cssi/SciSciGPT-SciSciNet huggingface dataset:
Bend-stretch Fermi resonance in NO2+ observed by delayed pulsed-field ionization zero-electron kinetic energy photoelectron spectroscopy

Abstract By means of zero-electron kinetic energy (ZEKE) threshold photoelectron spectroscopy, we examine bend-stretch Fermi resonance in NO2+. Accurate fundamental frequencies are obtained by using the (000) 3pσ Rydberg state as a reference state for all ionic vibrational ZEKE spectra. The degree of (100)–(02°0) Fermi resonance observed in NO2+ is comparable to that found in the NO2 3pσ Rydberg state, and results for both systems agree well with recent CCSD(T) and MRD-CI ab initio calculations. Comparison of the vibrational frequencies of the 3pσ Rydberg state and the cation suggests that the presence of the Rydberg electron slightly perturbs the harmonic potential and its second-order anharmonicities, but has little effect on the cubic coupling term associated with core Fermi resonance.
Influence of dietary lipids upon lipids in larvae and adults of the dried-fruit moth

Abstract The dried-fruit moth was reared on three diets differing in quantity and types of fatty acids. Triacylglycerols (TAG) were the major lipid present in both larvae and adults and their fatty acid compositions reflected dietary fatty acids to some extent. However, larval and adult contained relatively high levels of 16:0, 16:1, and 18:1 even when these acids were not predominant in the dietary lipid. Diacylglycerols were present in larvae and adults at lower levels than TAG and their fatty acid compositions were similar to those of the corresponding TAG. Adults contained more phospholipid (PL) and cholesterol than larvae regardless of diet employed. Phosphatidyl-ethanolamine and phosphatidyl-choline were the major PL present with appreciable levels of diphosphatidyl-glycerol and lesser amounts of lysophosphatidyl-ethanolamine and choline, sphingomyelin, phosphatidyl-serine, and inositol being present. The higher level of PL noted in the adults were due to a general increase in all of the individual phospholipids and not to any specific PL. Dietary fatty acids did influence fatty acid compositions of larval and adult PL. However, there appeared to be compensations in the proportions of other fatty acids in the PL in that high 18:1 was accompanied by lowered levels of 18:2 and high 18:2 was accompanied by lowered levels of saturated fatty acids. In every case adult PL contained more polyenoic fatty acids than did larval PL. There were no apparent compensations in other fatty acids accompanying these changes.
Absolute Optical Absorption from Diffuse Reflectance

An equation relating the diffuse reflectance of crystalline powders to particle size, index of refraction, and absolute optical absorption coefficient is derived. Absorption spectra calculated by means of this equation from diffuse reflectance of KCl:Tl, KBr:Tl, and didymium glass are shown to be in satisfactory agreement with absolute absorption measurements on clear crystals of the same materials.
Microprocessor memory management units

This tutorial describes the current crop of commercial memory management units (MMUs) for 32-bit microprocessors. The discussion includes both complex- and reduced-instruction-set computers (CISCs and RISCs). The rationale, principles, and issues related to hardware support for memory management and virtual memory are reviewed. The design and features of high-end microprocessor MMUs are reviewed and compared with respect to a common set of criteria. Special attention is paid to Unix requirements and multiprocessor, multiple MMU considerations. The MMUs covered are Intel 80386, i486, and i860; Motorola's 68851 (MMU for the 68020), 68030, 68040, and 88200 (MMU for the 88000 series); the Fujitsu MB86920 (Sparc MMU); and the MIPS R2000/R3000. >
Hydrophobic aerogels for oil-spill clean up : synthesis and characterization

Abstract Hydrophobic aerogels were synthesized, characterized by IR, surface areas, relative pore size distributions and decomposition behavior. The materials were then tested for oil absorbing capacity in oil salt-water mixtures for applications to oil-spill clean up processes. Aerogels containing the CF 3 (CH) 2 -group (CF 3 -aerogel) were successfully synthesized using (CH 3 O) 4 Si and nominally 30, 10, 1.5 mol% CF 3 (CH 2 ) 2 Si(OCH 3 ) 3 in CH 3 OH by a NH 4 OH catalyzed reaction followed by supercritical extraction with CH 3 OH. The aerogels were found to be hydrophobic based on water absorption and sessile drop experiments. By IR, the CF 3 (CH 2 ) 2 -group was found to be intact after the gelation process and after supercritical drying. Si–OH-groups were also found in all cases, with decreasing amounts with increasing amounts of the CF 3 (CH 2 ) 2 -group. Heating under air caused the 30% CF 3 -aerogel to decompose, where the transition temperature from hydrophobic to hydrophilic appeared around 375–400 °C, which corresponded to disappearance of the CF 3 (CH 2 ) 2 -moiety bands in the IR. Treating oil and salt-water mixtures with the aerogel at an oil to aerogel ratio of 3.5 showed that all CF 3 -aerogels cleanly separated the oil from the water, regardless of CF 3 (CH) 2 -group concentration. This indicates that CF 3 -aerogels can absorb oil as much as 237 times their weight, much more than previously determined.
EFFECTIVE POTENTIAL FOR E-NEON AND E-ARGON SCATTERING BY DCS MINIMIZATION AT INTERMEDIATE ENERGIES

The differential scattering cross-section (DCS) for electrons scattered elastically by neon and argon atoms is studied using a model potential. In the present study the long-range polarization potential is represented by an energy-dependent function, and the short-range part is constructed from the nonrelativistic Hartree-Fock wave function of the target atom. The computed differential cross section obtained using the approximate effective interaction potential for electrons scattered by neon and argon atoms in their ground state is compared with available published results. In the present study the parameters contained in the energy-dependent effective potential are determined by the minimization of the DCS with respect to angle {theta} and the incident energy. The resulting DCS in the angular range 2{degree} < {theta} < 178{degree} is found to be in good agreement with the available experimental and theoretical results in the intermediate energy range.
Cryo-EM Structure of Functional BK Channels in Lipid Bilayers

A natural way to preserve the native conformation of membrane proteins for structural study is to reconstitute them into liposomes (lipid vesicles). Here we applied this method to single-particle cryo-EM imaging of the hSlo large-conductance voltage- and Ca2+-activated potassium channel (BK channel). In an assay using the JC-1 voltage-sensitive dye, proteoliposomes develop a membrane potential that is equal to that produced by valinomycin, and to that of empty liposomes when the BK channels are blocked by barium (A). For cryo-EM imaging the reconstituted BK proteoliposomes were tethered to a 2D streptavidin crystal (B). From this image the periodic crystal information was removed (C) and a liposome model of electron scattering was used to subtract the lipid bilayers (D). For 3D reconstruction, single-particle images (boxes) were oriented with constraints based on the spherical vesicle geometry. A structure based on these particle images will be presented. Scale bar in the figures is 50 nm.View Large Image | View Hi-Res Image | Download PowerPoint Slide
Influence of polyimide precursor synthesis route and ortho-position functional group on thermally rearranged (TR) polymer properties: Conversion and free volume

Abstract Thermal rearrangement of polyimides with ortho-position groups to polybenzoxazoles and related structures has been of recent interest for producing gas separation membranes. This study explores the influence of synthesis route and ortho-position functional group on the thermal rearrangement process and the fractional free volume of thermally rearranged (TR) polymers produced from polyimides derived from 3,3′-dihydroxy-4,4′-diamino-biphenyl and 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (HAB–6FDA). Acetate, propanoate, and pivalate ortho-position functional groups were considered. Thermogravimetric analysis (TGA) was used to study thermal rearrangement at temperatures between 350 and 450 °C, and evolved gases from TGA were analyzed via mass spectrometry to characterize the byproducts of thermal rearrangement and thermal degradation. CO2 was the major byproduct of thermal rearrangement for all samples, and its evolution began well before the onset of thermal degradation. When non-hydroxyl ortho-position groups were present in the polymers, several byproducts other than CO2 were also observed due to the loss of these ortho-position groups before thermal rearrangement. Free volume generally increased with increasing extent of thermal rearrangement, but precise values of free volume could not be accurately determined for polymers with propanoate and pivalate ortho-position functional groups due to uncertainties in the chemical structure of partially converted materials. For polymers with acetate and hydroxyl ortho-position groups, free volume could be determined within the uncertainty of density measurements. Thermal rearrangement behavior and free volume results for acetate containing polymers synthesized via different routes were very similar. Based on these results, the chemical structure of the ortho-position functional group has a larger impact on TR polymer properties than the polyimide precursor synthesis route.
Asymmetric dimethylarginine and impaired cardiovascular healing

Asymmetric dimethylarginine (ADMA) typically accumulates in the plasma of patients with chronic renal failure. Moreover, its plasma levels are raised in the presence of virtually all of the traditional cardiovascular risk factors. ADMA inhibits the three isoforms of nitric oxide (NO) synthase, thereby blunting the known cardioprotective effects of NO. Through its NO inhibitor actions, ADMA also exerts pro-apoptotic effects and suppresses progenitor cell mobilization, differentiation and function. Among patients with ischemic heart disease, low progenitor cell bioavailability and kidney dysfunction are emerging as strong predictors of death and recurrent cardiovascular events. We propose that patients with ischemic heart disease, kidney dysfunction, and high risk factor burden exhibit adverse cardiovascular outcomes, at least in part, through ADMA-mediated NO depression, enhanced apoptotic signalling, and reduced progenitor cell bioavailability, with consequent blunting of cardiovascular healing. Further research into the mechanisms that regulate the NO/ADMA balance may advance our understanding of cardiovascular diseases.
Mitosis in vertebrates: the G2/M and M/A transitions and their associated checkpoints

In this review, I stress the importance of direct data and accurate terminology when formulating and communicating conclusions on how the G2/M and metaphase/anaphase transitions are regulated. I argue that entry into mitosis (i.e., the G2/M transition) is guarded by several checkpoint control pathways that lose their ability to delay or stop further cell cycle progression once the cell becomes committed to divide, which in vertebrates occurs in the late stages of chromosome condensation. After this commitment, progress through mitosis is then mediated by a single Mad/Bub-based checkpoint that delays chromatid separation, and exit from mitosis (i.e., completion of the cell cycle) in the presence of unattached kinetochores. When cells cannot satisfy the mitotic checkpoint, e.g., when in concentrations of spindle poisons that prohibit the stable attachment of all kinetochores, they are delayed in mitosis for many hours. In normal cells, the duration of this delay depends on the organism and ranges from ∼4 h in rodents to ∼22 h in humans. Recent live cell studies reveal that under this condition, many cancer cells (including HeLa and U2OS) die in mitosis by apoptosis within ∼24 h, which implies that biochemical studies on cancer cell populations harvested in mitosis after a prolonged mitotic arrest are contaminated with dead or dying cells.
Analysis of Dispute Review Boards Application in U.S. Construction Projects from 1975 to 2007

Since their first successful implementation in 1975, dispute review boards (DRBs) gained popularity as a standing neutral alternative dispute resolution (ADR) technique, and were implemented on a number of high profile construction projects in the United States and worldwide. The purpose of this study is to present a review, trend analysis, and classification of U.S. construction projects that had DRBs for the period of 1975–2007. Thus, a total of 1,042 U.S. construction projects that had DRB as part of their contract provisions are extracted from the Dispute Review Board Foundation database and are analyzed. The results of this study are presented in two major sections. In the first section, results of trend analysis are reported as growth in number of projects with DRB since 1975, as well as the distribution of these projects in terms of construction type (i.e., building, highway, and tunnel), and construction volume category. On the other hand, the second section includes the results of the analysis undertaken to study the mechanics of DRB application in construction projects. In this context, the effectiveness of DRB as a preventive measure against the escalation of conflicts to disputes is first studied. For those projects that had disputes heard by a DRB panel, the data was further analyzed to determine the effectiveness of the DRB as an ADR technique that can help in the resolution of a dispute at the project level without further escalation to arbitration or litigation. The results of the study indicate that DRBs have been successfully implemented in all three construction sectors in the United States. The effectiveness of DRB as a prevention technique was observed on approximately 50% of the 810 projects where no disputes were ever heard through a DRB panel formal hearing. For the remaining 50% of the projects, the effectiveness of DRB as an ADR technique was found to exceed 90% when comparing the number of disputes that were settled due to DRB recommendation to those that were actually heard during a DRB hearing session. Finally, the paper concludes with a set of questions and hypotheses that may be undertaken to explain the recorded observations, and set the way for future research efforts in this area.
Relative effect of thymocytes from irradiated donors on hemopoiesis in P-F 1 Chimeras.

SummaryThymocytes exposed in vivo to 200 R of X-rays 72 hr prior to transplantation enhanced marrow growth almost twice that seen in mice similarly treated with non-irradiated thymocytes. Growth of marrow was evaluated by the spleen colony-forming technique. These results confirm and extend previous data from this laboratory for which a cell-to-cell interaction has been postulated as a basis for augmentation of bone marrow growth by thymocytes. The present data show a minimal effective ratio (thymocyte: marrow cell) of 8:1 for irradiated thymocytes compared to a value of 16:1 for unirradiated thymocytes.On the basis of our results and the known differential radiosensitivity of thymocytes, we suggest that the less radiosensitive blastic lymphoid cells of the thymus are responsible for augmentation of poor growth of parental bone marrow transplanted into lethally X-irradiated F1 mice.
Differential near-field scanning optical microscopy based on sensor arrays

We introduce a new aperture-type near-field scanning optical microscopy (NSOM) system, which rely on large area (e.g., > 200 x 200 nm) aperture geometries that have sharp corners. The spatial resolution of this new near-field imaging modality is not determined by the size of the aperture, but rather by the sharpness of the corners of the large aperture. This approach significantly improves the light throughput of the near-field probe and therefore increases the optical signal-to-noise ratio (SNR). Here we discuss the basics of this new near-field microscopy approach and illustrate both theoretically and experimentally that an array of detectors can be utilized to further improve the SNR of the near-field image.
High-speed software raycasting on a dual-CPU PC using cache optimizations, MMX, streaming SIMD extensions, multithreading, and DirectX

We discuss work in progress towards a comprehensive software system for interactive volume rendering and the techniques we use to achieve high frame rates. The system was designed for Pentium-III CPUs and is currently running under Windows NT. It accepts three voxel formats and provides perspective views, on-the-fly classification and gradient shading. For high rendering speed, the entire recasting algorithm has been implemented and optimized in assembler, taking advantage of the MMX instructions and the Streaming SIMD Extensions of Pentium-III CPUs. These instructions are used to speed up frequently performed volume rendering operations such as tri-linear interpolations and ray-volume intersection test. The algorithm run is in parallel on two CPUs using multi-threading, and fast access to the frame buffer is established using DirectDraw. For further speed- up, early ray termination has been implemented as well. However, the major obstacle towards high performance is the limited memory bandwidth, even more so because volume rendering requires 3D access to the data set, and frequency access to tables. Thus, a memory layout was developed which maximizes the processor cache hit rate and keeps frequently used tables in the L1 cache, although at the cost of an increased memory consumption.
Incubation of conditioned fear in the conditioned suppression model in rats: role of food-restriction conditions, length of conditioned stimulus, and generality to conditioned freezing.

Abstract We recently adapted the conditioned suppression of operant responding method to study fear incubation. We found that food-restricted rats show low fear 2 days after extended (10 d; 100 30-s tone-shock pairings) fear training and high fear after 1–2 months. Here, we studied a potential mechanism of fear incubation: extended food-restriction stress. We also studied whether fear incubation is observed after fear training with a prolonged-duration (6-min) tone conditioned stimulus (CS), and whether conditioned freezing incubates after extended training in rats with or without a concurrent operant task. Conditioned fear was assessed 2 days and 1 month after training. In the conditioned suppression method, fear incubation was reliably observed in rats under moderate food-restriction conditions (18–20 g food/day) that allowed for weight gain, and after extended (10 d), but not limited (1 d), fear training with the 6-min CS. Incubation of conditioned freezing was observed after extended fear training in rats lever-pressing for food and, to a lesser degree, in rats not performing an operant task. Results indicate that prolonged hunger-related stress does not account for fear incubation in the conditioned suppression method, and that fear incubation occurs to a longer-duration (6-min) fear CS. Extended training also leads to robust fear incubation of conditioned freezing in rats performing an operant task and weaker fear incubation in rats not performing an operant task.
Pluggable reflection: decoupling meta-interface and implementation

Reflection remains a second-class citizen in current programming models, where it's assumed to be imperative and tightly bound to its implementation. In contrast, most object-oriented APIs allow interfaces to vary independently of their implementations. Components take this separation a step further by describing unforeseeable attributes---the key to pluggable third-party components. This paper describes how reflection can benefit from a similar evolutionary path.
Submodular Utility Maximization for Deadline Constrained Data Collection in Sensor Networks

We study the utility maximization problem for data collection in a wireless sensor network subject to a deadline constraint, where the data on a selected subset of nodes are collected through a routing tree subject to the 1-hop interference model. Our problem is closely related to the traditional utility maximization problems in networking and communications. However, instead of a separable concave form of utility functions commonly seen in this area, we consider the class of monotone submodular utility functions defined on subsets of nodes, which is more appropriate for the applications we consider. While submodular maximization subject to a cardinality constraint has been well understood, our problem is more challenging due to the multi-hop data forwarding nature even under the simple interference model. We have derived efficient approximation solutions to this problem both for raw data collection and when in-network data aggregation is applied.
Efficacy of zoledronate against neuroblastoma.

Background We investigated the antitumor and antiosteoclastic effects of zoledronate against human neuroblastoma in vitro and in a murine model of bone metastasis. Methods Antitumor activity of zoledronate against neuroblastoma cell lines was assessed by evaluating proliferation, apoptosis, and cell-cycle progression. A murine model of bone invasion was used to assess antiosteoclastic and antitumor activity in vivo. Mice were followed by radiographic and bioluminescence imaging. Results Treatment of human neuroblastoma cells resulted in a decrease in cell count, increase in apoptosis, and arrest of cell-cycle progression. In the model of bone invasion, mice were treated weekly with zoledronate or vehicle control 10 days after tumor cell inoculation. Five weeks later, radiographs revealed a large degree of osteolytic disease in control mice. Impressively, mice treated with zoledronate demonstrated minimal radiographic changes at this time. Bioluminescence imaging of these mice revealed a significant restriction of tumor growth during the course of therapy. Conclusions Zoledronate exhibits significant antitumor activity against human neuroblastoma cells in vitro, prevents development of osteolytic lesions, and restricts tumor growth in a murine model of bone metastasis. These results suggest that clinical investigation of zoledronate or similar bisphosphonates as adjuvant therapy in neuroblastoma patients is warranted.
Phase II study of thalidomide in patients with metastatic carcinoid and islet cell tumors

Carcinoid and islet cell tumors are known to be highly vascular. There is no effective systemic therapy currently available for metastatic disease. We conducted a phase II trial to evaluate the efficacy of the anti-antiangiogenic agent thalidomide in metastatic neuroendocrine tumors. Eighteen patients with measurable, histologically proven metastatic carcinoid neuroendocrine carcinomas (well-differentiated, n = 13; moderately-differentiated, n = 5) were enrolled on this study. The majority of the patients had gastrointestinal primaries (small bowel, 8; pancreas, 5; colon, 1). All but one patient had hepatic metastases, and 12 patients (67%) had carcinoid syndrome. All patients had Eastern Cooperative Oncology Group performance status of zero or one. Eight patients (44%) had received previous hepatic artery chemoembolization and 11 (61%) had undergone surgical resection. Patients were started on oral thalidomide at a daily dose of 200 mg that was escalated to the target dose of 400 mg daily after 2 weeks. Tumor response was assessed at 12-week intervals using RECIST criteria. Planned treatment duration was 24 weeks unless unacceptable toxicity or disease progression was observed. No patient achieved a partial remission or a complete remission. Best response was stable disease (SD) in 11 of 16 response-evaluable patients (69%). Serum pancreastatin results did not correlate with clinical response. Grade 3 toxicities included dizziness with orthostatic hypotension (n = 5), sensory neuropathy (n = 2), fatigue (n = 2), hemorrhagic cystitis (n = 1), and deep venous thrombosis (n = 1). Frequent Grade 1–2 toxicities were: fatigue (n = 13), constipation (n = 13), dry mouth (n = 12), somnolence (n = 12), dizziness/syncope (n = 10), weight gain (n = 5), and peripheral neuropathy (n = 5). Thalidomide was fairly well tolerated in patients with metastatic carcinoid/islet cell tumors, but failed to reveal any objective responses. The single stage design of the trial makes it difficult to determine whether observed SD in a subset of patients was attributable to the indolent nature of these tumors, or to beneficial effect of thalidomide.
Indoor housing during development affects moult, carotenoid circulation and beak colouration of mallard ducks (Anas platyrhynchos).

Developmental conditions are known to influence adult phenotypes, including naturally selected traits such as structural size, as well as sexually selected traits such as song and colouration. Biot...
Calcium requirement for lipoxygenase catalyzed linoleate oxidation

In further studies of the calcium (Ca2+) activation of lipoxygenase, it was observed that Ca2+ was the most specific cation for this enzyme activation. However, Mn2+ and Mg2+ were also activators, while Fe3+ and Cu2+ were competitive inhibitors. The pH activity curves for lipoxygenase showed different pH optima in the presence and absence of Ca2+. The difference can be explained by the presence of two enzymes or a single enzyme requiring two ionizable groups for activity. Buffer type and concentration were found to affect the enzyme activity at constant Ca2+ concentration. Order of addition of enzyme and Ca2+ to reaction mixture was investigated to better understand Ca2+ activation. Tween 20 was found to strongly inhibit the Ca2+ activated lipoxygenase at pH 7.5, while stimulating non-Ca2+-activated lipoxygenase at pH 6.4. These results seem to vie for the possibility of two different enzymes. A cold insoluble material was recovered from navy bean extracts which, when added to the reaction mixture, caused stimulation of lipoxygenase activity when low concentrations of imidazole were used as the buffer. These studies give additional evidence to show that despite previous reports to the contrary, a lipoxygenase does exist which requires the presence of a divalent cation for its activity.
A focusing image probe for assessing neural activity in vivo.

We describe a compact, focusing image probe to record rapid optical changes from neural tissue. A gradient index (GRIN) lens served as a relay lens from tissue to a microscope objective which projected an image onto a CCD camera. The microscope objective and camera assembly was adjusted independently from the GRIN lens, allowing focus changes without disturbing the probe/tissue interface; firm contact minimized movement and specular reflectance. Fiber optics around the probe perimeter provided diffuse illumination from a 780 nm laser, or 660 and 560 nm light emitting diodes. To characterize depth-of-field, we imaged a black suture through increasing tissue thicknesses. Light modulation by the suture remained detectable down to 900 μm using 780 nm illumination. We acquired images from cardiorespiratory areas of the rat dorsal medulla, at different depths and illumination wavelengths. Images illuminated at 560 nm were dominated by vasculature flow patterns, while 660 nm illumination revealed different spatial patterns which preceded vascular flow by 40 ms and may represent cardiac-related neural activity. Using 780 nm light, image sequences triggered by the cardiac R-wave showed vascular perfusion changes with delayed and broader responses at deeper levels. Electrical stimulation within the vagal bundle caused fast optical changes which track the electrical response, with a different spatial distribution from hemodynamic signals.
Spigelian Hernias: Repair and Outcome for 81 Patients

Spigelian hernia is a rare partial abdominal wall defect. The frequent lack of physical findings along with vague associated abdominal complaints makes the diagnosis elusive. A retrospective review of Mayo Clinic patients was performed to find all patients who had undergone surgical repair of a Spigelian hernia from 1976 to 1997. Patients were scrutinized for presentation, work-up, therapy, and outcome. The goal of this study was to obtain long-term outcome. The study was set in a tertiary referral center. There were 76 patients in whom 81 Spigelian hernias were repaired. Symptoms most commonly included an intermittent mass (n = 29), pain (n = 20), pain with a mass (n = 22), and bowel obstruction (n = 5). Five patients were asymptomatic. Preoperative imaging was performed in 21 patients and correctly diagnosed the hernia in 15. Spigelian hernias were repaired by primary suture closure (n = 75), mesh (n = 5), and laparoscopic (n = 1) techniques. Eight patients (10%) required emergent operations. Thirteen hernias (17%) were found to be incarcerated at the time of the operation. Overall mean follow-up for the 76 patients was 8 years, with three hernia recurrences identified. Spigelian hernia is rare and requires a high index of suspicion given the lack of consistent symptoms and signs. An astute physician may couple a proper history and physical examination with preoperative imaging to secure the diagnosis. Mesh and laparoscopic repairs are viable alternatives to the durable results of standard primary closure. Given the high rate of incarceration/strangulation, the diagnosis of Spigelian hernia is an indication for surgical repair.
A population-based analysis of ethnic differences in admission to the intensive care unit after stroke.

Background Mexican–Americans (MAs) have shown lower post-stroke mortality compared to non-hispanic whites (NHWs). Limited evidence suggests race/ethnic differences exist in intensive care unit (ICU) admissions following stroke. Our objective was to investigate the association of ethnicity with admission to the ICU following stroke.
A high resolution laser induced fluorescence study of a supersonic zirconium atom beam

Abstract We report high resolution fluorescence excitation spectra of zirconium atoms formed via pulsed laser evaporation of a zirconium metal rod. Results obtained from an optogalvanic study are also commented upon. Quantitative values for isotope and hyperfine shifts for the transition (4d 2 5s 2 )a 3 F 2 →(4d 2 5s5p)z 3 F 0 2 at 613.6 nm are given. The magnitude of the obse rved hyperfine shifts are consistent with requirements for laser isotope separation.
Hepatocellular carcinoma and intrahepatic peripheral cholangiocarcinoma: enhancement patterns with quadruple phase helical CT--a comparative study.

PURPOSE: To define the hemodynamic features of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma by using quadruple phase helical computed tomography (CT) and determine the value of this information in characterizing tumors. MATERIALS AND METHODS: Helical CT of the liver was performed in 45 patients with newly diagnosed HCC or peripheral cholangiocarcinoma. Scans were obtained before and 25 seconds, 70 seconds, and 2–6 minutes after the start of the contrast material injection. The intensity and spatial distribution of contrast material uptake were evaluated during all phases. Time-attenuation curves were established for each lesion. Relative attenuation and lesion conspicuity were assessed. A diagnostic confidence level was assigned to each lesion. RESULTS: In the majority of HCC lesions, a single, early peak of enhancement followed by a continuous decrease in tumor attenuation over time was seen. The greatest tumor conspicuity occurred during the delayed phase. In cholangiocarcinoma, tu...
Discussion: Guidelines for Agricultural Policy

Professors Campbell and MacGregor have interpreted the goals and 6 of the 7 realities developed by the Task Force, the latter regarded as synonymous with guidelines for the next decade.
Atropine influence on altered hemodynamics of the primate kidney in hemorrhagic shock.

SummaryAtropine sulfate was infused intra-aortically (0.275 mg/kg/min) to attempt blockade of medullary cholinergic fibers which might function during hemorrhagic shock to promote washout of the medullary gradient of osmolality by maintaining MBF. It was found that infusion of atropine in the dosage used and by the route described, resulted in relative increase in CPAH and CIn over the trend observed in a group of untreated animals, similarly subjected to hemorrhagic hypotension, with no change in FF. Results could be explained by blockade of preganglionic (aorticorenal) cholinergic fibers, resulting in reduction of postganglionic adrenergic vasoconstrictor influences on afferent arterioles. No influence of atropine could be detected on urine vollume sodium clearance, and osmolar clearance when expressed as a fraction of CIn, nor on U/P osmolality. If intrarenal cholinergic fibers were blocked, the expected results of this (increase in FF and reduced total RBF) were covered up by the more marked influence...
Evaluating the Risk of Establishing a Self-Sustaining Population of Non-Native Oysters Through Large-Scale Aquaculture in Chesapeake Bay

ABSTRACT A multistep invasive species methodology was used to evaluate the probability that the deployment of sterile non-native oysters (Crassostrea ariakensis, called Asian oyster) in field-based aquaculture could give rise to a reproductive population in Chesapeake Bay. Several pathways that could potentially lead to the unintentional release of reproductive C. ariakensis from aquaculture were identified. For the four quantifiable pathways, a probability was estimated for each step based on knowledge of ecological rates. A conservative estimate for the number of reproductive C. ariakensis that could arise over one spawning season at a hypothetical aquaculture site was estimated. A statistical expansion of this probability estimated that it is highly likely that the cultivation of putatively sterile C. ariakensis would initiate a reproductive population in Chesapeake Bay over a 10-year time span. The potential benefits of restoration actions involving non-native species in estuarine ecosystems must be w...
Residence times of alluvium in an east Texas stream as indicated by sediment color

Abstract The relationships between sediment production, storage, and transport in fluvial systems are complex and variable. Key issues in addressing these relationships are the residence times of sediment delivered to the channel, and the proportion derived from recent upland erosion as opposed to remobilized alluvium. The systematic changes in iron geochemistry often experienced by sediments deposited in an anaerobic environment, such as a stream channel or waterlogged floodplain, are used here as an indicator of residence time over contemporary time scales. In areas such as east Texas, where upland soils are high in iron oxide content, these changes are reflected in soil color. Alluvium with red, yellow, or brown colors indicating ferric (oxidized) iron and sufficient organic matter for reduction to occur indicates a short ( 1 year). Sediments with the longest residence times in alluvial environments (≫1 year) will not oxidize on exposure to the atmosphere due to the loss of iron, while those with ferrous iron remaining will experience oxidation and color change on exposure. In Loco Bayou, Texas, these indicators of residence time are shown to be generally consistent with other field evidence of erosion and sedimentation. Further, the color indicators correctly indicate the residence time in several cases where the latter is known from field observations.
Effect of temperature on frequencies of spots in drosophila wing‐spot assay

The effect of temperature on spontaneous mutation frequencies was studied in the Drosophila somatic mutation and recombination test. Transdihybrid mwh +/+ flr3 larvae were grown at various temperatures (15, 18, 20, 22, 25, 27, and 29 degrees C) in the absence of any chemical mutagen. Wings of surviving adults were removed and scored for presence of small single spots, large single spots, and twin spots. No significant effect of temperature was found on mean frequency per wing of twin spots. Similarly, no significant effect of temperature was found for large singles within the temperature range of 18-29 degrees C; however, at 15 degrees C, the mean frequency per wing of large spots was significantly elevated. A significant quadratic relationship was found between mean frequency of small spots and temperature. Frequency of small spots per wing was minimized within the temperature range of 20-27 degrees C and increased at higher and lower temperatures. Maximum frequency of small spots per wing was observed at 15 degrees C. The qualitative nature of the small single spots induced at high and low temperatures is unclear; they may represent slow-growing segmentally aneuploid (deleted) cells or possibly even monosomic cells. Both heat and cold were found to be mutagenic in the Drosophila wing-spot assay. However, the mutagenic potency associated with temperature was much less than that of most chemical mutagens, and no significant effect of temperature was observed in the range of 20-27 degrees C.
Air-sea flux of CO2 in the Arctic Ocean, 1998–2003

[1] The Arctic Ocean has experienced an unprecedented reduction in sea ice over the last 3 decades, increasing the potential for greater exchange of gases such as carbon dioxide (CO2) between the atmosphere and the upper ocean. The present study utilizes remotely sensed data on distributions of both sea ice and chlorophyll a, together with modeled temperature and salinity fields, to obtain high-resolution basin-scale estimates of the air-sea flux of CO2 (FCO2) in the Arctic Ocean for the years 1998–2003. Concentrations of dissolved inorganic carbon (DIC) were derived from multiple linear regression relationships with sea surface temperature, salinity, and chlorophyll a. The partial pressure of carbon dioxide (pCO2) in surface waters was computed from DIC and alkalinity, the latter of which varied with salinity. FCO2 was calculated from the air-sea difference in pCO2 and wind speed. Annual FCO2 was highest in the Atlantic-dominated Greenland and Barents sectors due to their lower sea ice cover, although area-normalized FCO2 in these sectors was low. Only the Siberian sector exhibited a significant increase in annual FCO2 during the time of our study, due to a corresponding increase in ice-free water. Overall, the Arctic Ocean was a net atmospheric sink for CO2, with annual FCO2 averaging 118 ± 7 Tg C yr−1 during 1998–2003.
Integrating virtual reality to expand the public health role of community pharmacists

Abstract Objectives To describe a potential future role of the community pharmacist in public health using virtual centers that provide immediate feedback to patients regarding behavior changes. Summary Community pharmacists would provide a comprehensive standardized patient-centered interview to collect pertinent information regarding patients that, together with a computerized body scan of the individual, would be fed into the virtual center to create a baseline likeness of the person. The virtual center then would predict the person's appearance and overall body health at a predetermined interval in the future, as well as provide feedback to the patient, engaging multiple senses and using an advanced body suit to represent changes in body mass and exercise tolerance as the person moves in the center. Pharmacists would work with the patient to identify patient-centered behavior changes, which would be programmed into the virtual center to demonstrate to the person how their new lifestyle goal may change their future appearance and health. Achievements and social networking in the virtual world would be incorporated to motivate patients to continue to make positive decisions regarding their health. Conclusion Virtual reality technology can be a powerful motivational tool that community pharmacists can use in a variety of ways to help patients implement and sustain positive lifestyle changes.
Sodium channel inactivation goes with the flow.

Voltage-dependent inactivation of Na+ channels is a consequence of voltage-dependent activation ([Aldrich et al., 1983][1]), and inactivation is characterized by at least two distinguishable kinetic components: an initial rapid component (fast inactivation) and a slower component (slow inactivation
Summary of 'Hot Line' sessions presented at the European Society of Cardiology Congress 2008: August 30, 2008 to September 3, 2008, Munich, Germany.

The European Society of Cardiology Congress, the largest medical meeting in Europe, was held August 30, 2008, to September 3, 2008, in Munich, Germany. Among the conference's main sessions, workshops and symposia, several ‘Hot Line’ sessions presented new scientific data and study results. The following are a summary of these Hot Line sessions. Brunner-La Rocca and colleagues presented results from TIME-CHF [Trial of Intensified (BNP-guided) versus standard (symptom-guided) Medical therapy in Elderly patients with Congestive Heart Failure], which aimed to compare intensified BNP-guided therapy to standard symptom-guided therapy on 18-month outcome. They also assessed whether or not there was a difference in response to such therapy in patients ≥75 years old (n=289) compared to those b75 years of age (n=210). It was found that intensified, BNP-guided therapy did not improve the primary endpoint of all-cause hospitalization free survival overall; however, it did improve the more disease-specific endpoint of heart failure hospitalization free survival. Response to therapy differed significantly between age groups with those b75 years of age showing reduced mortality and improved hospitalization survival while those ≥75 years old showing no benefit on outcome and less improvement in quality of life. The BEAUTIFUL (morBidity–mortality EvAlUaTion of the IF inhibitor ivabradine in patients with CAD and left
A questionable future: The vision of revolution in white South African writing

(1984). A questionable future: The vision of revolution in white South African writing. Journal of Contemporary African Studies: Vol. 4, No. 1-2, pp. 215-223.
THE PHYSICAL PROPERTIES OF SPIDER'S SILK AND THEIR ROLE IN THE DESIGN OF ORB-WEBS

SUMMARY 1. Determinations were made of several physical properties of the viscid and frame silks of the orb-webs built by the spider Araneus sericatus (Cl.). 2. Both types of silk show a breaking stress of approximately 1 GN/m 2 and an initial resilience of approximately 0-35. 3. The breaking extension ratio of viscid silk (A = 3*00) is much greater than that of frame silk (A = i # 2s), and the viscid silk relaxes to a relatively greater extent. 4. These properties are correlated with the degree of crystallization of the protein from which the silk is made, this factor being controlled by the sequence of amino acids in the protein. 5. The physical properties of the viscid and frame silks allow them to function effectively as shock absorbers and structural elements, respectively; and allow the orb-web to function as an aerial filter with a minimum expenditure of material and energy.
Nonlinear transmission lines with saturable ferrite inductors

Nonlinear transmission lines have been demonstrated to be an effective technique for generating high power ultrawideband or mesoband radiation without the need for a vacuum system, electron beam, or magnet. Experiments have been performed at UM on a discrete element nonlinear transmission line that uses ferrite inductors as the nonlinear element. A 100 MW driver is used to drive the experiment. Pulse sharpening of multi-kA input pulses has been observed in addition to the generation of RE Results from these experiments and plans for GW power level nonlinear transmission line experiments will be presented.
Hilda: A High-Level Language for Data-DrivenWeb Applications

We propose Hilda, a high-level language for developing data-driven web applications. The primary benefits of Hilda over existing development platforms are: (a) it uses a unified data model for all layers of the application, (b) it is declarative, (c) it models both application queries and updates, (d) it supports structured programming for web sites, and (e) it enables conflict detection for concurrent updates. We also describe the implementation of a simple proof-ofconcept Hilda compiler, which translates a Hilda application program into Java Servlet code.
Checking Traces for Regulatory Conformance

We consider the problem of checking whether the operations of an organization conform to a body of regulation. The immediate motivation comes from the analysis of the U.S. Food and Drug Administration regulations that apply to bloodbanks - organizations that collect, process, store, and use donations of blood and blood components. Statements in such regulations convey constraints on operations or sequences of operations that are performed by an organization. It is natural to express these constraints in a temporal logic. There are two important features of regulatory texts that need to be accommodated by a representation in logic. First, the constraints conveyed by regulation can be obligatory (required) or permitted (optional). Second, statements in regulation refer to others for conditions or exceptions. An organization conforms to a body of regulation if and only if it satisfies all the obligations. However, permissions provide exceptions to obligations, indirectly affecting conformance. In this paper, we extend linear temporal logic to distinguish between obligations and permissions, and to allow statements to refer to others. While the resulting logic allows for a direct representation of regulation, evaluating references between statements has high complexity. We discuss an empirically motivated assumption that lets us replace references with tests of lower complexity, leading to efficient trace-checking algorithms in practice.
Stability analysis of a general class of hybrid dynamical systems

Hybrid dynamical systems which are capable of exhibiting simultaneously several kinds of dynamic behavior, such as continuous-time dynamics, discrete-time dynamics, jump phenomena, switching and logic commands, discrete events, and the like, are of great current interest. In the present paper we employ a general model of a dynamical system suitable in the qualitative analysis of such systems in which generalized time is not represented, as is usually the case, by R/sup +/=[0,/spl infin/) or N={0,1,2,...}, but by an abstract metric space on which certain suitable hypotheses are imposed. This model of the dynamical system allows discontinuous motions, and convergence of motions is relative to generalized time. In the context of the model for hybrid dynamical systems described above we establish the principal Lyapunov stability results for invariant sets and the principal Lagrange stability results for motions. The present work constitutes a continuation of the work initiated by the authors in a previous paper (Michel and Hou, 1995). Some of the results of the present paper are applied in the analysis of a specific class of systems.
Windkessel modeling of pulsatile ultrasonic strain wave

The present study aims to propose a Doppler strain imaging technique to measure the tissue deformation due to local blood perfusion. The measured tissue strain waveforms were previously analyzed by Fast Fourier Transform and Harmonic Analysis. The current approach is to simulate local microcirculation as a two-port Windkessel model and derive the analytical formula of ultrasonic tissue plethysmographic waveform as an attenuated sinusoid function. This formula in our study is shown to delineate normal tissue plethysmographic waveform rationally and effectively.