bluuebunny/crossref_metadata_2025 huggingface dataset:
Dexmedetomidine as an adjunct to local anesthetics in nerve block relieved pain more effectively after TKA: a meta-analysis of randomized controlled trials
Authors: Pan Liping , Wu Hao , Liu Heng , Yang Xin , Meng Zhichao , Cao Yongping
Published: December 2020

Background

Dexmedetomidine has shown potential in pain control in patients undergoing total knee arthroplasty (TKA). However, the combination of nerve block and dexmedetomidine may be a preferred alternative for postoperative analgesia after TKA. The aim of this study was to perform a meta-analysis on existing randomized controlled trials (RCTs) to determine the efficacy and safety of dexmedetomidine as an adjunct to local anesthetics in nerve block after TKA.

Methods

A literature survey was conducted in the databases of PubMed, Embase, Cochrane Library, Web of science, and ScienceDirect for the RCTs completed before February 1st, 2020 that met pre-specified inclusion criteria. The primary outcomes included the pain scores, duration of analgesia, opioid consumption within 24 h postoperatively, and the level of patient satisfaction. The secondary outcomes included the motor strength, degree of sedation, postoperative nausea and vomiting, and other related complications. The methodological quality was assessed by the Cochrane risk of bias tool.

Results

The initial literature search yielded 143 studies, out of which seven studies met the inclusion criteria. The pooled data indicated that dexmedetomidine combined with local anesthetics in nerve block in TKA decreased the postoperative pain scores at rest as well as at motion (SMD = − 1.01 [95% CI − 1.29 to − 0.72], p < 0.01; SMD = − 1.01 [− 1.25 to − 0.77], p < 0.01) respectively, decreased the total opioid consumption within 24 h (SMD = − 0.63 [− 0.86 to − 0.40], p < 0.01), prolonged the duration of analgesia (SMD = 0.90 [0.64 to 1.17], p < 0.01), improved motor strength (SMD = 0.23 [0.01 to 0.45], p = 0.04), improved the degree of sedation (SMD = 0.94 [0.70 to 1.18], p < 0.01), and increased the level of patient satisfaction (SMD = 0.88 [0.60 to 1.17], p < 0.01) without increasing nausea and vomiting (RD = − 0.05 [− 0.11 to 0.01], p = 0.14), as well as other complications (RD = − 0.01 [− 0.08 to 0.07], p = 0.89), compared with local anesthetics alone.

Conclusions

It is effective and safe for dexmedetomidine as an adjunct to local anesthetics in nerve block in TKA to relieve postoperative pain, decrease total opioid consumption, prolong analgesic duration, and increase patient satisfaction without increasing related complications. Based on the quality of evidence, this meta-analysis recommends that dexmedetomidine can be used in a regular treatment regimen and as an adjunct addition to local anesthetics in nerve block for patients undergoing TKA.

Registration

This meta-analysis was prospectively registered on PROSPERO (International prospective register of systematic reviews) and the registering number was CRD42020169171.
Challenges and strategies in conducting sexual and reproductive health research among Rohingya refugees in Cox’s Bazar, Bangladesh
Authors: Ahmed Rushdia , Aktar Bachera , Farnaz Nadia , Ray Pushpita , Awal Abdul , Hassan Raafat , Shafique Sharid Bin , Hasan Md Tanvir , Quayyum Zahidul , Jafarovna Mohira Babaeva , Kobeissi Loulou Hassan , El Tahir Khalid , Chawla Balwinder Singh , Rashid Sabina Faiz
Published: December 2020

Background

Rohingya diaspora or Forcibly Displaced Myanmar Nationals (FDMNs), took shelter in the refugee camps of Cox’s Bazar, Bangladesh due to armed conflict in the Rakhine state of Myanmar. In such humanitarian crises, delivering sexual and reproductive health (SRH) services is critical for better health outcomes of this most-at-risk population where more than half are adolescent girls and women. This is a reflective paper on challenges and related mitigation strategies to conduct SRH research among FDMNs. The research on which this paper is based employed a concurrent mixed-method design combining a cross-sectional survey and qualitative interviews and group discussions with FDMNs to understand their SRH needs and demand-side barriers. Assessment of health facilities and qualitative interviews with healthcare providers and key stakeholders were carried out to assess facility readiness and supply-side barriers.

Challenges and strategies

The researchers faced different challenges while conducting this study due to the unique characteristics of the FDMN population and the location of the refugee camps. The three key challenges researchers encountered include: sensitivity regarding SRH in the FDMNs, identifying appropriate sampling strategies, and community trust issues. The key approaches to overcome these challenges involved: actively engaging community members and gatekeepers in the data collection process to access respondents, identifying sensitive SRH issues through survey and exploring in-depth during qualitative interviews; and contextually modifying the sampling strategy.

Conclusion

Contextual adaptation of research methods and involving community and local key stakeholders in data collection are the key lessons learnt from this study. Another important lesson was researchers’ identity and positionality as a member of the host country may create distrust and suspicion among the refugees. The multi-level complexities of humanitarian settings may introduce unforeseen challenges and interrupt research plans at different stages of research which require timely and contextual adaptations.
Amplification-free long-read sequencing reveals unforeseen CRISPR-Cas9 off-target activity
Authors: Höijer Ida , Johansson Josefin , Gudmundsson Sanna , Chin Chen-Shan , Bunikis Ignas , Häggqvist Susana , Emmanouilidou Anastasia , Wilbe Maria , den Hoed Marcel , Bondeson Marie-Louise , Feuk Lars , Gyllensten Ulf , Ameur Adam
Published: December 2020

Background

One ongoing concern about CRISPR-Cas9 genome editing is that unspecific guide RNA (gRNA) binding may induce off-target mutations. However, accurate prediction of CRISPR-Cas9 off-target activity is challenging. Here, we present SMRT-OTS and Nano-OTS, two novel, amplification-free, long-read sequencing protocols for detection of gRNA-driven digestion of genomic DNA by Cas9 in vitro.

Results

The methods are assessed using the human cell line HEK293, re-sequenced at 18x coverage using highly accurate HiFi SMRT reads. SMRT-OTS and Nano-OTS are first applied to three different gRNAs targeting HEK293 genomic DNA, resulting in a set of 55 high-confidence gRNA cleavage sites identified by both methods. Twenty-five of these sites are not reported by off-target prediction software, either because they contain four or more single nucleotide mismatches or insertion/deletion mismatches, as compared with the human reference. Additional experiments reveal that 85% of Cas9 cleavage sites are also found by other in vitro-based methods and that on- and off-target sites are detectable in gene bodies where short-reads fail to uniquely align. Even though SMRT-OTS and Nano-OTS identify several sites with previously validated off-target editing activity in cells, our own CRISPR-Cas9 editing experiments in human fibroblasts do not give rise to detectable off-target mutations at the in vitro-predicted sites. However, indel and structural variation events are enriched at the on-target sites.

Conclusions

Amplification-free long-read sequencing reveals Cas9 cleavage sites in vitro that would have been difficult to predict using computational tools, including in dark genomic regions inaccessible by short-read sequencing.
Stability analysis of a neural field self-organizing map
Authors: Detorakis Georgios , Chaillet Antoine , Rougier Nicolas P.
Published: December 2020

We provide theoretical conditions guaranteeing that a self-organizing map efficiently develops representations of the input space. The study relies on a neural field model of spatiotemporal activity in area 3b of the primary somatosensory cortex. We rely on Lyapunov’s theory for neural fields to derive theoretical conditions for stability. We verify the theoretical conditions by numerical experiments. The analysis highlights the key role played by the balance between excitation and inhibition of lateral synaptic coupling and the strength of synaptic gains in the formation and maintenance of self-organizing maps.
Computation offloading through mobile vehicles in IoT-edge-cloud network
Authors: Long Jun , Luo Yueyi , Zhu Xiaoyu , Luo Entao , Huang Mingfeng
Published: December 2020

With the developing of Internet of Things (IoT) and mobile edge computing (MEC), more and more sensing devices are widely deployed in the smart city. These sensing devices generate various kinds of tasks, which need to be sent to cloud to process. Usually, the sensing devices do not equip with wireless modules, because it is neither economical nor energy saving. Thus, it is a challenging problem to find a way to offload tasks for sensing devices. However, many vehicles are moving around the city, which can communicate with sensing devices in an effective and low-cost way. In this paper, we propose a computation offloading scheme through mobile vehicles in IoT-edge-cloud network. The sensing devices generate tasks and transmit the tasks to vehicles, then the vehicles decide to compute the tasks in the local vehicle, MEC server or cloud center. The computation offloading decision is made based on the utility function of the energy consumption and transmission delay, and the deep reinforcement learning technique is adopted to make decisions. Our proposed method can make full use of the existing infrastructures to implement the task offloading of sensing devices, the experimental results show that our proposed solution can achieve the maximum reward and decrease delay.
A hierarchical game-based power allocation algorithm in 5G heterogeneous integrated networks
Authors: Chen Geng , Ma Luyao , Zeng Qingtian , Zhang Jinjin
Published: December 2020

In this paper, we proposed a novel power allocation algorithm based on hierarchical game in 5G heterogeneous integrated networks. The radio network controller is the first layer, the base stations are the second layer, and the base station users are the third layer. The stackelberg game model is used between the first and second layers, in which the radio network controller is the leader and the base stations are the followers. The radio network controller sets the interference prices for the base stations and the users in the third layer can update their transmission power by non-cooperative game based on the setting interference price. According to the proposed scheme, the users power allocation can reach the Nash equilibrium through by non-cooperative game and obtain the optimal transmission power. Moreover, it is proved that the equilibrium solution is composed of the optimal price and the optimal transmission power, and the convergence of this algorithm is also verified. The simulation results show that the proposed algorithm can decrease the interference and improve the system capacity.
Approximation by bivariate generalized Bernstein–Schurer operators and associated GBS operators
Authors: Mohiuddine S. A.
Published: December 2020

We construct the bivariate form of Bernstein–Schurer operators based on parameterα. We establish the Voronovskaja-type theorem and give an estimate of the order of approximation with the help of Peetre’sK-functional of our newly defined operators. Moreover, we define the associated generalized Boolean sum (shortly, GBS) operators and estimate the rate of convergence by means of mixed modulus of smoothness. Finally, the order of approximation for Bögel differentiable function of our GBS operators is presented.
Dynamical analysis and adaptive fuzzy control for the fractional-order financial risk chaotic system
Authors: Sukono  , Sambas Aceng , He Shaobo , Liu Heng , Vaidyanathan Sundarapandian , Hidayat Yuyun , Saputra Jumadil
Published: December 2020

In this paper, a fractional-order model of a financial risk dynamical system is proposed and the complex behavior of such a system is presented. The basic dynamical behavior of this financial risk dynamic system, such as chaotic attractor, Lyapunov exponents, and bifurcation analysis, is investigated. We find that numerical results display periodic behavior and chaotic behavior of the system. The results of theoretical models and numerical simulation are helpful for better understanding of other similar nonlinear financial risk dynamic systems. Furthermore, the adaptive fuzzy control for the fractional-order financial risk chaotic system is investigated on the fractional Lyapunov stability criterion. Finally, numerical simulation is given to confirm the effectiveness of the proposed method.
On approximate solutions for a fractional prey–predator model involving the Atangana–Baleanu derivative
Authors: Ghanbari Behzad
Published: December 2020

Mathematical modeling has always been one of the most potent tools in predicting the behavior of dynamic systems in biology. In this regard, we aim to study a three-species prey–predator model in the context of fractional operator. The model includes two competing species with logistic growing. It is considered that one of the competitors is being predated by the third group with Holling type II functional response. Moreover, one another competitor is in a commensal relationship with the third category acting as its host. In this model, the Atangana–Baleanu fractional derivative is used to describe the rate of evolution of functions in the model. Using a creative numerical trick, an iterative method for determining the numerical solution of fractional systems has been developed. This method provides an implicit form for determining solution approximations that can be solved by standard methods in solving nonlinear systems such as Newton’s method. Using this numerical technique, approximate answers for this system are provided, assuming several categories of possible choices for the model parameters. In the continuation of the simulations, the sensitivity analysis of the solutions to some parameters is examined. Some other theoretical features related to the model, such as expressing the necessary conditions on the stability of equilibrium points as well as the existence and uniqueness of solutions, are also examined in this article. It is found that utilizing the concept of fractional derivative order the flexibility of the model in justifying different situations for the system has increased. The use of fractional operators in the study of other models in computational biology is recommended.
Knowledge towards standard precautions among healthcare providers of hospitals in Amhara region, Ethiopia, 2017: a cross sectional study
Authors: Kasa Ayele Semachew , Temesgen Worku Animaw , Workineh Yinager , Tesfaye Tadesse Dagget , Kerie Sitotaw , Amsalu Eden , Awoke Solomon Emishaw
Published: December 2020

Background

Literatures revealed that healthcare-associated infections are still a great concern in many developing countries including in Ethiopia. Despite the development of detailed guidelines for infection control, they remain as a critical challenge for the public health sectors and the knowledge of standard precautions among healthcare workers in many developing countries is low and not properly applied. Hence, the present study tried to determine the level of knowledge about standard precautions among healthcare workers of Amhara region, Ethiopia.

Methods

Institutional based cross-sectional study was conducted on a randomly selected public hospitals of Amhara region, Northwest Ethiopia from March 01–April 01/2017. A multistage sampling strategy was utilized to select 795 sampled healthcare workers. Data were collected using pretested self-administered questionnaire. The collected data entered using EpiData Version 3.1 statistical software and analyzed using SPSS version 20 statistical package. After using binary logistic regression, multivariable logistic regression analysis used to form the model. Variables which had statistically significant association with the outcome variable (P < 0.05) were identified as significant in the multivariable logistic regression analysis.

Results

Almost half (49.2%) of the study participants were female healthcare workers. Three-fourth (74.3%) of the healthcare workers involved in the current study had good knowledge towards standard precautions. Good knowledge towards standard precautions refers to scoring correct responses to > 60% of knowledge items from the survey. Year of service (AOR: 0.27, 95% CI: 0.16 to 0.44), educational status (AOR: 1.7, 95% CI: 1.13 to 2.56) were among the predictor variables. In addition, physicians were 6.97 times more likely to be knowledgeable (AOR: 6.97, 95% CI 2.42 to 20.12) than laboratory technician/technology counterparts. Study participants working in medical, Gyn/obs, pediatrics wards, and OPD were about 2.23, 4.27, 2.81 and 2.52 times more likely to be knowledgeable than study participants working in surgical ward.

Conclusions

Overall, the majority of healthcare workers had good knowledge of standard precautions. But variation in knowledge was detected across healthcare workers by hospital type and ward/units. This may help to design a solution by prioritizing the problem.
Why psychiatry is different - challenges and difficulties in managing a nosocomial outbreak of coronavirus disease (COVID-19) in hospital care
Authors: Rovers J. J. E. , van de Linde L. S. , Kenters N. , Bisseling E. M. , Nieuwenhuijse D. F. , Oude Munnink B. B. , Voss A. , Nabuurs-Franssen M.
Published: December 2020

Objective

Coronavirus disease (COVID-19) was officially declared a pandemic in March 2020. Many cases of COVID-19 are nosocomial, but to the best of our knowledge, no nosocomial outbreaks on psychiatric departments of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in Europe. The different nature of psychiatry makes outbreak management more difficult. This study determines which psychiatry specific factors contributed to a nosocomial outbreak taking place in a psychiatric department. This will provide possible interventions in future outbreak management.

Method

A case series describing a nosocomial outbreak in a psychiatric department of an acute care hospital in the Netherlands between March 13, 2020 and April, 14 2020. The outbreak was analyzed by combining data from standardized interviews, polymerase chain reaction (PCR) tests and whole genome sequencing (WGS).

Results

The nosocomial outbreak in which 43% of staff of the psychiatric department and 19% of admitted patients were involved, was caused by healthcare worker (HCW)-to-HCW transmissions, as well as patient-to-HCW-to-patient transmission. We identified four aspects associated with the mental health care system which might have made our department more susceptible to an outbreak.

Conclusions

Infection control measures designed for hospitals are not directly applicable to psychiatric departments. Psychiatric patients should be considered a high-risk group for infectious diseases and customized measures should be designed and implemented. Extra attention for psychiatric departments is necessary during a pandemic as psychiatric HCWs are less familiar with outbreak management. Clear communication and governance is crucial in correctly implementing these measures.
Breeding schemes for intervertebral disc disease in dachshunds: Is disc calcification score preferable to genotyping of the FGF4 retrogene insertion on CFA12?
Authors: Bruun Camilla Sichlau , Bruun Charlotte , Marx Tine , Proschowsky Helle Friis , Fredholm Merete
Published: December 2020

Background

Approximately every fifth Dachshund is affected by disc herniation - a painful, hereditary condition which is typically preceded by disc calcification. Therefore, the selection of dogs suitable for breeding can be based on radiographic examination of calcification status.

Recently, an insertion of an FGF4 retrogene on CFA12 has been identified and associated with the risk of developing disc herniation in chondrodystrophic breeds and a DNA test is now offered.

In this study we investigate the incidence of disc herniation in the smooth-haired, long-haired and wire- haired Dachshund populations. We also evaluate and compare the accuracy of the two breeding schemes predicting the risk of disc herniation: the DNA test and the radiography based scheme.

Results

The overall incidence of disc herniation in Danish Dachshunds was 18% and no significant difference was found between the long-haired (17%), smooth-haired (22%) and wire-haired (16%) populations (p > 0.05). We found a significant association (p <  0.0001) between calcification status and the risk of disc herniation with a relative risk of 14.78. Using calcification status (≥ 5 or <  5 calcifications) as a risk indicator has a sensitivity of 0.79 and a specificity of 0.91.

A significant association between the FGF4 retrogene insertion and the disc calcification status was found in the wire-haired population (p <  0.0001) where the DNA test has a sensitivity of 1.0 and a specificity of 0.14. In the long- and smooth-haired populations no association was found (p > 0.05) and here the insertion allele was almost fixed.

Conclusion

Our results show that the FGF4 retrogene insertion on CFA12 is not a valid risk indicator on its own. Relying on the DNA test will have an irreversible effect on the Dachshund breed excluding almost all dogs from breeding. Thus, using calcification status remains the most reliable breeding scheme for disc herniation in Dachshunds.
Exploring the factors that influence the career decision of STEM students at a university in South Africa
Authors: Abe Ethel Ndidiamaka , Chikoko Vitallis
Published: December 2020

Background

Science, Technology, Engineering, and Mathematics (STEM) educators and stakeholders in South Africa are interested in the ways STEM students make their career decisions because of the shortages in these critical skills. Although various factors including family, teachers, peers, and career interest have been reported as determinants of career decision-making, there is a scarcity of studies that have qualitatively explored the levels of influences of any of these factors in the South African context. The main aim of this study was to investigate the factors that influence career decision-making among STEM student majors in a South African university. By better understanding students’ viewpoint on these factors, educators and policymakers can assist students in making career decisions that fit their experiences, personality, and expectations. Students in their 1st, 2nd, 3rd, and 4th year of study respectively, were invited to respond to a semi-structured questionnaire about the factors that were influential in their decision to pursue a career in STEM. A total of 203 texts (response rate: 63%) were qualitatively analyzed utilising a hermeneutic phenomenology approach to traditional content analysis, whereby themes develop inductively from the data.

Results

We used a hermeneutic phenomenological method to traditional content analysis to examine the factors influencing participants’ career decision-making. Peer interrogation, modified member verification, compact description, code-recode tactics, and assessment trails were engaged to confirm quality and rigour. Three key results emerged, namely interpersonal, intrapersonal, and career outcomes expectancy. The perceptions of STEM students of their career decision-making in the South African context are more multifaceted than reported previously. The insights could inform policies to counter skills shortages in the STEM area.

Conclusions

In this exploratory study, we gave attention to describing the various ranges of students’ perceptions and experiences regarding their career decision-making. Several students reported, among other factors, that their families, personality, and expectations played influential roles in their career decision-making. Here, we discuss the meaning of interpersonal, intrapersonal, and outcome expectations with respect to career decision-making from the perspective of STEM students in a South African university.
Tauroursodeoxycholic acid attenuates neuronal apoptosis via the TGR5/ SIRT3 pathway after subarachnoid hemorrhage in rats
Authors: Wu Huihui , Yu Nini , Wang Xia , Yang Yina , Liang Hui
Published: December 2020

Background

Neuronal apoptosis plays a critical event in the pathogenesis of early brain injury after subarachnoid hemorrhage (SAH). This study investigated the roles of Tauroursodeoxycholic acid (TUDCA) in attenuate neuronal apoptosis and underlying mechanisms after SAH.

Methods

Sprague–Dawley rats were subjected to model of SAH and TUDCA was administered via the internal carotid injection. Small interfering RNA (siRNA) for TGR5 were administered through intracerebroventricular injection 48 h before SAH. Neurological scores, brain water content, Western blot, TUNEL staining and immunofluorescence staining were evaluated.

Results

TUDCA alleviated brain water content and improved neurological scores at 24 h and 72 h after SAH. TUDCA administration prevented the reduction of SIRT3 and BCL-2 expressions, as well as the increase of BAX and cleaved caspase-3.Endogenous TGR5 expression were upregulated after SAH and treatment with TGR5 siRNA exacerbated neurological outcomes after SAH and the protective effects of TUDCA at 24 h after SAH were also abolished by TGR5 siRNA.

Conclusions

Our findings demonstrate that TUDCA could attenuated neuronal apoptosis and improve neurological functions through TGR5/ SIRT3 signaling pathway after SAH. TUDCA may be an attractive candidate for anti-apoptosis treatment in SAH.
Mediation criteria for interactive serious games aimed at improving learning in children with attention deficit hyperactivity disorder (ADHD)
Authors: Coma-Roselló Teresa , Blasco-Serrano Ana Cristina , Garrido Laparte María Ángeles , Aguelo Arguis Antonio
Published: December 2020

The PASS intelligence theory (Planning, Attention-Arousal, Simultaneous and Successive) was used together with Feuerstein’s mediation model to develop a system of categories for mediation in educational games. This system was used to analyze and improve the design of interactive games that can enhance mediation in learning, particularly in children with attention deficit hyperactivity disorder (ADHD). To this end, interactive games designed for a tabletop device were evaluated within an educational context. 27 children (3–14 years old), who had been diagnosed with ADHD, took part. The tabletop has an intuitive system that allows children to interact directly with objects with which they are familiar, providing opportunities for play and communication. These games were evaluated by the participant observation of individual and group playing experiences, interviews, and two focus groups. The results show that mediation recommendations can be useful in the design of the games. They also confirm the need to improve the adaptability of the games to enable children with ADHD to mediate, plan, and focus their attention. With the aid of a facilitator, the mediating function of learning-games can therefore be applied in the development of the executive functions that are key to learning.
Impact of the penetration of distributed generation on optimal reactive power dispatch
Authors: Das Tanmay , Roy Ranjit , Mandal Kamal Krishna
Published: December 2020

Optimal reactive power dispatch (ORPD) is a complex and non-linear problem, and is one of the sub-problems of optimal power flow (OPF) in a power system. ORPD is formulated as a single-objective problem to minimize the active power loss in a transmission system. In this work, power from distributed generation (DG) is integrated into a conventional power system and the ORPD problem is solved to minimize transmission line power loss. It proves that the application of DG not only contributes to power loss minimization and improvement of system stability but also reduces energy consumption from the conventional sources. A recently proposed meta-heuristic algorithm known as the JAYA algorithm is applied to the standard IEEE 14, 30, 57 and 118 bus systems to solve the newly developed ORPD problem with the incorporation of DG. The simulation results prove the superiority of the JAYA algorithm over others. The respective optimal values of DG power that should be injected into the four IEEE test systems to obtain the minimum transmission line power losses are also provided.
Historic review: select chapters of a history of stroke
Authors: Karenberg Axel
Published: December 2020

Background

There is no shortage of books, chapters and papers on the history of stroke focusing predominantly on the last 150 years and enumerating endless “milestones”. Instead of adding another article to this body of knowledge, this essay aims at ensuring awareness for the “big picture”, the “grandes routes”, and the “striking breakes” without overloading the reader with too much detail.

Results

From a medical point of view, the history of stroke consists of two periods: the early era from the beginnings to 1812, and the following period from 1812 up to the present. It is argued that both periods require different methodical approaches, including disparate historiographical perspectives and varying forms of interpretation. In order to fully understand medical writings of the Greco-Roman era (Hippocratic writings, Galenic corpus) on “apoplexy”, a solid knowledge of ancient doctrines concerning health and disease is indispensable. During the Middle Ages, the spiritual perspective can be highlighted by focusing on miracle healing and patron saints. While stroke basically remained a conundrum for many doctors and patients in early modern times (ca. 1500–1800; Platter, Wepfer), the revolutionary perception and definition of the disease as a result of a lesion in the 1810s (Rochoux, Rostan) opened the door to a productive relationship of the upcoming discipline “neurology” with the natural sciences during the nineteenth century and beyond (Virchow et al.). The mostly unwritten history of stroke in the twentieth century should not only include the medical, but also the patient’s and the societal perspective.

Conclusion

A deeper insight into the recent and distant past will produce better educated strokologists – physicians who are able to put their own work into perspective.
Extended blood group profiles for Malays, Chinese, and Indians in Peninsular Malaysia
Authors: Hajar Che Ghazali Norul , Zefarina Zulkafli , Md. Riffin Nor Suhaila , Tuan Mohammad Tuan Hulwani , Hassan Mohd Nazri , Poonachi Prathapan , Safuan Sabreena , ElGhazali Gehad , Chambers Geoffrey Keith , Edinur Hisham Atan
Published: December 2020

Background

Blood group antigens are immunogenic polymorphic molecules presented on the surface of RBCs. This study aimed to determine extended blood group profiles (ABO, Rhesus, Kell, Kidd, Duffy, MNS, Cartwright, Dombrock, Colton, Lutheran, and Vel) in Malays, Chinese, and Indians in Peninsular Malaysia.

Results

Here, ABO Type O, DCCee, MNs, and Fy (a+b−) were the most frequent major blood group phenotypes in all three ethnic groups. Other minor blood group systems distributed differently across these ethnic groups, except for the Kell, Lutheran, Cartwright, and Vel blood group systems, where only K−k+, Lu (8+14), Yt (a+b−), and Vel (+) phenotypes were observed. Exact tests of population differentiation generally showed no significant differences between Malays included in the present study vs. other ethnically similar datasets from previous surveys. However, many significant differences were recorded in comparison between blood group datasets from ethnically unrelated populations (Malays vs. Chinese vs. Indians) especially for Rhesus, Kidd, and Duffy blood group systems. A Principal component analysis (PCA) plot showed that population groups from the Peninsular Malaysia map closely together as compared with population groups from other geographical regions.

Conclusions

Overall, our present study has successfully provided an extended blood group profiles for Malays, Chinese, and Indians in Peninsular Malaysia. These new blood group datasets can be used as guidelines for donor recruitment and as reference standards for studying diseases associated with blood group systems.
Introduction to this special section: Geothermal energy
Authors: Kaven J. O. , Templeton D. C. , Bathija Arpita P.
Published: December 2020

Geothermal energy is a global renewable resource that has the potential to provide a significant portion of baseload energy in many regions. In the United States, it has the potential to provide 8.5% of the electric generation capacity by the middle of the century. In general, geothermal systems require heat, permeability, and water to be viable for energy generation. However, with current technologies, only heat is strictly necessary in a native system. Engineered geothermal systems (EGS) introduce water into the subsurface at elevated pressures and reduced temperatures and enhance permeability through hydraulic and/or shear fracturing. Additionally, although moderate- to high-temperature resources currently dominate geothermal energy production, low-temperature resources have been utilized for direct-use cases. When well balanced and maintained, geothermal resources can produce significant amounts of heat and achieve long-term sustainability on the order of an estimated tens to hundreds of years.
Reviews
Authors: Bartel David
Published: December 2020

• Shale: Subsurface Science and Engineering, by Thomas Dewers, Jason Heath, and Marcelo Sánchez, ISBN 978-1-119-06668-2, 2019, American Geophysical Union and Wiley, 320 p.
Sec71 separates Golgi stacks in Drosophila S2 cells
Authors: Fujii Syara , Kurokawa Kazuo , Tago Tatsuya , Inaba Ryota , Takiguchi Arata , Nakano Akihiko , Satoh Takunori , Satoh Akiko K.
Published: December 2020

Golgi stacks are the basic structural units of the Golgi. Golgi stacks are separated from each other and scattered in the cytoplasm of Drosophila cells. Here, we report that the ARF-GEF inhibitor Brefeldin A (BFA) induces the formation of BFA bodies, which are aggregates of Golgi stacks, trans-Golgi networks and recycling endosomes. Recycling endosomes are located in the centers of BFA bodies, while Golgi stacks surround them on their trans sides. Live imaging of S2 cells revealed that Golgi stacks repeatedly merged and separated on their trans sides, and BFA caused successive merger by inhibiting separation, forming BFA bodies. S2 cells carrying genome-edited BFA-resistant mutant Sec71M717L did not form BFA bodies at high concentrations of BFA; S2 cells carrying genome-edited BFA-hypersensitive mutant Sec71F713Y produced BFA bodies at low concentrations of BFA. These results indicate that Sec71 is the sole BFA target for BFA body formation and controls Golgi stack separation. Finally, we showed that impairment of Sec71 in fly photoreceptors induces BFA body formation, with accumulation of both apical and basolateral cargoes, resulting in inhibition of polarized transport.
Biphasic regulation of glutamine consumption by WNT during osteoblast differentiation
Authors: Shen Leyao , Sharma Deepika , Yu Yilin , Long Fanxin , Karner Courtney
Published: December 2020

Osteoblasts are the principal bone forming cells. As such, osteoblasts have enhanced demand for amino acids to sustain high rates of matrix synthesis associated with bone formation. The precise systems utilized by osteoblasts to meet these synthetic demands are not well understood. WNT signaling is known to rapidly stimulate glutamine uptake during osteoblast differentiation. Using a cell biology approach, we identified two amino acid transporters, Slc7a7 and Slc1a5, as the primary transporters of glutamine in response to WNT. Slc1a5 mediates the majority of glutamine uptake, whereas Slc7a7 mediates the rapid increase in glutamine uptake in response to WNT. Mechanistically, WNT signals through the canonical/β-catenin dependent pathway to rapidly induce Slc7a7 expression. Conversely, Slc1a5 expression is regulated by the transcription factor ATF4 downstream of the mTORC1 pathway. Targeting either Slc1a5 or Slc7a7 using shRNA reduced WNT induced glutamine uptake and prevented osteoblast differentiation. Collectively these data highlight the critical nature of glutamine transport for WNT induced osteoblast differentiation.
What Do Survey Data Tell Us about US Businesses?
Authors: Bhandari Anmol , Birinci Serdar , McGrattan Ellen R. , See Kurt
Published: December 2020

This paper examines the reliability of survey data on business incomes, valuations, and rates of return, which are key inputs for studies of wealth inequality and entrepreneurial choice. We compare survey responses of business owners with available data from administrative tax records, brokered private business sales, and publicly traded company filings and document problems due to nonrepresentative samples and measurement errors across several surveys, subsamples, and years. We find that the discrepancies are economically relevant for the statistics of interest. We investigate reasons for these discrepancies and propose corrections for future survey designs. (JEL C82, C83, D22)
Efficiency, Justified Envy, and Incentives in Priority-Based Matching
Authors: Abdulkadiroǧlu Atila , Che Yeon-Koo , Pathak Parag A. , Roth Alvin E. , Tercieux Olivier
Published: December 2020

Top trading cycles (TTC) is Pareto efficient and strategy-proof in priority-based matching, but so are other mechanisms including serial dictatorship. We show that TTC minimizes justified envy among all Pareto-efficient and strategy-proof mechanisms in one-to-one matching. In many-to-one matching, TTC admits less justified envy than serial dictatorship in an average sense. Empirical evidence from New Orleans OneApp and Boston Public Schools shows that TTC has significantly less justified envy than serial dictatorship. (JEL C78, D61)
Invisible Geniuses: Could the Knowledge Frontier Advance Faster?
Authors: Agarwal Ruchir , Gaule Patrick
Published: December 2020

A better understanding of the determinants of idea/knowledge production remains critical for long-run growth. Toward this end, this paper establishes two results using data from the International Mathematical Olympiad (IMO). First, individuals who excelled in teenage years are especially capable of advancing the knowledge frontier. Second, such talented individuals born in poorer countries are systematically less likely to engage in knowledge production. IMO participants from low-income countries produce 34 percent fewer publications and 56 percent fewer citations than equally talented rich-country counterparts. Policies to encourage talented youth to pursue scientific careers—especially those from poorer countries—could advance the knowledge frontier faster. (JEL D83, O30, O47)
Find the ‘golden thread’ in the natural world
Authors: Solly Kathryn
Published: December 2020

Frobelian Margaret Hutchinson (1904 – 1997) developed an ethos for learning linked to the natural world which Kathryn Solly finds powerful and relevant today.
Listen carefully
Authors: Hewson Claire
Published: December 2020

Communication and language skills facilitate deep learning. Without it children cannot make connections between what is already known, apply their learning in different ways or relate it to other experiences.
CH and NO planar laser-induced fluorescence and Rayleigh-scattering in turbulent flames using a multimode optical parametric oscillator
Authors: Miller Joseph D. , Tröger Johannes W. , Engel Sascha R. , Seeger Thomas , Leipertz Alfred , Meyer Terrence R.
Published: December 2020

An optical parametric oscillator (OPO) is developed and characterized for the simultaneous generation of ultraviolet (UV) and near-UV nanosecond laser pulses for the single-shot Rayleigh scattering and planar laser-induced-fluorescence (PLIF) imaging of methylidyne (CH) and nitric oxide (NO) in turbulent flames. The OPO is pumped by a multichannel, 8-pulse Nd:YAG laser cluster that produces up to 225 mJ/pulse at 355 nm with pulse spacing of 100 µs. The pulsed OPO has a conversion efficiency of 9.6% to the signal wavelength of

∼

430

n
m

when pumped by the multimode laser. Second harmonic conversion of the signal, with 3.8% efficiency, is used for the electronic excitation of the A-X (1,0) band of NO at

∼

215

n
m

, while the residual signal at 430 nm is used for direct excitation of the A-X (0,0) band of the CH radical and elastic Rayleigh scattering. The section of the OPO signal wavelength for simultaneous CH and NO PLIF imaging is performed with consideration of the pulse energy, interference from the reactant and product species, and the fluorescence signal intensity. The excitation wavelengths of 430.7 nm and 215.35 nm are studied in a laminar, premixed

C
H

4

−

H

2

−

N
H

3

–air flame. Single-shot CH and NO PLIF and Rayleigh scatter imaging is demonstrated in a turbulent

C
H

4

−

H

2

−

N
H

3

diffusion flame using a high-speed intensified CMOS camera. Analysis of the complementary Rayleigh scattering and CH and NO PLIF enables identification and quantification of the high-temperature flame layers, the combustion product zones, and the fuel-jet core. Considerations for extension to simultaneous, 10-kHz-rate acquisition are discussed.
Optimized high-speed all-optical 2-bit ADCbased on two-dimensional photonic crystal nanoresonators
Authors: Taheri Afshin , Seifouri Mahmood , Olyaee Saeed
Published: December 2020

In the present paper, a new 2-bit analog-to-digital converter (ADC) was
designed and simulated by using 2D photonic crystal (PC) structures to
create a relatively faster and smaller structure. For this purpose, a
PC structure with a square lattice and silicon rods in the air bed was
used. In the proposed structure, a combination of an optical filter
with a linear waveguide, optical nanoresonators, and interference
effects was used to create a 2-bit ADC. To create a structure in
optimal conditions with maximum output optical power, the size of
nanoresonators was scanned to reach the best size. The proposed
structure operated at the operating wavelength of 1550 nm with a
response time of about 1.63 ps, a sampling rate of about 613 GS/s, and
a resolution sampling rate product (RSRP) value of about 2453 ks.
Additionally, the size of the structure was about

194

µ

m

2

, which is small compared with other
structures proposed in this field; it also enjoys high simplicity and
flexibility like structures with other functions, including 4-bit
converters. The amount of power used to create different logic states
was at the rate of

m
W

/

µ

m

2

, which is much lower than the amount
used in similar structures and is achieved using nonlinear effects and
materials. Therefore, due to the excellent results obtained, this
structure is recommended to be used in optical integrated circuits.
The plane wave expansion method was used to extract the photonic
bandgap, and the finite-difference time-domain method was used to
obtain the results related to the output spectrum of the designed
structures.
Steering of quantum signals along coupled paths of arbitrary curvature
Authors: Valagiannopoulos Constantinos
Published: December 2020

Quantum engineering, as a field of research, is currently attracting a huge scientific, funding, and commercial interest. A generic operation behind most of the related device setups is the efficient steering of quantum signals, by channeling or coupling them with specified intensities, to various spatial sections. This work provides several alternative material combinations for a planar guiding configuration, able to squeeze matter waves into tiny apertures while being maximally apt to evanescently couple them. It is also shown that the proposed designs can work under arbitrary curvature by supporting proper resonances, resulting in propagating or standing-wave patterns around them. The signal interaction between straight semiconducting wires and circular rings is demonstrated in layouts that can be used in a variety of components: from beam splitters and quantum memory elements to matter-wave transformers and quantum circuits.
Mode-splitting in a microring resonator for self-referenced biosensing
Authors: de Goede M. , Dijkstra M. , Chang L. , Acharyya N. , Kozyreff G. , Obregón R. , Martínez E. , García-Blanco S. M.
Published: December 2020

Self-referenced biosensing based on mode-splitting on a microring resonator is experimentally demonstrated. A Bragg grating integrated on the surface of the ring provides coupling between the clockwise and counterclockwise travelling modes of the pristine ring resonator lifting their degeneracy. The amount of mode-splitting is directly related to the reflectivity of the grating and it is only affected by structurally modifying the grating. Environmental perturbations to the surroundings of the gratings, such as temperature and bulk refractive index variations, have a minor effect on the amount of mode-splitting. This principle allows the realization of a self-referenced sensing scheme based on the detection of variations of the mode-splitting induced by structural changes to the grating. In this work, a polymethyl methacrylate (PMMA) Bragg grating is integrated onto a ring resonator in Al2O3. It is shown both theoretically and experimentally that the amount of splitting of a resonance varies minimally under temperature or bulk refractive index perturbations. However, the structural change of attaching a layer of biomolecules inside the grating does affect its reflectivity and the amount of mode splitting present. This result represents the first proof-of-concept demonstration of an integrated mode-splitting biosensor insensitive to temperature and refractive index variations of the liquid matrix where the molecules to be detected are embedded. The reported results pave the road towards the realization of truly self-referenced biosensors.
Photonic 2-D angle-of-arrival estimation based on an L-shaped antenna array for an early radar warning receiver
Authors: Lin Tao , Zhang Zhike , Wang Yuehui , Zhu Zihang , Zhao Shanghong , Liu Jianguo , Jiang Wei , Wu Guozhang
Published: December 2020

Early radar warning is a significant step to lessen the fine scanning range of a receiver. The small size two-dimension (2-D) angle-of-arrival (AOA) estimation part with moderate accuracy and sensitivity is important for an early radar warning receiver. In our method, we specially design an L-shaped antenna array (L-sAA) and connect it with dual-polarization binary phase shift keying modulator (DP-BPSKM). The dual-sideband (DSB) modulation is performed to transfer most of the optical power to electrical, so as to increase the sensitivity. It is also possible to map the AOA information of the incoming beam to photo-detected electrical power without a high extinction ratio modulator or optical filter. During the estimation, the 2-D AOA is firstly measured, whose measurement range is 18.22°∼90° and the measurement error is lower than 1°. Then, based on the 2-D AOA estimation results, the third one is mathematically calculated to construct 3-D location of the target. Noteworthy, the amplitude comparison function (ACF) is adopted in this method to make the system response irrelative to the received signal power, which endows the system with signal power fluctuation immunity. Experimental results show that this method is capable of measuring a single-tone signal and a bandwidth signal. This structure is very concise and meets the potential of on-chip integration.