cssi/SciSciGPT-SciSciNet huggingface dataset:
Suppression effects in feature-based attention.

Attending to a feature enhances visual processing of that feature, but it is less clear what occurs to unattended features. Single-unit recording studies in middle temporal (MT) have shown that neuronal modulation is a monotonic function of the difference between the attended and neuron's preferred direction. Such a relationship should predict a monotonic suppressive effect in psychophysical performance. However, past research on suppressive effects of feature-based attention has remained inconclusive. We investigated the suppressive effect for motion direction, orientation, and color in three experiments. We asked participants to detect a weak signal among noise and provided a partially valid feature cue to manipulate attention. We measured performance as a function of the offset between the cued and signal feature. We also included neutral trials where no feature cues were presented to provide a baseline measure of performance. Across three experiments, we consistently observed enhancement effects when the target feature and cued feature coincided and suppression effects when the target feature deviated from the cued feature. The exact profile of suppression was different across feature dimensions: Whereas the profile for direction exhibited a “rebound” effect, the profiles for orientation and color were monotonic. These results demonstrate that unattended features are suppressed during feature-based attention, but the exact suppression profile depends on the specific feature. Overall, the results are largely consistent with neurophysiological data and support the feature-similarity gain model of attention.
Long-term ecological changes in the densely populated rural landscapes of China

Asia's densely populated agricultural landscapes are undergoing unprecedented ecological changes caused by population growth and adoption of industrial technologies such as fossil fuel and chemical fertilizer. Covering nearly 6 × 10 6 km 2 , these landscapes now release more than half of global greenhouse gas emissions from agricultural land and biomass fuel. Measuring ecological processes and their changes in these highly heterogeneous village landscapes is made difficult by their very small scale of management, with households typically managing many small plots using a wide variety of inputs and methods. This chapter describes the global extent of village landscapes, characterizes their spatial heterogeneity, establishes appropriate scales for ecological change measurement, and demonstrates methods developed to measure long-term ecological changes across village landscapes in China. Reliable measurements of ecological change in village landscapes can be made by integrating high-resolution (≤1 m) landscape change measurements with household-level resource management data. These methods link local land use practices with regional and local ecological change, potentially aiding land use decision-making, but require far greater research effort than conventional land use measurements based on 30-1000 m resolution imagery and county or provincial data. Therefore, a multi-scale sampling and analysis system was developed to integrate local and regional data for estimating regional change across village landscapes in China. The strengths and weaknesses of this approach in measuring and mediating the impacts of ecological changes in densely populated landscapes are discussed in light of preliminary results indicating that population increase and modernization are increasing carbon sequestration across these landscapes.
Filecules in High-Energy Physics: Characteristics and Impact on Resource Management

Grid computing has reached the stage where deployments are mature and many collaborations run in production mode. Mature grid deployments offer the opportunity for revisiting and perhaps updating traditional beliefs related to workload models, which in turn leads to the re-evaluation of traditional resource management techniques. This paper analyzes usage patterns in a typical grid community, a large-scale data-intensive scientific collaboration in high-energy physics. We focus mainly on data usage, since data is the major resource for this class of applications. Our observations led us to propose a new abstraction for resource management in scientific data analysis applications: we define a filecule as a group of files that is always used together. We show that filecules exist and present their characteristics. The existence of filecules suggests a new granularity for data management, which, if incorporated in design, can significantly outperform the traditional solutions for data caching, replication and placement based on single-file granularity. We reason about the impact of filecules on resource management and show compelling evidence for using this abstraction when designing data management services
Survival of Denitrifiers in Nitrate-Free, Anaerobic Environments

Abstract Experiments were undertaken to explain the occurrence of a high denitrification capacity in anaerobic, NO3--free habitats. Deep layers of freshwater sediments that were buried more than 40 years ago and digested sludge were the habitats studied. The denitrifier populations were 3.1 × 103 and 3.1 × 105 cells cm-3 in deep sediments from a river and lake, respectively, and 5.3 × 106 cells cm-3 in digested sludge. The denitrification capacities of the samples reflected the population densities. Strict anaerobic procedures were used to obtain the predominant isolates that would grow on anaerobic medium with NO3-. All strict anaerobes isolated failed to denitrify. All isolates that denitrified were aerobic, gram-negative bacteria, particularly species of Pseudomonas and Alcaligenes. No detectable growth was observed when these strains were incubated with electron acceptors other than NO3- or O2. When representative isolates were added to sterile, O2- and NO3--free porewater from their original locations at their natural densities (105 cells cm-3), no change in viable population was noted over 3 months of incubation. Metabolic activity was demonstrated in these cells by slow formation of formazan granules when exposed to tetrazolium and by observation of motile cells. When [14C]glucose was added to cell suspensions of the pseudomonads that had been starved for 3 months without electron acceptors (O2 or NO3-), 14C-labeled products, including cell biomass, 14CO2, and fermentation products, were produced. The high denitrification capacity of these anaerobic environments appears to be due to conventional respiratory denitrifiers. These organisms have the capacity for long-term survival without O2 or NO3- and appear to be capable of providing for their maintenance by carrying on a low level of fermentation.
Empirical Bayes, with Application to Genomics†

When certain estimation situations are encountered many times, the data from all these situations can be used to construct estimates for each individual case. This overview shows how empirical Bayes has evolved and expanded since its 1955 origins in order to useful practical procedures, which are good not only asymptotically but also in moderately sized samples. Various distributional models are described, as is an application to gene expression data. Keywords: random effects; Robbins; posterior distribution; Stein's estimator; shrinkage; regression toward the mean; gene expression; multiple comparisons
Close Linkage Between Ochre and Missense Suppressors in Escherichia coli

It was previously shown that the ochre suppressor mutation sup15B in Escherichia coli determines the accumulation of altered 30S ribosomal subunits and the presence of altered transfer ribonucleic acid (tRNA) capable of suppressing in vitro the UAG codon. This mutation has been mapped in the present study by means of conjugation and transduction experiments. After establishing the location of sup15B near argH, the following order was determined for the markers tested: metB-argH-(sup15B, supA36)-rif-thi. A comparison of location, growth rate, and suppressor pattern determined by sup15B and supM indicates the high probability that both suppressor mutations are identical. This study has also yielded a more precise location for the rifampin resistance gene. The most interesting finding is the very close (if not adjacent) location of the suppressor mutations sup15B and supA36, both of which determine tRNA alterations.
Acoustic Purification of Extracellular Microvesicles

Microvesicles (MVs) are an increasingly important source for biomarker discovery and clinical diagnostics. The small size of MVs and their presence in complex biological environment, however, pose technical challenges in sample preparation, particularly when sample volumes are small. We herein present an acoustic nanofilter system that size-specifically separates MVs in a continuous and contact-free manner. The separation uses ultrasound standing waves to exert differential acoustic force on MVs according to their size and density. By optimizing the design of the ultrasound transducers and underlying electronics, we were able to achieve a high separation yield and resolution. The “filter size-cutoff” can be controlled electronically in situ, which enables versatile MV-size selection. We applied the acoustic nanofilter to isolate nanoscale (<200 nm) vesicles from cell culture media as well as MVs in stored red blood cell products. With the capacity for rapid and contact-free MV isolation, the developed sys...
Tumorigenic and molecular characterization of novel phorbol ester-resistant and -sensitive lines of mice.

Two outbred lines of CD-1 mice were developed using males and females in an initiation (dimethyl-benz[a]anthracene; DMBA), promotion (12-O-tetradecanoylphorbol-13-acetate; TPA) challenge, posttumorigenesis breeding protocol. Our results indicate that the phorbol ester-resistive (PESTI) line developed tumors at a rate 4.1 times faster than the CD-1 parental line, while the phorbol ester-resistant (PERTI) line developed tumors at a rate 36 times slower than the CD-1 parents. The average number of tumors per mouse reached levels of 27.5 at 12 wk in the PESTI line, 0.1 at 16 wk in the PERTI line, and 6.7 at 16 wk in the CD-1 line. Biochemical tests showed that the PESTI line had both a high basal level and an enhanced epidermal ornithine decarboxylase (E.C. 4.1.1.17) response to TPA, the latter being nine times that of the PERTI line at their maximum dosages. An autoradiographic analysis of in vivo epidermal cell protein phosphorylation indicated marked differences in basal protein phosphorylation profiles (with high phosphate incorporation, PERTI, 112.7, 95.5, 64.4, 40.8, 18.6, 17.4, and 12.3 kDa; PESTI, 64.4, 40.8, 31.8, and 12.3 kDa) as well as TPA-dependent changes in these profiles (difference from basal levels, PERTI, 31.8 and 12.8 kDa; PESTI, 139.6, 126.3, 37.2, and 18.6 kDa). These heterogeneous profiles indicate strong genetic segregation of these protein kinase C target substrates. This dermatologically based selection and breeding process also resulted in cosegregating genetic changes in TPA binding constants (Kd) for brain protein kinase C, which were reversed for cytosolic and plasma membrane fractions in the PESTI (cytosolic, 0.50 nM; plasma membrane, 1.89 nM) and PERTI (cytosolic, 2.02 nM; plasma membrane, 0.51 nM) mice. Moreover, TPA-inducible phosphorylation of 43 and 110 kDa proteins in vivo in the brains of only the PERTI line mice suggests that the PESTI line has either high levels of endogenous phosphorylation or reduced expression of these proteins. In contrast, in vitro screening of brain cytosolic proteins indicated that both lines have a 120 kDa protein whose phosphorylation can be induced by TPA while the PESTI line has a 14 kDa protein whose phosphorylation regulatory controls differ from the PERTI line. Thus, these lines of mice provide experimental systems for defining the skin tumorigenesis process and possibly extending initiationpromotion observations and concepts to other tissues.
The role of sphingomyelin synthetase and sphingomyelinase in 1,2-dimethylhydrazine-induced lipid alterations of rat colonic plasma membranes

Abstract Recently, our laboratory, utilizing the 1,2-dimethylhydrazine model of colonic adenocarcinoma, demonstrated alterations in the ‘dynamic component’ of fluidity in brush-border membranes prepared from distal colonocytes of rats administered this agent for 5, 10 and 15 weeks, i.e., before the development of colon cancer. Furthermore, changes in the sphingomyelin content and sphingomyelin/phosphatidylcholine molar ratio of these membranes appeared, at least partially, to be responsible for these fluidity alterations. In an attempt to elucidate the mechanism(s) involved in these dimethyhydrazine-induced lipid changes, in the present studies the activities of sphingomyelin synthetase and magnesium-dependent neutral sphingomyelinase, enzymes involved in the synthesis and degradation of this phospholipid, respectively, were examined and compared in distal colonic brush-border membranes prepared from rats after 5, 10 or 15 weeks administration of dimethylhydrazine or diluent. The results of these studies demonstrate that alterations in both these enzymatic activities can be detected after administration of dimethylhydrazine and appear to, at least in part, be responsible for the changes in membrane sphingomyelin composition noted previously. These results as well as a discussion of their possible significance serve as the basis for the present report.
Ultraviolet laser induced fluorescence of human aorta

Abstract Laser induced fluorescence from normal human aorta is studied with u.v. excitations of 305 to 310 nm, observing emission from 320 to 500 nm. In this region LIF lineshapes are strongly dependent on the excitation wavelength, suggesting that at least two fluorophores are being observed. The short wavelength fluorophore, peaking at 34Onm, is identified as tryptophan, while the longer wavelength fluorophore, peaking at 387 nm, is associated with collagen and elastin. In addition, fluorescence time decays of each component are measured with a time correlated photon counting system. A four-exponential fit of each decay is necessary to extract fluorescence lifetimes, which range from 33 ps to 8.6 ns.
Quantifying changes in age distributions and the hydrologic balance of a high-mountain watershed from climate induced variations in recharge

Summary Changes in the spatial distribution and flow-paths of water in a high-mountain, headwaters watershed are evaluated using an integrated hydrologic model based on a heterogeneous domain in the Rocky Mountains of Colorado in the United States. The model framework simulates both surface and subsurface flow and age. Four different recharge scenarios that span the range of recharge changes across North America due to climate change are compared. The changes in the distribution of water are quantified in terms of stream flow and groundwater level changes. Composite age distributions that represent the total time spent in the terrestrial hydrologic system are used to link these flow perturbations to alterations of residence time. This integrated approach permits delineation of the time spent in the surface water system, the vadose zone, and saturated groundwater. For the range of recharge scenarios considered, the biggest changes to the hydrologic system manifest in the vadose zone, which then propagate into the groundwater system and heavily affect the composite age distribution. Overall, this approach shows that composite age distributions and domain specific age distributions provide an excellent accounting of the changes in the distribution of water mass and the extent of characterization is far more descriptive than only considering stream flow or groundwater levels.
The effect of varying acquisition parameters on the interpretation of SIR-C radar data: The Virunga volcanic chain

Abstract In 1994, the Spaceborne Imaging Radar experiment C (SIR-C) acquired five data takes with different acquisition parameters over the Virunga volcanic chain, Zaire. Changes in incidence angle (20.0–48.1°), look direction (west- and east-looking), and pulse bandwidth (10 MHz, 20 MHz, and 40 MHz) affect the geologic interpretations drawn from these data. We examine differences in spatial distortion of features near the summit of Nyiragongo volcano, finding that opposite look direction data are helpful in interpreting volcanic features, such as the shape of small craters, in areas of high relief. The relative brightness of lava flows and vegetation change (and actually reverse) for different wavelengths and polarizations. Although L-band data are best for mapping the outline of the flows, C- and X-band cross-polarization data show differences in backscatter intensity between and within flows. In addition, our ability to discriminate lava flows and vents from surrounding vegetation is strongly influenced by pulse bandwidth (resolution) and angle of incidence. Pulse bandwidth is the most important parameter in mapping small topographic features such as volcanic cones and a set of particularly thick flows on the flanks of Karisimbi volcano. These examples illustrate important considerations of the tradeoffs and priorities in acquisition parameters for future missions such as ENVISAT, as well as potential pitfalls for interpretation of existing data.
Pickup Protons in the Heliosphere

We calculate the conditions of pickup protons inside the termination shock. Outside 50 AU the partial pressure of pickup protons is greater than the magnetic pressure by a factor of > 10, and greater than the partial pressure of solar wind protons by a factor of > 100. Thus, pickup protons have a significant dynamical influence on the structures of the solar wind in the outer heliosphere.
Tissue plasminogen activator-induced secretion of type-1 plasminogen activator inhibitor in cultured human fibroblasts

Tissue plasminogen activator (t-PA) regulation of type-1 plasminogen activator inhibitor (PAI-1) secretion by WI-38 human fibroblasts was investigated utilizing a specific ELISA to measure PAI-1 antigen levels. Incubation of confluent fibroblasts with t-PA in serum-free medium resulted in a concentration and time-dependent increase in the secretion of PAI-1, with the maximum response (a two-fold increase) observed following a 4 hour incubation with 0.1 microM t-PA. This t-PA effect was reduced by cycloheximide, suggesting that the involvement of specific protein synthesis, and by inhibitors of t-PA's enzymatic activity, suggesting a requirement for a free catalytic site. The t-PA effect could not be attributed to endotoxin contamination. Increased levels in cell-associated PAI-1 were also detected following incubation of fibroblasts with t-PA. This previously undescribed effect, although seen at relatively high concentrations of t-PA, may have important biological implications.
Subendocardial vascular distortion at small ventricular volumes

Abstract Greater distortion of subendocardial vessels compared to subepicardial vessels with decreasing ventricular volume was predicted from a simple mathematical model. The left ventricular wall near the base behaves as the wall of a sphere with changing ventricular volumes. Photomicrographs of barium injected coronary vessels at different ventricular volumes demonstrates the distortion of subendocardial vessels at small ventricular volumes. Venous obstruction was observed in the subendocardium of the contracted fibrillating heart following cardiopulmonary bypass. Small ventricular volume appears to predispose the heart to subendocardial hemorrhagic lesions.
The isomers of ionized ethane

The previously reported 2Ag, 2A1g, and 2Bg states of ionized ethane are characterized at several levels of theory. The diborane-like 2Ag state, which gives rise to the observed ESR spectrum, is predicted by SCF and CCD calculations not to exist in a separate minimum from the 2A1g state formed by ionization of the C(SINGLE BOND)C bond. However, as reported by Lunell and Huang, second-order Moller-Plesset theory places the 2Ag lowest, provided polarization functions are included on carbon. QCISD theory predicts that both A states correspond to potential energy minima, but places the long-bond 2A1g state lower, at least with moderately large basis sets. F orbitals on carbon stabilize the diborane structure more than the long-bond one. When a potential energy surface is generated for a series of fixed C(SINGLE BOND)C bond lengths by optimizing all variables except for the C(SINGLE BOND)C bond length with MP2 theory and calculating the energy with QCISD(T), the 2Ag state is predicted to be the lowest energy state with the 2A1g state 1.83 kJ/mol above it. The two A states are predicted to be separated by a barrier 2.79 kJ/mol above the lower state. This barrier is above the zero-point energy in the C(SINGLE BOND)C stretch for the lower state but below the ZPE for this stretch in the upper state, which is therefore predicted not to exist as a stable species. A single quantum of vibrational excitation in the low frequency C(SINGLE BOND)C stretch is predicted to yield an ion with a poorly defined C(SINGLE BOND)C bond length. The highest levels of theory employed give poor agreement with the experimental hyperfine coupling constants. The discrepancy could either be due to neglect of vibrational effects, to poor inherent accuracy of the calculation, as one author has concluded, or to compression of the ion by the matrix as suggested by another. The 2Bg state is found to be higher in energy than the A states at all theoretical levels and is predicted to have a large (160.2–177.4 G) hyperfine coupling from four hydrogens. The transition state for simultaneous exchange of two hydrogen atoms between the carbons by a diborane structure is predicted to lie above the lowest energy fragmentation threshold, in agreement with experiment. © 1996 by John Wiley & Sons, Inc.
Homosexual parents: a comparative forensic study of character and harms to children.

Stimma~.40 appeals cases of custody disputes drawn systematically from all cases involving a homosexual parent in the United Stares were compared to 38 appeals cases involving heterosexual custody disputes drawn randomly from Listings under parental "character" and 18 appeals cases drawn randomly from "general" cases in Dicennial Digest from 1966 to 1991. Each case involving homosexual us heterosexual claimants was examined for recorded information about (1) the character of the homosexual parent, the associares of the homosexual parent, the heterosexual parenr, and the associates of the heterosexual parent, (2) the effects, particularly harms, upon the childhen), and (3) psychiatric opinion. 82% of the homosexual us 18% of the heterosexual parents and 54% of the homosexual's associates us 19% of che heterosexuals' associates were recorded as having poor character in cases involving a homosexual claimant. Of the 66 recorded harms, e.g., molestation, physical abuse, to the 73 children, homosexual persons accounted for 64 (97%). Of the 32 lesbians, 6 were recorded as having engaged in criminal activity and 3 of bringing false charges of child sexual abuse against the father. Psychiatric opinion, however, ran 25 to 12 in favor of custody for the homosexual parent. In the 56 heterosexual us heterosexual comparison cases, 38% of the heterosexual parents and 28% of their associares were recorded as having poor character. Six harms to their 105 children and 3 instances of criminality but no false charges of sexual abuse were recorded. In the appeals court literature, homosexual parents were disproportionately of poor character and disproportionately associated with various harms to their children.
Mucosal antibody expression following rapid SIV(Mne) dissemination in intrarectally infected Macaca nemestrina.

ABSTRACT The early kinetics of antibody expression following transmucosal infection by SIVMne, were examined in several mucosal compartments in Macaca nemestrina. Five male–female pairs of macaques were inoculated intrarectally with SIVMne E11S, a biological clone, and serially euthanized at 1, 2, 4, 8, and 12 weeks postinoculation. Plasma, tears, saliva, rectal secretions, and vaginal washes were collected serially and just prior to euthanasia. Both total and SIV-specific IgG and IgA levels were measured by immunoglobulin isotype-specific quantitative enzyme-linked immunosorbent assays (ELISAs), and were further examined by conventional and enhanced chemiluminescence (ECL) immunoblots. Virus coculture, polymerase chain reaction, and in situ hybridization assays revealed the systemic spread of virus as early as 1 week postinoculation in 8 of 10 animals. ECL immunoblots detected SIV-specific antibodies in mucosal samples collected 1 week postinoculation. The most dramatic increases in both total and SIV-sp...
Generational Differences and the Diaspora in The Joy Luck Club

(1993). Generational Differences and the Diaspora in The Joy Luck Club. Critique: Studies in Contemporary Fiction: Vol. 34, Women Writers, pp. 193-199.
Item Response Theory Analysis of Two Questionnaire Measures of Arthritis-Related Self-Efficacy Beliefs from Community-Based US Samples

Using item response theory (IRT), we examined the Rheumatoid Arthritis Self-efficacy scale (RASE) collected from a People with Arthritis Can Exercise RCT (346 participants) and 2 subscales of the Arthritis Self-efficacy scale (ASE) collected from an Active Living Every Day (ALED) RCT (354 participants) to determine which one better identifies low arthritis self-efficacy in community-based adults with arthritis. The item parameters were estimated in Multilog using the graded response model. The 2 ASE subscales are adequately explained by one factor. There was evidence for 2 locally dependent item pairs; two items from these pairs were removed when we reran the model. The exploratory factor analysis results for RASE showed a multifactor solution which led to a 9-factor solution. In order to perform IRT analysis, one item from each of the 9 subfactors was selected. Both scales were effective at measuring a range of arthritis SE.
Part D plan enrollment by uninsured medicare beneficiaries.

Objectives: The objective of the study was to examine the patient factors and medication acquisition strategies that impacted PDP enrollment in early 2006 by Medicare beneficiaries without prior drug coverage. Research Design and Subjects: A retrospective cohort study identified 2282 Medicare beneficiaries without prior drug coverage from the 2005 Access to Care Module of the Medicare Current Beneficiary Survey. Measures: Bivariate statistics (eg, χ 2 and t-tests) were used to compare beneficiaries without drug coverage in 2005 who enrolled or did not enroll in a PDP in early 2006. A logistic regression was estimated to examine which patient factors were associated with PDP enrollment, controlling for demographic, socioeconomic, and health status variables, as well as medication purchasing strategies and size of the PDP choice set. Results: In early 2006, 44% of Medicare beneficiaries without prior drug coverage enrolled in a standalone PDP. Beneficiaries without prior drug coverage were more likely to enroll if they were younger (age 65-74), female, non-Hispanic white, married or widowed, had more self-reported conditions, requested prescription drug samples from their provider, or compared medication prices prior to purchase. Seniors without prior drug coverage were less likely to enroll if they had incomes <$50,000 or obtained medication via mail or the internet. Conclusions: Enrollment in PDPs by beneficiaries without prior drug coverage was fairly low in early 2006, and vulnerable subgroups of these beneficiaries who did not enroll require follow-up to ensure that they realized the benefits of the Medicare Part D program.
A method for measuring the apparent self-diffusion coefficient of in vivo lactic acid using double-quantum coherence-transfer spectroscopy

Knowledge of the apparent self-diffusion coefficient of in vivo metabolites can potentially yield important information about the microenvironment of these compounds. The extent of molecular displacement by diffusion processes reflects the local temperature, mobility, and compartmentalization of the metabolite and may be useful in characterizing the disease state of a tissue or organ. The apparent self-diffusion coefficients of in viva 3’P metabolites have been studied using spin-echo NMR spectroscopy pulse sequences which contain diffusion-sensitive pulsed field gradients ( 1) , such as the Stejskal-Tanner sequence ( 2) in Fig. 1. Molecular diffusion in the presence of these gradient fields results in an attenuation of the echo signal amplitude given by
Interagency Relationships Among Rural Early Intervention Collaboratives

Interagency collaboration is used to coordinate services and programs, pool resources, or achieve goals. This study utilizes the Interagency Collaboration Model to assess interagency relationships of Early Intervention (EI) collaboratives in three rural Ohio counties. The model includes five constructs: environmental factors (broader community environment), situational factors (organizational factors), task characteristics (project's scope and complexity), interagency processes (between agency processes), and outcomes (end products). Respondents from 42 agencies completed the 18-item Interagency Collaboration Assessment Tool (ICAT) and demographic questions. The ICAT uses a 5-point Likert-type scale to assess the five domains of the model. Respondents included public health nurses, representatives from schools, social service agencies, and hospitals. State policies were perceived as encouraging local interagency collaboration; respondents knew staff and goals of other agencies, but agencies did not share funding sources or provide similar services. Diverse specialists were needed to accomplish goals. Some information was exchanged between agencies. Interagency activities were not perceived to be well coordinated and outcomes were only moderately positive. Path analysis revealed that interagency processes were directly affected by environmental and situational factors, but not task characteristics (R2 = 0.42). Situational factors, and interagency processes predicted outcomes (R2 = 0.60). Awareness of personnel, goals and services of other agencies were key to positive interagency process and perceived outcomes.
Fiber optic based gas sensor with nanoporous structure for the selective detection of NO2 in air samples

A fiber optic based sensor (FOS) system for the selective detection of NO2 in air samples has been developed. In the present design, a signal transduction mechanism based on the spectroscopic changes at the nanopores of a sol–gel element has been utilized. The sensor is prepared by uniformly immobilizing NO2 sensing reagents at the pores during the sol–gel process. This facilitates an easy tailoring of the transducer element to build different optical designs. In the present paper, we describe two different fiber optic sensor designs, which are operating in extrinsic and intrinsic configurations. The extrinsic design is based on the fiber optic transflection probe geometry with its sensor element placed at the distal end of the fiber bundle. A part per billion (ppb) level detection has been achieved with the intrinsic sensor design with an active sol–gel fiber core as a sensor element. The two different optical designs improve the NO2 detection level and sensitivity of detection. The nitrogen dioxide mediated coloration reaction ensures the high specificity of detection when tested in a mixture of gas samples. The test results indicate the potential use of the fiber optic sensor for real time detection of NO2 in air samples.
Localization of synaptic responses in the in vitro turtle olfactory bulb using the [14C]2-deoxyglucose method

Abstract Studies were carried out on the in vitro turtle olfactory bulb preparation with a modification of the [14C]2-deoxyglucose (2-DG) technique. Electrical stimulation of either the dorsal or ventral division of the olfactory nerve produced broad bands of activity, spreading across laminae, in the corresponding half of the olfactory bulb. Pretreatment of the isolated preparation in a low calcium bath eliminated focal 2-DG uptake induced by electrical stimulation of the nerve. In contrast, pretreatment with the GABAergic antagonist, bicuculline, produced a notable increase in 2-DG accumulation. These findings are discussed in the light of the topographical innervation of the olfactory bulb by the olfactory nerve as well as the known synaptic organization of the olfactory bulb and the putative neurotransmitters operative in local circuits.
Inhibition of β-Lactamases by 6,6-Bis(hydroxylmethyl)penicillanate

Abstract β-Lactamases of classes A and C are the two most prevalent resistant determinants to β-lactam antibiotics among bacterial pathogens. Both these enzymes pursue different mechanisms for their catalytic processes, highlighted by the fact that the hydrolytic water molecule in each approaches the ester of the intermediary acyl-enzyme species from the opposite ends. 6,6-Bis(hydroxylmethyl)penicillanate was designed as an inhibitor that would impair the approach of the hydrolytic water molecule in either of these enzymes upon formation of the acyl-enzyme species. The design, synthesis, and kinetic evaluation of this inhibitor are disclosed herein.
Amnesty, Revenge, and the Threat of Conflict Relapse

Recent decades have witnessed an increase in internal armed conflicts, resulting in significant consequences for affected civilian populations. At the same time, there has been rapid growth in international criminal law and a trend towards accountability. Yet, attempts to mitigate violence may come at the cost of accountability, leading to the commonly referenced to peace-versus-justice dispute. Blanket amnesties are one tool for conflict mitigation, bargaining chips that allow actors to come to the negotiating table. This article examines issues related to blanket amnesties that are absent from the amnesty versus accountability debate. The basis of the analysis is not whether accountability reduces a victim’s desire for revenge. Instead, the analysis examines whether amnesty increases a victim’s desire for revenge, and when combined with other socio-political factors that contribute to conflict relapse, finds that this increased desire may escalate the potential for renewed violence in post-conflict regions.
Grape seed proanthocyanidins increase collagen biodegradation resistance in the dentin/adhesive interface when included in an adhesive

Abstract Objectives Contemporary methods of dentin bonding could create hybrid layers (HLs) containing voids and exposed, demineralised collagen fibres. Proanthocyanidins (PA) have been shown to cross-link and strengthen demineralised dentin collagen, but their effects on collagen degradation within the HL have not been widely studied. The purpose of this study was to compare the morphological differences of HLs created by BisGMA/HEMA model adhesives with and without the addition of grape seed extract PA under conditions of enzymatic collagen degradation. Methods Model adhesives formulated with and without 5% PA were bonded to the acid etched dentin. 5-μm-thick sections cut from the bonded specimens were stained with Goldner's trichrome. The specimens were then exposed to 0.1% collagenase solution for 0, 1, or 6 days. Following collagenase treatment, the specimens were analysed with SEM/TEM. Results Staining did not reveal a difference in the HLs created with the two adhesives. SEM showed the presence of intact collagen fibrils in all collagenase treatment conditions for specimens bonded with adhesive containing PA. These integral collagen fibrils were not observed in the specimens bonded with adhesive without PA after the same collagenase treatment. TEM confirmed that the specimens containing PA still showed normal collagen fibril organisation and dimensions after treatment with collagenase solution. In contrast, disorganised collagen fibrils in the interfacial zone lacked the typical cross-banding of normal collagen after collagenase treatment for specimens without PA. Conclusions The presence of grape seed extract PA in dental adhesives may inhibit the biodegradation of unprotected collagen fibrils within the HL.
Predictive Modeling for Pharmaceutical Processes Using Kriging and Response Surface

Powder feeding is a fundamental unit operation in the pharmaceutical industry. For the cases in which first-principle process models are unknown, such as when new powder mixture feeding operations are being evaluated, or no longer accurately describe current operating behavior, surrogate model-based approaches can be employed in order to quantify input–output behavior. In this work, two such metamodeling techniques—kriging and response surface methods—are used to predict a loss-in-weight feeder unit’s flow variability in terms of unit flowability and feed rate. Based on a comparison of predicted with experimental values, an iteratively constructed kriging model is found to more accurately capture the feeder system behavior compared with the response surface methodology. Although feeders are used as a case study in this paper, the kriging methodology is general to address other processes where first-principle models are not available.
Pediatric resident and faculty knowledge of the Denver II.

Objective To assess knowledge of the Denver II, the revised developmental screening tool recommended by the American Academy of Pediatrics, in residents and faculty, and to evaluate a teaching intervention for incoming postgraduate year 1 (PGY-1) trainees. Design A cross-sectional test of knowledge for all subjects and pretesting and posttesting of the incoming PGY-1 trainees. Setting University of Texas–Houston Medical School Department of Pediatrics. Participants Faculty (n=9) and residents (n=78), including an intervention group (n=45), of incoming PGY-1 trainees over 2 years. Interventions Postgraduate year 1 trainees in both 1994 through 1995 and 1995 through 1996 viewed the Denver II training videotape on entry into a continuity clinic. Trainees were encouraged to perform Denver II evaluations on at least 1 appropriate patient at each pediatric clinic session and had access to Denver II support materials. Main Outcome Measures Scores on the Denver II Proficiency Written Test, self-reported measures of comfort, and number of Denver II evaluations performed. Results The mean (SD) test scores for incoming, preintervention PGY-1 trainees (n=45) (41.3 [9.6]) did not differ from scores for outgoing PGY-1 trainees (n=13) (38.5 [10.4]) who had not received the intervention. Postintervention PGY-1 test results were significantly improved (59.4 [10.6]) ( P Conclusions Residents had a greater knowledge of the Denver II after completing a developmental pediatrics rotation. Our intervention produced significant improvement in PGY-1 trainees' knowledge, raising it to levels similar to those of upper-level residents exposed to developmental pediatrics. Faculty were not expert in using the Denver II.
Enhanced identification and exploitation of time scales for model reduction in stochastic chemical kinetics

Widely different time scales are common in systems of chemical reactions and can be exploited to obtain reduced models applicable to the time scales of interest. These reduced models enable more efficient computation and simplify analysis. A classic example is the irreversible enzymatic reaction, for which separation of time scales in a deterministic mass action kinetics model results in approximate rate laws for the slow dynamics, such as that of Michaelis–Menten. Recently, several methods have been developed for separation of slow and fast time scales in chemical master equation (CME) descriptions of stochastic chemical kinetics, yielding separate reduced CMEs for the slow variables and the fast variables. The paper begins by systematizing the preliminary step of identifying slow and fast variables in a chemical system from a specification of the slow and fast reactions in the system. The authors then present an enhanced time-scale-separation method that can extend the validity and improve the accuracy of existing methods by better accounting for slow reactions when equilibrating the fast subsystem. The resulting method is particularly accurate in systems such as enzymatic and protein interaction networks, where the rates of the slow reactions that modify the slow variables are not a function of the slow variables. The authors apply their methodology to the case of an irreversible enzymatic reaction and show that the resulting improvements in accuracy and validity are analogous to those obtained in the deterministic case by using the total quasi-steady-state approximation rather than the classical Michaelis–Menten. The other main contribution of this paper is to show how mass fluctuation kinetics models, which give approximate evolution equations for the means, variances, and covariances of the concentrations in a chemical system, can feed into time-scale-separation methods at a variety of stages.
Dispersion of surface polaritons in uniaxial Al 2 O 3

The dispersion of ordinary and extraordinary surface polaritons in uniaxial ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ crystals has been measured with use of the attenuated-total-reflection method. Some additional reflectivity minima are observed, which are not associated with the excitation of surface polaritons, but are due to the low-reflectivity regions bounded by the optical-phonon-mode frequencies and the bulk-polariton dispersion curve. The discrepancies among the theoretical surface-polariton dispersion curves calculated with the use of various methods are discussed.
DNA as a vehicle for the self-assembly model of computing

A DNA version of the self-assembly model of computing, feasible using currently available laboratory techniques, is proposed. Input signals are coded into unmethylated and methylated oligonucleotides which then hybridize with a backbone that contains complementary sequences. Different input signal patterns are thus represented as DNA duplexes with distinctly different conformational dynamics, in particular different equilibria of B and Z DNA. The pattern classification activity of the system is mediated by the interactions that lead to the secondary structural organization. Circular dichroism may be used for readout.
Temporal variation of energy reserves in mayfly nymphs (Hexagenia spp.) from Lake St Clair and western Lake Erie

Summary 1. We analysed changes in energy reserves (lipid and glycogen) and length–weight relationships of burrowing mayflies (Hexagenia spp.) in 1997–99 to compare an established population in Lake St Clair with a recovering population in western Lake Erie of the Laurentian Great Lakes. In addition, we measured changes in water temperature and potential food in both water columns and sediments. 2. Although overall mean values of lipid and glycogen levels of Hexagenia nymphs from Lake St Clair and western Lake Erie were not significantly different, there were differences in seasonal patterns between the two lakes. In Lake St Clair, levels were highest in early spring, declined throughout the year, and reached their lowest levels in fall during all 3 years of study. In contrast, levels in western Lake Erie were lower in spring, increased to a maximum in summer, then declined in fall. Seasonal patterns in length–weight relationships were similar to those for lipid and glycogen. 3. Total lipid as a percentage of dry weight did not increase with developmental stage of nymphs until just prior to metamorphosis and emergence from water. However, the major reserve lipid, triacylglycerols, increased systematically with development stage. In the final stage of development, triacylglycerols declined, probably as a result of energy consumption and its conversion to other biochemical components for metamorphosis and reproduction. 4. Indicators of potential food (algal fluorescence in the water column and chlorophyll a and chlorophyll a/phaeophytin ratio in sediments) suggest that Hexagenia in Lake St Clair have a food source that is benthic based, especially in early spring, whereas in western Lake Erie nymphs have a food source that is water column based and settles to the lake bottom during late spring and summer.
The influence of mild cognitive impairment on measures of fall risk in community-dwelling older adults

The link between ET and PD has frequently been debated in the literature and such patients developing PD after ET are named ETPD, however, the development of dementia has not been described in patients with ETPD. In this study, we have described a clinical case series of 17 patients with initially diagnosed as ET, who developed parkinsonism and subsequent development of dementia. We named this combination of ET, PD and dementia as ETPDD and in these patients, using clinical presentation and FDG-PET studies, the similarities and differences to Parkinson Disease Dementia and other dementia are described. Methods: All patients underwent a detailed neurologic history and examination by samemovement disorders specialist. Medical informations of patients were obtained from the patients and family members to clarify the relationship between these disorders. The patient’s global cognitive status and severity of dementia were assessed with MMSE and CDR. Demographic and historical data including age, sex, age at tremor onset, duration of postural tremor, type of tremor, age at parkinsonism and dementia onset, the time between ETand PD and PD and dementia, family history of PD, ET, other movement disorders and dementia, and similarities and differences to other dementia were recorded. The diagnosis of PD was established according to the UK-PD Society Brain Bank criteria and the criteria for dementia from DSM-IV was applied. Results: RESULTS Patients who met the following criteria were classified as having ETPDD. (1) presence of both postural-action hand tremor as first symptom on their medical history. (2) symptoms of postural-action tremor for at least 3 to 5 years prior to the onset of other signs of PD.(3) cognitive dysfunctions, impaired activities of daily living and measured by MMSE. Conclusions: Present study specifically focused on the similarities and differences to PD dementia and other dementia, including clinical presentation and FDG-PET studies, leading clinicians to suspect a link among them. To our knowledge, this is the first case series to describe the coincidental occurrence of these three disorders in a single patient.
Monolignol Pathway 4-Coumaric Acid:Coenzyme A Ligases in Populus. trichocarpa: Novel Specificity, Metabolic Regulation, and Simulation of Coenzyme A Ligation Fluxes

4-Coumaric acid:coenzyme A ligase (4CL) is involved in monolignol biosynthesis for lignification in plant cell walls. It ligates coenzyme A (CoA) with hydroxycinnamic acids, such as 4-coumaric and caffeic acids, into hydroxycinnamoyl-CoA thioesters. The ligation ensures the activated state of the acid for reduction into monolignols. In Populus spp., it has long been thought that one monolignol-specific 4CL is involved. Here, we present evidence of two monolignol 4CLs, Ptr4CL3 and Ptr4CL5, in Populus trichocarpa. Ptr4CL3 is the ortholog of the monolignol 4CL reported for many other species. Ptr4CL5 is novel. The two Ptr4CLs exhibited distinct Michaelis-Menten kinetic properties. Inhibition kinetics demonstrated that hydroxycinnamic acid substrates are also inhibitors of 4CL and suggested that Ptr4CL5 is an allosteric enzyme. Experimentally validated flux simulation, incorporating reaction/inhibition kinetics, suggested two CoA ligation paths in vivo: one through 4-coumaric acid and the other through caffeic acid. We previously showed that a membrane protein complex mediated the 3-hydroxylation of 4-coumaric acid to caffeic acid. The demonstration here of two ligation paths requiring these acids supports this 3-hydroxylation function. Ptr4CL3 regulates both CoA ligation paths with similar efficiencies, whereas Ptr4CL5 regulates primarily the caffeic acid path. Both paths can be inhibited by caffeic acid. The Ptr4CL5-catalyzed caffeic acid metabolism, therefore, may also act to mitigate the inhibition by caffeic acid to maintain a proper ligation flux. A high level of caffeic acid was detected in stem-differentiating xylem of P. trichocarpa. Our results suggest that Ptr4CL5 and caffeic acid coordinately modulate the CoA ligation flux for monolignol biosynthesis.