cssi/SciSciGPT-SciSciNet huggingface dataset:
Perspectives of US Direct Care Workers on the Grief Process of Persons with Intellectual and Developmental Disabilities: Implications for Practice.

Background The study explored the grief process of persons with intellectual and developmental disabilities (PWIDDs) as perceived by direct care workers (DCWs) and how such workers can guide and support PWIDDs experiencing grief. Materials and Methods A thematic analysis approach was used to examine data from nine focus groups with 60 DCWs from five community-based organizations. Results Findings were supported in the context of seminal grief and bereavement theories. Three themes (i.e. reactions to loss, processing the loss and incorporating the loss) and related subthemes emerged from the data. Conclusions PWIDDs are susceptible to traumatic grief, and DCWs are often key witnesses to such experiences. DCWs’ perspectives can guide the development of grief and bereavement training which can lead to more tailored support systems.
Patterns of genetic diversity in the polymorphic ground snake ( Sonora semiannulata )

We evaluated the genetic diversity of a snake species with color polymorphism to understand the evolutionary processes that drive genetic structure across a large geographic region. Specifically, we analyzed genetic structure of the highly polymorphic ground snake, Sonora semiannulata, (1) among populations, (2) among color morphs (3) at regional and local spatial scales, using an amplified fragment length polymorphism dataset and multiple population genetic analyses, including FST-based and clustering analytical techniques. Based upon these methods, we found that there was moderate to low genetic structure among populations. However, this diversity was not associated with geographic locality at either spatial scale. Similarly, we found no evidence for genetic divergence among color morphs at either spatial scale. These results suggest that despite dramatic color polymorphism, this phenotypic diversity is not a major driver of genetic diversity within or among populations of ground snakes. We suggest that there are two mechanisms that could explain existing genetic diversity in ground snakes: recent range expansion from a genetically diverse founder population and current or recent gene flow among populations. Our findings have further implications for the types of color polymorphism that may generate genetic diversity in snakes.
Centrifugal control of gustatory responses.

Abstract The effect of gastric distention upon responses to lingual stimulation with NaCl, quinine hydrochloride and dextrose was recorded from a glossopharyngeal nerve of toads. The multiunit neural responses were quantified with a digitallized electronic summator. Maximum response magnitude, time to maximum, and magnitude at 10 sec after maximum were measured. With both glossopharyngeal nerves intact, maximum magnitude increased for NaCl during distention, decreased with quinine hydrochloride, but did not change for dextrose. No significant changes in rise or fall times occurred. After both glossopharyngeal nerves were mechanically blocked, gastric distention produced no changes in magnitude or time course of responses. It is hypothesized that these effects of gastric distention may modify gustatory selection of food intake.
Hyperglycemia modulates plasminogen activator inhibitor-1 expression and aortic diameter in experimental aortic aneurysm disease.

Background Extracellular matrix degradation is a sentinel pathologic feature of abdominal aortic aneurysm (AAA) disease. Diabetes mellitus, a negative risk factor for AAA, may impair aneurysm progression through its influence on the fibrinolytic system. We hypothesize that hyperglycemia limits AAA progression through effects on endogenous plasminogen activator inhibitor-1 (PAI-1) levels and subsequent reductions in plasmin generation. Methods Experimental AAAs were induced in diabetic and control mice via the intra-aortic elastase infusion method. Serial transabdominal high-frequency ultrasound examinations were performed to monitor aortic diameter following elastase infusion. Circulating PAI-1 and plasmin α2-antiplasmin (PAP) complex concentrations were determined by ELISA and local expression of PAI-1 levels was examined by RT-PCR and immunohistochemistry. Results Hyperglycemia was associated with reduced AAA diameter, increased plasma PAI-1 concentration and reduced plasmin generation. Aneurysmal aortic PAI-1 gene expression increased in parallel with plasma concentration, with peak expression occurring early after aneurysm initiation. Conclusion Hyperglycemia increases PAI-1 expression and attenuates AAA diameter in experimental AAA disease. These results emphasize the role of the fibrinolytic pathway in AAA pathophysiology, and suggest a candidate mechanism for hyperglycemic inhibition of AAA disease.
Audio watermarking techniques for the National Gallery of the Spoken Word

This is one of two companion papers describing technical challenges faced in the development of the National Gallery of the Spoken Word (NGSW). The present paper describes watermarking technologies for intellectual property protection. Following an introduction to data watermarking, the paper focuses on a new algorithm called \textit{transform encryption coding} (TEC) and its application to watermarking the NGSW archives. TEC has a number of flexible features that make it amenable to the NGSW development.
Do machines understand more than they did

To be able to communicate in ordinary English, a machine must have access to common sense information about the real world. The first computer systems to attempt such communication lived in very limited worlds. Now, with a “second generation” of programs, those worlds are widening, although the exact significance of the recent advances is still in dispute.
Down-regulation of fast-twitch skeletal muscle fiber with cardiac troponin-C and recombinant mutants Structure/function studies with site-directed mutagenesis

Structure/function relationships in troponin C are studied with vertebrate fast-twitch fibers by exchanging the skeletal troponin C with two bacterially synthesized recombinant proteins designed by site-directed mutagenesis of cardiac troponin C. One mutant (CBM1) contained an additional active site, by deleting Val-28 and converting Leu-29, Gly-30, Ala-31 and Glu-32 to Asp, Ala, Asp and Gly, respectively, in the normally inactive trigger site 1 in the N-terminus. In another mutant (CBM2A), the normally active site 2 was inactivated by conversion of Asp-65 to Ala. The fibers were found to be down-regulated with recombinant cardiac troponin C (CTnC3), as with tissue-cardiac-troponin-C. With mutants, in one case (CBM1) the regulation was unmodified despite Ca2+ coordination by all sites. In contrast, regulation was found to be completely blocked with the mutant (CBM2A) where both trigger sites were inactive. The results provide the first indication that structural specification of the entire EF-hand motif of site 1, and not just Ca2+ coordination, is needed to operate fully the Ca2+ switch in fast-twitch fibers.
Strategic management of a transformation in a multi-program technology program involving convergence and divergence of programs: observations from NASA

This paper contributes a framework for dealing with complex, technical program transitions. This paper offers a framework of strategic management tools. Tools such as scenario planning, organisational roadmaps, objectives and measures are integrated into a systematic planning process. Using the KSC response to the new NASA vision for space exploration, this paper offers a framework of strategy tools that leads from initial analysis to the business plan. An engineering manager can use this paper to follow a simple set of steps and tools to help manage strategy for an organisational transformation.
Getting off the fence:: Procedures to engage treatment-resistant drinkers

Historically there have been few options for individuals seeking help for treatment-resistant loved ones with substance abuse problems. This article describes a program with empirical backing called Community Reinforcement and Family Training (CRAFT). This cognitive-behavioral treatment teaches the concerned significant other how to use behavioral principles to reduce the loved one's drinking and to encourage the drinker to seek treatment. Additionally it assists the concerned significant other in alleviating other types of stress and in introducing meaningful reinforcers into his or her own life.
The sounds of silence in communicative encounters

The interplay between intrapersonal and interpersonal communication is highlighted through an exploration of the conditions under which people experience silences in conversation to be discomforting. Preliminary experimental findings indicated that conversations between acquaintances were devalued in certain ways when they did contain silences. However, when silences were sanctioned by an accompanying activity, the conversations were rated more favorably. The inferences subjects provided regarding the thoughts and feelings of conversants during their silences suggest that more negative, anxiety‐producing thoughts might accompany those silences which are not sanctioned. It is suggested that those intrapersonal awarenesses which accompany silence, as well as other features of conversation, might illuminate personal, cultural, and relational “communicative norms” or expectations. Furthermore, they might affect resulting patterns of interpersonal attraction, interpersonal relatedness, and communication satisf...
Effect of Structural Variation on Photocurrent Efficiency in Alkyl-Substituted Porphyrin Solid-State Thin Layer Photocells

Three structurally variant alkyl-substituted porphyrins [zinc(II) 2,3,7,8,12,13,17,18-octa-n-decylporphyrin 2, metal(II) meso-5,10,15,20-tetra-n-undecylporphyrin 3 (metal = cobalt, copper, palladium, and zinc), and zinc(II) meso-5,10,15,20-tetrakis(phenoxy-n-nonyl)porphyrin 4] exist as photoconductive insulators and produce significant short circuit photocurrent and open circuit photopotential when irradiated as solid thin films in an indium−tin oxide sandwich cell. Liquid crystalline phase stability, the identity of the inserted metal, and the nature of its supramolecular packing all influence the observed photoelectrochemical response. Porphyrin 2, which has a stable liquid crystalline phase, produces higher steady-state photocurrents than do the corresponding meso-substituted porphyrins 3 and 4, although liquid crystallinity is not an absolute requirement for observation of a photoresponse. Among porphyrins 3, the zinc complex gave the highest steady-state photocurrent. When a phenyl ring orthogonal to...
Pseudomonas aeruginosa Degrades Pulmonary Surfactant and Increases Conversion In Vitro

Although it is known that surfactant lipids and proteins are altered in patients with Pseudomonas aeruginosa infections, the mechanisms and implications of these alterations are not clear. In this study, the effects of P. aeruginosa on the surfactant large aggregate fraction were examined using an in vitro surface area cycling model. Large aggregates were isolated from porcine bronchoalveolar lavage fluid and incubated with supernatants from P. aeruginosa cultures (PAO1, parent strain; PAO1-A1, lasA-negative mutant; PAO1-B1, elastase-negative mutant) or purified elastase. Amounts of surfactant protein (SP)-A and SP-B, phospholipid content, and large aggregate conversion were assessed. In addition, lipid degradation was assessed by incubating a mixture of radiolabeled phospholipids with P. aeruginosa supernatants. The results demonstrated that SP-A was degraded by PAO1 and PAO1-A1 supernatants, and by purified elastase. SP-B was degraded by PAO1 and PAO1-B1 supernatants, but not by elastase. P. aeruginosa ...
On the nature of molecular conformations inferred from high-resolution NMR

The basic, usually unstated, premises underlying the derivation of "average" conformations of flexible molecules from high-resolution NMR parameters (shifts, coupling constants and relaxation times) are critically examined. It is shown that in cases where the individual conformers contributing to the average are not known the "average" derived from spectroscopic data represents a virtual structure devoid of physical meaning.
Reasons and reminder instructions: Their effects on problematic behavior of kindergarten children

Measures of kindergarten children's problematic toilet-flushing behavior were taken during baseline, treatment, and follow-up. Treatment involved giving four groups of three classes one of four kinds of reasons for toilet flushing. Each reason stated the instruction to flush and the consequence of flushing or not flushing. The reasons were positive or negative and object-oriented or person-oriented. Two classes were given a daily reminder instruction to flush and two served as controls. Both the children given reasons and those simply given the reminder instruction showed significantly improved toilet-flushing behavior at follow-up. The added consequence to the instruction to flush did not have a significant effect. Trend differences in the effects of the reasons are discussed.
Interaction of the lipid and protein components of pulmonary surfactant Role of phosphatidylglycerol and calcium

Abstract We investigated the interaction of a major apolipoprotein of pulmonary surfactant with mixtures of lipids analogous to those found in natural surfactant. The apolipoprotein was extracted from canine surfactant and was purified to about 90% homogeneity. The apolipoprotein was mixed with liposomes of lipids in buffers containing 0.1 M sodium chloride and 3 mM calcium chloride at 22°C for 2 h or 37°C for 30 min. Two fractions were separated by centrifugation in sucrose density gradients at 15 000 rev./min. One was comprised of an aggregated, relatively high density recombinant lipoprotein which sedimented to a position toward the bottom of the centrifuge tube; the other remained at the top of the centrifuge tube and was mainly comprised of unbound lipid. The amount of lipid recovered as a sedimenting lipoprotein was dependent upon its composition. Those mixtures of lipids which contained dipalmitoyl phosphatidylglycerol formed sedimenting complexes which comprised 14% to 53% of the recovered lipid; those without phosphatidylglycerol formed such aggregates with less than 13% of the available lipid. Moreover, the lipid-to-protein stoichiometry of the recombinant was also dependent upon phosphatidylglycerol, and lipids containing this phospholipid displayed enhanced binding at a critical concentration of lipid which varied with temperature and composition. Calcium was required to form the sedimenting complex at 37°C. These results suggest that phosphatidylglycerol may be involved in the formation of a micelle-like complex, the stoichiometry of which is regulated over a narrow range of lipid concentration, and the structure of which involves calcium. The physiological advantage of forming this complex has not been determined. We found, however, that lipids containing phosphatidylglycerol absorbed more rapidly to an air/liquid interface than did those without. This rate of adsorption was further increased after interaction with the apolipoprotein.
Monovalent and Divalent Promoted GAAA Tetraloop-Receptor Tertiary Interactions from Freely Diffusing Single-Molecule Studies

Proper assembly of RNA into catalytically active three-dimensional structures requires multiple tertiary binding interactions, individual characterization of which is crucial to a detailed understanding of global RNA folding. This work focuses on single-molecule fluorescence studies of freely diffusing RNA constructs that isolate the GAAA tetraloop-receptor tertiary interaction. Freely diffusing conformational dynamics are explored as a function of Mg(2+) and Na(+) concentration, both of which promote facile docking, but with 500-fold different affinities. Systematic shifts in mean fluorescence resonance energy transfer efficiency values and line widths with increasing [Na(+)] are observed for the undocked species and can be interpreted with a Debye model in terms of electrostatic relaxation and increased flexibility in the RNA. Furthermore, we identify a 34 +/- 2% fraction of freely diffusing RNA constructs remaining undocked even at saturating [Mg(2+)] levels, which agrees quantitatively with the 32 +/- 1% fraction previously reported for immobilized constructs. This verifies that the kinetic heterogeneity observed in the docking rates is not the result of surface tethering. Finally, the K(D) value and Hill coefficient for [Mg(2+)]-dependent docking decrease significantly for [Na(+)] = 25 mM vs. 125 mM, indicating Mg(2+) and Na(+) synergy in the RNA folding process.
Auditory brain-stem response and temperature: relationship in the guinea pig

Abstract The neurological applications of the auditory brain-stem response depend largely on the stability of the interval between the peaks of waves I and V. Using guinea pigs, it was demonstrated that hyperthermia and small temperature changes, as well as hypothermia, may affect interpeak latency (IPL) sufficiently to affect its clinical interpretation. The relationship between temperature and IPL is specified by a power function such that there is a 5.3% increase in IPL for a 1°C drop. Although the constant for humans may differ from that of guinea pigs, the results of this animal study demonstrate that the relationship between temporature and IPL is invariant from 27°C to 40°C.
Achieving Timely Adoption

While family reunification is the primary permanency objective for children who must be placed temporarily outside of their homes, reunification is not possible for all children. For those children who do not return to their parents and cannot find permanent homes with other family members, adoption is the favored outcome. This review examines the composite measure in the federal Child and Family Services Review that measures agency performance related to the timeliness of adoptions of foster children. It summarizes the multiple factors that research has found to be associated with increased risk for adoption delay and disruption. These include child characteristics, family of origin and adoptive family characteristics, and features of child welfare services and systems. Practices that have been broadly linked to adoption timeliness or address risk factors associated with delays in adoption are described, including social worker activities and agency or system-wide practice.
On bayes-type estimators of linearly or log-linearly constrained multinomial cell probabilities

Two Bayes-type procedures for estimating a multinomial cell probabilities vector, P, in the presence of linear constraints on the parameters are proposed and illustrated by examples from contingency table analysis. Estimation under log-linear constraints is also considered.
Learning about gravity: segmental assessment of upright control as infants develop independent sitting.

The question of how infants attain upright sitting is at the core of understanding the development of most functional abilities. Our simple, practical method of securing the hips and different trun...
Catalytic epoxidations of styrene using a manganese functionalized polymer

Abstract Herein we report preliminary results on enantioselective epoxidations of styrene using molecular imprint polymers incorporating an analog of the Jacobsen epoxidation catalyst. We have synthesized molecular imprint polymers (MIPs) containing the pre-catalyst, ( R , R )- N , N ′-bis-(4-acryloyl-salicylidene)-1,2-cyclohexanediaminato manganese(III) phenylacetate ( I ), ethyleneglycoldimethacrylate (EGDMA) as the crosslinking agent and varying amounts of styrene as a non-crosslinking monomer and dichloroethane as a porogen. The molecular catalyst ( I ) shows modest enantioselectivity for styrene epoxidation (21% EE) and the MIPs show less selectivity (4–14% EE). There was no discernable trend in EE when porogen content and crosslinking were varied. The effect of porosity and crosslinking on activity has been explored and optimum conditions of 40–50% porogen and 70% crosslinking have been identified. The MIPs can be reused with no loss of activity for at least three cycles.
Low-dose inotropic stimulation during left ventricular ischaemia does not worsen post-ischaemic dysfunction

Objective: Inotropic agents are used clinically to improve ventricular function during ischaemia. The goal of this study was to determine whether inotropic stimulation during moderate left ventricular (LV) ischaemia exacerbates post-ischaemic LV dysfunction. Methods: In 18 open-chest, anesthetized pigs, LV pressure versus subendocardial segment length loops were used to generate regional preload-recruitable stroke work (PRSW) and LV end-diastolic pressure (EDP) versus end-diastolic segment length (EDL) relations. Ischaemia was produced by constant, partial constriction of the mid anterior descending coronary artery for 90 min. Nine pigs received dobutamine (4 μg·kg−1·min−1, i.v.) during the final 60 min of ischaemia (Group 2), while 9 other pigs did not (Group 1). Results: During unstimulated ischaemia, anterior subendocardial blood flow (Group 1, 0.27 ± .05; Group 2, 0.30 ± .07 ml·g−1·min−1, mean ± s.e.m.) and steady-state PRSW (Group 1, 30 ± 4%; Group 2, 27 ± 5% of baseline) were similar in both groups. Dobutamine stimulation during ischaemia increased heart rate, mean arterial pressure, subendocardial blood flow, oxygen consumption and steady-state PRSW of the ischaemic zone, but not lactate release. After 60 min reperfusion, steady-state ischaemic zone PRSW remained markedly and nearly equally reduced in both groups (Group 1, 28 ± 4%; Group 2, 23 ± 5% of baseline). Reduced PRSW after reperfusion was due primarily to persistent rightward shift of the PRSW intercept with only a modest contribution from reduced PRSW slope. Conclusions: Low-dose inotropic stimulation during moderate regional LV ischaemia increases aerobic, but not anaerobic energy metabolism, and does not worsen post-ischaemic dysfunction.
Free fatty acid accumulation in the pathogenesis and therapy of ischemic-anoxic brain injury

Energy depletion and lactate are at plateau levels within five minutes of complete ischemic-anoxia in the brain; however, irreversible brain injury has not occurred in this time. Brain free fatty acids (FFA) rise sharply during the first five minutes of ischemic-anoxia, but then continue to rise during the following hour without plateauing. Barbiturate anesthesia preischemia attenuates the FFA rise. Other agents which also attenuate the FFA increase include, among others, phenytoin and Innovar. The Ca2+ antagonists flunarizine and gallopamil also attenuated FFA rise, but were not as effective as pentobarbital during ischemia. Protective effects of Ca2+ antagonists may be more important during recirculation than during ischemia.
Bad Data Detection and Identification Using Neural Network-Based Reduced Model State Estimator

This paper explores the capability of the reduced model artificial neural network-based power system state estimator to accurately identify single and multiple bad data. This state estimator uses fewer measurements than conventional state estimators and does not require network observability analysis. A comparison of the single bad data detection and identification between the proposed state estimator and the Weighted Least Squares state estimator on GE 6-bus and IEEE 14-bus power systems is provided. The results show that the proposed state estimator is more accurate and faster than the WLS state estimator. Furthermore, the proposed methodology is a great alternative to the conventional techniques and is therefore well suited for smart grid applications.
Simplified Data Envelopment Analysis: What Country Won the Olympics, and How about our CO 2 Emissions?

This paper introduces a simplified version of Data Envelopment Analysis a conventional approach to evaluating the performance and ranking of competitive objects characterized by two groups of factors acting in opposite directions: inputs and outputs. Examples of DEA applications discussed in this paper include the London 2012 Olympic Games and the dynamics of the United States’ environmental performance. In the first example, we find a team winner and rank the teams; in the second, we analyze the dynamics of CO2 emissions adjusted to the gross domestic product, population, and energy consumption. Adding a virtual Perfect Object – one having the greatest outputs and smallest inputs we greatly simplify the DEA computational procedure by eliminating the Linear Programming algorithm. Simplicity of computations makes the suggested approach attractive for educational purposes, in particular, for use in Quantitative Reasoning courses.
The Inter-American Development Bank and its role in supportive economic and developmental research

Abstract In the areas of Latin American development economics and regional economic integration, one institution may be viewed as the focal point for most of the activity associated with these fields. This institution is the Inter-American Development Bank. It is important that the librarian charged with book collecting in these areas be familiar with the operations of the Bank and its publishing program. Significant as they are, however, the Bank's publications are not its only contribution to scholarly research and publication in development economics. The very nature of the Bank's lending programs provides a vital stimulus to government, business and academia to conduct their own independent studies in these fields. A careful reading of the Bank's annual reports should underscore the importance of this supportive role, and one might further suggest that the Bank, through its reports, can be seen as a bellwether of future research in those areas of the society and economy of Latin America in which it is so manifestly involved.
Pediatric tracheotomy: a 30-year experience.

Abstract Background/Purpose The aim of this study was to investigate changes of pediatric tracheotomy practice over time. Methods A retrospective analysis of all tracheotomies at the University Children's Hospital Zurich from January 1990 to December 2009 was performed. Data analyzed included the indication for tracheotomy, patient comorbidities, age, duration of cannulation, and complications. The second part of the study consisted of comparing our results with data from an earlier study done at the same institution by Simma et al. ( Eur J Pediatr 1994;153:291–296) reviewing the patients with tracheotomies treated from 1979 to 1989. Results Between 1990 and 2009, 119 patients were included. The indication for tracheotomy was airway obstruction in 70% and prolonged ventilation in 30%. 70% of the patients were operated on before 1year of age. Serious postoperative complications occurred in 25 patients (23%). There was one death related to tracheotomy. Successful decannulation was achieved in 60%, on average 28months after tracheotomy. The decannulation rate in patients with airway obstruction was 74% compared to 52% for the patients in prolonged ventilation group; a statistically significant difference was observed ( p Conclusion Over 30years, a shift in the indications of pediatric tracheotomy, with an increasing number of procedures performed for prolonged ventilation, was found. The tracheotomy-related mortality was under 1%. Tracheotomy remains a valid and safe option for pediatric patients. Level of evidence 2c.
MRA studies of arterial stenosis: Improvements by diastolic acquisition

Cardiac-phase-specific data acquisition is used to reduce signal loss in MR Angiography resulting from disturbed flow. RF pulses are delivered continuously throughout the cardiac cycle, but incrementation of phase-encoding gradients and data storage are enabled only during the chosen part of the cycle. Studies in a stenotic pulsatile flow phantom demonstrate that poststenotic signal loss is primarily determined by the mean flow velocity, and is not appreciably affected by acceleration or deceleration of the mean flow rate. The signal loss is least in diastole. In vivo studies in patients with carotid artery disease show that data acquisition in diastole reduces the apparent degree and extent of carotid bifurcation stenosis and provides a crisper definition of the vascular lumen. The additional time required for cardiac-phase-specific acquisition can be reduced by gating only the lower-order phase-encoding lines while retaining acceptable image quality.
Renal functions during positive pressure respiration.

SummaryDogs under barbiturate anesthesia with one kidney acutely denervated and respiring air at greater than atmospheric pressure show two types of renal functional changes. In half the animals studied, a reduction in glomerular filtration rate, renal plasma flow, maximal tubular transport of glucose, urine volume, and sodium excretion occurred in the intact kidney. No change in these functions occurred in the denervated kidney. In the rest of the animals, changes in glomerular filtration, renal plasma flow, and urine formation were smaller, while the TmG increased. The renal functions of these animals appear to have been depressed during control observations, perhaps due to trauma or deep anesthesia. but positive pressure respiration caused partial restoration. Since both kidneys participated, the mechanism must be independent of the renal nerves.
The extended center of a skew power series ring

For a prime ring R with σ ∊ Aut(R), we examine the extended center of the skew power series ring R[[x;σ]]. We prove the extended center of R[[x;σ]] is isomorphic to: (1) Cσ if no power of σ is X-inner where Cσ is the fixed field of a acting on the extended center C of R (2) Cσ((vx')) (Laurent series) if some positive power of a is X-inner and R is closed prime. In this case I is the least positive integer such that a1 is X-inner with σ1= inn(v). We provide an example showing this result fails if R is not closed prime.
Chromium determination by supercritical fluid chromatography with inductively coupled plasma mass spectrometric and flame ionization detection

Supercritical fluid chromatography (SFC) has been investigated for the separation of a pair of beta-ketonate chromium compounds and a thermally labile organochromium dimer. A limited comparison between flame ionization detection (FID) and inductively coupled plasma mass spectrometric (ICP-MS) detection of these compounds is presented. The beta-ketonate complexes were observed with both detectors, while the thermally labile dimer was not observed with ICP-MS detection. Detection limits for these compounds with ICP-MS were in the range of 0.9 to 3 pg with FID giving values between 10 and 250 pg. Reproducibility of the method is between 1 and 4% relative standard deviation (R.S.D.). The technique provided a linear response over approximately three orders of magnitude. The effect of two mobile phases (nitrous oxide and carbon dioxide) on the detection by each of the detectors are presented in a qualitative manner. Finally, the SFC-ICP interface heating method and the manner in which the restrictor is heated in the FID system are compared and there effect on the chromatography discussed.
Effects of intravenous magnesium sulfate on the QT interval in patients receiving ibutilide.

Study Objective. To determine the effect of intravenous magnesium sulfate on the QT and QTc intervals in patients receiving ibutilide for immediate chemical cardioversion of atrial flutter or fibrillation. Design. Prospective, randomized, double-blind, placebo-controlled trial. Setting. Hospital cardiology unit. Patients. Twenty patients (mean age 72 ± 14 yrs) with atrial fibrillation (12 patients) or atrial flutter (8 patients) who were scheduled to receive ibutilide. Intervention. After determining that the patients' baseline QTc intervals were less than 440 msec and baseline serum magnesium levels were within normal limits (mean 2.1 ± 0.29 mg/dl), the patients were randomly assigned to receive either a 10-minute infusion of magnesium sulfate 2 g in 50 ml of 0.9% sodium chloride or placebo immediately before ibutilide therapy. An additional 2 g of intravenous magnesium sulfate or placebo was given over 1 hour, 10 minutes after the first dose of ibutilide. Measurements and Main Results. QT interval duration was measured manually in all 12 leads by using a 0.5-mm-scale precision ruler and magnifying lens. The QT interval increased 29% from baseline at 30 minutes after ibutilide therapy in the placebo group (p=0.007), but no significant change from baseline occurred in the magnesium sulfate group. The 30-minute QTc interval in the placebo group was 18% higher than the baseline value (p=0.01) but did not change significantly in the magnesium sulfate group. QTc changes from baseline were greater in the placebo group than in the magnesium sulfate group at 30 minutes (75 vs 19 msec, respectively, p=0.04). Magnesium sulfate reduced the risk of an ibutilide-induced QTc interval increase of greater than 30 msec or greater than 60 msec and reduced the risk of a QTc interval value of more than 500 msec by 65%, 60%, and 68%, respectively (p=0.07, p=0.175, and p=0.160). Conclusions. Prophylactic administration of intravenous magnesium sulfate prevents increases in the QT and QTc interval 30 minutes after the last infusion of ibutilide.
The universal ancestor

A genetic annealing model for the universal ancestor of all extant life is presented; the name of the model derives from its resemblance to physical annealing. The scenario pictured starts when "genetic temperatures" were very high, cellular entities (progenotes) were very simple, and information processing systems were inaccurate. Initially, both mutation rate and lateral gene transfer levels were elevated. The latter was pandemic and pervasive to the extent that it, not vertical inheritance, defined the evolutionary dynamic. As increasingly complex and precise biological structures and processes evolved, both the mutation rate and the scope and level of lateral gene transfer, i.e., evolutionary temperature, dropped, and the evolutionary dynamic gradually became that characteristic of modern cells. The various subsystems of the cell "crystallized," i.e., became refractory to lateral gene transfer, at different stages of "cooling," with the translation apparatus probably crystallizing first. Organismal lineages, and so organisms as we know them, did not exist at these early stages. The universal phylogenetic tree, therefore, is not an organismal tree at its base but gradually becomes one as its peripheral branchings emerge. The universal ancestor is not a discrete entity. It is, rather, a diverse community of cells that survives and evolves as a biological unit. This communal ancestor has a physical history but not a genealogical one. Over time, this ancestor refined into a smaller number of increasingly complex cell types with the ancestors of the three primary groupings of organisms arising as a result.
Optimization of Equipment Control Parameters to Minimize HVAC Energy Consumption

Heating, Ventilating, and Air Conditioning Systems (HVAC) consume nearly one-third of household energy in the United States. The optimization of the control parameters in HVAC equipment allows for a reduction in energy consumption. In this study, a supervisory control method is applied to a lumped parameter model of an HVAC system of interest containing a chiller and three dampers. The method determines the choice of control parameters that minimize the energy consumption for 1000 sampled steady-state loads. An energy savings of 39% was achieved using the method in this study compared to the base case.Copyright © 2011 by ASME
Resonant photoionization spectroscopy of refractory metal-rare gas complexes: AlAr

Abstract Mass-resolved resonance-enhanced multiphoton ionization is used to probe AlAr complexes in the spectral region about the Al 2S 1 2 -2P 1 2 transition. Analysis of a vibrational progression in the AlAr 2Σ+state provides lower limits for binding energies in the X2Π 1 2 and B2Σ+ states of 133 and 373 cm−1, respectively.
Herding cats: the sociology of data integration.

Upon this gifted age, in its dark hour, Rains from the sky a meteoric shower Of facts…they lie unquestioned, uncombined. Wisdom enough to leech of our ill Is daily spun; but there exists no loom To weave it into fabric; —Edna St. Vincent Millay (from Huntsman, What Quarry? 1939)
Comparison of yield versus depth for particle induced and photon induced x-ray emission analysis

Abstract The depth sensitivity using 1.0, 2.5 and 5.0 MeV protons and Ti, Mo and Sm K α X-rays for excitation is compared in the elemental analysis by X-ray emission of cellulose, fluorapatite and stainless steel samples.
Effect of pulmonary vein isolation on the left-to-right atrial dominant frequency gradient in human atrial fibrillation

Background We previously demonstrated the existence of a left-to-right atrial dominant frequency gradient during paroxysmal but not persistent atrial fibrillation (AF) in humans. One possible mechanism of the left-to-right dominant frequency gradient involves the role of the pulmonary veins (PVs) in AF maintenance. Objectives The purpose of this study was to examine the effect of PV isolation on the dominant frequency gradient and outcome after PV isolation. Methods Patients with either paroxysmal or persistent AF were studied. Recordings were made from catheters in the coronary sinus (CS), posterior right atrium (RA), and posterior left atrium (LA) during AF before and after PV isolation. Mean left-to-right dominant frequency gradient was measured before and after segmental PV isolation. Patients were followed for AF recurrence after PV isolation. Results Twenty-seven patients with paroxysmal (n = 15) or persistent (n = 12) AF were studied. In the paroxysmal group, baseline dominant frequency was greatest in the posterior LA with a significant left-to-right atrial dominant frequency gradient (posterior LA=6.2 ± 0.9 Hz, CS=5.8 ± 0.8 Hz, posterior RA=5.4 ± 0.9 Hz; P P = NS). In the persistent AF group, there was no overall difference in dominant frequency among sites before or after PV isolation ( P = NS); however, patients with long-term freedom from AF after PV isolation had a higher left-to-right dominant frequency gradient compared with patients with recurrent AF (0.4 vs 0.1 Hz; P Conclusion PV isolation results in a loss in the left-to-right dominant frequency gradient in patients with paroxysmal AF. This finding supports the critical role of PVs in the maintenance of ongoing paroxysmal AF. Patients with persistent AF and a baseline left-to-right dominant frequency gradient have a better success rate with PV isolation alone compared with patients without a dominant frequency gradient.
Evaluation of a storable fluorine based pilot for scramjets

An ignitor/pilot device for scramjet engines has been tested with C2H4, C2H6, and CH4 gaseous hydrocarbon fuels at Mach 2. The pilot was designed to operate with storable nontoxic propellants rather than hazardous pyrophorics; the pilot fluid is a mixture of ethylene, oxygen, and sulfur hexafluoride. The pilot reduced the minimum temperature at which all three hydrocarbon fuels ignited; a comparison was then conducted between combustion efficiency calculations for these test results and those of pilots using nitrogen in place of sulfur hexafluoride, and using silane-hydrogen (yielding equivalent energy). The nitrogen-substituted pilot exhibited the highest efficiency.
Recommendations for additional imaging on emergency department CT examinations: comparison of emergency- and organ-based subspecialty radiologists

Purpose Past studies have identified a high frequency of recommendations for additional imaging (RAI) for computed tomography (CT) studies performed in an emergency department (ED), thereby potentially contributing to increased imaging utilization and costs. The purpose of this study was to compare rates of RAI within the ED setting between ED-based and organ-based subspecialty radiologists.
Progesterone Withdrawal Stimulates Mammary Gland Tubulin Polymerization in Pregnant Rats

The size of the polymerized tubulin pool in mammary glands of late pregnant rats increased 2.4-fold 24 h after bilateral ovariectomy using a [3H]colchicine binding assay for tubulin. The total (free plus polymerized) tubulin concentration was not altered. Stimulation of tubulin polymerization as well as the induced rise in lactose content were both completely inhibited in rats that had been fitted with progesterone implants at the time of surgery. The increase in polymerized tubulin was not blocked by 17β-estradiol implants, although this treatment did partially inhibit the rise in tissue lactose following overiectomy. The results indicate that increased polymerization during induced lactogenesis reflects a shift of free tubulin into the polymerized pool and that this shift is related to the withdrawal of progesterone. (Endocrinology 116: 2543–2547,1985)
Role of ultrastructural studies in the analysis of cell lineage in the mammalian pre-implantation embryo.

Ultrastructural studies have contributed significantly to our understanding of cell lineage differentiation in the mammalian pre-implantation embryo. Such studies have documented, and continue to document, morphological, biochemical, and physiological characteristics of the cell lineages established during the pre-implantation period in eutherian embryos, principally that of the mouse. This review evaluates these contributions and identifies areas of study in which ultrastructural analysis is most likely to have an important role in the future. © 1992 Wiley-Liss, Inc.
Profession and gender in relationships between advanced practice nurses and physicians.

Relationships between registered nurses and physicians have often been described in terms of two models: one based on interactions between two health professions and one based on the patriarchy of male physicians and the deference of female nurses. To evaluate nurses' perceptions of the two models, 125 advanced practice nurses at a statewide professional conference completed a closed-ended self-administered questionnaire that asked about their relations with male and female physicians. Nurses rated male and female physicians very similarly; both groups were rated most favorably on their confidence in the nurse's expertise and least favorably on their recognition of the nurse's responsibilities unrelated to the care of individual patients. Nurses rated female physicians under the age of 50 more favorably than older female physicians and rated male physicians of all ages similarly. These findings provide greater support for the professional than for the gender model of nurse–physician relations.
Condoms as evidence of prostitution in the United States and the criminalization of sex work.

The vulnerability of sex workers and transgender women to HIV infection is a result of many factors including stigma, social and physical isolation, economic deprivation, and legal and policy environments that criminalize their behaviour. Recent systematic reviews have found high HIV prevalence among both populations, including an 11.8% pooled HIV prevalence among female sex workers in 50 countries and a 19.1% HIV prevalence among male-tofemale transgender women in 15 countries worldwide. Studies in the United States have also documented high HIV prevalence among people who report transactional sex and transgender populations. (Published: 24 May 2013) Citation: Wurth MH et al. Journal of the International AIDS Society 2013, 16:18626 http://www.jiasociety.org/index.php/jias/article/view/18626 | http://dx.doi.org/10.7448/IAS.16.1.18626
Transiently misacylated tRNA is a primer for editing of misactivated adenylates by class I aminoacyl-tRNA synthetases.

The genetic code depends on amino acid fine structure discrimination by aminoacyl-tRNA synthetases. For isoleucyl- (IleRS) and valyl-tRNA synthetases (ValRS), reactions that hydrolyze misactivated noncognate amino acids help to achieve high accuracy in aminoacylation. Two editing pathways contribute to aminoacylation fidelity: pretransfer and post-transfer. In pretransfer editing, the misactivated amino acid is hydrolyzed as an aminoacyl adenylate, while in post-transfer editing a misacylated tRNA is deacylated. Both reactions are dependent on a tRNA cofactor and require translocation to a site located ∼30 A from the site of amino acid activation. Using a series of 3‘-end modified tRNAs that are deficient in either aminoacylation, deacylation, or both, total editing (the sum of pre- and post-transfer editing) was shown to require both aminoacylation and deacylation activities. These and additional results with IleRS are consistent with a post-transfer deacylation event initiating formation of an editing-a...
Vibration-Assisted Machining Study Based on 2R-2P Parallel Mechanism

During the traditional cutting processing, cutting tool and the workpiece contact each other continuously along with the chip removal, this paper puts forward a kind of vibration cutting structure based on the parallel mechanism known as 2R-2P, in which certain elliptical trajectory could be taken, according to the principle of applying separate characteristic between vibrating cutting tool and workpiece to lower cutting force, cutting temperature, so as to improve the machining accuracy. Firstly, illustration in the mechanism of formating the surface morphology in elliptical vibration cutting and the micro trajectory of tip is carried out, secondly, completing the structure design and kinematics analysis, the tip vibration curve has been attained. Finally, through the statics and dynamics analysis, distribution rule of stress and strain is concluded when the structure is subjected to external force changing periodically, as the vibration mode and the harmonious response, verifying the feasibility of the structure and the ability of tip vibrating in ellipse trajectory.
Cluster synthesis 44. The synthesis and structural characterization of an unusual new high nuclearity platinum-osmium cluster complex, Pt5Os6(CO)25

The reaction of Pt2Os4(CO)18 (1) with H2 in refluxing octane (125°C) yielded the new compound Pt5Os6(CO)25 (2), 58%. Compound 2 was characterized by IR, elemental and single crystal X-ray diffraction analyses. Compound 2 contains 11 metal atoms. five platinum, and six osmium. The cluster can be viewed as two fused trigonal bipyramidal clusters that share one platinum vertex. These two clusters are also joined by three metal-metal bonds, and Os(CO)4 groups bridge two of these three metal-metal bonds. Crystal data for 2·CH2Cl2: space group itP1¯ma=12.250(1) A,b=17.476(4) A,c=11.89(2) A,α=109.87(1)°,β=112.66(1)°,γ=83.05(2)°,Z=2, 2986 reflections,R=0.033.
A transitive closure algorithm

An algorithm is given for computing the transitive closure of a directed graph in a time no greater thana1N1n+a2n2 for largen wherea1 anda2 are constants depending on the computer used to execute the algorithm,n is the number of nodes in the graph andN1 is the number of arcs (not counting those arcs which are part of a cycle and not counting those arcs which can be removed without changing the transitive closure). For graphs where each arc is selected at random with probabilityp, the average time to compute the transitive closure is no greater than min{a1pn3+a2n2, 1/2a1n2p−2+a2n2} for largen. The algorithm will compute the transitive closure of an undirected graph in a time no greater thana2n2 for largen. The method uses aboutn2+n bits and 5n words of storage (where each word can holdn+2 values).
Review Article: Current Thoughts on Migraine

SYNOPSIS Current theories of migraine etiology and migraine mechanisms are reviewed. A complete discussion of general therapeutic measures, abortive, and prophylactic treatments, their indications and proper selection of patients is presented.
What do parents have to do with my cognitive reserve? life course perspectives on twelve-year cognitive decline

Background/Aims: To examine the cognitive reserve hypothesis by comparing the contribution of early childhood and life course factors related to cognitive functio