cssi/SciSciGPT-SciSciNet huggingface dataset:
Stiff and strong compressive properties are associated with brittle post-yield behavior in equine compact bone material.

Abstract Our hypothesis was that post-yield mechanical behavior of compact bone material in compression, defined as the stress, strain, or energy absorbed between 0.2% strain-offset and the point of maximum stress, is correlated with material density, modulus, strength, histomorphometric evidence of remodeling, and post-failure gross specimen morphology. Post-yield behavior of compact bone material from the third metacarpal bone of 10 horses, ages 5 months to 20 years, was investigated using single-load compression-to-failure. The post-yield stress, strain, and absorbed energy were compared with the compressive elastic modulus, yield stress, ash density, post-failure macroscopic appearance of the specimen, and histologic evidence of remodeling. High values of elastic modulus, yield stress, and ash density were associated with low values of post-yield mechanical properties (stress, strain, and absorbed energy). Macroscopic post-failure morphology was associated with post-yield mechanical behavior, in that specimens displaying fractures were associated with lower post-yield mechanical properties, and that those without evidence of frank fracture were associated with higher post-yield mechanical properties. Microscopic evidence of remodeling activity was associated with high post-yield mechanical properties, but not with gross post-failure morphology. There was an abrupt change from relatively high values to extremely low values of post-yield mechanical properties at intermediate levels of ash density. This feature may serve as a functional upper limit to the maximization of bone material stiffness and strength.
Dilation of retinal arterioles in response to lactate: role of nitric oxide, guanylyl cyclase, and ATP-sensitive potassium channels.

PURPOSE. Lactate, a key metabolite in the retinal tissue, has been implicated in regulating retinal blood flow to match retinal metabolic demand. However, the direct effect of lactate on retinal vascular tone and the possible underlying signaling mechanisms remain unknown. In the present study, the roles of endothelium-derived vasodilators, guanylyl cyclase, and potassium channels were examined in lactate-induced dilation of retinal arterioles in vitro. METHODS. Porcine second-order retinal arterioles were isolated, cannulated, and pressurized to 55 cm H2O lumenal pressure without flow. Diameter changes in response to agonists were recorded with videomicroscopic techniques. RESULTS. All vessels developed basal tone (70 m in internal diameter) and dilated dose dependently in response to neutralized L-lactate (0.01‐10 mM). Inhibition of cyclooxygenase by indomethacin only slightly reduced the vasodilatory response to lactate. In contrast, blockade of monocarboxylate transporters, nitric oxide (NO) synthase, soluble guanylyl cyclase, and ATP-sensitive potassium (KATP) channels nearly abolished lactate-induced vasodilation. The cGMP phosphodiesterase inhibitor zaprinast enhanced the vasodilation response to lactate. Similar to the lactate-induced response, the vasodilation elicited by S-nitroso-N-acetylpenicillamine, an NO donor that activates cGMP signaling, was also inhibited by the soluble guanylyl cyclase and KATP channel blockers. CONCLUSIONS. These data suggest that uptake of lactate by vascular cells via monocarboxylate transporters causes retinal arteriolar dilation predominantly via stimulation of NO synthase and subsequent activation of guanylyl cyclase. The guanylyl cyclase/cGMP signaling triggers opening of KATP channels for vasodilation. A better understanding of the fundamental signaling pathways responsible for lactate-induced dilation of retinal arterioles may help shed light on the possible mechanisms contributing to the metabolic regulation of retinal blood flow under physiological and pathophysiological conditions. (Invest Ophthalmol Vis Sci. 2006;47:693‐699)
Reversibility of ganglioside effects on astrocyte morphology

The B-subunit of cholera toxin (BCT) induces a morphological change in cultured rat cerebral astrocytes from flat (epithelioid) to stellate (process-bearing). This stellation is reversed by the gangliosides GM1 and GD1a at concentrations of 10 microM or higher. Upon changing to a ganglioside-free medium, the flat astrocytes reacquire the stellate morphology within 3 hr, indicating that the antistellation effect of gangliosides is reversible. The possibility that this reversibility was due to a loss of exogenously acquired gangliosides from the cell membrane can be ruled out since pretreatment with GM1, but not GD1a, which does not bind BCT, results in an increased responsiveness to BCT, which was identical whether measured immediately after withdrawal of the ganglioside or 3 hr later. Asialo-GM1, which neither binds BCT nor reverses BCT-induced stellation by itself, prevents the return to stellation after withdrawal of the gangliosides. These data suggest that while gangliosides remain associated with the cell, their effect on astrocytes can change from opposing to permitting the stellate morphology.
Structure Evolution and Phase Behavior of Polymer Blends Under the Influence of Shear

Abstract The effect of shear flow on the phase behavior, structure formation and morphology of a near-critical composition blend of poly(styrene- co -acrylonitrile)/poly(methyl methacrylate) (SAN/PMMA) and an off-critical composition blend of SAN/poly(e-caprolactone) (SAN/PCL) were investigated. Both blends exhibited lower critical solution temperature (LCST) behavior. Rheo-SALS (small angle light scattering) was used to characterize the time-dependent structure evolution during flows with shear rates from 0.01 to 0.05 s −1 and stresses from 8 to 60 kPa. Two types of transient “dark-streak” scattering patterns were observed. One featured a dark streak that diverged with increasing scattering vector, q , which corresponded to a chevron-like structure in the morphology of the blend. The other type of dark streak converged with increasing q , and may be due to a spinodal structure that was stretched in the flow direction. A capillary viscometer was used to achieve shear stresses as high as 400 kPa for the SAN/PCL blends, and microscopy analysis of microtomed extrudates revealed a dispersed phase morphology of cylindrical PCL-rich domains highly oriented in the flow direction. No shear-induced phase transitions were observed for either blend for the range of shear stress studied.
Effect on guinea-pigs of feeding nitrosomorpholine and its precursors in combination with ascorbic acid.

Summary Nitrosomorpholine (70 mg/litre drinking-water) or morpholine (6·33 g/kg food) plus sodium nitrite (1·0g/litre drinking-water) was administered to guinea-pigs, which were fed a diet containing either a high or a low level of ascorbic acid or no ascorbic acid at all. Animals on the ascorbic acid-deficient diet developed scurvy before toxic effects of either the nitrosamine or the nitrosamine precursors were evident. Precancerous liver changes occurred in guinea-pigs receiving nitrosomorpholine together with the high or low levels of ascorbic acid. Animals receiving the nitrosamine precursors together with ascorbic acid were not affected. Guinea-pigs and other species that require exogenous sources of ascorbic acid may be protected from the hazard of in vivo nitrosation by the presence of ascorbic acid in the stomach.
Association of glycogen storage disease 1b and Crohn disease: results of a North American survey

Glycogen storage disease (GSD)-1b has been associated with neutropenia and abnormalities of neutrophil function. Many individuals with GSD-1b manifest chronic gastrointestinal inflammation. Our study was performed to precisely establish the type, frequency, and spectrum of gastrointestinal disease in patients with GSD-1b. We established a medical database of 36 individuals affected with GSD-1b, utilizing patients at our center, disease registries, and direct contacts with North American referral centers specializing in genetic disorders. Records were reviewed, focusing on documentation of gastrointestinal involvement. Gastrointestinal symptoms or manifestations were present in approximately 75% of the patients, including chronic abdominal pain and diarrhea, perianal fistula or abscess, and oral aphthous ulceration. Of patients identified, 28% had documented inflammatory bowel disease (IBD) and an additional 22% of patients had symptoms highly suggestive of IBD, but had not undergone comprehensive diagnostic evaluation. Gastrointestinal involvement was found to be indistinguishable from idiopathic Crohn disease (CD) by detailed review of clinical, radiologic, endoscopic and histopathologic findings. Many patients had significant improvement or resolution of gastrointestinal disease in response to G-CSF treatment. The expression of CD in patients with GSD-1b may be delayed or prevented by G-CSF treatment.Conclusion: a strong association exists between glycogen storage disease type 1b and inflammatory bowel disease. A high index of suspicion for Crohn disease should be applied in evaluating patients with glycogen storage disease type 1b and intestinal symptoms. These results provide further support for the hypothesis that some forms of inflammatory bowel disease may result from impaired mucosal innate immunity. Additional investigations into the intestinal disease in glycogen storage disease type 1b may be directly relevant to the etiology and treatment of idiopathic Crohn disease.
Lack of Tyrosylprotein Sulfotransferase-2 Activity Results in Altered Sperm-Egg Interactions and Loss of ADAM3 and ADAM6 in Epididymal Sperm

Tyrosine O-sulfation is a post-translational modification catalyzed by two tyrosylprotein sulfotransferases (TPST-1 and TPST-2) in the trans-Golgi network. Tpst2-deficient mice have male infertility, sperm motility defects, and possible abnormalities in sperm-egg membrane interactions. Studies here show that compared with wild-type sperm, fewer Tpst2-null sperm bind to the egg membrane, but more of these bound sperm progress to membrane fusion. Similar outcomes were observed with wild-type sperm treated with the anti-sulfotyrosine antibody PSG2. The increased extent of sperm-egg fusion is not due to a failure of Tpst2-null sperm to trigger establishment of the egg membrane block to polyspermy. Anti-sulfotyrosine staining of sperm showed localization similar to that of IZUMO1, a sperm protein that is essential for gamete fusion, but we detected little to no tyrosine sulfation of IZUMO1 and found that IZUMO1 expression and localization were normal in Tpst2-null sperm. Turning to a discovery-driven approach, we used mass spectrometry to characterize sperm proteins that associated with PSG2. This identified ADAM6, a member of the A disintegrin and A metalloprotease (ADAM) family; members of this protein family are associated with multiple sperm functions. Subsequent studies revealed that Tpst2-null sperm lack ADAM6 and ADAM3. Loss of ADAM3 is strongly associated with male infertility and is observed in knockouts of male germ line-specific endoplasmic reticulum-resident chaperones, raising the possibility that TPST-2 may function in quality control in the secretory pathway. These data suggest that TPST-2-mediated tyrosine O-sulfation participates in regulating the sperm surface proteome or membrane order, ultimately affecting male fertility.
Tumor necrosis factor-α in midtrimester amniotic fluid is associated with impaired intrauterine fetal growth

Abstract OBJECTIVE: To investigate whether abnormal immune system activation is involved in the pathogenesis of some instances of impaired fetal growth, we compared tumor necrosis factor-α levels in midtrimester amniotic fluid samples obtained from appropriate-for-gestational-age and small-for-gestational-age pregnancies. STUDY DESIGN : In a case-control study with the sensitive and specific WEHI cell assay, bioactive tumor necrosis factor-α levels in amniotic fluid samples from 24 gestations resulting in small-for-gestational-age infants were compared with levels in 35 samples obtained from gestations resulting in the birth of a term, appropriate-for-gestational-age infant. The two groups were not significantly different with regard to indication for amniocentesis, maternal age, race, smoking history, parity, or other factors. RESULTS : Elevated amniotic fluid tumor necrosis factor-α activity was associated with small-for-gestational-age birth, p = 0.028. With a threshold of 10 pg/ml, elevated amniotic fluid tumor necrosis factor-α had a sensitivity of 48% for the detection of small-for-gestational-age birth, with a specificity of 83%. CONCLUSION : Elevated tumor necrosis factor-α in midtrimester amniotic fluid is associated with impaired intrauterine fetal growth. Abnormal immune system activation, as manifested by increased amniotic fluid tumor necrosis factor-α activity, may mediate impaired fetal growth in some cases. (Am J Obstet Gynecol 1992;167:920–5.)
Commentary: teaching the teacher—spaced education as a novel approach to teaching interns to teach

In the present study, ‘‘Using Spaced Education to Teach Interns About Teaching Skills,’’ Pernar et al investigated the use of electronic distribution of content to interns with succinct teaching pearls on a weekly basis. Although the study was underpowered and focused on 3 distinct teaching skillsdeffective delivery of feedback, teaching and learning principles, and dissemination of core clerkship content to studentsdit provides evidence that a strategy of spaced education may be an effective approach for efficiently delivering this material to interns and engaging them in the teaching process. Given the expectation of the Liaison Committee on Medical Education that we provide our residents with formal training in teaching, coupled with a significant reduction in postgraduate year 1 duty hours, an approach such as that described in this study is very appealing. In this era of less time for interns to both receive content and to participate in teaching activities, a focus on just-in-time teaching skills is critical, and the described spaced education technique allows an emphasis on this approach and minimizes the time required to deliver the content to interns. Pedagogically, the approach of distributed practice in delivering the feedback and learning pearls and reminders to teach weekly is also sound. Although we typically think of the importance of distributed practice for technical skills acquisition, this concept almost certainly applies here as well. Delivery of content and teaching tips in small ‘‘digestible chunks’’ allows interns to better incorporate these skills by practicing them regularly. This approach is
The significance of continental derivation of the Proterozoic Mahanid Formation, southeastern Arabian Shield

The Mahanid Formation is a quartzo-feldspathic meta-sedimentary unit exposed in the southeastern part of the Arabian shield. Detritus was derived from a continental landmass located to the southeast. Erosional products were deposited in an adjacent marginal basin which existed from middle to late Proterozoic time. The Mahanid Formation is correlated with other formations in the eastern shield area, but differs from meta-sedimentary units in the western part of the Arabian shield.
Quantitation of D antigen content in inactivated poliovirus vaccine derived from wild-type or sabin strains.

Abstract Abstract. The enzyme-linked immunosorbent assay (ELISA) is currently the in vitro method for the measurement of the D antigen content of inactivated poliovirus vaccines (IPV) of greatest interest. The sensitivity and specificity of the test is dependent on the antibodies selected for use. We evaluated monoclonal and polyclonal antibodies for specificity to D antigen and wild or attenuated (Sabin) strains used in vaccine production. When used as detection antibodies the types 1 and 2 monoclonal antibodies raised against wild-type poliovirus strains were D antigen-specific and cross-reactive with the corresponding Sabin strains. The type 3 monoclonal antibody was weakly cross-reactive with Sabin type 3 vaccine. In contrast, polyclonal antibodies were less D antigen-specific, but reacted equally well with wild-type and Sabin strain vaccines. The ELISA using monoclonal antibodies was shown to be highly reproducible. Reactivity with these monoclonal antibodies implies that a D-specific neutralizing epitope of each respective poliovirus type has been preserved in the inactivation process. Evaluation with additional neutralizing D antigen-specific monoclonal antibodies may be necessary to determine whether reactivity with one epitope of each type in an in vitro test is sufficient to predict potency of the vaccine in humans.
Transfer between menu systems

This paper investigates whether changes in the user/computer dialogue structure will affect the performance of users who are familiar with an earlier version of the product. Quantitative predictions using the Kieras and Polson (1985) production system model were derived to test whether changing the lexical attributes and structure of a popular menu-driven word-processor would permit transfer of existing knowledge of the word-processor to a new version. The results show that changes to the dialogue structure of the menu-system are not detrimental, while changes to the lexical attributes of the menus will hinder user performance.
First-principles phonon spectra in Ca and Sr

Experimental phonon spectra for the fcc alkaline-earth metals Ca and Sr have only recently been obtained. First-principles, generalized-pseudopotential-theory predictions of these spectra, including the full effects of $d$-state hybridization, are reported and compared with these results. The overall agreement between theory and experiment is found to be quite good (within about 10%). In addition, anomalous behavior observed in the ${\mathrm{T}}_{1}$[110] branch for single-crystal Ca is also found theoretically.
A new response surface approach for time-variant reliability analysis

This paper presents a new approach, referred to as the nested extreme response surface (NERS), to efficiently carry out time-dependent reliability analysis and determine the optimal designs. The key of the NERS is to convert the time-dependent reliability analysis to time-independent one through constructing a kriging based nested time prediction model. The efficient global optimization technique is integrated with NERS to extract the extreme time responses of limit state functions and an adaptive response prediction and model maturation mechanism is developed for an optimal balancing of the model accuracy and the computational efficiency. With the nested response surface of time, existing advanced reliability analysis and design methods can be used. The NERS approach is integrated with RBDO for the design of engineered systems with time-dependent probabilistic constraints. The case study results demonstrate the accuracy and the effectiveness of the proposed approach.
Restricted coverage in wireless networks.

For wireless networks, coverage with different restrictions that can capture the practical requirements have received great research interests. We will study several restricted coverage problems. The first problem is about K-coverage , i.e., how to deploy wireless nodes such that each target is covered by at least K wireless nodes. We study the problem restricted to linear-K-coverage where there is a line, all targets lie in one side of this line and all wireless nodes lie in the other side. Assume each wireless node is associated with a weight, the objective is to select a minimum weighted subset of nodes such that each target is K-covered. We propose a 3-approximation for this problem by exploring geometric properties. The second problem is called Kroad-coverage. Given a road map in a two-dimensional area which contains a set of paths and a set of wireless nodes, the locations of nodes can either be arbitrary or fixed, the objective is to select a minimum number of wireless nodes such that each path can be K-covered. We will reduce the problem to K-coverage and apply the algorithmic results for K-coverage to solve it. Another line of this work is to investigate a well-motivated problem called strongly dominating set, which is intrinsically related to coverage. Given a wireless networking system represented by a digraph G = (V, −→ E ). Each wireless node u has a covering disk centering at u with its radius equal to the transmission range of u. We then draw a directed edge −→ uv in G if u’s corresponding covering disk contains v. A subset U ⊆ V of wireless nodes is a strongly dominating set if every wireless node in V \ U has both an in-neighbor in U and an out-neighbor in U . The objective is to find a minimum size strongly dominating set. Our method can achieve an approximation factor of (2 + ).
Poe and the printed word

Preface 1. The student and the book 2. Poetry in manuscript and print 3. Baltimore book culture 4. Booksellers' banquet 5. The novel 6. Poe's library 7. Cheap books and expensive magazines 8. The road to Literary America Notes Bibliography Index.
Processes and intelligibility in disordered phonology

Phonological process analysis is currently the most widely used analytical procedure for the investigation of phonological development in children. This study investigated the phonological processe...
Frequency measurement of radiation from normal to superconducting point contact junctions

Abstract The frequency of radiation from Ta(superconducting)-Al(normal) point contacts has been measured as a function of temperature. The dependence agrees with the Bardeen-Cooper-Schrieffer (BCS) gap equation for Ta.
Energy Metabolism in Audiogenically Seizure-Prone Chicks

Female chicks carrying the lethal, sex-linked recessive paroxysmal (px) gene are susceptible to spontaneous and audiogenic seizures. Because seizure activity does not begin until 1 to 2 weeks posthatching - coincidental with disappearance of the yolk-sac - it is postulated that a contributing factor to seizure activity may be a developmental failure of the chick's ability to switch from lipid to carbohydrate as a primary energy source. In testing this hypothesis, three experiments were performed: 1) to evaluate cerebral energy reserves - adenosine triphosphate (ATP), phosphocreatine - of px and normal chicks; 2) to determine effects of energy source (ethanol, glucose, insulin, and glucose-insulin combined) on audiogenically-induced seizure activity and electrical seizure threshold; 3) to evaluate energy source utilization as estimated by the respiratory quotient (RQ). Brain ATP and phosphocreatine levels in px chicks were both decreased (P less than .05) as early as 10 days posthatching. Ethanol increased electrical seizure threshold in 50% of px chicks and provided protection from audiogenic stimulation. No consistent effect was found with any of the other substances. The RQ of px chicks were lower (P less than .05) than those of controls by 18 days posthatching.
Delayed neonatal lung macrophage differentiation in a mouse model of in utero ethanol exposure.

We have previously demonstrated that fetal ethanol exposure deranges the function and viability of the neonatal alveolar macrophage. Although altered differentiation of the alveolar macrophage cont...
What works in market-oriented health policy?

The use of market forces in health policy typically involves altering out-of-pocket prices and information for consumers (the demand side) and incentives for providers (the supply side). Meredith Rosenthal writes that the main question is how to design these interventions to improve the medical system, without harmful side effects.
The influence of delay upon an idealized channel's bandwidth

An optimization problem in calculating the bandwidth of a covert timing channel is discussed. In particular, the question of how dependent the bandwidth is on the magnitude of the modulation is addressed. A generalization of that covert channel is presented and its bandwidth (capacity) is studied. Attention is given to how the delay that HIGH uses to signal LOW affects the bandwidth. Increasing the delay lessens the noise but increases the time required to pass a symbol along the channel. What the optimal delay should be and how it influences the security of the system was studied. Because of the complicated nature of the formulas involved, closed-form solutions for some of the terms of interest cannot be given. Instead, numerical techniques and plotted results are used. >
Gibberellin‐like Substances in Developing Watermelon Seeds

Watermelon seeds were analyzed 4, 7, 9, 11, 19, 25 and 35 days after pollination. The gibberellin-like substances were low up to 7 days after pollination, but increased rapidly in the next two days attaining a peak on the 9th day after pollination. The amount then declined and remained low till the seeds matured. Since the peak of gibberellin-like activity coincided with (but did not precede) the time when the seeds attained their maximum size, it was concluded that it could not account for their growth. Instead, evidence was obtained to show that the peak may be correlated with the growth of the embryo and endosperm. Thin-layer chromatography revealed the presence of three active gibberellin-like factors at the 9th day after pollination. The chromatographic behavior of two of these active factors are similar to gibberellins A1 and A3. The data currently available are insufficient regarding the identification of a third gibberellin from watermelon seeds.
Communication-Sensitive Static Dataflow for Parallel Message Passing Applications

Message passing is a very popular style of parallel programming, used in a wide variety of applications and supported by many APIs, such as BSD sockets, MPI and PVM. Its importance has motivated significant amounts of research on optimization and debugging techniques for such applications. Although this work has produced impressive results, it has also failed to fulfill its full potential. The reason is that while prior work has focused on runtime techniques, there has been very little work on compiler analyses that understand the properties of parallel message passing applications and use this information to improve application performance and quality of debuggers.This paper presents a novel compiler analysis framework that extends dataflow to parallel message passing applications on arbitrary numbers of processes. It works on an extended control-flow graph that includes all possible inter-process interactions of any numbers of processes. This enables dataflow analyses built on top of this framework to incorporate information about the application's parallel behavior and communication topology. The parallel dataflow framework can be instantiated with a variety of specific dataflow analyses as well as abstractions that can tune the accuracy of communication topology detection against its cost.The proposed framework bridges the gap between prior work on parallel runtime systems and sequential dataflow analyses, enabling new transformations, runtime optimizations and bug detection tools that require knowledge of the application's communication topology. We instantiate this framework with two different symbolic analyses and show how these analyses can detect different types of communication patterns, which enables the use of dataflow analyses on a wide variety of real applications.
Commentary: Feedback activities of instructors during a trauma surgery course.

Although an expanding area of inquiry, our understanding of instruction for the acquisition of technical and nontechnical skills by surgical trainees is fairly limited. ‘‘Feedback activities of instructors during a trauma surgery course’’ provides us with new information by describing how instructors guide trainees during a structured surgical exercise; the Definitive Surgical Trauma Care (DSTC) scenarios used were designed to assess both technical and nontechnical skills of the trainees. The authors identified that their instructors were most likely to provide nonreinforced instructions focusing on technical skills. Although nontechnical skills were a core component of DSTC, the findings show that the surgeon–instructors generally shied away from addressing communication and team dynamics. One notable feature of DSTC as administered in this study is the reliance on the instructors’ status as Advanced Trauma Life Support (ATLS) instructors as the source of their training. Although ATLS instructors are put through a rigorous process to attain their instructor status, it is not clear how recently these instructors participated in the initial certification process as ATLS instructors. The added focus on nontechnical skills in
Numerical solution of optimal control problems

A numerical method for solving optimal control problems is presented. The method consists of representing the solution of the optimal control problem by a Chebyshev polynomial, discretizing the problem using a cell averaging technique, thereby reducing the problem to a parameter optimization problem, applying the Lagrange multiplier method, and finally Newton's method. This method is efficient, easy to code, and yields accurate results. A numerical example is provided, and a comparison is made with a similar method in the literature. >
Response to Comments on Howard (2004)

These remarks respond to the comments offered by four colleagues on my paper "Speaking of Decisions: Precise Decision Language" (Howard 2004). The response gives me the opportunity to clarify and expand on the paper and to note different views. In particular, I further discussrandom variable, distinction, expected value, option, utility as a measure of happiness or satisfaction,subjective probability, the necessity of avalue measure for computing thevalue of clairvoyance, decision analysis as anormative discipline, and the inability of the clairvoyant to provide probabilities. I conclude with aconcept map for the language and a table showing where the terms are most useful in conversations with students and clients.
Central hemodynamic effects of an oxytocin receptor antagonist (atosiban) in the isolated, perfused rat heart.

OBJECTIVE Atosiban is a selective oxytocin receptor antagonist capable of inhibiting oxytocin-induced contractility of the uterus. Trials of this agent in intact animals and women as a tocolytic agent for preterm labor have shown atosiban to be devoid of cardiac effects. This is in contrast to other tocolytic agents, which have profound hemodynamic effects. We conducted this study to determine the cardiac effect of atosiban in the isolated, perfused rat heart model. METHODS Hearts were excised from 60 female Sprague-Dawley rats and attached to a Langendorff apparatus. Left ventricular systolic pressure, heart rate, and contractility were measured. Hearts from half of the animals were exposed serially to 300 micrograms/min, 600 micrograms/min, and 1200 micrograms/min of atosiban. The remaining hearts formed the control group and were exposed to aerated Krebs solution. RESULTS There were no significant differences between hearts exposed to atosiban and hearts within the control group for heart rate, left ventricular systolic pressure, and contractility. P values ranged from .12 to .73. CONCLUSIONS Using a classic physiologic model to study cardiac performance and drug effects, we were unable to detect any central hemodynamic effects of atosiban. This is in contrast to oxytocin, which we previously studied and found negative chronotropic and positive ionotropic effects.
Influence of the hole-transport layer on the initial behavior and lifetime of inverted organic photovoltaics

Abstract The inverted organic photovoltaic (OPV) device architecture represents an important advancement due to the relative environmental stability of the electron transport layer (ETL) and hole-collecting contact. We investigated the initial and long-term behavior of inverted devices to identify changes taking place at the Ag hole-collecting contact. We show that efficient hole collection can be obtained after modifying the Ag contact by thermal annealing, long-term exposure to ambient atmosphere, or employing a high work function organic hole-transport layer (HTL). We find that whether or not the device employs an organic HTL, degradation of the photocurrent initially follows a simple exponential decay. After prolonged illumination (>500 h), devices with an organic HTL fail catastrophically due to a precipitous drop in photocurrent. Based on evidence for pinhole-induced degradation observed in photocurrent maps, we propose a nucleation and island growth mechanism and a model for the photocurrent behavior employing a modified Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation. Devices that do not contain an HTL appear to degrade by a mechanism other than pinhole ingress resulting in a more uniform degradation of the photocurrent across the active area.
Kidney biopsies in multiparous patients with vascular renal disease in pregnancy

Abstract Renal biopsies were obtained at delivery from 66 multiparas who had toxemia in one or more pregnancies and from 10 multiparas whose pregnancies were uncomplicated by toxemia. There were no renal abnormalities in this latter group. Ten individuals who had had previous pre-eclampsia and eclampsia, and 24 individuals in whom the diagnosis of hypertensive disease was made exhibited normal histologic findings. Fourteen individuals presented findings characteristic of nephrosclerosis. Six had chronic renal disease of uncertain etiology. Four had chronic pyelonephritis in the absence of clinical evidence of the disease, and 2 individuals in this group had clinically undiagnosed bilateral polycystic kidneys as an additional finding. Lupus nephritis was present in 2 patients. The so-called “reversible toxemic lesion” was present in a moderate or severe form in 18 per cent of these patients, and the status of this lesion was regarded as uncertain. Many individuals had considerable renal disease with little clinical evidence of it, while others had a clinically severe toxemia of pregnancy in the absence of demonstrable renal disease. It was impossible to predict the presence of organic renal changes or the magnitude of the renal lesion on the basis of the fundoscopic findings. It was concluded that pre-eclampsia and eclampsia did not result in permanent renal damage and evidence was presented to support the contention that an increase in hypertension, proteinuria, and edema, or the initial occurrence of these manifestations of toxemia during the last 14 weeks of gestation in an individual with renal-vascular disease was the result of an exacerbation of this disease rather than the result of superimposed pre-eclampsia.
Buoyancy transfer across a diffusive interface

An experimental investigation of various aspects of buoyancy transfer across a diffusive density interface that separates stably stratified, turbulently convecting layers of relatively fresh cold water overlying hot salty water is described. It is argued that the interfacial layer should possess a double boundary-layer structure, in which the thicknesses of the salt and heat interfacial layers are determined by a balance between the opposing effects of diffusion and entrainment. Based on this argument, a simple theory, that predicts the interfacial-layer thickness, the diffusive heat and salt fluxes across the density interface, and the time variation of the temperature and salt concentrations in the convecting layers, is proposed for the case in which the convection is driven by a constant heat flux supplied to the lower layer. During a certain time interval, the theory and experiment agree well, but thereafter distinct differences can be seen. Measurements suggest that these differences may be due to the distortion of the density interface at low interfacial stabilities by turbulent eddies, which leads to a change in the buoyancy transfer mechanism. When the Richardson number falls below a critical value Riv, the interface was found to migrate slowly upwards and the mechanism of entrainment was the detachment of thin sheets of fluid by eddies scouring the interface.
Day-night pattern in accidental exposures to blood-borne pathogens among medical students and residents

The purpose of this study was to determine whether the occurrence of accidental blood-borne pathogen exposure incidents in medical students and residents in training varies during the 24h. A retrospective review of reported exposures was conducted in a large urban teaching institution—the University of Texas Health Science Center in Houston—between November 1993 and July 1998. Professional level (year of student or level of resident), time of exposure, means/route of exposure (needle stick, laceration, or splash), and type of medical service were recorded. Analysis of the clock time of the 745 reported blood-borne pathogen exposures showed they occurred more frequently during the day than night. Over the nearly 5-year span, 531 incidents took place between 06:00 and 17:59 in comparison to only 214 between 18:00 and 05:59. To account for the day-night difference in medical student and resident hospital staffing, the data were reexpressed as exposure rates, that is, in terms of the number of events per hour...
The NCl's cancer centers program: Past, present, and future

Since passage of the National Cancer Act in 1971, the NCI Centers Program has promoted the establishment and the development of cancer centers of many types throughout the nation. These now include 20 comprehensive cancer centers, as well as a number of clinical and basic science centers that are supported through NCI core grants. Scientific productivity at NCI-supported centers has been high. While cancer center core grants usually represent only a small proportion of the total extramural research support for a given institution, they are essential in providing shared resources and in pulling together the various component research programs of a center into a unified program. The future directions of the NCI centers program as a whole, as well as the role of cancer research centers within their communities and regions, are discussed.
Possible role of root border cells in detection and avoidance of aluminum toxicity.

Root border cells are living cells that surround root apices of most plant species and are involved in production of root exudates. We tested predictions of the hypothesis that they participate in detection and avoidance of aluminum (Al) toxicity by comparing responses of two snapbean (Phaseolus vulgaris) cultivars (cv Dade and cv Romano) known to differ in Al resistance at the whole-root level. Root border cells of these cultivars were killed by excess Al in agarose gels or in simple salt solutions. Percent viability of Al-sensitive cv Romano border cells exposed in situ for 96 h to 200 μm total Al in an agarose gel was significantly less than that of cv Dade border cells; similarly, relative viability of harvested cv Romano border cells was significantly less than that of cv Dade cells after 24 h in 25 μm total Al in a simple salt solution. These results indicate that Al-resistance mechanisms that operate at the level of whole roots also operate at the cellular level in border cells. Al induced a thicker mucilage layer around detached border cells of both cultivars. Cultivar Dade border cells produced a thicker mucilage layer in response to 25 μM Al compared with that of cv Romano cells after 8 h of treatment and this phenomenon preceded that of observed cultivar differences in relative cell viability. Release of an Al-binding mucilage by border cells could play a role in protecting root tips from Al-induced cellular damage.
Has GPRA Increased the Availability and Use of Performance Information

The underlying logic of the Government Performance and Results Act (GPRA) suggests that programs should be evaluated based on empirical evidence that they actually produce the intended outcomes. This study applies the same logic to GPRA itself, investigating empirically whether GPRA may have increased the availability and use of performance information in federal agencies. Better GPRA performance reporting is correlated with greater availability and use of several kinds of performance information by federal managers in the programs and operations they supervise. The results are statistically significant and relatively large. Correlations are especially significant for types of activities GPRA sought to encourage, such as output and outcome measures and use of performance information to allocate resources, set priorities, and develop measures and goals. These findings are consistent with the theory that GPRA has indeed prompted improvements in the availability and use of performance information in the federal government. Leadership commitment to achieving results also has a big effect on the availability and use of performance information. Leaders respond to institutional constraints and incentives, but they have leeway to pursue performance management more or less aggressively. Program types have a small effect on the availability and use of performance information; agency ideology has a similarly small effect. A more focused mission has a moderately large and positive effect. Congressional interest in using performance information can spur agencies to develop and use performance measures.
Boundary behavior of non-isotropic potentials in the unit ball of

On the unit sphere S of “non-isotropic” potential of the function is given by , where 0 1 and as a consequence the y possess boundary limits σ almost everywhere on S within regions having tangential contact with the boundary S. We also give an application of our results to the Hardy Sobolev spaces of holomorphic functions on B.
Celebrating a Diamond Anniversary: Pennsylvania Bar Association Quarterly Volumes 1-74 (1929-2003): A History

This article reviews the history of the scholarly journal published by the Pennsylvania Bar Association for its 75th anniversary.
To Ignore or Not to Ignore: A Silly Debate in the U.S. Supreme Court?

Among the many important and trenchant debates that take place in the U.S. Supreme Court, there occasionally emerges a debate that at first glance could be described as silly for grown professionals. Justice Scalia could be seen as contending that the Court must turn a blind eye to what other nations think about an issue of law, even if there is a consensus among the international community on the issue. In truth, however, his approach is part of a more subtle and broader debate, primarily regarding the degree to which constitutional interpretation should take account of changing societal norms.
Effect of pressure on supercritical CO2 compatibility of structural alloys at 750 °C

Several power generation technologies have interest in employing a supercritical CO2 (sCO2) cycle but relatively little compatibility work has been conducted at the target pressure range of 200–300 bar, particularly at ≥700 °C. With the goal of utilizing lower pressure data sets (especially with controlled O2 and H2O contents), this initial assessment compared the effect of CO2 pressure at 1–300 bar on the compatibility of potential Fe- and Ni-base structural alloys after 500 h exposures at 750 °C. For highly-alloyed alumina- and chromia-forming alloys, a minimal effect of pressure was observed on the mass change and reaction products, which were similar to those observed in 1 bar dry air, CO2, CO2–0.15%O2 and CO2–10%H2O. After these relatively short exposures, there was no obvious indication of internal carburization and the Cr depletion in the precipitation strengthened Ni-base alloys (740 and 282) was minimal. In addition to coupons, 25 mm long tensile specimens of alloy 740, 247, 310HCbN, and E-Brite (Fe–Cr) were exposed in each condition but did not show any detrimental effect of the high-purity CO2 environments on room temperature tensile properties.
Classification of rotavirus VP4 and VP7 serotypes

Rotaviruses, members of the Reoviridae family, are major etiologic agents of acute nonbacterial gastroenteritis of the young in a wide variety of mammalian and avian species, including humans. The need for effective immunoprophylaxis against rotaviral gastroenteritis has stimulated interest in the biochemical, molecular, genetic, and clinical aspects of these agents with the aim of developing safe and effective vaccines. Because neutralizing antibodies appear to play an important role in protection against many viral diseases, rotavirus antigens that induce neutralizing antibodies have played a central role in research and development of a rotavirus vaccine. The VP7 glycoprotein and VP4 spike protein that constitute the outer capsid of a complete rotavirus particle have been shown to be independent neutralization antigens. Since type specificity of the outer capsid proteins of a rotavirus appears to play an important role in protection against disease in experimental animal models, continued efforts have been made for classification and typing of neutralization specificities on the VP7 or VP4 capsid protein. Based on a criterion of > 20-fold differences between the homologous and heterologous reciprocal neutralizing antibody titers, fourteen VP7 (G) serotypes have been established. Studies are underway to characterize and classify the VP4 (P) serotypes among the strains that exhibit the fourteen different G serotypes. Attempts to classify the VP4 serotypes based on the same criterion (i.e., > 20-fold antibody differences) that is applied to classification of VP7 serotypes are in progress. This standard of > 20-fold antibody differences can be applied with hyperimmune serum raised to a reassortant possessing the VP4 encoding gene (and an unrelated VP7 encoding gene). Genotypes can provide leads towards classification but the serotype of a strain should be based on neutralization.
Numerical Algorithms for H ∞ Optimization in Control Theory

In this short chapter we will present one of the connections between operator theory and control theory. In Section 1 we will show how some of the previous H∞ optimization problems introduced in Chapter IX naturally arise in robust control theory. One of the simplest of these problems will be solved in Section 3, by another method inspired by the functional model theory presented in Section IX.5. For this purpose some useful operator theoretical preparations are given in Section 2.
Blending computational and experimental neuroscience

The launch of the United States' BRAIN Initiative brings with it a new era in systems neuroscience that is being driven by innovative neurotechnologies, increases in computational power and network-style artificial intelligence. A new conceptual framework for understanding cognitive behaviours based on the dynamical patterns of activity in large populations of neurons is emerging.
Cortical Dysfunction in Autism

Cerebellar and cortical systems in 26 high-functioning adolescents and young adults with autism were examined and compared to 26 healthy controls at the University of Pittsburgh School of Medicine.
Sinonasal Tract: Nonneoplastic

If it appears strange that that one etiologic agent gives rise to such a diversity of disease, then consider the three major components of any infectious process: (1) the inherent virulence of the agent, (2) the infectious dose, and (3) the patient status. Allergic fungal sinusitis represents the most common form of sinonasal fungal disease. Invasive fungal sinusitis {acute, ( 12 weeks)} represents the most serious sinonasal fungal disease, which develops in the setting of neutropenia, or neutrophil dysfunction. Other more rare and exotic sinonasal infectious conditions, or infectious mimickers are also discussed in this chapter.