M
Published: August 2020

In the present work, initially, the microwave sintering was used to fabricate a magnesium-based metal matrix composite (MgMMCs) especially Mg3Zn1Ca15Nb, at the same process parameters which were used to develop aforesaid material using conventional sintering. But, no improvement in the results were found, which may be owing to non-optimized parameters of microwave sintering. To carry out the optimization of microwave sintering parameters, first, the range of process parameters was obtained in this study. Sintering temperature (ST), heating rate (HR), and holding time (HT) were selected as sintering parameters. Additionally, the effects of these parameters on the ultimate compressive strength (UCS) as well as the sintered density of Mg3Zn1Ca15Nb were studied. After performing the compression test on the sintered samples (Ø10 × 15 mm2), an increment in both density and UCS was noted with the increase in sintering temperature and heating rate. Whereas sintering the sample above a certain period of holding time, the downward inclination of both UCS and sintered density was observed. The obtained UCS, as well as the density of microwave sintered samples were in the range of orthopedic implantable materials. The images obtained from scanning electron microscopy (SEM) affirmed the reduced porosity in the sintered samples as the heating rate increased. Additionally, a combined reduction in agglomeration, as well as cracks in the fabricated sample was observed by increasing sintering temperature. Energy-dispersive X-ray (EDX) study of the microwave fabricated Mg3Zn1Ca15Nb exhibited the presence of only parent elements in the fabricated sample. Also, no phase constituent was recorded in the fabricated sample, as confirmed by X-ray diffraction (XRD) spectra.
A high-resolution sediment record of East Asian summer monsoon from the northern South China Sea spanning the past 7500 years
Authors: Huang Chao , Li Mingkun , Liu Zhifeng , Wei Gangjian , Chen Fajin , Kong Deming , Huang Xin , Ye Feng
Published: August 2020

High-resolution Holocene marine sediment records are limited, which hampers our understanding of paleomonsoon evolution. Continental shelf sediment records are derived mainly from terrestrial weathering products and are thus often sensitive to paleoclimate variations. In this study, the grain size and magnetic mineral composition of a well-dated sediment core (YJ Core) from the northern inner shelf of the South China Sea (SCS) were analyzed to provide a high-resolution record of the Holocene evolution of the East Asian summer monsoon (EASM). These magnetic and grain size records indicate that EASM intensity followed a general declining trend between approximately 6800 and 2000 cal yr BP. This general pattern is synchronous with other geologic archives from monsoon regions, and can be attributed to solar radiation forcing in the Northern Hemisphere. On centennial timescales, a weak EASM closely coincides with periods of weak solar activity. In addition, spectral analysis of clays reveals five prominent cycles, with periodicities of approximately 364, 202, 158, 119, and 104 years, which correspond to solar activity cycles. The similarities between the cyclicities of the Asian monsoon signal in sedimentary records and those of solar activity demonstrate that solar forcing has a relatively large influence on the centennial-scale variability of the EASM.
In the Blood: The Consequences of Naturalising Microsegregation in Workplace Social Networks
Authors: Canham Hugo , Maier Christoph
Published: August 2020

This study explored workplace social networks in order to understand practices of inclusion and exclusion in the context of an increasingly diverse workplace in post-apartheid South Africa. We found that the ways in which space is occupied shows marked continuities with the era of formalised segregation during the preceding periods of colonialism and apartheid. We contend that intergroup relations theory and homophily assist in providing a partial understanding of the pervasive microsegregation observed within a South African organisation. We offer that a historied account of the continuing race-based accounts of microsegregation is more productive for understanding this phenomenon in a country with a past that formalised segregation across all areas of social life. We explore the meanings that people assign to segregation patterns within the workplace based on data emerging out of 54 interviews, nine naturalistic observations and a group discussion conducted within the headquarters of a major bank in Johannesburg. Discourses of linguistic and cultural differences were used to rationalise segregation and naturalise racialised differences. The material effects of segregation were noted to be particularly onerous for Black bankers. As a capitalist class, we however found that Black bankers resist, adapt, subvert and reinscribe power relations in ways that simultaneously serve their interests while also potentially limiting their opportunities. We point to the agentic aspects of social networks for marginalised groups and contend that representation is not sufficient to ensure inclusion.
Change in the First Cuneiform–Second Metatarsal Distance After Simulated Ligamentous Lisfranc Injury Evaluated by Weightbearing CT Scans
Authors: Sripanich Yantarat , Weinberg Maxwell , Krähenbühl Nicola , Rungprai Chamnanni , Saltzman Charles L. , Barg Alexej
Published: August 2020

Background:

This study aimed to investigate the widening between the first cuneiform (C1) and second metatarsal (M2) in a Lisfranc ligamentous complex (LLC) joint injury model subjected to successive ligament dissections evaluated by weightbearing computed tomography (CT) scans.

Methods:

Twenty-four intact cadaveric feet served as the control (condition 1). Each component of the LLC (dorsal, interosseous, and plantar ligaments—conditions 2, 3, and 4, respectively) were then sequentially dissected. The specimens were equally randomized to 1 of 3 additional dissections (first or second tarsometatarsal [TMT] joint capsule or first-second intercuneiform ligament [ICL]—conditions 5a, 5b, and 5c, respectively). One additional ligament was then randomly transected (eg, condition 6ac—transection of the first TMT capsule and ICL). Finally, the remaining ligament was transected (condition 7). After each dissection, CT scans were acquired under nonweightbearing (NWB, 0 kg), partial-weightbearing (PWB, 40 kg), and full-weightbearing (FWB, 80 kg) conditions. The distance between the lateral border of C1 and the medial border of M2 was assessed to evaluate diastasis. Linear regressions with 95% CIs and converted q values were used to compare the measured data.

Results:

No significant differences were found within the control. In condition 4, an average axial plane widening relative to control of 1.6 mm (95% CI, 1.5-1.8) and 2.1 mm (95% CI, 1.9-2.2) was observed under PWB and FWB. A coronal plane widening of 1.5 mm (95% CI, 1.3-1.6) and 1.9 mm (95% CI, 1.7-2.1) under PWB and FWB, respectively, was measured. A 95% CI of at least a 2-mm widening during PWB was demonstrated in 5c, 6ac, 6bc, and 7.

Conclusions:

Weightbearing computed tomography (WBCT) scans were used to detect ligamentous Lisfranc injuries in a cadaveric model. Relative axial widening greater than 1.5 mm under PWB conditions could indicate a complete LLC injury. Complete transection of the intercuneiform 1-2 ligament was required to detect a 2-mm widening in the nonweightbearing condition.

Clinical Relevance:

This study provides insight on the detection of various severities of LLC injuries using WBCT imaging.
Development of carpal tunnel syndrome in association with checkpoint inhibitors
Authors: Eisenbud Lauren , Ejadi Samuel , Mar Nataliya
Published: August 2020

Introduction

The incidence of neuropathy with checkpoint inhibitors is 0.3–1%, typically occurring 2–12 weeks after treatment initiation. Common neuropathy phenotypes include inflammatory myopathies, myasthenia gravis, acute and chronic demyelinating polyradiculopathies, vasculitic neuropathies, isolated cranial neuropathies, aseptic meningitis, autoimmune encephalitis, multiple sclerosis and hypophysitis. Carpal tunnel syndrome is the most common entrapment neuropathy in the general population; however, the association of carpal tunnel syndrome with checkpoint inhibitors is exceedingly rare.

Case Report

We report two cases of patients with no prior history of carpal tunnel syndrome treated with checkpoint inhibitors that developed de novo bilateral carpal tunnel syndrome. Management & Outcome: For both patients, the neurologic symptoms improved with cessation of the checkpoint inhibitor and initiation of corticosteroids.

Discussion

Given the prevalence of carpal tunnel syndrome in the general population, a high index of suspicion for carpal tunnel in patients receiving checkpoint inhibitors and prompt treatment with corticosteroids is essential.
The impact of uneven temperature distribution on stability of concrete structures using data analysis and numerical approach
Authors: Tan Xuyan , Chen Weizhong , Wang Luyu , Yang Jianping
Published: August 2020

Temperature variation is an essential factor to influence the stability of concrete structure. In contrast to the uniform distribution of temperature in most existing approaches, this paper aims to study the natural temperature distribution in concrete structure and analyze its impact on structural mechanical behaviors in field. As a case study, an underwater shield tunnel is investigated using the presented method. Firstly, temperature sensors are installed in different positions to achieve real-time monitoring in field. Then, a statistical model is derived by monitoring data to describe temperature variation. As a core component of the approach, the devised statistical model is integrated into our program to determine the external loads imposed on model. Finally, the mechanical behaviors of concrete structure are discussed under uneven temperature distribution. Analytical results indicated the magnitudes of temperature distribution is related to different positions of structure, in which the significant distinctions can be observed at upper and lower of tunnel as well as the inside and outside structures. Also, the tensile stress of tunnel lining increases with the rise of temperature, for instance, in this case study per temperature rising would lead to an increment 25.3 KPa of tensile stress. As a promising application, the analytical results provide an assessment of concrete structure stability.
Heterogeneity of acute subdural collections: In search of a unifying feature
Authors: Duy Lindsay , Badeeb Arwa , Duy Walter , Alqahtani Eman , Champion Walter , Kim Dae Hee , Martin Dann , Vartanians Vartan , Coffin Phillip , Small Juan
Published: August 2020

Introduction

A variety of different acute subdural hematoma patterns of density have been reported in the literature and are commonly seen in clinical practice, including rare hypodense acute subdural hematomas. It is unclear if these acute hypodense collections are entirely hypodense or if on close inspection, they can reveal subtle, tiny hyperdense components. The purpose of this study was to determine if all acute subdural hemtomas contain a hyperdense component, including seemingly entirely hypodense subdural collections.

Methods

Non-contrast CT scans of 111 patients containing 320 hyperacute or acute subdural collections were analyzed for the presence of a hyperdense component. Hounsfield measurements were recorded.

Results

All hyperacute and acute subdural hematomas in our study had a hyperdense component. Hyperacute subdural hematomas have a hyperdense component >97.5% of the time (95% confidence), and acute subdural hematomas have a hyperdense component >99% of the time (95% confidence).

Conclusion

Lack of a hyperdense component in a subdural hematoma makes acute or hyperacute hematoma highly unlikely, and alternative diagnoses should be considered.
The democratic limits of political experiments
Authors: Beerbohm Eric , Davis Ryan , Kern Adam
Published: August 2020

Since field experiments in democratic politics influence citizens and the relationships among citizens, they are freighted with normative significance. Yet the distinctively democratic concerns that bear upon such field experiments have not yet been systematically examined. In this paper, we taxonomize such democratic concerns. Our goal is not to justify any of them, but rather to reveal their basic structure, so that they can be scrutinized at further length. We argue that field experiments could be democratically objectionable even if they are not decisive – even if they do not swing the results of elections or other political decisions. Rather, if a class of campaign experiments is objectionable, one reason for this is that they undermine citizens’ equal standing. The ideal of equal standing affords nuanced judgments about the permissibility of field experiments in democratic politics.
Homeostatic generative design process: Emergence of the adaptive architectural form and skin to excessive solar radiation
Authors: Showkatbakhsh Milad , Kaviani Saam
Published: August 2020

Natural organisms through their evolutionary developments, acquire adaptive morphological and behavioural characteristics within their environmental contexts. Through homeostatic behaviours, organisms, individually and collectively, will sustain internal and external equilibrium in face of environmental fluctuations. There is a wide range of morphological and behavioural traits across multiple species that are rooted in their homeostatic mechanisms throughout their lives. This paper presents an evolutionary design workflow with embedded homeostatic principles to generate a building cluster that is adapted to the contexts with extreme solar radiation.
Saudi women’s physical activity habits during pregnancy
Authors: Alaglan Abeer A , Almousa Rania F , Alomirini Arwa A , Alabdularazaq Elaf S , Alkheder Renad S , Alzaben Khawlah A , Alonayzan Ghaida A , Saquib Juliann
Published: August 2020

Background:

Despite many benefits of physical exercise to women during pregnancy, the majority of Saudi women do not engage in an adequate amount of activity because of common barriers such as fatigue, lack of motivation, and childcare. The purpose of this study was to estimate the proportion of Saudi women who get adequate exercise during pregnancy as well as to evaluate their knowledge of, attitude toward, and barriers to physical exercise during pregnancy.

Methods:

This study had a cross-sectional design. Data were collected retrospectively (average time: 1 year after the birth), using translated questionnaires (English to Arabic), from primary health care centers and from the Maternity and Children Hospital in Qassim, Saudi Arabia. Logistic regression was employed to assess the a priori correlates of adequate exercise during pregnancy (primary outcome).

Results:

The sample included 274 women, who had a mean age of 31.9 years. A majority of the women thought that physical exercise during pregnancy was necessary and had high knowledge levels (mean = 77; median = 75) about types and amount of physical activity. Less than half of the women were either walking (26%) or exercising (42%) adequately (i.e. ⩾150 min/week). Age (odds ratio: 1.79), number of pregnancies (odds ratio: 2.41), attitude toward exercise (odds ratio: 2.71), and self-rated health (odds ratio: 2.50) were significant correlates of adequate exercise during pregnancy. Among those who reported no physical exercise during pregnancy ( n = 68), the following barriers were most common: tiredness (25.0%), fear (18.1%), dislike of exercise (16.7%), and lack of information (16.7%).

Conclusion:

For Saudi women, interventions are needed during pre-natal checkups to promote and maintain adequate physical activity levels during pregnancy.
The Lisfranc Injury: A Literature Review of Anatomy, Etiology, Evaluation, and Management
Authors: Chen Jie , Sagoo Navraj , Panchbhavi Vinod Kumar
Published: August 2020

Despite being first described in the 1800s, the Lisfranc injury remains one of the most controversial topics in foot and ankle surgery. From the basic anatomy of the ligament complex to the optimal diagnostic and management methods, new research both sharpens and yet confounds our understanding of this unique injury. This article reviews the literature from established and classic papers to recent studies evaluating newer techniques. We discuss the unique bony and ligamentous anatomy, which confer strength to the Lisfranc complex, the typical mechanisms of injury, the most common classification systems, the clinical presentation, current imaging modalities, and conservative and surgical treatment options. We review studies comparing open reduction and internal fixation with primary arthrodesis of acute injuries, in addition to studies evaluating the various methods for obtaining fixation, including intra-articular screws, dorsal plates, and flexible fixation. It is clear from this review that despite the vast number of studies in the literature, much is still to be learned about the diagnosis and management of this challenging injury.

Levels of Evidence: Level V: Expert opinion