cssi/SciSciGPT-SciSciNet huggingface dataset:
Trends in adolescent contraceptive use, unprotected and poorly protected sex, 1991-2003.

Abstract Purpose To estimate trends in use and nonuse of effective protection among adolescents 1991–2003, and to assess factors associated with poorly protected sex in 2003. Methods We analyzed seven Youth Risk Behavior Surveys (YRBSs) of 9th–12th graders conducted from 1991 through 2003. We estimated trends in use of condoms, effective contraception, withdrawal, and no method, using linear logistic regression models, and evaluated correlates of the use of no method or withdrawal in 2003. Results Throughout 1991–2003, about one third of students reported that they had been sexually active in the previous 3 months. Condom use increased significantly throughout 1991–2003, from 46.2% (± 3.3%) in 1991 to 63.0% (± 2.5%) in 2003, and the percentage reporting use of either withdrawal or no method steadily declined, from 32.6% (± 2.7%) to 18.8% (± 2.1%). In 2003, use of withdrawal or no method was greater among females, Hispanics, those who had been pregnant or had caused a pregnancy, and those who reported feeling sad or hopeless or had considered suicide. Conclusions Reported unprotected sex decreased, while use of condoms increased. A high-risk group engaging in poorly protected sex was identified, accounting for 6.4% of students.
Boundaries in digital spaces

Intuitively, a boundary in an N-dimensional digital space is a connected component of the (N − 1)-dimensional surface of a connected object. In this paper we make these concepts precise, and show that the boundaries so specified have properties that are intuitively desirable. We provide some efficient algorithms for tracking such boundaries. We illustrate that the algorithms can be used, in particular, for computer graphic display of internal structures (such as the skull and the spine) in the human body based on the output of medical imaging devices (such as CT scanners). In the process some interesting mathematical results are proven regarding “digital Jordan boundaries,” such as a specification of a local condition that guarantees the global condition of “Jordanness.”
Stimulus parameters affecting tissue injury during microstimulation in the cochlear nucleus of the cat

We investigated the effects of continuous microstimulation in the cats' posteroventral cochlear nucleus, using chronically implanted activated iridium microelectrodes. We examined 51 electrode sites (39 pulsed sites, and 12 unpulsed sites). Seven hours of continuous stimulation at 500 Hz often produced tissue injury near the tips of the pulsed microelectrodes. The damage took the form of a region of vacuolated tissue extending 200 microns or more from the site of the electrode tip. Electron microscope studies showed the vacuoles to be severely edematous segments of myelinated axons. The statistical correlation between the amount of damaged tissue and the charge per phase was large and highly significant (P < 0.0001). When the electrodes were pulsed for 7 h at 500 Hz with charge-balanced biphasic pulse pairs, the threshold for the damage was approximately 3 nC/phase. The damage threshold was not appreciably lower than the stimulation protocol was extended to 35 h (7 h/day for 5 days). In contrast, the threshold for exciting neurons near the microelectrode is approximately 1 nC/phase, as determined by the evoked response recorded in the inferior colliculus. There was little correlation between the severity of the tissue damage and the geometric charge density at the surface of the electrodes, between the damage and amplitude of the cathodic phase of the voltage transient induced across the stimulating electrodes by the stimulus current pulses, or between the damage and the stimulus pulse duration.
Cell surface accumulation of a truncated transmembrane prion protein in Gerstmann-Straussler-Scheinker disease P102L.

Abstract A familial prion disorder with a proline to leucine substitution at residue 102 of the prion protein (PrP102L) is typically associated with protease-resistant PrP fragments (PrPSc) in the brain parenchyma that are infectious to recipient animals. When modeled in transgenic mice, a fatal neurodegenerative disease develops, but, unlike the human counterpart, PrPSc is lacking and transmission to recipient animals is questionable. Alternate mice expressing a single copy of PrP102L (mouse PrP101L) do not develop spontaneous disease, but show dramatic susceptibility to PrPSc isolates from different species. To understand these discrepant results, we studied the biogenesis of human PrP102L in a cell model. Here, we report that cells expressing PrP102L show decreased expression of the normal 18-kDa fragment on the plasma membrane. Instead, a 20-kDa fragment, probably derived from transmembrane PrP (CtmPrP), accumulates on the cell surface. Because the 20-kDa fragment includes an amyloidogenic region of PrP that is disrupted in the 18-kDa form, increased surface expression of 20-kDa fragment may enhance the susceptibility of these cells to PrPSc infection by providing an optimal substrate, or by amplifying the neurotoxic signal of PrPSc. Thus, altered susceptibility of PrP101L mice to exogenous PrPSc may be mediated by the 20-kDa CtmPrP fragment, rather than PrP102L per se.
Homologous recombination within the capsid gene of porcine circovirus type 2 subgroup viruses via natural co-infection

Several studies had reported homologous recombination between two porcine circovirus (PCV) type 2 subgroup viruses, PCV2a and PCV2b. The recombination events described thus far mapped either within the Rep gene sequences or the sequences flanking the Rep gene region. Previously, the presence of both PCV2a and PCV2b DNA sequences in tissues of the same infected swine from the 2005 United States PCV-associated disease outbreak was reported, which indicates that the animal was co-infected with both PCV2 subgroup viruses. Here, two naturally occurring chimeric genomes were identified that exhibited homologous recombination within the capsid gene sequences, and infectious viruses were recovered from both chimeric genomes after transfection into tissue culture cells.
Experimental Study on Surface Roughness in Quick-Point Grinding Engineering Ceramics

Through grinding experiment on mica glass ceramic, the mechanism of material removal was analysed, the fracture and removal of engineering ceramics was suitable for Griffiths fracture strength theory. And the factors of affected surface roughness were studied. The results indicated, The surface roughness was significantly affected by the grinding depth, inclining angle and deflecting angle in quick-point grinding engineer ceramics. The surface roughness value decreased with increasing of the wheel velocity, increased with increasing of the workpiece feed, decreased with increasing of grinding depth, increased with increasing of grinding wheel inclining angle and decreased with increasing of grinding wheel deflecting angle.
Patterning of martensitic nanotwins

We perform the atomistic Monte Carlo simulations of formation of nanostructured martensites in nickel–titanium thin films. The results reveal the atomistically resolved patterning of martensitic nanotwins, including coarsening, branching and twinning within twins, as mediated by temperature and substrate constraints. A scaling law is derived to elucidate the physical effects governing the characteristic nanostructure length scale of the twin width. Our modeling approach opens up possibilities for the atomistically based design of martensitic nanostructures to produce advanced alloys with optimized properties.
Vancomycin-induced release of histamine from rat peritoneal mast cells and a rat basophil cell line (RBL-1).

Rapid intravenous adminstration of the glycopeptide antibiotic, vancomycin, may cause a hypotensive reaction which can usually be prevented by infusing vancomycin in dilute solutions. The release of histamine from circulating cells such as basophils and tissue mast cells has been implicated in hypotensive reactions since the effects can be prevented by antihistamine pretreatment. The direct effects of vancomycin on histamine release were therefore investigated in rat peritoneal mast cells and rat leukemic basophils (RBL-1 cells). Suspension cultures of mast cells or RBL-1 cells were exposed to vancomycin for 30–60 minutes at concentrations comparable to those infused clinically (2.28 or 4.56 mg/ml). Vancomycin induced a time- and dose-dependent release of histamine into the culture media from both cell types. The reference degranulating agent, Compound 48/80 (CP 48/80), was also shown to induce histamine release from mast cells and RBL-1 cells. Mast cells were significantly more sensitive to vancomycin and CP 48/80 than RBL-1 cells and, unlike RBL-1 cells, were responsive to the inhibitory effects of cromolyn sodium on histamine release. Cromolyn sodium did not inhibit vancomycin-induced histamine release in RBL-1 or mast cells. Morphologically, mast cells exposed to either vancomycin or CP 48/80 exhibited dose-releated degranulation. On the other hand, treatment-related degranulation effects of either vancomycin or CP 48/80 on RBL-1 cells could not be reliably distinguished from controls by qualitative evaluation. Based upon these findings it is concluded that mast cells may represent a more useful model to evaluate the potential of investigational agents to relase histamine and to study mechanisms of histamine release than RBL-1 cells.
Overcoming resistance to change in engineering and construction: Change management factors for owner organizations

Abstract For owner organizations in the architecture, engineering, and construction industry, successful implementation of new processes for procuring, contracting, and managing requires a concerted change management effort. The objective of this study was to empirically measure the impact of individual change management factors on minimizing resistance from organizational members during implementation, which is often cited as a major reason for organizational change failure. Project team resistance to the implementation of a new project delivery system was tracked across sixteen owner organizations. Findings include identification of six change management factors that contribute to minimizing resistance to change, including certain aspects of project scope, size and duration, organizational expectations of change implementation speed, the establishment of formal change agents, and the level of change agent involvement with implementation activities. Implications for change leaders and practitioners are discussed to recommend strategies for reducing resistance to change.
High-grade prostatic sarcoma seen in a catheterized urine specimen: Case report and differential diagnosis

Urine cytology has been effectively used in the diagnosis and management of epithelial bladder tumors, particularly high-grade urothelial carcinoma. Indeed it is the gold standard for bladder cancer screening. Although urothelial carcinoma is the most frequently identified bladder tumor by urine cytology, metastatic carcinomas from the kidney, colon, and a variety of other regional organs have been detected. Stromal lesions such as inflammatory myofibroblastic tumor, gastrointestinal stromal tumor, and leiomyosarcoma are other much rarer entities occurring within the bladder. Few to no case reports exist documenting their identification within urine cytology specimens. Herein we report the detection of a high-grade prostatic sarcoma within a catheterized urine specimen of a young male having a diffusely enlarged prostate. The specimen consisted of numerous fragments of relatively uniform spindle cells having ovoid nuclei with rounded ends and finely dispersed chromatin. Cytoplasmic borders were indistinct. No mitoses or significant atypia was present. The background consisted of numerous red blood cells, cellular debris, and a few clusters of unremarkable urothelial cells. Followup surgical biopsy of the patient's prostate revealed a high-grade spindle-cell sarcoma. Further immunohistochemical and molecular delineation of the tumor was not informative for a more definitive diagnosis. Although rare, sarcomas and other mesenchymal tumors involving the bladder are unique entities with a broad differential diagnosis. Diagn. Cytopathol. 2010. © 2010 Wiley-Liss, Inc.
Multipole correction of atomic monopole models of molecular charge distribution I: peptides

The defects in atomic monopole models of molecular charge distribution have been analyzed for several model-blocked peptides and compared with accurate quantum chemical values. The results indicate that the angular characteristics of the molecular electrostatic potential around functional groups capable of forming hydrogen bonds can be considerably distorted within various models relying upon isotropic atomic charges only. It is shown that these defects can be corrected by augmenting the atomic point charge models by cumulative atomic multipole moments (CAMMs). Alternatively, sets of off-center atomic point charges could be automatically derived from respective multipoles, providing approximately equivalent corrections. For the first time, correlated atomic multipoles have been calculated for N-acetyl, N'-methylamide-blocked derivatives of glycine, alanine, cysteine, threonine, leucine, lysine, and serine using the MP2 method. The role of the correlation effects in the peptide molecular charge distribution are discussed.
Forensic psychiatric evaluation of Alaska native homicide offenders.

The purpose of this study is to examine characteristics of 30 Alaska natives referred for psychiatric evaluation following indictment for homicide, by comparing them with 27 non-native Alaskan homicide offenders also referred for psychiatric evaluation. Alaska native’ is a shorthand designation for the diverse indigenous peoples of Alaska, including Eskimos,2 Aleuts,3 sub-arctic Athapascan Indians,4 and the Indian tribes of the southeast Alaska coast: the Tlinglit, Haida and Tsimshians.5 This study is an extension of previous work undertaken by the author in cross-cultural forensic psychiatry. Previous papers6 have attempted to delineate an approach to the forensic psychiatric examination using a cross-cultural perspective. These studies were descriptive and focused on delineating a method to approach the cross-cultural situation in court.
Selecting measures for balance and mobility to improve assessment and treatment of individuals after stroke

Assessment of individuals with stroke using reliable and valid outcome measures is a key component of the treatment planning process. Health care professionals may have difficulty selecting balance and mobility measures given the large number of measures to choose from. This article utilizes a case-based approach to describe the benefits of using a common set of outcome measures and a process for selecting optimal measures across body structure/function, activity, and participation domains of the International Classification of Functioning, Disability and Health (ICF) model and stages of stroke recovery. Specific measures for use in acute care, rehabilitation, outpatient, and home health care settings are discussed based on StrokEDGE task force recommendations by the Neurology Section of the American Physical Therapy Association.
The Real Estate Brokerage Market: A Critical Reevaluation

This paper presents an analysis of the theories and evidence regarding the structure and performance of the market for real estate brokerage services. Some of the theoretical models found in the literature appear to suffer from logical inconsistencies, while others lack empirical support for their underlying assumptions and/or their predictions of market inefficiencies. Moreover, several important legal and institutional changes that have occurred recently have not been given sufficient attention in the existing literature. Although some new evidence on this market is presented here, additional empirical research is warranted in at least two areas: the current pricing structure and the underlying production and cost functions of the real estate brokerage industry.
Herpes simplex encephalitis (HSE) and the immunocompromised: A clinical and autopsy study of HSE in the settings of cancer and human immunodeficiency virus-type 1 infection

Although herpes simplex encephalitis (HSE) is not regarded as an opportunistic infection, the occurrence of HSE in immunocompromised patients has been documented and the suggestion made that unusual clinical and neuropathologic features characterize the disorder in this population. To further characterize HSE as it affects the immunodeficient, the authors reviewed the clinical and pathological findings in three immunocompromised patients with autopsy-proven HSE. Two patients had cancer (one with lymphoma and another with glioblastoma multiforme), one was known to be human immunodeficiency virus-type 1 (HIV-1)-seropositive and a second was suspected of harboring underlying HIV-1 infection. Two were receiving dexamethasone at onset of HSE. All had fever, mental status changes and new, focal neurological deficits or worsening of established deficits. Cerebrospinal fluid (CSF) pleocytosis was absent or minimal and head computerized tomographic (CT) scans, performed in all cases, were unrevealing. No patient was clinically suspected of having HSE, only one received acyclovir (for concurrent mucocutaneous herpes) and HSE played a major role in all deaths. Autopsy revealed an unusual form of HSE characterized by a noninflammatory, pseudoischemic histological presentation and the unexpected persistence of viral antigens in abundance despite survival beyond the clinical stage during which inflammatory responses usually peak and productive brain infection wanes. The incidence of HSE in the immunocompromised may be underestimated. Preexistent neurological disease, a noninflammatory CSF profile and negative CT scan may confound the diagnosis in this population, a typical clinical presentation notwithstanding. Increased clinical suspicion, the use of magnetic resonance imaging and polymerase chain reaction analysis of CSF for herpes simplex virus nucleic acid sequences may permit more rapid diagnosis and treatment. The absence of inflammatory infiltrates in some fatal cases of HSE suggests that an intact immune response is not requisite to the devastating neurological injury characteristic of this disorder.
AN EMPIRICAL STUDY OF A FeFET-BASED ANALOG AMPLIFIER

ABSTRACT The use of ferroelectric field-effect transistors (FeFETs) to create simple amplifiers is not completely understood and has not been extensively studied. This paper summarizes the results of behavioral characterization of a FeFET-based analog amplifier. The characterization incorporates several variables that affect the amplifier's output, including frequency, load resistance, and gate-to-source voltage. More specifically, the relationship between the frequency of the input signal and each of the peak output voltage, phase shift of the output signal, and voltage gain is examined. Also analyzed is the effect of load resistance on each of these three output parameters. These relationships are noted in actual oscilloscope outputs.
An efficient Matlab script to calculate heterogeneous anisotropically elastic wave propagation in three dimensions

We have created a second-order finite-difference solution to the anisotropic elastic wave equation in three dimensions and implemented the solution as an efficient Matlab script. This program allows the user to generate synthetic seismograms for three-dimensional anisotropic earth structure. The code was written for teleseismic wave propagation in the 1-0.1Hz frequency range but is of general utility and can be used at all scales of space and time. This program was created to help distinguish among various types of lithospheric structure given the uneven distribution of sources and receivers commonly utilized in passive source seismology. Several successful implementations have resulted in a better appreciation for subduction zone structure, the fate of a transform fault with depth, lithospheric delamination, and the effects of wavefield focusing and defocusing on attenuation. Companion scripts are provided which help the user prepare input to the finite-difference solution. Boundary conditions including specification of the initial wavefield, absorption and two types of reflection are available.
Macrophage Polarization by Angiotensin II-Type 1 Receptor Aggravates Renal Injury-Acceleration of Atherosclerosis

Objective— Angiotensin II is a major determinant of atherosclerosis. Although macrophages are the most abundant cells in atherosclerotic plaques and express angiotensin II type 1 receptor (AT1), the pathophysiologic role of macrophage AT1 in atherogenesis remains uncertain. We examined the contribution of macrophage AT1 to accelerated atherosclerosis in an angiotensin II-responsive setting induced by uninephrectomy (UNx). Methods and Results— AT1−/− or AT1+/+ marrow from apolipoprotein E deficient (apoE−/−) mice was transplanted into recipient apoE−/− mice with subsequent UNx or sham operation: apoE−/−/AT1+/+→apoE−/−+sham; apoE−/−/AT1+/+ →apoE−/−+UNx; apoE−/−/AT1−/−→apoE−/−+sham; apoE−/−/AT1−/−→apoE−/−+UNx. No differences in body weight, blood pressure, lipid profile, and serum creatinine were observed between the 2 UNx groups. ApoE−/−/AT1+/+ →apoE−/−+UNx had significantly more atherosclerosis (16907±21473 versus 116071±8180 μm2, P <0.05). By contrast, loss of macrophage AT1 which reduced local AT1 expression, prevented any effect of UNx on atherosclerosis (77174±9947 versus 75714±11333 μm2, P =NS). Although UNx did not affect total macrophage content in the atheroma, lesions in apoE−/−/AT1−/−→apoE−/−+UNx had fewer classically activated macrophage phenotype (M1) and more alternatively activated phenotype (M2). Further, UNx did not affect plaque necrosis or apoptosis in apoE−/−/AT1−/−→apoE−/− whereas it significantly increased both (by 2- and 6-fold, respectively) in apoE−/−/AT1+/+ →apoE−/− mice. Instead, apoE−/−/AT1−/−→apoE−/− had 5-fold–increase in macrophage-associated apoptotic bodies, indicating enhanced efferocytosis. In vitro studies confirmed blunted susceptibility to apoptosis, especially in M2 macrophages, and a more efficient phagocytic function of AT1−/− macrophages versus AT1+/+. Conclusion— AT1 receptor of bone marrow-derived macrophages worsens the extent and complexity of renal injury-induced atherosclerosis by shifting the macrophage phenotype to more M1 and less M2 through mechanisms that include increased apoptosis and impaired efferocytosis.
The role of antipsychotics in treating delirium.

The mainstay of the pharmacologic management of delirium remains typical antipsychotics, primarily haloperidol. Typical antipsychotics are associated with significant side effects, particularly in the elderly. This article reviews the literature on the use of both typical and atypical antipsychotics in the management of acute delirium, with a focus on the elderly. In this population, typical antipsychotics are associated with substantially more drug induce side effects—either extrapyramidal side effects or anticholinergic effects from the antipsychotics alone or in combination with benztropine or trihexyphenidyl. Anticholinergic toxicity is especially problematic in delirious, demented patients, because most dementias are associated with pre-existing deficiencies in cholinergic neurotransmission. These issues will be reviewed for typical antipsychotics as well as the emerging literature on the use of atypical antipsychotics—risperidone, olanzapine, and quetiapine—for pharmacologic management of acute delirium. Data from two studies conducted at the Wesley Woods Center at Emory University will be briefly reviewed as they constitute the largest series to date investigating the pharmacologic management of delirious demented patients.
Spatial and temporal evolution of foredeep basins: lateral strength variations and inelastic yielding in continental lithosphere

Lateral strength variations in foreland lithosphere in front of an advancing subduction zone (or thrust belt) can exert strong controls on the spatial and temporal evolution of the foredeep basin because local weak zones within the foreland serve to localize the position of the outer flexural bulge (with respect to the foreland) for extended periods of time. This occurs because the weak segment bends more easily than the surrounding, suffer plate, so that plate bending is concentrated within the weak zone. With time, the dip of the down-going (foreland) plate becomes steeper, narrowing and/or deepening the foredeep basin. If several weak zones are present within the foreland, basin development can become episodic, with protracted periods of time during which the basin remains fixed with respect to the foreland, interspersed by brief periods of time during which the basin advances rapidly toward the foreland. The flexural behaviour will be directly reflected in the stratigraphic record, producing facies belts which migrate toward the foreland in an episodic fashion. If the foreland lithosphere behaves as an elastic sheet, the weak zones must have a flexural rigidity about an order of magnitude lower than (or an elastic plate thickness about half of) the surrounding, stiffer plate in order to induce strongly episodic behaviour. When the effects of inelastic yielding in a lithosphere of brittle-elastic-ductile rheology are considered, the strength contrast required to produce episodic behaviour is reduced to about a factor of two in flexural rigidity (or 10–15 % in initial elastic plate thickness). Examples taken from two foredeep basins show evidence for episodic foredeep basin development: in both the early Proterozoic Kilohigok basin of northern Canada and the Pliocene-Quaternary Apennine foredeep basin beneath the Adriatic Sea, the outer flexural bulge appears to have remained fixed with respect to the foreland while the inner part of the basin deepened through time. In addition, the flexural geometry of the Pliocene-Quaternary Apennine foredeep basin is well modelled by an elastic plate varying laterally in strength of thickness Telastic=8.5 km with a 20 km-long weak zone of thickness Tweak= 4.25 km.
The structure and properties of ion-implanted A12O3

Abstract The effects of implantation temperature (77–640 K), ion species (Cr, Zr, Mb, Al + O, Xe), and fluence (1 × 1014 to 1 × 1017 ions cm−2) on the structure and surface hardness of A12O3 have been studied. Low temperatures favor the rapid accumulation of damage and formation of an amorphous layer. Except for zirconium, fluences in excess of 1 × 1017 ions cm −2 are required to amorphize A12O3 at 300 K. The amorphous phase has a hardness about 65% of that of the crystalline phase.
Shiny Happy People Holding Guns: 21st-Century Images of War

When U.S. troops in Iraq and Afghanistan filter their war experiences through visual aesthetics characteristic of contemporary mobile messaging culture, they produce a new visual discourse for war in the Internet age. A critical reading of 250 Facebook photos reveals an emphasis on colloquial representations of young adult life: hanging out, goofing off, playing games, and wearing costumes. For example, one image depicts two Marines in full desert camouflage posing for a picture while wearing skeleton masks. The Marine on the left looks down at his digital camera, either reviewing a photo or getting ready to hand it off to the “shooter.” The gear in the photo (masks aside) suggests that they are prepared for a combat scenario. Mortars and rockets could hit their base at any moment. The silliness and nonchalance captured in the photo seems antithetical to their physical locale, especially a condition of imminent danger. Most audiences would not recognize this as a combat scenario. Photos like this reflect ...
The role of Nkx3.2 in chondrogenesis

Transcription factor, Nkx3.2, is a member of the NK family of developmental genes and is expressed during embryogenesis in a variety of mammalian model organisms, including chicken and mouse. It was first identified in Drosophila as the Bagpipe (bap) gene, where it has been demonstrated to be essential during formation of the midgut musculature. However, mammalian homolog Nkx3.2 has been shown to play a significant role in axial and limb skeletogenesis; in particular, the human skeletal disease, spondylo-megaepiphyseal-metaphyseal dysplasia (SMMD), is associated with mutations of the Nkx3.2 gene. In this review, we highlight the role of Nkx3.2 during musculoskeletal development, with an emphasis on the factor’s role in determining chondrogenic cell fate and its subsequent role in endochondral ossification and chondrocyte survival.
Saturated and Unsaturated Polymer Flows: Microphenomena and Modeling

Fabrication of large composite parts via resin impregnation necessarily involves both saturated and unsaturated flow. While Darcy’s law assumptions classically model only the saturated flow, the idea of a Darcy-type “permeability has been widely used to describe unsaturated flows as well. Differences between saturated and unsaturated resin flow through fibrous preforms have long been reported in the literature, however, and selection of permeability values for use in numerical simulation requires a clear understandingof the differences between these two flow types. Here, we present a new model for use in prediction of the ratios of these two permeabilities. Capillary effect and the fiber roughness are shown not to be dominant phenomena, as previously assumed by other workers. Instead, transverse flow into tows, which occurs after the fluid has permeated the intertow gaps, is found to produce significant differences in saturated and unsaturated flow velocities. Our model, which is based on Berman’s flow in...
Effect of Dietary Protein on the Liver Content and Subunit Composition of the Branched-Chain α-Ketoacid Dehydrogenase Complex

Abstract Levels of expression of two subunits of the liver branched-chain α-ketoacid dehydrogenase complex in response to extremes of dietary protein intake (50% versus 0% protein diet) were determined by quantitative immunoblotting. Dietary protein deficiency decreased the amount of E1α protein to a greater extent than E2 protein. The ratio of E1α to E2 was below 1 in the liver of animals starved for protein and above 1 in the liver of animals fed the high-protein diet. Supplementation of the 0% protein diet with 5% leucine (but not 5% valine) had the same effect as the 50% protein diet. The extremes of dietary protein also resulted in a divergent pattern of expression of the mRNAs for the subunits of the complex. The E1β message showed the expected corollary of being greater in the liver of the high-protein-fed rats than the no-protein-fed rats. In contrast, the E2 message was not affected by the two extremes of dietary protein and the E1α message was greater in the liver of the no-protein-fed rats than the high-protein-fed rats. Thus, coordinate regulation of gene expression of the subunits of the complex does not occur in response to dietary protein. Post-transcriptional regulatory mechanisms most likely determine the amount of the complex and the ratio of its subunits. The decrease in E1α/E2 protein ratio that occurs in dietary protein deficiency may increase sensitivity of the complex to phosphorylation-mediated inhibition by branched-chain α-ketoacid dehydrogenase kinase.
An Analysis of the Assumptions Underlying the Taxonomy of Educational Objectives: Cognitive Domain.

The assumption that the first four cognitive levels of the taxonomy of educational objectives are arranged hierarchically and that this hierarchy is cummulative was evaluated. Mental ability and motivation scores were used to divide 144 high school biology students into six blocks. A 93-frame program in genetics was administered, and at the completion of the program the subjects took a 28-item posttest that had subscores for the cognitive levels of knowledge, comprehension, application, and analysis. Results indicated that no significant differences were found between knowledge and comprehension or application and analysis. A significant difference was found beyond the .0005 level, however, between comprehension and application. These results indicate that the cognitive processes at work at each level of the taxonomy may not be equitable, and that the previously mentioned assumptions are at least questionable.
The Stability of the Products of a Finite Set of Matrices

Let \(F = \{ {{A}_{t}}, \ldots ,{{A}_{N}}\}\) be a set of n × n matrices. Given a sequence \(S = \{ {{A}_{{{{i}_{k}}}}}\} _{{k = 1}}^{\infty }\), with \({{A}_{{{{i}_{k}}}}} \in F\), we consider products of the form \({{B}_{{M,S}}} = \prod\limits_{{k = 1}}^{M} {{{A}_{{{{i}_{k}}}}}}\). We are interested in questions of the following type: 1. Is the set {B M,S: M = 1, 2, ... } bounded for all sequences S? (We will then say that F is stable.) Does B M,S converge to zero, as M → ∞ for all S? 2. What happens if we impose some restrictions on the set of allowed sequences S? 3. What are some simple classes of matrices for which the answers to 1 and 2 become simpler?
A shear stress component to the modulation of capillary hydraulic conductivity (Lp).

Objective: Two major factors that determine transcapillary exchange are Starling forces and hydraulic conductivity (Lp) of capillary walls. Although chemical stimuli alter Lp, the influence of mechanical stimuli has been neglected. Therefore, we tested the hypothesis that the Lp of intact capillaries would increase with the magnitude of changes in shear stress presented to each capillary.Methods: Capillaries (n = 26) in the mesentery of pithed frogs (n = 23) were cannulated at 30 cm H2O (average in situ pressure = 9.2) to alter shear stress. For the calculation of shear stress, velocities of both frog red blood cells (RBC) and human RBC in the pipette solution were measured in each capillary before and after cannulation, respectively. Lp was assessed 2 min after cannulation.Results: Venular capillaries only responded to the changes in shear stress. The magnitude of the changes in shear stress correlated positively with the values for capillary Lp (Kendall's tau = 0.56; p = 0.02).Conclusions: While Starlin...
Comparison of Mannitol Salt Agar and Blood Agar Plates for Identification and Susceptibility Testing of Staphylococcus aureus in Specimens from Cystic Fibrosis Patients

Antimicrobial susceptibilities of Staphylococcus aureus strains can be determined accurately by using isolates from mannitol salt agar, and yellow isolates on mannitol salt agar at quantities of >1+ can be reported as S. aureus. These methods decrease the time to identification/antimicrobial susceptibility testing of S. aureus and decrease costs through eliminating additional testing.
Debt, demographics, and dual degrees: American medicine at the crossroads: part 1: marketplace issues.

After a quarter century of national policy guided by two principal themes—fear of a physician workforce glut and official preference for careers in primary care medicine—the Council on Graduate Medical Education in January 2005 reversed course and announced its projection of a general physician shortage by 2020 and specifically named several specialties, including radiology, in which the shortage would be most severe. In response, the Association of American Medical Colleges initially proposed that medical schools increase enrollment by 15% and subsequently by 30% over the next 10 years. In the first of 3 articles devoted to the physician workforce crisis, the market model is applied to medical services, and questions are raised about the feasibility of the proposed medical school expansion.
Epidemic Enhancement in Partially Immune Populations

We observe that a pathogen introduce/pmcdata/journal/plosone/2-2007/1/ingest/pmcmod/sgml/pone.0000165.xmld into a population containing individuals with acquired immunity can result in an epidemic longer in duration and/or larger in size than if the pathogen were introduced into a naive population. We call this phenomenon “epidemic enhancement,” and use simple dynamical models to show that it is a realistic scenario within the parameter ranges of many common infectious diseases. This finding implies that repeated pathogen introduction or intermediate levels of vaccine coverage can lead to pathogen persistence in populations where extinction would otherwise be expected.
Conductive Nano-brush Synthesized by Physical Grafting of Conducting Polymers on Carbon Nanotube

We report a novel method for synthesizing electrically conductive nano-brush (CNB) by physical grafting of organic conducting polymers on carbon nano tubes (CNT). The objective for this synthesis is to produce nano tubes having a CNT stem coated with flexible electronic conducting polymers. The nano-brush is to be blended into common polymers (e.g. epoxy, polyurethane, and poly(vinyl alcohol)) to form electrically conductive composite material. The flexible organic conducting polymer in CNB is a potentially sensitive electronic probe for mechanically induced nano-deformation of the composite because it is molecularly entangled with the host polymers. The electrical networks of CNB embedded in polymeric composites are potentially useful as in situ sensors for monitoring material deformation with an unprecedented level of sensitivity. The composite material is “smart” in the sense that it self-reports the structural “health” before load induced material failure.Our method for grafting conducting polymer does not require chemical reactions with the surface atoms of the carbon nano tube. We used physical adsorption to graft electronic conducting polymer to CNT. We first synthesized a water-soluble electronic conducting polymer which is a molecular complex between poly(acrylic acid) and polyaniline. The CNT solid were dispersed and un-bundled by sonnication in the conducting polymer solution. Due to the high affinity between CNT and the conducting polymer, the surface of CNT can be fully covered with the conducting polymer. The experimental data is consistent with a structure of nano brush with high density of conducting polymers grafted on the CNT surface.
Digital Compensation of Dynamic Acquisition Errors at the Front-End of High-Performance A/D Converters

The track-and-hold stage at the front-end of high-speed, high-resolution ADCs is usually the limiting factor in their linearity performance at high input frequencies. In this paper, we propose a digital correction algorithm for the dynamic errors generated in this stage. The digital post-processing scheme uses circuit insight and judicious modeling of the relevant nonidealities to minimize complexity. We show that the number of coefficients required in our model is significantly smaller than the number of coefficients in the general form of the Volterra series. The coefficients are extracted in a foreground calibration approach using least square (LS) solutions on a set of input and output samples from training signals. Simulation results on a nonlinear track-and-hold circuit model show approximately 40 dB of improvement in linearity (SFDR) until the fourth Nyquist zone (at fs = 100 MHz). The method was also applied to a commercially available 14-bit, 155-MS/s ADC and showed to improve its SFDR to more than 83 dB up to an input frequency of 470 MHz in a lab experiment.
Three additional genes required for deoxyribonucleic acid synthesis in Saccharomyces cerevisiae.

Deoxyribonucleic acid (DNA) synthesis was examined in asynchronous and synchronous cultures of a number of cdc (cell division cycle) temperature-sensitive mutant strains. The kinetics of DNA synthesis after a shift to the restrictive temperature was compared with that obtained after inhibition of protein synthesis at the permissive temperature, a condition that specifically blocks the initiation of new rounds of DNA replication, but does not block those in progress. Mutations in three genes (cdc 4, 7, and 28) appear to block a precondition for DNA synthesis since cells carrying these lesions cannot start new rounds of DNA replication after a shift from permissive to restrictive temperature, but can finish rounds that were in progress. These three genes are classified as having roles in the “initiation” of DNA synthesis. Mutations in two genes (cdc 8 and 21) block DNA synthesis, itself, since cells harboring these lesions that had started DNA synthesis at the permissive temperature arrest synthesis abruptly upon a shift to the restrictive temperature. Mutations in 13 other cdc genes do not impair DNA synthesis in the first cell cycle at the restrictive temperature.
Not your mother's view: the dynamics of toddler visual experience

Human toddlers learn about objects through second-by-second, minute-by-minute sensory-motor interactions. In an effort to understand how toddlers’ bodily actions structure the visual learning environment, mini-video cameras were placed low on the foreheads of toddlers, and for comparison also on the foreheads of their parents, as they jointly played with toys. Analyses of the head camera views indicate visual experiences with profoundly different dynamic structures. The toddler view often consists of a single dominating object that is close to the sensors and thus that blocks the view of other objects such that individual objects go in and out of view. The adult view, in contrast, is broad and stable, with all potential targets continually in view. These differences may arise for several developmentally relevant reasons, including the small visuo-motor workspace of the toddler (short arms) and the engagement of the whole body when actively handling objects.
Developing Interventions for Cancer-Related Cognitive Dysfunction in Childhood Cancer Survivors

Survivors of childhood cancer frequently experience cancer-related cognitive dysfunction, commonly months to years after treatment for pediatric brain tumors, acute lymphoblastic leukemia (ALL), or tumors involving the head and neck. Risk factors for cancer-related cognitive dysfunction include young age at diagnosis, treatment with cranial irradiation, use of parenteral or intrathecal methotrexate, female sex, and pre-existing comorbidities. Limiting use and reducing doses and volume of cranial irradiation while intensifying chemotherapy have improved survival and reduced the severity of cognitive dysfunction, especially in leukemia. Nonetheless, problems in core functional domains of attention, processing speed, working memory and visual-motor integration continue to compromise quality of life and performance. We review the epidemiology, pathophysiology and assessment of cancer-related cognitive dysfunction, the impact of treatment changes for prevention, and the broad strategies for educational and pharmacological interventions to remediate established cognitive dysfunction following childhood cancer. The increased years of life saved after childhood cancer warrants continued study toward the prevention and remediation of cancer-related cognitive dysfunction, using uniform assessments anchored in functional outcomes.
Effects of Noisy Drive on Rhythms in Networks of Excitatory and Inhibitory Neurons

Synchronous rhythmic spiking in neuronal networks can be brought about by the interaction between E-cells and Icells (excitatory and inhibitory cells). The I-cells gate and synchronize the E-cells, and the E-cells drive and synchronize the I-cells. We refer to rhythms generated in this way as PING (pyramidal-interneuronal gamma) rhythms. The PING mechanism requires that the drive II to the I-cells be sufficiently low; the rhythm is lost when II gets too large. This can happen in at least two ways. In the first mechanism, the I-cells spike in synchrony, but get ahead of the E-cells, spiking without being prompted by the E-cells. We call this phase walkthrough of the I-cells. In the second mechanism, the I-cells fail to synchronize, and their activity leads to complete suppression of the E-cells. Noisy spiking in the E-cells, generated by noisy external drive, adds excitatory drive to the I-cells and may lead to phase walkthrough. Noisy spiking in the I-cells adds inhibition to the E-cells and may lead to suppression of the E-cells. An analysis of the conditions under which noise leads to phase walkthrough of the I-cells or suppression of the E-cells shows that PING rhythms at frequencies far below the gamma range are robust to noise only if network parameter values are tuned very carefully. Together with an argument explaining why the PING mechanism does not work far above the gamma range in the presence of heterogeneity, this justifies the "G" in "PING."
Artificial Refuges for tsetse flies (Glossina spp.)

In Rhodesia from 1966 to 1970 Glossina morsitans Westw. and G. pallidipesAust. in natural and artificial refuges were studied by in situ counts or captured by a hand-net, mechanical, electric or sticky trapping, or a curtain drawn across the entrance. A modification of mechanical trapping permitted investigation of the pattern in whichtsetse vacated a refuge. Coolness and shade were features of effective refuges. Large numbers of tsetse utilised refuges only during the hot dry months of September, October and November. Entries occurred when temperatures reached 32°C in the morning and continued until mid-afternoon; exits occurred mainly in the evening. G. morsitansentering at 12.00–14.00 h were relatively abundant in fat; G. pallidipes entering at 12.00–16.00 h were relatively abundant in residual blood-meal. Greatest numbers of tsetse occupied refuges in naturally shaded situations such as riverine fringes. Few of the many tsetse marked in refuges and releasedwere found again at the refuge of marking. Artificial refuges were not used extensively for larval deposition. Comparisons between the catches from refuges, oxen, Morris traps and a fly round illustrate the problem of obtaining representative samples of tsetse populations. The application of insecticides to natural refuges is a policy of merit.
The Impact of Delay on the Diversity, Multiplexing, and ARQ Tradeoff

A substantial amount of research has focused on analyzing and achieving the diversity-multiplexing tradeoff in multiple antenna (MIMO) wireless communications. Recently, ARQ protocols have been added to these formulations and shown to perform as a type of diversity. Our goal in this paper is to find the optimal operating point in the diversity-multiplexing-ARQ tradeoff, with a particular focus on delay sensitive systems. Previous results in this area construct performance measures through the use of high SNR asymptotic approximations. While effective, these approximations tend to trivialize the delay performance of MIMO systems. We present a dynamic programming formulation for finding the optimal diversity gain, multiplexing gain, and ARQ window size, without relying on a high SNR approximation. Our results show that the a delay sensitive system requires one to adapt diversity and multiplexing to the time-requires workload in the system. We provide numerical examples that demonstrate the significant performance gains that can be achieved by choosing an adaptive policy over a static allocation of diversity and multiplexing.
Edgeworth expansions for errors-in-variables models

Abstract Edgeworth expansions for sums of independent but not identically distributed multivariate random vectors are established. The results are applied to get valid Edgeworth expansions for estimates of regression parameters in linear errors-in-variable models. The expansions for studentized versions are also developed. Further, Edgeworth expansions for the corresponding bootstrapped statistics are obtained. Using these expansions, the bootstrap distribution is shown to approximate the sampling distribution of the studentized estimators, better than the classical normal approximation.