cssi/SciSciGPT-SciSciNet huggingface dataset:
The effect of muscle fatigue on the isometric contractile characteristics of skeletal muscle in the cat

Abstract The rise time of an isometric twitch, the tetanic tension, the twitch tetanus ratio, the frequency-tension relationship, and the height of the MUAP (motor unit action potential) were measured in fast twitch (medial gastrocnemius) and slow twitch (soleus) muscles of the cat immediately before, in the middle, and immediately after fatiguing isometric contractions at tensions of 30, 50 and 80% of each muscle's initial strength (tetanic tension recorded from the unfatigued muscle). Although the twitch-tetanus ratio was always less for the soleus than for the medial gastrocnemius muscles, the twitch-tetanus ratio for any one muscle was constant throughout the duration of fatiguing isometric contractions at any of the tensions examined. In contrast, the twitch tension and tetanic tension of the muscles were both less after the contractions, the largest reduction occurring for both muscles during contractions sustained at the lowest isometric tensions. The time to peak tension of an isometric twitch was prolonged for both muscles following the contractions. This was associated with a corresponding shift in the frequency tension relationship such that at the point of muscular fatigue, the muscles tetanized at lower frequencies of stimulation than did the unfatigued muscle. In contrast, the amplitude of the MUAP showed only a modest reduction throughout the duration of the fatiguing contractions.
The Mariner '69 and '71 high-resolution camera and recent additions to its lens design program

Various types of designs were stu-died by the author at the Jet Propulsion Laboratory (JPL) for the optics of the high-resolution television camera for the Mariner '69 and '71 missions to Mars. This telescope had to perform over the spectral range 7100-4850A, weigh less than 9. 1 kg (20 lb), and have a rear clear-ance of 38 mm (1. 5 in. ). The goal for this 2° full field, f/2. 5, Ti< 4. 0, 5.08 mm (20. 0 in. ) efl cassegrain system was 40% response at 80 ip/mm; such resolution implied an rms spot size of about O. 00025 in.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Markov chain formalism for polarized light transfer in plane-parallel atmospheres, with numerical comparison to the Monte Carlo method

Building on the Markov chain formalism for scalar (intensity only) radiative transfer, this paper formulates the solution to polarized diffuse reflection from and transmission through a vertically inhomogeneous atmosphere. For verification, numerical results are compared to those obtained by the Monte Carlo method, showing deviations less than 1% when 90 streams are used to compute the radiation from two types of atmospheres, pure Rayleigh and Rayleigh plus aerosol, when they are divided into sublayers of optical thicknesses of less than 0.03.
A new method for calculating time-dependent atomic level populations

A method is described for reducing the number of levels to be dealt with in calculating time-dependent populations of atoms or ions in plasmas. The procedure effectively extends the collisional-radiative model to consecutive stages of ionization, treating ground and metastable levels explicitly and excited levels implicitly. Direct comparisons of full and simulated systems are carried out for five-level models.
Isotope Effect in Self-Diffusion in Palladium

The diffusion of ${\mathrm{Pd}}^{103}$ in single crystals of palladium has been measured over the temperature range of 1050-1500\ifmmode^\circ\else\textdegree\fi{}C by the tracer-sectioning technique. The results are $D={{0.205}_{\ensuremath{-}0.04}}^{+0.05}\mathrm{exp}[\ensuremath{-}\frac{(63600\ifmmode\pm\else\textpm\fi{}650)}{\mathrm{RT}}]{\mathrm{cm}}^{2}/sec.$Four measurements of the isotope effect for diffusion of ${\mathrm{Pd}}^{103}$ and ${\mathrm{Pd}}^{112}$ in each of four single crystals of palladium have been made between 1450 and 1500\ifmmode^\circ\else\textdegree\fi{}C. The measured isotope effect ${E}_{\ensuremath{\beta}}$ as defined by the equation ${E}_{\ensuremath{\beta}}=\frac{(1\ensuremath{-}\frac{{D}_{\ensuremath{\beta}}}{{D}_{\ensuremath{\alpha}}})}{[1\ensuremath{-}{(\frac{{m}_{\ensuremath{\alpha}}}{{m}_{\ensuremath{\beta}}})}^{\frac{1}{2}}]}$, where $\frac{{D}_{\ensuremath{\beta}}}{{D}_{\ensuremath{\alpha}}}$ and $\frac{{m}_{\ensuremath{\alpha}}}{{m}_{\ensuremath{\beta}}}$ are the ratios of the diffusion coefficients and masses of the two isotopes $\ensuremath{\alpha}$ and $\ensuremath{\beta}$ was found to be 0.8134\ifmmode\pm\else\textpm\fi{}0.0424. This value is consistent only with diffusion by the vacancy mechanism, and indicates that the translational kinetic energy of the activated state in the jump direction is possessed entirely by the jumping atom as it crosses the saddle point.
Mitotic chromosomes and the W-sex chromosome of the great horned owl (Bubo V. virginianus).

Mitotic chromosomes from the feather pulp and leucocyte cultures of the great horned owl (Bubo v. virginianus) were analyzed in both the sexes. The largest pair of chromosomes are acrocentrics while those of the second and the third pair have a short arm 1/6th the size of the large one. Chromosomes of the fourth and the fifth pairs have a median constriction while those of the 6th to 9th pairs are all acrocentrics. These are followed in order of size by a large number of smaller chromosomes, the smallest of which appear as dots. In 15 plates out of a total of 21, 82 to 84 chromosomes were counted and it is presumed that either of these numbers represents the diploid number. In the female sex besides the single unpaired 4th Z-chromosome, there is a small metacentric unpaired “W” chromosome which is nearly equal in size to the chromosomes of the 7th pair.
Unifying theories of creativity: Metaphorical thought and the unification process

Abstract Theories of creativity collectively provide a rich but fragmented knowledge base for research. In order to better understand the nature of creativity, investigators must provide a more coherent theoretical foundation by integrating many theories from different disciplines. Unfortunately, interdisciplinary groups of theorists who attempt collaborative theoretic integration have trouble finding common conceptual ground for their unification efforts. The implicit influence of metaphor on thought causes some of these difficulties, but metaphor also holds potential for bridging the conceptual gaps between differing theoretical and philosophical positions. Interdisciplinary teams of theorists can engage in parallel processes of metaphorical exploration and nonmetaphorical verification to illuminate the barriers to integration, and to capitalize on the integrative potential of metaphoric thought.
A high-energy cladding-pumped 80 nanosecond Q-switched fiber laser using a tapered fiber saturable absorber

We report a passively Q-switched all-fiber laser using a large mode area (LMA) Yb 3+ -doped fiber cladding-pumped at 915 nm and an unpumped single-mode Yb 3+ -doped fiber as the saturable absorber (SA). The saturable absorber and gain fibers were first coupled with a free-space telescope to better study the composite system, and then fusion spliced with fiber tapers to match the mode field diameters. ASE generated in the LMA gain fiber preferentially bleaches the SA fiber before depleting the gain, thereby causing the SA fiber to act as a passive saturable absorber. Using this scheme we first demonstrate a Q-switched oscillator with 40 μJ 79 ns pulses at 1026 nm using a free-space taper, and show that pulses can be generated from 1020 nm to 1040 nm. We scale the pulse energy to 0.40 mJ using an Yb 3+ -doped cladding pumped fiber amplifier. Experimental studies in which the saturable absorber length, pump times, and wavelengths are independently varied reveal the impact of these parameters on laser performance. Finally, we demonstrate 60 μJ 81 ns pulses at 1030 nm in an all fiber architecture using tapered mode field adaptors to match the mode filed diameters of the gain and SA fibers.
Double and multiple primary cancers in an adult head and neck radiation therapy clinic.

Abstract The records of 321 consecutive patients referred to the Radiation Oncology Center between January 1, 1980, and December 30, 1982, for head and neck cancers were reviewed to determine the incidence of other cancers. Two hundred sixty-two patients have had a single primary cancer in the head and neck region. Fifty-nine patients (18°10) have had more than one cancer. These 59 patients have had 68 other cancers. While other head and neck cancers lead the list of second primaries, second cancers also occurred in the esophagus, lung, genitourinary system and elsewhere. Twenty cancers had occurred prior to the patient developing head and neck cancer. Thirty-two cancers were synchronous with the head and neck cancer; 16 have been metachronous. These numbers emphasize that patients with head and neck cancers are in a cancer-prone group that develops a variety of other cancers. These findings have important implications in work-up, radiation treatment planning, treatment goals and follow-up programs.
Role of Polyamines in Apoptosis and Other Recent Advances in Plant Polyamines

Numerous citations in the literature indicate that polyamines are intensively studied in plants. Polyamines are implicated in many functions of the plant cell. Excellent recent reviews cover much of this original research. This article is focused primarily on literature that relates research on the role of polyamines in apoptosis and programmed cell death in both plants and animals. Apoptosis and programmed cell death are considerably better studied in animal systems, and this review demonstrates that the role of polyamines in these processes in plant systems are remarkably congruent with what is known in animal systems. In addition, key recent research reports are reviewed that describe the functional analysis of key polyamine biosynthesis genes in plants in relation to responses to environmental stress signals. Molecular analysis is providing strong evidence for the polyamine biosynthetic pathways to play major roles in ameliorating plant responses to abiotic stresses.
In Vitro-Assembled Alphavirus Core-Like Particles Maintain a Structure Similar to That of Nucleocapsid Cores in Mature Virus

In vitro-assembled core-like particles produced from alphavirus capsid protein and nucleic acid were studied by cryoelectron microscopy. These particles were found to have a diameter of 420 A with 240 copies of the capsid protein arranged in a T=4 icosahedral surface lattice, similar to the nucleocapsid core in mature virions. However, when the particles were subjected to gentle purification procedures, they were damaged, preventing generation of reliable structural information. Similarly, purified nucleocapsid cores isolated from virus-infected cells or from mature virus particles were also of poor quality. This suggested that in the absence of membrane and glycoproteins, nucleocapsid core particles are fragile, lacking accurate icosahedral symmetry.
PARVOVIRUS CAUSING CARDIAC HYPERTROPHY. 1383

Screening and therapy for causes of immune fetal hydrops have decreased it's incidence, making nonimmune fetal hydrops and its causes more important. From 1/80 to 6/95, 105 cases of fetal hydrops were identified (23 weeks to term). In 79 (75%), the cause was identified. There were 16 cases of immune fetal hydrops, 7 (44%) died; 15 cases had atrial tachycardia, 2 (13%) died; 7 had structural heart disease, 6 (86%) died; 5 had renal/urolgoic disease, 3(60%) died; 4 had cytomegalovirus, 2 (50%) died; 4 had chromosomal abnormalities (1 also had significant structural heart disease), 0 died; 3 had metabolic disease, 2 (67%) died; 3 had hepatitis, 2 (67%) died; 3 had syndromes, 3 (100%) died; 2 had cystic adenomatoid malformation, 1 died; 2 had twin-twin transfusion, 1 twin died; 2 had diaphragmatic hernia, 2 died. There was one case each of fetal-maternal transfusion [alive (A)]; sacrococcygial teratoma [died (D)]; osteogenesis imperfecta (A); pulmonary arteriosclerosis(D); cystic fibrosis (A); erythrophagacytic lymphohistiocytosis (D); streptococcal sepsis (D). Three cases had unknown viral infection, 1 died. There were 26 of unknown etiology, 12 (46%) died.
Ventricular arrhythmias and mitral valve prolapse in childhood.

Although ventricular arrhythmias are well described in adults with mitral valve prolapse, this association remains controversial in children. To assess the incidence of ventricular premature complexes (VPCs), 103 consecutive children with mitral valve (MV) prolapse confirmed by echocardiography were evaluated prospectively by treadmill exercise and ambulatory ECG. A group of 50 normal children without clinical, ECG, or echocardiographic evidence of heart disease who had undergone treadmill exercise and ambulatory ECG served as controls. In the group with MV prolapse. 16 patients had VPCs with treadmill exercise and 39 had VPCs on ambulatory ECG. High-grade ventricular ectopy (multiform VPCs, couplets, or ventricular tachycardia) was recorded in four patients with MV prolapse during treadmill exercise and in eight during ambulatory ECG. In contrast, no control patient had a single VPC in response to treadmill exercise and only four control patients had rare uniform VPCs on ambulatory ECG. Neither physical examination findings, standard ECG results, nor symptoms could be correlated with VPCs in the patients with MV prolapse. Although the prognostic implications of these findings are unvertain, this study demonstrates that potentially serious ventricular arrhythmias are frequently observed in children with MV prolapse.
Anabolic and catabolic pathways regulating skeletal muscle mass

Purpose of review the purpose of this review is to discuss recent findings as they pertain to anabolic and catabolic signaling pathways involved in the regulation of adult skeletal muscle mass.
Variability: The common factor linking low dose-induced genomic instability, adaptation and bystander effects

The characteristics of low dose radiation-induced genomic instability, adaptive responses, and bystander effects were compared in order to probe possible underlying mechanisms, and develop models for predicting response to in vivo low dose radiation exposures. While there are some features that are common to all three (e.g., absence of a true dose-response, the multiple endpoints affected by each), other characteristics appear to distinguish one from the other (e.g., TP53 involvement, LET response, influence of DNA repair). Each of the responses is also highly variable; not all cell and tissue models show the same response and there is much interindividual variation in response. Most of these studies have employed in vitro cell culture or tissue explant models, and understanding underlying mechanisms and the biological significance of these low dose-responses will require study of tissue-specific in vivo endpoints. The in vitro studies strongly suggest that modeling low dose radiation effects will be a complex process, and will likely require separate study of each of these low dose phenomena. Knowledge of instability responses, for example, may not aid in predicting other low dose effects in the same tissue.
β -Ether cleavage of the lignin model compound 4-ethoxy-3-methoxyphenylglycerol- β -guaiacyl ether and derivatives by Phanerochaete chrysosporium

The white rot basidiomycete Phanerochaete chrysosporium metabolized 4-ethoxy-3-methoxyphenyl-glycerol-β-guaiacyl ether (V) in low nitrogen, stationary cultures under which conditions the ligninolytic enzyme system is expressed. 4-Ethoxy-3-methoxyphenylglycerol XIII, guaicol and 4-ethoxy-3-methoxybenzyl alcohol (II) were isolated as metabolic products. Exogenously added XIII was rapidly converted to 4-ethoxy-3-methoxybenzyl alcohol indicating that it is an intermediate in the metabolism of V. P. chrysosporium also metabolized 1-(4′-ethoxy-3′-methoxyphenyl)-2-(2″-methoxyphenoxy)-3-hydroxypropane VI. The degradation pathway for this dimer also included initial β-ether cleavage and α-hydroxylation of the diol product 1-(4′-ethoxy-3′-methoxyphenyl) 2,3 dihydroxypropane (XI) to yield the triol XIII which was cleaved at the α, β bond to yield 4-ethoxy-3-methoxybenzyl alcohol. Finally P. chrysosporium also cleaved the dimer 1-(4′-ethoxy-3′-methoxyphenyl)-2-(2″-methoxyphenoxy)-1-hydroxypropane (VIII) at the β-ether linkage yielding 1-(4′-ethoxy-3′-methoxyphenyl) 1,2 dihydroxypropane (IX) which was subsequently cleaved at the α, β bond to yield II. All of the results indicate that oxidative β-ether cleavage is an important initial reaction in the metabolism of β-aryl ether lignin substructure dimeric compounds. Metabolities were identified after comparison with chemically synthesized standards by gas liquid chromatography-mass spectrometry.
Co-Phasing And Co-Aligning The Multiple Mirror Telescope

The Multiple Mirror Telescope is an array of six 1.8 m diameter folded Cassegrain telescopes used to achieve the collecting area equivalent to that of a telescope with a single 4.5 m primary mirror. For most applications, the six images are co-aligned in such a way that overlapping images appear to result from a single telescope. Another application requires that the wavefronts from all six telescopes be co-phased within 1 micron, concurrent with co-alignment. This paper describes the successful operation of the co-alignment and co-phasing capabilities, the control system and devices used in the applications, and test results to date.
An alternative approach to state estimation in linear time-invariant systems

Abstract An alternative approach to state estimation problem in linear, time-invariant dynamic systems is presented in this paper. The approach developed first identifies the initial state of the system by using a proportional plus integral parameter identification method. The Lyapunov design technique is used to guarantee the asymptotic convergence of the initial state identifier. A state estimator is then constructed to operate in series with the initial state identifier. The estimator generates an estimate of the unobserved part of the system state. Simulation studies have shown that satisfactory state estimation can be achieved in the presence of measurement or disturbance noise. An example problem is considered to demonstrate the response characteristics of the estimator-identifier combination.
Rapid Diffusion and Policy Reform: The Adoption and Modification of Three Strikes Laws

Despite many important recent advances in the study of policy diffusion, this research has devoted limited attention to what happens after the adoption decision. This article attempts to fill this gap in diffusion research by examining the adoption and subsequent modification of “Three Strikes and You’re Out” laws in the American states. Its analysis suggests that distinct political forces affected state-level outcomes at these two stages of the policymaking process. The rapid spread of Three Strikes laws in the 1990s seems to have occurred because states with more conservative leanings and higher proportions of African-American residents gravitated to a salient and visible policy. In contrast, the modification of Three Strikes laws appears to have been encouraged by financial necessity and shifting ideological environments but hindered by the mobilization of stakeholders with an interest in preserving the status quo, including private prison operators and prison officer unions. The contrast illustrates t...
Effects of Psychotherapeutic Treatments for PTSD: A Meta-Analysis of Controlled Clinical Trials

This meta-analysis synthesized the results from controlled, clinical trials of psychotherapeutic treatments for posttraumatic stress disorder (PTSD). Psychotherapeutic modalities included behavioral, cognitive, and psychodynamic treatments, in group and individual settings. Participants in the studies included combat veterans from the Vietnam and Lebanon Wars, crime-related victims, and severe bereavement sufferers. The impact of psychotherapy on PTSD and psychiatric symptomatology was significant, d = .52, r = .25, when measured immediately after treatments were administered. Similarly, there was no decay in the effect of treatment at follow-up, d = .64, r = .31. Moreover, for target symptoms of PTSD and general psychological symptoms (intrusion, avoidance, hyperarousal, anxiety, and depression), effect sizes were significant, ranging from r's of .2–.49. Results suggest substantial promise for improving psychological health and decreasing related symptoms for those suffering from PTSD.
Predicting ICU admission in community-acquired pneumonia: clinical scores and biomarkers.

Community-acquired pneumonia (CAP) remains a common and serious worldwide health problem. Despite all the advances in therapy, significant interest has focused on the identification of patients with CAP who require intensive care unit admission to improve their outcomes. The severity assessment of CAP provides an important guide to clinicians in deciding the site of care and the use of empiric antibiotics and adjuvant therapy. For years, several clinical assessment scores have been suggested and validated to achieve this goal. The recent introduction of biomarkers as prognostic indicators of severe CAP, whether used alone or in conjunction with other clinical severity of illness scores, has been investigated. An objective scoring system with a high level of sensitivity and specificity to predict the severity of CAP and the need for high levels of care do not exist. Today, the addition of clinical scores and biomarkers to clinical judgment is the best approach to optimize the care of severe CAP. Future res...
An overview of digital spectrometers for MR imaging

Most magnetic resonance (MR) imaging systems were originally designed with analog spectrometers, since that was the “state of the art” in the late 1970s, when they were developed. Advances in technology have allowed the design of radio-frequency electronics with a much larger percentage of digital components while the cost of such components has decreased. This has given manufacturers the incentive to develop new spectrometers that incorporate these electronics for cost reduction and potentially better performance. Upgrades and new models of MR units have become available with these so-called “digital spectrometers.” Because of the interest in the new systems, the Instrumentation Subcommittee of the Basic Science Council of the Society for Magnetic Resonance Imaging has produced this report to review the basic features of analog and digital spectrometers to help the MR imaging community better understand the similarities and differences of these systems. Some details of actual commercial implementations were left out to focus on the basic features. Regardless, the authors hope they have provided a readable introduction to this important topic.
Planning for Retirement: The Accuracy of Expected Retirement Dates and the Role of Health Shocks

This paper explores the relationship between expectations about retirement, realizations of retirement, and the role of health shocks. Using waves 1 through 4 of the Health and Retirement Study we follow people into retirement. We explore the factors that affect changes to plans that were made in wave 1 paying special attention to changes in health status. We find that health shocks since the planning horizon trigger earlier retirement than planned. Existing health problems have little impact on changes to retirement plans. Health insurance availability continues to be a significant predictor of retirement.
ChemmineR: a compound mining framework for R

Motivation: Software applications for structural similarity searching and clustering of small molecules play an important role in drug discovery and chemical genomics. Here, we present the first open-source compound mining framework for the popularstatistical programming environment R. The integration with a powerful statistical environment maximizes the flexibility, expandability and programmability of the provided analysis functions. Results: We discuss the algorithms and compound mining utilities provided by the R package ChemmineR. It contains functions for structural similarity searching, clustering of compound libraries with a wide spectrum of classification algorithms and various utilities for managing complex compound data. It also offers a wide range of visualization functions for compound clusters and chemical structures. The package is well integrated with the online ChemMine environment and allows bidirectional communications between the two services. Availability: ChemmineR is freely available as an R package from the ChemMine project site: http://bioweb.ucr.edu/ChemMineV2/chemminer Contact: ude.rcu@ekrig.samoht
Chronic family stress interacts with 5-HTTLPR to predict prospective depressive symptoms among youth

Background: Previous research, predominantly with adults, has shown that the serotonin transporter gene (5-HTTLPR) interacts with stress (G × E) to predict depressive symptoms; however, few G × E studies have been conducted with youth using rigorous methods, particularly a prospective design and contextual interview to assess stress. This study examined the interaction between 5-HTTLPR and stress, both chronic and episodic, to predict longitudinal change in depressive symptoms among children and adolescents. Methods: A general community sample of youth (N = 200; 57% girls; mean age: 12.09 years old) was genotyped for 5-HTTLPR (rs 25531) at baseline. They were interviewed via contextual stress procedures to ascertain chronic family stress and episodic stressors and completed depressive symptoms questionnaires at baseline and 6 months later. Results: A significant G × E showed that chronic family stress predicted prospective increases in depressive symptoms over 6 months among youth possessing the high-risk S allele. This G × E was not found for episodic stressors occurring in the last 6 months. There was no moderation by sex or pubertal status. Conclusions: These findings advance knowledge on G × E effects in depression among youth. This is the first study to show that chronic family stress, but not episodic stressors, when ascertained by rigorous stress interview, interacts with 5-HTTLPR to prospectively predict depressive symptoms among children and adolescents. Depression and Anxiety 0:1-7, 2011. © 2011 Wiley Periodicals, Inc. Language: en
Study of instructional modalities for introductory computing

The School of Engineering at Vanderbilt University requires all engineering students in their first semester to take a course that introduces computers in engineering. Two questions arise: is the best setting in which to teach this type of material either a combination of lecture and laboratory or all-laboratory; and does a student-owned laptop computer contribute more to learning? For two years the course was organized with these two different modalities of instruction. For a third year the students learned in the all-laboratory environment and 30% of the students used their own laptop computer. At the end of the semester an in-depth questionnaire with quantitative ratings was given to the students to determine if there were differences in learning preferences. Contingency tables were used to compare responses. There were several statistically significant differences in student responses favoring the all laboratory structure and students using laptop computers. Several of them are: the students are much more comfortable with computers at the end of the semester; either laboratory or working by oneself were the preferred settings for learning; and lecture was not a preferred setting for learning any topic.
Genetic Analysis of the Localization of APOBEC3F to Human Immunodeficiency Virus Type 1 Virion Cores

Members of the APOBEC3 family of cytidine deaminases vary in their proportions of a virion-incorporated enzyme that is localized to mature retrovirus cores. We reported previously that APOBEC3F (A3F) was highly localized into mature human immunodeficiency virus type 1 (HIV-1) cores and identified that L306 in the C-terminal cytidine deaminase (CD) domain contributed to its core localization (C. Song, L. Sutton, M. Johnson, R. D'Aquila, J. Donahue, J Biol Chem 287:16965–16974, 2012, http://dx.doi.org/10.1074/jbc.M111.310839). We have now determined an additional genetic determinant(s) for A3F localization to HIV-1 cores. We found that one pair of leucines in each of A3F's C-terminal and N-terminal CD domains jointly determined the degree of localization of A3F into HIV-1 virion cores. These are A3F L306/L368 (C-terminal domain) and A3F L122/L184 (N-terminal domain). Alterations to one of these specific leucine residues in either of the two A3F CD domains (A3F L368A, L122A, and L184A) decreased core localization and diminished HIV restriction without changing virion packaging. Furthermore, double mutants in these leucine residues in each of A3F's two CD domains (A3F L368A plus L184A or A3F L368A plus L122A) still were packaged into virions but completely lost core localization and anti-HIV activity. HIV virion core localization of A3F is genetically separable from its virion packaging, and anti-HIV activity requires some core localization. IMPORTANCE Specific leucine-leucine interactions are identified as necessary for A3F's core localization and anti-HIV activity but not for its packaging into virions. Understanding these signals may lead to novel strategies to enhance core localization that may augment effects of A3F against HIV and perhaps of other A3s against retroviruses, parvoviruses, and hepatitis B virus.
Programming up to Congruence

This paper presents the design of Zombie, a dependently-typed programming language that uses an adaptation of a congruence closure algorithm for proof and type inference. This algorithm allows the type checker to automatically use equality assumptions from the context when reasoning about equality. Most dependently-typed languages automatically use equalities that follow from beta-reduction during type checking; however, such reasoning is incompatible with congruence closure. In contrast, Zombie does not use automatic beta-reduction because types may contain potentially diverging terms. Therefore Zombie provides a unique opportunity to explore an alternative definition of equivalence in dependently-typed language design. Our work includes the specification of the language via a bidirectional type system, which works "up-to-congruence,'' and an algorithm for elaborating expressions in this language to an explicitly typed core language. We prove that our elaboration algorithm is complete with respect to the source type system, and always produces well typed terms in the core language. This algorithm has been implemented in the Zombie language, which includes general recursion, irrelevant arguments, heterogeneous equality and datatypes.
Overexpression of the Cell Cycle Inhibitor p16INK4a Promotes a Prothrombotic Phenotype Following Vascular Injury in Mice

Objective—Age-associated cellular senescence is thought to promote vascular dysfunction. p16INK4a is a cell cycle inhibitor that promotes senescence and is upregulated during normal aging. In this study, we examine the contribution of p16INK4a overexpression to venous thrombosis. Methods and Results—Mice overexpressing p16INK4a were studied with 4 different vascular injury models: (1) ferric chloride (FeCl3) and (2) Rose Bengal to induce saphenous vein thrombus formation; (3) FeCl3 and vascular ligation to examine thrombus resolution; and (4) lipopolysaccharide administration to initiate inflammation-induced vascular dysfunction. p16INK4a transgenic mice had accelerated occlusion times (13.1±0.4 minutes) compared with normal controls (19.7±1.1 minutes) in the FeCl3 model and 12.7±2.0 and 18.6±1.9 minutes, respectively in the Rose Bengal model. Moreover, overexpression of p16INK4a delayed thrombus resolution compared with normal controls. In response to lipopolysaccharide treatment, the p16INK4a transgenic...
Advances in Biomaterials, Drug Delivery, and Bionanotechnology

Biomaterials are widely used in numerous medical applications. Chemical engineering has played a central role in this research and development. Polymers as biomaterials, materials and approaches used in drug and protein delivery systems, materials used as scaffolds in tissue engineering, and nanotechnology and microfabrication techniques applied to biomaterials are reviewed.
Investigation of the rupture process of the 28 June 1992 Landers earthquake utilizing TERRAscope

Abstract Displacement seismograms recorded by TERRAscope for the 28 June 1992 Landers earthquake ( M W 7.3) are deterministically modeled using a forward, point-source summation technique. Although the data set is sparse, it was possible to robustly determine important rupture parameters such as gross slip distribution, rupture velocity, rise time, and total source duration. The relatively simple approach lends itself to rapid application following large earthquakes, provided that a catalog of Green9s functions appropriate for the region is available. The fault used in the modeling of the Landers mainshock has a length of 70 km along strike and a width of 15 km along dip. A model was found in which the distribution and amplitude of slip at the surface matches the observed surface slip and provides a very good level of fit to the seismic data. Seismically, the Landers earthquake is characterized as two subevents. The peak slip of the first subevent is 10 km north of the epicenter and the second is 40 km northwest along strike from the epicenter. The seismic moment is distributed as 2 × 10 26 dyne-cm to the first and 6 × 10 26 to the second subevent, respectively. It was assumed in our modeling that the distribution of seismic moment along strike was the same at all depths. This assumption implies that slip at depth is 69% of that at the surface as a result of differences in the material properties in the velocity model. the sensitivities of the source model to rupture velocity and dislocation rise time were examined. A rupture velocity of 2.9 km/sec (80% of the shear-wave velocity) and a rise time of 1 to 3 sec were found to satisfy the data. The rise time is only a fraction of the total source process time of 24 sec, and implies that slip on the fault occurred within a narrow band (3 to 10 km), at any instant during the rupture.
Recalculated Nitrogen Conversion Factors for Several Soybean Protein Products

Amino acid composition and micro-Kjeldahl N contents of various soybean protein products are used for calculating N conversion factors by the Factor Method and Kjeldahl Method. Efforts were made to refine these methods and to minimize the magnitude of the discrepancies within these N conversion factors. Recalculated N conversion factors by the Factor Method ranged from 5.66–5.80, and by the Kjeldahl Method from 5.66–5.79. It is recommended that these conversion factors be used (rather than the common 6.25 factor) for converting N values to protein content in soy protein-containing products.
Current status of granulocyte transfusions to treat neonatal sepsis

Neonates are unusually susceptible to severe bacterial infections. Antibiotic therapy has been supplemented with granulocyte transfusions (GTX) to treat neonatal infections. The precise role of GTX to treat neonatal sepsis is controversial, and 11 reports (including six controlled studies) were critically analyzed. When all data are combined, 79% of 78 neonates receiving antibiotics plus GTX survived vs. 62% of 90 infants treated only with antibiotics. Among the six controlled trials, four found significantly better survival for neonates given GTX plus antibiotics. However, each of these trials can be criticized (few subjects, heterogeneous patients, defective design, inadequate granulocyte product, etc.). Although firm recommendations for GTX cannot be made currently, it seems reasonable to combine them with antibiotics to treat septic neonates that exhibit neutropenia for age and evidence of a diminished neutrophil marrow storage pool. Once the decision to transfuse is made, neonates should receive a minimum dose of 1 × 109 fresh neutrophils per kg per transfusion.
Quantitation of tyrosine hydroxylase protein in the locus coeruleus from postmortem human brain.

In this study, we developed an immuno-autoradiographic method to obtain quantitative estimates of tyrosine hydroxylase (TH) protein in tissue sections from post-mortem human brain. Protein from tissue sections containing the locus coeruleus (LC) was directly transferred to a polyvinylidene fluoride (PVDF) membrane. Immunoreactive TH on PVDF membranes was identified with optimized concentrations of TH antibody followed by application of [ 125 I]labeled secondary antibody. Quantities of TH on autoradiograms were estimated by comparing optical densities of transferred immunoblots to a calibrated standard curve produced with purified recombinant TH dotted onto the same PVDF membranes. Amounts of TH-immunoreactivity in the LC were proportional to the thickness of tissue sections up to 15 mm. However, the amounts of total protein, as measured by Ponceau S staining, were linearly related to section thicknesses up to 30 mm. Comparisons of quantities of immunoreactive TH in the LC using this method to amounts determined using traditional Western blotting, in which LC tissue was punched from adjacent sections from the same subject, showed a positive correlation (r 2 0.99, PB 0.01). Using the transfer immunoblot method, an uneven distribution of TH protein was observed along the rostrocaudal axis of the human LC (PB 0.01). This method may provide a sensitive and useful tool for the study of the role of human TH expression in the pathophysiology of psychiatric disease. © 2000 Elsevier Science B.V. All rights reserved.
Frequent Users of Emergency Departments: The Myths, the Data, and the Policy Implications

Study objective Frequent emergency department (ED) users have been the targets of health care reform proposals and hospital crowding interventions, but it is not clear that common assumptions about this group are supported by data. We review the literature pertaining to frequent ED users, their demographics, acuity of illness, and patterns of health care utilization. We seek to inform development of policies directed at frequent ED use and to highlight potential related challenges. Methods A systematic review of the literature on frequent ED users was performed. Results Frequent users comprise 4.5% to 8% of all ED patients but account for 21% to 28% of all visits. Most frequent ED users are white and insured; public insurance is overrepresented. Age is bimodal, with peaks in the group aged 25 to 44 years and older than 65 years. On average, these patients have higher acuity complaints and are at greater risk for hospitalization than occasional ED users. However, the opposite may be true of the highest-frequency ED users. Frequent users are also heavy users of other parts of the health care system. Only a minority of frequent ED users remain in this group long term. Complaints vary with age, location, and usage patterns. Conclusion Frequent ED users are a heterogeneous group along many dimensions and defy popular assumptions. The subgroups have not yet been sufficiently defined to allow clearly directed policy design, and many frequent users present with true medical needs, which may explain why existing attempts to address the phenomena have had mixed success at best.
Hemodynamic Changes Quantified in Abdominal Aortic Aneurysms with Increasing Exercise Intensity Using MR Exercise Imaging and Image-Based Computational Fluid Dynamics

Abdominal aortic aneurysm (AAA) is a vascular disease resulting in a permanent, localized enlargement of the abdominal aorta. We previously hypothesized that the progression of AAA may be slowed by altering the hemodynamics in the abdominal aorta through exercise [Dalman, R. L., M. M. Tedesco, J. Myers, and C. A. Taylor. Ann. N.Y. Acad. Sci. 1085:92–109, 2006]. To quantify the effect of exercise intensity on hemodynamic conditions in 10 AAA subjects at rest and during mild and moderate intensities of lower-limb exercise (defined as 33 ± 10% and 63 ± 18% increase above resting heart rate, respectively), we used magnetic resonance imaging and computational fluid dynamics techniques. Subject-specific models were constructed from magnetic resonance angiography data and physiologic boundary conditions were derived from measurements made during dynamic exercise. We measured the abdominal aortic blood flow at rest and during exercise, and quantified mean wall shear stress (MWSS), oscillatory shear index (OSI), and particle residence time (PRT). We observed that an increase in the level of activity correlated with an increase of MWSS and a decrease of OSI at three locations in the abdominal aorta, and these changes were most significant below the renal arteries. As the level of activity increased, PRT in the aneurysm was significantly decreased: 50% of particles were cleared out of AAAs within 1.36 ± 0.43, 0.34 ± 0.10, and 0.22 ± 0.06 s at rest, mild exercise, and moderate exercise levels, respectively. Most of the reduction of PRT occurred from rest to the mild exercise level, suggesting that mild exercise may be sufficient to reduce flow stasis in AAAs.
Verb Subcategorization Frequency Differences between Business- News and Balanced Corpora: The Role of Verb Sense

We explore the differences in verb subcategorization frequencies across several corpora in an effort to obtain stable cross corpus subcategorization probabilities for use in norming psychological experiments. For the 64 single sense verbs we looked at, subcategorization preferences were remarkably stable between British and American corpora, and between balanced corpora and financial news corpora. Of the verbs that did show differences, these differences were generally found between the balanced corpora and the financial news data. We show that all or nearly all of these shifts in subcategorization are realised via (often subtle) word sense differences. This is an interesting observation in itself, and also suggests that stable cross corpus subcategorization frequencies may be found when verb sense is adequately controlled.
Effects of glial toxins on extracellular acidification in the hippocampal CA1 region in vivo

In the pyramidal cell layer of the CA1 region of the hippocampus in the urethane-anesthetized adult rat, there is an initial alkalinization followed by an acidification in response to synchronized seizure activity induced by stimulus trains. In this study, the role of astrocytes in these extracellular pH changes during neuronal activity was examined using local injection of two relatively selective glial toxins (fluorocitrate (FC) and fluoroacetate (FA)) into the CA1 cell layer. Both glial toxins reduced the peak level of acidification reached after 20 Hz stimulus trains to the contralateral CA3 region, without changing the lengthening of the afterdischarge, when compared to animals that had received a local injection of vehicle. After administration of either glial toxin, the peak level of acidification still correlated with the total discharge duration, but the levels of acidification were consistently lower than in control animals. Administration of either glial toxin had no effect on the peak alkalinization during the stimulus train, or on the rate of recovery from peak level of acidification. Injection of either vehicle, FA, or FC had no effect on the amplitude or frequency of the neuronal discharge during the afterdischarge. The results suggest that, in normal conditions, astrocytes contribute to the acidification of the extracellular space that occurs in response to intense neuronal activity. This acidification may contribute to feedback regulation of neuronal excitability.
A template for change and response to work hour restrictions

Surgical program directors are seeking how to best meet the work hour restrictions recently mandated by the American College of Graduate Medical Education. Implementation of an 80-hour work week forces major change to graduate medical education, especially surgical education. Creative restructuring of surgical training is necessary to ensure compliance. Developing an innovative solution to meet these requirements must consider programmatic needs, requiring commitment to a change process. The Department of Surgery at Eastern Virginia Medical School experienced a 5-month strategic planning process that generated the Mendoza plan. This plan uses an every third night call model and a night float model to meet site-specific needs. The specifics of the Mendoza plan protect the cornerstone of surgical education, which is continuity of patient care and resident education. The Mendoza plan, and the process leading to its development, may provide insightful information for other surgical residency programs planning to meet work hour guidelines.
Designing a Macintosh interface to a mainframe database

This work is part of a large project called MIST (Materials Information for Science and Technology) to develop a prototype information system for materials science. In the future, this architecture is expected to provide the basis for a common interface to a network of quasi-autonomous databases. MacMIST, the interface to the database, uses standard Macintosh as well as application-specific paradigms. MIST provides not only raw data, but also extensive metadata, including a thesaurus and glossary, knowledge of class hierarchies, and summaries of what data is currently available. MacMIST supplements users' a priori knowledge of context and meaning by incorporating such metadata into the interface dynamically. Use of caching and embedded menus facilitates fast and efficient access. >
Fuzzy Reasoning and Rough Sets

Fuzzy concepts are represented by fuzzy sets, so a fuzzy knowledge is defined to be a collection of fuzzy sets (concepts) which includes two constants, 1 (true) and 0 (false). Abstractly, a logical derivation is a finite series of logical operations acting on a given knowledge. In fuzzy world, logical operations are defined by mathematical operations. So fuzzy logical derivations are mathematical derivations, and vice versa In this paper, the closure of fuzzy reasoning is characterized by fuzzy rough sets, and by topologies (neighborhood systems). A new fuzzy concept F N is derivable from the old knowledge K iff the membership function of F N is continuous in K-topology, or equivalently, iff F N is a rough fuzzy set (concept) of I N D(K),or plainly, iff the membership function of F N is a “step” function in the sense that it takes a constant value in each equivalence class of I N D(K).A fuzzy set L partitions the universe into equivalence classes; each equivalence class consists of those elements which have the same degree of membership. The indiscernibility relation I N D(K)over K is the “intersection” of all the equivalence relations induced by the fuzzy sets in K. The membership function of a fuzzy set is a real valued function, so U can be given the minimal topology such that the membership function of each fuzzy set in K is a continuous function. Such topology is called K-topology.
Proportional hazards models and age–period–cohort analysis of cancer rates

Age-period-cohort (APC) analysis is widely used in cancer epidemiology to model trends in cancer rates. We develop methods for comparative APC analysis of two independent cause-specific hazard rates assuming that an APC model holds for each one. We construct linear hypothesis tests to determine whether the two hazards are absolutely proportional or proportional after stratification by cohort, period, or age. When a given proportional hazards model appears adequate, we derive simple expressions for the relative hazards using identifiable APC parameters. To demonstrate the utility of these new methods, we analyze cancer incidence rates in the United States in blacks versus whites for selected cancers, using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. The examples illustrate that each type of proportionality may be encountered in practice.