cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure and magnetic order of EuB 6

We present a study of the structural and magnetic properties of single-crystalline EuB{sub 6}. Temperature-dependent x-ray diffraction found no significant anomalies at the onset of ferromagnetic order. The resistivity, dc susceptibility, magnetization, and specific heat prove the crystal to be of extraordinarily high quality. Two ferromagnetic transitions at T{sub c1}=15.3 K and T{sub c2}=12.5 K are observed in all investigated properties. The ordered state displays an unexpected anisotropy, and we derive the magnetic phase diagrams for the three principal cubic directions. We argue that the two magnetic phases are connected by spin reorientation, enabled by a reduction of the crystalline symmetry from cubic. An additional anomaly in the specific heat is observed at low temperatures, which we interpret as arising from the splitting of the Eu ground-state multiplet in internal magnetic fields. {copyright} {ital 1998} {ital The American Physical Society}
Visualizing mathematics: evolution of vortical flows

Abstract Computers, used as a heuristic tool, allow us to explore complex nonlinear dynamical behavior and to discover unexpected linkages and new concepts in realistic continuum systems. Recent developments in coherent vortex dynamics are illustrated. Techniques for interactive visualization of evolving functions are discussed.
Initial-boundary value problems for integrable evolution equations with 3×3 Lax pairs

Abstract We present an approach for analyzing initial-boundary value problems for integrable equations whose Lax pairs involve 3×3 matrices. Whereas initial value problems for integrable equations can be analyzed by means of the classical Inverse Scattering Transform (IST), the presence of a boundary presents new challenges. Over the last fifteen years, an extension of the IST formalism developed by Fokas and his collaborators has been successful in analyzing boundary value problems for several of the most important integrable equations with 2×2 Lax pairs, such as the Korteweg–de Vries, the nonlinear Schrodinger, and the sine-Gordon equations. In this paper, we extend these ideas to the case of equations with Lax pairs involving 3×3 matrices.
Large-N scaling limits of symmetric-matrix models as systems of fluctuating unoriented surfaces.

Models of a single real symmetric matrix are exactly solved in the scaling limit where the size of the matrix is taken to infinity and a physical cosmological constant is kept fixed. This limit represents the quantization of unoriented surfaces with various kinds of matter content but without surfacelike extrinsic properties.
CD95 Expression and Apoptosis during Pediatric HIV Infection: Early Upregulation of CD95 Expression

Pediatric HIV infection is characterized by a progressive decline in CD4 T lymphocytes and faster disease progression than is typically seen in adults. Apoptosis, possibly mediated through the CD95 antigen, has been proposed as a mechanism for cell loss which eventually leads to immune dysfunction. In this study of peripheral blood lymphocytes from HIV-infected children, classified according to CDC immunologic categories, we found that the percentage of CD4 and CD8 T cells expressing CD95 and the percentage of lymphocytes undergoing apoptosis were increased in children with HIV infection and were greater in children from immunologic Category III as compared to those in Category I. Most striking was our observation that an increased percentage of CD95-positive cells appeared as early as 3 months of age, at a time when these children did not have elevated levels of apoptosis. These data demonstrate early upregulation of CD95 expression in HIV-infected infants, an abberation which may have profound implications for the pathogenesis of perinatally acquired HIV disease.
Treatment with sd/01 relative to chemotherapy in mice

Abstract The effectiveness of Filgrastim SD/01 (SD/01) has been demonstrated in the relief of neutropenia associated with cancer chemotherapy. The studies reported to date administered SD/01 primarily on the day after chemotherapy in a similar manner to the injection of conventional Filgrastim. It was not clear whether the same dosing paradigm would be optimum for an engineered form of Filgrastim with substantially altered pharmacokinetics. In order to examine the optimum timing of SD/01 relative to chemotherapy, mice were treated with 325 mg/kg cyclophosphamide (CY) on study day 0. They were also treated with a bolus dose of 1000 g/kg SD/01 on days −5, −4, −3, −2, −1, 1, 2, 3, 4 or 5. Blood was collected for complete blood counts on study days −1, +1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12. Normal untreated mice have an ANC of 0.75 to 1.25 × 10 3 /μL. Following CY treatment ANC fell to a nadir of .01 × 10 3 /μL on day 4 then quickly rebounded to a high of 3.5 × 10 3 /μL on day 8, returning to normal by day 10. Post-CY treatment with SD/01 on days 1, 2 or 3 improved the ANC nadir and brought counts back to baseline between days 4 and 5 (one day earlier). Delaying the SD/01 to days 4 and 5 after CY did not accelerate the return to baseline ANC. Pretreatment with SD/01 did not impact the depth or timing of the nadir or the day ANC passed the baseline count during recovery. Pre-treatment with SD/01 raised the ANC depending on the interval between treatment and CY exposure. Thus, 5 days pretreatment yielded an ANC of 14 × 10 3 /μL, 4 days 11 × 10 3 /μL, 3 days 8 × 10 3 /μL, 2 days 3 × 10 3 /μL, and 0.53 × 10 3 /μL with 1 day pre-treatment. Pre-treatment with SD/01 (ie before chemo) is relatively ineffective compared to post-chemo treatment. Day 1 post-chemotherapy treatment appears to be the most effective timing for decreasing the severity and duration of neutropenia—delaying administration makes it less effective, and pre-treating does not appear to improve or worsen ANC recovery.
The pre/post LTP debate.

The pre/post debate involves the question of whether long-term potentiation (LTP) is mediated by enhancement of release, enhancement of postsynaptic receptors, or both. Recent papers have presented evidence for purely postsynaptic or purely presynaptic changes, and a paper by Ahmed and Siegelbam (in this issue of Neuron ) suggests a mechanism by which release is enhanced. This debate is increasingly constrained by technical advances that allow central synapses to be studied with increasing precision. A possible of way of reconciling conflicting evidence is suggested.
Acid strength of silica-alumina and silica studied by microcalorimetric measurements of pyridine adsorption

Abstract Microcalorimetric measurements of the differential heat of pyridine adsorption at 473 K were used to probe the distribution of acid strength on silica and silica-supported alumina catalysts. Depositing alumina on silica increased the acid strength of the catalyst. The acid strength distribution curves for the Al2O3/SiO2 sample showed three regions of constant heat of adsorption while silica had an energetically homogeneous surface. The Al2O3/SiO2 catalyst was found to have both Bronsted and Lewis acidity. Incremental adsorption of pyridine on Al2O3/SiO2 indicated that the initial region of constant heat corresponds to strong Lewis acidity while the intermediate region seemed to be Bronsted sites or a combination of weaker Lewis sites and Bronsted sites. The final region observed at higher extents of adsorption showed only H-bonded pyridine which corresponds to adsorption on silica. Estimates of the entropies of adsorption were determined, providing information about the mobility of the adsorbed basic molecules. Surface diffusion over the silica support provides an important pathway for the equilibration of pyridine between acid sites on the Al2O3/SiO2 sample.
Thrombostatin, a bradykinin metabolite, reduces platelet activation in a model of arterial wall injury

Objective: Thrombin activates platelets and contributes to the occlusion of arteries following thrombolytic therapy or angioplasty. Thrombostatin (RPPGF), the angiotensin converting enzyme degradation product of bradykinin, inhibits α-thrombin induced platelet activation. We hypothesized that thrombostatin prevents platelet aggregation and adhesion after balloon angioplasty (BA). Methods: Platelet-rich plasma (PRP) was obtained from 22 Beagle dogs before sacrifice and 10% of the PRP was labeled with 111In. Carotid arteries were then removed from each dog and mounted in a dual perfusion chamber and intimal injury was performed with BA. 111In-PRP with or without thrombostatin or aspirin alone was perfused through the arteries for 60 min. During perfusion, platelet volume was measured using a Coulter counter and a laser-light scattering technique. Platelet adhesion to arteries was measured by radioactivity count. Results: Arterial injury alone compared to non-injury increased platelet volume in the circuit by 1.4 times (×) ( P <0.05) using a Coulter counter or 1.8× ( P <0.05) using laser-light scattering and increased platelet adhesion by 2.3× ( P <0.01). When compared to BA injury alone, the addition of thrombostatin reduced platelet volume by 1.8× ( P <0.03) as measured by Coulter counter or 1.9× ( P <0.01) by laser-light scattering and platelet adhesion by 4.2× ( P <0.05). Compared to BA injury alone, aspirin reduced platelet volume by 1.2× ( P <0.01) as assessed by Coulter counter or 1.5× ( P <0.03) using laser-light scattering and platelet adhesion by 1.8× ( P <0.02). Conclusion: Thrombostatin or aspirin independently decreases evidence of platelet activation in the canine carotid artery model of BA injury.
QUALITY OF LIFE AMONG WOMEN WITH INTERSTITIAL CYSTITIS

Purpose: Clinical case series suggest that the impact of interstitial cystitis on quality of life is severe and debilitating, however, little epidemiologic information is available. We examined the impact of interstitial cystitis on quality of life in a population based cohort of United States women.Materials and Methods: We collected multidimensional measures of quality of life from 159,419 participants in the Nurses’ Health Study I and II using a validated instrument, the Medical Outcome Study Short-Form 36 Health Survey Instrument. This instrument measures physical function, role limitations due to physical and emotional problems, bodily pain, vitality, social function and mental health. Quality of life measures were collected on 99 women with prevalent self reported interstitial cystitis confirmed by medical record review.Results: After adjusting for age and co-morbid conditions, women with interstitial cystitis had significantly lower quality of life scores in 4 of the 7 quality of life dimensions, i...
The Principal's Role in Fostering Collaborative Learning Communities Through Faculty Study Group Development

This article explores the leadership of school principals with respect to faculty study group development as a key element of the professional learning community. Questions asked concern the approaches that principals use to facilitate study group processes that, in turn. foster teacher learning and student achievement, and ways in which principals might best support the integration of schoolwide faculty teams and school–university partnerships. For this writing, the authors analyzed research on the principal's role in facilitating and maintaining the study group as a strategy of embedded professional development. They also reviewed the research on partnerships that supports study groups as a strategy of professional development and school reform. Referencing literature and real-world examples, the authors offer conceptualizations and illustrations of the principals' role in supporting the professional learning of their faculties.
Winter MIZEX 87, Operations Overview

MIZEX (Marginal Ice Zone Experiment), a multinational, interdisciplinary study of the Arctic environment, has the overall goal to better understand the mesoscale interaction of ice, ocean, and atmosphere at the polar margin. Winter MIZEX is the natural extension of the successful 1983-84 Summer programs and this paper presents an overview of the MIZEX 87 operations, March 19 to April 13, 1987. Principal scientific areas studied were: oceanography, meteorology, remote sensing, ice and waves, acoustics, and biology. Operations benefitted greatly from SAR imagery, downlinked daily, in near real-time, directly from SAR aircraft to POLAR CIRCLE. Preliminary reviews of just part of all the data acquired during MIZEX 87, indicate that knowledge of the Arctic enviorment will expand significantly when all the data are evaluated.
Finite dimensional approximation of pairs of algebras and obstructions for the index

Abstract We first discuss the methods introduced by the authors (Ann. Sci. Ecole Norm. Sup.19, 1986, 57–106) to study subfactors having finite Jones' index. Then we show that for pairs of finite dimensional algebras A ⊂ B with embedding matrix T we have the inequalities H(B¦A) ⩽ ln ∥T∥ 2 ,∥T∥ 2 ⩽ λ(B, A) −1 , where H(B¦A), λ(B, A) are the relative entropy and the generalized index λ(B, A)−1 introduced by the authors (referenced above). This proves that if H is closed to ln λ−1 then the index λ−1 is close to the square of the norm of the inclusion matrix of A in B. We then deduce that if N ⊂ R is a subfactor of the hyperfinite II1, factor with N′ ∩ R = C and so that R can be approximated by finite dimensional algebras Bn in a way that the relation (∗) EBnEN = EBn ∩ N holds for all n, then the index of N in R, [R:N], is equal to the square of the norm of a (possibly infinite dimensional) matrix with nonnegative integer entries. By A. J. Hoffman (“Lecture Notes in Math.,” Vol. 303, pp. 165–172, Springer-Verlag, New York/Berlin, 1972 ) this yields gaps in the set of values of indices in the interval (4, 2 + √5), for this class of subfactors of R. We prove that for any pair of hyperfinite II1 factors N ⊂R there exists an increasing sequence of finite dimensional subfactors Bn ⊂R so that ∪ B n = R, ∪ (B n ∩ N) = N , (but without the condition (∗) satisfied).
Gender distinctiveness, communicative competence, and the problem of gender judgments in computer-mediated communication

Abstract Despite persistent claims regarding the ability of text-based computer-mediated communication to neutralize gender identities, few researchers have worked on the problem of gender distinctiveness in textual production and interpretation, gender judgments, and more importantly, the role of gender in the process of impression formation in electronic communication. Against this background, the author addresses the theoretical aspects of gender in textual communication and places the problem of gender distinctiveness and gender judgments in CMC in the context of Hymes’ model of communicative competence. He also isolates several variables worthy of investigation, namely, the provision of gender judgments, accuracy, and certainty. He then reconceptualizes the problem of gender distinctiveness and impression formation in CMC by bridging the gap between textual markedness and expectations.
On the finite blocklength performance of HARQ in modern wireless systems

Future wireless communications will face the dual challenge of supporting large traffic volume while providing reliable service for various kinds of delay-sensitive traffic. In the light of this challenge, this paper investigates the throughput performance of hybrid automatic repeat request (HARQ) systems under finite blocklength constraint. We present a framework to compute the maximum achievable rate with HARQ over the Rayleigh fading channel for a given probability of error. In the proposed framework, the operation of HARQ over the Rayleigh fading channel is modeled as a finite-state Markov chain. The state transition probabilities of the proposed Markov model are estimated from the fading characteristics of the wireless channel as well as the dispersion associated with different channel state sequence realizations. With this framework we are able to link the HARQ throughput performance to the characteristics of the underlying physical channel as well as the system design parameters such as modulation and transmit power. Furthermore, we discuss the relationship between the system throughput, and the number of HARQ rounds. The results show that the required number of HARQ rounds to take full advantage of HARQ depends on the choice of modulation, and varies as a function of the signal-to-noise ratio (SNR).
Introduction to the toxin reviews special issue “Aspergillus flavus, aflatoxin, cyclopiazonic acid, and biological control”

The first report of mycotoxin poisoning in humans occurred in medieval times, around the 7th to 9th century when soldiers ingested bread made from moldy rye infested with an ergot-producing fungus....
Linearized broadband optical detector: study and implementation of optical phase-locked loop

Optical phase-locked loop (OPLL) is used to improve the linearity of an optical link for transmission of analog signals. The finite loop delay and the presence of a low-pass filter, required for stable loop operation, lead to a nontrivial frequency response. Here, the linearity improvement in OPLL is investigated, and simple relation among the loop delay, the open-loop gain, and the loop-filter bandwidth that must be satisfied for stable operation of the OPLL is found. This relation is used to determine the fundamental limit on spur-free dynamic range (SFDR) improvement that OPLL can offer over a conventional Mach-Zehnder (MZ)-type detector.
Intrauterine fetal brain NMR spectroscopy: 1H and 31P studies in rats

Fetal brain metabolism was investigated in utero noninvasively using multinuclear nuclear magnetic resonance spectroscopy in rats at two representative prenatal stages: early (17-18 days) and late (20-21 days) stages. Phosphorus-31 (31P) spectroscopy revealed that phosphocreatine is significantly lower in the early stage and increases to the level of early neonates by the late prenatal stage. Intracellular pH at the early stage was found to be strikingly high (7.52 +/- 0.21) and decreased to a level similar to that of neonates by the late stage (7.29 +/- 0.07). Phosphomonoester levels at both stages were similar to the values reported for early neonates. Water-suppressed proton (1H) spectroscopy demonstrated a distinctive in vivo fetal brain spectral pattern characterized by low levels of N-acetyl aspartate and high levels of taurine. High-resolution proton spectroscopy and homonuclear chemical-shift correlate spectroscopy of brain perchloric acid extracts confirmed these in vivo findings. In vitro 31P spectroscopy of acidified chloroform methanol extracts showed the characteristic membrane phospholipid profiles of fetal brain. The phosphatidylethanolamine (PE)-to-phosphatidylcholine (PC) ratio (PE/PC) did not show significant changes between the two stages at 0.40 +/- 0.11, a value similar to that of early neonates.
The effect of model structure on projections of greenhouse-gas-induced climatic change

The transient response of global-mean temperature to greenhouse-gas forcing between 1765 and 2030 is studied using two types of ocean model, a pure diffusion model and an upwelling-diffusion model. The results are almost the same for both types of model. If the greenhouse-gas contribution to global warming over the period 1880-1985 is Δ, then the contribution to future warming over the period 1985-2030 is shown to be approximately 1.6 Δ independent of model type and model parameters (viz. climate sensitivity and ocean mixing rate).
Biochemical pharmacology of acivicin in rat hepatoma cells

Abstract The antiglutamine agent acivicin, l -(αS,5S)-α-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid, inhibited the growth of hepatoma 3924A cells in culture. After 7 days of incubation with the drug, an lc 50 of 1.4 μM was observed by determination of colony forming ability. A combination of cytidine (1 mM), deoxycytidine (10 μM) and guanosine (10 μM) completely protected the hepatoma cells against the cytotoxic action of acivicin, but each nucleoside by itself had no effect. Acivicin (0.1 mM) inhibited the incorporation of uridine and thymidine into macromolecules, but not that of leucine. Acivicin depressed the pools of CTP, GTP, dCTP, dGTP and dTTP to 46, 62, 40, 64 and 53%, respectively, but it increased UTP level to 152% of the values of untreated cancer cells. The activity of a highly purified CTP synthetase (EC 6.3.4.2) from rat liver and hepatoma 3924A was inhibited by acivicin. The inhibition was competitive with respect to l -glutamine, and the Ki values with liver and hepatoma enzymes, determined by Dixon and reciprocal plots, were 1.1 and 3.6 μM respectively. The hydroxy analog of acivicin was also a competitive inhibitor, but it was less effective than acivicin, with a Ki value of 1.8 mM for the hepatoma enzyme. Our observations on the impact of acivicin on the behavior of pools of ribonucleotides and deoxyribonucleotides and the competitive inhibition of purified CTP synthetase from hepatoma cells suggest that a major mechanism of action for this drug is the inhibition of CTP synthetase and GMP synthetase (EC 6.3.5.2).
Use of Vaccination against Enteric Septicemia of Catfish and Columnaris Disease by the U.S. Catfish Industry

Abstract Vaccination is an effective strategy used for the protection of food animals against infectious diseases. A 2010 U.S. Department of Agriculture questionnaire examined U.S. catfish industry use (in 2009) of two commercial vaccines that provide protection against enteric septicemia of catfish (ESC) and columnaris disease, catfish producers’ opinions regarding the percentage of vaccinated fish they expect to be protected, and producers’ general expectations regarding survival of vaccinated fish compared with unvaccinated fish. During 2009, 9.7% of the total fingerling operations used one or both vaccines; 12.3% of the total industry fry production was vaccinated against ESC, and 17.0% was vaccinated against columnaris disease. Of the producers who grew food-sized catfish to harvest, 6.7% used vaccinated catfish. The farms that did not use vaccinated fish for grow out had a mean size of 63.4 water surface hectares (156.6 water surface acres). The operations that used vaccinated fish were larger (mean...
The role of material damping in the stability of rotating systems

Abstract In this paper we consider a whirling shaft, modeled as an elastic continuum subject to general descriptions of the initial conditions and broad descriptions of the boundary conditions. We show that for this class of dynamic systems material damping tends to destabilize the system when the impressed angular velocity exceeds the fundamental critical velocity of the system.
Drought Occurrence Probabilities and Risks of Dependent Hydrologic Processes

The occurrence probabilities, return periods, and risk of drought events are estimated for dependent hydrologic processes. Traditionally, Markovian models have been used for modeling hydrologic processes having short-term time dependence. However, they are inadequate for processes exhibiting longer time dependence. In this paper, low-order discrete autoregressive moving average (DARMA) models are used for modeling the variability of wet and dry years. Specifically, we center our attention on the occurrence of drought events, particularly their duration, by using the concept of runs. The probability distribution of drought occurrence, expected values and variances of first arrival and interarrival times of drought events, and the associated risks are derived. The derived equations and algorithms are verified by Monte Carlo simulation experiments. The applicability of the proposed methods is demonstrated by using annual streamflow data of the South Platte River in Colorado and the Niger River in Africa. It ...
Goblet Cell Response to Vitamin a Treatment for Corneal Xerophthalmia

Abstract In 11 patients with active corneal xerophthalmia, conjunctival biopsies were obtained at various intervals after massive-dose systemic vitamin A therapy. Goblet cells began to repopulate the inferonasal quadrant of the conjunctivas after two weeks, and they reached normal concentrations after one month. Corneal healing proceeded much more rapidly than that, suggesting that a full complement of mucus-secreting conjunctival goblet cells is not essential for restoration and maintenance of normal corneal appearance
Structure and transport mechanism of a high-affinity potassium uptake transporter from higher plants

POTASSIUM is the most abundant cation in higher plants and is crucial for plant nutrition, growth, tropisms, enzyme homeostasis and osmoregulation1–4. K+ accumulation can be rate-limiting for agricultural production2–4. K+ uptake from soils into roots is largely mediated by high-affinity K+ uptake (Km≈10–40 μM) (refs 1, 2, 5–7). But although K+channels allow low-affinity K+ uptake8–10, both the transport mechanism and structure of the high-affinity K+ nutrition pathway remain unknown. Here we use expression cloning to isolate a complementary DNA encoding a membrane protein (HKT1) from wheat roots which confers the ability to take up K+. The substrate affinity, saturation and cation selectivity of HKT1 correspond to hallmark properties of classical high-affinity K+ uptake in plants1,2,11. The transport mechanism of HKT1 uses K+-H+ co-uptake. Expression of HKT1 is localized to specific root and leaf regions which represent primary sites for K+ uptake in plants2,3. HKT1 is important for plant nutrition and could possibly contribute to environmental alkali metal toxicities11–13.
Determination of 2,4-Dichlorophenoxyacetic acid in soils by capillary gas chromatography with ion-mobility detection

Abstract A simplified procedure for quantifying 2,4-dichlorophenoxyacetic acid (2,4-D) residues in soils has been developed. Soil samples are extracted, esterified with methanol in the presence of a boron trifluoride catalyst and analyzed by capillary gas chromatography without further time-consuming cleanup steps. The success of the procedure depends on substituting a tunable selective ion-mobility detector for the commonly used electron-capture detector. By selectively monitoring the product ion formed when the methyl ester of 2,4-D undergoes electron capture, the ion-mobility detector can detect 2,4-D in the presence of other electron-capturing compounds. A recovery of 93% of 2,4-D at the 50 ppb level in spiked soils is achieved.
Surface brightness profiles of 10 comets

CCD photometric observations of the comae of 10 comets, obtained at the 4-m and 2.1-m telescopes at KPNO during 1985-1986 using filters centered at 700.5, 650.0, or 546.0 nm, are reported. The data are presented in extensive tables and graphs and characterized in detail. The radial surface brightness profiles are shown to be steeper than predicted by an idealized spherically symmetric steady-state comet model, the steepness increasing with the projected distance from the nucleus. These profiles are attributed, on the basis of Monte Carlo simulations, to imperfect coupling between the sublimated gas and the optically dominant grains of the coma.
Identification of RNAs that bind to a specific protein using the yeast three-hybrid system

We have adapted the yeast three-hybrid system to identify RNA ligands for an RNA-binding protein. In this assay system, a protein-RNA interaction is detected by the reconstitution of a transcriptional activator using two hybrid proteins and a hybrid RNA. The RNA molecule is tethered to the promoter of a reporter gene by binding to a hybrid protein consisting of the bacteriophage MS2 coat protein fused to the DNA-binding protein LexA; the RNA-binding domain to be analyzed is fused to the transcriptional activation domain of the yeast Gal4 protein; and the bifunctional RNA consists of binding sites for the coat protein and for the other RNA-binding domain. We built an RNA library such that short fragments of genomic DNA from yeast were transcribed in yeast together with binding sites for the coat protein. We screened this hybrid RNA library for RNAs that bound to the yeast Snp1 protein, a homolog of the human U1-70K protein. The screen yielded as the strongest positive the fragment of U1 RNA that contains loop I, which is known to bind to Snp1 in U1 snRNP. We also identified four other RNA ligands that produced weaker three-hybrid signals, suggesting lower affinities for Snp1 as compared to U1 RNA. In addition, this search also yielded a set of RNA sequences that can activate transcription on their own when bound to a promoter through a protein interaction.
Computer-aided software development process design

The authors describe an intelligent tool designed to aid managers of software development projects in planning, managing, and controlling the development process of medium- to large-scale software projects. Its purpose is to reduce uncertainties in the budget, personnel, and schedule planning of software development projects. It is based on dynamic models for the software development and maintenance life-cycle process. This dynamic process is composed of a number of time-varying, interacting developmental phases, each characterized by its intended functions and requirements. System dynamics is used as a modeling methodology. The resulting software life-cycle simulator (SLICS) and the hybrid expert simulation system of which it is a subsystem are described. >
EIGENVALUES AND EIGENVECTORS OF TRIDIAGONAL MATRICES

This paper is continuation of previous work by the present author, where explicit formulas for the eigenvalues associated with several tridiagonal matrices were given. In this paper the associated eigenvectors are calculated explicitly. As a consequence, a result obtained by Wen- Chyuan Yueh and independently by S. Kouachi, concerning the eigenvalues and in particular the corresponding eigenvectors of tridiagonal matrices, is generalized. Expressions for the eigenvectors are obtained that differ completely from those obtained by Yueh. The techniques used herein are based on theory of recurrent sequences. The entries situated on each of the secondary diagonals are not necessary equal as was the case considered by Yueh. n−1 j=1 are two finite subsequences of the sequences {aj} ∞ j=1 and {cj} ∞=1 of the field of complex numbers C, respectively, and α, β and b are complex numbers. We suppose that
Parallel multipliers for Quantum-Dot Cellular Automata

This paper explores the optimization of parallel multipliers for Quantum-Dot Cellular Automata. To reduce the complexity, multipliers are designed with quasi-modularity to accommodate large word sizes. The regular quasi-modular product method is used to make n × n multipliers using 4 (n/2 × n/2) modules. This may be continued with further decomposition to 16 (n/4×n/4) modules, etc. The last two rows in Wallace or Dadda reduction trees are summed by an adder that is 3n/2 – 1 bits long to produce the final product. This design is constructed using coplanar layouts and compared with other QCA multipliers (bit-serial and array multipliers). The delay, area and complexity are compared for several different operand sizes using the QCADesigner simulator.
Primary biliary cirrhosis: safety and benefits of established and emerging therapies.

Introduction: Primary biliary cirrhosis (PBC) is a chronic, cholestatic liver disease characterized histologically by lymphocytic cholangitis and intralobular bile duct destruction. It is a progressive disorder associated with increased mortality and decreased quality of life related to hepatic fibrosis, troublesome symptoms such as fatigue and pruritus, and ultimately endstage cirrhosis. PBC affects adults around the world, and therefore effective treatment of PBC and its associated symptoms constitute significant issues for patients and providers as well as on a public health level. The only approved pharmacotherapy for PBC to date is ursodeoxycholic acid (UDCA), a choleretic, hydrophilic bile acid which has been in clinical use for decades. UDCA is effective in a majority of patients with PBC, but nearly a third of patients are UDCA non-responders. Non-response to UDCA is associated with an increased risk of death or need for liver transplantation (LT). Whereas LT is an effective treatment, it engender...
Architectural Synthesis Integrated with Global Placement for Multi-Cycle Communication

Multiple clock cycles are needed to cross the global interconnects for multi-gigahertz designs in nanometer technologies. For synchronous design, this requires the consideration of multi-cycle on-chip communication at the high level. In this paper, we present a new architectural synthesis system integrated with global placement, named MCAS (Multi-Cycle Architectural Synthesis), on top of the recently-proposed Regular Distributed Register (RDR) micro-architecture. The RDR architecture provides a regular synthesis platform for supporting multi-cycle communication. Novel architectural synthesis algorithms that integrate high-level synthesis with global placement have been developed in MCAS, including scheduling-driven placement and distributed controller generation, etc. Experimental results show that our methodology can achieve a clock period improvement of 31% and a total latency improvement of 24% on average compared to the conventional architectural synthesis flow.
Can Community-Based High School Transition Programs Improve the Cost-Efficiency of Supported Employment?

This study investigates the potential impact that community-based, high school transition programs have on the cost-efficiency of individuals with disabilities when they become adults. Outcomes achieved by 246 supported employees were compared. Results indicated that supported employees who participated in community-based transition programs in high school were more cost-efficient from the taxpayers’ perspective than were individuals who received only in-school transition services or received no transition services at all. Supported employees who received community-based transition services also kept their jobs in the community significantly longer than did individuals from the comparison groups.
A phase-field method for 3D simulation of two-phase heat transfer

We formulate new multi-phase convective heat transfer equations by combining the three-dimensional (3D) Navier–Stokes equations, the energy equation and the Cahn–Hilliard equation for the phase field variable /ðx; tÞ. The density, viscosity, heat capacity and conductivity are functions of /ðx; tÞ. The equations are solved in time with a splitting scheme that decouples the flow and temperature variables, yielding time-independent coefficient matrices after discretization, which can be computed during preprocessing. Here, a spectral element method is employed for spatial discretization but any other Eulerian grid discretization scheme is also suitable. We test the new method in several 3D benchmark problems for convergence in time/space including a conjugate heat transfer problem and also for a realistic transient cooling of a 3D hot object in a cavity with a moving air–water interface. These applications demonstrate the efficiency of the new method in simulating 3D multi-phase convective heat transfer on stationary grids, different modes of heat transfer (e.g. convection/conduction), as well as its robustness in handling different fluids with large contrasts in physical properties.
Resonant Acoustic Oscillations with Damping: Small Rate Theory

Abstract : A gas in a tube is excited by a reciprocating piston operating at or near a resonant frequency. Damping is introduced into the system by three means: radiation of energy from one end of the tube, rate dependence of the gas, and boundary layer friction. A lumped damping coefficient is defined to account for the effects of all three. It is shown that in the small rate limit the signal in the periodic state suffers negligible distortion in one travel time, and hence its propagation according to acoustic theory is valid. The shape of the signal is determined by a nonlinear ordinary differential equation. The small rate condition provides a test of the applicability of the theory to given experimental conditions. The resonant band is analyzed for both damped and inviscid cases. The predictions of the theory are compared with experiment.
The College Fraternity as an Opportunity Structure for Meeting Academic Demands

Studies have generally shown that college cheating is more common among fraternity members than among independents. On the basis of such findings, others have argued that the fraternity serves its members as an illicit opportunity structure for meeting academic demands. This paper examines the extent to which fraternities in different college contexts display the characteristics of an illegitimate opportunity structure—specifically, the extent to which they are “learning environments” and “performance structures” for academic dishonesty. Our data on 697 Greeks and 950 independents at 58 colleges do not support the general proposition that college fraternities serve as such illegitimate opportunity structures; we find that in some campus contexts they do, while in others they do not. There is consistent evidence in all campus contexts, however, that the fraternity is serving as a legitimate opportunity structure for meeting academic demands by providing acceptable “short cuts” to improved academic performance.
Chemistry in lasers. XI. Non-classical aspects of fusion: the Zhabotinsky effect and communications theory

Abstract Developed from the application of operational mathematics and Markoff-theory in quantum mechanics [CA: 81: 8225v], transform space treatment of Einstein diffusion [CA: 82: 49699s], and acoustoopic effects in lasers [CA: 82: 162686y], the paper examines non-classical aspects of laser driven fusion presenting favorable options which remain generally inexplored.
Pharmacologic support of the myocardium following aortocoronary bypass surgery: a comparative study.

To evaluate the hemodynamic effects of simultaneous nitroglycerin and epinephrine infusion following aortocoronary bypass surgery, 16 patients were monitored and studied in the early postoperative period. All patients were given intravenous nitroglycerin, epinephrine, epinephrine combined with nitroglycerin, and dobutamine in a randomized manner. The dose of pharmacologic agent was gradually increased to achieve the required circulatory response. The measured variables included heart rate (HR), central venous pressure (CVP), arterial blood pressure (BP), pulmonary artery pressure (PA), pulmonary artery wedge pressure (PAWP), cardiac output, and arterial and venous oxygen saturations. A nitroglycerin infusion at 1.1 +/- 2 micrograms/kg/min caused the PAWP to decrease by 37% (P less than or equal to .005). All other parameters were not significantly different from control. Epinephrine at a dose of 0.06 +/- 0.02 micrograms/kg/min increased the mean blood pressure by 21% (P less than or equal to .005). The rate-pressure product (RPP) and PAWP were elevated by 18% and 12%, respectively (P less than or equal to .005). Cardiac index, however, was not increased. When nitroglycerin was added to the epinephrine infusion, a PAWP increase was not seen. Also the right ventricular stroke work index was increased by 23% (P less than or equal to .01), and the left ventricular stroke work index increased by 21% (P less than or equal to .01). Dobutamine 4.8 +/- 1.0 micrograms/kg/min caused ventricular stroke work indexes to increase significantly (P less than or equal to .005). The CVP and PAWP were unchanged with this mode of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
Control of Sindbis Virus Infection by Antibody in Interferon-Deficient Mice

Antibodies clear Sindbis virus from infected animals through an unknown mechanism. To determine whether interferon-induced pathways are required for this clearance, we examined mice which are unable to respond to alpha/beta interferon or gamma interferon. Although extremely susceptible to infection, such mice survived and completely cleared virus if antibodies against Sindbis virus were given.
Bilateral spatial summation of cooling of symmetrical sites

The possibility of spatial summation of conducted −‡Ts (temperature decrements from the adapted skin temperature) was tested when the −‡Ts were presented simultaneously and individually at symmetrical sites on either side of the body. The use of a signal detection rating method yielded data that indicate that spatial summation is complete (area and intensity trade reciprocally) for −‡s near threshold and at clearly suprathreshold intensities of stimulation is invariant of the adapted skin temperature (AT), and the intensity of stimulation within the range of stimuli used (from as little as −0.05‡C to as much as −1.25‡C). In view of the characteristics ascribed to the thermosensory apparatus in humans, it is postulated that spatial summation occurs in the central nervous system.
Gamma-Ray Bursts from Extinct Neutron Stars

The paper concentrates on disks around old extinct pulsars, that can produce gamma-ray bursts owing to viscous evolution of the disk bringing it into the near vicinity of the neutron star, with runaway ionization of the disk and simultaneous precipitation of this plasma onto the neutron star. An old extinct pulsar is modeled as a magnetized neutron star circled by a ring of cold dense matter with an orbital period approximately equal to the rotational period of the neutron star. The numerical estimates produced are found to be consistent with the observed properties of gamma-ray bursters.
Prospective study of carotid endarterectomy with modified polytetrafluoroethylene (ACUSEAL) patching: early and late results.

Objective Carotid endarterectomies (CEAs) with standard polytetrafluoroethylene (PTFE) patching have been shown to have results comparable with those of autogenous vein patching; however, prolonged bleeding through needle holes in PTFE is a commonly recognized problem. This is the first study of CEA using a new hemostatic modified PTFE patch (GORE-TEX) analyzing the early and late outcomes. Methods Two hundred consecutive CEAs were entered into this protocol. All patients had an immediate postoperative carotid duplex ultrasound scan that was repeated at 1 month and every 6 to 12 months thereafter. A Kaplan-Meier analysis was used to estimate the stroke-free survival and the risk of restenosis. The mean follow-up was 21 months (range, 1 to 48 months). Results The perioperative stroke rate was 1.5% (1% ipsilateral and 0.5% contralateral, two minor strokes and one major stroke) with no perioperative mortality or perioperative carotid thrombosis. The incidence of perioperative transient ischemic attacks was 3.5% (2.5% ipsilateral and 1% contralateral). The mean hemostasis time after completion of the patching was 3 minutes, in contrast to 14 minutes for conventional PTFE (in a previous study). The rates of freedom from ipsilateral strokes at 1, 2, 3, and 4 years were 99%, 99%, 99%, and 99%, respectively. The cumulative stroke-free survival rates at 1, 2, 3, and 4 years were 98%, 96%, 93%, and 93%, respectively. The rates of freedom from ≥70% restenosis at 1, 2, 3, and 4 years were 97%, 97%, 94%, and 94%, respectively. Conclusions CEAs with a new modified PTFE patch are safe, have low perioperative stroke rates, are durable, and have an acceptable hemostasis time.
New method of analysing transient processes in picosecond photoconductive switch

A new rigorous method of analysing transient processes in picosecond photoconductive switches is presented in the letter. This method combines the time-domain finite difference algorithm of the Maxwell equations with the ensemble Monte Carlo simulation method and therefore it is generally applicable to other ultrafast semiconductor optoelectronic devices.
Charge-screening role of c -axis atomic displacements in YBa 2 Cu 3 O 6 + x and related superconductors

The importance of charge reservoir layers for supplying holes to the ${\mathrm{CuO}}_{2}$ planes of cuprate superconductors has long been recognized. Less attention has been paid to the screening of the charge transfer by the intervening ionic layers. We address this issue in the case of ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6+x}$, where CuO chains supply the holes for the planes. We present a simple dielectric-screening model that gives a linear correlation between the relative displacements of ions along the $c$ axis, determined by neutron powder diffraction, and the hole density of the planes. Applying this model to the temperature-dependent shifts of ions along the $c$ axis, we infer a charge transfer of 5--10% of the hole density from the planes to the chains on warming from the superconducting transition to room temperature. Given the significant coupling of $c$-axis displacements to the average charge density, we point out the relevance of local displacements for screening charge modulations and note recent evidence for dynamic screening of in-plane quasiparticles. This line of argument leads us to a simple model for atomic displacements and charge modulation that is consistent with images from scanning-tunneling microscopy for underdoped ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}$.
Abstract B34: The impact of chromosome 17p loss on cancer

Chromosome 17p deletions are associated with short survival and poor response to current chemotherapy treatment in non-Hodgkin9s lymphomas. Although the prevailing view is that these deletions serve as a “second hit” event to inactivate p53, these deletions often hundreds of other genes. Using an in vivo RNAi screening approach for tumor suppressor genes, we identified and validated two additional tumor suppressors adjacent to p53 suggesting these deletions may do more than merely inactivate p53. To test this hypothesis, we constructed a new mouse model conditionally targeting a broad region of 17p and are intending to investigate whether and how genes co-deleted with well-known tumor suppressor p53 affect lymphoma development and chemotherapy responses. These results will elucidate the aggressive nature of tumors harboring 17p deletions and create the first mouse model that can be used to test strategies to overcome its deleterious effects. Citation Format: Yu Liu, Claudio Scuoppo, Scott Lowe. The impact of chromosome 17p loss on cancer. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B34.
The accuracy of anterior-posterior measurements in the assessment of spinal canal compromise in burst fractures.

The amount of spinal canal compromise is one of the primary criteria employed to specify treatment of thoracolumbar burst fractures. Canal compromise has been calculated utilizing measurement of an...
NGK-State Relations during UP Governance (1934–47)

The year 1934 marked a turning point for South Africa. The rise of Fusion government coincided with key changes in the political-economic environment. The doubling of the gold price after 1932 made it possible for the mining industry to finance industrial diversification, but the impact of urbanization and the demands of industrial capitalists led the government to relax its implementation of race policy. The latter changes intensified the Afrikaner nationalists’ opposition toward the Fusion government. Tensions between leaders dominating the NGK and the state grew during the 1930s and 1940s as the NGK increasingly expressed its solidarity with the Afrikaner community.