cssi/SciSciGPT-SciSciNet huggingface dataset:
Mapping polymer birefringence in 3D using a polarizing microscope with oblique illumination

We have been developing a polarized light microscope with liquid crystal universal compensator and circular polarizer(the LC-PolScope) for recording images, which are independent of the orientation of birefringent objects. Separateimages show the retardance and the slow axis azimuth distributions of the in-plane birefringence of the focused region inthe specimen. However the measured (apparent) retardance still depends on the angle between the crystal optic axis andthe axis of the illuminating beam of light. If the illuminating beam is close to parallel to the optic axis the measuredretardance value decreases dramatically and becomes zero when the two axes are parallel. The description of birefringentobjects oriented in 3-dimensional space requires the introduction of two additional parameters: the principal retardanceand the inclination angle. Together with the azimuth angle they completely characterize the birefringence properties of aspecimen, assuming the specimen has a uniaxial optical indicatrix. We devised a new technique for measuring the threebirefringence parameters without moving the specimen. For exploring the out-of-plane birefringence the new instrumentwhich is based on the LC-PolScope technique contains an additional spatial light modulator, implemented here as aliquid crystal mask. The mask is located in the aperture plane of the condenser lens. Partial occlusion of the condenseraperture changes the direction of the central ray of the cone of light converging on the specimen. So we can obtain theretardance and azimuth images using different sets of illumination rays. For experimental verification we used abiological object called an aster. An aster consists of nearly parallel arrays of microtubules, a stiff biopolymer, radiatingfrom a common organizing center called a centrosome. The object is spherically symmetric, and its 3 dimensionaldistribution of birefringence orientation can be predicted. Experimental results have shown the developed polarizingmicroscope can successfully be used for imaging and measuring three-dimensional orientation of birefringent objects.
Folic Acid Supplementation and Cardiac and Stroke Mortality among Hemodialysis Patients

Objective We sought to assess whether the use of folic acid vitamin supplements reduced cardiac and stroke mortality in hemodialysis patients. Further, we examined whether the consumption of folic acid from vitamin supplements >1000 μg compared with the standard 1000 μg, and 1000 μg compared with either a lower dose or no consumption, were associated with reduced cardiac and stroke mortality risk. Design We performed a secondary analysis of data from the Hemodialysis Study, a randomized clinical trial examining dialysis treatment regimens over a 3-year follow-up. Participants Participants included 1846 hemodialysis patients previously participating in the Hemodialysis Study. Interventions There were no interventions. Main Outcome Measure Cardiac and stroke mortality were our main outcome measures. Results Based on time-dependent Cox proportional hazard regression models, folic acid consumption from vitamin supplements, above or below the standard 1000-μg dose, was not associated with a decrease or increase in cardiac mortality ( P = .53, above vs. standard dose; P = .46, below vs. standard dose). There was also no association between folic acid consumption and mortality from stroke ( P = .27, above vs. standard dose; P = .64, below vs. standard dose). Conclusion The consumption of higher than the standard 1000-μg prescribed dose of folic acid was not beneficial in reducing cardiac or stroke mortality in hemodialysis patients. Similarly, the consumption of less than the standard dose was not associated with an increase in either cardiac or stroke mortality.
Preliminary studies on soil permeability and its application

The procedure of a preliminary study on soil permeability is described. Water was applied to soil cores at their initial field soil moisture content in such a way as to simulate natural conditions. Data are presented showing variation of transmission rates and percolation rates with initial field soil moisture content for the topsoil and subsoil of Muskingum silt loam and Keene silt loam. Some comparisons were made with transmission rates and percolation rates obtained by hydrograph analysis and soil moisture changes of small watersheds under natural conditions. The data indicate considerable replication appears necessary to obtain average representative values by the core method. Even when sufficient replication establishes significant values, core data must be applied with caution and preferably in the light of watershed performance. Potential infiltration rate curves are established based on transmission rates aid soil moisture changes. The use of such curves for estimating surface supplies to runoff is indicated.
Effects of gait and cognitive task difficulty on cognitive-motor interference in aging

Although gait-related dual-task interference in aging is well established, the effect of gait and cognitive task difficulty on dual-task interference is poorly understood. The purpose of this study was to examine the effect of gait and cognitive task difficulty on cognitive-motor interference in aging. Fifteen older adults (72.1 years, SD 5.2) and 20 young adults (21.7 years, SD 1.6) performed three walking tasks of varying difficulty (self-selected speed, fast speed, and fast speed with obstacle crossing) under single- and dual-task conditions. The cognitive tasks were the auditory Stroop task and the clock task. There was a significant Group × Gait Task × Cognitive Task interaction for the dual-task effect on gait speed. After adjusting for education, there were no significant effects of gait or cognitive task difficulty on the dual-task effects on cognitive task performance. The results of this study provide evidence that gait task difficulty influences dual-task effects on gait speed, especially in older adults. Moreover, the effects of gait task difficulty on dual-task interference appear to be influenced by the difficulty of the cognitive task. Education is an important factor influencing cognitive-motor interference effects on cognition, but not gait.
Hyper-parallel algorithms for centroid molecular dynamics: application to liquid para-hydrogen

Abstract Centroid molecular dynamics (CMD) calculations are performed on liquid para-hydrogen at low temperatures. The quantum mechanical velocity time correlation functions and self-diffusion constants are calculated at 14 and 25 K, and the self-diffusion constants compare well with experiment. The CMD calculation is done in a multi-tiered parallel, or “hyper-parallel”, manner that significantly extends the range of applications.
Detecting frontotemporal dysfunction in ALS: Utility of the ALS Cognitive Behavioral Screen (ALS-CBS™)

AbstractUp to half of patients with ALS develop cognitive impairment during the course of the illness. Despite this, there is no simple tool for screening patients in the clinical setting. This study examines the sensitivity, specificity and accuracy of the ALS Cognitive Behavioral Screen (ALS-CBS™). We administered the measure to 112 ALS patients, including 31 who also underwent comprehensive neuropsychological testing. Screen results were validated by determining the accuracy against the full battery. Optimal cut-off scores for predicting the correct diagnosis were determined, and mean scores were compared between patients, controls and different diagnostic groups. The results demonstrated that mean cognitive scores differed between ALS and normal controls (p <0.0001). The cognitive section differentiated ALS-FTD from other ALS patients with 100% accuracy. Cognitively normal ALS patients could be distinguished from those with any cognitive deficit with 71% specificity and 85% sensitivity. A separate beh...
An Absence of Malice The Limited Utility of Campaigning Against Party Corruption

We examine whether repeated scandals within one party generate collective sanctions for fellow partisans. Do voters punish a party’s candidates because of multiple corruption scandals? Our data com...
On the Input-Output Behavior of a Class of Second-Order Nonlinear Adaptive Systems

The paper deals with a class of second-order nonlinear nonautonomous systems which occur frequently in the context of adaptive control of linear plants with unknown parameters. In the absence of external inputs, such systems are (i) uniformly stable, and (ii) uniformly asymptotically stable when their nonautonomous components are persistently exciting. When external inputs are present, the stability behavior of these systems are critically dependent on the nature of these inputs. This paper presents sufficient conditions for the stability and instablity of the nonlinear system for different kinds of external input. These results have important implications on the design of robust adaptive systems.
Estimation of ultrasound attenuation from broadband echo-signals using bandpass filtering

A problem with video signal analysis for estimating frequency-dependent ultrasonic attenuation is that relative echogenicity versus depth curves are distorted when broadband pulses are used. In this correspondence, we present results that demonstrate improved accuracy of attenuation estimates computed from B-mode or envelope data derived after narrowband (1 MHz BW) filtering at different frequencies around the center frequency of the broadband echo signal. Based on the premise that transducer center frequencies are selected in part on penetration or imaging depth requirements, simulation and experimental results for a typical ultrasound imaging system show that narrowband video signal analysis for frequencies lower than or at the center frequency of the broadband pulse provide unbiased attenuation estimation over this depth. Filtered signals above the center frequency of the pulse yield accurate results only at shallow depths.
Quantification of Feline immunodeficiency virus (FIVpco) in peripheral blood mononuclear cells, lymph nodes and plasma of naturally infected cougars.

Infection of domestic cats with Feline immunodeficiency virus (FIV) results in a fatal immunodeficiency disease, similar to Human immunodeficiency virus 1 (HIV-1) in humans. Elevated plasma viral loads in domestic cats are correlated to decreased survival time and disease progression. However, FIV is also maintained as an apathogenic infection in other members of the family Felidae including cougars, Puma concolor (FIVpco). It is not known whether the lack of disease in cougars is a result of diminished virus replication. A real-time PCR assay was developed to quantify both FIVpco proviral and plasma viral loads in naturally infected cougars. Proviral loads quantified from peripheral blood mononuclear cells (PBMC) ranged from 2·90×101 to 6·72×104 copies per 106 cells. Plasma viral loads ranged from 2·30×103 to 2·81×106 RNA copies ml−1. These data indicate that FIVpco viral loads are comparable to viral loads observed in endemic and epidemic lentivirus infections. Thus, the lack of disease in cougars is not due to low levels of virus replication. Moreover, significant differences observed among cougar PBMC proviral loads correlated to viral lineage and cougar age (P=0·014), which suggests that separate life strategies exist within FIVpco lineages. This is the first study to demonstrate that an interaction of lentivirus lineage and host age significantly effect proviral loads.
Dynamically produced refractive-index variations with thickness of volume holograms in electrooptic crystals

Dynamic theory of volume holography is used to calculate the variations in the thickness direction of the hologram-constituting refractive-index modulation and the externally observable effects of these variations in electrooptic materials. It is shown that thick holographic gratings may exhibit significant amplitude and grating phase variations with thickness including amplitude sign reversal. These nonuniformities strongly affect holographic grating recording and readout characteristics such as maximum possible diffraction efficiency and angular selectivity. Thus a variety of grating applications will be affected by these nonuniformities.
Stimulus Dependence of Disparity Coding in Primate Visual Area V4

Disparity tuning in visual cortex has been shown using a variety of stimulus types that contain stereoscopic depth cues. It is not known whether different stimuli yield similar disparity tuning curves. We studied whether cells in visual area V4 of the macaque show similar disparity tuning profiles when the same set of disparity values were tested using bars or dynamic random dot stereograms, which are among the most commonly used stimuli for this purpose. In a majority of V4 cells (61%), the shape of the disparity tuning profile differed significantly for the two stimulus types. The two sets of stimuli yielded statistically indistinguishable disparity tuning profiles for only a small minority (6%) of V4 cells. These results indicate that disparity tuning in V4 is stimulus-dependent. Given the fact that bar stimuli contain two-dimensional (2-D) shape cues, and the random dot stereograms do not, our results also indicate that V4 cells represent 2-D shape and binocular disparity in an interdependent fashion, revealing an unexpected complexity in the analysis of depth and three-dimensional shape.
Peer Review of Teaching: Multiple Raters

Abstract Peer review of teaching is relatively new in many academic programs. Primarily focused on formative, rather than summative, assessment, peer reviews differ in types of artifacts and teaching behaviors observed during the review. The purpose of this study was to begin a preliminary investigation of peer review of teaching among internal faculty. Two faculty members in the Department of Communication Sciences and Disorders (CSD) at Wichita State University participated in this study. Both instructors agreed to have one class session each videotaped within the same week. Two comparable 10-minute presentation segments were selected and edited from the recordings. The recordings were then viewed and rated in counter-balanced order by 17 faculty peers in CSD programs. Ratings were collected using a 5-point Likert scale rating form, which was created for the study. Results were found to be generally positive with mean ratings of 2.23 (s.d = 1.19) and 2.41 (s.d. = 1.19) for the two instructors. Interesti...
Novel inverse methods for wire fault detection and diagnosis

In recent years, methods used to locate and diagnose wiring faults have increased in complexity and variety. However, there is much research yet to take place in order to develop high resolution models for accurately analysis of the effects of small faults, gradual impedance discontinuities, and signal propagation over diverse frequency ranges. In solving these problems, advanced forward models for simulation of various wiring systems and their corresponding challenges have been developed and combined with inversion theory in order to correctly retrace impedance changes from reflectometry data. Particular attention is paid to the chafed shielded wire fault type, which has been of interest because of its prevalence and the challenges it presents.
Maximum quantum yield and action spectrum of photosynthesis and fluorescence in Chlorella.

SUMMARY The maximum yield of oxygen production in Chlorella was found, in new, systematic experiments, not to exceed o.12, under a great variety of conditions. Measurements were made on autospores and other synchronous cultures, at different CO~ concentrations, at very low light intensities, and in the presence of 'catalytic' amounts of blue light. The action spectra (quantum yield as a function of wavelength) of photosynthesis, and of chlorophyll a fluorescence in vivo, were measured on the same Chlorella cell suspensions. In both cases, a decline in the yield was observed in the red beginning at about 675-680 nm. The yield declines to 5o % of the maximum, on both curves, at 69o-695 nm. A strong dip was observed in the action spectra of both fluorescence and photosynthesis at 660-665 nm.
Mutagen Sensitivity and Genetic Variants in Nucleotide Excision Repair Pathway: Genotype-Phenotype Correlation

The rationale behind gene-disease association studies is that genetic variants (polymorphisms) result in alterations in intermediate phenotypes. However, genotype-phenotype correlations have not been established for most polymorphisms. In this study, we correlated genotype data of genes involved in the nucleotide excision repair pathway with mutagen sensitivity phenotype, quantified by benzo(a)pyrene diol epoxide (BPDE)-induced chromatid breaks in peripheral blood lymphocytes in 422 healthy subjects recruited into a twin study that included 138 pairs of monozygotic twins, 51 pairs of dizygotic twins, and 44 siblings. Among a panel of single nucleotide polymorphisms examined, we found that BPDE sensitivity was modified by individual polymorphisms in XPC, RAD23B, and XPA genes. Specific haplotypes and diplotypes of XPC also modified BPDE sensitivity profiles. In addition, a more consistent and stronger correlation was observed between mutagen sensitivity phenotype and the combination of multiple polymorphisms in the nucleotide excision repair pathway. Specifically, when XPC-PAT, XPC Lys939Gln, XPA A23G, and RAD23B Val249Ala were analyzed together, we observed a significant dose-response relationship between increasing mutagen sensitivity with increasing number of adverse alleles: mutagen sensitivity for those carrying zero to two, three to five, and six or more adverse alleles were 0.64, 0.68, and 1.06, respectively (P for trend = 0.008), and the results remained significant after adjusting for multiple comparisons. Using individuals carrying zero to two adverse alleles as the reference group, the risks of being mutagen sensitive (mutagen sensitivity values greater than the median) were 1.05 (95% confidence interval, 0.68-1.64) and 4.48 (95% confidence interval, 1.21-16.61) for those carrying three to five and six or more adverse alleles, respectively. Analyses of the effects of genotype combinations yielded similar results. These findings underscore the importance of assessing the collective effects of a panel of polymorphisms in the same pathway in modulating mutagen sensitivity. As risk assessment for cancer risk is moving toward a multigenic pathway-based approach, future genotype-phenotype correlation studies should also investigate the combined effects of multiple genetic variants.
Wireless, magnetic-based sensors for biomedical applications

Wireless magnetic sensor technologies are gaining popularity in biomedical community due to their remote query nature, which allows them to be used as long-term implantable sensors. Some of these sensors are also low cost so they are suitable for use on a disposable basis. In this paper, two wireless magnetic sensors are described: the magnetoelastic sensor and the magneto-harmonic sensor. Magnetoelastic sensors are made of magnetoelastic materials that when under an AC magnetic field excitation, vibrate and resonate at their resonant frequencies. Since the resonant frequency of a magnetoelastic sensor is proportional to the mass or viscosity of the surrounding material, it has been used to detect chemical and biological targets by incorporating coatings that change mass/elasticity in response to the parameters of interest. Conversely, magneto-harmonic sensors detect parameters of interest by monitoring the change in the pattern or amplitude of the magnetic higher-order harmonic fields. Typically, a magneto-harmonic sensor consists of a magnetically soft material (sensing element) and a permanent magnet (biasing element). When energized by an AC magnetic field, the sensing element generates higher-order magnetic fields that change with the biasing field from the biasing element. By designing the sensor so the separation distance between these two elements varies with the parameters of interest, the magneto-harmonic sensor has been used for remote measurement of pressure and stress. This paper presents the operating principles and biomedical applications of these sensors.
Principals, bureaucrats, and responsiveness in clean air enforcements.

A principal-agent perspective has been employed in recent studies to rediscover the importance of democratic hierarchies in shaping public bureaucratic outputs. I test the robustness of the hierarchy model for explaining outputs from an agency that has often been cast in the image of bureaucratic independence, the Environmental Protection Agency. Examining the effect of the Reagan presidency on EPA outputs for clean air, Box-Tiao models are constructed to explain shifts in the vigor of air pollution enforcements between 1977 and 1985. The analysis shows that the influence of elected institutions is limited when an agency has substantial bureaucratic resources and a zeal for their use. Moreover, under these conditions, bureaucracy can even move outputs in directions completely opposite from what a model of hierarchy would predict. The implication is that for some agencies it is necessary to give greater consideration to the agent in explaining implementation outcomes through time.
1‐Anilino‐8‐naphthalene sulfonate as a protein conformational tightening agent

1-Anilino-8-naphthalene sulfonate (ANS) anion is conventionally considered to bind to preexisting hydrophobic (nonpolar) surfaces of proteins, primarily through its nonpolar anilino-naphthalene group. Such binding is followed by an increase in ANS fluorescence intensity, similar to that occurring when ANS is dissolved in organic solvents. It is generally assumed that neither the negative sulfonate charge on the ANS, nor charges on the protein, participate significantly in ANS-protein interaction. However, titration calorimetry has demonstrated that most ANS binding to a number of proteins occurs through electrostatic forces, in which ion pairs are formed between ANS sulfonate groups and cationic groups on the proteins (D. Matulis and R. E. Lovrien, Biophys. J., 1998, Vol. 74, pp. 1-8). Here we show by viscometry and diffusion coefficient measurements that bovine serum albumin and gamma-globulin, starting from their acid-expanded, most hydrated conformations, undergo extensive molecular compaction upon ANS binding. As the cationic protein binds negatively charged ANS anion it also takes up positively charged protons from water to compensate the effect of the negative charge, and leaves the free hydroxide anions in solution thus shifting pH upward (the Scatchard-Black effect). These results indicate that ANS is not always a definitive reporter of protein molecular conformation that existed before ANS binding. Instead, ANS reports on a conformationally tightened state produced by the interplay of ionic and hydrophobic characters of both protein and ligand.
Restoration of phosphorylation-dependent regulation to the skeletal muscle myosin regulatory light chain.

Abstract Regulation of the ATPase activity of smooth and non-muscle myosin II involves reversible phosphorylation of the regulatory light chain (RLC). The RLC from skeletal muscle myosin (skRLC) is unable to confer regulation (myosin is locked in an inactive state) to smooth muscle myosin when substituted for the endogenous smooth RLC (smRLC). Studies of chimeric light chains comprised of the N- or C-terminal half of each skRLC and smRLC suggest that the structural basis for the loss of this regulation is within the C-terminal half of the RLC (Trybus, K. M., and Chatman, T. A.(1993) J. Biol. Chem. 268, 4412-4419). The purpose of this study is to delineate the structural elements within the C-terminal half of the smRLC that are absent in the skRLC and are necessary for regulation. By sequence comparison, six residues, Arg-103, Arg-123, Met-129, Gly-130, Arg-143, and Arg-160, which are conserved in regulated myosin RLCs but missing in nonregulated myosin RLCs, were identified in smRLC. To test whether these amino acids provide the missing structural elements necessary for phosphorylation-mediated regulation, a skRLC was engineered that replaced the corresponding skRLC amino acids (positions 100, 120, 126, 127, 140, and 157, respectively) with their smRLC counterparts. Using a newly developed RLC exchange procedure, the purified mutant protein was evaluated for its ability to regulate chicken gizzard smooth muscle myosin. Substitution of the six conserved amino acids into the skRLC completely restored phosphorylation-mediated regulation. Thus, a subset of these amino acids, including four basic arginine residues located in the E, F, G, and H helices which are missing in skRLC, may be the structural coordinates for the phosphorylserine in the N terminus. Based on this result, the regulation of glycogen phosphorylase is discussed as a model for the regulation of smooth muscle myosin.
A necessary condition for a doubly recursive rule to be equivalent to a linear recursive rule

Nonlinear recursive queries are usually less efficient in processing than linear recursive queries. It is therefore of interest to transform non-linear recursive queries into linear ones. We obtain a necessary and sufficient condition for a doubly recursive rule of a certain type to be logically equivalent to a single linear recursive rule obtained in a specific way.
Auditory cortical activity in amnestic mild cognitive impairment: Relationship to subtype and conversion to dementia

Mild cognitive impairment (MCI) patients have a high risk of converting to Alzheimer's disease. The most common diagnostic subtypes of MCI have an episodic memory disorder (amnestic MCI) occurring either alone [single domain (SD)] or with other cognitive impairments [multiple domain (MD)]. Previous studies report increased amplitudes of auditory cortical potentials in MCI, but their relationships to MCI subtypes and clinical outcomes were not defined. We studied subjects with amnestic MCI (n = 41: 28 SD, 13 MD), Alzheimer's disease (n = 14), and both younger (n = 22) and age-matched older controls (n = 44). Baseline auditory sensory (P50, N100) and cognitive potentials (P300) were recorded during an auditory discrimination task. MCI patients were followed for up to 5 years, and outcomes were classified as (i) continued diagnosis of MCI (MCI-stable, n = 16), (ii) probable Alzheimer's disease (MCI-convert, n = 18), or other outcomes (n = 7). Auditory potentials were analysed as a function of MCI diagnosis and outcomes, and compared with young, older controls, and mild Alzheimer's disease subjects. P50 amplitude increased with normal ageing, and had additional increases in MCI as a function of both initial diagnosis (MD > than SD) and outcome (MCI-convert > MCI-stable). P300 latency increased with normal ageing, and had additional increases in MCI but did not differ among outcomes. We conclude that auditory cortical sensory potentials differ among amnestic MCI subtypes and outcomes occurring up to 5 years later.
Predictors of length of stay among OEF/OIF/OND veteran inpatient PTSD treatment noncompleters.

High rates of attrition occur in outpatient and inpatient evidence-based treatments (EBTs) targeting newly returning veterans from Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF) and Operation New Dawn (OND) with posttraumatic stress disorder (PTSD). Traditionally, research has examined attrition as a dichotomous variable (i.e., noncompleters vs. completers) and focused almost exclusively on outpatient EBTs for PTSD. These studies have provided little information to inpatient psychiatric providers about timing-related predictors of treatment discontinuation. The present study attempted to mend these gaps by examining attrition as a continuous variable and investigated predictors of length of stay (LOS) among 282 OEF/OIF/OND male veterans, 69 of which did not complete the full 25-day intensive, multimodal inpatient PTSD EBT program. At admission, participants completed a series of clinician-rated, biological, and self-report assessments. Linear regression analyses were used to identify pred...
Non-random biodiversity loss underlies predictable increases in viral disease prevalence

Disease dilution (reduced disease prevalence with increasing biodiversity) has been described for many different pathogens. Although the mechanisms causing this phenomenon remain unclear, the disassembly of communities to predictable subsets of species, which can be caused by changing climate, land use or invasive species, underlies one important hypothesis. In this case, infection prevalence could reflect the competence of the remaining hosts. To test this hypothesis, we measured local host species abundance and prevalence of four generalist aphid-vectored pathogens (barley and cereal yellow dwarf viruses) in a ubiquitous annual grass host at 10 sites spanning 2000 km along the North American West Coast. In laboratory and field trials, we measured viral infection as well as aphid fecundity and feeding preference on several host species. Virus prevalence increased as local host richness declined. Community disassembly was non-random: ubiquitous hosts dominating species-poor assemblages were among the most competent for vector production and virus transmission. This suggests that non-random biodiversity loss led to increased virus prevalence. Because diversity loss is occurring globally in response to anthropogenic changes, such work can inform medical, agricultural and veterinary disease research by providing insights into the dynamics of pathogens nested within a complex web of environmental forces.
Role of the cephalic tentacles in trail following by Littoraria irrorata (Say)

Gastropod molluscs deposit mucous trails on surfaces over which they crawl Littorinids, as well as certain other gastropods, follow conspeafic mucous trails in the direction in which they were laid, that is "with polarity" '• The stimuli and sense organs used by snails to determine mucous trail polarity are not known; however, six mechanisms of trail polarity detection have been suggested in the literature' Of these, the hypothesis which has received the most attention is that trails possess a concentration macrogradient of a volatile chemical which is detectable across the points of contact of a pair of sensory structures UJJi The assumption that polarity detection involves a concentration macro-gradient has been tested by experimentally reversing the assumed concentration macro-gradient in trails of Littoraria irrorata} Snails still travelled against the assumed gradient in favour of the actual direction of trail deposition. Furthermore, snails exhibited random directional choices when trail polarity was rendered ambiguous for all potential cues except for a hypothetical concentration macro-gradient Thus, it was concluded that a concentration macro-gradient is not involved in trail polarity detection in L. irrorata Further evaluation of hypotheses for the mechanism underlying trail polarity detection would be aided by knowledge of the sensory basis for this behaviour. The paired lips of Euglandmd and the anterior lateral folds of Navanax' are reportedly involved in detecting the trails of prey and mates, but neither species can apparently detect trail polarity.' The oral lappets are supposedly involved in detecting mucous trails in Onchidium, which can detect trail polarity.' As a Littoraria irrorata progresses along the substratum, the cephalic tentacles alternately move up and down, contacting the substratum with the ventral surface of the tentacle tips an average of 16-20 times per minute under normal conditions." The paired cephalic tentacles of littorinids are known to be tactile and one of the sites where chemical detection of predator mucus is possible.' Thus, the cephalic tentacles are likely locations for sensory receptors involved in trail polarity detection. This report presents an experiment designed to examine the role of the cephalic tentacles of L. irrorata in
Expression, purification, crystallization and preliminary X-ray crystallographic analysis of a novel plant-type ferredoxin/thioredoxin reductase-like protein from Methanosarcina acetivorans.

The genome of Methanosarcina acetivorans contains a gene (ma1659) that is predicted to encode an uncharacterized chimeric protein containing a plant-type ferredoxin/thioredoxin reductase-like catalytic domain in the N-terminal region and a bacterial-like rubredoxin domain in the C-terminal region. To understand the structural and functional properties of the protein, the ma1659 gene was cloned and overexpressed in Escherichia coli. Crystals of the MA1659 protein were grown by the sitting-drop method using 2 M ammonium sulfate, 0.1 M HEPES buffer pH 7.5 and 0.1 M urea. Diffraction data were collected to 2.8 A resolution using the remote data-collection feature of the Advanced Light Source, Lawrence Berkeley National Laboratory. The crystal belonged to the primitive cubic space group P23 or P213, with unit-cell parameters a = b = c = 92.72 A. Assuming the presence of one molecule in the asymmetric unit gave a Matthews coefficient (VM) of 3.55 A3 Da−1, corresponding to a solvent content of 65%.
Investigation on microwave plasma diamond etching

This paper reports a Lambda Technologies, 2.45 GHz, 1.5 kW, microwave plasma-assisted etching reactor utilized to develop anisotropic and high rate etching processes on a variety of diamond substrates including polycrystalline, nanocrystalline and single substrates. This etching system consists of a 25 cm diameter discharge located inside a 30 cm microwave resonant cavity applicator. The plasma etcher also incorporates a rf bias for the substrate that operates at 13.56 MHz with induced dc bias up to 250 V.m The electron temperature Te, charge density ne and electron energy distribution function (EEDF) are measured using a single Langmuir probe (SLP). Direct comparisons are made at selected pressures for the reactor operating with and without electron cyclotron resonance (ECR) magnets.
Synthesis and Characterization of Novel Amphiphilic Polymers as Drug Delivery Nano Carriers

Polymer nano-particles have been widely investigated in the last decade due to a variety of potential applications. In particular, polymers which can self assemble into micellar nano-particles can be effectively used as vehicles for drug delivery. Considerable efforts are underway to develop better drug delivery nano carriers for high drug loading capacity for a wide variety of bioactive compounds. In this study, several new polymers were synthesized in bulk (solventless condition) by a chemo-enzymatic methodology using Candida antarctica lipase B (Novozyme 435) and molecular sieves (MS). The synthesized polymers demonstrated high drug loading capacity and the potential to encapsulate drugs which are poorly soluble in aqueous solvents.
New Distributional Bird Data from the Cordillera Central of the Colombian Andes, with Implications for the Biogeography of Northwestern South America

Abstract Northwestern South America is a complex area that has witnessed the differentiation and expansion of a major portion of the Neotropical avifauna. The northern end of the Cordillera Central of the Colombian Andes contributes to this complexity by bringing a continuum of humid habitats from the Andean highlands to the lowland rainforests. We present new distributional information on 36 avian species of the cloud forests and paramos of this region (1300–3250 m), gained through eight years of fieldwork and general collecting. These new records reflect the mixed biogeographic affinities of the avifauna of the northern Cordillera Central, which is composed of taxa from the pluvial foothills of the Choco (e.g., Indigo Flowerpiercer [Diglossa indigotica], Scarlet-and-white Tanager [Chrysothlypis salmoni]), Central America and Darien (e.g., Purple-throated Woodstar [Calliphlox mitchellii]), and elsewhere in the Andean mountains (e.g., Semicollared Hawk [Accipiter collaris], Yellow Manakin [Xenopipo flavic...
In Vitro Biocompatibility Studies of Fibroblast Cells on Ti-Ta Alloys

Medical science has enabled the substitution and reinforcement of body organs and tissue through the evolution of better materials. Metallic implants have been utilized to aid in injury wound healing as bone replacements, endoprosthesis, and percutaneous devices. Of concern with metallic devices is the prolonged effects and service life of the implant. It is known that metallic dissolution and premature failure can occur in the body leading to complications for the host. In an effort to provide more corrosion resistant materials with adequate strength for better resistance against high cycle fatigue, Ti–Ta alloys are presented to compete with current, popular materials such as Ti6Al4V. This research focuses on the binary alloy systems of Ti40Ta and Ti50Ta alloys for implant consideration. Three heat-treated versions of the Ti–Ta system that demonstrated high strength properties were also assessed. Cell culture testing of NIH-3T3 fibroblast cells was conducted to perform biocompatibility testing on these metal substrates. MTT cytotoxicity assays were performed to evaluate cellular behavior on the metal substrates. Flow cytometry assays were conducted to analyze rates of cell growth and cycling to determine best surface conditions among these metals. Results indicate very similar cellular activity on the Ti alloys and to a lesser degree on the commercially pure titanium and tantalum. Flow cytometry tests showed similar cellular growth rates on the different materials and on the control plastic. MTT assays indicate a higher degree of proliferation on the Ti–Ta alloys and on the Ti6Al4V. Although the Ti and Ta elemental materials supported slightly fewer cells on their surface, differences were minimal. Ti–Ta alloys appear to be comparable if not slightly more compatible than the standard Ti6Al4V.
Future Suburban Development and the Environmental Implications of Lawns: A Case Study in New England, USA

Lawns cover more land than irrigated corn in the United States according to the most recent estimates (Milesi et al. 2009). The associated ecological ramifications – such as habitat fragmentation, water quality and availability – may be far-reaching. The way lawns are maintained, especially intensive fertilization and watering, also presents risks for water use and quality, nutrient cycling, urban climate regimes, and even human health. However, the lack of broad-extent, high-resolution land cover data has limited the ability of researchers to measure or project the extent of lawns. In this chapter, we first produce a high resolution (0.5 m) land-cover classification to quantify existing lawn extent for the year 2005 in the Plum Island Ecosystem (PIE), a collection of 26 suburban towns northeast of Boston, MA, USA. We then use this dataset in conjunction with the GEOMOD land-change model to project lawn extent under two scenarios of urban growth for the year 2030. We find that in 2005, 76 km2 of lawn – defined as grass on residential land – existed in the PIE study region. Under a Current Trends scenario, we project residential lawns may increase by 7.0 % to 81 km2, while under a Smart Growth scenario we project a 1.6 % increase to 77 km2. We estimate this could result in up to 61 million additional liters of annual water use under the Current Trends scenario, and 14 million under Smart Growth, putting additional stress on utilities that already face regular water shortages.
Physiology of cochlear efferent and afferent neurons: direct comparisons in the same animal

Exposure of the vestibulo-cochlear anastomosis in the cat allows single-unit recording of afferent fibers originating from inner hair cells and olivocochlear efferent fibers to the outer hair cells. Comparison of data obtained from individual animals show similarities in absolute threshold and dynamic range between the efferent fibers and that subset of auditory-nerve afferents with low spontaneous rates and high thresholds [Liberman (1978) J. Acoust. Soc. Am. 63, 442-455]. The afferent-efferent comparisons also show that interanimal variability in efferent excitability (thresholds and maximum discharge rates) is directly correlated with variation in the mean spontaneous discharge rate of the afferent fiber population. It is suggested that interanimal differences in efferent excitability may explain some of the interanimal variability in susceptibility to acoustic trauma.
Demonstration of differential post-stenotic myocardial technetium-99m-teboroxime clearance kinetics after experimental ischemia and hyperemic stress.

The clearance kinetics of the perfusion tracer 99mTc-teboroxime were evaluated in post-stenotic and normal myocardium using dynamic planar gamma camera imaging in pre-instrumented dogs in the control state (n = 9) and following total occlusion (2 min), pharmacologic stress with adenosine [80 and 160 micrograms/kg/min] or dipyridamole, and rapid atrial pacing (220/min). Technetium-99m-teboroxime clearance in normal myocardium was accelerated by adenosine and by dipyridamole compared to the control state (8.9 +/- 1.1 and 9.3 +/- 1.9 min versus 11.9 +/- 1.8 min; p less than 0.05). Post-stenotic 99mTc-teboroxime clearance half-time was most significantly prolonged compared to nonoccluded contralateral perfusion zones by 160 micrograms/kg/min adenosine stress (11.2 +/- 3.7 versus 6.3 +/- 1.5 min) and by complete coronary occlusion (12.1 +/- 3.3 versus 6.6 +/- 1.2 min; both p less than 0.05). Differential tracer clearance from post-stenotic versus nonoccluded zones produced quantitative evidence of relative defect "redistribution" in 71% of maximal stress studies at a mean of 8.8 +/- 2.5 min postinjection. Sensitivity, specificity, and diagnostic accuracy of prolonged regional 99mTc-teboroxime clearance rates for post-stenotic perfusion abnormalities were 62%, 100% and 81% in maximal stress studies. Future clinical trials of exercise and nonexercise stress 99mTc-teboroxime imaging should consider these kinetic characteristics and examine the correlates of perfusion defect "redistribution."
The Volkswagen scandal: Deception, driving and deaths

News that a major car manufacturer had used “defeat devices” to cheat emissions tests led many to wonder how many deaths may have been caused by excess pollution. But as Jenna R. Krall and Roger D. Peng explain, such calculations are riddled with uncertainties
Exclusionary Structure or Cultural Clash, why do Immigrants Dropout? a Comparison of One Group in Two Different Countries

Every year schools lose secondary students. Some of these students are pulled from their institutions due to health, safety, or economic reasons. Some or many of these students leave against their own desire and with the intention of returning when possible. However, some students willingly disengage from the educational process, eventually leaving the institution—“dropping out.“
The Neurobiological Impact of Postpartum Maternal Depression: Prevention and Intervention Approaches

The lasting negative impact of postpartum depression (PPD) on offspring is well established. PPD seems to have an impact on neurobiological pathways linked to socioemotional regulation, cognitive and executive function, and physiologic stress response systems. This review focus on examining the current state of research defining the effect of universal, selected, and indicated interventions for PPD on infant neurodevelopment. Given the established lasting, and potentially intergenerational, negative implications of maternal depression, enhanced efforts targeting increased identification and early intervention approaches for PPD that have an impact on health outcomes in both infants and mothers represent a critical public health concern.
Gender-Specific Jealousy and Infidelity Norms as Sources of Sexual Health Risk and Violence Among Young Coupled Nicaraguans.

Gender inequity negatively affects health in Central America. In 2011, we conducted 60 semistructured interviews and 12 photovoice focus groups with young coupled men and women in Leon, Nicaragua, to explore the ways in which social norms around marriage and gender affect sexual health and gender-based violence. Participants’ depictions of their experiences revealed gendered norms around infidelity that provided a narrative to justify male expressions of jealousy, which included limiting partner autonomy, sexual coercion, and physical violence against women, and resulted in increased women’s risk of sexually transmitted infections, including HIV. By understanding and taking account of these different narratives and normalized beliefs in developing health- and gender-based violence interventions, such programs might be more effective in promoting gender-equitable attitudes and behaviors among young men and women in Nicaragua.
HIV Impairs Lung Epithelial Integrity and Enters the Epithelium to Promote Chronic Lung Inflammation

Several clinical studies show that individuals with HIV are at an increased risk for worsened lung function and for the development of COPD, although the mechanism underlying this increased susceptibility is poorly understood. The airway epithelium, situated at the interface between the external environment and the lung parenchyma, acts as a physical and immunological barrier that secretes mucins and cytokines in response to noxious stimuli which can contribute to the pathobiology of chronic obstructive pulmonary disease (COPD). We sought to determine the effects of HIV on the lung epithelium. We grew primary normal human bronchial epithelial (NHBE) cells and primary lung epithelial cells isolated from bronchial brushings of patients to confluence and allowed them to differentiate at an air- liquid interface (ALI) to assess the effects of HIV on the lung epithelium. We assessed changes in monolayer permeability as well as the expression of E-cadherin and inflammatory modulators to determine the effect of HIV on the lung epithelium. We measured E-cadherin protein abundance in patients with HIV compared to normal controls. Cell associated HIV RNA and DNA were quantified and the p24 viral antigen was measured in culture supernatant. Surprisingly, X4, not R5, tropic virus decreased expression of E-cadherin and increased monolayer permeability. While there was some transcriptional regulation of E-cadherin, there was significant increase in lysosome-mediated protein degradation in cells exposed to X4 tropic HIV. Interaction with CXCR4 and viral fusion with the epithelial cell were required to induce the epithelial changes. X4 tropic virus was able to enter the airway epithelial cells but not replicate in these cells, while R5 tropic viruses did not enter the epithelial cells. Significantly, X4 tropic HIV induced the expression of intercellular adhesion molecule-1 (ICAM-1) and activated extracellular signal-regulated kinase (ERK). We demonstrate that HIV can enter airway epithelial cells and alter their function by impairing cell-cell adhesion and increasing the expression of inflammatory mediators. These observed changes may contribute local inflammation, which can lead to lung function decline and increased susceptibility to COPD in HIV patients.
Evidence for a low Km transporter for non-transferrin-bound iron in isolated rat hepatocytes.

Non-transferrin-bound iron (NTBI) plays an important role in the hepatocellular injury induced by iron overload. However, the mechanism responsible for NTBI uptake into hepatocytes remains poorly defined. The purpose of this study was to define the kinetics of NTBI uptake by isolated rat hepatocytes and to characterize the uptake process. NTBI uptake was time and temperature dependent, exhibited a Michaelis-Menten constant (Km) value of 1.25 microM and maximum uptake of 241 pmol.10(6) cells-1.min-1, and 55Fe was incorporated in part into intracellular ferritin. Uptake was Ca2+ dependent, exhibiting 15 and 80% of maximal uptake in the presence of 0.6 and 0.75 mM CaCl2, respectively. The putative NTBI transporter was highly specific; divalent (Zn2+, Mn2+, Cd2+, and Co2+) or trivalent (La3+) cations did not inhibit Fe3+ uptake. Reduction from Fe3+ to Fe2+ was not essential for uptake or the process occurred deep within the membrane bilayer, since the Fe2+ chelator ferrozine did not influence 55Fe uptake. These data provide evidence for a low Km plasma membrane transporter for NTBI, which should be functional at physiological serum concentrations and saturated in iron-overload diseases, such as hemochromatosis.