cssi/SciSciGPT-SciSciNet huggingface dataset:
Association between self-reported environmental tobacco smoke exposure and lung cancer: modification by GSTP1 polymorphism.

Environmental Tobacco Smoke (ETS) exposure has been associated with lung cancer risk. ETS is composed of emissions from cigarette smoke and contains a higher concentration of tobacco smoke carcinogens than mainstream smoke. Polymorphisms in genes that metabolize tobacco smoke carcinogens have been studied as effect modifiers of the association between active smoking and lung cancer risk. GSTP1 is a polymorphic gene that encodes for GST pi, a detoxification enzyme and has a high expression in the lung. We investigated the association between ETS and lung cancer risk and the modification of this association by the GSTP1 polymorphism. Using a case-control design, individuals were genotyped for GSTP1 using PCR-RFLP techniques. All analyses were carried out using multiple logistic regression. The association between ETS exposure and lung cancer risk was evaluated in different strata based on smoking habits to evaluate the consistency of results. The effect of the GSTP1 polymorphisms on lung cancer risk was evaluated by considering the joint effect of having both an ETS exposure and the GSTP1 GG genotype compared to the absence of ETS exposure and the GSTP1 AA genotype as a reference group as well as doing stratified analysis by genotype. ETS exposure was associated consistently with higher lung cancer risk in all the strata considered. The adjusted odds ratios (AOR) evaluating the association between ETS and lung cancer risk for the different strata were: nonsmokers (Cases/Controls 66/413; AOR = 1.38; 95% CI = 0.78-2.43), ex-smokers (Cases/Controls 560/527; AOR = 1.66; 95% CI = 1.22-2.25), current smokers (Cases/Controls 415/219; AOR = 1.56; 95% CI = 1.00-2.41). The AORs for ex-smokers and light smoking subgroups were: ex-smokers who quit for 19 years or more (Cases/Controls 144/244; AOR = 2.64; 95% CI = 1.55-4.50), ex-smokers who quit for 10-19 years (Cases/Controls 141/128; AOR = 1.16; 95% CI = 0.66-2.04), ex-smokers who quit for 10 years or less (Cases/Controls 247/122; AOR = 1.45; 95% CI = 0.83-2.55) and participants who had <15 packyears and nonsmokers combined (Cases/Controls 143/640; AOR = 1.52; 95% CI = 1.02-2.28). Among those with the GSTP1 GG genotype the ETS-lung cancer risk association was greater than those with the GSTP1 AA genotype: nonsmokers (GSTP1 GG AOR = 7.84; 95% CI = 0.80-76.68; GSTP1 AA AOR = 1.15; 95% CI = 0.46-2.90), ex-smokers (GSTP1 GG AOR = 2.32; 95% CI = 0.90-5.96; GSTP1 AA AOR = 2.15; 95% CI = 1.34-3.44), current smokers (GSTP1 GG AOR = 1.75; 95% CI = 0.42-7.32; GSTP1 AA AOR = 1.32; 95% CI = 0.67-2.58) and participants who had <15 packyears and nonsmokers (GSTP1 GG AOR = 1.93; 95% CI = 0.54-6.97; GSTP1 AA AOR = 1.58; 95% CI = 0.83-3.01). We found that ETS exposure is associated with higher lung cancer risk. Furthermore, the presence of the GSTP1 GG genotype appears to enhance the magnitude of the association between ETS exposure and lung cancer. Larger studies will be needed to confirm these preliminary findings.
The effect of oxidation pre-treatment on the cyclic life of EB-PVD thermal barrier coatings with platinum-aluminide bond coats

Abstract A simple method of improving the durability of EB-PVD thermal barrier coatings (TBC) based on pre-oxidation of the bond coat is described. The method produces a twofold increase in TBC cyclic life and is effective in postponing the two major types of the oxidation-induced failure typical of TBC systems with platinum–aluminide bond coats: the gradual growth of separations between the TBC and the thermally grown alumina scale (TGO), and spontaneous failure by spallation. The stable alpha-alumina scale, formed on the bond coat surface prior to TBC deposition, is less susceptible to separation along the TBC–TGO interface and also exhibits a lower growth rate in comparison with the TGO that develops on a similar bond coat without pre-oxidation. Based on these and related observations, some key principles and requirements of the oxidation pre-treatment as well as the origin of its beneficial effect are discussed.
Failure to Confirm the Existence of Short-Latency, Short-Loop Feedback Regulation (Autoregulation) of Growth Hormone Secretion in the Human

That growth hormone (GH) regulates its own secretion by negative feedback both directly and indirectly via somatomedins has been well-documented in the rat and assumed, on the basis of limited studies
Luotonin A. A Naturally Occurring Human DNA Topoisomerase I Poison

Luotonin A is a pyrroloquinazolinoquinoline alkaloid isolated from the Chinese herbal medicinal plant Peganum nigellastrum. Although previously shown to exhibit cytotoxicity against the murine leukemia P-388 cell line, the mechanism of action of luotonin A is unknown. Presently, we demonstrate that luotonin A stabilizes the human DNA topoisomerase I-DNA covalent binary complex, affording the same pattern of cleavage as the structurally related topoisomerase I inhibitor camptothecin. Luotonin A also mediated topoisomerase I-dependent cytotoxicity toward Saccharyomyces cerevisiae lacking yeast topoisomerase I, but harboring a plasmid having the human topoisomerase I gene under the control of a galactose promoter. This finding identifies a putative biochemical locus for the cytotoxic action of luotonin A and has important implications for the mechanism of action of camptothecin and the design of camptothecin analogues.
Human Rights in Chinese Thought: A Cross-Cultural Inquiry

What should we make of claims by members of other groups to have moralities different from our own? Human Rights in Chinese Thought gives an extended answer to this question in the first study of its kind. It integrates a full account of the development of Chinese rights discourse - reaching back to important, though neglected, origins of that discourse in 17th and 18th century Confucianism - with philosophical consideration of how various communities should respond to contemporary Chinese claims about the uniqueness of their human rights concepts. The book elaborates a plausible kind of moral pluralism and demonstrates that Chinese ideas of human rights do indeed have distinctive characteristics, but it nonetheless argues for the importance and promise of cross-cultural moral engagement.
Traffic into the prevacuolar/endosomal compartment of Saccharomyces cerevisiae: A VPS45-dependent intracellular route and a VPS45-independent, endocytic route

Abstract The vps ( v acuolar p rotein s orting) mutants have been used to dissect and charaterize the vacuolar biogenesis pathway in the yeast Saccharomyces cerevisiae . The vps mutants were isolated through their loss of ability to correctly sort the vacuolar hydrolase CPY, which travels from Golgi membranes to the vacuole through a prevacuolar compartment. Over 50 VPS genes have been divided into 6 classes according to vacuolar morphology. Mutations in any one of the class E VPS genes, such as VPS27 , lead to an exaggerated form of the prevacuolar compartment. This class E compartment contains endocytosed proteins as well as proteins en route to the vacuole, and is thus taken to represent an intersection point between the endocytic and biosynthetic pathways. Mutations in the class D gene VPS45 can be used to define a second transport intermediate along the vacuolar biogenesis pathway, Golgi-derived transport vesicles carrying vacuolar membrane proteins on their way to the vacuole. Here we demonstrate that the Sec1p-like protein Vps45p is required for the fusion of Golgi-derived vesicles with the prevacuolar compartment indicating that VPS45 functions before VPS27 in the vacuolar biogenesis pathway. In addition, we show that VPS45 function is not required for the delivery of endocytosed proteins to the prevacuolar compartment from the plasma membrane suggesting that the function of Vps45p is restricted to a single vesicular pathway.
The effects of bayluscide and malathion on the survival of Schistosoma mansoni miracidia.

Abstract Laboratory experiments were conducted to assess the toxic effects of bayluscide and malathion against Schistosoma mansoni miracidia. The results indicate that survival of miracidia varied with times of exposure and concentrations of tested chemicals. Statistical analyses reveal that LC5, LC50 and LC95 for bayluscide were 0.04 ppm, 0.06 ppm and 0.12 ppm after 2 hours of exposure; 0.02 ppm, 0.03 ppm and 0.06 ppm after 4 hours of exposure; and 0.01 ppm, 0.02 ppm and 0.04 ppm after 6 hours of exposure respectively. These data indicate that bayluscide is much more toxic to the first stage larvae of schistosomes than to snail intermediate hosts cited in the literature. Application of lower concentrations of molluscicide in the transmission sites is thus expected to curtail the survival of miracidia; therefore controlling schistosomiasis at relatively low costs. Such applications also reduce the risk of toxicity to non target organisms present in the aquatic environment. Statistical analysis of the resu...
Using packet probes for available bandwidth estimation: a wireless testbed experience

Evaluating available bandwidth estimation methods requires a malleable MAC protocol implementation, precise MAC layer packet timing measurements, and the ability to create control topologies in laboratory setups so that not all nodes are within communication range. To address these challenges,we have exploited IEEE 802.11e-derived features to obtain more control over the MAC layer operation of off-the-shelf radios and implemented a measurement-system that uses CPU timestamp counter and radio hardware timestamps to monitor MAC activity with microsecond resolution. In addition to presenting performance of our available bandwidth estimation method using packet probes, we also discuss solutions and open issues to provide useful information for other testbed cross-layer protocol evaluations, which are likely to face similar challenges.
Tests of the fermion and Higgs multiplet structure of the SU(2)×U(1) model

We try to analyze the possible representation content of the fermion and Higgs sectors of the SU(2)\ifmmode\times\else\texttimes\fi{}U(1) model by using several different kinds of constraints such as universality of charged currents, gauge invariance, and the present neutral-current data. Our analysis highly favors the assignment of ${u}_{L}$ and ${d}_{L}$ (and, separately, ${\ensuremath{\nu}}_{L}^{e}$ and ${e}_{L}$) to a doublet although multiplets with possibly higher values of weak isospin cannot be completely ruled out. Various other tests are discussed.
The determinants of home price appreciation among community reinvestment homeowners

Homeownership is considered an effective wealth creation mechanism for low-income households. This study examines the appreciation of homes purchased with community reinvestment loans in a national pilot in the USA called the Community Advantage Program (CAP). Homes purchased between 1998 and 2002 are found to have appreciated at a median annual rate of 5.4% between the time of purchase and spring 2003. This is less than the national house price appreciation index of 7.0% (covering 1998–2003) but higher than other types of investments such as the Dow Jones Index (2.78% annual growth rate) and the average rate on a 6-month CD (4.34%) over the same time period. The median increase in net housing wealth of the Community Advantage homeowners is $17 492. Returns have been particularly impressive for the lowest-income borrowers. Borrowers with less than $20 000 in annual household income at the time of purchase had a median down-payment of $1790 and have experienced a median equity increase of $24 724. Price an...
Effects of inequity on job satisfaction and self-evaluation in a national sample of African-American workers

Data from a national survey of African-American workers were used to test predictions from equity theory regarding the "distress" that results from negative inequity (below expected level) and positive inequity (above expected level) in pay and occupational prestige. The results showed differential effects of the two types of inequity on dependent variables of job satisfaction and self-report of job-related skill. Although those faced with opposite forms of inequity fostered different strategies for inequity reduction, in each case, workers chose a strategy that was self-protective.
Investigation of the effect of coefficient of thermal expansion on prediction of refractive index of thermally formed glass lenses using FEM simulation

During the cooling phase of thermal forming processes, the properties of glass undergo minor changes. These changes are a result of structural relaxation near the glass transition region. One such property, refractive index, is the most important material property that governs the optical performance of a glass lens. Therefore, it must be properly considered prior to manufacturing. A finite element model is established in this research to simulate structural relaxation behavior of glass during cooling. This is done in order to accurately predict the refractive index change which occurs during and after the forming process. This study shows that the success of the simulation model depends largely on the accuracy of material information available to the lens manufacturers. Specifically, the comparison between simulated and experimental data demonstrates that the published information for the generic coefficient of thermal expansion is inadequate for precisely predicting volume change. To resolve the issue, a reverse calculation method was presented. In addition, simulated finite element results showed that the value of the liquid coefficient of thermal expansion has a major effect on the simulated results, as compared to fraction parameter.
Rattlesnake predatory behaviour: mediation of prey discrimination and release of swallowing by cues arising from envenomated mice.

Abstract Responses of rattlesnakes to envenomated mice were examined in five experiments. In experiment 1 rattlesnakes ( Crotalus durissus terrificus and C. viridis viridis ) discriminated mice that they had envenomated, as indexed by number of tongue flicks and accumulated investigation time, when these prey items were paired with control mice killed by the experimenter. Experiment 2 demonstrated that rattlesnakes also exhibited this discrimination when presented with mice envenomated by a conspecific and controls killed by the experimenter. In experiments 1 and 2, we observed that rattlesnakes delivered a large number of tongue flicks to exudates associated with nasal-oral tissues of envenomated mice. It has commonly been noted that rattlesnakes typically swallow envenomated, dead mice head first. In experiment 3 this observation was statistically verified. Evidence obtained in experiment 4 indicated that nasal-oral tissues of envenomated, dead mice were discriminated from anogenital tissues by rattlesnakes. Cues arising from the nasal-oral tissues probably (1) assisted the snakes in locating the head-end of the rodent, and (2) released the swallowing modal-action pattern, the final phase of the predatory sequence. In experiment 5, rattlesnakes exhibited no discrimination between nasal-oral and anogenital tissues of non-envenomated, dead mice, indicating that the results of experiment 4 were probably dependent upon effects of envenomation.
Genetic and environmental control of Douglas-fir stem defects

Abstract We studied the genetic and environmental control of Douglas-fir (Pseudotsuga menziesii var. menziesii) stem defects across 22 breeding programs in western Oregon and Washington. Our goal was to understand the relationships between stem defects (forks and ramicorn branches) and growth. We tested the hypotheses that stem defects are associated with progeny test site productivity and distance to the coast, and then obtained robust estimates of genetic variances, heritabilities, and genetic correlations that can be used to design effective breeding programs. Stem defects were more frequent on high productivity sites and near the coast. Compared to the least productive site within each breeding program, the proportion of trees with stem defects was about twice as great on the most productive site. For example, the proportion of trees with ramicorn branches increased from 11% to 24%, and the proportion of trees with forks increased from 5% to 14%, between the shortest and tallest plantations. However, the relationships between stem defects and growth varied substantially within and among breeding programs (R2 ⩽ 27%). Stem defects were also more frequent near the coast, but even harder to predict based on the locations of the plantations (R2 ⩽ 18%). Although stem defects are genetically variable, heritable, and have positive genetic correlations with growth, genetic variation and heritabilities for stem defects were low and highly variable. Nonetheless, stem defects can be reduced using direct backward selection, and are expected to increase only a small amount when genotypes are selected based on volume growth alone. The quantitative genetics of stem defects in Douglas-fir are generally consistent with what has been observed in other conifers. In general, focused breeding could be used to develop low-defect varieties, and these could be deployed to problematic sites. This approach might increase the value of reforestation programs overall, but it will be difficult to deploy low-defect varieties optimally because site productivity and distance to the coast are only weakly associated with stem defects. Although current multi-trait breeding approaches that consider growth and stem defects seem appropriate for most sites, controlled crosses between low-defect parents could be made in seed orchards, and the resulting seedlots could be deployed to sites that are known to be prone to defects (e.g., based on past data). Our results also suggest that (1) it might be possible to improve protocols and training for measuring stem defects, (2) breeders should monitor the among-site relationships between growth and stem defects in advanced generation breeding programs, and (3) low-defect genotypes should be identified and archived so they are available for future breeding.
Dual Marginality and the Intersecting Paradoxes of Race, Class, and Gender:

threads together so well that we follow the connections between those seemingly disparate parts; at other times, the reader is left hanging. Perhaps not since Du Bois' Souls of Black Folk, have we had a book that so cogently and consistently illustrates a social scientist's ability to personalize his life and the events of his life and those around him, and to frame and explain those lives within a social theory whose components entail micro and macro dimensions. But as creative and socio-
An Exploration of the Coupling Reactions of Epoxides and Carbon Dioxide Catalyzed by Tetramethyltetraazaannulene Chromium(III) Derivatives: Formation of Copolymers versus Cyclic Carbonates

The high catalytic activity of a tetramethyltetraazaannulene (tmtaa) chromium complex toward the copolymerization of cyclohexene oxide and carbon dioxide to discriminatively provide poly(cyclohexylene carbonate) has directed further studies into the capabilities of the catalyst system. Various [PPN]X (PPN+ = bis(triphenylphosphoranylidene)ammonium) cocatalysts, where X = Cl, N3, Br, CN, and OBzF5, in the presence of (tmtaa)CrCl were examined for catalytic reactivity and selectivity for polycarbonate formation, achieving turnover frequencies of 1500 h−1 at 80 °C in the case of PPNCl. The catalyst system was examined under varied pressures and found to be active even at 1 bar of CO2 pressure. In addition to cyclohexene oxide, the (tmtaa)CrCl complex was investigated for catalytic activity toward the coupling of carbon dioxide with propylene oxide, isobutylene oxide, 1,2-epoxyhexane, styrene oxide, and 4-vinyl cyclohexene oxide. Activation energies were found for the copolymerization reaction between cyclohe...
Cultural Studies and Food Sovereignty: Afterword

The discourse on food in the First World or Global North is generally split in two. A binary of panic versus pleasure asks: is food safe for the children, will ft make for an enjoyable holiday or evening out and how can one survive the dross and share the joy of purchasing, preparing and disposing of II?
Ultrabroadband Photonic Structures To Achieve High-Performance Daytime Radiative Cooling

If properly designed, terrestrial structures can passively cool themselves through radiative emission of heat to outer space. For the first time, we present a metal-dielectric photonic structure capable of radiative cooling in daytime outdoor conditions. The structure behaves as a broadband mirror for solar light, while simultaneously emitting strongly in the mid-IR within the atmospheric transparency window, achieving a net cooling power in excess of 100 W/m2 at ambient temperature. This cooling persists in the presence of significant convective/conductive heat exchange and nonideal atmospheric conditions.
The Effects Of Physical Attractiveness On Honesty: A Socially Desirable Response

Two studies were conducted to determine if a female confederate's physical attractiveness affected how honest others were toward her, when honesty was seen as the socially expected behavior. A total of 180 subjects in phone cubicles were approached by a con federate who had left change there. The confederate was made to ap pear either attractive or unattractive. She asked each subject whether he/she had found the money. In both studies, subjects in the attractive condition, regardless of their sex, race, or age were more likely to respond in the socially desirable manner, than sub jects in the unattractive condition.
Prediction of rose shoot development: model validation for the cultivar ‘Cara Mia’ and extension to the cultivars ‘Royalty’ and ‘Sonia’

Abstract Temperature effects on the rate of rose shoot development were previously modeled using a thermal units (heat units) approach (Pasian and Lieth, 1994). To validate that model, developmental events were tracked over time for ‘Cara Mia’, ‘Royalty’, and ‘Sonia’ rose ( Rosa hybrida ) plants. These events, consisting of the occurrence of ‘bud break’, unfolding of each leaf, ‘visible flower bud’, or ‘ready for harvest’ were recorded daily throughout the experiment period for shoots of each cultivar. Hourly average air temperatures were monitored continuously and used to compute the accumulated thermal units (benchmarks) to each developmental stage. The shoot development model developed previously was found to be valid for predicting the stages of development of ‘Cara Mia’ flowering shoots. This model, however, required adjustments for successful use with ‘Royalty’ and ‘Sonia’. Although the base temperatures used in the thermal units computation for ‘Royalty’ and ‘Sonia’ did not differ significantly from the one for ‘Cara Mia’, using cultivar-specific benchmarks resulted in significant prediction improvements. This indicates that benchmarks for each phenological stage need to be specific to each cultivar. The newly calculated benchmarks for the cultivars ‘Royalty’ and ‘Sonia’ require future validation. The model is suitable for timing of rose crops and deciding on temperature set-points.
REMOTE, HIGH SENSITIVITY RAMAN SPECTROSCOPY WITh FIBER OPTICS, DIODE LASERS AND CCD SPECTROMETERS

Several recent technological developments have greatly improved the sensitivity and simplicity of Raman spectroscopy, and have reduced interference from fluorescence. These developments include fiber optic sampling, diode laser excitation, holographic filters, compact spectrographs, and charged coupled device detectors. Spectrometers based on these developments are simple to use and can detect part-per-million levels of strong Raman scatterers in solution. Examples will be presented.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Local-Deadline Assignment for Distributed Real-Time Systems

In a distributed real-time system (DRTS), jobs are often executed on a number of processors and must complete by their end-to-end deadlines. Job deadline requirements may be violated if resource competition among different jobs on a given processor is not considered. This paper introduces a distributed, locally optimal algorithm to assign local deadlines to the jobs on each processor without any restrictions on the mappings of the applications to the processors in the distributed soft real-time system. Improvedschedulability results are achieved by the algorithm since disparate workloads among the processors due to competing jobs havingdifferent paths are considered. Given its distributed nature, the proposed algorithm is adaptive to dynamic changes of the applications and avoids the overhead of global clock synchronization. In order to make the proposed algorithm more practical, two derivatives of the algorithm are proposed and compared. Simulation results based on randomly generated workloads indicate that the proposed approach outperforms existing work both in terms of the number of feasible jobs (between 51% and 313% on average) and the number of feasible task sets (between 12% and 71% on average).
Evaluating the potential 'economic attractiveness' of new therapies in patients with non-ST elevation acute coronary syndrome.

Objective: To evaluate the relationship between how much a new cardiovascular therapy improves clinical outcomes over current therapies and how much more it can cost while still remaining ‘economically attractive’. Design: We developed a decision model to predict the 6-month cumulative cost savings and increased life expectancy that could be associated with new therapies for patients with non-ST elevation acute coronary syndrome. Setting: This modelling study used outcome and cost data from US sources. Methods: Event probabilities at 30 days and 6 months were estimated from US patients with non-ST elevation in the Global Use of Strategies To Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO) IIb trial; cost estimates were derived from patients enrolled in the Economics and Quality of Life substudy of this trial. Patient life expectancy estimates were calculated using survival estimates for similar patients treated at Duke University Medical Center. Results: We found that new therapies costing up to $US2000 per episode that reduce 6-month mortality by 0.5%, death and nonfatal myocardial infarction (MI) by 1%, or death, nonfatal MI and revascularisation by 3%, may be cost effective by current standards. When new therapies costing up to $US1000 per episode reduce the absolute rate of death, nonfatal MI and revascularisation at 6 months by 6.5% or more, they may be cost saving. Conclusion: Our analysis suggests that economic constraints should not inhibit the development of effective new therapies.
Design of voltage multipler circuits using artificial intelligence techniques

Abstract The paper shows that engineering design may be enhanced through the use of computers to automate the generation and evaluation of design alternatives. A computer program based on this concept has been developed for the design of voltage multiplier circuits. This program has generated some unconventional circuits that give better performance than the conventional circuits for some applications. The paper describes the theory and implementation of this program, presents some results and discusses several research issues related to this approach.
Incorporating economies of scale into facility location problems in carpet recycling

The Carpet America Recovery Effort (CARE) set a goal to divert 40% of used carpet from landfills in the United States by 2012, but only achieved a 10% diversion rate. To achieve the 40% diversion rate, approximately 1.4 billion lbs would need to have been diverted. Diverting this significant quantity may require the design of a larger, more effective reverse logistics network to process the used materials. A new facility location heuristic originally developed for the forward distribution of products is applied to the reverse logistics system for carpet recycling. The objective is to locate an unknown number of carpet recycling facilities to minimize the total cost. The model includes transportation costs, as well as fixed facility and processing costs at the recycling plant, the latter exhibiting economies of scale (EOS) as the facility size increases. We evaluate the model using data from the CARE collection network in the continental United States and compare these findings to models that assume a sign...
Morphogenetic and histopathological effects of the insect growth regulator cyromazine in larvae of Culex quinquefasciatus (Diptera: Culicidae).

The insect growth regulator cyromazine [Larvadex (N-cyclopropyl-l,3,5-triazine-2,4,6-triamine)] induced various morphogenetic aberrations in the mosquito Culex quinquefasciatus after treatment of 4th-instar larvae. Most of the treated larvae died as pupae, exhibiting various degrees of morphogenetic aberrations. The most characteristic aberration was the formation of a transparent anterodorsal thoracic bulbous projection followed by dorsal splitting of the thoracic cuticle of the prepupa. Albino pupae and distended pupae were also noted. At a marginal lethal concentration most of the morphogenetic effects occurred in the adult stage, while at higher concentrations most occurred in the pupal stage. There was a direct relationship between concentration and the magnitude and frequency of morphogenetic aberrations. Histological examinations revealed no noticeable effects in any tissue of treated larvae.
Threonine Synthase of Escherichia coli: Inhibition by Classical and Slow-Binding Analogues of Homoserine Phosphate

L-threo-3-Hydroxyhomoserine phosphate, derived from the antimetabolites L-threo-3-hydroxyaspartate and L-threo-3-hydroxyhomoserine [Shames, S. L., Ash, D. E., Wedler, F. C., and Villafranca, J. J. (1984) J. Biol. Chem. 258, 15331-15339], is a classical competitive inhibitor of threonine synthase (Ki = 6 microM) with structural elements of both substrate and product. L-2-Amino-5-phosphonovaleric acid also inhibits the enzyme competitively with a Ki (31 microM), comparable to Km for L-homoserine phosphate. In contrast, a structural analogue of Hse-P, L-2-amino-3-[(phosphonomethyl)thio]propionic acid exhibits a Ki = 0.11 microM (ca. 100-fold less than Km for L-Hse-P), along with "slow, tight" inhibition kinetics. Nuclear magnetic resonance was used with these inhibitors to probe for pyridoxal phosphate-catalyzed hydrogen-deuterium exchange reactions characteristic of substrates. With L-threo-3-hydroxy-homoserine phosphate, H-D exchange occurs only at the C-alpha position, but for homoserine in the presence of phosphate and for L-2-amino-5-phosphonovaleric acid and L-amino-3[(phosphonomethyl)thio]propionic acid (APMTP), H-D exchange occurs at C-alpha and stereospecifically at C-beta. For L-homoserine plus phosphate and L-2-amino-5-phosphonovaleric acid, the rate of H-D exchange at C-alpha is 8-45 times faster than at C-beta. For L-2-amino-3-[(phosphonomethyl)thio]propionic acid, the C-alpha to C-beta exchange rate ratio is near unity, due to a 700-fold decrease in the C-alpha rate for the analogue. Taken with information from molecular modeling, these data can be interpreted in terms of the current working hypothesis for the catalytic mechanism. Specifically, the slow, tight inhibition by APMTP results from its being carried further into the catalytic cycle than other analogues prior to forming an intermediate that is blocked from further catalysis.
Lifetime Predictions of a Titanium Silicate Glass with Machined Flaws

A dynamic fatigue study was performed on a Titanium Silicate glass to assess its susceptibility to delayed failure and to compare the results with those of a previous study. Fracture mechanics techniques were used to analyze the results for the purpose of making lifetime predictions. The material strength and lifetime was seen to increase due to the removal of residual stress through grinding and polishing. Influence on time-to-failure is addressed for the case with and without residual stress present. Titanium silicate glass otherwise known as ultra-low expansion (ULE)* glass is a candidate for use in applications requiring low thermal expansion characteristics such as telescope mirrors. The Hubble Space Telescope s primary mirror was manufactured from ULE glass. ULE contains 7.5% titanium dioxide which in combination with silica results in a homogenous glass with a linear expansion coefficient near zero. delayed failure . This previous study was based on a 230/270 grit surface. The grinding and polishing process reduces the surface flaw size and subsurface damage, and relieves residual stress by removing the material with successively smaller grinding media. This results in an increase in strength of the optic during the grinding and polishing sequence. Thus, a second study was undertaken using samples with a surface finish typically achieved for mirror elements, to observe the effects of surface finishing on the time-to-failure predictions. An allowable stress can be calculated for this material based upon modulus of rupture data; however, this does not take into account the problem of delayed failure, most likely due to stress corrosion, which can significantly shorten lifetime. Fortunately, a theory based on fracture mechanics has been developed enabling lifetime predictions to be made for brittle materials susceptible to delayed failure. Knowledge of the factors governing the rate of subcritical flaw growth in a given environment enables the development of relations between lifetime, applied stress and failure probability for the material under study. Dynamic fatigue is one method of obtaining the necessary information to develop these relationships. In this study, the dynamic fatigue method was used to construct a time-to-failure diagram for polished ULE glass.
Sustaining knowledge work in student engineering clubs

This essay explores the role of professional writers in one specific student engineering club, an electric vehicle project at Purdue University, and outlines the difficulties that arose in supporting the technical project. The scope of the engineering project is explained, as are the methods of project management that supported the student engineering group that performed much of the work — version control software and monthly reports. Distinctions are made between the material production work and the knowledge work that supported manufacturing and design. After reasons for the club's eventual closing are explored, suggestions are made as to how current and future documentation strategies can sustain the knowledge of the technical project in a sustainable, responsible manner. Finally, after reviewing the specific case, several suggestions for how professional writers can position themselves within student engineering clubs are given.
Interferon alpha induced intrahepatic pSTAT1 inversely correlate with serum HCV RNA levels in chronic HCV infection

Background The Jak-STAT signaling of hepatitis C virus (HCV) infected hepatocyte is critical for the antiviral action of endogenously produced interferon (IFN) as well as exogenously administered interferon alpha (IFN-α). The activation of cellular Jak-STAT signaling by IFN-α results in the phosphorylation and nuclear translocation of pSTAT1 and pSTAT2 proteins to induce antiviral gene transcription. Clinical studies show that chronic HCV patients with high viral load show poor response to interferon alpha and ribavirin combination therapy.
The Perpetual Homelessness of College Experiences: Tensions between Home and Campus for African American Women.

There is an ongoing debate about whether African American students need to sever ties with their families to be successful in college. Adding nuance to this debate, this ethnographic study examines African American women’s experiences of navigating family relationships in a predominantly White institution. The women described multiple pressures from their families and on campus, often resulting in a sense of “homelessness,” as if they fit neither on campus nor in their families.
C911: A Bench-Level Control for Sequence Specific siRNA Off-Target Effects

Small interfering RNAs (siRNAs) have become a ubiquitous experimental tool for down-regulating mRNAs. Unfortunately, off-target effects are a significant source of false positives in siRNA experiments and an effective control for them has not previously been identified. We introduce two methods of mismatched siRNA design for negative controls based on changing bases in the middle of the siRNA to their complement bases. To test these controls, a test set of 20 highly active siRNAs (10 true positives and 10 false positives) was identified from a genome-wide screen performed in a cell-line expressing a simple, constitutively expressed luciferase reporter. Three controls were then synthesized for each of these 20 siRNAs, the first two using the proposed mismatch design methods and the third being a simple random permutation of the sequence (scrambled siRNA). When tested in the original assay, the scrambled siRNAs showed significantly reduced activity in comparison to the original siRNAs, regardless of whether they had been identified as true or false positives, indicating that they have little utility as experimental controls. In contrast, one of the proposed mismatch design methods, dubbed C911 because bases 9 through 11 of the siRNA are replaced with their complement, was able to completely distinguish between the two groups. False positives due to off-target effects maintained most of their activity when the C911 mismatch control was tested, whereas true positives whose phenotype was due to on-target effects lost most or all of their activity when the C911 mismatch was tested. The ability of control siRNAs to distinguish between true and false positives, if widely adopted, could reduce erroneous results being reported in the literature and save research dollars spent on expensive follow-up experiments.
The role of a sertoli cell actin‐myosin system in sperm bundle formation in the ratfish, Hydrolagus colliei (Chondrichthyes, Holocephali)

Sertoli cells in the ratfish entirely surround a clone of spermatids to form a spermatocyst. As spermiogenesis proceeds within the cyst cavity, the acrosome areas become apposed to the Sertoli cell plasma membrane lining the spermatocyst. The spermatids elongate and are gathered into an increasingly compact bundle oriented with acrosomal tips directed toward the Sertoli cell base. As all acrosome areas move closer together, Sertoli cell microfilaments oriented parallel to the long spermatid axis appear and increase in concentration. Actin and myosin were demonstrated in the microfilament area with fluorescent antibodies and NBD-Phallacidin. Simultaneously, endocytosis of Sertoli cell membrane between spermatid attachment sites removes the intervening membrane and allows the latter sites to approach each other. Sertoli cell endocytosis is spatially and temporally related to a unique projection at the basal rim of each acrosome. During midspermiogenesis, structured intercellular material appears between the Sertoli cell and the acrosomal region of each spermatid. Its periodicity is closely related to periodic arrangement of Sertoli cell actin and material within the spermatids. These attachment sites move together upon endocytosis, gathering a clone of spermatids into a closely packed bundle.
Preserving the Iowa Corn Crop: Energy Use and CO2 Release

A study was undertaken to estimate energy use and CO2 release due to postharvest preservation of the 38.8 × 106-Mg (1.52 ×109-bu) Iowa corn crop. About 87% of the crop is artificially dried. Other preservation methods include cribbing ear corn (7%), oxygen-limiting storage (5%) and chemical preservative treatment (1%). Preservation of the corn crop requires, in total, 18 200 TJ of energy and releases 1614 Gg of CO2. Combustion of fuel (liquefied petroleum or natural gas) and electricity accounted for 77 and 10% of total energy use, respectively. CO2 from combustion of fuel and generation of electricity accounted for 57 and 32% of the CO2 release, respectively. Preservation methods varied in total energy use and CO2 release from farm natural-air drying at 1020 MJ/Mg corn and 262 kg CO2/Mg corn to chemical preservative treatment at 116 MJ/Mg corn and 9.3 kg CO2/Mg corn.
The Glass Coffin

In San Francisco's Castro District, the gay bar Twin Peaks Tavern has long had a reputation as “the Glass Coffin” due to its high visibility and aging clientele. This essay explores the history of how Twin Peaks Tavern earned its reputation. To understand its transformation, we need to look at its visibility and particular kind of sociability that attracted older, predominantly white and middle-class gay men. The documentary Beauty Before Age (Symons, 1997) provides a window into how mid-1990s patrons and passersby viewed Twin Peaks differently. The kinds of viability a visible glass coffin allows requires a consideration of the changing effects of AIDS on the Castro's gay male culture. The concepts of social time and successful aging illuminate these effects. Recent efforts to preserve Twin Peaks Tavern as a historical landmark suggest what glass coffins do for and to all of us today.
DENSITY MATRICES FOR CORRELATED GAUSSIANS : HELIUM AND DIPOSITRONIUM

Formulas are derived for the density matrices belonging to an n-particle wave function built on the basis of single-center explicitly correlated Gaussian basis functions. An explicit formula for the first-order density matrix, P(r{sub 1}, r{sub 1}{prime}), is obtained for computing the probability distribution P(r{sub 1}, r{sub 1}). Other formulas are derived for matrix elements of the first-order density operator P on a basis of single-particle Gaussian orbitals so that natural orbitals (NOs) can be expressed in such a basis. The method is illustrated for the case of the ground state of the helium atom using the 16-term (geminal) wave function by Singer and Longstaff (E = -2.90233 au) and a set of even-tempered Gaussian orbitals. The resulting natural orbitals compare favorably with natural orbitals from Cl expansions. The method is also applied to a 20 term (trimal) wave function for the ground state of dipositronium (E = -0.51560 au). Analysis is made in this case for pair correlation functions of both the electron-electron and the positron-electron pairs; results include the radial distributions of these pairs and their relative angular momentum. 13 refs., 4 figs., 3 tabs.
Integration of information about corporate social performance

Purpose – The aim of this research was to examine psychological processes that may mediate effects of corporate social performance on evaluations of and behavior toward organizations.Design/methodology/approach – An experimental design examined how previously formed, summary attitudes versus consideration of specific information about CSP affected intended behaviors toward fictitious organizations. Theories of attitude structure and attitude change form the theoretical basis for the paper.Findings – In general, participants relied on summary attitudes toward stimulus organizations. However, when fear of making an invalid decision was stimulated, participants were more likely to consider specific attributes of organizations (such as CSP) when making decisions about them.Research limitations/implications – The study is limited by its use of fictitious organizations in an experimental situation. The study suggests that organizational managers as well as those who study crisis management and CSP should consid...
Utility of biodegradable plasmonic nanoclusters in photoacoustic imaging.

Plasmonic metal nanoparticles are used in photoacoustic imaging as contrast agents because of their resonant optical absorption properties in the visible and near-IR regions. However, the nanoparticles could accumulate and result in long-term toxicity in vivo, because they are generally not biodegradable. Recently, biodegradable plasmonic gold nanoclusters, consisting of sub-5nm primary gold nanoparticles and biodegradable polymer stabilizer, were introduced. In this Letter, we demonstrate the feasibility of biodegradable nanoclusters as a photoacoustic contrast agent. We performed photoacoustic and ultrasound imaging of a tissue-mimicking phantom with inclusions containing nanoclusters at various concentrations. The results indicate that the biodegradable gold nanoclusters can be used as effective contrast agents in photoacoustic imaging.
The role of probability and intentionality in preschoolers' causal generalizations

Three experiments examined whether preschoolers recognize that the causal properties of objects generalize to new members of the same set given either deterministic or probabilistic data. Experiment 1 found that 3- and 4-year-olds were able to make such a generalization given deterministic data but were at chance when they observed probabilistic information. Five-year-olds reliably generalized in both situations. Experiment 2 found that 4-year-olds could make some probabilistic inferences, particularly when comparing sets that had no efficacy with sets in which some members had efficacy. Children had some difficulty discriminating between completely effective sets and stochastic ones. Experiment 3 examined whether 3- and 4-year-olds could reason about probabilistic data when provided with information about the experimenter's beliefs about causal outcomes. Children who were more successful on standard false-belief measures were more likely to respond as if the data were deterministic. These data suggest th...
The impact of credit rationing on the real sector: a study of the effect of mortgage rates and terms on housing starts

Various studies of the impact of credit rationing on the housing sector have examined its effect on mortgage terms and flows. If credit rationing has a significant effect on the economy, it must affect the real sector, i.e. housing starts. This paper examines the causal relationships between six different variables which describe mortgage rates and terms and single family housing starts. Two different types of tests for economic causality are used. The results indicate that neither credit rationing nor mortgage rates affect housing starts for the period 1963–1980. There is some evidence that housing prices have a causal relationship to housing starts, possibly reflecting speculative motives. On balance, the results are consistent with the rational expectations theory.