cssi/SciSciGPT-SciSciNet huggingface dataset:
Single Amino Acid Substitutions in Procollagen VII Affect Early Stages of Assembly of Anchoring Fibrils

Procollagen VII is a homotrimer of 350-kDa pro-alpha1(VII) chains, each consisting of a central collagenous domain flanked by the noncollagenous N-terminal NC1 domain and the C-terminal NC2 domain. After secretion from cells, procollagen VII molecules form anti-parallel dimers with a C-terminal 60-nm overlap. Characteristic alignment of procollagen VII monomers forming a dimer depends on site-specific binding between the NC2 domain and the triple-helical region adjacent to Cys-2634 of the interacting procollagen VII molecules. Formation of the intermolecular disulfide bonds between Cys-2634 and either Cys-2802 or Cys-2804 is promoted by the cleavage of the NC2 domain by procollagen C-proteinase. By employing recombinant procollagen VII variants harboring G2575R, R2622Q, or G2623C substitutions previously disclosed in patients with dystrophic epidermolysis bullosa, we studied how these amino acid substitutions affect intermolecular interactions. Binding assays utilizing an optical biosensor demonstrated that the G2575R substitution increased affinity between mutant molecules. In contrast, homotypic binding between the R2622Q or G2623C molecules was not detected. In addition, kinetics of heterotypic binding of all analyzed mutants to wild type collagen VII were different from those for binding between wild type molecules. Moreover, solid-state binding assays demonstrated that R2622Q and G2623C substitutions prevent formation of stable assemblies of procollagen C-proteinase-processed mutants. These results indicate that single amino acid substitutions in procollagen VII alter its self-assembly and provide a basis for understanding the pathomechanisms leading from mutations in the COL7A1 gene to fragility of the dermal-epidermal junction seen in patients with dystrophic forms of epidermolysis bullosa.
Rituximab therapy for refractory biliary strictures in immunoglobulin G4-associated cholangitis.

Background & Aims: Biliary strictures occur in a third of patients with autoimmune pancreatitis and have been termed immunoglobulin G subclass 4 (IgG4) associated cholangitis (IAC). IAC often responds to steroid therapy. Methods: A patient with autoimmune pancreatitis and (IAC) refractory to steroids and 6-mercaptopurine was treated with rituximab, a monoclonal antibody directed against the CD20 antigen on B lymphocytes. Results: The patient's biliary strictures improved after rituximab therapy, permitting removal of his biliary stents. Systemic manifestations of IgG4-associated disease also improved. Conclusions: Rituximab may be a treatment option for patients with refractory or recurrent autoimmune pancreatitis or IAC.
On the design of optimal input signals in system identification

The problem of designing optimal inputs in the identification of multi-input multi-output linear systems with unknown time varying parameters is considered using a Bayesian approach. A sensitivity index gives a measure of performance for the closed-loop system inputs. The computation of the optimal closed-loop mappings is shown to be a nontrivial exercise in stochastic control with no analytic solution, but optimal open-loop and affine laws yield much more tractable problems. For time invariant systems, the sensitivity index considered is shown to be equivalent to the trace of the (strictly positive definite) Information Matrix associated with the system. Numerical examples are given. A Kalman filter is used to estimate the parameters. A necessary condition for the Kalman filter not to diverge when applying linear feedback, is also given.
Information Consistency and Perceptual Set: Overcoming the Mental Retardation “Schema”1

Two factors that were thought to promote or inhibit schema-based or stereotypic responding in impression formation were examined in two experiments. Subjects were asked to provide evaluations of artwork supposedly painted by either mentally retarded or nonretarded children. Based on previous research, it was assumed that subjects would expect relatively poor quality artwork from retarded children, which would he consistent with a negative schema that they maintain for this group. It was also predicted that this negative schema would result in cursory examinations and unfavorable evaluations of the retarded artists' artwork, but only when the evaluative conditions were conducive to schematic responding. Specifically, the schema effect was predicted to occur when the artwork was of poor quality and subjects were instructed to provide an overall evaluation of the painting rather than an assessment of its specific characteristics. No derogation was expected when these factors were not present. Results supported these hypotheses. Additional analyses indicated that subjects were conducting a cursory search of the target stimuli when conditions favored schema-based responding.
A net inflow method for incompressible viscous flow with moving free surface

A new finite element procedure called the net inflow method has been developed to simulate time-dependent incompressible viscous flow including moving free surfaces and inertial effects. As a fixed mesh approach with triangular element, the net inflow method can be used to analyse the free surface flow in both regular and irregular domains. Most of the empty elements are excluded from the computational domain, which is adjusted successively to cover the entire region occupied by the liquid. The volume of liquid in a control volume is updated by integrating the net inflow of liquid during each iteration. No additional kinetic equation or material marker needs to be considered. The pressure on the free surface and in the liquid region can be solved explicitly with the continuity equation or implicitly by using the penalty function method. The radial planar free surface flow near a 2D point source and the dam-breaking problem on either a dry bed or a still liquid have been analysed and presented in this paper. The predictions agree very well with available analytical solutions, experimental measurements and/or other numerical results.
Three dimensional graphene foam supported platinum-ruthenium bimetallic nanocatalysts for direct methanol and direct ethanol fuel cell applications

Abstract A novel composite material of hierarchically structured platinum–ruthenium (PtRu) nanoparticles grown on large surface area three dimensional graphene foam (3D GF) is reported. 3D GF was incorporated with PtRu bimetallic nanoparticles as an electrochemical nanocatalyst for methanol and ethanol oxidation. PtRu/3D GF nanocatalyst showed a higher tolerance to poisoning by CO and exhibited improved catalytic activity for both methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). Cyclic voltammetry (CV) results and long-term cycling stability tests demonstrated that GF provided a promising platform for the development of electrochemical nanocatalysts. Specifically, PtRu/3D GF nanocatalyst showed excellent catalytic activity toward MOR and EOR compared with PtRu/Graphene (Commercial graphene), PtRu/C (Vulcan XC-72R carbon), and PtRu alone. The crystal size of PtRu on 3D GF was reduced to 3.5 nm and its active surface area was enhanced to 186.2 m 2 g −1 . Consequently, the MOR and EOR rates were nearly doubled on PtRu/3D GF compared to those on PtRu/Graphene.
Oxidative phosphorylation by suspensions of mitochondria following freezing and drying by sublimation in vacuo

The cryotolerances of suspensions of mitochondria prepared in solutions of sucrose, glucose, dextran, polyvinylpyrrolidone or dimethylsulphoxide, alone or in combination, and frozen slowly at —76° were determined. The levels of oxidative phosphorylation by suspensions prepared and frozen as the above, dried by sublimation in vacuo at bath temperatures of 0°, and rehydrated with water, physiologic saline, different tonicities of sucrose, dextran in physiologic saline, polyvinylpyrrolidone in glucose (fresh, autoclaved or aged) or sucrose, and dimethylsulphoxide in sucrose were measured. Three steps appear to be necessary for the successful freezing and freeze-drying of suspensions of mitochondria: (a) the addition of protective substances (b) the use of hypertonic sucrose in the final suspension, both to wash away excessive amounts of protective compounds and to produce a preliminary dehydration (c) rehydration with solutions of compounds of high molecular weight. Under these conditions the highest balanced rate of oxidative phosphorylation was by suspensions of mitochondria prepared initially in 10% dimethylsulphoxide in 0.25 M sucrose, suspended finally in 0.50 M sucrose, frozen slowly at —76°, dried by sublimation in vacuo at a bath temperature of 0°, and rehydrated with 5% dextran in physiologic saline.
Pentamethylcyclopentadienyl rhodium complexes

We report syntheses and structures of pentamethylcyclopentadienyl (Cp∗) rhodium(III) and rhodium(I) complexes. Dicationic rhodium(III) complexes, [Cp∗Rh(bpy)(MeCN)](PF_6)_2 and [Cp∗Rh(vbpy)(MeCN)](PF_6)_2 (bpy = 2,2′-bipyridyl and vbpy = 4-vinyl-2,2′-bipyridyl), were prepared by treatment of [Cp∗Rh(MeCN)_3](PF_6)_2 with bpy and vbpy, respectively. The monocationic rhodium(III) complex, [Cp∗Rh(Me_4phen)Cl]Cl (Me_4phen = 3,4,7,8-tetramethyl-1,10-phenanthroline), was prepared by treatment of the chloride-bridged rhodium dimer, [Cp∗RhCl_2]_2, with Me_4phen. Two rhodium(I) complexes were synthesized via reduction of their rhodium(III) counterparts using two different methods: Cp∗Rh(bpy) was produced via a new route involving treatment of [Cp∗Rh(bpy)Cl]Cl with thallium formate in dry acetonitrile, whereas [Cp∗Rh(Me_4phen)Cl]Cl was reduced with Na(Hg) to give Cp∗Rh(Me_4phen). The colors of the Rh(I) complexes are attributable to relatively intense visible-region MLCT absorptions.
Catecholamine synthesizing enzymes in the hypothalamus during the estrous cycle

Abstract The activities of tyrosine hydroxylase and dopamine-β-hydroxylase were measured in the medial basal hypothalamus and remaining hypothalamic tissue of female rats at various times during diestru 2, proestrus and estrus. Tyrosine hydroxylase activity in the medial basal hypothalamus was significantly lower at 12.00 h compared with other times on proestrus. This decrease preceded the elevation of serum prolactin and LH during the afternoon of proestrus. Tyrosine hydroxylase activity did not change significantly during diestrus 2 or estrus nor was it altered at any time in the remainder of the hypothalamus. Dopamine-β-hydroxylase activity in the basal medial hypothalamus was significantly elevated at 12.00 h on proestrus and at 14.00 h on diestrus. The results provide further evidence for a decrease in dopaminergic neuron activity in the medial basal hypothalamus which may precipitate the series of events leading to the LH surge during proestrus. The increase in dopamine-β-hydroxylase activity suggests that an increase in noradrenergic neuron activity may also be involved in triggering the release of LH.
Crown retreat of open-grown Southern live oaks (Quercus virginiana) due to canopy encroachment in Florida, USA

Broad-crowned, open-grown southern live oaks (Quercus virginiana) standing in open, park-like landscapes figure prominently in the history of the southeastern USA where they represent important natural, cultural, and literary icons. Similar to other savannas in North America, Europe, and Australia that are maintained by frequent, low-intensity fires and grazing pressure, live oaks and the open landscapes they dominate have been extensively replaced by forests during the past century. To explore the process of savanna loss, we studied the response of open-grown live oak crowns to increasing crown encroachment by other tree species as stand density increased after fires were suppressed and cattle grazing ceased in north-central Florida. To document the rate and to describe the process of crown encroachment and resulting die-back, we mapped and measured open-grown live oak crowns in two formerly open stands with different degrees of canopy encroachment and three stands that remained open and savanna-like. To understand why open-grown live oaks are threatened by forest succession, we compared crown densities, light compensation points, and maximum photosynthetic rates of open-grown live oaks and the principal encroaching tree species but found no significant differences. Instead, the crowns of mature open-grown live oaks apparently retreat in response to canopy encroachment because they do not grow substantially in height in response to crowding from taller-growing neighbors. If open-grown live oaks are to be maintained in the landscapes of the South, active management interventions that mimic historical disturbance regimes are needed.
Fast computation of the temperature distribution in VLSI chips using the discrete cosine transform and table look-up

Temperature-related effects are critical in determining both the performance and reliability of VLSI circuits. Accurate and efficient estimation of the temperature distribution corresponding to a specific circuit layout is indispensable in physical design automation tools. In this paper, we propose a highly accurate fast algorithm for computing the on-chip temperature distribution due to power sources located on the top surface of the chip. The method is a combination of several computational techniques including the Green function method, the discrete cosine transform (DCT), and the table look-up technique. The high accuracy of the algorithm comes from the fully analytical nature of the Green function method, and the high efficiency is due to the application of the fast Fourier transform (FFT) technique to compute the DCT and later obtaining the temperature field for any power source distribution using the pre-calculated look-up table. Experimental results have demonstrated that our method has a relative error of below 1% compared with commercial computational fluid dynamic (CFD) softwares for thermal analysis, while the efficiency of our method is orders of magnitude higher than the direct application of the Green function method.
Line Scanner for Biometric Applications

Fingerprints are the most common biometric measure taken, and in recent years electronic fingerprint scanning has become commonplace. Although contactless fingerprinting methods are used, it is more common that the fingerprint is taken by pressing the finger against a computer scanner. In the current study, the advantages of the contactless technique are combined with the very promising attributes of line scanning. Line scanner views each portion of the finger perpendicularly, therefore removing the projection errors of conventional flat scanning. The three dimensional image of a finger is recorded in pixel-thick lines by scanning the camera around the finger. The final image captures an uncoiled view of the finger. Emerging technology for biometric identification is based on storing the blood vessel map in the finger. We developed a system where line scanning of finger ridges in conventional light is taken as the camera goes clockwise around a finger and in the Infrared light the image of blood vessels is recorded as the camera goes back to its initial position. Line scanning also opens a new possibility in face recognition where the comparison of major anthropometric lines would help to immunize the recognition system against benign cosmetics as well as intentional efforts to defeat such systems through the use of make-up or plastic surgery.
Leaky ryanodine receptors cause delayed afterdepolarizations and ventricular arrhythmias.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease characterized by the absence of structural heart disease, syncope, and sudden cardiac death.1 Typically, acceleration of the heart rate during physical exercise or emotional distress provokes an increasing number of ventricular premature complexes followed by runs of bidirectional or polymorphic ventricular tachycardia (VT). During clinical testing, about 30–50% of the patients will reproducibly develop VT following exercise testing or catecholamine injection.1,2 The ECG morphology of ventricular tachyarrhythmias observed in patients with CPVT resembles that of VTs commonly described in digitalis toxicity (which is associated with cellular calcium overload), and in metabolic disturbances as seen in severe HF (which is associated with high adrenergic tone).3 In conditions of cytoplasmic Ca2+ overload or enhanced β-adrenergic signalling, cardiac myocytes exhibit greater ectopic activity. It has therefore been suggested that arrhythmias in CPVT are mediated by triggered activity and delayed afterdepolarizations (DADs), which are defined as oscillations in the membrane potential of the cardiac myocyte after repolarization of an action potential has been completed.1 The most common, autosomal-dominant form of CPVT is caused by genetic mutations in the gene encoding the cardiac ryanodine receptor ( RyR2 ), the principal intracellular Ca2+ release channel involved in excitation-contraction coupling.4 Although experimental studies have provided evidence that mutant RyR2 channels can give rise to DADs in isolated cardiomyocytes,5 the study by Paavola et al .6 demonstrates DADs in monophasic action potential (MAP) recordings for the first time in CPVT patients with RyR2 mutations. In contrast to conventional electrode catheter recordings, MAP recordings provide precise information not only about the local activation time, but also about the entire repolarization time course. Electrophysiological data for the occurrence of DADs in patients with CPVT have been scarce in the literature, with … *Corresponding author. Tel: +1 713 798 4261; fax: +1 713 798 3475. E-mail address : wehrens{at}bcm.edu
Progression-related expression of β3 integrin in melanomas and nevi

The expression of the beta3 integrin subunit was investigated in 130 fixed, paraffin-embedded specimens of human melanomas and nevi using two different monoclonal antibodies. Expression was not observed in melanocytes and was absent or low in most nevi. In primary melanomas, expression was absent or low in the nontumorigenic radial growth phase, which includes the classes of in situ and microinvasive melanomas. In contrast, expression was high in the tumorigenic or vertical growth phase compartment of many primary melanomas and in most metastatic melanomas. Expression patterns were similar with the two antibodies, SSA6 and SAP, and was membrane-related as well as cytoplasmically expressed. In those nevi that reacted focally, the reactivity tended to occur in the dermal component of neurotized nevi, and in Spitz nevi, where the reactivity was stronger and more diffuse. A few dysplastic nevi showed focal reactivity of the junctional component. These results are consistent with tumor progression-related expression of the beta3 integrin, which is expressed in melanocytic tumors as the alphavbeta3 integrin, having affinity for matrix molecules, including vitronectin and fibronectin. In all melanomas, and in the subset of tumorigenic vertical growth phase melanomas, expression increased with thickness (P < .01). For this reason, and because ligation of this integrin has been shown in vitro to have several properties that may be related to the malignant phenotype, it is likely that expression of this marker may have prognostic value. However, because of its consistent and strong expression in Spitz nevi, the diagnostic utility of this marker will likely be limited.
Crane scheduling in batch annealing process

In this paper, we study the crane scheduling problem of batch annealing process to minimize the last job completion (makespan). Some special characteristics of our crane scheduling are contrasted with that of existing two categories. We prove it to be strongly NP-hard and develop a resource assignment problem based heuristic algorithm in a bottleneck level. The heuristics is analysed from an absolute worst-case performance ratio of 3 and an asymptotic worst-case performance ratio is 2 respectively.
Adrenocortical response to mating, social interaction and restraint in the female Japanese quail

In some species, the act of mating may be the only occasion when a female judges the male and the course of the sexual encounter might influence forms of maternal investment that are mediated by hormonal pathways. Despite the growing interest in fitness consequences of acute adrenocortical responses, it has not been determined to what extent the act of mating provokes such responses in females. We used female Japanese quail (Coturnix japonica) to determine to what extent any increase in corticosterone (CORT) is specific to actually mating with a male compared to visual and auditory contact with a male, and compared to social interaction with a female. We also asked if greater mating experience decreases the CORT response. We assessed how body condition of the individuals and their behavior during testing contributed to the variation in CORT response. As an additional reference for CORT increase we used a restraint procedure which resulted in the highest CORT. Our results show that females mating with a male have plasma CORT concentrations significantly increased from the baseline, which is not the case in females interacting with a male without the possibility of mating. Greater previous mating experience does not affect the CORT change caused by sexual interaction. Interestingly, social interaction with a female elicited a similar CORT response as mating with a male, which suggests that the effect on CORT was due to direct social interactions per se and not specific to the act of mating. Behavior during social and sexual interactions did not predict the CORT response, but larger females exhibited lower baseline and response CORT concentrations. We suggest that the lesser adrenocortical response of larger females might be related to their better control of the course of mating and might help them to adjust their reproductive investment, as reported in earlier studies.
Variation in leaf stomatal traits of 28 tree species in relation to gas exchange along an edaphic gradient in a Bornean rain forest

 Premise of the study : Quantifying variation in functional traits associated with shifts in the species composition of plant communities along resource gradients helps identify environmental attributes important for community assembly. Stomates regulate the balance between carbon assimilation and water status in plants. If environmental attributes affecting photosynthetic water-use effi ciency govern species distribution along an edaphic gradient, then adaptive variation in stomatal traits of plant species specializing on different soils should refl ect belowground resource availability.  Methods : We tested this hypothesis by quantifying stomatal trait variation in understory saplings of 28 Bornean tree species in relation to gas exchange and water-use effi ciency (WUE).  Key results : Comparisons between congeneric specialists of the more fertile, moister clay and the less fertile, well-drained sandy loam revealed little evidence of similar shifts in stomatal traits across genera, nor was stomatal pore index correlated with g max , A max , or WUE ( A max / g max or Δ 13 C), suggesting that stomates may be overbuilt in these shaded juveniles. A max was higher on sandy loam, likely due to higher understory irradiance there, but there were no other signifi cant differences in gas exchange or WUE.  Conclusions : Despite substantial diversity in stomatal anatomy, there were few strong relationships between stomatal, photosynthetic, and WUE traits in relation to soil resources. Routine differences in water availability therefore may not exert a dominant control on the distributions of these Bornean tree species. Furthermore, the clades represented by these 12 genera may possess alternative functional designs enabling photosynthetic WUE that is suffi cient to these humid, understory environments, due to whole plant-functional integration of stomatal traits with other, unmeasured traits infl uencing gas exchange.
Postcricoid vascular lesions: histopathological and immunohistochemical diagnosis.

Objectives/Hypothesis: Postcricoid vascular lesions are a rare cause of dysphagia and stridor in the pediatric population. Currently, there is no clear consensus on what type of vascular lesions are common in the postcricoid area because adequate histological or immunohistochemistry studies are lacking. This study aimed to describe the histology and immunohistochemistry of postcricoid masses in our institutions' experience, and consolidate available data on the symptoms, management, and histology of these unusual malformations with a comprehensive literature review. Study Design: Retrospective patient and literature review. Methods: A retrospective review of patients with postcricoid vascular lesions was performed at two pediatric tertiary care institutions. Histology and immunohistochemistry studies were performed in patients undergoing a lesion biopsy. A complete literature review of the English language was completed for cases involving vascular lesions of the postcricoid area. Results: Four patients were identified in our study with postcricoid vascular lesions. All patients presented with symptoms of dysphagia and intermittent stridor. Histology and immunohistochemistry studies were performed in three patients. GLUT-1 was negative in all three patients, and CD34 was positive in all patients tested. Lewis Y antigen was performed in one patient and was negative. A description of 19 cases reported in the English literature is included. Conclusions: Patients with postcricoid vascular lesions usually present with mild to moderate feeding difficulties, and stridor or dyspnea with agitation. Histopathology and immunohistochemistry results suggest that postcricoid vascular lesions may often represent congenital vascular malformations instead of infantile hemangiomas.
Theory of fractionally spaced cyclic-prefix equalizers

The cyclic prefix system is widely used for frequency domain equalization in discrete multitone channels. In this paper we show how the idea of fractionally spaced equalization (FSE) can be adapted to cyclic prefix systems. We derive the condition for a perfect FSE, and show that there is a certain freedom in the choice of the equalizer coefficients. This freedom is then exploited to minimize the effect of additive noise at the detector input. The theory is generally applicable to any deconvolution problem, though the setting used for our development uses the language of digital communication.
Instrumenting the dynamic web

One of the most critical driving forces in the evolution of interfaces on the Internet has been the logging built into common Web servers and the decade-long deployment of analytics based upon this data source. Page-view logging has slowly moved to callback systems using client-side scripting to capture more aspects of the user experience. With the rise of JavaScript-based client-side interactivity and, more recently, asynchronous Javascript and XML (AJAX), server-side logging is less able to capture the user experience of Web sites and applications that are rising in complexity. We present a new technique for the in-page logging of interaction events that will help interaction designers make more informed design decisions based on how users are interacting with their systems. The potential benefit of our technique is demonstrated in a case study with a working system.
Three conditions under which experiments and observational studies produce comparable causal estimates: New findings from within-study comparisons

This paper analyzes 12 recent within-study comparisons contrasting causal estimates from a randomized experiment with those from an observational study sharing the same treatment group. The aim is to test whether different causal estimates result when a counterfactual group is formed, either with or without random assignment, and when statistical adjustments for selection are made in the group from which random assignment is absent. We identify three studies comparing experiments and regression-discontinuity (RD) studies. They produce quite comparable causal estimates at points around the RD cutoff. We identify three other studies where the quasi-experiment involves careful intact group matching on the pretest. Despite the logical possibility of hidden bias in this instance, all three cases also reproduce their experimental estimates, especially if the match is geographically local. We then identify two studies where the treatment and nonrandomized comparison groups manifestly differ at pretest but where the selection process into treatment is completely or very plausibly known. Here too, experimental results are recreated. Two of the remaining studies result in correspondent experimental and nonexperimental results under some circumstances but not others, while two others produce different experimental and nonexperimental estimates, though in each case the observational study was poorly designed and analyzed. Such evidence is more promising than what was achieved in past within-study comparisons, most involving job training. Reasons for this difference are discussed. © 2008 by the Association for Public Policy Analysis and Management.
On loading criteria in plasticity

Les criteres de chargement dans la formulation dans l'espace des deformations de Lagrange pour la plasticite independante du taux de deformation sont compares a deux autres types de conditions, celle de Nguyen et Bui et celle du type Kuhn-Tucker. Quand ces dernieres sont exprimees entierement dans l'espace des deformations, leur relation au critere de chargement en formulation d'espace de deformations devient transparent.
Extinction learning of rewards in the rat: is there a role for CB1 receptors?

Rationale Endocannabinoids have been widely studied in the context of addiction and reward due to their role in reinstatement. However, little is known about the role of CB1 receptors during extinction learning of an appetitively motivated task.
bag-of-marbles and benign gonial cell neoplasm act in the germline to restrict proliferation during Drosophila spermatogenesis

Stem cells divide asymmetrically, regenerating a parental stem cell and giving rise to a daughter cell with a distinct fate. In many stem cell lineages, this daughter cell undergoes several amplificatory mitoses, thus generating more cells that embark on the differentiation program specific for the given lineage. Spermatogenesis in Drosophila is a model system to identify molecules regulating stem cell lineages. Mutations at two previously identified loci, bag-of-marbles (bam) and benign gonial cell neoplasm (bgcn), prevent progression through spermatogenesis and oogenesis, resulting in the overproliferation of undifferentiated germ cells. Here we investigate how bam and bgcn regulate the male germline stem cell lineage. By generating FLP-mediated clones, we demonstrate that both bam and bgcn act autonomously in the germline to restrict proliferation during spermatogenesis. By using enhancer trap lines, we find that the overproliferating germ cells express markers specific to amplifying germ cells, while at the same time retaining the expression of some markers of stem cell and primary spermatogonial cell fate. However, we find that germ cells accumulating in bam or bgcn mutant testes most resemble amplifying germ cells, because they undergo incomplete cytokinesis and progress through the cell cycle in synchrony within a cyst, which are two characteristics of amplifying germ cells, but not of stem cells. Taken together, our results suggest that bam and bgcn regulate progression through the male germline stem cell lineage by cell-intrinsically restricting the proliferation of amplifying germ cells.
Combining space-based active and passive microwave observations to improve global snowfall estimates

Snowfall provides a significant source of freshwater for ecological and human needs at higher latitudes and represents a significant component of the energy and water cycles in northern climate systems. Furthermore, seasonal runoff from snowmelt, along with over-ocean snowfall, contributes to freshening in the Arctic and high-latitude North Atlantic oceans that can have a significant impact on global ocean circulations. Despite this importance, much of the region in which snowfall occurs is poorly monitored by surface observations. As a result, satellite measurements of falling snow are essential for providing large-scale estimates of this important component of the hydrologic cycle. This presentation will outline the latest techniques for identifying and inferring the intensity of falling snow using spaceborne radar. The dominant sources of uncertainty in these techniques will be highlighted and the potential for reducing these uncertainties using passive microwave constraints will be explored.
Top-down strategies for the structural elucidation of intact gram-negative bacterial endotoxins

Re-modelling of lipopolysaccharides, which are the primary constituent of the outer cell membrane of Gram-negative bacteria, modulates pathogenesis and resistance to microbials. Reported herein is the characterization of intact Gram-negative bacterial lipooligosaccharides (LOS) via a new strategy utilizing online liquid chromatography (LC) coupled with ultraviolet photodissociation (UVPD) mass spectrometry. Compared to collision-based MS/MS methods, UVPD and UVPD/HCD promoted a greater array of cleavages within both the glycan and lipid moieties, including C–C, C–N, C–O cleavages in the acyl chains as well as glycosidic and cross-ring cleavages, thus providing the most far-reaching structural characterization of LOS. This LC-MS/MS strategy affords a robust analytical method to structurally characterize complex mixtures of bacterial endotoxins that maintains the integrity of the core oligosaccharide and lipid A domains of LOS, providing direct feedback about the cell envelope architectures and LOS modification strategies involved in resistance of the host innate immune defense.
Quality Assurance in Health Care: Missions, Goals, Activities

The most challenging mission of medical personnel today is quality assurance in health care. To meet this challenge, the essential elements of a six-phase system for total quality control for the medical laboratory are outlined under the headings of design control, incoming material control, process control, output control, reliability control, and special verification studies. Review of existing goals and activities of programs related to this mission indicates both problems and rich opportunities for individual laboratory professionals and their organizations. For effective implementation of this mission, the laboratory professionals will have to create the atmosphere of a collegium where all interested scientists communicate across disciplines to eliminate the systematic biases and improve the accuracy, precision, and specificity of clinical laboratory measuring systems, to assure medically meaningful and useful assay results for the broad spectrum of health care that is necessary for the well, the near-well, and the sick.
Switch-like genes populate cell communication pathways and are enriched for extracellular proteins

Recent studies have placed gene expression in the context of distribution profiles including housekeeping, graded, and bimodal (switch-like). Single-gene studies have shown bimodal expression results from healthy cell signaling and complex diseases such as cancer, however developing a comprehensive list of human bimodal genes has remained a major challenge due to inherent noise in human microarray data. This study presents a two-component mixture analysis of mouse gene expression data for genes on the Affymetrix MG-U74Av2 array for the detection and annotation of switch-like genes. Two-component normal mixtures were fit to the data to identify bimodal genes and their potential roles in cell signaling and disease progression. Seventeen percent of the genes on the MG-U74Av2 array (1519 out of 9091) were identified as bimodal or switch-like. KEGG pathways significantly enriched for bimodal genes included ECM-receptor interaction, cell communication, and focal adhesion. Similarly, the GO biological process "cell adhesion" and cellular component "extracellular matrix" were significantly enriched. Switch-like genes were found to be associated with such diseases as congestive heart failure, Alzheimer's disease, arteriosclerosis, breast neoplasms, hypertension, myocardial infarction, obesity, rheumatoid arthritis, and type I and type II diabetes. In diabetes alone, over two hundred bimodal genes were in a different mode of expression compared to normal tissue. This research identified and annotated bimodal or switch-like genes in the mouse genome using a large collection of microarray data. Genes with bimodal expression were enriched within the cell membrane and extracellular environment. Hundreds of bimodal genes demonstrated alternate modes of expression in diabetic muscle, pancreas, liver, heart, and adipose tissue. Bimodal genes comprise a candidate set of biomarkers for a large number of disease states because their expressions are tightly regulated at the transcription level.
Understanding Professional Media

Ever since the emergence of professions and trades, when most people stopped designing and building directly by hand, media have played a pivotal role in communicating to clients proposals for future environments. Virtually all major development decisions are now made on the basis of simulations. This dependence has not been without its problems. Frank Lloyd Wright once said, “When man began to draw, architecture was lost.” His own work, a lifelong effort to reestablish a direct contact between the architect and the building, by having his students learn construction and build their own living quarters, had little effect on the inexorable trend toward dependence on simulation. Today, as communications and transportation have become cheaper, for better or worse, professionals can design buildings in one part of the globe to be constructed in another part without ever seeing the site or final product in the flesh. All can be done with simulation.
System Eigenvalues and Stability

The subject of this section is that of eigenvalues and eigenvectors of a compartmental matrix A. As we have seen, the solution of the model $$ \begin{array}{*{20}c} {\dot x(t) = Ax(t) + b(t),\:t \geq 0,} \\ {x(0) = x_0 } \\ \end{array} $$ (12.1) can be decomposed into a sum of terms involving eigenvectors associated with various eigenvalues.
Reciprocity Reconsidered: Gouldner's `Moral Norm of Reciprocity' and Social Support

In a classic statement three decades ago, Gouldner (1960) made an important analytic distinction between reciprocity as a pattern of social exchange and reciprocity as a general moral belief. Gouldner argued that the moral norm of reciprocity constitutes an important `causal force' in social life. The reciprocity norm dictates that Ego should not end up gaining at the expense of Alter's beneficial acts towards him or her. In contrast to equity theory, which suggests that people will react equally negatively to under- and overbenefiting, the reciprocity norm suggests that people will, above all, attempt to avoid overbenefiting from their socially supportive interactions. While many studies of social support have incorporated the concepts of reciprocity and exchange, virtually none has examined the validity of Gouldner's distinction nor its potential implications for the dynamics of social support. This paper explores the evidence for Gouldner's claims from studies on support and reciprocity. Evidence is fo...
Structuring Nursing Knowledge: A Priority for Creating Nursing's Future

Nursing's future will be created only as the discipline underlying nursing practices is identified, structured, and continuously updated by systematic inquiry. The kinds of knowledge contained within the disci pline are identified and an approach to its structure is proposed.
Impairment of pressure-natriuresis and renal autoregulation in ANG II-infused hypertensive rats

Chronic infusions of initially subpressor doses of angiotensin II (ANG II) lead to progressive hypertension over a 2-wk period and to augmented intrarenal ANG II levels. The present study was perfo...
Routine CT scans for occult malignancy not useful in patients with unprovoked VTE

There is no advantage to adding CT of the abdomen and pelvis to a basic screening protocol for occult malignancy in patients with unprovoked VTE.
Soil chamber method for determination of drip-applied fumigant behavior in bed-furrow agriculture: application to chloropicrin

To overcome the environmental impacts of soil fumigant use, emission reduction strategies such as tarping can be adopted. There is a need to experimentally quantify the effectiveness of such strategies, preferably in a low-cost manner. We report the design and initial testing of a laboratory soil chamber approach for quantifying the soil distribution and emissions of fumigants from bed-furrow agricultural systems. As far as possible, field conditions (e.g., soil type, bulk density, moisture content temperature) were maintained in the experiments. In studying the drip application of chloropicrin using this system, very good data reproducibility was observed between replicates, allowing confidence in the experimental design. For control chambers, high emissions, around 60% (of the total added), were observed due to the near-surface (5 cm depth) application. When the soil beds were tarped using high-density polyethylene (HDPE) or semi-impermeable film (SIF), emissions were reduced to around 40% due to an accumulation of chloropicrin below the tarp. The approach offers an inexpensive potential alternative to studying fumigant emissions from bed-furrow systems in the field and suggests that less permeable tarps would be required to drastically reduce chloropicrin emissions.
Risk-Taking in Contests: The Impact of Fund-Manager Compensation on Investor Welfare

We provide a tractable model of competition in rank-order contests with general prize structures. A leading example of such a situation is the competition between fund managers whose compensation depends on how well they performed relative to their peers. We analyze their trading behavior In a dynamic financial market model a la Black Scholes. In the unique symmetric equilibrium, fund managers use randomized trading strategies which endogenously create risk. This risk is unrelated to the uncertainty generated by the assets traded in the underlying financial market. Furthermore, this risk is excessive as there exists a trading strategy that dominates the equilibrium return distribution in the sense of second-order stochastic dominance. This trading strategy takes the form of a simple index strategy. Excessive risk-taking of fund managers leads to welfare losses if investors are risk-averse. Numerical examples indicate that welfare losses are substantial. Finally, we show that fund managers use more risky strategies, in the sense of second-order stochastic dominance, when competition between the agents increases.
WOODVILLE ICE CAVE (HANTS COUNTY, NOVA SCOTIA) AND NOTES ON THE ‘ICE CAVES’ OF THE MARITIME PROVINCES

Several caves and sinkholes where snow and ice persist well into the summer exist in Nova Scotia and New Brunswick. In the past they were sometimes used as a source of ice or for cold storage, and are known locally as ‘ice caves’ or ‘ice holes’. Although they are not true ice caves in the speleological sense of the term because they do not contain perennial ice, they are very similar. Woodville Ice Cave in Hants County, Nova Scotia, described here, is a particularly good example. Invertebrates and bats recorded from such sites are briefly discussed and the possibility of finding psychrophilic fauna in them is suggested. Plusieurs grottes et dolines sont presentes la ou la neige et la glace ne disparaissent que tard durant l’ete en Nouvelle‑Ecosse et au Nouveau-Brunswick. Autrefois, elles etaient parfois utilisees comme sources de glace ou aux fins d’entreposage sous froid. A l’echelle locale, elles sont connues sous le nom de glacieres ou de puits de neige. Elles ne sont pas de veritables glacieres au sens habituel dans le domaine de la speleologie parce qu’elles ne contiennent pas de glace perenne, mais elles sont tres semblables. La grotte Woodville (Woodville Ice Cave) dans le comte de Hants (N.-E.) decrite dans le present document, est un tres bon exemple. Nous discutons brievement des invertebres et des chauves‑souris observes dans de telles grottes et dolines, et nous suggerons qu’il est peut-etre possible d’y observer des organismes psychrophiles.
Automated text analysis in psychology: methods, applications, and future developments*

Recent years have seen rapid developments in automated text analysis methods focused on measuring psychological and demographic properties. While this development has mainly been driven by computer scientists and computational linguists, such methods can be of great value for social scientists in general, and for psychologists in particular. In this paper, we review some of the most popular approaches to automated text analysis from the perspective of social scientists, and give examples of their applications in different theoretical domains. After describing some of the pros and cons of these methods, we speculate about future methodological developments, and how they might change social sciences. We conclude that, despite the fact that current methods have many disadvantages and pitfalls compared to more traditional methods of data collection, the constant increase of computational power and the wide availability of textual data will inevitably make automated text analysis a common tool for psychologists.
An Experimental Study of Jamming Attacks in Underwater Acoustic Communication

As Underwater Acoustic Networks (UANs) are being widely utilized in scientific, commercial and military areas, there has been a shift in attention to secure communication. Jamming is a Denial-of-Service (DoS) attack which prohibits the reliable data transfer from one node to another. Although a lot of studies are carried out on security techniques and defense mechanisms in terrestrial networks, little work has been done in UANs. In this paper, we have set up single jamming and collaborative jamming tests on existing commercial modems in both laboratory and pool environments. Our results show that collaborative jamming in UANs are not always more efficient or effective than a single jammer. Furthermore, we propose an anti-jamming approach to increase the successful delivery of messages by reducing disruptions from jamming attacks.
Evaluation of a silylene divalent lanthanide interaction in the metallocene complex (C5Me5)2Sm[SiNtBuCHCHNtBu]

An R2Si: →Ln(II) complex 1, has been synthesized in 90% yield by reaction of (C5Me5)2Sm with 1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2-diazasilol-2-ylidene in toluene. Structural features of the (C5Me5)2Sm part of 1 are similar to those in (C5Me5)2Sm(THF). The silylene ligand is located asymmetrically in the metallocene wedge with one tert-butyl group (Sm−C(Me) = 3.396(4) A) much closer to the metal than the other (Sm−C(Me) = 4.741(4) A). The Si−Sm(II) distance is 3.1910(1) A.
Positive end-expiratory pressure to increase internal jugular vein size is poorly tolerated in obese anesthetized adults.

BACKGROUND:Central venous cannulation is technically challenging in obese patients. We hypothesized that positive end-expiratory pressure (PEEP) increases the size of the internal jugular vein (IJV) in obese adults.METHODS:The circumference and cross-sectional area of the IJV were measured in obese