cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of total body potassium with other techniques for measuring lean body mass in men and women with AIDS wasting

BACKGROUND Lean body mass is an important predictor of survival and functional status in patients with AIDS wasting. The bias between different techniques for assessing body composition in AIDS wasting is not known. DESIGN We compared total body potassium (TBK) with fat-free mass (FFM) determined by dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and skinfold-thickness measurement (SKF) in 132 patients (63 men, 69 women) with AIDS wasting (weight 10% of original, or both). None of the subjects exhibited clinical lipodystrophy. Comparisons were made by using different BIA equations. RESULTS Lean body mass determined by DXA was highly correlated with TBK in men (r = 0.79, P: < 0.0001) and women (r = 0.84, P: < 0.0001). FFM(BIA) and FFM(DXA) were significantly different (P: < 0.01 in men and P: < 0.0001 in women). The difference between FFM(DXA) and FFM(BIA) was significantly greater with greater weight and body fat, particularly in HIV-infected women (r = -0.39, P: = 0.001 for weight; r = -0.60, P: < 0.0001 for fat). The comparability of FFM and fat mass determined by DXA and BIA was dependent on the specific BIA equation used. Among men, no single BIA equation was more highly predictive of fat mass and FFM in comparison with DXA. CONCLUSIONS The differences between DXA, BIA, and SKF in the determination of fat mass and FFM are significant in patients with AIDS wasting. BIA overestimates FFM compared with DXA in those with greater body fat. Standard BIA equations may not accurately estimate FFM and fat mass in men and women with AIDS wasting.
Two monomers of yeast transcription factor ADR1 bind a palindromic sequence symmetrically to activate ADH2 expression.

ADR1 is a transcription factor from Saccharomyces cerevisiae that regulates ADH2 expression through a 22-bp palindromic sequence (UAS1). Size fractionation studies revealed that full-length ADR1 and a truncated ADR1 protein containing the first 229 amino acids, which has the complete DNA-binding domain, ADR1:17-229, exist as monomers in solution. However, two complexes were formed with target DNA-binding sites. UV-cross-linking studies suggested that these two complexes represent one and two molecules of ADR1 bound to DNA. Studies of ADR1 complexes formed with wild-type UAS1, asymmetrically altered UAS1, and one half of UAS1 showed that ADR1 can bind to one half of UAS1 and gives rise to a complex containing one molecule of ADR1. Dimethyl sulfate interference studies were consistent with this interpretation and in addition indicated that purine contact sites in each half of UAS1 were identical. Increasing the distance between the two halves of UAS1 had at most a minor effect of the thermodynamics of formation of the two complexes. These data are more consistent with ADR1 binding as two independent monomers, one to each half of UAS1. However, binding of two ADR1 monomers at UAS1 is apparently essential for transactivation in vivo. Further, we have identified a stretch of 18more » amino acid residues amino terminal to the zinc two-finger domains of ADR1 which is essential for DNA-binding activity. Single amino acid substitutions of residues in this region resulted in severely reduced DNA-binding activity.« less
Instruments and methods for measuring the backward-scattering coefficient of ocean waters

The backward-scattering coefficient bb is an important optical property that plays a central role in studies of ocean-color remote sensing, suspended particle distributions, water clarity, and underwater visibility. We investigate the fixed-angle backscattering sensor approach for the application of measuring bb . Analysis shows that the sensor response to volume scattering can be expressed as the integral of the volume scattering function (VSF) over the backward angles (90 -180 degrees ) weighted by the sensor-response function. We present a procedure for determining the sensor-response function that contains all the information necessary to calibrate the sensor fully to measure the VSF at a nominal backscattering angle. It is shown that, for fixed-angle backscattering sensors,bb is most accurately estimated when the sensor-response function covers the middle range of backscattering angles, roughly 110 -160 degrees , where the shape of the VSF has the least variability. Backscattering at and near the end angles, namely, 90 degrees and 180 degrees , are least correlated with bb . We describe a variety of spectral backscattering sensors that we have developed, and we present their sensor-response functions.
Change in ozone trends at southern high latitudes

Long-term ozone variations at 60-70degS in spring are investigated using ground-based and satellite measurements. Strong positive correlation is shown between year-to-year variations of ozone and temperature in the Antarctic collar region in Septembers and Octobers. Based on this relationship, the effect of year-to-year variations in vortex dynamics has been filtered out. This process results in an ozone time series that shows increasing springtime ozone losses over the Antarctic until the mid-1990s. Since approximately 1997 the ozone losses have leveled off. The analysis confirms that this change is consistent across all instruments and is statistically significant at the 95% confidence level. This analysis quantifies the beginning of the recovery of the ozone hole, which is expected from the leveling off of stratospheric halogen loading due to the ban on CFCs and other halocarbons initiated by the Montreal Protocol.
The Air Apparent: A Rare Complication During Flexible Bronchoscopy

Flexible bronchoscopy is a common and safe outpatient procedure, with complications arising in less than 1% of cases. The case presented herein details the occurrence of pneumomediastinum, pneumopericardium, pneumoperitoneum, interstitial lung emphysema and subcutaneous emphysema during flexible bronchoscopy. Although these complications have been reported individually in various circumstances, they have not been reported concomitantly in this setting. Recovery was rapid and complete, requiring only supplemental oxygen and monitoring. After a literature and chart review, the authors postulate that the complications were not a direct result of bronchoscopy but rather the simple act of placing an oxygen delivery cannula in a patient with possible prior trauma to the site.
Finite element reliability analysis of fatigue life

Abstract Fatigue reliability is addressed by the first-order reliability method combined with a finite element method. Two-dimensional finite element models of components with cracks in mode I are considered with crack growth treated by the Paris law. Probability density functions of the variables affecting fatigue are proposed to reflect a setting where nondestructive evaluation is used, and the Rosenblatt transformation is employed to treat non-Gaussian random variables. Comparisons of the first-order reliability results and Monte Carlo simulations suggest that the accuracy of the first-order reliability method is quite good in this setting. Results show that the upper portion of the initial crack length probability density function is crucial to reliability, which suggests that if nondestructive evaluation is used, the probability of detection curve plays a key role in reliability.
Electrical Properties of Sodium Tungsten Bronze

With the addition of sodium atoms the ferroelectric insulator W${\mathrm{O}}_{3}$ acquires metallic properties. We have grown single crystals of ${\mathrm{Na}}_{x}{\mathrm{WO}}_{3}$ using a method developed at the Linde Air Products Company. Chemical analyses for sodium concentration showed $x=0.66$. The electrical resistivity was found to have a value of (1.9\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ ohm-cm at 0\ifmmode^\circ\else\textdegree\fi{}C and to decrease approximately linearly with decreasing temperature in the range 20\ifmmode^\circ\else\textdegree\fi{}C to -160\ifmmode^\circ\else\textdegree\fi{}C. The Hall coefficient was found to have a value of (-5.1\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ ${\mathrm{cm}}^{3}$/coulomb at 20\ifmmode^\circ\else\textdegree\fi{}C and to decrease slightly with decreasing temperature. This value for the Hall coefficient indicates one electron carrier for each sodium atom added to the crystal. Using Pauli's theory of paramagnetism for free electrons in simple metals the calculated magnetic susceptibility is 0.53\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$. The value observed by Stubbin and Mellor for a sodium concentration corresponding to $x=0.9$ was 0.45\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$. Using the free electron theory of metals, the following properties have been calculated: electron mobility and mean free path, energy at the surface of the Fermi distribution, thermal conductivity, and electronic specific heat.
Inelastic collisions between selectively excited rubidium 6/sup 2/D-state atoms and noble-gas atoms: Fine-structure-state mixing

Inelastic collisional processes in fine-structure-state mixing have been studied by selective stepwise excitation and observation of the resulting fluorescence during collisions of excited rubidium 6/sup 2/D/sub 5/2/ state atoms with various noble-gas atoms. It is shown that for intermediately excited rubidium atoms the fine-structure-state mixing cross sections are generally p increasing from helium to xenon. The cross sections for the process Rb(6/sup 2/D/sub 5/2/)+A(n /sup 1/S/sub 0/)..-->..Rb(6/sup 2/D/sub 3/2/)+ A(n /sup 1/S/sub 0/)+..delta..E /sup 1/S/sub 0/)+..delta..E have the values sigma/sub fs/( = 2.4 +- 0.9, 3.1 +- 1.2, 2.6 +- 1.0, 5.8 +- 2.2, and 9.3 +- 5.6 in units of 10/sup -14/ cm/sup 2/, where A denotes in sequence any one of the noble gas atoms He, Ne, Ar, Kr, and Xe, respectively. Transfer cross sections for the transfer of excited Rb6 /sup 2/D-state atoms out of the doublet were also determined and are about an order of magnitude smaller than the fine-structure-mixing cross sections.
Perinatal Rat Lung Retinol (Vitamin A) and Retinyl Palmitate

The potential role for retinol (vitamin A alcohol) in the differentiation of the developing lung prompted this study in the perinatal rat. High performance liquid chromatography was used to separate, detect, and quantitate retinol and retinyl palmitate in lipid extracts of tissue and serum. Fetal and maternal blood showed the presence of retinol, whereas no retinyl palmitate was detected. On the other hand, fetal and postnatal lungs contained retinyl palmitate as well as retinol. Considerable changes in the content of lung retinyl palmitate were found during lung development. Fetal lungs (17-21 days of gestation) contained 2.3 +/- 0.36 micrograms/g wet weight (mean +/- SD) of retinyl palmitate and 0.14 +/- 0.05 micrograms/g of retinol. Lungs of pups (1-10 days old) contained much less retinyl palmitate, 0.63 +/- 0.20 micrograms/g, whereas the amount of retinol was the same as in fetal lungs. The surprisingly high content of retinyl palmitate in fetal lung and its depletion after birth may be functionally related to retinol action in the developing lung.
Channeling and dechanneling at high energy

Abstract The possibility of using channeling as a tool for high energy particle physics has now been extensively investigated. Bent crystals have been used as an accelerator extraction element and for particle deflection. Applications as accelerating devices have been discussed but appear remote. The major advantage in using a bent crystal rather than a magnet is the large deflection that can be achieved in a short length. The major disadvantage is the low transmission. A good understanding of dechanneling is important for applications.
Expansion of a restricted residual host T reg-cell repertoire is dependent on IL-2 following experimental autologous hematopoietic stem transplantation.

We previously identified a population of residual Treg cells following autologous hematopoietic stem transplantation (HSCT), that rapidly undergoes significant expansion in lymphopenic transplant recipients prior to repopulation by donor de novo derived Treg cells. These CD4+Foxp3+ T cells provide protection from the development of autoimmune disease. Although ablative conditioning results in excess IL-7 and IL-15, IL-2 is typically not found at high levels following autologous HSCT. We therefore examined the role of these three STAT-5 signaling cytokines in the expansion of residual Treg cells after autologous HSCT. The present study found that the residual Treg cell population included surviving peripheral host Foxp3+CD4+ T cells whose expansion was critically dependent on IL-2, which could be solely provided by surviving host cells. IL-7 was found to contribute to Treg cell homeostasis, however, not as a growth factor but rather for their persistence. In conjunction with this expansion, TCR spectratype analyses revealed that the residual host Treg-cell compartment differed from that present in non-conditioned healthy mice since the residual host Treg cells exhibit a limited TCR diversity. Collectively, these data indicate that the proliferation of Treg and T effector (Teff) cells post-HSCT utilize separate pools of cytokines which has important implications regarding the development of clinical strategies to elicit the desired immune responses in patients post-transplant.
Imapct of systems ambiguity on guideline compliance in intensive care units

Health care associated infections (HAI) in intensive care units (ICU) can be significantly reduced or eliminated by increasing care providers’ compliance with evidence-based guidelines. Using a human factors and systems engineering approach, we conducted a qualitative study to identify the underlying causes of non-compliance with evidence-based guidelines for preventing four types of HAI in ICUs.
The involvement of extracellular enzymes in the metabolism of Bdellovibrio.

1. Three host-independent (H-I)Bdellovibrio species are stimulated in growth by addition to the medium of cell-free host extracts. A mixture of fifteen labeled amino acids was used to follow incorporation of counts into trichloroacetic acid (TCA) insoluble material. No label was recovered in the nucleic acids. 2. LabeledEscherichia coli RNA, protein, andAeromonas DNA preparations were hydrolyzed byBdellovibrio extracellular enzymes. The hydrolyzed protein or nucleic acids were added to a host free medium and inoculated withBdellovibrio. The amount of uptake and TCA precipitable counts in stationary phase cells was then determined. From these studies it has been demonstrated thatBdellovibrio extracellular enzymes hydrolyze host macromolecules to products which are subsequently used in the biosynthetic pathways ofBdellovibrio. 3. It is also suggested thatBdellovibrio cannot synthesize their own nucleotide bases, since neither14C-glycine nor3H-aspartic acid was incorporated into hot TCA soluble material.
Explorer XXXI total current monitor experiments

Measurements have been made of the suprathermal electron flux by means of retarding potential analyzers on Explorer XXXI. Samples of various types of data are presented and some of the analysis procedures are discussed. Detailed analyses of particle flux measurements obtained in the energy range 7 eV to 200 eV are presented for the data from three spacecraft transits of the polar region. The integral flux and derived differential velocity distributions yield the result that in the polar trough region there is an enhanced energy density of the suprathermal particles, with a value comparable to that of the ambient thermal plasma. At lower latitudes, the pressure of suprathermal particles is significantly less than that of the thermal plasma.
A digital pulse-pair detecting circuit

Abstract A completely digital pulse-pair detecting circuit is described. The inspection interval ranges from approximately 100 ns to 1.3 ms in steps of 20 ns. tests of the circuit indicate reliable operation at input rates up to 25 MHz.
AIDS‐Related Dementia and Calcium Homeostasisa

Approximately a third of adults and half of children with acquired immunodeficiency syndrome (AIDS) eventually suffer from neurological manifestations, including dysfunction of cognition, movement, and sensation. Among the various pathologies reported in the brain of patients with AIDS is neuronal injury and loss. A paradox arises, however, because neurons themselves are for all intents and purposes not infected by human immunodeficiency virus type 1 (HIV-1). This paper reviews evidence suggesting that at least part of the neuronal injury observed in the brain of AIDS patients is related to excessive influx of Ca2+. There is growing support for the existence of HIV- or immune-related toxins that lead indirectly to the injury or death of neurons via a potentially complex web of interactions between macrophages (or microglia), astrocytes, and neurons. Human immunodeficiency virus-infected monocytoid cells (macrophages, microglia, or monocytes), especially after interacting with astrocytes, secrete substances that potentially contribute to neurotoxicity. Not all of these substances are yet known, but they may include eicosanoids, that is, arachidonic acid and its metabolites, as well as platelet-activating factor. Macrophages activated by HIV-1 envelope protein gp120 also appear to release arachidonic acid and its metabolites. These factors can lead to increased glutamate release or decreased glutamate reuptake. In addition, gamma interferon (IFN-gamma) stimulation of macrophages induce release of the glutamate-like agonist quinolinate. Human immunodeficiency virus-infected or gp120-stimulated macrophages also produce cytokines, including tumor necrosis factor-alpha and interleukin-1 beta, which contribute to astrogliosis. A final common pathway for neuronal susceptibility appears to be operative, similar to that observed in stroke, trauma, epilepsy, neuropathic pain, and several neurodegenerative diseases, possibly including Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This mechanism involves the activation of voltage-dependent Ca2+ channels and N-methyl-D-aspartate (NMDA) receptor-operated channels, and therefore offers hope for future pharmacological intervention. This review focuses on clinically tolerated calcium channel antagonists and NMDA antagonists with the potential for trials in humans with AIDS dementia in the near future.
Observations of deep convective influence on stratospheric water vapor and its isotopic composition

[1] In situ observations of H2O and HDO in the midlatitude stratosphere are used to evaluate the role of convection in determining the stratospheric water budget. The observations show that water vapor in the overworld stratosphere (potential temperature > 380 K) is isotopically heavier than expected. Measurements in an airmass with anomalously high concentrations of water vapor show isotopic water signatures that are characteristic of evaporated ice lofted from the troposphere during convective storms. Observed H2O and HDO concentrations in the plume of enhanced water and in the background stratosphere suggest that extratropical convection can account for a significant fraction of the observed water vapor in the summertime overworld stratosphere above the mid-North American continent.
A Preliminary Investigation of a Telephone Administration of the Quality of Marriage Index

Follow-up data collection presents many challenges for longitudinal research. Validating paper-and-pencil assessments for use via telephone may alleviate these issues. This study evaluates psychometric properties of the Quality of Marriage Index (QMI; Norton, 1983, Journal of Marriage and the Family, 45, 141) when administered by telephone and compares scores with the paper-and-pencil version. Participants included women with major depressive disorder and dyadic discord and their male spouses (n = 24 couples). Results suggest excellent scale reliability for the verbal QMI. However, a significant mean difference was found: participants scored on average 3 points higher on the telephone-administered QMI than on the written QMI. Recommendations for future research and clinical implications are discussed.
Probabilistic Prediction Models for Aggregate Quarry Siting

Weights-of-evidence (WofE) and logistic regression techniques were used in a GIS framework to predict the spatial likelihood (prospectivity) of crushed-stone aggregate quarry development. The joint conditional probability models, based on geology, transportation network, and population density variables, were defined using quarry location and time of development data for the New England States, North Carolina, and South Carolina, USA. The Quarry Operation models describe the distribution of active aggregate quarries, independent of the date of opening. The New Quarry models describe the distribution of aggregate quarries when they open. Because of the small number of new quarries developed in the study areas during the last decade, independent New Quarry models have low parameter estimate reliability. The performance of parameter estimates derived for Quarry Operation models, defined by a larger number of active quarries in the study areas, were tested and evaluated to predict the spatial likelihood of new quarry development. Population density conditions at the time of new quarry development were used to modify the population density variable in the Quarry Operation models to apply to new quarry development sites. The Quarry Operation parameters derived for the New England study area, Carolina study area, and the combined New England and Carolina study areas were all similar in magnitude and relative strength. The Quarry Operation model parameters, using the modified population density variables, were found to be a good predictor of new quarry locations. Both the aggregate industry and the land management community can use the model approach to target areas for more detailed site evaluation for quarry location. The models can be revised easily to reflect actual or anticipated changes in transportation and population features.
The Historical Evolution of Thought Regarding Multiple Micronutrient Nutrition

Multiple micronutrient nutrition is an idea that originated in the 1940s and exemplifies the iterative nutritional paradigm. In the first four decades of the 20th century, scientists sought to separate and characterize the vitamins that were responsible for xerophthalmia, rickets, pellagra, scurvy, and beriberi. The dietary requirements of the different micronutrients began to be established in the early 1940s. Surveys showed that multiple micronutrient deficiencies were widespread in industrialized countries, and the problem was addressed by use of cod-liver oil, iodized salt, fortified margarine, and flour fortification with multiple micronutrients, and, with rising living standards, the increased availability and consumption of animal source foods. After World War II, surveys showed that multiple micronutrient deficiencies were widespread in developing countries. Approaches to the elimination of multiple micronutrient deficiencies include periodic vitamin A supplementation, iodized salt, targeted iron/folate supplementation, fortified flour, other fortified foods, home fortification with micronutrient powders, and homestead food production. The prevention of multiple micronutrient malnutrition is a key factor in achieving the Millennium Development Goals, given the important effects of micronutrients on health and survival.
SABOT: specification-based payload generation for programmable logic controllers

Programmable Logic Controllers (PLCs) drive the behavior of industrial control systems according to uploaded programs. It is now known that PLCs are vulnerable to the uploading of malicious code that can have severe physical consequences. What is not understood is whether an adversary with no knowledge of the PLC's interface to the control system can execute a damaging, targeted, or stealthy attack against a control system using the PLC. In this paper, we present SABOT, a tool that automatically maps the control instructions in a PLC to an adversary-provided specification of the target control system's behavior. This mapping recovers sufficient semantics of the PLC's internal layout to instantiate arbitrary malicious controller code. This lowers the prerequisite knowledge needed to tailor an attack to a control system. SABOT uses an incremental model checking algorithm to map a few plant devices at a time, until a mapping is found for all adversary-specified devices. At this point, a malicious payload can be compiled and uploaded to the PLC. Our evaluation shows that SABOT correctly compiles payloads for all tested control systems when the adversary correctly specifies full system behavior, and for 4 out of 5 systems in most cases where there where unspecified features. Furthermore, SABOT completed all analyses in under 2 minutes.
Epitaxial growth of body-centered-cubic nickel on iron

Abstract Studies by low-energy electron diffraction (LEED) and Auger electron spectroscopy of nickel films grown in ultra-high vacuum onto a clean Fe{001} surface show that the films have the body-centered cubic structure with the same lattice constant and the same multilayer relaxation as the clean substrate, as long as they are thinner than about 6 layers. LEED intensity analyses show that the multilayer relaxation of both clean Fe{001} and 3-layer thick Ni films involves 5% contraction of the first and 5% expansion of the second interlayer spacing. These new values of the multilayer relaxation of clean Fe{001} represent an improvement over previous determinations. Thicker Ni films, up to 100 layers, have a complicated structure that is neither b.c.c. nor f.c.c. Short anneals at temperatures between 200 and 650°C cause rapid diffusion of Ni into the Fe substrate with little evidence for formation of the stable f.c.c. phase of Ni.
Surface atomic vacancies created by ion bombardment and desorption

Abstract Scanning tunneling microscopy (STM) images of Si(100−(2 × 1) surfaces bombarded by low-dose 3 keV Ar+ ions show random missing Si dimer vacancies which order into line-vacancies perpendicular to the dimer rows upon annealing to 600–850°C. STM images also show the creation of dimer vacancies by desorption on the Si(100)−(2 × 1) surface when it reacts with molecular oxygen and atomic hydrogen forming volatile SiO and SiH4 respectively. For the oxygen case, the reaction takes place at temperatures between 600 and 700°C; while for the atomic hydrogen case, the reaction takes place at room temperature followed by annealing to 550°C. In both cases, line-vacancies perpendicular to the dimer rows similar to ion bombardment are observed. Irrespective of the method of creation of dimer vacancies, their ordering into lines can be explained theoretically by a long-range repulsion between vacancies located in the same dimer row and a slight attraction between vacancies in adjacent rows. The formation of vacancy lines is thus thermodynamically driven but kinetically controlled.
Development of a calcium-sensing receptor molecular imaging agent.

Background Calcium-sensing receptor (CaSR) is expressed by parathyroid cells and thyroid C-cells (from which medullary thyroid carcinoma [MTC] is derived). A molecular imaging agent localizing to the CaSR could improve the detection of parathyroids and MTC preoperatively or intraoperatively. We synthesized a novel compound containing a fluorine residue for potential future labeling and demonstrated that the compound inhibited CaSR function in vitro. Methods We synthesized compound M, a derivative of a known calcilytic compound, Calhex-231. Human embryonic kidney cells transfected with green-fluorescent protein-tagged CaSR or control vector were preincubated with compound M before the addition of calcium. Immunoblotting for total mitogen-activated protein kinase (MAPK: ERK1/2), activated MAPK (phosphorylated ERK1/2), and glyceraldehyde 3-phosphate dehydrogenase was performed. Results Synthesis of compound M was confirmed by mass spectrometry. Inhibition of the MAPK signaling pathway by compound M was demonstrated in a dose-dependent manner by a decrease in phosphorylated ERK1/2 with no change in total ERK1/2 levels. Compound M inhibited MAPK signaling slightly better than the parent compound. Conclusion We have developed a novel molecule which demonstrates functional inhibition of CaSR and has a favorable structure for labeling. This compound appears to be appropriate for further development as a molecular imaging tool to enhance the surgical treatment of parathyroid disease and MTC.
Cholesterol-Phospholipid Association in Fluid Bilayers: A Thermodynamic Analysis from Nearest-Neighbor Recognition Measurements

The mixing behavior of exchangeable, disulfide-based mimics of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol has been examined as a function of temperature in host membranes made from DPPC and cholesterol in the liquid-disordered phase (ld), in the liquid-ordered phase (lo), and in the liquid-disordered/liquid-ordered coexistence region (ld/lo). In the ld region, lipid mixing was found to be temperature insensitive, reflecting close to ideal behavior. In contrast, a significant temperature dependence was observed in the lo phase from 45 to 60 degrees C, when 35 or 40 mol % sterol was present. In this region, sterol-phospholipid association was characterized by DeltaHo = -2.06 +/- 0.14 kcal/mol of phospholipid and DeltaS degrees = -4.48 +/- 0.44 cal/K mol of phospholipid. From 60 to 65 degrees C, the mixing of these lipids was found to be insensitive to temperature, and sterol-phospholipid association was now entropy driven; that is, DeltaHo = -0.23 +/- 0.38 kcal/mol of phospholipid and DeltaS degrees = +1.68 +/- 1.12 cal/K mol of phospholipid. In the liquid-disordered/liquid-ordered coexistence region, changes in lipid mixing reflect changes in the phase composition of the membrane.
Methionine sulfoxide reductases: ubiquitous enzymes involved in antioxidant defense, protein regulation, and prevention of aging-associated diseases.

Abstract Oxidative damage to proteins is considered to be one of the major causes of aging and age-related diseases, and thus mechanisms have evolved to prevent or reverse these modifications. Methionine is one of the major targets of reactive oxygen species (ROS), where it is oxidized to methionine sulfoxide (MetO). Recently, evidence has accumulated suggesting that methionine (Met) oxidation may play an important role in the development and progression of neurodegenerative diseases like Alzheimer's and Parkinson's diseases. Oxidative alteration of Met to Met(O) is reversed by the methionine sulfoxide reductases (consisting of MsrA enzymes that reduce S-MetO and MsrB enzymes that reduce R-MetO, respectively). A major biological role of the Msr system is suggested by the fact that the MsrA null mouse (MT) exhibits a neurological disorder in the form of ataxia (“tip toe walking”), is more sensitive to oxidative stress, and has a shorter life span (by ∼40%) than wild-type (WT) mice. By their action, the Msr enzymes can regulate protein function, be involved in signal-transduction pathways, and prevent cellular accumulation of faulty proteins. Malfunction of the Msr system can lead to cellular changes resulting in compromised antioxidant defense, enhanced age-associated diseases involving neurodegeneration, and shorter life span. In this review, the function and possible roles of the Msr system in prokaryotes and eukaryotes, in general, and in neurodegenerative diseases, in particular, will be discussed.
Investigation of High-Temperature Printed Circuit Heat Exchangers for Very High Temperature Reactors

Very high-temperature reactors require high-temperature (900-950°C) and high-integrity heat exchangers with high effectiveness during normal and off-normal conditions. A class of compact heat exchangers, namely the printed circuit heat exchangers (PCHEs), made of high-temperature materials and found to have these above characteristics, are being increasingly pursued for heavy duty applications. A high-temperature helium test facility, primarily aimed at investigating the heat transfer and pressure drop characteristics of the PCHEs, was designed and is being built at Ohio State University. The test facility was designed to facilitate operation at temperatures and pressures up to 900°C and 3 MPa, respectively. Owing to the high operating conditions, a detailed investigation on various high-temperature materials was carried out to aid in the design of the test facility and the heat exchangers. The study showed that alloys 617 and 230 are the leading candidate materials for high-temperature heat exchangers. Two PCHEs, each having 10 hot plates and 10 cold plates, with 12 channels in each plate, were fabricated from alloy 617 plates and will be tested once the test facility is constructed. Simultaneously computational fluid dynamics calculations have been performed on a simplified PCHE model, and the results for three flow rate cases of 15, 40, and 80 kg/h at a system pressure of 3 MPa are discussed. In summary, this paper focuses on the study of the high-temperature materials, the design of the helium test facility, the design and fabrication of the PCHEs, and the computational modeling of a simplified PCHE model.
A rapid method for hemoglobin chain recombination

Abstract A rapid method for hemoglobin chain recombination which gives a homogeneous product was developed. The method utilizes a small carboxymethylcellulose column as a medium for chain recombination and concentration of the hemoglobin. Equimolar amounts of p -hydroxymercuribenzoate derivatives of α- and β-chains were mixed with 300× molar excess of β-mercaptoethanol over the p -hydroxy mercuribenzoate groups. After 10 min of incubation in an ice bath, the mixture was adjusted to pH 5.85, and was loaded on a carboxymethylcellulose column. The column was washed with 10 m m phosphate buffer-1 m m Na 2 EDTA-47 m m β-mercaptoethanol, pH 5.85 and then with 10 m m phosphate buffer, pH 5.85. The hemoglobin was eluted from the column by use of 15 m m K 2 HPO 4 . The hemoglobin was homogeneous on polyacrylamide gel electrophoresis and had a visible spectrum, electrophoretic mobility, and number of -SH groups comparable to those shown by control hemoglobin.
Inductive and differentiative signals delivered by C8-substituted guanine ribonucleosides

The C8-substituted guanine ribonucleosides area recently described class of immunomodulator which among a variety of pleiotropic effects have T-cell-replacing activity in vitro and immunopotentiating activity in immunocompromised hosts. In this article Michael Goodman discusses the mechanism of nucleoside transport, the immunobiologic activities of these compounds, and the nature of the cellular interactions involved.
The synthesis of optically active 5-phenylhydantoins

A number of reagents have been examined for effecting the conversion of an optically pure 2-phenylhydantoic acid to an optically active 5-phenylhydantoin. Trifluoroacetic anhydride (TFAA method) and dilute hydrochloric acid (acid-catalysis method) proved to be the reagents of choice. The dependence of the kinetics of racemization of the 5-phenylhydantoin system on temperature has been studied in dilute hydrochloric acid solution to support the conclusion that 5-phenylhydantoins prepared by the acid-catalysis method are nearly, if not entirely, optically uniform.
A Note on Probability Forecasts and “Hedging”

Abstract The consideration of a maxim and a statement, both of which are concerned with “hedging” on the part of meteorologists who prepare probability forecasts, leads to the identification of a property which all proper scoring systems for such forecasts should possess. A scoring system, to be proper, should encourage the meteorologist to make his probabilities correspond to his true beliefs. The conditions which a proper scoring system must satisfy are formulated in mathematical terms. Several existing scoring systems are examined to ascertain whether or not the systems are proper.
Modulation of α4 integrin mRNA levels is coupled to deficits in vasomotor function in rat arterioles by allylamine

Abstract Allylamine, a selective cardiovascular toxin that induces oxidative stress, is known to alter expression of extracellular matrix and cell adhesion proteins that are central to arterial remodeling. Our goals were to determine whether AAM treatment in rats modulates integrin/matrix-dependent arteriolar function, and to what extent integrin expression correlated to these alterations. Integrins are transmembrane proteins that facilitate mechanical and molecular signaling between the extracellular matrix and cytoskeleton, and so are suitable candidates for involvement in phenotypic and functional alterations of smooth muscle in response to oxidative stress. Arg-Gly-Asp (RGD) and Leu-Asp-Val (LDV), two integrin-binding motifs found in ECM proteins such as collagens and fibronectin, are known to interact with integrins α v β 3 and α 4 β 1 , respectively. Previously, we found that RGD containing peptides induce vasodilation through α v β 3 , while LDV containing peptides induce vasoconstriction through α 4 β 1 of normal rat cremasteric arterioles. In allylamine-treated rats (AAM), the vasomotor response to LDV, but not RGD, was attenuated in a dose-dependent manner. To determine whether changes in integrin subunit mRNA levels correlated with these functional changes, we performed reverse transcription and Real-time PCR for α 4 and β 3 integrin subunits on RNA isolated from single, first-order cremasteric arterioles. AAM treatment caused a dose-dependent decrease in α 4 mRNA expression, but not β 3 mRNA expression, suggesting that the changes in vasomotor activity to LDV peptides may be attributable in part to reduced α 4 expression upon exposure to AAM. These data are supported by similar decreases in α 4 integrin cell surface protein expression in cultured vascular smooth muscle cells treated either in vivo and in vitro with AAM.
Microfluidic formation of monodispersed spherical microgels composed of triple‐network crosslinking

A microfluidic emulsification method for producing monodispersed microgels from a triple interpenetrating network (3XN) hydrogel was reported. This 3XN system is comprised of minimally modified natural GRAS materials, partially oxidized dextran (Odex), Teleostean, and N-carboxyethyl chitosan (CEC), without the need of utilizing extraneous crosslinkers or photo-initiators, which has been proved to be a novel biodegradable and mechanically strong in-situ gelable hydrogel systems. A microfluidic chip was specifically designed to produce microgels from the 3XN hydrogel system. The study shows that microfluidic emulsification method could yield microgels with better size and morphology than the conventional in-emulsion-crosslinking method, and the size of microgels could be modulated by simply adjusting the flow rates of the oil and/or the individual precursor fluids. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Generic Airspace Concepts and Research

The purpose of this study was to evaluate methods for reducing the training and memorization required to manage air traffic in mid-term, Next Generation Air Transportation System (NextGen) airspace. We contrasted the performance of controllers using a sector information display and NextGen automation tools while working with familiar and unfamiliar sectors. The airspace included five sectors from Oakland and Salt Lake City Centers configured as a "generic center" called "West High Center." The Controller Information Tool was used to present essential information for managing these sectors. The Multi Aircraft Control System air traffic control simulator provided data link and conflict detection and resolution. There were five experienced air traffic controller participants. Each was familiar with one or two of the five sectors, but not the others. The participants rotated through all five sectors during the ten data collection runs. The results addressing workload, traffic management, and safety, as well as controller and observer comments, supported the generic sector concept. The unfamiliar sectors were comparable to the familiar sectors on all relevant measures.
White Man's Medicine: Government Doctors and the Navajo, 1863-1955

In 1863 the Dine began receiving medical care from the federal government during their confinement at Bosque Redondo. Over the next ninety years, a familiar litany of problems surfaced in periodic reports on Navajo health care: inadequate funding, understaffing, and the unrelenting spread of such communicable diseases as tuberculosis. In 1955 Congress transferred medical care from the Indian Bureau to the Public Health Service. The Dine accepted some aspects of western medicine, but during the nineteenth century most government physicians actively worked to destroy age-old healing practices. Only in the 1930s did doctors begin to work with - rather than oppose - traditional healers. Medicine men associated illness with the supernatural and the disruption of nature's harmony. Indian service doctors familiar with Navajo culture eventually came to accept the value of traditional medicine as an important companion to the scientific-based methods of the western world.
Relative Reactivity of C4 Olefins toward the Polyisobutylene Cation

The capping reaction of living polyisobutylene cation (PIB+) with 1-butene, cis-2-butene, trans-2-butene, or 1,3-butadiene in hexanes (Hex)/methyl chloride (MeCl) 60/40 (v/v) solvent mixtures at −80 °C was studied. The reaction products were characterized by elemental analysis, gel permeation chromatography, and NMR spectroscopy. Monoaddition (capping) was observed with 1-butene and cis-2-butene but not with trans-2-butene, which did not react with PIB+. Monoaddition of 1,3-butadiene followed by instantaneous halide transfer from the counteranion and selective formation of the 1,4-adduct were observed in Hex/MeCl 60/40 (v/v) solvent mixtures at −80 °C at [1,3-butadiene] ≤ 0.05 mol L-1. The polymerization of isobutylene (IB) was studied in the presence of 1-butene, cis-2-butene, trans-2-butene, or 1,3-butadiene as capping agent in Hex/MeCl 80/20 to 40/60 (v/v) in the temperature range of −40 to −80 °C. From the limiting conversion and limiting number-average degrees of polymerization the reactivity ratio, ...
Bovine serum albumin oligomers in the E- and B-forms at low protein concentration and ionic strength

The manuscript describes the study of the oligomerization process of bovine serum albumin (BSA) in two different structural monomeric forms: the extended-form (E) at pH 2.0 and the basic-form (B) at pH 9.0. The study was conducted at low protein concentration (1mg/ml) and relatively short incubation time (maximum 56 days) in order to investigate early oligomerization events rather than the formation of mature fibrils. The comparison between the two isoforms show that oligomers form much faster (∼6 days) in the E-form than in the B-form where formation of oligomers requires ∼4 weeks. The oligomers appear to be limited to a maximum of tetramers with size <30 nm. Hydrophobic interactions from exposed neutral amino acid residues in the elongated E-form are the likely cause for the quick formation of aggregates at acidic pH. We used an array of biophysical techniques for the study and determined that oligomerization occurs without further large changes in the secondary structure of the monomers. Under the conditions adopted in this study, aggregation does not seem to exceed the formation of tetramers, even though a very small amount of much larger aggregates seem to form.
First proof of concept of sustainable metabolite production from high solids fermentation of lignocellulosic biomass using a bacterial co-culture and cycling flush system.

Abstract To improve the lignocellulose conversion for ABE in high solids fermentation, this study explored the feasibility of cycling the process through the cellulolytic or/and solventogenic phases via intermittent flushing of the fermentation media. Five different flushing strategies (varying medium ingredients, inoculum supplement and cycling through phases) were investigated. Flushing regularly throughout the cellulolytic phase is necessary because re-incubation at 65 °C significantly improved glucose availability by at least 6-fold. The solvents accumulation was increased by 4-fold using corn stover (3-fold using miscanthus) over that produced by flushing only through the solventogenic phase. In addition, cycling process was simplified by re-incubating the flushed cellulolytic phase with no re-inoculation because the initial inoculum of Clostridium thermocellum remained viable throughout sequential co-culture. This study served as the first proof of the cycling flush system applied in co-cultural SSC and the knowledge gained can be used to design a farm-scale flushing system.
Development of a Model of Natural Infection with Mycobacterium bovis in White-Tailed Deer

The objective of this study was to develop a suitable experimental model of natural Mycobacterium bovis infection in white-tailed deer (Odocoileus virginianus), describe the distribution and character of tuberculous lesions, and to examine possible routes of disease transmission. In October 1997, 10 mature female white-tailed deer were inoculated by intratonsilar instillation of 2 × 103 (low dose) or 2 × 105 (high dose) colony forming units (CFU) of M. bovis. In January 1998, deer were euthanatized, examined, and tissues were collected 84 to 87 days post inoculation. Possible routes of disease transmission were evaluated by culture of nasal, oral, tonsilar, and rectal swabs at various times during the study. Gross and microscopic lesions consistent with tuberculosis were most commonly seen in medial retropharyngeal lymph nodes and lung in both dosage groups. Other tissues containing tuberculous lesions included tonsil, trachea, liver, and kidney as well as lateral retropharyngeal, mandibular, parotid, tra...
Mechanical modeling of viral capsids

As revealed by techniques of structural biology and single-molecule experimentation, the protein shells of viruses (capsids) are some of nature’s best examples of highly symmetric multiscale self-assembled structures, with impressive mechanical properties of strength and elasticity. Mechanical models of viral capsids built “from the bottom up,” i.e., from all-atom models in the context of molecular dynamics and normal mode analysis, have chiefly focused on unforced vibrational capsid dynamics. Due to the size of viral capsids, which can contain several hundred thousand atoms, the computer power needed for these types of methods has only recently reached the level required for all-atom simulations of entire viral capsids. Coarse-grained normal mode analysis has provided a simplified means of studying the unforced vibrational dynamics of viral capsids. Recent focus on “top-down” mechanical models of viral capsids based on two- and three-dimensional continuum elasticity have provided a theoretical complement to single molecule experiments such as atomic force microscopy, and have advanced the fundamental understanding of the forced mechanics. This review serves to assess the current state of modeling techniques for the study of the mechanics of viral capsids, and to highlight some of the key insights gained from such modeling. In particular, a theme is established of a link between shape—or geometry—and the global mechanical properties of these hierarchical multiscale biological structures.