cssi/SciSciGPT-SciSciNet huggingface dataset:
Stem Cell-Derived Cardiomyocytes Demonstrate Arrhythmic Potential

To the Editor: We applaud the work by Zhang et al1 demonstrating abnormal action potential characteristics in cardiomyocytes derived from pluripotent stem cells. This offers experimental evidence …
7 – BASIC BOOTSTRAP METHODS

This chapter discusses the basics of a modern statistical tool called the bootstrap. Percentile bootstrap method has considerable practical value for a wide range of problems, even with very small sample sizes, and modifications of the method have practical value as well. However, this technique does not perform well when the goal is to make inferences about the population mean based on the sample mean, unless the sample size is very large. Although the percentile bootstrap is not recommended when working with the sample mean, it is perhaps easiest to explain in terms of the sample mean. The percentile bootstrap method uses the estimate of the sampling distribution of the sample mean that makes no assumptions about what this distribution might be. In particular, it does not assume the distribution is normal. If in a statistical problem, the distribution from which observations are sampled is not known, the data available can be used to estimate this distribution, and this is the basic idea behind all bootstrap techniques. In the simplest case, the strategy is to use the observed relative frequencies as estimates of the probabilities associated with possible values observed, and use a computer to generate observations based on these probabilities.
Electrical Conduction in Polymers, Ceramics, and Amorphous Materials

Materials which are electrical (and thermal) insulators are of great technical importance and are, therefore, used in large quantities in the electronics industry, e.g., as handles for a variety of tools, as coatings of wires, or for casings of electrical equipment. Most polymeric materials have the required insulating properties and have been used for decades for this purpose. It came, therefore, as a surprise when it was discovered that some polymers and organic substances may have electrical properties which resemble those of conventional semiconductors, metals, or even superconductors. We shall focus our attention mainly on these materials. This does not imply that conducting polymers are of technical importance at this time. Indeed, they are not yet. This is due to the fact that many presently known conducting polymers seem to be unstable in air or above room temperature. In addition, many dopants used to impart a greater conductivity are highly toxic, and doping often makes the polymers brittle. These problems might be overcome, however, as more conducting polymers are synthesized.
Tympanosclerosis of the Stapes: Hearing Results for Various Surgical Treatments

When tympanosclerosis involves the tympanic membrane or the lateral ossicles, treatment is usually straightforward and uncomplicated. When the stapes is involved, therapy is more controversial and may be more difficult. We report our results in 154 patients who underwent different surgical procedures for tympanosclerosis of the stapes. Followup was up to 10 years. Pure-tone average threshold was significantly improved (p < 0.05) in patients who underwent mobilization procedures or stapedectomy for definitive treatment. The air-bone gap was less than 20 dB at 6 months postoperative in 72% of patients and less than 30 dB in 90%. At 6 months, 2 years, and 5 years there were no statistically significant differences in hearing results between stapedectomy and mobilization patients, some of whom were followed for up to 10 years. No patient had a profound hearing loss after surgery. Surgical treatment for tympanosclerosis of the stapes is a safe procedure, with hearing results similar to those of surgery for other chronic ear diseases involving the ossicular chain.
BK virus nephropathy after simultaneous pancreas-kidney transplantation.

Akpinar E, Ciancio G, Sageshima J, Chen L, Guerra G, Kupin W, Roth D, Ruiz P, Burke G. BK virus nephropathy after simultaneous pancreas–kidney transplantation. Clin Transplant 2010: 24: 801–806. © 2010 John Wiley & Sons A/S. Abstract: Background: BK virus nephropathy (BKVN) was reported in up to 7.5% of patients after simultaneous pancreas–kidney transplantation (SPK). Its management by reduction in immunosuppression might pre-dispose to pancreatic graft loss. Methods: A retrospective analysis of 178 SPK recipients was performed. All patients received thymoglobulin, daclizumab and a maintenance of low-dose steroids, tacrolimus, and either sirolimus or mycophenolate. Results: Two (1.1%) patients were identified with BKVN. Time of diagnosis was 22 and 45 months after transplant. Both patients had superimposed calcineurin toxicity in their graft biopsies. Immunosuppression was reduced in both patients, and leflunomide (LEF) was used in one patient. Concurrent kidney rejection episodes were treated with steroid pulses in both patients. One kidney graft improved with a last estimated glomerular filtration rate (GFR) of 43 mL/min, and another kidney graft showed limited improvement with a last GFR of 30 mL/min. Pancreatic graft function remained excellent in both patients as assessed by serum c-peptide, glycosylated hemoglobin, amylase-lipase, and urine amylase levels. Conclusion: Low incidence of BKVN was observed in our SPK series. Reduction in immunosuppression and sometimes LEF can be effective. The underlying mechanism of stable pancreatic allograft function despite ongoing kidney rejection warrants further investigation.
Mechanisms underlying syntactic comprehension deficits in vascular aphasia: new evidence from self-paced listening.

Sixty-one people with aphasia (pwa) and 41 matched controls were tested for the ability to understand sentences that required the ability to process particular syntactic elements and assign particular syntactic structures. Participants paced themselves word-by-word through 20 examples of 11 spoken sentence types and indicated which of two pictures corresponded to the meaning of each sentence. Sentences were developed in pairs such that comprehension of the experimental version of a pair required an aspect of syntactic processing not required in the corresponding baseline sentence. The need for the syntactic operations required only in the experimental version was triggered at a “critical word” in the experimental sentence. Listening times for critical words in experimental sentences were compared to those for corresponding words in the corresponding baseline sentences. The results were consistent with several models of syntactic comprehension deficits in pwa: resource reduction, slowed lexical and/or synt...
The management and treatment of habitual abortion

Abstract Habitual abortion is still one of the most discouraging conditions to deal with in the field of medicine. Spontaneous abortion presents a diversity of causes, such as: abnormalities, displacements, and inflammations of the genital tract; infectious diseases; germ plasm defects; tumors of the genital organs; dietary deficiencies; vitamin deficiencies; many alleged causes indicating serious investigation; and, last, the endocrine system in which the thyroid, ovaries, and pituitary gland are so important. Important chemical investigations in endocrinology as related to the thyroid gland, ovaries, and pituitary gland, coupled with recent experimental data upon function, have been responsible for such advances in therapy as the use of progesterone and progestin-like extracts in the treatment of habitual abortion. It has been very well established in the human being that the corpus luteum remains active until about the fourth month of pregnancy, and then begins to degenerate slowly until about the seventh month, when there remains little evidence of its presence or activity. It has been shown experimentally in animals that the corpus luteum substance is necessary for the maintenance of normal pregnancy. There is every reason to believe that this stabilizing factor is present in the human being until the placenta is a controlling factor. Experimental studies by Falls and his collaborators show very clearly in the human being that the estrogenic substance increases uterine irritability and muscle contraction, and the corpus luteum substance is the antagonistic factor. It was also shown that progesterone nullifies posterior pituitary response. These findings are important in relation to habitual spontaneous abortion and its treatment.
The embryology of cryptobranchus allegheniensis. III. Formation of the blastula

In the blastula the region of accelerated cell division is on the ventral side of the egg, nearly opposite the site of the future beginning blastopore. The ventral wall of the blastocoele is thicker than the dorsal. In the very early gastrula a new region of accelerated cell division appears in the vicinity of the dorsal lip of the blastopore. A downward movement of material comprising the marginal zone of micromeres and the portion of the wall of the blastocoele immediately above it occurs during all the later blastula stages and continues until this material is carried below the level of the equator and involved in the process of gastrulation. On the dorsal side of the egg, this movement is more rapid than on the ventral side. In the late blastula stage there are evidences of growth in the region of smaller micromeres. In the very late blastula, a vertical groove appears at the dorsal margin of the floor of the blastocoele; this groove is believed to indicate the operation of factors concerned with gastrulation. In connection with the first nuclear division, evidences of cytoplasmic activity leading to the formation of the first cleavage furrow are described. As the blastomeres become smaller, progressive changes take place in the distribution of their cytoplasm.
Children's Pattern Perception, Accuracy, and Preference in Three Response Modes

The purpose of this study was to investigate the length of patterns children perceived from melodic contexts and their preference and accuracy in three response modes for demonstrating those patterns. Eighteen students, six each from Grades 4, 2, and kindergarten, participated in 10 videotaped sessions and were asked to demonstrate their perceptions in vocal, motor, and graphic response modes. Results indicated that students were not significantly more accurate in one response mode than in another, nor were age-groups significantly different from each other in accuracy of responses. The most frequently preferred response mode was the vocal mode, and mode preferences became more varied with increased age. Results also indicated that each age-group perceived patterns fitting a four-beat duration significantly more frequently than other pattern lengths. Also, with apparent focus on figural groupings, 16 of the 18 students accurately included anacruses in their response patterns more than 50% of the time.
Sensitivity of Cortisol and Adrenal Androgens to Dexamethasone Suppression in Hirsute Women

To test the hypothesis that adrenal androgen secretion is more easily suppressed than is cortisol secretion by glucocorticoids, we examined the dose-response relationship for suppression of serum dehydroepiandrosterone (DHA), DHA sulfate (DHAS), testosterone, and cortisol by dexamethasone. Nine hirsute women received daily doses of dexamethasone, starting with 0.1 mg and increasing by 0.1-mg increments every 4 weeks, until the cortisol response to ACTH was reduced to 20% or less of the response before treatment. Serum hormone levels were measured at each dexamethasone dose before and after iv administration of 25 U synthetic ACTH. Although low doses of dexamethasone caused a similar suppression of basal cortisol, DHA, and DHAS levels, ACTH-stimulated DHA levels were suppressed to a greater extent than ACTH-stimulated cortisol levels. Higher dexamethasone doses did not result in a significant difference between the degree of cortisol and adrenal androgen suppression, as near-maximal suppression occurred for all three hormones. Maximal suppression of basal testosterone levels occurred at or below the dexamethasone dose of 0.3 mg. We conclude that the adrenal androgen secretory capacity is more sensitive to suppression by dexamethasone than is the adrenal cortisol secretory capacity. Furthermore, glucocorticoid therapy for hirsutism need not achieve complete cortisol suppression to effect a major reduction in adrenal androgen levels.
Non-homologous end joining is important for repair of Cr(VI)-induced DNA damage in Saccharomyces cerevisiae

Hexavalent chromium is known to be a potent carcinogen that leads to many different DNA lesions, including DNA-protein crosslinks, and single- and double-strand breaks. In Saccharomyces cerevisiae, DNA double-strand breaks are mainly repaired by either homologous recombination (HR) or non-homologous end-joining (NHEJ) repair pathways. Here, we show that mutants deficient in NHEJ (yku70Delta, rad50Delta, dnl4Delta, mre11Delta, xrs2Delta) of S. cerevisiae are more sensitive to Cr(VI) toxic effects than wild-type cells. Also, a deletion mutant of SAE2 showed a similar sensitivity to Cr(VI), even though it has no apparent direct role in NHEJ. We also found that double mutants in HR and NHEJ (yku70Delta/rad52Delta, rad50Delta/rad52Delta, dnl4Delta/rad52Delta, mre11Delta/rad52Delta, xrs2Delta/rad52Delta) are synergistically more sensitive to Cr(VI) exposure than any of the single mutants, indicating that both repair pathways are involved in the repair of Cr(VI)-induced lesions. Finally, when the NHEJ mutants were exposed to Cr(VI) under anaerobic growth conditions, Cr(VI) toxicity was suppressed.
Real-time monitoring of steady-state pulsed chemical beam epitaxy by p-polarized reflectance

Abstract The structure in the p-polarized reflectance (PR) intensity R p4 ( t ) - observed under conditions of pulsed chemical beam epitaxy (PCBE) - is modeled on the basis of the four-layer stack: ambient/surface reaction layer (SRL)/epilayer/substrate. Linearization of the PR intensity with regard to the phase factor associated with the SRL results in a good approximation that can be expressed as R p4 = R p3 + ΔR p . R p3 is the reflectivity of the three-layer stack ambient-epilayer-substrate. ΔR p describes the properties of the SRL. An explicit relation is derived between ΔR p ( t ) and the time-dependent surface concentrations c h ( t ) ( h = 1, 2, …, N ) of the constituents of the SRL, which holds for conditions of submonolayer coverage of the surface by source vapor molecules. Under conditions of low temperature PCBE at high flux, the SRL is expected to exhibit nonideal behavior, mandating replacement of the surface concentrations by activities. Also, in this case, the thickness of the SRL must be represented in terms of partial molar volumina V h . Since the relation between ΔR p ( t ) and the activities of reactants, intermediates and products of the chemical reactions driving heteroepitaxial growth is non-linear, the extraction of kinetic parameters from the measured time dependence of the PR signal generally requires numerical modeling.
Modified-orientation log to assess hepatic encephalopathy.

Summary Background The subjectivity of the West-Haven criteria (WHC) hinders hepatic encephalopathy (HE) evaluation. The new HE classification has emphasised assessment of orientation. The modified-orientation log (MO-log, eight questions, scores 0–24; 24 normal) is adapted from a validated brain injury measure. Aim To validate MO-log for HE assessment in cirrhosis. Methods Cirrhotics admitted with/without HE were administered MO-log. We collected cirrhosis/HE details, admission/daily MO-logs and WHC (performed by different examiners), time to reach normal mentation (MO-log ≥23) and MO-log/WHC change (Δ) over day 1. Outcomes were in-hospital mortality, duration to normal mentation and length-of-stay (LOS). Regressions were performed for each outcome. MO-log inter-rater reliability was measured. Results Ninety-six HE (55 ± 8 years, MELD 21) and 20 non-HE (54 ± 5 years, MELD 19) in-patients were included. In HE patients, median admission WHC was 3 (range 1–4). Mean MO-log was 12 ± 8 (range 0–22). Their LOS was 6 ± 5 days and 13% died. Time to reach normal mentation was 2.4 ± 1.7 days. Concurrent validity: there was a significant negative correlation between admission MO-log and WHC (r = −0.79, P < 0.0001). Discriminant validity: admission MO-logs were significantly lower in those who died (7 vs. 12, P = 0.03) and higher in those admitted without HE (23.6 vs. 12, P < 0.0001). MO-log improved in 69% on day 1 (ΔMO-log 4 ± 8) which was associated with lower duration to normal mentation (2 vs. 3.5 days, P = 0.03) and mortality (3% vs.43%, P < 0.0001), not ΔWHC. Regression models for all outcomes included admission/ΔMO-log but not WHC as a predictor. Inter-rater reliability: ICC for MO-log inter-rater observations was 0.991. Conclusions Modified-orientation log is a valid tool for assessing severity and is better than West-Haven criteria in predicting outcomes in hospitalised hepatic encephalopathy patients.
Eigenshape analysis of microfossils: A general morphometric procedure for describing changes in shape

A general morphometric procedure is described that organizes collections of microfossil outlines according to their shape. It involves representing the greatest proportion of variation observed among a collection of shapes by the least number of different shapes. Since these are determined as empirical orthogonal shape functions—eigenfunctions—of the observed shapes, the procedure is termed eigenshape analysis. Observed shapes are arranged and their shape differences systemized by reference to these determined eigenshape functions. The well-known ecophenotypic shape variation with latitude exhibited by the Pleistocene planktonic foraminifer Globorotalia truncatulinoides (d'Orbigny)serves as an example.
Transplacental induction of carcinogen-hydroxylating systems with 2,3,7,8-tetrachlorodibenzo-p-dioxin

Abstract The effects of a highly toxic herbicide contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) upon rates of hydroxylation of N-2-fluorenylacetamide (FAA) and of benzo[a]-pyrene (BP) were studied in fetal livers, in placentas, maternal livers, and adrenal glands of pregnant Sprague-Dawley rats. Aryl hydrocarbon hydroxylase (AHH) activity was increased 14- and 100-fold in maternal and fetal livers, respectively, but only minimal increases were observed in placentas and adrenal glands. Similar results were obtained with respect to rates of 7-, 5-, N-, 3-, and 1-hydroxylations of FAA. Histologic examinations revealed extensive cellular damage in the placentas as well as pathologic changes in fetal and maternal livers. Electron microscopy indicated enlarged mitochondria and extensive glycogen deposition in maternal and fetal livers and increases in the amounts of rough endoplasmic reticulum in fetal livers. Analyses of BP metabolism with high-pressure liquid chromatography also revealed that the formation of diols (relative to phenols) was markedly increased in fetal and maternal livers following treatments with TCDD. The results suggested that the relative lack of response of fetal hepatic mixed-function oxidase systems to commonly employed inducing agents (polycyclic aromatic hydrocarbons) was not due to a lack of appropriate structural and/or regulatory genes required for the expression of enzyme induction during fetal life.
Water Barrier Properties of Zein-Oleic Acid Films

ABSTRACT Free-standing films were prepared from zein formulations containing 30, 40, 50, 60, 70, and 80% oleic acid (OA). Zein/OA formulations were also used as coating films for rodent diet bars. Water vapor permeability (WVP) of films and moisture loss rate (MLR) of coated rodent diet bars were measured at 4 and 25°C. Temperature affected the water barrier properties of films and coatings. At 4°C, WVP of films decreased with OA concentration while it increased at 25°C. WVP behavior was attributed to oleic acid phase changes due to temperature. At 4°C, OA is a crystalline solid that limits water diffusion through the films. At 25°C, liquid OA increased the system free volume and allowed for water diffusion. The effect was more pronounced the higher the OA concentration in films. Differential scanning calorimetry (DSC) of zein/OA films showed endothermic peaks at 12–18°C, confirming the melting of OA in that temperature range. MLR of coated rodent diet bars was also affected by temperature and OA concentr...
Comment on the spin of the 5.46-MeV level of $sup 19$O

The neutron width of the unbound 5.46-MeV state in $^{19}\mathrm{O}$ and its strength in the $^{18}\mathrm{O}(d,p)^{19}\mathrm{O}$ reaction are consistent only with ${J}^{\ensuremath{\pi}}={\frac{3}{2}}^{+}$.
Development and maintenance of connectivity in the visual system of the frog. II. The effects of eye removal

Abstract The interdependence of retinotectal and intertectal connections in the ontogeny of the visual system of the frog (Rana pipiens) was studied. To remove the direct afferent input from retina to one side of the tectum one eye was taken out at different embryonic and larval stages of development. Animals were allowed to pass through metamorphosis, at which time intertectal connections linking the visual input to the two sides of the tectum normally develop. Responses to visual stimulation were then recorded with extracellular microelectrodes from both sides of the tectum. In all animals eye removal resulted in size reduction of the tectum on the side of the remaining eye. Eye removal prior to the onset of metamorphosis (stage XIX) resulted in gross abnormalities of visually evoked responses in the tectum ipsilateral to the remaining eye; receptive fields were much larger than normal, localization was poor, and responses fatigued rapidly upon repeated stimulation. Eye removal after the onset of metamorphosis, on the other hand, did not result in any detectable abnormalities of the ipsilateral visual responses; receptive fields were small and well localized. This normal ipsilateral visuotectal projection persisted indefinitely (up to 273 days) in the absence of one eye. We conclude that there is a Necessary interaction between the developing intertectal pathways and the afferent fibers linking retina and tectum. This interaction appears to be completed during metamorphosis. The data presented in this and the preceding paper12 argue against any subsequent interactions between the retinotectal and intertectal connections. Furthermore, the two papers together suggest that the interactions taking place during metamorphosis are the result of intrinsic developmental mechanisms and are not altered by sensory stimulation.
A photon echo study of pentacene in naphthalene at high pressure

Abstract Temperature-dependent (2–10 K) photon echo measurements are presented for pentacene in naphthalene at high pressure (12.5 kbar) in a diamond anvil cell. A decrease in the homogeneous dephasing rate (i.e. a narrowing of the homogeneous linewidth) is observed at high pressure. In addition, the temperature dependence of the homogeneous dephasing rate is used to obtain the effect of pressure on the frequency and lifetime of the pseudolocal phonon associated with a pentacene impurity in a crystalline naphthalene matrix.
Canadian and U.S. sources impacting the mercury levels in fine atmospheric particulate material across New York state

An extensive atmospheric sampling and analysis program has been completed in order to identify and apportion the sources of mercury associated with fine atmospheric particulate material. Samples of fine atmospheric particulate material were collected daily, at five remote sites in New York State, over a period of 2 years. The trace element composition of 1200 of these samples was determined by Instrumental Neutron Activation Analysis. Results of both meteorological and statistical analyses of the data indicate that approximately 55% of the fine particulate mercury originated from smelters in Ontario and Quebec, and 25% originated from a mixture of regional sources in the Midwestern United States. A decline in the average measured particulate Hg concentration, beginning in February 1993, has been attributed to reduced emissions from one or more of the major Canadian smelters.
Optically Connected Multiprocessors For Simulating Artificial Neural Networks

This paper investigates the architectural requirements in simulating large neural networks using a highly parallel multiprocessor with distributed memory and optical interconnects. First, we model the structure of a neural network and the functional behavior of individual cells. These models are used to estimate the volume of messages that need to be exchanged among physical processors to simulate the weighted connections of the neural network. The distributed processor/memory organization is tailored to an electronic implementation for greater versatility and flexibility. Optical interconnects are used to satisfy the interprocessor communication bandwidth demands. The hybrid implementation attempts to balance the processing, memory and bandwidth demands in simulating asynchronous, value-passing models for cooperative parallel computation with self-learning capabilities.
Bacterial communities in urban aerosols collected with wetted-wall cyclonic samplers and seasonal fluctuations of live and culturable airborne bacteria

Airborne transmission of bacterial pathogens from point sources (e.g., ranches, dairy waste treatment facilities) to areas of food production (farms) has been suspected. Determining the incidence, transport and viability of extremely low levels of pathogens require collection of high volumes of air and characterization of live bacteria from aerosols. We monitored the numbers of culturable bacteria in urban aerosols on 21 separate days during a 9 month period using high volume cyclonic samplers at an elevation of 6 m above ground level. Culturable bacteria in aerosols fluctuated from 3 CFU to 6 million CFU/L of air per hour and correlated significantly with changes in seasonal temperatures, but not with humidity or wind speed. Concentrations of viable bacteria determined by fluorescence staining and flow cytometry correlated significantly with culturable bacteria. Members of the phylum Proteobacteria constituted 98% of the bacterial community, which was characterized using 16S rRNA gene sequencing using DNA from aerosols. Aquabacterium sp., previously characterized from aquatic environments, represented 63% of all clones and the second most common were Burkholderia sp; these are ubiquitous in nature and some are potential human pathogens. Whole genome amplification prior to sequencing resulted in a substantial decrease in species diversity compared to characterizing culturable bacteria sorted by flow cytometry based on scatter signals. Although 27 isolated colonies were characterized, we were able to culture 38% of bacteria characterized by sequencing. The whole genome amplification method amplified DNA preferentially from Phyllobacterium myrsinacearum, a minor member of the bacterial communities, whereas Variovorax paradoxus dominated the cultured organisms.
The evolution of a silicic magma system: isotopic and chemical evidence from the Woods Mountains volcanic center, eastern California

The isotopic compositions of Nd and Sr and concentrations of major and trace elements were measured in flows and tuffs of the Woods Mountains volcanic center of eastern California to assess the relative roles of mantle versus crustal magma sources and of fractional crystallization in the evolution of silicic magmatic systems. This site was chosen because the contrast in isotopic composition between Precambrian-to-Mesozoic country rocks and the underlying mantle make the isotope ratios sensitive indicators of the proportions of crustal- and mantle-derived magma. The major eruptive unit is the Wild Horse Mesa tuff (15.8 m.y. old), a compositionally zoned rhyolite ignimbrite. Trachyte pumice fragments in the ash-flow deposits provide information on intermediate composition magma types. Crustal xenoliths and younger flows of basalt and andesite (10 m.y. old) provide opportunities to confirm the isotopic compositions of potential mantle and crustal magma sources inferred from regional patterns. The trachyte and rhyolite have ɛNd values of -6.2 to -7.5 and initial 87Sr/86Sr ratios mostly between 0.7086 and 0.7113. These magmas cannot have been melted directly from the continental basement because the ɛNd values are too high. They also cannot have formed by closed system fractional crystallization of basalt because the 87Sr/86Sr ratios are higher than likely values for parental basalt. Both major and trace element variations indicate that crystal fractionation was an important process. These results require that the silicic magmas are end products of the evolution of mantle-derived basalt that underwent extensive fractional crystallization accompanied by assimilation of crustal rock. The mass fraction of crustal components in the trachyte and rhyolite is estimated to be between 10% and 40%, with the lower end of the range considered more likely. The generation of magmas with SiO2 contents greater than 60% appears to be dominated by crystal fractionation with minimal assimilation of upper crustal rocks.
Trajectory Studies of SN2 Nucleophilic Substitution. 6. Translational Activation of the Cl- + CH3Cl Reaction

Classical trajectory simulations are used to study the translational activation of the Cl- + CH3Cl SN2 reaction at energies in the range 20−80 kcal/mol. The trajectories are calculated on the PES3 analytic potential energy surface. The shape of the reactive cross section versus relative translational energy Erel and the translational threshold of 18 kcal/mol are both similar to recent experimental results [J. Phys. Chem. A 1997, 101, 5969]. The reactive trajectories are direct, with negligible trapping in the ion−dipole complexes. The product energy is primarily partitioned to relative translation with small and similar amounts of energy partitioned to vibration and rotation. The velocity scattering angle distribution suggests backward scattering and a rebound mechanism for translational activation at low Erel, with increasing importance of forward scattering and a stripping mechanism as Erel is increased. An analysis of angular momenta terms and their correlations shows that the total angular momentum is...
Oligochaete influence on settlement, growth and reproduction in a surface-deposit-feeding polychaete

Abstract The functional-group hypothesis predicting that a mobile subsurface-deposit feeder would inhibit the recruitment and subsequent development of a more sedentary tubiculous surface-deposit feeder was tested through a series of laboratory and field manipulations of the oligochaete Monopylephorus evertus Brinkhurst and the polychaete Streblospio benedicti Webster. Laboratory and field studies indicated that settlement of S. benedicti was unaffected by the presence of M. evertus. Settlement of syllid, capitellid and other spionid polychaetes, gastropods and Gemma gemma Totten also appeared to be unaffected. In laboratory cultures, M. evertus caused decreased survivorship of S. benedicti from age 11 wk through senescence and decreased growth (addition of setigers) at age 6–11 wk. Growth of newly settled and older worms may be decreased by the presence of M. evertus, however, the experimental design had insufficient power to determine significance when treatment differences were small. Reduced growth of juveniles, leading to smaller size, was predicted to cause decreased reproductive output in S. benedicti although size-specific reproductive capacity of individual worms was unaffected. Results are consistent with functional-group theory predicting mobile burrowing forms to have negative effects on more stationary tubiculous forms. However, significant decreases in growth rate were limited to the juvenile (recruitment) stages of S. benedicti, emphasizing the importance of examining the entire life cycle of the species of interest. This study also highlights the need for future investigations to determine the role of marine oligochaetes in the dynamics of salt-marsh and estuarine communities.
Gender and the residential telephone, 1890–1940: Technologies of sociability

Recent work on gender and technology debunks the claim that household technologies have “liberated” women from domestic work. The history of telephone use in North America suggests, however, that global conclusions about gender and consumer technologies may be misleading. Although marketed primarily as a business instrument and secondarily as an instrument to facilitate housework, the telephone was, in a sense, “appropriated” by women for social and personal ends. This paper explores the “affinity” of women for the telephone, how women in the half-century before World War II used the telephone, and why. It suggests that there is a class of technologies that women have exploited for their own, gender-linked, social and personal ends.
Issues of Parent Compliance

The purpose of this paper was to discuss the issues of parent compliance that are of concern to pediatric physical and occupational therapists who prescribe home exercise and to clinical researchers who study the effects of treatment on child development. Parents of disabled children are at risk for low levels of compliance due to the characteristics of the home program, which are complex, continue over many years, and require the parent to make changes in his or her lifestyle. Although many methods have been used to measure compliance, the use of disposable treatment items or a daily journal are most appropriate for therapists. Therapists can assist parents by simplifying the program and closely monitoring, with the parent, and the home activities.
Femtosecond laser-assisted intracorneal keratoprosthesis implantation: a laboratory model.

Purpose To demonstrate femtosecond laser-assisted intracorneal keratoprosthesis implantation and determine the mechanical stability as a function of intraocular pressure. Methods Eight human corneoscleral rims were mounted on an artificial anterior chamber. The femtosecond laser microkeratome was used to create a 2.5-mm diameter posterior corneal cap. A 7.2-mm-diameter lamellar stromal pocket was then created at mid-corneal depth. Finally, a 6-mm arc opening to the corneal surface was created at the periphery of the lamellar cut. The posterior lenticule was removed using corneal forceps and a 7.0-mm biopolymer keratoprosthesis was inserted into the stromal pocket. The surface wound was sealed using two 10-0 nylon sutures. A 3.0-mm anterior corneal opening was trephined to expose the keratoprosthesis. Intrachamber pressure was raised until wound leak was observed. Results Seven of the 8 implants withstood pressures of at least 135 mm Hg without implant extrusion. Conclusion Femtosecond laser corneal dissection provides an alternative to more challenging manual dissection methods for keratoprosthesis implantation. Use of the femtosecond laser microkeratome will further refine keratoprosthesis surgical technique and may allow rapid and easy execution of the surgery.
Evidence for post-transcriptional modification of human salivary amylase (amyl) isozymes.

Human parotid salivary amylase (Amy1) isozymes may be separated into two families: (1) one of higher molecular weight and slower electrophoretic mobility, odds, and (2) the other of lower molecular weight and faster electrophoretic mobility, evens. An enzyme has been detected in whole saliva, and also partially purified from human oral bacterial flora, which converts the isoamylases from odds to evens. No similar modifying activity was detected in parotid saliva or submandibular and sublingual salivas. A model is presented which explains the multiple isozymes of salivary amylase by post-transcriptional modification of a single gene product.
FOLATE SUPPLEMENTATION DOES NOT PREVENT NEURAL TUBE DEFECTS INDUCED BY ALCOHOL OR HEAT

Recent studies suggest that either maternal binge drinking or maternal hyperthermia might be one cause for neural tube defects. Timed pregnant golden hamsters were exposed to a double dose of ethanol on the morning of the 8th day of gestation (the day of neural tube closure in this species), and a 44 percent incidence of neural tube defects was observed). Similar defects could be engendered by treating the animals with varying periods of heat in a water-jacketed incubator at 39.5 degrees centigrade on the morning of Day 8. A 50-minute heat exposure resulted in a 35 percent incidence of neural tube defects, and a shorter exposure (44 minutes) resulted in a 23 percent incidence, while a longer exposure (56 minutes) resulted in a 68 percent incidence. We attempted to explore the hypothesis that maternal vitamin supplementation with folate may be effective in reducing the incidence of neural tube defects. Osmotic pumps filled with either folate or saline were placed subcutaneously in pregnant hamsters on the 6th day of gestation. Despite significantly increased maternal folate levels prior to providing a teratogenic insult with either a double dose of alcohol 4 hours apart or 50 minutes of heat in water-jacketed incubator, no significant protection from neural tube defects was afforded by supplementing the mother with folate. We question whether preconceptual vitamin supplementation may promote careful pregnancy planning which includes avoidance of known teratogens.
Inspections as program evaluation: A partial overlap

OIG activities are evaluative in some senses, but they cover a narrow set of potential evaluative criteria that are needed to judge the worth of social programs. If OIGs are becoming main players in program evaluation, a dangerous trend is developing.
The paradox of transcendent machines in the demystification of the Boxley Christ

The discourse of posthumanism considers the body a site of negotiation between the material and the transcendent, and medievalists have noted the resemblance between this posthuman body-as-nexus and the medieval notion of the body of Christ as a material pathway to transcendence. The physical incarnation of Christ, in elevating the standing of humanity through a synecdochic association between the embodied divine and the body of the faithful, provided a material means to salvation. But whereas posthumanism imagines a body readied for a literal transcendence through machinic interventions, the late medieval relationship to the divine body was largely affective. These discourses therefore mostly run parallel, but may be bridged through an interesting if little-known incident in the representational history of the embodied divine, in the story of the Boxley Christ.
Subcooled Flow Film Boiling Across a Horizontal Cylinder: Part I—Analytical Model

An analytical model of stable subcooled flow film boiling on the front of a horizontal cylinder and a model for the wake region downstream of the flow separation points were developed. The flow and temperature fields upstream of the separation points were represented by a 'local-similarity' solution obtained through a rigorous mathematical transformation. The transformed governing equations were solved numerically using a finite-difference scheme. Numerical solutions for the vapor layer thickness, the velocity, and the temperature fields were obtained for both the liquid and vapor layers. The results showed that the liquid boundary layer was thicker than the vapor film. Increases in the liquid subcooling and in the free-stream velocity decreased the vapor layer thickness. The influence of convection in the vapor layer is small yielding a near-linear temperature distribution. A two-dimensional vapor wake model was developed based on mass and energy balances. Numerical solutions, including the vapor layer thickness and the temperature field of the front part and the wake part, were matched at the separation points. The results showed that increases in the liquid subcooling decreased the vapor layer thickness. Heat transfer in the wake region can amount up to 20 percent of the heat transfer in themore » forward region and should not be neglected especially at high subcooling. 19 refs., 8 figs.« less
Gas chromatography of some alkenyl- and cycloalkenylnaphthalenes on bentone 34, silicone fluid DC 550, and Apiezon L phases

Abstract Gas chromatographic retention data are reported for sixteen alkenyl- and cycloalkenylnaphthalenes with stationary phases of Bentone 34; silicone fluid DC 550, and Apiezon L at 200°C. Retention data with the silicone and apiezon phases are interpreted in terms of volatility of the solute, which varies with molecular weight and intramolecular twisting. Retention values with Bentone 34 are interpreted in terms of two factors: principally (a), adsorbability of the solute (to the aluminosilicate sheets of Bentone), which varies with inductive effect and intramolecular twisting; as well as (b), volatility.
Patterns of acid-base regulation in urodele amphibians in response to variations in environmental temperature

Abstract 1. 1. Larval and adult Ambystoma tigrinum, adult Amphiuma means and Necturus maculosus were acclimated to 5, 15 and 25°C for analysis of blood pH, PCO2, and [HCO3−]. 2. 2. They demonstrated the typical poikilothennic maintenance of “relative alkalinity” by significantly decreasing their pH with warming; δpH/δT ranged from −0.015 to −0.018. 3. 3. Necturus remained a water breather with constant PCO2 (4.8–5.6 torr) and significantly decreased [HCO3−] (19.5–8.6 mM) with warming. 4. 4. Larval A. tigrinum and Amphiuma, water breathing at 5°C and then water-air breathing at 15 and 25°C, significantly increased PCO2(3.9–13.6 torr and 5.8–12.5 torr, respectively) with warming. Larval A. tigrinum significantly increased their [HCO3−] (17.5–26.9mM) while Amphiuma made insignificant change (30.4–22.4mM). 5. 5. Adult A. tigrinum remained an air breather with a relatively elevated PCO2 which significantly rose (9.1–14.2 torr) and an [HCO3−] which significantly decreased (35.8–22.2mM) with warming. 6. 6. This suggests that these urodeles manipulate their extracellular PCO2 and [HCO3−] relationship as they pursue maintenance of “relative alkalinity” during thermal acclimation and altered metabolism.
Variation in female southern pine beetle size and lipid content in relation to fungal associates

Female southern pine beetles, Dendroctonus frontalis Zimmermann, may propagate two species of symbiotic fungi in a prothoracic mycangium. Females can carry either Ceratocystiopsis ranaculosus Bridges and Perry or an unnamed basidiomycete or both; some carry no fungi. Thus, females can be categorized into one of four groups based on mycangial content. We examined size and lipid content of emerging brood adult females based on these mycangial fungal classes. Female beetles carrying the basidiomycete, either alone or in combination with C . ranaculosus , were larger, heavier, and contained more lipid than did females carrying only C . ranaculosus . Size and lipid content also varied by season, as did the number of females carrying different fungal combinations. Regression analysis showed that variation in the occurrence of the basidiomycete was significantly related to variation in averages of beetle size and lipid content measurements.
Computerised measures of electro-oculographic activity during sleep.

Abstract Since electro-oculographic (EOG) activity during human sleep appears to be of medical diagnostic and prognostic value, the vast amount of EOG data representative of even a single night's sleep warrants the development of automated pattern recognition and information extraction techniques. Such a technique for the analysis of sleep EOG rapid eye movement (REM) is presented in which the time of occurrence, area, height, duration and binocular synchrony for each REM are measured. This automated technique for sleep EOG analysis is currently used in the investigation of periodicities and values of REM parameters for normal subjects and in the differential diagnosis of affective disorders.
Analysis of lubricated planar stagnation die flow

Abstract Lubricated die flows with a low-viscosity liquid separating a viscous material from the solid walls have been proposed for extensional rheometers. Steady, two-dimensional flow through a lubricated planar stagnation die is analyzed here by Galerkin's method of weighted residuals with finite element basis functions on streamlined subdomains. For the more viscous liquid, the shear-thinning Carreau model is chosen. Alternatives for modelling the Newtonian lubricant are two-dimensional flow analysis, lubrication approximation, and Navier's slip boundary condition: all are examined. An approximate analytical solution suggested by the computations is also presented. Portraits are shown of lubricant layer thickness and pressure velocity, deformation rate, γ, and vorticity, ω, fields. From the last two, Giesekus's local flow classification, Φ =(γ − ω)(γ + ω), is evaluated. Both the approximate solution and the theoretical calculations are compared to available experimental data. The approximate analytical solution leads to a new relation between the extensional viscosity and the pressure profile in the die. Pure planar extension throughout the die is prevented by the interaction of the die shape with the normal viscous stresses at the free interface. The sign change of the normal viscous stresses as the flow switches from a diverging to a converging channel is the key feature. However, two regions of the flow are nearly extensional and can be analyzed with the analytic approximation. Implications for extensional rheometry and design of lubricated flows are discussed.
Lovastatin inhibits the stimulation of mitogen-activated protein kinase by insulin in HIRcB fibroblasts.

Abstract Lovastatin, a cholesterol biosynthesis inhibitor, has recently been shown to inhibit mitogenesis and tumor growth. We have investigated the effects of lovastatin on the activation of MAP kinase by insulin using as a model HIRcB cells, a rat fibroblast cell line that overexpresses the human insulin receptor. Treatment with lovastatin (1–30 μ M ) for 24 h decreased the level of activation of MAP kinase by insulin by as much as 60%. Immunoblotting experiments using a specific anti-MAP kinase monoclonal antibody demonstrated that the amount of MAP kinase protein in the cells was not altered by lovastatin treatment. Likewise, lovastatin had no apparent effects on the expression of the insulin receptor. Treatment with lovastatin (20 μ M ) reduced the percentage of farnesylated Ras by 50%. Immunoprecipitation of tyrosine phosphorylated proteins from HIRcB cell lysates followed by immunodetection of MAP kinase using specific antibodies demonstrated a reduced level of insulin-induced tyrosine phosphorylation levels of MAP kinase in lovastatin-treated cells. Furthermore, immunodetection of the β-subunit of the insulin receptor in anti-phosphotyrosine immunoprecipitates revealed that treatment with lovastatin reduced the tyrosine phosphorylation levels of the receptor. Lysates obtained from cells treated with increasing concentrations of lovastatin demonstrated a dose-dependent inhibition of the insulin-induced tyrosine phosphorylation of the receptor. Treatment with mevalonic acid prevented the effects of lovastatin demonstrating that the effects of the drug are a consequence of its inhibitory effects on the synthesis of steroids. It is concluded that, in addition to inhibition of Ras farnesylation, lovastatin reduces receptor tyrosine phosphorylation levels which also contributes to the blockade of MAPK activation by the insulin receptor.