bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequence stratigraphic model for repeated “butter shale” Lagerstätten in the Ordovician (Katian) of the Cincinnati, Ohio region, USA
Authors: Aucoin Christopher D. , Brett Carlton E. , Dattilo Benjamin F. , Thomka James R.
Published: March 2016

The “butter shale” Lagerstätten of the Cincinnati Arch have produced an abundance of articulated trilobites, along with assorted bivalves and cephalopods. These bluish gray shales are rich in clay, poorly calcified, and show vague internal bedding in outcrop. Butter shales form a repetitive motif with similar lithological and paleontological characteristics, suggesting conditions existed that can be explained by the interference between different orders of sequence stratigraphic cyclicity. The characteristics that define butter shales include rarity of coarser interbeds, homogenous, fine grain size, and abundance of burial horizons. The overriding control is siliciclastic sediment supply. During third-order transgressions, sediment supply to the basin is too low to produce thick shale-prone intervals. Conversely, during third-order falling stages, sediment supply is generally too high to favor butter shale deposition. Butter shales formed preferentially during a third-order highstand systems tract, and two subtly different variants resulted from the superimposed effects of higher order cycles. Highstands moderated by small-scale transgressions are characterized by lower background sedimentation and fewer, thinner mud deposition events. Superposition of small-scale sea-level fall on highstands produced increased background sedimentation, higher silt, and patchy fossil occurrences. Juxtaposition of various scaled highstand systems tracts provided the optimal butter shale conditions, characterized by elevated mud influx and frequent episodic burial events, leading to abundant, articulated trilobites and associated fauna. In these scenarios, episodic events provide sufficient mud to smother local faunas and create a soft, fine-grained substrate that prohibited recolonization by taxa adapted to firm substrates. Each scenario differs from the others with respect to sedimentology and faunal composition.
Evaluating the influence of predator–prey interactions on stock assessment and management reference points for a large lake ecosystem
Authors: Kurota Hiroyuki , McAllister Murdoch K. , Parkinson Eric A. , Johnston N.T.
Published: March 2016

Ecosystem models are thought to offer advantages over single-species models in terms of management policy analysis. This hypothesis has proven difficult to test because of underlying system complexities, coupled with short time series and minimal contrast in environmental conditions or management policies. This paper presents a Bayesian statistical catch-at-age model to compare ecosystem models and test hypotheses about the management of a recreational fishery based on a predator–prey system using a relatively simple and data-rich ecosystem in a large lake, Kootenay Lake, British Columbia, where kokanee (Oncorhynchus nerka) are the prey and piscivorous rainbow trout (Oncorhynchus mykiss) are the predator. A model that explicitly incorporates the predator–prey interaction explained long-term data of field and fishery surveys much better than single-species models without any interactions. Minimally realistic multispecies models that treated predation identically but differed in their representation of the effects of prey abundance on predator mortality produced quite different results. Management reference points, for example, differed considerably between the models. Our study thus emphasizes that the choice of a management approach for this type of fishery will depend strongly on the model form and should take into consideration results from empirically based models that include species interactions.
Interacting effects of latitude, mass, age, and sex on winter survival of Surf Scoters (Melanittaperspicillata): implications for differential migration
Authors: Uher-Koch Brian D. , Esler Daniel , Iverson Samuel A. , Ward David H. , Boyd W. Sean , Kirk Molly , Lewis Tyler L. , VanStratt Corey S. , Brodhead Katherine M. , Hupp Jerry W. , Schmutz Joel A.
Published: March 2016

We quantified variation in winter survival of Surf Scoters (Melanitta perspicillata (L., 1758)) across nearly 30° of latitude on the Pacific coast of North America to evaluate potential effects on winter distributions, including observed differential distributions of age and sex classes. We monitored fates of 297 radio-marked Surf Scoters at three study sites: (1) near the northern periphery of their wintering range in southeast Alaska, USA, (2) the range core in British Columbia, Canada, and (3) the southern periphery in Baja California, Mexico. We detected 34 mortalities and determined that survival averaged lower at the range peripheries than in the range core, was lower during mid-winter than during late winter at all sites, and was positively correlated with body mass within locations. Although neither age nor sex class had direct effects, mass effects led to differential survival patterns among classes. When simultaneously incorporating these interacting influences, adult males of mean mass for their location had highest survival at the northern range periphery in Alaska, whereas adult females and juveniles had higher survival at the range core and the southern periphery. Our observations help to explain patterns of differential migration and distribution reported for this species and highlight seasonal periods (mid-winter) and locations (range peripheries) of elevated levels of mortality for demographically important age–sex classes (adult females).
Two-dimensional noncommutative quantum mechanics with the central potential
Authors: Chung Won Sang
Published: March 2016

Quantum mechanics in a noncommutative plane with both space noncommutativity and momentum noncommutativity is considered. For a general two-dimensional central field, we show that the theory can be perturbatively solved for large values of the space noncommutative parameter [Formula: see text] when the momentum noncommutative parameter [Formula: see text] is proportional to [Formula: see text]. We obtain the expressions for the eigenstates and eigenvalues. We also discuss the more general noncommutative algebra which have the nonvanishing commutator for [Formula: see text] for different [Formula: see text], [Formula: see text].
Yang–Mills theories at high energy accelerators
Authors: Sterman George
Published: March 2016

I will begin with a brief review of the triumph of Yang–Mills theory at particle accelerators, a development that began some years after their historic paper. This story reached a culmination, or at least local extremum, with the discovery at the Large Hadron Collider of a Higgs-like scalar boson in 2012. The talk then proceeds to a slightly more technical level, discussing how we derive predictions from the gauge field theories of the Standard Model and its extensions for use at high energy accelerators.
Asymmetric dark matter and the scalar-tensor model
Authors: Wang Shun-Zhi , Iminniyaz Hoernisa , Mamat Mamatrishat
Published: March 2016

The relic abundance of asymmetric dark matter particles in the scalar-tensor model is analyzed in this paper. We extend the numerical and analytical calculations of the relic density of the asymmetric dark matter in the standard cosmological scenario to the nonstandard cosmological scenario. We focus on the scalar-tensor model. Hubble expansion rate is changed in the nonstandard cosmological scenario. This leaves its imprint on the relic density of dark matter particles. In this paper we investigate to what extent the asymmetric dark matter particle’s relic density is changed in the scalar-tensor model. We use the observed present day dark matter abundance to find the constraints on the parameter space in this model.
The chiral phase transition and the role of vacuum fluctuations
Authors: Khan Rashid , Andersen Jens O. , Kyllingstad Lars T. , Khan Majid
Published: March 2016

We apply optimized perturbation theory to the quark–meson model at finite temperature [Formula: see text] and quark chemical potential [Formula: see text]. The effective potential is calculated to one loop both in the chiral limit and at the physical point and used to study the chiral dynamics of two-flavor QCD. The critical temperature and the order of the phase transition depend heavily on whether or not one includes the bosonic and fermionic vacuum fluctuations in the effective potential. A full one-loop calculation in the chiral limit predicts a first-order transition for all values of [Formula: see text]. At the physical point, one finds a crossover in the whole [Formula: see text]–[Formula: see text] plane.
Relativistic scalar particle subject to a confining potential and Lorentz symmetry breaking effects in the cosmic string space–time
Authors: Belich H. , Bakke K.
Published: March 2016

The behavior of a relativistic scalar particle subject to a scalar potential under the effects of the violation of the Lorentz symmetry in the cosmic string space–time is discussed. It is considered two possible scenarios of the Lorentz symmetry breaking in the CPT-even gauge sector of the Standard Model Extension defined by a tensor [Formula: see text]. Then, by introducing a scalar potential as a modification of the mass term of the Klein–Gordon equation, it is shown that the Klein–Gordon equation in the cosmic string space–time is modified by the effects of the Lorentz symmetry violation backgrounds and bound state solution to the Klein–Gordon equation can be obtained.
Study of the angular distribution of W-L X-ray intensity ratios in photoionization
Authors: Wang Xing , Xu Zhongfeng , Zhang Limin
Published: March 2016

The angular distribution of W-[Formula: see text], [Formula: see text] and [Formula: see text] X-rays induced by 13.1 keV bremsstrahlung has been measured at different emission angles from 110[Formula: see text] to 140[Formula: see text] at intervals of 10[Formula: see text]. The investigation of angular dependence of [Formula: see text] X-ray intensity ratios by bremsstrahlung is barely found in previous works. The [Formula: see text] X-ray yield shows isotropic emission, while the measured [Formula: see text] and [Formula: see text] X-ray yields are found to be spatially anisotropic. At last, the anisotropy parameters for [Formula: see text] and [Formula: see text] X-rays have been derived.
The numerical investigation of magnetic properties of single domain MnP:GaP nanoparticles
Authors: Gerami Adeleh Mokhles , Vaez-Zadeh Mehdi
Published: March 2016

The magnetic properties of MnP:GaP nanoparticles are calculated using a statistical mechanical approach and effect of various factors on magnetization of nanoparticles is studied. The calculation is based on solution of localized partition function and evolution of magnetic moment affected by thermal fluctuation and external field is included by solving master equation. Instead of constant magnetic saturation approximation, a temperature dependent magnetic moment saturation is included to improve calculation efficiency for larger nanoparticles. In the present work, the field-cooled and zero-field-cooled (FC/ZFC) magnetization of randomly oriented anisotropy and log-normal volume distributed nanoparticles are calculated.
Encapsulated grating for three-port beam splitter in reflection
Authors: Shu Wenhao , Wang Bo , Li Hongtao , Lei Liang , Chen Li , Zhou Jinyun
Published: March 2016

An encapsulated grating with a metal slab is designed as a reflection three-port beam splitter at the wavelength of 1550 nm under normal incidence. Such a new grating is aimed to separate energies into the ±1st and the 0th orders for both TE and TM polarizations. The grating parameters such as grating period, duty cycle and grating depth are optimized by using rigorous coupled-wave analysis. Based on optimized grating parameters, efficiencies can reach more than 32% with the polarization-independent property. It indicates that reflection three-port beam splitter with high efficiency can be obtained by the encapsulated grating. Moreover, the presented reflection three-port grating has advantages of wide incident wavelength range and angular bandwidth, which would be useful in practical application.
The Einstein–Maxwell-aether-axion theory: Dynamo-optical anomaly in the electromagnetic response
Authors: Alpin Timur Yu. , Balakin Alexander B.
Published: March 2016

We consider a pp-wave symmetric model in the framework of the Einstein–Maxwell-aether-axion theory. Exact solutions to the equations of axion electrodynamics are obtained for the model, in which pseudoscalar, electric and magnetic fields were constant before the arrival of a gravitational pp-wave. We show that dynamo-optical interactions, i.e. couplings of electromagnetic field to a dynamic unit vector field, attributed to the velocity of a cosmic substratum (aether, vacuum, dark fluid[Formula: see text]), provide the response of axionically active electrodynamic system to display anomalous behavior.
TURTLE GRAPHICS OF MORPHIC SEQUENCES
Authors: ZANTEMA HANS
Published: March 2016

The simplest infinite sequences that are not ultimately periodic are pure morphic sequences: fixed points of particular morphisms mapping single symbols to strings of symbols. A basic way to visualize a sequence is by a turtle curve: for every alphabet symbol fix an angle, and then consecutively for all sequence elements draw a unit segment and turn the drawing direction by the corresponding angle. This paper investigates turtle curves of pure morphic sequences. In particular, criteria are given for turtle curves being finite (consisting of finitely many segments), and for being fractal or self-similar: it contains an up-scaled copy of itself. Also space-filling turtle curves are considered, and a turtle curve that is dense in the plane. As a particular result we give an exact relationship between the Koch curve and a turtle curve for the Thue–Morse sequence, where until now for such a result only approximations were known.
Weitzenböck derivations of free metabelian associative algebras
Authors: Dangovski Rumen , Drensky Vesselin , Fındık Şehmus
Published: March 2016

By the classical theorem of Weitzenböck the algebra of constants [Formula: see text] of a nonzero locally nilpotent linear derivation [Formula: see text] of the polynomial algebra [Formula: see text] in several variables over a field [Formula: see text] of characteristic 0 is finitely generated. As a noncommutative generalization one considers the algebra of constants [Formula: see text] of a locally nilpotent linear derivation [Formula: see text] of a finitely generated relatively free algebra [Formula: see text] in a variety [Formula: see text] of unitary associative algebras over [Formula: see text]. It is known that [Formula: see text] is finitely generated if and only if [Formula: see text] satisfies a polynomial identity which does not hold for the algebra [Formula: see text] of [Formula: see text] upper triangular matrices. Hence the free metabelian associative algebra [Formula: see text] is a crucial object to study. We show that the vector space of the constants [Formula: see text] in the commutator ideal [Formula: see text] is a finitely generated [Formula: see text]-module, where [Formula: see text] acts on [Formula: see text] and [Formula: see text] in the same way as on [Formula: see text]. For small [Formula: see text], we calculate the Hilbert series of [Formula: see text] and find the generators of the [Formula: see text]-module [Formula: see text]. This gives also an (infinite) set of generators of the algebra [Formula: see text].
On Schur p-Groups of odd order
Authors: Ryabov Grigory
Published: March 2016

A finite group [Formula: see text] is called a Schur group if any [Formula: see text]-ring over [Formula: see text] is associated in a natural way with a subgroup of [Formula: see text] that contains all right translations. We prove that the groups [Formula: see text], where [Formula: see text], are Schur. Modulo previously obtained results, it follows that every noncyclic Schur [Formula: see text]-group, where [Formula: see text] is an odd prime, is isomorphic to [Formula: see text] or [Formula: see text], [Formula: see text].
Four-dimensional context of Earth's supercontinents
Authors: Evans D. A. D. , Li Z. X. , Murphy J. B.
Published: March 2016

The supercontinent-cycle hypothesis attributes planetary-scale episodic tectonic events to an intrinsic self-organizing mode of mantle convection, governed by the buoyancy of continental lithosphere that resists subduction during closure of old ocean basins, and consequent reorganization of mantle convection cells leading to opening of new ocean basins. Characteristic timescales of the cycle are typically 500–700 myr. Proposed spatial patterns of cyclicity range from hemispheric (introversion) to antipodal (extroversion), to precisely between those end-members (orthoversion). Advances in our understanding can arise from theoretical or numerical modelling, primary data acquisition relevant to continental reconstructions, and spatiotemporal correlations between plate kinematics, geodynamic events and palaeoenvironmental history. The palaeogeographic record of supercontinental tectonics on Earth is still under development. The contributions in this special publication provide snap-shots in time of these investigations and indicate that Earth's palaeogeographic record incorporates elements of all three endmember spatial patterns.
Science, Reason, and Robots
Authors: Yaffe Philip
Published: March 2016

Science depends on logical reasoning. However, the conclusions one comes to intimately depend on the explicit, or more often implicit, assumptions on which the reasoning is based. Here is an example of how logical reasoning based on different assumptions can lead to diametrically opposite conclusions.
Simulation of the effects of moderate stimulation/inhibition of the β1-adrenergic signaling system and its components in mouse ventricular myocytes
Authors: Grinshpon Mark , Bondarenko Vladimir E.
Published: March 2016

The β1-adrenergic signaling system is one of the most important protein signaling systems in cardiac cells. It regulates cardiac action potential duration, intracellular Ca2+ concentration ([Ca2+]i) transients, and contraction force. In this paper, a comprehensive experimentally based mathematical model of the β1-adrenergic signaling system for mouse ventricular myocytes is explored to simulate the effects of moderate stimulations of β1-adrenergic receptors (β1-ARs) on the action potential, Ca2+ and Na+ dynamics, as well as the effects of inhibition of protein kinase A (PKA) and phosphodiesterase of type 4 (PDE4). Simulation results show that the action potential prolongations reach saturating values at relatively small concentrations of isoproterenol (∼0.01 μM), while the [Ca2+]i transient amplitude saturates at significantly larger concentrations (∼0.1–1.0 μM). The differences in the response of Ca2+ and Na+ fluxes to moderate stimulation of β1-ARs are also observed. Sensitivity analysis of the mathematical model is performed and the model limitations are discussed. The investigated model reproduces most of the experimentally observed effects of moderate stimulation of β1-ARs, PKA, and PDE4 inhibition on the L-type Ca2+ current, [Ca2+]i transients, and the sarcoplasmic reticulum Ca2+ load and makes testable predictions for the action potential duration and [Ca2+]i transients as functions of isoproterenol concentration.
Vascular smooth muscle-specific deletion of the leptin receptor attenuates leptin-induced alterations in vascular relaxation
Authors: Ryan Michael J. , Coleman T. Taylor , Sasser Jennifer M. , Pittman Katarina M. , Hankins Michael W. , Stec David E.
Published: March 2016

Obesity is a risk factor for cardiovascular disease and is associated with increased plasma levels of the adipose-derived hormone leptin. Vascular smooth muscle cells (VSMC) express leptin receptors (LepR); however, their physiological role is unclear. We hypothesized that leptin, at levels to mimic morbid obesity, impairs vascular relaxation. To test this, we used control and VSM-LepR knockout mice (VSM-LepR KO) created with a tamoxifen-inducible specific Cre recombinase to delete the LepR gene in VSMC. Control (10–12 wk old) and VSM-LepR KO (10–12 wk old) mice were fed a diet containing tamoxifen (50 mg/kg) for 6 wk, after which vascular reactivity was studied in isolated carotid arteries using an organ chamber bath. Vessels were incubated with leptin (100 ng/ml) or vehicle (0.1 mM Tris·HCl) for 30 min. Leptin treatment resulted in significant impairment of vessel relaxation to the endothelial-specific agonist acetylcholine (ACh). When these experiments were repeated in the presence of the superoxide scavenger tempol, relaxation responses to ACh were restored. VSM-LepR deletion resulted in a significant attenuation of leptin-mediated impaired ACh-induced relaxation. These data show that leptin directly impairs vascular relaxation via a VSM-LepR-mediated mechanism, suggesting a potential pathogenic role for leptin to increase cardiovascular risk during obesity.
The hypophagic response to heat stress is not mediated by GPR109A or peripheral β-OH butyrate
Authors: Hepler Chelsea , Foy Caroline E. , Higgins Mark R. , Renquist Benjamin J.
Published: March 2016

Rising temperatures resulting from climate change will increase the incidence of heat stress, negatively impacting the labor force and food animal production. Heat stress elevates circulating β-OH butyrate, which induces vasodilation through GPR109a. Interestingly, both heat stress and intraperitoneal β-OH butyrate administration induce hypophagia. Thus, we aimed to investigate the role of β-OH butyrate in heat stress hypophagia in mice. We found that niacin, a β-OH butyrate mimetic that cannot be oxidized to generate ATP, also reduces food intake. Interestingly, the depression in food intake as a result of 8-h intraperitoneal niacin or 48-h heat exposure did not result from changes in hypothalamic expression of orexigenic or anorexigenic signals (AgRP, NPY, or POMC). Genetically eliminating GPR109a expression did not prevent the hypophagic response to heat exposure, intraperitoneal β-OH butyrate (5.7 mmol/kg), or niacin (0.8 mmol/kg). Hepatic vagotomy eliminated the hypophagic response to β-OH butyrate and niacin but did not affect the hypophagic response to heat exposure. We subsequently hypothesized that the hypophagic response to heat stress may depend on direct effects of β-OH butyrate at the central nervous system: β-OH butyrate induced hormonal changes (hyperinsulinemia, hypercorticosteronemia, and hyperleptinemia), or gene expression changes. To test these possibilities, we blocked expression of hepatic hydroxyl methyl glutaryl CoA synthase II (HMGCS2) to prevent hepatic β-OH butyrate synthesis. Mice that lack HMGCS2 maintain a hypophagic response to heat stress. Herein, we establish that the hypophagia of heat stress is independent of GPR109a, the hepatic vagus afferent nerve, and hepatic ketone body synthesis.
Spontaneous one-kidney rats are more susceptible to develop hypertension by DOCA-NaCl and subsequent kidney injury compared with uninephrectomized rats
Authors: Wang Xuexiang , Johnson Ashley C. , Sasser Jennifer M. , Williams Jan M. , Solberg Woods Leah C. , Garrett Michael R.
Published: March 2016

There is little clinical data of how hypertension may influence individuals with nephron deficiency in the context of being born with a single kidney. We recently developed a new rat model (the heterogeneous stock-derived model of unilateral renal agenesis rat) that is born with a single kidney and exhibits progressive kidney injury and decline in kidney function with age. We hypothesized that DOCA-salt would induce a greater increase in blood pressure and therefore accelerate the progression of kidney injury in rats born with a solitary kidney compared with rats that have undergone unilateral nephrectomy. Time course evaluation of blood pressure, kidney injury, and renal hemodynamics was performed in the following six groups of animals from weeks 13 to 18: 1) DOCA-treated rats with a solitary kidney (DOCA+S group), 2) placebo-treated rats with a solitary kidney, 3) DOCA-treated control rats with two kidneys (DOCA+C group), 4) placebo-treated control rats with two kidneys, 5) DOCA-treated rats with two kidneys that underwent uninephrectomy (DOCA+UNX8 group), and 6) placebo-treated rats with two kidneys that underwent uninephrectomy. DOCA+S rats demonstrated a significant rise ( P < 0.05) in blood pressure (192 ± 4 mmHg), proteinuria (205 ± 31 mg/24 h), and a decline in glomerular filtration rate (600 ± 42 μl·min−1·g kidney weight−1) relative to the DOCA+UNX8 (173 ± 3 mmHg, 76 ± 26 mg/24 h, and 963 ± 36 μl·min−1·g kidney weight−1) and DOCA+C (154 ± 2 mmHg, 7 ± 1 mg/24 h, and 1,484 ± 121 μl·min−1·g kidney weight−1) groups. Placebo-treated groups showed no significant change among the three groups. An assessment of renal injury markers via real-time PCR/Western blot analysis and histological analysis was concordant with the measured physiological parameters. In summary, congenital solitary kidney rats are highly susceptible to the induction of hypertension compared with uninephrectomized rats, suggesting that low nephron endowment is an important driver of elevated blood pressure, hastening nephron injury through the transmission of elevated systemic blood pressure and thereby accelerating decline in kidney function.
Systolic-diastolic functional coupling in healthy children and in those with dilated cardiomyopathy
Authors: Friedberg Mark K. , Margossian Renee , Lu Minmin , Mercer-Rosa Laura , Henderson Heather T. , Nutting Arni , Friedman Kevin , Molina Kimberly M. , Altmann Karen , Canter Charles , Sleeper Lynn A. , Colan Steven D. ,   Pediatric Heart Network Investigators
Published: March 2016

Systolic and diastolic function affect dilated cardiomyopathy (DCM) outcomes. However, systolic-diastolic coupling, as a distinct characteristic, may itself affect function but is poorly characterized. We hypothesized that echocardiographic left ventricular (LV) longitudinal systolic tissue velocities (S') correlate with diastolic longitudinal velocities (E') and that their relationship is associated with ventricular function and that this relationship is impaired in pediatric DCM. We analyzed data from the Pediatric Heart Network Ventricular Volume Variability study, using linear regression and generalized additive modeling to assess relationships between S' and E' at the lateral and septal mitral annulus. We explored relationships between the systolic:diastolic (S:D) coupling ratio (S':E' relative to age) and ventricular function. Up to 4 echocardiograms from 130 DCM patients (mean age: 9.3 ± 6.1 yr) and 1 echocardiogram from each of 591 healthy controls were analyzed. S' and E' were linearly related in controls ( r = 0.64, P < 0.001) and DCM ( r = 0.83, P < 0.001). In DCM, the magnitude of association between S' and E' was reduced with progressive ventricular remodeling. The S:D ratio was more strongly associated with LV function in controls vs. DCM. The septal S:D ratio was higher (presumed worse) in DCM vs. controls (0.69 ± 0.13 vs. 0.62 ± 0.12, P = 0.001). A higher septal S:D ratio was associated with worse LV dimensions (parameter estimate: 0.0061, P = 0.004), mass (parameter estimate: 0.0074, P = 0.002), ejection fraction (parameter estimate: −0.0303, P = 0.024), and inflow propagation (parameter estimate: −0.3538, P < .001). S:D coupling becomes weaker in DCM with LV remodeling and dysfunction. The S:D coupling ratio may be useful to assess coupling, warranting study in relation to patient outcomes.
Categorically distinct types of receptive fields in early visual cortex
Authors: Talebi Vargha , Baker Curtis L.
Published: March 2016

In the visual cortex, distinct types of neurons have been identified based on cellular morphology, response to injected current, or expression of specific markers, but neurophysiological studies have revealed visual receptive field (RF) properties that appear to be on a continuum, with only two generally recognized classes: simple and complex. Most previous studies have characterized visual responses of neurons using stereotyped stimuli such as bars, gratings, or white noise and simple system identification approaches (e.g., reverse correlation). Here we estimate visual RF models of cortical neurons using visually rich natural image stimuli and regularized regression system identification methods and characterize their spatial tuning, temporal dynamics, spatiotemporal behavior, and spiking properties. We quantitatively demonstrate the existence of three functionally distinct categories of simple cells, distinguished by their degree of orientation selectivity (isotropic or oriented) and the nature of their output nonlinearity (expansive or compressive). In addition, these three types have differing average values of several other properties. Cells with nonoriented RFs tend to have smaller RFs, shorter response durations, no direction selectivity, and high reliability. Orientation-selective neurons with an expansive output nonlinearity have Gabor-like RFs, lower spontaneous activity and responsivity, and spiking responses with higher sparseness. Oriented RFs with a compressive nonlinearity are spatially nondescript and tend to show longer response latency. Our findings indicate multiple physiologically defined types of RFs beyond the simple/complex dichotomy, suggesting that cortical neurons may have more specialized functional roles rather than lying on a multidimensional continuum.
Nicotinic acetylcholine receptor-mediated responses in medial vestibular and prepositus hypoglossi nuclei neurons showing distinct neurotransmitter phenotypes
Authors: Zhang Yue , Yanagawa Yuchio , Saito Yasuhiko
Published: March 2016

Cholinergic transmission in both the medial vestibular nucleus (MVN) and prepositus hypoglossi nucleus (PHN) plays an important role in horizontal eye movements. We previously demonstrated that the current responses mediated via nicotinic acetylcholine receptors (nAChRs) were larger than those mediated via muscarinic acetylcholine receptors (mAChRs) in cholinergic MVN and PHN neurons that project to the cerebellum. In this study, to clarify the predominant nAChR responses and the expression patterns of nAChRs in MVN and PHN neurons that exhibit distinct neurotransmitter phenotypes, we identified cholinergic, inhibitory, and glutamatergic neurons using specific transgenic rats and investigated current responses to the application of acetylcholine (ACh) using whole cell recordings in brain stem slices. ACh application induced larger nAChR-mediated currents than mAChR-mediated currents in every neuronal phenotype. In the presence of an mAChR antagonist, we found three types of nAChR-mediated currents that exhibited different rise and decay times and designated these as fast (F)-, slow (S)-, and fast and slow (FS)-type currents. F-type currents were the predominant response in inhibitory MVN neurons, whereas S-type currents were observed in the majority of glutamatergic MVN and PHN neurons. No dominant response type was observed in cholinergic neurons. Pharmacological analyses revealed that the F-, S-, and FS-type currents were mainly mediated by α7, non-α7, and both α7 and non-α7 nAChRs, respectively. These findings suggest that cholinergic responses in the major neuronal populations of the MVN and PHN are predominantly mediated by nAChRs and that the expression of α7 and non-α7 nAChRs differ among the neuronal phenotypes.
Getting to the Outer Leaflet: Physiology of Phosphatidylserine Exposure at the Plasma Membrane
Authors: Bevers Edouard M. , Williamson Patrick L.
Published: March 2016

Phosphatidylserine (PS) is a major component of membrane bilayers whose change in distribution between inner and outer leaflets is an important physiological signal. Normally, members of the type IV P-type ATPases spend metabolic energy to create an asymmetric distribution of phospholipids between the two leaflets, with PS confined to the cytoplasmic membrane leaflet. On occasion, membrane enzymes, known as scramblases, are activated to facilitate transbilayer migration of lipids, including PS. Recently, two proteins required for such randomization have been identified: TMEM16F, a scramblase regulated by elevated intracellular Ca2+, and XKR8, a caspase-sensitive protein required for PS exposure in apoptotic cells. Once exposed at the cell surface, PS regulates biochemical reactions involved in blood coagulation, and bone mineralization, and also regulates a variety of cell-cell interactions. Exposed on the surface of apoptotic cells, PS controls their recognition and engulfment by other cells. This process is exploited by parasites to invade their host, and in specialized form is used to maintain photoreceptors in the eye and modify synaptic connections in the brain. This review discusses what is known about the mechanism of PS exposure at the surface of the plasma membrane of cells, how actors in the extracellular milieu sense surface exposed PS, and how this recognition is translated to downstream consequences of PS exposure.
Abnormal Expressions of DNA Glycosylase Genes NEIL1, NEIL2, and NEIL3 Are Associated with Somatic Mutation Loads in Human Cancer
Authors: Shinmura Kazuya , Kato Hisami , Kawanishi Yuichi , Igarashi Hisaki , Goto Masanori , Tao Hong , Inoue Yusuke , Nakamura Satoki , Misawa Kiyoshi , Mineta Hiroyuki , Sugimura Haruhiko
Published: March 2016

The effects of abnormalities in the DNA glycosylases NEIL1, NEIL2, and NEIL3 on human cancer have not been fully elucidated. In this paper, we found that the median somatic total mutation loads and the median somatic single nucleotide mutation loads exhibited significant inverse correlations with the median NEIL1 and NEIL2 expression levels and a significant positive correlation with the median NEIL3 expression level using data for 13 cancer types from the Cancer Genome Atlas (TCGA) database. A subset of the cancer types exhibited reduced NEIL1 and NEIL2 expressions and elevated NEIL3 expression, and such abnormal expressions of NEIL1, NEIL2, and NEIL3 were also significantly associated with the mutation loads in cancer. As a mechanism underlying the reduced expression of NEIL1 in cancer, the epigenetic silencing of NEIL1 through promoter hypermethylation was found. Finally, we investigated the reason why an elevated NEIL3 expression level was associated with an increased number of somatic mutations in cancer and found that NEIL3 expression was positively correlated with the expression of APOBEC3B, a potent inducer of mutations, in diverse cancers. These results suggested that the abnormal expressions of NEIL1, NEIL2, and NEIL3 are involved in cancer through their association with the somatic mutation load.
Metabolomic Analysis of Biochemical Changes in the Plasma of High‐Fat Diet and Streptozotocin‐Induced Diabetic Rats after Treatment with Isoflavones Extract of Radix Puerariae
Authors: Zhang Yan , Wang Ping , Xu Youdong , Meng Xianli , Zhang Yi
Published: March 2016

The main purpose of this study was to investigate the protective effects of total isoflavones from Radix Puerariae (PTIF) in diabetic rats. Diabetes was induced by a high‐fat diet and intraperitoneal injection of low‐dose streptozotocin (STZ; 40 mg/kg). At 26 weeks onwards, PTIF 421 mg/kg was administrated to the rats once daily consecutively for 10 weeks. Metabolic profiling changes were analyzed by Ultraperformance Liquid Chromatography‐Quadrupole‐Exactive Orbitrap‐Mass Spectrometry (UPLC‐Q‐Exactive Orbitrap‐MS). The principal component discriminant analysis (PCA‐DA), partial least‐squares discriminant analysis (PLS‐DA), and orthogonal partial least‐squares discriminant analysis (OPLS‐DA) were used for multivariate analysis. Moreover, free amino acids in serum were determined by high‐performance liquid chromatography with fluorescence detector (HPLC‐FLD). Additionally, oxidative stress and inflammatory cytokines were evaluated. Eleven potential metabolite biomarkers, which are mainly related to the coagulation, lipid metabolism, and amino acid metabolism, have been identified. PCA‐DA scores plots indicated that biochemical changes in diabetic rats were gradually restored to normal after administration of PTIF. Furthermore, the levels of BCAAs, glutamate, arginine, and tyrosine were significantly increased in diabetic rats. Treatment with PTIF could regulate the disturbed amino acid metabolism. Consequently, PTIF has great therapeutic potential in the treatment of DM by improving metabolism disorders and inhibiting oxidative damage.
Immunological and Clinical Responses following the Use of Antiretroviral Therapy among Elderly HIV-Infected Individuals Attending Care and Treatment Clinic in Northwestern Tanzania: A Retrospective Cohort Study
Authors: Mpondo Bonaventura C. T. , Gunda Daniel W. , Kilonzo Semvua B. , Mgina Erick
Published: March 2016

Background. Limited information exists on adults ≥50 years receiving HIV care in sub-Saharan Africa despite their increasing number. We aimed at studying immunologic and clinical responses to ART in this population. Methods. Data of patients who initiated HAART between 30th of June 2004 and 1st of May 2008 at Sekou Toure Care and Treatment Clinic were retrospectively analyzed. Date of ART initiation was used as a baseline and 48 months as a follow-up date. Immune recovery was defined as a CD4 count of ≥350 cells/mm3 at 48 months and late presentation as presentation with WHO stage 3 or 4 at clinic enrollment. Proportions of patients reaching this endpoint were compared between the two groups. Results. A total of 728 patients were included in our study; of these 73 (10.0%) were aged 50 years and above. Late presentation was more common in elderly patients than young patients (65.7% versus 56.1%, P=0.12). Proportion of patients with CD4 count ≥350 (immune recovery) was higher in younger patients than in elderly patients, although this was not statistically significant (54.5% versus 44.9%, P=0.2). Median absolute increase in CD4 at 48 months was higher in younger patients than in elderly patients (+241.5 cells/mm3 versus +146 cells/mm3, P=0.007). Conclusion. Elderly HIV patients have higher rates of late presentation, with lower immune recovery. Strategies to increase HIV testing in this group are required for early diagnosis and treatment to improve outcomes.
A Case of Solitary Nonvascularized Corneal Epithelial Dysplasia
Authors: Morii Tomoya , Sumioka Takayoshi , Izutani-Kitano Ai , Takada Yukihisa , Okada Yuka , Kao Winston W.-Y. , Saika Shizuya
Published: March 2016

Background. Epithelial dysplasia is categorized as conjunctival/corneal intraepithelial neoplasia which is a precancerous lesion. The lesion is usually developed at the limbal region and grows towards central cornea in association with neovascularization into the lesion. Here, we report a case of isolated nonvascularized corneal epithelial dysplasia surrounded by normal corneal epithelium with immune histochemical finding of ocular surface tissues cytokeratins, for example, keratin 13 and keratin 12.Case Presentation. A 76-year-old man consulted us for visual disturbance with localized opacification of the corneal epithelium in his left eye. His visual acuity was 20/20 and 20/200 in his right and left eye, respectively. Slit lamp examination showed a whitish plaque-like lesion at the center of his left corneal epithelium. No vascular invasion to the lesion was found. The lesion was surgically removed and subjected to histopathological examination and diagnosed as epithelial dysplasia. Amyloidosis was excluded by direct fast scarlet 4BS (DFS) staining. Immunohistochemistry showed that the dysplastic epithelial cells express keratin 13 and vimentin, but not keratin 12, indicating that the neoplastic epithelial cells lacked corneal-type epithelium differentiation.Conclusions. The lesion was diagnosed as nonvascularized epithelial dysplasia of ocular surface. Etiology of the lesion is not known.
IDHOCNET: A Novel ID Centric Architecture for Ad Hoc Networks
Authors: Khalid Shahrukh , Mahboob Athar , Azim Choudhry Fahad , Rehman Aqeel Ur
Published: March 2016

Ad hoc networks lack support of infrastructure and operate in a shared bandwidth wireless environment. Presently, such networks have been realized by various adaptations in Internet Protocol (IP) architecture which was developed for infrastructure oriented hierarchical networks. The IP architecture has its known problem and issues even in infrastructure settings, like IP address overloading, mobility, multihoming, and so forth. Therefore, when such architecture is implemented in ad hoc scenario the problems get multiplied. Due to this fact, ad hoc networks suffer from additional problems like IP address autoconfiguration, service provisioning, efficient bandwidth utilization, and node identification. In this paper we present IDHOCNET which is a novel implementation of service provisioning and application development framework in the ad hoc context. We illustrate a number of implemented features of the architecture which include IP address autoconfiguration, identification of nodes by using real world identifiers, IP based services support in ad hoc networks, and a new class of application known as ID based application. Moreover how identifiers can completely replace the IP addresses to run the IP based applications is shown. It is expected that this work will open new research horizons and paradigms for ad hoc networks.
Colorimetric Detection of Caspase 3 Activity and Reactive Oxygen Derivatives: Potential Early Indicators of Thermal Stress in Corals
Authors: Ros Mickael , Pernice Mathieu , Le Guillou Sebastien , Doblin Martina A. , Schrameyer Verena , Laczka Olivier
Published: March 2016

There is an urgent need to develop and implement rapid assessments of coral health to allow effective adaptive management in response to coastal development and global change. There is now increasing evidence that activation of caspase-dependent apoptosis plays a key role during coral bleaching and subsequent mortality. In this study, a “clinical” approach was used to assess coral health by measuring the activity of caspase 3 using a commercial kit. This method was first applied while inducing thermal bleaching in two coral species,Acropora milleporaandPocillopora damicornis. The latter species was then chosen to undergo further studies combining the detection of oxidative stress-related compounds (catalase activity and glutathione concentrations) as well as caspase activity during both stress and recovery phases. Zooxanthellae photosystem II (PSII) efficiency and cell density were measured in parallel to assess symbiont health. Our results demonstrate that the increased caspase 3 activity in the coral host could be detected before observing any significant decrease in the photochemical efficiency of PSII in the algal symbionts and/or their expulsion from the host. This study highlights the potential of host caspase 3 and reactive oxygen species scavenging activities as early indicators of stress in individual coral colonies.
Nonfeedback Distributed Beamforming Using Spatial-Temporal Extraction
Authors: Sriploy Pongnarin , Uthansakul Monthippa
Published: March 2016

So far, major phase synchronization techniques for distributed beamforming suffer from the problem related to the feedback procedure as a base station has to send the feedback reference signal back to the transmitting nodes. This requires stability of communication channel or a number of retransmissions, introducing a complicated system to both transmitter and receiver. Therefore, this paper proposes an alternative technique, so-called nonfeedback beamforming, employing an operation in both space and time domains. The proposed technique is to extract a combined signal at the base station. The concept of extraction is based on solving a simultaneous linear equation without the requirement of feedback or reference signals from base station. Also, the number of retransmissions is less compared with the ones available in literatures. As a result, the transmitting nodes are of low complexity and also low power consumption. The simulation and experimental results reveal that the proposed technique provides the optimum beamforming gain. Furthermore, it can reduce Bit Error Rate to the systems.
Time-Dependent Regional Myocardial Strains in Patients with Heart Failure with a Preserved Ejection Fraction
Authors: Smith Shane P. , Secomb Timothy W. , Hong Brian D. , Moulton Michael J.
Published: March 2016

Objectives. To better understand the etiology of HFpEF in a controlled human population, regional time-varying strains were computed using echocardiography speckle tracking in patients with heart failure with a preserved ejection fraction and normal subjects.Methods. Eleven normal volunteers and ten patients with echo-graded diastolic dysfunction and symptoms of heart failure were imaged with echocardiography and longitudinal, circumferential, and rotational strains were determined using speckle-tracking. Diastolic strain rate was also determined. Patient demographics and echo-derived flows, volumes, and pressures were recorded.Results. Peak longitudinal and circumferential strain was globally reduced in patients (p<0.001), when compared to controls. The patients attained peak longitudinal and circumferential strain at a consistently later point in systole than controls. Rotational strains were not different in most LV regions. Early diastolic strain rate was significantly reduced in the patients (p<0.001). LV mass and wall thickness were significantly increased in the patients; however ejection fraction was preserved and stroke volume was diminished (p<0.001).Conclusions. This study shows that patients with HFpEF have reduced early diastolic strain rate and reduced peak strain that is regionally homogeneous and that they also utilize a longer fraction of systole to achieve peak axial strains.
Social Isolation of the Stateless and the Destitute: A Study on the Refugee-Camp and the Sullied Slum of Dhaka City
Authors: Masoom Muhammad Rehan
Published: March 2016

The lower-class segment of the population of the developing nations often fails to form meaningful social relations and remain disengaged from essential social institutions. The research examines those people who live in refugee-camp and sullied slum of Dhaka city and inspect how much they are socially isolated. Certain characteristics, taken as indicators to test the level of social isolation, indicate that a large segment of camp and slum dwellers are feeling isolated. However, the evidence shows no differences in the predicted direction with respect to the objective demographic variables; nonetheless, a pattern of perceived social isolation was found from the survey data.
Genotype Cluster Analysis in PathogenicEscherichia coliIsolates Producing Different CDT Types
Authors: Javadi Maryam , Oloomi Mana , Bouzari Saeid
Published: March 2016

Diarrheagenic and uropathogenicE. colitypes are mainly characterized by the expression of distinctive bacterial virulent factors.stx1,stx2(Shiga toxins), andcdt(cytolethal distending toxin) genes have been acquired by horizontal gene transfer. Some virulent genes such asespP(serine protease),etpD(part of secretion pathway), andkatP(catalase-peroxidase), orsfpAgene (Sfp fimbriae), are on plasmids and the others likefliC(flagellin) and thefimHgene (fimbriae type-I) are located on chromosome. Genomic pathogenicity islands (PAIs) carry some virulent genes such ashlygene. To determine the existence of virulence genes incdtclinical isolates, genes includingstx1,stx2,cdt,hly,espP,katP,sfpA,etpD,fliC, andfimHwere assessed by Polymerase Chain Reaction (PCR). The most prevalent isolates foretpDandkatPgenes were 85.7% incdtII.katPgene was also observed 83.3% incdtI. However, in 42.85% ofcdtIIIisolates,espPgene was the most detected. Moreover,hlygene was also the most prominent gene incdtIII(71.42%).sfpA genewas observed in 66.6% ofcdtV.stx1gene was detected in 100% ofcdtII,cdtIV, andcdtVtypes. Presence and pattern of virulence genes were considered amongcdtpositive isotypes and used for their clustering and profiling.