cssi/SciSciGPT-SciSciNet huggingface dataset:
Potassium administration increases and potassium deprivation reduces urinary calcium excretion in healthy adults

Potassium administration increases and potassium deprivation reduces urinary calcium excretion in healthy adults. This study was undertaken to evaluate the effects of dietary K intake, independent of whether the accompanying anion is Cl - or HCO 3 - , on urinary Ca excretion in healthy adults. The effects of KCl, KHCO 3 , NaCl and NaHCO 3 supplements, 90 mmol/day for four days, were compared in ten subjects fed normal constant diets. Using synthetic diets, the effects of dietary KCl-deprivation for five days followed by recovery were assessed in four subjects and of KHCO 3 -deprivation for five days followed by recovery were assessed in four subjects. On the fourth day of salt administration, daily urinary Ca excretion and fasting U Ca V/GFR were lower during the administration of KCl than during NaCl supplements (Δ = -1.11 ± 0.28 SEM mmol/day; P 3 than during control (-1.26 ± 0.29 mmol/day; P 3 deprivation (mean reduction in dietary K intake -67 ± 8 mmol/day) were accompanied by an increase in daily urinary Ca excretion and fasting U Ca V/GFR that averaged on the fifth day +1.31 ± 0.25 mmol/day (P Ca V/GFR returned toward or to control at the end of recovery. These observations indicate that: 1) KHCO 3 decreases fasting and 24-hour urinary Ca excretion; 2) KCl nor NaHCO 3 , unlike NaCl, do not increase fasting or 24-hour Ca excretion and 3) K deprivation increases both fasting and 24-hour urinary Ca excretion whether the accompanying anion is Cl - or HCO 3 - . The mechanisms for this effect of K may be mediated by: 1) alterations in ECF volume, since transient increases in urinary Na and CI excretion and weight loss accompanied KCl or KHCO 3 administration, while persistent reductions in urinary Na and Cl excretion and a trend for weight gain accompanied K deprivation; 2) K mediated alterations in renal tubular phosphate transport and renal synthesis of 1, 25-(OH) 2 -vitamin D, since KCl or KHCO 3 administration tended to be accompanied by a rise in fasting serum PO 4 and TmPO 4 and a fall in fasting U PO 4 V/GFR, a fall in serum 1,25-(OH) 2 -D and a decrease in fasting U Ca V/GFR, while dietary KCl or KHCO 3 deprivation were accompanied by a reverse sequence.
Antiplane shear crack growth under quasistatic loading in a damaging material

Abstract Antiplane shear crack growth is examined numerically in a precracked rectangular specimen subjected to quasi-static antisymmetric loading, by cohesive layer modeling. Material in the cohesive layer ahead of the crack tip is modeled to be linear elastic-softening with a damaging locus while bulk material of the specimen is assumed to be linear elastic. The evolution of physical and fictitious crack tips is obtained from solutions to the boundary value problem formulated. Critical values of the J -integral and crack opening displacement (COD) for onset of either stable or unstable crack growth are examined, and shown to be dependent upon initial crack length, loading distribution as well as material properties. It is also shown that a unique relationship between a critical value of J -integral and a critical COD cannot be obtained in general. The iterative method of Successive-Over-Relaxation (SOR) is applied in the present work.
An O(√ n )-approximation algorithm for directed sparsest cut

We give an O(√n)-approximation algorithm for the Sparsest Cut Problem on directed graphs. A naive reduction from Sparsest Cut to Minimum Multicut would only give an approximation ratio of O(√nlogD), where D is the sum of the demands. We obtain the improvement using a novel LP-rounding method for fractional Sparsest Cut, the dual of Maximum Concurrent Flow.
Microbiologic Comparison of Dental Handpieces 2. Aerosol Decay and Dispersion

SYNOPSIS IN INTERLINGUACOMPARATION MICROBIOLOGIC DE DENTAL PECIAS DE MANO: DECOMPOSITION E DISPERSION DE PARTICULAS DE AEROSOL.-Esseva construite un simulate situation de operationes dental in le qual le ventilation e le dilution aeree poteva esser regulate pro le objectivo de studiar le effecto de aerosol producite per pecias de mano propulsionate (1) per corregia e (2) per turbina a aere. Un frescamente extrahite tertie molar esseva montate in un dispositivo de cauchu attachate al appoio-capite del sede operatori. Illo esseva equipate con un cophino de cauchu e un adjustate suspension de Serratia marcescens. Placas de Petri sin copertura e collectores de specimens de aere del typo Andersen esseva arrangiate in un configuration semi-circular o linear relative al dente montate. Durante le uso del pecia de mano a propulsion per corregia, practicamente nulle particulas de aerosol continente le organismo indicatori esseva detegite. Tamen, le numero de nucleos de guttetta in le ordine de magnitude de approxim...
Hegel, Race, Genocide

Etude de la conception raciale de l'histoire du monde defendue par Hegel a travers l'exemple de l'Amerique. Etablissant une hierarchie entre les continent americain, africain et asiatique, l'A. montre que Hegel realise une rationalisation des pratiques coloniales europeennes et offre une justification philosophique du genocide des Indiens d'Amerique.
MCTAGGART'S PARADOX AND THE INFINITE REGRESS OF TEMPORAL ATTRIBUTIONS: A REPLY TO SMITH

In arecent article in this journal, Quentin Smith attempts to demonstrate "that the idea that presentness, pastness and futurity are properties does indeed entail an infinite regress, but that this regress is neither vicious nor constituted of tenseless predications." 1 Although I have no quarrel with his thesis that the regress is not constituted by tenseless predications, it is the main purpose of this paper to show that the regress is in fact vicious. I shall do this by arguing that Smith's way out of "McTaggart's Paradox" involves precisely that vicious infinite regress of temporal attributions his analysis sought to avoid. According to Smith, the paradox involved in McTaggart's argument for the unreality of time does not involve any contradiction in temporal attribution. Rather, it is McTaggart's own remarks about the infinite regress that are paradoxical, not the infinite regress! Why does he say that? McTaggart claims, correctly according to Smith, that the attribution of presentness, pastness and futurity leads to a contradiction unless they are attributed successively. Smith continues,
Amaurosis Fugax: Diagnostic and Therapeutic Aspects

The three to eight-year follow-up study of 34 patients with unilateral amaurosis fugax (AF) suggests the following points: (1) A significant number of frequent unilateral AF patients suffer from small ulcerative plaques or irregular stenoses without any bruit in the neck or major changes in ophthalmodynamometry (ODM). The most important diagnostic test in these cases is angiography. (2) Surgery in patients with frequent unilateral AF seems to be more successful than anticoagulation. (3) No treatment cannot be considered a policy of "benign neglect" and may result in serious complications. (4) Cholesterol plaques, carotid bruits, and abnormal ODM are suggestive of carotid artery disease in unilateral AF. However, the absence of these signs is not helpful in differentiating carotid artery from cardiac origin of the emboli. (5) Heart disease may be the main etiological factor in a few patients with AF. It plays a major role in mortality regardless of the type of treatment.
Boomerang Effects in Science Communication How Motivated Reasoning and Identity Cues Amplify Opinion Polarization About Climate Mitigation Policies

The deficit-model of science communication assumes increased communication about science issues will move public opinion toward the scientific consensus. However, in the case of climate change, public polarization about the issue has increased in recent years, not diminished. In this study, we draw from theories of motivated reasoning, social identity, and persuasion to examine how science-based messages may increase public polarization on controversial science issues such as climate change. Exposing 240 adults to simulated news stories about possible climate change health impacts on different groups, we found the influence of identification with potential victims was contingent on participants’ political partisanship. This partisanship increased the degree of political polarization on support for climate mitigation policies and resulted in a boomerang effect among Republican participants. Implications for understanding the role of motivated reasoning within the context of science communication are discussed.
Expression of Y53A-Actin in Dictyostelium Disrupts the Cytoskeleton and Inhibits Intracellular and Intercellular Chemotactic Signaling

We showed previously that phosphorylation of Tyr53, or its mutation to Ala, inhibits actin polymerization in vitro with formation of aggregates of short filaments, and that expression of Y53A-actin in Dictyostelium blocks differentiation and development at the mound stage (Liu, X., Shu, S., Hong, M. S., Levine, R. L., and Korn, E. D. (2006) Proc. Natl. Acad. Sci. U.S.A. 103, 13694–13699; Liu, X., Shu, S., Hong, M. S., Yu, B., and Korn, E. D. (2010) J. Biol. Chem. 285, 9729–9739). We now show that expression of Y53A-actin, which does not affect cell growth, phagocytosis, or pinocytosis, inhibits the formation of head-to-tail cell streams during cAMP-induced aggregation, although individual amoebae chemotax normally. We show that expression of Y53A-actin causes a 50% reduction of cell surface cAMP receptors, and inhibits cAMP-induced increases in adenylyl cyclase A activity, phosphorylation of ERK2, and actin polymerization. Trafficking of vesicles containing adenylyl cyclase A to the rear of the cell and secretion of the ACA vesicles are also inhibited. The actin cytoskeleton of cells expressing Y53A-actin is characterized by numerous short filaments, and bundled and aggregated filaments similar to the structures formed by copolymerization of purified Y53A-actin and wild-type actin in vitro. This disorganized actin cytoskeleton may be responsible for the inhibition of intracellular and intercellular cAMP signaling in cells expressing F-Y53A-actin.
SU-FF-T-395: An Integrated GRID Boost Technique for Gamma Knife Radiosurgery

Purpose: To develop an integrated boost approach with the GRID technique for Gamma Knife radiosurgeryMethod and Materials: The GRID technique was originally developed for external beam radiation therapy where a high dose being delivered via a multi‐hole collimator. The goal of the technique is to debulk large tumor with spatially fractionated dose distributions. In this study, we developed an integrated GRID boost approach for Gamma Knife radiosurgery where an array of high dose areas was placed inside the target volume using a series of 4‐mm shots. The dose grid was added on top of the existing dose distributions where a peripheral isodose line (e.g. 50%) covers the full target volume. We optimized the weights of the 4‐mm shots to equalize the integral dose at each shot location. Treatment plans were developed and evaluated based on peripheral dose fall‐off and dose to normal brain as compared with the conventional Gamma Knife treatment plans. The comparison was also performed using equivalent uniform dose (EUD), tumor control probabilities (TCP), and normal tissue complication probabilities (NTCP). Results: All parameters for the target volume (mean dose, EUD, and TCP) increased significantly (> 5–30%) for the GRID boost technique as compared with the conventional Gamma Knife plans. The peripheral isodose coverage of the target volume (as measured with conformity index) remained unchanged for the GRID boost technique. In contrast, the EUD and the NTCP for the normal brain tissue adjacent to the target decreased significantly (as much as 40% in NTCP) for the GRID boost plans. Slightly faster dose fall‐off near the peripheral target region was noted for the GRID delivery.Conclusion: We demonstrated a new GRID technique for Gamma Knife radiosurgery in escalating the dose to the target volume while improving adjacent normal brain sparing.
Numerical calculations of the convective cooling of an infinite sill

Abstract There is now ample evidence that hydrothermal circulations of ground water influence the cooling of many intrusions. In this paper numerical calculations are presented for the hydrothermal circulations above a cooling infinite sill. Solutions are obtained for porous layers which prior to the emplacement of the intrusion are either below or above the critical Rayleigh number for thermal convection. If convection is occurring prior to the emplacement of the intrusion the hydrothermal circulation is found to be very vigorous. If the initial layer is stable, thermal convection develops quite slowly.
A Reference Interview in 2025

[This column is a collection of reference interview stories within a number of diverse mediums (chat, phone, face-to-face, immersive environments) sharing one academic librarian's real dialogues wi...
Effect of foam quality on effectiveness of hydraulic fracturing in shales

Abstract The goal of this work is to study the effect of foam quality on the gas productivity of fractured wells in shales. A numerical model of fracture propagation is developed which incorporates a 2D fracture model, proppant transport, and foam rheology. The fracture conductivity distribution is computed from the local proppant concentration, which is incorporated in a reservoir simulation model to predict the gas production by depressurization. Given the rock mechanical properties, the fracturing fluid, proppants, and rock permeability control the shape and conductivity of the fractures created during hydraulic fracturing. The shape and conductivity of the fracture, in turn, control the gas productivity of such a well. Foam quality, proppant size, proppant concentration, and rock permeability are varied. The results show that, in most cases, the gas production is optimum at an intermediate foam quality (of about 65%) because it creates the largest propped fracture area and minimizes leak-off. Only for the case of 0.1 micro-Darcy rock, low proppant concentration and large proppant size, the gas production increases monotonically with foam quality because high quality foam can place a partial monolayer of proppants. Fracturing with water as the initial pad and a high quality (65–85%) foam as the proppant carrier is more effective than using the same foam for both pad and slurry.
Oesophageal hyperkeratosis: clinicopathological associations.

Aims Oesophageal hyperkeratosis is rarely described. In contrast to hyperkeratosis of orolaryngeal mucosa, where its risk factors and association with squamous neoplasia are well-studied, the prevalence and clinicopathological features of oesophageal hyperkeratosis are unknown. Methods and results We reviewed prospectively 1845 oesophageal biopsies and found hyperkeratosis in 37 (2.0%). Among 98 patients studied, hyperkeratosis occurred in two distinct settings: group 1 [within Barrett's oesophagus (BO)/adenocarcinoma, n = 61, 62%] and group 2 (outside BO/adenocarcinoma, n = 37, 38%). In contrast to group 1, hyperkeratosis in group 2 was more often multifocal (>3 foci in 51% versus 16%, P = 0.0001), involved mid-oesophagus (51% versus 2%, P < 0.0001), showed endoscopic leucoplakia (24% versus 3%, P = 0.003) and involved current/former alcohol users (51% versus 19%, P = 0.0012). Importantly, invasive squamous carcinoma and squamous dysplasia were seen only in group 2 (47% and 19% versus 0%, P < 0.0001). Further, 42% of group 2, but none of group 1, had benign or malignant squamous lesions of the oral cavity/larynx (P < 0.0001). Conclusion Hyperkeratosis involves ~2% of oesophageal biopsies and can be divided into cases occurring within BO/adenocarcinoma and those occurring outside BO/adenocarcinoma. The former lack clinical significance, whereas the latter are associated frequently with oesophageal squamous neoplasia and squamous pathology of the head and neck region.
Combining sensitivities and prior information for covariance localization in the ensemble Kalman filter for petroleum reservoir applications

Sampling errors can severely degrade the reliability of estimates of conditional means and uncertainty quantification obtained by the application of the ensemble Kalman filter (EnKF) for data assimilation. A standard recommendation for reducing the spurious correlations and loss of variance due to sampling errors is to use covariance localization. In distance-based localization, the prior (forecast) covariance matrix at each data assimilation step is replaced with the Schur product of a correlation matrix with compact support and the forecast covariance matrix. The most important decision to be made in this localization procedure is the choice of the critical length(s) used to generate this correlation matrix. Here, we give a simple argument that the appropriate choice of critical length(s) should be based both on the underlying principal correlation length(s) of the geological model and the range of the sensitivity matrices. Based on this result, we implement a procedure for covariance localization and demonstrate with a set of distinctive reservoir history-matching examples that this procedure yields improved results over the standard EnKF implementation and over covariance localization with other choices of critical length.
Composite trust-based public key management in mobile ad hoc networks

Public key management in mobile ad hoc networks (MANETs) has been studied for several decades. Yet no single solution has completely resolved well known design challenges resulting from the unique characteristics of MANETs. These challenges include no centralized trusted entities, resource constraints, and high security vulnerabilities. This work proposes a fully distributed trust-based public key management approach for MANETs using a soft security mechanism based on the concept of trust. Instead of using hard security approaches, as in traditional security techniques, to eliminate security vulnerabilities, our work aims to maximize performance by trading off risk (i.e., security vulnerability) for trust. In this work, we propose a composite trust-based public key management (CTPKM) with no centralized trust entity with the goal of maximizing performance (e.g., service availability or efficiency) while mitigating security vulnerability. Each node employs a trust threshold to determine whether or not to trust another node. Each node's decision making using the given trust threshold affects performance and security of CTPKM. Our simulation experimental results show that there exists an optimal trust threshold that can best balance and meet the conflicting goals between performance and security, exploiting the inherent tradeoff between trust and risk.
The regulation of the first peak of haemolymph juvenile hormone esterase activity during the last stadium of the cabbage looper, Trichoplusia ni

Abstract The role of the head and a juvenoid, epofenonane, in the regulation of the first peak of haemolymph juvenile hormone esterase activity was examined during the fifth (last) stadium of the cabbage looper, Trichoplusia ni. The topical application of epofenonane to unligated day-1 larvae brought about an average 36% increase in the haemolymph juvenile hormone esterase activity. Epofenonane treatment also resulted in a 2-fold increase in the juvenile hormone and α-naphthyl acetate esterase activity of the whole body of unligated larvae suggesting that the juvenoid causes an increase in esterase biosynthesis or activation. Ligation and starvation prevented the appearance of the first peak of haemolymph juvenile hormone esterase activity. Application of epofenonane to newly ligated larvae had no effect whereas it significantly increased the juvenile hormone and α-naphthyl acetate esterase activity of the haemolymph in larvae ligated for 24 h prior to the treatment. In newly starved larvae, epofenonane increased the haemolymph juvenile hormone and α-naphthyl acetate esterase activity above respective controls. In 24 h starved larvae, juvenile hormone esterase activity of the haemolymph increased in response to epofenonane, head extract, or a combination of head extract injection and epofenonane application whereas α-naphthyl acetate esterase activity increased only to head extract or to a combination of head extract injection and epofenonane application. Injection of head extracts of day-1, fifth-instar larvae into the same aged ligated larvae increased both the juvenile hormone and α-naphthyl acetate esterase activity in the haemolymph by about 3-fold 5 h later compared to the respective controls. This increase, however, was not reflected in a similar increase in the whole body esterase levels suggesting that head extract may have caused a release of esterases from tissues into the haemolymph. Injection of head extract from day-1 larvae into the same aged unligated larvae inhibited the normal increase in the haemolymph juvenile hormone esterase activity seen between day 1 and 2 and no inhibition was noted with injections of body extracts or bovine serum albumin. Head extract injection significantly decreased the juvenile hormone esterase activity in the whole body, and haemolymph of unligated and 24 h ligated larvae treated with epofenonane. The head-extract-induced inhibition of haemolymph juvenile hormone esterase activity was dose dependent and the esterase activity in the haemolymph was unaffected when incubated in vitro with head extract for a period of 4 days at 30°C.
Management approaches for pediatric obesity.

Obesity rates are increasing alarmingly in children and infants, with predictable but devastating consequences for health. This article outlines the causes for these increases and suggests strategies to prevent and treat childhood obesity. These include a systematic approach from pediatricians and input from the family, school and community. Childhood obesity is a worldwide problem that has reached epidemic proportions, resulting in an increased prevalence of premature obesity-related morbidities, and, thus, probable increased health-care costs to treat children. The development of viable approaches to manage this epidemic is crucial. Most experts in the field of childhood obesity agree that the prevention of obesity in children should be the first line of management. Pediatricians must be adept at recognizing children at risk of obesity, calculating and plotting the BMI at all visits, using a change in the BMI to identify excessive weight gain, and monitoring for comorbidities associated with obesity. If obesity is present, the cornerstone of treatment is modification of dietary and exercise habits. Practice-based counseling and community-based programs that support and encourage lifestyle modifications have yielded promising short-term results. Children with severe comorbidities who are unable to achieve lifestyle modifications can be considered for either pharmacologic therapy or surgery, but these options should be considered as a last resort. Early intervention and prevention strategies are the most cost-effective methods of dealing with this issue.
Factores que impulsan la desdolarización en el Perú

Durante la ultima decada el Peru ha experimentado un exitoso proceso de desdolarizacion financiera impulsado por factores de mercado. El nivel de dolarizacion de los creditos y depositos en el sistema bancario - en todos los sectores y plazos - se ha reducido, observandose una mayor disminucion del grado de dolarizacion en los creditos comerciales, depositos a plazo y depositos de ahorro. El presente analisis confirma que la desdolarizacion financiera ha sido impulsada por la estabilidad macroeconomica, la introduccion de politicas macroprudenciales disenadas para reflejar mejor los riesgos cambiarios y el desarrollo del mercado de capitales en nuevos soles.
Nutrient-dependent regulation of autophagy through the target of rapamycin pathway

In response to nutrient deficiency, eukaryotic cells activate macroautophagy, a degradative process in which proteins, organelles and cytoplasm are engulfed within unique vesicles called autophagosomes. Fusion of these vesicles with the endolysosomal compartment leads to breakdown of the sequestered material into amino acids and other simple molecules, which can be used as nutrient sources during periods of starvation. This process is driven by a group of autophagy-related (Atg) proteins, and is suppressed by TOR (target of rapamycin) signalling under favourable conditions. Several distinct kinase complexes have been implicated in autophagic signalling downstream of TOR. In yeast, TOR is known to control autophagosome formation in part through a multiprotein complex containing the serine/threonine protein kinase Atg1. Recent work in Drosophila and mammalian systems suggests that this complex and its regulation by TOR are conserved in higher eukaryotes, and that Atg1 has accrued additional functions including feedback regulation of TOR itself. TOR and Atg1 also control the activity of a second kinase complex containing Atg6/Beclin 1, Vps (vacuolar protein sorting) 15 and the class III PI3K (phosphoinositide 3-kinase) Vps34. During autophagy induction, Vps34 activity is mobilized from an early endosomal compartment to nascent autophagic membranes, in a TOR- and Atg1-responsive manner. Finally, the well-known TOR substrate S6K (p70 ribosomal protein S6 kinase) has been shown to play a positive role in autophagy, which may serve to limit levels of autophagy under conditions of continuously low TOR activity. Further insight into these TOR-dependent control mechanisms may support development of autophagy-based therapies for a number of pathological conditions.
Engineering adenylate cyclases regulated by near-infrared window light

Bacteriophytochromes sense light in the near-infrared window, the spectral region where absorption by mammalian tissues is minimal, and their chromophore, biliverdin IXα, is naturally present in animal cells. These properties make bacteriophytochromes particularly attractive for optogenetic applications. However, the lack of understanding of how light-induced conformational changes control output activities has hindered engineering of bacteriophytochrome-based optogenetic tools. Many bacteriophytochromes function as homodimeric enzymes, in which light-induced conformational changes are transferred via α-helical linkers to the rigid output domains. We hypothesized that heterologous output domains requiring homodimerization can be fused to the photosensory modules of bacteriophytochromes to generate light-activated fusions. Here, we tested this hypothesis by engineering adenylate cyclases regulated by light in the near-infrared spectral window using the photosensory module of the Rhodobacter sphaeroides bacteriophytochrome BphG1 and the adenylate cyclase domain from Nostoc sp. CyaB1. We engineered several light-activated fusion proteins that differed from each other by approximately one or two α-helical turns, suggesting that positioning of the output domains in the same phase of the helix is important for light-dependent activity. Extensive mutagenesis of one of these fusions resulted in an adenylate cyclase with a sixfold photodynamic range. Additional mutagenesis produced an enzyme with a more stable photoactivated state. When expressed in cholinergic neurons in Caenorhabditis elegans, the engineered adenylate cyclase affected worm behavior in a light-dependent manner. The insights derived from this study can be applied to the engineering of other homodimeric bacteriophytochromes, which will further expand the optogenetic toolset.
Harold: a world made of drawings

The problem of interactively creating 3D scenes from 2D input is a compelling one, and recent progress has been exciting. We present our system, Harold, which combines ideas from existing techniques and introduces new concepts to make an interactive system for creating 3D worlds. The interface paradigm in Harold is drawing :a ll objects are created simply by drawing them with a 2D input device. Most of the 3D objects in Harold are collections of planar strokes that are reoriented in a view-dependent way as the camera moves through the world. Virtual worlds created in Harold are rendered with a stroke-based system so that a world will maintain a hand-drawn appearance as the user navigates through it. Harold is not suitable for representing certain classes of 3D objects, especially geometrically regular or extremely asymmetric objects. However, Harold supports a large enough class of objects that a user can rapidly create expressive and visually rich 3D worlds.
EVALUATION OF THE ESTIMATION OF DIFFUSE IRRADIANCE FROM GLOBAL AND DIRECT NORMAL IRRADIANCE MEASUREMENTS

As part of a radiometer intercomparison experiment, different combinations of pyranometer and pyrheliometers were used to estimate diffuse solar irradiance on a horizontal surface. Sixteen combinations were possible with four pyranometers and four pyrheliometers. The values were inter- compared and then compared to the measured values, obtained with a solar tracking/occulting disc system. The difference in estimated values using different radiometer combinations varied from 1 to 21 W/m 2. It was found that uncertainty in measuring the global irradiance accounted for most of the difference in estimated values. In the worst case, a 2.1 per cent difference in the global irradiance as measured by two different pyranometers caused a 12 per cent difference in estimates of the diffuse irradiance. It is shown that, if the estimated and measured values are analyzed statistically, agreement to within 1 per cent is possible.
Robotics in reproductive medicine.

Objective To review the history, development, current applications, and future of robotic technology. Design The MEDLINE database was reviewed for all publications on robotic technology in medicine, surgery, reproductive endocrinology, its role in surgical education, and telepresence surgery. Setting University medical center. Conclusion(s) Robotic-assisted surgery is an emerging technology, which provides an alternative to traditional surgical techniques in reproductive medicine and may have a role in surgical education and telepresence surgery.
Hyperbaric Oxygen Therapy of Acute Ischemic Stroke

To the Editor: We read with interest the review article by Hankey et al.1 In an attempt to assess the treatment of acute stroke with hyperbaric oxygen (HBO) the authors performed a review of 3 trials. Although we agree with the statement that there is no level I data to support the use of HBO in the treatment of acute ischemic stroke, we would like to emphasize that the trials evaluated by the authors were not adequate to support their conclusion. First, none of these studies actually enrolled patients during what most neurologists would accept as the acute period of ischemic stroke. Two …
The Metamorphism of the Pre-Cambrian Dolomites of Southern Eyre Peninsula, South Australia

THE basement platform of Southern Eyre Peninsula consists of a series of igneous and metamorphic rocks of pre-Cambrianage. Rising from beneath the Mesozoic and Tertiary strata of the Nullarbor plains, they may be regarded as a south-easterly prolongation of the great pre-Cambrian Shield of Western Australia. The platform is for the most part within a few hundred feet of sea-level, and large areas of the region are covered by the products of long-continued weathering of the older rocks or by siliceous deposits of late Tertiary age. The best sections for geological study are those exposed along the coastline, and in the hilly areas of Hutchison and Warrow.
Update on Pharmacological Heart Failure Therapies in Children Do Adult Medications Work in Children and if Not, Why Not?

Heart failure is a serious problem in children with acquired and congenital heart disease (CHD). In 2006, there were nearly 14 000 hospitalizations related to heart failure in pediatric patients.1 The disease is also costly, not only in terms of lives lost with a 20-fold increase in hospital mortality compared with children without heart failure but also in terms of morbidities, prolonged hospitalizations, and dramatically high hospital charges.1–3 However, it is not clear that there has been an overall improvement in the outcomes of children with heart failure. Although the risk-adjusted hospital mortality has declined, several single-center and multicenter studies of dilated cardiomyopathy (DCM) failed to demonstrate any change in survival over several decades.4–7 Multiple large, prospective, multicenter, randomized, controlled trials in adult heart failure patients have demonstrated the survival advantage of β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone antagonists.8–12 However, many drugs shown to be beneficial in the treatment of heart failure in adults have not been proven to be effective in children.4,13–17 There are many potential reasons for this. One potential reason is that the medications are actually beneficial, but the design and populations included in prior studies were not sufficient to demonstrate the benefit. However, there are other problems that may have more to do with the potential differences between adults and children with heart failure and their response to medications that treat heart failure. These issues are the focus of this review. One potential explanation for the negative findings of many pediatric heart failure studies is that the medications actually work, but the challenges in study design and study implementation make it difficult, if not impossible, to see the beneficial treatment effect. Prospective pediatric heart failure drug trials are …
Taming Our Brave New World

Advances in reproductive technology have already revolutionized our culture in various ways, and future potential developments, particularly in genetics, promise more of the same. The practice of surrogacy threatens to upend the way we understand the family. Germline engineering of human embryos could, among other things, lead to the treatment of genetic diseases hitherto incurable; but the widespread use of such engineering could have broader ramifications for our culture, for better and for worse. Parents may eventually be able to select for desirable traits in their offspring, whether by genetic modification at conception or by choosing to implant one of several genetically profiled embryos. Authors in this issue of The Journal of Medicine and Philosophy address some of the ethical implications of these technological and cultural changes.
Mutations in the BMP pathway in mice support the existence of two molecular classes of holoprosencephaly.

Holoprosencephaly (HPE) is a devastating forebrain abnormality with a range of morphological defects characterized by loss of midline tissue. In the telencephalon, the embryonic precursor of the cerebral hemispheres, specialized cell types form a midline that separates the hemispheres. In the present study, deletion of the BMP receptor genes, Bmpr1b and Bmpr1a, in the mouse telencephalon results in a loss of all dorsal midline cell types without affecting the specification of cortical and ventral precursors. In the holoprosencephalic Shh-/- mutant, by contrast, ventral patterning is disrupted, whereas the dorsal midline initially forms. This suggests that two separate developmental mechanisms can underlie the ontogeny of HPE. The Bmpr1a;Bmpr1b mutant provides a model for a subclass of HPE in humans: midline inter-hemispheric HPE.
A.C. conductivity of a plasma

Conductivity of fully ionized spatially homogeneous plasma under uniform periodically alternating electric field
The impact of problem-oriented animated learning modules in a CS1-style course

CS educators face many challenges in teaching basic computer programming to first-year students. As a result, faculty must find new and interesting ways to engage students and to provide opportunities for student success. This paper reports on a two-year study involving the Problem-Oriented Animated Learning Modules for Introductory Computer Science (PALMS for CS1) project. PALMS for CS1 is a set of animated learning modules designed to enhance student engagement, success, and retention through the use of computer animation, video, audio, and storytelling. The results of this study indicate that PALMS for CS1 has been successful in engaging introductory students but more work remains to improve student success and retention. Marked improvement in student success and retention was seen during the second year of the study, though success and retention are still a challenge for traditionally underrepresented groups.
Subcapsular Urinoma: An Unusual Form of Page Kidney in a High School Wrestler

The Page kidney phenomenon is usually associated with blunt renal trauma and accompanying perinephric or subcapsular hematoma. We describe a case of Page kidney due to a subcapsular urinoma, likely resultant from blunt trauma. CASE REPORT In March 2001 a 16-year-old white male was referred for evaluation of acute right flank pain. The patient’s medical, surgical, social and family histories were remarkable only for a family history of nephrolithiasis and, at the time of evaluation, participation on his high school wrestling team. Physical examination was remarkable for a blood pressure of 140/90 mm. Hg and right flank tenderness. Urinalysis revealed microhematuria. Noncontrast enhanced computerized tomography of the abdomen and pelvis demonstrated bilateral subcapsular fluid collections. Subsequent images, following intravenous administration of contrast agent, showed extravasation of contrast material into the subcapsular fluid collections (fig. 1). For further definition of the nature of the fluid collections the patient underwent magnetic resonance imaging of the kidneys. Characteristics of the fluid collections on T1 and T2-weighted images were consistent with that of urine (fig. 2). In addition, peripheral plasma renin activity was found to be 36 ng./ml. per hour (normal less than 3.3). Hypertension was treated with lisinopril. Initial surgical management included cystoscopy, retrograde pyelography and ureteral stent placement. Retrograde pyelography revealed bilateral pyelotubular backflow, with extravasation of contrast material. A right ureteral stent was placed to optimize drainage of the collecting system as this was the side on which the patient was symptomatic. Following stent placement, the patient refrained from strenuous physical activity. Followup imaging of the kidneys 2 months later showed resolution of the subcapsular fluid collections. In addition, blood pressure normalized, and the patient was weaned off of the antihypertensive medication 4 months after initial presentation.
Similarity between craze morphology and shear-band morphology in polystyrene

The formation of shear bands and crazes in thin films as well as in bulk samples of polystyrene were examined in the electron microscope using a variety of replication techniques. The morphologies of shear bands and crazes are quite similar both depending initially upon the relative shear displacement of 400 to 1000 A domains. As deformation continues and orientation increases, fibrils varying from 50 to 700 A are formed within the deformation zone, lateral constraint of the normal Poisson contraction causing voids to form in the crazes but not in the shear bands. Shear-band width was found not to be a unique function of either temperature or strain-rate and both craze and shear-band morphologies were found not to be strong functions of molecular weight. Regardless of molecular weight, fibrils formed within the deformation zone were always on the order of a few hundred Angstroms in diameter. However, for thin films of molecular weight less than 20 000 insufficient numbers of tie molecules between fundamental structural units or domains made it difficult for these fibres to span the craze width.
Aeromagnetics and the Transition Between the Colorado Plateau and Basin Range Provinces

An aeromagnetic survey of central Utah has given improved resolution of a regional anomaly previously recognized from satellite magnetometer data. The anomaly consists of a gradient from a high over the Colorado Plateau to a low over the Basin Range province. Magnetic profiles are fit by a model in which the Curie isotherm deepens eastward in a belt up to 80 km wide, whose western side is about 50 km east of the Basin Range physiographic margin. The magnetic profiles could also be fit be a change of average crustal susceptibility instead of Curie depth. In either case we conclude that the major lateral change between Basin Range and Colorado Plateau crustal geophysical parameters occurs not at the Fenneman physiographic boundary but more than 50 km eastward of it. This suggestion is found to be consistent with data from seismic refraction, geomagnetic variation, geochemistry, and geologic structures.
A New Logic Programming Framework for Heterogeneous Verification of Embedded Control Systems

Heterogeneous verification is the integration of verification results from several formal and informal activities using different tools and different models to achieve system-level verification. In previous papers we introduced an ontology- based approach to heterogeneous verification. A static ontology provides a structure for the heterogeneous information and an epistemic ontology provides rules for reasoning about this information. This paper presents our heterogeneous verification tool that implements a new logic programming language EOLC (Epistemic Ontology Language with Constraints) for specifying the epistemic ontology for heterogeneous verification. We describe the features of EOLC and illustrate them for the verification of the mode logic of a redundant flight guidance system.
Developments in Optical Testing Technology During the Last Decade

Modern electronics, computers, and software have made it possible to greatly improve the testing of optical components and optical systems and the resulting improvements in the new optical instruments and devices we use are evident. Until recently a major limitation of interferometry for precision metrology was the sensitivity to the environment. In recent years many techniques for performing high quality interferometric measurements in non-ideal environments have been developed and new techniques are being introduced all the time. This talk discusses one very powerful technique for reducing the effects of vibration and atmospheric turbulence on interferometric measurements. The application of this technique for the measurement of surface vibration, the testing of optical components including large astronomical optics, the phasing of segmented optical components, and the measurement of deformations of diffuse structures will be described.
Diurnal Variation in Serum Uric Acid of Rats Fed Potassium Oxonate

The uric acid plasma levels produced in rats fed a hyperuricemic diet including uric acid and potassium oxonate are highly variable and do not attain steady-state blood levels. The levels are dependent on the time of day that the blood was collected.
Vertical Heat Flux Components in the Northern Atmosphere

Abstract The large-scale atmospheric heat balance in zonally-averaged form is investigated for the northern atmosphere (50 mb≤p≤1000 mb; 10°S≤ϕ≤75°NN), both for annual and for summer and winter conditions. The basic equation is the conservation law for potential heat cpT+gz. The diabatic heating is written as a flux divergence, following van Mieghem. Only the vertical component of the corresponding flux is considered. It comprises radiation flux (HR) and precipitation flux (HC) and is combined with the convective potential heat flux into a generalized net vertical heat flux (Fp). Since the heat flux vector in the meridional-vertical plane is practically nondivergent, Fp can be calculated from the synoptic horizontal heat flux divergence by vertical integration, with the satellite-observed HR across the atmosphere's top as a boundary condition. The vertical pattern HR is separately calculated employing a model with 20 vertical layers for short-and longwave radiation, including 14 cloud layers. Its results ...
Conservation Status of the Eastern Spotted Skunk Spilogale putorius in the Appalachian Mountains of Tennessee

Abstract The conservation status of the eastern spotted skunk (Spilogale putorius) was assessed in the Appalachian Mountains of Tennessee from November 1995 through June 1997. Population status and seasonal abundance were examined using live-trapping on an 8 × 8 grid in Monroe County. Relative abundance was assessed at selected sites in Blount, Greene, Monroe, Unicoi and Washington counties employing additional live-trapping methods. In 5723 trap-nights only four S. putorius were captured (trap-success rate = 0.07%). The most common mammals captured were the opossum (Didelphis virginiana) and the raccoon (Procyon lotor). All eastern spotted skunks were captured in rhododendron (Rhododendron spp.) thickets near streams. A program to monitor the status of the species in the Appalachians is recommended as a management measure.
Expression cloning of a Xenopus T-related gene (Xombi) involved in mesodermal patterning and blastopore lip formation

We have used a functional assay to identify a putative T-box transcription factor (Xombi) that has the ability to induce sites of invagination in the ectoderm of Xenopus embryos that resemble the blastopore lip. Maternal Xombi transcript is first localized to the oocyte's vegetal cortex and cytoplasm, early sources of mesoderm and endoderm-inducing signals. Soon after zygotic transcription begins, there is a wave of Xombi expression, beginning in dorsal mesoderm and then extending to lateral and ventral mesoderm, that precedes and parallels blastopore lip formation at the border between the mesoderm and endoderm. Transcripts encoding brachyury, Xwnt8 and goosecoid colocalize with Xombi transcripts within the marginal zone; ectopic expression of Xombi induces expression of all three mesodermal genes. In ectodermal explants, Xombi expression is induced by the secreted mesoderm inducers activinA, activinB, Xnrl and eFGF, and by brachyury, another Xenopus T-box containing gene. The time course and location of Xombi expression, its biological activities and the partial dependence of Xombi expression and blastopore lip formation on fibroblast growth factor (FGF) signaling suggest that Xombi contributes to a traveling wave of morphogenesis and differentiation during Xenopus gastrulation.
Evidence for central chemoreception in the midline raphe

We injected acetazolamide (AZ; 5 x 10(-6) M; 1 nl; n = 14), its inactive analogue 2-acetylamino-1,3,4-thiadiazole-5-sulfon-t-butylamide (5 x 10(-5) M; n = 6), or mock cerebrospinal fluid (n = 5) into the caudal raphe in the midline brain stem of anesthetized paralyzed ventilated rats. These AZ injections have been shown to produce a focal region of tissue acidosis with a radius < 350 microns and are used as a probe for sites of central chemosensitivity. Compared with control injections, AZ injection into the raphe, as demonstrated by anatomic analysis of injection location, significantly increased the amplitude of the integrated phrenic neurogram over 10-40 min. Not all raphe injections produced such a response. AZ injections identified as responders (n = 8 of 14) increased integrated phrenic amplitude 43.3 +/- 10.7% (SE) of baseline 20 min after the injection. We conclude that the midline caudal raphe contains sites of ventilatory chemoreception.
Parity Conditions in International Markets

This note reviews the four central parity conditions that underlie most theories regarding the relationship between exchange rates, inflation and interest rates. The concepts are illustrated through a unified example exploring the relation between the U.S. dollar and Norwegian krone. The note presents both an intuitive understanding of the relations as well as precise mathematical formulas frequently employed in analysis.