cssi/SciSciGPT-SciSciNet huggingface dataset:
Smoking and male reproduction: a review.

Because of the large number of men worldwide who smoke and the fact that cigarette smoke contains known mutagens and carcinogens, there has been concern that smoking may have adverse effects on male reproduction. A review of the epidemiological literature indicates that cigarette smoking is associated with modest reductions in semen quality including sperm concentration, motility and morphology. The associations between male smoking and sperm concentration and motility are stronger among studies of 'healthy' men (e.g. volunteers and sperm donors) than among men from infertility clinic populations. Smoking has also been associated with alterations in hormone levels in males, for example increases in the levels of oestrone and oestradiol. Despite modest reductions in semen quality and altered hormone levels among smokers compared to non-smokers, studies have not shown a reduction in male fertility in association with paternal smoking. There is some evidence to suggest that paternal smoking is associated with congenital anomalies and childhood cancer (with ORs in positive studies generally < 2.0). Smoking has not been shown to be mutagenic to human spermatozoa, although studies have been small and have had methodological shortcomings. It is concluded that, although smokers as a group may not experience reduced fertility, men with marginal semen quality who wish to have children may benefit from quitting smoking, since several small studies indicate the potential for improved semen quality after quitting smoking. More research on the benefits of quitting smoking among men with marginal semen quality is needed. Methodological improvements in studies aimed at clarifying the association between paternal smoking and reproductive and developmental outcomes in offspring should include obtaining accurate paternal smoking dose information, evaluating smoking exposure information in relation to various time windows (e.g. prior to conception, during gestation), and controlling for potential confounders and modifying factors such as age and maternal smoking habits. More sensitive and specific laboratory assays and increased sample sizes are required to establish whether smoking induces mutations in human spermatozoa.
Is the afferent pathway from the rectum impaired in children with chronic constipation and encopresis

Abstract Background & Aims: Rectal sensations to balloon distention are impaired in children with chronic constipation and encopresis. The impairment of rectal sensation, which is often persistent and is related to nonrecovery, could be caused by a defect in the visceral afferent pathways. The aim of this study was to test whether the afferent pathway from the rectum is impaired in children with constipation and encopresis. Methods: Fifteen healthy children and 15 children with constipation and encopresis were studied. Cerebral evoked potentials (EPs) were studied by averaging results of 100 rectal distentions, which used 10, 20, and 30 mL air. EPs were recorded from Cz′ to Fz. Results: Two different types of EPs were recorded in each control subject and each child with constipation and encopresis. One EP had an early onset and showed multiple positive and negative peaks. The other EP had a much later onset and was triphasic. Early-onset EPs were recorded with significantly smaller distention volumes than the late-onset EPs. N1 and P2 latencies of the early-onset EPs and NI, PI, and NII latencies of the late-onset EPs were significantly prolonged in children with constipation and encopresis compared with controls. Conclusions: The prolonged latencies suggest a defect in the afferent pathway from the rectum in children with chronic constipation and encopresis.
Temporal concepts and predicted duration judgments

The present research investigated whether certain conceptualizations of time influence the planning fallacy or the tendency to underestimate predicted task durations. In Experiment 1, participants were presented with one of three types of primes (video, linguistic, video + linguistic) that reflected either an ego or time motion perspective (i.e. an individual moving through time vs. time moving toward an individual). Afterwards, all participants predicted the amount of time required to sort and shelve a stack of journals before actually completing the task. The results showed that across all priming conditions, subjects in the ego motion condition underestimated to a greater extent than those in the time motion condition. Experiment 2 replicated this effect and also found that underestimations are reduced when the implied duration of the experimental session is short vs. long. As a set, these findings have relevant theoretical implications and suggest some potential de-biasing techniques.
Correlation between longitudinal, circumferential, and radial moduli in cortical bone: effect of mineral content.

Abstract Previous studies indicate that changes in the longitudinal elastic properties of bone due to changes in mineral content are related to the longitudinal strength of bone tissue. Changes in mineral content are expected to affect bone tissue mechanical properties along all directions, albeit to different extents. However, changes in tissue mechanical properties along the different directions are expected to be correlated to one another. In this study, we investigate if radial, circumferential, and longitudinal moduli are related in bone tissue with varying mineral content. Plexiform bovine femoral bone samples were treated in fluoride ion solutions for a period of 3 and 12 days to obtain bones with 20% and 32% lower effective mineral contents. Transmission ultrasound velocities were obtained in the radial, circumferential, and longitudinal axes of bone and combined with measured densities to obtain corresponding tensorial moduli. Results indicate that moduli decreased with fluoride ion treatments and were significantly correlated to one another ( r 2 radial vs. longitudinal = 0.80, r 2 circumferential vs. longitudinal = 0.90, r 2 radial vs. circumferential = 0.85). Densities calculated from using ultrasound parameters, acoustic impedance and transmission velocities, were moderately correlated to those measured by the Archimedes principle ( r 2 = 0.54 , p 0.01 ). These results suggest that radial and circumferential ultrasound measurements could be used to determine the longitudinal properties of bone and that ultrasound may not be able to predict in vitro densities of bones containing unbonded mineral.
Empty toe phenomenon: a big problem for a little toe

The authors present a case report and review of the sparse literature of a rare closed degloving injury to the toe, referred to by Flaherty as an "empty toe phenomenon." A 25-year-old man sustained a twisting injury to his left foot when he was involved in a motorcycle accident. The skin was not lacerated around the toe but on physical exam it appeared that part of the toe was empty of its bony contents.
Gender bias in clinical judgment: An assessment of the analogue method's transparency and social desirability

The main purpose of this research was to determine whether clinicians discern the intent of an analogue study of gender bias in clinical judgment and, if so, whether they respond in a socially desirable manner. A total of 147 psychologists responded to a national mail survey in which they were instructed to make clinical ratings of a case summary describing either a female or male client. In one condition (the Social Desirability condition), clinicians were informed of the study's intent and instructed to respond in a socially desirable fashion. In another condition (the No Social Desirability condition), the study's intent was not revealed and clinicians were asked to guess the study's hypothesis following their ratings. Results indicate that only 10 of 100 clinicians reported having deduced the purpose of the study. The small number of guessers prohibited examination of whether guessing the intent leads to socially desirable responses. Results provide no evidence that either therapist or client gender influenced clinical judgment. Implications for evaluating experimental findings which fail to support gender bias in clinical judgment are discussed.
Effects of Frequency of Data Collection and Graph Characteristics on Visual Inference.

Though visual inference is the most frequently used procedure in the analysis of behavioral and performance data, accuracy and reliability continue to be of concern. This study addressed the questions of whether different trends on graphs produced different judgments, and whether different frequencies of data collection produced different judgments. Also addressed was the question of whether there was an interaction between trend and frequency that influenced judgments of student performance. Results indicate that judgments tend to be accurate and consistent when performance data represent systematic improvement, but when graphed data represent a decrease in performance, no change, or highly variable performance, judgments tend to differ by frequency.
Diagnosing Celiac Disease in 2002: Who, Why, and How?

In this issue of Pediatrics , Barera et al1 expand on the significant, recognized relationship between type 1 diabetes and celiac disease (CD). The authors confirm the increased prevalence of CD in type 1 diabetes and characterize the timing of the identification of CD relevant to the onset of type 1 diabetes. The study shows that the diagnosis of CD may be made before, at the same time, or several years after the diagnosis of type 1 diabetes. Although most cases in this study were identified within 5 years of diagnosis of type 1 diabetes, the number of subjects tested declined over the 5-year period so that by the sixth year only 10% were actually retested. It is possible, therefore, that over time even more cases of CD/type 1 diabetes will be identified. As in most populations where screening is done to detect CD, most of the patients in this series were either asymptomatic or had unrecognized symptoms. Why should we be concerned about the identification of apparently asymptomatic CD in patients with type 1 diabetes? First, CD is characterized by small intestinal inflammation with mucosal atrophy. Therefore, absorption of nutrients could be variable or overt malabsorption could occur, altering insulin requirements and affecting diabetic control. Improvement in diabetic control and a decrease in hypoglycemic episodes have been observed in children with CD and type 1 diabetes after institution of a gluten-free diet.2 Second, CD can affect growth as demonstrated by the increase in body mass index in the patients after treatment. In the study by Barera et al, this improvement could be attributed, in part, to management of type 1 diabetes as well. Third, CD is associated with other diseases or conditions that are reduced or eliminated when individuals with CD follow a gluten-free diet. These include …
Effects of anethole dithiolthione and 2(3)-tert-butyl-4-hydroxyanisole on schistosome granuloma formation

Administration of the antioxidants 2(3)-tert-butyl-4-hydroxyanisole (BHA) or 5-(P-methoxyphenyl)-3H-1,2-dithiol-3-thione (ADT) to female CD-1 mice starting 4 weeks after infection with 70 cercariae of Schistosoma mansoni resulted in a decrease in the size of the inner fibrotic region of the hepatic granuloma. The cellular composition of the granuloma was not altered by treatment with these two compounds. The administration of the specific superoxide scavenger copper diisopropylsalicylate (CuDIPS) resulted in a similar decrease in granuloma size, suggesting a role of superoxide radicals in the granulomatous response.
Response to selection for increased pupa weight in Tribolium castaneum as related to population structure

The effectiveness of selection for increased pupa weight in Tribolium was compared for three different selection systems. In all three systems the same number of breeding individuals was used each generation. Population L was a large random mating population with 24 males and 48 females selected each generation. The C 4 and C 8 populations were each divided into 6 subpopulations (lines) consisting of 4 males and 8 fem ales. Each of the three populations was replicated. In C 4 , selection for pupa weight was within lines for three generations, followed by a generation of among-line selection when the best two out of six lines were selected. These lines were then crossed to produce 6 new subpopulations, and the cycle was repeated. The C 8 population was handled in exactly the same manner except that seven generations of selection within lines were practised before each generation of among-line selection. Selection response for the 42-generation period was significantly greater in the L population than in either subdivided population. No consistent differences among the selection systems were apparent when evaluating short-term response for the first 12 generations of the experiment. The results were interpreted as indicating that the influence of multiple-peak epistasis was not of major importance for this trait in determining ultimate response to selection when starting from a base population of previously unselected lines and utilizing a within- and among-line selection regime.
With greater power comes greater responsibility? takeover protection and corporate attention to stakeholders

Using takeover protection as an indicator of corporate governance, this study examines how an exogenous shift in power from shareholders to managers affects corporate attention to non-shareholding stakeholders. Two competing hypotheses are entertained. The shareholder view predicts that stronger takeover protection will lead to a decrease in corporate attention to shareholders and non-shareholding stakeholders alike, as managers divert resources from shareholders to the pursuit of their private interests. The stakeholder view, in contrast, predicts that stronger takeover protection will increase corporate attention to non-shareholding stakeholders. Because catering to non-shareholding stakeholders contributes to the long-term value of the firm, managers will be more likely to attend to those stakeholders when relieved from short-termism triggered by the threat of hostile takeovers. Using a sample of 878 U.S. firms from 1991 to 2002, the study finds that an exogenous increase in takeover protection leads to higher corporate attention to community and the natural environment, but has no impact on corporate attention to employees, minorities, and customers. Additional analyses show that firms that increase their attention to stakeholders experience an increase in long-term shareholder value. These findings provide additional evidence that relief from short-termism is a likely source of the increase in corporate attention to non-shareholding stakeholders following the increase in takeover protection. Copyright © 2008 John Wiley & Sons, Ltd.
Depth determination using complex logarithmic mapping

There is growing interest in using the complex logarithmic mapping for depth determination in motion stereo applications. This has lead to a need for a comprehensive error analysis. Rather than just giving an analytic description of the errors inherent in the approach an attempt will be made to characterize the errors that occur when using the mapping with real images. Techniques to reduce the impact of these errors will also be discussed. 1.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The effect of distracting stimuli on the runway performance of limbic damaged rats

The introduction of novel visual stimuli failed to disturb the performance of animals with extensive bilateral destruction of the hippocampus in a linear runway. Animals with destruction restricted to the dorsal hippocampus and animals with damage of the septal area were less distracted on first presentation of the distracting stimuli but recovered former running speeds more quickly than control groups. Novel tactual stimuli failed to affect the performance of animals in all groups.
Mitral Valve Repair Surgery in a Patient With Sickle Cell Disease

Sickle cell disease (SCD) affects between 70,000 and 100,000 Americans, making it one of the most prevalent genetic disorders in the United States. It is an autosomal, recessive disorder characterized by a single amino acid change in the betaglobin chain of hemoglobin (Hob) leading to its pathological polymerization, red cell rigidity and poor microvascular blood flow. These changes also produce the characteristic sickle shape of the red cells, which lose the pliability required to successfully traverse small capillaries. The use of cardiopulmonary bypass (CPB) during adult cardiac surgery initiates many of the conditions that contribute to the sickling of the hemoglobin S cells. Traditionally during CPB the patients are hypothermic and can become acidotic during intermediate periods of surgery. The experience of adult cardiac surgery with CPB on patients with SCD is limited. The purpose of our manuscript is to review the first case of adult cardiac surgery in a patient with SCD at our institution and also to review the literature on the management of patients with SCD who undergo adult cardiac surgery. J Hematol. 2014;3(1):10-12 doi: http://dx.doi.org/10.14740/jh102w
Fast Mass Transport Through Sub-2-Nanometer Carbon Nanotubes

We report gas and water flow measurements through microfabricated membranes in which aligned carbon nanotubes with diameters of less than 2 nanometers serve as pores. The measured gas flow exceeds predictions of the Knudsen diffusion model by more than an order of magnitude. The measured water flow exceeds values calculated from continuum hydrodynamics models by more than three orders of magnitude and is comparable to flow rates extrapolated from molecular dynamics simulations. The gas and water permeabilities of these nanotube-based membranes are several orders of magnitude higher than those of commercial polycarbonate membranes, despite having pore sizes an order of magnitude smaller. These membranes enable fundamental studies of mass transport in confined environments, as well as more energy-efficient nanoscale filtration.
The histone methylase Set2p and the histone deacetylase Rpd3p repress meiotic recombination at the HIS4 meiotic recombination hotspot in Saccharomyces cerevisiae

The rate of meiotic recombination in the yeast Saccharomyces cerevisiae varies widely in different regions of the genome with some genes having very high levels of recombination (hotspots). A variety of experiments done in yeast suggest that hotspots are a feature of chromatin structure rather than a feature of primary DNA sequence. We examined the effects of mutating a variety of enzymes that affect chromatin structure on the recombination activity of the well-characterized HIS4 hotspot including the Set2p and Dot1p histone methylases, the Hda1p and Rpd3p histone deacetylases, the Sin4p global transcription regulator, and a deletion of one of the two copies of the genes encoding histone H3-H4. Loss of Set2p or Rpd3p substantially elevated HIS4 hotspot activity, and loss of Hda1p had a smaller stimulatory effect; none of the other alterations had a significant effect. The increase of HIS4 hotspot activity in set2 and rpd3 strains is likely to be related to the recent finding that histone H3 methylation by Set2p directs deacetylation of histones by Rpd3p.
Health insurance and child mortality in Costa Rica

This study uses a natural experiment approach to evaluate the effect of health insurance on infant and child mortality. In the 1970s Costa Rica adopted national health insurance, which expanded children's insurance coverage from 42 percent in 1973 to 73 percent by 1984. Aggregate infant and child mortality rates dropped rapidly during this period, but this trend had begun prior to the insurance expansion, and may be related to other changes during this period. We use county-level vital statistics and census data to isolate the causal insurance effect on mortality using county fixed effects models. We find that insurance increases are strongly related to mortality decreases at the county level before controlling for other time-varying factors. However, after controlling for changes in other correlated maternal, household, and community characteristics, fixed effects models indicate that the insurance expansion could have explained only a small portion of the mortality change. These results question the proposition that health insurance can lead to large improvements in infant and child mortality, and that expanding insurance to the poor can substantially narrow socioeconomic differentials in mortality.
RASS: a web server for RNA alignment in the joint sequence-structure space

Comparison of ribonucleic acid (RNA) molecules is important for revealing their evolutionary relationships, predicting their functions and predicting their structures. Many methods have been developed for comparing RNAs using either sequence or three-dimensional (3D) structure (backbone geometry) information. Sequences and 3D structures contain non-overlapping sets of information that both determine RNA functions. When comparing RNA 3D structures, both types of information need to be taken into account. However, few methods compare RNA structures using both sequence and 3D structure information. Recently, we have developed a new method based on elastic shape analysis (ESA) that compares RNA molecules by combining both sequence and 3D structure information. ESA treats RNA structures as 3D curves with sequence information encoded on additional coordinates so that the alignment can be performed in the joint sequence-structure space. The similarity between two RNA molecules is quantified by a formal distance, geodesic distance. In this study, we implement a web server for the method, called RASS, to make it publicly available to research community. The web server is located at http://cloud.stat.fsu.edu/RASS/.
DNA-Templated Formation of a Helical Cyanine Dye J-Aggregate

UV−vis and CD spectroscopy reveal that a tricationic cyanine dye spontaneously assembles into a helical J-aggregate in the presence of a double-helical DNA template. The stability of the J-aggregate is strongly dependent on the dye concentration and DNA length in a manner that reflects a high degree of cooperativity in formation of the aggregate. Slight changes in environmental conditions such as temperature and ionic strength result in interconversion between J- and H-aggregates. The aggregate likely consists of dimeric units assembled in an offset, face-to-face orientation within the minor groove of the DNA template, analogous to an earlier report of H-aggregation on DNA by a related cyanine dye. A model is proposed that relates the two aggregate structures by translation of one monomer from a given dimer along the floor of the minor groove. This translation requires adjacent monomers to also translate, leading to the observed cooperativity.
Association between essential tremor and Parkinson's disease

To examine a possible relationship of essential tremor to Parkinson's disease (PD), 130 patients with essential tremor were studied. Twenty-five patients had both essential tremor and PD. These 25 patients were matched for age and duration of PD symptoms with 25 patients who had idiopathic PD. Bradykinesia, postural instability, and gait difficulty were more severe in the patients with idiopathic PD. Degree of tremor, rigidity, and functional disability did not differ in the two groups. The prevalence of PD in the population with essential tremor was 24 times greater than expected. This study suggests that some patients with essential tremor have a genetically increased risk for PD.
Stereochemical Basis for a Unified Structure Activity Theory of Aromatic and Heterocyclic Rings in Selected Opioids and Opioid Peptides

This paper presents a novel unified theory of the structure activity relationship of opioids and opioid peptides. It is hypothesized that a virtual or known heterocyclic ring exists in all opioids which have activity in humans, and this ring occupies relative to the aromatic ring of the drug, approximately the same plane in space as the piperidine ring of morphine. Since the rings of morphine are rigid, and the aromatic and piperidine rings are critical structural components for morphine's analgesic properties, the rigid morphine molecule allows for approximations of the aromatic and heterocyclic relationships in subsequent drug models where bond rotations are common. This hypothesis and five propositions are supported by stereochemistry and experimental observations.Proposition #1 The structure of morphine provides a template. Proposition #2 Steric hindrance of some centric portion of the piperidine ring explains antagonist properties of naloxone, naltrexone and alvimopam. Proposition #3 Methadone has an active conformation which contains a virtual heterocyclic ring which explains its analgesic activity and racemic properties. Proposition #4 The piperidine ring of fentanyl can assume the morphine position under conditions of nitrogen inversion. Proposition #5 The first 3 amino acid sequences of beta endorphin (l-try-gly-gly) and the active opioid dipeptide, l-tyr-pro, (as a result of a peptide turn and zwitterion bonding) form a virtual piperazine-like ring which is similar in size, shape and location to the heterocyclic rings of morphine, meperidine, and methadone. Potential flaws in this theory are discussed.This theory could be important for future analgesic drug design.
Evolving Concepts on Human SMN Pre-mRNA Splicing

SMN1 and SMN2 represent two nearly identical copies of the survival motor neuron gene in humans. Deletion of SMN1 coupled with the inability of SMN2 to compensate for the loss of SMN1 leads to spinal muscular atrophy (SMA), a leading genetic cause of infant mortality. SMN2 holds the promise for cure of SMA if skipping of exon 7 during pre-mRNA splicing of SMN2 could be prevented. Previous reports have shown that a C to Tmutation at the 6th position of exon 7 (C6U substitution in the transcript) is the primary cause of SMN2 exon 7 skipping. Cumulative evidence suggests that C6U abrogates an enhancer associated with SF2/ASF, as well as, creates a silencer associated with hnRNP A1. There is also evidence to suggest that C6U creates an extended inhibitory context (Exinct). Recently, an intronic hnRNP A1 motif, which is not conserved between two human SMN genes, has been implicated in skipping of SMN2 exon 7. However, mechanism by which two SMN2-specific hnRNP A1 motifs interact is not known. Systematic approaches including site-specific mutations, in vivo selections, RNA structure probing and antisense oligonucleotide microwalks have revealed additional cis-elements in exon 7 as well as in flanking intronic sequences. A unique intronic splicing silencer (ISS-N1) has emerged as an effective target for correction of SMN2 exon 7 splicing by short antisense oligonucleotides (ASOs). Low nanomolar concentrations of ASOs against ISS-N1 fully restored SMN2 exon 7 inclusion and increased levels of SMN in SMA patient cells. Such a robust antisense response could be due to accessibility of the target as well as the complete nullification of a strong inhibitory impact rendered by ISS-N1. Bifunctional oligonucelotides with capability to recruit stimulatory splicing factors in the vicinity of weak splice sites of exon 7 have also shown promise for correction of SMN2 exon 7 splicing. Considering an antisense-based strategy confers a unique advantage of sequence specificity, availability of many target worthy cis-elements holds strong potential for antisense-mediated therapy of SMA.
Voa1p Functions in V-ATPase Assembly in the Yeast Endoplasmic Reticulum

The yeast Saccharomyces cerevisiae vacuolar ATPase (V-ATPase) is a multisubunit complex divided into two sectors: the V1 sector catalyzes ATP hydrolysis and the V0 sector translocates protons, resulting in acidification of its resident organelle. Four protein factors participate in V0 assembly. We have discovered a fifth V0 assembly factor, Voa1p (YGR106C); an endoplasmic reticulum (ER)-localized integral membrane glycoprotein. The role of Voa1p in V0 assembly was revealed in cells expressing an ER retrieval-deficient form of the V-ATPase assembly factor Vma21p (Vma21pQQ). Loss of Voa1p in vma21QQ yeast cells resulted in loss of V-ATPase function; cells were unable to acidify their vacuoles and exhibited growth defects typical of cells lacking V-ATPase. V0 assembly was severely compromised in voa1 vma21QQ double mutants. Isolation of V0–Vma21p complexes indicated that Voa1p associates most strongly with Vma21p and the core proteolipid ring of V0 subunits c, c′, and c″. On assembly of the remaining three V0 subunits (a, d, and e) into the V0 complex, Voa1p dissociates from the now fully assembled V0–Vma21p complex. Our results suggest Voa1p functions with Vma21p early in V0 assembly in the ER, but then it dissociates before exit of the V0–Vma21p complex from the ER for transport to the Golgi compartment.
Application of h-, p-, and hp -Mesh Adaptation Techniques to the SP 3 Equations

This paper is devoted to the application of isotropic and anisotropic mesh adaptivity techniques to the SP 3 equations. We compare uniform refinements, h-, p-, and hp-adaptivity techniques. h-versions only refine the mesh cells whereas p-versions increase locally the polynomial order of the approximation. hp-adaptivity combines both techniques but requires more knowledge regarding the shape of the error. The hp-finite element method (hp-FEM) generates a sequence of adapted meshes by either performing h- or p-refinements, based upon which choice is locally more efficient. At each adaptivity step, a pair of coarse/fine adapted meshes is employed to compute the local error and to determine the next adapted mesh that best minimizes the projection-based interpolation error. The implementation of the various hp-strategies analyzed is performed with the hp-FEM Hermes2D code and numerical results are presented for the SP 3 equations.
Kinetics and mechanisms of action of drugs on microorganisms VII. Quantitative adherence of sulfonamide action on microbial growth to a receptor‐site model

The lag time between sulfonamide addition to a balanced growth culture of Escberichia coli B/r and the observation of action on microbial growth is 5.5 ± 0.5 generations. It is independent of temperature and the degree of growth inhibition by simultaneously added chloramphenicol. The apparent first-order growth rate constants of E. coli in the subsequent drug-affected steady state can be rigorously defined as Kapp. = k0 − k0K1K2S/(1 + K1K2S) where k0 is the rate constant in the absence of a sulfonamide concentration, S; K1 is the steady-state equilibration of sulfonamide between the nutrient medium and the biophase; K2 is the drug-receptor site association constant; and k0 and K1K2 have been defined as functions of absolute temperature. The death rate of completely sulfonamide-inhibited organisms is independent of sulfonamide concentrations. The ΔH values of 1/K1K2 differ for sulfisoxazole (15.9 Kcal./mole), sulfathiazole (4.3 Kcal./mole), and from the k0 (24 Kcal./mole). The techniques provide sensitive and reliable estimates of differences in sulfonamide activities. The derived 1/K1K2 values for sulfisoxazole are directly proportional to the growth rate constant in its absence but in the presence of rateinhibiting chloramphenicol. This indicates that the numbers of receptor sites available for sulfonamide action are directly proportional to the microbial growth rate. The apparent first-order growth rate constant of E. coli in the presence of simultaneously added sulfonamide (S) and chloramphenicol (C) concentrations can be rigorously defined as kapp. = [k′0 − kcC][1 + K1K2(S − 1)]/(1 + K1K2S), where k0′ is the growth rate constant in the absence of chloramphenicol and sulfonamide and k0 is the determined inhibitory constant for chloramphenicol. Variations of sulfonamide concentrations after the lag phase demonstrate that reversibility exists and the ultimate kapp. is in accordance with the cited predictive equation. Dilution of organisms but maintenance of sulfonamide concentrations maintains the steady-state growth rate. Addition or dilution of sulfonamide concentrations show a time-dependent re-equilibration. These facts are consistent with a competitive receptor site model for sulfonamide and a generation rate-dependent metabolite which produces modified metabolites that are stored during drug-free balanced growth.
Developmental pathways to adolescent cannabis abuse and dependence: Child maltreatment, emerging personality, and internalizing versus externalizing psychopathology

Child maltreatment is strongly associated with adolescent psychopathology and substance abuse and dependence. However, developmental processes unfolding from childhood into adolescence that delineate this trajectory are not well understood. The current study used path analysis in a structural equation modeling framework to examine multiple mediator models, including ego control, ego resiliency, and internalizing and externalizing symptoms to investigate this developmental process. Participants were 415 children, assessed across 3 waves of data, (i.e., at ages 7 to 9, 10 to 12, and 13 to 15). The sample included maltreated (n = 259) and nonmaltreated (n = 156) children; groups were comparable in sociodemographic characteristics. Findings support an transactional-ecological model by revealing a developmental sequence in which severity of early childhood maltreatment potentiates less adaptive childhood personality functioning, followed by externalizing problems in preadolescence, and ultimately adolescent cannabis abuse and dependence symptoms. A developmental pathway from child maltreatment to adolescent cannabis abuse and dependence symptoms via personality and preadolescent internalizing problems was not supported. Understanding developmental pathways by which maltreatment experiences increase risk for substance abuse and dependence symptoms in youth has far-reaching implications for the treatment and prevention of substance use disorders.
Variation in Propensity to Exhibit Thanatosis in Nasonia vitripennis (Hymenoptera: Pteromalidae)

Thanatosis (death-feigning) has rarely been documented for Hymenoptera but occurs in the parasitoid wasp Nasonia vitripennis. The propensity to exhibit thanatosis did not differ with age, sex, or food deprivation. Squeezing a female’s abdomen and contacting her antennae were equally likely to trigger thanatosis. Dropping an object next to a female in order to cause substrate vibrations never triggered thanatosis, and dropping a female from a test tube rarely triggered thanatosis. Thanatosis was not seen during interactions between females. There was some tendency for females to exhibit fewer thanatosis responses on white than on colored backgrounds. Females that were least active had the greatest tendency to exhibit thanatosis.
THE THERMOSTABILE ANTICOMPLEMENTARY CONSTITUENTS OF THE BLOOD

Blood serum contains normally certain principles which inhibit serum haemolysis by interfering with the action of complement. In the case of most sera the anticomplementary action appears only after heating to 56° C. or higher. The inhibiting action of this principle is directed against alien as well as native complements, and is non-specific in character. It would appear as if the inactivation of serum at 50° C. or thereabouts were due to a partial liberation of the antilytic principle which just about suffices to neutralize the action of the native complement. As the temperature of the serum is raised, up to a certain point, more and more of the antilysin is set free until the serum comes to contain an overplus, in excess of the quantity neutralizing its own complement, which is capable of interfering with the action of additional native or alien complements. Serum heated to 90° C. is less antilytic than serum heated to 70° C., either because the antilysin has entered into new, more stable compounds which prevent its action, or, as is more probable, because of the liberation from the serum of a second group of principles in themselves haemolytic directly, or indirectly by increasing the power of serum haemolysins (auxilysins). This latter action tends to mask and to suppress the inhibitory influences of the antilysin. The antilysin is removed from serum by digestion with many kinds of blood corpuscles which, apparently, absorb the principle. While, by reason of this treatment, the serum is deprived of its inhibitory power, the corpuscles have acquired greater resistance to serum haemolysins. By treating blood serum and corpuscles with ether the antilysin can be extracted. The ethereal extract, freed from lecithin and certain related bodies, contains the antilysin in a concentrated but not in a pure form, which can now be taken up in saline solution in which it dissolves. The saline solution of the antilysin, which for convenience has been denominated "protectin," behaves in all respects like the native antilytic sera except that it is uninfluenced by temperatures of 90°C. or even higher temperatures. Protectin inhibits serum haemolysis directly by neutralizing complement and indirectly after absorption by corpuscles by increasing their resistance. Hence it is highly probable that the antilytic principle of heated serum and protectin extracted from serum and corpuscles are the same substance. Thermostability is one of the characteristic properties of protectin. Serum and corpuscles, first dried, may be heated to 150°C. without losing the protecting principle, and the principle persists in such heated products for at least two years. Protectin in solution is unaffected by a temperature of 100° C. maintained for one hour, and suffers only slight reduction in activity at the expiration of two hours; while temperatures ranging from 135° to 150°C. bring about marked reduction in protective power. As these alterations are produced by high temperatures the reaction of the solution changes from acid, through neutral, to alkaline.
Isolated Extramedullary Relapse in Childhood Acute Lymphocytic Leukemia

Although the vast majority of children with acute lymphocytic leukemia attain remission with modern therapies, an unacceptably high number will suffer a disease relapse. Both the duration of remission and the site of relapse are important prognostic factors. This review focuses on leukemic relapse isolated to sites outside the bone marrow (extramedullary sites). Data from cooperative study groups as well as large single institutions are reviewed with respect to the incidence of isolated extramedullary relapse as well as the outcome following relapse. The unique anatomic and physiologic properties of the testes and the central nervous system—the two most common sites of isolated extramedullary relapse—are discussed. Finally, the evolution of leukemia therapy is reviewed, bringing into focus the goals and challenges of future therapeutic endeavors.
Medical Data Breaches: What the Reported Data Illustrates, and Implications for Transitioning to Electronic Medical Records

Breaches involving private consumer data are gaining more attention with the increasing push towards electronic records, and the demand for freer access to data. In the medical field, these breaches assume greater significance as they involve private data, and are regulated in far greater measure. The health care industry stores vast amounts of data, and the opportunity for breaches is considerable. This article examines reported medical data breaches and identifies patterns in the data. The results provide insights into the nature of breaches, their frequency, and trends. Implications for health care organizations and individuals are discussed.
Cluster Fragmentation and Facile Cleavage of Phenyl Groups from the SnPh3 Ligand in Reactions of Os3(CO)11(SnPh3)(μ-H) with CO and HSnPh3

Two new cluster complexes, Os3(CO)12(Ph)(μ3-SnPh), 8 (35% yield), and Os4(CO)16(μ4-Sn), 9 (10% yield), were formed when the complex Os3(CO)11(SnPh3)(μ-H), 6, was heated to reflux in toluene solvent under a CO atmosphere. Compound 8 was transformed to 9 in 28% yield when a solution in octane solvent was heated to reflux under a CO atmosphere. Biphenyl was a coproduct in this reaction. Compound 8 contains three osmium atoms with a triply bridging SnPh group. The triosmium cluster has opened and there is only one Os−Os bond between the three osmium atoms. Compound 9 contains two Os2(CO)8 groups held together by a central quadruply bridging tin atom, giving an overall bow-tie structure for the five metal atoms. Two other new compounds, Os2(CO)6(μ-SnPh2)2(SnPh3)2, 10, and HOs(CO)4(SnPh3), 11, were formed in 51% and 20% yields, respectively, from the reaction of 6 with HSnPh3. Compound 10 contains only two osmium atoms linked by an Os−Os bond and two bridging SnPh2 ligands. Each osmium atom also contains one te...
A system dynamics approach to demand and allocation of wireless spectrum for mobile communication

Abstract The National Broadband Plan recommends that the Federal Communication Commission (FCC) should make 300 megahertz (MHz) of spectrum available for mobile broadband use within five years. Finding this spectrum is a major issue as radio spectrum is an encumbered and finite resource. Therefore, the case must be made that “Spectrum Utilization” is not optimal under current conditions and the “Spectrum Scarcity” is for real. The study presented here takes the System Dynamics approach to demonstrate how this situation might be justified. We utilize Stock and Flow model to reconstruct the framework recommended by the FCC and present results that justify the need for more spectrum. The paper also explains why System Dynamics appears to be a comprehensive approach to address wireless industry's “Spectrum Scarcity and Utilization” problem. Dynamic behavior among different variables of the wireless ecosystem is also analyzed through simulation. Preliminary simulation results show that mobile data demand will exceed the current capacity of cellular networks and will create a deficit if more spectrum is not released. We conclude the paper highlighting future research work - expanding and calibrating the model - using System Dynamics techniques.
Chromatin Structure Regulates Gene Conversion

Homology-directed repair is a powerful mechanism for maintaining and altering genomic structure. We asked how chromatin structure contributes to the use of homologous sequences as donors for repair using the chicken B cell line DT40 as a model. In DT40, immunoglobulin genes undergo regulated sequence diversification by gene conversion templated by pseudogene donors. We found that the immunoglobulin Vλ pseudogene array is characterized by histone modifications associated with active chromatin. We directly demonstrated the importance of chromatin structure for gene conversion, using a regulatable experimental system in which the heterochromatin protein HP1 (Drosophila melanogaster Su[var]205), expressed as a fusion to Escherichia coli lactose repressor, is tethered to polymerized lactose operators integrated within the pseudo-Vλ donor array. Tethered HP1 diminished histone acetylation within the pseudo-Vλ array, and altered the outcome of Vλ diversification, so that nontemplated mutations rather than templated mutations predominated. Thus, chromatin structure regulates homology-directed repair. These results suggest that histone modifications may contribute to maintaining genomic stability by preventing recombination between repetitive sequences.
Transport and Retention of Nanoscale C60 Aggregates in Water-Saturated Porous Media

Experimental and mathematical modeling studies were performed to investigate the transport and retention of nanoscale fullerene aggregates (nC60) in water-saturated porous media. Aqueous suspensions of nC60 aggregates (95 nm diameter, 1 to 3 mg/L) were introduced into columns packed with either glass beads or Ottawa sand at a Darcy velocity of 2.8 m/d. In the presence of 1.0 mM CaCl2, nC60 effluent breakthrough curves (BTCs) gradually increased to a maximum value and then declined sharply upon reintroduction of nC60-free solution. Retention of nC60 in glass bead columns ranged from 8 to 49% of the introduced mass, while up to 77% of the mass was retained in Ottawa sand columns. When nC60 suspensions were prepared in deionized water alone, effluent nC60 BTCs coincided with those of a nonreactive tracer (Br−), with minimal nC60 retention. Observed differences in nC60 transport and retention behavior in glass beads and Ottawa sand were consistent with independent batch retention data and theoretical calculat...
A highly sensitive ultra performance liquid chromatography–tandem mass spectrometric (UPLC–MS/MS) technique for quantitation of protein free and bound efavirenz (EFV) in human seminal and blood plasma

Abstract A combined UPLC–tandem mass spectrometric (UPLC–MS/MS) technique has been validated for quantitation of protein free efavirenz (EFV) as well as total concentrations of EFV in human blood and seminal plasma. The analytical method possesses capabilities for concentration measurements of EFV ranging from 0.5 to 10,000 ng/ml with an accuracy (%dev) of −5.2–8.0% and precision (%CV) of r 2 ) >0.98. The method employs a racemic fluorinated analog of EFV (F-EFV) as the internal standard. EFV and F-EFV were eluted from a reverse-phase UPLC column via gradient elution with detection via negative ion multiple reaction monitoring (MRM). EFV and F-EFV, respectively, were detected via the following MRM transitions: m / z 314.0 > 244.1 and m / z 298.0 > 227.9. The time required for the analysis of each sample was 8.0 min. The analytical technique is capable of a reliable detection limit of ∼15–20 fmol of EFV injected on column.
New FOCI pulses with reduced radiofrequency power requirements

Purpose To propose new frequency offset corrected inversion (FOCI) pulses with significantly reduced radiofrequency (RF) power deposition for spin echo imaging by incorporating the variable-rate selective excitation (VERSE) schemes into the pulse design. Materials and Methods Two schemes are proposed to design the new FOCI pulses with dramatically reduced peak RF power requirements. In scheme A, the time-dilation function is derived from a predefined adiabaticity factor modulation function. In scheme B, the time-dilation function is predefined, while the adiabaticity factor is conserved. Results The new FOCI pulses are shown to be able to operate at reduced specific absorption rate (SAR), specifically at the same peak RF power as that of a five- or seven-lobe sinc inversion pulse of the same duration. Using the new FOCI pulse, significant gain in sensitivity was observed in in vivo spin-echo echo-planar imaging, which was attributed to the improved refocusing slice profile. Conclusion The new FOCI pulses can replace the 180° five- or seven-lobe sinc pulses in spin-echo imaging with the same peak RF power requirement and significantly improved slice profile. J. Magn. Reson. Imaging 2004;20:531–537. © 2004 Wiley-Liss, Inc.
Filling the Interstices: Ghrelin Neurons Plug Several Holes in Regulation of Energy Balance

Of several circulating hormones that act on hypothalamus to affect body energy balance, only ghrelin is also expressed in hypothalamic neurons. From the studies of Horvath and colleagues appearing in this issue of Neuron, it appears that neuronal ghrelin acts presynaptically to stimulate release of the orexigenic peptide, neuropeptide Y, and other neurotransmitters, thus defining a new and subtle modulatory circuit.