cssi/SciSciGPT-SciSciNet huggingface dataset:
Surface crystallography of Re(0001)−(2×2)−S and Re(0001)−(2√3× 2√3)R30°−6S: a combined LEED and STM study

Abstract We analyze two structures formed by sulfur adsorbed on Re(0001) by using a combination of LEED and STM techniques. At Iow coverage (0.25 ML) sulfur atoms adsorb in three-fold hcp hollow sites forming a (2 × 2) structure. At higher coverages (0.5 ML) sulfur adsorbs close to three-fold hcp hollow sites and forms distorted hexamers arranged in a (2√3 × 2√3)R30° pattern. A complete structural determination was performed by using automated Tensor LEED, aided by STM, showing substantial substrate relaxations that become more pronounced with increasing sulfur coverage. The sulfur height above the first rhenium layer in the case of the (2 × 2) structure agrees well with that determined by a quantitative theoretical analysis of the STM images.
Magnesium monophosphate cements derived from diammonium phosphate solutions

Abstract Rapid-setting magnesium monophosphate cementitious materials were prepared by mixing calcined magnesium oxide (MgO) powder with an aqueous solution of diammonium phosphate (ADP) at 24°C. The activation energy for the curing reaction of the cement paste was determined to be 30.29 kcal/mole, and at age 1 hr the compressive strength was ≈900 psi (6.2 MPa). X-ray diffraction studies of the cured cement indicated that the major reaction product was magnesium orthophosphate tetrahydrate [Mg3(PO4)2·4H2O]. Magnesium ammonium phosphate hexahydrate [MgNH4PO4·6H2O] and Mg(OH)2 were also detected. Subsequent heating of the cement to 1300°C resulted in the conversion of the three compounds to a single phase of anhydrous magnesium orthophosphate [Mg3(PO4)2]. The resultant product had a compressive strength of 7000 psi (48.23 MPa) and was thermally stable in air at temperatures >1000°C.
Renal function in Antarctic teleost fishes: Serum and urine composition

The urine and serum compositions in 11 species of Antarctic teleost fishes were studied. The body fluids of these fishes were hypoosmotic to seawater. Both urine and serum osmoconcentrations were conspicuously greater than those of temperate species. The elevated serum osmolality was due to increased levels of NaCl, while elevated urine osmolality was due chiefly to increased concentrations of magnesium and chloride. The kidney was unable to form a urine hyperosmotic to serum under field conditions. The renal tubular epithelium secreted magnesium and calcium against a concentration gradient, while effectively preventing the renal excretion of significant amounts of sodium and potassium. Bladder urine of Antarctic teleosts may often be supercooled by as much as 0.8°C. Coelomic fluid and the integument probably act as a barrier in preventing ice propagation in the supercooled bladder urine, since they both contain glycoprotein “antifreeze” agents.
Diminishing returns epistasis among beneficial mutations decelerates adaptation

Epistasis has substantial impacts on evolution, in particular, the rate of adaptation. We generated combinations of beneficial mutations that arose in a lineage during rapid adaptation of a bacterium whose growth depended on a newly introduced metabolic pathway. The proportional selective benefit for three of the four loci consistently decreased when they were introduced onto more fit backgrounds. These three alleles all reduced morphological defects caused by expression of the foreign pathway. A simple theoretical model segregating the apparent contribution of individual alleles to benefits and costs effectively predicted the interactions between them. These results provide the first evidence that patterns of epistasis may differ for within- and between-gene interactions during adaptation and that diminishing returns epistasis contributes to the consistent observation of decelerating fitness gains during adaptation.
How important are dispersive Alfvén waves for auroral particle acceleration

[1] The means by which charged particles are accelerated in space to form the aurora is still not fully understood. This acceleration produces earthward streaming electrons driving auroral luminosity and outward streaming ionospheric ions which populate space with terrestrial matter. With the advent of high resolution space borne field and particle instruments, dispersive Alfven waves (DAWs) have been identified as drivers of auroral particle acceleration and it has been shown that the Alfven wave energy observed is sufficient to power a significant fraction of auroral luminosity. Since previously it has been considered that auroral particle acceleration occurs in quasi-steady field-aligned currents, quantifying the amount of particle acceleration occurring in DAWs relative to the traditionally invoked processes is fundamental to our understanding of how the aurora works. We combine coincident satellite measurements of fields and particles to demonstrate that as functions of increasing auroral activity 25–39% of the total electron energy deposited in the ionosphere and 15–34% of total energetic ion outflow may be attributed to the action of DAWs. In fact in the vicinity of the polar cusps and pre-midnight auroral oval, DAWs may provide the dominant means for powering electron and ion acceleration during active times.
Assessment of Preservation Induced Reperfusion Injury via Intraoperative Renal Transplant Blood Flow and Endothelin Concentration Studies

AbstractPurpose: We investigated a possible relationship between levels of the vasoconstrictive peptide endothelin and renal transplant reperfusion injury, and modified a technique for measuring renal blood flow with an ultrasonic perivascular transit time flow probe.Materials and Methods: Renal grafts in a swine transplant model were cold flushed with either Collins-2 or University of Wisconsin solution. Renal blood flow and renal vein endothelin levels after reperfusion of transplanted grafts, as well as histological parameters within the transplanted kidney were measured. The 5-minute post-reperfusion renal blood flow was used as the baseline allograft flow. The definition of reperfusion injury was a decrease in flow from baseline with no recovery within 1 hour of reperfusion. In 9 human recipients reperfusion injury was further verified by monitoring subsequent serum creatinine, urine output, graft survival and rejection episodes.Results: In the swine model and human transplant recipients no evidence ...
A Crowd Sourced Pharmacovigilance Approach Using SMS-based Asymmetric Encryption

With the explosive international growth in mobile phone adoption, there is an increasing number of text message-based applications providing mission-critical services to mobile phone owners. With such an unexpected leap in the mobile subscriber base, questions have arisen over the reliability of Short Message Service (SMS) as a communication channel in regions of high mobile teledensity growth. This paper provides insight on two points - the architecture of new SMS-based services and an examination of SMS reliability in low resource environments. This is achieved by providing research results detailing the design and implementation of a crowd sourced mobile-based authentication service using asymmetric encryption and data from an in-field view of the reliability of SMS messages using the SMS product authentication service described. A new Mobile Product Authentication (MPA) platform has been designed and implemented using cloud-based distributed computing (server virtualization) and a mobile network reliability server has been built to emulate a quad-SIM cell phone with 2 GB of RAM, 200 GB storage and 2.5 GHz dual-core processing power. To evaluate network throughput, response time and fault-tolerance, time-stamped SMS messages are sent from the network reliability server to the MPA platform on a round-trip flight through Nigeria’s largest mobile telecommunications company over varying time periods and network conditions.
Time Scales in the Unstable Atmospheric Surface Layer

Calculation of eddy covariances in the atmospheric surface layer (ASL) requires separating the instantaneous signal into mean and fluctuating components. Since the ASL is not statistically stationary, an inherent ambiguity exists in defining the mean quantities. The present study compares four methods of calculating physically relevant time scales in the unstable ASL that may be used to remove the unsteady mean components of instantaneous time signals, in order to yield local turbulent fluxes that appear to be statistically stationary. The four mean-removal time scales are: (t c ) based on the location of the maximum in the ogive of the heat flux cospectra, ( $$\tilde t_{MR}$$ ) the location of the zero crossing in the multiresolution decomposition of the heat flux, (t *) the ratio of the mixed-layer depth over the convective velocity, and ( $$\tilde t\,$$ ) the convergence time of the vertical velocity and temperature variances. The four time scales are evaluated using high quality, three-dimensional sonic anemometry data acquired at the Surface Layer Turbulence and Environmental Science Test (SLTEST) facility located on the salt flats of Utah’s western desert. Results indicate that $$t_c\approx t_{MR}$$ and $$t^*\approx \tilde t$$ , with t c achieving values about 2–3 times greater than t *. The sensitivity of the eddy covariances to the mean-removal time scale (given a fixed 4-h averaging period during midday) is also demonstrated.
Electronic compressibility and polarizability: origins of a correlation.

Recently, two new chemical concepts have been introduced, namely, the atomic compressibility β‘ = r4/Zeff and the corresponding group (molecular) compressibility Gβ‘ = . Here, r is the radius of th...
On the molecular origin of photoreceptor noise

RETINAL photoreceptors are noisy. They generate discrete electrical events in the dark indistinguishable from those evoked by light1,2 and thereby limit visual sensitivity at low levels of illumination3,4. The random spontaneous events are strongly temperature-dependent and have been attributed to thermal isomerizations of the vitamin A chromophore of rhodopsin, the light-sensitive molecule in photoreceptors1,5,6. But thermal generation of dark events in both vertebrate and invertebrate photoreceptors requires activation energies in the range of 23 to 27 kcal mol−1, which are significantly less than the energy barrier of 45 kcal mol −1 for photoisomerization of the chromophore of native rhodopsin7–9. We propose that photoreceptor noise results from the thermal isomeriz-ation of a relatively unstable form of rhodopsin, one in which the Schiff-base linkage between the chromophore and protein is unprotonated. This molecular mechanism is supported by both theoretical calculations of the properties of rhodopsin and experimental measurements of the properties of photoreceptor noise.
Greater learnability is not sufficient to produce cultural universals.

Looking across human societies reveals regularities in the languages that people speak and the concepts that they use. One explanation that has been proposed for these “cultural universals” is differences in the ease with which people learn particular languages and concepts. A difference in learnability means that languages and concepts possessing a particular property are more likely to be accurately transmitted from one generation of learners to the next. Intuitively, this difference could allow languages and concepts that are more learnable to become more prevalent after multiple generations of cultural transmission. If this is the case, the prevalence of languages and concepts with particular properties can be explained simply by demonstrating empirically that they are more learnable. We evaluate this argument using mathematical analysis and behavioral experiments. Specifically, we provide two counter-examples that show how greater learnability need not result in a property becoming prevalent. First, more learnable languages and concepts can nonetheless be less likely to be produced spontaneously as a result of transmission failures. We simulated cultural transmission in the laboratory to show that this can occur for memory of distinctive items: these items are more likely to be remembered, but not generated spontaneously once they have been forgotten. Second, when there are many languages or concepts that lack the more learnable property, sheer numbers can swamp the benefit produced by greater learnability. We demonstrate this using a second series of experiments involving artificial language learning. Both of these counter-examples show that simply finding a learnability bias experimentally is not sufficient to explain why a particular property is prevalent in the languages or concepts used in human societies: explanations for cultural universals based on cultural transmission need to consider the full set of hypotheses a learner could entertain and all of the kinds of errors that can occur in transmission.
Predicting spacing effects on growth and optimal rotations of tropical multipurpose trees

Abstract In order to improve our ability to analyze growth of tropical fast-growing trees, we developed a simple model (MPTGro) to predict development of even-aged stands from allometric equations of leaf area and total biomass. and a competition index based on wood production per unit leaf area, or net assimilation rate (E). In this study we (1) tested te model assumption that our competition index is valid across plant spacings, (2) tested the performance of MPTGro on two species of tropical multipurpose trees, and (3) applied the model to optimize rotations based on tree size, biomass allocation, or annual biomass increment. Measurements of E and stand leaf area index (LAI) at three-month intervals in spacing trials of Acacia auriculiformis and Leucaena diversifolia supported the assumption that a single relationshp between E and LAI would explain growth at a variety of planting densities. Increasing plant density in the simulations decreased time unitl maximum mean annual increment (MAI) and diameter at maximum MAI, but increased leaf: wood biomass ratio at maximum AMI
ACINIC CELL CARCINOMA OF THE MAJOR SALIVARY GLANDS.

Abstract A study was made of fifty patients having acinic cell carcinoma, including forty-seven tumors of the parotid gland and three sub-maxillary tumors, treated at the Mayo Clinic from 1918 through 1961. Follow-up study in forty-six cases ranged from one to forty-one years after initial treatment. Evidence presented supports the concepts that these tumors originate in acini of the salivary gland and that they should be considered as malignant tumors. The results of treatment indicate that a more aggressive surgical approach at the time of initial therapy offers the best opportunity for cure. More than 100 cases of acinic cell carcinoma of the parotid gland have been reported in the literature.
Recent Developments in Probabilistic Approaches to Optimal Control Theory

Modeling and control design of modern complex systems entail an appreciable degree of uncertainty due to modeling approximations, noise and tolerances in components, random effects, parametric errors and other changes. Probabilistic approaches to complex control systems often lead to linear ordinary differential/difference equations with multiplicative and additive noise. The characteristics of such systems are different from regular linear quadratic Gaussian systems, the basic difference being the inapplicability of the separation or the certainty equivalence principle. An optimal controller may not exist in some cases, and the optimal filter is of infinite dimension. Control systems with multiplicative and additive noise are presented and new results that extend the existing theory on linear stochastic systems are given.
Pain assessment instruments for use in the Emergency Department

Each patient's pain experience is uniquely his or her own. Standardized pain assessment methodologies and procedures provide a window to this experience and constitute a necessary first step to our understanding of pain, in both clinical and research settings. All too often, emergency department pain assessment is cursory--performed more to satisfy regulatory requirements than to guide our therapies or evaluate our practices. This article provides information on a number of assessment techniques that are appropriate for clinical and research use. Their use should inform our practice and lead to continuous improvements in our management of pain.
Cystic fibrosis and the gastrointestinal tract

Cystic fibrosis is known to be a serious genetic disease among those of northern European ancestry. Well known to nurses are the pulmonary insults to survival for children with cystic fibrosis. An aspect of health care not often found in the nursing literature is a focus on cystic fibrosis gastrointestinal presentation. Because of the chronic nature of cystic fibrosis, those providing health care to children must have an understanding of the disease in the growing infant and child. An overview of cystic fibrosis and the possible effect on the pancreas, gut, and liver are reviewed. Areas of developmental concern to the pediatric nurse practitioner are listed.
Evaluation of a Fingerling-to-Stocker Phase as Part of a New Production Strategy for the Commercial Farming of Channel Catfish

Abstract Within a three-phase production strategy for farming channel catfish Ictalurus punctatus, the second phase, fingerling to stocker production, was evaluated. A complementary economic analysis compared the cost of producing stockers, food-size fish net returns, and overall cost of production for a three-phase production system with that of the traditional multiple-batch system. Pond run fingerlings (mean length = 10.7 cm; mean weight = 10 g) were stocked into 0.05-ha experimental earthen ponds at densities of 98,840, 123,550, and 148,260 per hectare. They were fed floating fingerling feed with 36% crude protein to satiation during a 180-d grow-out period. At harvest, mean survival (63.7–72.6%) and mean feed conversion ratio (1.5–1.6) did not differ significantly among treatments. Mean harvested biomass (kg/ha) ranged from 5,766.5 to 9,135.6 and increased as density increased. Mean harvest weight (85.8–94.3 g) decreased as density increased but was not statistically different among treatments. Stock...
Analysis of losses in a double‐negative metamaterial composed of magnetodielectric spheres embedded in a matrix

A simple-cubic lattice of identical, magnetodielectric spheres exhibiting double-negative (DNG) behavior is analyzed.An analytic expression for the threshold loss angle δth of the spheres, above which DNG behavior is extinguished, is derived by utilizing the Mobius transformation. The formula is valid for either dielectric or magnetic loss exhibited by the particles, and is derived based on the dipole approximation of Mie's theory of scattering by a sphere. For spheres with equal real relative permittivity and permeability, it is shown that δth increases as particle volume fraction increases. It is also shown that the loss angle of the effective medium can be controlled by appropriate choice of frequency. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26081
Polymorphous low-grade adenocarcinoma: Glial fibrillary acidic protein staining in the differential diagnosis with cellular mixed tumors

Polymorphous low-grade adenocarcinoma is a recently recognized salivary gland carcinoma arising primarily within the oral cavity. Most of these tumors are readily diagnosed; occasionally, however, they may be confused histologically with cellular mixed tumors. The difficulty stems from the bland cytologic nature of cellular mixed tumors and their organizational diversity, together with the irregular pushing growth at their interface with adjacent soft tissues, on histologic examination. Because of this diagnostic problem, we evaluated the use of glial fibrillary acidic protein localization in the differential diagnosis of polymorphous low-grade adenocarcinoma and cellular mixed tumor. Twelve oral polymorphous low-grade adenocarcinomas (polymorphous low-grade adenocarcinoma) and twelve cellular mixed tumors were selected and stained for glial fibrillary acidic protein (glial fibrillary acidic protein) using a strept-avidin-biotin system and examined independently by each investigator. In addition, five tumors with limited material (three cellular mixed tumors and two polymorphous low-grade adenocarcinoma) from the consultation service of one author were evaluated using the same techniques. Two polymorphous low-grade adenocarcinoma stained positive in very focal areas and only in the epithelial component; staining did not occur in the stroma. Fourteen of fifteen mixed tumors focally to diffusely expressed glial fibrillary acidic protein. Only one tumor did not express glial fibrillary acidic protein. In mixed tumors with only focal staining, the most helpful differential diagnostic feature was positive staining of the mesenchyme-like cells adjacent to epithelial nests. We did not find this latter staining pattern in any of the polymorphous low-grade adenocarcinoma.
Pressure- and temperature-dependent combustion reactions

Abstract In combustion systems, many reactions are simple thermal unimolecular isomerizations or dissociations, or the reverse thereof. It is well understood that these reactions typically depend on temperature, pressure and the nature of the bath gas. These kinds of reactions are a subset of the more general behavior that can be described as free radical association reactions that produce highly energized intermediates, which can isomerize or dissociate via multiple chemical pathways. Each reaction rate depends on excitation energy and all of the competing reactions occur in competition with collisional activation and deactivation. These complicated multi-well, multi-channel reaction systems can only be simulated accurately by using master equation techniques. In this paper, master equation calculations are discussed for several examples of reactions important in combustion (and atmospheric chemistry). Current master equation codes are based on statistical RRKM reaction rate constants (including quantum mechanical tunneling) and simplified models for collisional energy transfer. A pragmatic semi-empirical approach is adopted in order to compensate for limited knowledge. The reaction energies needed for RRKM calculations are usually obtained from quantum chemistry calculations, which are often of limited accuracy and may be adjusted empirically. Energy transfer cannot be predicted accurately and must be parameterized by fitting experimental data. For combustion modeling, the master equation results are usually expressed as chemical reactions with rate constants fitted to empirical algebraic equations. However, the results may be expressed more accurately by interpolating from look-up tables. Several current research issues are also mentioned, including the effects of angular momentum conservation, vibrational anharmonicity, slow intramolecular vibrational energy redistribution, and assumptions surrounding the details of collisional energy transfer.
Regulation of egg maturation in the mosquito by the neurosecretory system: the role of the corpus cardiacum

Abstract In mosquitoes, the corpus allatum (CA) and the neurosecretory system each produce a hormone essential for egg development. Ablation experiments showed that when the female takes a blood meal 2–3 days after emergence, CA hormone had been secreted, whereas the neurosecretory hormone (EDNH) had been produced but was stored in the axons that form the corpus cardiacum. The cardiacum had accumulated enough EDNH for maturation of several batches of eggs. Nerve-sectioning and parabiosis experiments indicated that blood-feeding initiates some hemolymph-borne stimulus to the cardiacum that resulted in the release of enough EDNH, within 8–16 hr, for egg maturation. EDNH did not persist in the circulation after eggs were mature. Thus, the corpus cardiacum appears to regulate egg maturation by storing and “metering” the release of EDNH for each batch of eggs. Electron micrographs of Aedes sollicitans showed that the corpus cardiacum is both a ganglion and a neurohemal organ; it has no intrinsic neurosecretory cells. Bioassay of corpora cardiaca demonstrated that paraldehyde-fuchisin staining was not correlated with the presence of EDNH.
"Breaking the bureaucracy": drug registration and neocolonial relations in Egypt.

Abstract According to the Egyptian Ministry of Health, the per capita use of prescription drugs in Egypt is amongst the highest in the world. Multinational pharmaceutical companies license their proprietary products for manufacture and sale in Egypt through their Egyptian subsidiaries. A Ministry of Health Committee reviews and approves for sale all drugs marketed in the country. Aside from being an extremely lucrative market itself, approval of a drug for sale and manufacture in Egypt also opens to the pharmaceutical companies other markets in the Arab world. The Egyptian drug approval process is thus both important for assuring the health of Egyptian nationals and a high-stakes activity for the pharmaceutical companies. This paper examines the social relations and interactions of multinational pharmaceutical representatives in Egypt with Egyptian researchers in relation to the Ministry of Health's drug approval process. From time-to-time events focus attention on the huge financial rewards reaped by multinational pharmaceutical companies from their activities in lesser developed countries. This attention not infrequently has revealed the “drugging of the Third World” as a result of actions by expatriate multinational pharmaceutical officials. Indigenous review procedures such as those established by the Egyptian Ministry of Health might guard against such external exploitation. This paper shows how in place of external exploitation, indigenous pharmaceutical company officials have manipulated local patterns of social interaction to construct a system of reciprocal obligations which may frustrate intended safeguards, and by reconstructing colonial institutional structures, creates a pattern of neocolonialism in Egypt.
Characteristic time as a descriptive parameter in steam reformation hydrogen production processes

In the study of steam reformation, space velocity has been used as a scaling parameter to quantify reactor performance. However, in a real system, reactor geometry, steam-to-carbon ratio, temperature and pressure of the reaction, flow pattern inside the reactor, etc. are all factors that affect a reformer's performance. Previous studies have proven that space velocity alone is insufficient to describe steam reformer performance. This study presents an analysis and discussion of characteristic time as a descriptive parameter. Based on the analysis, this parameter must contain the physical and chemical reaction information of a steam reformer and is generally more insightful than using space velocity alone. Accurate individual analysis of each limiting mechanism (heat transfer, mass transfer and chemical kinetics) is perhaps the preferred method for quantifying reactor performance, but the interactions between the mechanisms often make such combined analysis difficult, if not impossible. Methanol steam reformation is viewed as a first-order chemical reaction to convert methanol to hydrogen; thus, a first-order characteristic time is used to identify and characterize reactor performance across all space velocities and with various limiting mechanisms. In this study, five physical reactor conditions were tested and analyzed using each reactor's fuel conversion as the output metric. After analyzing the reactor conversion data, the characteristic time was derived and discussed as based on a fit of the data to a mean first-order conversion equation. This simplification of the reactor model to a single characteristic time embodies concentration gradients, temperature gradients, non-homogeneous flow fields, reaction chemistry, etc., yet, still provides a meaningful description of reactor performance across a range of space velocities.
Client server architectures for nonlinear video services

Many commercial and academic disciplines need digital video libraries. Such libraries must provide the user with the opportunity to manipulate the material non-linearly. This paper discusses digital video libraries and various non-linear services these libraries will provide. The architectural components of such libraries are discussed and a model of user access is developed. Results from caching experiments utilizing that model are reported for several usage patterns and four cache organizations.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Caspase Inhibition by Baculovirus P35 Requires Interaction between the Reactive Site Loop and the β-Sheet Core

Baculovirus P35 is a universal substrate-inhibitor of the death caspases. Stoichiometric inhibition by P35 is correlated with cleavage of its reactive site loop (RSL) and formation of a stable P35·caspase complex through a novel but undefined mechanism. The P35 crystal structure predicts that the RSL associates with the β-sheet core of P35 positioning the caspase cleavage site at the loop's apex. Here we demonstrate that proper interaction between the RSL and the β-sheet core is critical for caspase inhibition, but not cleavage. Disruption of RSL interaction with the β-sheet by substituting hydrophobic residues of the RSL's transverse helix α1 with destabilizing charged residues caused loss of caspase inhibition, without affecting P35 cleavage. Restabilization of the helix/sheet interaction by charge compensation from within the β-sheet partially restored anti-caspase potency. Mutational effects on P35 helix/sheet interactions were confirmed by measuring intermolecular helix/sheet association with the yeast two-hybrid system. Moreover, the identification of P35 oligomers in baculovirus-infected cells suggested that similar P35 interactions occur in vivo. These findings indicate that P35's anti-caspase potency depends on a distinct conformation of the RSL which is required for events that promote stable, post-cleavage interactions and inhibition of the target caspase.
Pituitary hyperplasia secondary to primary hypothyroidism: a case report and review of the literature.

Pituitary hyperplasia secondary to primary hypothyroidism has been reported in the literature in both adults and children. We report a case of a young woman who was diagnosed with hypothyroidism in her teenage years. Despite frequent follow-up, her TSH levels remained greater than 100 mIU/ml. A few years later, pituitary enlargement was found on an MRI at a time when her TSH was 177 mIU/ml and her free T4 was 0.2 ng/dl. Observed administration of 600 mcg of L-thyroxine was performed to determine the effectiveness of hormone absorption. Total T4 levels of 0.2 rose to 7.1 mcg/dl at two hours with a decrease in her TSH levels from 88.6 to 66.8 mIU/ml at 24 hours. With the exception of one short period, her TSH levels have remained elevated over eight years of observation without change in the size of the pituitary mass.
Reachability analysis of closed-loop switching power converters

A design verification method for closed-loop switching power converters is presented in this paper. The method computes the set of reachable states from an initial set of states. Case studies are presented for closed-loop buck converters using this approach. The buck converter is first modeled as a switched linear system. Two controllers are studied, first a simple hysteresis controller, and then a linear controller. The analysis method is automated and uses the hybrid systems reachability analysis tool SpaceEx. The applications and limitations of the analysis method are explored in this study.
Orthostatic Hypotension in Spinal Cord Injury

73 O include dizziness, visual changes, faintness, nausea, and blacking out. Orthostatic hypotension may be seen following spinal cord injury (SCI) resulting in tetraplegia or paraplegia. In this population, the term has been used to describe an inability to tolerate an upright posture, whether sitting or standing. The autonomic nervous system plays a major role in maintaining blood pressure. However, during SCI, the sympathetic nervous system is affected as the thoracic and lumbar outflow tracts of the sympathetic nervous system become “disordered.” Mechanical factors may also contribute to alteration of blood pressure management. By understanding the importance of the autonomic nervous system and mechanical factors in blood pressure regulation as well as its impact on the patient following SCI, it is possible to arrive at a rational approach to the medical management of orthostatic hypotension. This article describes the treatment of a patient with orthostatic hypotension after SCI, followed by a discussion of orthostatic Top Spinal Cord Inj Rehabil 1997;4(1):73–80 © 1998 Aspen Publishers, Inc. RTHOSTATIC hypotension is a symptomatic decrease in blood pressure upon standing. Symptoms
Advances in injection molding of fiber‐reinforced thermoplastics during 1991—Part I: Materials and processing

This is the first part of a survey of developments reported in the open literature during 1991 on the subject of injection molding of fiber-reinforced thermoplastics. Topics discussed include materials, polymers, reinforcing fibers and composite properties, advances in the injection molding process, fiber breakage, shrinkage, and warpage, as well as alternatives to the injection molding process. © 1992 John Wiley & Sons, Inc.
Regulation of photoreceptor Per1 and Per2 by light, dopamine and a circadian clock

In the Xenopus laevis retina, a principal model for retinal circadian organization, photoreceptors have all the properties of circadian oscillators. However, rhythmic oscillations of Per1 gene expression in the inner retina (but not photoreceptors) have been reported in mice with the suggestion that mice and frogs have a different retinal circadian organization. Although it is known that two period genes (xPer1 and xPer2) exhibit different temporal patterns of expression in the Xenopus retina, and that one (xPer2) is directly responsive to light and dopamine, it is not known whether this reflects the properties of period genes within photoreceptor oscillators or among distinct retinal cell populations. We addressed this by determining the cellular site of light and dopamine regulated xPer2 expression, and the diurnal expression of both xPer1 and xPer2 using in situ hybridization. Our data show that both xPer1 and xPer2 are expressed in most cell types in the retina, including inner nuclear neurons and ganglion cells. However, light and quinpirole, a dopamine agonist, increase xPer2 levels specifically in photoreceptors, and the effect of quinpirole, but not light, is blocked by pCPT-cAMP. Furthermore, antiphasic diurnal expression of xPer1 and xPer2 also occurs in photoreceptors. Our analysis does not provide insight into the near constitutive expression of period genes in the inner retina, but supports a model in which light- and dopamine regulated-xPer2 and rhythmic xPer1 play critical roles in entrainment and circadian oscillations within photoreceptors.
Histochemical study of bone in parathyroidectomized rats.

Sections of the tibias from intact and from aparathyroid animals were examined histologically and histochemically to determine the changes in bone following parathyroidectomy. The proximal epiphyseal cartilages of parathyroidectomized rats showed arelative increase of intercellular matrix, decrease in cellularity, and disorganization of the cellular arrangement. The epiphyseal cartilages of the aparathyroid rats exhibited an intense PAS-positive intercellular matrix in contrast to the alcianophilic nature of the matrix from control animals. The diaphyseal trabeculae from aparathyroid animals stained red with PAS and contained wide regions of calcified cartilaginous cores. In addition, the epiphyseal cartilages and bone trabeculae from the parathyroidectomized animals stained less intensely to the ninhydrin-Schiff reaction than did the bone from the intact animal. The response to the various histochemical reactions indicated that following parathyroidectomy there was a change in the collagen-protein mucopolysaccharide components. This condition would produce an alteration in the calcification of bone.
Interacting continuous medium composed of an elastic solid and an incompressible newtonian fluid

Abstract The constitutive equations for an interacting continuum composed of an elastic solid and an incompressible Newtonian fluid are developed. The condition of incompressibility alters the equations previously obtained by Green and Steel. The concept of thermodynamic pressure is introduced and the new equations are compared with those developed by previous investigators. Using these constitutive equations, methods of solution are presented in terms of displacements or a stress function for the steady state condition. The equations developed are shown to reduce to Darcy's law for flow of fluids through a rigid porous medium and Biot's equation of fluid flow through a linear elastic solid. One and two-dimensional steady-state problems are solved as examples.
Cimetidine and Delirium: Assessment and Management

Abstract A number of reports have appeared of possible cimetidine- induced delirium. In many cases it appears that this delirium may have resulted from inadvertently overdosing the patient with cimetidine. The author briefly reviews the drug's pharmacokinetics and interactions with other drugs. He then explains the use of a formula and a nomogram for accurate dosage adjustment in patients with cimetidine-induced delirium.
The inhibition of butyl acrylate by p‐methoxyphenol

The lengths of polymerization induction periods for butyl acrylate (BA) in the presence of air were measured at temperatures from 54 to 122.5°C. The kinetics of MEHQ and oxygen consumption at 80 and 100°C are characterized by their own induction periods followed by sharply accelerated rates immediately prior to the BA polymerization. It is proposed that these phenomena are consistent with an “intrinsic” BA radical formation rate that is extremely slow compared to the ultimate rate of radical production from the decomposition of peroxides. These oligomeric peroxides build up during the induction period and, at its end, rapidly decompose with a resulting “radical cascade effect,” causing the accelerated inhibitor and oxygen consumption followed rapidly by BA polymerization. Thus, confirmation that a supply of BA has a normal MEHQ concentration may not be sufficient to ensure its stability. Strict adherence to the storage conditions and shelf life recommended by the supplier6 is absolutely vital to storage safety, especially because uncontrolled poly-merization of BA has the potential to be violent (polymerization exotherm rates higher than 1000°C/min were observed). © 1996 John Wiley & Sons, Inc.
Solenopsis enigmatica, a new species of inquiline ant from the island of Dominica, West Indies (Hymenoptera: Formicidae).

Abstract A new species of ant, Solenopsis enigmatica, is described from 2 dealate queens and 3 workers collected from nests of Pheidole antillana Forel in rainforest on the island of Dominica, West Indies. The queen of S. enigmatica is similar to that of another inquiline, S. phoretica Davis and Deyrup, known only from 1 queen collected in Florida. The 2 species differ in mandibular dentition and other ways. Worker S. enigmatica do not closely resemble those of other known species. They lack clypeal carinae, have short antennal scapes, and have long, coarse hairs arising from conspicuous punctures. The presence of workers suggests that S. enigmatica might be a temporary nest parasite, but many questions remain about the relationship of this species to its host.
Increased Expression of ampC in Pseudomonas aeruginosa Mutants Selected with Ciprofloxacin

Two Pseudomonas aeruginosa mutants exhibiting increased expression of ampC were selected during exposure to ciprofloxacin. These mutants also exhibited significant increases in mexCD-oprJ expression, but further studies failed to show a link between the increased expression of mexCD-oprJ and ampC. Increased ampC expression was not related to mutations within ampR, the ampC-ampR intergenic region, ampD, ampDh2, or ampDh3 or to changes in the levels of expression of these amidase genes. However, ampD complementation restored wild-type levels of ampC expression and ceftazidime susceptibility, suggesting alternative mechanisms of ampC regulation.
Dorsal tenosynovectomy and tendon transfer in the rheumatoid hand.

Seventy-three patients with rheumatoid arthritis had tenosynovitis of the tendon sheath of the extensors of the fingers (ninety-three hands). Forty-one hands had ruptures of extensor tendons which were repaired at operation in addition to the dorsal tenosynovectomy. The hands in which dorsal tenosynovectomy was done prophylactically showed no rupture except in two in which errors in a Darrach procedure accompanying the tenosynovectomy allowed attrition of tendons on the roughened ulnar stump. Our present indications for prophylactic tenosynovectomy are: (1) persistent dorsal tenosynovitis despite adequate medical treatment; (2) extensor tendon rupture; and (3) recurrent dorsal tenosynovitis. Tendon rupture is considered an urgent indication for operation because further ruptures may thus be prevented.
Knowledge analysis on process models

Helping end users build and check process models is a challenge for many science and engineering fields. Many AI researchers have investigated useful ways of verifying and validating knowledge bases for ontologies and rules, but it is not easy to directly apply them to checking process models. Other techniques developed for checking and refining planning knowledge tend to focus on automated plan generation rather than helping users author process information. In this paper, we propose a complementary approach which helps users author and check process models. Our system, called KANAL, relates pieces of information in process models among themselves and to the existing KB, analyzing how different pieces of input are put together to achieve some effect. It builds interdependency models from this analysis and uses them to find errors and propose fixes. Our initial evaluation shows that KANAL was able to find most of the errors in the process models and suggest useful fixes including the fixes that directly point to the sources of the errors.
Economic Inequality, Working-Class Power, Social Capital, and Cause-Specific Mortality in Wealthy Countries:

This study tests two propositions from Navarro's critique of the social capital literature: that social capital's importance has been exaggerated and that class-related political factors, absent fr...
Antelope Mirror 10

This picture was taken in a Southwest slot canyon. The image was mirrored in Photoshop twice and rotated to a horizontal. …
Distribution and Power of the Absolute Normal Scores Test

Abstract Some rejection limits of the absolute normal scores test (K) for symmetry are extended from sample size 10 to 17 and partially to 20, by essentially forming all possible values of K for fixed sample size. These limits are compared with normal and Edgeworth approximations, which seem to be quite satisfactory in that the percent error in test size for sample size greater than 20 should be less than 12% for the normal approximation and less than 2% for the Edgeworth approximation (see (3.3)), for test size ≥ .01. The powers of the absolute normal scores (K), Wilcoxon (W), binary (B), sign (S), and t(T) tests are estimated from Monte Carlo trials for shifts of symmetrical hypothesized populations which are normal, logistic, double exponential, and rectangular. The powers of T and K are usually very close, with T more powerful for normal shifts and large rectangular shift, and K more powerful for the others, though the differences may not be substantial. In terms of decreasing power, the tests are ord...
Much ado about α: reframing the debate over appropriate fate descriptors in nanoparticle environmental risk modeling

Large-scale fate and transport models have used different approaches to account for engineered nanoparticle (ENP) heteroaggregation and its effects on fate. Praetorius et al. and Cornelis, in recent Perspectives in this journal, favor the use of particle number-based kinetic models and attachment efficiency, α, in place of mass-based approaches relying on partition coefficients, or Kd values, because the former is more theoretically faithful to the particulate nature of ENPs. Here, we provide perspective on these two popular modeling frameworks, particle balance and mass balance, with regards to their ability to capture ENP fate processes at large scales. We show that particle balance using α is not unique in its ability to describe ENP heteroaggregation kinetically, since mathematically equivalent rates can be created for mass balance, and that the ability of particle balance to accurately describe particle behaviors is still severely hindered by evolving scientific understanding of ENP heteroaggregation. Ultimately, we find that models at this scale are relatively insensitive to the particulate nature of ENPs. In the short term, mass-based models that rely on simple heuristics can be more practical, and less error-prone, than particle balance alternatives using α.
Design, fabrication, and testing of a high-speed analog sampler

The authors describe the design, fabrication, and first successful operation in the gigahertz frequency range of a Josephson-junction-based sampling circuit designed to provide 6 b of resolution ( approximately 35 dB) and 10 GHz or more of bandwidth. The first experimental demonstration of a prototype circuit sampling a sine wave at up to 1 GHz is reported. This sampler has properties that make it amenable to incorporation into complex, mixed-analog/digital integrated circuits. Such a circuit can be used in the implementation of such signal processing subsystem components as a transient waveform data recorder, a programmable analog-binary correlator, and a flash analog-to-digital converter. >
Optimal approach to the management of intrathoracic esophageal leak following esophagectomy: a systematic review

Abstract Background Recently, endoscopic interventions (eg, esophageal stenting) have been successfully used for the management of intrathoracic leak. The purpose of this systematic review was to assess the safety and efficacy of techniques used in the management of intrathoracic anastomotic leak. Data Sources We performed a systematic review of MEDLINE, EMBASE, and PubMed to identify eligible studies analyzing management of intrathoracic esophageal leak following esophagectomy. Conclusions Intraoperative anastomotic drain placement was associated with earlier identification and resolution of anastomotic leak (mean 23.4 vs 80.7 days). In addition, reinforcement of the anastomosis with omentoplasty may reduce the incidence of anastomotic leak by nearly 50%. Endoscopic stent placement was associated with leak resolution in 72%; fatal complications were reported, however, and safety remains to be proven. Negative pressure therapy, a potentially useful tool, requires further study. If stenting and wound vacuum are used, undrained mediastinal contamination and persistent leak require surgical intervention.
Relation of Alkali Mobility and Mechanical Relaxation in Mixed‐Alkali Silicate Glasses

Internal friction and Na and K self-diffusion coefficients for (I–X)Na2OXK2O-3SiO2 glasses were measured. Alkali diffusion was measured between 300° and 500°C using radioactive isotopes and a thin-sectioning technique; internal friction was determined at room temperature to 500°C at 0.1 to 2000 Hz. Comparison of the data for alkali diffusion and internal friction in Na-K glasses with those for other mixed-alkali glasses shows that the mixed-alkali peak is related to alkali mobility. It is concluded that the mechanism of mixed-alkali internal friction is cooperative rearrangement of dissimilar alkali ions, with the slower-moving ion controlling the rate of reorientation.