bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Density Lipoprotein from Chronic Kidney Disease Patients Modulates Polymorphonuclear Leukocytes
Authors: Raupachova Jana , Kopecky Chantal , Cohen Gerald
Published: February 2019

The anti-inflammatory properties of high-density lipoproteins (HDL) are lost in uremia. These HDL may show pro-inflammatory features partially as a result of changed protein composition. Alterations of polymorphonuclear leukocytes (PMNLs) in chronic kidney disease (CKD) may contribute to chronic inflammation and high vascular risk. We investigated if HDL from uremic patients is related to systemic inflammation by interfering with PMNL function. PMNL apoptosis was investigated by assessing morphological features and DNA content. CD11b surface expression was quantified by flow cytometry. Oxidative burst was measured via cytochrome c reduction assay. Chemotaxis was assessed by using an under-agarose migration assay. We found that HDL from CKD and hemodialysis (HD) patients significantly attenuated PMNL apoptosis, whereas HDL isolated from healthy subjects had no effect on PMNL apoptosis. The use of signal transduction inhibitors indicated that uremic HDL exerts anti-apoptotic effects by activating pathways involving phosphoinositide 3-kinase and extracellular-signal regulated kinase. Healthy HDL attenuated the surface expression of CD11b, whereas HDL from CKD and HD patients had no effect. All tested isolates increased the stimulation of oxidative burst, but did not affect PMNL chemotactic movement. In conclusion, HDL may contribute to the systemic inflammation in uremic patients by modulating PMNL functions.
Malaysian Cobra Venom: A Potential Source of Anti-Cancer Therapeutic Agents
Authors: Zainal Abidin Syafiq Asnawi , Lee Yee Qian , Othman Iekhsan , Naidu Rakesh
Published: February 2019

Cancer is a deadly disease and there is an urgent need for the development of effective and safe therapeutic agents to treat it. Snake venom is a complex mixture of bioactive proteins that represents an attractive source of novel and naturally-derived anticancer agents. Malaysia is one of the world’s most biodiverse countries and is home to various venomous snake species, including cobras. Naja kaouthia, Naja sumatrana, and Ophiophagus hannah are three of the most common cobra species in Malaysia and are of medical importance. Over the past decades, snake venom has been identified as a potential source of therapeutic agents, including anti-cancer agents. This present review highlights the potential anticancer activity of the venom and purified venom protein of N. kaouthia, N. sumatrana, and O. hannah. In conclusion, this review highlights the important role of the venom from Malaysian cobras as an important resource that researchers can exploit to further investigate its potential in cancer treatment.
Biological System Responses of Dairy Cows to Aflatoxin B1 Exposure Revealed with Metabolomic Changes in Multiple Biofluids
Authors: Wang Qian , Zhang Yangdong , Zheng Nan , Guo Liya , Song Xiaoming , Zhao Shengguo , Wang Jiaqi
Published: February 2019

Research on mycotoxins now requires a systematic study of post-exposure organisms. In this study, the effects of aflatoxin B1 (AFB1) on biofluids biomarkers were examined with metabolomics and biochemical tests. The results showed that milk concentration of aflatoxin M1 changed with the addition or removal of AFB1. AFB1 significantly affected serum concentrations of superoxide dismutase (SOD) and malon dialdehyde (MDA), SOD/MDA, and the total antioxidant capacity. Significant differences of volatile fatty acids and NH3-N were detected in the rumen fluid. Eighteen rumen fluid metabolites, 11 plasma metabolites, and 9 milk metabolites were significantly affected by the AFB1. These metabolites are mainly involved in the pathway of amino acids metabolism. Our results suggest that not only is the study of macro-indicators (milk composition and production) important, but that more attention should be paid to micro-indicators (biomarkers) when assessing the risks posed by mycotoxins to dairy cows.
Occupational Exposure to Mycotoxins in Swine Production: Environmental and Biological Monitoring Approaches
Authors: Viegas Susana , Assunção Ricardo , Martins Carla , Nunes Carla , Osteresch Bernd , Twarużek Magdalena , Kosicki Robert , Grajewski Jan , Ribeiro Edna , Viegas Carla
Published: February 2019

Swine production workers are exposed simultaneously to multiple contaminants. Occupational exposure to aflatoxin B1 (AFB1) in Portuguese swine production farms has already been reported. However, besides AFB1, data regarding fungal contamination showed that exposure to other mycotoxins could be expected in this setting. The present study aimed to characterize the occupational exposure to multiple mycotoxins of swine production workers. To provide a broad view on the burden of contamination by mycotoxins and the workers’ exposure, biological (urine) samples from workers (n = 25) and 38 environmental samples (air samples, n = 23; litter samples, n = 5; feed samples, n = 10) were collected. The mycotoxins biomarkers detected in the urine samples of the workers group were the deoxynivalenol-glucuronic acid conjugate (60%), aflatoxin M1 (16%), enniatin B (4%), citrinin (8%), dihydrocitrinone (12%) and ochratoxin A (80%). Results of the control group followed the same pattern, but in general with a lower number of quantifiable results (<LOQ). Besides air samples, all the other environmental samples collected presented high and diverse contamination, and deoxynivalenol (DON), like in the biomonitoring results, was the most prominent mycotoxin. The results demonstrate that the occupational environment is adding and contributing to the workers’ total exposure to mycotoxins, particularly in the case of DON. This was confirmed by the biomonitoring data and the high contamination found in feed and litter samples. Furthermore, he followed multi-biomarker approach allowed to conclude that workers and general population are exposed to several mycotoxins simultaneously. Moreover, occupational exposure is probably described as being intermittent and with very high concentrations for short durations. This should be reflected in the risk assessment process.
Assessing Aflatoxin Exposure Risk from Peanuts and Peanut Products Imported to Taiwan
Authors: Lien Keng-Wen , Wang Xin , Pan Min-Hsiung , Ling Min-Pei
Published: February 2019

Aflatoxins are highly toxic and cause disease in livestock and humans. In order to assess Taiwan population exposure to aflatoxin from peanuts and peanut products, a total of 1089 samples of peanut candy, peanut butter, and peanuts etc. were collected in the period from 2011 to 2017 and analyzed using a liquid chromatography/tandem mass spectrometer. The overall mean contamination levels of aflatoxin in peanuts and peanut products were 2.40 μg/kg of aflatoxin B1, 0.41 μg/kg of aflatoxin B2, 0.19 μg/kg of aflatoxin G1, and 0.03 μg/kg of aflatoxin G2. We use margin of exposure (MOE) as a tool to improve food safety management. According to MOE levels of aflatoxins in peanuts and peanut products from China, Indonesia, Thailand, the United States, and the Philippines were above the safe lower limit of 10,000, indicating an absence of public health or safety risk for the majority of the population. However, products from Vietnam were under the MOE safe lower limit, suggesting that regulatory actions must be continued to avoid excessive consumer exposure.
Diverse Components of Resistance to Fusarium verticillioides Infection and Fumonisin Contamination in Four Maize Recombinant Inbred Families
Authors: Morales Laura , Zila Charles T. , Moreta Mejía Danilo E. , Montoya Arbelaez Melissa , Balint-Kurti Peter J. , Holland James B. , Nelson Rebecca J.
Published: February 2019

The fungus Fusarium verticillioides can infect maize ears, causing Fusarium ear rot (FER) and contaminating the grain with fumonisins (FUM), which are harmful to humans and animals. Breeding for resistance to FER and FUM and post-harvest sorting of grain are two strategies for reducing FUM in the food system. Kernel and cob tissues have been previously associated with differential FER and FUM. Four recombinant inbred line families from the maize nested associated mapping population were grown and inoculated with F. verticillioides across four environments, and we evaluated the kernels for external and internal infection severity as well as FUM contamination. We also employed publicly available phenotypes on innate ear morphology to explore genetic relationships between ear architecture and resistance to FER and FUM. The four families revealed wide variation in external symptomatology at the phenotypic level. Kernel bulk density under inoculation was an accurate indicator of FUM levels. Genotypes with lower kernel density—under both inoculated and uninoculated conditions—and larger cobs were more susceptible to infection and FUM contamination. Quantitative trait locus (QTL) intervals could be classified as putatively resistance-specific and putatively shared for ear and resistance traits. Both types of QTL mapped in this study had substantial overlap with previously reported loci for resistance to FER and FUM. Ear morphology may be a component of resistance to F. verticillioides infection and FUM accumulation.
Development of a QuEChERS-Based UHPLC-MS/MS Method for Simultaneous Determination of Six Alternaria Toxins in Grapes
Authors: Guo Wenbo , Fan Kai , Nie Dongxia , Meng Jiajia , Huang Qingwen , Yang Junhua , Shen Yuanyuan , Tangni Emmanuel K. , Zhao Zhihui , Wu Yongjiang , Han Zheng
Published: February 2019

A simple and reliable analytical method for the simultaneous determination of alternariol (AOH), altenuene (ALT), tentoxin (TEN), altenusin (ALS), tenuazonic acid (TeA), and alternariol monomethyl ether (AME) in grapes was developed by ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure with the extraction by acetonitrile and purification by sodium chloride (0.5 g) and anhydrous magnesium sulfate (0.5 g) was established to recover the six Alternaria toxins. After validation by determining the linearity (R2 > 0.99), recovery (77.8–101.6%), sensitivity (limit of detection in the range of 0.03–0.21 μg kg−1, and limit of quantification in the range of 0.09–0.48 μg kg−1), and precision (relative standard deviation (RSD) ≤ 12.9%), the analytical method was successfully applied to reveal the contamination state of Alternaria toxins in grapes. Among 56 grape samples, 40 (incidence of 71.4%) were contaminated with Alternaria toxins. TEN was the most frequently found mycotoxin (37.5%), with a concentration range of 0.10–1.64 μg kg−1, followed by TeA (28.6%) and AOH (26.8%). ALT (10.7%), AME (3.6%), and ALS (5.4%) were also detected in some samples. To the best of our knowledge, this is the first report about the Alternaria toxins contamination in grapes in China.
Contamination of Wheat Cultivated in Various Regions of Poland during 2017 and 2018 Agricultural Seasons with Selected Trichothecenes and Their Modified Forms
Authors: Bryła Marcin , Ksieniewicz-Woźniak Edyta , Yoshinari Tomoya , Waśkiewicz Agnieszka , Szymczyk Krystyna
Published: February 2019

Cross-interaction of antibodies within the immunoaffinity columns used in this study facilitated the simultaneous determination of nivalenol (NIV), deoxynivalenol (DON), their glucoside derivatives (NIV-3G, DON-3G), and 3-acetyl-deoxynivalenol (3-AcDON) in wheat grain harvested in various regions of Poland. In Poland, 2018 was a warm, dry agricultural season, and hence, was relatively less favourable for cereal cultivation than 2017. Data on the natural occurrence of NIV-3G in wheat grain are among the first published in the literature. DON was the most frequently found mycotoxin in the tested samples; the percentage occurrence of DON-positive samples was 92% in 2017 and 61% in 2018. Moreover, DON concentrations were generally higher in 2017 samples (5.2–1670.7 µg/kg) than those in 2018 samples (range 5.0–461.7 µg/kg). A similar pattern was found for DON-3G. However, no statistically significant differences between the samples from the two agricultural seasons were observed for the other three mycotoxins that were analysed, and their concentrations were generally considerably lower. DON was strongly correlated with DON-3G (correlation coefficient r = 0.9558), while NIV was strongly correlated with NIV-3G (r = 0.9442). The percentage occurrence of NIV-3G- and DON-3G-positive samples was 14% in 2017 and 49% in 2018. The NIV-3G/NIV ratio was 5.9–35.7%, while the DON-3G/DON ratio range was 3.2–53.6%. In 2018, wheat samples from Southern Poland exhibited statistically significantly higher levels of DON than those from Northern Poland. The dry and hot summer of 2018 not only reduced wheat yields, but also limited development of Fusarium spp. Therefore, grain harvested that year was generally contaminated with relatively low levels of mycotoxins. Lower levels of DON were also accompanied by lesser amounts of DON-derivatives.
Mass Gap in Nonperturbative Quantization à La Heisenberg
Authors: Dzhunushaliev Vladimir , Folomeev Vladimir
Published: February 2019

The approximate method of solving nonperturbative Dyson-Schwinger equations by cutting off this infinite set of equations to three equations is considered. The gauge noninvariant decomposition of SU(3) degrees of freedom into SU(2) × U(1) and SU(3)/(SU(2) × U(1)) degrees of freedom is used. SU(2) × U(1) degrees of freedom have nonzero quantum average, and SU(3)/(SU(2) × U(1)) have zero quantum average. To close these equations, some approximations are employed. Regular spherically symmetric finite energy solutions of these equations are obtained. Energy spectrum of these solutions is studied. The presence of a mass gap is shown. The obtained solutions describe quasi-particles in a quark-gluon plasma.
The Influence of Envelope C-Terminus Amino Acid Composition on the Ratio of Cell-Free to Cell-Cell Transmission for Bovine Foamy Virus
Authors: Zhang Suzhen , Liu Xiaojuan , Liang Zhibin , Bing Tiejun , Qiao Wentao , Tan Juan
Published: February 2019

Foamy viruses (FVs) have extensive cell tropism in vitro, special replication features, and no clinical pathogenicity in naturally or experimentally infected animals, which distinguish them from orthoretroviruses. Among FVs, bovine foamy virus (BFV) has undetectable or extremely low levels of cell-free transmission in the supernatants of infected cells and mainly spreads by cell-to-cell transmission, which deters its use as a gene transfer vector. Here, using an in vitro virus evolution system, we successfully isolated high-titer cell-free BFV strains from the original cell-to-cell transmissible BFV3026 strain and further constructed an infectious cell-free BFV clone called pBS-BFV-Z1. Following sequence alignment with a cell-associated clone pBS-BFV-B, we identified a number of changes in the genome of pBS-BFV-Z1. Extensive mutagenesis analysis revealed that the C-terminus of envelope protein, especially the K898 residue, controls BFV cell-free transmission by enhancing cell-free virus entry but not the virus release capacity. Taken together, our data show the genetic determinants that regulate cell-to-cell and cell-free transmission of BFV.
Enhanced Water Demand Analysis via Symbolic Approximation within an Epidemiology-Based Forecasting Framework
Authors: Navarrete-López Claudia , Herrera Manuel , Brentan Bruno M. , Luvizotto Edevar , Izquierdo Joaquín
Published: February 2019

Epidemiology-based models have shown to have successful adaptations to deal with challenges coming from various areas of Engineering, such as those related to energy use or asset management. This paper deals with urban water demand, and data analysis is based on an Epidemiology tool-set herein developed. This combination represents a novel framework in urban hydraulics. Specifically, various reduction tools for time series analyses based on a symbolic approximate (SAX) coding technique able to deal with simple versions of data sets are presented. Then, a neural-network-based model that uses SAX-based knowledge-generation from various time series is shown to improve forecasting abilities. This knowledge is produced by identifying water distribution district metered areas of high similarity to a given target area and sharing demand patterns with the latter. The proposal has been tested with databases from a Brazilian water utility, providing key knowledge for improving water management and hydraulic operation of the distribution system. This novel analysis framework shows several benefits in terms of accuracy and performance of neural network models for water demand.
Assessment of a Smartphone Application for Real-Time Irrigation Scheduling in Mediterranean Environments
Authors: Abi Saab Marie Therese , Jomaa Ihab , Skaf Sleiman , Fahed Salim , Todorovic Mladen
Published: February 2019

The suitability of cloud-based irrigation technologies remains questionable due to limited information on their evaluation in the field. This study focussed on the on-field assessment of a smartphone irrigation scheduling tool—Bluleaf®—with respect to traditional water application practices. Bluleaf® uses weather, crop, soil, and irrigation system data to support a farmer’s decision on the timing and amounts of irrigation. The smartphone application was tested in Bekaa Valley, Lebanon, on durum wheat, a strategic Mediterranean crop, during the 2017 and 2018 growing seasons. The simulation results on soil water balance were in “acceptable to very good” agreement with the measured soil moisture values, with a root mean square error (RMSE) between 15.1 and 26.6 mm and a modelling efficiency (NSE) that ranged from 0.77 to 0.92. The appropriateness of the adopted smartphone irrigation scheduling was confirmed also by leaf water potential measurements and the Crop Water Stress Index (CWSI). A water saving of more than 1000 m3/ha (25.7%) was observed with Bluleaf® with respect to traditional irrigation scheduling. Therefore, new technologies could bring about substantial benefits to farmers and support water saving efforts in the Mediterranean region.
Spectral Decomposition and a Waveform Cluster to Characterize Strongly Heterogeneous Paleokarst Reservoirs in the Tarim Basin, China
Authors: Shan Xiaocai , Tian Fei , Cheng Fuqi , Yang Changchun , Xin Wei
Published: February 2019

The main components of the Ordovician carbonate reservoirs in the Tahe Oilfield are paleokarst fracture-cavity paleo-channel systems formed by karstification. Detailed characterization of these paleokarst reservoirs is challenging because of heterogeneities in characteristics and strong vertical and lateral non-uniformities. Traditional seismic analysis methods are not able to solve the identification problem of such strongly heterogeneous reservoirs. Recent developments in seismic interpretation have heightened the need to describe the fracture-cavity structure of a paleo-channel with more accuracy. We propose a new prediction model for fracture-cavity carbonate reservoirs based on spectral decomposition and a waveform cluster. By the Matching Pursuit decomposition algorithm, the single-frequency data volumes are obtained. The specific frequency data volume that is the most sensitive to the reservoir is chosen based on seismic synthesis traces of well-logging data and geological interpretability. The waveform cluster is then applied to delineate the complex paleokarst systems, particularly the fracture-caves in the runoff zone. This method was applied to the area around Well T615 in the Tahe oilfield, and a paleokarst fracture-cavity system with strong heterogeneity in the runoff zone was delineated and characterized. The findings of this research provide insights for predicting other similar karst systems, such as karstic groundwater and karst hydrogeological systems.
Electric Car Chassis for Shell Eco Marathon Competition: Design, Modelling and Finite Element Analysis
Authors: Tsirogiannis Evangelos Ch. , Stavroulakis Georgios E. , Makridis Sofoklis S.
Published: February 2019

The increasing demand for energy efficient electric cars, in the automotive sector, entails the need for improvement of their structures, especially the chassis, because of its multifaceted role on the vehicle dynamic behaviour. The major criteria for the development of electric car chassis are the stiffness and strength enhancement subject to mass reduction as well as cost and time elimination. Towards this direction, this work indicates an integrated methodology of developing an electric car chassis considering the modeling and simulation concurrently. The chassis has been designed in compliance with the regulations of Shell Eco Marathon competition. This methodology is implemented both by the use of our chassis load calculator (CLC) model, which automatically calculates the total loads applied on the vehicle’s chassis and by the determination of a worst case stress scenario. Under this extreme stress scenario, the model’s output was evaluated for the chassis design and the FEA method was performed by the pre-processor ANSA and the solver Ansys. This method could be characterized as an accurate ultrafast and cost-efficient method.
EFFECITVE LEADERSHIP FOR THE GLOBAL ECONOMY IN THE 21ST CENTURY
Authors: Saee John
Published: February 2019

Effective leadership of modern organizations within contemporary global economy in the 21st century is seen as a highly crucial function in organizations and good leadership is the most critical ingredient for successful organizations world over. In this research article, an examination is made of a broad range of theories and conceptualizations of leadership. Differences between managers and leaders are discussed. In addition, the notion of leadership in different cultures is explored which has considerable implications for management of enterprises internationally.
ANALYSIS OF PRIVATIZATION: DIFFERENT APPROACHES
Authors: Tvaronavičiene Manuela , Kalašinskaite Kristina
Published: February 2019

Presented paper strives to elaborate privatization as one of national economy development tools. Performance of privatized enterprises has been taken into consideration. The authors examine different opinions about privatization process and its efficiency taking a close look at the researches that have been already made. Analysis has been targeted to implications’ diversity due to foresee those in transition countries. Governance issues in case of privatization of monopolistic enterprises have been discussed.
PERSONNEL STRATEGY AND THEIR REALIZATION AT THE BELARUSIAN ENTERPRISES
Authors: Alena Vankevich
Published: February 2019

In the article problems of the theory and practice of development of personnel strategy of the enterprises are reflected. The basic kinds of personnel strategy are opened, the forms of their realization, the international experience is investigated. The dialectics of personnel positions of the Belarus enterprises for 1991–2003 is investigated, influence of a labor market on the given processes is shown. Necessity of transition to strategy of socially responsible re‐structuring is proved. Theoretical bases and applied aspects of realization of strategy of socially responsible re‐structuring at the enterprises of Byelorussia are given.
THE INVESTIGATION OF INDUSTRIAL INTELLECTUAL PROPERTY PROTECTION METHODS AND THEIR IMPROVEMENT / PRAMONINĖS INTELEKTINĖS NUOSAVYBĖS APSAUGOS METODŲ TYRIMAS IR JŲ TOBULINIMAS
Authors: Paškonytė Diana
Published: February 2019

This article main purpose is to analyse the existing industrial intellectual property protection methods and to provide some suggestions for improvements. It gives insights on all possible protection methods, when it is best to use it and how to choose. This article shows a different approach taken to solve a complex and lengthy process. In this paper, Business Process Modelling techniques have been introduced and applied providing a different point of view to solve some of the issues. The main idea is to remove non-value adding processes and introduce ICT based software between different parties involved.
RESEARCH AND IMPROVEMENT OF SUPPLY CHAIN IN THE METALLURGICAL INDUSTRY / TIEKIMO GRANDINĖS TOBULINIMO GALIMYBIŲ TYRIMAS METALURGIJOS PRAMONĖJE
Authors: Fregoso Pablo Villanueva
Published: February 2019

As the recent industrial situation is characterized by a growing global competition, decreasing product life cycles and increased levels of global outsourcing, among other challenges, the importance of supply chain integration between companies and its suppliers has become a critical factor for their survival in the international market. The way on how they arrange their supply networks to accomplish a flexible supply chain will define the future of modern enterprises. This article aims to explore Supply Chain Management in the Lithuanian metallurgical industry. More precisely, it will be focused on determining its supply chain and describing actual situation and relationships that affect it. Additionally, this paper looks to analyze the possible improvements that could be made in order to make it more efficient. In addition, to get an overview of the present supply chain in the metallurgical sector, a survey has been sent to a selection of metal-manufacturing companies inside Lithuania. The conducted survey-questionnaire represents the empirical research base for this study.
RIEBALŲ ATSKYRIMO NUO POPIERIAUS EKSPERIMENTINIAI TYRIMAI / EXPERIMENTAL RESEARCH OF FAT SEPARATION FROM PAPER
Authors: Pačekajūtė Martyna , Bazienė Kristina
Published: February 2019

The article analyzes the separation of fats from paper waste packaging. The method is based on interaction with boiling water and greaseproof paper. The cooking process is considered the formation of emulsions according to different slots. The research data are presented and discussed obtained from the analysis of ready-made samples. 20 different fat-coated paper samples have been prapared for research. Ten of them have been selected for printing paper, and another dozen cartons. The half of the samples analyzed are covered with vegetable fat, the remaining samples are vegetable fat. It was found that the carton samples were less opposed to the separation of fat. During the experiment, it was determined that by cooking the cardboard samples coated with olive oil for 5 minutes, 30% of the total fat content was removed. The most effective samples of this type were heated for a long time.
METHODS FOR DETERMINING THE FRICTION COEFFICIENT OF THE ROAD SURFACE / TRINTIES KOEFICIENTO SU KELIO DANGA NUSTATYMO METODAI
Authors: Perova Elena , Ugnenko Evgeniya , Viselga Gintas , Tetsman Ina
Published: February 2019

In spite of advances in aviation technology, operational procedures and weather forecasting, safe winter runway operations remain a challenge for airport operators, air traffic controllers, airlines and pilots who must coordinate their actions under rapidly-changing weather conditions. The paper analyses most popular methods for determining the friction coefficient of the road surface. Their advantages, disadvantages and comparison of their modern instruments for measuring the frictional properties of airfields is shown. Most of the information was derived from a comprehensive literature review.

Santrauka

Nepaisant aviacijos technologijų pažangos, operacinių procedūrų ir oro prognozių, saugios kilimo ir tūpimo tako operacijos žiemą išlieka iššūkiu oro uostų valdytojams, skrydžių vadovams, oro linijoms ir pilotams, kurie turi koordinuoti savo veiksmus sparčiai besikeičiančiomis oro sąlygomis. Straipsnyje analizuojami populiariausieji kelio dangos trinties koeficiento nustatymo metodai. Pateikiami jų privalumai, trūkumai ir lyginami jų modernūs prietaisai, skirti aerodromų trinties savybėms matuoti. Didžioji dalis informacijos buvo gauta iš išsamios literatūros apžvalgos.
A Two-sided Loop X-Ray Solar Coronal Jet Driven by a Minifilament Eruption
Authors: Sterling Alphonse C. , Harra Louise K. , Moore Ronald L. , Falconer David A.
Published: February 2019

Most of the commonly discussed solar coronal jets are the type that consist of a single spire extending approximately vertically from near the solar surface into the corona. Recent research supports that eruption of a miniature filament (minifilament) drives many such single-spire jets and concurrently generates a miniflare at the eruption site. A different type of coronal jet, identified in X-ray images during the Yohkoh era, are two-sided loop jets, which extend from a central excitation location in opposite directions, along low-lying coronal loops that are more-or-less horizontal to the surface. We observe such a two-sided loop jet from the edge of active region (AR) 12473, using data from Hinode X-Ray Telescope (XRT) and Extreme Ultraviolet Imaging Spectrometer (EIS), and from Solar Dynamics Observatory’s (SDO) Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI). Similar to single-spire jets, this two-sided loop jet results from eruption of a minifilament, which accelerates to over 140 km s−1 before abruptly stopping after striking an overlying nearly horizontal-loop field at ∼30,000 km in altitude and producing the two-sided loop jet. An analysis of EIS raster scans shows that a hot brightening, consistent with a small flare, develops in the aftermath of the eruption, and that Doppler motions (∼40 km s−1) occur near the jet formation region. As with many single-spire jets, the magnetic trigger here is apparently flux cancelation, which occurs at a rate of ∼4 × 1018 Mx hr−1, broadly similar to the rates observed in some single-spire quiet-Sun and AR jets. An apparent increase in the (line-of-sight) flux occurs within minutes of the onset of the minifilament eruption, consistent with the apparent increase being due to a rapid reconfiguration of low-lying fields during and soon after the minifilament-eruption onset.
A Hypothetical Effect of the Maxwell–Proca Electromagnetic Stresses on Galaxy Rotation Curves
Authors: Ryutov D. D. , Budker Dmitry , Flambaum V. V.
Published: February 2019

Maxwell–Proca electrodynamics corresponding to finite photon mass causes a substantial change in the Maxwell stress tensor, and under certain circumstances, may cause electromagnetic stresses to act effectively as “negative pressure.” This paper describes a model where this negative pressure imitates gravitational pull and may produce forces comparable to gravity and may even become dominant. The effect is associated with random magnetic fields with correlation lengths exceeding the photon Compton wavelength. The stresses act predominantly on the interstellar gas and cause an additional force pulling the gas toward the center and toward the galactic plane. Stars do not experience any significant direct force but get involved in this process via a “recycling loop,” where rapidly evolving massive stars are formed from the gas undergoing galactic rotation and then lose their mass back to the gas within a time shorter than roughly 1/6 of the rotation period. This makes their dynamics inseparable from that of the rotating gas. As soon as the lighter, slowly evolving stars are formed, they lose their connection to the gas and are only gravitationally confined within the galaxy. Peculiarities in the dynamics of these slowly evolving stars may serve as an experimental test of the presence and magnitude of the Maxwell–Proca stresses. In fact, observational data for Sun-like stars in our galaxy appear to be incompatible with the assumption of the Maxwell–Proca stresses contributing at a level needed to explain the galactic rotation curve, although they could contribute a 10%–20% addition to the observed centripetal pull. It may be interesting to also explore possible broader cosmological implications of the negative-pressure model.
Ultra-wideband Detection of 22 Coherent Radio Bursts on M Dwarfs
Authors: Villadsen Jackie , Hallinan Gregg
Published: February 2019

Coherent radio bursts detected from M dwarfs have some analogy with solar radio bursts but reach orders of magnitude higher luminosities. These events trace particle acceleration, powered by magnetic reconnection, shock fronts (such as those formed by coronal mass ejections (CMEs)), and magnetospheric currents, in some cases offering the only window into these processes in stellar atmospheres. We conducted a 58 hr ultra-wideband survey for coherent radio bursts on five active M dwarfs. We used the Karl G. Jansky Very Large Array to observe simultaneously in three frequency bands covering a subset of 224–482 MHz and 1–6 GHz, achieving the widest fractional bandwidth to date for any observations of stellar radio bursts. We detected 22 bursts across 13 epochs, providing the first large sample of wideband dynamic spectra of stellar coherent radio bursts. The observed bursts have diverse morphology, with durations ranging from seconds to hours, but all share strong (40%–100%) circular polarization. No events resemble solar Type II bursts (often associated with CMEs), but we cannot rule out the occurrence of radio-quiet stellar CMEs. The hours-long bursts are all polarized in the sense of the x-mode of the star’s large-scale magnetic field, suggesting that they are cyclotron maser emission from electrons accelerated in the large-scale field, analogous to auroral processes on ultracool dwarfs. The duty cycle of luminous coherent bursts peaks at 25% at 1–1.4 GHz, declining at lower and higher frequencies, indicating source regions in the low corona. At these frequencies, active M dwarfs should be the most common galactic transient source.
Implementing Dust Shielding as a Criteria for Star Formation
Authors: Byrne Lindsey , Christensen Charlotte , Tsekitsidis Marios , Brooks Alyson , Quinn Tom
Published: February 2019

Star formation is observed to be strongly correlated to dense regions of molecular gas. Although the exact nature of the link between star formation and molecular hydrogen is still unclear, some have suggested that shielding of dense gas by dust grains is the key factor enabling the presence of both. We present a subgrid model for use in galaxy formation simulations in which star formation is linked explicitly to local dust shielding. We developed and tested our shielding and star formation models using smoothed particle hydrodynamic simulations of solar and subsolar metallicity isolated Milky Way–mass disk galaxies. We compared our dust-shielding-based star formation model to two other star formation recipes that used gas temperature and H2 fraction as star formation criteria. We further followed the evolution of a dwarf galaxy within a cosmological context using both the shielding and H2-based star formation models. We find that the shielding-based model allows for star formation at higher temperatures and lower densities than a model in which star formation is tied directly to H2 abundance, as requiring H2 formation leads the gas to undergo additional gravitational collapse before star formation. However, the resulting galaxies are very similar for both the shielding and H2-based star formation models, and both models reproduce the resolved Kennicutt–Schmidt law. Therefore, both star formation models appear viable in the context of galaxy formation simulations.
Following the Cosmic Evolution of Pristine Gas. III. The Observational Consequences of the Unknown Properties of Population III Stars
Authors: Sarmento Richard , Scannapieco Evan , Côté Benoit
Published: February 2019

We study the observational consequences of several unknown properties of Population III stars using large-scale cosmological simulations that include a subgrid model to track the unresolved mixing of pollutants. Varying the value of the critical metallicity that marks the boundary between Population III and Population II star formation across 2 dex has a negligible effect on the fraction of Population III stars formed and the subsequent fraction of Population III flux from high-redshift galaxies. However, adopting a lognormal initial mass function (IMF) for Population III stars, in place of a baseline Salpeter IMF, results in a Population III star formation rate density that is 1/4 of the baseline rate. The flux from high-redshift galaxies modeled with this IMF is highly bimodal, resulting in a tiny fraction of z ≤ 8 galaxies with more than 75% of their flux coming from Population III stars. However, at z = 9, right before reionization in our simulations, ≈20% of galaxies are Population III-bright with

mag, and at least 75% of their flux is generated by Population III stars. Additionally, the lognormal Population III IMF results in a population of carbon-enhanced, metal-poor stars in reasonable agreement with MW halo observations. Our analysis supports the conclusion that the Population III IMF was dominated by stars in the 20–120

range that generate supernovae with carbon-enhanced ejecta.
Predictions for the Detection and Characterization of Galactic Disk Microlensing Events by LSST
Authors: Sajadian Sedighe , Poleski Radosław
Published: February 2019

The upcoming Large Synoptic Survey Telescope (LSST) survey will provide an unprecedented opportunity for studying populations of intrinsically faint objects using microlensing. The LSST’s large field of view and aperture allow effective time-series observations of many stars in the Galactic disk and bulge. Here, we combine Galactic models (for

) and simulations of LSST observations to study how observing strategies affect the number and properties of microlensing events detected by LSST. Generally, detectable microlensing events are (a little) longer than events observable with current surveys. In Galactic bulge fields, LSST should detect on the order of 600 microlensing events per square degree as compared to 19 in disk fields. Improving the cadence from 6 to 2 days approximately doubles the number of detectable microlensing events throughout the Galaxy. We develop an Operations Simulator (OpSim)–based simulation to predict the characteristics of detectable microlensing events in different OpSim strategies and compare them. Based on baseline_2018a, minion_1016, and colossus_2664 OpSim simulations, LSST will observe with either 900 or 170 epochs in different observing times and cadences. With worse cadences LSST will detect longer microlensing events of brighter stars with lower blending. Although increasing the observing time from 1 to 10 yr with a fixed number of epochs does not change the total number of microlensing events significantly, the longer observing time lets one discern artificial effects and measure baseline fluxes, parallax, etc. If LSST spends enough time observing near the Galactic plane, then the large number of microlensing events will allow studies of the Galactic distribution of planets and searches for isolated black holes among a wealth of other scientific cases.
Serum Biomarkers for Prediction of Response to Methotrexate Monotherapy in Early Rheumatoid Arthritis: Results from the SWEFOT Trial
Authors: Hambardzumyan Karen , Bolce Rebecca J. , Wallman Johan K. , van Vollenhoven Ronald F. , Saevarsdottir Saedis
Published: February 2019

Objective.

To investigate baseline levels of 12 serum biomarkers that constitute a multibiomarker disease activity test, as predictors of response to methotrexate (MTX) in patients with early rheumatoid arthritis (eRA).

Methods.

In 298 patients from the Swedish Pharmacotherapy (SWEFOT) clinical trial, baseline serum levels of 12 proteins were analyzed for association with disease activity based on the 28-joint count Disease Activity Score (DAS28) after 3 months of MTX monotherapy using uni-/multivariate logistic regression. Primary outcome was low disease activity (LDA; DAS28 ≤ 3.2).

Results.

Of 298 patients, 104 achieved LDA after 3 months on MTX. Four of the 12 biomarkers [C-reactive protein (CRP), leptin, tumor necrosis factor receptor I (TNF-RI), and vascular cell adhesion molecule 1 (VCAM-1)] significantly predicted LDA based on stepwise logistic regression analysis. Dichotomization of patients using receiver-operating characteristic curve analysis-based cutoffs for these biomarkers showed significantly higher proportions with LDA among patients with lower versus higher levels of CRP or leptin (40% vs 23%, p = 0.004, and 40% vs 25%, p = 0.011, respectively), as well as among those with higher versus lower levels of TNF-RI or VCAM-1 (43% vs 27%, p = 0.004, and 41% vs 25%, p = 0.004, respectively). Combined score based on these biomarkers, adjusted for known predictors of LDA (smoking, sex, and age), associated with decreased chance of LDA (adjusted OR 0.45, 95% CI 0.32–0.62).

Conclusion.

Low baseline levels of CRP and leptin, and high baseline levels of TNF-RI and VCAM-1 were associated with LDA after 3 months of MTX therapy in patients with eRA. Combination of these 4 biomarkers increased accuracy of prediction. [Trial registration number: NCT00764725]
Peripheral Lymphocyte Multidrug Resistance Activity as a Predictive Tool of Biological Therapeutic Response in Rheumatoid Arthritis
Authors: Toldi Gergely , Batel Patrizia , Baráth Sándor , Szerémy Péter , Apjok András , Filkor Kata , Szántó Sándor , Szűcs Gabriella , Szamosi Szilvia , Häupl Thomas , Grützkau Andreas , Szekanecz Zoltán
Published: February 2019

Objective.

Multidrug resistance (MDR) transporters may be used as biomarkers to monitor disease progression in RA and as a predictive tool to establish responsiveness to biological therapy. In this multicenter clinical trial, we aimed to assess the predictive value of activity measurement of transporters MDR1, MD resistance protein (MRP)1, and breast cancer resistance protein (BCRP) for biological therapeutic response in RA before the initiation of biological therapy as well as 4 to 6 and 12 weeks after.

Methods.

Peripheral blood samples were collected from 27 responders and 12 nonresponders to biological disease-modifying antirheumatic drugs (bDMARD) at the indicated timepoints as well as from 35 healthy controls. MDR activity factor (MAF) of MDR1, MRP1, and BCRP was measured in CD3+ and CD19+ cells using the Solvo MDQ Kit and cell surface staining by flow cytometry following peripheral blood mononuclear cells isolation.

Results.

At the start of therapy, MAFC (composite MAF of MRP1 and MDR1) and MAFMDR values, and at 4 to 6 weeks of treatment, MAFC, MAFMRP, and MAFMDR values of CD3 cells were higher in nonresponders compared to responders. Receiver-operation characteristic curve analysis revealed that RA patients with MAFC values above 21.3 in CD3 cells at the start of bDMARD therapy are likely to be nonresponders. At 4 to 6 weeks of treatment, these also predict unfavorable response: MAFC values above 20.3, MAFMRP values above 6.0, and MAFMDR values above 13.9 in CD3 cells.

Conclusion.

Our results indicate that the determination of MAFC values in CD3 cells of patients with RA may be of predictive value prior to the initiation of biological therapy, to establish whether the patient will demonstrate sufficient therapeutic response.
OMERACT Definitions for Ultrasonographic Pathologies and Elementary Lesions of Rheumatic Disorders 15 Years On
Authors: Bruyn George A. , Iagnocco Annamaria , Naredo Esperanza , Balint Peter V. , Gutierrez Marwin , Hammer Hilde B. , Collado Paz , Filippou Georgios , Schmidt Wolfgang A. , Jousse-Joulin Sandrine , Mandl Peter , Conaghan Philip G. , Wakefield Richard J. , Keen Helen I. , Terslev Lene , D’Agostino Maria Antonietta
Published: February 2019

Objective.

The Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Working Group (WG) operates research activities for the validation of US as an outcome measurement instrument according to the Filter 2.0 framework.

Methods.

Original publications on definitions and scoring systems for pathophysiological manifestations and elementary lesions of various rheumatic disorders were reviewed from the onset of the WG research in 2005.

Results.

Definitions and scoring systems according to new terminology are provided.

Conclusion.

We have redefined OMERACT US pathology and elementary lesions as well as scoring systems, which are now proposed for OMERACT approval for application in clinical trials.
Assessment of outcome-based integrated design project
Authors: Basir Noordin , Chai Lian Oh , Muhd Salmizi Ja'afar , Shaharin Hamid
Published: February 2019

Outcome-Based Education (OBE) implementation is one of the qualifying requirements for engineering programme accreditation in Malaysia.  Implementation of the OBE in Integrated Design Project (IDP) is essential in producing high quality engineering graduates that are able to meet the challenges especially in the era of Industry 4.0 in Malaysia.  IDP is the course offered to the final year students of undergraduate programme in Faculty of Civil Engineering, University Teknologi MARA.  This paper presents the mapping of the addressing Course Outcomes (CO) and Programme Outcomes (PO) to the scopes of assessment in a capstone project (CP) for IDP. The explicitness in the measurement of CO and PO in the course is demonstrated. The rubrics for the assessment of CP are also presented. Finally, evaluation of student performance in IDP particularly CP is discussed through a sample analysis of the CO and PO attainments.
Concept cartoon in problem-based learning : A systematic literature review analysis
Authors: Jamal Siti , Ibrahim Nor , Surif Johari
Published: February 2019

Concept cartoon teaching strategy have the potential to increase creativity and innovation as well as the students' interest in understanding concepts. It is considered as a method that encourages students to continue exploring the issues raised and seeking solutions. This concept cartoon lesson is very suitable to be applied in the field of Science, Technology, Engineering and Mathematics which is often regarded as an abstract and difficult field. Therefore, it is becoming a necessity to see how far the cartoon concept in learning has been implemented in schools. This systematic literature review analysis aims to focus on the similarities and differences such as the objective used, the methodology used and the findings of the study. The study article was selected through a database of various types of journals according to keywords. Keywords used in the search are Concept Cartoon AND comic AND Problem-based learning. The search has been limited between 2009 and 2017. A total of 9 studies have been selected to be analyzed based on the four steps in systematic literature review. The four steps included frame a question, run a search, read the abstract and tittle of individual papers and abstract information from selected set of final articles.  The results of the systematic literature review analysis can be concluded on recent research and previous research that cartoon concept teaching strategy is very effective in enhancing creative thinking as well as cultivating students' interest in Science, Technology, Engineering and Mathematics.
Total Calcaneus Resection and Reconstruction Using a 3-dimensional Printed Implant
Authors: Papagelopoulos Panayiotis J. , Megaloikonomos Panayiotis D. , Korkolopoulou Penelope , Vottis Christos T. , Kontogeorgakos Vasileios A. , Savvidou Olga D.
Published: February 2019

Considering the specific anatomic features of the foot, below-knee amputation is the treatment of choice for foot malignancies. However, advances in imaging modalities, adjuvant therapies, and improved surgical techniques have made foot salvage surgery increasingly possible. The calcaneus is an unusual location for malignant tumors, and there is limited information about foot salvage. Currently, 3-dimensional printed implants may successfully address reconstruction challenges after tumor resection. The authors present 2 patients with Ewing's sarcoma of the calcaneus who underwent total calcaneus resection and reconstruction using a custom-made 3-dimensional printed implant. [
Orthopedics
. 2019; 42(2):e282–e287.]