cssi/SciSciGPT-SciSciNet huggingface dataset:
Analysis and modeling of nitrous oxide chemistry in lean, premixed combustion☆

Abstract A modeling study of N 2 O chemistry in lean, premixed, atmospheric-pressure combustion is presented. Laminar flame and homogeneous combustion modeling calculations were performed using the PREMIX and CHEMKIN codes, respectively. Four systems containing H 2 , O 2 , Ar, and an N-containing dopant (NH 3 , NO, or N 2 O) were modeled and compared to recent flat-flame burner experiments. Agreement between measured and computed N 2 O, NO, and N 2 concentration profiles indicated that the model is a reasonable representation of the chemistry and transport in the flame system. The effects of assumed burner temperature, temperature profile shape, mass diffusion, and probing are investigated. A sensitivity analysis of the flame calculations is presented. For cases where burner temperatures were identical but temperatures were either determined by solving the energy equation numerically or were specified to be equivalent to measured temperatures, calculated N 2 O, NO, and N 2 profiles differed by 2%–15%. Calculations that differed only in specified flameholder surface temperature (400–1000 K) produced concentration profiles that varied by approximately 20% in NO and N 2 and by as much as a factor of 7 in N 2 O. Computations performed with and without mass diffusion demonstrated that profile shapes and final, postflame concentrations of N 2 O, NO, and N 2 differed by factors of 1.5–3.0, due to the fast transport of low mass, reactive species. Nitrogeneous species profiles are sensitive to values of diffusion coefficients. A probe-quench simulation indicated that sampling may alter the N 2 O concentration in gases extracted very near the burner surface, but that relatively little species interconversion takes place at heights greater than 1 mm. Reaction rate and sensitivity results from these computations indicate that the principal formation and destruction reactions for N 2 O are NH + NO = N 2 O + H H + N 2 O = N 2 + OH and that H + O 2 + M= H 2 O + M plays a significant role in trapping H atoms to enhance N 2 O survival.
Chemical environment of coastal marshes and swamps, Louisiana

Abstract Water, sediment and interstitial water in nearshore marshes and swamps along a proposed oil pipeline route in the Louisiana coastal zone were analyzed. The primary objectives were to understand the chemical mechanisms involved and to depict the levels of chemical components in natural environments and in environments altered by man's activities. The brackish and fresh marshes showed the highest organic deposition due to low tidal flushing and runoff rate. High nutrient levels were found in waters of these environments due in part to release from the nutrientladen interstitial water which maintained a dynamic equilibrium with biological activities and organic matter in sediments. Sulfides, expressed as ratio of FeS to organic content was much higher in the saline environment than in the low saline system. Low activities of sulfate reducing microorganisms, limited sulfate and organic-S concentrations in the freshwater environment accounted for the low sulfide level. Impairment of water circulation in the salt marsh resulted in drastic fluctuation in dissolved oxygen and concurrent but inverse changes in sulfide level in sediments and in interstitial NH + 4 and PO −3 4 in spite of relatively low sediment organic matter. Drainage of fertilizer from agricultural fields and to stagnation in freshwater swamps resulted in persistently lowest dissolved oxygen in swamp water without raising the sulfide level to a great extent in sediment. Detailed discussion on the interrelationships among various factors is presented.
Deduction of the cell volume and mass from forward scatter intensity of bacteria analyzed by flow cytometry

Abstract Forward scatter signals (0–20°) from a flow cytometer can be converted into cellular volumes or cellular wet or dry biomasses by the calculations presented here. The results are applicable to bacteria, and including very small bacteria (0.02–0.6 μm3), rods as well as cocci. The physical limitations and the mathematical basis of the calculations are discussed to justify the application of the proposed formula for practical use in microbial ecology and physiology of extremely small aquatic bacteria as well as the more well-studied forms. Although the method was developed for the small bacteria present in natural populations that are difficult to size by alternative methods, it will also be useful for laboratory cultures of bacteria when present in very low concentrations as well as for the characterization of subpopulations and different growth phases. Bacteria, in general, are small enough so that inclusion of the phase shifts of the light passing through the bacteria (the Mie theory) is superfluous. That theory is, however, useful for instrumental calibration with latex microspheres and for some blue-green algae. Even the interference between rays scattered from different parts of the cell (the Rayleigh-Gans theory), although significant, is minor, particularly from elongated particles which are oriented by the fluidics. The computer programs, provided here, correct for intraparticle interference and generate cell volumes (or wet or dry masses) from the forward scatter intensity. The result of the calculations of the light scattered into the collection system of the flow cytometer is presented. From analysis of these values a rule is developed to relate the observed intensities, when scaled by an empirical constant and raised to a power between 0.5 and 0.75, to the cell biomass.
Role of prolactin in growth of the rat mammary tumor MTW9

The growth of MTW9 mammary tumors exhibits different degrees of responsiveness to ovariectomy, ranging from sensitivity to resistance. This range of response is a function of time elapsing from tumor inoculation until performance of ovariectomy provided that prolactin (PRL) level is kept continuously high. In vivo studies showed that the MTW9 tumors developed by chronic administration of spiramide were sensitive to ovariectomy by 60 days, but they became resistant to ovariectomy by 100 days. However, when spiramide treatment was discontinued after tumor appearance, the tumors were still sensitive to ovariectomy by 100 days. Chromatofo-cusing (CF) profile of cytosolic estrogen receptors (ER) correlated with the responsiveness to ovariectomy. A 2-peak profile for tumors sensitive to ovariectomy, and only a one-peak profile for tumors resistant to ovariectomy, were seen. Although the prolactin level in rats bearing the tumors was higher than in the normal rats, no correlation between the PRL level and the change in CF profile of ER over time was seen. Also, these changes could not be correlated with the tumor size. In vitro studies showed that incubation of cytosolic ER from a sensitive tumor (2 peaks) with PRL led to a CF profile with only one peak, characteristic of a resistant tumor. Leupeptin, molybdate and phenylmethylsulfonylfluoride (PMSF) could not prevent this transition. The effect was not reproduced by incubation with growth hormone or progesterone. Our data suggest that PRL, either directly or through intermediates, may play a role in changing the response to hormonal therapy of the mammary tumor MTW9.
D∗(R;⩽) does not imply D1∗

Abstract We prove that the cyclic monotonically normal space T of Rudin is not a J2-space. Consequently, T has the monotone extension property but does not have D 1 ∗ or D ∗ ( R ; + ;cch) . This answers some questions of van Douwen.
Use of barbiturate therapy in severe perinatal asphyxia: A randomized controlled trial

The possible cerebral sparing effect of thiopental was evaluated in 32 severely asphyxiated neonates randomly assigned to either a thiopental treatment or control group. All infants had neurologic manifestations of asphyxia and required assisted ventilation. Thiopental was begun at a mean age of 2.3 hours and was given as a constant infusion that delivered 30 mg/kg over 2 hours. Treatment was continued at a lower dose for 24 hours. Seizure activity occurred in 76% of infants given thiopental and 73% of control infants at a mean age of 1.5 and 2.5 hours, respectively. Although initial arterial blood pressure was similar in both groups, hypotension occurred in 88% of treated and 60% of control infants. The amount of blood pressure support required was significantly greater (P
Ion separation by selective crystallization of organic frameworks

Selective crystallization of organic frameworks is presented as a promising alternative to ion separation from competitive aqueous environments. The review focuses primarily on the principles determining ion selectivity in crystallization, as well as on structure-selectivity relationships. Specific examples involving anion separation by selective crystallization are discussed.
Human oral epithelial cell culture. II. Keratin expression in fetal and adult gingival cells.

Epithelial cells from human fetal and adult gingiva were cultured in keratinocyte growth medium (KGM), a serum-free medium. The expression of keratin proteins in these cells was evaluated using immunohistochemistry and SDS-PAGE-immunoblot analysis and compared with expression in the tissue. Keratins 5, 6, 14, 16, and 19 were identified in cells cultured from both fetal and adult tissues. K19 was localized in basal cells of fetal oral tissue but was not seen in adult gingiva (except for scattered Merkel cells). K1 and K10 were expressed in tissue, but not in cultured cells. The keratin profiles of cultured epithelial cells from several adult donors were similar and were identical in cultures from primary through Passage 5. K13, a differentiation-specific keratin, was expressed in all suprabasal cells of fetal oral epithelium, but shows only spotty expression in adult gingival tissue. K13 was expressed in cultures of fetal cells, but very weakly or not at all in cultures of adult cells. K13 expression was greater in cultures grown with physiologic calcium concentrations (1.2 mM) than in those grown at 0.15 mM or less. Our findings are consistent with basal-like characters of these cells in 0.15 mM calcium growth conditions. Differentiation of fetal oral cells in culture to the suprabasal basal cell stage in 1.2 mM Ca2+ is shown by the expressionof K13.
Some Effects of Chloramphenicol and Ethidium Bromide on Tetrahymena pyriformis

SYNOPSIS. Very similar results are obtained by the addition of 300 μg/ml chloramphenicol or of 15 μg/ml ethidium bromide to cultures of Tetrahymena pyriformis strain ST. In such cultures the exponential growth rates and the yields are reduced. Unlike the untreated ciliates, which retain the pyriform shape throughout the exponential and stationary phases, those exposed to either of the drugs become more spherical. In the control organisms progressively less surface area/unit of cell volume is exposed to the environment during the growth cycle; in the drug-treated ciliates this pattern is reversed. Increased endogenous respiration, reduced specific activities of states 3 and 4, and reduction in the levels of cytochromes a, a3, b, and c+c1 are found in mitochondria from ciliates exposed to chloramphenicol and ethidium bromide.
Job Change in the Future.

Job change now and in the future is a reality. Currently, job change appears to be a continental occurrence and is moving toward a global phenomenon. The present discussion of job change in the global marketplace is not meant to be an exhaustive explicative of the topic nor is it inclusive of all future contexts for employment. The intent, instead, has been to encourage the consideration of a multitude of issues related to job change, and to highlight the importance and implications of the evolution of the world of work in regard to this process. Research questions have also been delineated in anticipation of the refinement and expansion of current conceptualizations of job change in the future.
Optical Specifications And Tolerances For Large Optics

The term "large" has specific implications about types of optics and their uses. In this paper large optics are defined and figure, beauty, and blank characteristics are specified with tolerances for each. Because it is useless to discuss specifications for properties that cannot be measured, tests for each specification are described. The specification of a large optic takes far more thought and insight than is the case for small optics because of the high cost and demanding applications of large optics.
XLV. Some new cases of interference and diffraction

(1904). XLV. Some new cases of interference and diffraction. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 7, No. 40, pp. 376-388.
Can permeability measurements add to blood volume measurements in differentiating tumefactive demyelinating lesions from high grade gliomas using perfusion CT

Tumefactive demyelinating lesions (TDLs) can mimic a neoplasm on conventional imaging and may necessitate biopsy for diagnosis. The purpose of this study was to differentiate TDLs from high grade gliomas based on physiologic (permeability) and hemodynamic (blood volume) parameters using perfusion CT. Five patients who presented with tumefactive enhancing lesions on initial MRI that mimicked a neoplasm underwent perfusion CT. We compared the perfusion CT parameters of these patients with those of 24 patients with high grade gliomas. TDLs showed lower permeability surface area product (PS) (0.8 ± 0.2 vs 2.4 ± 1.4 ml/100 g/min, P-value 0.014) and lower cerebral blood volume (CBV) (1.0 ± 0.2 vs 2.8 ± 1.2 ml/100 g, P-value 0.006) as compared to high grade gliomas. TDLs show lower PS and CBV as compared to high grade gliomas, to which they can mimic on conventional MR imaging, due to lack of neoangiogenesis and vascular endothelial proliferation and hence perfusion CT can be used to differentiate the two entities.
Sensor web enables rapid response to volcanic activity

Rapid response to the onset of volcanic activity allows for the early assessment of hazard and risk [Tilling, 1989]. Data from remote volcanoes and volcanoes in countries with poor communication infrastructure can only be obtained via remote sensing [Harris et al., 2000]. By linking notifications of activity from ground-based and spacebased systems, these volcanoes can be monitored when they erupt. Over the last 18 months, NASA's Jet Propulsion Laboratory (JPL) has implemented a Volcano Sensor Web (VSW) in which data from ground-based and space-based sensors that detect current volcanic activity are used to automatically trigger the NASA Earth Observing 1 (EO-1) spacecraft to make highspatial-resolution observations of these volcanoes.
Size Distribution and Amino Acid Chemistry of Base-extractable Proteins from Washington Coast Sediments

Proteinaceous components from four Washington coast margin sediments were extracted with base, fractionated into one of four size classes ( 100 kDa), and analyzed for their amino acid contents. Base-extracted material accounts for ~30% of the total hydrolyzable amino acids (THAA) and each size fraction has a unique composition, regardless of where the sediment was collected (shelf or upper slope). The 100 kDa size fraction (~38% of base-extractable THAA) is not dominated by any particular amino acid and can not be modeled by mixing the amino acid compositions of the other size fractions. We propose that the larger size fractions (10–100 kDa and >100 kDa) represent intact, or near intact, proteins. Estimates of isoelectric points and relative hydrophobicity suggest the base-extractable proteins are primarily acidic and have globular structures. Statistical comparisons to several known proteins indicates that the base-extractable component is most similar to planktonic cytoplasmic proteins.
Combined Effect of Sucrose and Heat Treatment Temperature on the Thermal Resistance of Staphylococcus aureus MF-31

The combined effect of sucrose and heat treatment temperature on the thermal resistance of Staphylococcus aureus MF-31 was examined by determining the relationships between the D value, temperature and each of three parameters (water activity, osmotic pressure and water binding energy) related to sucrose-water binding. The results showed that sucrose and temperature had a significant interactive effect on thermal resistance. More specifically, sucrose increased the heat resistance, and this effect was greater at lower temperatures than at higher temperatures. The effect of sucrose on the Z value was slight compared to its effect on the D value.
Resuspension of non-Newtonian slurries by submerged jet-nozzles

Experiments were conducted to determine the fluid velocity required for resuspension and removal of the radioactive waste sludge, which is characterized as a non-Newtonian fluid, from the tanks at the Savannah river site (SRS) (Georgia, USA) to accelerate the closure of the tanks with high level waste (HLW). Five different non-Newtonian fluids, which simulated the actual waste characteristics, were used to investigate the resuspension of the slurries with a jet-nozzle mixer. The laboratory tests were conducted at different flow rates and jet-nozzle orientations in a cylindrical tank with 0.3-m diameter and 0.46 m in height. Resuspension of the slurries was achieved by the submerged jets produced by two horizontal discharge nozzles located under the liquid level and positioned at 180° from each other. The fluids exhibited Bingham plastic behavior; therefore, the mixing power depends not only on the Reynolds number but also on the yield stress and high shear viscosity. A similarity analysis was performed to determine the effective cleaning radius (ECR) of the jet. The mixing efficiency was evaluated by visual analysis of the images during the experiments conducted at three nozzle orientations at 0°, 45°, and 90° and two nozzle exit velocities of 2.33 m/s and 0.56 m/s. The centerline velocity decayed with the distance from the jet-nozzle. The experimental results were compared with other mixing models.
How ephedrine escaped regulation in the United States: a historical review of misuse and associated policy.

Abstract Objective Ephedrine is not only efficacious in the treatment of numerous ailments, but also has a long history of misuse. Research was needed to examine ephedrine policy over time in order to determine potential regulatory flaws that allowed misuse to continue. Methods This review is based on primary literature derived from systematic searches of historical and scientific archives, as well as grey literature. Results Ephedrine managed to pass through numerous regulatory loopholes within seventy years. Despite warnings of misuse over the latter half of the century, ephedrine, and its herbal source, ephedra, were regulated in a piecemeal fashion and remained easily available to the public. Health authorities have struggled to control ephedrine, as an amphetamine “look-alike,” as a methamphetamine precursor, as a dietary supplement, and as a medication. Despite being a potentially dangerous stimulant, under-regulation was perhaps more problematic than the substance itself. Conclusions Tighter control of all ephedrine products, drugs and dietary supplements alike, might have prevented adverse outcomes and allowed this substance to remain available in a safer manner. Stringent regulation of all ephedrine products is necessary to prevent misuse and to protect the public's health.
Ability of monovalent cations to replace potassium during stimulation of lymphoid cells

Abstract Stimulation of hamster thymocytes, splenocytes, or lymph node cells occurred to a minimal extent in the absence of K + . This observation was found for stimulation by T-cell mitogens (phytohemagglutinin and concanavalin A), A B-cell mitogen (lipopolysaccharide), or antigen (KLH). Marginal restoration of the responses to these stimulants occurred in the presence of 0.1 m M K + and responsiveness returned to near maximal levels on addition of 1 m M K + to the cultures. Attempts to restore the responsiveness with other monovalent cations revealed an order of effectiveness of K + ≥ Rb + ⪢ NH 4 + ≥ Li + . At the 1 m M level K + and Rb + were equally effective in supporting stimulation by phytohemagglutinin while all concentrations of Li + tested (0.1–10 m M ) would not support stimulation. However, addition of Li + to cultures reconstituted with 1 m M K + or Rb + revealed that this ion could enhance the phytohemagglutinin response by approximately 100% in the presence of K + and only 30% in the presence of Rb + . These data support the hypotheses that the Na,K ATPase must be active for lymphocyte stimulation to occur and that some of the biological effects of Li + on lymphocyte stimulation are mediated at the level of the Na,K ATPase.
Electrostriction tensor components of Alkaline-earth fluoride single crystals

Abstract The separated electrostriction tensor components for alkaline-earth fluoride single crystals have been measured by the converse method using the uniaxial stress dependence of the dielectric permittivity. Values obtained for the individual components of the electrostrictive voltage coefficients were M 11 = −0.116, M 12 = 0.109 and M 44 = 0.538 for SrF 2 and M 11 = −0.107, M 12 = 0.123 and M 44 = 0.594 for BaF 2 , respectively, in units of 10 −20 m 2 /V 2 . The corresponding values for CaF 2 have been reported elsewhere.
Sulfidization and flotation of chrysocolla and brochantite

Abstract A detailed investigation of the physical chemistry of interaction of oxide copper minerals, chrysocolla and brochantite, with aqueous ammonium sulfide solutions has been carried out. The principal experimental variables that have been explored are solution pH, degree of agitation, conditioning time, and sulfide ion concentration. Attempts have been made to assess the change in the surface characteristics of the minerals using gas adsorption (surface area), X-ray diffraction, and microelectrophoresis techniques. The results obtained indicate that sulfide ions interact more intensely and rapidly with oxide copper mineral at acidic pH values than at basic pH values. Sulfidization affects the surface charge characteristics of brochantite more than it does chrysocolla. The porous nature of chrysocolla is hardly reduced by sulfidization. Sulfidization followed by xanthate flotation is a very effective method for the recovery of brochantite irrespective of either sulfidization or flotation pH. Chrysocolla responds rather poorly to flotation even after sulfidization. Conditioning at acidic pH values makes chrysocolla more amenable to flotation.
The interpersonal orientation in mental health consultation: Toward a model of ethnic variations in consultation†

A model of an interpersonal orientation to consultation was proposed in an effort to conceptualize the initial response of Black consultess to the use of consultation. The model describes five stages in the consultee's approach to the entry phase of consultation, along with five corresponding dimensions of behavior evoked by the consultant. The author suggests that Blacks, due to a combination of historical circumstances and cultural and social patterns and values, initially focus more on the interpersonal aspects of the consultation relationship than on the instrumental aspects. Seven “critical incidentrs” were described to illustrate the differences between Black and White consultees in an inner-city school setting. The implications of the proposed model were discussed in terms of its applicability to other interpersonal transactions such as the therapeutic relationship, student-administrator relationships and other professional relationships. Finally, the usefulness of the concept of an interpersonal orientation which is distinct from an instrumental orientation was demonstrated.
Referral sources, diagnoses, and service types of youth in public outpatient mental health care: a focus on ethnic minorities.

Racial/ethnic variations in clinical and service delivery characteristics among youth in public outpatient mental health services were examined using data from San Diego County mental health service programs for fiscal year 1996 to 1997 (N=3,962). Differences in referral sources, primary diagnoses, and service types were investigated for three racial/ethnic groups (African Americans, Asian/Pacific Islander Americans, and Latinos) compared to non-Hispanic whites. Controlling for age, gender, functional impairment, and prior service use, significant differences by race/ethnicity were found for all three variables studied. Possible explanations for these variations and future directions for research are discussed.
230 and 492 GHz low noise sis waveguide receivers employing tuned Nb/AlOx/Nb tunnel junctions

We report results on two full height waveguide receivers that cover the 200–290 GHz and 380–510 GHz atmospheric windows. The receivers are part of the facility instrumentation at the Caltech Submillimeter Observatory on Mauna Kea in Hawaii. We have measured receiver noise temperatures in the range of 20K–35K DSB in the 200–290 GHz band, and 65–90K DSB in the 390–510 GHz atmospheric band. In both instances low mixer noise temperatures and very high quantum efficiency have been achieved. Conversion gain (3 dB) is possible with the 230 GHz receiver, however lowest noise and most stable operation is achieved with unity conversion gain.
Case report 288

Osteomalaire et hyperparathyroidisme secondaire (consecutif a la dyalise) avec depots d'aluminium
Melanocytoma of optic disc in 115 cases: the 2004 Samuel Johnson Memorial Lecture, part 1

Abstract Purpose To report clinical variations and the natural course of melanocytoma of the optic disc. Patients and methods A retrospective study was conducted on a consecutive series of patients with melanocytoma of the optic disc who were evaluated at the Ocular Oncology Service at Wills Eye Hospital. Demographic information and variations in appearance and size of the tumor and local ocular complications were noted. Frequency of tumor growth and malignant transformation was recorded. Clinical factors, including patient data and tumor features, were analyzed for their impact on visual acuity loss of 2 or more Snellen lines and the tumor growth, using Cox proportional hazards regression models. Kaplan-Meier survival estimates of probability of visual acuity loss of 2 or more Snellen lines and probability of tumor growth were performed as a function of time from the initial examination. Main outcome measures Visual acuity loss of 2 or more Snellen lines, tumor growth, and malignant transformation of the tumor. Results There were 115 patients (116 eyes) with melanocytoma of the optic disc. The mean age at diagnosis was 50 years; 38% of patients were male and 62% of patients were female; 65% of patients were white, 29% of patients were African American, and 6% of patients were Asian, Hispanic, Indian, or Arabic. The lesion was unilateral in 99% of patients. Visual symptoms that seemed to be related to the melanocytoma were present in 24% of patients, and an afferent pupillary defect was noted in 9% of patients. Associated ocular abnormalities included ocular melanocytosis (8%), racial melanosis (7%), optic nerve hypoplasia (2%), and retinitis pigmentosa (1%). The melanocytoma was dark brown to black in 100% of patients. The mean tumor diameter was 2 mm and the mean thickness was 1 mm. Associated findings included a choroidal component (54%), retinal component (30%), optic disc edema (25%), retinal edema (16%), localized subretinal fluid (14%), retinal exudation (12%), retinal hemorrhage (5%), vitreous seeds (4%), and retinal vein obstruction (3%). Fluorescein and indocyanine green angiography typically showed persistent hypofluorescence of the lesion. Using Kaplan-Meier survival curves, related visual loss occurred in 18% of patients by 10 years, and minor tumor enlargement occurred in 11% of patients by 5 years and in 32% of patients by 10 years. Malignant transformation was documented in 2 patients (2%). Conclusions Although melanocytoma of the optic disc generally is considered to be a benign, stationary lesion, it can produce several local complications, can cause visual loss, can grow slowly, and, rarely, can undergo malignant transformation into melanoma. Patients with optic disc melanocytoma should undergo periodic ocular examination.
Molecular association and the viscosity of hemoglobin solutions

Assuming that hemoglobin in solution associates isodesmically, it is possible to calculate the concentrations of the different oligomeric species at each concentration and to estimate the effect they have on the viscosity of the solution. The calculations show an increasing viscosity with concentration, and suggest a change from flexible chain to rigid rod at the higher concentrations. This could come about if higher oligomers of normal hemoglobin form coils as a result of head to tail interactions in the same chain. The association properties of human sickle hemoglobin may, therefore, be a special case of association, where the strength of the subunit interactions and the geometry of the resulting structures strongly favor the associated forms.
Prediction of Probable Pathways of Folding in Globular Proteins

A method is described for the prediction of probable folding pathways of globular proteins, based on the analysis of distance maps. It is applicable to proteins of unknown spatial structure but known amino acid sequence as well as to proteins of known structure. It is based on an objective procedure for the determination of the boundary of compact regions that contain high densities of interresidue contacts on the distance map of a globular protein. The procedure can be used both with contact maps derived from a known three-dimensional protein structure and with predicted contact maps computed by means of a statistical procedure from the amino acid sequence alone. The computed contact map can also be used to predict the location of compact short-range structures, viz. α-helices and β-turns, thereby complementing other statistical predictive procedures. The method provides an objective basis for the derivation of a theoretically predicted pathway of protein folding, proposed by us earlier [Tanaka and Scheraga (1977) Macromolecules10, 291–304; Nemethy and Scheraga (1979) Proc. Natl. Acad. Sci., U.S.A.76, 6050–6054].
The preparation and structural characterization of ruthenium carbonyl cluster complexes containing 3,3 dimethylthietane ligands

The reaction of Ru3(CO)12 with 3,3 dimethylthietane (DMT) at 68°C yielded the new tetraruthenium cluster complex Ru4(CO)12(μ-SCH2CMe2CH2)2,1 in 23% yield. Compound1 was characterized crystallographically and was shown to consist of a puckered square of four ruthenium atoms with two DMT ligands bridging opposite sides of the cluster via the sulfur atoms. Compound1 reacts with CO (98°C/1 atm) to yield the new tetraruthenium complex Ru4(CO)13 (μ-SCH2CMe2CH2),2 in 69% yield. Compound2 consists of a butterfly tetrahedral cluster of four ruthenium atoms with a DMT ligand bridging the wing-tip metal atoms. Addition of DMT to2 regenerates1 in 67% yield. Crystal data—1: space group =\(P\bar 1\),a=17.490(2) A,b=18.899(3) A,c=9.781(1) A, α=93.06(1)°, β=91.06(1)°, γ=105.239(9)°,Z=4, 5799 reflections,R=0.026; for2: space group = P21/n,a=15.430(3) A,b=18.285(4) A,c=9.850(2) A, β=90.05(2)°,Z=4, 2111 reflections,R=0.036.
Instantaneous preference was a stronger instrumental variable than 3- and 6-month prescribing preference for NSAIDs

Abstract Objective Prescriber preference has been used as an instrumental variable (IV) in a prior study of nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) vs. selective cyclooxygenase-2 (COX-2) inhibitors, with preference expressed as the drug constituting the immediately preceding prescription by the same prescriber (instantaneous preference). We sought to compare the correlations between different IV measures with exposure. Study Design and Setting In an ambulatory electronic medical record database of university-based physicians, we compared correlations with exposure among three measures of prescriber preference: instantaneous preference, and the proportion of that prescriber's prescriptions in the past 3 and 6 months that were for an NSAID. Results We identified 37,934 initial NSAID/COX-2 prescriptions. The correlation with exposure was 0.283 (95% confidence interval 0.274–0.292) for instantaneous preference, 0.197 (0.187–0.206) for 3-month preference, and 0.170 (0.160–0.180) for 6-month preference. Conclusion Instantaneous NSAID/COX-2 prescribing preference was most strongly correlated, and therefore the strongest IV. Future research should focus on the robustness of IV methods to violations of underlying assumptions, extension of IV methods to more than two groups, ratio measures of association, second and subsequent prescriptions per person, and time-varying exposures.
Domain-specific models for innovation in analytics

Big data is a transformational force for businesses and organizations of every stripe. The ability to rapidly and accurately derive insights from massive amounts of data is becoming a critical competitive differentiator so it is driving continuous innovation among business analysts, data scientists, and computer engineers. Two of the most important success factors for analytic techniques are the ability to quickly develop and incrementally evolve them to suit changing business needs and the ability to scale these techniques using parallel computing to process huge collections of data. Unfortunately, these goals are often at odds with each other because innovation at the algorithm and data model level requires a combination of domain knowledge and expertise in data analysis while achieving high scale demands expertise in parallel computing, cloud computing and even hardware acceleration. In this talk, I will examine various approaches to bridging these two goals, with a focus on domain-specific models which simultaneously improve the agility of analytics development and the achievement of efficient parallel scaling.
Mechanisms for the stimulatory and inhibitory effects of carbamoylcholine on canine gastric D-cells

We have previously reported that carbamoylcholine (carbachol), a recognized inhibitor of somatostatin release from D-cells, can act as stimulant following pretreatment of cells with pertussis toxin. In the present studies we have observed that pertussis toxin reverses the inhibitory effects of carbachol on D-cell stimulated with either cAMP or 12-0-tetradecanoyl-phorbol 13-acetate. Furthermore, the stimulatory effects of carbachol on D-cells pretreated with pertussis toxin potentiated the actions of pentagastrin without further enhancing the release of 3 H-inositol trisphosphate from prelabeled cells. These studies suggest that carbachol exerts its inhibitory effects on D-cells via pertussis toxin sensitive guaninine nucleotide binding proteins at a point distal to the activation of different signal transduction mechanisms and that the stimulatory effects of carbachol are mediated by mechanisms that are independent of membrane phosphoinositide turnover.
System design considerations for sensor network applications

Systems research in the emerging space of wireless sensor networks has exploded. Researchers have deployed nodes composed of a wireless radio, MEMS sensors and low power computation for applications from medical sensing to volcanic monitoring. We must consider several requirements - including the need for inexpensive, long-lasting, highly reliable devices coupled with very low performance requirements - when designing devices for wireless sensor networks. An untethered, fully-integrated node that operates off of energy scavenged from the ambient environment is the ultimate goal. We take an application-driven approach to the design of a wireless sensor network node. Our approach addresses the event-driven nature that is characteristic of many sensor network workloads. We have completed a detailed architectural analysis of this space using a full-system simulator and RTL model. From this analysis, we chose to implement a design that best achieves the power goals and performance requirements of wireless sensor network applications.
Reproductive system of the obese male zucker rat. Reproductive capacity, artificial insemination and plasma testosterone levels.

The sexual behavior of obese and lean male Zucker rats placed with receptive lean female rats was evaluated longitudinally. At 3 to 4 months of age and at 5 to 8 months of age, obese males intromitted less consistently than lean males and fewer obese males ejaculated during the observation periods. By 9 to 12 months of age, none of the obese males were sexually active during the observation period. More obese males ejaculated if left overnight with receptive females. However, at all ages studied, the pregnancy rate for females left overnight with obese males was lower than that for females left overnight with lean males. Sperm from obese and lean male rats was used to artificially inseminate proestrous lean female rats. The pregnancy rate was similar for females artificially inseminated with sperm from obese versus lean males. Even sperm from obese males which previously had failed to naturally inseminate lean females was successfully used to artificially inseminate lean females. Furthermore, the number of implanted embryos was similar for females inseminated, naturally or artificially, with sperm from obese versus lean males. These findings support the suggestion that sperm from obese males is normal in fertilizing capability, and suggest that inadequate sexual behavior is the primary factor limiting their reproductive capacity. Plasma testosterone levels in obese and lean rats were measured by radioimmunoassay. Plasma levels were lower in obese males 8 to 12 months of age compared to lean males of comparable age, and compared to obese males 3 to 6 months of age. However, reduced plasma testosterone levels cannot account for the reproductive inadequacy of obese male Zucker rats since sexual behavior was inadequate and the natural insemination rate was reduced at 3 to 4 months of age despite normal plasma testosterone levels. Furthermore, testosterone levels in obese males are adequate to maintain normal spermatogenesis. The reproductive defect in obese male Zucker rats appears to be behavioral rather than functional.
Pharmacological Treatment of the Overweight Patient

To use medications properly for treatment of the overweight patient, it is important to start with a framework based on the realities associated with this treatment. These are briefly summarized below: 1. Overweight is due to an imbalance between energy intake and energy expenditure. 2. Drugs
A Real Time Data Compactor (Sparsifier) and 8 Megabyte High Speed Fifo for Hep.

A Video-Data-Acquisition-System (VDAS) has been developed to record image data from a scintillating glass fiber-optic target developed for High Energy Physics.[1],[2] The major components of the VDAS are a flash ADC, a "real time" high speed data compactor, and high speed 8 megabyte FIFO memory. The data rates through the system are in excess of 30 megabytes/second. The compactor is capable of reducing the amount of data needed to reconstruct typical images by as much as a factor of 20. The FIFO uses only standard NMOS DRAMS and TTL components to achieve its large size and high speed at relatively low power and cost.
Design of a Motion Compensated Tissue Resection Catheter for Beating Heart Cardiac Surgery

Cardiac catheters allow clinicians to minimally invasively interact with the beating heart without stopping the heart or opening the chest. However, the fast motion of the intracardiac structures makes it difficult to modify and repair the tissue in a controlled and safe manner. To enable surgical procedures on the inside of the beating heart, we have developed an ultrasound-guided catheter system that virtually freezes the heart by compensating for the fast cardiac motions. The device presented in this paper is a resection tool that allows the catheter system to cut moving tissue, a key surgical task required for many intracardiac procedures including valve and leaflet repair. The motion tracking system is demonstrated in vivo and the tissue resection tool is evaluated by resecting tissue mounted on a cardiac motion simulator. The motion compensated catheter is shown to greatly improve the resection cut quality on the moving tissue target while reducing the forces experienced by the tissue by almost 80%.
Effect of Dibromoacetic Acid on DNA Methylation, Glycogen Accumulation, and Peroxisome Proliferation in Mouse and Rat Liver

Dibromoacetic acid (DBA) is a drinking water disinfection by-product. Its analogs, dichloroacetic acid (DCA) and trichloroacetic acid (TCA), are liver carcinogens in rodents. We evaluated the ability of DBA to cause DNA hypomethylation, glycogen accumulation, and peroxisome proliferation that are activities previously reported for the two other haloacetic acids. Female B6C3F1 mice and male Fischer 344 rats were administered 0, 1,000, and 2,000 mg/l DBA in drinking water. The animals were euthanized after 2, 4, 7, and 28 days of exposure. Dibromoacetic acid caused a dose-dependent and time-dependent decrease of 20%-46% in the 5-methylcytosine content of DNA. Hypomethylation of the c-myc gene was observed in mice after 7 days of DBA exposure. Methylation of 24 CpG sites in the insulin-like growth factor 2 (IGF-II) gene was reduced from 80.2% +/- 9.2% to 18.8% +/- 12.9% by 2,000 mg/l DBA for 28 days. mRNA expression of the c-myc and IGF-II genes in mouse liver was increased by DBA. A dose-dependent increase in the mRNA expression of the c-myc gene was also observed in rats. In both mice and rats, DBA caused dose-dependent accumulation of glycogen and an increase of peroxisomal lauroyl-CoA oxidase activity. Hence, DBA, like DCA and TCA, induced hypomethylation of DNA and of the c-myc and IGF-II genes, increased mRNA expression of both genes, and caused peroxisome proliferation. Again like DCA, DBA also induced glycogen accumulation. These results indicate that DBA shares biochemical and molecular activities in common with DCA and/or TCA, suggesting that it might also be a liver carcinogen.
Public and private prenatal care providers in urban Mexico: how does their quality compare?

Objective. To evaluate variations in prenatal care quality by public and private clinical settings and by household wealth. Design. The study uses 2003 data detailing retrospective reports of 12 prenatal care procedures received that correspond to clinical guidelines. The 12 procedures are summed up, and prenatal care quality is described as the average procedures received by clinical setting, provider qualifications, and household wealth. Setting. Low-income communities in 17 states in urban Mexico. Participants. A total of 1253 women of reproductive age who received prenatal care within 1 year of the survey. Main outcome measure. The mean of the 12 prenatal care procedures received, reported as unadjusted and adjusted for individual, household, and community characteristics. Results. Women received significantly more procedures in public clinical settings [80.7, 95% confidence interval (CI) = 79.3–82.1; P ≤ 0.05] compared with private (60.2, 95% CI = 57.8–62.7; P ≤ 0.05). Within private clinical settings, an increase in household wealth is associated with an increase in procedures received. Care from medical doctors is associated with significantly more procedures (78.8, 95% CI = 77.5–80.1; P ≤ 0.05) compared with non-medical doctors (50.3, 95% CI = 46.7–53.9; P ≤ 0.05). These differences are independent of individual, household, and community characteristics that affect health-seeking behavior. Conclusions. Significant differences in prenatal care quality exist across clinical settings, provider qualifications, and household wealth in urban Mexico. Strategies to improve quality include quality reporting, training, accreditation, regulation, and franchising.
Contributions of processing ability and knowledge to verbal memory tasks across the adult life-span.

This study investigated the relationships of processing capacity and knowledge to memory measures that varied in retrieval difficulty and reliance on verbal knowledge in an adult life-span sample (...
A Nine-point Algorithm for Estimating Para-Catadioptric Fundamental Matrices

We present a minimal-point algorithm for finding fundamental matrices for catadioptric cameras of the parabolic type. Central catadioptric cameras-an optical combination of a mirror and a lens that yields an imaging device equivalent within hemispheres to perspective cameras-have found wide application in robotics, tele-immersion and providing enhanced situational awareness for remote operation. We use an uncalibrated structure-from-motion framework developed for these cameras to consider the problem of estimating the fundamental matrix for such cameras. We present a solution that can compute the para-catadioptirc fundamental matrix with nine point correspondences, the smallest number possible. We compare this algorithm to alternatives and show some results of using the algorithm in conjunction with random sample consensus (RANSAC).
T-cell co-stimulatory blockade in kidney transplantation: back to the bench

It is believed that blocking positive T-cell co-stimulatory pathways should lead to long-term graft acceptance. Despite the exciting initial achievements in experimental animal models, targeting co-stimulatory pathways has shown to be much more complex in the clinic. In addition to multiple binding partners, some co-stimulatory interactions have been found to be inhibitory in nature, whereas others were demonstrated to be important in the development of regulatory T cells. Moreover, memory T cells have been shown to be resistant to co-stimulation blockade. Herein we focus on the B7:CD28 pathway and describe the evolution of targeting this pathway with cytotoxic T-lymphocyte antigen-4-Ig from bench to clinic. We also attempt to address possible causes for the unexpected high rejection rate observed in the phase III clinical trials with belatacept, using experimental data obtained from basic science research.
Distributed vector modulation for broadband phase control

A high-performance phase shifter based on vector phase modulation was designed using a segmented dual-gate distributed amplifier MMIC (monolithic microwave integrated circuit). The phase shifter has equalled the widest instantaneous bandwidth yet reported (4.5-18 GHz). This device exhibits excellent phase error, VSWR (voltage standing wave ratio), and amplitude variation characteristics. >
Too Much of a Good Thing? Tim-3 and TCR Signaling in T Cell Exhaustion

T cell exhaustion is thought to be a natural mechanism for limiting immune pathology, although it may be desirable to circumvent this mechanism to help eliminate viral reservoirs or tumors. Although there are no definitive markers, a fingerprint for exhausted T cells has been described that includes the transmembrane proteins PD-1, LAG3, and Tim-3. However, apart from the recruitment of tyrosine phosphatases to PD-1, little is known about the biochemical mechanisms by which these proteins contribute to the development or maintenance of exhaustion. Tim-3 contains no known motifs for the recruitment of inhibitory phosphatases, but it may actually increase signaling downstream of TCR/CD3, at least under acute conditions. Other studies showed that T cell exhaustion results from chronic stimulation that extends the effector phase of T cell activation, at the expense of T cell memory. We suggest that Tim-3 may contribute to T cell exhaustion by enhancing TCR-signaling pathways.