cssi/SciSciGPT-SciSciNet huggingface dataset:
Short-term effects of herbicides on primary productivity of periphyton in lotic environments

Freshwater algae are quite sensitive to herbicides that enter running water ecosystems through direct application, aerial drift, and/or watershed run-off. However, due to a lack of suitable methodologies, few studies examine the effects of such contamination on naturally occurring attached algal communities under field conditions (i. e., exposure regimes using pulsed doses or brief episodes of peak concentrations to simulate surface run-off during storm events). This paper describes a method for determining the acute short-term effects of four herbicides (hexazinone, atrazine, tebuthiuron and metolachlor) on the net primary productivity (NPP) of periphytic algae in the field using a portable bankside incubator; NPP was measured by monitoring changes in oxygen production (mg O2 per m2) upper surface of rock substrate per h and mg O2 h per mg chlorophyll using the light-dark technique. All herbicides with photosynthetic inhibition as a mode of action significantly reduced NPP. The lowest observed effect concentrations (LOECs) for the herbicides were 43 μg hexazinone l−1, 109 μg atrazine l−1 and 137 μg tebuthiuron l−1. The no observed effect concentrations (NOECs) for these chemicals were <43 μg hexazinone l−1, 93 μg atrazine l−1 and 52 μg tebuthiuron l−1. Metolachlor did not significantly reduce NPP at the concentrations that were tested (range 19.6–274 μg l−1). However, community respiration (which included respiration by invertebrates) was significantly reduced at the highest metolachlor concentration (274 μg l−1). Community respiration was not significantly affected by any concentration of the other three herbicides used.
Use of B lymphocyte stimulator inhibitor belimumab may be associated with a decrease in the serum concentration of epidermal growth factor in patients with primary Sjögren's syndrome.

B cell activating factor (BAFF), also called the B lymphocyte stimulator, has been known to show increased expression in primary Sjogren’s syndrome (pSS) which could explain increased B cell activation characteristic of this disease. Belimumab, a fully human IgG1λ recombinant monoclonal antibody directed against B lymphocyte stimulator (Blys), has been reported to be efficacious in systemic lupus erythematosus (SLE) through its B cell-mediated action. Randomized controlled trials of belimumab in a selected target population of pSS patients are further warranted.
Glycosidase activity from midgut region of Stomoxys calcitrans (Diptera: Muscidae)☆

Abstract Midgut homogenates from Stomoxys calcitrans (L.) contain at least eight glycosidases. Glycosidase activity was found to change during digestion of the first blood meal. Enzyme activity was found for α-glycosidase, α-mannosidase, α-galactosidase, α- l -arabinosidase, β-galactosidase, β-glucosidase, β-glucuronidase, and N- acetylglucosaminidase . All enzymes had acidic pH optima of 5.0–6.5.
Experimental Study of the Diamagnetism of Gaseous Plasmas with Electron and Nuclear Spin Resonance Techniques

The occurrence of diamagnetism in active discharges was observed by measuring shifts in spin absorption resonance frequencies of foreign substances located near the plasma. Narrow spin electronic resonances in DPPH were used to show that the magnetization of a gaseous discharge in low-pressure mercury vapor increases linearly with applied magnetic field up to about 40 gauss, where maximization occurs. Observation of the phase change in the Larmor precession of protons in a strong homogeneous field showed that the diamagnetism in a modified Penning ionization gauge (P.I.G.) discharge increased linearly with power input and decreased approximately as l/H. Irradiation of the plasma with high-power microwaves with frequency near the free-electron gyrofrequency resulted in an increase of dismagnetism of the discharge. The discharge magnetic moment ranged from -0.001 to -0.32 erg/cm/sup 3/gauss, depending on experimental conditions. The sensitivity of the nuclear resonance technique is one part in 10/sup 6/, and it permits observstion of diamagnetism to be deferred until the discharge is over. The theory of plasma diamagnetism is summarized. (auth)
THE NONLINEAR DYNAMICS OF TWO-PHASE FLOW IN A SIMPLE HEATED LOOP†

Abstract The nonlinear dynamics of two-phase flow in heated channels has been studied numerically. Parallel channel density-wave stability analysis has been extended to the case of a simplified loop which includes the heated channel and pump characteristics. A set of two nonlinear functional ODEs obtained for the dynamics of the simplified heated loop with two-phase flow was integrated numerically for parameter values in different regions of the parameter space and various initial conditions. Stable limit cycles exist for parameter values in the region in which the two-phase flow fixed point is unstable, close to the density-wave MSB, and the oscillation amplitude grows monotonically with the distance from the MSB. Delicate dependence upon certain initial histories (t < 0) and initial conditions (f = 0) is found for parameter values for which there exist more than one attracting set-stable fixed points, stable limit cycle.
Evaluation of the national prevention strategy in reference to historical population health.

Abstract Scientists have estimated that approximately half of all deaths in the United States are attributed to largely preventable behaviors and exposures, such as tobacco use, diet and physical activity, and alcohol consumption. These findings are similar to reflections reported more than 100 years ago by public health authorities. Is it inevitable that half of the population will die prematurely, even as the average life span increases?
The effect of long-range interfacial forces on the dynamics of wetting layers at a liquid-vapor interface

Abstract For certain binary liquid solutions, the denser fluid will form a thin wetting layer between the less dense fluid and the vapor. We consider the possible effect of interfacial van der Waals forces on the capillary waves residing on such wetting layers. In the limit where wetting layer thickness, h, is much smaller than the capillary wavelength, we find a damped peristaltic mode that behaves as ω 2 ∼ k 2 h 3 for typical wavenumbers. Such a mode, if observable, could provide an alternate means of measuring wetting layer thicknesses and could be used to check the dependence of wetting layer thickness on long-range interfacial forces.
Surface complexation of Pb(II) at oxide-water interfaces: I. XAFS and bond-valence determination of mononuclear and polynuclear Pb(II) sorption products on aluminum oxides

Abstract Pb(II) sorption on Al2O3 powders was studied as functions of sorption density (from 0.5 to 5.2 μmoles/m2) and [Pb]eq (0.03–1.4 mM) in 0.1 M NaNO3 electrolyte solution using XAFS spectroscopy. At pH 6 and 7, Pb(II) ions were found to be fully hydrolyzed and adsorbed preferentially as mononuclear bidentate complexes to edges of AlO6 octahedra. At higher sorption densities (Γ ≥ 3.4 μmoles · m−2), XAFS results suggest the presence of dimeric Pb(II) surface complexes. A bond-valence model was used in conjunction with these results to constrain the compositions and reaction stoichiometries of adsorption complexes. We conclude that Pb(II) adsorption on alumina is aattributable to complexation by [ Al Al Al  O −1 2 ] and [ AlOH −1 2 ] surface functional groups. Several plausible Pb(II) adsorption reactions are proposed, based on these results, which provide a basis for chemically realistic descriptions of surface complexation of Pb(II) on aluminum oxides.
Multicopy integration and expression of heterologous genes in Methylobacterium extorquens ATCC 55366

High-level expression of chromosomally integrated genes in Methylobacterium extorquens ATCC 55366 was achieved under the control of the strong M. extorquens AM1 methanol dehydrogenase promoter (PmxaF) using the mini-Tn7 transposon system. Stable maintenance and expression of the integrated genes were obtained in the absence of antibiotic selective pressure. Furthermore, using this technology, a multicopy integration protocol for M. extorquens was also developed. Chromosomal integration of one to five copies of the gene encoding the green fluorescent protein (gfp) was achieved. The multicopy-based expression system permitted expression of a preset number of gene copies. A unique specific Tn7 integration locus in the chromosome of M. extorquens, known as the Tn7 attachment site (attTn7 site), was identified. This single attTn7 site was identified in an intergenic region between glmS, which encodes the essential enzyme glucosamine-6-phosphate synthetase, and dhaT, which encodes 1,3-propanediol dehydrogenase. The fact that the integration event is site specific and the fact that the attTn7 site is a noncoding region of the chromosome make the mini-Tn7 transposon system very useful for insertion of target genes and subsequent expression. In all transformants tested, expression and segregation of the transforming gene were stable without generation of secondary mutations in the host. In this paper, we describe single and multicopy chromosome integration and stable expression of heterologous genes (bgl [beta-galactosidase], est [esterase], and gfp [green fluorescent protein]) in M. extorquens.
Youth after Yugoslavia: subcultures and phantom pain

This article examines recent cinematic representations of male youth subcultures in two Serbian films – Skinning (Stevan Filipovic, 2010) and Tilva Ros (Nikola Ležaic, 2010) – and argues that subcultural belonging in these films performs an enactment of phantom pain which haunts youth in the wake of the turbulent times that their parent culture went through in recent history. By adopting the framework of ‘postmemory’ (Hirsch 2008), I inspect how vicarious remembering of violence permeates the youth's subcultural activities, whether that violence is now directed at others (as is the case with the skinhead youth in Skinning), or towards one's own body (as is the case in Tilva Ros). These depictions of subcultural youth lives offer glimpses into the clandestine processes of coming to terms with the postmemory of a troubled inheritance of catastrophe. They also bring to the fore the classed implications of trauma, war, violence and memory, as in both films social class plays a pivotal role in the youth's prox...
Huh, what was I Doing? How People Use Environmental Cues after an Interruption:

We examine the effect of environmental cues on being interrupted while performing a task. We conducted an experiment in which participants, after an interruption, received either a blatant environm...
Transarterial Therapies for the Treatment of Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma, whether arising from the intrahepatic or extrahepatic biliary system, is a rare but devastating malignancy. Prognosis is poor, with 5-year overall survival <5% including patients undergoing surgery. Resection is the only curative treatment; however, only ∼30% of patients present at a resectable stage, and intrahepatic recurrence is common even after complete resection. This article discusses the current role of transarterial therapies in the treatment of intrahepatic cholangiocarcinoma.
Anisotropy of the Knight shift at planar oxygen sites in YBa2Cu3Ox: Possible location of the doped holes

Abstract The anisotropy of the Knight shift at planar oxygen sites in four superconducting YBa 2 Cu 3 O x samples has been analyzed based on an ionic model. Characteristic variation of the hyperfine fields as a function of hole concentration was found. Crude analysis suggests that such variation could be assigned to an increase of spin fractions in the oxygen 2p π orbitals, which point perpendicular to the CuO bonding. This fact as well as a crystallographic argument may suggest to reconsider second bands associated with the 2p π orbitals, whose symmetry should be distinct from the CuO bonding hybrid.
Strategies for investigation of CNS mechanisms of phenotypic variation in blood pressure and salt appetite in genetic hypertensive rats

Several characteristics of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY), make these homozygous strains particularly well suited for investigating the interactions of salt appetite, blood pressure control, and their neuroendocrine substrates. Appropriate genetic and developmental investigations of sources of variation in salt appetite, blood pressure, and their putative neuroendocrine substrates in these homozygous strains can provide valuable insights into fundamental mechanisms of disease, as well as factors controlling homeostatic behavioral and physiological processes. However, inappropriate use of these strains can produce misleading, although seductively plausible, conclusions regarding mechanisms. Selective inbreeding for hypertension has concentrated in SHR the "high pressure" allele for several genes that influence blood pressure, whereas breeding for normal blood pressure has left WKY with the "normal pressure" allele for all or most of these genes. In principle, inbred hypertensive strains could provide information about specific genetic alterations that mediate the hypertensive phenotype. The benefits of work with these strains are discussed, but several false assumptions and logical pitfalls are described that might cause misleading or erroneous interpretations of results from work with such strains. These problems illustrate the importance of the research strategy in elucidating the particular information that can be provided by these inbred animal models of hypertension. Two strategic approaches for studying hypertension and other genetically determined or influenced characteristics in inbred animal models such as SHR are discussed: cosegregation analysis for identifying or rejecting genetic linkage, and brain graft techniques for identifying brain specific genetic influences on cardiovascular or behavioral phenotypes. Examples of each approach are described.
Vulnerability of Streams to Legacy Nitrate Sources

The influence of hydrogeologic setting on the susceptibility of streams to legacy nitrate was examined at seven study sites having a wide range of base flow index (BFI) values. BFI is the ratio of base flow to total streamflow volume. The portion of annual stream nitrate loads from base flow was strongly correlated with BFI. Furthermore, dissolved oxygen concentrations in streambed pore water were significantly higher in high BFI watersheds than in low BFI watersheds suggesting that geochemical conditions favor nitrate transport through the bed when BFI is high. Results from a groundwater–surface water interaction study at a high BFI watershed indicate that decades old nitrate-laden water is discharging to this stream. These findings indicate that high nitrate levels in this stream may be sustained for decades to come regardless of current practices. It is hypothesized that a first approximation of stream vulnerability to legacy nutrients may be made by geospatial analysis of watersheds with high nitrogen...
Color-coded binary fringe projection technique for 3-D shape measurement

Color coding has been used for 3-D shape measurement in many recently developed fringe projection techniques. Use of color allows for more information to be coded in the same number of patterns as compared to the black-and-white techniques. However, one major problem of using color is that the appearance of the color fringe patterns projected onto the object can be affected by the color of the object surface itself. Thus, correctly decoding the fringe patterns can be difficult and sometimes even impossible. We describe a color-coded binary fringe projection technique that solves this problem. The use of an adaptive threshold scheme enables the extraction of the 3-D information and texture of an object without being affected by the color of the object surface. The development of a color gray-code concept, which is an extension of the gray-code technique, further reduces decoding errors. In addition, this technique can be used to measure objects with discontinuous features. The system has small digitizing errors and its measurement accuracy is hardly affected by system noise and nonlinearity errors. The system setup, color pattern design, shape reconstruction, and experimental results are presented
Effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature in neonatal foals

The effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature were investigated in six foals at 10 and 28 days of age. These variables were also measured in three foals at 19 days of age when saline alone was injected. Rectal temperature fell significantly after 30 mins in both groups of xylazine treated foals and was still depressed after 120 mins. Hypothermia did not occur in the saline control group. There was no significant change in blood glucose or plasma insulin concentrations during the 120 mins following either xylazine or saline administration and no significant differences between the three groups of foals. When foals were allowed to suckle after being away from their dams for 2 h, there was a significant (P less than 0.01) rise in plasma insulin levels in all the groups. Blood glucose showed a concomitant rise but this was only significant in the saline group. Unlike adults, intravenous xylazine (1.1 mg/kg) does not produce hypoinsulinaemia and hyperglycaemia in foals. This study suggests that the inhibition of insulin release from pancreatic beta-cells by xylazine, which in adults is alpha 2-adrenoceptor mediated, is immature or absent in foals under one month of age.
Feasibility of Improving the Economic Return from the Gulf of Mexico Brown Shrimp Fishery

Abstract A bioeconomic model was developed to investigate the feasibility of improving the economic return from the fishery for brown shrimp Penaeus aztecus through cooperative federal and state management closures in the U.S. Gulf of Mexico. Four different closure periods were simulated with the model. The closure options were evaluated for Texas only (current condition) and for the entire U.S. Gulf of Mexico (proposed condition). The model provided an accurate biological simulation of the brown shrimp fishery in the Gulf of Mexico. Each of the evaluated closures gave positive net profits to the fishery as a whole, However, these benefits were mainly for larger vessels (>50 ft in length). None of the proposed closures increased the profits for boats (undocumented vessels of unknown lengths), and only some closures increased the profits for smaller vessels (≤50 ft in length).
Systemic bioavailability of penclomedine (NSC-338720) from oil-in-water emulsions administered intraduodenally to rats

Abstract Penclomedine (NSC-338720) is a low melting point, poorly water-soluble cytotoxic agent with good solubility in triglycerides and a high octanol/water partition coefficient. Its pharmacokinetics in anesthetized rats was studied after i.v. bolus injection of a soybean oil emulsion. Penclomedine displayed biexponential behavior with an apparent t 1 2 (± SE ) of 1.9 ± 0.3 h and a clearance of 3.3 ± 0.1 ml/min per kg. After intraduodenal administration to anesthetized rats as either a 10% o/w emulsion of tributyrin, trioctanoin, triolein, soybean oil or mineral oil, or as a suspension, the rank order of absolute bioavailability was trioctanoin > soybean oil ≈ triolein > mineral oil > tributyrin > suspension. The results were rationalized by assuming that drug release from the emulsions was by a combination of vehicle metabolism and diffusional drug release. The poor bioavailability from tributyrin was rationalized by the rapid release of penclomedine resulting in its possible precipitation and subsequent need to redissolve.
Yeast topoisomerase II is inhibited by etoposide after hydrolyzing the first ATP and before releasing the second ADP.

Abstract Topoisomerase II-catalyzed DNA transport requires coordination between two distinct reactions: ATP hydrolysis and DNA cleavage/religation. To further understand how these reactions are coupled, inhibition by the clinically used anticancer drug etoposide was studied. The IC50 for perturbing the DNA cleavage/religation equilibrium is nucleotide-dependent; its value is 6 μm in the presence of ATP, 25 μm in the presence of a nonhydrolyzable ATP analog, and 45 μm in the presence of ADP or no nucleotide. This inhibition was further characterized using steady-state and pre-steady-state ATPase and decatenation assays. Etoposide is a hyperbolic noncompetitive inhibitor of the ATPase activity with aK i(app) of 5.6 μm; no inhibition of ATP hydrolysis is seen in the absence of DNA cleavage. In order to determine which steps of the ATPase mechanism etoposide inhibits, pre-steady-state analysis was performed. These results showed that etoposide does not reduce the rate of binding two ATP, hydrolyzing the first ATP, or releasing the second ADP. Inhibition is therefore associated with the first product release step or hydrolysis of the second ATP, suggesting that DNA religation normally occurs at one of these two steps. Multiple turnover decatenation is inhibited when etoposide is present; however, single turnover decatenation occurs normally. The implications of these results are discussed in terms of their contribution to our current model for the topoisomerase II mechanism.
An application of the experience sampling method to the study of aphasia: A case report

Background: Researchers stress that functional health and psychological well-being are important aspects of quality of life in the investigation of individuals with aphasia. Employed in the social sciences, the experience sampling method (ESM) has begun to shed light on deviations in participants' momentary responses to behavioural contingencies in naturalistic environments. Applications of ESM have demonstrated value in monitoring within-participant variations in mood, psychopathology, and treatment outcomes while minimising the effect of memory bias. Additionally, the application of ESM in psychological cognitive-behavioural therapy and occupational therapy (OT) research reportedly appeared to contribute to treatment success. A time-based, fixed-schedule sampling application of ESM was used in this study to attain self-reports throughout an aphasia treatment programme. Aims: The current investigation introduced the ESM paradigm to the study of aphasia and piloted its use in measuring psychoemotional var...
A computational method for determining segmental and overall geothermal gradients and geothermal heat flow values

A new computational method is presented which calculates geothermal heat flow values and geothermal gradients with more precision than permitted by previously published techniques. The data required are: geothermal temperature at a known depth, mean surface temperature, the rock types in the stratigraphic column and the thermal resistivity values for the different types of rocks. This method is valuable in areas that have no measured gradient values. Basic equation used was the Fourier heat transfer equation Q/A = −1/ρi (∂T/∂x) where Q/A is heat flux in μcal/(cm2 s), ρi is thermal resistivity (°C s cm/μcal) and ∂T/∂x is the x component of the temperature gradient (°C/cm). The thermal resistivity was allowed to vary linearly with temperature ρi = ρio [1 + Ki (T − 30)] where ρi is thermal resistivity of the lithographic segment «ia at a temperature T, ρio is thermal resistivity at 30°C and Ki is the temperature coefficient of thermal resistivity. The procedure consisted of integrating the combined equation for heat flux in terms of temperature dependent resistivity. Two iterative solutions were used to simplify the calculations: exact and approximate. The heat flux for each well was assumed to be 1.0 HFU and segmental temperatures were calculated from the bottom (arbitrarily) up, until a surface temperature was obtained. The calculated surface temperature could then be compared with the mean surface temperature (MST). Correction in the heat flux value was made until the calculated surface temperature and MST agreed. An analysis of three deep Appalachian test wells was made and the results showed the critical importance of lithographic ordering and the temperature dependence of thermal resistivity upon calculated geothermal quantities.
Pathogenicity of Phialophora pedrosoi.

Zusammenfassung 30 Kaninchen wurden mit Phialophora pedrosoi intravenos (durch eine randstandige Ohrvene) infiziert. 15 der Tiere erhielten 2 Tage vor der Inokulation s. c. 100 mg Cortisonacetat und 4 weitere Injektionen alle 2 Tage. Die anderen Tiere erhielten kein Cortisonacetat. Inokuliert wurden 3 Stamme, pro Stamm 5 Kaninchen. 1 Stamm war frisch isoliert, die anderen wurden der Sammlung entnommen und bildeten weniger Konidien. Keines der 30 Kaninchen starb wahrend des Versuches, so das planmasige, in bestimmte Zeitabstande gestufte Autopsien mit mykologischen und histopathologischen Untersuchungen vorgenommen werden konnten. Die Tiere wurden nach 1, 2, 3, 5 und 8 Wochen getotet. In der Cortisongruppe zeigten 9 Tiere Krankheitsherde, vor allem in der Lunge und Leber, in einem Falle auch in der Niere. Die Herde waren noch nach 2 Monaten aktiv. In der anderen Gruppe erkrankten nur 5 Tiere, und die Krankheitserscheinungen heilten innerhalb von 3 Wochen wieder ab. Die mikroskopische Untersuchung von infiziertem Gewebe nach Aufhellung in 10 %iger Kalilauge ergab lange braune Faden. Mit Hamatoxylin und Eosin gefarbte Schnitte zeigten eine nur geringe Gewebsreaktion um die Pilzelemente. In einzelnen Fallen fanden sich bei den nach 4–5 Wochen getoteten Tieren Granulome im Lungengewebe. In Riesenzellen waren runde bis ovale, gelblichbraune Pilzzellen nachzuweisen. Die von Aravysky und Aronson berichtete Hemmung der Riesenzellreaktion durch Cortison war bei den vorliegenden Untersuchungen nicht festzustellen. Insgesamt wird das Ergebnis der Versuche als Beweis fur die Pathogenitatssteigerung von Phialophora pedrosoi durch Cortison interpretiert.
Sexual Decision Making by Inner City Black Adolescent Males: A Focus Group Study

This research was designed to illuminate the cognitive and emotional bases of the sexual decisions made by young Black men. It was guided by the assumption that the Black male's understanding and e...
Mitigating race: Understanding the role of social connectedness and sense of belonging in African–American student retention in hospitality programs

Abstract Given the shifting demographic composition of the U.S., and the need to have qualified ethnic minority professionals serving diverse communities in the hospitality industry, retention and matriculation of ethnic minority students are of paramount importance. Since many predominately White institutions (PWIs) experience challenges retaining these students, this exploratory study sought to better understand how social connectedness related to retaining African–American students in a hospitality management program. The findings suggest that (1) being connected to the program and university; (2) the depth and quality of relationships with faculty; and (3) the presence of minority faculty is important in retaining African–American students.
Medication use in a female orofacial pain population

Objective This study compared, both quantitatively and qualitatively, the self-reported medication usage between an adult female orofacial pain population and a comparison group. Study design Eighty-seven subjects from both an orofacial pain center (OPC) and undergraduate dental clinic (UDC) completed a standardized medical history questionnaire. Both groups had a similar distribution with regard to age. The number of medications and medication categories were compared between the two groups. Statistical analysis used the Student t -test, Fisher’s exact tests, Pearson’s χ 2 tests, and calculated odds ratios. Results The number of pain and non-pain medications, and the number of medication categories endorsed by OPC subjects was significantly higher compared with the UDC group. Conclusion Adult female orofacial pain subjects report greater overall and higher rate of medication use, which was not limited to only the analgesic/narcotic categories, than the comparison group.
Postextrasystolic U Wave Augmentation, a New Marker of Increased Arrhythmic Risk in Patients Without the Long QT Syndrome

Objectives We attempted to determine the correlation between the presence of postextrasystolic changes in the STU segment and a history of sustained ventricular arrhythmias. Background Postextrasystolic U wave augmentation (a marked increment in U wave amplitude after premature ventricular complexes [PVCs]) is an adverse prognostic sign in the “pause-dependent long QT syndrome.” However, the prevalence of post-extrasystolic changes in patients without the long QT syndrome is unknown. Methods We compared the configuration of the STU segment of the postextrasystolic beat (the sinus beat after a PVC) with the STU configuration during sinus rhythm in three patient groups: 1) 41 patients with spontaneous ventricular tachycardia/ fibrillation (VT/VF) (VT/VF group), 2) 63 patients with heart disease and high grade ventricular arrhythmias (control group), and 3) 29 patients with high grade ventricular arrhythmias but no heart disease (reference group). Results Postextrasystolic T wave changes did not correlate with a history of ventricular tachyarrhythmias. However, postextrasys-tolic U wave changes were more common among the patients with VT/VF than among control subjects (39% vs. 8.7%, p Conclusions Postextrasystolic T wave changes are common and lack predictive value. Postextrasystolic U wave changes may be a specific marker of a tendency to the development of spontaneous ventricular arrhythmias. Prospective studies should be performed to confirm this association.
Late nonresponsiveness to steroids in children with the nephrotic syndrome

Among 195 nephrotic children, ten developed resistance to prednisone therapy after responding to this drug on one or more occasions (late nonresponders). All were found to have "minimal lesions" on renal biopsy. Nine of these patients went into remission: one responded to further prednisone therapy, one went into remission while receiving azathioprine, and the remaining seven children responded to cyclophosphamide. Five of these seven patients subsequently relapsed; three of them have continued to respond to prednisone. The other two eventually became steroid resistant a second time, but in both instances a second course of cyclophosphamide again induced a remission. These nine patients have been followed for periods ranging from 6 months to 9.5 years (median = 53 months); all are doing well and have normal renal function. The tenth patient died from sepsis four months after the onset of steroid resistance.
Lessons from the past: the collapse of Jamaican coral reefs

Since Pre-Columbian times, humans have exploited Jamaican marine ecosystems with significant consequences for flora and fauna. This study focuses on the history of reef fish exploitation in Jamaica, from first human occupation to the present day, to determine how past fishing activities contributed to subsequent declines in the coral reef ecosystem. The pattern of declining reef fish populations was nonlinear. Reef fish first declined in prehistoric times but then potentially recovered, following genocide of the native human population. Reduced fishing pressure lasted until the mid-19th century. At that time, depletion of reef fish populations again occurred with a precipitous decline from the 1850s to the 1940s. The final shift from relatively abundant to overfished marine fauna corresponded to subtle changes in fish trap design as well as development of recreational fishing. Government subsidies throughout the second half of the 20th century exacerbated the declines. This analysis shows that local artisanal fisheries with relatively low levels of effort and seemingly subtle shifts in technology can significantly impact the coral reef ecosystem and that declines occurred decades to centuries before modern ecological studies began. This research shows how historical analysis can be a powerful tool to minimize shifted baselines and establish realistic targets for recovery and sustainable management of marine ecosystems.
Flocculation of sulfides and the role of a complexing agent in it

Abstract Selective flocculation using polymers is one of the promising methods for the separation of mineral fines. In this paper, possibilities for selective flocculation of chalcopyrite and pentlandite using polyacrylamide and polyethylene oxide are examined under different experimental conditions. Selective flocculation tests with synthetic mineral mixtures showed the selectivity to depend on polymer type and concentration, and the presence of dissolved species from either mineral. The dissolved species are found to interact with minerals to be treated and reagents, resulting in non-selective flocculation. The interference by dissolved species can be eliminated by using a complexing agent such as diphenylguanidine that interacts specifically with copper minerals. Interactions between many components are possible in these systems and these are examined in order to identify the governing mechanisms.
Glutamic acid decarboxylase mRNA in the suprachiasmatic nucleus of rats housed in constant darkness.

Abstract This study demonstrates that the levels of the mRNAs encoding the two isoforms of glutamic acid decarboxylase (GAD) (i.e., GAD65 and GAD67) do not differ over the circadian activity cycle in the suprachiasmatic nucleus (SCN) of rats housed in constant darkness. These data indicate that the rhythmic expression of GAD65 mRNA previously observed in animals housed in a light:dark cycle [K.L. Huhman, A.C. Hennessey, H.E. Albers, Rhythms of glutamic acid decarboxylase mRNA in the suprachiasmatic nucleus, J. Biol. Rhythms 11 (1996) 311–316.] is the result of the activity of retinal afferents.
Dietary fat is not a major determinant of body fat.

The percentage of energy from fat in diets has been thought to be an important determinant of body fat, and several mechanisms have been proposed. Comparisons of diets and the prevalence of obesity between affluent and poor countries have been used to support this relationship, but these contrasts are seriously confounded by differences in physical activity and food availability. Within areas of similar economic development, regional intake of fat and prevalence of obesity have not been positively correlated. Randomized trials are the preferable method to evaluate the effect of dietary fat on adiposity and are feasible because the number of subjects needed is not large. In short-term trials, a modest reduction in body weight is typically seen in individuals randomized to diets with a lower percentage of calories from fat. However, compensatory mechanisms appear to operate, because in randomized trials lasting >or=1 year, fat consumption within the range of 18% to 40% of energy appears to have little if any effect on body fatness. The weighted mean difference was -0.25 kg overall and +1.8 kg (i.e., less weight loss on the low-fat diets) for trials with a control group that received a comparable intensity intervention. Moreover, within the United States, a substantial decline in the percentage of energy from fat during the last 2 decades has corresponded with a massive increase in the prevalence of obesity. Diets high in fat do not appear to be the primary cause of the high prevalence of excess body fat in our society, and reductions in fat will not be a solution.
The influence of increasing growth temperature and CO2 concentration on the ratio of respiration to photosynthesis in soybean seedlings

Using controlled environmental growth chambers, whole plants of soybean, cv. ‘Clark’, were examined during early development (7‐20 days after sowing) at both ambient (µ 350 μ LL ‐1 ) and elevated (µ 700 μ LL ‐1 ) carbon dioxide and a range of air temperatures (20, 25, 30, and 35 °C) to determine if future climatic change (temperature or CO2 concentration) could alter the ratio of carbon lost by dark respiration to that gained via photosynthesis. Although whole-plant respiration increased with short-term increases in the measurement temperature, respiration acclimated to increasing growth temperature. Respiration, on a dry weight basis, was either unchanged or lower for the elevated CO2 grown plants, relative to ambient CO2 concentration, over the range of growth temperatures. Levels of both starch and sucrose increased with elevated CO2 concentration, but no interaction between CO2 and growth temperature was observed. Relative growth rate increased with elevated CO2 concentration up to a growth temperature of 35 °C. The ratio of respiration to photosynthesis rate over a 24-h period during early development was not altered over the growth temperatures (20‐35 °C) and was consistently less at the elevated relative to the ambient CO2 concentration. The current experiment does not support the proposition that global increases in carbon dioxide and temperature will increase the ratio of respiration to photosynthesis; rather, the data suggest that some plant species may continue to act as a sink for carbon even if carbon dioxide and temperature increase simultaneously.
Argon 420.1–419.8 nm emission line ratio for measuring plasma effective electron temperatures

We explore the feasibility of using the ratio of two argon emission line intensities at 420.1 and 419.8 nm to measure the effective electron temperature in argon-containing plasmas. Experimental measurements in numerous plasma sources reveal the ratio varies from a value of approximately 1 at high electron temperatures, to a value near 4 at low electron temperatures. This variation is understood in terms of the magnitudes of the electron excitation cross sections into the upper energy levels of the two transitions. At high electron temperatures, the upper levels of the two emission lines, the J = 3 3p9 level for the 420.1 nm line and the J = 0 3p5 level for the 419.8 nm line, are both primarily populated by excitation from the ground state and have similar optical emission cross sections. At low electron temperatures, excitation is dominated by excitation from the metastable levels which have very different cross sections into the two levels. Temperatures obtained with this line pair ratio in an inductively coupled plasma are found to be consistent with values obtained from a Langmuir probe as well as an analysis of the entire set of 2px → 1sy emission lines (665–1150 nm) under a wide variety of plasma conditions.
Growth hormone and cardiac glycogen: influence of environmental and genetic factors.

The rise in cardiac glycogen levels observed in the rat during fasting and after growth hormone administration is more difficult to demonstrate in the mouse. At room temperature fasting lowers the cardiac glycogen of the mouse. Large doses of growth hormone are needed to maintain the cardiac glycogen at the level seen in fed animals. At 30 °C mice of the A strain increase their cardiac glycogen during a 24-hour fast. Growth hormone increases the glycogen level still further. At this elevated temperature (close to the critical temperature of the mouse) fasting lowers the cardiac glycogen of the I strain mouse, but growth hormone raises the glycogen above the level of fed animals. It is suggested that the fasting stimulus evokes a greater secretion of growth hormone in A strain mice or that the tissues of these mice are more sensitive to the hormone.
MMP-1-PAR1 axis mediates LPA-induced epithelial ovarian cancer (EOC) invasion

Abstract Objectives MMP-1 is over-expressed in many cancers, with high expression often associated with poor survival. In the present study, we examined the expression of MMP-1 in EOC and its role in EOC invasion. Moreover, we evaluated the role of a newly identified MMP-1-protease activated receptor (PAR)-1 axis in LPA-induced EOC invasion. Methods MMP-1 and PAR1 mRNA expression in EOC cell lines was determined by real time PCR. MMP-1 mRNA expression in 96 normal and carcinoma ovarian tissue specimens was analyzed using a TissueScan real time PCR array. MMP-1 concentration in conditioned medium was measured by MMP-1 ELISA. PAR1 protein expression was detected by Western blotting. Cell invasion was evaluated by in vitro Matrigel invasion assay. Results In ovarian tumor tissues more MMP-1 expression was observed than in normal ovarian tissues ( p grade 2>grade 1). Human recombinant MMP-1 as well as serum free conditioned medium containing high levels of MMP-1 from DOV13 and R182 cells significantly promoted DOV13 cell invasion ( p p Conclusions Our results suggest that the MMP-1-PAR1 axis is involved in EOC invasion and at least partially mediates LPA-induced EOC invasion. Therefore, blocking MMP-1 or PAR1 may represent a new therapeutic option for metastatic EOC.
Infrared laser spectroscopy of imidazole complexes in helium nanodroplets: monomer, dimer, and binary water complexes.

Infrared laser spectroscopy has been used to characterize imidazole (IM), imidazole dimer (IMD), and imidazole−water (IMW) binary systems formed in helium nanodroplets. The experimental results are compared with ab initio calculations reported here. Vibrational transition moment angles provide conclusive assignments for the various complexes studied here, including IM, one isomer of IMD, and two isomers of the IMW binary complexes.
Managing diverse risks: An integrative framework

Abstract Risk is a crucial part of any business and managing risk is an essential function for management. This paper reviews current managerial practice and academic research in managing diverse risks. There are numerous elements of risk, some exogenous to the firm and others that are endogenous. In recent years exogenous elements of risk have increased both in number and complexity, and distinctions have blurred between national and international elements of risks because of the integration across borders of markets, institutions, and political and operational risks. An explicit classification of risks as exogenous and endogenous will focus managerial attention to the changing exogenous elements, to the often ignored endogenous elements, and to the needed integration of managing exogenous and endogenous risks. While there is an increasing body of research examining risk, there is a need to examine exogenous risk elements as systems of risk rather than as independent elements and integrate endogenous elements including behavioral and incentive-related aspects with the systems of exogenous risks. Additionally, international case studies and surveys about risk perceptions and attitudes of managers across different organizations and within levels of organizations will improve our understanding of the diverse risks faced by multi-national corporations.
Extensions of a Simple Model with Applications in Reliability, Extinction of Species, Inventory Depletion and Urn Sampling.

This paper is devoted to the study of che following tsodel:A series-parallel system consists of (k + 1) subsystem C0C1 ,…,Ck, , also called cut sets. Cut sec C1 has ni. com­ponents arranged in parallel, i = 0,1,…,k. Jo two cut sets have a component in comeon. This model was introduced and studied by El-Heweihi, Proschan, and Sethuraiaan (1978) under the assumption that component lifelengths are continuous, indepdent, and identically distributed random variables. They obtained several equivalent expressions for the probability that a specified cut set C0, say, fails first. These expressions aere then used to derive qualitative properties of this probability, such as monotonicity, Schur-concavity, etc. In this paper we obtain extensions of these results, tinder -he same assumptions ve study the probability that a. specified cut set C0say, fails in the rth place, r = l,2,…,k. This probability Is shown to retain most of the interesting qualitative features enjoyed in the special case r = 1. We then assure* th...
Protection against methanol-induced retinal toxicity by LED photostimulation

We have initiated experiments designed to test the hypothesis that 670-nm Light-Emitting Diode (LED) exposure will attenuate formate-induced retinal dysfunction in a rodent model of methanol toxicity. Methanol intoxication produces toxic injury to the retina. The toxic metabolite formed in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit cytochrome oxidase activity. 670-nm LED light has been hypothesized to act by stimulating cytochrome oxidase activity. To test this hypothesis, one group of animals was intoxicated with methanol, a second group was intoxicated with methanol and LED-treated and a third group was untreated. LED treatment (670 nm for 1 min 45 seconds equals 50 mW/cm2, 4 joules/cm2) was administered at 5, 25, and 50 hours after the initial dose of methanol. At 72 hours of methanol intoxication, retinal function was assessed by measurement of ERG responses and retinas were prepared for histologic analysis. ERG responses recorded in methanol-intoxicated animals revealed profound attenuation of both rod-dominated and UV-cone mediated responses. In contrast, methanol- intoxicated animals exposed to LED treatment exhibited a nearly complete recovery of rod-dominated ERG responses and a slight improvement of UV-cone mediated ERG responses. LED treatment also protected the retina against the histopathologic changes produced by formate in methanol intoxication. These data provide evidence that LED phototherapy protects the retina against the cytotoxic actions of formate and are consistent with the hypothesis that LED photostimulation improves mitochondrial respiratory chain function.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Protection against hypoxia-induced blood-brain barrier disruption: changes in intracellular calcium

Tissue damage after stroke is partly due to disruption of the blood-brain barrier (BBB). Little is known about the role of calcium in modulating BBB disruption. We investigated the effect of hypoxic and aglycemic stress on BBB function and intracellular calcium levels. Bovine brain microvessel endothelial cells were treated with A-23187 to increase intracellular calcium without hypoxia or treated with a calcium chelator (BAPTA) or calcium channel blockers (nifedipine or SKF-96365) and 6 h of hypoxia. A-23187 alone did not increase paracellular permeability. Hypoxia increased intracellular calcium, and hypoxia or hypoxia-aglycemia increased paracellular permeability. Treatment with nifedipine and SKF-96365 increased intracellular calcium under normoglycemic conditions, instead of blocking calcium influx, and was protective against hypoxia-induced BBB disruption under normoglycemia. Protection by nifedipine and SKF-96365 was not due to antioxidant properties of these compounds. These data indicate that increased intracellular calcium alone is not enough to disrupt the BBB. However, increased intracellular calcium after drug treatment and hypoxia suggests a potential mechanism for these drugs in BBB protection; nifedipine and SKF-96365 plus hypoxic stress may trigger calcium-mediated signaling cascades, altering BBB integrity.
An edge detection approach for mapping of the human cone photoreceptor mosaic using adaptive optics scanning laser ophthalmoscope

In this study, a novel edge detection algorithm and an adaptive optics scanning laser ophthalmoscopy were applied to visualize the cone photoreceptor mosaic from approximately 4° to 8° eccentricities in the vertical, superior retina.