bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of The Thermochemistry- Hots-Tawheed Multiple Choice Instrument
Authors: Darmana A , Sutiani A , Jasmidi
Published: March 2020

This research is part of the development research in thermochemistry-hots-tawheed teaching materials. the purpose of this research is to develop the thermochemistry tawheed High Order Thinking skills (HOTs) test instrument. the stages of the research began by designing 45 multiple choice items with five options. The instrument assessed by three science education experts, and pilot tested to 56 chemistry students. analysis of the test items was carried out using the rasch measurement model approach, the multiple choice test analyzed with winsteps software, and expert validation analyzed using facets software. Multirater validation test results showed 27 of 45 test items were in good quality (60%) according to the experts. The multiple choice items results : (1) the reliability of the test items was good quality (reliability index 0.89); (2) test of item fit, 34 out of 45 test items are good in fit statistics indices (75.6%); (3) person map item test, showing difficulty level, easy: medium: difficult = 50%: 33%: 17%; (4) the test distractor work well for 23 of the 45 test items (51%); (5) there are 19 of 45 valid test items based on pilot tested results that are in accordance with expert judgment.
Biology Students Perception of Learning Ethnobotany based on Electronic Learning (E-Learning)
Authors: Nasution Aswarina , Hasairin Ashar , Arwita Widya
Published: March 2020

Internet connection has become useful part of education. Many teachers and lecturers create electronic learning to support their learning-teaching process. The aim of this research is to know the student’s perception of e-learning in ethnobotany. Descriptive research was used to get the data by giving 28 students questioners. Based on the questioners that have been analyzed, researcher found that 100% of students know about e-learning and have access to e-learning 96.43% of students state that e-learning can helps the learning process and 100% of students agree that e-learning help them to access the subject matter. There are 5 obstacles identified from the survey including connection problem (96.42%), the lack of information about how to use e-learning (50%), interaction problem with lecturers through e-learning (21.43%), lack of discipline to use e-learning to study (14.29%), and don’t know how to use e-learning (7.14%). Further research is needed to overcome this problems.
Levels Pb (Lead) Content in The Thallus Lichens at Three Shade Tress in The Terminal Pinang Baris Medan, North Sumatera
Authors: Hasairin A , Harsono T , Nasution A , Siregar R
Published: March 2020

This research aims to know the levels of Pb (Lead) on thalus lichens found on the three forest shade trees road in the area of Terminal Pinang Medan, North Sumatera. Type of this research is a descriptive exploratory survey method. Measurement of the levels of lead (Pb) using Furnace (destruction of dried) and Atomic Absorbance Spectrophotometer (AAS) in Medical Field Laboratory Hall. From the results of research conducted in the Terminal Area of Pinang Baris Medan, it is known that there are 12 different types of lichens. Results of the study known types of lichens that have levels of lead (Pb) is a type of most lichens Parmelia grabratula 49,01 mg/kg from Acacia trees (Acacia auriculiformis) I, and the lowest levels of lead (Pb) is a Palm tree from Buellia canescens 10,19 mg/kg III (Hyophorbe sp.).
MEMS and IoT Applications in ISLE-based STEM Physics Learning Media for Mechanics Topic with LabVIEW Integration
Authors: Irwandi I , Sari I M , Oktavia R , Syukri M
Published: March 2020

The development of technology in the 21st century is so rapid both in the field of sensor and data communication. In fact, almost all smartphones have used the technology. In addition to using cutting edge sensor technology, smartphones are also equipped with internet communication features so they can be categorized as IoT (Internet of Things) devices. However, both of these technologies have not been optimally used as a media for learning physics. This paper discusses the use of MEMs (Micro-electromechanical system) sensor (ADXL-345) to detect the oscillation of the spring-mass system. Data obtained by MEMs is read by IoT based Microcontrollers (NodeMCU EPS8266) and directly transferred to the intranet WIFI network via the UDP (User Datagram Protocol). The data transmitted in the UDP packet is received by a computer that is integrated with LabVIEW, a user-friendly software that is based on a Graphical Programming. Students were encouraged to conduct several experiments to investigate the dependence of the period of the spring-mass system on the mass, the spring constant, and the amplitude. The oscillation of the spring-mass system received by the computer recorded the amplitude and the period of oscillation. Then students will compare the data from various observational experiments to predict the relation among the variables. Finally, they tested their prediction by conducting a testing experiment. This learning model is using ISLE (Investigation Sciences Learning Environment) syntax where students constructed their knowledge about mechanics, especially about spring-mass system, and enjoyed their discoveries as scientists did. Since the learning media has used technology and also carried out engineering process stages and involved the calculation of mathematics to understand the measurement results, it can be said to have used the STEM (Sciences, Technology, Engineering, and Mathematics) approach. We observed that an atmosphere of “learning is fun” existed during the lesson.
The Final Thesis Project is the Main Determinant of the Length of Study Period for Undergraduate Students of the Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan
Authors: Sipahutar H , Mukhtar  , Nasution M Y , Gaol A Y D L
Published: March 2020

The purpose of this study was to find out the factors affecting the students’ length of study period especially those related to the academic governance, thesis guidance, and supporting facilities at the Faculty of Mathematics and Natural Sciences (FMNS) of the State University of Medan (Unimed) in the academic year of 2017/2018. Questionnaires were distributed to 469 final year students and 170 thesis supervisors (TS), which represented eight study programs and one Bilingual Program, as well as to 32 administration staff (AS) in FMNS of Unimed. Questionnaires consist of 44 (students) or 40 (TS) or 15 (AS) closed and open questions related to administrative and TS services, supporting facilities, and subjects. Data were analyzed descriptively. The results show that the average length of the study period is 8.9 semesters, far longer than the ideal one (8 semesters). The most important factor contributing to the prolongation of the study period is the length of time needed by the students to complete the thesis final project (TFP), which is an average of 1.6 semesters. Factors causing the prolongation of the TFP completion period include: (a) the administrative staff service function is less supportive, (b) supporting facilities (such as SOPs, Thesis Guidebooks, internet, references in libraries, and laboratory facilities) cannot be utilized properly by students, (c) supporting subjects, especially English and Statistics, have not contributed well to the completion of TFP, and (d) the commencement of TFP work, namely in semester VIII, is too late. To overcome the problems, the following actions need to be taken: (a) improving the quality of administrative services and simplifying TFP governance, (b) updating SOPs and thesis guidebooks, library references, internet, and laboratory, (c) increasing the relevance of the contents of supporting thesis courses, and (d) repositioning of TFP courses one semester earlier. Train students early to find and use references to conduct mini-research and student creativity programs, and their involvement in the lecturer’s research will also be very helpful.
Incorporating canopy structure from simulated GEDI lidar into bird species distribution models
Authors: Burns Patrick , Clark Matthew , Salas Leonardo , Hancock Steven , Leland David , Jantz Patrick , Dubayah Ralph , Goetz Scott J
Published: March 2020

The Global Ecosystem Dynamics Investigation (GEDI) lidar began data acquisition from the International Space Station in March 2019 and is expected to make over 10 billion measurements of canopy structure and topography over two years. Previously, airborne lidar data with limited spatial coverage have been used to examine relationships between forest canopy structure and faunal diversity, most commonly bird species. GEDI’s latitudinal coverage will permit these types of analyses at larger spatial extents, over the majority of the Earth’s forests, and most importantly in areas where canopy structure is complex and/or poorly understood. In this regional study, we examined the impact that GEDI-derived Canopy Structure variables have on the performance of bird species distribution models (SDMs) in Sonoma County, California. We simulated GEDI waveforms for a two-year period and then interpolated derived Canopy Structure variables to three grid sizes of analysis. In addition to these variables, we also included Phenology, Climate, and other Auxiliary variables to predict the probability of occurrence of 25 common bird species. We used a weighted average ensemble of seven individual machine learning models to make predictions for each species and calculated variable importance. We found that Canopy Structure variables were, on average at our finest resolution of 250 m, the second most important group (32.5%) of predictor variables after Climate variables (35.3%). Canopy Structure variables were most important for predicting probability of occurrence of birds associated with Conifer forest habitat. Regarding spatial analysis scale, we found that finer-scale models more frequently performed better than coarser-scale models, and the importance of Canopy Structure variables was greater at finer spatial resolutions. Overall, GEDI Canopy Structure variables improved SDM performance for at least one spatial resolution for 19 of 25 species and thus show promise for improving models of bird species occurrence and mapping potential habitat.
Increase in beaver dams controls surface water and thermokarst dynamics in an Arctic tundra region, Baldwin Peninsula, northwestern Alaska
Authors: Jones Benjamin M , Tape Ken D , Clark Jason A , Nitze Ingmar , Grosse Guido , Disbrow Jeff
Published: March 2020

Beavers are starting to colonize low arctic tundra regions in Alaska and Canada, which has implications for surface water changes and ice-rich permafrost degradation. In this study, we assessed the spatial and temporal dynamics of beaver dam building in relation to surface water dynamics and thermokarst landforms using sub-meter resolution satellite imagery acquired between 2002 and 2019 for two tundra areas in northwestern Alaska. In a 100 km2 study area near Kotzebue, the number of dams increased markedly from 2 to 98 between 2002 and 2019. In a 430 km2 study area encompassing the entire northern Baldwin Peninsula, the number of dams increased from 94 to 409 between 2010 and 2019, indicating a regional trend. Correlating data on beaver dam numbers with surface water area mapped for 12 individual years between 2002 and 2019 for the Kotzebue study area showed a significant positive correlation (R2 = 0.61; p < .003). Beaver-influenced waterbodies accounted for two-thirds of the 8.3% increase in total surface water area in the Kotzebue study area during the 17 year period. Beavers specifically targeted thermokarst landforms in their dam building activities. Flooding of drained thermokarst lake basins accounted for 68% of beaver-influenced surface water increases, damming of lake outlets accounted for 26%, and damming of beaded streams accounted for 6%. Surface water increases resulting from beaver dam building likely exacerbated permafrost degradation in the region, but dam failure also factored into the drainage of several thermokarst lakes in the northern Baldwin Peninsula study region, which could promote local permafrost aggradation in freshly exposed lake sediments. Our findings highlight that beaver-driven ecosystem engineering must be carefully considered when accounting for changes occurring in some permafrost regions, and in particular, regional surface water dynamics in low Arctic and Boreal landscapes.
Role of additives in silica-supported polyethylenimine adsorbents for CO2 adsorption
Authors: Fang Qianxi , Huang Weiqiu , Wang Hongning
Published: March 2020

SiO2 aerogels were prepared by sol-gel method and methyl alkylation reaction using TEOS as silicon sources. Silica-supported polyethylenimine (PEI/SiO2) adsorbents for CO2 adsorption were prepare by grafting techniques, in which mesoporous SiO2 aerogel was loaded with PEI and organic compounds functionalized by hydroxyl or amino groups as dopants. CO2 adsorption isotherms of PEI amine-modified SiO2 aerogels were measured and the results show that the maximum CO2 adsorption capacity (1.8 mmol g−1) was obtained over a doped SA-PEI-N-Y loaded with 45% PEI and 15% N-Y (N-[3-(Trimethoxysilyl)propyl]ethylenediamine, denoted as N-Y). In addition, SA-PEI-N-Y has stronger thermal stability than SA-PEI-60% in nitrogen from room temperature to 800 °C at a heating rate of 10 °C min−1. It turns out that N-[3-(Trimethoxysilyl)propyl]ethylenediamine is the best dopant.
Interpretable embeddings from molecular simulations using Gaussian mixture variational autoencoders
Authors: Bozkurt Varolgüneş Yasemin , Bereau Tristan , Rudzinski Joseph F
Published: March 2020

Extracting insight from the enormous quantity of data generated from molecular simulations requires the identification of a small number of collective variables whose corresponding low-dimensional free-energy landscape retains the essential features of the underlying system. Data-driven techniques provide a systematic route to constructing this landscape, without the need for extensive a priori intuition into the relevant driving forces. In particular, autoencoders are powerful tools for dimensionality reduction, as they naturally force an information bottleneck and, thereby, a low-dimensional embedding of the essential features. While variational autoencoders ensure continuity of the embedding by assuming a unimodal Gaussian prior, this is at odds with the multi-basin free-energy landscapes that typically arise from the identification of meaningful collective variables. In this work, we incorporate this physical intuition into the prior by employing a Gaussian mixture variational autoencoder (GMVAE), which encourages the separation of metastable states within the embedding. The GMVAE performs dimensionality reduction and clustering within a single unified framework, and is capable of identifying the inherent dimensionality of the input data, in terms of the number of Gaussians required to categorize the data. We illustrate our approach on two toy models, alanine dipeptide, and a challenging disordered peptide ensemble, demonstrating the enhanced clustering effect of the GMVAE prior compared to standard VAEs. The resulting embeddings appear to be promising representations for constructing Markov state models, highlighting the transferability of the dimensionality reduction from static equilibrium properties to dynamics.
Topological manifold bundles and the 𝐴-theory assembly map
Authors: Raptis George , Steimle Wolfgang
Published: March 2020

We give a new proof of an index theorem for fiber bundles of compact topological manifolds due to Dwyer, Weiss, and Williams, which asserts that the parametrized

A
A

-theory characteristic of such a fiber bundle factors canonically through the assembly map of

A
A

-theory. Furthermore our main result shows a refinement of this statement by providing such a factorization for an extended

A
A

-theory characteristic, defined on the parametrized topological cobordism category. The proof uses a convenient framework for bivariant theories and recent results of Gomez-Lopez and Kupers on the homotopy type of the topological cobordism category. We conjecture that this lift of the extended

A
A

-theory characteristic becomes highly connected as the manifold dimension increases.
Projective modules with unique maximal submodules are cyclic
Authors: Sato Masahisa
Published: March 2020

There is a question formulated by R. Ware in 1971. That is, if a projective right

R
R

-module

P
P

has a unique maximal submodule

L
L

, then

L
L

is the largest maximal submodule of

P
P

. First we give a structure theorem for such a projective module. Next we define the notion of a minimal generator set and give an affirmative answer to this question by using this notion. In the last section, we give an example of a non-quasi-small module to discuss whether the answer to this question is affirmative or negative. The key theorem in Comm. Algebra 31 (2003), pp. 4195–4241 asserts that answer to this question is negative. But our example seems to be a counterexample of this key theorem.
A Reappraisal of Superficial Pleomorphic Liposarcoma
Authors: Berg Scott Hilliard , Massoud Cathy Meade , Jackson-Cook Colleen , Boikos Sosipatros Alexander , Smith Steven Christopher , Mochel Mark Cameron
Published: March 2020

Objectives

Superficial pleomorphic liposarcoma (PL) has a favorable prognosis compared to deeply seated PL. Given developments in the classification of lipomatous neoplasms, we reappraised a series of cases.

Methods

Retrospective clinicopathologic evaluation and genome-wide single-nucleotide polymorphism (SNP) microarray studies were performed for cases previously designated superficial PL.

Results

Four cases were identified (age, 48-70 years). Two were dermally confined, whereas two were superficial subcutaneous; no recurrences or metastases were reported. Tumors demonstrated pleomorphic spindled morphology with variable cellularity. Multivacuolated atypical lipoblasts were focal in 3 and abundant in 1. Dermal tumors demonstrated atypical cells within sclerotic collagen. Genome-wide SNP microarray studies revealed consistent gains and losses, including losses at the 13q14.2 locus encompassing RB1 and DLEU2 and deletion/disruption of the TP53 locus. Although subcutaneous examples showed genomic changes similar to deep PL, the dermal examples showed fewer genetic alterations, including changes reported in the spectrum of atypical spindle cell/pleomorphic lipomatous tumors (ASPLT). All lacked MDM2 amplification.

Conclusions

Careful integration of histologic and genetic features may improve classification of lipomatous neoplasms with atypia, allowing reclassification of some superficial PL as ASPLT.
The multiple roles of chemokines in the mechanisms of stent biocompatibility
Authors: Ravindran Dhanya , Karimi Galougahi Keyvan , Tan Joanne T M , Kavurma Mary M , Bursill Christina A
Published: March 2020

While the advent of drug-eluting stents has been clinically effective in substantially reducing the rates of major stent-related adverse events compared with bare metal stents, vascular biological problems such as neointimal hyperplasia, delayed re-endothelialization, late stent thrombosis are not eliminated and, increasingly, neoatherosclerosis is the underlying mechanism for very late stent failure. Further understanding regarding the mechanisms underlying the biological responses to stent deployment is therefore required so that new and improved therapies can be developed. This review will discuss the accumulating evidence that the chemokines, small inflammatory proteins, play a role in each key biological process of stent biocompatibility. It will address the chemokine system in its specialized roles in regulating the multiple facets of vascular biocompatibility including neointimal hyperplasia, endothelial progenitor cell (EPC) mobilization and re-endothelialization after vascular injury, platelet activation and thrombosis, as well as neoatherosclerosis. The evidence in this review suggests that chemokine-targeting strategies may be effective in controlling the pathobiological processes that lead to stent failure. Preclinical studies provide evidence that inhibition of specific chemokines and/or broad-spectrum inhibition of the CC-chemokine class prevents neointimal hyperplasia, reduces thrombosis and suppresses the development of neoatherosclerosis. In contrast, however, to these apparent deleterious effects of chemokines on stent biocompatibility, the CXC chemokine, CXCL12, is essential for the mobilization and recruitment of EPCs that make important contributions to re-endothelialization post-stent deployment. This suggests that future chemokine inhibition strategies would need to be correctly targeted so that all key stent biocompatibility areas could be addressed, without compromising important adaptive biological responses.
Integrating image caption information into biomedical document classification in support of biocuration
Authors: Jiang Xiangying , Li Pengyuan , Kadin James , Blake Judith A , Ringwald Martin , Shatkay Hagit
Published: March 2020

Gathering information from the scientific literature is essential for biomedical research, as much knowledge is conveyed through publications. However, the large and rapidly increasing publication rate makes it impractical for researchers to quickly identify all and only those documents related to their interest. As such, automated biomedical document classification attracts much interest. Such classification is critical in the curation of biological databases, because biocurators must scan through a vast number of articles to identify pertinent information within documents most relevant to the database. This is a slow, labor-intensive process that can benefit from effective automation.

We present a document classification scheme aiming to identify papers containing information relevant to a specific topic, among a large collection of articles, for supporting the biocuration classification task. Our framework is based on a meta-classification scheme we have introduced before; here we incorporate into it features gathered from figure captions, in addition to those obtained from titles and abstracts. We trained and tested our classifier over a large imbalanced dataset, originally curated by the Gene Expression Database (GXD). GXD collects all the gene expression information in the Mouse Genome Informatics (MGI) resource. As part of the MGI literature classification pipeline, GXD curators identify MGI-selected papers that are relevant for GXD. The dataset consists of ~60 000 documents (5469 labeled as relevant; 52 866 as irrelevant), gathered throughout 2012–2016, in which each document is represented by the text of its title, abstract and figure captions. Our classifier attains precision 0.698, recall 0.784, f-measure 0.738 and Matthews correlation coefficient 0.711, demonstrating that the proposed framework effectively addresses the high imbalance in the GXD classification task. Moreover, our classifier’s performance is significantly improved by utilizing information from image captions compared to using titles and abstracts alone; this observation clearly demonstrates that image captions provide substantial information for supporting biomedical document classification and curation.

Database URL:
Toxicity of Baits and Their Effects on Population Suppression of Anastrepha fraterculus (Diptera: Tephritidae): Implications for Field Management
Authors: Nunes Marcelo Z , Baronio Cleber A , Schutze Inana X , Bernardi Daniel , Arioli Cristiano J , Junior Ruben M , Botton Marcos
Published: March 2020

Anastrepha fraterculus (Wiedemann, 1830) is the main pest of fruit in southern Brazil. The use of toxic baits is one of the alternatives for its management. In this study, the toxic baits Anamed + malathion (10,000 mg/liter), Flyral 1.25% + malathion (2,000 mg/liter), and Gelsura (alpha-cypermethrin, 2,000 and 4,000 mg/liter) were highly toxic to the adults of A. fraterculus (lethal time [LT50] < 7 h). In contrast, Success 0.02 CB had an LT50 of 48.4 h. In the absence of rain, all the formulations had residual effects (>90% mortality) on A. fraterculus adults up to 21 d after treatment (DAT). In the presence of 5, 25, and 50 mm of rainfall, there was a significant reduction in the residual effect over time. However, with up to 50 mm of rain, Anamed + malathion and Gelsura 2,000 and 4,000 mg/liter caused between 43.0 and 79.0% of mortality. In the field, during two consecutive seasons (2015/2016 and 2016/2017), applications of Gelsura 2,000 mg/liter (four applications/season) caused population suppression of the pest throughout the apple fruiting period. However, in the 2016/2017 season, in the area using Gelsura, a higher percentage (≈12%) of apple fruits damaged by A. fraterculus females was observed when compared with the area with insecticide application (damage <3%). The toxic bait Gelsura (2,000 and 4.000 mg/liter) was shown to be promising for use in the management of A. fraterculus, with results similar to those with the application of synthetic insecticides.
A Court with Many Faces: Judicial Characters and Modes of Norm Development in the European Court of Human Rights
Authors: Yildiz Ezgi
Published: March 2020

It is well established in the literature that international courts make law and develop norms. Yet there is no systematic analysis of how adjudication refashions a given norm’s trajectory. This article addresses this gap by combining legal analysis with social science methods. It takes a closer look at the European Court of Human Rights and provides a framework for understanding how court rulings develop norms – that is, how judicial decisions modify norms’ content or scope. The framework is composed of a typology of court characters (arbitrator, entrepreneur and delineator) and the distinct modes of norm development that each character typically generates (incremental/inconspicuous, pronounced and peripheral development). The typology is informed by interviews carried out at the Court as well as the literature on judicial review and, in particular, the debate on judicial activism and restraint. Unlike the concepts of judicial activism and restraint, these characters are not antithetical, but complementary. I show how court characters complement one another by looking at the case of the norm against torture under Article 3 of the European Convention on Human Rights. I examine 157 judgments issued between 1967 and 2006. I find that the percentage of entrepreneur rulings considerably decreased in the post-1998 period, while arbitrator rulings increased by nearly the same amount. My analysis of nearly four decades of jurisprudence not only sheds light on how the Court operates but also furthers our understanding of how it refashions codified norms.
Using a group medical visit model to promote healthy behaviour change with an underserved population
Authors: Russell Holly Ann , Sanders Mechelle , Moll Lynn , Murphy Melanie , Lanigan Angela M , Carroll Jennifer K
Published: March 2020

Background

Models of care are needed to address physical activity, nutrition promotion and weight loss in primary care settings, especially with underserved populations who are disproportionately affected by chronic illness. Group medical visits (GMVs) are one approach that can help overcome some of the barriers to behaviour change in underserved populations, including the amount of time required to care for these patients due to socio-economic stressors and psychosocial complexities (1). GMVs have been shown to improve care in coronary artery disease and diabetes, but more evidence is needed in underserved settings.

Objective

This project sought to evaluate a GMV incorporating a physical activity component in an underserved patient population, measuring biometric and motivation outcome measures.

Methods

This project used a pre–post intervention study design through patient surveys at baseline and 12 weeks. We included validated motivational measures along with self-reported demographic information. A GMV intervention promoting physical activity and nutrition to promote weight loss was delivered by an interdisciplinary primary care team and community partners in a Federally Qualified Health Center in Rochester, NY. The intervention consisted of six, 2-hour sessions that occurred every other week at the clinic site.

Results

Participants lost a significant amount of weight and maintained the weight loss at 6 months. In addition, there was a significant improvement in motivation measures.

Conclusion

This study provides preliminary evidence that our GMV model can improve weight loss and autonomous motivation in an underserved population. This project has potential for scalability and sustainability.
Metagenomic investigation of African dust events in the Caribbean
Authors: Waters Samantha Marie , Purdue S K , Armstrong R , Detrés Y
Published: March 2020

African dust from the Sahara and Sahel regions of Northern Africa is blown intercontinental distances and is the highest portion of atmospheric dust generated each year. During the Northern Hemisphere summer months (boreal summer), these dust events travel into the Caribbean and southern United States. While viability assays, microscopy and bacterial amplicon analyses have shown that dust-associated microbes may be diverse, the specific microbial taxa that are transported intercontinental distances with these dust events remain poorly characterized. To provide new insights into these issues, five metagenomes of Saharan dust events occurring in the Caribbean, collected in the summer months of 2002 and 2008, were analyzed. The data revealed that similar microbial composition existed between three out of the five of the distinct dust events and that fungi were a prominent feature of the metagenomes compared to other environmental samples. These results have implications for better understanding of microbial transport through the atmosphere and may implicate that the dust-associated microbial load transiting the Atlantic with Saharan dust is similar from year to year.
Metagenome analyses reveal the role of Clostridium perfringens in alfalfa silage anaerobic deterioration
Authors: Zheng Mingli , Niu Dongze , Jiang Di , Li Rongrong , Meng Lin , Xu Chuncheng
Published: March 2020

The clostridial fermentation caused by the outgrowth of Clostridia was mainly responsible for the silage anaerobic deterioration. Our previous results showed that Clostridium perfringens dominated the clostridial community in poor-fermented alfalfa silage. This study was conducted to further examine the role of C. perfringens in silage anaerobic deterioration through fermentation products and the microbial community analyses. Direct-cut alfalfa was ensiled with C. perfringens contamination (CKC) or with the addition of Lactobacillus plantarum, sucrose and C. perfringens (LSC). Contamination with C. perfringens enhanced the clostridial fermentation in CKC silage, as indicated by high contents of butyric acid, ammonia nitrogen and Clostridia, while LSC silage was well preserved. The genera Bifidobacterium, Garciella and Clostridium dominated the bacterial community in CKC silage, while predominate genus was replaced by Lactobacillus in LSC silage. The clostridial community in CKC silage was dominated by Garciella sp. (26.9 to 58.1%) and C. tyrobutyricum (24.4 to 48.6%), while the relative abundance of C. perfringens was below 5.0%. Therefore, the effect of Clostridia contamination on ensiling fermentation was dependent on the ensilability of the silage material. Garciella sp. and C. tyrobutyricum, rather than C. perfringens, played dominant role in the clostridial fermentation in CKC silage.
Enzyme immobilization offers a robust tool to scale up the production of longer, diverse, natural glycosaminoglycan oligosaccharides
Authors: Alabbas Alhumaidi , Desai Umesh R
Published: March 2020

Although structurally diverse, longer glycosaminoglycan (GAG) oligosaccharides are critical to understand human biology, few are available. The major bottleneck has been the predominant production of oligosaccharides, primarily disaccharides, upon enzymatic depolymerization of GAGs. In this work, we employ enzyme immobilization to prepare hexasaccharide and longer sequences of chondroitin sulfate in good yields with reasonable homogeneity. Immobilized chondroitinase ABC displayed good efficiency, robust operational pH range, broad thermal stability, high recycle ability and excellent distribution of products in comparison to the free enzyme. Diverse sequences could be chromatographically resolved into well-defined peaks and characterized using LC-MS. Enzyme immobilization technology could enable easier access to diverse longer GAG sequences.
The Ethics of Creating and Using Human-Animal Chimeras
Authors: Devolder Katrien , Yip Lauren J , Douglas Thomas
Published: March 2020

Rapid advances in gene-editing and stem-cell technology have expanded the range of possible future applications in human-animal chimera research. Most notably, recent developments may allow researchers to generate whole personalized human organs in pigs for the purpose of transplantation into human patients. Though human-animal chimera research in small animals, such as mice, is routine, human-animal chimeric techniques are now increasingly being applied to larger animals. Moreover, these chimeras include increasing amounts of human material, which is potentially present in more morally significant locations, such as the brain and the reproductive system. These developments raise important ethical questions about whether we should create such chimeras, and if so, how we should treat them. Answers to these ethical questions are needed to inform the development of policies regulating human-animal chimera research and its applications. Here, we provide a review of some of the most important or widespread ethical concerns.
Bayesian degradation modelling for spare parts inventory management
Authors: Ruiz Cesar , Pohl Edward , Liao Haitao
Published: March 2020

Decision makers in various sectors, such as manufacturing and transportation, strive to minimize downtime costs. Often, brief-planned stoppage times allow for changes in shifts and line configurations and longer periods are scheduled for major repairs. It is quite important to proactively make use of these downtimes to reduce the costs of unexpected downtimes due to failures. Among many aspects, the availability of spare parts significantly affects the operational costs of such systems. Current sensor technologies enable the condition monitoring of critical components and degradation-based spare parts management. This paper focuses on Bayesian degradation modelling for spare parts inventory management for a new system. We propose a stochastic dynamic program to minimize the expected spare parts inventory cost for a fixed planning horizon. A numerical example illustrates the value of Bayesian analysis in this management setting. The proposed methodology finds the optimal time between long stoppages and optimal spare parts order quantity when the prior information about the degradation process is accurate. The methodology can be used to analyse the sensitivity of the optimal solution to changes in the accuracy and bias of the prior distributions of the model parameters, the cost structure and the number of machines in the system.
Manifolds of Isospectral Matrices and Hessenberg Varieties
Authors: Ayzenberg Anton , Buchstaber Victor
Published: March 2020

We consider the space $X_h$ of Hermitian matrices having staircase form and the given simple spectrum. There is a natural action of a compact torus on this space. Using generalized Toda flow, we show that $X_h$ is a smooth manifold and its smooth type is independent of the spectrum. Morse theory is then used to show the vanishing of odd degree cohomology, so that $X_h$ is an equivariantly formal manifold. The equivariant and ordinary cohomology rings of $X_h$ are described using GKM theory. The main goal of this paper is to show the connection between the manifolds $X_h$ and regular semisimple Hessenberg varieties well known in algebraic geometry. Both spaces $X_h$ and Hessenberg varieties form wonderful families of submanifolds in the complete flag variety. There is a certain symmetry between these families, which can be generalized to other submanifolds of the flag variety.
Population pharmacokinetics and biodistribution of benznidazole in mice
Authors: Perin Luísa , Pinto Leonardo , Balthazar Nardotto Glauco Henrique , da Silva Fonseca Kátia , Oliveira Paiva Beatriz , Fernanda Rodrigues Bastos Mendes Thaís , Molina Israel , Correa-Oliveira Rodrigo , Melo de Abreu Vieira Paula , Martins Carneiro Cláudia
Published: March 2020

Objectives

To evaluate the population pharmacokinetics of different benznidazole treatment regimens and the drug’s biodistribution in mice.

Methods

Two hundred mice were divided into five groups according to benznidazole dosing regimens: (1) 100 mg/kg/day for 20 days; (2) 100 mg/kg/day for 40 days; (3) 200 mg/kg/day for 20 days; (4) 40 mg/kg/day for 20 days; or (5) 40 mg/kg/day for 40 days. The mice were euthanized and blood, heart, liver, colon and brain were collected. Samples were prepared by liquid-liquid extraction and analysed by HPLC-diode-array detection. The pharmacokinetic analysis of benznidazole was evaluated via non-linear mixed-effects modelling using the NONMEN program.

Results

Our results demonstrate that mouse weight allometrically influences benznidazole clearance; the AUC curve and the highest plasma concentration are dose proportional; benznidazole does not influence its own metabolism; its tissue distribution is limited; and the standard treatment regimen for Chagas’ disease in mice (100 mg/kg/day for 20 days) is inadequate from a pharmacokinetic standpoint, as are the other regimens tested in this study (100 mg/kg/day for 40 days, 200 mg/kg/day for 20 days and 40 mg/kg/day for 20 or 40 days).

Conclusions

Benznidazole reformulations that allow better tissue penetration and plasma and tissue exposure should be evaluated to enable higher cure rates in both animals and patients. The population pharmacokinetic model developed here can allow optimization of the dosing regimen of benznidazole to treat experimental Chagas’ disease. Determining appropriate treatment regimens in animals allows translation of these to clinical studies.
MicroRNA-548-3p overexpression inhibits proliferation, migration and invasion in osteoblast-like cells by targeting STAT1 and MAFB
Authors: Ramírez-Salazar Eric G , Almeraya Erika V , López-Perez Tania V , Patiño Nelly , Salmeron Jorge , Velázquez-Cruz Rafael
Published: March 2020

Osteoporosis is the most common bone disease and a public health issue with increasing prevalence in Mexico. This disease is caused by an imbalance in the bone remodelling process mediated by osteoclast and osteoblast. MicroRNAs have emerged as key players during the differentiation of both types of cells specialized involved in bone metabolism. We found high expression levels of miR-548x-3p in circulating monocytes derived from postmenopausal osteoporotic women. This study aimed to analyse the functional characterization of miR-548x-3p roles in the bone remodelling process. We validated by RT-qPCR, the elevated levels of miR-548x-3p in circulating monocytes derived from osteoporosis women. Through bioinformatics analysis, we identify MAFB and STAT1 as potential target genes for miR-548x-3p. Both genes showed low levels of expression in circulating monocytes derived from osteoporotic women. In addition, we demonstrated the binding of miR-548x-3p to the 3′-UTR of both mRNAs. MiR-548x-3p was overexpressed in osteoblasts-like cell lines decreasing the levels of MAFB and STAT1 mRNA and protein. We found that miR-548x-3p overexpression inhibits the proliferation, migration and invasion of the cell lines evaluated. Our results identified, by the first time, the potential role of miR-548x-3p as a modulator of the bone remodelling process by regulating the expression of MAFB and STAT1.
Binary chemical reaction with activation energy in rotating flow subject to nonlinear heat flux and heat source/sink
Authors: Ijaz Khan M , Nasir Tehreem , Hayat T , Khan Niaz B , Alsaedi A
Published: March 2020

Time-dependent rotating flow in presence of heat source/sink, applied magnetic field, Joule heating, thermal radiation, and viscous dissipation is considered. Chemical reaction with Arrhenius activation energy is implemented. The governing partial differential equations have been reduced to ordinary differential systems. Shooting scheme is implemented for the computations of governing systems. Graphical results are arranged for velocity, temperature, and concentration, skin friction coefficients, and heat and mass transfer rates. Main results are mentioned in conclusion portion. It is analyzed that velocity decays in the presence of magnetic variable while temperature and concentration fields are enhanced via Eckert number and fitted rate constant. Moreover drag force and mass and heat transfer rates decrease through higher estimations of rotation rate variable, magnetic parameter, and Eckert number.
Reexamination of the Influence of Oebalus pugnax (Hemiptera: Pentatomidae) Infestations on Rice Yield and Quality
Authors: Wilson Blake E , Stout Michael J
Published: March 2020

The rice stink bug, Oebalus pugnax (F.), is the most important pest of headed rice, Oryza sativa L., in the United States. Numerous studies have attempted to quantify the impact of O. pugnax feeding on rice yield and grain quality, but these studies have often produced conflicting results. Across mid-south U.S. rice, thresholds based on sweep net sampling are used to determine the need for insecticide applications, but few studies have related sweep net captures to rice quality parameters. Field trials were conducted in Louisiana in 2015 and 2016 that used different rates of insecticides to establish rice plots with mean O. pugnax infestations ranging from 0.8 to 24.6 insects per 10 sweeps. Insecticide applications improved panicle weight and head yields as well as decreased percentage peck. A series of linear regressions examined relationships between O. pugnax captures and rice yield and quality parameters, including panicle weight, head yield (% whole kernels), and peck (discolored grains). Mean O. pugnax sweep net captures across all sampling dates in both years were significantly and negatively correlated to panicle weight and head yield and positively correlated to percentage peck. Peck was negatively correlated with head yield. Results from sampling at different maturity stages indicate sweep net captures at grain fill and soft dough stages had the greatest influence on rice yield and quality parameters, respectively. Further research into impacts of milling quality reductions on farm revenue and the influence of cumulative infestations over grain development is needed to improve economic thresholds for O. pugnax in rice.
Joint migration inversion: features and challenges
Authors: Sun Yimin , Kim Young Seo , Qu Shan , Verschuur Eric
Published: March 2020

Joint migration inversion is a recently proposed technology, accommodating velocity model building and seismic migration in one integrated process. Different from the widely accepted full waveform inversion technology, it uses imaging parameters, i.e. velocities and reflectivities of the subsurface, to parameterize its solution space. The unique feature of this new technology is its explicit capability to exploit multiples in its inversion scheme, which are treated as noise by most current technologies. In this paper, we comprehensively evaluate the state-of-the-art joint migration inversion technology from various angles: we first benchmark its performance, on both velocity model building and seismic imaging, against that of the well-accepted workflow comprising full waveform inversion and reverse-time migration using a fully controlled 2D realistic synthetic dataset. Next, we demonstrate its application on a 2D field dataset. Last, we use another 2D synthetic dataset to clearly illustrate the challenges the current joint migration inversion technology is facing. With this paper, we transparently reveal the pros of cons of the current joint migration inversion, and we will also point out the imminent research directions joint migration inversion technology should focus on in the next phase for it to be more widely accepted by the geophysics community.
Reflection signals and wellbore scattering waves in acoustic logging while drilling
Authors: Pan Yue , He Xiao , Chen Hao , Wang Xiuming
Published: March 2020

In sonic logging while drilling (LWD), it is difficult to extract reflection signals for the goal of geo-steering as the wave fields are so complicated. It is important to analyse the reflection and scattering effects based on the synthetic acoustic signals of the real LWD models, while considering the medium discontinuity at the end of the borehole. We numerically investigate the acoustic LWD responses to reflective boundaries out of the borehole. To simulate the received signals, the 3D finite difference in time domain method is implemented. Mode conversions between the collar and the Stoneley waves are revealed. Strong reflections are generated at the bottom of the well, which can be equivalent to an additional scattering source (i.e. an apparent point source). The scattering waves by the wellbore bottom are generally much stronger than the reflections from the layer interfaces of formations. By comparing the models with stratified interfaces of opposite inclination directions, the propagation mechanisms of two newly recognised reflection waves are revealed in addition to the traditional body wave reflections (P and S waves) in LWD models. The energy of the collar wave radiates outside the borehole and then reflects at the bedding boundaries; meanwhile, the scattering waves from the well bottom can generate reflections too. These reflection arrivals match well with the time predicted by ray theories, respectively. Finally, we propose a possible means to estimate the dipping directions of geological interfaces by reflection waves emitted from both LWD transmitters and the apparent source at the well bottom.
Integrative taxonomy of extant maras supports the recognition of the genera Pediolagus and Dolichotis within the Dolichotinae (Rodentia, Caviidae)
Authors: Campo Denise H , Caraballo Diego A , Cassini Guillermo H , Lucero Sergio O , Teta Pablo
Published: March 2020

The subfamily Dolichotinae (Rodentia, Caviidae) includes two living species (Dolichotis patagonum and D. salinicola) of cursorial, long-legged rodents that inhabit semiarid thorn scrubs and shrublands in southern South America. Some authors consider that the morphological differences between D. patagonum and D. salinicola warrant circumscription of the latter in its own genus, Pediolagus. Based on a phylogeny and divergence times grounded on molecular data, as well as a qualitative and quantitative assessment of morphological differences, the distinction between Dolichotis and Pediolagus is equal to or greater than differences seen for other intergeneric comparisons within Cavioidea. Based on these results, we argue that the taxonomic designations of Dolichotis and Pediolagus should be retained.