cssi/SciSciGPT-SciSciNet huggingface dataset:
Topological filtering for 3D microstructure segmentation

Abstract Tomography is a widely used tool for analyzing microstructures in three dimensions (3D). The analysis, however, faces difficulty because the constituent materials produce similar grey-scale values. Sometimes, this prompts the image segmentation process to assign a pixel/voxel to the wrong phase (active material or pore). Consequently, errors are introduced in the microstructure characteristics calculation. In this work, we develop a filtering algorithm called PerSplat based on topological persistence (a technique used in topological data analysis) to improve segmentation quality. One problem faced when evaluating filtering algorithms is that real image data in general are not equipped with the ‘ground truth’ for the microstructure characteristics. For this study, we construct synthetic images for which the ground-truth values are known. On the synthetic images, we compare the pore tortuosity and Minkowski functionals (volume and surface area) computed with our PerSplat filter and other methods such as total variation (TV) and non-local means (NL-means). Moreover, on a real 3D image, we visually compare the segmentation results provided by our filter against TV and NL-means. The experimental results indicate that PerSplat provides a significant improvement in segmentation quality.
Auto-Tuned Sim-to-Real Transfer

Policies trained in simulation often fail when transferred to the real world due to the ‘reality gap’ where the simulator is unable to accurately capture the dynamics and visual properties of the real world. Current approaches to tackle this problem, such as domain randomization, require prior knowledge and engineering to determine how much to randomize system parameters in order to learn a policy that is robust to sim-to-real transfer while also not being too conservative. We propose a method for automatically tuning simulator system parameters to match the real world using only raw RGB images of the real world without the need to define rewards or estimate state. Our key insight is to reframe the auto-tuning of parameters as a search problem where we iteratively shift the simulation system parameters to approach the real world system parameters. We propose a Search Param Model (SPM) that, given a sequence of observations and actions and a set of system parameters, predicts whether the given parameters are higher or lower than the true parameters used to generate the observations. We evaluate our method on multiple robotic control tasks in both sim-to-sim and sim-to-real transfer, demonstrating significant improvement over naive domain randomization. Project videos at https://yuqingd.github.io/autotuned-sim2real/.
Square Root Principal Component Pursuit: Tuning-Free Noisy Robust Matrix Recovery

We propose a new framework -- Square Root Principal Component Pursuit -- for low-rank matrix recovery from observations corrupted with noise and outliers. Inspired by the square root Lasso, this new formulation does not require prior knowledge of the noise level. We show that a single, universal choice of the regularization parameter suffices to achieve reconstruction error proportional to the (a priori unknown) noise level. In comparison, previous formulations such as stable PCP rely on noise-dependent parameters to achieve similar performance, and are therefore challenging to deploy in applications where the noise level is unknown. We validate the effectiveness of our new method through experiments on simulated and real datasets. Our simulations corroborate the claim that a universal choice of the regularization parameter yields near optimal performance across a range of noise levels, indicating that the proposed method outperforms the (somewhat loose) bound proved here.
Utility of a Routine 24-Hour Follow-Up Computed Tomography Scan in Patients with Acute Ischemic Stroke (P07.238)

OBJECTIVE: To determine the utility of routine 24-hour computed tomography (CT) brain scans in acute ischemic stroke (AIS) patients treated with tissue plasminogen activator (tPA). BACKGROUND: Evidence is lacking for the utility of a routine 24-hour CT in AIS patients treated with tPA when early neurological deterioration (END) does not occur. DESIGN/METHODS: Consecutive AIS patients given tPA between June 2008 and December 2011 were retrospectively identified. Cases were excluded if intra-arterial treatment was received (n=15), a 24-hr CT was not performed (n=9), or 24-hr NIHSS score was not documented (n=6). The remaining cases were divided into: END (>/=2pt increase in NIHSS) and No END. Baseline characteristics and medical history, 24-hr computed tomography (CT) scan findings, new medical and/or surgical orders within 6 hours of imaging, and administration of anti-thrombotics by 10 a.m. the following day were compared between the two groups. RESULTS: Two-hundred cases met criteria: END n=26 and No END n=174. Median age was significantly higher in the END group compared to no END (77 vs. 63 years, p CONCLUSIONS: While END was associated with hemorrhage and acute management changes, including decisions to limit intervention, a routine 24-hour CT may not be warranted amongst tPA patients without END. Alarmingly, one-third of patients without END experienced unnecessary delay in first antithrombotics, possibly due to waiting on the interpretation of a routine post-tPA CT scan. Supported by: Debakey Scholars Program of Tulane University School of Medicine. Disclosure: Dr. George has received research support from Tulane University School of Medicine. Dr. Boehme has nothing to disclose. Dr. Dunn has nothing to disclose. Dr. Beasley has nothing to disclose. Dr. Siegler has nothing to disclose. Dr. Behring has nothing to disclose. Dr. Albright has received research support from The Agency for Healthcare Research and Quality (AHRQ) and The National Institute on Minority Health and Health Disparities (NIMHD), National Institutes of Health. Dr. Martin-Schild has nothing to disclose.
Mass Spectrometric Characterization of Microscale Enzyme Catalyzed Reactions of Surface-Bound Peptides and Proteins

Many important biomolecules occur in nature only in very low abundance. Ever more sensitive analytical tools are thus required for the elucidation of their structure and chemical behavior. We have recently demonstrated (1,2) a new mass spectrometric method for investigating microscale chemical reactions of both gas and condensed phase reagents with the surface of organic solids. Here we report the results of an investigation of the utility of this new method for measuring enzyme catalyzed reactions of surface-bound peptides and proteins.
Rickettsia and Orientia.

Publisher Summary The term rickettsia has, for many years, been loosely applied to a very wide range of gram-negative bacteria simply because of their obligate association with arthropods or other hosts, their size, and their intracellular habitat. These microorganisms are, however, now known to be a highly polyphyletic group. Molecular approaches to the phylogeny of rickettsiae are used to demonstrate that most species in the genera Rickettsia, Orientia, Ehrlichia, Anaplasma, Wolbachia, Cowdria and Neorickettsia have similar evolutionary origins and that all these genera belong to the α subdivision of Proteobacteria. Micro-organisms in the genera Rickettsia and Orientia are obligately intracellular, gram-negative bacteria. The genus Rickettsia is classically separated into the typhus group and the spotted fever group based on the presence of distinct group lipopolysaccharide antigens. Improvements in isolation techniques for rickettsiae and widespread application of molecular tools for the identification of these fastidious micro-organisms have resulted in the recognition of some new species and other as yet unnamed genotypes. Orientia tsutsugamushi is the aetiological agent of scrub typhus, also known as tsutsugamushi disease. It is a single species that contains many antigenic and genotypic variants. Immunological techniques—such as complement fixation and fluorescent antibody tests with guinea pig or rabbit antisera; biological tests, including in vivo and in vitro neutralisation assays; and cross-vaccination protection tests—were originally used to define antigenic prototypes.
Composable abstractions for synchronization in dynamic threading platforms

High-level abstractions for parallel programming simplify the development of efficient parallel applications. In particular, composable abstractions allow programmers to construct a complex parallel application out of multiple components, where each component itself may be designed to exploit parallelism. This dissertation presents the design of three cornposable abstractions for synchronization in dynamic-threading platforms, based on ideas of task-graph execution, helper locks, and transactional memory. These designs demonstrate provably efficient runtime scheduling for programs with synchronization. For applications that use task-graph synchronization, I demonstrate provably efficient execution of task graphs with arbitrary dependencies as a library in a fork-join platform. Conventional wisdom suggests that a fork-join platform can execute an arbitrary task graph only with special runtime support or by converting the graph into a series-parallel computation which has less parallelism. By implementing Nabbit, a Cilk++ library for arbitrary task-graph execution, I show that one can in fact avoid introducing runtime modifications or additional constraints on parallelism. Nabbit achieves an asymptotically optimal completion-time bound for task graphs with constant degree. For applications that use lock-based synchronization, I introduce helper locks, a new synchronization abstraction that enables programmers to exploit asynchronous task parallelism inside locked critical regions. When a processor fails to acquire a helper lock, it can help complete the parallel critical region protected by the lock instead of simply waiting for the lock to be released. I also present HELPER, a runtime for supporting helper locks, and prove theoretical performance bounds which imply that HELPER achieves linear speedup on programs with a small number of highly parallel critical regions. For applications that use transaction-based synchronization, I present CWSTM, the first design of a transactional memory (TM) system that supports transactions with nested parallelism and nested parallel transactions of unbounded nesting depth. CWSTM demonstrates that one can provide theoretical bounds on the overhead of transaction conflict detection which are independent of nesting depth. I also introduce the concept of ownership-aware TM, the idea of using information about which memory locations a software module owns to provide provable guarantees of safety and correctness for open-nested transactions. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
SHOSLIF: a framework for object recognition from images

A new framework called self-organizing hierarchical optimal subspace learning and inference framework (SHOSLIF) is introduced for recognizing and segmenting real-world objects from images. It addresses critical problems in real-world recognition including visual attention, feature representation efficiency, shape variation in unsegmented data (including size, position and orientation), decision optimality, and geometric inference. >
The infinitesimal holonomy group structure of EEnstein-Maxwell space-times

This paper further investigates and interprets the structure of Einstein-Maxwell space-times in terms of the infinitesimal holonomy groups (IHG) of theC ∞ Riemannian connection. In particular, this investigation provides a fundamental physical classification of Einstein-Maxwell space-times in terms of the IHG group structure of the Riemann curvature tensor. It will be shown that the Maxwell fieldsF μλ and *F μλ of a given Einstein-Maxwell space-time define a representation of a subalgebra of the Lie algebra of the IHG. The main results of this paper are stated in the form of two theorems and a corollary. Also the results obtained here indicate that physical insight could be gained by studying more general gauge fields in terms of the IHG of the relevant Einstein-Yang-Mills space-times.
X-Ray Ablation and Debris Venting for the HIF Point Design

This paper presents detailed design and analysis for x-ray ablation and venting in the 120-beam, 7-MJ heavy-ion fusion (HIF) 'robust' point design. The HI Robust Point Design ('RPD-2002') is a self-consistent, non-optimized system design that has been generated as a point of reference for ongoing research in the HIF program. The point design uses a thick-liquid protected chamber, derived from HYLIFE-II - no structural surfaces face the target. A ternary salt mixture called flinabe (LiNaBeF{sub 4}) has been selected for the liquid structures. Detailed two-dimensional, axially symmetric TSUNAMI calculations have been performed to determine the mass of ablation debris generated by the target x-rays following ignition and to predict the venting of the debris from the inside of the pocket into the main chamber and beam lines. These calculations provide predictions of the impulse loading to the surfaces of the liquid pocket - The closest liquid structures will experience a somewhat strong impulse, but further optimization of the design will easily decrease this impulse. The integrated mass and energy fluxes of ablation and target debris reaching the beam-line magnetic shutters are given as well: A small and acceptable magnetic dipole will prevent any debris ingression up in the final focusmore » magnet region.« less
Stock Option Adoption and Irrational Exuberance: The Impact On Profitability

We evaluate the impact of the adoption of stock options on firms' financial performance. If stock options are an efficient incentive contract we would expect their adoption to increase both operating income (OI) and return on assets (ROA). Alternatively, stock options may provide an incentive to focus too much on growth resulting in either lower OI or higher OI but lower ROA. We find evidence that stock options significantly increase OI and investments in assets but significantly decrease ROA.
Explaining inefficient policy instruments

The purpose of this paper is to provide an overview of the literature on the political economy of policy instrument choice and relate it to the experiences in agriculture. The paper is therefore organized as follows. The second section provides a ranking of policies as to their transfer efficiency and determines the standard of evaluation, given that no policy is perfect in achieving its goals. The third section explores why political competition does not ensure that an efficient policy instrument is chosen. The following two sections explain the two key theories: enforcement and commitment problems in section four, and information and agency problems in section five. Section six presents the important Grossman-Helpman model of inefficient policy choice that falls outside these two general theories. Section seven describes how policy instrument choice in agriculture is often a discrete outcome in response to a crisis and therefore becomes path dependent, resulting in a status quo bias. Section eight describes how trade agreements can affect policy instrument choice. The final section gives some guidance as to the outstanding issues.
Inteligência competitiva é estratégia

Mas retomando as origens, foi em 1986, que um grupo formado por profissionais de marketing, de agencias governamentais e professores universitarios fundou, nos Estados Unidos da America, uma associacao chamada atualmente, Strategic and Competitive Intelligence Professionals - SCIP. Poderia parecer so mais uma associacao - em um pais com competicao acirrada, inovacao em produtos e servicos, mas voltado a alta performance empresarial. Apos 28 anos, o tempo mostrou que nao se tratava apenas de mais uma associacao, mas sim daquela que comecou a registrar uma das questoes empresariais mais desafiantes para qualquer profissional da atualidade: a competicao.
Is nutritional anestrus precipitated by subfunctional corpora lutea in beef cows

Thirty-four multiparous, lactating, cyclic beef cows which calved in moderate body condition were used to determine effects of restricted nutrition on corpus luteum (CL) development and endocrine status. At 78 d postpartum, six cows were assigned to a control (CON) diet (26.0 Mcal ME), fed to increase bodyweight (BW) and body condition score (BCS), and the remaining 28 cows were fed to lose BW and BCS on a restricted (RES) diet (14.0 Mcal ME). Following a 40-d adjustment period on respective diets, estrous cycles were synchronized and cows bled daily for determination of progesterone (P4), luteinizing hormone (LH) and insulin (INS) beginning at the synchronized estrus. Ultrasonography was used to determine the ovulatory follicle and CL development. Control cows were maintained for one estrous cycle and were ovariectomized on day 11 of their second cycle. Ten cows on restricted diet (RES-C) continued to form a functional CL (P4 > 1.5 ng/ml at day 10 of an estrous cycle) through as many as 5 cycles, after which observations were discontinued. Fourteen cows on restricted diet (RES-A) were ovariectomized on day 11 of a cycle when a CL was identified by ultrasonography, but was subfunctional (P4 < 1.5 ng/ml on day 10 of that cycle). Four additional RES-A cows which had subfunctional CL were not ovariectomized but were bled for an additional 25 d. At ovariectomy, CL and ovarian weights were collected. Luteal tissue was prepared for evaluation of P4 synthesis, LH responsiveness in vitro, and for determination of P4 content and total LH receptors. Bodyweight and BCS increased in CON cows; whereas, RES cows lost BW and BCS (P < .05). In the cycle prior to ovariectomy, serum P4 and LH were not different in 18 RES-A cows which developed subfunctional CL in comparison to CON cows. Four RES-A cows not ovariectomized but bled for an additional 25 d neither exhibited estrus, ovulated, nor had P4 concentrations greater than .3 ng/ml. Serum INS was lower in RES-A cows during the cycle prior to ovariectomy than in CON cows (P < .05). During the 11-d period prior to ovariectomy, mean serum P4 and INS were lower in RES-A cows than in CON cows (P < .05); however, serum LH was not different. Furthermore, CL and ovarian weights, P4 content of CL, secretion of P4 by luteal tissue in response to LH in vitro and LH receptor number were not different between CON and RES-A cows. In conclusion, nutritional anestrus may be preceded by the formation of a CL with lower steroidogenic output in vivo. However, luteal tissue, collected from RES-A cows, did not appear to be subfunctional during in vitro incubation when substrate availability and gonadotropin support were equal between diets.
BLACK CHILDREN AND THE POLITICAL SYSTEM

From a study of four age groups of black and white middle and lower class children in two cities, the author concludes that there is a small but significant difference between white and black children's support for the political system, with black children becoming less supportive as they get older. The findings call into question current assumptions about both the agents of political socialization and about the stability of political orientations acquired in early childhood. The author is Assistant Professor of Political Science at Stanford University. His major research and teaching interests relate to the politics of minority groups.
“Wait, how did I miss that?:” Understanding the “twist” in Fritz Lang's The Woman in the Window

“Expectation thus becomes the basic condition for truth: truth, these narratives tell us, is what is at the end of expectation.”—Roland Barthes (1974, 76) “This ending is a cheat used to rescue the...
Do urodynamic parameters predict persistent postoperative stress incontinence after midurethral sling? A systematic review.

It is unclear whether preoperative urodynamic study (UDS) values are predictive of outcomes after midurethral sling. We systematically reviewed multiple databases from January 1989 to October 2011 for English-language studies correlating UDS data with postoperative outcomes after midurethral slings. We performed random effects model meta-analyses, as indicated. Relative risk (RR) ratios for the outcome of stress urinary incontinence (SUI) cure were calculated using high maximum urethral closure pressure (MUCP) and Valsalva leak point pressure (VLPP) values as the reference group. High preoperative MUCP was associated with cure after retropubic [RR 0.67; 95% confidence interval (CI) 0.47–0.97)] and transobturator slings (RR 0.65; 95% CI 0.49–0.90). High preoperative VLPP was also associated with cure after retropubic sling (RR 0.89; 95% CI 0.82–0.96), but this relationship did not achieve statistical significance for cure after transobturator sling (RR 0.86; 95% CI 0.74–1.00). Preoperative MUCP and VLPP values may add insight into postoperative outcomes after surgical treatment for SUI.
Dysmenorrhea and use of oral contraceptives in adolescent women attending a family planning clinic.

Summary OBJECTIVES : This study examined the prevalance of dysmenorrhea in female adolescents and the effectof experiencing a reduction in dysmenorrhea on oral contraceptive use. STUDY DESIGN : This was a prospective panel study in which 308 adolescent women at an inner-cityfamily planning clinic were interviewed about their experiences with dysmenorrhea and their oral contraceptive use at three points in time over a 6-month period. A X 2 test and multiple logistic regression analysis were done. RESULTS : The overall prevalence of dysmenorrhea in this population was 79.6%; 18.2% reported severedysmenorrhea. Those who had severe dysmenorrhea and also experienced the reduction of dysmenorrhea as a result of oral contraceptives were eight times more likely to be consistent oral contraceptive users (p ≤ 0.02). CONCLUSIONS : It is important to screen female adolescents for dysmenorrhea, provide them withinformation about the beneficial side effects of oral contraceptives, and follow up these young women to make sure they are experiencing the alleviation of their symptoms
THE KANSAS CITY WARM ROOM PROJECT: ECONOMICS, ENERGY SAVINGS, AND HEALTH AND COMFORT IMPACTS

Abstract The warm room retrofit is a response to a common problem: how to stay warm in a large, poorly insulated house during the coldest parts of winter. The problem is especially acute for low-income and elderly homeowners who may not have sufficient resources to improve the thermal integrity of their entire house. Although still an experimental technique, the warm room retrofit has the potential for achieving significant energy savings in houses at costs similar to those currently allocated by low-income weatherization programs. The retrofit is a combination of zoning, heating systems modification and insulation which allows the occupant to heat selected areas of her home while maintaining the unused areas at a cooler temperature. This study presents the results from a retrofit project in Kansas City, sponsored by the Urban Consortium in 1985–1986. Nine houses were selected for the study, four controls and five houses that received the warm room retrofit. The houses are all single-family detached structures, occupied by low-income owners (with the owners' ages between 60 and 80 yr), and heated with gas-fired forced-air or gravity-fed furnaces. The warm zone was designed to include the kitchen, bathroom, and one to two additional rooms depending on family size. The costs of the retrofit averages $1425 per house. Our analysis included regressions of total gas use vs outdoor temperatures to measure savings, which averaged 26%. Because of potential health and safety problems, we also measured indoor air quality before and after the retrofit, sampling levels of indoor radon, nitrogen dioxide, and formaldehyde. An important part of the study was to determine occupant response and the acceptability of the retrofit. The residents participated in the design of the retrofits, and were interviewed after the retrofits were installed to determine improvements in comfort and their satisfaction with the results.
Generating a hot big bang as a quantum fluctuation

This brief review provides an overview of work exploring the hypothesis that the Universe “tunneled into being” as a quantum fluctuation. The basic picture is formulated within the context of a semiclassical description, in which the tunneling is interpreted as a gravitational instanton interpolating between some Planck-sized, metrically and topologically complicated, pretunneling entity and a rapidly expanding, topologically trivial, post-tunneling Universe. It is argued that the tunneling hypothesis may provide a simple explanation of gross observed features of the current Universe, such as the fact that it is big, nearly homogeneous and nearly flat, and that the massless particles contained therein seem characterized by a near-thermal distribution.
Assessing the influence of adsorbed-state conformation on the bioactivity of adsorbed enzyme layers.

Systems using immobilized enzymes are attractive for a wide range of industrial and medical applications because they allow for the fabrication of stable, reusable substrates with highly specific functionality. The performance of these systems is greatly dependent upon the orientation and conformation of the adsorbed enzymes. To investigate these relationships, we have developed and applied methods to quantitatively assess the secondary structure of adsorbed enzyme layers on planar surfaces using circular dichroism (CD) spectroscopy and evaluate their bioactivity using colorimetric assays. These combined measurements provide molecular-level insights regarding whether observed changes in adsorbed enzyme bioactivity are due to the adsorbed orientation of an enzyme or adsorption-induced changes in its conformation. Using this approach, we investigated the adsorption behavior of lysozyme (HEWL), xylanase (XYL), and glucose oxidase (GOx) on OH-, CH3-, NH2-, and COOH-terminated alkanethiol self-assembled monola...
A family systems approach to grief

This article blends two important viewpoints on grief: a stage theory on the individual's grief and the family systems literature on grief. A case study is examined from both the individual and systemic viewpoints. Pastoral implications for intervention with the case study family as a system are noted. The theological questions which the family and pastor face are also discussed.
The Impact of Representation Per Capita on the Distribution of Federal Spending and Income Taxes

Abstract. A vote-maximizing incumbent government is expected to adjust discretionary spending and taxation in ways that increase its probability for re-election. Unequal voters per electoral district in Canada distort this calculation in favour of small electoral districts. Using two measures of federal expenditures, and one of income taxes, between the years 1961–2000, empirical estimates indicate that greater representation per capita (lower relative electoral district populations) results in higher federal spending, and lower income taxes, per capita, even after controlling for income and unemployment.Resume. Un gouvernement en place tentant de maximiser les votes en sa faveur est cense ajuster les depenses discretionnaires et les impots de maniere a augmenter la probabilite de sa reelection. L'inegalite du nombre d'electeurs des districts electoraux au Canada cree une distorsion en faveur des districts de petite taille. En utilisant deux mesures des depenses federales et une mesure des impots sur le revenu entre 1961 et 2000, nos resultats empiriques montrent qu'une plus forte representation par habitant (plus petits districts electoraux) entraine des depenses federales plus importantes et des impots sur le revenu moins eleves par personne, meme en controlant pour le revenu et le taux de chomage.
High-precision robotic equatorial C-ring telescope mounts: design, fabrication, and performance

The performance of the C-ring telescope mount rivals other designs in stiffness, tracking, simplicity, lack of field rotation, mechanical size and operating envelope. Issues relating to cost, fabrication, and complexity have suppressed the prevalence of the C-ring mount. The Las Cumbres Observatory Global Telescope (LCOGT) robotic C-ring telescope mounts, built for its network of 1.0m and 0.4m telescopes, solve many of these issues. The design yields a scalable mount with performance capabilities well suited for telescopes located at the best astronomical sites in the world at a low cost. Pointing has been demonstrated to be under 7 arc-sec RMS. Unguided tracking performance is 0.6 arc-sec for 1 minute and 2 arc-sec for 15 minutes. Slew speeds of 10deg/sec are reliably used with sub-second settling times. The mount coupled with the 1.0m telescope yields a well damped 16 Hz system. Axes are driven with zero backlash direct drive motors with a 0.01 arc-sec resolution. High system bandwidth yields superb disturbance rejection making it ideal for open air operation. Drive and bearings are maintenance free and feature a novel "bug cover" to seal them from wear and damage. Low costs are achieved with the drive/feedback configuration, structure design, and fabrication techniques, as well minimizing operating and maintenance.
Laser dye structures and synonyms.

Laser dyes are organic chemicals whose systematic names are lengthy and confusing. Other names—some jargon, some trade—have come into everyday use, but there is no consistency, and sometimes research workers will have dyes from different suppliers that are identical in structure although different in name. This paper tabulates laser dyes by a characteristic identification number.
Shapes of rotating free drops: Spacelab experimental results

The experimental observation of the behavior of acoustically rotated free drops in the microgravity environment of low earth orbit has yielded the first data which meet the restrictions of existing theoretical treatments. Rotating drops displayed both 'axisymmetric' and 'two-lobed' shapes in the presence and absence of applied torques. Their dimensions and general development confirm the existence of the distinct shape families and the bifurcation point between them. The data also indicate that the secular instability in the axisymmetric family occurs at a lower rotation velocity than predicted
Effects of methyl xanthine derivatives on cyclic AMP levels and ornithine decarboxylase activity of rat tissues.

Abstract The administration of aminophylline results in rapid increases in cyclic AMP in the adrenal medulla, adrenal cortex, liver, and kidney of the rat. The injection of theophylline results in a similar increase in cyclic AMP in the liver of the rat. In all instances, these increases are followed by 4- to 2-fold elevations of ornithine decarboxylase activity. The generality of this phenomena suggests that ornithine decarboxylase activity is regulated by an increase in cyclic AMP.
Characterization of the CheAS/CheZ complex: a specific interaction resulting in enhanced dephosphorylating activity on CheY-phosphate

The cheA gene encodes two overlapping polypeptides with a common carboxyl terminus: CheAL and CheAS. CheAL plays a central role in the Escherichia coli chemotaxis signalling pathway by autophosphorylation and transferring the phosphate to both CheY and CheB. On the other hand, the physiological functions of CheAS remain unknown. We have observed that overproduction of CheAS in wild-type cells increased counterclockwise-biased flagellar rotation, and this effect is dependent on the presence of CheZ. CheZ specifically facilitates CheY-phosphate (CheY-P) dephosphorylation and generates a smooth swimming signal. A physical interaction was detected between CheZ and CheAS in wild-type cell lysates by immunoprecipitation. The CheAS/CheZ interaction does not require other chemotaxis components, as we could form the complex using purified CheAS and CheZ proteins. The ability of CheAS to bind to CheZ depends on its being in the reduced state. We found that under non-reducing conditions, CheAS appears to form intermolecular disulphide bonds and loses the ability to bind to CheZ. Finally, the CheAS/CheZ complex formed in vitro shows a greater dephosphorylating activity on CheY-P than does free CheZ.
Cooperative Study of Intracranial Aneurysms and Subarachnoid Hemorrhage. Report on a Randomized Treatment Study: II. Objectives and Design of Randomized Aneurysm Study

Four selected treatments, namely, regulated bed rest, drug-induced hypotension, carotid ligation, and intracranial surgery, were randomly allocated with respect to location of the aneurysm and interval following last bleed. The objective of the Study was to answer the question. "What mode of treatment offers a patient with a single ruptured intracranial aneurysm during the previous three months the highest probability of optimal results with respect to survival. residual neurological deficit, capacity for self-care, and gainful employment? " Various treatments were suspended at specific intervals when a particular mode of therapy became inferior to the others. A group of 33 patients was disqualified after treatment was randomly allocated. The numbers of protocols remaining for analysis within each treatment category were 202 for regulated bed rest, 309 for drug-induced hypotension, 187 for carotid ligation, and 274 for intracranial surgery.
On essential right congruences of a semigroup

In ring theory one can give several approaches to the introduction of the concept of semisimplicity and a large number of equivalent formulations of this concept [5, 13]. Analogues of some of these formulations have been made, and studied, for semigroups [4, 6, 7, 8, 10, 11, 12] in terms of ideals or congruence relations. It seems possible that suitable and effective analogues can be made for each of these ring theoretical formulations in terms of congruence relations. However, unlike the situation for rings most of these analogues give inequivalent formulations in semigroups. One of the weakest of these is the nonexistence of a proper, essential right congruence. A right congruence ~ in a semigroup S is essential if for any right congruence a we have Q N a = z (the identity relation) implies a = z. The main result of this paper is a characterization of semigroups with the d.c.c, on right ideals and having no proper essential right ideals and having no proper essential right congruences. The first step in this characterization is a description of the lattice of right ideals in such a semigroup. Our results of this description in Section 2 should be compared with the work of Feller and Gantos [2] and Fountain [3]. While the class of semigroups studied in these two papers are defined quite differently than the class in this paper there is a striking similarity in the results; thus, suggesting a common area of investigation. In the subsequent sections the main technique used is the examination of a selection of proper right congruences and the implications on the multiplicative properties obtained from the assumption of nonessentiality.
Clostridium difficile strain NAP-1 is not associated with severe disease in a nonepidemic setting.

Background & Aims Recent outbreaks of Clostridium difficile infection (CDI) in North America and in Europe with very high case-fatality rates have been associated with infection by North American Pulsed Field Type I (NAP-1) isolates. This study examined whether NAP-1 strains are associated with worse outcomes of CDI in a nonepidemic, nosocomial setting. Methods All cases of CDI that occurred over a 13-month period at a tertiary medical center were examined for risk factors associated with increased severity of CDI and other outcomes. Stool samples from each patient were cultured for C difficile and the resulting isolates were strain-typed by pulsed-field gel electrophoresis. Results Strain types were obtained from 236 of 272 CDI samples; the NAP-1 strain was identified in 59 (25%). In this inpatient cohort of patients with CDI, the incidence of in hospital death was 12.1% and of death caused by CDI was 4.0%. Of the patients with CDI, 22.1% met the combined outcome end point of severe CDI. In both univariate and multivariate analyses, patients infected with the NAP-1 strain did not have worse outcomes compared with those infected with non-NAP-1 strains. Infection with the NAP-1 strain was correlated with admission from outside health care facilities regardless of whether symptoms of CDI began before or after admission to the study hospital. Conclusions The NAP-1 strain of C difficile was found to cause 25% of cases of CDI in the hospital where the study was performed. However, compared with non-NAP-1 strains, CDI was not associated with increased severity of disease in this nonepidemic setting.
Software radio: a broad change in RF communications systems design

Software radio is a deceptively simple idea: Identify all the features that specialize an RF communications device to a particular waveform (e.g. GSM cell phone or FM walkie talkie), and implement these features in flexible software on a generic platform, rather than in fixed-function hardware. This change should provide significant advantages compared to legacy hardware radios: the ability to support multiple waveforms on the same device, to upgrade the waveforms on the device through software downloads, and to dynamically adapt modulation or other physical layer parameters to a wide range of channel conditions. However, taking full advantage of software radio turns out to require a broad change in communications systems. Affected hardware components include antennas, filters, A/D converters, and power amplifiers. Affected device-level software components include signal processing, timing control, inter-layer APIs, and security. The hardware architectures optimal for this software are not GPPs, DSPs or FPGAs, but an interesting hybrid among these approaches. At the network level, new MAC algorithms and topology management are needed to exploit the flexibility of individual nodes. In this talk I present a slice through these varied and interrelated systems and research challenges, taking a total systems view of software radio.
Highly Tailorable Materials based on 2-Vinyl-4,4-dimethyl Azlactone: (Co)Polymerization, Synthetic Manipulation and Characterization

Through rigorous spectroscopic characterizations, including in situ, real-time monitoring, and size-exclusion chromatography (SEC) we describe the functionalization of polymers and copolymers based...
Physiology and cell biology update: polypeptide growth factors and their relation to renal disease.

Summary A number of polypeptide growth factors have been shown to act on different types of renal cells, and many are produced by the kidney itself. It is unclear whether the compensatory hypertrophy that follows the destruction of nephrons is under the control of growth factors, but they undoubtedly participate in various forms of progressive renal injury, including chronic glomerular and tubulointerstitial diseases via autocrine, paracrine, and possibly even endocrine routes. As new developments occur in this rapidly changing field, it is hoped that this knowledge can be used to ameliorate the damage, halt the progression, or enhance the recovery from a disease process in the kidney and in other tissues.
Complications of Celect, Günther tulip, and Greenfield inferior vena cava filters on CT follow-up: a single-institution experience.

Abstract Purpose To evaluate and compare the rates of complications on follow-up computed tomography (CT) studies of patients with Celect, Gunther Tulip, and Greenfield inferior vena cava (IVC) filters. Materials and Methods Retrospective review of CT studies obtained 0–1,987 days after infrarenal placement of an IVC filter identified 255 Celect, 160 Tulip, and 50 Greenfield filters. Follow-up CT studies were independently evaluated by two observers for IVC perforation, contact with adjacent organs, and filter fracture. Multivariate analysis was performed to identify factors associated with higher rates of IVC perforation, including age, IVC diameter, sex, and history of malignancy. Results IVC perforation was observed in 126 of 255 Celect filters (49%) with a mean follow-up of 277 days, 69 of 160 Tulip filters (43%) with a mean follow-up of 437 days, and one of 50 Greenfield filters (2%) with a mean follow-up of 286 days. A significantly higher IVC perforation rate was observed in women (45.5%) compared with men (30.8%; P = .002) and in patients with a history of malignancy (43.7%) compared with patients with no history of malignancy (29.9%; P Conclusions No significant difference was observed in IVC perforation rate between Celect and Tulip filters. Greenfield filters had a significantly lower rate of IVC perforation than Celect and Tulip filters. Higher IVC perforation rates were observed in women and patients with a history of malignancy.
Color vision testing

The science of color vision testing has evolved since its inception in the late 1700s. Since then, the rudimentary technique of comparing color names has been replaced by more sophisticated methods...
Leveraging lidar data to aid in hyperspectral image target detection in the radiance domain

This paper talks about the problem of nding targets in shadows. It discusses, through example and empirical analysis, why shadowed targets look dierent to a sensor. A forward modeling approach is used to describe how ground materials (i.e., targets) manifest themselves through the atmosphere and appear to the sensor in the radiance domain. Changes in illumination can be obtained by processing co-registered LiDAR point cloud data to obtain solar and sky-loading scaling factors. These scaling factors are then used in the forward model to better estimate varying illuminated targets in the scene. A target detection application was applied and showed that the modied or dynamic forward model was able to detect targets in both the open and hard shadow.
Biological Basis of Sex Differences in the Propensity to Self-administer Cocaine

Women are at greater risk for cocaine addiction than are men, and female rats similarly show a greater propensity to self-administer cocaine than do male rats. This could be due to the intrinsic sex differences in brain organization, to the activational effects of circulating gonadal hormones, or both. For example, estradiol enhances dopamine release in the striatum and nucleus accumbens, and facilitates the behavioral sensitization induced by repeated cocaine exposure. We report here that independent of circulating gonadal hormones, female rats acquire cocaine self-administration behavior more rapidly, and they self-administer more cocaine at a faster rate than do male rats. This indicates that there is an intrinsic difference between male and female subjects in the neural systems mediating drug-seeking behavior due to sexual differentiation of the brain. Furthermore, we find that the administration of estradiol to gonadectomized female subjects greatly facilitates the acquisition of cocaine self-administration. These data demonstrate that both intrinsic sex differences in brain organization and the actions of circulating estradiol contribute to increased vulnerability for cocaine use in female subjects.
Mechanical properties of high porosity low-k dielectric nano-films determined by Brillouin light scattering

Integrating nanometre sized pores into hybrid organic-inorganic interconnect layers is one of the key approaches being undertaken by the semiconductor industry to sustain the continued scale down of micro-electronic devices. While increasing porosity of the layers achieves the desirable lowering of the dielectric constant (k), it also has the potential to reduce mechanical and thermal stability and degrade device functionality. We report on Brillouin light scattering to measure the independent elastic constants, and thus the mechanical properties, of ultrathin dielectric films with porosity levels up to 45%, the highest in the industry. Longitudinal and transverse acoustic standing mode type excitations were observed from sub 200nm thick low-k thin films, and their frequency dispersion and associated light scattering intensities were utilized to determine Poisson’s ratio (ν)and Young’s modulus (E). In comparison with SiO2 and non-porous low-k materials, significant modifications were found in ν and E of these highly porous carbon-doped SiO2 (Si‐O‐C‐H) and amorphous carbon (a-C:H) low-k interlayer dielectrics.
Future atmospheric and accelerator neutrino oscillation experiments

Abstract As interest in neutrino oscillations has grown - spurred on by recent new results from Super-Kamiokande, K2K and SNO - plans for new experiments to study these phenomena in detail are moving forward. Here we summarize proposals for future atmospheric and accelerator experiments, concentrating on the reasonably near future, say the next decade. We give some attention to proposed superbeams, but not to neutrino factories, which lie farther in the future and are addressed elsewhere in these Proceedings.
The shear modulus of bulk amorphous Pd40Ni40P20 and its relation to viscosity and specific heat

Abstract We have measured the shear modulus and its temperature dependence of Pd40Ni40P20 using an EMAT technique. Measurements were made of the temperature dependence at constant heating rate of the infinite frequency shear modulus G. Values of the shear softening parameter γ are estimated and compared with those obtainable from frequency dependent shear moduli, specific heat and viscosity measurements. There is overall agreement with the Interstitialcy Theory of Condensed Matter States.
Signal Transduction by a Death Signal Peptide: Uncovering the Mechanism of Bacterial Killing by Penicillin

The binding of bactericidal antibiotics like penicillins, cephalosporins, and glycopeptides to their bacterial targets stops bacterial growth but does not directly cause cell death. A second process arising from the bacteria itself is necessary to trigger endogenous suicidal enzymes that dissolve the cell wall during autolysis. The signal and the trigger pathway for this event are completely unknown. Using S. pneumoniae as a model, we demonstrate that signal transduction via the two-component system VncR/S triggers multiple death pathways. We show that the signal sensed by VncR/S is a secreted peptide, Pep27, that initiates the cell death program. These data depict a novel model for the control of bacterial cell death.
Microstructural development in sol-gel derived lead zirconate titanate thin films: The role of precursor stoichiometry and processing environment

The role of precursor stoichiometry and local firing environment on the microstructural development of sol-gel derived lead zirconate titanate (PZT) thin films was investigated. Typically, excess Pb is added to films to compensate for PbO volatilization during heat treatment. Here, it is shown that the use of stoichiometric precursors with either a PbO atmosphere powder or a PbO overcoat during the crystallization heat treatment is an attractive and viable alternative method for control of film stoichiometry. Using these approaches, we have fabricated single phase perovskite thin films with microstructures and electrical properties (Pr ∼ 36 μC/cm2 and Ec ∼ 45 kV /cm) comparable to those of films using optimized solution chemistries and excess Pb additions. The potential advantage of increasing PbO partial pressure, or activity, during firing versus excess Pb additions is discussed from the standpoint of a proposed crystallization scenario based on the kinetic competition between Pb loss and the nucleation and growth rates of the perovskite phase.
Antisampling for Estimation: An Overview

We survey a new way to get quick estimates of the values of simple statistks (like count, mean, standard deviation, maximum, median, and mode frequency) on a large data set. This approach is a comprehensive attempt (apparently the first) to estimate statistics without any sampling. Our "antisampling" techniques have analogies to those of sampling, and exhibit similar estimation accuracy, but can be done much faster than sampling with large computer databases. Antisampling exploits computer science ideas from database theory and expert systems, building an auxiliary structure called a "database abstract." We make detailed comparisons to several different kinds of sampling.