bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiplicity and clustering in Taurus star-forming region
Authors: Joncour Isabelle , Duchêne Gaspard , Moraux Estelle
Published: December 2016

Aims. This work analyses the spatial distribution of stars in Taurus with a specific focus on multiple stars and wide pairs in order to derive new constraints on star formation and early dynamical evolution scenarios.

Methods. We collected the multiplicity data of stars in Taurus to build an up-to-date stellar/multiplicity catalog. We first present a general study of nearest-neighbor statistics on spatial random distribution, comparing its analytical distribution and moments to those obtained from Monte Carlo samplings. We introduce the one-point correlation Ψ function to complement the pair correlation function and define the spatial regimes departing from randomness in Taurus. We then perform a set of statistical studies to characterize the binary regime that prevails in Taurus.

Results. The Ψ function in Taurus has a scale-free trend with a similar exponent as the correlation function at small scale. It extends almost 3 decades up to ~60 kAU showing a potential extended wide binary regime. This was hidden in the correlation function due to the clustering pattern blending. Distinguishing two stellar populations, single stars versus multiple systems (separation ≤1 kAU), within Class II/III stars observed at high angular resolution, we highlight a major spatial neighborhood difference between the two populations using nearest-neighbor statistics. The multiple systems are three times more likely to have a distant companion within 10 kAU when compared to single stars. We show that this is due to the presence of most probable physical ultra-wide pairs (UWPs, defined as such from their mutual nearest neighbor property), that are themselves generally composed of multiple systems containing up to five stars altogether. More generally, our work highlights; 1) a new large population of candidate UWPs in Taurus within the range 1–60 kAU in Taurus and 2) the major local structural role they play up to 60 kAU. There are three different types of UWPs; either composed of two tight and comparatively massive stars (MM), by one single and one multiple (SM), or by two distant low-mass singles (SS) stars. These UWPs are biased towards high multiplicity and higher-stellar-mass components at shorter separations. The multiplicity fraction per ultra-wide pair with separation less than 10 kAU may be as high as 83.5 ± 19.6%.

Conclusions. We suggest that these young pre-main sequence UWPs may be pristine imprints of their spatial configuration at birth resulting from a cascade fragmentation scenario of the natal molecular core. They could be the older counterparts, at least for those separated by less than 10 kAU, to the ≤0.5 Myr prestellar cores/Class 0 multiple objects observed at radio/millimeter wavelengths.
Spiral-driven accretion in protoplanetary discs
Authors: Hennebelle Patrick , Lesur Geoffroy , Fromang Sébastien
Published: December 2016

Context. Understanding how accretion proceeds in proto-planetary discs, and more generally, understanding their dynamics, is a crucial questions that needs to be answered to explain the conditions in which planets form.

Aims. The role that accretion of gas from the surrounding molecular cloud onto the disc may have on its structure needs to be quantified.

Methods. We performed tridimensional simulations using the Cartesian AMR code RAMSES of an accretion disc that is subject to infalling material.

Results. For the aspect ratio of H/R ≃ 0.15 and disc mass Md ≃ 10-2M⊙ used in our study, we find that for typical accretion rates of the order of a few 10-7M⊙ yr-1, values of the α parameter as high as a few 10-3 are inferred. The mass that is accreted in the inner part of the disc is typically at least 50% of the total mass that has been accreted onto the disc.

Conclusions. Our results suggest that external accretion of gas at moderate values onto circumstellar discs may trigger prominent spiral arms that are reminiscent of recent observations made with various instruments, and may lead to significant transport through the disc. If confirmed from observational studies, such accretion may therefore influence disc evolution.
Best-Practice-Award 2017: Prospitalia sucht Impuls- und Ideengeber
Authors: Kucera Martin
Published: December 2016

Der Einkaufsdienstleister Prospitalia sucht für seinen „Best-Practice-Award“ Bewerber aus Krankenhäusern, die Lösungen zur Optimierung ihres Einkaufs entwickeln und umsetzen. Kriterien sind Innovationsgrad, Effektivität, Übertragbarkeit und Nachhaltigkeit.
Charité-Mindestpersonalbesetzung: „Auch wir müssen Leuten hinterherrennen“
Authors: Kohrs Jens
Published: December 2016

Dass ein Personalengpass besonders in der Pädiatrie leicht Schlagzeilen hervorrufen kann, hat jetzt die Charité erleben müssen. „Notstand auf der Kinderkrebsstation“, titelte der „Tagesspiegel“. Grund genug für kma, Pflegedirektorin Judith Heepe nach dem Stand der Umsetzung des bundesweit einmaligen Tarifvertrags der Charité zu fragen.
Kliniken Schmieder: Wie schön, wenn Kinder übernehmen
Authors: Rößing Sabine
Published: December 2016

Im deutschen Reha-Markt sind viele kleine Krankenhausketten in Familienhand, wie die Kliniken Schmieder in Baden-Württemberg. Firmenchefin Dagmar Schmieder spricht im Interview mit kma über die Aufgabe, einen reibungslosen Generationswechsel vorzubereiten und die eigenen Kinder für den schwierigen Klinikmarkt zu begeistern.
Branche in Zahlen
Authors: Mewis Dirk
Published: December 2016

Dieser Artikel ist nur als PDF-Dokument verfügbar.
FKT 2017: Viel vor
Authors: Träger Horst , Siewert Wolfgang , Franzen Christoph
Published: December 2016

Das Jahr 2016 war für die FKT von großen Wagnissen und viel Neuem geprägt: Auf große Resonanz stieß bei Ausstellern und Besuchern unsere erste Fachmesse Krankenhaus Technologie. Zunehmender Beliebtheit erfreuen sich auch unsere Webinare. Das ermutigt uns, im selben Stil weiterzumachen.
Christiane Becker: Frischblut für die Pflege
Authors: Gaede Kirsten
Published: December 2016

Die neue Pflegedirektorin der Uniklinik Halle rüttelt an herkömmlichen Strukturen und möchte pflegewissenschaftlichen Erkenntnissen zu mehr Einfluss im Stationsalltag verhelfen. Dass sie selbst diesen Alltag nur wenige Jahre erlebt hat, sieht sie dabei als Vorteil.
Chaotic sedimentation of particle pairs in a vertical channel at low Reynolds number: Multiple states and routes to chaos
Authors: Verjus Romuald , Guillou Sylvain , Ezersky Alexander , Angilella Jean-Régis
Published: December 2016

The sedimentation of a pair of rigid circular particles in a two-dimensional vertical channel containing a Newtonian fluid is investigated numerically, for terminal particle Reynolds numbers (ReT) ranging from 1 to 10, and for a confinement ratio equal to 4. While it is widely admitted that sufficiently inertial pairs should sediment by performing a regular DKT oscillation (Drafting-Kissing-Tumbling), the present analysis shows in contrast that a chaotic regime can also exist for such particles, leading to a much slower sedimentation velocity. It consists of a nearly horizontal pair, corresponding to a maximum effective blockage ratio, and performing a quasiperiodic transition to chaos while increasing the particle weight. For less inertial regimes, the classical oblique doublet structure and its complex behavior (multiple stable states and hysteresis, period-doubling cascade and chaotic attractor) are recovered, in agreement with previous work [Aidun, C. K. and Ding, E.-J., “Dynamics of particle sedimentation in a vertical channel: Period-doubling bifurcation and chaotic state,” Phys. Fluids 15, 1612 (2003)]. As a consequence of these various behaviors, the link between the terminal Reynolds number and the non-dimensional driving force is complex: it contains several branches displaying hysteresis as well as various bifurcations. For the range of Reynolds number considered here, a global bifurcation diagram is given.
Overview: Nucleation of clathrate hydrates
Authors: Warrier Pramod , Khan M. Naveed , Srivastava Vishal , Maupin C. Mark , Koh Carolyn A.
Published: December 2016

Molecular level knowledge of nucleation and growth of clathrate hydrates is of importance for advancing fundamental understanding on the nature of water and hydrophobic hydrate formers, and their interactions that result in the formation of ice-like solids at temperatures higher than the ice-point. The stochastic nature and the inability to probe the small length and time scales associated with the nucleation process make it very difficult to experimentally determine the molecular level changes that lead to the nucleation event. Conversely, for this reason, there have been increasing efforts to obtain this information using molecular simulations. Accurate knowledge of how and when hydrate structures nucleate will be tremendously beneficial for the development of sustainable hydrate management strategies in oil and gas flowlines, as well as for their application in energy storage and recovery, gas separation, carbon sequestration, seawater desalination, and refrigeration. This article reviews various aspects of hydrate nucleation. First, properties of supercooled water and ice nucleation are reviewed briefly due to their apparent similarity to hydrates. Hydrate nucleation is then reviewed starting from macroscopic observations as obtained from experiments in laboratories and operations in industries, followed by various hydrate nucleation hypotheses and hydrate nucleation driving force calculations based on the classical nucleation theory. Finally, molecular simulations on hydrate nucleation are discussed in detail followed by potential future research directions.
Electronic excitation and relaxation dynamics of the LUMO-derived level in rubrene thin films on graphite
Authors: Ueba Takahiro , Yamada Takashi , Munakata Toshiaki
Published: December 2016

Time resolved two-photon photoemission (TR-2PPE) spectroscopy has been performed for rubrene films on highly oriented pyrolytic graphite. When a second layer is formed on the first monolayer (ML), 2PPE intensity from the lowest unoccupied molecular orbital (LUMO)-derived level shows a clear resonance at a pump photon energy of 4.1 eV. In contrast, the resonance is very weak for sub-ML films. Substrate-molecule interaction blurs the intramolecular resonant transition for sub-ML films. The lifetime of electrons in the LUMO-derived level increases exponentially with increasing film thickness, for thickness up to 3 ML. The lifetime increase becomes more moderate for further increase in the film thickness. This change in the slope of the increase in lifetime suggests a transition in the relaxation mechanism, from electron tunneling to intramolecular relaxation medicated by the substrate. When ultraviolet photons of 4.45 eV are used to pump electrons to the LUMO-derived level, the decay profiles for films thicker than 1 ML deviate from a simple exponential decay. Such deviation is not significantly observed for sub-ML films. When visible photons of 2.97 eV are used for pumping, the decay profiles are well reproduced by a simple exponential decay, irrespective of the film thickness. The deviation from simple exponential decay is attributed to the relaxation of holes produced at deep occupied levels to the highest occupied molecular orbital-derived level.
Amplitude and size scaling for interchange motions of plasma filaments
Authors: Kube R. , Garcia O. E. , Wiesenberger M.
Published: December 2016

The interchange dynamics and velocity scaling of blob-like plasma filaments are investigated using a two-field reduced fluid model. For incompressible flows due to buoyancy, the maximum velocity is proportional to the square root of the relative amplitude and the square root of its cross-field size. For compressible flows in a non-uniform magnetic field, this square root scaling only holds for ratios of amplitudes to cross-field sizes above a certain threshold value. For small amplitudes and large sizes, the maximum velocity is proportional to the filament amplitude. The acceleration is proportional to the amplitude and independent of the cross-field size in all regimes. This is demonstrated by means of numerical simulations and explained by the energy integrals satisfied by the model.
Threshold collision-induced dissociation of protonated hydrazine and dimethylhydrazine clustered with water
Authors: McNary Christopher P. , Armentrout P. B.
Published: December 2016

Threshold collision-induced dissociation using a guided ion beam tandem mass spectrometer is performed on (N2H4)H+(H2O)n, where n = 1 and 2, and on the protonated unsymmetrical 1,1-dimethylhydrazine one-water complex. The primary dissociation pathway for all clusters is a loss of a single water molecule, which for n = 2 is followed by the sequential loss of an additional water molecule at higher collision energies. The data are analyzed using a statistical model after accounting for internal and kinetic energy distributions, multiple collisions, and kinetic shifts to obtain 0 K bond dissociation energies (BDEs). These are also converted using a rigid rotor/harmonic oscillator approximation to yield thermodynamic values at room temperature. Experimental BDEs compare favorably to theoretical BDEs determined at the B3LYP, M06, mPW1PW91, PBE0, MP2(full), and CCSD(T) levels of theory with a 6-311+G(2d,2p) basis set both with and without empirical dispersion. These calculations also allow visualization of the structures of these complexes, which are simple hydrogen-bonded donor-acceptors.
Ultrafast α –CC bond cleavage of acetone upon excitation to 3p and 3d Rydberg states by femtosecond time-resolved photoelectron imaging
Authors: Hüter O. , Temps F.
Published: December 2016

The radiationless electronic relaxation and α –CC bond fission dynamics of jet-cooled acetone in the S1 (nπ*) state and in high-lying 3p and 3d Rydberg states have been investigated by femtosecond time-resolved mass spectrometry and photoelectron imaging. The S1 state was accessed by absorption of a UV pump photon at selected wavelengths between λ = 320 and 250 nm. The observed acetone mass signals and the S1 photoelectron band decayed on sub-picosecond time scales, consistent with a recently proposed ultrafast structural relaxation of the molecules in the S1 state away from the Franck-Condon probe window. No direct signatures could be observed by the experiments for CC dissociation on the S1 potential energy hypersurface in up to 1 ns. The observed acetyl mass signals at all pump wavelengths turned out to be associated with absorption by the molecules of one or more additional pump and/or probe photons. In particular, absorption of a second UV pump photon by the S1 (nπ*) state was found to populate a series of high-lying states belonging to the n = 3 Rydberg manifold. The respective transitions are favored by much larger cross sections compared to the S1  ←  S0 transition. The characteristic energies revealed by the photoelectron images allowed for assignments to the 3p and 3dyz states. At two-photon excitation energies higher than 8.1 eV, an ultrafast reaction pathway for breaking the α –CC bond in 50–90 fs via the 3dyz Rydberg state and the elusive ππ* state was observed, explaining the formation of acetyl radicals after femtosecond laser excitation of acetone at these wavelengths.
Appropriate use of the particle-in-cell method in low temperature plasmas: Application to the simulation of negative ion extraction
Authors: Garrigues L. , Fubiani G. , Boeuf J. P.
Published: December 2016

The Particle-In-Cell Monte Carlo Collision (PIC MCC) method has been used by different authors in the last ten years to describe negative ion extraction in the context of neutral beam injection for fusion. Questionable results on the intensity and profile of the extracted negative ion beamlets have been presented in several recently published papers. Using a standard explicit PIC MCC method, we show that these results are due to a non-compliance with the constraints of the numerical method (grid spacing, number of particles per cell) and to a non-physical generation of the simulated plasma. We discuss in detail the conditions of mesh convergence and plasma generation and show that the results can significantly deviate from the correct solution and lead to unphysical features when the constraints inherent to the method are not strictly fulfilled. This paper illustrates the importance of verification in any plasma simulation. Since the results presented in this paper have been obtained with careful verification of the method, we propose them as benchmarks for future comparisons between different simulation codes for negative ion extraction.
Design of an accurate wireless data logger for vibration analysis with Android interface
Authors: Blanco J. R. , Menéndez J. , Ferrero F. J. , Campo J. C. , Valledor M.
Published: December 2016

In this work a new accurate wireless data logger using the Android interface was developed to monitor vibrations at low-cost. The new data logger is completely autonomous and extremely reduced in size. This instrument enables data collection wirelessly and the ability to display it on any tablet or smartphone with operating system Android. The prototype allows the monitoring of any industrial system with minimal investment in material and installation costs. The data logger is capable of making 12.8 kSPS enough to sample up to 5 kHz signals. The basic specification of the data logger includes a high resolution 1-axis piezoelectric accelerometer with a working range of ±30 G. In addition to the acceleration measurements, temperature can also be recorded. The data logger was tested during a 6-month period in industrial environments. The details of the specific hardware and software design are described. The proposed technology can be easily transferred to many other areas of industrial monitoring.
Note: On the choice of the appropriate excitation-pulse-length for assessment of slow luminescence decays
Authors: Greben M. , Valenta J.
Published: December 2016

The decay-time distribution deduced from luminescence kinetics experiments is, in general, dependent on the excitation pulse length as a direct consequence of different onset dynamics. We demonstrate this effect for the case of square excitation pulses applied to study the luminescence kinetics in Si nanocrystals. The short- and long-pulse limits are defined as 0.1 times the shortest lifetime in the distribution and 3 times the longest time, respectively. Outside these limits the decay-time distribution is independent on the pulse duration. In addition, we describe experimental conditions required to obtain a correct depiction of slow luminescence decay in the μs to ms time range.
Combined optical sizing and acoustical characterization of single freely-floating microbubbles
Authors: Luan Ying , Renaud Guillaume , Raymond Jason L. , Segers Tim , Lajoinie Guillaume , Beurskens Robert , Mastik Frits , Kokhuis Tom J. A. , van der Steen Antonius F. W. , Versluis Michel , de Jong Nico
Published: December 2016

In this study we present a combined optical sizing and acoustical characterization technique for the study of the dynamics of single freely-floating ultrasound contrast agent microbubbles exposed to long burst ultrasound excitations up to the milliseconds range. A co-axial flow device was used to position individual microbubbles on a streamline within the confocal region of three ultrasound transducers and a high-resolution microscope objective. Bright-field images of microbubbles passing through the confocal region were captured using a high-speed camera synchronized to the acoustical data acquisition to assess the microbubble response to a 1-MHz ultrasound burst. Nonlinear bubble vibrations were identified at a driving pressure as low as 50 kPa. The results demonstrate good agreement with numerical simulations based on the shell-buckling model proposed by Marmottant et al. [J. Acoust. Soc. Am. 118, 3499–3505 (2005)]. The system demonstrates the potential for a high-throughput in vitro characterization of individual microbubbles.
Acoustic solitons in a magnetized quantum electron-positron-ion plasma with relativistic degenerate electrons and positrons pressure
Authors: Abdikian A. , Mahmood S.
Published: December 2016

The obliquely nonlinear acoustic solitary propagation in a relativistically quantum magnetized electron-positron (e-p) plasma in the presence of the external magnetic field as well as the stationary ions for neutralizing the plasma background was studied. By considering the dynamic of the fluid e-p quantum and by using the quantum hydrodynamics model and the standard reductive perturbation technique, the Zakharov-Kuznetsov (ZK) equation is derived for small but finite amplitude waves and the solitary wave solution for the parameters relevant to dense astrophysical objects such as white dwarf stars is obtained. The numerical results show that the relativistic effects lead to propagate the electrostatic bell shape structures in quantum e-p plasmas like those in classical pair-ion or pair species for relativistic plasmas. It is also observed that by increasing the relativistic effects, the amplitude and width of the e-p acoustic solitary wave will decrease. In addition, the wave amplitude increases as positron density decreases in magnetized e-p plasmas. It is indicated that by increasing the strength of the magnetic field, the width of the soliton reduces and it becomes sharper. At the end, we have analytically and numerically shown that the pulse soliton solution of the ZK equation is unstable and have traced the dependence of the instability growth rate on electron density. It is found that by considering the relativistic pressure, the instability of the soliton pulse can be reduced. The results can be useful to study the obliquely nonlinear propagation of small amplitude localized structures in magnetized quantum e-p plasmas and be applicable to understand the particle and energy transport mechanism in compact stars such as white dwarfs, where the effects of relativistic electron degeneracy become important.
Organisms with potential to assist in the control of Helicoverpa armigera in Australian cotton production systems
Authors: Knox Oliver G. G. , Anderson Chris M. T. , Ross Jenna L. , Tann Colin C. R. , Gupta Vadakattu V. S. R.
Published: December 2016

Helicoverpa armigera was once considered the most important insect pest to Australian cotton production. The introduction of genetically modified cotton altered this status and made this insect pest control less chemically dependent, but resistance to the insecticidal compounds expressed in genetically modified cotton has evolved in laboratory-reared H. armigera populations and is shown to exist in natural populations. Preventing the development of resistance in field populations is complicated by the over wintering of potentially resistant individuals in the soil. Biocontrol may assist in reducing the population of resistant individuals. Several projects investigating the ecology of Australian cotton highlighted the existence of several native organisms with ability to limit the growth or utilise H. armigera as a host. The work reported here set about establishing the presence of such organisms in Australian cotton soils by recovering them from soil and farm-collected H. armigera that exhibited abnormal growth, disease or death. The recovered organisms were identified as the fungi Lecanicillium lecanii, Actinomucor elegans and several Aspergillus species. L. lecanii was subsequently shown to reduce moth emergence to 56% of the larvae to which it was applied. We also identified a species of Rhabditis nematode, which killed 34% of the larvae to which it was applied and reduced moth emergence to 28%. In light of these observations these organisms are reported as potential candidates for biological control of H. armigera.
Unified framework for information integration based on information geometry
Authors: Oizumi Masafumi , Tsuchiya Naotsugu , Amari Shun-ichi
Published: December 2016

Significance

Measuring the degree of causal influences among multiple elements of a system is a fundamental problem in physics and biology. We propose a unified framework for quantifying any combination of causal relationships between elements in a hierarchical manner based on information geometry. Our measure of integration, called geometrical integrated information, quantifies the strength of multiple causal influences among elements by projecting the probability distribution of a system onto a constrained manifold. This measure overcomes mathematical problems of existing measures and enables an intuitive understanding of the relationships between integrated information and other measures of causal influence such as transfer entropy. Inspired by the integration of neural activity in consciousness studies, our measure should have general utility in analyzing complex systems.
Imaging the He
2
quantum halo state using a free electron laser
Authors: Zeller Stefan , Kunitski Maksim , Voigtsberger Jörg , Kalinin Anton , Schottelius Alexander , Schober Carl , Waitz Markus , Sann Hendrik , Hartung Alexander , Bauer Tobias , Pitzer Martin , Trinter Florian , Goihl Christoph , Janke Christian , Richter Martin , Kastirke Gregor , Weller Miriam , Czasch Achim , Kitzler Markus , Braune Markus , Grisenti Robert E. , Schöllkopf Wieland , Schmidt Lothar Ph. H. , Schöffler Markus S. , Williams Joshua B. , Jahnke Till , Dörner Reinhard
Published: December 2016

Significance

In bound matter on all length scales, from nuclei to molecules to macroscopic solid objects, most of the density of the bound particles is within the range of the interaction potential which holds the system together. Quantum halos on the contrary are a type of matter where the particle density is mostly outside the range of the interaction potential in the tunneling region of the potential. Few examples of these fascinating systems are known in nuclear and molecular physics. The conceptually simplest halo system is made of only two particles. Here we experimentally image the wavefunction of the He
2
quantum halo. It shows the predicted exponential shape of a tunneling wavefunction.
Conveying moods and knowledge-what-it-is-like through lyric poetry
Authors: Gittel Benjamin , Deutschländer Robert , Hecht Martin
Published: December 2016

A very influential idea in western aesthetics is that poems convey multifaceted affective states (moods). This interdisciplinary study compares the moods aroused by the poems with the moods the reader thinks the poem expresses. Further, aroused and expressed mood are compared to the mood the professional authors of the poems had intended. An experimental design with a total of 234 participants was employed. Main results are: (1) Readers’ expressed and aroused moods differ on average and between-person variation is somewhat higher in aroused mood. (2) Authors’ intended moods differ from readers’ expressed moods as well as from readers’ aroused moods. (3) Some readers acquire a special kind of experiential knowledge (knowledge-what-it-is-like to be in a specific mood) through the reception of a poem. In an exploratory fashion, the effects of literary education, classification as fiction, ascription of mood to a situation described in the poem, and reading time were investigated.
Ecology and Environmental Challenges of the Persian Gulf
Authors: Bayani Niloufar
Published: December 2016

The extreme salinity and temperature fluctuations of the Persian Gulf waters have created unique marine and coastal ecosystems, with numerous benefits to Iran and neighboring countries. However, human activities, including rapid coastal development, land-based pollution, oil and gas extraction, and shipping, are threatening the survival of these ecosystems. With long shorelines, a large coastal population, and locally important fisheries and tourism-related jobs, Iran has a lot at stake in the degradation of its marine and coastal environments. However, it is not too late to put a stop to further degradation. This article recommends a number of targeted actions at the local, national, and regional levels to address the threats to the Persian Gulf ’s environment and protect this important renewable resource.
The Caspian Forests of Northern Iran during the Qajar and Pahlavi Periods: Deforestation, Regulation, and Reforestation
Authors: Sadeghian Saghar
Published: December 2016

Uniquely among the world’s temperate forests, much of the vegetation of the Caspian forests is now endangered. But while deforestation has accelerated in Iran, these processes were actually underway in the nineteenth century. This article offers a brief introduction to the history of forest exploitation and concessions during the Qajar and Pahlavi periods, addressing actions taken by the Iranian state to protect and extend forest cover, but also the deficiencies of that legislation and the reasons for its failure. Though it is one of the most forested countries in the Middle East, Iran’s forests remain understudied. Existing scholarship mostly addresses the contemporary period; this paper extends the scope of our knowledge, offering a deeper history of forest exploitation in Iran.
Dams, Drought and Water Shortage in Today’s Iran
Authors: Yazdandoost Farhad
Published: December 2016

Iran has a long history of effective and sustainable water resource management under arid and semi-arid conditions. However, today the country is faced with serious challenges in the water sector, including rising water demand and shortages, declining groundwater levels, deteriorating water quality, and increasing threats to the environment and various ecosystems. If these issues persist, tragedy will be the inevitable result. Over the last three decades tremendous efforts have been made to supply water, primarily through an extensive program of development, with dam building at the forefront. This paper offers an introduction to the different factors and elements influencing the water balance in today’s Iran and presents a perspective on the trend of dam building in recent times.
Psychosocial Stressors and Alcohol use, Severity, and Treatment Receipt across Human Immunodeficiency virus (HIV) Status in a Nationally Representative Sample of US Residents
Authors: Williams Emily C. , Joo Young Sun , Lipira Lauren , Glass Joseph E.
Published: December 2016

Background

Human immunodeficiency virus (HIV) is stigmatized and disproportionately impacts vulnerable populations. Thus, people living with HIV (PLWH) may have greater exposure to psychosocial stressors than those without HIV. Exposure to psychosocial stressors may increase alcohol use and serve as barriers to alcohol treatment receipt. The authors evaluate whether psychosocial stressors and alcohol use, symptom severity, and treatment receipt vary across HIV status in a general population sample of US residents and assess whether psychosocial stressors mediate identified associations.

Methods

Data from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) were used to assess associations between HIV status and psychosocial stressors (perceived stress, alcohol-related stigma, and perceived discrimination based on race/ethnicity, sexual orientation, or sex) and alcohol-related outcomes (any use, heavy drinking, symptom severity, and treatment receipt). For each outcome, regression models were fit and iteratively adjusted for sociodemographic characteristics and comorbidities. Indirect effects of HIV on alcohol-related outcomes through stressors were estimated to assess mediation when main effects were significant.

Results

Among 34,653 NESARC Wave 2 respondents, 161 were PLWH. PLWH were more likely than those without HIV to experience discrimination and had higher levels of perceived stress than those without HIV ( P values <.05), but the 2 groups did not differ regarding alcohol-related stigma. PLWH were less likely to use alcohol and had similar rates of heavy drinking relative to participants without HIV, but alcohol symptom severity and treatment receipt were greater among PLWH. Perceived stress but not discrimination mediated associations.

Conclusions

Findings from this first study of variation in psychosocial stressors and alcohol use, severity, and treatment receipt across HIV status further highlight PLWH as a population that is particularly vulnerable to experiences of psychosocial stress and certain adverse alcohol-related outcomes. Future longitudinal research is needed in a larger sample of PLWH to identify intervention targets.
B cell antigen extraction is regulated by physical properties of antigen-presenting cells
Authors: Spillane Katelyn M. , Tolar Pavel
Published: December 2016

Antibody production and affinity maturation are driven by B cell extraction and internalization of antigen from immune synapses. However, the extraction mechanism remains poorly understood. Here we develop DNA-based nanosensors to interrogate two previously proposed mechanisms, enzymatic liberation and mechanical force. Using antigens presented by either artificial substrates or live cells, we show that B cells primarily use force-dependent extraction and resort to enzymatic liberation only if mechanical forces fail to retrieve antigen. The use of mechanical forces renders antigen extraction sensitive to the physical properties of the presenting cells. We show that follicular dendritic cells are stiff cells that promote strong B cell pulling forces and stringent affinity discrimination. In contrast, dendritic cells are soft and promote acquisition of low-affinity antigens through low forces. Thus, the mechanical properties of B cell synapses regulate antigen extraction, suggesting that distinct properties of presenting cells support different stages of B cell responses.
Deubiquitinase USP13 maintains glioblastoma stem cells by antagonizing FBXL14-mediated Myc ubiquitination
Authors: Fang Xiaoguang , Zhou Wenchao , Wu Qiulian , Huang Zhi , Shi Yu , Yang Kailin , Chen Cong , Xie Qi , Mack Stephen C. , Wang Xiuxing , Carcaboso Angel M. , Sloan Andrew E. , Ouyang Gaoliang , McLendon Roger E. , Bian Xiu-wu , Rich Jeremy N. , Bao Shideng
Published: December 2016

Glioblastoma is the most lethal brain tumor and harbors glioma stem cells (GSCs) with potent tumorigenic capacity. The function of GSCs in tumor propagation is maintained by several core transcriptional regulators including c-Myc. c-Myc protein is tightly regulated by posttranslational modification. However, the posttranslational regulatory mechanisms for c-Myc in GSCs have not been defined. In this study, we demonstrate that the deubiquitinase USP13 stabilizes c-Myc by antagonizing FBXL14-mediated ubiquitination to maintain GSC self-renewal and tumorigenic potential. USP13 was preferentially expressed in GSCs, and its depletion potently inhibited GSC proliferation and tumor growth by promoting c-Myc ubiquitination and degradation. In contrast, overexpression of the ubiquitin E3 ligase FBXL14 induced c-Myc degradation, promoted GSC differentiation, and inhibited tumor growth. Ectopic expression of the ubiquitin-insensitive mutant T58A–c-Myc rescued the effects caused by FBXL14 overexpression or USP13 disruption. These data suggest that USP13 and FBXL14 play opposing roles in the regulation of GSCs through reversible ubiquitination of c-Myc.
Estrogen activation of microglia underlies the sexually dimorphic differences in Nf1 optic glioma–induced retinal pathology
Authors: Toonen Joseph A. , Solga Anne C. , Ma Yu , Gutmann David H.
Published: December 2016

Children with neurofibromatosis type 1 (NF1) develop low-grade brain tumors throughout the optic pathway. Nearly 50% of children with optic pathway gliomas (OPGs) experience visual impairment, and few regain their vision after chemotherapy. Recent studies have revealed that girls with optic nerve gliomas are five times more likely to lose vision and require treatment than boys. To determine the mechanism underlying this sexually dimorphic difference in clinical outcome, we leveraged Nf1 optic glioma (Nf1-OPG) mice. We demonstrate that female Nf1-OPG mice exhibit greater retinal ganglion cell (RGC) loss and only females have retinal nerve fiber layer (RNFL) thinning, despite mice of both sexes harboring tumors of identical volumes and proliferation. Female gonadal sex hormones are responsible for this sexual dimorphism, as ovariectomy, but not castration, of Nf1-OPG mice normalizes RGC survival and RNFL thickness. In addition, female Nf1-OPG mice have threefold more microglia than their male counterparts, and minocycline inhibition of microglia corrects the retinal pathology. Moreover, pharmacologic inhibition of microglial estrogen receptor-β (ERβ) function corrects the retinal abnormalities in female Nf1-OPG mice. Collectively, these studies establish that female gonadal sex hormones underlie the sexual dimorphic differences in Nf1 optic glioma–induced retinal dysfunction by operating at the level of tumor-associated microglial activation.
Final report on the key comparison CCM.P-K4.2012 in absolute pressure from 1 Pa to 10 kPa
Authors: Ricker Jacob , Hendricks Jay , Bock Thomas , Dominik k , Kobata Tokihiko , Torres Jorge , Sadkovskaya Irina
Published: December 2016

The report summarizes the Consultative Committee for Mass (CCM) key comparison CCM.P-K4.2012 for absolute pressure spanning the range of 1 Pa to 10 000 Pa. The comparison was carried out at six National Metrology Institutes (NMIs), including National Institute of Standards and Technology (NIST), Physikalisch-Technische Bundesanstalt (PTB), Czech Metrology Institute (CMI), National Metrology Institute of Japan (NMIJ), Centro Nacional de Metrología (CENAM), and DI Mendeleyev Institute for Metrology (VNIIM). The comparison was made via a calibrated transfer standard measured at each of the NMIs facilities using their laboratory standard during the period May 2012 to September 2013. The transfer package constructed for this comparison preformed as designed and provided a stable artifact to compare laboratory standards. Overall the participants were found to be statistically equivalent to the key comparison reference value.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Final report of the key comparison APMP.QM-K91: APMP comparison on pH measurement of phthalate buffer
Authors: Hioki Akiharu , Asakai Toshiaki , Maksimov Igor , Suzuki Toshihiro , Miura Tsutomu , Ketrin Rosi , Nuryatini  , Thanh Ngo Huy , Chinh Nguyen Truong , Vospelova Alena , Bastkowski Frank , Sander Beatrice , Matzke Jessica , Prokunin Sergey , Frolov Dmitry , Aprelev Alexey , Dobrovolskiy Vladimir , Uysal Emrah , Liv Lokman , Lara-Manzano Judith Velina , Montero-Ruiz Jazmin , Ortiz-Aparicio Luis , Canaza Galia Ticona , Amin Khirul Anuar Mohd , Kadir Haslina Abd , Bakovets Nickolay , Wong Siu-Kay , Lam Wai-Hing
Published: December 2016

The APMP.QM-K91 was organised by TCQM of APMP to test the abilities of the national metrology institutes in the APMP region to measure a pH value of a phthalate buffer. This APMP comparison on pH measurement was proposed by the National Metrology Institute of Japan at the APMP-TCQM meeting held September 22–23, 2014. After approval by TCQM, the comparison has been conducted by NMIJ. The comparison is a key comparison following CCQM-K91. The comparison material was a phthalate buffer of pH around 4.0 and the measurement temperatures were 15 °C, 25 °C and 37 °C. This is the third APMP key comparison on pH measurement and the fifth APMP comparison on pH measurement following APMP.QM-P06 (two phosphate buffers) in 2004, APMP.QM-P09 (a phthalate buffer) in 2006, APMP.QM-K9/APMP.QM-P16 (a phosphate buffer) in 2010-2011 and APMP.QM-K19/APMP.QM-P25 (a borate buffer) in 2013-2014.

The results can be used further by any participant to support its CMC claim at least for a phthalate buffer. That claim will concern the pH method employed by the participant during this comparison and will cover the used temperature(s) or the full temperature range between 15°C and 37 °C for the participant which measured pH values at the three temperatures.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Explicit determination of root numbers of abelian varieties
Authors: Brumer Armand , Kramer Kenneth , Sabitova Maria
Published: December 2016

Let

A
A

be an abelian variety over a nonarchimedean local field of definition

K
K

and let

W
(
A
)

W(A)

be the root number of

A
A

. Let

F
F

be a Galois extension of

K
K

over which

A
A

has semistable reduction, allowing

F
=
K

F = K

. We analyze

W
(
A
)

W(A)

in terms of contributions from the toric and abelian variety components of the closed fibers of the Néron models of

A
A

over the ring of integers of

K
K

and of

F
F

. In particular, our results can be used to calculate

W
(
A
)

W(A)

in two main instances: first, for abelian varieties with additive reduction over

K
K

and totally toroidal reduction over

F
F

, provided that the residue characteristic of

K
K

is odd; second, for the Jacobian

A
=
J
(
C
)

A = J(C)

of a stable curve

C
C

over

K
K

.
The two definitions of the index difference
Authors: Ebert Johannes
Published: December 2016

Given two metrics of positive scalar curvature on a closed spin manifold, there is a secondary index invariant in real

K
K

-theory. There exist two definitions of this invariant: one of a homotopical flavor, the other one defined by an index problem of Atiyah-Patodi-Singer type. We give a complete and detailed proof of the folklore result that both constructions yield the same answer. Moreover, we generalize this result to the case of two families of positive scalar curvature metrics, parametrized by a finite CW complex. In essence, we prove a generalization of the classical “spectral-flow-index theorem” to the case of families of real operators.
Special values of hypergeometric functions and periods of CM elliptic curves
Authors: Yang Yifan
Published: December 2016

Let

X
0
6

(
1
)

/

W
6

X_0^6(1)/W_6

be the Atkin–Lehner quotient of the Shimura curve

X
0
6

(
1
)

X_0^6(1)

associated to a maximal order in an indefinite quaternion algebra of discriminant

6
6

over

Q

\mathbb {Q}

. By realizing modular forms on

X
0
6

(
1
)

/

W
6

X_0^6(1)/W_6

in two ways, one in terms of hypergeometric functions and the other in terms of Borcherds forms, and using Schofer’s formula for values of Borcherds forms at CM-points, we obtain special values of certain hypergeometric functions in terms of periods of elliptic curves over

Q

¯

\overline {\mathbb {Q}}

with complex multiplication.
Derivative of the standard 𝑝-adic 𝐿-function associated with a Siegel form
Authors: Rosso Giovanni
Published: December 2016

In this paper we first construct a two-variable

p
p

-adic

L
L

-function for the standard representation associated with a Hida family of parallel weight genus

g
g

Siegel forms, using a method developed by Böcherer–Schmidt in one variable. When a form

f
f

has weight

g
+
1

g+1

a non-crystalline trivial zero could appear. In this case, using the two-variable

p
p

-adic

L
L

-function we have constructed, we can apply the method of Greenberg–Stevens to calculate the first derivative of the

p
p

-adic

L
L

-function for

f
f

and show that it has the form predicted by a conjecture of Greenberg on trivial zeros.
Current Understandings of Plant Nonhost Resistance
Authors: Lee Hyun-Ah , Lee Hye-Young , Seo Eunyoung , Lee Joohyun , Kim Saet-Byul , Oh Soohyun , Choi Eunbi , Choi Eunhye , Lee So Eui , Choi Doil
Published: December 2016

Nonhost resistance, a resistance of plant species against all nonadapted pathogens, is considered the most durable and efficient immune system of plants but yet remains elusive. The underlying mechanism of nonhost resistance has been investigated at multiple levels of plant defense for several decades. In this review, we have comprehensively surveyed the latest literature on nonhost resistance in terms of preinvasion, metabolic defense, pattern-triggered immunity, effector-triggered immunity, defense signaling, and possible application in crop protection. Overall, we summarize the current understanding of nonhost resistance mechanisms. Pre- and postinvasion is not much deviated from the knowledge on host resistance, except for a few specific cases. Further insights on the roles of the pattern recognition receptor gene family, multiple interactions between effectors from nonadapted pathogen and plant factors, and plant secondary metabolites in host range determination could expand our knowledge on nonhost resistance and provide efficient tools for future crop protection using combinational biotechnology approaches.

[Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
Using Contribution Analysis to Evaluate Competency-Based Medical Education Programs: It’s All About Rigor in Thinking
Authors: Van Melle Elaine , Gruppen Larry , Holmboe Eric S. , Flynn Leslie , Oandasan Ivy , Frank Jason R.
Published: December 2016

Competency-based medical education (CBME) aims to bring about the sequential acquisition of competencies required for practice. Although it is being adopted in centers of medical education around the globe, there is little evidence concerning whether, in comparison with traditional methods, CBME produces physicians who are better prepared for the practice environment and contributes to improved patient outcomes. Consequently, the authors, an international group of collaborators, wrote this article to provide guidance regarding the evaluation of CBME programs.

CBME is a complex service intervention consisting of multiple activities that contribute to the achievement of a variety of outcomes over time. For this reason, it is difficult to apply traditional methods of program evaluation, which require conditions of control and predictability, to CBME. To address this challenge, the authors describe an approach that makes explicit the multiple potential linkages between program activities and outcomes. Referred to as contribution analysis (CA), this theory-based approach to program evaluation provides a systematic way to make credible causal claims under conditions of complexity. Although CA has yet to be applied to medical education, the authors describe how a six-step model and a postulated theory of change could be used to examine the link between CBME, physicians’ preparation for practice, and patient care outcomes.

The authors argue that adopting the methods of CA, particularly the rigor in thinking required to link program activities, outcomes, and theory, will serve to strengthen understanding of the impact of CBME over time.