cssi/SciSciGPT-SciSciNet huggingface dataset:
Genetic Matters: Thirty years of progress using mouse models in nicotinic research

This research update summarizes thirty years of studies on genetic influences on responses to the acute or chronic administration of nicotine. Early studies established that various inbred mice are differentially sensitive to the effects of the drug. Classical genetic analyses confirmed that nicotine effects on locomotion, body temperature and seizures are heritable. A significant inverse correlation between the locomotor and hypothermic effects and the density of nicotine binding sites suggested that differential expression α4β2-neuronal nicotinic acetylcholine receptor (nAChR) mediated some of this genetic variability. Subsequent studies with α4 and β2 nAChR null (decreased sensitivity) and gain of function mutants (increased sensitivity) supports the role of the α4β2*nAChR subtype. However, null mutant mice still respond to nicotine, indicating that other nAChR subtypes also mediate these responses. Mice differing in initial sensitivity to nicotine also differ in tolerance development following chronic treatment: those mice that are initially more sensitive to nicotine develop tolerance at lower treatment doses than less sensitive mice, indicating that tolerance is an adaptive response to the effects of nicotine. In contrast, the sensitivity of mice to pre-pulse inhibition of acoustic startle response is correlated with the expression of α7-nAChR. While genetic variability in nAChR expression and function is an important factor contributing to differences in response to nicotine, the observations that altered activity of opioid, glutamate, and cannabinoid receptors among others also change nicotine sensitivity reinforces the proposal that the genetics of nicotine response is more complex than differences in nAChRs.
Hyperlipidemia disrupts cerebrovascular reflexes and worsens ischemic perfusion defect

Hyperlipidemia is a highly prevalent risk factor for coronary and cervical atherosclerosis and stroke. However, even in the absence of overt atherosclerosis, hyperlipidemia disrupts endothelial and smooth muscle function. We investigated the impact of hyperlipidemia on resting-brain perfusion, fundamental cerebrovascular reflexes, and dynamic perfusion defect during acute focal ischemia in hyperlipidemic apolipoprotein E knockout mice before the development of flow-limiting atherosclerotic stenoses. Despite elevated blood pressures, absolute resting cerebral blood flow was reduced by 20% in apolipoprotein E knockout compared with wild type when measured by [(14)C]-iodoamphetamine technique. Noninvasive, high spatiotemporal resolution laser speckle flow imaging revealed that the lower autoregulatory limit was elevated in apolipoprotein E knockout mice (60 vs. 40 mm Hg), and cortical hyperemic responses to hypercapnia and functional activation were attenuated by 30% and 64%, respectively. Distal middle cerebral artery occlusion caused significantly larger perfusion defects and infarct volumes in apolipoprotein E knockout compared with wild type. Cerebrovascular dysfunction showed a direct relationship to the duration of high-fat diet. These data suggest that hyperlipidemia disrupts cerebral blood flow regulation and diminishes collateral perfusion in acute stroke in the absence of hemodynamically significant atherosclerosis.
Controlled Microfluidic Encapsulation of Cells, Proteins, and Microbeads in Lipid Vesicles

Cells have been encapsulated inside lipid vesicles by using a new microfluidic lipid vesicle formulation technique. Lipid vesicles are formulated within minutes without using toxic lipid solvents. The encapsulation efficiency inside the vesicles is controlled by the microfluidic flows. Green fluorescent proteins (GFP), carcinoma cells, and bead encapsulated vesicles have mean diameters of 27.2 μm, 62.4 μm, and 55.9 μm, respectively. The variations of vesicle sizes are ∼20% for the GFP and cell encapsulated vesicles and ∼10% for the bead encapsulated vesicles.
High-density model for server allocation and placement

It is well known that optimal server placement is NP-hard. We present an approximate model for the case when both clients and servers are dense, and propose a simple server allocation and placement algorithm based on high-rate vector quantization theory. The key idea is to regard the location of a request as a random variable with probability density that is proportional to the demand at that location, and the problem of server placement as source coding, i.e., to optimally map a source value (request location) to a code-word (server location) to minimize distortion (network cost). This view has led to a joint server allocation and placement algorithm that has a time-complexity that is linear in the number of clients. Simulations are presented to illustrate its performance.
A decomposition of Toeplitz matrices and optimal circulant preconditioning

Abstract A factorization of the given Toeplitz matrix T , obtained in this work, is used to derive an optimal circulant preconditioner C in the sense of minimizing the Frobenius norm of I − CT . By use of the fast Fourier transform, the computation of the new preconditioner can be performed in O ( n log n ) operations.
Analysis of the Functional Role of Steroid Receptor Coactivator-1 in Ligand-Induced Transactivation by Thyroid Hormone Receptor

The nuclear hormone receptors belonging to the steroid/thyroid/retinoid receptor superfamily are ligand-inducible transcription factors. These receptors modulate transcription of specific cellular genes, either positively or negatively, by interacting with specific hormone response elements located near the target promoters. Recent studies indicated that the hormone- occupied, DNA-bound receptor acts in concert with a cellular coregulatory factor, termed coactivator, and the basal transcription machinery to mediate gene activation. Consistent with this scenario, a number of nuclear proteins with potential coactivator function have been isolated. In the present study, we demonstrate that steroid receptor coactivator-1 (SRC-1), a recently isolated candidate coactivator, functions as a positive regulator of the thyroid hormone receptor (TR)-mediated transactivation pathway. In transient transfection experiments, coexpression of SRC-1 significantly enhanced ligand-dependent transactivation of a thyroid hormon...
Comparative Echolocation by Fishing Bats

The acoustic orientation of two species of fish-catching bats was studied as they negotiated a row of strings or fine wires extending across their flight path. Orientation sounds of Pizonyx vivesi consisted of a steep descending FM sweep lasting about 3 msec. Noctilio leporinus used 8 to 10 msec pulses composed of an initial nearly constant frequency portion followed by a descending frequency modulation. The echolocation of small wires by N. leporimis differed from that of surface fish in that during wire avoidance no nearly constant frequency or entirely FM pulses were emitted, nor was the pulse duration markedly shortened as the barrier was approached. There was extensive temporal overlap at the animal's ear of returning echoes with the emitted cries when the bat was near the barrier—a strong contrast to the apparent careful minimization of such overlap during feeding maneuvers. Noctilio increased its average pulse duration about 2 msec when confronted with a barrier of 0.21 mm, as opposed to 0.51 mm, diameter wires. Pizonyx detected these wires well before pulse-echo overlap began, but at a shorter range than did N. leporinus , suggesting the latter species may have a longer effective range of echolocation.
High-temperature phase equilibria in Cr-Cr3Si two-phase alloys

Phase equilibria in two-phase Cr-Cr3Si alloys have been investigated using metallography, XRD, and electron microprobe analysis. Cr-Si alloys with compositions of up to 15.0% Si were directionally solidified using cold crucible Czochralski crystal growth and equilibrated chemically at either 1200,1400, or 1600 °C. Measured Si concentrations of the Cr and the Cr3Si phases were found to be significantly lower than those given by the most recent assessment of the Cr-Si phase diagram, particularly at temperatures above 1200 °C. This explains why the volume fraction of Cr3Si in the directionally solidified eutectic is lower than that predicted by the assessed phase diagram. X-ray lattice parameter data for both Cr and Cr3Si are also reported.
Multiple authorship, basic research, and other trends in the emergency medicine literature (1975 to 1986)

Abstract As emergency medicine comes of age, it is interesting to examine the scientific nature of the specialty as reflected in the literature. Representative volumes of three emergency medicine journals were reviewed for number and type of article, institutional origin, article length, and number of authors. For Annals of Emergency Medicine , (AEM) volumes for 1975, 1980, and 1985 were studied. For The American Journal of Emergency Medicine (AJEM) and The Journal of Emergency Medicine (JEM), articles from the first 12 months of publication (1983 to 1984) and the complete 1986 issue were examined. Analysis of the scientific sections of the journals discloses some interesting trends. While the average article length has remained about the same (four to six pages), the average number of authors per article has steadily risen. The percentage of articles listing an academic origin has remained steady in AEM and JEM, but has risen in AJEM. Multicenter collaborations and basic science articles are appearing with significantly increased frequency. A noteworthy trend is the rise in multiple authorship of articles. There have been significant p −4 ) increases in the number of multiple-authored (more than three authors) articles in AEM and JEM. As reflected by the literature, scientific progress in EM is maintaining a rapid pace. However, there are increasing numbers of papers with multiple authors. Listing of multiple authors on papers has prompted critlcism of the literature in other medical specialties. If this trend continues, there may be a risk of compromising the integrity of the published research.
Black, White, and Rainbow [of Desire]: the colour of race-talk of pre-service world language educators in Boalian theatre workshops

This article examines how Boalian Theatre of the Oppressed exercises helped instructors and pre-service teachers navigate the consequences of ventriloquized, racialized discourses in a pre-service world language teacher education classroom. Applying a critical and performative approach, we analyse the mostly White student–actors’ varying representations of a “White teacher’s” use of the term “hoodlum” for classroom management and the resulting communication breakdown that occurred between the teacher and a “Black parent.” Findings indicate that rehearsing pre-service teachers’ classroom struggles helped to move the group away from monochromatic perceptions of White/Black, Teacher/Parent interactions to a polychromatic view of interlocutors’ multiple histories and investments. This study has implications for revitalizing the place of world language education in K-12 education, extending the acquisition of second language verbs and nouns to incorporate connections between language, culture, history, and power.
A dislocation model for two-level electron-hopping conductivity in V2O5: Implications for catalysis

Abstract The electrical conductivity of single-crystal V2O5 and V2O5 doped with copper (α phase) has been measured along the c axis from 77°K to 298°K. Ln σ vs. 1 T can be approximated by two straight lines with an average activation energy above 170°K of 0.20 eV and below 170°K of 0.077 eV. Comparison with EPR data and with the V2O5-β phase leads to an interpretation for the high-temperature conductivity as arising from thermal excitation of electrons from vanadium-pair traps with an activation energy of 0.15 eV and electron hopping from one vanadium site to another with an activation energy of 0.05 eV. Together with the Seebeck coefficient, the low-temperature data also require direct electron hopping between traps with an activation energy of 0.077 eV. A dislocation model is presented to account for the vanadium pair traps, the electrical conductivity and EPR data. The model require the formation of interstitial oxygen which it is suggested may be involved in the catalytic properties of V2O5.
The life cycles of professional associations: Organizational and administrative dynamics

The life cycles of professional associations have received little attention in the literature. Using the Canadian Group Psychotherapy Association as an example, the author discusses the general dynamic underpinnings of systems and organizations, and caveats for the leaders of professional associations.
Solvent microextraction of chlorinated pesticides

This paper is a preliminary report on a fast method for the extraction of organochlorine pesticides from river water which is inexpensive, fast and has little to no waste that has been developed. Pesticide extraction was achieved using the relatively new technique of solvent microextraction. In this technique a 2 μL drop of organic solvent is suspended on the tip of a microsyringe in a stirred aqueous sample solution. After the prescribed extraction time the drop is drawn back into the syringe. The syringe is then removed and the contents are injected into a gas chromatograph for analysis. Extraction of eleven organochlorinated pesticides from aqueous solutions with concentrations down to 1 ng mL−1 was achieved. The developed procedure was tested as a screening method for pesticides with spiked river water samples and was found to be linear over the concentration range of interest.
SU-FF-T-22: A Model to Evaluate the Spatial and Dosimetric Resolutions of IMRT for Desired High-Gradient Dose Distributions

Purpose: To create a 3D model to simulate IMRT treatment delivery. The model includes dose distribution resolution degradation from the MLC leaf width and dose deposition. The resulting deliverable distribution may be evaluated to determine conformity and the achievable spatial and dosimetric resolution. Method and Materials: Phantom image sets were created to represent head and neck anatomy with critical structures. Image sets contained 128 slices, each 128×128 pixels, with 1mm pixel size. Target volumes with radioresistant subvolumes of varying size and shape were added to the image sets. A nine‐field treatment technique was simulated. Slice‐by‐slice along the beam central axis, the image set was sampled in the direction perpendicular to leaf motion at each leaf width center. Each slice was convolved with a rect function representing MLC leaf width and convolved with a dose spread kernel appropriate for the depth along the central axis of the beam. The resulting 3D dose distributions for each field were summed to give the deliverable dose distribution for the nine‐field treatment. Results: The result of the model is a deliverable dose distribution in 3D. This deliverable dose distribution may be analyzed by comparison with the desired dose distribution. Information on the distribution's conformity may be attained by calculation of a distance‐to‐agreement map to provide information on spatial resolution, or by calculation of a map containing percent differences in dose to give insight into the dosimetric resolution. Dose intensity profiles may be extracted from the deliverable dose distribution as a means to determine achievable dosimetric gradients. Conclusion: This 3D model simulates the degradation of an ideal dose distribution due to the IMRT treatment delivery process. The resulting deliverable dose distribution may be used for evaluating the achievable spatial and dosimetric resolution for the current IMRT technique.
Interdisciplinarity as Critical Inquiry: Visualizing the Art/Bioscience Interface

Different disciplines rely on particular methods and assumptions in their knowledge practices. However, there may be significant costs in the conceptual and social boundaries that disciplines set as specialized communities. Engaging with the biological sciences, for example, has become a necessity in our everyday lives in ways unimaginable just a few years before, ranging from genetically modified organisms and new reproductive technologies to emerging diseases and issues of ecological sustainability. However, how can non-specialists be a part of this scientific knowledge and decision-making as a matter of personal agency given the complex and interwoven nature of these biological phenomena? A number of practices in contemporary art and design are engaging with biology and questions of participation in novel ways, including in the emerging area of ‘BioArt’. Discussed here are examples of practices that challenge traditional assumptions about both art as well as biology, and raise important questions about the possibilities and prospects for certain forms of critical interdisciplinary engagement.
A new method for polynomial real root isolation

A new method is presented for the isolation of the real roots of a given integral, univariate, square-free polynomial P. This method is based on Vincent's theorem and only uses: (i) Descartes' rule of signs, and (ii) transformations of the form x = a1 + 1/x′, x′ = a2 + 1/x″, x″ = a3 + 1/xt, ..., for positive, integral ai's. The key element in this procedure is the calculation of the quantities a1, a2, a3,... . We compute them as "positive lower root bounds" of polynomials and the resulting algorithm has the best theoretical computing time achieved thus far. Empirical results also verify the superiority of our method over all others existing.
Quantitative intercomparison of transmission electron microscopy, flow cytometry, and epifluorescence microscopy for nanometric particle analysis.

Nanometric biological particles such as viruses have received increased attention in a wide range of scientific fields. Evaluation of viral contributions to environmental processes and the use of viruses in medical applications such as gene therapy require viruses to be routinely and accurately enumerated. There are a variety of existing techniques for counting viruses, namely, plaque assays, transmission electron microscopy (TEM), epifluorescence microscopy (EFM), and flow cytometry (FCM); each has advantages and disadvantages. While there have been attempts to intercompare some of these techniques to determine the most effective means to count viruses, no previous study used a technique-independent standard for quantitative comparison of collection efficiency, accuracy, and precision. In this work, polystyrene nanospheres were used as standards for the intercomparison of performance characteristics for TEM, EFM, FCM, as well as a custom-built flow cytometer (the Single Nanometric Particle Enumerator, SNaPE). EFM and SNaPE exhibited the highest degree of accuracy and precision, with particle concentrations deviating ≤5% from true and relative errors less than half that of TEM, EFM and SNaPE are also significantly more time and cost efficient than TEM.
A molecular simulation picture of DNA hydration around A- and B-DNA.

Recent results from molecular dynamics (MD) simulations on hydration of DNA with respect to conformation are reviewed and compared with experimental data. MD simulations of explicit solvent around DNA can now give a detailed model of DNA that not only matches well with the experimental data but provides additional insight beyond current experimental limitations. Such simulation results are analyzed with a focus on differential hydration properties between A- and B-DNA and between C/G and A/T base pairs. The extent of hydration is determined from the number of waters in the primary shell and compared to experimental numbers from different measurements. High-resolution hydration patterns around the whole DNA are shown and correlated with the conformations. The role of ions associating with DNA is discussed with respect to changes in the hydration structure correlating with DNA conformation.
How Misconceptions on Heat Flow May have Delayed Discovery of Plate Tectonics

Since 1906 it has been known that sialic rocks are richer in heat-generating radioactive elements than simatic rocks. This led to the assumption that convection in the mantle must rise under the sialic continents and descend under the simatic ocean floors. So persistent was this view that convective flow in the opposite direction was evaluated seriously only after Hess and Dietz proposed it in the 1960's.
Association of antibiotic treatment-resistant Lyme arthritis with T cell responses to dominant epitopes of outer surface protein A of Borrelia burgdorferi.

Objective To explore further the association of antibiotic treatment–resistant Lyme arthritis and T cell reactivity with outer surface protein A (OspA) of Borrelia burgdorferi, including the identification of T cell epitopes associated with this treatment-resistant course. Methods The responses of peripheral blood and, if available, synovial fluid lymphocytes to B burgdorferi proteins, fragments, and synthetic peptides, as determined by proliferation assay and interferon-γ production, were compared in 16 patients with treatment-responsive and 16 with treatment-resistant Lyme arthritis. Results The maximum severity of joint swelling correlated directly with the response to OspA. Moreover, the only significant difference between patients with treatment-resistant and treatment-responsive arthritis was in reactivity with N-terminal and C-terminal fragments of OspA, OspA1 (amino acids [aa] 16–106), and OspA3 (aa 168–273). Epitope mapping showed that 14 of the 16 patients with treatment-resistant arthritis had responses to OspA peptides (usually 4 or 5 epitopes), whereas only 5 of the 16 patients with treatment-responsive arthritis had reactivity with these peptides (usually 1 or 2 epitopes) (P = 0.003). Patients with HLA–DRB1 alleles associated with treatment-resistant arthritis were more likely to react with peptide 15 (aa 154–173) and, to a lesser degree, with peptide 21 (aa 214–233) than patients with other alleles, whereas the responses to other epitopes were similar in both groups. Conclusion The maximum severity of joint swelling and the duration of Lyme arthritis after antibiotic treatment are associated with T cell responses to specific epitopes of OspA.
1,4-Fullerene Derivatives: Tuning the Properties of the Electron Transporting Layer in Bulk-Heterojunction Solar Cells**

Light and flexible photovoltaic devices based on organic materials are extensively studied as an alternative to expensive and fragile silicon-based solar cells. The efficiency of these devices is rapidly increasing with the most recent power conversion efficiency (PCE) of greater than 8% bringing them closer to commercial viability. Further improvements are needed and can be achieved by optimizing the ratio between donor and acceptor, modifying the electronic properties of the materials, and optimizing the morphology of the resulting bulk heterojunction (BHJ). A direct way to increase the efficiency is to lower the band gap of the donor material in order to absorb a greater fraction of the solar spectrum. This concept has been explored through the synthesis of a series of new low band gap polymers, which exhibit a decreased band gap as a result of lowering the lowest unoccupied molecular orbital (LUMO). An emerging challenge is the need for electronically compatible acceptors with sufficiently low LUMO levels so that charge separation is efficiently promoted. Optimum miscibility of a specific polymer and fullerene combination to create the optimum degree of phase separation is also a feature to take into account. Typically, the approach used to test new donor materials is to fabricate devices using PC61BM ([6,6]-phenyl-C61-butyric acid methyl ester), a well-studied benchmark acceptor. Only a limited number of other fullerene derivatives have been successfully employed. Although these fullerene derivatives bear different functional groups, they are related by the positioning of the substituents on carbons 1 and 2 of a six-membered ring. From literature studies it is apparent that even subtle modification of the nature and especially position of substituents can drastically alter the electronic properties of fullerene derivatives. For example, PC71BM has reduced symmetry that increases visible light absorption and has a positive effect on current generation in polymer BHJ cells. Here we report the synthesis of a series of novel fullerene derivatives functionalized through the “1,4” position and their use in organic photovoltaics (OPVs). Features that distinguish this class of fullerene derivatives are: 1) straightforward synthesis which includes versatility of functionalization with different substrates starting from the same material (fullerenol, Scheme 1); 2) tunable LUMO energy by appending electron-donating or electron-withdrawing groups; 3) lower symmetry which decreases the optical gap and produces an increased absorption in the visible (the extinction coefficient at 480 nm of a 1,4-adduct is approximately 8 times larger than that of PCBM) ; 4) tunable solubility which influences the morphology of the BHJ. Like PC71BM, 1,4addends have increased light absorption at ca. 500 nm (Figure 1) with the advantage that all the C60 derivatives
Effect of carbon dioxide on pigment and membrane content in Synechococcus lividus

The effect of carbon dioxide on pigment and membrane content in Synechococcus lividus was studied by depriving cells of CO2 and examining cell populations biochemically and by electron microscopy. After 120 h of CO2 deprivation, S. lividus lost all detectable chlorophyll a and C-phycocyanin. Such bleached cultures were “mustard yellow”, the result of approximately 1.8 times more carotenoid per cell than green control cultures. Although cells from beached cultures appeared morphologically identical to control green cells when examined by light microscopy, electron microscopic examination revealed them to be devoid of detectable thylakoid membrane. Thylakoid membrane could not be recovered by physical isolation or revealed by freeze etching of bleached S. lividus. In addition, inclusion bodies characteristically found in S. lividus were also absent. Reintroduction of CO2 into bleached cultures resulted in a rapid resynthesis of both chlorophyll a and C-phycocyanin. Electron microscopic examination of these regreening cultures revealed that thylakoid membrane was also rapidly resynthesized. Growth of regreened cultures did not occur until there was the synthesis of a full complement of chlorophyll a, C-phycocyanin, and thylakoid membrane. A time course study of the cytological events occurring during bleaching and regreening is presented.
Altered frontocortical, cerebellar, and basal ganglia activity in adjuvant-treated breast cancer survivors 5-10 years after chemotherapy

Purpose To explore the relationship of regional cerebral blood flow and metabolism with cognitive function and past exposure to chemotherapy for breast cancer. Patients and methods Subjects treated for breast cancer with adjuvant chemotherapy remotely (5–10 years previously) were studied with neuropsychologic testing and positron emission tomography (PET), and were compared with control subjects who had never received chemotherapy. [O-15] water PET scans was acquired during performance of control and memory-related tasks to evaluate cognition-related cerebral blood flow, and [F-18] fluorodeoxyglucose (FDG) PET scans were acquired to evaluate resting cerebral metabolism. PET scans were analyzed by statistical parametric mapping and region of interest methods of analysis. Results During performance of a short-term recall task, modulation of cerebral blood flow in specific regions of frontal cortex and cerebellum was significantly altered in chemotherapy-treated subjects. Cerebral activation in chemotherapy-treated subjects differed most significantly from untreated subjects in inferior frontal gyrus, and resting metabolism in this area correlated with performance on a short-term memory task previously found to be particularly impaired in chemotherapy-treated subjects. In examining drug-class specific effects, metabolism of the basal ganglia was significantly decreased in tamoxifen + chemotherapy-treated patients compared with chemotherapy-only breast cancer subjects or with subjects who had not received chemotherapy, while chemotherapy alone was not associated with decreased basal ganglia activity relative to untreated subjects. Conclusion Specific alterations in activity of frontal cortex, cerebellum, and basal ganglia in breast cancer survivors were documented by functional neuroimaging 5–10 years after completion of chemotherapy.
Comparative Genomics and Evolution of the Alpha-Defensin Multigene Family in Primates

Defensin genes encode small cationic antimicrobial peptides that form an important part of the innate immune system. They are divided into three families, alpha (α), beta (β), and theta (θ), according to arrangement of the disulfide bonding pattern between cysteine residues. Considering the functional importance of defensins, investigators have studied the evolution and the genomic organization of defensin genes. However, these studies have been restricted mainly to β-defensins. To understand the evolutionary dynamics of α-defensin genes among primates, we identified the α-defensin repertoires in human, chimpanzee, orangutan, macaque, and marmoset. The α-defensin genes in primates can be classified into three phylogenetic classes (class I, II, and III). The presence of all three classes in the marmoset indicates that their divergence occurred before the separation of New World and Old World monkeys. Comparative analysis of the α-defensin genomic clusters suggests that the makeup of the α-defensin gene repertoires between primates is quite different, as their genes have undergone dramatic birth-and-death evolution. Analysis of the encoded peptides of the α-defensin genes indicates that despite the overall high level of sequence divergence, certain amino acid residues or motifs are conserved within and between the three phylogenetic classes. The evolution of α-defensins in primates, therefore, appears to be governed by two opposing evolutionary forces. One force stabilizes specific amino acid residues and motifs to preserve the functional and structural integrity of the molecules and the other diversifies the sequences generating molecules with a wide range of activities against a large number of pathogens.
Effects of endolymphatic duct occlusion on the structure and function of the endolymphatic sac in the adult guinea pig

The endolymphatic sac (ELS) has been shown to respond rapidly to sudden disruptions in fluid balance such as labyrinthectomy or systemic administration of hyperosmolar agents. The present study was designed to determine the ELS response to slower changes in fluid dynamics by occluding the endolymphatic duct (ELD), thereby interrupting the longitudinal flow of endolymph to the ELS. Morphologic studies and autoradiographic techniques were used to evaluate the effects of ELD obstruction on the structure and function of the ELS after 48 hours. There were no significant changes in cellular morphology and a slight decrease in the incorporation of radiolabeled glucose when compared with normal ELS cells. We conclude that it is rapid change in fluid balance that triggers the ELS response, which is not seen with disruption of longitudinal flow.
Changing relationships between radiologists and hospitals. Part I. Background and major issues.

James H. Thrall, MD As a specialty, radiology has prospered from its close relationship with hospitals, which have typically underwritten substantial capital costs for equipment and facilities and have supplied a steady stream of patients requiring diagnostic imaging and interventional procedures. Likewise, hospitals have benefited from having close associations with radiologists who have generally taken comprehensive responsibility for providing imaging services in exchange for some level of exclusivity or “franchise.” Under the historic, often informal, franchise concept, radiologists have taken the good and the challenging alike as their responsibility—covering the emergency department, providing venous access services, and dealing with timeconsuming complex cases, among other issues—in exchange for benefits to the overall practice. Radiology groups are now losing substantial components of their favored status as franchise holders owing to a variety of factors, including the loss of turf to other providers and the shift in the protocol for care delivery from a predominantly hospital-based inpatient focus to an increasingly outpatient focus. At the same time, the needs and expectations of hospitals for better quality and more timely delivery of imaging services are steadily increasing, so radiologists are being asked to do more— for example, provide real-time 24-hoursper-day, 7-days-per-week (ie, 24-7) coverage—with less exclusivity and less practice security. The progressive erosion of the franchise model is threatening the historic symbiotic relationship between hospitals and radiologists and is reshaping the way imaging services will be provided in the future.
Coffee Drinking and Risk of Bladder Cancer

The relationship between coffee drinking and risk of bladder cancer was assessed with the use of data from a case-control study of bladder cancer. Incident cases (2,982) and general population controls (5,782) were interviewed. Overall, the relative risk (RR) of bladder cancer for subjects who had ever drunk coffee was estimated as 1.4 (95% confidence interval = 1.1-1.8). There was no consistent relation between the RR estimate and the current consumption level. Among men who drank coffee, those who drank more than 49 cupfuls of coffee per week had an apparent excess in risk, but women who drank that much had an apparent deficit in risk.
C-met Proto-Oncogene Expression in Benign and Malignant Human Prostate Tissues

AbstractPurpose: Hepatocyte growth factor/scatter factor (HGF/SF) is a potent mitogen to renal epithelial cells in vitro and in vivo. HGF/SF signals through its receptor which is coded by the c-met proto-oncogene. We hypothesized that altered expression of the HGF/SF receptor, c-met, may be involved in the pathogenesis of certain renal cell carcinomas. Our objectives were to 1) assess the presence and localization of c-met protein in benign and malignant human renal tissues, and 2) correlate the presence of c-met protein with renal carcinoma histological subtype, tumor stage and tumor grade.Materials and Methods: Immunohistochemical analysis of c-met protein was performed in 41 normal and malignant human renal samples.Results: c-met Immunostaining was detected in the normal kidney tissue in all 41 samples. In the normal kidney c-met immunostaining was limited to the cell membrane and/or cytoplasm of epithelial cells in specific tubular segments, including the proximal convoluted tubule, thin and thick lim...
Genetic Variation and the Fate of Beneficial Mutations in Asexual Populations

The fate of a newly arising beneficial mutation depends on many factors, such as the population size and the availability and fitness effects of other mutations that accumulate in the population. It has proved difficult to understand how these factors influence the trajectories of particular mutations, since experiments have primarily focused on characterizing successful clones emerging from a small number of evolving populations. Here, we present the results of a massively parallel experiment designed to measure the full spectrum of possible fates of new beneficial mutations in hundreds of experimental yeast populations, whether these mutations are ultimately successful or not. Using strains in which a particular class of beneficial mutation is detectable by fluorescence, we followed the trajectories of these beneficial mutations across 592 independent populations for 1000 generations. We find that the fitness advantage provided by individual mutations plays a surprisingly small role. Rather, underlying “background” genetic variation is quickly generated in our initially clonal populations and plays a crucial role in determining the fate of each individual beneficial mutation in the evolving population.
Cutting Losses for Student‐Athletes in Transition: An Integrative Transition Model

This article provides a framework from which to address the transition, decisio-making, personal, and career counseling strategies useful with athletes. Counseling strategies, both personal and career, accompany each stage in the integrated model for working with this special population.
Adsorption of a polyampholyte on a charged spherical particle

We develop a scaling theory for a single polyampholyte chain adsorbed on a charged spherical particle in a theta-solvent. Adsorption of a polyampholyte molecule is due to its polarization in the electrostatic field of the particle. For large particles with sizes exceeding the thickness of the adsorbed layer, the conformations of the chain are similar to the one found for polyampholyte adsorption on charged planar surface. However, an adsorbed polyampholyte chain forms a self-similar flower-like structure near the particles with sizes smaller than its Gaussian size. These self-similar structures result from the balance of the polarization energy of loops and the excluded volume interactions between monomers. The structure of an adsorbed polyampholyte in the flower-like conformation is similar to that of a neutral star polymer.
MALE INFERTILITY DUE TO A BENIGN PROSTATIC POLYP

Prostatic polyps are rare benign lesions. They are derived from hyperplastic prostate tissue and usually appear as exophytic growths in the posterior urethra. We report on a patient with a prostatic urethral polyp found incidentally during evaluation for male factor infertility. The polyp caused partial ejaculatory duct obstruction, which was corrected following surgical resection. CASE REPORT A 36-year-old man presented for evaluation of male infertility. He and his partner had undergone 2 failed attempts at in vitro fertilization. Following these cycles, a full-term pregnancy was naturally achieved. However, the newborn died at age 4 days due to spinal muscular atrophy. History was significant for left varicocelectomy and a recent episode of gross painless hematuria. Physical examination was remarkable for left testicular atrophy. Laboratory studies revealed microscopic hematuria. Hormonal profile was normal. Multiple semen analyses revealed an average value of 0.9 ml., 10.8 million total sperm count and 29% motility. Hematuria evaluation included urinalysis and culture, urine cytology and magnetic resonance imaging (MRI) of the abdomen and pelvis. MRI identified a 1 cm. cystic mass in the prostatic urethra associated with prominent seminal vesicles (fig. 1). Cystoscopy demonstrated a normal bladder and trigone, and confirmed a 2 cm. grayish papillary mass arising from the verumontanum in the prostatic urethra. Transurethral resection was performed and efflux of milky, viscous fluid was demonstrated at the base of the resection. Efflux of additional fluid was observed at this location during intraoperative massage of the seminal vesicles. Pathological examination revealed a benign prostatic polyp (fig. 2). Several semen analyses 1 month postoperatively were improved with a mean ejaculatory volume of 5.2 ml., total count of 36 million and motility of 57%. The couple conceived naturally 2 months postoperatively, and a healthy male neonate was delivered at term without any congenital abnormalities.
Estimation of linear parametric models using inverse filter criteria and higher order statistics

Considers the problem of estimating the parameters of a stable, scalar ARMA (p, q) signal model (causal or noncausal, minimum phase or mixed phase) driven by an i.i.d. non-Gaussian sequence. The driving noise sequence is not observed. The Wiggins-Donoho (1978, 1991) class of inverse filter criteria for estimation of model parameters are analyzed and extended. These criteria have been considered in the past only for moving average inverse filters. These criteria are extended to general ARMA inverses. Computer simulation examples are presented to illustrate the proposed approaches. >
A Comparative Analysis Between the Nile Valley’s Liberal Arts Tradition and the Development of Western Education

This article is an analysis of the original purpose of studying the seven liberal arts in the context of contemporary higher education. Nile Valley theorists in ancient Africa tied the purpose of s...
North Atlantic Simulations with the Hybrid Coordinate Ocean Model (HYCOM): Impact of the Vertical Coordinate Choice, Reference Pressure, and Thermobaricity

The viability of a generalized (Hybrid) Coordinate Ocean Model (HYCOM), together with the importance of thermobaricity and the choice of reference pressure, is demonstrated by analyzing simulations carried out using the World Ocean Circulation Experiment (WOCE) Community Modeling Experiment (CME) Atlantic basin configuration. The standard hybrid vertical coordinate configuration is designed to remain isopycnic throughout as much of the water column as possible while smoothly making a transition to level (pressure) coordinates in regions with weak vertical density gradients, such as the surface mixed layer, and to terrain-following coordinates in shallow-water regions. Single-coordinate (pressure or density) experiments illustrate the flexibility of the model but also bring forward some of the limitations associated with such a choice. Hybrid experiments with potential density referenced to the surface ( su) and to 20 MPa (;2000 m) (s 2) illustrate the increased influence of pressure errors with increasing distance from the reference pressure. The su hybrid experiment does not properly reproduce the northward flow of Antarctic Bottom Water (AABW), and large errors in near-surface pressure gradients in the s 2 experiment produce a wind-driven gyre circulation that is too strong, when compared with observations, and a North Atlantic Current that follows an unrealistic path. These near-surface and nearbottom pressure errors are removed when thermobaric effects are included, resulting in a more accurate representation of the upper-ocean gyre circulation, the northward AABW flow near the bottom, and the meridional overturning circulation and heat flux.
Mapping T and B lymphocyte epitopes of bovine herpesvirus-1 glycoprotein B.

Glycoprotein B (gB) is a major envelope protein of bovine herpesvirus-1 (BHV-1). As a subunit vaccine, the extracellular domain of recombinant gB induces neutralizing antibody and T cell responses that engender protection against virus challenge. Here, lymphocytes from animals of different parentage were analysed for T cell proliferation to the gB extracellular domain for immune recognition. Four truncated overlapping gB gene segments encoding 742 amino acids were expressed from a baculovirus vector to identify antigenic regions. One immunodominant region (amino acids 254–532) was recognized by T cells from immune individuals of different parentage. Serial synthetic peptides spanning this region localized the T cell (amino acids 319–340 and 415–436) and B cell (amino acids 331–352, 475–496 and 487–508) epitopes. Elucidation of gB epitopes indicates the diverse and distinctive recognition by T cells and antibodies of this envelope glycoprotein by cattle, the natural host of BHV-1.
Deep-Levels Associated with Implanted Titanium in Silicon

Titanium was ion implanted at 180 KeV into p-type silicon to form a buried TiSi2 layer. DLTS measurements of n+p junctions have shown two minority carrier traps at Ec − Et = 0.24 and 0.51 eV. Also, a single majority trap at Ev + Et = 0.41 eV was observed. The concentrations of these levels were calculated to be approximately 1013 cm−3. DLTS measurements of low-fluence 50 KeV Ti implantations using Schottky diodes showed four levels dependent on silcon type.
Attempts to Induce Chromosomal Breakage in Chicken Embryos with Aroclor 1242

Fertile White Leghorn eggs were injected with Aroclor 1242 and incubated for four to five days. More than 65 percent of the exposed embryos died prior to examination at the end of the incubation period. The five largest pairs of chromosomes from allantoic squashes were examined for the presence of chromosomal breakage in 753 metaphases from PCB-treated eggs and 196 metaphases from controls. Failure to detect chromosomal aberrations in either group indicated that Aroclor 1242, in concentrations of 10 p.p.m. or 20 p.p.m. in the egg, is not an effective clastogen in the chicken embryo.
Atomistic Simulation and Elastic Theory of Surface Steps

Atomistic computer simulations and anisotropic elastic theory are employed to determine the elastic fields of surface steps and vicinal surfaces. The displacement field of and interaction energies between steps on an {001} Ni surface are determined using atomistic simulations and EAM potentials. The step-step interaction energy found from the simulations is consistent with a surface line force dipole elastic model of a step. We derive an anisotropic form for the elastic field associated with a surface line force dipole using a two dimensional surface Green tensor for a cubic elastic half-space. Both the displacement fields and step-step interaction energy predicted by the theory are shown to be in excellent agreement with the simulations.
Achieving renal denervation: catheter-based and surgical management for neural ablation in the management of hypertension.

Hypertension refractory to conventional management with medication remains a significant cause of cardiovascular morbidity and mortality. Alternative strategies are warranted in this subgroup of pa...
Delirium in the hospitalized elderly.

BACKGROUND As many as one third of elderly hospitalized patients become delirious, and most do not fully recover. Delirium may impart a higher mortality rate and may be a marker for future cognitive decline. OBJECTIVE To review the clinical features, etiology, diagnosis, and management of delirium in elderly hospitalized patients. SUMMARY Delirium can be caused by primary intracranial disease, systemic diseases, withdrawal from alcohol or sedative hypnotic agents, or drug intoxication, the most common cause. Because delirium may present with diverse clinical features, physicians should suspect it in any elderly patient with a change in mental status, personality, or behavior. Bedside screening tools may help distinguish delirium from dementia and psychosis. Causative factors should be sought and removed or treated. Anticholinergic drugs are the worst offenders, but all drugs are suspect and should be discontinued or reduced in dosage. If a sedative is needed, haloperidol is the drug of choice. Because of the prevalence and seriousness of alcohol withdrawal, all delirious patients should receive intravenous thiamine to reduce the risk of Wernicke9s encephalopathy. CONCLUSIONS An organized, systematic approach with early diagnosis and treatment may prove to be life-saving in many patients.
Targeted Topic Modeling for Focused Analysis

One of the overarching tasks of document analysis is to find what topics people talk about. One of the main techniques for this purpose is topic modeling. So far many models have been proposed. However, the existing models typically perform full analysis on the whole data to find all topics. This is certainly useful, but in practice we found that the user almost always also wants to perform more detailed analyses on some specific aspects, which we refer to as targets (or targeted aspects). Current full-analysis models are not suitable for such analyses as their generated topics are often too coarse and may not even be on target. For example, given a set of tweets about e-cigarette, one may want to find out what topics under discussion are specifically related to children. Likewise, given a collection of online reviews about a camera, a consumer or camera manufacturer may be interested in finding out all topics about the camera's screen, the targeted aspect. As we will see in our experiments, current full topic models are ineffective for such targeted analyses. This paper studies this problem and proposes a novel targeted topic model (TTM) to enable focused analyses on any specific aspect of interest. Our experimental results demonstrate the effectiveness of the TTM.