bluuebunny/crossref_metadata_2025 huggingface dataset:
Educational analytics in distance learning: application features and development prospects
Authors: Car'kova Evgeniya
Published: March 2022

The article discusses aspects of the application of educational analytics, which is currently an actual scientific and technical direction, to improve the effectiveness of the educational process in the professional training of university students. Due to the widespread use of modern information technologies, which continue to develop and become an important part of a person's daily life, it is natural to pay increasing attention to determining the areas of application of these technologies, including for improving the activities of educational organizations. The use of educational analytics in universities serves as an important prerequisite for building high-quality systems for analyzing "digital traces" of students in electronic educational environments (EE), allowing them to make reliable forecasts, solve problems of classification and clustering of EE users, establish non-obvious dependencies between events and phenomena, and offer recommendations for improving the methods and approaches used in the learning process.

Considerable attention is paid to the consideration of the specifics of the use of various types of data sources that can be used when analyzing the behavior of students in the learning process.

Along with the enumeration of the undeniable advantages of using educational analytics, the problem of staffing in educational organizations is identified, which prevents its widespread use. The author suggests ways to solve this problem, including through the development and implementation of special programs of additional professional education in the field of data analysis.

Based on the review of scientific literature and his own pedagogical experience, the author notes the barriers hindering the widespread introduction of educational analytics tools into the activities of educational organizations, and formulates recommendations on the selection and use of tools when conducting data mining in electronic educational environments.
Involving foreign-language speaking simulated patients in medical interpreter training: A qualitative study
Authors: Van De Walle Céline , De Wilde July , Van Praet Ellen
Published: March 2022

This paper reports on an interdisciplinary training initiative involving student interpreters and medical students. It provides qualitative evidence on how the stakeholders involved perceive the effects of including foreign-language speaking simulated patients (SPs) in medical interpreter training. We conducted three focus group interviews, during which we explored the perspectives of different stakeholders involved in the interdisciplinary training. The first focus group involved three clinical communication trainers and four interpreter trainers, the second focus group comprised eight student interpreters and the third focus group involved three SPs. The data was analysed using NVivo 12 software. The results reveal that the presence of foreign-language speaking SPs generated an increased level of authenticity, a higher degree of affective social distance, an increased interactional and linguistic complexity, increased (language) learning potential and an increased level of stress vis à vis regular interpreting classes in which traditional role plays were used. All stakeholders deem working with foreign-language speaking SPs highly beneficial, as the added value and advantages of working with SPs outweighed the disadvantages.
Multiple Volatility Real Options Approach to Investment Decisions Under Uncertainty
Authors: Chandra Atul , Hartley Peter R. , Nair Gopalan
Published: March 2022

We present a novel multiple volatility real options approach (MVR) to value investment projects with embedded flexibility and affected by multiple uncertainties. A core innovation is the MVR decision tree composed of MVR synthetic tree components, each reflecting a unique binomial process that approximates a geometric Brownian motion of project value induced by one uncertainty source. MVR uses Monte Carlo simulation to generate volatility of project value log-returns arising from each uncertainty source. MVR produces a multidimensional surface, which is hidden in other approaches, representing enhanced net present value (ENPV) as a function of each uncertainty. It allows the impact of each uncertainty’s volatility on ENPV to be measured through three MVR sensitivity analysis levers. To illustrate MVR, it is applied to a real-world investment project, revealing that MVR provides a more accurate valuation than alternative approaches that do not account for separate impacts of each uncertainty. MVR with its greater veracity, provides robust investment decisions through MVR decision rules.
Dynamic Relaxations for Online Bipartite Matching
Authors: Torrico Alfredo , Toriello Alejandro
Published: March 2022

Online bipartite matching (OBM) is a fundamental model underpinning many important applications, including search engine advertisement, website banner and pop-up ads, and ride hailing. We study the independent and identically distributed (i.i.d.) OBM problem, in which one side of the bipartition is fixed and known in advance, whereas nodes from the other side appear sequentially as i.i.d. realizations of an underlying distribution and must immediately be matched or discarded. We introduce dynamic relaxations of the set of achievable matching probabilities; show how they theoretically dominate lower dimensional, static relaxations from previous work; and perform a polyhedral study to theoretically examine the new relaxations’ strength. We also discuss how to derive heuristic policies from the relaxations’ dual prices in a similar fashion to dynamic resource prices used in network revenue management. We finally present a computational study to demonstrate the empirical quality of the new relaxations and policies.

Summary of Contribution: Online bipartite matching (OBM) is one of the fundamental problems in the area of online decision analysis with a wide variety of applications in operations research and computer science, for example, online advertising, ride sharing, and general resource allocation. Over the last decades, both communities have been interested in the design and analysis of new approaches. Our main contribution is to provide a polyhedral study that considers the problem’s sequential nature. Specifically, we achieve this via dynamic relaxations. We also discuss how to derive heuristic policies from the relaxations’ dual prices. We support our theoretical findings with a detailed computational study.
Exact Algorithms for Maximum Lifetime Data-Gathering Tree in Wireless Sensor Networks
Authors: Casazza Marco , Ceselli Alberto
Published: March 2022

We tackle an optimization problem arising in the design of sensor networks: given a set of sensors, only one being connected to a backbone, to establish connection routes from each of them to the sink. Under a shortest path routing protocol, the set of connections form a spanning tree. Energy is required to transmit and receive data, and sensors have limited battery capacity: as soon as one sensor runs out of battery, a portion of the network is disconnected. We, therefore, search for the spanning tree maximizing the time elapsed before such a disconnection occurs, and therefore, maintenance is required. We propose new mathematical formulations for the problem, proving and exploiting theoretical results on its combinatorial structure. On that basis, we design algorithms offering a priori guarantees of global optimality. We undertake an extensive experimental campaign, showing our algorithms to outperform previous ones from the literature by orders of magnitude. We also identify which instance features have higher impact on network lifetime.
Lender Trust and Bank Loan Contracts
Authors: Hagendorff Jens , Lim Sonya , Nguyen Duc Duy
Published: March 2022

We examine the contractual implications of a lender’s trust for corporate loans. We measure how trusting a lender is using the average trust attitude in the chief executive officer’s ancestral country of origin. We find that banks with trusting CEOs charge lower interest rates in U.S. syndicated loans. This effect is identified within existing lender–borrower relationships and similar types of loans. Further analyses indicate that trust reduces the cost of credit by boosting the perceived credibility of borrower information and by mitigating contracting problems. We corroborate our findings by conducting a survey of loan officers with experience in loan syndication.

This paper was accepted by Gustavo Manso, finance.

Supplemental Material: The internet appendix and data are available at https://doi.org/10.1287/mnsc.2022.4371 .
Explaining the Failure of the Unconditional CAPM with the Conditional CAPM
Authors: Hasler Michael , Martineau Charles
Published: March 2022

When the cost of hedging is nil, the conditional capital asset pricing model (CAPM) holds. We empirically test the conditional CAPM by regressing asset returns onto the product of their conditional betas and market returns. Estimated intercepts are not statistically different from zero, implying that the conditional CAPM successfully explains the conditional level of asset returns. Yet, unconditional betas do not explain the cross section of average asset returns; the unconditional CAPM fails. We show why and how the success of the conditional CAPM actually explains the failure of the unconditional CAPM, thereby rationalizing the coexistence of these two intriguing results.

This paper was accepted by Gustavo Manso, finance.

Funding: The University of Texas at Dallas and the University of Toronto provided financial support.

Supplemental Material: The data files and online appendix are available at https://doi.org/10.1287/mnsc.2022.4381 .
Is Adopting Mass Customization a Path to Environmentally Sustainable Fashion?
Authors: Alptekinoğlu Aydın , Örsdemir Adem
Published: March 2022

Problem definition: In high-product-variety businesses like fashion, mass production (MP) systems create environmental waste in the form of overproduction on a colossal scale. Mass customization (MC) has been proposed—without solid evidence—as a solution. In this paper, we analyze whether MC can indeed offer a win-win solution that helps both the bottom line and the environment. We also study the impact of three real policy options: promoting MC, charging a disposal fee for overproduction, and recycling. Academic/practical relevance: There is increasing interest in mass-customizing fashion goods, not only because consumers value customization, but also because MC is perceived to be environmentally friendly. Our paper puts this advocacy for MC to the test. We contribute to the literature, which has been largely silent on the issue, by uncovering when MC offers a win-win and relating such market outcomes to policy ideas. Methodology: We develop an analytical model of an MP firm adopting MC (going hybrid). The firm’s profit-maximizing variety, price, and inventory decisions then form the basis of our understanding the environmental impact of adopting MC and assessing various policy options. Results: Adopting MC can be a win-win, but it can also increase overproduction and hurt the environment. Our policy analyses reveal two kinds of insights. The first kind is about whether a policy expands win-win outcomes—encouraging sustainable adoption of MC. Among the policy ideas we explore, only promoting MC so as to increase consumers’ tolerance for waiting for mass-customized products can do that unambiguously. The second kind of insight is about whether a policy reduces the hybrid firm’s environmental impact. Only a disposal fee and costly recycling programs can do that unambiguously. Managerial implications: For MC adoption to be a win-win, policy makers must (1) work on convincing consumers to wait for bespoke fashion; (2) target MP firms with low cost of variety (high product-mix flexibility) with disposal fees or costly recycling programs; and (3) encourage those with relatively higher cost of variety to develop/acquire technology that would make recycling profitable.

History: This paper has been accepted for the Manufacturing & Service Operations Management Special Section on Responsible Research in Operations Management.

Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2022.1088 .
A Branch-and-Price-and-Cut Algorithm for the Vehicle Routing Problem with Two-Dimensional Loading Constraints
Authors: Zhang Xiangyi , Chen Lu , Gendreau Michel , Langevin André
Published: March 2022

The vehicle routing problem with two-dimensional loading constraints (2L-CVRP) is a practical variant of the classic capacitated vehicle routing problem. A number of algorithms have been developed for the problem, but it is very difficult for the existing exact methods to optimally solve instances featuring with large rectangular items. To address this issue, a branch-and-price-and-cut (BPC) algorithm is proposed in this study. A novel data structure and a new dominance rule are developed to build an exact pricing algorithm that takes the loading constraints into account. Several valid inequalities are used to strengthen the linear relaxation. Extensive computational experiments were conducted on the benchmark instances of the 2L-CVRP, showing that the BPC algorithm outperforms all the existing exact methods for the problem in terms of the solution quality. Fourteen instances are solved to optimality for the first time. In particular, the size of solvable instances with large items is nearly doubled. Moreover, managerial insights about the impact of respecting the last-in-first-out constraint are also obtained.
Spring poisoning hazards for pets
Authors: Bates Nicola
Published: March 2022

Warmer weather in the spring may encourage owners and their animals to spend more time outdoors where pets may be exposed to garden products and spring plants. Ingestion of common spring flowering plants, such as tulips, primrose, hyacinth, snowdrops, grape hyacinth, spring crocus, bluebells and daffodil, often cause gastrointestinal signs in pets. Severe poisoning is uncommon but there is a risk of more pronounced clinical signs in some cases and ingestion of plant bulbs may cause gastrointestinal obstruction. Similarly, ingestion of fertiliser may cause gastrointestinal signs and ingestion of bone meal is a potential obstruction risk. Plants containing grayanotoxins, such as Rhododendron and Pieris species cause gastrointestinal and potentially cardiac effects. Patio cleaners and disinfectants containing cationic detergents such as benzalkonium chloride or didecyldimethylammonium chloride, are a particular risk to pets, especially cats. They are usually exposed after walking over a treated surface and then grooming, presenting hours later with salivation, hyperthermia and oral injury. Treatment of pets with clinical signs after exposure to a spring poisoning hazard is supportive.
Surgical safety checklists from concept to implementation
Authors: Ebeck Liza
Published: March 2022

With the availability of free, readily downloadable surgical safety checklists from various websites the checklist has become accessible for any practice wishing to implement it. There is now a good research base into how the surgical safety checklist can work in veterinary practice and this article will help you to choose, adapt and implement the checklist into your practice in a streamlined and professional manner. Ultimately the goal is to improve communication of the teams involved, provide consistency of standards, improve patient safety, reduce the instance of errors and improve morbidity and mortality rates.
Zarządzanie różnorodnością w organizacji
Authors: Szejniuk Aleksandra , Michalski Konrad
Published: March 2022

In the face of rapid changes, modern organizations must be ready for the development of technology and changes related to the globalization process in the world. The result of these changes is a shift from managing monocultural organizations to managing multicultural organizations. Migration processes are the cause of the growth of cultural diversity in enterprises. It is the result of aging societies as well as changes in corporate structures. Diversity also means division according to sex, age, skin color, etc. It can also refer to physical and mental abilities as well as religion. The introduction of the concept of diversity management is a requirement of the modern world. Especially with regard to human resource management and the accompanying social and economic processes. This is a requirement of the modern world. Currently, the market forces organizations to be open. Enterprises should create such working conditions that each employee celebrates the comfort of fulfilling professional duties. So that he can develop his potential. Managing diversity should be characterized by actual care for the employees of the organization because they are the source of its success. Enterprises operating in the conditions of constant changes should react and verify strategic goals in order not only to survive but also constantly develop. Moreover, they must implement innovations in all areas of their activity. It is extremely important to adapt the organizational structure to the current market situation. It is also important to understand diversity in the conditions of the enterprise. If it is properly managed, it should bring benefits to the organization. It is important to take into account the requirements and needs of both employees and customers. These activities should become a norm or even a standard in order to build a competitive advantage of an organization.
Bezpieczeństwo jako nowe wyzwanie w usługach – ochrona w czasie i po kryzysie
Authors: Kamiński Jacek
Published: March 2022

The COVID-19 pandemic has made security a central challenge in the service sector. It applies equally to customers and employees of service organizations. The article discusses the sources of security threats in services in connection with the COVID-19 pandemic, which result from the feature of services, which is the interactivity of services and activities carried out to increase the level of security in services.
Koronaobligacje a zrównoważony rozwój w Polsce
Authors: Sitek Paweł
Published: March 2022

The period of the pandemic in Poland and in the world created new, sudden challenges for public authorities. At the same time, the public’s attention was paid primarily to health issues and ways of protection against the pandemic. From the very beginning of the pandemic in Poland, i.e. from March 2020. a concept, unknown in Poland, was created to finance the government’s tasks by issuing bonds, the state-owned company PFR S.A. and financing them by the NBP. At the same time, the public space in Poland has been saturated with information that other recognized economies of the world have applied analogous solutions as did Poland. This is a confusion of reality. When treating the subject of this study honestly, it should be emphasized that the basis of the inflation targeting law and the status quo of the Japanese central bank, the ECB and the Fed differ significantly. In each of the above-mentioned areas, there are other external and internal factors shaping the price level. And what is also important, in each of the above-mentioned areas, there is a well-established and continued legal culture of interpretation of system regulations. Poland cannot be compared in any of the above-mentioned areas. In Poland, the crown bonds were financed by the NBP, bypassing the constitutional ban on financing the state budget. At the same time, the actions taken and carried out by the National Bank of Poland regarding “koronaobligacje” reveal that the NBP, departing from its cardinal task, does not see inflationary threats in Poland, which affects the sustainable development and security of the future generation of Poles.
Annular illumination in 2D quantitative phase imaging: a systematic evaluation
Authors: Kulkarni Pranav P. , Bao Yijun , Gaylord Thomas K.
Published: March 2022

Quantitative phase imaging (QPI) is an invaluable microscopic technology for definitively imaging phase objects such as biological cells and optical fibers. Traditionally, the condenser lens in QPI produces disk illumination of the object. However, it has been realized by numerous investigators that annular illumination can produce higher-resolution images. Although this performance improvement is impressive and well documented, the evidence presented has invariably been qualitative in nature. Recently, a theoretical basis for annular illumination was presented by Bao et al. [Appl. Opt. 58, 137 (2019)APOPAI0003-693510.1364/AO.58.000137]. In our current work, systematic experimental QPI measurements are made with a reference phase mask to rigorously document the performance of annular illumination. In both theory and experiment, three spatial-frequency regions are identified: low, mid, and high. The low spatial-frequency region response is very similar for disk and annular illumination, both theoretically and experimentally. Theoretically, the high spatial-frequency region response is predicted to be much better for the annular illumination compared to the disk illumination––and is experimentally confirmed. In addition, the mid-spatial-frequency region response is theoretically predicted to be less for annular illumination than for disk illumination. This theoretical degradation of the mid-spatial-frequency region is only slightly experimentally observed. This bonus, although not well understood, further elevates the performance of annular illumination over disk illumination.
3D time-lapse imaging of a mouse embryo using intensity diffraction
tomography embedded inside a deep learning framework
Authors: Pierré William , Hervé Lionel , Paviolo Chiara , Mandula Ondrej , Remondiere Vincent , Morales Sophie , Grudinin Sergei , Ray Pierre F. , Dhellemmes Magali , Arnoult Christophe , Allier Cédric
Published: March 2022

We present a compact 3D diffractive microscope that can be inserted directly in a cell incubator for long-term observation of developing organisms. Our setup is particularly simple and robust, since it does not include any moving parts and is compatible with commercial cell culture containers. It has been designed to image large specimens (

>

100
×
100
×
100

µ

m

3

) with subcellular resolution. The sample’s optical properties [refractive index (RI) and absorption] are reconstructed in 3D from intensity-only images recorded with different illumination angles produced by an LED array. The reconstruction is performed using the beam propagation method embedded inside a deep-learning network where the layers encode the optical properties of the object. This deep neural network is trained for a given multiangle intensity acquisition. After training, the weights of the neural network deliver the 3D distribution of the optical properties of the sample. The effect of spherical aberrations due to the sample holder/air interfaces are taken into account in the forward model. Using this approach, we performed time-lapse 3D imaging of preimplantation mouse embryos over six days. Images of embryos from a single cell (low-scattering regime) to the blastocyst stage (highly scattering regime) were successfully reconstructed. Due to its subcellular resolution, our system can provide quantitative information on the embryos’ development and viability. Hence, this technology opens what we believe to be novel opportunities for 3D label-free live-cell imaging of whole embryos or organoids over long observation times.
Cantilevered adaptive fiber-optics collimator based on piezoelectric bimorph actuators
Authors: Ma Yanxing , Luo Gen , He Shuyue , Chen Zilun , Su Rongtao , Ma Pengfei , Zhou Pu , Si Lei
Published: March 2022

A novel, to the best of our knowledge, cantilever construction design of an adaptive fiber-optics collimator (AFOC) based on piezoelectric bimorph actuators for tip/tilt control is introduced. With this new cantilever structure, an AFOC with a diameter of only 6 mm was developed, and the output laser beam deviation angle and resonance frequency of the device were measured. The experimental results show that this new AFOC can provide more than 1 mrad deflection angle at a 20 V driving voltage, and the first resonance frequency is about 500 Hz. Further, in order to verify whether the cantilever structure can be used in a high-power fiber collimator, a high-power

X

−

Y

positioner with an 8 mm diameter fiber end cap was developed. The experimental results show that the high-power

X

−

Y

positioner can output more than 2 kW laser power and provide about 330 µm displacement of the fiber end cap in the

X

direction and about 770 µm in the

Y

direction at a 150 V driving voltage.
Wavelength-dependence reduction of the scale factor for tactical-grade fiber optic gyroscopes
Authors: Kong Linghai , Zhang Chunxi , Zheng Yue , Wang Xiaxiao
Published: March 2022

Fiber optic gyroscopes (FOGs) suffer from the scale-factor inaccuracy induced by the wavelength instability of the broadband source, which remains a bottleneck both in theory and in practical application. In this work, we propose a simple but effective technique for reducing the wavelength dependence of the scale factor by employing the size of the digital-ramp register as the actuator in the closed-loop scheme for nulling the ramp-reset-induced errors, instead of the conventionally-used feedback-chain gain. Experiments show that, for the tactical-grade FOG equipped with the super-luminescent diode (SLD) operating under temperatures from −40 °C to +60 °C, the proposed technique reduces the compensated scale-factor inaccuracy to 282 ppm, with respect to 2065ppm in the conventional case. This technique relaxes the stringent requirements on the wavelength stability of SLDs, which contributes to the large-scale production and application of tactical-grade FOGs.
Universal calibration for a ring camera array based on a rotational target
Authors: Ge Pengxiang , Wang Yonghong , Wang Biao
Published: March 2022

Panoramic dynamic and static measurements of objects in the application of vision measurement are difficult due to the constraints of a camera field of view and multicamera calibration technology. This paper proposes a universal global calibration method for ring multicamera systems based on rotating target and multi-view vision technology. This method uses a rotating target to establish the relationship between ring multi-camera arrays, retrieves the coordinates of the target corners from the fields of view of different cameras, and combines them with the rotation angle to complete the coordinate unification of the system. The unification of coordinates is unaffected by the overlapping fields of view between cameras, and the number of cameras can be configured arbitrarily. The calibration accuracy, validity, and precision of the proposed method are verified through reprojection error, dynamic tensile test, and 3D reconstruction.
Interactions between sensory prediction error and task error during implicit motor learning
Authors: Tsay Jonathan S. , Haith Adrian M. , Ivry Richard B. , Kim Hyosub E.
Published: March 2022

Implicit motor recalibration allows us to flexibly move in novel and changing environments. Conventionally, implicit recalibration is thought to be driven by errors in predicting the sensory outcome of movement (i.e., sensory prediction errors). However, recent studies have shown that implicit recalibration is also influenced by errors in achieving the movement goal (i.e., task errors). Exactly how sensory prediction errors and task errors interact to drive implicit recalibration and, in particular, whether task errors alone might be sufficient to drive implicit recalibration remain unknown. To test this, we induced task errors in the absence of sensory prediction errors by displacing the target mid-movement. We found that task errors alone failed to induce implicit recalibration. In additional experiments, we simultaneously varied the size of sensory prediction errors and task errors. We found that implicit recalibration driven by sensory prediction errors could be continuously modulated by task errors, revealing an unappreciated dependency between these two sources of error. Moreover, implicit recalibration was attenuated when the target was simply flickered in its original location, even though this manipulation did not affect task error – an effect likely attributed to attention being directed away from the feedback cursor. Taken as a whole, the results were accounted for by a computational model in which sensory prediction errors and task errors, modulated by attention, interact to determine the extent of implicit recalibration.
Dissecting mutational allosteric effects in alkaline phosphatases associated with different Hypophosphatasia phenotypes: An integrative computational investigation
Authors: Xiao Fei , Zhou Ziyun , Song Xingyu , Gan Mi , Long Jie , Verkhivker Gennady , Hu Guang
Published: March 2022

Hypophosphatasia (HPP) is a rare inherited disorder characterized by defective bone mineralization and is highly variable in its clinical phenotype. The disease occurs due to various loss-of-function mutations inALPL, the gene encoding tissue-nonspecific alkaline phosphatase (TNSALP). In this work, a data-driven and biophysics-based approach is proposed for the large-scale analysis ofALPLmutations-from nonpathogenic to severe HPPs. By using a pipeline of synergistic approaches including sequence-structure analysis, network modeling, elastic network models and atomistic simulations, we characterized allosteric signatures and effects of theALPLmutations on protein dynamics and function. Statistical analysis of molecular features computed for theALPLmutations showed a significant difference between the control, mild and severe HPP phenotypes. Molecular dynamics simulations coupled with protein structure network analysis were employed to analyze the effect of single-residue variation on conformational dynamics of TNSALP dimers, and the developed machine learning model suggested that the topological network parameters could serve as a robust indicator of severe mutations. The results indicated that the severity of disease-associated mutations is often linked with mutation-induced modulation of allosteric communications in the protein. This study suggested thatALPLmutations associated with mild and more severe HPPs can exert markedly distinct effects on the protein stability and long-range network communications. By linking the disease phenotypes with dynamic and allosteric molecular signatures, the proposed integrative computational approach enabled to characterize and quantify the allosteric effects ofALPLmutations and role of allostery in the pathogenesis of HPPs.
Meiotic, genomic and evolutionary properties of crossover distribution in Drosophila yakuba
Authors: Pettie Nikale , Llopart Ana , Comeron Josep M.
Published: March 2022

The number and location of crossovers across genomes are highly regulated during meiosis, yet the key components controlling them are fast evolving, hindering our understanding of the mechanistic causes and evolutionary consequences of changes in crossover rates.Drosophila melanogasterhas been a model species to study meiosis for more than a century, with an available high-resolution crossover map that is, nonetheless, missing for closely related species, thus preventing evolutionary context. Here, we applied a novel and highly efficient approach to generate whole-genome high-resolution crossover maps inD.yakubato tackle multiple questions that benefit from being addressed collectively within an appropriate phylogenetic framework, in our case theD.melanogasterspecies subgroup. The genotyping of more than 1,600 individual meiotic events allowed us to identify several key distinct properties relative toD.melanogaster. We show thatD.yakuba, in addition to higher crossover rates thanD.melanogaster, has a stronger centromere effect and crossover assurance than anyDrosophilaspecies analyzed to date. We also report the presence of an active crossover-associated meiotic drive mechanism for theXchromosome that results in the preferential inclusion in oocytes of chromatids with crossovers. Our evolutionary and genomic analyses suggest that the genome-wide landscape of crossover rates inD.yakubahas been fairly stable and captures a significant signal of the ancestral crossover landscape for the wholeD.melanogastersubgroup, even informative for theD.melanogasterlineage. Contemporary crossover rates inD.melanogaster, on the other hand, do not recapitulate ancestral crossovers landscapes. As a result, the temporal stability of crossover landscapes observed inD.yakubamakes this species an ideal system for applying population genetic models of selection and linkage, given that these models assume temporal constancy in linkage effects. Our studies emphasize the importance of generating multiple high-resolution crossover rate maps within a coherent phylogenetic context to broaden our understanding of crossover control during meiosis and to improve studies on the evolutionary consequences of variable crossover rates across genomes and time.
HiCuT: An efficient and low input method to identify protein-directed chromatin interactions
Authors: Sati Satish , Jones Parker , Kim Hali S. , Zhou Linda A. , Rapp-Reyes Emmanuel , Leung Thomas H.
Published: March 2022

3D genome organization regulates gene expression, and disruption of these long-range (>20kB) DNA-protein interactions results in pathogenic phenotypes. Chromosome conformation methods in conjunction with chromatin immunoprecipitation were used to decipher protein-directed chromatin interactions. However, these methods required abundant starting material (>500,000 cells), sizable number of sequencing reads (>100 million reads), and elaborate data processing methods to reduce background noise, which limited their use in primary cells. Hi-C Coupled chromatin cleavage and Tagmentation (HiCuT) is a new transposase-assisted tagmentation method that generates high-resolution protein directed long-range chromatin interactions as efficiently as existing methods, HiChIP and ChIA-PET, despite using 100,000 cells (5-fold less) and 12 million sequencing reads (8-fold fewer). Moreover, HiCuT generates high resolution fragment libraries with low background signal that are easily interpreted with minimal computational processing. We used HiCuT in human primary skin cells to link previously identified single nucleotide polymorphisms (SNPs) in skin disease to candidate genes and to identify functionally relevant transcription factors in an unbiased manner. HiCuT broadens the capacity for genomic profiling in systems previously unmeasurable, including primary cells, human tissue samples, and rare cell populations, and may be a useful tool for all investigators studying human genetics and personalized epigenomics.
Development of a dual antigen lateral flow immunoassay for detecting Yersinia pestis
Authors: Hau Derrick , Wade Brian , Lovejoy Chris , Pandit Sujata G. , Reed Dana E. , DeMers Haley L. , Green Heather R. , Hannah Emily E. , McLarty Megan E. , Creek Cameron J. , Chokapirat Chonnikarn , Arias-Umana Jose , Cecchini Garett F. , Nualnoi Teerapat , Gates-Hollingsworth Marcellene A. , Thorkildson Peter N. , Pflughoeft Kathryn J. , AuCoin David P.
Published: March 2022

Background

Yersinia pestis is the causative agent of plague, a zoonosis associated with small mammals. Plague is a severe disease, especially in the pneumonic and septicemic forms, where fatality rates approach 100% if left untreated. The bacterium is primarily transmitted via flea bite or through direct contact with an infected host. The 2017 plague outbreak in Madagascar resulted in more than 2,400 cases and was highlighted by an increased number of pneumonic infections. Standard diagnostics for plague include laboratory-based assays such as bacterial culture and serology, which are inadequate for administering immediate patient care for pneumonic and septicemic plague.

Principal findings

The goal of this study was to develop a sensitive rapid plague prototype that can detect all virulent strains of Y. pestis. Monoclonal antibodies (mAbs) were produced against two Y. pestis antigens, low-calcium response V (LcrV) and capsular fraction-1 (F1), and prototype lateral flow immunoassays (LFI) and enzyme-linked immunosorbent assays (ELISA) were constructed. The LFIs developed for the detection of LcrV and F1 had limits of detection (LOD) of roughly 1–2 ng/mL in surrogate clinical samples (antigens spiked into normal human sera). The optimized antigen-capture ELISAs produced LODs of 74 pg/mL for LcrV and 61 pg/mL for F1 when these antigens were spiked into buffer. A dual antigen LFI prototype comprised of two test lines was evaluated for the detection of both antigens in Y. pestis lysates. The dual format was also evaluated for specificity using a small panel of clinical near-neighbors and other Tier 1 bacterial Select Agents.

Conclusions

LcrV is expressed by all virulent Y. pestis strains, but homologs produced by other Yersinia species can confound assay specificity. F1 is specific to Y. pestis but is not expressed by all virulent strains. Utilizing highly reactive mAbs, a dual-antigen detection (multiplexed) LFI was developed to capitalize on the diagnostic strengths of each target.
Care-seeking and health insurance among pregnancy-related deaths: A population-based study in Jember District, East Java Province, Indonesia
Authors: Anggondowati Trisari , Deviany Poppy E. , Latief Kamaluddin , Adi Annis C. , Nandiaty Fitri , Achadi Anhari , Kalter Henry D. , Weaver Emily H. , Rianty Tika , Ruby Mahlil , Wahyuni Sri , Riyanti Akhir , Lisnawati Naintina , Kusariana Nissa , Achadi Endang L. , Setel Philip W.
Published: March 2022

Background

Despite the increased access to facility-based delivery in Indonesia, the country’s maternal mortality remains unacceptably high. Reducing maternal mortality requires a good understanding of the care-seeking pathways for maternal complications, especially with the government moving toward universal health coverage. This study examined care-seeking practices and health insurance in instances of pregnancy-related deaths in Jember District, East Java, Indonesia.

Methods

This was a community-based cross-sectional study to identify all pregnancy-related deaths in the district from January 2017 to December 2018. Follow-up verbal and social autopsy interviews were conducted to collect information on care-seeking behavior, health insurance, causes of death, and other factors.

Findings

Among 103 pregnancy-related deaths, 40% occurred after 24 hours postpartum, 36% during delivery or within the first 24 hours postpartum, and 24% occurred while pregnant. The leading causes of deaths were hemorrhage (38.8%), pregnancy-induced hypertension (20.4%), and sepsis (16.5%). Most deaths occurred in health facilities (81.6%), primarily hospitals (74.8%). Nearly all the deceased sought care from a formal health provider during their fatal illness (93.2%). Seeking any care from an informal provider during the fatal illness was more likely among women who died after 24 hours postpartum (41.0%, OR 7.4, 95% CI 1.9, 28.5, p = 0.049) or during pregnancy (29.2%, OR 4.4, 95% CI 1.0, 19.2, p = 0.003) than among those who died during delivery or within 24 hours postpartum (8.6%). There was no difference in care-seeking patterns between insured and uninsured groups.

Conclusions

The fact that women sought care and reached health facilities regardless of their insurance status provides opportunities to prevent deaths by ensuring that every woman receives timely and quality care. Accordingly, the increasing demand should be met with balanced readiness of both primary care and hospitals to provide quality care, supported by an effective referral system.
The diagnostic performance of combined conventional cytology with smears and cell block preparation obtained from endoscopic ultrasound-guided fine needle aspiration for intra-abdominal mass lesions
Authors: Pausawasdi Nonthalee , Hongsrisuwan Penprapai , Chalermwai Wipapat Vicki , Butt Amna Subhan , Maipang Kotchakon , Charatchareonwitthaya Phunchai
Published: March 2022

Background/Aim

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the primary method for tissue acquisition of intra-abdominal masses. However, the main limitation of cytology alone is the lack of tissue architecture and inadequate samples. This study aimed to evaluate the diagnostic performance of combined conventional cytology and cell block preparation obtained from EUS-FNA of intra-abdominal masses without Rapid On-site Evaluation (ROSE).

Methods

Cytologic smears and cell block slides of 166 patients undergoing EUS-FNA during 2010–2015 were reviewed by an experienced cytopathologist blinded to clinical data.

Results

125 patients had neoplastic lesions. Pancreatic adenocarcinoma was the most common etiology (35.5%), followed by lymph node metastasis (27.7%). The mean mass size was 2.5±1.3 cm. The mean number of passes was 1.9±1.28. Tissue adequacy for conventional cytology and cell block preparation was 78.9% and 78.1%, respectively. Factors associated with tissue adequacy were assessed. For cytology, lesions of > 2.1 cm, masses in the pancreatic body or tail, malignancy, and pancreatic cancer were positively associated with adequate cellularity. For cell block preparation, lesions of > 3 cm and malignancy were associated with increased tissue adequacy. The conventional cytology alone had a sensitivity of 68.5%, a specificity of 95.7%, and an area under the receiver operating characteristics (AUROC) of 0.821. The cell block preparation alone had a sensitivity of 65.4%, a specificity of 96%, and an AUROC of 0.807. The combined conventional cytology and cell block preparation performed significantly better than either method alone (p<0.05), as demonstrated by an increased AUROC of 0.853. Furthermore, cell block detected malignancy in 9.3% of cases where the cytologic smears failed to identify malignant cells.

Conclusions

The combined conventional cytology and cell block preparation increased the diagnostic accuracy of EUS-FNA compared to either method alone. This approach should be implemented in routine practice, especially where ROSE is unavailable.
High school science fair: Ethnicity trends in student participation and experience
Authors: Grinnell Frederick , Dalley Simon , Reisch Joan
Published: March 2022

In this paper, we report ethnicity trends in student participation and experience in high school science and engineering fair (SEFs). SEF participation showed significant ethnic diversity. For survey students, the approximate distribution was Asian-32%; Black-11%; Hispanic-20%; White-33%; Other-3%. Comparing the SEF level at which students competed from school to district to region to state levels, we observed that black students made up only 4.5% of the students who participated in SEF beyond the school level, whereas students from other ethnic groups were more equally represented at all levels. The lower percentage of Black students resulted from a combination of lower overall participation in SEF and lower percentage of those students who did participate to advance to SEFs beyond the school level. Students who advanced to SEFs beyond the school level frequently received help from scientists, coaching for the interview, and were not required to participate in SEF. Black students received the least help from scientists, were least likely to receive coaching for the interview, and were most likely to be required to participate in SEF. They also were most likely to receive no help from parents, teachers, or scientists. Asian and Hispanic students (63.8% and 56.8%) indicated a greater interest in careers in science and engineering (S&E) compared to Black and White students (43.7% & 50.7%). In addition to career interest, the most important experiences that correlated with students who indicated that SEF increased their interests in S&E were getting help from the internet, books and magazines; getting help fine tuning the report; and overcoming obstacles by doing more background research, making a timeline, and perseverance. Black students did not report a positive effect of any of these strategies but experienced time pressure as more of an obstacle than did other students. Our findings identify a wide range of student experiences associated with positive SEF outcomes that could be enhanced for all students but especially Black students. More involvement of scientists in helping students who participate in SEFs would be particularly valuable.
Using agent-based modeling to compare corrective actions for Listeria contamination in produce packinghouses
Authors: Barnett-Neefs Cecil , Sullivan Genevieve , Zoellner Claire , Wiedmann Martin , Ivanek Renata
Published: March 2022

The complex environment of a produce packinghouse can facilitate the spread of pathogens such asListeria monocytogenesin unexpected ways. This can lead to finished product contamination and potential foodborne disease cases. There is a need for simulation-based decision support tools that can test different corrective actions and are able to account for a facility’s interior cross-contamination dynamics. Thus, we developed agent-based models ofListeriacontamination dynamics for two produce packinghouse facilities; agents in the models represented equipment surfaces and employees, and models were parameterized using observations, values from published literature and expert opinion. Once validated with historical data fromListeriaenvironmental sampling, each model’s baseline conditions were investigated and used to determine the effectiveness of corrective actions in reducing prevalence of agents contaminated withListeriaand concentration ofListeriaon contaminated agents. Evaluated corrective actions included reducing incomingListeria, modifying cleaning and sanitation strategies, and reducing transmission pathways, and combinations thereof. Analysis ofListeriacontamination predictions revealed differences between the facilities despite their functional similarities, highlighting that one-size-fits-all approaches may not always be the most effective means for selection of corrective actions in fresh produce packinghouses. Corrective actions targetingListeriaintroduced in the facility on raw materials, implementing risk-based cleaning and sanitation, and modifying equipment connectivity were shown to be most effective in reducingListeriacontamination prevalence. Overall, our results suggest that a well-designed cleaning and sanitation schedule, coupled with good manufacturing practices can be effective in controlling contamination, even if incomingListeriaspp. on raw materials cannot be reduced. The presence of water within specific areas was also shown to influence corrective action performance. Our findings support that agent-based models can serve as effective decision support tools in identifyingListeria-specific vulnerabilities within individual packinghouses and hence may help reduce risks of food contamination and potential human exposure.