cssi/SciSciGPT-SciSciNet huggingface dataset:
Building dynamic models and theories to advance the science of symptom management research

brant j.m., beck s. & miaskowski c. (2010) Building dynamic models and theories to advance the science of symptom management research. Journal of Advanced Nursing66(1), 228–240. Abstract Title. Building dynamic models and theories to advance the science of symptommanagement research. Aim. This paper is a description, comparison, and critique of two models and two theories used to guide symptom management research, and a proposal of directions for new theory or model development. Background. Symptom management research has undergone a paradigmatic shift to include symptom clusters, longitudinal studies that examine symptom trajectories, and the effects of interventions on patient outcomes. Models and theories are used to guide descriptive and intervention research. Over the past 15 years, four conceptual models or theories (i.e. Theory of Symptom Management, the Theory of Unpleasant Symptoms, the Symptoms Experience Model and the Symptoms Experience in Time Model) were used in a variety of symptom management studies. Data sources. Literature searches were performed in Medline and the Cumulative Index of Nursing and Allied Health Literature between 1990 and 2008 for models and theories that guide symptom management research. Related papers and book chapters were used as supporting documentation. Discussion. Comparison and critique of the models and theories revealed important gaps including lack of consideration of symptom clusters, failure to incorporate temporal aspects of the symptom experience and failure to incorporate the impact of interventions on patient outcomes. Conclusion. New models and theories should incorporate current trends in symptom management research, capture the dynamic nature of symptoms and incorporate concepts that will facilitate transdisciplinary research in symptom management. Researchers and clinicians need to build more expansive and dynamic symptom management models and theories that parallel advances in symptom research and practice.
Delayed Hypersensitivity to Simple Protein Antigens

Publisher Summary This chapter discusses the relation of delayed hypersensitivity to simple protein antigens and defines delayed reaction as an immunologically specific inflammatory reaction, which takes some hours to reach a maximum, occurring in the absence of demonstrable antibody of the conventional type. It discusses the relationships of contact sensitivity and delayed sensitivity to antibody production and describes several methods of producing pure delayed hypersensitivity to simple proteins in guinea pigs. Further, it describes the characteristics of the state of delayed hypersensitivity, including histology and physiopathology, passive transfer, effects of irradiation, systemic reaction, desensitization, Hodgkin's disease, and status of the homograft reaction. It reveals that delayed hypersensitivity is a stage in the production of antibodies. It is shown that delayed hypersensitivity reactions are observed in the course of immunization with protein antigens in animal species that are best capable of exhibiting this type of immune reactivity, guinea pig, and man.
Classification of gene expression data using fuzzy logic

Microarray technologies have allowed the measurement of expression of multiple genes simultaneously. Gene expression levels can be used to classify tissues into diagnostic or prognostic categories. As measurements from different microarray technologies are made in different scales (which are not guaranteed to be linear and not easily re-scalable), it is helpful to develop an easy-to-interpret technology-independent classification scheme. To capture the essentials of the problem of classification using gene expression data, we show how fuzzy logic can be applied using two examples. Using information from genes previously shown to be important, the classification performance of the fuzzy inference is similar to that of other classifiers, but simpler and easier to interpret. The fuzzy inference system has the theoretical advantage that it does not need to be retrained when using measurements obtained from a different type of microarray. Although the data sets for gene expression analysis utilized in this paper are relatively small, they are among the largest available in this domain.
Introduction of functional artificial introns into the naturally intronless ura4 gene of Schizosaccharomyces pombe.

Insertion of a 36-base-pair (bp) synthetic oligonucleotide comprising the sequence 5'-GTAGGT(19N)CTAAT (4N)AG-3' into several different positions within the coding region of the naturally intronless ura4 gene of Schizosaccharomyces pombe leads to an efficiently spliced gene producing a functional product. This suggests that the proper signals within an intron are sufficient to initiate and complete a splicing event independent of the location of the intron in the gene. Point mutations in the 5' junction (5'-GTAGGT-3') and in the putative branch sequence (5'-CTAAT-3') affect splicing efficiency significantly. A G-to-A transition at the first nucleotide at the 5' splice junction (5'-ATAGGT-3') abolishes the use of the authentic splice junction and leads to the increased use of an alternative splice site. No functional product is produced from this transcript. An A-to-G transition of the second A in the putative branch sequence (5'-CTAGT-3') lowers the splicing efficiency drastically, but still results in a functional gene product. Furthermore, extension of the 36-bp intron to introns more than 180 bp in size abolishes splicing, suggesting that the splicing apparatus might be restricted to very short introns. We discuss the possibility that S. pombe introns represent a simple type of eucaryotic intron.
Multifluid MHD study of the solar wind interaction with Mars' upper atmosphere during the 2015 March 8th ICME event

We study the solar wind interaction with the Martian upper atmosphere during the 8 March 2015 interplanetary coronal mass ejection (ICME) by using a global multifluid MHD model. Comparison of the simulation results with observations from Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft shows good agreement. The total ion escape rate is increased by an order of magnitude, from 2.05 × 1024 s−1 (pre-ICME phase) to 2.25 × 1025 s−1 (ICME sheath phase), during this time period. Two major ion escape channels are illustrated: accelerated pickup ion loss through the dayside plume and ionospheric ion loss through the nightside plasma wake region. Interestingly, the tailward ion loss is significantly increased at the ejecta phase. Both bow shock and magnetic pileup boundary (BS and MPB) locations are decreased from (1.2RM, 1.57RM) at the pre-ICME phase to (1.16RM, 1.47RM), respectively, during the sheath phase along the dayside Mars-Sun line. Furthermore, both simulation and observational results indicate that there is no significant variation in the Martian ionosphere (at altitudes ≲ 200 km, i.e., the photochemical region) during this event.
Low-Dimensional Conduction Mechanisms in Highly Conductive and Transparent Conjugated Polymers.

Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract DAAD-19-02D-0002)
Outsourcing Corporate Governance: Conflicts of Interest and Competition in the Proxy Advisory Industry

Proxy advisors, private firms that help institutional investors decide how to vote their shares, play an extremely powerful role in shaping corporate governance. However, investors and policymakers are concerned about undesirable features of the industry, especially potential conflicts of interest. In this paper, I model how conflicts of interest may arise when a proxy advisor provides services to both investors and corporate issuers on the same governance issues. I then study how increased competition can alleviate these conflicts. Using a unique data set on voting recommendations, I show that the entry of a new advisory firm reduces favorable recommendations for management proposals by the incumbent advisor, which is consistent with our theory as the incumbent is subject to conflicts of interest by serving both investors and corporations. These results shed light on the policy debate on whether and how to regulate the proxy advisory industry.
Arabinose 5-phosphate covalently inhibits transaldolase

Arabinose 5-phosphate (A5P) is the aldopentose version of the ketohexose fructose 6-phosphate (F6P), having identical stereochemistry but lacking atoms corresponding to the 1-carbon and 1-hydroxyl. Despite structural similarity and conservation of the reactive portion of F6P, F6P acts as a substrate whereas A5P is reported to be an inhibitor of transaldolase. To address the lack of A5P reactivity we determined a crystal structure of the Francisella tularensis transaldolase in complex with A5P. This structure reveals that like F6P, A5P forms a covalent Schiff base with active site Lys135. Unlike F6P, A5P binding fails to displace an ordered active site water molecule. Retaining this water necessitates conformational changes at the A5P-protein linkage that possibly hinder reactivity. The findings presented here show the basis of A5P inhibition and suggest an unusual mechanism of competitive, reversible-covalent transaldolase regulation.
Modelling and simulation of fluid structure interaction by meshfree and FEM

In this paper, the implementation of a 3-D parallel CFD code using the meshless method. Reproducing Kernel Particle Method (RKPM) is described. A novel procedure for implementing the essential boundary condition using the hierarchical enrichment method is presented. The Total Arbitrary Lagrangian Eulerian (ALE) formulations using Finite Element Method are developed and implemented in the parallel code. The flow past a cylinder problem served as examples throughout the paper. Both methods have shown promising results compared with analytical solution. Copyright © 2003 John Wiley & Sons, Ltd.
Spatial and Temporal Variability of Ambient Air Toxics Data

This paper summarizes information on the spatial and temporal variability of selected air toxics pollutants collected on a national basis primarily for a period encompassing 1990-2003. Spatial information on pollutant concentrations is characterized in terms of within-city and between-city variability. Temporal information is summarized as diurnal and seasonal variability and in multiyear trends. The information on variability is presented in the framework of a larger need for systematic documentation of information on air toxics pollutants to assess progress in air pollution control programs.
The Critical Role of the Conserved Thr247 Residue in the Functioning of the Osmosensor EnvZ, a Histidine Kinase/Phosphatase, in Escherichia coli

The histidine kinase/phosphatase EnvZ helpsEscherichia coli adapt to osmotic shock by controlling the phosphorylation state of the transcription factor OmpR, which regulates the levels of the outer membrane porin proteins OmpF and OmpC. We examined the effects of mutating the highly conserved Thr247 residue in EnvZ. Using purified C-terminal domains of wild-type and mutant EnvZ proteins, we demonstrate that Thr247 plays a vital role in EnvZ function, variously affecting its autokinase and phosphotransferase activities, but mostly its function as a phosphatase. The cytoplasmic domain of EnvZ (EnvZc) is composed of three segments: the linker domain (residues 180–222), domain A (residues 223–289), and domain B (residues 290–450). It has been shown that the isolated domain A itself can dephosphorylate phosphorylated OmpR. Here we show that mutating Thr247 to Arg in domain A abolishes its phosphatase activity. Furthermore, using an in vivo β-galactosidase activity assay of Taz1-1 (hybrid of the aspartate receptor Tar and EnvZ) constructs of the Thr247 mutants in RU1012 cells expressingompC-lacZ, we demonstrate that the external signal primarily down-regulates the phosphatase activity of EnvZ. Of the nine EnvZc(T247X) mutants (X = Ser, Ala, Cys, Lys, Asn, Glu, Gln, Tyr, or Arg) analyzed, only Ser functionally substituted for Thr at this position, whereas all the others displayed constitutive expression of β-galactosidase.
Sleep restriction decreases the physical activity of adults at risk for type 2 diabetes.

STUDY OBJECTIVE To test the hypothesis that recurrent sleep curtailment will result in decreased physical activity in adults at risk for type 2 diabetes. DESIGN Two-condition 2-period randomized crossover study. SETTING University General Clinical Research Center. PARTICIPANTS Eighteen healthy patients with parental history of type 2 diabetes (9 females and 9 males, age 27 yr [standard deviation 3], body mass index 23.7 [2.3] kg/m²). INTERVENTIONS Two week-long inpatient sessions with 8.5 or 5.5-hr nighttime sleep opportunity. Participants who exercised regularly (39%) could follow their usual exercise routines during both sessions. MEASUREMENTS AND RESULTS Sleep and total body movement were measured by wrist actigraphy and waist accelerometry. Subjective mood and vigor was assessed using visual analog scales. The main outcome was the comparison of total activity counts between sleep conditions. Ancillary endpoints included changes in sedentary, light, and moderate plus vigorous activity, and their association with changes in mood and vigor. Daily sleep was reduced by 2.3 hr (P < 0.001) and total activity counts were 31% lower (P = 0.020) during the 5.5-hr time-in-bed condition. This was accompanied by a 24% reduction in moderate-plus-vigorous activity time (P = 0.005) and more sedentary behavior (+21 min/day; P = 0.020). The decrease in daily activity during the 5.5-hr time-in-bed condition was seen mostly in participants who exercised regularly (-39 versus -4% in exercisers versus nonexercisers; P = 0.027). Sleep loss-related declines in physical activity correlated strongly with declines in subjective vigor (R = 0.90; P < 0.001). CONCLUSIONS Experimental sleep restriction results in decreased amount and intensity of physical activity in adults at risk for type 2 diabetes.
HIV-1 Promotes Renal Tubular Epithelial Cell Protein Synthesis: Role of mTOR Pathway

Tubular cell HIV-infection has been reported to manifest in the form of cellular hypertrophy and apoptosis. In the present study, we evaluated the role of mammalian target of rapamycin (mTOR) pathway in the HIV induction of tubular cell protein synthesis. Mouse proximal tubular epithelial cells (MPTECs) were transduced with either gag/pol-deleted NL4-3 (HIV/MPTEC) or empty vector (Vector/MPTEC). HIV/MPTEC showed enhanced DNA synthesis when compared with Vector/MPTECs by BRDU labeling studies. HIV/MPTECs also showed enhanced production of β-laminin and fibronection in addition to increased protein content per cell. In in vivo studies, renal cortical sections from HIV transgenic mice and HIVAN patients showed enhanced tubular cell phosphorylation of mTOR. Analysis of mTOR revealed increased expression of phospho (p)-mTOR in HIV/MPTECs when compared to vector/MPTECs. Further downstream analysis of mTOR pathway revealed enhanced phosphorylation of p70S6 kinase and associated diminished phosphorylation of eEF2 (eukaryotic translation elongation factor 2) in HIV/MPTECs; moreover, HIV/MPTECs displayed enhanced phosphorylation of eIF4B (eukaryotic translation initiation factor 4B) and 4EBP-1 (eukaryotic 4E binding protein). To confirm our hypothesis, we evaluated the effect of rapamycin on HIV-induced tubular cell downstream signaling. Rapamycin not only attenuated phosphorylation of p70S6 kinase and associated down stream signaling in HIV/MPTECs but also inhibited HIV-1 induced tubular cell protein synthesis. These findings suggest that mTOR pathway is activated in HIV-induced enhanced tubular cell protein synthesis and contributes to tubular cell hypertrophy.
SELF-ACTUALIZATION AND RETROSPECTIVE REPORTS OF PARENT-CHILD RELATIONSHIPS AMONG COLLEGE FEMALES

Summary.-The relationship between self-acrualization and retrospective perceptions of parental child-rearing attitudes and behaviors was investigated. 20 high and 20 low self-acrualizing college-aged females, pre-selected on the basis of their scores on Shostrom's Personal Orientation Inventory, were compared on Schaefer's Children's Reports of Parental Behavior Inventory. As predicted, high self-actualizing subjects scored significantly higher than low selfactualizing subjects on the majoriry of the paternal and maternal scales on the inventory, reflecting perceived parenml attitudes of acceptance, psychological autonomy, and lax control. Likewise, as predicted, high self-actualizing subjects scored significantly lower than low self-actualizing subjects on the majority of the paternal and maternal sales of the inventory, reflecting perceived parental attitudes of rejection, psychological control, and firm control. Interest in Maslow's ( 1962, 1970) theoretical conception of self-acrualization or optimal personality functioning has increased rapidly within recent years. A major factor in this upsurge of interest is the encounter-group movement and its humanistically based emphasis on the realization of inherent human potentialities. The development of the Personal Orientation Inventory as a reasonably valid and reliable measure of self-actualization (Shostrorn, 1966) has also spawned numerous studies relevant to Maslow's metapsychological model of the self-actualizing being (Hekmat & Theiss, 197 1; Wexler, 1974). This self-report inventory was designed to provide a comprehensive measure of values and behavior construed to be of importance in the development of self-actualization. Consisting of 150 two-choice (paired opposites) comparative value judgments, ic is scored in terms of rwo major scales, Time Competence and Inner-directed, and 10 secondary subscales. Virtually all of the reported usages of the inventory to date have employed it as a diagnostic indicator of positive personality change in adults undergoing personal growth-group experiences (e.g., Guinan & Foulds, 1970; Treppa & Fricke, 1972; Young & Jacobson, 1970). The purpose of the present study is to explore the relationship between various dimensions of parental behavior, i.e., child-rearing attitudes and practices, and level of self-actualization among young adult females. Specifically, we sought to examine whether high and low self-actualizing individuals as assessed by Shostrom's inventory can be differentiated with respect to their retrospective perceptions of parent-child relationships. If such differential perceptions do
Iodine 131 (131I) as adjuvant therapy of differentiated thyroid cancer

The importance of the optimization of the up front management of DTC cannot be underestimated. An aggressive approach is advocated, except in situations widely accepted to be low risk (i.e., female patients <40 y, with tumors <1.0 cm confined to the gland). Distant tumor greatly reduces the chances for survival in all patients. The loss of iodine-concentrating ability removes systemic radioiodine from the therapeutic equation and thereby virtually eliminates chances for cure. The role of chemotherapy in non iodine responsive DTC is still in question, and a benefit in advanced disease has not been established. For non iodine-concentrating tumor that cannot be approached surgically, external beam therapy remains an option, both within the neck and for dominant foci of distant metastatic tumor (i.e., brain and bone). Any distant lesion demonstrating the capacity for radioiodine uptake also should be addressed with (131)1, because this will potentially treat tumor not evident on diagnostic survey. In conclusion, (131)1 has demonstrated efficacy for the postsurgical management of DTC. Although its acute and long-term side-effect profile is not especially worrisome relative to other forms of systemic cancer therapy, the administration of (131)1 is not entirely without risk. Taking into account many of the issues described in this article, the administration of (131)I should in every case be optimized. It also should be applied carefully and judiciously to patients expected to derive benefit.
Steroidogenic enzyme P450c17 is expressed in the embryonic central nervous system

Neurosteroids are steroids that are synthesized de novo in the brain and include some classical (adrenal and gonadal steroids) and some unique brain-specific steroids. Neurosteroids are thought to mediate their action through ion gated channel receptors such as gamma-aminobutyric acid(A) and N-methyl-D-aspartate rather than through classical nuclear steroid hormone receptors. Some enzymes involved in neurosteroidogenesis have been identified as those found in steroidogenic tissues, and some may be unique to the brain. We previously demonstrated that the messenger RNAs (mRNA) for the cholesterol side-chain cleavage enzyme, cytochrome P450scc, and one form of 11 beta-hydroxylase, cytochrome P450c11 beta, are regionally expressed in the adult rat brain. However, cytochrome P450c17, which has 17-hydroxylase and 17,20-lyase activity and is thought to be required for the synthesis of dehydroepiandrosterone, was not detected in any region of the rat brain, even though dehydroepiandrosterone is one of the most abundant neuroactive steroids. We now demonstrate that P450c17 is expressed in the nervous system of the developing rodent embryo. By ribonuclease protection assays, P450c17 mRNA was found in the trunk but not in the head of rat embryos but reverse transcriptase-polymerase chain reaction analysis showed expression of P450c17 mRNA in the head of E15.5 to E19.5 rat embryos. Immunocytochemically detectable P450c17 protein was expressed in the nervous system as early as embryonic day E10.5 in the mouse, mainly in tissue derived from the neural crest. Neuronal cell bodies as well as fibers staining for P450c17 were observed in the central and peripheral nervous systems. The sites of P450c17 expression in the peripheral nervous system suggest it may be involved in a wide variety of sensory-motor functions. In the central nervous system, cell bodies expressing P450c17 are found in the hind brain, in mesencephalic nuclei, and in a region in the location of the locus coeruleus, but in cells distinct from those expressing the dopamine-beta-hydroxylase. Furthermore, its particular location and temporal expression in axons reaching the cortical areas suggest it is a marker for the axonal growth in this region, and that its neurosteroid product may be a signal for targeting cortical axons during embryogenesis.
Issues of online research repositories from the perspective of the biomedical sciences

This commentary on Joseph Y. Halperns proposal for a computing research repository discusses difference in traditions and practices of online publishing and repositories between computing and biomedicals ciences. Issues of accessibility and archiving are also discussed.
Optical connectionist machine with polarization-based bipolar weight values

Associative memory and pattern recognition systems have many similarities. Autoassociative memories can be viewed as image restoration, and heteroassociative memories as classification or feature extraction systems. Connectionist, or neural network, architectures are well suited to perform associative memory operations. The predominant calculation in these systems is vector-matrix multiplication. While requiring 0(N2) operations on a serial machine, a simple optical architecture can perform this calculation in nearly constant time. We have demonstrated an optoelectronic connectionist module with modifiable inputs and weight matrices that performs associative memory operations. The weight matrix can be generated with or without the optical hardware, providing a testbed for simulations of physically implemented connectionist systems. Low cost commercial liquid crystal television sets are used to encode unit activities as intensity of linearly polarized light and signed multiplication as rotation of this light. Integrated computer control allows the extension to many connectionist models.
The nutcracker syndrome: an underrecognized cause of hematuria

Nutcracker syndrome (NCS) is an uncommon cause of hematuria. It refers to the compression of the left renal vein between the aorta and superior mesenteric artery. It can cause both microscopic and gross hematuria. Hematuria may be associated with left flank pain. The diagnosis of NCS is often delayed. Most patients may have symptoms for many years and non-diagnostic evaluations before accurate diagnosis can be established. It should be included in the differential diagnosis of unexplained hematuria. The diagnosis and treatment of nutcracker syndrome are discussed. Conclusion: NCS is a rare but treatable clinical condition. An inclusion of this entity in the differential diagnosis of patients with unknown cause of hematuria and flank pain can achieve efficient management of this condition.
The effects of correlated arrivals at a server with credit‐based traffic policing

In this paper we observe the steady state and transient behaviour of correlated cell arrivals into a server with credit-based traffic policing. We derive expressions for the lag-k correlations of the departure process from the traffic policing mechanism, and observe how dependencies in the departure stream affect cell loss at the server. The results illustrate the impact of the second-order statistics and the higher moments of the cell arrival processes on the traffic policing mechanism performance. Copyright © 2001 John Wiley & Sons, Ltd.
Anatomic relationships of the tension-free vaginal mesh trocars

Objective The objective of the study was to describe the distances between the major anatomic structures to the path of the tension-free vaginal mesh (TVM) trocars. Study Design Four anterior transobturator and 2 posterior ischiorectal TVM trocars were inserted bilaterally into 8 fresh frozen cadavers. Dissections were performed and mean distances (95% confidence interval) were measured between the closest points along the trocar's path and significant anatomic structures. Results The mean distances between both anterior transobturator trocars and the medial branch of the obturator vessels were 0.8 cm (range, 0.6 to 1.0) and 0.7 cm (range, 0.4 to 1.1), and bladder were 0.7 cm (range, 0.5 to 0.9) and 1.3 cm (range, 0.8 to 1.9), respectively. The mean distances between the posterior trocar and the rectum and inferior rectal vessels were 0.8 cm (range, 0.6 to 1.0) and 0.9 cm (range, 0.7 to 1.1), respectively. Conclusion The bladder and medial branch of the obturator vessel may be at risk of injury during the passage of the anterior trocars, whereas the rectum and inferior rectal vessels may be at risk during the passage of the posterior trocar.
Effect of Differing Blood Lines on Delivered Blood Flow During Hemodialysis

Background The influence of differing blood tubing sets on delivered dialyzer blood flow (QB) was studied using ReadySet (RS; Medisystem Inc, Seattle, WA) and CombiSet (CS; Fresenius, Walnut Creek, CA). Methods In vitro, we measured QB and pre-pump arterial pressures (PA; in millimeters of mercury) during 4 hours at a prescribed blood pump flow (QP) of 450 mL/min, using a glycerin-water mixture for RS and CS blood tubing sets (n = 10 each). We then performed 3 clinical studies to determine the difference between QP and QB as a function of PA for both tubing types and any effects of tubing type on delivered Kt/V in patients. Results In vitro, 4-hour time-averaged QB was 451 mL/min with RS versus 422 mL/min with CS. QB was approximately 40 mL/min greater using RS than CS blood tubing sets at QP of approximately 445 mL/min with [QP − QB] increasing linearly with PA for CS, but not RS (study 1). At a mean QP of approximately 408 mL/min, CS blood tubing significantly increased Kt/V by approximately 0.1 (90 patients; study 2). In study 3, [QP − QB] increased with treatment time with CS (8 to 29 mL/min), but not RS (from −4 to 6 mL/min). For patients achieving equal QP of 400 mL/min or greater for all treatments (n = 11), paired analysis showed greater values for urea reduction ratio (+3.5%; P = 0.039) and Kt/V (+0.14; P = 0.04) with RS than CS tubing sets. Conclusion Differences in [QP − QB] occur both in vitro and in vivo, are much smaller with RS than CS tubing sets, and result in a greater delivered Kt/V of up to 0.14 for RS.
Denoising and dimensionality reduction of genomic data

Genomics represents a challenging research field for many quantitative scientists, and recently a vast variety of statistical techniques and machine learning algorithms have been proposed and inspired by cross-disciplinary work with computational and systems biologists. In genomic applications, the researcher deals with noisy and complex high-dimensional feature spaces; a wealth of genes whose expression levels are experimentally measured, can often be observed for just a few time points, thus limiting the available samples. This unbalanced combination suggests that it might be hard for standard statistical inference techniques to come up with good general solutions, likewise for machine learning algorithms to avoid heavy computational work. Thus, one naturally turns to two major aspects of the problem: sparsity and intrinsic dimensionality. These two aspects are studied in this paper, where for both denoising and dimensionality reduction, a very efficient technique, i.e., Independent Component Analysis, is used. The numerical results are very promising, and lead to a very good quality of gene feature selection, due to the signal separation power enabled by the decomposition technique. We investigate how the use of replicates can improve these results, and deal with noise through a stabilization strategy which combines the estimated components and extracts the most informative biological information from them. Exploiting the inherent level of sparsity is a key issue in genetic regulatory networks, where the connectivity matrix needs to account for the real links among genes and discard many redundancies. Most experimental evidence suggests that real gene-gene connections represent indeed a subset of what is usually mapped onto either a huge gene vector or a typically dense and highly structured network. Inferring gene network connectivity from the expression levels represents a challenging inverse problem that is at present stimulating key research in biomedical engineering and system biology. Several attempts have been made to describe gene networks with only limited interactions, thus exploiting the inherent sparsity of these systems. This in turn suggests that a certain redundancy of links in gene networks, or equivalently the inherent sparsity structure of these systems, might let the essential connections be identified and the inverse problem be given both satisfactory definition and computationally efficient tractability.
An electronic stopping power model for Monte Carlo and molecular dynamics simulation of ion implantation into silicon

We develop a phenomenological model of electronic stopping power for modeling the physics of ion implantation into crystalline silicon. In the framework of effective charge theory, this electronic stopping power for an ion is factorized into (i) a globally averaged effective charge taking into account effects of close and distant collisions by target electrons with the ion, and (ii) a local charge density dependent electronic stopping power for a proton. This model is implemented into both molecular dynamics and Monte Carlo simulations. There is only one free parameter in the model, namely, the one electron radius r/sub s//sup 0/ for unbound electrons. By fine tuning this parameter, it is shown that the model can work successfully for both boron and arsenic implants. We report that the results of the dopant profile simulation for both species are in excellent agreement with the experimental profiles measured by secondary-ion mass spectroscopy (SIMS) over a wide range of energies and with different incident directions. This model also provides a good physically-based damping mechanism for molecular dynamics simulations in the electronic stopping power regime, as evidenced by the striking agreement of dopant profiles calculated in the molecular dynamics simulations with the SIMS data.
A nonhuman primate model of age-related bone loss: a longitudinal study in male and premenopausal female rhesus monkeys

Aging is associated with gradual bone loss in men and premenopausal women, with an accelerated rate of loss after menopause in women. Although many studies have investigated bone loss due to surgically induced estrogen depletion, little is known regarding normal age-related changes in bone mass in animal models. We used dual-energy X-ray absorptiometry (DXA) to measure bone mineral density (BMD), bone mineral content (BMC), and projected area (PA) at four skeletal sites over 4 years in 20 premenopausal female (8-23 years) and 29 male (8-27 years) rhesus monkeys (Macaca mulatta). Forearm BMD declined with age in both male and female monkeys. Lean mass was positively associated with BMD at all sites in males and with the distal radius in females. Serum osteocalcin declined and urinary cross-links increased with age in males but not females. Serum 25-hydroxyvitamin D concentrations decreased with age in females, and a similar trend was observed in males. In conclusion, an age-related decline in forearm BMD was observed in male and female rhesus monkeys. Total body BMC declined over time in older females, with a similar trend in males. Changes in markers of bone turnover with age were also observed in male monkeys. The results of this longitudinal study suggest that the rhesus monkey is a potential model for age-related changes in the human skeleton.
Wild double tangent ball embeddings of spheres in En

Abstract It has been known for years that a 2-sphere Σ in E 3 must be flatly embedded if it has double tangent balls on opposite sides of Σ at each of its points. However, when the double tangent balls are not required to be on opposite sides of Σ , pathological embeddings exist. This paper details the allowable wild embeddings of spheres having these indiscrete double tangent balls and discusses the higher dimensional analogues.
Age estimations based on amino acid racemization: Reply to comments of J.F. Wehmiller

Abstract Determining geologic ages of fossils by amino acid racemization techniques is often difficult because of the uncertainties in assumptions about diagenetic temperatures. Two kinetic model methods have been employed. Method 1, used by us, assumes that racemization of amino acids in the bivalve mollusk Saxidomus giganteus from Willapa Bay, Washington, follows linear kinetics. Ages are calculated by means of first-order kinetic equations. Method 2, used by Wehmiller, involves an empirical non-linear kinetic model Method 1 is simpler in concept and more easily applied. Wehmiller claims that ambiguities in paleotemperature arise when method 1 is used and that these ambiguities can be reconciled by the use of method 2. We show that application of method 1 can also provide reasonable temperature histories and leads to age estimates that are consistent with the geologic history of the sedimentary deposits at Willapa Bay.
Excitation and Stability of Ultrahigh Rydberg States in Stray Electric Fields

We demonstrate the feasibility of exciting long-lived, circular Rydberg states by time dependent weak electric fields such as might be encountered in typical ZEKE-PES (zero-electron-kinetic-energy photoelectron spectroscopy) conditions. Through a geometric interpretation of the dynamics, we identify the field configurations needed for either the stability or the excitation of ultra-long-living Rydberg states and conclude that nonuniform stray fields could be (partially) responsible for the observed, anomalously long lifetimes exhibited by ultrahigh Rydberg states, although under typical ZEKE-PES conditions other mechanisms like, for example, ion-Rydberg collisions constitute the main stabilization agent.
Evaluating the cost-effectiveness of treatment with third-generation cephalosporins

Abstract Spreadsheet computer software was used to compare the estimated global treatment costs of the third-generation cephalosporins, cefotaxime and ceftriaxone, in the management of pneumonia using treatment schedules taken from current studies (see Table 8). Included in the analysis were not only acquisition costs, but also costs that contribute to total expenses for a course of treatment, such as those of (a) preparation and administration (disposable supplies, nursing, and pharmacy time), (b) projected laboratory costs to monitor for hypoprothrombinemia, and (c) complication costs (diarrhea, superinfection, pseudocholelithiasis, and so on). The cost analysis was performed using United States trial-derived factors. Where published cost factors were not available, reasonable estimates were sought. Our analysis indicates that cefotaxime therapy may be less costly than ceftriaxone therapy in the dosage schedules used in these clinical studies and routine clinical practice.
Rethinking localism in the broadband era: A participatory community development approach

Abstract This research presents findings from a case study of how three municipal access channels were transformed into channelAustin, a digital community access center in Austin, TX. More generally, it addresses the question of how states and municipal governments can employ video franchise resources to promote sustainable adoption and use of broadband services. Drawing on participatory approaches to community development, this paper offers a model of community participation in local information ecosystems to guide planning and evaluation of these interventions. Findings indicate that digital community media projects like channelAustin can help municipalities serve information needs of ethnically diverse local publics, while also promoting advanced digital skills, economic opportunities, civic engagement, and social cohesion. However, the article recommends that more attention be placed on community outreach, partnerships with nonprofits and other local public media, local curation of citizen-produced, digital content, and the consolidation of accessible online distribution channels through which residents can connect and deliberate about local issues. I discuss the implication of these findings for efforts to connect broadband and media localism policies in the U.S.
The impact of data errors on measurement of the foreign exchange risk premium

Abstract In most situations measurement error produces bias which it less likely that the null hypothesis will be rejected. In the case of regression equations designed to estimate the premiums impounded in forward exchange rates, the reverse is true. Because the forward rate appears on both sides of the equation, measurement error makes it more likely that a risk premium will be found. However, the empirical results reported here indicate that there is still evidence of a risk premium even after taking account of measurement error.
New Crystalline Polymers of Ag(TCNQ) and Ag(TCNQF4): Structures and Magnetic Properties

Abstract Reaction of Ag(BF4) with [n-Bu4N][TCNQ] in CH3CN yields a new phase of Ag(TCNQ) referred to as phase I (1). A second polymorph of Ag(TCNQ), denoted phase II (2), which had earlier been prepared by electrocrystallization methods, can be accessed directly from silver powder and neutral TCNQ. The products were characterized by a combination of spectroscopic and physical methods. A powder X-ray diffraction pattern of (1) was indexed as a tetragonal cell with a=b=12.1422 A, c=17.0498 A, and V=2513.70 A3. Compound (2) crystallizes in the orthorhombic system with a=7.2892 A, b=16.5790 A, c=17.4448 A, and V=2108 A3, which correlates well with the lattice parameters a=6.975 A, b=16.686 A, c=17.455 A, and V=2031.5 A3 reported for Ag(TCNQ) phase II. Ag(TCNQF4) (5), prepared by electrochemical reduction of TCNQF4 at an Ag electrode, crystallizes in the monoclinic space group C2/c, a=13.429(3) A, b=6.9331(14) A, c=25.735(5) A, β=116.66(3)°. Ag(TCNQF4) consists of coordinated TCNQF4 radicals arranged in a parallel stacking arrangement along the b axis. The nearly “eclipsed” type stacking of the TCNQF4 radicals leads to a short intradimer distance of 3.119(2) A and an interdimer separation of 3.330(2) A. Single crystal X-ray data for the salts [Bu4N][TCNQ] (3) and [n-Bu4N][TCNQF4] (4a) and (4b) are also included for comparison to the Ag(I) materials. [n-Bu4N][TCNQ] (3) crystallizes in the monoclinic space group P21/n with a=9.3028(7) A, b=19.3520(14) A, c=15.3880(11) A, β=100.979 (2)°, V=2719.6(3) A3. [n-Bu4N] [TCNQF4] crystallizes in two forms; in a monoclinic space group P21/n (4a), a=7.4244(15) A, b=20.212(4) A, c=19.758(4) A, β=97.32(3)°, V=2940.8(10) A3, and in the triclinic space group P 1 (4b), a=9.6335(3)A, b=14.9574(3) A, c=21.3615(5) A, α=107.440(1)°, β=93.437(2)°, γ=104.785(2)° and V=2808.07(12) A3. Ring–edge “slipped” stacking arrangements are present in both (4a) and (4b), in which a strongly paired set of TCNQF4 anions interacts with another set. The shortest distance within a dimer pair TCNQF4 in (4a) is 3.09 A. In contrast, there are two independent types of TCNQF4 interactions in (4b), one that involves strongly interacting anions and one that comprises only weakly dimerized anions. The presence of the latter type in (4b) leads to magnetic properties indicative of thermal population of the triplet excited state at higher temperatures.
Phylogenetic trees support the coevolution of parasites and their hosts

The close correspondence often observed between the taxonomy of parasites and their hosts has led to Fahrenholz's rule, which postulates that parasites and their hosts speciate in synchrony. This leads to the prediction that phylogenetic trees of parasites and their hosts should be topologically identical. We report here a test of this prediction which involves the construction of phylogenetic trees for rodents and their ectoparasites using protein electrophoretic data. We find a high degree of concordance in the branching patterns of the trees which suggests that there is a history of cospeciation in this host-parasite assemblage. In several cases where the branching patterns were identical in the host and parasite phylogenies, the branch lengths were also very similar which, given the assumptions of molecular clock theory, strongly suggests that the speciation of these hosts and ectoparasites was roughly contemporaneous and causally related.
The trigeminal depressor response: A novel vasodepressor response originating from the trigeminal system

Electrical stimulation within discrete sites of the spinal trigeminal complex in anesthetized or decerebrated rabbits results in arterial hypotension, often over 50 mm Hg, bradycardia of up to 60 beats/min, apnea, and gastric hypermotility, collectively termed the trigeminal depressor response (TDR). The threshold for the TDR is less than or equal to 10 muA and is graded up to 3-6 times threshold. It can only be elicited by trains of stimuli of low frequency (0.5-20 Hz); at 50 Hz the response disappears or becomes pressor. The bradycardia is only abolished by bilateral vagotomy combined with beta-adrenergic blockade, and thus results from combined excitation of cardio-vagal and inhibition of cardiac sympathetic nerves. The hypotension is unassociated with changes in cardiac output, does not change after blockade of the bradycardia, but disappears after alpha-adrenergic blockade and hence is entirely attributable to inhibition of ongoing sympathetic vasoconstrictor nerve activity. Below threshold stimulation the TDR can only be elicited from the root entry zone of the Vth nerve, from dorsal portions of the spinal tract of the Vth nerve, and to portions of the nucleus of the spinal tract, notably the nucleus caudalis. A TDR of reduced magnitude can also be elicited by low frequency stimulation of numerous branches of the Vth nerve arising from all three divisions and including the supra- and infra-orbital, the inferior alveolar, and lingual nerves. Bilateral electrolytic lesions of the nucleus tractus solitarii at the obex, with complete abolition of baroreceptor reflexes from carotid sinus and aortic depressor nerves, fail to alter the TDR elicited from the brain or from branches of the Vth nerve, or the vasodepressor responses elicited by electrical stimulation of the central ends of the IXth and Xth cranial nerves transescted distal to the branches of baro-receptor nerves. In contrast, caudal lesions of the trigeminal complex abolish the TDR elicited from brain and Vth nerve and substantially reduces the vasodepressor responses from the IXth and Xth nerves, without altering baroreceptor reflexes. We conclude that the TDR represents a heretofore recognized vasodepressor response dependent upon the spinal trigeminal complex which is at least in part anatomically distinct from pathways subserving arterial baroreceptor and somatic vasodepressor reflexes. The TDR can be reflexly elicited from widely distributed but yet unidentified receptors innervated by branches of the Vth and of the IXth and Xth cranial nerves other than those innervating arterial baroreceptors. It is of unknown function, but may be related to pain mechanisms.
The use of citalopram in resistant cataplexy

Abstract Background : Cataplexy is a disabling component of the narcolepsy tetrad that is sometimes resistant to standard treatment. Case reports : Three of our patients with narcolepsy, including one who had post-traumatic narcolepsy, suffered from intractable cataplexy with failure of treatment with established drugs due to unacceptable side-effects. Results : We explored the use of citalopram (Celexa), the newest and most specific of the serotonin reuptake inhibitors, and were successful in treating cataplexy without significant side-effects. Stimulant drugs remained necessary for controlling symptoms of excessive drowsiness. Conclusions : Citalopram was effective in relieving the symptoms of resistant cataplexy in out patients.
Fear responses to mock magnetic resonance imaging among college students: toward a prototype experiment

Abstract Two hundred randomly selected student participants (139 females, 61 males) responded initially to questionnaires that quantified variables such as state and trait anxiety, anxiety sensitivity, claustrophobia, and panic/agoraphobia. Later they were informed that a mock magnetic resonance imaging (MRI) procedure was upcoming, and were prompted to provide self-efficacy ratings vis-a-vis completing the procedure. Finally, the participants’ behavioral reactions to a mock MRI procedure were characterized; their heart beats were recorded and ratings of fearfulness were acquired. One purpose of the research was simply to tally numbers of participants who responded fearfully in various ways: 7 failed the procedure behaviorally, 7 others completed the procedure but did so fearfully, 17 others completed the procedure but manifested excessive heart-rate responsivity. A second purpose of the research was to “predict” subjects’ fear-response categorization psychometrically and/or with self-efficacy ratings: psychometric data related to claustrophobia predicted subjects’ fear-response categorization as did self-efficacy ratings. According to these results mock MRI assessment among college students provides a promising context for research on claustrophobia.
Subcellular localization of cryptic prolactin receptors in mammary tumor cells

Primary cultures of carcinogen-induced rat mammary tumors incubated at 37 degrees C with 125I-labeled ovine prolactin (5 ng/ml) accumulate intact prolactin. A steady state is reached at 24--48 h and loss of accumulated prolactin is slow t1/2 24 h). Accumulated prolactin is rapidly released when cryptic prolactin receptors are unmasked by energy depletion, suggesting that accumulated prolactin and cryptic receptors reside in the same cellular compartment. Under normal conditions, the accumulated prolactin is released slowly and is partially degraded. Subcellular fractionation on discontinuous sucrose gradients indicates that cryptic receptors reside in vesicle fractions (p less than or equal to 1.16). After energy depletion, the unmasked receptors are in cell surface membrane fractions (p = 1.18-1.20). Prolactin accumulation within receptor-containing vesicles in mammary tumor cells may account for their increased growth sensitivity (compared with normal mammary cells) to low physiologic levels of prolactin.