bluuebunny/crossref_metadata_2025 huggingface dataset:
The One Health Approach is Necessary for the Control of Rift Valley Fever Infections in Egypt: A Comprehensive Review
Authors: Fawzy Mohamed , Helmy Yosra A.
Published: February 2019

Rift Valley fever (RVF) is an emerging transboundary, mosquito-borne, zoonotic viral disease caused high morbidity and mortality in both human and ruminant populations. It is considered an important threat to both agriculture and public health in African and the Middle Eastern countries including Egypt. Five major RVF epidemics have been reported in Egypt (1977, 1993, 1994, 1997, and 2003). The virus is transmitted in Egypt by different mosquito’s genera such as Aedes, Culex, Anopheles, and Mansonia, leading to abortions in susceptible animal hosts especially sheep, goat, cattle, and buffaloes. Recurrent RVF outbreaks in Egypt have been attributed in part to the lack of routine surveillance for the virus. These periodic epizootics have resulted in severe economic losses. We posit that there is a critical need for new approaches to RVF control that will prevent or at least reduce future morbidity and economic stress. One Health is an integrated approach for the understanding and management of animal, human, and environmental determinants of complex problems such as RVF. Employing the One Health approach, one might engage local communities in surveillance and control of RVF efforts, rather than continuing their current status as passive victims of the periodic RVF incursions. This review focuses upon endemic and epidemic status of RVF in Egypt, the virus vectors and their ecology, transmission dynamics, risk factors, and the ecology of the RVF at the animal/human interface, prevention, and control measures, and the use of environmental and climate data in surveillance systems to predict disease outbreaks.
Diversity and Biotechnological Potential of Xylan-Degrading Microorganisms from Orange Juice Processing Waste
Authors: Zerva Ioanna , Remmas Nikolaos , Ntougias Spyridon
Published: February 2019

The orange juice processing sector produces worldwide massive amounts of waste, which is characterized by high lignin, cellulose and hemicellulose content, and which exceeds 40% of the fruit’s dry weight (d.w.). In this work, the diversity and the biotechnological potential of xylan-degrading microbiota in orange juice processing waste were investigated through the implementation of an enrichment isolation strategy followed by enzyme assays for the determination of xylanolytic activities, and via next generation sequencing for microbial diversity identification. Intracellular rather than extracellular endo-1,4-β-xylanase activities were detected, indicating that peripheral cell-bound (surface) xylanases are involved in xylan hydrolysis by the examined microbial strains. Among the isolated microbial strains, bacterial isolates belonging to Pseudomonas psychrotolerans/P. oryzihabitans spectrum (99.9%/99.8% similarity, respectively) exhibited activities of 280 U/mg protein. In contrast, almost all microbial strains isolated exerted low extracellular 1,4-β-xylosidase activities (<5 U/mg protein), whereas no intracellular 1,4-β-xylosidase activities were detected for any of them. Illumina data showed the dominance of lactic and acetic acid bacteria and of the yeasts Hanseniaspora and Zygosaccharomyces. This is the first report on indigenous xylanolytic microbiota isolated from orange juice processing waste, possessing the biotechnological potential to serve as biocatalysts for citrus biomass valorization through the production of high-added value products and energy recovery.
Using a Distributed Recharge Model to Quantify Recharge Processes in a Semi-Arid Karst Catchment: An Example from Wadi Natuf, West Bank
Authors: Mansour Majdi , Peach Denis , Robins Nick , Hughes Andrew
Published: February 2019

The Wadi Natuf catchment is situated to the west of the Palestinian capital city of Ramallah which is in the West Bank. The catchment has been instrumented since 2003 to identify and examine recharge processes in semi-arid upland karst terrain, in which both direct and indirect recharge are important. The key recharge processes are direct rainfall recharge, and indirect recharge via wadis including the lateral routing of potential recharge in the unsaturated zone to springs which supply the wadis. A conceptual model describing these processes was developed. A distributed recharge model was then employed to test this conceptual model and to calculate recharge. A semi-arid wetting threshold method, based on local field experiments was used for recharge estimation. The model was calibrated by comparing simulated wadi flows to those recorded during a relatively short historical event. The study demonstrates that short-term monitoring can enable a sensible validation of a conceptual model leading to the estimation of recharge. Confidence in the model simulation requires further field work to strengthen the understanding of processes taking place in semi-arid climates and karstic flow environments.
Evaluation of Health Risks Due to Heavy Metals in a Rural Population Exposed to Atoyac River Pollution in Puebla, Mexico
Authors: Pérez Castresana Gabriela , Castañeda Roldán Elsa , García Suastegui Wendy A. , Morán Perales José L. , Cruz Montalvo Abel , Handal Silva Anabella
Published: February 2019

The health risks of Emilio Portes Gil’s population, for the exposition to the Atoyac River pollution in the State of Puebla, was evaluated. The objective was to determine the concentration of nine heavy metals by ingesting water from wells and spri ngs. The chronic daily water intake (CDI), hazard quotient (HQ), hazard index (HI), and carcinogenic risk index (CRI) in adults, teenagers, and children were estimated. The results showed that the concentration of Fe, Al, Ni, and Pb in some of the samples exceeded the recommended standards for human consumption and was significantly higher in the dry season. The hazard index (HI), due to the collective intake of metals, was higher in children (>50% compared to adults), due to the consumption of spring water in the dry season. Risk of noncancerous diseases was not detected in the long term, since the indices did not exceed the unit (reference value). The carcinogenic risk from oral exposure to Cr (CRIchildren = 3.2 × 10−4), was greater than the acceptable limit (1 × 10−6) in the water spring, and Cr and Pb were the main metals that contributed to the potential health risk of the inhabitants. The study showed the risks by the intake of polluted water from the sources of supply in the region, and that the risk is higher in the dry season (>100% compared with rainy season).
Analysis of Precipitation and Temperature Extremes over the Muda River Basin, Malaysia
Authors: Tan Mou Leong , Samat Narimah , Chan Ngai Weng , Lee Anisah Jessica , Li Cheng
Published: February 2019

Trends in precipitation and temperature extremes of the Muda River Basin (MRB) in north-western Peninsular Malaysia were analyzed from 1985 to 2015. Daily climate data from eight stations that passed high quality data control and four homogeneity tests (standard normal homogeneity test, Pettitt test, Buishand range test, and von Neumann ratio test) were used to calculate 22 Expert Team on Climate Change Detection and Indices (ETCCDI) extreme indices. Non-parametric Mann–Kendall, modified Mann–Kendall and Sens’ slope tests were applied to detect the trend and magnitude changes of the climate extremes. Overall, the results indicate that monthly precipitation tended to increase significantly in January (17.01 mm/decade) and December (23.23 mm/decade), but decrease significantly in May (26.21 mm/decade), at a 95% significance level. Monthly precipitation tended to increase in the northeast monsoon, but decrease in the southwest monsoon. Mann–Kendall test detected insignificant trends in most of the annual climate extremes, except the extremely wet days (R99p), mean of maximum temperature (TXmean), mean of minimum temperature (TNmean), cool days (TX10p), cool nights (TN10p), warm days (TX90p) and warm nights (TN90p) indices. The number of heavy (R10mm), very heavy (R20mm), and violent (R50mm) precipitation days changed at magnitudes of 0~2.73, −2.14~3.33, and −1.67~1.29 days/decade, respectively. Meanwhile, the maximum 1-day (Rx1d) and 5-day (Rx5d) precipitation amount indices changed from −10.18 to 3.88 mm/decade and −21.09 to 24.69 mm/decade, respectively. At the Ampangan Muda station, TNmean (0.32 °C/decade) increased at a higher rate compared to TXmean (0.22 °C/decade). The number of the cold days and nights tended to decrease, while an opposite trend was found in the warmer days and nights.
Differentiation in Aquatic Metabolism between Littoral Habitats with Floating-Leaved and Submerged Macrophyte Growth Forms in a Shallow Eutrophic Lake
Authors: Stefanidis Konstantinos , Dimitriou Elias
Published: February 2019

The metabolic balance between gross primary production (GPP) and ecosystem respiration (R) is known to display large spatial and temporal variations within shallow lakes. Thus, although estimation of aquatic metabolism using free-water measurements of dissolved oxygen concentration has become increasingly common, the explanation of the variance in the metabolic regime remains an extremely difficult task. In this study, rates of GPP, respiration (R) and the metabolic balance (net ecosystem production, NEP) were estimated in four littoral habitats with different macrophyte growth forms (floating-leaved vs submerged) over a 28-month period in lake of Kastoria (Greece), a shallow eutrophic lake. Our results showed that net heterotrophy prevailed over the studied period, suggesting that allochthonous organics fuel respiration processes in the littoral. Temporal variation in the metabolic rates was driven mainly by the seasonal variation in irradiance and water temperature, with the peak of metabolic activity occurring in summer and early autumn. Most importantly, significant spatial variation among the four habitats was observed and associated with the different macrophyte growth forms that occurred in the sites. The results highlight the importance of habitat specific characteristics for the assessment of metabolic balance and underline the potentially high contribution of littoral habitats to the whole lake metabolism.
Transport signatures of an Andreev molecule in a quantum dot–superconductor–quantum dot setup
Authors: Scherübl Zoltán , Pályi András , Csonka Szabolcs
Published: February 2019

Hybrid devices combining quantum dots with superconductors are important building blocks of conventional and topological quantum-information experiments. A requirement for the success of such experiments is to understand the various tunneling-induced non-local interaction mechanisms that are present in the devices, namely crossed Andreev reflection, elastic co-tunneling, and direct interdot tunneling. Here, we provide a theoretical study of a simple device that consists of two quantum dots and a superconductor tunnel-coupled to the dots, often called a Cooper-pair splitter. We study the three special cases where one of the three non-local mechanisms dominates, and calculate measurable ground-state properties, as well as the zero-bias and finite-bias differential conductance characterizing electron transport through this device. We describe how each non-local mechanism controls the measurable quantities, and thereby find experimental fingerprints that allow one to identify and quantify the dominant non-local mechanism using experimental data. Finally, we study the triplet blockade effect and the associated negative differential conductance in the Cooper-pair splitter, and show that they can arise regardless of the nature of the dominant non-local coupling mechanism. Our results should facilitate the characterization of hybrid devices, and their optimization for various quantum-information-related experiments and applications.
TRACTOR BALLASTING IN FIELD TRANSPORT WORK
Authors: Giedra Kazimieras , Janulevičius Algirdas
Published: February 2019

The article presents the investigation of the interaction of tractor traction force, mass, trailer and tractor mass ratio and wheel slippage. The analysis of the influence of ballast weight and wheel slippage on the fuel consumption under various field and road conditions was carried out. Wheel slippage dependence on the pull force, a weight force utilization coefficient and ratio of the mass of a trailer and tractor were stated and analyzed.

The nomogram for operative selection of the optimal ballast weight and its location place is presented when instantaneous wheel slippage is known. The nomogram consists of three parts. In the lower part dependence δ = f(mp / m), (wheel slippage on the ratio of the mass of a trailer and tractor) is placed. In the middle part there is dependence of the tractor mass m made of the expression of the wheel grip weight force utilization coefficient ϕg = Ft / G on the ratio of the mass of a trailer and tractor m=f (mp / m). The upper part is designed for dependence ?mp = f(mp) (transferred mass of tractor Dmp on the rear wheels on the mass trailer mp . The bottom part of the nomogram is connected with the middle part by the common abscissa axle on which the ratio of the mass of a trailer and tractor is placed. The curves of the middle part of the nomogram m = f (mp /m)are connected with the analogical concrete mass trailer values mp, placed in the abscissa axle by intermediate lines.
VERIFICATION OF AN ENTROPY DISSIPATIVE QGD-SCHEME
Authors: Zlotnik Alexander , Lomonosov Timofey
Published: February 2019

An entropy dissipative spatial discretization has recently been constructed for the multidimensional gas dynamics equations based on their preliminary parabolic quasi-gasdynamic (QGD) regularization. In this paper, an explicit finite-difference scheme with such a discretization is verified on several versions of the 1D Riemann problem, both well-known in the literature and new. The scheme is compared with the previously constructed QGD-schemes and its merits are noticed. Practical convergence rates in the mesh L1-norm are computed. We also analyze the practical relevance in the nonlinear statement as the Mach number grows of recently derived necessary conditions for L2-dissipativity of the Cauchy problem for a linearized QGD-scheme.
GLOBAL EXISTENCE AND FINITE TIME BLOW-UP OF SOLUTIONS TO A NONLOCAL P-LAPLACE EQUATION
Authors: Han Yuzhu , Li Jian
Published: February 2019

In this paper a class of nonlocal diffusion equations associated with a p-Laplace operator, usually referred to as p-Kirchhoff equations, are studied. By applying Galerkin’s approximation and the modified potential well method, we obtain a threshold result for the solutions to exist globally or to blow up in finite time for subcritical and critical initial energy. The decay rate of the L 2 norm is also obtained for global solutions. When the initial energy is supercritical, an abstract criterion is given for the solutions to exist globally or to blow up in finite time, in terms of two variational numbers. These generalize some recent results obtained in [Y. Han and Q. Li, Threshold results for the existence of global and blow-up solutions to Kirchhoff equations with arbitrary initial energy, Computers and Mathematics with Applications, 75(9):3283–3297, 2018].
COMBINED NONPARAMETRIC CHI-SQUARED AND BINOMIAL STATISTICAL TEST ON TRUCK TRAFFIC VOLUME CHANGES IN CANADIAN PROVINCIAL HIGHWAY NETWORK
Authors: Roh Hyuk-Jae , Sharma Satish
Published: February 2019

This paper examines the effect of weather conditions on truck type distribution using combined nonparametric chi-squared and binomial probability statistical tests. Influence of the winter conditions on truck type distribution is investigated in this paper by classifying trucks into single-unit trucks, single-trailer, and multi-trailer units. The investigation is based on 5 years Weigh-In-Motion (WIM) traffic data collected from Alberta provincial highway network in Canada. The WIM data is collected from six WIM sites located on Highway 2, Highway 2A, Highway 3, Highway 16 and Highway 44. The objective of this study is to investigate the association of three truck type distribution with month and season depending on weather conditions by means of nonparametric statistical test. The statistical results indicate that the variation of truck type distribution is influenced by type of highway facility, such as regional commuter roads and rural long distance highways. The season of the year (winter and non-winter) may also affect the truck type distribution on some types of roads. Findings of this study can benefit highway agencies in developing programs and policies related to efficient monitoring of truck traffic and maintaining highway network throughout the year.
ON DEPLOYING VEHICULAR COMMUNICATION AT THE DEVELOPING SEAPORT AND RELATED INNOVATION SUCCESS IMPEDIMENTS
Authors: Bauk Sanja , Leon Calvo Jose Angel , Schmeink Anke , Azam Sadia , Mathar Rudolf
Published: February 2019

The paper concerns the employment of a vehicular communication concept for traffic management and safety purposes in a developing seaport environment. A general scenario considering centralized and ad-hoc networks has been analysed, since the requirements for the safety of seaports are similar in terms of reliability and latency. The main enhancement of the proposed model is a communication-based cooperative scheme for improving the safety of workers and optimizing the management of on-port vehicles. The simulation analyses have been realized over the container terminal of the developing Port of Bar (South-East Adriatic Sea, Montenegro). Considering the fact that it operates in transitional conditions, related innovation success impediments have been taken into consideration, as well.
APPLICATION OF DIVERGENT SPLIT INJECTION IN A CIDI DIESEL ENGINE TO REDUCE EMISSIONS AND BOOST THE EFFICIENCY
Authors: Taghavifar Hadi
Published: February 2019

The application of single injection in diesel engines has been becoming outdated given the advent of High-Pressure Common Rail (HPCR) system. Multiple injection or split injection presents more controllability over the economic use of fuel during the injection process. In this sense, a thorough investigation of a new concept with the use of divergent injection and split injection is proposed, based on which the whole chamber area was covered with two nozzles of different angles. Moreover, the system allows the optimal use of time span for injection in by assigning different dwell-time periods between injection pulses. The results indicate that increasing the divergence of nozzle angles could possibly bring about arise of Uniformity Index (UI) and Indicated Power (IP) of engine. In contrast, increase of dwell time leads to deterioration of Indicated Mean Effective Pressure (IMEP) and Indicated Specific Fuel Consumption (ISFC). The data points of several injection schemes are presented in IMEP-NOx and ISFC-soot plots in comparison with single injection that shows adoption of a proper injection policy can establish an ideal trade-off between emissions and engine performance.
K2-287 b: An Eccentric Warm Saturn Transiting a G-dwarf
Authors: Jordán Andrés , Brahm Rafael , Espinoza Néstor , Cortés Cristián , Díaz Matías , Drass Holger , Henning Thomas , Jenkins James S. , Jones Matías I. , Rabus Markus , Rojas Felipe , Sarkis Paula , Vučković Maja , Zapata Abner , Soto Maritza G. , Bakos Gáspár Á. , Bayliss Daniel , Bhatti Waqas , Csubry Zoltan , Lachaume Regis , Moraga Víctor , Pantoja Blake , Osip David , Shporer Avi , Suc Vincent , Vásquez Sergio
Published: February 2019

We report the discovery of K2-287b, a Saturn mass planet orbiting a G-dwarf with a period of P ≈ 15 days. First uncovered as a candidate using K2 campaign 15 data, follow-up photometry and spectroscopy were used to determine a mass

, radius

, period

days, and eccentricity

. The host star is a metal-rich V = 11.410 ± 0.129 mag G-dwarf for which we estimate a mass

, radius

, metallicity [Fe/H] = 0.20 ±0.05, and

K. This warm eccentric planet with a time-averaged equilibrium temperature of

K adds to the small sample of giant planets orbiting nearby stars whose structure is not expected to be affected by stellar irradiation. Follow-up studies on the K2-287 system could help constrain theories of planet migration in close-in orbits.
Photometric Redshifts of Emission-line Galaxies Using Ramp Filters
Authors: Lesser Ryan William , Moody J. Ward , Steele Jackson , Bohman John , McNeff Matthew , Joner Michael D. , Barnes Jonathan
Published: February 2019

Broadband photometric redshifts are routinely obtained for galaxies to estimate their distances. While effective for many uses, the common resolution in z of 0.01–0.02 is too coarse for detailed large-scale structure mapping, particularly in low-density volumes where the galaxy distribution is least understood. To map galaxies in these low-density volumes, and noting that the percentage of galaxies having emission tends to rise as number density decreases, we have designed a filter system to photometrically measure the redshifts of galaxies with emission. The system consists of two “ramp” filters that cover a common wavelength range with transmission curves sloping from blue to red and from red to blue respectively. This causes the intensity of the image through either filter to be a function of the wavelength of the emission line. A third filter with a bandpass to the side is used to measure and remove the continuum. We have obtained a set of such filters that are tuned for isolating Hα in the redshift range of 3,000–9,000 km s−1. Simulated photometry, applied to spectra of 197 emission-line galaxies from the SDSS, shows the accuracy of the method to be between 250 and 620 km s−1, depending on line strength. Actual photometry of a sample of 16 active galaxies measured their redshifts with an accuracy of 573 km s−1. This is approximately an order of magnitude more accurate than broadband photometric redshifts. We discuss the errors inherent in this method and present ways to modify the filter set to further improve accuracy.
The Discreteness-driven Relaxation of Collisionless Gravitating Systems: Entropy Evolution and the Nyquist–Shannon Theorem
Authors: Beraldo e Silva Leandro , de Siqueira Pedra Walter , Valluri Monica
Published: February 2019

The time irreversibility and fast relaxation of collapsing N-body gravitating systems (as opposed to the time reversibility of the equations of motion for individual stars or particles) are traditionally attributed to information loss due to coarse graining in the observation. We show that this subjective element is not necessary once one takes into consideration the fundamental fact that these systems are discrete, i.e., composed of a finite number, N, of stars or particles. We show that a connection can be made between entropy estimates for discrete systems and the Nyquist–Shannon sampling criterion. Specifically, given a sample with N points in a space of d dimensions, the Nyquist–Shannon criterion constrains the size of the smallest structures defined by a function in the continuum that can be uniquely associated with the discrete sample. When applied to an N-body system, this theorem sets a lower limit to the size of phase-space structures (in the continuum) that can be resolved in the discrete data. As a consequence, the finite N system tends to a uniform distribution after a relaxation time that typically scales as

. This provides an explanation for the fast achievement of a stationary state in collapsing N-body gravitating systems such as galaxies and star clusters, without the need to advocate for the subjective effect of coarse graining.
Radioactive Gamma-Ray Emissions from Neutron Star Mergers
Authors: Li Li-Xin
Published: February 2019

Gravitational waves and electromagnetic radiations from a neutron star merger were discovered on 2017 August 17. Multiband observations of the optical transient have identified brightness and spectrum features broadly consistent with theoretical predictions. According to the theoretical model, the optical radiation from a neutron star merger originates from the radioactive decay of unstable nuclides freshly synthesized in the merger ejecta. In about a day the ejecta transits from an optically thick state to an optically thin state owing to its subrelativistic expansion. Hence, we expect that about a day after the merger the gamma-ray photons produced by radioactive decays start to escape from the ejecta and make it bright in the MeV band. In this paper, we study the features of the radioactive gamma-ray emission from a neutron star merger, including the brightness and the spectrum, and discuss the observability of the gamma-ray emission. We find that more than 95% of the radiated gamma-ray energy is carried by photons of 0.2–4 MeV, with a spectrum shaped by the nucleosynthesis process and the subrelativistic expansion of the ejecta. Under favorable conditions, a prominent pair annihilation line can be present in the gamma-ray spectrum with the energy flux about 3%–5% of the total. For a merger event similar to GW170817, the gamma-ray emission attains a peak luminosity of ≈2 × 1041 erg s−1 at ≈1.2 days after the merger and fades by a factor of two in about 2 days. Such a source will be detectable by satellite-ETCC if it occurs at a distance ≲12 Mpc.
HAZMAT. V. The Ultraviolet and X-Ray Evolution of K Stars
Authors: Richey-Yowell Tyler , Shkolnik Evgenya L. , Schneider Adam C. , Osby Ella , Barman Travis , Meadows Victoria S.
Published: February 2019

Knowing the high-energy radiation environment of a star over a planet’s formation and evolutionary period is critical in determining if that planet is potentially habitable and if any biosignatures could be detected, as UV radiation can severely change or destroy a planet’s atmosphere. Current efforts for finding a potentially habitable planet are focused on M stars, yet K stars may offer more habitable conditions due to decreased stellar activity and more distant and wider habitable zones (HZs). While M star activity evolution has been observed photometrically and spectroscopically, there has been no dedicated investigation of K star UV evolution. We present the first comprehensive study of the near-UV, far-UV, and X-ray evolution of K stars. We used members of young moving groups and clusters ranging in age from 10 to 625 Myr combined with field stars and their archived GALEX UV and ROSAT X-ray data to determine how the UV and X-ray radiation evolve. We find that the UV and X-ray flux incident on an HZ planet is 5–50 times lower than that of HZ planets around early-M stars and 50–1000 times lower than those around late-M stars, due to both an intrinsic decrease in K dwarf stellar activity occurring earlier than for M dwarfs and the more distant location of the K dwarf HZ.
New Constraints on IGM Thermal Evolution from the Lyα Forest Power Spectrum
Authors: Walther Michael , Oñorbe Jose , Hennawi Joseph F. , Lukić Zarija
Published: February 2019

We determine the thermal evolution of the intergalactic medium (IGM) over 3 Gyr of cosmic time

by comparing measurements of the Lyα forest power spectrum to a suite of ∼70 hydrodynamical simulations. We conduct Bayesian inference of IGM thermal parameters using an end-to-end forward modeling framework whereby mock spectra generated from our simulation grid are used to build a custom emulator that interpolates the power spectrum between thermal grid points. The temperature at mean density T
0 rises steadily from

at z = 5.4, peaks at 14,000 K for z ∼ 3.4, and decreases at lower redshift, reaching T
0 ∼ 7000 K by z ∼ 1.8. This evolution provides conclusive evidence for photoionization heating resulting from the reionization of

, as well as the subsequent cooling of the IGM due to the expansion of the universe after all reionization events are complete. Our results are broadly consistent with previous measurements of thermal evolution based on a variety of approaches, but the sensitivity of the power spectrum, the combination of high-precision measurements of large-scale modes (

) from the Baryon Oscillation Spectroscopic Survey with our recent determination of the small-scale power, our large grid of models, and our careful statistical analysis allow us to break the well-known degeneracy between the temperature at mean density T
0 and the slope of the temperature–density relation γ that has plagued previous analyses. At the highest redshifts, z ≥ 5, we infer lower temperatures than expected from the standard picture of IGM thermal evolution leaving little room for additional smoothing of the Lyα forest by free streaming of warm dark matter.
Strong Gravitational Lensing by Wave Dark Matter Halos
Authors: Herrera-Martín Antonio , Hendry Martin , Gonzalez-Morales Alma X. , Ureña-López L. Arturo
Published: February 2019

Wave dark matter (WaveDM) has recently gained attention as a viable candidate to account for the dark matter content of the universe. In this paper we explore the extent to which, and under what conditions, dark matter halos in this model are able to reproduce strong-lensing systems. First, we explore analytically the lensing properties of the model, finding that a pure WaveDM density profile, the soliton profile, produces a weaker lensing effect than similar cored profiles. Then, we analyze models with a soliton embedded within a Navarro, Frenk, and White (NFW) profile, as has been found in numerical simulations of structure formation. We use a benchmark model with a boson mass of m

a
 = 10−22 eV, for which we see that there is a bimodality in the contribution of the external NFW part of the profile, and some of the free parameters associated with it are not well constrained. We find that for configurations with boson masses 10−23 to 10−22 eV, a range of masses preferred by dwarf galaxy kinematics, the soliton profile alone can fit the data, but its size is incompatible with the luminous extent of the lens galaxies. Likewise, boson masses of the order of 10−21 eV, which would be consistent with Lyα constraints and consist of more compact soliton configurations, necessarily require the NFW part in order to reproduce the observed Einstein radii. We then conclude that lens systems impose a conservative lower bound m

a
 > 10−24 eV and that the NFW envelope around the soliton must be present to satisfy the observational requirements.
Compton-thick AGNs in the NuSTAR Era. III. A Systematic Study of the Torus Covering Factor
Authors: Marchesi S. , Ajello M. , Zhao X. , Marcotulli L. , Baloković M. , Brightman M. , Comastri A. , Cusumano G. , Lanzuisi G. , La Parola V. , Segreto A. , Vignali C.
Published: February 2019

We present the analysis of a sample of 35 candidate Compton-thick active galactic nuclei (AGNs) selected in the nearby universe (average redshift

) with the Swift-BAT 100-month survey. All sources have available NuSTAR data, thus allowing us to constrain with unprecedented quality important spectral parameters such as the obscuring torus line-of-sight column density (N
H,z), the average torus column density (N
H,tor), and the torus covering factor (f

c
). We compare the best-fit results obtained with the widely used MYTorus (Murphy & Yaqoob 2009) model with those of the recently published borus02 model (Baloković et al. 2018) used in the same geometrical configuration of MYTorus (i.e., with f

c
 = 0.5). We find a remarkable agreement between the two, although with increasing dispersion in N
H,z moving toward higher column densities. We then use borus02 to measure f

c
. High-f

c
sources have, on average, smaller offset between N
H,z and N
H,tor than low-f

c
ones. Therefore, low f

c
values can be linked to a “patchy torus” scenario, where the AGN is seen through an overdense region in the torus, while high-f

c
objects are more likely to be obscured by a more uniform gas distribution. Finally, we find potential evidence of an inverse trend between f

c
and the AGN 2–10 keV luminosity, i.e., sources with higher f

c
values have on average lower luminosities.
Effects of Gas on Formation and Evolution of Stellar Bars and Nuclear Rings in Disk Galaxies
Authors: Seo Woo-Young , Kim Woong-Tae , Kwak SungWon , Hsieh Pei-Ying , Han Cheongho , Hopkins Phil F.
Published: February 2019

We run self-consistent simulations of Milky Way-sized, isolated disk galaxies to study the formation and evolution of a stellar bar as well as a nuclear ring in the presence of gas. We consider two sets of models with cold or warm disks that differ in the radial velocity dispersions, and vary the gas fraction

by fixing the total disk mass. A bar forms earlier and more strongly in the cold disks with larger

, while gas progressively delays the bar formation in the warm disks. The bar formation enhances a central mass concentration, which in turn causes the bar to decay temporarily, after which it regrows in size and strength, eventually becoming stronger in models with smaller

. Although all bars rotate fast in the beginning, they rapidly turn to slow rotators. In our models, only the gas-free, warm disk undergoes rapid buckling instability, while other disks thicken more gradually via vertical heating. The gas driven inward by the bar potential readily forms a star-forming nuclear ring. The ring is very small when it first forms and grows in size over time. The ring star formation rate is episodic and bursty due to feedback, and is well correlated with the mass inflow rate to the ring. Some expanding shells produced by star formation feedback are sheared out in the bar regions and collide with dust lanes to appear as filamentary interbar spurs. The bars and nuclear rings formed in our simulations have properties similar to those in the Milky Way.
Particle Acceleration at 5 au Associated with Turbulence and Small-scale Magnetic Flux Ropes
Authors: Zhao L.-L. , Zank G. P. , Chen Y. , Hu Q. , le Roux J. A. , Du S. , Adhikari L.
Published: February 2019

An observational analysis of an atypical energetic particle event near 5 au measured by the Ulysses spacecraft is presented. A previous study has attributed the unusual enhancement of energetic proton flux to the presence of small-scale dynamic magnetic islands or flux ropes. Here, we find that the generation of these magnetic islands may be related to the interaction of a stream interaction region (SIR) and the heliospheric current sheet (HCS). Particles are accelerated and trapped within the SIR structure characterized by a forward shock–reverse wave pair. Analysis of the energetic particle intensity spectra shows that the 63 keV–4.4 MeV protons form a power-law (PL) spectrum near the shock, with a slope much steeper than predicted by the diffusive shock acceleration (DSA) theory. Double PL spectra are found in the region of unusual particle flux enhancement, and the lower energy part of the spectrum gets harder farther away from the shock. In comparison, we discuss a later forward wave–reverse wave pair with an embedded large-scale magnetic cloud (MC). In contrast to small-scale magnetic islands, the MC corresponds to a decrease in energetic proton fluxes. A power spectral density analysis suggests that the turbulence level increases in the compression regions, and the majority of the observed turbulence power resides in the two-dimensional (2D) component because the spacecraft velocity is almost perpendicular to the interplanetary magnetic field. This is consistent with the enhanced generation of magnetic flux ropes, which are instrinsic to quasi-2D MHD turbulence, in the SIR. An automatic Grad–Shafranov reconstruction technique is used to identify flux rope structures within the period of interest, and their detailed parameters are included in the paper. The observational evidence suggests that the interaction of shock/compressional waves with the HCS may be a key element in generating small-scale dynamic magnetic islands, which subsequently accelerate charged particles and complement the classical DSA mechanism.
The Signature of a Windy Radio Supernova Progenitor in a Binary System
Authors: Yalinewich Almog , Zwart Simon Portegies
Published: February 2019

Type II supernova progenitors are expected to emit copious amounts of mass in a dense stellar wind prior to the explosion. When the progenitor is a member of a binary, the orbital motion modulates the density of this wind. When the progenitor explodes, the high-velocity ejecta collides with the modulated wind, which in turn produces a modulated radio signal. In this Letter we derive general analytic relations between the parameters of the radio signal modulations and binary parameter in the limit of large member-mass ratio. We use these relations to infer the semimajor axis of SN 1979c and a lower bound for the mass of the companion. We further constrain the analytic estimates by numerical simulations using the Astrophysical Multipurpose Software Environment framework. In these calculations we simulate the progenitor binary system including the wind and the gravitational effect of a companion star. The simulation output is compared to the observed radio signal in supernova SN 1979C. We find that it must have been a binary with an orbital period of about 2000 yr. If the exploding star evolved from a ∼18 M
⊙ zero-age main sequence at solar metallicity, we derive a companion mass of 5–12 M
⊙ in an orbit with an eccentricity lower than about 0.8.
Foodborne disease outbreaks in Barbados (1998-2009): a 12-year review
Authors: Hull-Jackson Carol , Adesiyun Abiodun A
Published: February 2019

Introduction: Microbes such as Salmonella, Campylobacter and S. aureus have been implicated in Foodborne disease outbreaks (FBDOs) worldwide, yet information on their occurrence in Barbados is scanty. The purpose of this study was to determine the aetiological agents, food vehicles, locations and peak seasons of FBDOs in Barbados; assess the quality of epidemiological investigations; and identify deficiencies in food production practices and laboratory detection.

Methodology: A search of FBDOs occurring in Barbados between 1998-2009 was conducted among published and unpublished literature sources and reports. The search terms included the keywords “foodborne disease,” “outbreaks” and “Barbados”.

Results: During the period 1998 to 2009, there were 24 foodborne outbreaks, 215 cases of illness, one hospitalisation and no deaths. Overall, 37.5% of outbreaks were associated with hotels/resorts. Salmonella Enteritidis phage type 8 was most commonly implicated with eggs and poultry being the primary vehicles. Three outbreak reports were available for assessment and revealed that there were deficiencies in the outbreak investigations. These reports also recorded high levels of food contamination with indicator organisms, suggesting that improvements in food hygiene and production practices were required.

Conclusions: The number of FBDOs is low in comparison to developed countries. However, the data was likely affected by under-reporting and inadequacies in the outbreak investigations and laboratory detection. Improvements in these areas would lead to not only better detection and characterisation of FBDOs in Barbados but improved food safety control measures.
Argentinian multicenter study on urinary tract infections due to Streptococcus agalactiae in adult patients
Authors: Vigliarolo Laura , Arias Barbara , Suárez Mariana , Van Haute Evert , Kovacec Verónica , Lopardo Horacio , Bonofiglio Laura , Mollerach Marta
Published: February 2019

Introduction: Streptococcus agalactiae (group B streptococcus, GBS) is a recognized urinary pathogen both in males and pregnant or non-pregnant women. Data regarding GBS serotypes recovered from urinary tract infections (UTIs) are scarce. The aim of this study was to describe the clinical and microbiological characteristics of UTIs caused by GBS in adult patients in Argentina.

Methodology: A prospective multicenter study involving 86 centers was conducted in Argentina between July 1st, 2014 and June 30th, 2015. Antimicrobial susceptibility and serotype distribution of GBS isolated from the urinary tract of adult patients were determined. Susceptibility tests were performed by the disk diffusion and/or agar dilution methods. Epidemiological and clinical characteristics of the patients were considered to identify associated comorbilities.

Results: Seven hundred and one GBS were sent to the reference laboratory in the above mentioned period, however, only 211 fulfilled our selection criteria (demographic data availability, underlying diseases reported, colony counts greater than 105 CFU/mL, single organism isolated from the urine sample). No penicillin-resistant GBS was found but fluoroquinolone resistance was high (12.8%), especially among GBS isolated from men and non-pregnant women. UTIs due to GBS were associated to underlying diseases in men and non-pregnant women, particularly diabetes mellitus. Most of the isolates showed serotypes Ia and III.

Conclusions: GBS are still susceptible to penicillin but fluoroquinolone resistance is a growing concern, at least in Argentina. There are underlying conditions that could be associated to urinary infections caused by GBS.
β-lactamase genes in carbapenem resistance Acinetobacter baumannii isolates from a Turkish university hospital
Authors: Say Coskun Umut Safiye , Caliskan Emel , Copur Cicek Asegul , Turumtay Halbay , Sandalli Cemal
Published: February 2019

Introduction: The spread of Acinetobacter baumannii, resistant to most of the available antimicrobial agents, is a serious health problem. The high rate of carbapenem resistance among Acinetobacter baumannii isolates is considered as a threat to public health. In this study, we aimed to determine the antibiotic resistance and related genes in carbapenem-resistant Acinetobacter baumannii isolates.

Methodology: Ninety six isolates of A. baumannii were included. Antimicrobial susceptibility was performed by Phoenix Automated System and disk diffusion method. Carbapenem resistane was characterized by scrneeing of resistance genes such as blaTEM, blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES, blaNDM, blaVIM, blaIMP and blaOXA23-24-51-58 using multiplex polymerase chain reaction.

Results: Resistance for the levofloxacin, gentamicin, amikacin, and tigecycline were determined as 96.9%, 93.7%, 72.9% and 45.8% respectively. Colistin was the only susceptible antibiotic against all clinical isolates. All isolates were defined as multidrug resistance and of these, 31.2% were extensively drug-resistant (sensitive only to colistin). BlaOXA-51­  and blaOXA-23 genes were detected in 100% strains while blaTEM was found in only 2% strains. There was no amplification for the blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES blaNDM, blaVIM, blaIMP and blaOXA24-58 genes.

Conclusions: The high frequency of blaOXA-23 and low frequency of blaTEM gene was observed that indicate prevalence of a variety of A. baumannii strains. The rates of resistance genes vary from region to region. Studies are required for the prevention and control of A. baumannii infection and to formulate the strategies of antibiotic usage.
Fosfomycin in the treatment of extended spectrum beta-lactamase-producing Enterobacteriaceae- related urinary tract infections
Authors: Tumturk Ayhanim , Tonyali Senol , Tezer Tekce Ayse Yasemin , Isikay Levent , Cime Hakan
Published: February 2019

Introduction: We aimed to demonstrate if fosfomycin tromethamine (FT) treatment could be the treatment of choice in ESBL-producing Enterobacteriaceae strains as an alternative to carbapenem particularly in patients who we would like to treat on an outpatient basis.

Methodology; We retrospectively analyzed the medical records of all patients who admitted to infectious disease outpatient clinic with complaints of dysuria and frequency and received FT for lower UTI between May 2016 and May 2017.

Results: A total of 48 patients, 19 females (39.6%) and 29 males (60.4%), with a mean age of 62.5 (ranging from 27 to 85) years were included the study. 26 (76.4%) of patients with a history of urinary operation or intervention had also a history of antibiotic use within the past 3 months. The isolated pathogens included Escherichia Coli (n = 32), Klebsiella spp. (n = 12), Enterobacter spp. (n = 4). The overall microbiological response after treatment was 70.8% (34/48) and the clinical response was 75% (36/48). Clinical and microbiological response rates of patients with and without urinary operation/intervention, diabetes mellitus, history of antibiotic use and malignancy were found similar (p > 0.05). However, patients with a urinary stone disease history had significantly higher response rates than those without a urinary stone disease history (P = 0.042).

Conclusion: Oral fosfomycin tromethamine might be the treatment of choice in ESBL-producing enterobactericea related UTIs especially caused by Escherichia Coli.
New collection records for Theraphosidae (Araneae, Mygalomorphae) in Angola, with the description of a remarkable new species of Ceratogyrus
Authors: Midgley John M. , Engelbrecht Ian
Published: February 2019

During 2015 and 2016 several baboon spider specimens (Araneae: Theraphosidae) were collected in central Angola during surveys undertaken for the Okavango Wilderness Project. These collections represent range and habitat extensions for Pterinochilus Pocock, 1897, Ceratogyrus Pocock, 1897 and Phoneyusa Karsch, 1884. The new species Ceratogyrusattonitifersp. n. is described from female specimens and the distribution of genera mapped. Central and eastern Angola is severely under sampled for theraphosid spiders, with every species collected during the survey either being potentially new to science or representing a significant range extension for the genus.
Revision of the ant-eating spider genus Mallinus Simon, 1893 (Araneae, Zodariidae)
Authors: Haddad Charles R. , Henrard Arnaud , Jocqué Rudy
Published: February 2019

The zodariine spider genus Mallinus Simon, 1893 is redescribed and diagnosed. The type species, M.nitidiventris Simon, 1893 from South Africa, was originally described from subadult specimens. Adults of both sexes of M.nitidiventris are described for the first time, based on recently collected material, and the genus is rediagnosed, redescribed, and its relationships discussed. A single aberrant male specimen from Namibia is here described as a morphospecies, as it is presumed to only be superficially related. A second species, M.defectus Strand, 1906 from Tunisia, is considered a ‘species inquirenda’, as the type specimens could not be traced, but this species is in any case unlikely to be congeneric. The genus is one of 10 cases of a monotypic genus in the Zodariidae. Notes are provided on the biology of M.nitidiventris.