cssi/SciSciGPT-SciSciNet huggingface dataset:
Brain Coated Vesicle Destabilization and Phosphorylation of Coat Proteins

: Two basic polypeptides, bee venom melittin and poly-L-lysine, induced concentration-dependent destabilization of bovine brain coated vesicles. Ultrastructurally the changes observed were aggregation of clathrin coats and segregation of the vesicle membrane, concomitant with the appearance of elongated cisternae of various sizes. Changes in coated vesicle morphology induced by melittin and poly-L-lysine were concurrent with stimulation of phosphate incorporation in proteins of the coat lattice: M, 33,000 and 100,000. Melittin-stimulated phosphorylation was Ca2+ sensitive and inhibited by EGTA. The initiation of vesicle membrane segregation by melittin, followed by fusion and formation of elongated membrane cisternae, paralleled an increase of endogenous phospholipase A2 activity. The data suggest that a correlation exists between the state of assembly of the coat proteins on coated vesicles and protein phosphorylation.
Diagnosing the equilibrium state of a coupled global biosphere‐atmosphere model

[1] This study combines a conceptual modeling approach and a physical process–based modeling approach to diagnose and understand the equilibrium state(s) of coupled biosphere-atmosphere models using the NCAR CAM3-CLM3-DGVM model as an example, with a focus on the West Africa and South America regions. First, a conceptual model is parameterized according to results from offline simulations using CAM3-CLM3 and CLM3-DGVM. The resulting conceptual model is then used to predict the potential biosphere-atmosphere equilibrium state(s) for the coupled CAM3-CLM3-DGVM model. Finally, simulations using the coupled CAM3-CLM3-DGVM model itself are carried out to verify the results of the conceptual model. Only one equilibrium state is found in both the conceptual model and the physically based numerical model. The CLM3 model features excessively high soil evaporation and very low plant transpiration, which leads to high bare-ground ET and low sensitivity of ET to vegetation cover changes in the land model. Despite the high sensitivity of precipitation to evapotranspiration changes in the atmospheric model, the land model deficiency leads to a high amount of precipitation in the absence of vegetation cover and a low sensitivity of precipitation to vegetation changes in CAM3-CLM3, two conditions that are found to anchor a coupled biosphere-atmosphere model to a single equilibrium state. This statement also holds for the up-to-date version of the models using CLM4. This study provides an example for the importance of land surface processes in determining the potential equilibrium states of fully coupled biosphere-atmosphere models.
Historical developments and recent advances in amino acid geochronology applied to loess research: examples from North America, Europe, and China

Abstract Amino acid geochronology provides important chronostratigraphic insight in the regional correlation and paleoclimatic evaluation of loess–paleosol sequences in the midwestern US, throughout western, central, and eastern Europe, and in China. In general, loess of the last four glacial cycles, corresponding to marine oxygen-isotope stages (OIS) 2–4, 6, 8, and 10, respectively, can be distinguished on the basis of alloisoleucine/isoleucine (A/I) ratios measured in fossil gastropod shells preserved in the loess. The racemization reaction is much slower in older samples, resulting in decreased temporal resolution. In the midwestern US and Europe, it is not possible to confidently subdivide the last glacial cycle on the basis of aminostratigraphic data. However, in China, where effective temperatures were higher during the Late Pleistocene, loess above and below L1SS1, the OIS-3 interstadial paleosol, can be distinguished using amino acid racemization data. With improvements in analytical methods, multiple amino acid d / l- enantiomers are now being measured using reverse-phase liquid chromatography. Aspartic acid racemizes at a higher rate than the traditionally measured alloisoleucine/isoleucine diastereomers and can be measured more rapidly. This development offers hope for better temporal resolution and enhanced stratigraphic subdivision of loess units than has been achieved previously.
Thermomechanical effects on transient temperature in non-conformal contacts experiencing reciprocating sliding motion

A thermomechanical analysis of a semi-infinite elastic solid in contact with a rigid adiabatic sphere subjected to oscillatory sliding motion is conducted to investigate the effects of transient mechanical and thermomechanical loads on the temperature variation in the solid. The interdependent mechanical and thermal analyses are coupled by an iteration scheme using the transfer matrix method combined with the finite element technique. The significance of interaction among heat generation, temperature rise and contact conditions are interpreted in light of numerical results. It is shown that the constraint of the thermal expansion in the indentation direction between the contacting bodies plays a significant role in the increase of contact pressure and heat generation, which in turn affect the temperature rise and thermal expansion.
Assessing significance of information flow in high dimensional dynamical systems with few data

Information-theoretical notions of causality provide a model-free approach to identification of the magnitude and direction of influence among sub-components of a stochastic dynamical system. In addition to detecting causal influences, any effective test should also report the level of statistical significance of the finding. Here, we focus on transfer entropy, which has recently been considered for causality detection in a variety of fields based on statistical significance tests that are valid only in the asymptotic regime, that is, with enormous amounts of data. In the interest of applications with limited available data, we develop a non-asymptotic theory for the probability distribution of the difference between the empirically-estimated transfer entropy and the true transfer entropy. Based on this result, we additionally demonstrate an approach for statistical hypothesis testing for directed information flow in dynamical systems with a given number of observed time steps.Copyright © 2014 by ASME
Acoustic diffraction by a perfectly soft annular spherical cap

Abstract The paper deals with the diffraction of time-harmonic axisymmetric acoustic waves by a perfectly soft annular spherical cap. An integral equation technique is used to solve this three-part boundary value problem. Formulae are presented for the far field amplitude as well as the scattering cross section for the case when the incident wave is a plane wave travelling along the polar axis towards the convex surface of the annular cap. By taking appropriate limits the solutions for the corresponding problems for an annular circular disk and the whole spherical cap are derived. Numerical results are presented to display the effects of an opening in the cap as well as the curvature of the surface on the value of the scattering cross section. The analysis of the paper is further used to evaluate the capacity of an annular spherical cap in free space.
Simultaneous Determination of Phase Equilibria Compositions and Phase Molar Densities of Hydrocarbon + CO2 Systems

This paper presents new phase equilibria compositions and density data for (1) a quaternary mixture of propane + pentane + octane + CO2 at temperatures from 310 K to 394 K and pressures from 3 MPa ...
Cultural studies of four North American species of Perenniporia (Aphyllophorales: Polyporaceae)

Perenniporia phloiophila colonizes the dead, outer bark of live oak ( Quercus virginiana ) and is known in the southeastern United States on this host only. On 2% malt extract agar, P. phloiophila has an average growth rate of 5–6 mm day −1 at its optimum temperature range of 30–35 °C. P. phloiophila gives strong oxidase reactions on gallic and tannic acid agar media and does not produce chlamydospores in cultures of single dikaryons or homokaryons. P. medulla-panis has an average growth rate of 6–8 mm day −1 at its optimum temperature range of 30–35°. It has strong reactions on gallic and tannic acid agar media and produces chlamydospores in culture. Vegetative incompatibility between different dikaryotic isolates of P. phloiophila resulted in antagonistic hyphal interactions and dark pigmented zones between opposing isolates. Chlamydospores developed in the interaction zones of incompatible dikaryotic isolates. Self crosses of dikaryons resulted in complete intermingling of isolates with no interaction zone or pigmentation. Incompatible matings of homokaryotic isolates of P. phloiophila have abundant chlamydospores in the interaction zone while chlamydospores are absent in compatible matings of single spore isolates. Chlamydospores occur in all homokaryotic isolates of P. medulla-panis . Both species are heterothallic and tetrapolar. In vitro wood decay abilities of P. phloiophila, P. medulla-panis, P. ohiensis and P. fraxinophila were studied using wood of silverleaf oak, white fir and velvet ash. Percent weight loss (PWL) was greatest on silverleaf oak wood for three of the four species tested. P. medulla-panis caused the greatest PWL on white fir while P. fraxinophila caused the greatest PWL on silverleaf oak and velvet ash wood. Significant ( P = 0·05) differences in PWL occurred with P. phloiophila isolates tested at 25 and 30°. Mycelium of P. phloiophila readily colonized Emory oak bark blocks but only one isolate caused significant PWL.
Non-linear filtering for distributed parameter systems having a small parameter

A general non-linear filter is derived for dynamic systems described by partial differential equations containing a small parameter multiplying the time derivatives of some state variables. By allowing this small parameter to approach zero, it is possible to approximate the system filter equations by low-order slow and fast filters. As an example, a fixed-bed chemical reactor is used to demonstrate the application of the present theory.
Termination of psychoanalysis: Theoretical, clinical, and pedagogic considerations

(1982). Termination of psychoanalysis: Theoretical, clinical, and pedagogic considerations. Psychoanalytic Inquiry: Vol. 2, Termination, pp. 473-497.
Porosity and Permeability of Oil Sands: Age and Depth: ABSTRACT

Porosity and permeability data available from the literature have been surveyed to determine as quantitatively as possible the relationships which may exist between these two properties of oil-producing sandstones, their geologic ages, and their present depths of burial. Thorough quantitative analysis of the data was not possible because (1) only ranges of porosity and permeability are available from some references, and (2) many references do not specify as to whether porosity and permeability averages are weighted or are only arithmetic means on thicknesses cored. The results verify existing belief that the depths from which oil may be produced in the future will be governed primarily by the depths to which sedimentary troughs have been filled and by progress in deep drilling techniques. The data provide some bases for additional speculation concerning the rate of compaction and consolidation of sediments and the relative time of migration and accumulation of petroleum and natural gas. End_of_Article - Last_Page 1108------------
"Mini-array" transcriptional analysis of the Listeria monocytogenes lecithinase operon as a class project: A student investigative molecular biology laboratory experience*

This report describes a molecular biotechnology-based laboratory curriculum developed to accompany an undergraduate genetics course. During the course of a semester, students researched the pathogen, developed a research question, designed experiments, and performed transcriptional analysis of a set of genes that confer virulence to the food-borne pathogen, Listeria monocytogenes. Gene fragments were amplified via PCR and utilized in "mini-arrays," a dot-blot-based format suitable for the simultaneous transcriptional analysis of multiple genes. The project provides exposure to a wide range of molecular techniques and can be easily modified for variations in class size. Data are generated at various steps of the process, allowing for student interpretation, troubleshooting, and assessment opportunities.
A multitechnique surface science examination of Sn deposition on Pt(100)

Abstract Interfaces prepared by vapor deposition of Sn onto Pt(100) surfaces have been examined using the following techniques: Auger electron and X-ray photoelectron spectroscopy (AES and XPS), low-energy electron diffraction (LEED), and low-energy ion surface scattering (LEISS) with Ne + ions. Tin deposition was conducted at 320 and 600 K, and the surface composition and order was examined as a function of further annealing to 1200 K. The AES uptake plots (signal versus deposition time) indicate that the Sn growth mode can be described by a layer-by-layer process only up to one adayer at 320 K. Some evidence of 3D growth is inferred from LEED and LEISS data for higher Sn coverages. For deposition at 600 K, AES data indicate significant interdiffusion and surface alloy formation. LEED observations (recorded at a substrate temperature of 320 K) show that the characteristic hexagonal Pt(100) reconstruction disappears with Sn exposures of 4.6 × 10 14 atoms cm 2 ( θ Sn = 0.35 monolayer (ML)). Further Sn deposition results in a c(2 × 2) LEED pattern starting at a coverage of slightly above 0.5 ML. The c(2 × 2) LEED pattern becomes progressively more diffuse with increasing Sn exposure with eventual loss of all LEED features above 2.2 ML. Annealing experiments with various precoverages of Sn on Pt(100) are also described by AES, LEED, and LEISS results. For specific Sn precoverages and annealing conditions, c(2 × 2), p(3√2 × √2) R 45°, and a combination of the two LEED patterns are observed. These ordered LEED patterns are suggested to arise from ordered PtSn surface alloys. In addition, the chemisorption of CO and O 2 at the ordered annealed Sn/Pt(100) surfaces was also examined using thermal desorption mass spectroscopy (TDMS), AES, and LEED.
Measuring the effectiveness of circa operations training program

The Center for Instructional and Research Computing Activities (CIRCA) at the University of Florida has a training program with the following design: philosophical approach, goals, training methodology, and evaluations. The philosophy is to train Technology Consultants (TCs) to maintain CIRCA as an institution and to empower them to offer the best service to students, faculties, and staff. The goals have been to improve the old training program, to evaluate the program to measure its effectiveness, and to encourage TCs to work professionally in four labs to maintain CIRCA as an institution. The program has eleven training sessions arranged in two phases, and it is offered every semester. Phase I covers policies and procedures and how to work with the hardware. Phase II deals with the most common software that users use in the labs. Lectures are offered with one of the following participatory methods: group discussion, role-play, and brainstorm. Evaluation is carried out by testing knowledge, skill, performance in the labs, and trainees. degree of satisfaction toward each session of the program. All questions received in our labs are recorded per week. Trainees must have 100% attendance, pass the knowledge and the skill tests, obtain at least a moderate score in the performance test, and submit all questions received per week to satisfactorily complete the program. The evaluations and the questions received in the labs help to modify the main topics covered in each phase, to change lesson plans, and to adjust participatory methods. We have successfully implemented this program since Fall 2000.
EWSR1‐POU5F1 fusion in soft tissue myoepithelial tumors. A molecular analysis of sixty‐six cases, including soft tissue, bone, and visceral lesions, showing common involvement of the EWSR1 gene

The diagnosis of myoepithelial (ME) tumors outside salivary glands remains challenging, especially in unusual clinical presentations, such as bone or visceral locations. A few reports have indicated EWSR1 gene rearrangement in soft tissue ME tumors, and, in one case each, the fusion partner was identified as either PBX1 or ZNF444. However, larger studies to investigate whether these genetic abnormalities are recurrent or restricted to tumors in soft tissue locations are lacking. Sixty-six ME tumors mainly from soft tissue (71%), but also from skin, bone, and visceral locations, characterized by classic morphological features and supporting immunoprofile were studied. Gene rearrangements in EWSR1, FUS, PBX1, and ZNF444 were investigated by fluorescence in situ hybridization. EWSR1 gene rearrangement was detected in 45% of the cases. A EWSR1-POU5F1 fusion was identified in a pediatric soft tissue tumor by 3'Rapid Amplification of cDNA Euds (RACE) and subsequently confirmed in four additional soft tissue tumors in children and young adults. An EWSR1-PBX1 fusion was seen in five cases, whereas EWSR1-ZNF444 and FUS gene rearrangement was noted in one pulmonary tumor each. In conclusion, EWSR1 gene rearrangement is a common event in ME tumors arising outside salivary glands, irrespective of anatomical location. EWSR1-negative tumors were more often benign, superficially located, and showed ductal differentiation, suggesting the possibility of genetically distinct groups. A subset of soft tissue ME tumors with clear cell morphology harbor an EWSR1-POU5F1 fusion, which can be used as a molecular diagnostic test in difficult cases. These findings do not support a pathogenetic relationship between soft tissue ME tumors and their salivary gland counterparts.
Potential of intraluminal ultrasound for angioplasty guidance

The manifestation of atherosclerotic lesions in arteries can vary from asymptomatic thickening in the vessel wall to complete occlusion. Experimental studies on non-human primates and on human subjects indicate that atherosclerotic lesions may progress without a reduction in luminal diameter because of dilatation of the arterial wall . Although angiography has been considered the "gold standard" for visualization of the arterial tree ar1 detection of luminal narrowing, it does not demonstrate arterial wall thickening or morphology. Moreover, the measurement of luminal diameter of the sane lesion can vary considerably depending on the plane of projection of the x-ray beam. This is attributed to the eccentric nature of the residual lumen in an atherosclerotic vessel . Extraluminal B-mode real time imaging has the feasibility of demonstrating arterial lumen and arterial wall thickness. However, it is still in some instances limited by inadequate resolution and image quality. Intraluminal ultrasound using a phased array or rotating transducer gives better definition of the vessel wall and luminal diameter as it is not limited by the tissue interposed between the vessel and the probe in transcutaneous devices. This paper demonstrates further experience with intravascular ultrasound as a diagnostic tool using B-mode real time imaging.
A-P positioning of medialization thyroplasty in an excised larynx model.

Hypothesis: Posterior positioning of medialization thyroplasty provides the best acoustic and aerodynamic outcomes. Study Design: Ex vivo excised canine larynx. Methods: Unilateral thyroplasty windows were cut in the thyroid cartilages of 10 excised canine larynges. Each larynx was mounted on an artificial lung and the vocal fold opposite the thyroid window was adducted by medializing its arytenoid cartilage. Then, medialization thyroplasty was simulated with a probe placed anterior, central, and posterior in the thyroid window. The glottal area, airway reduction, medialization force, phonation threshold pressure and flow, aerodynamic power, intensity, efficiency, jitter, shimmer, and signal-to-noise ratio (SNR) were measured at each medialization position. Results: Posterior medialization probe placement minimized the glottal area, provided the best voice as determined by perturbation measures and SNR, reduced the work of phonation, and increased efficiency. Anterior and middle probe placement minimized the work of phonation but provided only modest gains in sound quality and decreased sound intensity. Medializing the vocal fold with posterior probe placement required twice as much force as central and anterior probe placement. Conclusions: The results suggest that posterior medialization provides the greatest improvement in acoustic parameters and efficiency in patients who can tolerate the airway reduction. Middle and anterior medialization can decrease work of phonation, but in this experiment objective improvement in sound quality was limited. Subtle changes in displacement shim contour, especially in middle and anterior locations, have a substantial impact on voice outcome, affirming the value of intraoperative voice assessment. Laryngoscope, 119:591–596, 2009
Marking time with bivalve shells; oxygen isotopes and season of annual increment formation

Most bivalve shells contain macroscopic growth-increment patterns which form with an annual periodicity. These are best observed in radial shell cross-sections and consist of alternating dark (translucent in transmitted light) and light (opaque in transmitted light) increments. A couplet of dark and light increments constitutes one year's shell growth and subdivides the continuous shell growth record into successive, annual components. Conventional wisdom suggests that dark increments represent slow shell growth associated with cold winter temperatures. Such a pattern characterizes shells of the much-studied hard clam, Mercenaria mercenaria, from coastal New England. Investigations of other species indicate, however, that not all dark increments form in response to cold temperatures. Yearly cycles in oxygen isotopic data from fossil and modern bivalves demonstrate considerable variability in the season of growth increment formation. Isotopic data suggest Jurassic Gryphaea arcuata from Great Britain formed dark increments during the warmest season, as do many other bivalves. In fact, oxygen isotope profiles across the shells of modern and fossil Mercenaria spp. from the US. east coast and the Atlantic and Gulf Coastal Plains indicate that in northern latitudes the dark increment typically forms during the winter season whereas in lower latitudes it forms during the summer to early fall. A transition zone occurs in the Middle Atlantic region where aspects of both patterns are observed. Water temperature extremes (high or low) appear to be the primary factor controlling the timing of dark (translucent) increment formation. Because of this dichotomy in the season of growth-increment formation, high-resolution isotopic sampling is invaluable when interpreting shell records in sclerochronological contexts, particularly for fossil bivalves.
Preparation and characterization of radioactive samples for various areas of research

Abstract The Isotope Research Materials Laboratory (IRML) at the Oak Ridge National Laboratory (ORNL) prepares many radioactive targets to meet a myriad of experimental requirements. In general, most of the targets are either actinide or tritium deposits and are used for precision cross-section measurements, neutron dosimetry, material property measurements, compatibility studies or for the generation of neutrons. The materials have to be accurately characterized as to content and uniformity. The techniques used by IRML to prepare actinide oxide deposits and metals of plutonium, americium, and curium, will be reviewed. The IRML neutron dosimeter program, including types of materials, encapsulation and characterization procedures will be described in depth. The systems to be used in fabricating 50 cm diameter tritium targets in support of fusion reactor materials research will be described.
Breast cancer as a systemic disease: a view of metastasis

Breast cancer is now the most frequently diagnosed cancer and leading cause of cancer death in women worldwide. Strategies targeting the primary tumour have markedly improved, but systemic treatments to prevent metastasis are less effective; metastatic disease remains the underlying cause of death in the majority of patients with breast cancer who succumb to their disease. The long latency period between initial treatment and eventual recurrence in some patients suggests that a tumour may both alter and respond to the host systemic environment to facilitate and sustain disease progression. Results from studies in animal models suggest that specific subtypes of breast cancer may direct metastasis through recruitment and activation of haematopoietic cells. In this review, we focus on data implicating breast cancer as a systemic disease.
Machine learning and genetic algorithms in pharmaceutical development and manufacturing processes

We develop an adaptive Automated Intelligent Manufacturing System (AIMS) for Case 1:to a well-understood-pharmaceutical-process to demonstrate our methodology, Case 2:with clustering, to a not-well-controlled or understood-process for seemingly identical experiments yielding disparate results, Case 3:to scale-up a process from development to manufacturing, and Case 4:to deploy AIMS adaptively, to modify the process model and reoptimize the system contemporaneously, when predictive errors are significant. The results showed AIMS had both explanatory and predictive power. We have developed the following methodological extensions: a random probe method for feature selection, a simulation approach to establish tolerances for target inputs, and an adaptive capability integrated with statistical-process-control to modify the model.
Loop Transmission Systems--Mean Value Analysis

A simple analytical model is developed for loops with centralized control, random slot seizure, and fixed slot duration. Slots are assumed to be generated at regular intervals, regardless of whether they are utilized or not, while requests for service at terminals attached to the loop are described by Poisson arrival statistics, For loops used for data collection, mean waiting-line lengths and queue lengths are obtained both at instants when slots are due to arrive and at instants of arrivals of requests for service. Mean waiting times and queueing times are computed and the relative efficiencies of different loop sizes compared. Simultaneous data collection and distribution is also considered and the degradation in data-collection service due to use of resources for data distribution is plotted.
A study of inter-crystal scatter in small scintillator arrays designed for high resolution PET imaging

Inter-crystal scatter causes mispositioning of scintillation events, which is of particular concern in imaging detectors based on small discrete scintillator elements. Because it is difficult to measure the scatter and its effects on detector intrinsic spatial resolution, a Monte Carlo simulation has been used to study inter-crystal scatter effects for evaluating and optimizing the design of a high resolution animal PET detector based on an array of small scintillator crystals. In this simulation, the authors quantitatively assess the mispositioning of events due to inter-crystal scatter as a function of parameters such as different scintillator materials, crystal geometry, /spl gamma/-ray incident angle and applied energy threshold. In analyzing the tradeoff between the detector efficiency and the position detection accuracy, the authors found that the mispositioning is not sensitive to the energy threshold, however it does change rapidly with the crystal length and the gap between crystals. The authors also compared four different crystal positioning algorithms to provide a theoretical estimate of positioning accuracy and to determine the best algorithm to use. To study how inter-crystal scatter affects detector spatial resolution, the authors analyzed the coincidence line spread function with and without inter-crystal scatter and found that the inter-crystal scatter had very little effect on the FWHM and FWTM of the coincidence line spread function.
Process and Contamination Effects on the Single-Event Response of AlSb/InAs HEMTs

We investigate the dependence of the single-event response of AlSb/InAs HEMTs on details of the doping, layer thicknesses, and contamination levels. The transconductance depends on the Δ-doping and layer thickness, which are shown to have the maximum impact on charge collection when the device is biased near the pinch-off voltage. In the on condition (near zero gate bias), the effect is minimal. The possible role of carbon contamination near the substrate-buffer heterointerface in reducing some of the longer transients is discussed.
A single camera terrain slope estimation technique for natural arctic environments

Arctic regions present one of the harshest environments on earth for people or mobile robots, yet many important scientific studies, particularly those involving climate change, require measurements from these areas. For the successful deployment of mobile sensors in the arctic, a reliable, fault tolerant, low-cost method of navigating must be developed. One aspect of an autonomous navigation system must be an assessment of the local terrain, including the slope of nearby regions. Presented here is a method of estimating the slope of the terrain in the robot's coordinate frame using only a single camera, which has been applied to both simulated arctic terrain and real images. The slope estimates are then converted into the global coordinate frame using information from a roll sensor, used as an input to a fuzzy logic navigation scheme, and tested in a simulated arctic environment.
Feedbacks of Vegetation on Summertime Climate Variability over the North American Grasslands. Part II: A Coupled Stochastic Model

Abstract A coupled linear model is derived to describe interactions between anomalous precipitation and vegetation over the North American Grasslands. The model is based on biohydrological characteristics in the semiarid environment and has components to describe the water-related vegetation variability, the long-term balance of soil moisture, and the local soil–moisture–precipitation feedbacks. Analyses show that the model captures the observed vegetation dynamics and characteristics of precipitation variability during summer over the region of interest. It demonstrates that vegetation has a preferred frequency response to precipitation forcing and has intrinsic oscillatory variability at time scales of about 8 months. When coupled to the atmospheric fields, such vegetation signals tend to enhance the magnitudes of precipitation variability at interannual or longer time scales but damp them at time scales shorter than 4 months; the oscillatory variability of precipitation at the growing season time scale...
Ceramic Composites with Three-Dimensional Architectures Designed to Produce a Threshold Strength—II. Mechanical Observations

Finite element modeling and linear elastic fracture mechanics are used to model the residual stresses and failure stress of ceramic composites consisting of polyhedral alumina cores surrounded by thin alumina/mullite layers in residual compression. This type of composite architecture is expected to exhibit isotropic threshold strength behavior, in which the strength of the composite for a particular assumed flaw will be constant and independent of the orientation of tensile loading. The results of the modeling indicate that the strengths of such architectures will be higher than those of laminates of similar architectural dimensions that were previously found to exhibit threshold strength behavior for a particular flaw type. Flexural testing of the polyhedral architectures reveals that failure is dominated by processing defects found at junctions between the polyhedra. Fractography revealed the interaction of these defects with the residual stresses in the compressive layers that separate the polyhedra.
Microcystic macular oedema in multiple sclerosis is associated with disease severity

Macular oedema typically results from blood–retinal barrier disruption. It has recently been reported that patients with multiple sclerosis treated with FTY-720 (fingolimod) may exhibit macular oedema. Multiple sclerosis is not otherwise thought to be associated with macular oedema except in the context of comorbid clinical uveitis. Despite a lack of myelin, the retina is a site of inflammation and microglial activation in multiple sclerosis and demonstrates significant neuronal and axonal loss. We unexpectedly observed microcystic macular oedema using spectral domain optical coherence tomography in patients with multiple sclerosis who did not have another reason for macular oedema. We therefore evaluated spectral domain optical coherence tomography images in consecutive patients with multiple sclerosis for microcystic macular oedema and examined correlations between macular oedema and visual and ambulatory disability in a cross-sectional analysis. Participants were excluded if there was a comorbidity that could account for the presence of macular oedema, such as uveitis, diabetes or other retinal disease. A microcystic pattern of macular oedema was observed on optical coherence tomography in 15 of 318 (4.7%) patients with multiple sclerosis. No macular oedema was identified in 52 healthy controls assessed over the same period. The microcystic oedema predominantly involved the inner nuclear layer of the retina and tended to occur in small, discrete patches. Patients with multiple sclerosis with microcystic macular oedema had significantly worse disability [median Expanded Disability Score Scale 4 (interquartile range 3–6)] than patients without macular oedema [median Expanded Disability Score Scale 2 (interquartile range 1.5–3.5)], P = 0.0002. Patients with multiple sclerosis with microcystic macular oedema also had higher Multiple Sclerosis Severity Scores, a measure of disease progression, than those without oedema [median of 6.47 (interquartile range 4.96–7.98) versus 3.65 (interquartile range 1.92–5.87), P = 0.0009]. Microcystic macular oedema occurred more commonly in eyes with prior optic neuritis than eyes without prior optic neuritis (50 versus 27%) and was associated with lower visual acuity (median logMAR acuity of 0.17 versus −0.1) and a thinner retinal nerve fibre layer. The presence of microcystic macular oedema in multiple sclerosis suggests that there may be breakdown of the blood–retinal barrier and tight junction integrity in a part of the nervous system that lacks myelin. Microcystic macular oedema may also contribute to visual dysfunction beyond that explained by nerve fibre layer loss. Microcystic changes need to be assessed, and potentially adjusted for, in clinical trials that evaluate macular volume as a marker of retinal ganglion cell survival. These findings also have implications for clinical monitoring in patients with multiple sclerosis on sphingosine 1-phosphate receptor modulating agents. * Abbreviations : EDSS : Expanded Disability Score Scale OCT : optical coherence tomography RNFL : retinal nerve fibre layer
α-Isopropylmalate Synthase from Yeast: Purification, Kinetic Studies, and Effect of Ligands on Stability

α-Isopropylmalate synthase, the first specific enzyme in leucine biosynthesis, was purified approximately 100-fold from extracts of Saccharomyces sp. (strain 60615), the most effective step being specific elution with the feedback inhibitor leucine from a hydroxyapatite column. In the early steps of purification, special care was taken to protect the synthase against proteolytic activities. The apparent molecular weight of the enzyme as determined from gel filtration on a calibrated column was 137,000 in the absence and 121,000 in the presence of leucine. Inhibition by leucine was specific and strongly pH-dependent, with the leucine concentration necessary for half-maximal inhibition increasing about 10-fold as the pH increased from 7.5 to 8.5. Within this pH range, catalytic activity remained almost unchanged. The apparent Km values for the two substrates were found to be 16 μm for α-ketoisovalerate and 9 μm for acetyl-coenzyme A. K+ was required for full activity, the apparent Ka value being 2 mm. Leucine inhibition was of the mixed type, resulting in decreased Vmax and increased apparent Km values forboth substrates. Whereas no cooperative effects were observed with either substrate, positive cooperativity was seen with leucine in the presence of saturating substrate concentrations. Leucine and, to a lesser extent, α-ketoisovalerate stabilized the purified enzyme against heat-inactivation. The presence of acetyl-coenzyme A, on the other hand, accelerated the inactivation. In subsequent experiments, coenzyme A was recognized as the actual inactivating ligand, being effective even at lower temperatures and in concentrations which were estimated to be in the range of the enzyme concentration.
Chronic treatment with cholinesterase inhibitors increases alpha 2-adrenoceptors in rat brain.

The specific binding of [3H]clonidine to a2-adrenoceptors on neural membranes isolated from various brain areas was determined with rats treated for 7-14 days with the cholinesterase inhihitors neostigmine, triorthocresyl phosphate (TOCP), diisopropylfluorophosphate (DFP) and paraoxon, or with vehicle. Treatment with all four inhibitors increased the number of clonidine binding sites in various brain areas. In those areas which demonstrated significant increases in [3H]clonidine binding, there was also a significant inhibition of acetylcholinesterase activity. The possibility is discussed that increases in brain a2-adrenoceptors are related to the alterations in mood seen in individuals chronically exposed to organophosphorus cholinesterase inhibitors. a2-Adrenoceptors; rase inhibition (chronic); [3H]Clonidine binding; Brain; (Rat)
Frequency-based current-sharing techniques for paralleled power converters

A new current-sharing technique for paralleled power converters, which is based on frequency encoding of the current-sharing information, is introduced. The approach has significant advantages over existing methods, including the ability to transformer isolate or eliminate current-sharing control connections. Operation of the current-sharing technique is analyzed, and the design and experimental evaluation of a three-cell prototype system are presented.
Myocyte shearing, myocardial sheets, and microtubules.

See related articles, pages 81–87 and 125–132 The cytoskeleton of cardiac myocytes is a complex network of many interacting protein filaments and associated proteins with multiple functions: it forms structures responsible for maintaining cell shape and contractile filament registration, structural integrity, internal transport and cell division, and scaffolding for several putative signaling cascades.1 The tight coupling between the extracellular matrix and components of the cytoskeleton at the cell membrane suggests that, in addition to transmitting contractile forces generated by the myofilaments to the matrix and the cardiac chambers, the cytoskeleton may also be important for propagating external physical signals into the cell.2 Mutations in a growing list of cytoskeletal genes are associated with cardiomyopathies. Disruption of desmin, plakoglobin, N-cadherin, plectin, and vinculin all produce a dilated cardiac phenotype with impaired function, either in fetal development or after birth.3,4,5 These are elements of the cytoskeleton that connect intracellular structures with the extracellular matrix, and thus are likely force-transmitting components in the myocyte. Originally, Chien6 proposed that defects in the cytoskeletal component of the myocyte result in a dilated cardiomyopathic phenotype, whereas mutations in the sarcomeric proteins typically generate a pattern of hypertrophic cardiomyopathy with preserved ventricular systolic function in addition to the myocyte hypertrophy and disarray.7 But as more data have accumulated, the picture has become more complex, and cytoskeletal defects have been implicated in hypertrophic as well as dilated cardiomyopathies.8 Cytoskeletal proteins have been implicated in several load-sensing pathways, and there is evidence that cytoskeletal proteins play a critical role in biomechanical signaling and may be involved with ventricular dilation and heart failure.9,10 These studies have led to the hypothesis that there may exist a common pathway to cardiac dilation and failure, and the critical components of this “failure transition”11 …
Construction of inverse systems

A technique for constructing the transfer function of the left inverse to a linear multivariable finite-dimensional time-invariant system is presented. The technique is applicable to continuous- or discrete-time systems. Several illustrative examples are discussed.
Time trends of cardiovascular disease risk factors in China (LB463)

Fueled by rapid urbanization and changes in dietary and lifestyle choices, cardiovascular and other chronic diseases have emerged as a critical public health issue in China. To estimate the time trends of cardiovascular disease risk factors in China, we conducted a systematic review of the national representative studies of cardiovascular disease risk factors in China. The results indicated that the prevalence of hypertension in 2010 reached 33.5% (an estimated 330 million hypertensive patients), and the awareness and control rates were extremely low. Type 2 diabetes is an increasing epidemic in China with more than 100 million people affected. Although the Chinese population has a lower BMI than the global average level, abdominal obesity has become especially common in Chinese adults. Despite tobacco control efforts, the prevalence of smoking in China remains at a high level and domestic production of cigarettes continues to rise. Meanwhile, work and transportation-related physical activity levels have ...
The effects of audit firm rotation on perceived auditor independence and audit quality

Abstract Our study explores loan officers’ perceptions of auditors’ independence and audit quality under three experimental audit firm rotation scenarios. We use a case experiment with a between-subjects design to determine whether rotation of the audit firm impacts financial statement users’ perceptions of auditor’s independence and quality. Findings based on 212 useable responses indicate that loan officers do perceive an increase in independence when the company follows an audit firm rotation policy. However, the length of auditor tenure within rotation fails to significantly change loan officers’ perceptions of independence. Findings also indicate that neither the presence of a rotation policy nor the length of the auditor tenure within rotation significantly influences the loan officers’ perceptions of audit quality.
Central endoscopy reads in inflammatory bowel disease clinical trials: The role of the imaging core lab

Clinical trials in inflammatory bowel disease (IBD) are evolving at a rapid pace by employing central reading for endoscopic mucosal assessment in a field that was, historically, largely based on assessments by local physicians. This transition from local to central reading carries with it numerous technical, operational, and scientific challenges, many of which can be resolved by imaging core laboratories (ICLs), a concept that has a longer history in clinical trials in a number of diseases outside the realm of gastroenterology. For IBD trials, ICLs have the dual goals of providing objective, consistent assessments of endoscopic findings using central-reading paradigms whilst providing important expertise with regard to operational issues and regulatory expectations. This review focuses on current approaches to using ICLs for central endoscopic reading in IBD trials.
Spectral properties of the tubuloglomerular feedback system

A simple mathematical model was used to investigate the spectral properties of the tubuloglomerular feedback (TGF) system. A perturbation, consisting of small-amplitude broad-band forcing, was appl...
A fast direct solver for the integral equations of scattering theory on planar curves with corners

We describe an approach to the numerical solution of the integral equations of scattering theory on planar curves with corners. It is rather comprehensive in that it applies to a wide variety of boundary value problems; here, we treat the Neumann and Dirichlet problems as well as the boundary value problem arising from acoustic scattering at the interface of two fluids. It achieves high accuracy, is applicable to large-scale problems and, perhaps most importantly, does not require asymptotic estimates for solutions. Instead, the singularities of solutions are resolved numerically. The approach is efficient, however, only in the low- and mid-frequency regimes. Once the scatterer becomes more than several hundred wavelengths in size, the performance of the algorithm of this paper deteriorates significantly. We illustrate our method with several numerical experiments, including the solution of a Neumann problem for the Helmholtz equation given on a domain with nearly 10000 corner points.
Blue Dye and Red Light, a Dynamic Combination for Prophylaxis and Treatment of Cutaneous Candida albicans Infections in Mice

The objective of this study was to investigate photodynamic therapy (PDT), using blue dye and red light, for prophylaxis and treatment of cutaneous Candida albicans infections in mice. A mouse model of skin abrasion infected with C. albicans was developed by inoculating wounds measuring 1.2 cm by 1.2 cm with 10(6) or 10(7) CFU. The use of a luciferase-expressing strain of C. albicans allowed real-time monitoring of the extent of infection in mice noninvasively through bioluminescence imaging. The phenothiazinium salts toluidine blue O (TBO), methylene blue (MB), and new methylene blue (NMB) were compared as photosensitizers (PS) for the photodynamic inactivation of C. albicans in vitro. PDT in vivo was initiated either at 30 min or at 24 h after fungal inoculation to investigate the efficacies of PDT for both prophylaxis and treatment of infections. Light at 635 ± 15 nm or 660 ± 15 nm was delivered with a light dose of 78 J/cm(2) (for PDT at 30 min postinfection) or 120 J/cm(2) (for PDT at 24 h postinfection) in multiple exposures with bioluminescence imaging taking place after each exposure of light. In vitro studies showed that NMB was superior to TBO and MB as the PS in the photodynamic inactivation of C. albicans. The efficacy of PDT was related to the ratio of PS concentration to fungal cell density. PDT in vivo initiated either at 30 min or at 24 h postinfection significantly reduced C. albicans burden in the infected mouse skin abrasion wounds. These data suggest that PDT is a viable approach for prophylaxis and treatment of cutaneous C. albicans infections.
Traumatic handlebar hernia: a rare abdominal wall hernia.

Abstract Traumatic abdominal wall herniation (TAWH) caused by direct trauma from bicycle handlebars are rare. There are only 21 reported cases of handlebar hernias. An 11-year-old boy presented to the emergency room soon after falling from his bicycle and hitting his right lower quadrant on the handlebars. The patient’s vital signs and initial laboratory studies were normal. Physical exam showed a soft tissue bulge in the right lower quadrant with superficial ecchymosis and tenderness to palpation. Computed tomography showed intestinal loops protruding through a defect in the abdominal wall into the subcutaneous space. Surgical exploration found a defect throughout his entire abdominal wall including the fascia, muscular layers, and peritoneum, with bowel protruding into the subcutaneous space. The defect was repaired in layers, and the child’s postoperative course was unevenful. The authors recommend a high level of clinical suspicion for TAWH in all patients with traumatic abdominal wall injuries. Definitive treatment includes surgical exploration with primary repair of all tissue layers of the abdominal wall.