cssi/SciSciGPT-SciSciNet huggingface dataset:
Spatial variability of methane emissions from rice fields and implications for experimental design

[1] It is observed that side by side plots in rice fields, managed by the same practices, produce methane emissions that are often different by factors of 2 to 4. Similarly on a given day when many plots are sampled, the emissions from one plot may differ from another by factors of 3–4 on average. These large variations must be taken into account if these data are extrapolated to larger scales such as countries or the world. In this paper we analyze and delineate the nature of this variability. We distinguish temporal and spatial variability and examine the effects of both on the observed seasonal average emission rates. While temporal variability is managed well in most experiments because frequent measurements are taken, the spatial variability remains a potential major uncertainty in many experiments. Using the characteristics of the observed variability we use simulations to show that with a proper and realistic sampling strategy, it is possible to get to within 15%–20% of the true flux for most cases of interest. We calculate how many plots are needed and how often they should be sampled during the growing season to obtain a seasonal average flux within prescribed limits relative to the true flux.
Urinary polyamines in preterm infants

Abstract Polyamines were determined in urine of 22 preterm infants (mean 30.0 weeks gestation) from birth to 22 weeks of age, and in full-term infants in the first week of life. A significant decline in urine putrescine and spermidine levels occurred with increased postnatal age in preterm infants. At expected term, preterm infants had significantly higher levels of polyamines in urine than full-term infants at the same postconceptional age. No constant correlations between weight or linear growth velocity and urinary polyamine excretion could be established in this group of infants. Altered urine polyamine values were detected in two clinical situations: hyperbilirubinemia was associated with increased urine spermidine (and with increased spermidine/putrescine ratio), and liver disease was associated with increased levels of both putrescine and spermidine in urine.
CCN1 Induces β-Catenin Translocation in Esophageal Squamous Cell Carcinoma through Integrin α11.

Aims. Nuclear translocation of β-catenin is common in many cancers including esophageal squamous cell carcinoma (ESCC). As a mediator of Wnt signaling pathway, nuclear β-catenin can activate many growth-related genes including CCN1, which in turn can induce β-catenin translocation. CCN1, a matricellular protein, signals through various integrin receptors in a cell-dependent manner to regulate cell adhesion, proliferation, and survival. Its elevation has been reported in ESCC as well as other esophageal abnormalities such as Barrett’s esophagus. The aim of this study is to examine the relationship between CCN1 and β-catenin in ESCC. Methods and Results. The expression and correlation between CCN1 and β-catenin in ESCC tissue were examined through immunohistochemistry and further analyzed in both normal esophageal epithelial cells and ESCC cells through microarray, functional blocking and in situ protein ligation. We found that nuclear translocation of β-catenin in ESCC cells required high level of CCN1 as knockdown of CCN1 in ESCC cells reduced β-catenin expression and translocation. Furthermore, we found that integrin α11 was highly expressed in ESCC tumor tissue and functional blocking integrin α11 diminished CCN1-induced β-catenin elevation and translocation. Conclusions. Integrin α11 mediated the effect of CCN1 on β-catenin in esophageal epithelial cells.
Cell and explant culture of olfactory chemoreceptor cells.

Abstract An in vitro system for the study of maturation of rat and chick embryonic olfactory receptor cells is presented. A variety of dissociating agents, culture media and substrata were tried in attempts to obtain a preparation of mature living olfactory receptor cells readily visible in the microscope. Maturation was judged by the development of axons > 1 mm long, by the presence of cilia at the end of the dendrites and, in the rat, by the presence of immunohistochemically demonstrable olfactory marker protein, a protein present only in olfactory receptor cells. By these criteria, dissociated cells did not mature in vitro, though occasional bipolar cells with relatively short axons were seen. In explant culture, small fragments of rat tissue were positive for all 3 criteria after 6 days. In 9-day cultures, the axons had grown up to 3 mm long in both rat and chick cultures. Olfactory bulb fragments co-cultured close to the olfactory epithelium had no influence on the direction of outgrowth of axons from the olfactory receptor cells. Preliminary experiments with intracellular electrodes on the fragment cultures suggest that there are two cell types in the epithelium; one with a potential of −25 to −30 mV and, the other, −12 to −15 mV.
Two-dimensional discrete sine transform scheme for image mirroring and rotation

Mirroring an image (horizontally or vertically) and rotation by 90, 180, and 270 deg in the spatial domain is implemented by changing the signs of the 2-D discrete cosine transform (DCT) co- efficients of the original image appropriately. This approach leads to an efficient compressed domain-based image mirroring and rota- tion. This method is now extended to a 2-D discrete sine transform (DST), i.e., a 2-D DST possesses properties similar to 2-D DCT and it can be applied to image mirroring (horizontally or vertically) and also rotation by angles of 90, 180, and 270 deg. We illustrate these methods in a video-editing application. © 2008 SPIE and
Laboratory Constraints on the Rheology of the Upper Mantle

The dynamics of convection and the mechanical behavior of the lithosphere are controlled by the rheology of upper mantle rocks. For this reason, experimental and theoretical studies on the rheology of olivine aggregates have been fields of active research for at least the last 35 years. In this short-course paper, I briefly review some experimental and theoretical constraints on the rheology of upper mantle rocks and minerals and then discuss the application of these data for understanding the rheology of the upper mantle in different tectonic environments. There is an expansive literature on the subject of mantle rheology; extensive reviews and background can be found in several recent articles and books (Poirier 1985; Ranalli 1995; Karato and Wu 1993; Kohlstedt et al. 1995; Drury and FitzGerald 1998; Hirth and Kohlstedt 2003), as well as numerous references made throughout this chapter. I focus the discussion of this chapter on the application of experimental data for constraining the rheology of the oceanic lithosphere and mantle. Constraints on mantle rheology based on extrapolation of laboratory experiments to deformation conditions in the oceanic lithosphere and asthenosphere are illuminating for several reasons. First, the composition of the mantle is relatively well constrained by analyses of peridotites from ophiolites and mid-ocean ridges, as well as chemical analyses of basalts. Second, the oceanic lithosphere is comprised of rock that cooled from high temperature conditions at high pressure, and is therefore not previously fractured. In this way the lithosphere is similar to the “ideal” rocks we use in our experiments. Third, the temperature of the lithosphere is constrained by a number of geophysical observations. Fourth, microstructural observations on naturally deformed mantle rocks justify applying experimental flow laws at geologic conditions. Finally, several independent geophysical observations, such as constraints on viscosity based on analysis …
Designing and testing a web‐based board game for teaching information literacy skills and concepts

Purpose – This paper seeks to focus on the design and testing of a web‐based online board game for teaching undergraduate students information literacy skills and concepts.Design/methodology/approach – Project team members with expertise in game play, creative writing, programming, library research, graphic design and information seeking developed a web‐based board game in which students used digital library resources to answer substantive questions on a scholarly topic. The project team hosted game play in a class of 75 undergraduate students. The instructor offered an extra‐credit incentive to boost participation resulting in 49 students on 13 teams playing the game. Post‐game focus group interviews revealed problematic features and redesign priorities.Findings – A total of six teams were successful meeting the criteria for the instructor's grade incentive achieving a 53.1 percent accuracy rate on their answers to substantive questions about the black death; 35.7 percent was the accuracy rate for the se...
Inhibitory effects of the pineal hormone melatonin and underfeeding during the promotional phase of 7,12-dimethylbenzanthracene-(DMBA)-induced mammary tumorigenesis.

The effects of melatonin (Mel) and/or underfeeding (30% food restriction) on 7,12-dimethylbenzanthracene (DMBA)-induced mammary tumorigenesis were examined in female Sprague-Dawley rats fed a semipurified diet. During the promotional phase of tumorigenesis, the animals began receiving either daily afternoon Mel (250μg) or saline vehicle injections s.c. for 15 weeks. As compared with fed animals, underfed rats had a lower tumor incidence, tumor number and size while the latency to onset and regression of tumors was increased. Melatonin in fed rats moderately suppressed tumor incidence and number. However, the combination of Mel treatment and underfeeding caused the most marked inhibition of tumorigenesis as compared with either treatment alone. These results indicate that Mel administration and/or underfeeding during the promotional phase inhibit DMBA-induced mammary tumorigenesis perhaps via neuroendocrine and/or peripheral endocrine mechanisms.
Deadtime corrections reduced by electronics

Abstract The deadtime of a counting system composed of scintillator, photomultiplier, window-discriminator and counter, was reduced from 20 nsec to about 2 nsec. The improvement was achieved by using the ability of the discriminator to eject more than one logic impulse depending on the duration of the photomultiplier pulse.
Direct determination of electron-hole trap depth from delayed luminescence of poly-(N-vinylcarbazole)

Abstract Charge-recombination luminescence from 27 cm 2 films of poly-(N-vinylcarbazole) (PVK), alone or doped with 2,4,7-trinitrofluorenone, was greatly reduced when the temperature was suddenly changed from 294 to 273 K during the decay. The instantaneous drop in luminescence corresponded to mean activation energies of 0.4–0.6 eV, in excellent agreement with previous indirect estimates of the energies of deep traps in PVK. The “missing” luminescence from the cooled films could be recovered as excess thermoluminescence on warming to 353 K.
Microstructural analysis of reaction-bonded silicon nitride

Abstract Reaction-bonded silicon nitride contains at least two different crystallographic forms of Si3N4 and several different microconstituents and morphologies. Application of a comprehensive study using x-ray and electron diffraction, electron microprobe analysis, optical metallography, and scanning and transmission electron microscopy has allowed a complete microstructural characterization to be achieved.
The structure of gas-phase bradykinin fragment 1-5 (RPPGF) ions: an ion mobility spectrometry and H/D exchange ion-molecule reaction chemistry study.

Ion mobility-mass spectrometry (IM-MS) data is interpreted as evidence that gas-phase bradykinin fragment 1-5 (BK1-5, RPPGF) [M + H]+ ions exist as three distinct structural forms, and the relative abundances of the structural forms depend on the solvent used to prepare the matrix-assisted laser desorption ionization (MALDI) samples. Samples prepared from organic rich solvents (90% methanol/10% water) yield ions having an ion mobility arrival-time distribution (ATD) that is dominated by a single peak; conversely, samples prepared using mostly aqueous solvents (10% methanol/90% water) yield an ATD composed of three distinct peaks. The BK1-5 [M + H]+ ions were also studied by gas-phase hydrogen/deuterium (H/D) exchange ion-molecule reactions and this data supports our interpretation of the IM-MS data. Plausible structures for BK1-5 ions were generated by molecular dynamics (MD). Candidate MD-generated structures correlated to measured cross-sections suggest a compact conformer containing a β-turn whereas a more extended, open form does not contain such an interaction. This study illustrates the importance of intra-molecular interactions in the stabilization of the gas-phase ions, and these results clearly illustrate that solution-phase parameters (i.e., MALDI sample preparation) greatly influence the structures of gas-phase ions.
CAN APPLICANTS' CHARACTERISTICS EXPLAIN THE SEX-STRUCTURING OF ORGANIZATIONS?

This study investigates attitudes towards the job search held by a sample of 60 male and 55 female college seniors. Respondents completed a questionnaire which included hypothetical job-search situations and items to gauge attitudes about seeking a job. There were no significant differences in the responses of men and women, suggesting that differential behavior of job applicants along gender lines is not a valid explanation for the sex-structuring of organizations. Implications for future research are offered.
An analytically solvable model for biomechanical response of the cornea to refractive surgery.

Abstract An analttically solvable model that considers the elasticity of the cornea is developed for use in the current and novel corneal refractive surgery procedures. The model assumes that the cornea is a thin spheroid shell with an elastic response to intraocular pressure. The value of the Young's modulus of the post-operative cornea and its dependence on the geometric parameters of the ablation zone are estimated employing "best-fit" approach to nomograms currently used in corneal refractive surgery. These elasticity parameters are applied for quantitative modeling of different types of refractive surgery for myopia.
Technique for Tensile Creep Testing of Ceramics

An experimental technique for measuring tensile creep deformation in ceramic materials to temperatures of 1500{degrees}C is described. The technique uses simple flat dog-bone-shaped specimens and a hot-grip design for the loading fixture, which provide good alignment at minimum cost. Creep deformation is measured using laser extensometry to monitor the relative displacement of flags that are attached to the gauge section of the specimen.
An Ad Hoc Analysis Strategy With Missing Data

Abstract A subset of a real data set was used to illustrate an ad hoc analysis with missing data on multiple response variables. This strategy was initiated with a complete-case analysis to determine some variable(s) that may be deleted with no loss in effects of interest. By such a deletion, the number of complete observation vectors may very well increase. Two straightforward imputed means analyses are also illustrated. All illustrations are given in the context of predictive discriminant analysis.
HgTe/CdTe superlattices grown by molecular beam epitaxy

Abstract In this paper we present results concerning the optical absorption in HgTe-CdTe superlattices. We confirm the narrowing of the superlattice band-gap (the increase of cut-off wavelength, λc) compared to the band gap of the equivalent Hg1−xCdxTe alloy. We show also, as predicted by the theory, an increase of the cut-off wavelength of the superlattice when the HgTe layer thickness increases. At 300K, the agreement between theory and experiment is fairly good if we consider the onset of the absorption. The λc tail shifting towards shorter wavelengths could be explained by the interdiffusion between HgTe and CdTe layers. At 30K, no important change in the I.R. absorption is noticed for all the superlattices. We present for the first time a superlattice exhibiting an absorption in the 8–12 μm window. We have carried out Hall measurements on several superlattices and present for the first time transport properties on these alternate microstructures. The most important features concern the unexpected and not yet understood very high hole mobilities at 10K.
Testing and validating frames for online organizations

In this paper we suggest that online environments can function as alternate "organizations" for pre-service and beginning teachers who may find themselves struggling in schools. Building on prior work on framing and reframing in organizations and schools, the authors present a new frame of analysis specifically geared for web-based learning/support communities. Data consist of transcripts from three forms of online discourse--an email listserv, an electronic discussion board, and a course-related wiki--from three groups of preservice secondary teachers (grades 6-12) located in three U.S. states. The development and testing of the new frame and its potential use is relevant for teachers, teacher educators, and school administrators.
Cold Exposure Increases the Biosynthesis and Proteolytic Processing of Prothyrotropin-Releasing Hormone in the Hypothalamic Paraventricular Nucleus via β-Adrenoreceptors

Different physiological conditions affect the biosynthesis and processing of hypophysiotropic proTRH in the hypothalamic paraventricular nucleus, and consequently the output of TRH. Early studies suggest that norepinephrine (NE) mediates the cold-induced activation of the hypothalamic-pituitary-thyroid axis at a central level. However, the specific role of NE on the biosynthesis and processing of proTRH has not been fully investigated. In this study, we found that NE affects gene transcription, protein biosynthesis, and secretion in TRH neurons in vitro; these changes were coupled with an up-regulation of prohormone convertase enzymes (PC) 1/3 and PC2. In vivo, NE is the main mediator of the cold-induced activation of the hypothalamic-pituitary-thyroid axis at the hypothalamic level, in which it potently stimulates the biosynthesis and proteolytic processing of proTRH through a coordinated up-regulation of the PCs. This activation occurs via beta-adrenoreceptors and phosphorylated cAMP response element binding signaling. In contrast, alpha-adrenoreceptors regulate TRH secretion but not proTRH biosynthesis and processing. Therefore, this study provides novel information on the molecular mechanisms of control of hypophysiotropic TRH biosynthesis.
Expression of human 5-lipoxygenase cDNA in Escherichia coli

A cDNA for human 5-lipoxygenase (5LO) was inserted into the vector pKC (constructed from pKK223-3 by replacing its replication origin with that of pUC18) and expressed in Escherichia coli. The enzyme expressed was purified to homogeneity from the cellular soluble fraction. The purified enzyme showed both 5LO and leukotriene A4 synthase activities, which were stimulated by Ca2+ and ATP. Its molecular mass (78 kDa) and NH2-terminal sequence were identical with those of 5LO purified from human leukocytes. The availability of the expression system will facilitate further studies on its regulation and the reaction mechanism of the enzyme.
Relationship between alcohol dependence, escape drinking, and early neural attention to alcohol-related cues

Rationale Previous work has indicated that implicit attentional biases to alcohol-related cues are indicative of susceptibility to alcohol dependence and escape drinking, or drinking to avoid dysphoric mood or emotions.
Liberal–conservative conflict and consensus in policy making

Abstract This study argues that ideology can play a major and positive role in the policy making process. Using the policy areas of civil rights and public education, it demonstrates that when policy initiatives are both ideologically consistent and based on a clear delineation of the dynamics of how the policy will change the current situation for the better, the ensuing debate between liberals and conservatives generally results in effective policy. When both elements are not present, ineffective policy results.
Campaign Advertisements’ Impact on Voter Certainty and Knowledge of House Candidates’ Ideological Positions

One expectation for American election campaigns is that they inform citizens about candidates' policy inclinations, clarifying the policy directions advocated by the major party nominees. Evidence from the 1998 elections to the House of Representatives indicates that the more negative issue advertisements were broadcast, the more confident citizens became that they knew the targeted candidate's ideological position. However, the more negative issue advertisements about a candidate aired, the greater citizens' perceptual error of the candidate's ideological position. Issue attack ads lead citizens to believe they know more than they actually do, failing to produce the democratic ideal of an informed electorate.
Haunted by the specter of communism: Collective identity and resource mobilization in the demise of the Workers Alliance of America

This article seeks to integrate identity-oriented and strategic models of collective action better by drawing on Pierre Bourdieu’s theory of classification struggles. On the one hand, the article extends culture to the realm of interest by highlighting the role collective identity plays in one of the key processes that strategic models of collective action foreground: the mobilization of resources. The article extends culture to the realm of interest in another way as well: by challenging the notion that labor movements are fundamentally different from or antithetical to the identity-oriented new social movements. On the other hand, the article also extends the idea of interest to culture. Rather than viewing collective identity as something formed prior to political struggle and according to a different logic, I show that collective identity is constructed in and through struggles over classificatory schemes. These include struggles between movements and their opponents as well as struggles within movements. The article provides empirical evidence for these theoretical claims with a study of the demise of the Workers Alliance of America, a powerful, nation-wide movement of the unemployed formed in the United States in 1935 and dissolved in 1941.
Catalyst Design to Change Selectivity of Photocatalytic Oxidation

Abstract Different selectivities for photocatalytic oxidation (PCO) of ethanol were observed for two types of adsorption sites on TiO 2 , and this identification led to the design of a photocatalyst with enhanced selectivity to acetaldehyde, a partial oxidation product. Transient photocatalytic oxidation (PCO), steady-state reaction, temperature-programmed desorption (TPD), temperature-programmed oxidation, and isotope labeling were combined to determine the reactivity of the different adsorption sites. During PCO, weakly bound ethanol preferentially formed gas-phase acetaldehyde, whereas strongly bound ethanol (which decomposes during TPD) primarily produced CO 2 . Weakly bound ethanol appears to adsorb on sites that are not available for acetaldehyde adsorption. This information, combined with the fact that acetaldehyde decomposes to a strongly bound intermediate during TPD, led to the design of a catalyst that was modified with acetaldehyde TPD products, which were stable during PCO. The TPD products of acetaldehyde preferentially poison the sites where ethanol is strongly bound so that selectivity to acetaldehyde increased during ethanol PCO. Higher selectivity was seen during both transient and steady state experiments, and at 54–60% conversion the ratio of partial to complete oxidation on the poisoned catalyst was five times that on fresh TiO 2 .
Intelligent agent support for automated radiology exam

A difficult problem in automatic medical image understanding is that for every image type such as x-ray and every body organ such as heart, there exist specific solutions that do not allow for generalization. Just collecting all the specific solutions will not achieve the vision of a computerized physician. To address this problem, we propose an intelligent agent approach that is based on agent-oriented programming is that it combines the benefits of object-oriented programming and expert system. For radiology image understanding, we present a multi- agent system that is composed of two major types of intelligent agents: radiologist agents and patient agents. A patient agent asks for multiple opinions from radiologists agents in interpreting a given set of images and then integrates the opinions. A radiologist agent decomposes the image recognition task into smaller problems that are solved collectively by multiple intelligent sub-agents. Finally, we present a preliminary implementation and running examples of the multi-agent system.
Corner Detection From Thinned Edge Images Using A Kalman Filter

An algorithm is described to detect corners from thinned edge maps of polygonal or polyhedral objects using a Kalman filter. Straight lines are modelled as constant slope segments. The length of a line is assumed to increase at a constant rate as more points are added to the segment. The state vector consists of the angle of inclination of the straight line, its length and the rate of change of the length with each new pixel. A linear state transition equation is developed based on this model. Plant noise is added to account for the fact that the straight lines are digital straight lines, and it is assumed to be zero mean, Gaussian and uncorrelated. The system measurement consists of the pixel coordinates of the edge. These coordinates can be expressed as a nonlinear function of the state vector. The measurement errors are also assumed to be zero mean, Gaussian and uncorrelated. Using this linear plant model and a nonlinear measurement model, an extended Kalman filter is used to track the line segments. The divergence of the filter from its steady state is detected to locate a corner. Tests done indicate that this technique works well. The results are compared to the results obtained by using a difference of low pass (DOLP) corner detector.
Using Mathematics to Solve Some Problems in Industry

This paper describes how some industrial problems can be solved using relatively simple mathematical models. Models can be used also to provide insight into how industrial system components interact. This paper is useful for master's level students in that it describes what a model is as well as the modeling function. Master's students in engineering and MBAs and Ph.D. students who are interested in solving real industry problems should find this overview of models useful. Different types of industrial problems are discussed. Finally, some models that address industrial problems, such as inventory models, linear programming, network flow, decision analysis, queueing models, and simulation are examined. Future industrial modeling situations are described.
A simultaneous evaluation of 10 commonly used physical activity questionnaires

ABSTRACTTen commonly used physical activity questionnaires were evaluated for reliability and validity in 78 men and women aged 20–59, with varying physical activity habits. One month reliability was found to be high for all questionnaires except those pertaining only to the last week or month. Long
Effect of acceptor membrane phosphatidylcholine on the catalytic activity of bovine liver phosphatidylcholine transfer protein.

Protein-mediated transfer of phosphatidylcholine (PC) by bovine liver phosphatidylcholine transfer protein (PC-TP) was examined using a vesicle-vesicle assay system. Donor and acceptor membranes were prepared from Escherichia coli phospholipids and limiting amounts of egg yolk PC. PC transfer between vesicles of E. coli lipid/egg PC was markedly higher than transfer of PC from vesicles of E. coli lipid/egg PC to vesicles of E. coli lipid. Kinetic parameters of the interaction between PC-TP and E. coli lipid vesicles with or without PC was investigated. The apparent dissociation constants of the complex formed between PC-TP and these vesicles were determined kinetically and from double-reciprocal plots of intrinsic PC-TP fluorescence intensity increase versus vesicle concentration. The magnitude of the dissociation constant decreased as the PC content of the vesicles increased from 0 to 5 mol%. In addition, kinetic analysis revealed that the presence of PC in acceptor vesicles increased both the association and dissociation of PC-TP from vesicles. The effect of membrane PC molecules on transfer rates was examined using bis-phosphatidylcholine, a dimeric PC molecule which is not transferred by PC-TP. Rates of PC transfer to acceptor vesicles comprised of E. coli lipid/bis-PC were virtually identical to rates observed with acceptors vesicles prepared from E. coli lipid. The results suggest that transfer of PC by PC-TP is enhanced only when insertion of protein-bound PC occurs concurrently with the extraction of a molecule of membrane PC, i.e., a concerted, one-step catalytic mechanism for phospholipid exchange.
Long-term memory of a DRL task in mature and aged rats

Mature (6 mo.) and aged (26 mo.) rats were trained on a DRL 6-sec schedule. In order to produce equivalent levels of task performance, the mature rats were trained for 16 sessions while the aged rats were trained for 20 sessions. After a 21-day interval, rats were tested for retention of the DRL task. No age-related differences in LTM of the DRL task were found. If the DRL schedule is considered an analog of a recall task, the present results do not agree with Campbell et al. (1980) who found age differences in retention of a FI schedule after 8 days of training. In the present experiment animals were more extensively trained on the task to be remembered. Thus, the present experiment suggests that an age-related difference in LTM, even on recall tasks, will not be significant if aged animals are overtrained on the task to be remembered.
Anti-actin-peroxidase staining of the helical wall-free prokaryoteSpiroplasma citri

An antiserum made against sodium dodecyl sulfate-denatured actin from invertebrates and coupled to horseradish peroxidase specifically stains the wall-free prokaryoteSpiroplasma citri. The results of experiments with spiroplasmas reported here, coupled with the report of the extraction from them of an actin-like protein, suggest that these highly motile organisms possess an actin-like mediated mechanism of motility.
Easily Implementable Inventory Control Policies

This work was initiated and supported by a manufacturer of mail processing equipment, which stocks 30,000 distinct parts in a distribution center to support field maintenance of their equipment. To find an effective stocking policy for this system we formulate a constrained optimization model with the objective of minimizing overall inventory investment at the distribution center subject to constraints on customer service and order frequency. Because size, integrality, and nonconvexity make this problem intractable to exact analysis, we develop three heuristic algorithms based on simplified representations of the inventory and service expressions. These lead to what we call easily implementable inventory policies, in which the control parameters for a newly introduced part can be computed in closed form without reoptimizing the rest of the system. Numerical comparisons against a lower bound on the cost function show that even our simplest heuristic works well when a high service level is required. However...
Melatonin ameliorates neurologic damage and neurophysiologic deficits in experimental models of stroke.

: This review summarizes the numerous reports that have documented the neuroprotective actions of melatonin in experimental models of ischemia/reperfusion injury (stroke). In these investigations, which have used three species (rat, gerbil, and cat), melatonin was universally found to reduce brain damage that normally occurs as a consequence of the temporary interruption of blood flow followed by the reflow of oxygenated blood to the brain. The exogenous administration of melatonin in these experimental stroke models reduced infarct volume, lowered the frequency of apoptosis, increased the number of surviving neurons, reduced reactive gliosis, lowered the oxidation of neural lipids and oxidatively damaged DNA, induced bcl-2 gene expression (the activity of which improves cell survival), upregulated excision repair cross-complementing factor 6 (an essential gene for preferential DNA excision repair), restrained poly(ADP ribose) synthetase (which depletes cellular NAD resulting in the loss of ATP) activity, and improved neurophysiologic outcomes. Under no circumstances did melatonin exacerbate the damage associated with ischemia/reperfusion injury. As well as the beneficial pharmacologic actions of melatonin, several studies show that a relative deficiency of endogenous melatonin exaggerates neural damage due to stroke; this suggests that even physiologic concentrations of melatonin normally serve to protect the brain against damage. The primary action to explain melatonin's protective effects may relate to its ubiquitous direct and indirect antioxidative actions, although other beneficial functions of melatonin are not precluded.
A fast feature-assisted adaptive early termination approach for multiple reference frames motion estimation in H.264

The multiple reference frames motion estimation approach used in H.264 is computationally intensive. This paper presents a fast or computationally efficient feature-assisted adaptive early termination approach in order to reduce the computational complexity while maintaining more or less the same video quality. The introduced feature-assisted approach consists of three parts: (1) reduction of the number of available reference frames using predicted motion activity, extracted texture information, and skip mode from neighboring macroblocks, (2) the most probable reference frame prediction based on neighboring macroblocks, and (3) an adaptive early termination threshold derived from a theoretical analysis of all zero block detection. Extensive experimental results are performed to demonstrate the computational gain of the introduced approach over the standard approach for the multiple reference frames motion estimation.
WiFi Geographies: When Code Meets Place

This article argues that as our homes, offices, cities, and spaces get layered with digital information networks, it is vital that we develop new conceptual categories that integrate digital and physical spaces. With that objective in mind, it examines how WiFi networks interact with socioeconomic factors to reconfigure people, places, and information in physical spaces. Drawing on empirical research from ethnographic observations, a survey, and in-depth interviews, it shows how the availability of WiFi public hotspots has opened up new ways for freelancers to do their work, often using different locales for different phases of their work. Also, for freelancers in search of opportunities for co-working, WiFi hotspots are sites of informal interaction, social support, collaboration, and innovation. The article also illustrates how a WiFi network does not map onto existing physical or architectural boundaries. Instead, it reconfigures them in a number of ways by permeating walls, bleeding into public spaces...
Human reaction time during dark adaptation.

Reaction times of two subjects for different brief flashes are measured during the course of dark adaptation. Seven experimental conditions known to influence measures of dark adaptation are investigated. The results are discussed for their bearing on traditional psychophysical measures of threshold changes.
Clarification and integration of similar quality of life concepts.

Purpose: To identify major problems that obscure understanding of quality of life; to differentiate quality of life from other closely related concepts, and to offer a definition of quality of life. Quality of life is a term frequently used, but seldom defined, in nursing research. Multiple interpretations and measures make evaluating research difficult. The need to clarify concepts, develop nursing theory, and enhance communication is significant. Concept clarification is also essential for research instrument development and evaluation. Organizing Construct and Scope: Concept analysis as proposed by Walker and Avant. Preconceived theories were avoided to keep the analysis as unbiased as possible. The analyst considered many descriptions of quality of life, but eventually included only those in the scientific literature. Sources: CINAHL, Medline, Psych-Info, ERIC, Social Science Abstracts, and reference lists from published articles in nursing, medicine, psychology, and sociology were used. Twenty-seven theory-based articles and book chapters published since 1989 and a convenience sample of 88 research articles published in 1997 were used. This sample was selected from 16,480 articles published 1993 to 1998. Methods: Concept clarification comparisons to identify the major attributes of several closely related concepts, including well-being, satisfaction with life, and functional status. Major attributes were validated by a panel of cohorts who met weekly for five consecutive weeks for the purpose of analyzing various concepts. Findings: Quality of life is comprised of subjective indicators such as well-being and satisfaction with life and objective indicators, such as functional status. Continued dialog and research is necessary to distinguish between the concepts of health and quality of life. Conclusions: A model showing the relationships among quality of life, well-being, functional status, and satisfaction with life is provided and a definition of quality of life is offered. Researchers and authors should include the definition of quality of life used in their work. Instruments should reflect the theoretic definition used. Care should be taken to clarify if functional status, well-being, satisfaction with life are the concepts under consideration as reflecting a part of overall quality of life.
Hemodynamic characteristics of young men at risk for hypertension at rest and during laboratory stressors.

Examined hemodynamic activity--at rest, during mental arithmetic, and during hand cold pressor--in young men varying in risk for hypertension. Classification into low-risk (n = 72), moderate-risk (n = 20), and high-risk (n = 13) groups was based on resting systolic blood pressure (SBP) and parental history of essential hypertension (PH). Dependent variables were SBP, diastolic BP (DBP), heart rate, and rate-pressure product (RPP). Progressively greater hemodynamic activity was seen across risk groups at rest and during the tasks. Risk groups differed significantly in SBP, DBP, and RPP at baseline (ps less than .003) and in size of response to mental arithmetic (ps less than .05) but not to cold pressor. These relationships were either absent or weaker when using either risk factor alone to form risk groups. These findings suggest that hemodynamic reactivity to mental stress is predicted better by a combination of resting SBP and PH than by either risk factor alone and that physiological reactivity may be an important accompaniment of increased risk for hypertension.
Is a return to baseline sexual function possible? An analysis of sexual function outcomes following laparoscopic radical prostatectomy

Outcome measures following radical prostatectomy are not standardized. Though excellent potency rates are widely reported, few studies address a return to baseline function. We analyze validated sexual health-related quality-of-life outcomes by a strict definition, a return to baseline function, and compare them to less stringent, yet more frequently referenced, categorical definitions of potency. Patients undergoing laparoscopic radical prostatectomy from April 2001 to September 2007 completed the Expanded Prostate Cancer Index Composite (EPIC) questionnaire at baseline and 3, 6, 12, and 24 months postoperatively. We defined a return to baseline as a recovery to greater than one-half standard deviation of the studied population below the patient’s own baseline (clinically detectable threshold). We compared these outcomes to a categorical definition of potency involving intercourse frequency. To limit confounders, we performed subset analyses of preoperatively potent men who received bilateral nerve preservation. Factors predictive of return to baseline function were assessed in multivariable analysis. A total of 568 patients met inclusion criteria. Mean age and follow-up were 57.2 years and 16.9 months, respectively. Using the categorical definition, 85% of preoperatively potent men with bilateral nerve preservation were “potent” at 24 months; however, only 27% returned to their baseline sexual function. In multivariable analyses baseline function, number of nerves spared, and age were independent predictors of a return to baseline function. While most preoperatively potent men who receive bilateral nerve preservation engage in intercourse postoperatively, few return to their baseline sexual function. We believe that these data provide context for the expectations of patients who elect extirpative therapy.
Targeted drug delivery to the brain via phosphonate derivatives II. Anionic chemical delivery system for zidovudine (AZT)

Abstract The previously described anionic chemical delivery system (aCDS) approach (Somogyi, G., Nishitani, S., Nomi, D., Buchwald, P., Prokai, L., Bodor, N., 1997. Targeted drug delivery to the brain via phosphonate derivatives. I. Design, synthesis and evaluation of an anionic chemical delivery system for testosterone. Int. J. Pharm. (166, 15–26) was applied for brain-targeted delivery of AZT. For this system, the whole designed metabolic sequence, ending with release of the active drug at the targeted organ, was completed. As a less hindered ester function was built into this aCDS, cleavage by esterases, the first metabolic step in the decomposition process, was fairly rapid. The negatively charged decomposition product (AZT-P − ) could be detected for about 48 h in different organs. In vitro experiments proved that AZT is released from this phosphonate derivative after phosphorolytic attack, the second metabolic step of the designed sequence, but only at a slow rate. While the phosphonate derivative of a secondary hydroxyl group proved completely resistant to such phosphorolytic attacks, alkaline phosphatase, but not phosphodiesterase, was able to cleave the P–O bond of the phosphonate derivative at the primary hydroxyl group in this system. After i.v. administration of AZT-aCDS in rabbits, AZT could be detected in the brain, albeit only at very low concentrations. Even if sufficiently high drug levels could not be delivered with the present aCDSs, the sequence was completed, the rate of metabolism was controllable, and the approach is flexible enough; therefore, further, adequate manipulations might render such anionic chemical delivery systems into a useful addition of the drug targeting arsenal.
Endoscopy-related infections

SUMMARY Endoscopic procedures generate bacteraemia to different degrees. Under certain conditions, most notably valvular heart disease, clinically significant infections may occur. A large body of literature has grown around recommendations for antibiotic prophylaxis to prevent procedure-related infections. Most of this literature is in the form of anecdotal reports. Few prospective randomized studies have been performed. In this paper, the literature on endoscopy-related infections is reviewed. Recommendations for antibiotics from different sources are compared and a rational approach to prophylactic antibiotic therapy is presented.
The evaluation of the dielectric constants and loss tangents for different structural foams in wet and dry conditions

In this research, the evaluation of the dielectric constant and loss tangent of different structural foams such as Rohacell HF 71 and EC71 will be discussed. In addition to these foams being used as structural foams for aircraft, radomes, etc., they can also be used as substrates for microwave devices and antennas, so knowing both their mechanical characteristics as well as their electrical characteristics can be quite important. Dielectric constant and loss tangent measurements for the different foams were done under both dry conditions and under wet conditions. For the wet conditions, the foams were subjected to a constant relative humidity over a period of 17 days to simulate an environment in which the foams were considered to be saturated with moisture. In addition to the humidity testing, different densities of one type of foam, such as HF71, were tested to see how the different densities affected both the dielectric constant and loss tangent. Our tests were performed in rectangular waveguide from 1.7 GHz to 26.5 GHz so that the electrical characteristics were known over a wide frequency band. Waveguide TRL calibration kits and material test kits were designed at the University of Mississippi and fabricated for this testing. This research is important because not only are these materials increasingly used as radomes and in shielding environments, but since they can also be utilized as substrates, it is necessary to know these materials' electrical properties so that they can be used throughout the design process for antennas and microwave circuits by importing their electrical parameters into design software. All of the materials tested were measured on the Agilent PNA network analyzer at the University of Mississippi. In the presentation, a brief discussion of the design and fabrication of the TRL test fixtures will be shown, followed by a discussion of the measurement setup and material parameter extraction technique. Finally, the results obtained for the different foams will be presented and comparisons between different densities of the same foam type and comparisons of foams in the wet and dry conditions will be discussed.
Orthoptic indications for contact lens wear

Orthoptic anomalies are prevalent: they are encountered in at least 5% of patients seen in a typical primary eyecare practice. Several cases are reviewed that highlight the role of contact lenses in treating orthoptic anomalies. In particular, contact lenses are the preferred optical approach to the correction of anisometropia, and it is often argued that anisometropia should be corrected as young as possible. However, fitting contact lenses to patients, particularly children, with anisometropic amblyopia has been problematic because there is no immediate binocular acuity improvement when the contact lenses are inserted which reduces patient motivation. Continuous wear with silicone hydrogels represents a breakthrough for these cases and some illustrative case studies are given. The visual deficit in amblyopia can be reduced in some cases solely by fitting contact lenses, without the need for occlusion therapy. Other orthoptic uses of contact lenses are reviewed including: correcting motor deviations, occlusion, and infantile onset nystagmus. It is concluded that there are orthoptic anomalies where contact lenses are the preferred mode of correction. It is in patients' best interest for practitioners to discuss contact lenses in these cases.
Editorial polocies: International journal of public administration

(1989). Editorial polocies: International journal of public administration. International Journal of Public Administration: Vol. 12, No. 6, pp. ebi-ebii.