cssi/SciSciGPT-SciSciNet huggingface dataset:
Modern Greek student mobility in Italy: between inaccessibility and social reproduction

The main reason for the Greek student migration depends on the exclusion from the Greek university system. But this push factor does not exhaust the explanation for the Greek student mobility. By using the findings of a field study in Italy, this paper highlights that the acquisition of foreign educational credentials is considered as an attempt to obtain a more valuable form of education through mobility. Furthermore, it stresses the relationship between mobility and the accumulation of cultural capital through international education whereby the mobility of Greek students tends to create social reproduction in Greece.
GENETIC DIVERSITY AND MOLECULAR EPIDEMIOLOGY AMONG COXSACKIEVIRUS B2 (CVB2) DURING A COMMUNITY OUTBREAK. • 1087

An outbreak of CVB2 provided a unique opportunity to explore the degree of genetic drift exhibited by this virus during an epidemic and its genetic relationship to isolates from previous years. From 8.27-9.27 1994 consultations on 4 infants less than 2 months of age (9-54 days) with severe CVB2 infection were made: 2 had severe myocarditis, resulting in death in one and cardiac transplantation in the other; a third presented with severe hepatitis and DIC; the last had meningitis and hepatitis. Isolates from these and 6 other 1994 cases (including the first and last isolates for 1994) along with isolates from 1947 (prototype strain Ohio), 1986, 1987, 1991, were obtained. All were retyped to confirm they were CVB2. Using primers targeted to nucleotides 64-88 and 742-756 of the 5′ nontranslated region(5′NTR) a 696 bp fragment was amplified using a high fidelity reverse transcription (RT)-PCR procedure and cycle sequenced.
The Complexity of Nocardia Taxonomy: Implications for the Clinical Microbiology Laboratory

Abstract The use of gene sequencing has dramatically increased the number of recognized species of Nocardia, many of which have been described as human pathogens. Molecular techniques have also demonstrated differences among isolates previously considered to belong to the same species. These changes have made it difficult for clinical laboratories to identify isolates accurately to the species level and for clinicians and researchers to correlate current species designations with reports in the older literature. We present here an overview of current Nocardia taxonomy and information on current identification and reporting techniques.
Use of both direct and indirect 13C tags for probing nitrogen interactions in hairpin ribozyme models by 15N NMR.

We have used the synthesis and 15N NMR study of separate loop A and loop B domains of the hairpin ribozyme to demonstrate that multiple 15N atoms can be incorporated into an RNA strand and be unambiguously distinguished through a combination of direct and indirect tagging by 13C atoms. Absence of 15N chemical shift changes shows that the G8N1 in loop A does not become deprotonated up to pH 8, and that the G21N7 of loop B does not bind to Mg2 +. †In honor and celebration of the 70th birthday of Professor Leroy B. Townsend.
Interleukin-1α–induced proteolytic activation of metalloproteinase-9 by human skin

Background Increased activity of matrix metalloproteinase-9 (MMP-9) has been well documented in many diseases associated with inflammation, such as chronic wounds, bullous pemphigoid, liver failure, and tumor metastases. The mechanism for the proteolytic activation of pro–MMP-9 in human tissue still remains unknown. Methods We investigated this mechanism through reconstitution of an inflammatory condition in normal human skin, and epidermal and dermal cells derived from skin. Normal human skin was cultured with exogenous cytokines associated with inflammation and tissue repair. MMP-9 induction and activation were measured, and potential mechanisms were probed by inhibitors. Results Pathophysiologic concentrations of interleukin (IL)-1α rapidly induced pro–MMP-9 synthesis by human skin. In contrast, IL-1–induced activation of pro–MMP-9 was a slow process, which required 3 days. Tumor growth factor-β induced pro–MMP-9 but failed to promote activation of the precursor. When the skin was stimulated with the combination of tumor growth factor-β and IL-1α, substantial induction and activation of pro–MMP-9 occurred. This IL-1 induced activation of pro–MMP-9 was observed in intact skin but not in isolated dermal fibroblasts or keratinocytes. IL-1–induced activation of pro–MMP-9 was inhibited by chymostatin, a chymotrypsinlike proteinase inhibitor. Furthermore, IL-1α decreased tissue inhibitor of metalloproteinase 1 without changing MMP-9 activator activity. Conclusions The proteolytic activation of pro–MMP-9 in skin inflammatory diseases likely occurs via a pathway including IL-1α. The activation is mediated by downregulation of tissue inhibitor of MMP-1 and involves an as yet unidentified chymotrypsinlike proteinase.
Level Mixing and Energy Redistribution in Bacterial Photosynthetic Reaction Centers

We performed ultrafast polarized light experiments in which we pumped the 800 nm band and probed several near- and mid-IR transitions of photosynthetic reaction centers from Rhodobacter sphaeroides. Absorption into the upper excitonic level of the special pair (PY+) is part of this band, but it is not known whether PY+ behaves as a localized state or if it mixes with accessory bacteriochlorophyll (BChl) states. A calculation of the anisotropy of pump−probe signals fails to reproduce the experimental results if the localized picture is used. In fact, the transition into PY+ has to be 4-fold intensified over a simple exciton model prediction in order to give rise to anisotropies which are consistent with the experiment. This substantial intensification is inconsistent with previous experimental results. Agreement between theory and experiment can be achieved if the PY+ state is mixed with excited states of accessory BChl. Stimulated emission from the lower excitonic level of the special pair (PY-), probed a...
CASUISTRY AND COMPUTER ETHICS

Abstract: At the heart of the uniqueness debate is the possibility that the computer revolution may demand more in the way of ethical analysis than our traditional (that is, modern) ethical edification has prepared us for. In short, it may present new and unique problems and therefore demand new and unique solutions. In this article I argue that the solution is in fact an old and not-so-unique one: casuistry. Appealing to Jonsen and Toulmin's analysis of casuistry (1988), I argue that a casuistic methodology is a more accurate description of the moral reasoning used by contemporary computer ethicists than are other accounts. In addition, I argue that the strengths that enabled casuistry to deal successfully with radical social, economic, and religious changes in the sixteenth and seventeenth centuries render casuistry well suited to the task of dealing with radically new situations like those found in twentieth- and twenty-first-century computer technology. Before concluding, I briefly explore Pascal's fatal critique of casuistry and its relevance for contemporary computer ethics.
Scanning Electron Microscopy and Surface Enhanced Raman Spectroscopy Correlation Studies of Functionalized Composite Organic-Inorganic SERS Nanoparticles on Cancer Cells

Composite Organic-Inorganic Nanoparticles (COINs) are a novel type of surface-enhanced Raman (SER) scattering nanoparticle formed by aggregating inorganic silver particles in the presence of a chosen organic molecule with a distinct Raman fingerprint. Binding between antibody-functionalized COINs and cells is detected primarily using Raman spectroscopy, which measures spectral shifts of the excitation light due to inelastic scattering. It has been suggested that the amount of antibody-conjugated COINs binding on cells will vary according to the antigen-expression levels in cells and will lead to changes in measured SERS intensities. COINs functionalized with antibodies CD54 and CD8 were conjugated to U937 and SupT1 cancer cells and investigated in this study. SERS intensity measurements were obtained from each of the four sample variants and normalized against control samples comprising non-antibody-functionalized COINs with cells. The amount of COINs binding on cells was determined using scanning electron microscopy (SEM) and correlated with the SER spectroscopy intensity. Although we found a positive correlation between the number of COINs binding to cells and their respective SERS intensity, this relationship is not one-to-one, nor does it appear to be linear. We demonstrated that SEM imaging and SER spectroscopy can complement each other to provide information about COINs binding onto cancer cells.
Support effects on Brønsted acid site densities and alcohol dehydration turnover rates on tungsten oxide domains

The effects of support identity on catalytic 2-butanol dehydration rates, Bronsted acid site density, and reducibility are examined for WOx domains supported on ZrO2, Al2O3, SiO2 (MCM41), and SnO2. On WOx–Al2O3, 2-butanol dehydration rates (per W atom) increased with increasing WOx surface density and reached maximum values at WOx surface densities (9–10 W nm−2) similar to those required for two-dimensional polytungstates, as also found on WOx–ZrO2. UV–visible edge energies showed that WOx domains become larger as WOx surface density increases. Selective titration of Bronsted acid sites by sterically hindered 2,6-di-tert-butylpyridine during 2-butanol dehydration reaction showed that this reaction occurs predominately on Bronsted acid sites for WOx domains on ZrO2, Al2O3, SiO2, and SnO2 supports. Pre-edge features appear in the UV–visible spectra of WOx–Al2O3 samples during 2-butanol dehydration and their intensity increases with WOx surface density in parallel with measured Bronsted acid site densities and dehydration rates (per W atom). These d–d electronic transitions reflect the formation of reduced centers, consisting of acidic Hδ+(WO3)nδ− species, using 2-butanol as a stoichiometric reductant. These processes resemble those on WOx–ZrO2, indicating that temporary acid sites generally form from neutral WOx precursors on all supports. Dehydration turnover rates (per Bronsted acid site) were unaffected by the identity of the support, but for a given WOx surface density, the number of reduced centers and the density of Bronsted acid sites, but not their intrinsic reactivity, depend on the identity of the support; both reduced centers and Bronsted acid sites are more abundant on ZrO2-supported than on Al2O3-supported samples, as a result of electronic isolation of WOx domains on the more insulating and unreducible Al2O3 supports. The dehydration regioselectivity on Bronsted acid sites is strongly influenced by support, with more electropositive support cations leading to stronger interactions between α-hydrogens in reactants and lattice oxygens, favoring sterically hindered transition states required for the formation of cis-2-butene.
Efficacy of ziprasidone in dysphoric mania: Pooled analysis of two double-blind studies

Abstract Background Dysphoric mania is a common and often difficult to treat subset of bipolar mania that is associated with significant depressive symptoms. Objective This post hoc analysis was designed to evaluate the efficacy of ziprasidone in the treatment of depressive and other symptoms in a cohort of patients with dysphoric mania. Methods Pooled data were examined from two similarly designed, 3-week placebo-controlled trials in acute bipolar mania. Patients scoring ≥ 2 on at least two items of the extracted Hamilton Rating Scale for Depression (HAM-D) met criteria for dysphoric mania and were included in the post hoc analysis. Changes from baseline in symptom scores were evaluated by a mixed-model analysis of covariance. Results 179 patients with dysphoric mania were included in the post hoc analysis (ziprasidone, n = 124; placebo, n = 55). Beginning at day 4, HAM-D scores were significantly lower at all visits in patients treated with ziprasidone compared with those treated with placebo (p Limitations The main limitations are the use of a post hoc analysis and the pooling of two studies with slightly different designs. Conclusion In this analysis, ziprasidone significantly improved both depressive and manic mood symptoms in patients with dysphoric mania, suggesting that it might be a useful treatment option in this patient population. Further prospective controlled trials are needed to confirm these findings.
UV effects on the primary productivity of picophytoplankton: biological weighting functions and exposure response curves of Synechococcus

A model that predicts UV effects on marine primary productivity using a biological weighting function (BWF) coupled to the photosynthesis–irradiance response (BWF/P-E model) has been implemented for two strains of the picoplanktonic cyanobacteria Synechococcus , WH7803 and WH8102, which were grown at two irradiances (77 and 174 μmol m −2 s −1 photosynthetically available radiation (PAR)) and two temperatures (20 and 26 °C). The model was fit using photosynthesis measured in a polychromatic incubator with 12 long-pass filter configurations with 50% wavelength cutoffs ranging from 291 to 408 nm, giving an effective wavelength range of 280–400 nm. Examination of photosynthetic response vs. weighted exposure revealed that repair rate progressively increases at low exposure but reaches a maximum rate above a threshold exposure (" E max "). Adding E max as a parameter to the BWF/P-E model provided a significantly better fit to Synechococcus data than the existing " E " or " T " models. Sensitivity to UV inhibition varied with growth conditions for both strains, but this was mediated mainly by variations in E max for WH8102 while both the BWF and E max changed for WH7803. Higher growth temperature was associated with a considerable reduction in sensitivity, consistent with an important role of repair in regulating sensitivity to UV. Based on nominal water column conditions (noon, solstice, 23° latitude, "blue" water), the BWF E max /P-E model estimates that UV + PAR exposure inhibits Synechococcus photosynthesis from 78 to 91% at 1 m, and integrated productivity to 150 m 17–29% relative to predicted rates in the absence of inhibition.
A gas-liquid chromatographic procedure for the determination of indole and 3-methylindole in bovine plasma.

Abstract An accurate and specific method for indole and 3-methylindole is described. Gas-liquid chromatography was used to directly analyze indole and 3-methylindole in bovine blood plasma following a simple extraction with methylene chloride. Recovery of 91 and 97% of added indole and 3-methylindole was obtained. Resolution of these compounds was excellent and concentrations greater than 0.01 μg/ml bovine plasma can be measured.
Hydrophobic ions amplify the capacitive currents used to measure exocytotic fusion

The detection of exocytotic fusion in patch-clamped secretory cells depends on measuring an increase in the cell membrane capacitance as new membrane is added to the plasma membrane. However, in the majority of secretory cells, secretory vesicles are too small (
Hot carrier reliability of n-MOSFET with ultra-thin HfO/sub 2/ gate dielectric and poly-Si gate

The hot carrier reliability of n-channel MOSFETs with 11 /spl Aring/ EOT HfO/sub 2/ gate dielectric and poly-Si gates was studied. Under peak I/sub SUB/ stress conditions, n-FETs with HfO/sub 2/ gate dielectric show longer lifetime when compared to SiO/sub 2/ n-FETs for the same stress substrate current. At room temperature, the 0.15 /spl mu/m channel length HfO/sub 2/ n-FETs are projected to have a 10-year lifetime at V/sub D/ = 2.76 V.
Exponentiated Pareto distributions

Most Pareto distributions are defined on one side of the real line. For wider applicability, we introduce five exponentiated Pareto distributions and derive several of their properties including the moment generating function, expectation, variance, skewness, kurtosis, Shannon entropy, and the Renyi entropy.
Smoothness spaces and wavelet decomposition

174© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Abstract 2102: Exogenous microRNA-101 suppresses cell proliferation by downregulation of cyclooxygenase-2 expression in prostate cancer cell line

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC MicroRNAs, ∼22 nt non-coding small RNAs, have been newly focused as a potential cancer diagnostic biomarker and therapy target, because aberrant expressions of miRNAs have been often found to involve in tumorigenesis, cancer development and progression. For instance, microRNA-101 (miR-101) is significantly down-regulated in several types of cancer. In this study, we investigated the function of miR-101 on regulation of gene expression in cancer cells. A stable miR-101 over-expressed prostate cancer cell line (BPH1CAFTDmiR101) was established by using lentivirus-delivery system. Over-expressed miR-101 level in the stable transfected cell can be detected after the 5th or 100th cell culture passages and approximately 10-fold higher than non-transfected BPH1CAFTD cells. We found that over-expressed miR-101 suppressed cyclooxygenase-2 (COX-2) protein expression in BPH1CAFTDmiR101 cells. The miR-101 targeted gene was determined by using luciferase reporter gene, which carry 3’-UTR ([NM_000963][1] 3’-UTR 1735-1741) of COX-2 mRNA. The results indicated that miR-101 directly targets COX-2 gene and down-regulates COX-2 protein expression by binding to 3’-UTR of COX-2 mRNA. Interestedly, the reduced COX-2 protein expression in BPH1CAFTDmiR101can be restored by transient transfection of COX-2 3′UTR fragment. Compared with BPH1CAFTD cells, BPH1CAFTDmiR101 proliferation and colony formation were significantly inhibited, and the expressions of a series of cell proliferation-related protein were significantly changed, such as the levels of EGFR, PCNA, and Bcl-2 were decreased and the level of p53 was increased. In addition, MMP-15 protein level, a metastasis related protein, was also noticeably reduced. Taking together, our finings demonstrate that miR-101 inhibits prostate cancer cell proliferation by directly targeting COX-2 to down-regulating its protein level. The miR-101 may function as tumor suppressor and a potential target for cancer diagnosis and therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2102. [1]: /lookup/external-ref?link_type=GEN&access_num=NM_000963&atom=%2Fcanres%2F70%2F8_Supplement%2F2102.atom
Post-cure heat treatments for composites: properties and fractography

Abstract Two commercial and four experimental composites were subjected to post-cure heat treatments of 10 min and 3 h duration immediately after light-curing. Fracture toughness, flexural modulus, microhardness and degree of conversion (FTIR) were evaluated 24 h later. The results showed that post-cure heat treatments at 120°C of short or long duration can be used to produce significant improvements in the degree of cure and the mechanical properties of dental composites used as inlays. A 10 min heat treatment was as effective as a 3 h treatment in enhancing properties and degree of cure. In addition, a 3 h heat treatment carried out 7 days after the initial light-curing was capable of improving properties and cure to almost the same extent as the immediate heat treatments. The improvement in properties, in conjunction with the fractography, indicate a toughening of the filled resin matrix and possibly an improved filler/matrix adhesion in the microfills. The changes appear to be predominantly the result of an increase in degree of cure.
Response of copper nanowires in dynamic tensile deformation

Molecular dynamics (MD) simulations with an embedded atom method (EAM) potential are carried out to analyse the size and strain rate effects in the tensile deformation of single-crystal copper nano...
Evolution: A history of give and take.

Fossils of microorganisms from deep-sea sediment cores show that environmental change correlates closely with extinction but not with speciation, producing a nuanced view of the drivers of evolution. See Letter p.398 The fossil record is not a simple representation of the comings and goings of living things. There are interactions between life and Earth-system processes, and in this paper, Shanan Peters et al. describe how plate tectonics and climate change have together driven the extinction of planktonic foraminifera in the Atlantic basin throughout its history, beginning in the Jurassic. Major crises such as the end-Cretaceous mass extinction leave an imprint superimposed on this background. These factors have not, however, influenced the origin of new foraminifera species.
Post dural puncture headache in obstetric patients: experience from a West African teaching hospital

Abstract Background This prospective, non-randomised study examined the frequency and severity of post dural puncture headache in 96 Ghanaian women who consented to spinal anaesthesia for caesarean section at the Korle Bu Teaching Hospital, Accra, Ghana. Method Spinal anaesthesia was performed using 22-gauge ( n =22), 25-gauge ( n =46) or 26-gauge ( n =38) Quincke needles. Patients were followed up to determine the incidence and severity of post spinal headache. Result The overall incidence of post dural puncture headache was 8.3%, but was significantly higher (33%) in patients in whom 22-gauge Quincke needles were used than in the other two groups (4% and 5% respectively: P =0.003). Most patients rated their headache as mild to moderate on a 10-cm visual analogue scale. Conclusions In view of the high incidence of headache and the need for treatment associated with the use of the 22-gauge Quincke needle, we recommend that this should not be used in the obstetric population. We are also aware that the incidence of post dural puncture headache could be further reduced by the use of small calibre pencil-point needles but these are currently very expensive and many obstetric units in developing countries may not be able to afford them.
Implications of platinum-group element accumulation along U.S. roads from catalytic-converter attrition.

Automobile catalytic converters are dispersing platinum-group elements (PGEs) Rh, Pt, and Pd into the environment (1−3). This paper represents the first detailed study to assess the PGE content of soils and grasses from U.S. roadsides. These soils were analyzed using cation exchange pretreatment and ultrasonic nebulizer-ICP-MS (4). Highway and several urban sites showed Pt abundances of 64−73 ng/g immediately adjacent to the roadside, with corresponding Pd and Rh abundances of 18−31 ng/g and 3−7 ng/g, respectively. All Pt and most Pd and Rh abundances are statistically above local background soil values. Platinum, Rd, and Rh show positive correlations with traffic-related elements (Ni, Cu, Zn, and Pb) but no correlations with nontraffic-related elements (Y, Ga). Iridium and Ru show no correlations with any of these trace elements. These PGE abundances are comparable to European studies (5−7) and are approaching concentrations that would be economically viable to recover. This study also demonstrates trans...
ANGIOGENESIS AND STEM CELL TRANSPLANTATION AS POTENTIAL TREATMENTS OF CEREBRAL ISCHEMIC STROKE

Ischemic stroke is a leading cause of human death and disability. Although stroke survivors may gain spontaneous partial functional recovery, they often suffer from sensory-motor dysfunctions, behavioral/neurological alterations, and various degrees of paralysis. Currently, limited clinical intervention is available to prevent ischemic damage and restore lost function in stroke victims. In addition to the extensive research on protective maneuvers against ischemia-induced cell death, increasing attention has been focused on potential strategies of promoting tissue repair and functional recovery in the damaged post-ischemic brain. Angiogenesis, or the growth of new blood vessels, may contribute to cell survival and functional recovery of the area of insult. The study of angiogenesis will increase the understanding of the mechanism underlying post-ischemia neurovascular plasticity and regeneration. Additionally, stem cell transplantation has emerged in the last few years as a potential therapy for ischemic stroke, because of their capability to differentiate into multiple cell types and the possibility that they may provide trophic support for cell survival, tissue repair, and functional recovery.
Two-dimensional CCD arrays as parallel detectors in electron- energy-loss and X-ray wavelength-dispersive spectroscopy

Abstract Parallel detection systems for spectroscopy have generally been based upon linear detector arrays. Replacing the linear arrays with two-dimensional systems yields more complicated devices; however, there are corresponding benefits which can be realized for both X-ray and electron-energy-loss spectroscopy. The operational design of these systems as well as preliminary results from the construction of such a device used for electron spectroscopy are presented.
Fun with premultiplied alpha

The computer graphics universe consists of pixels. Pixels, in turn, consist of components: red, green, blue, and the coverage or opacity value alpha. For various reasons it is convenient to store and process a given rgb/spl alpha/ quadruple with the rgb values already multiplied by /spl alpha/. This was first pointed out in the original Porter-Duff compositing paper (1984) and I presented some further justifications in an earlier column ("Image Compositing-Theory", ibid., p.83-7, Sept. 1994). This premultiplication has some other interesting implications, and that's what I discuss this time.
The structure of the 27-layer polytype of BaCrO3

Abstract Twenty-seven-layer barium chromium oxide, BaCrO3, was prepared at 1200°C and 60–65 kbar by reaction of CrO2 and Ba2CrO4. The compound crystallizes in space group R 3 m with hexagonal cell dimensions a = 5.652 ± 0.002, c = 62.75 ± 0.02A. The structure was determined from 1070 independent reflections, of which 811 were considered observed, collected by automated counter methods, and refined by least-squares methods to a conventional R value of 4.1%. The structure consists of a 27-layer stacking sequence of close-packed BaO3 layers, Zhdanov notation for the sequence (3)2(2)2, with all of the O6 octahedral sites occuped by Cr. Strings of four pairs of face-sharing octahedra in which the pairs are linked to each other by corner sharing are in turn joined to each other by octahedra sharing only corners. The structure is thus closely related to the four-layer and six-layer polytypes of BaCrO3. Bariums in two of the five crystallographic positions showed large thermal anisotropy and are better described in terms of half atom occupancy in split sites.
Demonstration of Saturation Kinetics in the Intestinal Absorption of Vitamin C in Man and the Guinea Pig

Intestinal absorption of ascorbic acid is believed to be mediated through a sodium-dependent active transport process in man and in the guinea pig, both species having a nutritional requirement for the vitamin. Vitamin C transport was studied in man and in the guinea pig by in vivo intestinal perfusion of concentrations of vitamin C ranging from physiologic to clearly pharmacologic levels. Triple lumen intestinal perfusion of seven human volunteers with vitamin C concentrations ranging from 0.85 to 11.36 mM demonstrated saturation kinetics of absorption with a Km = 5.44 mM. Net secretion of water was observed in three of seven humans with the highest (11.36 mM) concentration of vitamin C. Perfusion of isolated segments of guinea pig intestines with intact blood supply also revealed saturation kinetics (Km = 5.54 mM) in the range of 1.42 to 56.8 mM vitamin C but linear absorption below this range. The phenomenon of decreased water absorption noted with incremental vitamin C dose in human volunteers could not be reproduced in the guinea pig, nor were the intestinal tissue levels of cyclic AMP and GMP increased by high-dose vitamin C in this species. This study suggests that "megavitamin" doses of vitamin C (greater than 1 Gm) are probably not as efficiently absorbed as smaller multiple doses of the vitamin. Intestinal secretion of water may contribute to the diarrhea which is the most common side effect of large doses of vitamin C. The guinea pig is a useful but limited model for vitamin C absorption in man.
THE INTERNATIONALIZATION OF PUBLIC ADMINISTRATION AND PUBLIC POLICY: IMPLICATIONS FOR TEACHING

Increasingly, the nations of the world are becoming more interdependent among themselves. This is true not only in an economic sense, but in a political sense as well. The field of public administration has become internationalized, presenting a new challenge to both teachers and students of the discipline. The article argues that special attention should be given to teaching students how to manage policy interdependency. Furthermore, the interdisciplinary approach is advocated as a method of broadening students' perspectives in public administration. In concluding the article, the author offers several recommendations for improving public administration programs.
The BTB/kelch protein, KRIP6, modulates the interaction of PICK1 with GluR6 kainate receptors.

Neuronal proteins of the BTB/kelch and PDZ domain families interact with different regions of the cytoplasmic C-terminal domain of the GluR6 kainate receptor subunit. The BTB/kelch protein KRIP6 binds within a 58 amino acid segment of GluR6 proximal to the plasma membrane. In contrast, PDZ domain proteins, such as PICK1 and PSD95, interact with the last 4 residues of the GluR6 C-terminus. KRIP6 reduces peak currents mediated by recombinant GluR6 receptors and by native kainate receptors in neurons, whereas PICK1 stabilizes kainate receptors at synapses. Thus, protein–protein interactions at the C-terminal domain of GluR6 are important for regulating kainate receptor physiology. Here, we show by co-clustering and co-immunoprecipitation that KRIP6 interacts with PICK1 in heterologous cells. In addition, we demonstrate a novel modulation of GluR6 receptors by PICK1 resulting in increased peak current and relative desensitization of GluR6-mediated currents, phenotypes opposite to those produced by KRIP6. Importantly, these effects cancel out when KRIP6 and PICK1 are co-expressed together with GluR6. KRIP6 and PICK1 strongly co-cluster and co-immunoprecipitate regardless of the presence of GluR6. Immunofluorescence analysis reveals that GluR6 can either join the KRIP6–PICK1 clusters or remain separate; however, co-expression of KRIP6 reduces the fraction of PICK1 that co-immunoprecipitates with GluR6. Taken together, these results indicate that, in addition to a previously demonstrated direct interaction with the GluR6 C-terminal domain, KRIP6 regulates kainate receptors by inhibiting PICK1 modulation via competition or a mutual blocking effect.
Immune Deviation and Fas-mediated Deletion Limit Antitumor Activity after Multiple Dendritic Cell Vaccinations in Mice

Genetic immunization with a single injection of dendritic cells (DCs) expressing a model melanoma antigen generates antigen-specific, MHC-restricted, protective immune responses. After initiating the immune response, additional vaccinations may increase the protection or conversely downregulate the immune response. Groups of mice were vaccinated several times with DCs transduced with the MART-1 gene, and the anti-tumor protection was compared with that of mice receiving a single vaccination. C3H mice had poorer protection from a syngeneic MART-1-expressing tumor challenge with multiple vaccinations. This was accompanied by lower levels of splenic CTL effectors and a shift from a type 1 to a type 2 cytokine profile. On the contrary, multiple vaccinations in C57BL/6 mice generated greater in vivo antitumor protection with no decrease in splenic CTLs and no cytokine shift. Antiadenoviral humoral or cellular immune responses did not seem to contribute to these effects. When studies were performed in Fas receptor-negative C3H.(lpr) mice, the adverse effect of multiple vaccinations disappeared, and there was no cytokine shift pattern. In conclusion, C3H mice but not C57BL/6 mice receiving multiple vaccinations with DCs expressing the MART-1 tumor antigen show decreased protection associated with deviation from a type 1 to a type 2 cytokine response attributable to a Fas-receptor mediated clearance of antigen-specific IFN-gamma-producing cells.
Correlates of Prosocial Behaviors of Students in Ethnically and Racially Diverse Middle Schools

This study examined the association between ethnicity-related context variables and the prosocial behavior of early adolescents in ethnically/racially diverse schools. Specifically, youths’ perceptions of greater representation of same-ethnic peers at school, school support for ethnic diversity, and engagement in and valuing cross-ethnic contact across varying levels of school ethnic/racial diversity were examined in relation to their prosocial behavior toward peers. Multilevel analyses indicated that prosociability in a sample of 2,369 sixth-grade students in 20 ethnically/racially diverse middle schools was associated with student engagement in and valuing of cross-ethnic contact in circumstances of relatively lower and average school ethnic/racial diversity but not higher diversity. In addition, prosocial behavior was marginally associated with greater representation of same-ethnic peers at school but not associated with school support for ethnic diversity. Findings offer new evidence of the psychological significance of experiences of ethnic similarity and diversity for early adolescents’ prosocial behavior.
Influence of soil development on the geomorphic evolution of landscapes: An example from the Transverse Ranges of California

Soil development can significantly influence the topographic evolution of a tectonically deforming mountain piedmont. Faults and folds associated with the North Frontal thrust system deform piedmont sediments of variable compositions along the north flank of the San Bernardino Mountains. The topographic expressions of folds with similar structural characteristics diverge appreciably, primarily as a function of differences in sediment composition and associated soil development. Soils with petrocalcic horizons in limestone- rich deposits are resistant to erosion, and anticlinal folds form prominent ridges. Folds forming in granite-derived deposits with argillic soil horizons are eroded and/or buried and are therefore topographically less pronounced. We propose that these landform contrasts can be explained by differences in soil-controlled hydrologic and erosion characteristics of deposits without calling upon changes in tectonic style along the mountain front.
Adapting extreme programming for a core software engineering course

Over a decade ago, the manufacturing industry determined it needed to be more agile to thrive and prosper in a changing, nonlinear, uncertain and unpredictable business environment The software engineering community has come to the same realization. A group of software methodologists has created a set of software development processes, termed agile methodologies that have been specifically designed to respond to the demands of the turbulent software industry. Each of the processes in the set of agile processes comprises a set of practices. As educators, we must assess the emerging agile practices, integrate them into our courses (carefully), and share our experiences and results from doing so. The paper discusses the use of extreme programming, a popular agile methodology, in a senior software engineering course at North Carolina State University. It then provides recommendations for integrating agile principles into a core software engineering course.
Molecular Mechanisms of TRPV4-Mediated Neural Signaling

In signal transduction of metazoan cells, ion channels of the family of transient receptor potential (TRP) have been identified to respond to diverse external and internal stimuli, among them osmotic stimuli. This review highlights a specific member of the TRPV subfamily, the TRPV4 channel, initially named vanilloid-receptor related osmotically activated channel (VR-OAC) or OTRPC4. In a striking example of evolutionary conservation of function, mammalian TRPV4 has been found to rescue osmo- and mechanosensory deficits of the TRPV mutant strain osm-9 in Caenorhabditis elegans. This is an astounding finding given the <26% orthology between OSM-9 and TRPV4 proteins. Here, recent findings pertaining to TRPV4's mechano- and osmosensory function in endothelia, in the alveolar unit of the lung, and in intestinal sensory innervation are reviewed, namely, transduction of mechanical shear stress in endothelia, maintenance of alveolar integrity on the endothelial side, and intestinal mechanosensation of noxious stimuli by dorsal root ganglion sensory neurons, which can be potently sensitized to mechanical stimuli by activation of the proteinase-activated receptor 2 (PAR-2), in a strictly TRPV4-dependent manner.
Nightly duration of pineal melatonin secretion determines the reproductive response to inhibitory day length in the ewe.

The pineal controls the reproductive response of ewes to both stimulatory (short) and inhibitory (long) day lengths. Melatonin, a pineal hormone whose nocturnal secretion is entrained by photoperiod, mediates the effect of stimulatory photoperiod. We now report that melatonin also mediates the effect of inhibitory day length, monitored as response to estradiol negative feedback on luteinizing hormone (LH) secretion. Ovariectomized, estradiol-implanted ewes were pinealectomized and intravenously infused with melatonin to restore the nightly melatonin rise. Following transfer from short to long days, and a concurrent switch from short- to long-day melatonin patterns, LH dropped precipitously in pinealectomized ewes, matching the photoinhibitory response of pineal intact controls. LH dropped similarly in pinealectomized ewes when long-day melatonin was infused under short days. Pinealectomized ewes transferred from long to short days displayed a marked LH rise, provided melatonin was also switched to the short-day pattern. LH remained suppressed if long-day melatonin was infused following transfer to short days. These data indicate the nighttime melatonin rise mediates reproductive responses to inhibitory, as well as stimulatory photoperiods; they further suggest the duration of this rise controls suppression of LH under long days. Rather than being strictly pro- or antigonadal, the pineal participates in measuring day length, BIOLOGY OF REPRODUCTION 30, 585-593 (1984)
Integration of Cellular Metabolism and Membrane Excitability in Cerebellar Purkinje Neurons

Calcium and membrane physiology are crucial to cerebellar Purkinje neuron function. Purkinje cell physiology involves phosphoinositide/calcium signaling and calcium influx through voltage-gated calcium channels, as well as potassium efflux through (i) voltage-gated, and (ii) calcium-activated voltage-gated channels (primarily the BK channel). The interaction between phosphoinositide-induced calcium signaling and calcium-activated/voltage-gated potassium channels have not been explored extensively. We have developed computational models to explore the integration of these mechanisms. We used an electrophysiological model in NEURON to parameterize a compartmental Virtual Cell (VCell) model. We then combined our published calcium metabolism model (created in VCell) with the electrophysiological model. We investigated the influence of IP3R1-mediated calcium release from smooth endoplasmic reticulum close to the plasma membrane on the activity of the BK channel and thus on membrane potential. The model predicts that supralinear IP3R1-mediated calcium release into a submembrane shell can activate BK channels. When coupled with synaptic conductance changes, this activation of the BK channels increases the rate of repolarization (RR) of the spine. As the voltage changes in the spine propagate to the soma, the corresponding RR in the soma is also increased. Simulation of IP3R1 ko abolishes any increase in the RR in both the spine and the soma. Reduced IP3R1 abundance (as found in some cerebellar ataxias; in model, 10% - 50% of the original value), almost completely abolishes any increase in the RR, in both spine and soma. Increasing the sensitivity of IP3R1 to IP3 restores normal IP3R1-mediated calcium, and restores increased activation of the BK channels. The resulting RR of both the spine and the soma are also restored. These results suggest that the BK channel may play a role in integrating signals from cellular metabolism and membrane excitability. (Supported by NIH P41 RR013186)
Distributed Target tracking and localization in multi-hop networks

We consider the problem of distributed target tracking under communication constraints between the sensor nodes, a problem that has recently received significant attention. On account of communication constraints the problem necessitates not only the dynamic selection of optimal sensor nodes but also corresponding fusion centers to enable local processing of sensor information. This coupled problem is generally intractable and significant effort has been devoted towards proposing greedy strategies under various performance criteria. In contrast our paper decouples the three aspects, namely non-linear partially observed state estimation, sensor selection and fusion center locationing, and adopts a certainty equivalence perspective. The main advantage of this approach is that since significant communication costs in target tracking with multi-hop networks arises primarily from the switching of fusion centers, this problem can be isolated and optimized. In particular, we show that optimal tracking algorithms that jointly optimizes the average multi-hop communications as well as average tracking error can be derived in an infinite horizon setting. Specifically, when target dynamics is described by a random walk, the optimal strategy exhibits a hybrid switching strategy, whereby active sensor locations are held stationary until the target moves outside a threshold radius around the sensors. This holds even when there are sensors located close to the target. Surprisingly this result is fundamental to the multi-hop communication penalty and does not hold for penalties that reflect free space attenuation.
Computation of Zames-Falb multipliers revisited

The convex approach to the absolute stability problem is considered. Gapski and Geromel's algorithm for computing Zames-Falb multipliers, used in determining stability, treats the problem as an optimization problem. It is found that their algorithm may terminate prematurely in some cases, failing to find the optimal multiplier. We propose an improvement that always finds an ascent direction and a multiplier that improves the objective function whenever one exists.
RNA polymerase II complexes in the very early phase of transcription are not susceptible to TFIIS-induced exonucleolytic cleavage

TFIIS is a transcription elongation factor for RNA polymerase II (pol II), which can suppress ribonucleotide misincorporation. We reconstituted transcription complexes in a highly purified pol II system on adenovirus Major-Late promoter constructs. We noted that these complexes have a high propensity for read-through upon GTP omission. Read-through occurred during the early stages at all registers analyzed. Addition of TFIIS reversed read-through of productive elongation complexes, which indicated that it was due to misincorporation. However, before register 13 transcription complexes were insensitive to TFIIS. These findings are discussed with respect to the structural models for pol II and we propose that TFIIS action is linked to the RNA:DNA hybrid.
Longevity, Aging, and Death: An Evolutionary Perspective

When viewed in evolutionary perspective, biogerontology becomes primarily the biology of longevity rather than the biology of aging and death. It is shown here that the life-span of mammals is fundamentally related to two quantitative characteristics: a specific measure of relative brain size, the cephalization coefficient; and a measure of lifetime metabolic activity that has the physical dimensions of action. Recent work is reviewed which shows that species life-span has a high correlation with the capacity of cultured cells to repair damage to their DNA. As an alternative to the widely accepted ''senescence gene hypothesis,'' the hypothesis is here proposed that natural selection acts to maintain and extend mammalian longevity by modifying a set of longevity assurance mechanisms that all mammals have in common.
Optimal Sampling Strategies for Statistical Models with Discrete Dependent Variables

The object of this paper is to improve the cost-effectiveness of data gathering procedures for models with discrete dependent variables. It is assumed throughout the paper that the true value of the parameter vector is approximately known and that, with that information, one must select a statistically optimal number of observations from different population subgroups to refine the accuracy of the estimate. It is shown that the problem can be reduced to a small mathematical program whose objective function can be written after a few preliminary algebraic manipulations. For binary choice models, these preliminary calculations are simple enough to be implementable on 1979 state-of-the-art programmable hand calculators. It is also shown that choice-based and mixed data can be optimally selected in a similar way; in particular, binary choice-based samples drawn from one single population group are so easy to analyze that all calculations can be performed by hand. Multinomial models are less amenable to hand calculations, except, perhaps, trinomial models which require evaluation of a double integral. The technique extends naturally to limited dependent variable regression models.
Lateral dimerization is required for the homophilic binding activity of C-cadherin

Regulation of cadherin-mediated adhesion can occur rapidly at the cell surface. To understand the mechanism underlying cadherin regulation, it is essential to elucidate the homophilic binding mechanism that underlies all cadherin-mediated functions. Therefore, we have investigated the structural and functional properties of the extracellular segment of Xenopus C-cadherin using a purified, recombinant protein (CEC 1-5). CEC 1-5 supported adhesion of CHO cells expressing C-cadherin. The extracellular segment was also capable of mediating aggregation of microspheres. Chemical cross-linking and gel filtration revealed that CEC 1-5 formed dimers in the presence as well as absence of calcium. Analysis of the functional activity of purified dimers and monomers demonstrated that dimers retained substantially greater homophilic binding activity than monomers. These results demonstrate that lateral dimerization is necessary for homophilic binding between cadherin extracellular segments and suggest multiple potential mechanisms for the regulation of cadherin activity. Since the extracellular segment alone possessed significant homophilic binding activity, the adhesive activity of the extracellular segment in a cellular context was analyzed. The adhesion of CHO cells expressing a truncated version of C-cadherin lacking the cytoplasmic tail was compared to cells expressing the wild-type C-cadherin using a laminar flow assay on substrates coated with CEC 1-5. CHO cells expressing the truncated C-cadherin were able to attach to CEC 1-5 and to resist detachment by low shear forces, demonstrating that tailless C-cadherin can mediate basic, weak adhesion of CHO cells. However, cells expressing the truncated C-cadherin did not exhibit the complete adhesive activity of cells expressing wild-type C-cadherin. Cells expressing wild-type C-cadherin remained attached to CEC 1-5 at high shear forces, while cells expressing the tailless C-cadherin did not adhere well at high shear forces. These results suggest that there may be two states of cadherin-mediated adhesion. The first, relatively weak state can be mediated through interactions between the extracellular segments alone. The second strong adhesive state is critically dependent on the cytoplasmic tail.