cssi/SciSciGPT-SciSciNet huggingface dataset:
Computer simulation of a plasma streaming across a magnetic field

A one‐dimensional electrostatic particle simulation code has been used to study a plasma streaming across a uniform magnetic field in vacuum. It is found that the plasma may be convected across the magnetic field even if the density is less than the critical density nc necessary to maintain steady propagation. For all densities studied, polarization charge layers are formed, but they do not become steady for plasmas with n/nc<1. For plasma densities at n<nc, the electric field keeps oscillating with the upper hybrid frequency, but for nc<n, the amplitude of the oscillations are damped at later times. The mechanism that produces this damping is associated with a nonlinear wave–particle interaction. For unequal mass species, the simulations show that the heavier particles are convected faster than the lighter ones; thus the positive particles move in front and the negatives move behind creating a virtual cathode. The polarization charge layers are asymmetric, with the thicker layer corresponding to the heav...
Synoptic Modeling in the Eastern Arabian Sea during the Southwest Monsoon Using Upwelling Feature Models

Abstract Hydrographic observations along the western coast of India during the southwest (SW) monsoon season reveal upwelling in the equatorward surface flow and downwelling below the thermocline with a weak poleward undercurrent. Observations made previously during the peak of the SW monsoon in boreal summer showed that upwelling temperatures are much cooler (<23°C) than compared to the available climatology data in this region. A feature modeling technique is used to describe the temperature distribution associated with the West India Coastal Current (WICC) upwelling. This kind of formulation captures the upwelling and downwelling associated with the WICC reasonably well, though it requires the specification of a few observed offshore and nearshore temperature profiles. The temperature–salinity relationship from the Levitus climatology data is further used to obtain a compatible salinity distribution for the feature model. The efficiency of this feature model is further validated via a dynamical model s...
Antibacterial compounds in the cell-free haemolymph of Drosophila melanogaster.

Abstract Third instar larvae, individuals in the white puparium stage, pharate pupae, and adults of Drosophila melanogaster were studied in order to detect the reason for the drop in the number of extracellular bacteria which occurs between the sixth and twenty-fourth hours after white puparium formation. Attempts were made to detect natural resistance in larvae and adults using unaltered haemolymph. Although larval haemolymph was free of bacteria, even after injection of bacteria, no isolatable antibacterial activity was found. After formation of the white puparium bacteria may be liberated from the alimentary tract by histolysis into the haemocoel. Other products of histolysis, antibacterial in nature, may also be present in the haemocoel. Several experiments were performed in order to detect such antibacterial compounds. Neutral extracts of whole larvae and pharate pupae and of fat bodies removed from larvae and from individuals in the white puparium stage proved ineffective in preventing bacterial growth. Significant antibacterial activity against Brevibacterium sp. and Bacillus sp. was found in acid extracts of haemolymph removed from pharate pupae, and its time of appearance corresponded to observed fluctuations in the numbers of gram-positive bacteria in vivo. A difference in the time of maximal antibacterial activity was found between two stocks; a difference in the response of the bacteria to the haemolymph extracts was also found, one of the bacteria, Bacillus sp., apparently being killed more efficiently by a lower concentration of haemolymph than a higher concentration. These results suggest that the growth of a bacterium must be adequately controlled if an association of Drosophila with bacteria is to be beneficial. Haemolymph of pharate pupae 24 hours after white puparium formation, when antibacterial activity against Brevibacterium sp. and Bacillus sp. is present, was tested against Escherichia coli and no antibacterial activity was found. This result agrees with the observation in vivo that numbers of E. coli did not drop at this time, and it is concluded that the material isolated in the acid is probably responsible for the fluctuations observed. Although the chemical nature of this basic material was not determined, indirect evidence indicates that it is a basic protein, either histone or lysosomal, and that variations in the amount or rate of release of such basic materials may be important in the association of an extracellular bacterium with a host Drosophila.
Early phases of humanoid vehicle ingress using depth cameras

This paper presents work on integrating perception and motion-planning for a humanoid robot to ingress, or enter, a small utility vehicle as a precursor to driving, a stage in the recent DARPA Robotics Challenge (DRC). Using a Hubo 2+ robot platform and a pair of RGB-D cameras, we describe a set of approaches to and present results on the first four phases of ingress: (1) visually search for the vehicle's doorway as a target to walk toward, (2) plan and execute a collision-free approach to the doorway via walking using visual odometry, (3) make visually-guided fine positioning adjustments near the entry door during docking, and (4) step from the ground up to the floor of the vehicle. All recognition is done on 3-D point clouds derived from the depth cameras without appearance information. Some further ingress results from the DRC-Hubo making use of grasping are also shown.
Major Surgery in Hemophilia

The commercial development in Britain of antihemophilic factor (AHF) from ox and pig blood represents a notable advance in the treatment of hemophilia. With these materials, the hemostatic mechanism of even severe hemophiliacs may be made completely normal for a significant period of time, and major surgery safely undertaken. Nevertheless, in their present form the materials are antigenic and have other drawbacks. Each may therefore only be used for one period of treatment in any one hemophiliac, and should be reserved for life-saving procedures. Administration must be controlled by frequent assays of the AHF activity resulting in the patient's blood. An illustrative case (a partial gastrectomy) is described and a number of practical details are discussed.
Atomic site occupancies and mechanical response of the eutectic C14 and A15 phases in a quinternary Nb-Mo-Cr-Al-Si alloy

Channeling effects in X-ray microanalysis have been used to deduce the character of the point defects in the C14 and A15 eutectic phases of a quinternary Nb–Mo–Cr–Al–Si alloy. It is shown that these defects are predominantly antisite transition metal atoms in the C14 phase and constitutional vacancies in the A15 phase. Nanoindentation measurements show different mechanical responses upon heat-treatment and these are related to the effects of the point defects upon the dislocations in the two phases.
The γc-cytokine regulated transcription factor, STAT5, increases HIV-1 production in primary CD4 T cells

Although HIV-1 (HIV) replicates poorly in non-dividing CD4 lymphocytes, resting T cells contribute to the latent reservoir. The gammac-related cytokines reverse this block to HIV infection; however, the molecular mechanisms controlling this process are not understood. We asked whether the gammac-cytokine regulated transcription factor, signal transducer and activator of transcription 5 (STAT5), activates HIV transcription. We identified three regions in the long terminal repeat (LTR) as close matches to the STAT5 consensus-binding site and show that STAT5 binds the LTR during HIV infection. Expression of Janus kinase 3 (JAK3) or STAT5 in primary human CD4 T cells activated LTR transcription, while transactivation-incompetent dominant-negative STAT5 inhibited JAK3-induced LTR activity and infection of activated HIV-producing CD4 T-cells. In addition, overexpression of STAT5 increased virus production in unstimulated primary T cells - both the number of p24+ cells and their level of p24 production - suggesting that STAT5 promotes a permissive state for HIV infection. These data may have implications for regulation of latency and therapeutic strategies for control of HIV disease.
The BED finger, a novel DNA-binding domain in chromatin-boundary-element-binding proteins and transposases

I would like to thank Eugene V. Koonin for reading the manuscript and providing suggestions.
PARALLEL VISUAL PROCESSING: A TUTORIAL OF RETINAL FUNCTION

The mammalian retina extracts a set of 12 different "movies" from the visual scene and send each movie to higher visual centers. These movies exist in physically distinct strata of the inner retina, embodied in the dendritic arborizations of a dozen different ganglion cell types. The dendritic arbors are stacked in discrete layers throughout the inner retina where they are synaptically contacted by excitatory and inhibitory connections from a variety of different cell types. This paper outlines the synaptic and physical structure of these layers, and follows the image of a face through the retina from photoreceptors to final output, graphically displaying the transformations that take place as the image is processed by different neural structures.
On the relationships between lightning frequency and thundercloud parameters of regional precipitation systems

[1] Seasonal variations on lightning activity of precipitation systems over south China and Taiwan before and after the onset of Mei-Yu have been observed by the lightning imager sensor (LIS) on board the Tropical Rainfall Measuring Mission (TRMM) satellite. Lightning storms before Mei-Yu onset show higher probability of lightning, higher flash rate, and larger radar reflectivity in the mixed-phase region than the Mei-Yu regime. However, the probability of lightning occurrence with the same threshold of maximum radar reflectivity or ice scattering signature is similar for land systems before and during Mei-Yu season. Oceanic systems show slightly lower probability of lightning even with the same thresholds. Relationships between a set of TRMM-observed parameters and LIS lightning frequency are further examined. For lightning systems over land, the total area of radar echo above 35 dBZ has a closer relationship with lightning flash rate at the temperature between −5°C and −15°C than other parameters. Area of lower radar reflectivity at colder temperature, e.g., area of 20 dBZ at −40°C, is also highly correlated with lightning frequency. The highest correlation between area of specific radar reflectivity and lightning frequency is found at lower temperatures when the oceanic lightning systems are examined.
A new substrate for alkaline phosphatase based on quercetin pentaphosphate

We describe the characterization and application of quercetin pentaphosphate (QPP), a new fluorimetric substrate for the detection of alkaline phosphatase (ALP) activity. QPP exhibits major absorbance peaks at 260/410 nm and a strong fluorescence at λex/λem = 425/510 nm at alkaline pH. The product of enzymatic reaction between QPP and ALP has a strong absorbance peak at 324 nm with no fluorescence at the investigated wavelengths. The product generated from the enzymatic reaction was found to be proportional to ALP activity, and the ALP activity was monitored by the absorbance difference at 310 nm and 410 nm. The change in absorbance was found to be proportional to the ALP concentration with a linear detection range and a limit of detection of 0.01-16 U L(-1) and 0.766 U L(-1), respectively. The enzyme activity was also monitored by evaluating the change in fluorescence emission at 530 nm with a linear range of 0.01-8 U L(-1) and a detection limit of 0.062 U L(-1). Further, the validity of the new substrate for ALP in conjugated form was tested using Bacillus globigii spores as the model sample. A detection limit of 5998 spores per mL was obtained using QPP as the substrate. Unlike the parent compound, QPP substrate exhibits stability in solution for over three and half months and was stable under storage for over 12 months. The results obtained demonstrate the effectiveness of QPP for ALP and compare well with other fluorescent substrates, such as Fluorescein, Alexa Fluor and Cy5.
Which Price is Right: Load or Premium?

This paper uses national time series data for the United States to investigate whether changes in the premium or loading fee offer a better explanation for variations in the percentage of the population with private health insurance from 1960 to 2004. The empirical results suggest that premium provides a better measure of price when estimating the demand for health insurance at the extensive margin. The empirical analysis also indicates that the aggregate short-run price and income elasticities of demand for health insurance are fairly close at −0.19 and 0.27, respectively. One implication is that the percentage of the population with private health insurance in the United States should continue to decline in the future if real premiums persistently grow significantly faster than the overall economy.
Neutron-induced fission cross section of 242Pu

Abstract The neutron-induced fission cross section of 242 Pu is reported from 50 eV to 5 keV and 0.1 to 3 MeV. Fission widths are given up to 381 eV. The half-height of the fission barrier is determined to be 0.76 MeV. The energy of the second minimum in the fission barrier is determined to be 3.6 MeV.
The Effect of Purchase Quantity and Timing on Variety-Seeking Behavior:

Two consumer strategies for the purchase of multiple items from a product class are contrasted. In one strategy (simultaneous choices/sequential consumption), the consumer buys several items on one...
New Approaches for Sample-Profile Estimation for Fast Atomic Force Microscopy

The Atomic Force Microscope (AFM) is a powerful tool for imaging and manipulating matter at the nanoscale. The sample-profile estimation problem in Atomic Force Microscopy is addressed using H∞ control. A new estimate signal for the sample profile is proposed and it is proved that this signal tracks perfectly the profile signal. i.e., the transfer function between the profile signal and the estimate signal is one. Experimental results are presented to corroborate these results.Copyright © 2005 by ASME
THE ROLE OF NITROGEN NUTRITION IN HIGH-TEMPERATURE TOLERANCE OF THE KELP, LAMINARIA SACCHARINA (CHROMOPHYTA)

Mechanisms of high-temperature tolerance in the kelp Laminaria saccharina (L.) Lamour. were examined by comparing a heat-tolerant ecotype from Long Island Sound (LIS), New York, and a population from the Atlantic (ATL) coast of Maine. Greater heat tolerance was not attributable to greater thermal stability of the photosynthetic apparatus: LIS and ATL plants exhibited similar short-term effects of high temperature on photosynthetic capacity (Pmax) and quantum yield (estimated as the ratio of variable to maximum chlorophyll fluorescence, Fv/Fm. As LIS plants had consistently higher N and protein content than ATL plants, the interaction between nitrogen nutrition and high-temperature tolerance was examined. When grown under high N supply and optimal temperature (12° C), LIS plants had a higher density of photosystem II reaction centers (RCII), higher activity of two Calvin cycle enzymes (ribulose bisphosphate carboxylase oxygenase [RUBISCO] and NADP-dependent glyceraldehyde-3-phosphate dehydrogenase [G3PDH]), and higher Pmax and Fv/Fm than ATL plants. Individual ATL plants, furthermore, exhibited close correlations of RCII density and enzyme activity with N and/or protein content. Variation in RCII density and enzyme activity, in turn, largely accounted for plant-to-plant differences in Pmax and Fv/Fm. Relationships among these parameters were generally weak or lacking among individual LIS plants grown under optimal conditions, apparently because luxury N consumption resulted in excess reserves of photosynthetic apparatus components. Exposure of N-replete LIS and ATL plants to a superoptimal temperature (22° C) for 4 days caused an increase in the minimum turnover time of the photosynthetic apparatus (tau) and a decrease in Pmax, but had no consistent effect on Fv/Fm RCII density, PSU size (chlorophyll a/RCII), or enzyme activities. When plants were subjected to concurrent N limitation and heat stress, however, LIS and ATL populations exhibited quite different responses. All photosynthetic parameters of N-limited ATL plants declined sharply in response to high temperature, resulting in a negative rate of daily net C fixation. In contrast, LIS plants showed a reduction in PSU size, but maintained other parameters, including daily C fixation, at levels similar to those of N-limited plants at optimal temperature. Overall, the ability of LIS plants to accumulate and maintain high N reserves appears to be critical for heat tolerance and, therefore, for survival during summer periods of simultaneous low N supply and superoptimal temperature. ATL plants, which also experience low summer N supply but not superoptimal temperatures, do not accumulate large reserves of nitrogenous components and are unable to tolerate the combined stress. Because low N supply often co-occurs with high temperatures in temperate marine systems, large-scale declines in algal productivity, such as during El Nino events, are probably due to the interactive effect of N limitation and heat stress.
Reflections from the outside in: Inside-Out Prison Exchange Program acting graduation

A new beginning. The first time this course was offered. First time acting for all … for one last time. Excitement, anticipation, and anxiety as the outside meets inside one last time. First one, a...
Conquering sexually transmitted diseases

Sexually transmitted diseases (STDs) are a major public-health problem and also a significant financial burden on the economy. Past and ongoing attempts to create vaccines against sexually transmitted pathogens have met with varying success. This article highlights some of the public-health and social problems that are associated with STDs and the technical and ethical challenges in treating them, and raises several questions that need to be addressed if STDs are to be conquered.
Application of the new MMPI-2 Malingered Depression scale to individuals undergoing neuropsychological evaluation: relative lack of relationship to secondary gain and failure on validity indices.

The Malingered Depression (Md) scale for the MMPI-2 (Steffan, Clopton, & Morgan, 2003) was recently developed to detect attempts at malingering depressive symptomatology. The Steffan et al. cutoffs for the Md scale were derived through comparisons of undergraduate malingering simulators with depressed undergraduates. In order to explore the potential utility for neuropsychological practice, we examined the Md scale among 160 individuals with and without a context of secondary gain referred for neuropsychological evaluation. Md results were compared to other MMPI-2 validity indices and performance on effort testing. While Md was found to correlate highly with other validity indices from the MMPI-2, it was also correlated significantly with measures of depression, both in individuals with and without a secondary gain context. Md scores were not significantly different between secondary gain and no secondary gain groups, whereas FBS and L were significantly different. The effect of passing or failing validit...
The polar bear in the room: diseases of poverty in the Arctic

In the face of global warming, budgetary austerity and impoverished Arctic residents, the nations of the circumpolar region are presented with a number of difficult choices regarding the provision of health care to the far-flung and isolated regions of their northernmost provinces. Complicating that picture is the reality of neglected tropical diseases in areas far from their perceived normal equatorial range as well as endemic foodborne diseases, including protozoan and helminth parasites, respiratory and gastrointestinal diseases and vaccine-preventable illnesses. This paper discusses the problems of caring for the health and well-being of indigenous populations suffering from extreme poverty, isolation and discrimination in the circumpolar region. After presenting difficulties as supported by the extant literature, the paper continues by suggesting solutions that include novel telenursing applications, targeted distance-educational programs and local community-based health care assistant (HCA) vocational training. These programs will provide cost-effective care that increases lifespans, improves quality of life and provides opportunities to distressed populations in isolated rural communities of the Far North. The toolkit presented in the paper is intended to spur discussion on community health programs that could be adopted to provide proper and humane care for marginalized Arctic populations in an extreme and rapidly changing environment. Keywords: Arctic; poverty; circumpolar; disease (Published: 5 August 2013) This paper is part of Supplement 1, 2013, ICCH15 Proceedings . More papers from this Supplement can be found here . Citation: Int J Circumpolar Health 2013, 72 : 21161 - http://dx.doi.org/10.3402/ijch.v72i0.21161
Runaway Hazard Assessment of Cumene Hydroperoxide From the Cumene Oxidation Process

Cumene hydroperoxide (CHP) is normally produced by the cumene oxidation process. Severe fire and explosion incidents have occurred in oxidation and concentration processes due to the thermal instability of CHP. In this study, we used DSC and ARC thermal analysis techniques to measure the runaway thermokinetic data. Data such as adiabatic time to maximum rate (TMRad), adiabatic temperature rise (ΔTad), self-heating rate (dT/dt), thermal inertia (φ), etc., are used for runaway hazard evaluation. The thermal decomposition of CHP in cumene was found to be dependent on the CHP concentration which was characterized by the Accelerating Rate Calorimeter (ARC) test, isothermal and dynamic Differential Scanning Calorimeter (DSC) tests. The reaction order of 35 wt% CHP decomposition was determined to be 0.5. The Arrhenius parameters were measured to be Ea (kJ mol-1) = 120.6 ± 3.0 and lnA (min-1M1/2) = 30.2 ± 1.3. By using the thermokinetic data, plant vessel conditions, and the Semenov model, one can evaluate the criteria of critical vessel conditions, such as temperature of no return (TNR) and critical heat transfer parameter, (US/V)cr. Thermal hazards affected by CHP concentration were also discussed.
A continuum sensitivity method for finite thermo‐inelastic deformations with applications to the design of hot forming processes

A computational framework is presented to evaluate the shape as well as non-shape (parameter) sensitivity of finite thermo-inelastic deformations using the continuum sensitivity method (CSM). Weak sensitivity equations are developed for the large thermo-mechanical deformation of hyperelastic thermo-viscoplastic materials that are consistent with the kinematic, constitutive, contact and thermal analyses used in the solution of the direct deformation problem. The sensitivities are defined in a rigorous sense and the sensitivity analysis is performed in an infinite-dimensional continuum framework. The effects of perturbation in the preform, die surface, or other process parameters are carefully considered in the CSM development for the computation of the die temperature sensitivity fields. The direct deformation and sensitivity deformation problems are solved using the finite element method. The results of the continuum sensitivity analysis are validated extensively by a comparison with those obtained by finite difference approximations (i.e. using the solution of a deformation problem with perturbed design variables). The effectiveness of the method is demonstrated with a number of applications in the design optimization of metal forming processes. Copyright © 2002 John Wiley & Sons, Ltd.
Univentricular and biventricular thoratec VAD support as a bridge to transplantation

As of October 1991, the Thoratec ventricular assist device (VAD) system has been used in 154 transplant candidates who were in imminent risk of dying before donor heart procurement at 39 medical centers in 10 countries. The VAD system consists of a prosthetic ventricle with a 65-mL pumping chamber made from Thoratec's BPS-215M polyurethane, cannulas for atrial or ventricular inflow and arterial outflow connections, and a pneumatic drive console. The devices can be used for partial or complete support of the pulmonary, systemic, or both circulations. In all patients (average age, 42 years; range, 11 to 64 years), the pumps were placed in a paracorporeal position on the anterior abdominal wall and connected to the heart and great vessels by cannulas crossing the chest wall. Biventricular support was used in 120 patients (78%) and isolated left VADs were used in 34. Average flow rate was 5.0 +/- 0.9 L/min for the left VAD and 4.3 +/- 0.8 L/min for the right VAD. The most frequent complications were bleeding (42% incidence, 7% mortality) and infection (36% incidence, 8% mortality). Ninety-eight patients (65%) recovered sufficiently to undergo heart transplantation after 8 hours to 226 days of support (average, 17.5 days), and 3 are waiting on VADs for transplantation. Eighty-two patients who received transplants have been discharged. This is an 84% early post-transplantation survival and a 54% overall survival. The actuarial survival 1 year after transplantation is 82%, comparable with that of conventional heart transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)
Promoting healthy nutritional habits by paradigmatic behavior therapy

Abstract Paradigmatic behavior therapy was applied to alter the maladaptive nutritional habits of a 41-year-old depressed female. The client's activities, affect, and cognitions were self-monitored, along with daily intake of processed sugar and fruits and vegetables. The intervention program included contingency contracting and the production of pleasant affective states. The program promoted a favorable attitude toward fruits and vegetables and led to a significant increase in their consumption with significant decrements in sugar intake. The client became less tense and depressed. The favorable effects were maintained at a 5- month follow-up.
Cost accounting method for cytometry facilities.

THE setup and successful operation of a core facility requires specialized accounting practices that, to our knowledge, have not been described recently within the cytometry community. While yearly budgeted expenses such as employee’s salaries, supplies, and instrument service contracts are easily estimated, it is more difficult to calculate overhead costs and equitably amortize total yearly expenses through core facility charges. At the most basic level, a facility must maintain accurate cost information so that fees for services can be set at levels to recuperate known portions of operating expenses. The charges recovered by the facility should be calculated in a way that complies with applicable grant funding standards such as Federal cost principles (OMB Circular A-21 and A-122) for US federal funding or higher education institutions’ (HEI) transparent approaches to costing (TRAC) in the UK. However, more advanced methods also provide resource usage and resource availability data, which can provide a context in which cost data can be more fully understood (i.e., the manner in which a resource is used depends on an empirical understanding of its availability). Furthermore, the combination of cost and resource capacity data allow new opportunities for strategic planning so that a facility can grow and change over time. Recently, we evaluated an activity-based accounting method called time-driven activity-based costing (TD-ABC) (1,2). This method is an alternative to conventional activitybased accounting, and it is more simplified so that a typical non-accountant laboratory manager can collect data and calculate a useful model within just a few days. Moreover, TDABC provides accurate resource usage data so that strategic decisions can be made to maximize resource use. TD-ABC deviates from the conventional method in two significant ways. First, activities are measured by time intervals rather than proportions of work intervals. This greatly simplifies the data collection process since it is fundamentally easier to determine how much time is required to perform a particular activity than to survey employees on what fraction of their time is spent performing various activities. Second, the resources that support these activities are assigned practical capacity limits (hours). Therefore, as activities are performed, used and unused capacity hours of resources can be assessed. The primary goals of implementing a TD-ABC analysis in our facility were to: Devise a method that estimates the true cost of flow cytometry experiments regardless of the instrument or combination of facility resources used Determine where significant discrepancies in cost recovery occur Model new fee schedules with the goal of more accurately reflecting resource usage in fees while maintaining the ability to motivate users to make efficient use of facility resources (e.g., unassisted usage during off-peak hours)
The effect of chronic propranolol treatment on salivary composition and caries in the rat.

Abstract Many drugs are known to affect salivary secretion. The purpose of this study was to explore the chronic effects of a commonly used β-adrenergic blocker, propranolol. Adult rats were desalivated or treated for 28 days with propranolol HCl (10 or 20 mg/kg, daily) or sterile buffer (sham-operated control) using osmotic pumps for delivery. The parotid and submandibular glands of each rat were cannulated and secretion elicited by pilocarpine (10 mg/kg, intravenous). There were no statistical differences in salivary protein content (Lowry) or output among the groups (ANOVA p > 0.05). Analysis of salivary proteins by SDS-PAGE revealed a constant profile for submandibular secretions, but peak A and SP-3 proline-rich proteins were not detectable in parotid saliva of animals treated with propranolol for the entire experiment. Significantly increased smooth-surface (p = 0.0003) and sulcal (p = 0.0011) caries scores were found within these propranolol groups (ANOVA). The findings provide further evidence that chronic administration of propranolol alters salivary composition by decreasing proline-rich proteins and concurrently enhances susceptibility to caries.
Ligand-independent dimerization activates the stress response kinases IRE1 and PERK in the lumen of the endoplasmic reticulum.

IRE1 and PERK are type I transmembrane serine/threonine protein kinases that are activated by unfolded proteins in the endoplasmic reticulum (ER) to signal adaptive responses. IRE1 is present in all eukaryotic cells and signals the unfolded protein response through its kinase and endoribonuclease activities. PERK signals phosphorylation of a translation initiation factor to inhibit protein synthesis in higher eukaryotic cells but is absent in the Saccharomyces cerevisiae genome. The amino acid sequences of the amino-terminal ER luminal domains (NLDs) from IRE1 and PERK display limited homology and have diverged among species. In this study, we have demonstrated that the NLD of yeast Ire1p is required for signaling. However, the NLDs from human IRE1α and murine IRE1β and the Caenorhabditis elegans IRE1 and PERK function as replacements for the S. cerevisiae Ire1p-NLD to signal the unfolded protein response. Replacement of the Ire1p-NLD with a functional leucine zipper dimerization motif yielded a constitutively active kinase that surprisingly was further activated by ER stress. These results demonstrate that ER stress-induced dimerization of the NLD is sufficient for IRE1 and PERK activation and is conserved through evolution. We propose that ligand-independent activation of IRE1 and PERK permits homodimerization upon accumulation of unfolded proteins in the lumen of the ER.
24,25-(OH)2D3 Regulation of Matrix Vesicle Protein Kinase C Occurs Both During Biosynthesis and in the Extracellular Matrix

Plasma membranes and matrix vesicles isolated from rat costochondral resting zone chondrocyte cultures contain predominantly protein kinase C alpha (PKCα) and PKCζ, respectively, and the level of PKC specific activity in these membrane fractions is regulated by 24,25-(OH)2D3 [14]. In the present study, we examined whether the effect of 24,25-(OH)2D3 on membrane PKC is via genomic mechanisms during biogenesis and through a nongenomic mechanism after the matrix vesicles are resident in the matrix. There was a dose-dependent decrease in matrix vesicle PKC specific activity and a significant increase in plasma membrane enzyme activity in cultures treated for 90 minutes with 10−9–10−7 M 24,25-(OH)2D3. However, at 12 hours, matrix vesicle PKC was stimulated, but no effect was seen in the plasma membranes, suggesting that the effect seen at 90 minutes was due to a direct action of the hormone on PKC activity in the membrane, and that the effect seen at 12 hours was due to new matrix vesicle production with altered PKC content. Neither actinomycin D nor cycloheximide inhibited matrix vesicle PKC at 30, 60, or 90 minutes, but by 12 hours, these inhibitors blocked the effect of the hormone. 24,25-(OH)2D3-dependent plasma membrane PKC was sensitive to both actinomycin D and cycloheximide at early time points, but by 12 hours, no effect of the inhibitors was seen. Monensin did not alter basal plasma membrane PKC activity or the 24,25-(OH)2D3-dependent increase, suggesting that this increase was due to translocation of cytosolic PKC rather than new membrane synthesis. Monensin did not affect matrix vesicle PKC at early time points, but it decreased 24,25-(OH)2D3-dependent enzyme activity at later times, indicating that new matrix vesicle production was blocked.
How and why scholars cite on Twitter

Scholars are increasingly using the microblogging service Twitter as a communication platform. Since citing is a central practice of scholarly communication, we investigated whether and how scholars cite on Twitter. We conducted interviews and harvested 46,515 tweets from a sample of 28 scholars and found that they do cite on Twitter, though often indirectly. Twitter citations are part of a fast-moving conversation that participants believe reflects scholarly impact. Twitter citation metrics could augment traditional citation analysis, supporting a "scientometrics 2.0."
Functional Outcomes and Complications in Patients With Bladder Cancer Undergoing Robotic-assisted Radical Cystectomy With Extracorporeal Indiana Pouch Continent Cutaneous Urinary Diversion

Objective To evaluate the functional outcomes and complications for patients with bladder cancer undergoing robotic-assisted laparoscopic radical cystectomy with Indiana pouch continent cutaneous urinary diversion. Methods From February 2004 to March 2010, 34 patients underwent robotic-assisted laparoscopic radical cystectomy with Indiana pouch continent cutaneous urinary diversion reconstruction. After surgery, the complications were identified, categorized, and graded using an established 5-grade modification of the original Clavien grading system, and continence was assessed. Descriptive statistics were used in evaluating the outcomes. Fischer's exact test was used in the comparison of early and late Clavien grade III complications. Results Overall, 175 (123 early and 52 late) complications after surgery were reported in 32 (94%) of 34 patients. Within 90 days of surgery, 31 (91%) of 34 patients experienced ≥1 early complication. Of 34 patients, 15 (44%) reported ≥1 late complications (>90 days). Most (85% and 69%, respectively) early and late complications were graded as minor (grade II or less). Fewer patients with early complications required an additional intervention (grade III) compared with patients with late complications (14% vs 31%; P = .116). The most common complication in both intervals was infection, reported in 22% and 37% of patients with early and late complications, respectively. The continence data for 31 patients at a mean follow-up of 20.1 months (median 12.0) showed that all but 1 patient (97%) had daytime and nighttime continence. Conclusion Patients undergoing robotic-assisted laparoscopic radical cystectomy with Indiana pouch continent cutaneous urinary diversion reconstruction have comparable complication rates and functional outcomes compared with patients in the open series.
Effects of Pulsed Electric Fields and Heat Treatment on Stability and Secondary Structure of Bovine Immunoglobulin G

Bovine immunoglobulin G (IgG) solutions were subjected to pulsed electric fields (PEF) or heat treatment to investigate the effect of processing on secondary structure monitored using circular dichroism spectrometry. Under heat treatment, the critical temperature for bovine IgG to change secondary structure at neutral pH in borate buffer is 72 °C. A conversion of the secondary structure from β-sheets into random coils along with the loss of immunoactivity of bovine IgG was observed when heated at 82 °C for 120 s. In contrast, PEF treatment at 41.1 kV/cm for 54 μs with bipolar pulses (outlet at 43.8 °C) caused no detectable changes in the secondary structure or the thermal stability of secondary structure. A shape factor, , ratio of magnitude of the positive CD band at 200 nm to that of the negative CD band at 217 nm, was closely correlated to the immunoactivity of bovine IgG (r2 = 0.99) and quantifies changes of secondary structure. Keywords: Bovine IgG, PEF, heat treatment, secondary structure, immunolog...
Plant ubiquitin ligases as signaling hubs.

The past decade has witnessed an explosion in the identification of ubiquitin-ligase complexes as the missing receptors for important small-molecule hormones regulating plant growth and development. These breakthroughs were initiated by genetic approaches, with structural analysis providing mechanistic insights into how hormone perception and signaling are coupled to protein ubiquitination. Although there are still many unknowns, plants have imparted valuable lessons about the pharmacology of ubiquitin modification.
Sensory nerve deformation in the stimulated frog muscle spindle.

Quantitative knowledge was sought for stretch-induced deformation of the nerve endings in frog muscle spindles. The fourth toe extensor muscles were stretched by means of joint positioning, preserved in situ, and processed for transmission electron microscopy. Spindles were serially sectioned and montage photographed. All accessible dimensions of the nerve bulbs and their links were measured in relaxed and maximally stretched spindles. Bulb endings contacting the muscle were analyzed separately from those without such contacts. Both compact and reticular zones of the muscle fiber were taken into account. Measurable shape differences in the nerve bulbs occurred with stretch. Contacting bulbs elongated in the compact zone and decreased in width in both zones. The noncontacting bulbs also elongated in the compact zone but no other shape change could be ascertained. Bulb volumes tended to increase with stretch but significance could only be established for contacting compact zone bulbs. Links between bulbs became thinner with stretch. It was concluded that differential deformational forces exist in the frog spindle system with stretch. Not only are nerve endings deformed differently according to whether or not they contact the muscle fiber, but also according to whether they are localized in compact or reticular sensory zones. The data support the notion that the structural specialization of the intrafusal muscle and the extracellular material influence this sensory transduction process. The shape and volume changes appear to be compatible with those anticipated to accompany excitatory nervous activity in the nerve endings with stretch.
San Pedro Bay Ports Rail Enhancement Program: 2010 Update

The San Pedro Bay Ports of Long Beach and Los Angeles continue to provide vital rail connections to the rest of the country. The Rail Enhancement Program sets forth the rail improvements necessary to maintain performance as cargo volumes grow through the year 2035. Implementation of the Rail Enhancement Program has faced hurdles including environmental permitting, funding and competing stakeholder concerns. Cargo growth eased in the years approaching 2010, but the timing of proposed improvements to the rail infrastructure remains critical and challenging. The Rail Enhancement Program is the result of work over the past ten years. Conditions affecting the program have continued to change since the original Rail Master Planning Study of 2000. Updates to the Master Plan have been performed in 2005 and 2010. These documents provide analyses and recommendations for rail improvements to maintain adequate rail service on the Alameda Corridor and through the Port to its rail yards. In developing the Rail Enhancement Program, simulation is used to understand the impacts of increasing cargo volumes on the rail system and to investigate infrastructure and operating improvements required to address deficiencies and to determine improvements to efficiently handle projected traffic. This paper describes the development process with a summary of the analysis methods, resulting proposed rail projects, implementation process and current status of implementation. The steps of the rail system development process include the following: (1) Evaluation of existing and proposed rail operations; (2) Conceptual design of over forty potential rail improvement projects; (3) Analysis of the capacity of existing and proposed facilities; (4) Scheduling of project development to meet demand; (5) Estimation of environmental, community and regional impacts and benefits; (6) Determination of schedule including environmental permit requirements; (7) Development of project funding plans; and (8) Preparation of engineering designs and construction documents. The paper will conclude with a summary of the status of key projects from the Rail Enhancement Program. Implementation of the Rail Enhancement Program has included permitting, funding and design efforts on individual projects. The projects currently under development total $1B out of the overall $2B program. The Rail Enhancement Program provides significant benefits to operating efficiencies, environmental impacts and economic impacts. Implementation has been a challenging effort and illustrates the myriad obstacles facing public infrastructure development.
Shedding light on proteins, nucleic acids, cells, humans and fish

I was trained as a physicist in graduate school. Hence, when I decided to go into the field of biophysics, it was natural that I concentrated on the effects of light on relatively simple biological systems, such as proteins. The wavelengths absorbed by the amino acid subunits of proteins are in the ultraviolet (UV). The wavelengths that affect the biological activities, the action spectra, also are in the UV, but are not necessarily parallel to the absorption spectra. Understanding these differences led me to investigate the action spectra for affecting nucleic acids, and the effects of UV on viruses and cells. The latter studies led me to the discovery of the important molecular nature of the damages affecting DNA (cyclobutane pyrimidine dimers) and to the discovery of nucleotide excision repair. Individuals with the genetic disease xeroderma pigmentosum (XP) are extraordinarily sensitive to sunlight-induced skin cancer. The finding, by James Cleaver, that their skin cells were defective in DNA repair strongly suggested that DNA damage was a key step in carcinogenesis. Such information was important for estimating the wavelengths in sunlight responsible for human skin cancer and for predicting the effects of ozone depletion on the incidence of non-melanoma skin cancer. It took experiments with backcross hybrid fish to call attention to the probable role of the longer UV wavelengths not absorbed by DNA in the induction of melanoma. These reflections trace the biophysicist's path from molecules to melanoma.
The effect of the venom of the honey bee, Apis mellifera L., on the adrenocortical response of the adult male rat☆

Abstract Adult male Sprague-Dawley rats were injected with pure honey bee venom and the serum corticosterone levels determined fluorometrically 1, 4, 8, and 24 hr after a single venom injection. Other rats received venom injections twice a week for a period of eight weeks during which serum corticosterone levels were determined as well as after a 4-week recovery period. In the acute study significant elevations in serum corticosterone levels occurred for periods up to 8 hr in those animals receiving the highest venom dose. The other experimental groups exhibited significantly elevated levels for periods up to 1 hr. The corticosterone levels of the injected groups were not significantly different from that of the controls 24 hr following injection. Large amounts of honey bee venom injected chronically were required to produce increases in adrenal gland corticosterone production. In vivo findings were confirmed by incubating the adrenal glands of the experimental animals in Krebs-Ringer bicarbonate buffer and fluorometrically determining the in vitro corticosterone production. Possible mechanisms of action of the venom are discussed.
The Social Contagion Effect of Marijuana Use among Adolescents

Background Research on adolescent substance use has consistently identified a strong relationship between adolescent behavior and the behavior of their peers. However, peer effects are difficult to estimate and causal interpretations must be undertaken with caution since individuals in most cases choose with whom to associate. In this paper we seek to empirically quantify the causal role of peer social networks in explaining marijuana usage among adolescents. Methods and Findings Using data from a nationally representative sample of adolescents we utilize a multivariate structural model with school-level fixed effects to account for the problems of contextual effects, correlated effects and peer selections to purge the potential biases from the estimates of peer influence. Our peer group measures are drawn not only from the nomination of close friends (N = 6,377), but also from classmates (N = 19,335). Marijuana usage among the peer groups were constructed using the peers' own report of their marijuana consumption. Controlling for parent level characteristics, and other demographic parameters, we find that a 10% increase in the proportion of close friends and classmates who use marijuana increases the probability that an individual chooses to use marijuana by 5%. Conclusion Our findings indicate that peer effects are important determinants of marijuana use even after controlling for potential biases We also found evidence to show that the influence of close friends and the more exogenous classmates are quite similar in magnitude under our preferred specification, supporting theory predicting the importance of peer influence. Effective policy aimed at reducing marijuana usage among adolescents would consider these significant peer effects.
Watching fat digestion

During fat digestion a number of physicochemical events can be seen directly by light microscopy. Under simulated physiological conditions, hydrolysis of emulsified fat droplets by human pancreatic lipase in the presence of colipase and bile salt micelles proceeds with the sequential formation of two visible product phases. A lamellar liquid crystalline or crystalline phase containing calcium and ionized fatty acid forms first; this is followed by the production of a "viscous isotropic" phase composed predominantly of monoglycerides and protonated fatty acids.