cssi/SciSciGPT-SciSciNet huggingface dataset:
Pharmacokinetic Factors Governing the Steady‐State Concentrations of Foreign Chemicals and Their Metabolites

It is well known that various environmental chemicals can either increase or decrease the activities of enzymes that metabolize foreign compounds and their metabolites. In addition, changes in the activities of these enzymes can alter the concentration of the foreign compounds and metabolites in tissues. However, the theoretical basis by which we can quantitatively relate a change in the activity of a given enzyme to a change in the concentrations of these compounds remains in its infancy. In some instances, the change in concentration of a foreign compound or metabolite will be inversely proportional to the change in the enzyme activity. But in other instances, marked changes in enzyme activity may result in only trivial changes in the concentration of the compounds and their metabolites at sites of action. Pharmacokinetics provide a means for testing the validity of our concepts of how the concentrations of foreign compounds and their metabolites depend on enzyme activities, rates of excretion by the kidneys and lung, reversible binding to tissue components, rates of diffusion across cellular membranes, blood flow rates and the sites of administration. The present paper presents mathematical equations that show the effects of the route of administration on the steady-state concentrations of foreign compounds and their metabolites in tissues when the substances are metabolized by the liver and excreted by the kidney. These equations are especially relevant to studies of chemically reactive metabolites.
Flexural plate-wave sensor: chemical vapor sensing and electrostrictive excitation

The authors describe the use of flexural plate waves traveling in thin composite plats of silicon nitride, zinc oxide, and aluminum for gravimetric chemical vapor sensing. Experiments with sorptive films of poly(dimethylsiloxane) and ethyl cellulose exposed to vapors of toluene, 1,1,1,-trichloroethane, and carbon-tetrachloride showed the high sensitivity of the plate sensor. Detection in the parts-per-billion range is achievable. The authors also demonstrate the use of electrostriction to generate flexural plate waves; optical-and capacitive-plate wave detection schemes are also described. Advantages of the electrostrictive structure include ease of fabrication and the possibility of achieving higher mass sensitivities, especially when operating the sensor in liquids. >
Basic differential cascode voltage switch (DCVS) circuits with functional and scan load

This paper describes a basic DCVS (Differential Cascode Voltage Switch) which can be used as a uniform basis for constructing DCVS logic circuits, register latch circuits and circuits which can be conditioned individually to function as either or both DCVS logic and register latch.
A RAPID PROCEDURE FOR THE ISOLATION OF C0T-1 DNA FROM PLANTS

In situ hybridization (ISH) for the detection of single- or low-copy sequences, particularly large DNA fragments cloned into YAC or BAC vectors, generally requires the suppression or "blocking" of ...
Transmission electron microscopy of milkfat globules in the low-density lipid fraction of Swiss cheese whey

A low-density lipid fraction (LDLF) was recovered from Swiss cheese whey (SCW) residual lipids by high-speed centrifugation. The present study was conducted to determine the microstructural properties of the extremely small-sized milkfat globules (MFG) in LDLF by: (i) freeze-fracture transmission electron microscopy (FF-TEM) and (ii) thin-section TEM (TS-TEM). FF-TEM results revealed that MFG in LDLF were ≤1 µm in size and were embedded in what appeared to be a smooth, protein-like matrix. The MFG in FF-TEM specimens exhibited either planarly cleaved fractions with smooth cores or peripherally cleaved fractions with surface laminations. TS-TEM results revealed that the MFG in LDLF were dispersed in an aggregated nonlipid matrix.
An unusual cause of the quadrilateral space impingement syndrome by a bone spike

The quadrilateral space impingement syndrome is a clinical syndrome resulting from compression of the axillary nerve and the posterior circumflex humeral artery, with subsequent focal atrophy of the teres minor, with or without involvement of portions of the deltoid muscle. This entity has many etiologies. We are reporting a case of this syndrome caused by a bone spike from a malunited old scapular fracture following a motor vehicle accident. The bone spike impinged on the axillary nerve as it passes through the quadrilateral space, causing focal atrophy of the teres minor muscle. The abnormality was well demonstrated by MD-CT.
200 PENTOBARBITAL THERAPY (P) DOES NOT IMPROVE NEUROLOGI CAL OUTCOME IN NEAR-DROWNED, FLACCID CHILDREN (C3)

The relative effect of P was evaluated in 51 C3 children who were divided into: A-16 treated with hypothermia (H=86±2°F) and P, achieving serum levels >25 mcg/cc. B-25 treated with H but P completely excluded and, C-10 receiving H but had P serum levels 100 torr, fluid restriction, pancuronium bromide, dexamethasone and Lasix or mannitol). Analysis of variance failed to detect statistically significant differences (SSD) among the 3 groups for age, submersion time, arterial pH, core temperature and mean intracranial pressure (ICP) prior to initiation of P. A had 9 intact survivals (IS), 6 brain damaged (BD) and 1 who expired (E). B had 7IS, 4BD, 14E and C had 3IS, 4BD, 3E. ICP in IS or BD was 10.6±4.7 and 13.1±6 mmHg respectively VS E (27.7±19.5 mmHg) (P <0.001). Chi Square analysis with Yates correction revealed higher mortality for B than A (P <0.01) and higher than A & C (P<0.01). No SSD in BD or IS among survivors for A, B and C. In conclusion: 1) P does not improve neurological outcome in C3. 2) ICP was lower for survivals (IS&BD) but could not predict neurological outcome. 3) The higher survival rate with P was associated with BD rather than IS. 4) P may not be justified in C3. 5) Previous claims implying better neurological outcome with combined H&P should probably be attributed to the effect of H alone.
WORK AND DELINQUENCY AMONG JUVENILES ATTENDING SCHOOL

Abstract Prior studies have found no relationship or a slight positive relationship between work and delinquency among juveniles attending school. Such studies, however, have simply compared employed to unemployed juveniles. This study predicts that certain types of jobs will reduce delinquency and focuses on the relationship between delinquency and five job characteristics: prestige, pay, satisfaction, hours, and length of employment. Data indicate that serious delinquency is positively associated with hours and negatively associated with prestige, while minor delinquency is positively associated with hours and pay, and negatively associated with prestige and length of employment. Juveniles in white-collar jobs of long duration, short hours, and low pay have lower rates of delinquency than juveniles who never worked.
Acute Rejection Accelerates Graft Coronary Disease in Transplanted Rabbit Hearts

Background The relation between episodes of acute rejection and the development of graft coronary arteriosclerosis remains controversial. We examined the hypothesis that acute rejection episodes accelerate graft coronary arteriosclerosis lesion formation in rabbit allografts. Methods and Results A control group (n=5) received cyclosporine 5 mg · kg−1 · d−1 for 6 weeks after heterotopic heart transplantation. In a rejection group (n=5), cyclosporine was omitted for 4 days at 1 and 4 weeks after transplantation. We studied cross sections of grafted hearts at 6 weeks and evaluated myocardial rejection grade, incidence, and severity and cell composition of intimal lesions in multiple coronary artery profiles. Episodic withdrawal of cyclosporine augmented myocardial rejection (International Society for Heart and Lung Transplantation grades 0, 0, 0, 0, and 1A in the control group to grades 1A, 1B, 2, 3A, and 3B in the rejection group). Episodes of acute rejection significantly increased the incidence (7.8±2.7% ...
Transition metal complexes of diazine N-oxides

Abstract Metal complexes of pyrazine 1,4 dioxide, pyridazine N-oxide and 4,6-dimethylpyrimidine N-oxide with 3d transition metal perchlorates were synthesized. Transition metal chloride complexes of 4,6-dimethylpyrimidine N-oxide were also synthesized. The new complexes were characterized by elemental analysis, IR spectra, molar electrolytic conductance measurements, magnetic susceptibility measurements and electronic spectra. Stoichiometries indicated 6-coordinated complexes except for the copper and chloride complexes which were 4-coordinated. Conductivity measurements demonstrated that the perchlorate anions were uncoordinated and the chloride complexes contained coordinated chloride. The complexes were found to be coordinated through the oxygen in all cases. Electronic spectra were used to calculate 10 Dq values for the complexes. The ligand field strengths found were equivalent to those determined for substituted pyridine N-oxide complexes. The pKa values of the N-oxides have been determined by comparing ΔνNO of the liquids and ΔνOH of phenol-ligand complexes to σPyNO values for pyridine N-oxides.
A race and gender-group analysis of the early career experience of MBAs.

This study examined race and gender differences in four career experience variables using a sample of Black and White MBAs (masters of business administration). Results supported hypothesized race ...
Using Self, Using History …

The intersection of "self" and "subject": what a dangerously self-absorbing theme! To be right up-front, I can imagine no way of proceeding with it apart from my own self and my own subjects. Hence the paragraphs to follow will trace a zigzag course of projects undertaken, books written, experiences processed, certainties questioned, doubts denied, intuitions reconsidered, and (I hope) an eventual, if relative, measure of comfort-all framed in highly personal terms. Looking back across forty years of scholarly effort, I see nothing else that looms as large as that framework-or seems more important. But this is one historian's journey only, and a reader's indulgence is needed. It began for me in the 1950s when, as a college undergraduate, I was treated to a variety of classes and seminars on the "philosophy of history." (Why do we hear that term much less nowadays?) Those encounters featured one pair of ideas above all others: the surpassing virtue of "objectivity" and (conversely) the dreaded contamination of "personal bias." The model scholar, I learned over and over again, is one who keeps vigilant guard against every whiff of bias, as and when it may well up inside him. His own self, his individual concerns-indeed, his entire life-must be held apart from his work, since his overriding goal is to reconstruct other people's lives from centuries ago. Well, if that was the lesson of my early years, I think that in all the time since I have been gradually and fitfully (if not always consciously) unlearning it. Actually, I think that at some level I never fully accepted it and even wanted to unlearn itthough I would not, till quite recently, have admitted as much. There is, after all, a certain grandeur in the scholar's traditional pose of self-abnegation. Almost reflexively we salute "that noble dream" (in Peter Novick's phrase): truth outside the self, truth above the self, truth for its own sake irrespective of the self.1 On the other hand-as a little voice began increasingly to whisper to me and in me-one might question the wisdom of investing a whole career in an activity that must be so carefully walled off from one's immediate and ongoing experience. But the actual process of unlearning the old work-apart-from-life lesson was long and tortuous. The 1960s, which included the years of my graduate training, would reset some of its terms and give it a more distinctly political coloration. "Relevance"
The metabolism of D- and L-lysine in the chicken.

Abstract The metabolism of d - and l -lysine has been studied in the chicken using both 14C and 15N labels. In contrast to the rat, the chicken actively metabolized d -lysine and l -pipecolate. The data indicate that d -lysine is degraded via conversion to pipecolate, α-aminoadipate, α-ketoadipate, and eventually to CO2. The α-nitrogen atom of d -lysine is the first one removed from the carbon skeleton by this route. l -Lysine is metabolized by two alternate pathways which converge at α-aminoadipate. The major pathway, which results in the retention of the α-nitrogen atom of l -lysine in α-aminoadipate, includes saccharopine as a precursor of α-aminoadipate and is thus identical to l -lysine catabolism in rats. The pathway which is indicated to be the minor one includes l -pipecolate as a precursor of α-aminoadipate and results in the retention of the ϵ-nitrogen atom of l -lysine in α-aminoadipate. Even though saccharopine is indicated to be an intermediate in l -lysine breakdown, a large percentage of an intramuscularly injected dose is excreted unchanged in the urine.
Deactivation in catalytic hydrodemetallation III. Random-spheres catalyst models

Abstract A “random-spheres” model is used to describe a porous catalyst, and to evaluate alternative postulates for the growth of metal-sulfide deposits in the catalyst during hydrodemetallation. The random-spheres model, unlike more common cylindrical-pore models, describes an interconnected three-dimensional pore space. Two alternatives are proposed for the form of the deposited metalsulfides: a crystallite-deposits model and a uniform-deposits model. The crystallite-deposits model is shown to be more consistent with catalyst activity and catalyst characterization evidence for the form of metal-sulfide deposits. It can be used to predict changes in catalyst properties as metalsulfide deposits accumulate, and can be applied to the industrially relevant case of diffusion-disguised metal deposition in catalyst pellets.
SOURCES OF ORGANIZATIONAL COMMITMENT: THE EFFECTS OF INTERNAL LABOR MARKETS AND WORKER VALUES

Data from the 1991 General Social Survey and National Organizations Survey are used to assess how organizational commitment is structured by one “demand side,” organizational-based factor, firm internal labor markets, and one “supply side,” individual-based factor, the values/preferences of workers. Findings indicate that organizational commitment is best explained by the joint influence of these two factors rather than by their independent effects. Specifically, firms with internal labor markets are conducive to the development of high levels of organizational commitment to the extent that what they offer, namely, opportunities for career-status and long-term employment “fit” what workers desire: job security and possibilities for promotion with their current employer. We offer directions for future research that may shed additional light on the manner in which internal labor markets and the values/preferences of workers may structure organizational commitment.
Effects of chirality and impurities on the performance of carbon nanotube-based piezoresistive sensors

Abstract This paper presents a method to fabricate high purity, single chirality carbon nanotube (CNT) based sensor systems. Ultracentrifugation is initially used to create an 85% pure (6,5) CNT sample. This 85% pure sample has a gauge factor of −22.7 ± 0.5 which is significantly lower than the predicted gauge factor of 57 for a pure (6,5) CNT. However, this measured gauge factor closely matches the predicted gauge factor for the measured distribution of chiralities in the 85% pure sample. This indicates at a small number of impurities in the sensor can have a large effect on the strain sensitivity of the sensor. In order to increase the gauge factor of the 85% pure (6,5) CNT sample, an electrical breakdown technique is used to remove the low resistance and low gauge factor CNTs from the sensor. Using this technique it is possible to increase the gauge factor of the CNT-based piezoresistive sensor from −22.7 ± 0.5 to 34 ± 1. This result indicates that the majority of the impurities in the sensor can be removed during the fabrication process using the electrical breakdown technique.
A molecular handoff between bacteriophage T7 DNA primase and T7 DNA polymerase initiates DNA synthesis

The T7 DNA primase synthesizes tetraribonucleotides that prime DNA synthesis by T7 DNA polymerase but only on the condition that the primase stabilizes the primed DNA template in the polymerase active site. We used NMR experiments and alanine scanning mutagenesis to identify residues in the zinc binding domain of T7 primase that engage the primed DNA template to initiate DNA synthesis by T7 DNA polymerase. These residues cover one face of the zinc binding domain and include a number of aromatic amino acids that are conserved in bacteriophage primases. The phage T7 single-stranded DNA-binding protein gp2.5 specifically interfered with the utilization of tetraribonucleotide primers by interacting with T7 DNA polymerase and preventing a productive interaction with the primed template. We propose that the opposing effects of gp2.5 and T7 primase on the initiation of DNA synthesis reflect a sequence of mutually exclusive interactions that occur during the recycling of the polymerase on the lagging strand of the replication fork.
Effect of Lanthanum on Cell Wall Elongation in Avena Coleoptile Segments: Physiological and Ultrastructural Studies

Summary The effects of millimolar concentrations of lanthanum (La3+) on cell wall elongation in Avena sativa (var. Victory) coleptile segments were investigated by means of a combined physiological and electron microscopic study. Following an initial inhibition of the elongation rate, La3+ caused a prolonged stimulation of elongation compared to the elongation rate of control segments. Electron microscopic examination of La3+-treated coleoptile segments revealed that electron-dense deposits of La3+ occurred in the cell walls and at localized sites along the outer surface of the plasmalemma of epidermal and contiguous parenchyma cells. In the outer walls of epidermal cells the deposits were mostly confined to the outer surface of the plasmalemma, whereas in the anticlinal walls of epidermal cells and walls of underlying contiguous parenchyma cells, La3+ deposition was most pronounced in the area of the middle lamella and along the outer plasmalemma surface. No deposits were present in the cytoplasmic phase of the cells, indicating lanthanum's inability to cross the plasmalemma. These results are discussed with respect to possible effects of La3+ binding to the calcium (Ca2+) binding sites on the plasmalemma. Implications for the mechanisms underlying monovalent cation transport and cytoplasmic Ca2+ distribution in the cells are discussed.
Changes in behavior and monoamine levels in microdialysate from dorsal striatum after 6-OHDA infusions into ventral striatum

Long-Evans rats received bilateral 6-hydroxydopamine infusions into the nucleus accumbens and were tested immediately (1 and 2 days) or after a recovery period (14 and 15 days) for changes in extracellular levels of dorsal striatal monoamines using in vivo microdialysis. Compared to controls, the monoamine metabolites 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid were generally enhanced when tested immediately after 6-hydroxydopamine treatment, including spontaneous levels and those following depolarizing infusions of potassium (60 mM, 20 min) through the microdialysis probes. Following 2 weeks recovery, dopamine metabolite levels were depressed and the serotonin metabolite levels remained enhanced. D-Amphetamine sulfate (1.5 mg/kg, SC) stimulated dopamine overflow was enhanced 2 days after 6-hydroxydopamine administration, but not after 2 weeks recovery. In contrast, potassium increased dopamine overflow to the same extent as control animals regardless of recovery period following 6-hydroxydopamine. The immediate changes in striatal monoamine activity were accompanied by a potentiation of amphetamine-induced stereotyped behaviors. We suggest that transient presynaptic changes within the dorsal striatum following disruption of the ventral striatum may mediate some general aspects of loss and recovery of behavior related to the time course of 6-hydroxydopamine neurotoxicity.
Production of Interleukin-6 by Anterior Pituitary Cells Is Stimulated by Increased Intracellular Adenosine 3',5' Monophosphate and Vasoactive Intestinal Peptide*

Interleukin-6 (IL-6) is an inflammatory cytokine that is produced by a variety of cells and tissues. We recently demonstrated that IL-6 is produced by anterior pituitary cells in response to the bacterial endotoxin lipopolysaccharide and phorbol diester in vitro. Lipopolysaccharide (0.01–100 ng/ml) increased, whereas dexamethasone (0.1–100 nM) decreased, IL-6 production by anterior pituitary cells in vitro as measured by the 7TD1 cell growth factor assay. In addition, we now report that IL-6 production by anterior pituitary cells is stimulated by agents that elevate intracellular cAMP concentrations. Exposure of anterior pituitary cells to (Bu)2cAMP (0.01– 10 mM), prostaglandin E2 (1.0–1000 nM), forskolin (50–1000 nM), or cholera toxin (0.25–250 ng/ml) for 6 h resulted in concentration related increases in the production of IL-6, which, in the cases of forskolin and cholera toxin, correlated well with increased intracellular cAMP concentrations. Vasoactive intestinal peptide (1–1000 nM), which stimulates ...
Spatial Distribution of Mite Associates of Within-tree Populations of Dendroctonus frontalis Zimm.

Routine sampling of southern pine beetle ( Dendroctonus frontalis Zimm.) populations disclosed seasonal and spatial fluctuations in populations of associated mite species. Mite diversity was greatest in beetle populations collected from the upper bole. The most common mites associated with the southern pine beetle were Trichouropoda australis Hirschmann, Dendrolaelaps neodisetus (Hurlbutt) and Tarsonemus krantzi Smiley and Moser.
Novice nurse productivity following workplace bullying.

Purpose: To determine the prevalence and effects of workplace bullying (WPB) on the work productivity of novice nurses (NNs). Design: Internet-based descriptive cross-sectional survey design. Methods: One hundred ninety seven NNs (91.4% female, 8.6% male) in practice less than 2 years completed the Healthcare Productivity Survey, Negative Acts Questionnaire, and a demographic survey. Findings: The majority (72.6%, n= 147) of NNs reported a WPB event within the previous month, with 57.9% (n= 114) the direct targets and another 14.7% (n= 29) witnesses of WPB behaviors. Using a weighted Negative Acts Questionnaire score, 21.3% (n= 43) of NNs were bullied daily over a 6-month period. When asked if bullied over the past 6 months, approximately 44.7% (n= 88) of NNs reported repeated, targeted WPB, with 55.3% (n= 109) reporting no WPB. WPB acts were primarily perpetrated by more experienced nursing colleagues (63%, n= 126). Further, work productivity regression modeling was significant and NN productivity was negatively impacted by workplace bullying (r=−.322, p= .045). Conclusions: WPB continues in the healthcare environment and negatively affects bullied NNs’ productivity by affecting cognitive demands and ability to handle or manage their workload. Clinical Relevance: Healthcare facilities should continue to measure WPB in the work environment after policy implementation as well as eliminate negative behaviors through root-cause analysis to correct environmental factors associated with WPB. Journal of Nursing Scholarship, 2011; XX:X, XXX–XXX. ©2011 Sigma Theta Tau International.
Race, ethnicity and nativity, family structure, socioeconomic status and welfare dependency

There is a major policy interest in knowing whether immigrants are more likely to depend on (as opposed to temporarily participate in) welfare compared to native-born persons. However little systematic empirical research has directly addressed this question. Using longitudinal survey from the California Work Pays Demonstration Project a mothers chance of welfare dependency in a time interval is examined. In general the results are not consistent with the perspective that foreign-born race and ethnic sub-groups are more likely to depend on Aid to Families with Dependent Children than are native-born race and ethnic sub-groups. This finding holds true irrespective of whether socioeconomic and demographic characteristics are controlled. (authors)
Kinetics of peptide binding to the bovine 70 kDa heat shock cognate protein, a molecular chaperone

We have measured the kinetics of binding and release of a fluorescently labeled seven-residue peptide (fluorescein-FYQLALT) to recombinant bovine heat shock cognate protein (Hsc70); additionally, we have determined the effect of peptide binding on the kinetic rate constants of individual steps of the Hsc70 ATPase cycle. In the presence of MgADP, peptide binding is a two-step process; the first step results in a low-affinity peptide-Hsc70 complex (Kd calcd approximately 14 microM), while the second step locks the peptide into a higher-affinity complex (Kd = 4.3 microM). In the presence of MgATP, peptide binding is a one-step process which yields a peptide-Hsc70 complex with an affinity of approximately 40-50 microM. The bimolecular rates of initial peptide-Hsc70 association differ less than 2-fold in the presence of MgADP and MgATP. Peptide binding increases the rates of ATP hydrolysis and product release in the Hsc70 ATPase cycle. Taken together with earlier results, these data suggest a model for the interaction of Hsc70 with peptides in which (i) with MgATP there is significant interaction between the carboxy terminal peptide binding domain and the amino terminal ATPase domain of Hsc70 such that the effect of peptide binding is transmitted to the ATPase domain (resulting in increased rates of ATP hydrolysis and product release) and, reciprocally, the ATPase domain constrains the peptide binding domain to a low-peptide affinity conformation; and (ii) with MgADP, the peptide binding domain is less constrained by the ATPase domain, allowing capture of peptides in complexes with significantly slower "off " rates than in the presence of MgATP.
Comments on Stack and Gundlach's “The Effect of Country Music on Suicide:” An “Achy Breaky Heart” May Not Kill You

Les AA. repondent a E. R. Maguire et J. B. Snipes dont la contribution s'inscrivait contre tout lien significatif entre musique country et taux de suicide. Ils leur reprochent des erreurs de mesure dans l'estimation du taux de suicide des Blancs
Electrodeposition of potassium bismuthate: KBiO3

Abstract Crystals of KBiO 3 have been grown for the first time. The crystals were obtained by the electrolysis of molten KOH to which Bi 2 O 3 had been added. Single crystal X-ray diffraction data were collected on a transparent red crystal. Analysis of this data confirms that KBiO 3 has essentially the same structure as KSbO 3 .
Oscillatory behavior of the peak energy for stopping cross sections as a function of Z 2 for He ions and protons

Experimental evidence is presented to demonstrate that the energy at the peak of stopping-cross-section curves oscillates with target element of atomic number ${Z}_{2}$ when He ions and protons impinge upon these substances. A qualitative description is given in terms of outer- and inner-shell participation of the target atoms in the slowing down of the ion based upon existing theories and mechanisms.
Alzheimer Disease: Caused by Primary Deficiency of the Cerebral Blood Flow

Alzheimer's disease (AD) is associated with considerably decreased cerebral blood flow (CBF) thought to be secondary, since dead neurons do not need oxygen and glucose. This view, however, needs to be critically re-examined. The role of CBF in AD was submitted to a thorough analysis, raising the question: "Is there really a lack of demand in the presence of undisturbed blood supply?" CBF decline is present in AD while the number of affected CNS systems is still quite small. The step-by-step evolution of AD mirrors a brain that progressively becomes ischemic. Areas related to memory function (hippocampus, temporal lobe cortex and vicinity) are bound to suffer first because of their particularly vulnerable blood supply. This is the scenario of a disorder caused by primary and not by secondary CBF deficiency--a deficiency perhaps attributable to the upright gait of homo sapiens. This new approach also opens new avenues for treatment and prevention, which will be briefly discussed.
Suitability and limitations of carbon fiber reinforced PEEK composites as bearing surfaces for total joint replacements

The suitability and limitations of carbon fiber reinforced polyether ether ketone (PEEK) composites as bearing surfaces for total joint replacements are investigated. The wear behaviour of the composites is studied under both high-stress non-conforming contact and low-stress conforming contact conditions. The former mimics the total knee contact conditions while the latter simulates the total hip contact conditions. For each contact geometry, the study focuses on the effects of carbon fiber type, carbon fiber loading and counterface material on the wear behaviour of the composite.
Parameter Estimation in Bayesian Networks Using Overlapping Swarm Intelligence

Bayesian networks are probabilistic graphical models that have proven to be able to handle uncertainty in many real-world applications. One key issue in learning Bayesian networks is parameter estimation, i.e., learning the local conditional distributions of each variable in the model. While parameter estimation can be performed efficiently when complete training data is available (i.e., when all variables have been observed), learning the local distributions becomes difficult when latent (hidden) variables are introduced. While Expectation Maximization (EM) is commonly used to perform parameter estimation in the context of latent variables, EM is a local optimization method that often converges to sub-optimal estimates. Although several authors have improved upon traditional EM, few have applied population based search techniques to parameter estimation, and most existing population-based approaches fail to exploit the conditional independence properties of the networks. We introduce two new methods for parameter estimation in Bayesian networks based on particle swarm optimization (PSO). The first is a single swarm PSO, while the second is a multi-swarm PSO algorithm. In the multi-swarm version, a swarm is assigned to the Markov blanket of each variable to be estimated, and competition is held between overlapping swarms. Results of comparing these new methods to several existing approaches indicate that the multi-swarm algorithm outperforms the competing approaches when compared using data generated from a variety of Bayesian networks.
Consistent Variable Selection in Linear Models

Abstract A method of estimating linear model dimension and variable selection is proposed. This new criterion, which generalizes the Cp criterion, the Akaike information criterion (AIC), the Bayes information criterion, and the phiv criterion and is consistent under certain conditions, is based on a new class of penalty functions and a procedure of sorting covariates based on t-statistics. In the course of introducing this method, we discuss the important role of the penalty function in the consistency of model dimension estimation and in variable selection. The proposed method requires less computation than resampling-based methods that search over all subsets of covariates for the true model. Simulation results show that the new method is superior to the Cp criterion and AIC in finite-sample situations as well.
Not Just Actin? A Role for Dynamic Microtubules in Dendritic Spines

Despite intense attention, the mechanisms regulating dendritic spine structure remain elusive. In this issue of Neuron, Jaworski and colleagues explore the morphological consequences of periodic spine incursions of dynamic microtubules and their associated protein, EB3. Microtubules, long thought to be absent from dendritic spines, are capable of controlling spine morphology, opening up a new line of investigation into mechanisms of spine plasticity and maintenance.
Differential gene expression in anthracene-exposed mummichogs (Fundulus heteroclitus).

Abstract The polycyclic aromatic hydrocarbon (PAH) anthracene is present in many estuarine systems at concentrations believed to cause sublethal adverse effects, although its exact mode of toxicity remains unclear. Knowledge of the induction or suppression of specific genes as a result of exposure may be useful in explaining these effects. We have generated a fingerprint of anthracene exposure using the mummichog (Fundulus heteroclitus), a non-migratory estuarine fish species. The fish were exposed in 7-day static renewal tests to environmentally relevant concentrations of 0, 27, 50, and 80 μg/l of anthracene. Total RNA was extracted from the livers and differential display reverse transcription polymerase chain reaction (DD RT-PCR) was used to recover 26 differentially expressed cDNA fragments. These cDNAs were isolated, sequenced, and compared to sequences of known genes in order to identify possible physiological consequences of exposure to anthracene. We then constructed macroarrays using these fragments and probed them with RNA from both anthracene-exposed fish and fish from a known PAH-impacted site. Three genes appear to be good indicators of exposure to anthracene in the range of concentrations tested, which included CYP2N2 and two expressed sequence tags (ESTs) termed 15C1 and 18C2. The expression of nine genes was altered in fish collected from a site with multiple PAHs. Band 15C1 and CYP2N2 again showed statistically significant upregulation in the field-caught fish, while a trypsin precursor and fatty acid-binding protein (FABP) all showed similar trends in induction as the laboratory-exposed fish. Further insight into the mechanism of toxicity of contaminants will be gained by the ability to identify and use differentially expressed genes as markers of exposure and effects.
Molecular Dynamics Simulations of Thermo-Mechanical Effects in Nanodrop Impact

Nanodrop impact onto a solid substrate is of interest for nano-scale liquid-impingement, phase-change cooling and for material deposition processes. In the present study, classical molecular dynamics (MD) simulation techniques were implemented to study the thermo-mechanical properties of the impact of nanometer scale liquid droplets upon an atomistic substrate at a temperature higher than that of the droplet. The droplets were comprised of approximately 50,000 Lennard-Jones atoms arranged in tetramer finitely extensible non-linear elastic (FENE) chain molecules forming a sphere of 8 nm radius. They were equilibrated and then projected towards a wall, where we observed the response upon collision by changes in shape, temperature, and density gradients, across a variety of impingement velocities, substrate temperatures, and wetting conditions. The baseline cases of equal substrate and nano-drop temperature were validated by comparison with previously reported results. A reaction spectrum ranging from full thermal vaporization of the drop, with respective substrate cooling, to complete kinetic disintegration upon impact and surface heating are analyzed. The variation of thermal and kinetic effects across the parametric environment is used to identify those regimes that optimize heat transfer from the surface, as well as those that best facilitate material deposition processes.© 2014 ASME
Detecting a peroxide-based explosive via molecular gelation

A convenient and portable triacetone triperoxide (TATP) sensor was developed utilizing a thiol-to-disulfide oxidation to trigger a solution-to-gel phase transition. Using this method, TATP can be detected visually without any instrumentation.
Documentation of Resuscitation Events

Documentation is an integral aspect of nursing. The well-known phrase ‘‘if it wasn’t documented, it never happened’’ aptly describes the importance of documentation. Resuscitation events are a potential documentation nightmare, with many events occurring nearly simultaneously and multiple personnel involved. Documentation of resuscitation events is essential to determining what care was actually provided during the event, critically evaluating how a patient responded to resuscitation interventions, ensuring that resuscitation standards were followed, and not only reflecting on areas in which care is exemplary but also identifying areas that could be improved. Documentation in the medical record should be concise, legible, and timely. Anecdotal reports and actual record reviews have shown that resuscitation documentation often has not met these criteria. Most nurses can recall recording ‘‘code data’’ on scraps of paper, paper towels, gloves, scrubs, and even bed linens. Entering data into the medical record from these multiple sources is time consuming and difficult after the event. Information recorded in such a fashion often is incomplete because times and details of treatment may be missing, inaccurate, or illegible. If the only available documentation is that recorded after the event, problems with accurate memory of timing, sequence, and performance of events are frequent. Resuscitation events are often chaotic and result in documentation that may not completely reflect the actions that occurred during resuscitation. For this reason, researchers have attempted to determine what measures will improve resuscitation documentation. This article provides an overview of what is known about resuscitation documentation, discusses the value of using Utstein guidelines [1] in resuscitation documentation, and presents some thoughts for future research related to recording resuscitation events. Existing comprehensive guidelines provide recommendations to health care providers regarding documentation and reporting of resuscitation events. These guidelines offer recommendations for reporting adult out-of-hospital cardiac arrest [2], reviewing, reporting, and conducting research on in-hospital resuscitation [3], and reporting pediatric advanced life support [4]. Despite these well-developed evidencebased documentation guidelines, there is limited evidence that they are being used as the gold standard for resuscitation documentation.
Tectonic inversion and basement buttressing: an example from the central Appalachian Blue Ridge province

Abstract The structural geometry of the central Appalachian Blue Ridge province is primarily the result of Paleozoic contractional deformation. However, the Tye River fault zone in the western Blue Ridge of central Virginia preserves an extensional map pattern. These ENE–WSW striking faults place Neoproterozoic to early Cambrian volcanic and sedimentary rocks over Grenvillian granitic basement. Detailed mapping, cross-section restoration, and balancing reveals partially inverted faults, original half grabens, and significantly thicker cover units on hanging walls. The orientation and geometry of the Tye River fault zone, as well as the thickness changes in the cover rocks are inconsistent with extensional reactivation of Paleozoic reverse faults during Mesozoic rifting. The extrusion and deposition of cover rocks was contemporaneous with normal displacement on the Tye River fault zone and the formation of rift basins recording ∼5% crustal extension. Faults were reactivated as Paleozoic contractional structures, but an extensional map pattern is generally still preserved. Regional shortening of 10–20% was accomplished primarily by folding of the cover rocks rather than by reactivation of older faults. The basement formed a rigid buttress that controlled the geometry of folding in the cover sequence.
Identifying QT prolongation from ECG impressions using a general-purpose Natural Language Processor

Abstract Objective Typically detected via electrocardiograms (ECGs), QT interval prolongation is a known risk factor for sudden cardiac death. Since medications can promote or exacerbate the condition, detection of QT interval prolongation is important for clinical decision support. We investigated the accuracy of natural language processing (NLP) for identifying QT prolongation from cardiologist-generated, free-text ECG impressions compared to corrected QT (QTc) thresholds reported by ECG machines. Methods After integrating negation detection to a locally developed natural language processor, the KnowledgeMap concept identifier, we evaluated NLP-based detection of QT prolongation compared to the calculated QTc on a set of 44,318 ECGs obtained from hospitalized patients. We also created a string query using regular expressions to identify QT prolongation. We calculated sensitivity and specificity of the methods using manual physician review of the cardiologist-generated reports as the gold standard. To investigate causes of “false positive” calculated QTc, we manually reviewed randomly selected ECGs with a long calculated QTc but no mention of QT prolongation. Separately, we validated the performance of the negation detection algorithm on 5000 manually categorized ECG phrases for any medical concept (not limited to QT prolongation) prior to developing the NLP query for QT prolongation. Results The NLP query for QT prolongation correctly identified 2364 of 2373 ECGs with QT prolongation with a sensitivity of 0.996 and a positive predictive value of 1.000. There were no false positives. The regular expression query had a sensitivity of 0.999 and positive predictive value of 0.982. In contrast, the positive predictive value of common QTc thresholds derived from ECG machines was 0.07–0.25 with corresponding sensitivities of 0.994–0.046. The negation detection algorithm had a recall of 0.973 and precision of 0.982 for 10,490 concepts found within ECG impressions. Conclusion NLP and regular expression queries of cardiologists’ ECG interpretations can more effectively identify QT prolongation than the automated QTc intervals reported by ECG machines. Future clinical decision support could employ NLP queries to detect QTc prolongation and other reported ECG abnormalities.
Puzzles in the study of daily hassles

Theory and research in psychological stress has shifted from an earlier perspective of environmental inputs or outputs to a relational one. Stress is now treated as harms, threats and challenges, the quality and intensity of which depend on personal agendas, resources and vulnerabilities of the person, as well as on environmental conditions. This implies a knowing person who construes or appraises the significance of what is happening for his or her well-being. Such a “paradigm shift” requires a different approach to stress measurement, one that takes into account the cognitive activity evaluating the personal significance of transactions, and examines the multiple specific variables of person and environment that influence the appraisal process. The need for a different approach to stress measurement has generated research by the Berkeley Stress and Coping Project on what we have called daily hassles and uplifts.
Reactions to acceptance and rejection: Effects of level and sequence of relational evaluation.

Abstract Two experiments examined the effects of various levels and sequences of acceptance and rejection on emotion, ratings of self and others, and behavior. In Experiment 1, participants who differed in agreeableness received one of five levels of acceptance or rejection feedback, believing that they either would or would not interact with the person who accepted or rejected them. In Experiment 2, participants who differed in rejection sensitivity received one of four patterns of feedback over time, reflecting constant acceptance, increasing acceptance, increasing rejection, or constant rejection. In both studies, rejection elicited greater anger, sadness, and hurt feelings than acceptance, as well as an increased tendency to aggress toward the rejector. In general, more extreme rejection did not lead to stronger reactions than mild rejection, but increasing rejection evoked more negative reactions than constant rejection. Agreeableness and rejection-sensitivity scores predicted participants’ responses but did not moderate the effects of interpersonal acceptance and rejection.
Corpus luteum - uterine relationships in the control of uterine contraction in the lizard Anolis carolinensis.

The lizard Anolis carolinensis exhibits unilateral uterine contraction and oviposition. The present study investigated the control of unilateral uterine contraction by exposing uteri to arginine vasotocin (AVT) in vitro. In cycling Anolis females, the uterus on the same side as an ovary with a large corpus luteum failed to contract in vitro in response to AVT. In contrast, the contralateral uterus (on the side where a corpus luteum was degenerating or absent) exhibited rhythmic contractions when exposed to AVT. Unilateral deluteinization removed the unilateral inhibition of uterine contraction. The inhibitory substance(s) produced by the corpus luteum could be delivered to the ipsilateral uterus via small uteroovarian blood vessels.
Proposed Substrates for Reproducible Surface-Enhanced Raman Scattering Detection

The electromagnetic contribution to the surface-enhanced Raman scattering (SERS) derives from the distribution of electromagnetic “hot spots” around nanostructured metal surfaces. For an optimized SERS signal, analyte molecules need to be placed within the intense electric fields localized at these hot spots. Using numerical simulations, we demonstrate the possibility of creating controllable hot spots through proper engineering of the plasmonic modes supported by periodic arrays of nanoscale cavities in thin silver films. We investigate the tunability of surface plasmon resonance wavelength and local field enhancement by systematically varying the sample thickness, periodicity, and the nanocavity morphology. The gradual evolution of the absorption spectrum with these parameters helps reveal the relative contributions from surface plasmon polaritons propagating or localized at the metal surfaces. The calculations suggest that when the nanocavities are deep relative to the film thickness, there is strong c...