cssi/SciSciGPT-SciSciNet huggingface dataset:
Representation: Structural Complexity of Assemblies to Create Neural Network Based Assembly Time Estimation Models

Assembly time estimation is traditionally a time intensive manual process requiring detailed geometric and process information to be available to a human designer. As a result of these factors, assembly time estimation is rarely applied during early design iterations. This paper explores the possibility that the assembly time estimation process can be automated while reducing the level of design detail required. The approach presented here trains artificial neural networks (ANNs) to estimate the assembly times of vehicle sub-assemblies at various stages using properties of the connectivity graph at that point as input data. Effectiveness of estimation is evaluated based on the distribution of estimates provided by a population of ANNs trained on the same input data using varying initial conditions. Results suggest that the method presented here can complete the time estimation of an assembly process with +/− 15% error given an initial sample of manually estimated times for the given sub-assembly.Copyright © 2012 by ASME
Biosphere Reserves - Suggested Model of the Institution of Commons (Case study of the Šumava Biosphere Reserve)

An attempt to address the interdependence between human economies and natural ecosystems has been articulated in ecological economics, among others, in terms of ecosystem services. Introducing ecosystem services yields positive result in the sense that the theoretical concept of cultural landscape has been complemented by the more or less effective political scheme, suitable as a basis for practical decision making. Nevertheless, practical management of ecosystem services on landscape scale is a rather complex task. The concept of institution of commons could be suggested to be used when dealing with the problem of implementation of ecosystem services concept in practice. The overall aim of the contribution is to discuss whether or not, or to which extent, UNESCO Biosphere Reserve, the modern strategy in biodiversity conservation backed up by internationally agreed upon conventions, can be used as a model for institution of commons in landscape- scale nature protection. The discussion is based on empirical evidence gained within a long- term research conducted in the Sumava Biosphere Reserve, Czech Republic.
Evidence for Space-Time Clustering of Lung Cancer Deaths

One parish in Louisiana has the highest reported incidence of lung cancer in the United States. Statistically significant space-time clustering (P < 1.0) was present among lung cancer deaths (1960-1975) in residents of the urban portion of this parish. The spatial distribution of cancer deaths in the urban portion of the parish was compared to age, year of death, race, and sex matched control deaths to determine the risk of lung cancer associated with residential proximity to industry. For industries with independently increased risks, the combination of industries produced risks of 1.9 to 3.2 (P < .05) for residing within 1.2 km of one or more industries to three or more industries, respectively. The results suggest residential exposure to industrial effluents is a factor contributing to the rate of lung cancer.
Dysmorphology of Cilia: Association With Chronic Suppurative Respiratory Disease

RECENTLY attention has been called to a small group of patients who were sterile, who had chronic lung disease, and whose sperm tails and respiratory tract cilia were abnormal when examined by electron microscopy. 1,2 Cilia showed an absence of dynein arms, which contain adenosine triphosphatase (ATPase), and thus account for the lack of movement of the cilia. This absence of dynein arms (ATPase) was considered to be hereditary. 1 Additional reports have noted abnormal cilia from the respiratory tracts of patients with several diseases of the lung. 3,4 These descriptions led us to examine mucosa of the respiratory tract in selected patients with chronic lung disease. In one such patient with normal immunologic function, a bizarre morphological condition of cilia was found. Report of a Case An 8-year-old boy had chronic suppurative respiratory disease, which had its onset at age 1 month. He also had chronic purulent otitis media
Chronic effects of intracerebral ventricular enterostatin in Osborne-Mendel rats fed a high-fat diet.

Abstract Enterostatin, a pentapeptide found in the procolipase molecule of the pancreas, has been infused chronically into the lateral ventricle of Osborne-Mendel rats for 11 days. Treatment with enterostatin acutely lowered food intake more in the treated animals than in the vehicle-treated controls. Weight gain and serum insulin were significantly reduced by enterostatin. Corticosterone was significantly increased in rats receiving chronic infusions of enterostatin into the lateral ventricle and was also increased following an acute ICV injection of enterostatin. CRH antagonist did not block the acute feeding response to enterostatin in Sprague-Dawley rats. The elevation of corticosterone during chronic infusion of enterostatin reduced the level of hepatic glucocorticoid receptor as measured by Western blot. We conclude that body weight gain of OM rats is reduced by centrally administered enterostatin, and that the acute effects of enterostatin on food inkake are not mediated through stimulation of CRH secretion.
Structural modifications imparting reduced toxicity in microcystins from Microcystis spp.

A cyanobacterial (blue-green algal) bloom containing Microcystis aeruginosa (dominant), M. viridis, and M. wesenbergii, was collected from Homer Lake (Illinois, U.S.A.) in the summer of 1988 and microcystins were isolated. One microcystin of substantially reduced toxicity was isolated, together with ten hepatotoxic microcystins. The compound with reduced toxicity was nonlethal at 1 mg/kg (i.p. mouse) and was determined to have a (C3H7O2) mono-ester of the alpha-carboxyl on the Glu unit of microcystin-LR. The other nine microcystins apart from MCLR had approximate LD50S ranging from 97 micrograms/kg to 750 micrograms/kg.
Communicating About Bioenergy Sustainability

Defining and measuring sustainability of bioenergy systems are difficult because the systems are complex, the science is in early stages of development, and there is a need to generalize what are inherently context-specific enterprises. These challenges, and the fact that decisions are being made now, create a need for improved communications among scientists as well as between scientists and decision makers. In order for scientists to provide information that is useful to decision makers, they need to come to an agreement on how to measure and report potential risks and benefits of diverse energy alternatives in a way that allows decision makers to compare options. Scientists also need to develop approaches that contribute information about problems and opportunities relevant to policy and decision making. The need for clear communication is especially important at this time when there is a plethora of scientific papers and reports and it is difficult for the public or decision makers to assess the merits of each analysis. We propose three communication guidelines for scientists whose work can contribute to decision making: (1) relationships between the question and the analytical approach should be clearly defined and make common sense; (2) the information should be presented in a manner that non-scientists can understand; and (3) the implications of methods, assumptions, and limitations should be clear. The scientists’ job is to analyze information to build a better understanding of environmental, cultural, and socioeconomic aspects of the sustainability of energy alternatives. The scientific process requires transparency, debate, review, and collaboration across disciplines and time. This paper serves as an introduction to the papers in the special issue on “Sustainability of Bioenergy Systems: Cradle to Grave” because scientific communication is essential to developing more sustainable energy systems. Together these four papers provide a framework under which the effects of bioenergy can be assessed and compared to other energy alternatives to foster sustainability.
Vegetative and sexual reproduction in Pfiesteria spp. (Dinophyceae) cultured with algal prey, and inferences for their classification

Abstract Algal-fed clonal zoospore cultures of Pfiesteria piscicida and Pfiesteria shumwayae enabled description of certain conserved morphological and reproductive features. Common modes of reproduction (especially via division cysts) were documented in herbivorous P. piscicida and P. shumwayae using cultures fed algal prey, together with supporting photography and flow cytometric DNA measurements. Other cysts were characterized such as vacuolate cysts in starved P. piscicida cultures and temporary cysts in both species fed algal prey. This study also represents the first report of sexual reproduction in Pfiesteria spp. cultures fed algal prey rather than live fish; the first report of a technique for cell cycle synchronization for these heterotrophic dinoflagellates; and the first information on storage products of cells released from Pfiesteria reproductive cysts. Sexual reproduction in algal-fed P. piscicida clonal cultures was evidenced by fusing gametes, cells with two longitudinal flagella, and nuclear cyclosis. Both isogamous and anisogamous fusions were observed, and resulting cells with two trailing flagella (i.e., planozygotes and planomeiocytes) sometimes comprised ≥50% of the flagellated cells. These cells continued feeding activity and eventually (hours) lost their flagella and formed cysts. Nuclear cyclosis and a subsequent cell division were observed in thin-walled reproductive cysts prior to release of two flagellated cells. One gamete fusion event was also documented in 1 of 20 algal-fed clones of P. shumwayae, with an aplanozygote as the product. We obtained high cell synchrony (≥90% 1C) in the tested cultures using our preferential lysis technique and tracked the decline in lipid content of excysted zoospore populations over time. The data from this study were considered together with previous research to gain insights about relationships between Pfiesteria spp. and other heterotrophic dinoflagellates. Pfiesteria spp. should be regarded as free-living predators rather than parasites because they are prey generalists without demonstrated “host” specificity and their flagellated feeding stages are not morphologically distinct from swimming stages. Although they originally were placed within the Dinamoebales because amoebae can predominate, this study as well as other published research consistently has shown that the dominant stage varies depending on culture conditions, prey type/availability and strains. The peridinoid plate structure of each Pfiesteria species, which thus far has been conserved across culture conditions and strains, supports placement of Pfiesteria spp. within the Peridiniales. At the species level, plate structure (differing by one precingular plate) and molecular data (18S rDNA) indicate that the two Pfiesteria spp. are closely related in comparison to species grouped within other genera.
Exact Uniform Confidence Bands for Periodic Regression

Exact uniform confidence bands are presented for a sinusoidal regression model with known period. A table of probability points is presented for an important special case. A comparsion is made with the Working - Hotelling - Scheffe confidence bands.
An Open- and Short-Circuit Technique for Analyzing Electronic Circuits

A simple approach is presented to analyze a typical high-frequency transistor stage. The analysis is based on eliminating some troublesome circuit element by open-circuiting and short-circuiting. As shown by an example, results are obtained almost by inspection.
882 INTERFERON GAMMA MODULATES PROTEIN KINASE C IN MURINE PERITONEAL MACROPHAGES

Macrophage (Mo) activation for tumoricidal activity can be induced by sequential application of two discrete molecular signals: interferon γ (IFNγ) and endotoxin. The mechanism of signal transduction leading to activation is unclear. Protein kinase C (PKc) has been implicated in cell regulatory functions and as a binding site for phorbol esters. PKc activity was measured in detergent extracts of murine peritoneal Mo before and after treatment with IFNγ. Treatment resulted in a specific 3-4 fold increase in maximal PKc activity. The optimal response occurred at a dose of 1-3 U IFNγ/ml at 3-6 hrs. Inhibition of protein synthesis by cyclohexamide did not prevent this effect. Phorbol binding sites were not affected by IFNγ treatment, and the subcellular localization of PKc was unchanged. Characterization of partially purified enzyme from control and treated Mo demonstrated 1) no direct in vitro activation of PKc by IFNγ, 2) no difference in cofactor (Ca# and phospholipid)requirements, 3) no difference in Km for substrate ATP, 4) increased Vmax in enzyme from treated cells, and 5) enhanced (2-3 fold) response to in vitro phorbols in enzyme from treated cells. These data suggest that the increased PKc activity does not require de novo synthesis of PKc but results from modification of existing PKc leading to enhanced catalytic efficiency. Additionally, we have shown that treatment of Mo with the pharmacologic agents calcium ionophore (A23187) and phorbol myristate acetate mimics the effect of IFNγ on activation. Thus Pkc appears to be an important regulator of Mo activation by IFNγ.
The cortical projections of the thalamic intralaminar nuclei, as studied in cat and rat with the multiple fluorescent retrograde tracing technique.

Abstract Two retrograde fluorescent tracers were injected in two different areas of the cerebral cortex in rats and in cats. In all the experiments many single labeled cells and only some double labeled ones were seen in the thalamic intralaminar nuclei. The present results suggest that the diffusely distributed intralaminarcortical projections mainly consist of axons of separate cells, and only to a minor extent of axon collaterals of the same cells.
Electrochemical removal of surfactants from Pt nanocubes

Abstract A straightforward procedure for removing commonly used surfactants in nanoparticle synthesis, PVP and oleylamine/oleic acid, from Pt nanocubes by electrochemical potential cycling in 0.5 M NaOH is reported. The cyclic voltammetric results demonstrate that this procedure can effectively remove surfactants from Pt nanocubes, while preserving their surface structure.
Overgrowth of Lean and Adipose Tissues in Adolescent Obesity

Extract: In 14 obese females and 9 obese males, body length was used as a base line for the detection of excess growth of lean and adipose tissue. Eighteen patients had increased lean body mass based on body water determinations (fig.1), and 40K was found to be an unreliable diagnostic agent for the prediction of lean body mass. A similar number of patients had excessive amounts of intracellular mass (fig.2). Males had an increment in total protein content within the adipose tissue mass (table IV), whereas half of the females (and all those possessing advanced bone age) had increments in muscle mass (fig.3) and in the DNA content of their musculature (fig.4). A sufficient number of female patients were studied to document two classes of obesity—one group with, and one group without advanced maturation, excess nuclei (fig.4), and reduced protein/DNA (fig.5) in the musculature. Studies of noncollagen protein in adipose tissue mass of male subjects indicated an increase in the number of adipocytes compared with those found in normal or obese females (table IV). In addition, protein and water concentrations of adipose tissue were reduced in all the obese patients studied (table III). The extracellular volume was found to be constant at 17% of body weight in obese adolescent males. Speculation: Obesity in adolescents is the result of genetic, environmental, nutritional, and hormonal factors. Over-nutrition in infancy influences hormonal secretion and produces advanced maturation and excessive cell growth in muscle (as found in this study in one group of obese females). Also, in one group of obese females, estrogens, which retard cell number increase (in the normal pubertal female), are possibly suppressed by androgens and thus allow androgen and growth hormone to exert maximal effects at the muscle level (increase of cell number). In the obese male, the superimposition of high levels of circulating insulin on androgen secretion enhances the growth of collagen and of adipocytes in the adipose tissue mass. Thus, the particular changes in body composition occurring in obesity are dependent on the sex of the individual.
Daily limited access to sweetened drink attenuates hypothalamic-pituitary-adrenocortical axis stress responses

Stress can promote palatable food intake, and consumption of palatable foods may dampen psychological and physiological responses to stress. Here we develop a rat model of daily limited sweetened drink intake to further examine the linkage between consumption of preferred foods and hypothalamic-pituitary-adrenocortical axis responses to acute and chronic stress. Adult male rats with free access to water were given additional twice-daily access to 4 ml sucrose (30%), saccharin (0.1%; a noncaloric sweetener), or water. After 14 d of training, rats readily learned to drink sucrose and saccharin solutions. Half the rats were then given chronic variable stress (CVS) for 14 d immediately after each drink exposure; the remaining rats (nonhandled controls) consumed their appropriate drinking solution at the same time. On the morning after CVS, responses to a novel restraint stress were assessed in all rats. Multiple indices of chronic stress adaptation were effectively altered by CVS. Sucrose consumption decreased the plasma corticosterone response to restraint stress in CVS rats and nonhandled controls; these reductions were less pronounced in rats drinking saccharin. Sucrose or saccharin consumption decreased CRH mRNA expression in the paraventricular nucleus of the hypothalamus. Moreover, sucrose attenuated restraint-induced c-fos mRNA expression in the basolateral amygdala, infralimbic cortex, and claustrum. These data suggest that limited consumption of sweetened drink attenuates hypothalamic-pituitary-adrenocortical axis stress responses, and calories contribute but are not necessary for this effect. Collectively the results support the hypothesis that the intake of palatable substances represents an endogenous mechanism to dampen physiological stress responses.
High-energy photons as a thermometer for ultra-relativistic nuclear collisions

I calculate the transverse momentum distribution for high-energy (pT=1–3 GeV) photons produced in ultra-relativistic nuclear collisions. I assume a strong first-order deconfinement phase transition, and consider transition temperatures in the range 150–200 MeV. For simplicity, I also assume thermal and chemical equilibrium throughout the collision. I then fit the transverse momentum distribution in the range 1–2 GeV to a thermal distribution. The fitting temperature depends only on the transition temperature, so this provides an accurate (although theory-dependent) measure of the QCD transition temperature.
System-Wide Analysis Reveals a Complex Network of Tumor-Fibroblast Interactions Involved in Tumorigenicity

Many fibroblast-secreted proteins promote tumorigenicity, and several factors secreted by cancer cells have in turn been proposed to induce these proteins. It is not clear whether there are single dominant pathways underlying these interactions or whether they involve multiple pathways acting in parallel. Here, we identified 42 fibroblast-secreted factors induced by breast cancer cells using comparative genomic analysis. To determine what fraction was active in promoting tumorigenicity, we chose five representative fibroblast-secreted factors for in vivo analysis. We found that the majority (three out of five) played equally major roles in promoting tumorigenicity, and intriguingly, each one had distinct effects on the tumor microenvironment. Specifically, fibroblast-secreted amphiregulin promoted breast cancer cell survival, whereas the chemokine CCL7 stimulated tumor cell proliferation while CCL2 promoted innate immune cell infiltration and angiogenesis. The other two factors tested had minor (CCL8) or minimally (STC1) significant effects on the ability of fibroblasts to promote tumor growth. The importance of parallel interactions between fibroblasts and cancer cells was tested by simultaneously targeting fibroblast-secreted amphiregulin and the CCL7 receptor on cancer cells, and this was significantly more efficacious than blocking either pathway alone. We further explored the concept of parallel interactions by testing the extent to which induction of critical fibroblast-secreted proteins could be achieved by single, previously identified, factors produced by breast cancer cells. We found that although single factors could induce a subset of genes, even combinations of factors failed to induce the full repertoire of functionally important fibroblast-secreted proteins. Together, these results delineate a complex network of tumor-fibroblast interactions that act in parallel to promote tumorigenicity and suggest that effective anti-stromal therapeutic strategies will need to be multi-targeted.
Efalizumab therapy for atopic dermatitis causes marked increases in circulating effector memory CD4+ T cells that express cutaneous lymphocyte antigen.

Efalizumab is an mAb directed against CD11a, a molecule involved in T-cell activation and extravasation from blood into tissue. Ten patients with severe atopic dermatitis were treated with efalizumab for 84 days, and peripheral blood mononuclear cells were analyzed for expression of activation and adhesion markers. Efalizumab treatment led to decreases in CD11a mean fluorescence intensity (MFI) on naive, central memory, and effector memory CD4+ and CD8+ T cell subsets. MFI for CD18 was decreased in both CD4+ and CD8+ T cells. Percentages of cells positive for cutaneous lymphocyte antigen (CLA) were increased fourfold in all CD4+ and CD8+ T cell subsets. Increases in the percentages of CD4+ and CD8+ T cells expressing β7 and CD49d were also observed. No significant changes were observed in the percentages of CD4+ and CD8+ T cells that produced either IFN-γ or IL-4. In summary, efalizumab treatment resulted in (i) decreases in CD11a and CD18 expression in all circulating T-cell subsets and (ii) increases in the percentages of blood T cells expressing tissue homing markers (CLA, β7, CD49d). These data suggest that blockade of T-cell extravasation into tissue is the major pathway by which efalizumab leads to improvement in cutaneous inflammation.
When a domain is not a domain, and why it is important to properly filter proteins in databases

Membership in a protein domain database does not a domain make; a feature we realized when generating a consensus view of protein fold space with our consensus domain dictionary (CDD). This dictionary was used to select representative structures for characterization of the protein dynameome: the Dynameomics initiative. Through this endeavor we rejected a surprising 40% of the 1,695 folds in the CDD as being non-autonomous folding units. Although some of this was due to the challenges of grouping similar fold topologies, the dissonance between the cataloguing and structural qualification of protein domains remains surprising. Another potential factor is previously overlooked intrinsic disorder; predictions suggest that 40% of proteins have either local or global disorder. One thing is clear, filtering a structural database and ensuring a consistent definition for protein domains is crucial, and caution is prescribed when generalizations of globular domains are drawn from unfiltered protein domain datasets.
Requirements for Presenilin-Dependent Cleavage of Notch and Other Transmembrane Proteins

Abstract Ligand binding to receptors of the LIN-12/Notch family causes at least two proteolytic cleavages: one between the extracellular and transmembrane domains, and the other within the transmembrane domain. The transmembrane cleavage depends on Presenilin, a protein also required for transmembrane cleavage of β-APP. Here, we have assayed the substrate requirements for Presenilin-dependent processing of Notch and other type I transmembrane proteins in vivo. We find that the Presenilin-dependent cleavage does not depend critically on the recognition of particular sequences in these proteins but rather on the size of the extracellular domain: the smaller the size, the greater the efficiency of cleavage. Hence, Notch, β-APP, and perhaps other proteins may be targeted for Presenilin-mediated transmembrane cleavage by upstream processing events that sever the extracellular domain from the rest of the protein.
A general method for the conversion of fly ash into zeolites as ion exchangers for cesium

A general method of converting various coal ashes into zeolites was investigated. Fly ashes from several utility power plants were fused with sodium hydroxide at 550 °C followed by dissolution in w...
Effect of salt and aging on aqueous surfactant formulations for tertiary oil recovery: A correlation of physical properties with microstructure using spin‐labels

Physical properties and molecular packing in surfactant aggregates of the surfactant formulation 5% (w/w) TRS 10–410 (a petroleum sulfonate), 3% (w/w) isobutanol and desired quantities of sodium chloride in distilled water were studied using electron spin resonance (ESR) technique and pH, density, viscosity, screen factor, specific conductance, surface tension and free sodium ion measurements of fresh and aged solutions. The results suggested that both salt concentration and aging lead to changes in molecular packing of surfactant aggregates. At optimal salinity, the order parameter was a maximum. With increasing salt concentration, the correlation time increases initially and decreases at higher salt concentration. Various physical property data substantiate the observed microstructural changes. A detailed discussion is presented of the interrelations of these parameters operative in this complex surfactant formulation.
Charles T. Brown, Trailblazer of Communication Education.

Charles T. Brown is well known as a scholar and as an author of four books in the speech‐communication field. This essay examines his contribution to the field as a teacher, including his philosophy which influenced a change in the direction of speech communication education and his teaching behavior.
Phase Synchronization of Two Anharmonic Nanomechanical Oscillators

We investigate the synchronization of oscillators based on anharmonic nanoelectromechanical resonators. Our experimental implementation allows unprecedented observation and control of parameters governing the dynamics of synchronization. We find close quantitative agreement between experimental data and theory describing reactively coupled Duffing resonators with fully saturated feedback gain. In the synchronized state we demonstrate a significant reduction in the phase noise of the oscillators, which is key for sensor and clock applications. Our work establishes that oscillator networks constructed from nanomechanical resonators form an ideal laboratory to study synchronization— given their high-quality factors, small footprint, and ease of cointegration with modern electronic signal processing technologies.
Translation arrest and ribonomics in post‐ischemic brain: layers and layers of players

A persistent translation arrest (TA) correlates precisely with the selective vulnerability of post-ischemic neurons. Mechanisms of post-ischemic TA that have been assessed include ribosome biochemistry, the link between TA and stress responses, and the inactivation of translational components via sequestration in subcellular structures. Each of these approaches provides a perspective on post-ischemic TA. Here, we develop the notion that mRNA regulation via RNA-binding proteins, or ribonomics, also contributes to post-ischemic TA. We describe the ribonomic network, or structures involved in mRNA regulation, including nuclear foci, polysomes, stress granules, embryonic lethal abnormal vision/Hu granules, processing bodies, exosomes, and RNA granules. Transcriptional, ribonomic, and ribosomal regulation together provide multiple layers mediating cell reprogramming. Stress gene induction via the heat-shock response, immediate early genes, and endoplasmic reticulum stress represents significant reprogramming of post-ischemic neurons. We present a model of post-ischemic TA in ischemia-resistant neurons that incorporates ribonomic considerations. In this model, selective translation of stress-induced mRNAs contributes to translation recovery. This model provides a basis to study dysfunctional stress responses in vulnerable neurons, with a key focus on the inability of vulnerable neurons to selectively translate stress-induced mRNAs. We suggest a ribonomic approach will shed new light on the roles of mRNA regulation in persistent TA in vulnerable post-ischemic neurons.
Differential regulation of CXCR2 trafficking by Rab GTPases

Intracellular trafficking of chemokine receptors plays an important role in fine-tuning the functional responses of neutrophils and lymphocytes in the inflammatory process and HIV infection. Although many chemokine receptors internalize through clathrin-coated pits, regulation of the receptor trafficking is not fully understood. The present study demonstrated that CXCR2 was colocalized with transferrin and low-density lipoprotein (LDL) after agonist treatment for different periods of time, suggesting 2 intracellular trafficking pathways for this receptor. CXCR2 was colocalized with Rab5 and Rab11a, which are localized in early and recycling endosomes, respectively, in response to agonist stimulation for a short period of time, suggesting a recycling pathway for the receptor trafficking. However, overexpression of a dominant-negative Rab5-S34N mutant significantly attenuated CXCR2 sequestration. The internalized CXCR2 was recycled back to the cell surface after removal of the agonist and recovery of the cells, but receptor recycling was inhibited by overexpression of a dominant-negative Rab11a-S25N mutant. After prolonged (4-hour) agonist treatment, CXCR2 exhibited significantly increased colocalization with Rab7, which is localized in late endosomes. The colocalization of CXCR2 with LDL and LAMP-1 suggests that CXCR2 is targeted to lysosomes for degradation after prolonged ligand treatment. However, the colocalization of CXCR2 with Lamp1 was blocked by the overexpression of a dominant-negative Rab7-T22N mutant. In cells overexpressing Rab7-T22N, CXCR2 was retained in the Rab5- and Rab11a-positive endosomes after prolonged (4-hour) agonist treatment. Our data suggest that the intracellular trafficking of CXCR2 is differentially regulated by Rab proteins.
pH studies of alpha-chymotrypsin with L-tryptophan esters.

Abstract The pH-rate profiles for the α-chymotrypsin-catalyzed hydrolyses of l -tryptophan benzyl (TBE) and ethyl (TEE) esters are obtained by automatic titration. These profiles are different. The profile for the benzyl ester reflects the contribution of both acylation and deacylation to the overall rate, whereas the one for the ethyl ester reflects rate-determining acylation. Hydrolysis of the ester TBE has three rate constants, k i 11 = 40.0, k i 21 = 18.2 and K i 10 = 2.18 sec −1 ( i = 2 or 3 for acylation and deacylation) indicative of three different ionic forms of the active site which are reactive. Three acid-base equilibrium groups with p K a values of 5.25, 6.75 and 7.0 occur for this ester and correspond to a functional carboxyl and imidazoyl in the enzyme and the free α-amino group in the ester, respectively. The pH-rate profile for TEE yields three acylation constants. They are k 211 = 70.0, k 221 = 30.0 and k 231 = 1.15 sec − . The rate constant k 231 shows that the ethyl ester behaves differently than the benzyl as it can be hydrolyzed by chymotrypsin at low pH where a functional carboxyl group is protonated. On the other hand only TBE has the rate constant k i 10 , which means this ester can be hydrolyzed at high pH where all functional ionizable groups in the system are deprotonated except the α-amino of Ile-16 in chymotrypsin. For TEE, four p K a values 5.45, 7.5, 7.25 and 8.5, are obtained from the profile, and they correspond to a carboxyl, imidazoyl, α-amino (ester) and α-amino (enzyme) groups, respectively. These results imply that chymotrypsin possesses various degrees of pH specificity which are dependent upon the ionic forms of the enzyme and the substrate. Based on x-ray structural data, two-dimensional maps are given to help explain the above findings.
Cytoskeletal mechanisms for synaptic potentiation

Excitatory synaptic transmission takes place at actin-rich protrusions called dendritic spines. Strong synaptic input activates NMDA-type glutamate receptors and induces calcium flux into these structures, initiating a program of cytoskeletal rearrangement that results in larger spines with stronger synapses. These changes in synaptic strength are thought to be the primary cellular mechanism underlying learning and memory. We recently reported that the dual Ras/Rac1 guanine nucleotide exchange factor (GEF) RasGRF2 links calcium flux to both spine enlargement and synaptic strengthening through its Rac-GEF activity. Additionally, we demonstrated that acute Rac1 activation is sufficient to enhance synaptic transmission. Since Rac1 is a major regulator of the actin cytoskeleton, these results suggest that the cytoskeleton itself regulates synaptic strengthening. Here we discuss models for how cytoskeletal modifications may enhance synaptic AMPA-type glutamate receptor abundance during long-term potentiation.
Evaluating the effectiveness of visualization techniques for schematic diagrams in maintenance tasks

In order to perform daily maintenance and repair tasks in complex electrical and mechanical systems, technicians commonly utilize a large number of diagrams and documents detailing system properties in both electronic and print formats. In electronic document views, users typically are only provided with traditional pan and zoom features; however, recent advances in information visualization and illustrative rendering styles should allow users to analyze documents in a more timely and accurate fashion. In this paper, we evaluate the effectiveness of rendering techniques focusing on methods of document/diagram highlighting, distortion, and navigation while preserving contextual information between related diagrams. We utilize our previously developed interactive visualization system (SDViz) for technical diagrams for a series of quantitative studies and an in-field evaluation of the system in terms of usability and usefulness. In the quantitative studies, subjects perform small tasks that are similar to actual maintenance work while using tools provided by our system. First, the effects of highlighting within a diagram and between multiple diagrams are evaluated. Second, we analyze the value of preserving highlighting as well as spatial information when switching between related diagrams, and then we present the effectiveness of distortion within a diagram. Finally, we discuss a field study of the system and report the results of our findings.
Modeling Transcriptional Regulation in Chondrogenesis Using Particle Swarm Optimization

Chondrogenesis is a complex developmental process involving many transcription factors. Using mRNA expression data and regulatory DNA sequences, we formulated a quantitative model to predict a set of transcription-factor binding motifs (TFBMs) as a combinatorial problem. To solve such a problem, an efficient computational algorithm should be employed. In the current study, particle swarm optimization was applied. Swarm intelligence is an artificial intelligence approach that mimics a behavior of swarm-forming agents. Such systems are made up with a population of individuals that interact locally and globally. Here, a group of TFBMs was predicted using 200 artificial bees and the results were compared to biologically known binding motifs.
Sex differences in neonatal and young adult rat lower urinary tract function caused by bladder reduction

Summary Introduction Pediatric urinary incontinence has been proposed as a cause for adult urinary incontinence, yet animal models mimic the findings of overactive bladder more closely than dysfunctional voiding. We used the bladder reduction (BR) model to study the effects of early external urethral sphincter (EUS) dysfunction on the maturation of lower urinary tract function in neonatal and young adult rats of both sexes. Objective To determine long-term alterations in bladder and EUS function in young adult rats caused by neonatal BR. Materials and methods 46 Sprague–Dawley rats underwent BR and 52 underwent sham surgery at 1 week of age. At 3, 6, and 9 weeks of life, cystometry was carried out, 8-OH-DPAT (serotonergic receptor agonist) and WAY 100,635 (serotonergic receptor antagonist) were administered intravenously. Pressure threshold (PT), volume threshold (VT), storage tonic AUC, contraction area under the curve (AUC), EUS burst amplitude and burst duration were measured at baseline and after administration of serotonergic agents. Results PT increased in 3-week BR females compared with shams (31.1 vs. 22.7 cm H2O, p Conclusions BR caused a temporary impairment of EUS emptying at 3 weeks of life, similar to dysfunctional voiding, while serotonergic agonists remained effective at enhancing EUS emptying in BR animals. Although EUS emptying spontaneously improved, the increase in VT in female young adult rats suggests that timely treatment of EUS dysfunction is required to decrease the risk of long-term bladder dysfunction. Download : Download high-res image (320KB) Download : Download full-size image Figure . Volume and pressure response to bladder reduction.
A systematic method for reaction invariants and mole balances for complex chemistries

Abstract Reaction invariants are quantities that take the same values before, during and after a reaction. We identify a set of reaction invariants that are linear transformations of the species mole numbers. The material balances for chemically reacting mixtures correspond exactly to equating these reaction invariants before and after reaction has taken place. We present a systematic method for determining these reaction invariants from any postulated set of chemical reactions. The strategy presented not only helps in checking the consistency of experimental data, and the reaction chemistry but also greatly simplifies the task of writing material balances for complex reaction chemistries. For examples where the reaction chemistry is not known, we employ Aris and Mah's (Ind. Eng. Chem. Fundam. 2 (1963) 90) classic method to determine a candidate set of chemical equations. Application of reaction invariants in validating proposed reaction chemistry is discussed. One of the important applications of this method is the automation of mole balances in the conceptual design of chemical processes.
Functional Separability and Partial Elasticities of Substitution

Theorems 3 and 4 of the recent paper by Berndt and Christensen [1] relate weak and strong separability [14] of a production function to certain equality restrictions on the partial elasticities of substitution. Both theorems are local. Also, homotheticity of the production function is a condition of both theorems but is not included in either set of necessary conditions. This note extends and strengthens the Berndt-Christensen results. First, Theorem 1 and Corollary 1 generalize Theorems 3 and 4 of Berndt and Christensen by showing that the relations hold globally (once certain details regarding differentiability are taken into account). Second, Theorem 2 and Corollary 2 strengthen the Berndt-Christensen results by showing that homotheticity of the specific aggregator functions (homothetic separability [2, 10]), but not necessarily of the production function itself, is sufficient for separability to induce the appropriate restrictions on the partial elasticities of substitution. Third, Theorem 3 and Corollary 3.1 show that homotheticity of the specific aggregator functions is a necessary condition for weak, and hence strong, separability together with equality restrictions on the partial elasticities of substitution. Finally, three additional corollaries (1.2, 2.2 and 3.2) of this note relate the partial elasticity of substitution restrictions to homothetically recursive production functions [3].
Hormone therapy in Fanconi anemia

Introduction: Fanconi anemia (FA) is a genetic condition with extreme cancer predisposition resulting from abnormalities in repair of DNA breakage and crosslinks. Children with FA develop bone marrow failure (BMF) that is treated with androgen or hematopoietic cell transplantation, and are at risk for developing acute myeloid leukemia. In adulthood, persons with FA commonly develop squamous cell carcinomas of the head, neck or gynecological tract. Endocrine problems are common in FA.Areas covered: Chromosomal breakage may lead to apoptosis of endocrine secretory cells. About 80% of children and adults with FA have at least one endocrine abnormality, and benefit from thyroid hormone therapy and vitamin D therapy. Some benefit from growth hormone therapy. Metformin may be beneficial if overweight develops, in view of the underlying insulin deficiency in FA. Estrogen or testosterone therapy is often required to complete pubertal development.Expert opinion: Individuals with FA should be routinely screened for...
An Axiomatic Approach to Location on Networks

The problem under consideration is that of locating a facility on a tree-network, given data specifying the locations of the users on the network. The approach taken is to formulate axioms that require consistent response of the solution to variations in the users' location data. It is shown that three independent axioms determine together a unique solution, located at the point that minimizes the sum of the squares of the distances to the users.
Zinc isotope fractionation during high-affinity and low-affinity zinc transport by the marine diatom Thalassiosira oceanica

We have measured the isotopic fractionation of zinc (Zn) during uptake by the marine diatom Thalassiosira oceanica cultured at a range of free Zn2+ concentrations representative of the natural range from coastal and oligotrophic regions of the ocean. Harvested cells were rinsed with either plain seawater or a wash designed to remove adsorbed extracellular metals. Unwashed cells had much higher levels of Zn and were isotopically heavier than the media, indicating a positive isotope effect for extracellular Zn adsorption. Internalized Zn, measured in washed cells, was isotopically lighter than the media. The magnitude of Zn isotope fractionation changed with free Zn2+ concentration, corresponding to a switch on the part of T. oceanica between the predominance of high- and low-affinity Zn transport pathways. The total isotope effect for uptake (δ66Zn) was -0.2% for high-affinity uptake at low Zn concentrations and -0.8% at the highest Zn concentrations, where low-affinity uptake is dominant. To our knowledge, this is the first study to describe a physiological basis for biological metal isotope fractionation during transport across the cell membrane. Similar high- and low-affinity Zn transport pathways are common among marine phytoplankton, suggesting that the processes described here are an important factor in natural marine Zn isotope variations.
Spawning migration and redd construction of Sakhalin taimen, Hucho perryi (Salmonidae) on northern Hokkaido Island, Japan

Spatial and temporal patterns of redd construction by Sakhalin taimen, Hucho perryi, were studied in small streams on northern Hokkaido, Japan. Spawning took place in late April with close relation to discharge patterns. Observed redd size (mean ± 95% C.I.) was 145 ± 11·8 cm in length and 84 ± 5·8 cm in width. The number of egg pockets per redd was either one or two, which is fewer than that of other salmonids reported in the literature. Spawning ground distributions in 1991 and 1992 were similar to each other in terms of the distribution mean and dispersion of the redds. Unlike other salmonids Sakhalin taimen probably constructed multiple redds during one spawning season.
Inequality, Diffusion, and the Status Gradient in Smoking

This study investigates the inverse relationship between status and cigarette smoking by comparing the varied strength of the relationship across nations, and identifying the contextual sources of the variation. In so doing, it evaluates two explanations. One emphasizes the importance of relative deprivation, arguing that the inverse status gradient in smoking emerges strongest with high societal inequality. Another emphasizes the importance of status-based differences in the adoption of innovative behaviors, arguing that the inverse status gradient emerges strongest in the later stages of cigarette diffusion. The analyses test these hypotheses using multilevel data from 15 European nations in 1995, measures of education, occupation, and income at the individual level, and measures of societal inequality and cigarette diffusion at the aggregate level. In supporting the diffusion rather than the societal inequality explanation, the results suggest the need to attend to cultural sources of innovation, fashion, and distinction in understanding status-based patterns of smoking.
Proton Pump Inhibitors and Histamine-2 Receptor Antagonists Are Associated With Hip Fractures Among At-Risk Patients

Background & Aims Drugs that inhibit gastric acid might increase the risk of hip fracture. However, little long-term exposure data exist and no large studies have been conducted in the United States. Methods We conducted a case-control study using data from an integrated health services organization. We evaluated 33,752 patients with incident diagnoses of hip/femur fractures (cases), 130,471 matched members without fractures (controls), prescription data for use of proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) (up to 10 years' cumulative duration), and confounders. Results Patients with hip fractures were more likely than controls to have previously received a ≥2-year supply of PPIs (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.21–1.39) or H2RAs (OR, 1.18; 95% CI, 1.08–1.29). The risk was reduced after discontinuation of medication (OR of 1.30 [95% CI, 1.21–1.41] for current PPI users vs OR of 1.09 [95% CI, 0.64–1.85] for patients who received their last prescription 2–2.9 years ago). Higher dosages (but not increasing cumulative durations) were associated with increased risk (eg, ≥1.5 pills/day: OR, 1.41 [95% CI, 1.21–1.64]; Conclusions Use of drugs that inhibit gastric acid is associated with an increased risk of hip fracture; however, this association was only found among persons with at least one other risk factor for hip fracture. Acid inhibition might therefore be associated with fracture risk in persons already at risk for osteoporosis, although other confounding cannot be excluded.