cssi/SciSciGPT-SciSciNet huggingface dataset:
Photoactivation of the water-oxidizing complex in Photosystem II membranes depleted of Mn and extrinsic proteins. I. Biochemical and kinetic characterization

Abstract Conditions were defined for obtaining photoligation of Mn 2+ and photoactivation of O 2 evolution in NH 2 OH- and Tris-extracted PS II membranes (TMF-2) completely devoid of the CF 0 /CF 1 complex and containing only approx. 2–3 PS II e − acceptor equivalents per PS II reaction center. At optiomal pH (pH 6.5) only light and Mn 2+ were essential for Mn ligation by the apo-S-state complex (approx. 4 Mn/reaction center); however, Ca 2+ addition was required for maximal expression of water oxidation activity of the photoligated Mn. In the absence of added PS II e − acceptors, the quantum efficiency and yield of photoactivation was diminished and was insensitive to atrazine. PS II e − acceptors increased the quantum efficiency/yield by approx. 2-fold and conferred sensitivity to atrazine. Kinetic analyses of the photoactivation process gave evidence for a rate constraint ( t 1 2 ≈ 125 ms ) and an unstable intermediate (half-life of approx. 1.0 s). Cl − was not absolutely essential for photoactivation. A 7-fold increase of rate of O 2 evolution was obtained without Cl − addition to Cl − -depleted NH 2 OH-TMF-2; Cl − addition during photoactivation gave only a 2-fold additional increase. This Cl − effect ( K m = 3.8 mM) was different from the Cl effect ( K m = 1.5 mM) on O 2 evolution. Weak light ageing of NH 2 OH-TMF-2 in the absence (but not in the presence) of Mn 2+ inhibited photoactivation and photoreduction of DCIP by Mn 2+ ; however, DCIP photoreduction by DPC or TPB was not diminished. Such weak light ageing also increased the VLP-form of Cyt b -559, but there was no apparent correlation between the increase in O 2 evolution and the conversion of the VLP- and LP-Cyt b -559 to the HP-Cyt b -559 during photoactivation. Photoactivation is suggested to be a two-quantum process in which two Mn 2+ are sequentially bound, photooxidized and ligated by the apo-S-state complex. This process facilitates ligation of two additional Mn ions to form the tetra-Mn S-state water-oxidizing complex.
Even-Even Intermolecular Multicentric Reactions

Ionic bicentric reactions constitute a most important class of organic reactions. Typical cases involve initial addition of a nucleophile (N−) or electrophile (E+) to an unsaturated system. The resulting adduct may then eliminate a chemical group giving rise to product formation. Typical examples are given below.
Self-Assembling Cyclic β3-Peptide Nanotubes as Artificial Transmembrane Ion Channels

A new class of self-assembling transmembrane ion channels based on cyclic β3-peptides is described. Cyclic peptide subunits were designed to adopt flat, ring shaped conformations and stack through extensive backbone-backbone hydrogen bonding to form tubular channel structures. Candidate channel-forming peptides cyclo[(-β3-HTrp)4-] 1, cyclo[(-β3-HTrp-β-HLeu)2-] 2, and cyclo[(-β3-HLeu)4-] 3 were examined in liposome-based proton transport assays and single channel conductance experiments. Compounds 1 and 2 exhibited remarkable ion transport activities with single-channel K+ conductance of 56 pS for peptide 1, while compound 3 was inactive, possibly due to its poor solubility. Additionally, the putative structure of transmembrane channels formed by peptides 1 and 2 was supported by FT-IR spectroscopy of membrane-peptide preparations. The present system not only complements that of channel-forming cyclic d,l-α-peptides previously reported from this laboratory but also is expected to exhibit novel properties a...
Water fluoridation and congenital malformations: no association

Data based on a total number of 1,387,027 births were used to compare the incidence of selected congenital malformations in fluoridated areas and that in areas where the water supply is deficient in fluoride. The incidence of selected congenital malformations in areas with fluoride supplementation of public water supplies was compared with the incidence in areas where the water supply is deficient in fluoride. Comparison of the incidences of several common birth defects (including Down’s syndrome) in fluoridated and nonfluoridated areas revealed no substantia! or significant differences in which there was a consistent pattern for both sets of data.
Role of α6 nicotinic receptors in CNS dopaminergic function: relevance to addiction and neurological disorders

Although a relative newcomer to the nicotinic acetylcholine receptor (nAChR) family, substantial evidence suggests that α6 containing nAChRs play a key role in CNS function. This subtype is unique in its relatively restricted localization to the visual system and catecholaminergic pathways. These latter include the mesolimbic and nigrostriatal dopaminergic systems, which may account for the involvement of α6 containing nAChRs in the rewarding properties of nicotine and in movement. Here, we review the literature on the role of α6 containing nAChRs with a focus on the striatum and nucleus accumbens. This includes molecular, electrophysiological and behavioral studies in control and lesioned animal models, as well as in different genetic models. Converging evidence suggest that the major α6 containing nAChRs subtypes in the nigrostriatal and mesolimbic dopamine system are the α6β2β3 and α6α4β2β3 nAChR populations. They appear to have a dominant role in regulating dopamine release, with consequent effects on nAChR-modulated dopaminergic functions such as reinforcement and motor behavior. Altogether these data suggest that drugs directed to α6 containing nAChRs may be of benefit for the treatment of addiction and for neurological disorders with locomotor deficits such as Parkinson's disease.
The effect of surface mass transfer on buoyancy-induced darcian flow adjacent to a horizontal heated surface

Abstract The effect of uniform surface mass transfer on the buoyancy-induced flow in a porous medium adjacent to a horizontal heated surface with a power law variation of wall temperature, Twαxλ, is considered in this paper. It is found that a similarity solution exists for the problem when λ = 2 . Approximate solutions based on the local nonsimilarity method are obtained for other values of λ. Numerical solutions were carried out up to the third-level of truncation and results are presented for a wide range of massflux parameter and wall temperature distributions.
Ocular pulse amplitude and associated glaucomatous risk factors in a healthy Hispanic population

Abstract Background With increasing evidence that vascular risk factors play a role in the development of glaucoma, it is critical to be familiar with factors related to intraocular blood flow, such as the ocular pulse amplitude (OPA). This study evaluates OPA and factors related to it in a healthy, Hispanic population. Methods Refractive error, corneal curvature, Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), OPA, axial length, and central corneal thickness (CCT) measurements were obtained on 104 Hispanic subjects recruited from the community. Results OPA ranged from 0.7 to 4.7 mmHg (mean, 2.1 ± 0.8 mmHg) and showed a significant correlation with refractive error, axial length, GAT, and DCT (r=0.250, -0.358, 0.460, 0.378; P=0.011, 1.00 D myopia. Conclusion Normal OPA values have not been studied in Hispanic populations. OPA is thought to provide information regarding ocular blood flow; however, more studies are needed to determine its significance in glaucoma treatment.
Tailored cricoplasty: an improved modification for reconstruction in subglottic tracheal stenosis.

Objective Subglottic laryngotracheal stenosis with side-to-side narrowing poses a challenge for successful reconstruction. The standard technique of anterior cricoid resection was modified to address a small ventricle with lateral narrowing. Methods This study was a retrospective chart review and telephone questionnaire follow-up of consecutive patients with subglottic stenosis at a single institution. Follow-up questionnaires used Likert scales (ratings 1–10) to describe preoperative and postoperative symptoms, satisfaction, and perceived effectiveness. Once the anterior cricoid is removed, resection of thickened submucosal tissue is performed. The inner third to half of the lateral wall of the remaining cricoid cartilage is carefully excised. Advancing the preserved mucosa over the cricoid resurfaces the exposed cartilage. This results in additional horizontal enlargement of the luminal diameter of the airway of 3 to 5 mm. Results Eighteen patients with subglottic stenosis, small laryngeal ventricle, and lateral narrowing underwent tailored cricoplasty during a 15-month period. Mean age was 51 years (range 20–75 years), and mean follow-up was 9.1 ± 1.2 months (range 2–17 months). There were 2 self-limited airway complications. All patients reported that they were satisfied and would undergo surgery again. Overall satisfaction was rated at 9.5 ± 1.0, and satisfactions with resting and exertional dyspnea were 9.7 ± 0.5 and 9.5 ± 1.0, respectively. Symptoms of recurrence at follow-up were rated as 0.6 ± 1.4. Conclusion Tailored cricoplasty is an effective technique to improve the outcome of reconstructive subglottic stenosis. It offers reconstructive possibilities for patients with diminished side-to-side dimensions in the subglottic airway.
Providing middleware support for the control and co-ordination of telecom mashups

The emerging Web 2.0 marketplace presents an important opportunity for Telecom operators to sell their own capabilities and content as services. Operators have a wealth of content associated with their network as well as core network enablers, e.g. call control, presence and messaging, which could serve as potential new revenue streams in a Web 2.0 world. Moreover, with the looming threat from Internet companies, there is an increasing need for operators to make both core and value-added functions reusable and mashable. To this end, operators are gradually embracing the IP Multimedia Subsystem (IMS) and looking at developing next-generation of SIP-based applications that can be mashed up in innovative ways. However, to do so, IMS/SIP-based services need to be empowered with the necessary co-ordination capabilities required in a mashup environment. This, in turn, implies protocol-level control to be rendered to the mashup developer - an issue that has not been sufficiently addressed by the community. We highlight the need for middleware support in facilitating the co-ordination of Telecom mashups, and describe an architecture that provides the necessary runtime control and mediation in an IMS-based operator network.
Large-Scale Computational Screening of Zeolites for Ethane/Ethene Separation

Large-scale computational screening of thirty thousand zeolite structures was conducted to find optimal structures for separation of ethane/ethene mixtures. Efficient grand canonical Monte Carlo (GCMC) simulations were performed with graphics processing units (GPUs) to obtain pure component adsorption isotherms for both ethane and ethene. We have utilized the ideal adsorbed solution theory (IAST) to obtain the mixture isotherms, which were used to evaluate the performance of each zeolite structure based on its working capacity and selectivity. In our analysis, we have determined that specific arrangements of zeolite framework atoms create sites for the preferential adsorption of ethane over ethene. The majority of optimum separation materials can be identified by utilizing this knowledge and screening structures for the presence of this feature will enable the efficient selection of promising candidate materials for ethane/ethene separation prior to performing molecular simulations.
Characterization of the reactivity, regioselectivity, and stereoselectivity of the reactions of butadiene monoxide with valinamide and the N-terminal valine of mouse and rat hemoglobin.

Occupational exposure to 1,3-butadiene (BD) has been monitored by measuring the level of hemoglobin N-terminal valine adduct formation with the primary reactive metabolite, butadiene monoxide (BMO)...
A survey of cooling tower water quality for condenser tube fouling potential

AbstractFouling from cooling tower water is a serious problem in both power and refrigeration industries. The effect of fouling on enhanced tubes could be worse than that on smooth tubes because fouling may degrade the superior heat transfer performance by filling the gaps between the roughness elements with foulant. Condensers that use cooling tower water usually experience four different fouling mechanisms: corrosion, scaling, particulate, and biological fouling. Corrosion is prevented with chemical inhibitors, which pacify the piping and protect the metal surfaces. Cooling tower water can also be treated with biocide to prevent biological fouling. Therefore, the current paper addresses scaling and particulate fouling. The paper also establishes a database of water quality based on chemical analysis of samples collected from cooling towers across the country. The objective of the database is to determine water qualities that are typical of those found in actual cooling towers. From chemical analysis, th...
Values, Gender, and Concern about Potentially Dangerous Wildlife:

In this study, the authors investigated wildlife value orientations, gender, and concern about risks posed by a large, potentially dangerous predator—the mountain lion. A survey (58% response rate) was used to collect data from a random sample of adult residents (N = 2,469) in Colorado metropolitan areas. Both gender and parental role predicted concern about being attacked. Women expressed greater concern than men, and participants with children living at home expressed greater concern than participants without children at home. Participants with utilitarian values were more likely than those with protectionist ones to accept destroying a lion in a residential area, and men were more likely than women to accept destroying it. Additional research is needed to understand why women perceived more risk from a mountain lion but were less willing to accept destroying it, as well as to understand the relationships among gender, parental role, and environmental risk concern.
Resting heart rate and risk of sudden cardiac death in the general population: influence of left ventricular systolic dysfunction and heart rate-modulating drugs.

Background Higher levels of resting heart rate (HR) have been associated with sudden cardiac death (SCD) but mechanisms are poorly understood. We hypothesized that severe left ventricular systolic dysfunction (LVSD) and HR-modulating drugs explain the HR-SCD relationship. Objective To evaluate the relationship between HR, severe LVSD, HR-modulating drugs, and SCD in the community by using a case-control approach. Methods From the ongoing Oregon Sudden Unexpected Death Study, SCD cases (n = 378) aged ≥35 years and with electrocardiogram-documented resting HR were compared to 378 age- and gender-matched control subjects with coronary artery disease (mean age 68 ± 13 years; 69% man). Associations with SCD were assessed by using multivariable logistic regression. Results Mean resting HR was significantly higher among SCD cases compared to controls (7.5 beats/min difference; P Conclusions Contrary to expectations, the significant relationship between increased resting HR and SCD persisted even after adjustment for LVSD and HR-modulating drugs. These findings suggest a potential role for additional novel interventions/therapies that modulate autonomic tone.
Preparation, Characterization, and Properties of Mixed Organic and Polymeric Self-Assembled Multilayers

Multilayer thin films consisting of layer-pairs of oppositely charged macrocycles (nickel phthalocyanine tetrasulfonate, NiPc) and macromolecules (poly(diallydimethylammonium) chloride, PDDA) were fabricated using self-assembly techniques. The film structures were characterized with X-ray reflectometry, from which the roughness (∼2−7 A) of the film growth surface, the average electron density of each layer-pair, the mean thickness of the layer-pairs (∼10.5 A), and the overall thickness of the multilayer samples were deduced. Measurements of film thicknesses were applied as constraints to an analysis of spectroscopic ellipsometry measurements of the films. Imposition of these constraints increased the confidence of the optical constant refinements deduced from ellipsometry. We find, for multilayers of PDDA and NiPc, a refractive index of n ≈ 1.6−1.8 in the nonabsorption region of the visible and near-infrared (IR) spectrum and an extinction coefficient in close agreement with the measured electron optical ...
Λ-like chromophores for chiral non-linear optical materials

Abstract The first hyperpolarizability of several Λ -like chromophores including Malachite Green and Brilliant Green were measured by means of Kleinman-disallowed hyper-Rayleigh (harmonic light) scattering (KD-HRS). Such chromophores are of interest as components of a new class of chiral and axial macroscopic materials. Light scattering measurements were carried out in both the non-resonant and the anomalous dispersion regime in order to compare experimental results with a two-level model that indicates that B-symmetry excited states will contribute. Large hyperpolarizabilities were observed in all cases and evidence that the lowest-lying excited state has B-symmetry was found in some molecules.
Two stage conditionally unbiased estimators of the selected mean

Abstract The problem is to estimate the mean of the selected population. The selection rule is to choose the population with the largest sample mean when such sample means are calculated from the first stage sample. An estimator of the selected mean is unbiased if its expected value equals the expected value of the selected mean. We seek conditionally unbiased estimators of the selected mean given the ordering of the set of sample means based on the first stage sample. Conditionally unbiased estimators are of course unconditionally unbiased. For several distributions such as the normal, with unknown mean, and binomial, no conditionally unbiased estimators exist based on a one stage sample. We propose a two stage sample where observations at stage two are taken from the selected population only. Such a procedure has the advantage of yielding conditionally unbiased estimators and enables, possibly a better allocation of available sample points. We find the uniformly minimum variance conditionally unbiased estimators (UMVCUE) for the normal case when the variance is known or when a common unknown variance is present. We also find the UMVCUE for the gamma case and indicate that the method is suitable for many other cases as well.
Public perceptions of biotechnology: Another look

A survey of New Jersey residents calls into question what the public really thinks about genetically engineered products
The Scope of Hyaluronic Acid as an Experimental Intraocular Implant

The inflammatory potential of hyaluronic acid (HA) varies from batch to batch of HA independent of tissue origin, concentration, or amino acid composition. The inflammatory potential can be determined by intravitreous testing only, not by intracameral testing. Retention of HA in the eye depends on molecular weight and concentration of HA, not on the ocular inflammatory response. Concentration, molecular weight, and inflammatory grade of any HA batch used in intraocular surgery should be specified. Monitoring of the postoperative intraocular pressure is recommended.
S-Allyl L-cysteine diminishes cerebral ischemia-induced mitochondrial dysfunctions in hippocampus

Ischemic brain is highly vulnerable to free radicals mediated secondary neuronal damage especially mitochondrial dysfunctions. Present study investigated the neuroprotective effect of S-allyl L-cysteine (SAC), a water soluble compound from garlic, against cerebral ischemia/reperfusion (I/R)-induced mitochondrial dysfunctions in hippocampus (HIP). We used transient rat middle cerebral artery occlusion (MCAO) model of brain ischemia. SAC (300 mg/kg) was given twice intraperitoneally: 15 min pre-occlusion and 2 h post-occlusion at the time of reperfusion. SAC significantly restored ATP content and the activity of mitochondrial respiratory complexes in SAC treated group which were severely altered in MCAO group. A marked decrease in calcium swelling was observed as a result of SAC treatment. Western blot analysis showed a marked decrease in cytochrome c release as a result of SAC treatment. The status of mitochondrial glutathione (GSH) and glucose 6-phosphate dehydrogenase (G6-PD) was restored by SAC treatment with a significant decrease in mitochondrial lipid peroxidation (LPO), protein carbonyl (PC) and H2O2 content. SAC significantly improved neurological deficits assessed by different scoring methods as compared to MCAO group. Also, the brain edema was significantly reduced. The findings of this study suggest the ability of SAC in functional preservation of ischemic neurovascular units and its therapeutic relevance in the treatment of ischemic stroke.
Assessment of chemical exchange in tryptophan-albumin solution through 19 F multicomponent transverse relaxation dispersion analysis

A number of NMR methods possess the capability of probing chemical exchange dynamics in solution. However, certain drawbacks limit the applications of these NMR approaches, particularly, to a complex system. Here, we propose a procedure that integrates the regularized nonnegative least squares (NNLS) analysis of multiexponential T2 relaxation into Carr–Purcell–Meiboom–Gill (CPMG) relaxation dispersion experiments to probe chemical exchange in a multicompartmental system. The proposed procedure was validated through analysis of 19F T2 relaxation data of 6-fluoro-DL-tryptophan in a two-compartment solution with and without bovine serum albumin. Given the regularized NNLS analysis of a T2 relaxation curve acquired, for example, at the CPMG frequency υ CPMG = 125, the nature of two distinct peaks in the associated T2 distribution spectrum indicated 6-fluoro-DL-tryptophan either retaining the free state, with geometric mean */multiplicative standard deviation (MSD) = 1851.2 ms */1.51, or undergoing free/albumin-bound interconversion, with geometric mean */MSD = 236.8 ms */1.54, in the two-compartment system. Quantities of the individual tryptophan species were accurately reflected by the associated T2 peak areas, with an interconversion state-to-free state ratio of 0.45 ± 0.11. Furthermore, the CPMG relaxation dispersion analysis estimated the exchange rate between the free and albumin-bound states in this fluorinated tryptophan analog and the corresponding dissociation constant of the fluorinated tryptophan–albumin complex in the chemical-exchanging, two-compartment system.
Diagnosis of the Source of GFS Medium-Range Track Errors in Hurricane Sandy (2012)

AbstractMedium-range forecasts of Hurricane Sandy’s track were characterized by widely diverging solutions, with some suggesting that Sandy would make landfall over the mid-Atlantic region of the United States, while others forecast the storm to move due east to the north of Bermuda. Here, dynamical processes responsible for the eastward-tracking forecasts are diagnosed using an 80-member ensemble of experimental Global Forecast System (GFS) forecasts initialized five days prior to landfall. Comparing the ensemble members with tracks to the east against those with tracks to the west indicates that the eastern members were characterized by a lower-amplitude upper-tropospheric anticyclone on the poleward side of Sandy during the first 24 h of the forecast, which in turn was associated with a westerly perturbation steering wind. The amplification of this ridge in each set of members was modulated by differences in the advection of potential vorticity (PV) by the irrotational wind associated with Sandy’s seco...
Behavioural plasticity mediates aggression in choruses of the Pacific treefrog

Abstract Abstract. Male Pacific treefrogs, Hyla regilla , produce advertisement and encounter calls in breeding choruses. Both types of call contribute to inter-male spacing. The aggressive threshold of males to the advertisement call, defined as the lowest amplitude of playback that elicits encounter calls, correlates positively with the maximum amplitude of the advertisement calls of neighbours, as measured at the focal male's position. Results of two studies support the hypothesis that this correlation derives from plasticity of a frog's aggressive threshold to the advertisement call, as opposed to the hypothesis that a frog has a fixed threshold and adjusts his spacing from his neighbours so that their call amplitudes fall below his threshold. First, aggressive thresholds decreased following removal of a male's closest calling neighbours. Second, playback of the advertisement call at superthreshold amplitudes elevated a male's aggressive threshold for this call. A third study tested the hypothesis that the mechanism underlying this threshold plasticity was sensory adaptation in the peripheral auditory system. The aggressive thresholds of frogs to both the encounter and advertisement calls, which have similar frequencies but different temporal structures, were measured before and after playback of the advertisement call at a superthreshold amplitude. Contrary to the prediction of the sensory adaptation hypothesis, the playback elevated the aggressive threshold to the advertisement call without significantly increasing the threshold to the encounter call. This result suggests that the plasticity of the aggressive threshold to the advertisement call occurs at higher, more central levels of the auditory system.
CELLULAR REACTIONS TO WAX-LIKE MATERIALS FROM ACID-FAST BACTERIA : THE UNSAPONIFIABLE FRACTION FROM THE TUBERCLE BACILLUS, STRAIN H-37.

1. The unsaponifiable fractions of the Mycobacteria, though insoluble in water and extremely stable chemical compounds, are nevertheless remarkable stimulants of cells. 2. They give rise to new monocytes which surround these waxes and then fuse into giant cells which engulf them. 3. The property of acid-fastness of the waxes makes it possible to identify them within the giant cells which have phagocytized them. 4. Within the foreign body giant cells the waxes are slowly disintegrated. They appear not to damage the cells which engulf them, and hence one may infer that they take no part in caseation. 5. They have no effect on the resistance of the host.
Unemployment In Developing Countries: Economist's Models in Light of Evidence From Sri Lanka

Observation of open unemployment in developing countries has lead some economist to formulate models which seek to explain this phenomenon. This paper examines unemployment in Sri Lanka in detail to see whether the assumptions and conclusions of economists' models are consistent with empirical data. In the case of Sri Lanka, these models provide a useful starting point but miss some of the essential details. Until one examines how the unemployed support themselves and how they spend their time, one's understanding of this phenomenon, as well as one's suggestions for policy changes, is necessarily incomplete. [820]
Forward Physics Results from ATLAS and CMS

Abstract We present recent forward and diffractive physics results from ATLAS and CMS experiments. Mainly, the physics results on diffraction, underlying event at forward rapidity and forward jets measurements are discussed. Also, using the combined CMS and TOTEM detectors, we show the first event candidate for central jets production with two leading protons detected in the TOTEM Roman Pot stations.
Algorithms for Model-Based Gaussian Hierarchical Clustering

Agglomerative hierarchical clustering methods based on Gaussian probability models have recently shown promise in a variety of applications. In this approach, a maximum-likelihood pair of clusters is chosen for merging at each stage. Unlike classical methods, model-based methods reduce to a recurrence relation only in the simplest case, which corresponds to the classical sum of squares method. We show how the structure of the Gaussian model can be exploited to yield efficient algorithms for agglomerative hierarchical clustering.
The high-temperature work function of sintered dilute solution tungsten-lridium alloys

The effect of transition element additives molybdenum, rhenium, iridium, and osmium on the effective work function of tungsten has been the focus of thermionics research for several years.[1- 5] In this study, iridium-added tungsten powder mixtures were cold compacted and sintered to produce a range of tungsteniridium electrodes. An electron emission study was subsequently carried out to evaluate the work function behavior of the consolidated alloys. The work function was obtained from measurements of the current emitted from the electrode surface under ultrahigh vacuum conditions in the temperature range of 1800 to 2500 K using a vacuum emission vehicle (VEV). The data show that the magnitude of the work function in these alloys varied with temperature. Microstructural evaluation of the alloys indicated that the tested surfaces displayed accentuated thermal etching of the grain boundaries together with the fact that the final grain sizes in the sintered alloys were three to five times smaller than those found in equivalent are-melted alloys that were studied in earlier work.[4,5] Scanning electron microscopy (SEM) micrographs of the tested surfaces of the sintered alloys containing the highest iridium levels (~2 wt % ) show a high level of structural distortion, particularly in the vicinity of grain boundaries and corners. The extent of these distortions was found to vary with the iridium content, i.e., the W-IR3M and W-IR2M. The samples with compositions lower than 0.5 wt % Ir were virtually devoid of distortions. It is proposed that, during homogenization carried out prior to testing, a net accumulation of iridium occurs near the surface, particularly in the vicinity of structural heterogeneities. Subsequent cooling leads to the precipitation of iridium-rich second phase sources, which when reheated to the testing temperatures supplies iridium to a surface monolayer. This mechanism is capable of explaining the observed work function trends during high- temperature testing.
X-ray Fluorescence: Detection of Lead in Wall Paint

An instrument has been developed for the in situ determination of lead on painted surfaces. It utilizes, as a source of gamma rays, radioactive cadmium-109 and its daughter silver-109 (metastable) to excite the K series x-rays of lead, and a solid-state, lithium-drifted germanium detector. The device, which is capable of detecting 0.26 milligram of lead per square centimeter of paint [approximately 3 percent (by weight) of lead in a single coat] beneath ten layers of lead-free paint, has been tested in a preliminary survey of several tenement apartments in New York City.
A Jungian Stage Theory of Individual Development in Personal Growth Groups.

Abstract This article describes personal growth group processes from a Jungian perspective. A 3-stage theory with 18 testable hypotheses is proposed. SUMMARY AND TENTATIVE CONCLUSIONS This article has proposed a Jungian stage theory of individual development in personal growth groups. A conceptual framework (Day, 1990) was used to develop this stage theory, which framework is based on Jung's theory of the individuation process in the first half of life. The central constructs of this Jungian conceptual framework-theory of psychological types, the persona, the shadow, and the personal complex-are discussed in a previous article from The Journal for Specialists in Group Work (Day & Matthes, 1992). The stage theory herein articulated includes three stages: (a) Individuation as Interpersonal Exploration, (b) Individuation as In-trapsychic Exploration, and (c) Individuation as Integration. Individual, group, and leader variables were considered. Explanations and outlines of individual behaviors, group issues, ...
Development of Cognitive and Affective Trust in Teams A Longitudinal Study

The present research examines the development of two dimensions of trust, cognitive and affective, in student project teams over the course of a semester. Empirical examination of the evolution of multidimensional trust and its unique antecedents was explored. The results show that early trust emerges as a one-dimensional factor early in the life span of a team; cognitive and affective trust emerge as separate components over time; unique and distinct predictors positively and negatively affect early trust, cognitive trust, and affective trust; and affective trust has a stronger positive relationship with team performance than cognitive trust.
An urgency-based prioritized MAC layer protocol for real-time traffic in ad-hoc wireless networks

This paper presents a distributed MAC layer protocol, prioritization by urgency - DCF (PU-DCF), which incorporates explicit support for real-time traffic in ad-hoc wireless networks. In PU-DCF, a packet's priority is updated dynamically according to its priority level and urgency (or laxity). Two collision resolution algorithms (CRAs) are proposed to guarantee timely delivery of packets. Simulations show that the proposed protocol performs well for hard real-time (HRT) traffic and has stable performance even when the channel is overloaded. Furthermore, several simulation scenarios are designed to discuss the effect of several system parameters and compare the performance of the two CRAs.
Investigating hydrologic alteration as a mechanism of fish assemblage shifts in urbanizing streams

Stream biota in urban and suburban settings are thought to be impaired by altered hydrol- ogy; however, it is unknown what aspects of the hydrograph alter fish assemblage structure and which fishes are most vulnerable to hydrologic alterations in small streams. We quantified hydrologic variables and fish assemblages in 30 small streams and their subcatchments (area 8-20 km 2 ) in the Etowah River Catchment (Georgia, USA). We stratified streams and their subcatchments into 3 landcover categories based on imperviousness (,10%, 10-20%, .20% of subcatchment), and then estimated the degree of hydrologic alteration based on synoptic measurements of baseflow yield. We derived hydrologic variables from stage gauges at each study site fo r1y( January 2003-2004). Increased imperviousness was positively correlated with the frequency of storm events and rates of the rising and falling limb of the hydrograph (i.e., storm ''flashiness'') during most seasons. Increased duration of low flows associated with impervi- ousness only occurred during the autumn low-flow period, and this measure corresponded with increased richness of lentic tolerant species. Altered storm flows in summer and autumn were related to decreased richness of endemic, cosmopolitan, and sensitive fish species, and decreased abundance of lentic tolerant species. Species predicted to be sensitive to urbanization, based on specific life-history or habitat require- ments, also were related to stormflow variables and % fine bed sediment in riffles. Overall, hydrologic variables explained 22 to 66% of the variation in fish assemblage richness and abundance. Linkages be- tween hydrologic alteration and fish assemblages were potentially complicated by contrasting effects of elevated flows on sediment delivery and scour, and mediating effects of high stream gradient on sediment delivery from elevated flows. However, stormwater management practices promoting natural hydrologic regimes are likely to reduce the impacts of catchment imperviousness on stream fish assemblages.
Multicultural Considerations in Physical Activity: An Introduction

(1995). Multicultural Considerations in Physical Activity: An Introduction. Quest: Vol. 47, No. 1, pp. 1-6.
Opening Up in the Classroom: Effects of Expressive Writing on Graduate School Entrance Exam Performance

Our study sought to determine whether experimental disclosure could improve exam performance and psychological health in students taking a graduate school entrance exam. Students preparing for the GRE, MCAT, LSAT, or PCAT were randomly assigned to write expressively about their upcoming exam or to a neutral writing condition. Participants completed measures of depressive symptoms and test anxiety before and after writing, and exam scores were collected. The experimental disclosure group had significantly higher test scores and significantly lower pre-exam depressive symptoms than the neutral writing group. Although benefits for depressive symptoms were found in expressive writers regardless of exam type, the advantage of expressive writing for test performance was only observed in students taking the MCAT or LSAT.
Shared infrastructures, informational asymmetries: Persians and Indians in Japan, c .1890–1930

Drawing on primary materials in Persian, Urdu, and English, this article compares Persian and Indian travel accounts to assess the similarities and differences of contemporaneous encounters with Japan. By linking Persian and Urdu writings from either side of 1900 to the differential impact of industrial communications (vernacular printing, steam travel) on Persia and India, the article reconstructs the global connections and inter-Asian networks that suddenly rendered Japan an important touchstone for intellectuals in the Middle East no less than South Asia. By presenting a triangulated and comparative model of inter-Asian exchange, the article contributes to building robust material foundations for positioning Asia, and its Muslims in particular, within global intellectual history, and concludes by contrasting the sources of information generation that preceded ideological formation.
Ongoing GC-Biased Evolution Is Widespread in the Human Genome and Enriched Near Recombination Hot Spots

Fast evolving regions of many metazoan genomes show a bias toward substitutions that change weak (A,T) into strong (G,C) base pairs. Single-nucleotide polymorphisms (SNPs) do not share this pattern, suggesting that it results from biased fixation rather than biased mutation. Supporting this hypothesis, analyses of polymorphism in specific regions of the human genome have identified a positive correlation between weak to strong (W→S) SNPs and derived allele frequency (DAF), suggesting that SNPs become increasingly GC biased over time, especially in regions of high recombination. Using polymorphism data generated by the 1000 Genomes Project from 179 individuals from 4 human populations, we evaluated the extent and distribution of ongoing GC-biased evolution in the human genome. We quantified GC fixation bias by comparing the DAFs of W→S mutations and S→W mutations using a Mann-Whitney U test. Genome-wide, W→S SNPs have significantly higher DAFs than S→W SNPs. This pattern is widespread across the human genome but varies in magnitude along the chromosomes. We found extreme GC-biased evolution in neighborhoods of recombination hot spots, a significant correlation between GC bias and recombination rate, and an inverse correlation between GC bias and chromosome arm length. These findings demonstrate the presence of ongoing fixation bias favoring G and C alleles throughout the human genome and suggest that the bias is caused by a recombination-associated process, such as GC-biased gene conversion.
Relation of epidermal growth factor receptor and estrogen receptor-independent pS2 protein to the malignant transformation of mucinous cystic neoplasms of the pancreas

Objective: To evaluate the role of epidermal growth factor receptor (EGF-R) and pS2 protein in the evolution of malignancy in mucinous cystic tumors of the pancreas. Background: Mucinous cystic tumors of the pancreas include histologically benign but premalignant mucinous cystic neoplasms and mucinous cystadenocarcinoma. The molecular events leading to transformation from a benign to a malignant mucinous tumor are not known. Overexpression of EGF-R and detection of an estrogen-induced protein (pS2) has been demonstrated in ductal adenocarcinomas of the pancreas, but these factors have not been evaluated in mucinous cystic tumors. Design: Twenty-six mucinous tumors were examined for EGF-R, pS2 protein, and estrogen and progesterone receptors. Results: Eight (61.2%) of 13 malignant tumors exhibited increased expression of EGF-R, whereas EGF-R was not detected in any of the 13 benign tumors ( P =.002). The pS2 protein was detected in nine of 11 malignant and 11 of 11 benign tumors ( P =.480). Estrogen and progesterone receptors were not detected in the epithelium of either tumor type. The median survival time of the patients with EGF-R-negative tumors was 29.0 months compared with 14.5 months for those with EGF-R-postive tumors, but this difference did not reach significance owing to the small population size. Conclusions: Overexpression of EGF-R in mucinous cystic tumors, as in ductal adenocarcinomas, may be an important feature associated with malignancy and may have prognostic significance. Failure to detect EGF-R in histologically benign epithelium suggests that the upregulation of EGF-R may be important in the evolution of aggressive behavior. The expression of pS2 protein appears to be independent of estrogen and may play a role in the proliferative activity of mucinous tumors. However, pS2 expression is not a feature associated exclusively with malignancy. (Arch Surg. 1995;130:69-72)
Clinical applications and prognostic implications of strain and strain rate imaging

Strain and strain rate imaging (also known as deformation imaging) are techniques used to measure myocardial deformation. These newer echocardiographic modalities overcome the limitations of conventional echocardiography and provide a sensitive means of objectively quantifying regional and global myocardial function. It has enabled us to better understand regional myocardial function and risk stratify patients with coronary artery disease, cardiomyopathies and valvular heart disease. Also, they have been used to assess left ventricular dyssynchrony, predict responders and optimize cardiac resynchronization therapy. However, the lack of standardization and inter-vendor variability in measurements are major roadblocks to using deformation imaging in routine clinical practice. This article discusses the fundamental concept of deformation, in particular relating to strain and strain rate imaging using speckle tracking imaging and tissue Doppler imaging, the clinical applications and its prognostic implications.
Diffusion MR Imaging of the Brain in Patients with Cancer

Over the last several years, there has been significant advancement in the molecular characterization of intracranial diseases, particularly cerebral neoplasms. While nuclear medicine technology, including PET/CT, has been at the foreground of exploration, new MR imaging techniques, specifically diffusion-weighted and diffusion tensor imaging, have shown interesting applications towards advancing our understanding of cancer involving the brain. In this paper, we review the fundamentals and basic physics of these techniques, and their applications to patient care for both general diagnostic use and in answering specific questions in selection of patients in terms of expected response to treatment.
Superoxide dismutase and cytochrome oxidase in collapsed lungs: possible role in reexpansion edema.

This study examined the effects of lung collapse, a condition that causes relative hypoxia in lung tissues, on superoxide dismutase (SOD), cytochrome oxidase (cyt ox), and pyruvate kinase (py ki) activities in rabbits. Cyanide-insensitive respiration measurements were done in collapsed and contralateral lungs, as an index of intracellular free radical production. Rabbits' right lungs were collapsed for 7 days after which the animals were killed. We found that control rabbit lungs contained approximately 25 SOD units/mg DNA measured with 10(-5) M KCN (total SOD) and approximately 11 SOD units/mg DNA measured with 10(-3) M KCN (mitochondrial or MnSOD). Right lung collapse caused a 25% decrease in mitochondrial SOD activity after 7 days (P less than 0.05), whereas no significant changes occurred in right or left lungs' total SOD activity. In control rabbits cyt ox activity averaged approximately 0.009 mumol ferrocytochrome c.min-1.mg DNA-1. Right lung collapse caused a greater than 40% decrease in cyt ox activity after 7 days of collapse (P less than 0.05), whereas cyt ox activity in contralateral left lungs did not change. Pyruvate kinase activity, a marker for anaerobic glycolysis resulting from tissue hypoxia, increased 49% in collapsed right lungs (P less than 0.01). Cyanide-insensitive respiration was 83% higher in 7 day-collapsed lungs (2.28 +/- 0.66 microliters O2.min-1.g-1) compared with contralateral lungs (1.24 +/- 0.34, P less than 0.05), indicating increased O2-. and H2O2 production in this tissue after homogenization at normoxic PO2 (approximately 150 Torr).(ABSTRACT TRUNCATED AT 250 WORDS)
Vibrational Spectroscopy of Carbohydrates

Effective use of infrared and Raman spectroscopy in investigating structure and conformation of carbohydrates requires an understanding of the structural and vibrational origin of the observed frequencies. A complete assignment of the observed vibrations in carbohydrate mole-cules is quite a formidable task, especially in the region below 1500 cm−1.
Interstate and Interregional Trade Flows for Agricultural Products

ASIGNIFICANT percentage of agricultural production, either in raw or processed form, is transported across State boundaries before it is consumed. For many products the divergence between per capita production and per capita consumption for given States and regions may show future increases in response to further regional specialization in production, changing transfer costs, and differential changes in population, incomes, and other forces influencing consumption. The purposes of this paper are to: (1) Indicate briefly the general uses in economic analysis of data showing commodity movements among geographic regions and States; (2) describe the principal present sources of such data, and (3) comment on the more likely sources and methods of data improvement. Uses
Can the volume of abnormal parathyroid tissue be predicted by preoperative biochemical measurement

A strong correlation between the biochemical manifestations of hyperparathyroidism and the volume of abnormal parathyroid tissue could be used to guide the extent of surgical exploration and parathyroid gland resection (i.e., finding a small "adenoma" in a patient with marked hypercalcemia would dictate further exploration). We examined this relationship in patients for whom data were collected prospectively (n = 14) and retrospectively (n = 27). We considered only patients cured after excision of a single gland and glands for which a three-dimensional description or volume of water displacement was available. To exclude artifactually elevated serum concentrations of parathyroid hormone (PTH), PTH values were used only from patients with levels of serum creatinine less than 2 mg/dl. To accommodate different assays, highest preoperative PTH, ionized calcium, and alkaline phosphatase (AP) values were expressed as percent above upper normal limit. There was excellent agreement (r = 0.93, p less than 0.05) between measured and calculated gland volume. In the prospective study (but not in the retrospective study) there was a significant (p less than 0.05) correlation (r = 0.61) between gland volume and highest preoperative total calcium value; however, there was considerable variation in gland size in patients with similar calcium levels. In neither study was there a significant correlation between gland volume and any of the following: calcium, ionized calcium, midregional PTH, carboxyterminal PTH, or intact PTH, alkaline phosphatase, and urine cyclic adenosine monophosphate (AMP). In the prospective study there was a tendency for urine cyclic AMP, ionized calcium, and AP to increase with increasing gland volume (r = 0.42, 0.45, and 0.51, respectively). Preoperative measurements of calcium, PTH, urine cyclic AMP, and AP are too inconsistent to rely on for determining the extent of parathyroid gland resection.