bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing LKPD Medicinal Plant Diversity with an Investigation Model Group on Learning Comprehension
Authors: Prayitno Novia Linda , Suryadarma IGP
Published: June 2019

This study has purposes to: (1) Determine the eligibility of Lembar Kegiatan Peserta Didik (LKPD); (2) Determine the eligibility of LKPD model of group investigation on the understanding of students grade X. This research uses research and development approaches with steps of 4-D (four-D-model). Subject of trial of the study were limited to 10 students of grade XI. Subject of operational product trials consists of two classes, the experimental classes and control class which consists of 24 students of grade X of one high school in Yogyakarta, Indonesia. Data were analyzed by using SPSS to determine the validity, reliability item, and analyze data by the Independent T-Test. This research resulted in the product of the LKPD fit for use as a learning resource. The results of 1) validation subject matter and learning experts showed good and very good results with an average score of 2.8 and 3.3.2) The value of the understanding the significance of students at the pre-test of learning is 0.125> 0.05, whereas, at post learning is 0.007 <0.05.
The Effects of Web-Assisted Problem Based Learning Model of Physics Learning on High School Students’ Critical Thinking Skills
Authors: Alandia Rahma Ghalda , Jumadi  , Wilujeng Insih , Kuswanto Heru
Published: June 2019

The purpose of this research is to determine differences in critical thinking skills outcomes between groups with students who take physics learning with web-assisted problem based learning model with students who take physics learning using learning commonly used by teachers to student of XI class. This research was a quasi-experimental (quasi experiment) with the draft “post-test only control group design”. The population in this study is a XI class of even semester in SMA Negeri 2 Yogyakarta, Indonesia. The sample selection is based on the adjustment of the material that is used. The data were taken using the test methods and instruments used for assessment is 8 essay questions with 8 indicators of critical thinking skills tests. Based on the results of hypothesis testing that has been done by t-test sample independent found that there are differences in critical thinking skills outcomes significantly among students who take physics learning with web-assisted problem based learning model. Furthermore, there are effects web-assisted problem based learning model in students’ critical thinking skills. This is evident from the high effect size of Cohen’s test is included in the high category. Based on this it can be concluded that physics learning with web-assisted problem based learning model influence on high school students critical thinking skills outcomes.
Application of Multimedia Learning Modules assisted by “Tracker” Virtual Laboratory to Train Verbal Representation of Class XI High School Students
Authors: Oktavia Danis Alif , Nursuhud Puji Iman , Kurniawan Mas Aji , Jumadi  , Wilujeng Insih , Kuswanto Heru
Published: June 2019

This study aims to determine the application of multimedia learning modules assisted by tracker virtual laboratory (virlab) to train the verbal representation of students in class XI. This study uses observation and documentation methods to collect data. Observation instruments in the form of assessment sheets used to assess the level of representation students by using 2 classes where each class is filled by different educators. The first class is class XI IPA 1 (modelling class) and the second class is class XI IPA 2 (implementation class). The ability of verbal representations of students is assessed based on indicators on the assessment sheet. The results of the analysis show that verbal representation skills based on indicators clearly explain the problem, the ability to express opinions in sentence form, and describe definitions and terms of a concept in the implementation class obtain results that are better than the modelling classes. Whereas, the fourth indicator is explaining the results of the graph in the form of verbal representations in the modelling class obtained results that are better than the implementation class. These results indicate that application of multimedia learning modules assisted by tracker virlab application can be used to train verbal representation skills.
Artificial Intelligent in Education: The Development of ‘Disabel’ System to Analyze Student Learning Styles
Authors: Dewantara Brezto Asagi , Ghufron A.
Published: June 2019

The industrial revolution 4.0 is Characterized by automation and digitalization in various sectors. This of course has an immediate impact on the development of education. The Science of Technology has been integrated into the education sector so that the modern era of education can Utilize technological developments to improve the quality of education. The quality of education is related to the learning process. Learners must maximize the learning process to improve learning outcomes. Learning style plays an important role in the learning process, learners must therefore Recognize the learning style they have. This study aims to analyze learning styles based on the type of learning style classification (visual, auditory and kinesthetic). The research uses waterfall method and developed based on the website by applying the principle of artificial intelligence by applying the forward chaining algorithm as an inference engine. The forward chaining is designed based on the rules of the system knowledge and collaborated with knowledge of learning styles. To assess the system, the program was tested twice by involving two program experts. The results of the first learning style analysis system test program obtained an average score of 3.68 on a scale of 4 with the criteria of "Very Good". Second program expert assessed this system with an average score of 3.89on a scale of 4 with criteria for "Very Good". Then the overall score for the learning style analysis system at a score of 3.87 with the criteria of "Very Good".
The Innovative Framework for Developing Science Teacher Education: NOS Within TPACK
Authors: Widowati Asri
Published: June 2019

Skill in using of effective technology in learning has become an important skill for science teachers and an important topic in current research. The integration of technology in education grew rapidly in the 21st century, and influenced the shift in pedagogical content knowledge, and was known as TPACK. Equally important in the science, the NOS payload must also be integrated in TPACK for the science teacher’s education so that the fundamental principles of science learning are not forgotten and the science learning that is held as characteristic of science. The innovation of integrating NOS loads in TPACK, hereinafter referred to as NOS-loaded TPACK is essential for the development of the quality of science teacher education.
STREAMIN Model for the Next Generation of Science Education in Indonesia
Authors: Imaduddin Muhamad , Zuhaida Anggun
Published: June 2019

The rapid development of science and technology globally becomes a challenge that must be faced in the present and in the future. Reorientation of science education has seen science in a collaborative perspective through the STEM (Science, Technology, Engineering, and Mathematics) approach. Nevertheless, the "arts" aspect needs to be taken into consideration that it is important to cultivate an innovative spirit in producing the work. Furthermore, self identity as a nation that believes in God and a united country in cultural diversity need to be nurtured. The STREAMIN Model is needed to realize the next generation of science education which has innovative, religious, and nationalist character. This paper reviews the literature through identification of science education (S) regarding technology (T), religion (R), engineering (E), arts (A), mathematics (M), indigenous culture (I), and nationalism (N). In the planning, “Spider Web” analysis is needed to see the orientation of science learning. Classroom management emphasizing reading and writing activities, as well as project-based learning is needed to improve learners’ literacy. The flipped classroom is designed in accordance with the current millennial generation. The evaluation also emphasizes the availability of authentic assessment prioritizing aspects of innovation, religious attitude, and spirit of nationalism.
Preparing 21st Century Teachers: Implementation of 4C Character’s Pre-Service Teacher through Teaching Practice
Authors: Astuti Andari Puji , Aziz Abdul , Sumarti Sri Susilogati , Bharati Dwi Anggani Linggar
Published: June 2019

The implementation of education in the 21st century has a different direction compared to the previous century. Education in the 21st century is expected to produce outcomes for students who are ready to enter the post-industrial era (industrial revolution 4.0). The direction of education in the 21st century is no longer holding education aimed at preparing people in a simple, static / linear, and predictable world. The characteristics and demands of the 21st century above produce four learning characters of 21st century, namely: (1). Critical Thinking and Problem Solving; (2) Creativity and Innovation; (3) Communication; (4) Collaboration. For this reason, pre-service and in-service teachers are expected to be able to create learning with HOTS (High Order Thinking Skills) outputs. the topic of this research is how to prepare 21st century teachers in terms of the 4C characters, especially for pre-service teachers.
Design of an extrusion machine for the manufacture of plastic tubes
Authors: García-León R A , Bohorquez-Niño A , Barbosa-Paredes J F
Published: June 2019

Currently in Colombia in the northern region of Santander, exist a large number of farmers who grow different agricultural products and require more appropriate irrigation systems hoses, but due to the high demand, local manufacturers do not meet the requirements and in many cases the hoses are brought from other parts of the country bringing higher costs. In the present work, the design of a prototype plastic extrusion machine for hose producers in the province of Ocaña was carried out. The development of the research was carried out through the execution of mathematical calculations with the support of specialized bibliographic material and a Finite Element Analysis with help of SolidWorks Simulation Software, where the geometric model of the machine in order to identify the elements subjected to maximum of efforts. The results obtained show that the prototype will be in charge of producing 1/2, 3/4 and 1 inch. In conclusion the prototype works in adequate conditions always ensuring high levels of safety and operation; Moreover, the machine will be low cost to promote growth and competitive capacity of hose producers, as a solution to the problems based on competitiveness, working conditions and resources economic.
Digital album with augmented reality: Francisco de Paula Santander Ocaña University botanic garden “Jorge Enrique Quintero Arenas”
Authors: Rico-Bautista D W , Barrientos-Avendaño E , Cuesta-Quintero F R , Areniz-Arevalo Y , Coronel-Rojas L A , Londoño-Torrado D A , Amaya-Amaya E
Published: June 2019

Francisco de Paula Santander Ocaña University has a botanic garden. The University Botanic Garden Jorge Enrique Quintero Arenas was created with the mission of preserving the dry forest ecosystem and the types of vegetation and flora present in the northeast of Colombia, providing adequate spaces for research and environmental education. From new technologies that can be integrated without affecting the environment and generate various changes in the way of learning, solutions are proposed for continuous improvement, which in the end is done in favor of sustainability, quality of life and a smart botanic garden. This paper presents the results of the software prototype, whose purpose is to make known all the biodiversity that is available. It was done through a digital album applying augmented reality, where those interested will find the different species with their relevant information.
Effect of turbulence model on flameless combustion simulation of a regenerative furnace
Authors: Yepes H A , Amell A A
Published: June 2019

The high energy consumes have generated the need of developing higher efficiency devices, in this sense flameless combustion is a great alternative. The design of flameless combustion systems by means of Computational Flow Dynamics simulation is an alternative value to reduce costs, however it required an adequate model selection. In the present study a capability evaluation of standard and realizable versions of k-e turbulence model was carried out. Experimental measurements of temperature and chemical species were performed in combustion chamber of a regenerative furnace in order to compare this with numerical data and in this way determinate the performance and the incidence of the selected models. The realizable version shows better results regarding at changes of flow direction and recirculation patterns inside the furnace.
Comparative study of costs for reinforced concrete portico buildings designed with different degrees of seismic performance
Authors: Cáceres J R , Márquez J F , Rojas J P
Published: June 2019

The Colombian regulation of earthquake resistant construction NSR-10 establishes that the seismic-resistant capacity of a building must be classified according to three degrees of energy dissipation: Special energy dissipation, moderate energy dissipation and minimum energy dissipation. The dimensioning and detailing requirements for structural elements that are demanded according to each grade depend on the need to withstand earthquakes in the inelastic range according to the seismic hazard zone in which the structure is located. This work presents an analysis of the incidence of the requirements of each degree of energy dissipation on the costs of multi-storey building structures. For this, the structural analysis and design of four building configurations (2, 3, 4 and 5 floors) for each minimum energy dissipation, moderate energy dissipation, and special energy dissipation grade has been carried out and the quantities of work with their respective total cost have been determined. As a general conclusion, it can be stated that the cost of building a structure that has special energy dissipation capacity for a given building can be twice that of a structure that has minimum energy dissipation capacity for the same building. On the other hand, it was observed that in order to guarantee a rigidity comparable to that of the other models analyzed, the system of reinforced concrete portal resistant to moments for DES level requires large column dimensions in the case of buildings of four or more floors, which suggests that other types of more efficient elements should be used in the vertical seismic resistance system.
Investigation of hydrodynamic features in two-stage steam-air-blown entrained-flow gasifier
Authors: Abaimov N A , Butakov E B , Burdukov A P , Ryzhkov A F
Published: June 2019

The goal of the work is to study the hydrodynamics features of media movement in IT SB RAS two-stage steam-air-blown entrained-flow gasifier. Analysis of the data obtained using the verified CFD model based on the results of the experiments showed that the conversion process in the mode proceeds in three phases, the localization of which depends on the input mode and design parameters. According to the results of CFD modeling, the injection of relatively cold, weakly superheated steam axial jet into second phases creates hydrodynamic, structural and temperature heterogeneity, which decreases markedly in the third phases. The supplied steam at the second phase performs mainly the functions of a cooler, causing a decrease in the temperature of the reaction mixture and a decrease in the rate of gasification reactions.
Experimental studies of ignition of a 5 MW semi-industrial installation in Ekibastuz coal using electrochemical activation technology
Authors: Burdukov A P , Butakov E B , Chernova G V
Published: June 2019

This work uses a high-frequency electrochemical ignition device that generates high-frequency cold plasma arcs that ionize the oxidizer, which contributes to the multiple acceleration of thermochemical transformations of carbon-containing solid fuels and wastes, and, consequently, to a more complete rapid burning out of the torch. Coal fuel research was carried out at the CDPP-2 station in the city of Ekibastuz, and experiments were conducted on the ignition and combustion of coal fuels using a high-frequency electrochemical ignition device. After the coal fuel was supplied to the street swirler, the combustion chamber was heated for 4 minutes, after reaching 500 ° C, the coal burned in the autothermal regime. These results will be used to design a pilot burner at the station in Ekibastuz, Kazakhstan.
A Study of Superlean Combustion Modes in a Reverse Flow Combustion Chamber Burning Multicomponent Fuel
Authors: Guryanov A I , Evdokimov O A , Guryanova M M , Piralishvili Sh A , Kononova V V , Veretennikov S V
Published: June 2019

Feasibility of using oxidant vortex reverse flow in designing jet burners for prospective combustion chambers fueled with synthesis gas. A complex of experimental studies of the reverse flow burner module fueled with methane with addition of synthesis gas is carried out; steady combustion concentration range is defined.
The composition determination of combustion products of modified ethanol
Authors: Henarava T M , Hrusheuski U U , Krivosheyev P N , Leschevich V V , Penyazkov O G , Yu Shimchenko S , Shushkov S V
Published: June 2019

The content of pyrolysis products during combustion of modified ethanol in the Rapid Compression Machine (RCM) was studied. It was found that significant reduction in the ignition delay time for lean reactive mixture (φ = 0.6) with a decrease in maximum pressure and unchanged mean rate of pressure. It indicates an increase in the burning rate of the mixture. It has been observed that the modification of ethanol with carbon nanoparticles leads to decrease in the content of methane and hydrogen in combustion products, but ignition delay time does not change (A1) or reduce by 35% (A2) at φ = 1.
Reduced model of chemical kinetic and two-dimensional structure of detonation wave in rich mixtures of methane with oxidizer
Authors: Trotsyuk A.V. , Fomin P.A.
Published: June 2019

Two-step reduced model of chemical kinetics of detonation combustion of methane mixtures is presented. The possibility of condensed carbon (soot) microparticles formation in reaction products is taken into account for the first time. The model is simple (only one ordinary differential equation in a main heat release zone) and physically grounded. It is in consistent with the second law of thermodynamics and Le Chatelier’s principle. The model verification has been performed via numerical calculations of parameters and two-dimensional structure of detonation wave in the fuel-rich methane-oxidizer mixture. The irregular cellular structure of the wave with all its main features, observed in the experiments, was reproduced in the calculations. The dominant size of the detonation cell is in good agreement with experimental data and corresponding estimations in the frames of generally accepted Vasil’ev-Nikolaev model of detonation cell.
Rockets, gauges, and pendulums: applying engineering principles to cell biology
Authors: Sullivan William
Published: June 2019

From flight to radar to Velcro, biological form and function have inspired engineers for centuries. It is equally valuable to consider whether concepts in engineering might provide insights into core biological processes. To explore this idea, cell cycle checkpoints, biological clocks, and signaling pathways are viewed here from an engineering perspective. Engineering concepts covered include gauge error, the distinction between precision and accuracy, and the Taguchi method of robust design. Also discussed is the Pareto principle, which describes the observation that, in complex systems, a minority of the components (or inputs) are responsible for a majority of the outputs. These concepts enable engineers to manage complexity, both in system design and in operation. Thus, with new techniques and large data sets revealing ever-increasing levels of biological complexity, an engineering mindset may be particularly valuable for the study of living systems.
Harnessing epithelial homeostatic mechanisms to fight cancer
Authors: Lahvic Jamie L. , Hariharan Iswar K.
Published: June 2019

Cancer treatments have, in general, targeted the cancer cell itself. This approach has often been unsuccessful in the long term, especially for solid tumors. Even targeted therapies based on sequencing cancer genomes can be thwarted by genetic heterogeneity within tumors. Furthermore, genomic instability in cancer cells accelerates the generation of variants that are resistant to the treatment. Immunotherapies and anti-angiogenic treatments, which target the tumor-interacting and tumor-adjacent cells, have overcome some of these challenges, suggesting that other methods that target wild-type cells could be valuable in arresting tumor progression. Studies in Drosophila have uncovered mechanisms by which cells within an epithelium can react to neighboring cells that have genetic differences, resulting in the elimination of one population at the expense of another. Some of these mechanisms are now known to be conserved in mammals. The possibility of harnessing such mechanisms to empower normal epithelial cells to eliminate their precancerous neighbors before they develop into fully fledged cancers is an area of research that merits more attention.
Extinction: A Very Short Introduction
Authors: Wignall Paul B.
Published: June 2019

Extinction has occurred throughout the history of life, with the result that nearly all the species that have ever existed are now extinct. Extinction: A Very Short Introduction looks at the causes and nature of extinctions, past and present, and the factors that can make a species vulnerable. Summarizing what we know about all of the major and minor extinction events, it examines some of the greatest debates in modern science, such as the relative role of climate and humans in the death of the Pleistocene megafauna, including mammoths and giant ground sloths, and the roles that global warming, ocean acidification, and deforestation are playing in present-day extinctions.
Old females rarely mate with old males in roe deer, Capreolus capreolus
Authors: Vanpé Cécile , Gaillard Jean-Michel , Hewison A J Mark , Quemere Erwan , Kjellander Petter , Pellerin Maryline , Lemaître Jean-François
Published: June 2019

Little is known about whether female mating tactics vary with age based on their preference for mates. To fill this knowledge gap, we examined how maternal age is related to the age of their mates using detailed individual long-term monitoring of a genotyped and pedigreed European roe deer (Capreolus capreolus Linnaeus, 1758) population. We found that mating between old females and prime-aged males was more frequent than mating between prime-aged females and prime-aged males. This suggests that old females avoid old mates. Old females might be more selective in their mate choice than prime-aged females owing to increased mate-sampling effort. Our finding is in line with the terminal investment/allocation hypothesis. The study of age-related variation in female mating behaviour is particularly important because this behaviour can inﬂuence the intensity and direction of sexual selection and the maintenance of variation in male sexually selected traits. Further studies are needed to quantify the exact fitness benefits of age-specific mating tactics in females.
Skeletal and dental effects of surgically assisted rapid palatal expansion: a systematic review of randomized controlled trials
Authors: Bortolotti Francesco , Solidoro Livia , Bartolucci Maria Lavinia , Incerti Parenti Serena , Paganelli Corrado , Alessandri-Bonetti Giulio
Published: June 2019

Background

Surgically assisted rapid maxillary expansion (SARME) is a surgical technique developed to correct transverse discrepancies in skeletally mature patients. However, there is limited evidence concerning the immediate skeletal and dental changes obtained only due to SARME.

Objective

The aim of the present systematic review is to investigate the immediate skeletal and dental effects of SARME in adult patients with transverse maxillary hypoplasia.

Search Methods

An electronic search of the literature in MEDLINE, The Cochrane Library, Lilacs and Scopus databases was performed.

Selection Criteria

Only randomized controlled trials (RCTs) studies investigating the skeletal and dental effects of SARME procedures in adult patients were included.

Data Collection and Analysis

The included studies received a methodological quality scoring according to the revised Cochrane risk-of-bias tool for randomized trials. The quality of evidence was assessed by means of the Grading Recommendation Assessment, Development and Evaluation (GRADE) system. For each included study and for each analysed parameter, the difference in means and 95 per cent confidence interval was calculated between baseline and immediate post-expansion. A meta-analysis of original outcome data, if possible, was conducted.

Results

Nine articles were selected. The methodological quality ratings indicated that one study was at low risk of bias, seven presented some concerns and only one was at high risk of bias. In all the included studies, the SARME procedure resulted in a significant expansion of the maxillary transverse dimension. The meta-analysis compared skeletal and dental inter-molar width before and after treatment: the mean difference was of 3.3 mm (2.8–3.9) and 7.0 mm (6.1–7.8), respectively (P-value less than 0.001). The quality of evidence was low-moderate.

Conclusions

SARME is effective in obtaining a significant expansion of the maxillary transverse dimension. However, the immediate SARME effect is mainly a molar expansion rather than a pure bone transverse widening of the maxilla.

Registration

The review protocol was registered at PROSPERO database with the registration number CRD42018117967.
Bi-Level Participatory Forest Management Planning Supported by Pareto Frontier Visualization
Authors: Marques S , Bushenkov V A , Lotov A V , Marto M , Borges J G
Published: June 2019

This research addresses the problem of forested landscape management planning in contexts characterized by multiple ecosystem services and multiple stakeholders. A new methodology for participatory landscape-level forest management is proposed. Specifically, a bilevel representation is used, whereas models of subsystems are used for constructing an integrated model of the master problem. Participatory workshops and interactive visualization of the Pareto frontier are used to support the solution of the multi-objective optimization upper- and lower-level problems. The visualization is implemented by a technique—Interactive Decision Maps—that displays interactively the Pareto frontier in the form of decision maps, that is, collections of the objectives’ tradeoff curves. Since the upper-level problem may be characterized by a large number of decision variables, we compare the Pareto frontier generated by the Interactive Decision Maps technique with the Pareto frontier generated by a decomposition approach that builds from the Pareto frontiers of the lower-level subproblems. The approach supports further the negotiation between upper- and lower-level goals. Results are discussed for a large-scale application in a forested landscape in northwest Portugal.
High Prevalence of Apical Periodontitis in Patients With Inflammatory Bowel Disease: An Age- and Gender- matched Case-control Study
Authors: Poyato-Borrego Manuel , Segura-Sampedro Juan J , Martín-González Jenifer , Torres-Domínguez Yolanda , Velasco-Ortega Eugenio , Segura-Egea Juan J
Published: June 2019

Results of this age- and gender- matched case-control study show that the prevalence of apical periodontitis, diagnosed as radiolucent periapical lesions, is higher in patients with inflammatory bowel disease than in healthy control subjects (OR = 5.71; p = 0.0048).
TDM of Anti-TNF Agents: The Importance of Being Active!
Authors: Annese Vito
Published: June 2019

Therapeutic drug monitoring (TDM) for anti-TNFα agents hass gained an increased momentum; although it is surely recommended in case of loss of response, its usefulness during maintenance therapy is still debated. Fernandes et al have added useful information in this regard.
pfhrp2 and pfhrp3 Gene Deletions That Affect Malaria Rapid Diagnostic Tests for Plasmodium falciparum: Analysis of Archived Blood Samples From 3 African Countries
Authors: Thomson Rebecca , Beshir Khalid B , Cunningham Jane , Baiden Frank , Bharmal Jameel , Bruxvoort Katia J , Maiteki-Sebuguzi Catherine , Owusu-Agyei Seth , Staedke Sarah G , Hopkins Heidi
Published: June 2019

Background

Malaria rapid diagnostic tests (mRDTs) that target histidine-rich protein 2 (HRP2) are important tools for Plasmodium falciparum diagnosis. Parasites with pfhrp2/3 gene deletions threaten the use of these mRDTs and have been reported in Africa, Asia, and South America. We studied blood samples from 3 African countries to determine if these gene deletions were present.

Methods

We analyzed 911 dried blood spots from Ghana (n = 165), Tanzania (n = 176), and Uganda (n = 570). Plasmodium falciparum infection was confirmed by 18S rDNA polymerase chain reaction (PCR), and pfhrp2/3 genes were genotyped. True pfhrp2/3 gene deletions were confirmed if samples were (1) microscopy positive; (2) 18S rDNA PCR positive; (3) positive for merozoite surface protein genes by PCR or positive by loop-mediated isothermal amplification; or (4) quantitative PCR positive with >5 parasites/µL.

Results

No pfhrp2/3 deletions were detected in samples from Ghana, but deletions were identified in Tanzania (3 pfhrp2; 2 pfhrp3) and Uganda (7 pfhrp2; 2 pfhrp3). Of the 10 samples with pfhrp2 deletions, 9 tested negative by HRP2-based mRDT.

Conclusions

The presence of pfhrp2/3 deletions in Tanzania and Uganda, along with reports of pfhrp2/3-deleted parasites in neighboring countries, reinforces the need for systematic surveillance to monitor the reliability of mRDTs in malaria-endemic countries.
PPR-SMR1 is required for the splicing of multiple mitochondrial introns, interacts with Zm-mCSF1, and is essential for seed development in maize
Authors: Chen Zongliang , Wang Hong-Chun , Shen Jiayu , Sun Feng , Wang Miaodi , Xu Chunhui , Tan Bao-Cai
Published: June 2019

Two maize nucleus-encoded splicing factors, PPR-SMR1 and Zm-mCSF1, are required for the splicing of most mitochondrial group II introns and subsequent complex I biogenesis, and therefore play important roles in seed development.
The Risk of Pregnancy Related Hypertension Disorder Associated with Sickle Cell Trait in U.S. Service Women
Authors: O’Hara Christina , Singer Darrell E , Niebuhr David W
Published: June 2019

Introduction

The health impact of the heterozygous (Hb Ss) Sickle Cell Trait (SCT) among the estimated one million females of reproductive age in the United States on pregnancy related hypertensive disorders (PRHD) including preeclampsia is not as well understood or researched as Sickle Cell Disease (SCD).

Materials and Methods

This retrospective cohort study included 25,020 U.S. enlisted, active duty service women during 1992 to 2013. Race within the sample is primarily black (84%) given that blacks have the highest prevalence of SCT. All 5,004 SCT positive individuals and a matched sample of 20,016 from those considered SCT negative were followed while on active duty for PRHD outcomes including gestational hypertension (GHTN), preeclampsia and eclampsia.

Results

The adjusted incidence rate ratio (IRR) for any PRHD in SCT positive compared to negative individuals was 1.46 (95% CI 1.32 – 1.62). SCT positive versus negative subjects had higher health care utilization rates and utilization rate ratios (URR) for all PRHD diagnoses combined 2.03 (95%CI: 1.97 – 2.10) and for each specific PHRD diagnosis. The prevalence of preeclampsia or eclampsia did not vary by SCT status. The overall PRHD attributable risk due to SCT was 30.4% (95% CI 23.1–37.1%) and the overall number needed to screen to detect a case of PRHD was 156 (95% CI 117–220).

Conclusions

The results of this study indicate that being SCT positive is a risk factor for PRHD and provides evidence that SCT status may have an adverse effect on reproductive health. Future research needs to include other known risk factors for PRHD to include gravity and parity history, BMI, past history of PRHD prior to enlistment as well as to examine the association with maternal/child pregnancy outcomes.
The assembly of the Virgo cluster, traced by its galaxy haloes
Authors: Taylor James E , Shin Jihye , Ouellette Nathalie N-Q , Courteau Stéphane
Published: June 2019

Kinematic studies have produced accurate measurements of the total dark matter mass and mean dark matter density within the optical extent of galaxies for large samples of objects. Here we consider theoretical predictions for the latter quantity, $\bar{\rho }_{\rm dm}$, measured within the isophotal radius R23.5, for isolated haloes with universal density profiles. Through a combination of empirical scaling relations, we show that $\bar{\rho }_{\rm dm}$ is expected to depend weakly on halo mass and strongly on redshift. When galaxy haloes fall into larger groups or clusters, they become tidally stripped, reducing their total dark matter mass, but this process is expected to preserve central density until an object is close to disruption. We confirm this with collisonless simulations of cluster formation, finding that subhaloes have values of $\bar{\rho }_{\rm dm}$ close to the analytic predictions. This suggests that $\bar{\rho }_{\rm dm}$ may be a useful indicator of infall redshift on to the cluster. We test this hypothesis with data from the SHIVir survey, which covers a reasonable fraction of the Virgo cluster. We find that galaxies with high $\bar{\rho }_{\rm dm}$ do indeed trace the densest regions of the cluster, with a few notable exceptions. Samples selected by environment have higher densities at a significance of 3.5–4σ, while samples selected by density are more clustered at 3–3.5σ significance. We conclude that halo density can be a powerful tracer of the assembly history of clusters and their member galaxies.
Vortex instabilities triggered by low-mass planets in pebble-rich, inviscid protoplanetary discs
Authors: Pierens A , Lin M-K , Raymond S N
Published: June 2019

In the innermost regions of protoplanerary discs, the solid-to-gas ratio can be increased considerably by a number of processes, including photoevaporative and particle drift. Magnetohydrodynamic disc models also suggest the existence of a dead zone at R ≲ 10 au, where the regions close to the mid-plane remain laminar. In this context, we use two-fluid hydrodynamical simulations to study the interaction between a low-mass planet (∼1.7 M⊕) on a fixed orbit and an inviscid pebble-rich disc with solid-to-gas ratio ϵ ≥ 0.5. For pebbles with Stokes numbers St = 0.1, 0.5, multiple dusty vortices are formed through the Rossby wave instability at the planet separatrix. Effects due to gas drag then lead to a strong enhancement in the solid-to-gas ratio, which can increase by a factor of ∼103 for marginally coupled particles with St = 0.5. As in streaming instabilities, pebble clumps reorganize into filaments that may plausibly collapse to form planetesimals. When the planet is allowed to migrate in an Minimum Mass Solar Nebula (MMSN) disc, the vortex instability is delayed due to migration but sets in once inward migration stops due a strong positive pebble torque. Again, particle filaments evolving in a gap are formed in the disc while the planet undergoes an episode of outward migration. Our results suggest that vortex instabilities triggered by low-mass planets could play an important role in forming planetesimals in pebble-rich, inviscid discs, and may significantly modify the migration of low-mass planets. They also imply that planetary dust gaps may not necessarily contain planets if these migrated away.
Hydrodynamical interaction of stellar and planetary winds: effects of charge exchange and radiation pressure on the observed Ly α absorption
Authors: Esquivel A , Schneiter M , Villarreal D’Angelo C , Sgró M A , Krapp L
Published: June 2019

Lyman α observations of the transiting exoplanet HD 209458b enable the study of exoplanet exospheres exposed to stellar extreme ultraviolet (EUV) fluxes, as well as the interacting stellar wind properties. In this study we present 3D hydrodynamical models for the stellar–planetary wind interaction including radiation pressure and charge exchange, together with photoionization, recombination, and collisional ionization processes. Our models explore the contribution of the radiation pressure and charge exchange to the Ly α absorption profile in a hydrodynamical framework, and for a single set of stellar wind parameters appropriate for HD 209458. We find that most of the absorption is produced by the material from the planet, with a secondary contribution of neutralized stellar ions by charge exchange. At the same time, the hydrodynamic shock heats up the planetary material, resulting in a broad thermal profile. Meanwhile, the radiation pressure yields a small velocity shift of the absorbing material. While neither charge exchange nor radiation pressure provides enough neutrals at the velocity needed to explain the observations at −100 km s−1 individually, we find that the two effects combined with the broad thermal profile are able to explain the observations.
Modelling decretion discs in Be/X-ray binaries
Authors: Brown R O , Coe M J , Ho W C G , Okazaki A T
Published: June 2019

As the largest population of high mass X-ray binaries, Be/X-ray binaries provide an excellent laboratory to investigate the extreme physics of neutron stars. It is generally accepted that Be stars possess a circumstellar disc, providing an additional source of accretion to the stellar winds present around young hot stars. Interaction between the neutron star and the disc is often the dominant accretion mechanism. A large amount of work has gone into modelling the properties of these circumstellar discs, allowing for the explanation of a number of observable phenomena. In this paper, smoothed particle hydroynamics simulations are performed whilst varying the model parameters (orbital period, eccentricity, the mass ejection rate of the Be star and the viscosity and orientation of the disc). The relationships between the model parameters and the disc’s characteristics (base gas density, the accretion rate of the neutron star and the disc’s size) are presented. The observational evidence for a dependency of the size of the Be star’s circumstellar disc on the orbital period (and semi-major axis) is supported by the simulations.
Spectro-timing analysis of MAXI J1535–571 using AstroSat
Authors: Bhargava Yash , Belloni Tomaso , Bhattacharya Dipankar , Misra Ranjeev
Published: June 2019

We report the results of the analysis of an AstroSat observation of the black hole candidate MAXI J1535–571 during its hard-intermediate state. We studied the evolution of the spectral and timing parameters of the source during the observation. The observation covered a period of ∼5 d and consisted of 66 continuous segments, corresponding to individual spacecraft orbits. Each segment was analysed independently. The source count rate increased roughly linearly by ∼30 per cent. We modelled the spectra as a combination of radiation from a thermal disc component and a power law. The timing analysis revealed the presence of strong quasi-periodic oscillations with centroid frequency νQPO fluctuating in the range of 1.7–3.0 Hz. We found a tight correlation between the QPO centroid frequency νQPO and the power-law spectral index Γ, while νQPO appeared not to be correlated with the linearly increasing flux itself. We discuss the implications of these results on physical models of accretion.
A comprehensive examination of the optical morphologies of 719 isolated galaxies in the AMIGA sample
Authors: Buta Ronald J , Verdes-Montenegro Lourdes , Damas-Segovia Ancor , Jones Michael , Blasco Javier , Fernández-Lorenzo Mirian , Sanchez Susana , Garrido Julian , Ramirez-Moreta Pablo , Sulentic Jack W
Published: June 2019

Using images from Sloan Digital Sky Survey Data Release 8, we have re-examined the morphology of 719 galaxies from the Analysis of the interstellar Medium in Isolated GAlaxies (AMIGA) project, a sample consisting of the most isolated galaxies that have yet been identified. The goal is to further improve the classifications of these galaxies by examining them in the context of the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system, which includes recognition of features that go beyond the original de Vaucouleurs point of view. Our results confirm previous findings that isolated galaxies are found across the complete revised Hubble sequence, with intermediate- to late-type (Sb-Sc) spirals being relatively more common. Elmegreen Arm Classifications are also presented, and show that more than 50 per cent of the 514 spirals in the sample for which an arm class (AC) could be judged are grand design (AC 8,9,12). The visual bar fraction for the sample is ≈50 per cent, but only 16 per cent are classified as strongly barred (SB). The dominant family classification is SA (non-barred), the dominant inner variety classification is (s) (pure spiral), and the dominant outer variety classification is no outer ring, pseudo-ring, or lens. The Kolmogorov–Smirnov test is used to check for potential biases in the morphological interpretations, and for any possible relation between rings, bars, and ACs with local environment and far-infrared excess. The connection between morphology and stellar mass is also examined for a subset of the sample.
Parallel Evolution of HIV-1 in a Long-Term Experiment
Authors: Bertels Frederic , Leemann Christine , Metzner Karin J , Regoes Roland R
Published: June 2019

One of the most intriguing puzzles in biology is the degree to which evolution is repeatable. The repeatability of evolution, or parallel evolution, has been studied in a variety of model systems, but has rarely been investigated with clinically relevant viruses. To investigate parallel evolution of HIV-1, we passaged two replicate HIV-1 populations for almost 1 year in each of two human T-cell lines. For each of the four evolution lines, we determined the genetic composition of the viral population at nine time points by deep sequencing the entire genome. Mutations that were carried by the majority of the viral population accumulated continuously over 1 year in each evolution line. Many majority mutations appeared in more than one evolution line, that is, our experiments showed an extreme degree of parallel evolution. In one of the evolution lines, 62% of the majority mutations also occur in another line. The parallelism impairs our ability to reconstruct the evolutionary history by phylogenetic methods. We show that one can infer the correct phylogenetic topology by including minority mutations in our analysis. We also find that mutation diversity at the beginning of the experiment is predictive of the frequency of majority mutations at the end of the experiment.
Meta-Omics Reveals Genetic Flexibility of Diatom Nitrogen Transporters in Response to Environmental Changes
Authors: Busseni Greta , Rocha Jimenez Vieira Fabio , Amato Alberto , Pelletier Eric , Pierella Karlusich Juan J , Ferrante Maria I , Wincker Patrick , Rogato Alessandra , Bowler Chris , Sanges Remo , Maiorano Luigi , Chiurazzi Maurizio , Ribera d’Alcalà Maurizio , Caputi Luigi , Iudicone Daniele
Published: June 2019

Diatoms (Bacillariophyta), one of the most abundant and diverse groups of marine phytoplankton, respond rapidly to the supply of new nutrients, often out-competing other phytoplankton. Herein, we integrated analyses of the evolution, distribution, and expression modulation of two gene families involved in diatom nitrogen uptake (DiAMT1 and DiNRT2), in order to infer the main drivers of divergence in a key functional trait of phytoplankton. Our results suggest that major steps in the evolution of the two gene families reflected key events triggering diatom radiation and diversification. Their expression is modulated in the contemporary ocean by seawater temperature, nitrate, and iron concentrations. Moreover, the differences in diversity and expression of these gene families throughout the water column hint at a possible link with bacterial activity. This study represents a proof-of-concept of how a holistic approach may shed light on the functional biology of organisms in their natural environment.
Prevalence and correlates of fatigue in patients with meningioma before and after surgery
Authors: van der Linden Sophie D , Gehring Karin , Rutten Geert-Jan M , Kop Willem J , Sitskoorn Margriet M
Published: June 2019

Background

Fatigue is a common symptom in patients with brain tumors, but comprehensive studies on fatigue in patients with meningioma specifically are lacking. This study examined the prevalence and correlates of fatigue in meningioma patients.

Methods

Patients with grade I meningioma completed the Multidimensional Fatigue Inventory (MFI-20) before and 1 year after neurosurgery. The MFI consists of 5 subscales: General Fatigue, Physical Fatigue, Mental Fatigue, Reduced Motivation, and Reduced Activity. Patients’ scores were compared with normative data. Preoperative fatigue was compared with postoperative fatigue. Correlations with sex, age, education, tumor hemisphere, preoperative tumor volume, antiepileptic drugs (AEDs), symptoms of anxiety/depression, and self-reported cognitive complaints were explored.

Results

Questionnaires were completed by 65 patients preoperatively, and 53 patients postoperatively. Of 34 patients, data from both time points were available. Patients had significantly higher fatigue levels on all subscales compared to normative values at both time points. Mean scores on General Fatigue, Physical Fatigue, and Mental Fatigue remained stable over time and improvements were observed on Reduced Motivation and Reduced Activity. Preoperatively, the prevalence of high fatigue (Z-score ≥ 1.3) varied between 34% for Reduced Motivation and 43% for General Fatigue/Mental Fatigue. The postoperative prevalence ranged from 19% for Reduced Activity to 49% on Mental Fatigue. Fatigue was associated with cognitive complaints, anxiety and depression, but not with education, tumor lateralization, tumor volume, or AEDs.

Conclusion

Fatigue is a common and persistent symptom in patients with meningioma undergoing neurosurgery. Findings emphasize the need for more research and appropriate care targeting fatigue for meningioma patients.
Lymphocyte Hydrogen Sulfide Production Predicts Coronary Artery Lesions in Children with Kawasaki Disease: A Preliminary, Single-Center Study
Authors: Lin Jing , Zhao Huacai , Jiao Fuyong , Ma Lei , Wang Weiqing , Ma Le
Published: June 2019

To identify whether lymphocyte hydrogen sulfide production is a potential biomarker for predicting coronary artery lesions (CAL) in children with Kawasaki disease (KD). Eighty-six children with KD, 33 normal children and 43 children with fever from June 2016 to January 2019 in Shaanxi Provincial People's Hospital were enrolled. Of 86 KD patients, 16 patients exhibited CAL. Lymphocyte hydrogen sulfide production was significantly greater in KD patients (13.7 ± 2.7) nmol/min/108 lymphocytes than in the controls (9.26 ± 3.33) nmol/min/108 lymphocytes and the fever group (8.21 ± 2.77) nmol/min/108 lymphocytes. The lymphocyte hydrogen sulfide production was greater in CAL patients than the non-CAL patients [(16.24 ± 1.81) vs. (13.12 ± 2.58), p < 0.001]. Receiver operating characteristic curve indicated when the lymphocyte hydrogen sulfide production was >15.285 nmol/min/108 lymphocytes, the sensitivity and specificity for predicting CAL at convalescence were 87.5% and 82.9%, respectively. Lymphocyte hydrogen sulfide production in the acute period is a potentially useful biomarker for predicting CAL in KD children.