cssi/SciSciGPT-SciSciNet huggingface dataset:
Response to "Comment on 'Association between Lifetime Exposure to Inorganic Arsenic in Drinking Water and Coronary Heart Disease in Colorado Residents'".

We thank Rylander for his interest in our article and for suggesting magnesium may confound the association we observed between inorganic arsenic in water and risk of coronary heart disease. We did not include measures of drinking water magnesium (or hardness) in our study. However, levels of calcium and magnesium reported for the Rio Grande aquifer (which served our study population in the San Luis Valley) indicate higher levels of hardness, with low variability in the San Luis Valley (Robson and Banta 1995). In contrast, the arsenic level in groundwater in the San Luis Valley water quality samples showed considerable variability of 0–95 µg/L. The correlation between magnesium and arsenic is unknown for the San Luis Valley aquifer. However, in response to Rylander’s letter, we calculated a Pearson correlation coefficient of 0.12 between arsenic and magnesium using arsenic data from Meliker et al. (2010) and unpublished magnesium data from a study in Michigan. We saw mean arsenic concentrations of 5.3, 0.6, and 6.5 µg/L for magnesium categories of 11 mg/L, respectively, with a total sample size of 1,500 water samples and at least 400 samples in each category. These estimates do not support the hypothesis that arsenic and magnesium are highly correlated in drinking water, hence reducing concerns about confounding between these two minerals. More importantly, given that low levels of magnesium (Rylander 1996) and conversely high levels of arsenic (Moon et al. 2013) are thought to be associated with heart disease, any positive correlation between arsenic and magnesium would result in an underestimation (not overestimation) of the size of the association between inorganic arsenic exposure and coronary heart disease found in our study. As with any observational epidemiologic study, it is important to continue to search for potential confounders and other risk factors. We continue to investigate the naturally occurring metals and minerals in the San Luis Valley drinking water supply and the potential associated long-term outcomes. This research will include investigating co-mixtures of elements and potential confounders that could be related to heart disease risk. We find Rylander’s letter thought provoking, and we thank him for bringing this evidence pertaining to magnesium to our attention.
Progress Towards a Molecular Surface Science: Dative Interactions in Chemistry at Metal Centres as Revealed by Spectroscopic, Kinetic and Dynamical Studies

Some ways of observing the chemistry between a few metal atoms (one, two, three, ... ) and a few ligand molecules are reviewed. These include kinetics studies of the chemistry of metal atoms in the gas-phase using the technique of UV-visible laser multiphoton dissociation of organometallic molecules; kinetics studies of metal dimer and metal cluster reactivity using a fast-flow tube; spectroscopic studies of small inorganic radicals produced by chemical reactions in a laser-produced plasma followed by supersonic expansion; spectroscopic studies on metal cluster beams and metal cluster-ligand complexes; and, some preliminary measurements of the dynamics of photo- and thermal desorption of ligands from cluster-ligand complexes. The importance of studies at temperatures close to ambient is emphasized.
A smoking cessation intervention for low-income smokers in the ED.

Abstract Background There is a high prevalence of smoking among caregivers who bring their children to the pediatric emergency department (PED) and even higher rates of tobacco smoke exposure (TSE) and related morbidity among their children. The PED visit presents an opportunity to intervene with caregivers, but it is unknown whether they are more likely to quit if their child has a TSE-related illness. We sought to examine a PED-based smoking cessation intervention and compare outcomes based on children’s TSE-related illness. Methods A single-arm, prospective trial, with baseline, 3, and 6 month assessments was used in this study. Caregivers whose child had either a TSE-related (n = 100) or non–TSE-related illness (n = 100) were given a brief intervention consisting of counseling, referral to the Quitline, and free nicotine replacement therapy. Results Participants were 91.5% female, 50.5% African American, 100% Medicaid recipients, 30.8 years old, child age mean of 5.5 years, 90% highly nicotine dependent, and 60.3% and 75.8% allowed smoking in the home and car, respectively. At follow-up (65% retention), 80% reported quit attempts at 3 months and 89% between 3 and 6 months. There were significant decreases in number of cigarettes smoked, time to first cigarette, and smoking in the home and car. Quit rates were 12.2% at 3 months, 14.6% at 6 months, and 7.3% at both time points (50% biochemically confirmed). There were no significant differences in outcomes based on children’s illness. Conclusions A brief PED-based smoking cessation intervention resulted in quit attempts and successful quits. However, the presence of a TSE-related illness did not result in different cessation outcomes.
The Quest for the Liberal Peace: Toward a Measure of Interstate Cooperation

Building on the Kantian tripod of peace in liberal peace theory, we test theories of state intergovernmental organization (IGO) membership and levels of state cooperation. We examine the measurement for IGO joint membership and find that it is inadequate to measure the level of cooperation among states. Using network analysis, we propose a new dyadic measure for the level of bilateral cooperation. We argue that states craft intergovernmental agreements, purposely nested within bilateral treaty networks, to further consolidate and bolster such agreements’ efficacy. States both express and safeguard their power interests via negotiated treaties, and while costs of violating individual treaties are small, violating treaties nested within broader treaty networks are more costly as this significantly inhibits future cooperation with all states in a region. By creating networks of treaties, states bolster compliance, enhance the prospects for cooperative foreign policy behavior, and strengthen the conditions for peace. We argue that the strength of a bilateral treaty network is a better measure than joint IGO membership for liberal peace theory. We test this measure in the post-Soviet space, where many scholars expect dyadic conflict due to Russia’s regional economic and military dominance. Using militarized interstate disputes (MID’s) as the dependent variable in our model, we find that dyads that have stronger treaty networks are significantly less likely to experience a MID than dyads without a strong treaty network. We propose that the strength of treaty networks is a better measure for tapping cooperation among states, yielding analytical results more compatible with liberal peace theory.
A Lipschitz estimate for Berezin’s operator calculus

F. A. Berezin introduced a general symbol calculus for linear operators on reproducing kernel Hilbert spaces. For the particular Hilbert space of Gaussian square-integrable entire functions on complex n-space, C n , we obtain Lipschitz estimates for the Berezin symbols of arbitrary bounded operators. Additional properties of the Berezin symbol and extensions to more general reproducing kernel Hilbert spaces are discussed.
Uterus, Cervix, and Vagina

Cervical and vaginal biopsies consist of an epithelial surface and varying amounts of underlying stroma. Usually, no grossly identifiable lesion can be seen. The most important objectives are to orient the specimen so that perpendicular sections will be taken through the surface and to secure the specimen properly to ensure that small pieces are not lost. These tasks can be accomplished in several ways. If the specimen is large enough (i. e., greater than 0.4 cm), the tissue can be bisected perpendicular to the surface and marked with either mercurochrome or tattoo powder to indicate the surface to be cut. If the specimen is small, it can be secured between Gelfoam sponges, within fine-mesh biopsy bags, or it can be wrapped in tissue paper. The gynecologist may also submit the biopsy oriented mucosal side up on a mounting surface such as filter paper. In this case, instruct your histotechnologist to embed and cut the biopsy specimen perpendicular to the mounting surface. All biopsy specimens should be entirely submitted, and it is often useful to routinely request that multiple levels be examined by the histology laboratory.
Phase 1/2 Trial of Single-Session Stereotactic Body Radiotherapy for Previously Unirradiated Spinal Metastases

BACKGROUND: In this phase 1/2 study, the authors tested the hypothesis that single-fraction stereotactic body radiotherapy (SBRT) for previously unirradiated spinal metastases is a safe, feasible, and efficacious treatment approach. METHODS: All patients were evaluated by a multidisciplinary team. Spinal magnetic resonance imaging studies were obtained before treatment and at regular intervals to define both target volume and response to treatment. SBRT was delivered to a peripheral dose of 16 to 24 grays in a single fraction while limiting the dose to the spinal cord. Higher doses were used for renal cell histology. The National Cancer Institute Common Toxicity Criteria 2.0 and McCormick neurologic function score were used as toxicity assessment tools. RESULTS: In total, 61 patients who had 63 tumors of the noncervical spine were enrolled and received SBRT between 2005 and 2010 on a prospective, phase 1/2 trial at The University of Texas M. D. Anderson Cancer Center. The mean follow-up was 20 months. The actuarial 18-month imaging local control rate for all patients was 88%, the actuarial 18-month overall survival rate for all patients was 64%, and the median survival for all patients was 30 months. No significant differences in outcomes were noted with respect to tumor histology or SBRT dose. Two patients experienced radiation adverse events (grade 3 or higher). The actuarial rate of 18-month freedom from neurologic deterioration from any cause was 82%. CONCLUSIONS: Data from this phase 1/2 trial supported an expanded indication for SBRT as first-line treatment of spinal metastases in selected patients. The authors concluded that additional studies that can prospectively identify predictive factors for spinal cord toxicity after SBRT are warranted to minimize the incidence of this serious yet rare complication. Cancer 2012. © 2012 American Cancer Society.
Load distribution for distributed stream processing

Distributed steam processing is necessary for a large class of stream-based applications To exploit the full power of distributed computation, effective load distribution techniques must be developed to optimize the system performance and cope with time-varying loads When traditional load balancing or load sharing strategies are applied to such systems, we find that they either fall short in achieving good load distribution or fail to maintain good task partition in the long run. In this paper, we study two important issues of dynamic load distribution in the context of data-intensive stream processing The first one is how to allocate processing resources for push-based tasks such that the average end-to-end data processing latency can be minimized The second issue is how to maintain a good load distribution dynamically for long running continuous queries We propose a new hybrid load distribution strategy that addresses the above concerns by load clustering To achieve scalability, our algorithm is completely decentralized and asynchronous.
Characterization of the Binding of Gallium, Platinum, and Uranium to Pseudomonas fluorescens by Small-Angle X-Ray Scattering and Transmission Electron Microscopy

Small-angle X-ray scattering (SAXS) was used to determine the binding of Ga, U, and Pt to Pseudomonas fluorescens in aqueous buffer. Atomic absorption spectrophotometry was used to quantify the heavy metals during bulk analysis, whereas transmission electron microscopy of whole mounts and thin sections was used to determine the locations of the cell-bound metal precipitates, as well as their sizes and physical structures. Energy-dispersive X-ray spectroscopy confirmed the compositions and identities of the precipitates and helped show that they were associated primarily with the envelope layers of the bacteria. Unlike Ga and Pt, which were located only at the cell surface, U was also found intracellularly in approximately 10% of the cells. This cytoplasmic location ultimately killed and lysed the cells. Surface-bound Ga and U were spread over the entire cell envelope (outer membrane-peptidoglycan-plasma membrane complex), whereas Pt was associated only with the lipopolysaccharide-rich, external face of the outer membrane. SAXS confirmed these data and showed that the bacteria were metal-enshrouded particles that were 1.0 to 1.5 mum in diameter. SAXS also provided a statistically significant representation of the bound metal precipitates, which ranged in size from 10 nm to 1 mum. The correlation between the microscopic data and the scattering data was extremely good. Since SAXS is performed in an aqueous milieu, it yields a more representative picture of the physical state of the metal bound to cell surfaces.
Frequency, Reasons for, and Perceptions of Lubricant Use among a Nationally Representative Sample of Self-Identified Gay and Bisexual Men in the United States

Abstract Introduction Few previous studies have examined lubricant use among gay and bisexual men outside the context of human immunodeficiency virus risk reduction associated with condom use during penile–anal intercourse and the potential use of lubricants to deliver rectal microbicides. The vast majority of studies examining lubricant use among gay and bisexual men have employed convenience sampling strategies for participant recruitment. Additionally, most studies have collapsed gay men and bisexual men into one category of "gay and bisexual men." Aims This study aimed to provide overall rates of lubricant use and related factors among a nationally representative sample of self‐identified gay and bisexual men. Frequencies of lubricant use, reasons for using lubricant, and perceptions of lubricant use were examined separately for subsamples of both gay and bisexual men. Methods Data were from the 2012 National Survey of Sexual Health and Behavior, which involved the administration of an online questionnaire to a nationally representative probability sample of women and men in the United States aged 18 and older, and we oversampled self‐identified gay and bisexual men and women; the results from male participants are included in this article. Main Outcome Measures Measure included demographic characteristics, recent and lifetime commercial lubricant use, lubricant use during specific sexual behaviors, frequency of lubricant use, and reasons for lubricant use during sexual activity. Results Over 90% of both gay and bisexual male participants reported lifetime lubricant use. Use was most common during partnered sexual activities, particularly among men aged 25–29 years old. The most commonly reported reasons for lubricant use included to increase comfort during anal intercourse, curiosity, and to make sex more comfortable. Conclusions Most gay and bisexual men in the United States have used lubricant to enhance a wide range of sexual activities, including but not limited to anal intercourse. Findings from this study will be of utility to clinicians and other health practitioners who seek to understand and promote sexual health among gay and bisexual men and other traditionally underserved public health populations. Dodge B, Schick V, Herbenick D, Reece M, Sanders SA, and Fortenberry JD. Frequency, reasons for, and perceptions of lubricant use among a nationally representative sample of self‐identified gay and bisexual men in the United States. J Sex Med 2014;11:2396–2405.
Coordinating the Party: Assembly Factors and Ribogenesis

Using hydroxyl-radical footprinting to map the structures of RNA molecules in whole cells, Soper et al. (2013) determine the specific role of assembly factors during the final stages of ribosomal subunit assembly and visualize structural features of intermediate states.
Staging laparoscopy with laparoscopic ultrasonography: Optimizing resectability in hepatobiliary and pancreatic malignancy

Abstract Background: Open laparotomy has traditionally been required to stage hepatobiliary and pancreatic (HBP) cancers accurately. For unresectable patients, costs and morbidity have been high. Today, laparoscopy alone or combined with laparoscopic ultrasonography (LUS) is being examined for its value in defining the extent of malignancy. Study Design: We have analyzed the effect of routine implementation of this new staging technique in our HBP center. Staging laparoscopy (SL) with LUS was performed in 50 consecutive patients with HBP malignancies. All patients were considered to have resectable tumors as determined by traditional preoperative staging modalities. Primary tumors were located in the liver (n = 7), biliary tract (n = 11), or pancreas (n = 32). An average of 2.7 preoperative studies per patient were performed prior to SL-LUS. Results: Staging laparoscopy with laparoscopic ultrasonography predicted resectable tumors in 28 patients (56%). At laparotomy, 26 of 28 were actually resectable: the false-negative rate was 4%. Staging laparoscopy with laparoscopic ultrasonography indicated unresectability in 22 patients (44%). Staging laparoscopy alone demonstrated previously unrecognized occult metastases in 11 patients (22%). In 11 other patients (22%) in whom SL alone was negative, LUS established unresectability from vascular invasion (n = 5), lymph node metastases (n = 5), or intraparenchymal hepatic tumor (n = 1). All cases of unresectability due to vascular invasion were validated by laparotomy. Five of six lymph node or hepatic metastases were proved histologically by LUS-guided needle biopsy rather than laparotomy. Conclusions: Unnecessary laparotomy can be safely avoided by SL-LUS in many patients with HPB malignancies, reducing costs and morbidity.
Anaphylaxis and red cell survival studies in a child with insulin-resistant diabetes mellitus.

Summary A child with the syndrome of diabetes mellitus, insulin-resistance, Coombs' positive autoimmune hemolytic anemia, lymphadenopathy, and hepatosplenomegaly was described. The patient's IgG anti-insulin antibody was shown to be negative for passive cutaneous anaphylaxis (PCA). In as much as the patient was refractory to prednisone therapy and presented a negative PCA test, he was consistent with the Oakley hypothesis that insulin-resistant prednisone-insensitive patients will be negative for PCA. The half-life of the patient's red blood cells was shown to vary as a function of the type of insulin used in therapy. The child was shown to have immune-complexes in his serum of insulin-anti-insulin specificity, and it was suggested that these complexes are partially responsible for the microangiopathy that is so often observed in diabetes mellitus.
Interfacing a laser induced breakdown spectroscopy system with a plasma torch control computer for hazardous waste process control

Toxic metal emissions from various waste processing off-gas systems present a potential health hazard The measurement of toxic metals in real-time in stack emissions is required to control the quantities of these species emitted into the atmosphere. Laser-induced breakdown spectroscopy (LIBS) is a laser based optical diagnostic technique which has been used to detect certain atomic and molecular species in various environments. The toxic metal concentration in stack emissions can be monitored in realtime with LIBS to provide necessary control for the waste treatment process. This paper describes the details of interfacing LIBS with a plasma torch control system during a plasma torch waste treatment test with simulated surrogate feed The results of this test are also presented.
The role of adsorption on the observed temperature dependencies of diffusion coefficients

Abstract In measurements of diffusion coefficients of gases in porous solids by unsteady-state (transient) methods, adsorption on the walls of the pores affects the analysis. Failure to account for the net adsorption or desorption occurring during the perturbation associated with such measurements yields apparent diffusion coefficients that are lower than the true values. Moreover, the temperature dependence is not the relatively weak dependence expected from the kinetic theory of gases for true gas diffusion coefficients, even when the pores are orders of magnitude larger than molecular dimensions. Instead it is exponential in nature, being determined largely by the temperature dependence of the adsorption process occurring in the pores. Thus, the diffusion process seems to be an activated one, although in fact there may not be a true activation barrier. The analysis presented in this paper appears to be very general, extending even to zeolites where the pore dimensions are of the order of molecular dimensions. It appears to account for the commonly reported observations in the literature that diffusion coefficients for gases in microporous solids obtained by transient methods can sometimes be as much as two to four orders of magnitude lower and can simultaneously exhibit temperature dependencies much stronger than those obtained under equilibrium conditions utilizing nuclear magnetic resonance.
The Coulomb gas, vertex operators and the c-theorem

Abstract We study the critical properties of the two-dimensional Coulomb gas of electric charges and magnetic monopoles. This theory is also equivalent to the planar model with N-fold symmetry breaking perturbations, and can be rewritten as a gaussian field theory perturbed by vertex operators. Using an operator product expansion based renormalization procedure, we show that this theory is renormalizable within an expansion in ϵ = N −4. An examination of the R.G. flows yields a non-trivial self-dual fixed point at which the long distance properties of the theory are described by a dilute gas of electric charges and magnetic monopoles with parafermionic long-wavelength excitations. This fixed point describes a new universality class with a continuous spectrum of anomalous dimensions. We compute the conformal anomaly in perturbation theory and find c = 1 + 3 8 ϵ 2 . An argument is provided that indicates that the fixed point theory is conformal invariant. For negative asymmetries the fixed point describes a non-unitary theory that provides an example of the violation of the c-theorem.
Geometrical and morphological image processing algorithm

Early vision processing involves segmenting and eliminating/minimizing extrinsic variations in an image. Tradition segmentation algorithms use a single threshold to reduce image data to the regions important to the vision system. A single threshold rarely gives good segmentation results over an entire image because it may reject too many of the objects as belonging to the background or may accept too much of the background as belonging to the objects. This paper presents a segmentation method that uses multiple thresholds for partitioning an image into objects and background. The segmentation process is a gradient approach whereby the multiple (or adaptable) thresholds are calculated from discriminant structural feature values.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Improving the performance of nonplanar systolic architectures through increased fan-out

We show that the performance of nonplanar systolic architectures implementing nonfeedback recurrences can be improved through increased processing element fan-out. As an illustrative example we demonstrate the speed improvement for matrix-matrix multiplication on a modified cylindrical array.
Adaptive Cache Compression for High-Performance Processors

Modern processors use two or more levels ofcache memories to bridge the rising disparity betweenprocessor and memory speeds. Compression canimprove cache performance by increasing effectivecache capacity and eliminating misses. However,decompressing cache lines also increases cache accesslatency, potentially degrading performance.In this paper, we develop an adaptive policy thatdynamically adapts to the costs and benefits of cachecompression. We propose a two-level cache hierarchywhere the L1 cache holds uncompressed data and the L2cache dynamically selects between compressed anduncompressed storage. The L2 cache is 8-way set-associativewith LRU replacement, where each set can storeup to eight compressed lines but has space for only fouruncompressed lines. On each L2 reference, the LRUstack depth and compressed size determine whethercompression (could have) eliminated a miss or incurs anunnecessary decompression overhead. Based on thisoutcome, the adaptive policy updates a single globalsaturating counter, which predicts whether to allocatelines in compressed or uncompressed form.We evaluate adaptive cache compression usingfull-system simulation and a range of benchmarks. Weshow that compression can improve performance formemory-intensive commercial workloads by up to 17%.However, always using compression hurts performancefor low-miss-rate benchmarks-due to unnecessarydecompression overhead-degrading performance byup to 18%. By dynamically monitoring workload behavior,the adaptive policy achieves comparable benefitsfrom compression, while never degrading performanceby more than 0.4%.
The Raj: India and the British, 1600-1947

Part 1 From Indian Rajas to the British Raj, Peter J.Marshall the Indian picturesque 1780-1800, Dr Giles Tillotson Indian Miniatures and "Company" painting 1600-1850, Robert Skelton. Part 2 Company and the Crown - the framework of British India c.1800-1900, Dr C.A.Bayly. Part 3 Anthropology, caste and the visual image, Dr Christopher Pinney Indian art and Indian Nationalism 1880 to the present. Part 4 Indian society and change, Dr Raj Chandavarkar Indian nationalism and the Raj, Dr Francis Robinson.
Hydatid disease of the liver in childhood: the success of medical therapy and surgical alternatives

Hydatid liver disease in children is a serious problem where the parasite is endemic. Although surgery is considered the treatment of choice, medical therapy is an alternative, but its curative efficacy is controversial. The aims of this study were to evaluate the curative efficacy of medical treatment and compare the results of surgical techniques with respect to postoperative complications in 102 consecutive children (64 male and 38 female, aged 4 to 15 years, mean 8.15 years) treated in two children's hospitals between 1988 and 1997. In 67, medication with albendazole was used as the initial therapy; 17 had multiple hepatic cysts and 8 had coexisting cysts in the lung. Success was defined as progressive shrinkage and solidification of the cyst. The overall success of medical therapy was approximately 27%: 18 of the 67 patients were cured with albendazole (15 had a single cyst, 3 multiple cysts) and 1 recurrence (6%) was observed. Age, sex, and the size, location, and number of cysts did not show any relationship to the response to medical therapy. After 12 to 14 weeks of medical treatment, a viable cyst on ultrasonography and/or computed tomography was accepted as a sign of treatment failure and these patients were scheduled for surgery. A total of 84 patients (35 primarily, 49 after unsuccessful medical therapy) were treated surgically. Procedures included cystectomy and tube drainage in 11 patients, cystectomy in 17, cystectomy and capitonnage in 24, and cystectomy and omentoplasty in 32. The incidence of early postoperative complications was 55% for tube drainage, 18% for cystectomy, 13% for capitonnage, and 0% for omentoplasty. During the follow-up period, 2 surgical patients (2%) developed recurrent disease. Medical treatment with albendazole resulted in fewer curative successes than expected. A longer period of medical treatment may increase the success rate; this question requires further study. Omentoplasty decreased the rate of early postoperative complications, especially cavity abscess and biliary fistula, after surgical treatment and should be recommended in this setting.
CN- secondary ions form by recombination as demonstrated using multi-isotope mass spectrometry of 13C- and 15N-labeled polyglycine.

We have studied the mechanism of formation CN− secondary ions under Cs+ primary ion bombardment. We have synthesized 13C and 15N labeled polyglycine samples with the distance between the two labels and the local atomic environment of the 13C label systematically varied. We have measured four masses in parallel: 12C, 13C, and two of 12C14N, 13C14N, 12C15N, and 13C15N. We have calculated the 13C/12C isotope ratio, and the different combinations of the CN isotope ratios (27CN/26CN, 28CN/27CN, and 28CN/26CN). We have measured a high 13C15N − secondary ion current from the 13C and 15N labeled polyglycines, even when the 13C and 15N labels are separated. By comparing the magnitude of the varied combinations of isotope ratios among the samples with different labeling positions, we conclude the following: CN− formation is in large fraction due to recombination of C and N; the C=O double bond decreases the extent of CN− formation compared to the case where carbon is singly bonded to two hydrogen atoms; and double-labeling with 13C and 15N allows us to detect with high sensitivity the molecular ion 13C15N−.
Gynoecious sex expression and stability in cucumber (Cucumis sativus L.)

Results indicated that gynoecious stability in the F1 is governed by partial dominance. The degree of gynoecious stability is dependent upon genotypes, stages of plant for AgNO3 application and number of sprays. Depending upon the genotypes, the one-true-leaf stage and one spray of 250 ppm AgNO3 showed more gynoecious stability in the F1. Twice application of AgNO3 at the two-true-leaf stage produced the maximum number of male flowers. Plants exposed to light for longer time (10.00 h) after AgNO3 application produced less flowers than when exposed for shorter time (15.00 and 20.00 h).
A geochemical model of non-ideal solutions in the methane–ethane–propane–nitrogen–acetylene system on Titan

Abstract Saturn’s largest moon, Titan, has an atmosphere and surface that are rich in organic compounds. Liquid hydrocarbons exist on the surface, most famously as lakes. Photochemical reactions produce solid organics in Titan’s atmosphere, and these materials settle or snow onto the surface. At the surface, liquids can interact with solids, and geochemical processes can occur. The consequences of these processes can be explored using a thermodynamic model to calculate the solubilities of gases and solids in liquid hydrocarbons at cryogenic temperatures. The van Laar model developed in this study was parameterized using experimental phase equilibrium data, and accurately represents the data for the CH 4 –C 2 H 6 –C 3 H 8 –N 2 –C 2 H 2 chemical system from 90 to 110 K. The model generally gives more accurate results than existing models. The model also features a suitable balance between accuracy and simplicity, and can serve as a foundation for studies of fluvial geochemistry on Titan because it can be extended to any number of components while maintaining thermodynamic consistency. Application of the model to Titan reveals that the equilibrium composition of surface liquids depends on the abundance of methane gas in the local atmosphere, consistent with prior studies. The concentration of molecular nitrogen in Titan’s lakes varies inversely with the ethane content of the lakes. The model indicates that solid acetylene should be quite soluble in surface liquids, which implies that acetylene-rich sedimentary rocks would be susceptible to chemical erosion, and acetylene evaporites may form on Titan. The geochemical character of acetylene in liquid hydrocarbons on Titan appears to be intermediate to those of calcite and gypsum in surface waters on Earth. Specific recommendations are given of observational, experimental, and theoretical work that will lead to significant advancements in our knowledge of geochemical processes on Titan. This paper represents the beginning of a new kind of geochemistry, called cryogenic fluvial geochemistry, with Titan starring as the first example.
Periglacial features indicative of permafrost: Ice and soil wedges

Ice wedges are wedge-shaped masses of ice, oriented vertically with their apices downward, a few millimeters to many meters wide at the top, and generally less than 10 m vertically. Ice wedges grow in and are confined to humid permafrost regions. Snow, hoar frost, or freezing water partly fill winter contraction cracks outlining polygons, commonly 5–20 m in diameter, on the surface of the ground. Moisture comes from the atmosphere. Increments of ice, generally 0.1–2.0 mm, are added annually to wedges which squeeze enclosing permafrost aside and to the surface to produce striking surface patterns. Soil wedges are not confined to permafrost. One type, sand wedges, now grows in arid permafrost regions. Sand wedges are similar in dimensions, patterns, and growth rates to ice wedges. Drifting sand enters winter contraction cracks instead of ice. Fossil ice and sand wedges are the most diagnostic and widespread indicators of former permafrost, but identification is difficult. Any single wedge is untrustworthy. Evidence of fossil ice wedges includes: wedge forms with collapse structures from replacement of ice; polygonal patterns with dimensions comparable to active forms having similar coefficients of thermal expansion; fabrics in the host showing pressure effects; secondary deposits and fabric indicative of a permafrost table; and other evidence of former permafrost. Sand wedges lack open-wedge, collapse structures, but have complex, nearly vertical, crisscrossing narrow dikelets and fabric. Similar soil wedges are produced by wetting and drying, freezing and thawing, solution, faulting, and other mechanisms. Many forms are multigenetic. Many socalled ice-wedge casts are misidentified, and hence, permafrost along the late-Wisconsinan border in the United States was less extensive than has been proposed.
Transduction of neurons lining the cerebral external capsules in mice with feline immunodeficiency virus based vectors.

Abstract Gene therapy in the brain has focused mainly on neurons (gray matter), with little comparable research on white matter. In this study, injections into mice cerebral white matter of mice were done to assess the distribution of gene transfer with recombinant feline immunodeficiency virus vectors expressing either β-galactosidase or β-glucuronidase. Our results show that vectors were preferentially distributed along the white matter of the external capsule, which was the site of vector injection as confirmed by horseradish peroxidase labeling. Moreover, we found gene transfer almost exclusively to NeuN + cells lining the external capsule, which then robustly secreted recombinant β-glucuronidase throughout the white matter of the entire external capsule on the injected side. These results may have application to lysosomal storage diseases with widespread central nervous system deficits, and other disorders such as multiple sclerosis and human immunodeficiency virus dementia.
Weibel Turbulence in Laboratory Experiments and GRB/SN Shocks

It has recently been realized that the Weibel instability plays a major role in the formation and dynamics of astrophysical shocks of gamma-ray bursts and supernovae. Thanks to technological advances in the recent years, experimental studies of the Weibel instability are now possible in laser-plasma interaction devices. We, thus, have a unique opportunity to model and study astrophysical conditions in laboratory experiments — a key goal of the Laboratory Astrophysics program. Here we briefly review the theory of strong non-magnetized collisionless GRB and SN shocks, emphasizing the crucial role of the Weibel instability and discuss the properties of radiation emitted by (isotropic) electrons moving through the Weibel-generated magnetic fields, which is referred to as the jitter radiation. We demonstrate that the jitter radiation field is anisotropic with respect to the direction of the Weibel current filaments and that its spectral and polarization characteristics are determined by microphysical plasma parameters. We stress that the spectral analysis can be used for accurate diagnostics of the plasma conditions in laboratory experiments and in astrophysical GRB and SN shocks.
The early effects of code 405 work rules on attitudes of orthopaedic residents and attending surgeons.

Background: The impact of strict enforcement of Section 405 of the New York State Public Health Code to restrict resident work to eighty hours per week and the adoption of a similar policy by the Accreditation Council on Graduate Medical Education in 2002 for orthopaedic residency training have not been evaluated. Adoption of these rules has created accreditation as well as staffing problems and has generated controversy in the surgical training community. The purposes of this study were (1) to evaluate the attitudes of orthopaedic residents and attending surgeons toward the Code 405 work-hour regulations and the effect of those regulations on the perceived quality of residency training, quality of life, and patient care and (2) to quantify the effect of the work-hour restrictions on the actual number of hours worked. Methods: We administered a thirty-four-question Likert-style questionnaire to forty-eight orthopaedic surgery residents (postgraduate years [PGY]-2 through 5) and a similar twenty-nine-question Likert-style questionnaire to thirty-nine orthopaedic attending surgeons. All questionnaires were collected anonymously and analyzed. Additionally, resident work hours before and after strict enforcement of the Code 405 regulations were obtained from resident time sheets. Results: The average weekly work hours decreased from 89.25 to 74.25 hours for PGY-2 residents and from 86.5 to 73.25 hours for PGY-3 residents, and they increased from 61.5 to 68.5 hours for PGY-4 residents. Residents at all levels felt that they had increased time available for reading. There was general agreement between attending and resident surgeons that their operating experience had been negatively impacted. Senior residents thought that their education had been negatively affected, while junior residents thought that their operating experience in general had been negatively affected. Senior residents and attending surgeons felt that continuity of care had been negatively impacted. All agreed that quality of life for the residents had improved and that residents were more rested. Conclusions: On the basis of the survey data, the implementation of the new work-hour restrictions was found to result in a decrease in the number of hours worked per week for PGY-2 and PGY-3 residents and in an increase in work hours for PGY-4 residents. This could explain the definite difference between the attitudes expressed by the senior residents and those of the junior residents. Senior residents felt that their education was negatively impacted by the work rules, while junior residents expressed a more neutral view. However, senior residents did not believe that their operative experience was as negatively impacted as did junior residents. Although junior and senior residents and attending surgeons agreed that resident quality of life had improved, we were not able to determine whether this offset the perceived negative impact on education, continuity of care, and operative experience.
Understanding Technology Literacy: A Framework for Evaluating Educational Technology Integration

Federal legislation in the United States currently mandates that technology be integrated into school curricula because of the popular belief that learning is enhanced through the use of technology. The challenge for educators is to understand how best to teach with technology while developing the technological expertise of their students. This article outlines a framework of technological literacy designed to help educators understand, evaluate, and promote effective and appropriate technology integration.
Fertility and Hatchability of Eggs from Two Varieties of Turkeys and Their Reciprocal Crosses

Abstract CONSIDERABLE losses occur every season as a result of low fertility and hatchability of eggs among the strains of Broad Breasted Bronze turkeys that now constitute the majority of the turkeys raised in the United States. It is estimated that of each 100 eggs incubated only about 55 poults hatch. If fertility and/or hatchability is inherited, then more poults can be hatched per 100 eggs set from flocks in which proper selection and breeding are practiced than from those in which little attention is given to those factors. Thus, considerable economic gain would result. The purpose of the present study was to compare crossbred matings with purebreds to determine whether or not efficiency in reproduction might be increased by crossing. A number of investigators have reported on the fertility and hatchability of various strains and varieties of turkeys and on the results of crossing different strains and varieties. Whitson, Marsden, . . .
The role of polycyclic aromatic hydrocarbons (PAH) in the formation of smoke particulates during the combustion of polymeric materials

The chemical analysis of stable combustion products found in the particulate smoke of polymeric materials is described. The chemical nature of the products produced during flaming and non-flaming modes yeilds valuable information on the possdible role of polynuclear aromatic hydrocarbons (PAH) in the smoke formation process. Samples of polyethylene, polypropylene, polymethylmetahcrylate and polystyrene were studied under controlled thermalo fluxes, and the first three showed similar trends: (1) In the non-flaming mode, aliphatic compounds predominated in the extractable portion of the particulate smoke. (2) In the flaming mode, PAH predominated in the extractable fraction. (3) In the non-flaming mode, of the PAH present, three- and four-membered ring compounds predominated, (4) In the flaming mode, again three- and four-membered ring compounds predominated, but many other PAH up to six-metmbered rings were found. Polysteyren gave rise to degradation products stillcontaining the basic-styrene-derived C 6 H 5 −C 2 units. The quantitative studies of polymer particulate smoke, taken together with further studies of combustion products of pure PAH, leads to a postulated chemical smoke formation pathway.
Path selection for conformational interconversions in [2]catenanes.

The conformational interconversions of several [2]catenanes containing a dibenzo-34-crown-10 ether (BPP34C10) interlocked with rings containing two 4,4‘-dipyridyls tethered by different aryl spacers have been studied. Blocking groups on the tethers enabled the two pathways for circumrotation of the BPP34C10 to be open or blocked. The activation barrier for migration along the open tethers varied from 11 to 13 kcal/mol. This study demonstrates an ability to select the pathway for conformational interconversions in [2]catenanes.
Improved treatment of coronary heart disease by implementation of a Cardiac Hospitalization Atherosclerosis Management Program (CHAMP).

Despite scientific evidence that secondary prevention medical therapies reduce mortality in patients with established coronary artery disease, these therapies continue to be underutilized in patients receiving conventional care. To address this issue, a Cardiac Hospital Atherosclerosis Management Program (CHAMP) focused on initiation of aspirin, cholesterol-lowering medication (hydroxymethylglutaryl coenzyme A [HMG CoA] reductase inhibitor titrated to achieve low-density lipoprotein [LDL] cholesterol <100 mg/dl), b blocker, and angiotensin-converting enzyme (ACE) inhibitor therapy in conjunction with diet and exercise counseling before hospital discharge in patients with established coronary artery disease. Treatment rates and clinical outcome were compared in patients discharged after myocardial infarction in the 2-year period before (1992 to 1993) and the 2-year period after (1994 to 1995) CHAMP was implemented. In the pre- and post-CHAMP patient groups, aspirin use at discharge improved from 68% to 92% (p <0.01), b blocker use improved from 12% to 62% (p <0.01), ACE inhibitor use increased from 6% to 58% (p <0.01), and statin use increased from 6% to 86% (p <0.01). This increased use of treatment persisted during subsequent follow-up. There was also a significant increase in patients achieving a LDL cholesterol <100 mg/dl (6% vs 58%, p <0.001) and a reduction in recurrent myocardial infarction and 1-year mortality. Compared with conventional guidelines and care, CHAMP was associated with a significant increase in use of medications that have been previously demonstrated to reduce mortality; more patients achieved an LDL cholesterol <100 mg/dl, and there were improved clinical outcomes in patients after hospitalization for acute myocardial infarction. Q2001 by Excerpta Medica, Inc. (Am J Cardiol 2001;87:819‐822)
The effects of dieldrin and isomeric aldrin diols on synaptic transmission in the American cockroach and their relevance to the dieldrin poisoning syndrome

Abstract Dieldrin and two of its metabolites, 6,7- trans -dihydroaldrindiol, and 6,7- cis -dihydroaldrindiol, were studied with regard to their toxicity to the American cockroach, effects on ganglia of the ventral nerve cord, and penetration into the ventral nerve cord of poisoned cockroaches. An approximate LD 50 for injected doses of dieldrin was 0.45 mg/kg. After injection at 115 mg/kg, the trans isomer of aldrin diol caused about 70%, and the cis isomer about 50% mortality. Injected doses of 40 mg/kg of the three compounds appeared in the ventral nerve cord to the extent of 0.13–0.26% of the doses. Dieldrin was more potent, but slower acting than the diols in causing synaptic after-discharge and elevated spontaneous activity in isolated nerve cords. The results are discussed in relation to other studies on these compounds. It was concluded that, in the American cockroach, dieldrin, rather than either of the diols, is the insecticidal agent in dieldrin poisoning, and that metabolic conversion of dieldrin to the cis and/or trans aldrindiol constitutes a detoxification.
Intraventricular Conduction Delay as a Determinant of Atrial Echo Beats

Re-entry within the atrioventricular (A-V) node is a common cause of atrial echo beats and paroxysmal atrial tachycardia. This report deals with observations made in four patients in whom the determining factor for atrial echo beats appeared to be a critical conduction delay occurring within the His-Purkinje system and not within the A-V node. The evidence in support of this conclusion is as follows: 1) at a constant A-V nodal delay, echo beats only occurred when a critical His-Purkinje delay was reached; 2) in the presence of different intraventricular conduction times, atrial echoes were dependent on a requisite His-Purkinje conduction delay; 3) at variable A-V nodal conduction times, echo beats appeared only when a requisite delay in His-Purkinje conduction developed; 4) at a constant premature coupling interval atrial echo beats could be abolished when refractoriness within the His-Purkinje system was decreased by decreasing the cycle length of the basic drive; and 5) at constant A-V nodal conduction ...