cssi/SciSciGPT-SciSciNet huggingface dataset:
Cosmological effects of superconducting strings

Abstract Superconducting cosmic strings are a plausible consequence of symmetry breaking in grand unified gauge theories. The luminosity in electromagnetic radiation of an oscillating current-carrying loop may substantially exceed the luminosity in gravitational radiation. In the typical case considered, the energy released electromagnetically is 1049 erg s−1, or 1066 erg in toto. Several consequences follow from this, the most interesting of which is the possibility that such loops may heat their surroundings, generating large, dense spherical shells of gas. Galaxies forming on these gravitationally unstable shells at moderate redshift will be seen at the present epoch to lie on bubbles having radii in the range 10–20h−1 Mpc if the initial ratio of luminosity in electromagnetic waves to that in gravitational wavess is > 10−3 for mass/length 1022 g cm−1. The required primordial energy density in magnetic fields is > 3 × 10−9 of the radiation energy density, if the charge carriers are bosons or superheavy fermions. Since these shells fill up space, the galaxies will have a distribution similar to that found in a recent survey of the northern sky. When the current saturates, a loop will emit particles copiously, and may be seen as an X-ray source at z ∼ 10–50. Such loops may also contribute significantly to the hard X-ray and γ-ray backgrounds and to 1020 eV cosmic rays.
Alkaloids from amphibian skin: a tabulation of over eight-hundred compounds.

A diverse array of biologically active, lipid-soluble alkaloids have been discovered in amphibian skin. Such alkaloids include the following: the steroidal samandarines from salamanders, the batrachotoxins, histrionicotoxins, gephyrotoxins, and epibatidine from neotropical poison frogs (Dendrobatidae), the pumiliotoxins, allopumiliotoxins, homopumiliotoxins, and decahydroquinolines from certain genera of anurans from four families (Dendrobatidae, Mantellidae, Bufonidae, and Myobatrachidae), a variety of izidines (pyrrolizidines, indolizidines, quinolizidines, lehmizidines), pyrrolidines, piperidines, various tricyclics (related in structures to the coccinellines), and spiropyrrolizidines from the first three of these four families, the pseudophrynamines from one genus of Australian frogs, and a variety of unclassified alkaloids as yet of undetermined structure. With the exception of the samandarines and the pseudophrynamines, all alkaloids appear to be derived from dietary sources. Although only a few of...
Kinetics of the monomer-monomer surface reaction model.

The two-dimensional monomer-monomer ([ital AB]) surface reaction model without diffusion is considered for infinitesimal, finite, and infinite reaction rates [ital k]. For equal reactant adsorption rates, in all cases, simulations reveal the same form of slow poisoning, associated with clustering of reactants. This behavior is also the same as that found in simulations of the two-dimensional [ital voter] [ital model] studied in interacting-particle systems theory. The voter model can also be obtained from the dimer-dimer or monomer-dimer surface reaction models with infinitesimal reaction rate. We provide a detailed elucidation of the slow poisoning kinetics via an analytic treatment for the [ital k]=0[sup +] [ital AB] reaction and the voter models. This analysis is extended to incorporate the effects of place-exchange diffusion which slows, but does not prevent poisoning. We also show that the [ital k]=0[sup +] [ital AB] reaction with no diffusion is equivalent to the voter model with diffusion at rate 1/2. Identical behavior of the monomer-monomer reaction and the voter model is also found in an epidemic'' analysis, where one considers the evolution of a surface poisoned by one species, except for a small patch. Finally, we apply our findings to elucidate the behavior of the monomer-dimer surfacemore » reaction model for small reaction rates.« less
Development Of A Large Field Of View 3-D Vision System

This paper outlines the development of a 3-D vision system based upon the synchronized scanning principle. The concept uses triangulation and through the use of a novel scanning mechanism, a large field of view is achieved while maintaining resolution. The design of the prototype camera is described. The optical design is based on the requirements set by the first application, that of measuring marine propellers with diameters in the range of 5 metres. The benefits of using this technology over current propeller measuring practices will be discussed. Furthermore the application of the 3-D camera in the measurement of museum artifacts is also demonstrated and results shown.
Synthesis of Catenane Structures via Ring-Closing Metathesis

This study presents a detailed description of a synthetic strategy to obtain catenane architectures through ring-closing metathesis. The approach is based on phenanthroline-based ligands containing terminal olefinic units that were designed to coordinate in a tetrahedral arrangement around a copper atom. Treatment of the assembled copper complexes with ruthenium catalyst 1 resulted in [2]catenates in high yields of 88−92%. Demetalation produced the corresponding [2]catenand in nearly quantitative yields. Hydrogenation of the catenates with Crabtree's catalyst and subsequent demetalation yielded fully saturated catenands. The presently described procedure makes [2]catenanes very accessible since the synthetic route consists of six steps (Schemes 2 and 4) from commercially available 1,10-phenanthroline, the overall yield being 51%.
Teaching Sociology Through Student Portfolios

AFTER SEVERAL YEARS of teaching Sociological Thought-an upper division course that focuses on classical, modern, and contemporary sociological theories-I came across the idea of student portfolios. As a consequence, the course has undergone farreaching changes. The content remains relatively intact; however, today the theory course differs fundamentally in form. This paper is a blueprint for building student portfolios into a writing-intensive theory course. (Although my experience with portfolios is limited to the theory course described here, the ideas presented in this paper could be adapted to many other courses. The topic is covered more fully at the end of the section on portfolio construction.) This paper begins with an overview of the history of student portfolios in the college curriculum; it then lists the course objectives and summarizes the written assignments. Next, the paper takes a close look at how the key components of the portfolio process enhance the assignments of the course and how each assignment fits into the portfolio schema; it also describes the evaluation process. Finally, the paper offers evidence of the effectiveness of the portfolio project. EARMARKS OF STUDENT PORTFOLIOS
Etiopathogenesis of Parkinson Disease: A New Beginning?

Parkinson disease (PD) probably represents a syndrome of different disorders and origins converging into a relatively uniform neurodegenerative process. Although clinical-pathological studies have suggested that the presymptomatic phase of PD may be relatively short, perhaps less than a decade, the authors postulate that the pathogenic mechanisms may begin much earlier, possibly even in the prenatal period. Thus, some patients with PD may be born with a fewer than normal number of dopaminergic (and nondopaminergic) neurons as a result of genetic or other abnormalities sustained during the prenatal or perinatal period; as a result of normal age-related neuronal attrition, they eventually reach the critical threshold (60% or more) of neuronal loss needed for onset of PD to become clinically manifest. The authors review the emerging evidence that genetic disruption of normal development, coupled with subsequent environmental factors (the so called multiple-hit hypothesis), plays an important role in the etiopathogenesis of PD.
Characterization of the Hokuyo URG-04LX laser rangefinder for mobile robot obstacle negotiation

This paper presents a characterization study of the Hokuyo URG-04LX scanning laser rangefinder (LRF). The Hokuyo LRF is similar in function to the Sick LRF, which has been the de-facto standard range sensor for mobile robot obstacle avoidance and mapping applications for the last decade. Problems with the Sick LRF are its relatively large size, weight, and power consumption, allowing its use only on relatively large mobile robots. The Hokuyo LRF is substantially smaller, lighter, and consumes less power, and is therefore more suitable for small mobile robots. The question is whether it performs just as well as the Sick LRF in typical mobile robot applications. In 2002, two of the authors of the present paper published a characterization study of the Sick LRF. For the present paper we used the exact same test apparatus and test procedures as we did in the 2002 paper, but this time to characterize the Hokuyo LRF. As a result, we are in the unique position of being able to provide not only a detailed characterization study of the Hokuyo LRF, but also to compare the Hokuyo LRF with the Sick LRF under identical test conditions. Among the tested characteristics are sensitivity to a variety of target surface properties and incidence angles, which may potentially affect the sensing performance. We also discuss the performance of the Hokuyo LRF with regard to the mixed pixels problem associated with LRFs. Lastly, the present paper provides a calibration model for improving the accuracy of the Hokuyo LRF.
Dietary myo-inositol intake and peripheral nerve function in diabetic neuropathy.

Abstract The effect of variations in dietary myo-inositol intake upon plasma myo-inositol concentrations, urinary myo-inositol excretion, motor nerve conduction velocities in the median and peroneal nerves, and sensory nerve conduction velocities in the median and sural nerves was studied in six nondiabetic subjects and in twenty patients with symptomatic distal symmetrical diabetic polyneuropathy. Diets were developed which provided either a low, a normal, or a high intake of myo-inositol. In control subjects, the low-myo-inositol diet was found to decrease, while the high-myo-inositol diet increased both the preprandial plasma myo-inositol concentrations and the daily urinary excretion of myo-inositol. These diets had little effect upon measured nerve function in the control subjects, although the high-myo-inositol diet appeared to slightly reduce the median sensory nerve conduction velocity in this group. In the neuropathic diabetics, the low- and high-myo-inositol diets were found to have similar effects upon the plasma myo-inositol concentrations and urinary myo-inositol excretion, but did not affect the plasma glucose concentrations. When analyzed by groups, no statistically significant changes were observed in any of the measured nerve conduction velocities in the diabetic patients. However, when the change in nerve conduction velocity was analyzed, it was found that the ingestion of the high-myo-inositol diet resulted in a statistically significant increase in the median sensory (+1.92 m/sec, p
Energy futures prices and commodity index investment: New evidence from firm-level position data

Abstract This study brings fresh data to the highly-charged debate about the price impact of long-only index investment in energy futures markets. We use high frequency daily position data for NYMEX crude oil, heating oil, RBOB gasoline, and natural gas that are available from a representative large commodity index fund (“the Fund”) from February 13, 2007 through May 30, 2012. Simple correlation tests, difference-in-means tests, and Granger causality tests generally fail to reject the null hypothesis that changes in Fund positions are unrelated to subsequent returns in all four energy futures markets. We also fail to find any evidence that Fund positions are related to price movements in the WTI crude oil futures market using Singleton's (2014) long-horizon regression specification. Our results suggest Singleton's original finding of significant impacts and high levels of predictability may be simply an artifact of the method used to impute crude oil positions of index investors in a particular sample period. Overall, the empirical tests in this study fail to find compelling evidence of predictive links between commodity index investment and changes in energy futures prices.
Genetic determinants of cardiac hypertrophy

Purpose of review Cardiac hypertrophy is a common phenotypic response of the heart to stimulants. It is associated with increased morbidity and mortality in various cardiovascular disorders. Genetic factors are important determinants of phenotypic expression of cardiac hypertrophy, whether in single-gene disorders or in complex traits. We focus on the molecular genetics of cardiac hypertrophy in various conditions with an emphasis on hypertrophic cardiomyopathy, a genetic paradigm of cardiac hypertrophic response.
Some pharmacological properties of the venom of the scorpionfish Scorpaena guttata. II.

Abstract Labile components of California scorpionfish venom produce marked respiratory and hemodynamic changes in cats, rabbits and dogs. The venom affects respiratory rate, causes bronchoconstriction and pulmonary edema; large doses cause respiratory arrest. The venom produces arterial hypotension within 15 sec, followed by a period of increased pressure. The hypotension represents a major distributive defect of blood volume in the peripheral circuit due to a defect in arterial resistance most likely due to the release of endogenous acetylcholine. This effect can be inhibited by pretreatment with atropine. Other prominent alterations include pulmonary artery hypertension, elevation of left ventricular end-diastolic pressure, portal venous hpertension, ECG changes, elevation of the packed cell volume and initial augmentation of systemic venous return. It is most likely that the venom acts through a combination of direct actions, neurogenic reflex mechanisms and effects induced by the liberation of autopharmacological substances.
Properties of apneusis produced by reversible cold block of the rostral pons

Abstract Reversible cold block of the rostral pons was used to compare properties of normal and apneustic respiration in anesthetized, vagotomized, artificially ventilated cats. During apneusis we observed frequency oscillations (HFO) in phrenic nerve activity which were reduced in frequency compared with those during a normal inspiration. Apneusis produced by mid-pontine transection or punctate pneumotaxic center (PC) lesion produced similar HFO changes. The minimal intensity of superior laryngeal nerve electrical stimulation needed to terminate a breath was higher early in an apneusis than at the same time during a normal breath. Later in apneusis the intensity required became constant and was approximately the same as that needed to end a normal inspiration at its natural termination. With intact vagi lung inflation produced a greater prolongation of expiration during apneustic respiration than during normal respiration. Apneustic type activity was observed in both phrenic and vagal inspiratory motoneurons. We suggest that: (1) HFO are generated without the PC, but the PC elevates the oscillation frequency; and (2) apneusis may result in part from a delayed activation of the normal inspiratory off-switch mechanism.
Small, simultaneous adjustments of orbital exponents in LCAO–MO–SCF calculations using self‐consistent perturbation theory

Self-consistent perturbation theory is introduced to facilitate making small, simultaneous variations in orbital exponents. This is accomplished by interpreting these variations as perturbations on the quantum mechanical system. The minimum-energy condition yields a set of linear equations for the desired exponential corrections.
From the Theory of Chaos to Nonequilibrium Statistical Mechanics

Abstract The theory of chaos has emerged from a multidisciplinary encounter of mathematics, physics, and other sciences. The study of chaotic (microscopic) dynamics is now contributing in a major way to our understanding of nonequilibrium statistical mechanics. In particular one does not want to be restricted to situations close to equilibrium. We shall discuss some of the successes and challenges that have been met in this new development.
Reptile and frog utilisation of rehabilitated bauxite minesites and dieback-affected sites in Western Australia's Jarrah Eucalyptus marginata forest

Abstract Alcoa of Australia Limited rehabilitate bauxite mined areas in the southwest of Western Australia. One of the aims of the revegetation programme is to promote the return of fauna species which inhabit areas prior to mining. This paper discusses the extent to which reptile and frog species utilise revegetated bauxite minesites. It was shown that 4–6 year old revegetated sites support similar numbers of reptile species as unmined sites, although densities are comparable to values recorded in poorer quality forest. Species utilisation of revegetated sites depended largely on the particular species microhabitat preferences. Comparison of community composition in various sites demonstrated high degrees of similarity between some rehabilitated sites and high quality forest sites. The effects of jarrah dieback disease on reptile and frog populations was also assessed. From the results, it is possible to assess the likely combined impact of dieback and mining on the longer term conservation of jarrah forest reptile and frog species.
Preface to Professions Today: Received Wisdom, Case Challenges, Contributor Issues and Questions

The vast majority of contributors to the sociology of professions literature fail to distinguish professions from other occupations, and it sees this as a virtue, not a noteworthy gap at a conceptual level. Talcott Parsons’ most methodical treatment of professions which earlier opposed this position has gone unread, and today has largely disappeared from the literature. Two cases, one historical (the Paris Academie de Peinture et de Sculpture), the other contemporary (the governance of publicly traded corporation as overseen by Delaware courts), challenge the majoritarian position as its core, at a conceptual level. They compel a more abstract, analytical, approach to profession and professionalism. We conclude by presenting the issues and questions presented to all contributors in preparation for this special topic.
Comparative growth, respiration and delayed feeding abilities of larval cod ( Gadus morhua ) and Haddock ( Melanogrammus aeglefinus ) as influenced by temperature during laboratory studies

Comparative growth and respiration were measured during the period hatching to metamorphosis for larval cod (Gadus morhua) at 4°, 7° and 10°Cand for haddock (Melanogrammus aeglefinus) at 4°, 7° and 9°C.Growth was positively correlated with temperature for both species. Specific growth rates on a daily basis indicated good growth for the two species at the upper two temperatures and suppressed growth at 4°C. Respiration rates measured by oxygen consumption were similar for both specie cies. Variable and elevated oxygen consumption at 4°C indicated physiological stress at that temperature. Delayed feeding abilities, feeding initiation, yolk absorption and morphological development related to first feeding ability were similar for both species at 7° to 10°C. Larvae could survive without food and still initiate feeding until 10 days after hatching at 7°C and until 8 days at 9° to 10°C.
Parents' and Sons' Perspectives on Video Game Play: A Qualitative Study.

Public policy efforts to restrict children's access to electronic games with violent or sexual content are often predicated on assumptions about parental concerns. As an initial step in determining whether those assumptions are accurate, the authors conduct focus groups of 21 adolescent boys and 21 of their parents or guardians to explore parents' concerns, compare parents' and children's perceptions, and see whether these are consistent with the focus of proposed legislation and other public policy efforts. Parents' primary concern is that games not interfere with their children's schoolwork, social skills, and exercise. They worry about exposure to violent content, but definitions of and opinions about what is harmful vary and may not match proposed public policies.
Technology Success and Failure in Winner-Take-All Markets: The Impact of Learning Orientation, Timing, and Network Externalities

In industries characterized by network externalities, a single technology standard often rises to dominance, locking out competing technologies. This research demonstrates that despite “path depend...
Caenorhabditis elegans cog-1 Locus Encodes GTX/Nkx6.1 Homeodomain Proteins and Regulates Multiple Aspects of Reproductive System Development

The development of the reproductive system in Caenorhabditis elegans is a well-established model system for patterning and organogenesis. We report the characterization of the cog-1 gene, mutations in which cause novel phenotypes in late patterning in vulval lineages, establishment of the vulva-uterine connection, development and function of the spermathecal-uterine junction, and the development of vas deferens-proctodeal connection in the male. We positionally cloned cog-1 and found that it encodes a homeobox protein most similar to the mammalian GTX and Nkx6.1 proteins. Analysis of cog-1 transcripts revealed that cog-1 is likely a complex locus with two promoters. Two mutant alleles of cog-1 differentially affect alternative transcripts and cause different phenotypes, suggesting that the two forms of cog-1 have distinct functions in C. elegans.
Stimuli-responsive nanoparticles, nanogels and capsules for integrated multifunctional intelligent systems

Abstract In this review we provide an analysis of recent literature reports on the synthesis and applications of stimuli-responsive polymeric and hybrid nanostructured particles in a range of sizes from nanometers to a few micrometers: nano- and microgels, core–shell structures, polymerosomes, block-copolymer micelles, and more complex architectures. The review consists of two major parts: synthesis and applications of nanoparticles in colloidal dispersions, thin films, delivery devices and sensors. We also broadly discuss potential directions for further developments of this research area.
Successful treatment of paradoxical cerebral herniation by lumbar epidural blood patch placement: technical case report.

OBJECTIVE: Death resulting from paradoxical cerebral herniation after the removal of cerebrospinal fluid from the lumbar cistern in a patient with a large craniectomy defect has recently been described. We report a case of successful treatment of this process by placement of a lumbar epidural blood patch. CLINICAL PRESENTATION: A 19-year-old man underwent a large craniectomy after a motorcycle-related trauma. He subsequently developed a progressive, large subgaleal fluid collection with very mild ventriculomegaly. A lumbar drain was placed, which resulted in paradoxical cerebral herniation. INTERVENTION: The patient was placed in the Trendelenberg position, and a lumbar epidural blood patch was placed. The next morning, there was complete resolution of the midline shift and restoration of visible basal cisterns. The patient has made an excellent recovery. CONCLUSION: We conclude that paradoxical cerebral herniation can be quickly reversed and successfully treated by placement of a lumbar epidural blood patch.
Dating of oil field brines using 129I

Abstract 129I/I ratios are reported here for oil field brines from two fields in Louisiana and one in Utah. In two cases, the ratios obtained indicate good agreement between the age obtained with the 129I system and the formations the waters were found in. In the third case, the 129 I I ratios are significantly above the decay curve for 129I and suggest a contribution of recent surface waters to the brines. Comparison to results concurrently obtained for 36 Cl Cl and 87 Sr 86 Sr ratios indicates that the 129I system is best suited for determinations concerning the origin and history of organic matter in aqueous fluids.
Equilibrium geometries and electronic structure calculations of divalent lead Pb(II) complexes with paramagnetic organic ligands

During the past several decades enormous effort has been dedicated to experimental and theoretical studies of metal-radical organic complexes. Equilibrium geometries and electron energy structure of divalent lead Pb(II) complexes with ortho-semiquinone radicals have been calculated by generalized gradient approximation method (GGA) within density functional theory (DFT). Optical absorption spectra were calculated within random phase approximation (independent particles picture). Predicted substantial modification of the absorption spectra in visible infrared regions is attributed to the atomic configuration changes and to modifications of electronic energy due to the metal-radical coupling. The results of the calculations are discussed in comparison with available experimental data on electron spin resonance spectra of Pb(II) with paramagnetic ortho-semiquinone ligands.
Multimodality non-invasive imaging of a coronary cameral fistula

A 69-year-old asymptomatic man was referred for transthoracic echocardiography to evaluate a diastolic heart murmur. Colour and pulse Doppler imaging demonstrated prominent diastolic transmyocardial flow from the epicardial surface into the left ventricular cavity (Supplementary data online, Video S1 ; Panels A and B ), and an intramyocardial diastolic, bi-directional colour flow Doppler signal suggestive of tortuous epicardial vessels ( Panel C …
Beyond desktop point and click: Immersive walkthrough of aerospace structures

There are a number of 3D applications that have shown the benefits of using visualization techniques for virtual prototyping and education in aerospace engineering. However, these applications typically run only on desktop computers and user interaction is limited to mouse and keyboard. Virtual reality technologies provide a richer set of user experience by combining stereoscopic images with interactive, multi-sensory, and viewer-centered environments. We present an interactive and immersive walk-through application of a space station that can be configured and executed on multiple operating systems and platforms. The hardware setup may vary for each platform. Some may be fully immersive environments with multiple projection screens that surround the user and provide spatial tracking, while others may only provide a single PC equipped with active stereo graphics output. Even a laptop using only monoscopic images is supported. The application has been tested in our omni-directional treadmill system, which includes spatial tracking of the user's head and is run on a graphics cluster which drives three projection screens around the treadmill. This kind of immersion using stereo projection and correctly scaled structures allows for a better sense of spatial relationships, because users receive bio-mechanical feedback during navigation by walking. For computer desktop setups, the software can be configured to run on a single screen and with a game controller for navigation.
Expression of 5-HT7 receptor mRNA in the hamster brain: effect of aging and association with calbindin-D28K expression.

Abstract Aging affects several processes modulated by the 5-HT 7 receptor subtype, including circadian rhythms, learning and memory, and depression. Previously, we showed that aging induces a decrease in the hamster dorsal raphe (DRN) in both 5-HT 7 receptor binding and circadian phase resetting responses to 8-OH-DPAT microinjection. To elucidate the mechanisms underlying the aging decrease in 5-HT 7 receptors, we investigated aging modulation of 5-HT 7 receptor mRNA expression in the DRN, brain regions afferent to the DRN, and brain regions regulating circadian rhythms or memory. In situ hybridization for 5-HT 7 receptor mRNA was performed on coronal sections prepared from the brains of young, middle-aged, and old male Syrian hamsters. 5-HT 7 receptor mRNA expression was quantified by densitometry of X-ray film autoradiograms. The results showed that aging did not significantly affect 5-HT 7 receptor mRNA expression in the DRN or most other brain regions examined, with the exception of the cingulate cortex and paraventricular thalamic nucleus. Within the suprachiasmatic nucleus, the site of the master circadian pacemaker in mammals, 5-HT 7 receptor mRNA expression was localized in a discrete subregion resembling the calbindin subnucleus previously described. A second experiment using adjacent tissue sections showed that 5-HT 7 receptor mRNA and calbindin mRNAs were concentrated in the same region of the SCN, and as well as in the same region of several other brain structures. The localization of 5-HT 7 receptors and calbindin mRNAs within the same regions suggests that the proteins they encode may interact to modulate processes such as circadian timekeeping.
Parallel distributed kernel estimation

Non-parametric kernel methods are becoming more commonplace for data analysis, modeling, and inference. Unfortunately, these methods are known to be computationally burdensome. The burden increases as the amount of available data rises and can quickly overwhelm the computational resources present in modern desktop workstations. Approximation-based approaches exist which can dramatically reduce execution time, however, these approaches remain just that--approximations, however good they may be. Along with the approximate nature of such approaches, they do not admit multivariate kernel estimation with general bandwidths (fixed, variable, and adaptive). In this paper, I consider a parallel implementation of a number of popular kernel methods based on the MPI standard. MPI is a freely available parallel distributed library that runs on 'commodity hardware' such as a network of workstations typically found in many office environments. A simple demonstration indicates how one can dramatically reduce the computational burden often associated with kernel methods thereby achieving an almost 'ideal' parallel speed-up, while the approach is valid for multivariate kernel estimation with general bandwidths and does not rely on approximations. Some straightforward applications illustrate just how disarmingly simple the MPI library can be to use.
Cardiac transgenic matrix metalloproteinase-2 expression directly induces impaired contractility.

Objective: Matrix metalloproteinase-2 (MMP-2) plays a major role in dysfunctional ventricular remodeling following myocardial injury induced by ischemia/reperfusion and heart failure. To directly assess the role of MMP-2 in the absence of superimposed injury, we generated cardiac-specific, constitutively active MMP-2 transgenic mice. Methods: Morphologic and functional studies were carried out using both intact and demembranated (skinned) right ventricular trabeculae dissected from hearts of 8-month-old MMP-2 transgenic mice and wild-type controls (WT). Results: Electron micrographs showed that compared to WT, MMP-2 myocardium had no gross, ultrastructural changes (no myocyte dropout or gross fibrosis). However, MMP-2 myocardium contained fibroblasts with abundant rough endoplasmic reticulum, consistent with an activated synthetic phenotype, suggesting extracellular matrix remodeling in MMP-2 trabeculae. Consistent with remodeling, mechanical studies found increased stiffness of intact unstimulated trabeculae (increasing sarcomere lengths from 2 to 2.3 μm caused a greater rise of passive muscle force for MMP-2 trabeculae versus WT). With electrical stimulation, MMP-2 trabeculae generated substantially less active force at all sarcomere lengths. Moreover, inotropic responses to increases of bath [Ca2+], pacing frequency, and isoproterenol were all significantly reduced versus WT trabeculae. Skinned fiber assessment of myofilament function revealed that maximum Ca2+-activated force of skinned MMP-2 trabeculae was reduced to ≈50% of WT, suggesting a myofilament contraction defect. Conclusion: Cardiac-specific, constitutively active MMP-2 expression leads to impaired contraction and diminished responses to inotropic stimulation. These findings indicate that MMP-2 can directly impair ventricular function in the absence of superimposed injury.
Programmed Cell Death and Radioresistance

Whereas apoptosis is a critical mode of cell deletion in normal organism development, apoptotic cells are also observed in tumors, especially following cytotoxic treatments, leading to questions about their role in tumor response to therapy. We have conducted a series of studies using murine tumor models and found that the ability of the tumor cells to undergo apoptosis correlates with tumor response to radiation. The best correlation was with the pretreatment apoptotic index, suggesting that apoptosis in some tumors may govern radiocurability by regulating the number of tumor clonogens. However, other roles for apoptosis in tumor response to radiation have not been ruled out. One of the important observations that has come from this work has been the heterogeneity in apoptosis propensity both within the cell population of a given tumor and among different types of tumors. Such findings underscore the fact that apoptosis is under complex genetic control and that some of the same oncogenes and tumor suppressor genes that are responsible for tumor initiation and progression to malignancy also dictate the apoptotic response to treatment. Understanding the biochemical and molecular pathways that govern this process may ultimately allow the development of strategies for modulating apoptosis for therapeutic benefit.
Direct Measurement of the Longitudinal Coherence Length of a Thermal Neutron Beam

When a series of aluminum slabs are placed in one leg of a perfect-silicon-crystal neutron interferometer, a continuous and significant loss of contrast is observed. This observation is interpreted as being due to the finite length of the neutron wave packets.
Busy Terminal Problem and Implications for MAC Protocols in Underwater Acoustic Networks

In half-duplex underwater acoustic networks, MAC protocols usually assume packet transmissions can interrupt packet receptions so that the exposed terminal problem can be easily handled and system performance is improved. In practice, however, an acoustic modem cannot be interrupted at will when it is transmitting or receiving. In other words, the modem cannot transmit packets when it is busy. This problem is referred to as the "busy terminal problem". In underwater environments, the low transmission rates of acoustic modems result in excessive long transmission time which makes the busy terminal problem more severe. As a result, the modem frequently appears to be too busy to transmit newly arrived packets. This would significantly alter packet sending patterns, which may affect collision behaviors in underwater MAC protocols. To better study the busy terminal problem, we theoretically model its impact on successful transmission probability in multi-hop underwater acoustic networks with long propagation delays. Extensive simulations show that the proposed model can effectively characterize how the busy terminal problem affects collision behaviors.
Alaskan-grown Remote Energy Camp Solutions☆

Abstract For many Alaskans in the remote, rural bush who survive in part due to subsistence economies, winter trapping lines, summer harvesting at fish camp, fall harvest at moose camp and spring to fall mining operations, their work and play are located far from any electrical grid or CHP. Thus it is all the more necessary to figure out efficient methods to get fuel to camp, use it methodically, and have unsophisticated equipment and appliances that will provide heat and power. Thus an Extension workshop created 2 years ago which has evolved since, covers: • methods on using 12 volt appliances and batteries, operating generators, and consolidating fuels. • several retro and new tech appliances recently available at a cost effective level. • various devices invented in Alaska which supply heat or electricity for seasonal, remote living.
Applicability of quadratic and threshold models to motion discrimination in the rabbit retina

Computational and behavioral studies suggest that visual motion discrimination is based on quadratic nonlinearities. This raises the question of whether the behavior of motion sensitive neurons early in the visual system is actually quadratic. Theoretical studies show that mechanisms proposed for retinal directional selectivity do not behave quadratically at high stimulus contrast. However, for low contrast stimuli, models for these mechanisms may be grouped into three categories: purely quadratic, quadratic accompanied by a rectification, and models mediated by a high level threshold. We discriminated between these alternatives by analyzing the extracellular responses of ON-OFF directionally selective ganglion cells of the rabbit retina to drifting periodic gratings. The data show that purely-quadratic or high-threshold systems do not account for the behavior of these cells. However, their behavior is consistent with a rectified-quadratic model.
Towards quantitative uncertainty assessment for cancer risks: central estimates and probability distributions of risk in dose-response modeling.

Regulatory agencies and the scientific community have been engaged in a long-term effort to strengthen health risk assessment procedures. Recently the momentum of this effort has accelerated to increasing biological information for a variety of toxic compounds and emphasis on the policy goal of broader characterization of scientific uncertainty (in contrast to providing only a single risk estimate). For example, the OMB Regulatory Analysis Guidelines [OMB, 2003. Office of Management and Budget. Circular A-4. Available from: ] suggest that a formal quantitative uncertainty analysis be performed for economic assessments in support of major regulatory analyses, a process that can utilize both expected values and probability distributions for risk estimates. Some efforts have been made in the past to provide probability distributions of risk estimates. In this article, we examine a procedure for constructing probability distributions and expected values of risk estimates using a Bayesian framework. This approach has the advantage of mathematical soundness and computational feasibility, given the Markov chain Monte Carlo software tools that are available today. Importantly, the Bayesian framework can serve as a unifying platform for uncertainty analysis in cancer risk assessment. This paper provides some initial applications of Bayesian methods in quantitative analysis of uncertainty in cancer risk assessment, including implementation with cancer dose-response data sets for two chemicals. The Bayesian expected risk calculations provide an approach to generating a central estimate of risk that does not have the instability problems that have often limited utility of MLE risk estimates.
Bedeutung und Bestimmung, grenzflächenenergetischer Größen im Hinblick, auf technische Fragestellungen

Es wurde ein streng statisches und kontinuierliches Verfahren zur Messung des zeitlichen Verlaufs und des Gleichgewichtes der Tensid-Adsorption, wie sie sich in der Oberflachenspannung ausdruckt, beschrieben. Das Verfahren beruht darauf, das die Wechselwirkung zwischen einem Festkorper und einer Flussigkeit durch die Flussigkeits-Oberflachenspannung und den Randwinkel erfast werden kann. Die Mesmethodik ist auch zur exakten und reproduzierenden Bestimmung von Randwinkeln geeignet, wozu auch Fasern verwendet werden konnen. Weiterhin werden die theoretischen Grundlagen bei der Benetzung von textilen Geweben und porosen Festkorpern sowie die Grundlagen und Mesmoglichkeiten der Benetzung pulverformiger Festkorper behandelt.
The stoichiometry of dissolved organic carbon, nitrogen, and phosphorus release by a planktonic grazer, Daphnia

We examined the relationship between Daphnia release rates and ratios of dissolved organic carbon (DOC), nitrogen (N), and phosphorus (P) and the elemental composition of algal food. We constructed a three-element (C, N, and P) mass-balance model to explore the relationships between food elemental composition and Daphnia release of DOC, N, and P. The model predicts that Daphnia DOC : N and DOC : P release ratios will increase with increasing food C : N and C : P ratios, respectively. These effects on DOC : N and DOC : P ratios are dependent, however, on the availability of the third element (P and N respectively) in our model. In addition, we experimentally measured the mass-specific release of DOC, ammonia (NH 4), and soluble reactive phosphorus (SRP) from Daphnia magna fed food of contrasting C : N : P ratios. Daphnia release rates of DOC were not significantly affected by algal C : N or C : P ratios. However, high C : N and C : P ratios in algal food raised the DOC : NH4 and DOC : SRP ratios (respectively) released from Daphnia. Our results, experimental and modeling, show a strong dependence of DOC : N and DOC : P release ratios by Daphnia on food C : N and C : P ratio. Thus, elevated C : N or C : P ratios in food can cause imbalanced release of DOC and NH4 or SRP, respectively, by Daphnia with potentially strong feedback on microbial heterotrophs in planktonic food webs.
Optical properties of PLD-deposited barium strontium titanate (Ba x Sr 1−x TiO 3 ) thin films

Optical properties of PLD-deposited barium strontium titanate thin-films consisting of three stoichiometries have been investigated. Dielectric layers containing Ba x Sr 1−x TiO 3 (x = 30, 40, 50) have been deposited on glass substrates using pulsed laser deposition techniques using oxygen partial pressures of 1.3 Pa ± 0.13 Pa at 500 °C. The optical property investigation includes direct measurement of reflectance and transmittance using spectrophotometric methods to subsequently determine the refractive index (n), extinction coefficient (k), optical conductivity (σ), absorption coefficient (α) and optical band gap (E g ) using swept spectra in the ultraviolet, visible and near-infrared range (200–1100 nm). In this work these parameters are reported for Ba 0.4 Sr 0.6 TiO 3 . Small differences in the transmittance were observed near the visible band edges when comparing each stoichiometry; sharp cutoffs were observed at the bands edges with a strong absorbance in the 200–300 nm band.
Privileged Biofuels, Marginalized Indigenous Peoples The Coevolution of Biofuels Development in the Tropics

Biofuels development has assumed an important role in integrating Indigenous peoples and other marginalized populations in the production of biofuels for global consumption. By combining the theories of commoditization and the environmental sociology of networks and flows, the author analyzed emerging trends and possible changes in institutions and behaviors brought about by the introduction of biofuels as a development option on ancestral lands. Using the Indonesian oil palm and the Philippine Jatropha experiences, the author argues that although there are efforts to integrate smallholder systems to the global integrated biofuels network, the effects of commoditization continue to undermine the more sustainable, less commoditized agricultural practices of Indigenous peoples. Indigenous peoples and their traditional agricultural practices are at risk of being either phased out from or eventually transformed by the global integrated biofuels network to accommodate large-scale, consolidated biofuel plantati...
Phenylarsine Oxide Causes an Insulin-dependent, GLUT4-specific Degradation in Rat Adipocytes*

An incubation of rat adipocytes with phenylarsine oxide (PAO) and then with insulin caused an inhibition of 3-O-methylglucose equilibrium exchange flux and a parallel reduction in cellular GLUT4 content detected by Western blots. Both the transport inhibition and the GLUT4 reduction were saturable with an increasing concentration of PAO showing essentially an identical Ki value of 35 microM. Both effects were not observed in the absence of insulin or if cells were incubated with insulin first. The reduction was specific to GLUT4; the immunoreactivities of GLUT1, insulin receptor, and clathrin were not affected in these experiments. The GLUT4 reduction occurred only in intact cells and was not observed in homogenized cells or fractionated membranes. GLUT4 in both the microsomal storage pool and the plasma membrane pool were affected with no indication of insulin-induced recruitment impairment. GLUT4 reduction was not observed in the presence of chloroquine or at 18 degrees C suggesting involvement of the lysosomal pathway. Based on these results, we propose that there is a PAO-sensitive protein mechanism that controls an insulin-dependent GLUT4 degradation pathway in adipocytes. This protein mechanism and the GLUT4 degradation pathway may play an important role in determining the steady-state GLUT4 level in the insulin-sensitive peripheral tissues in normal and diseased states.
Resolving the Anti‐Antievolutionism Dilemma: A Brief for Relational Evolutionary Thinking in Anthropology

ABSTRACT Anthropologists often disagree about whether, or in what ways, anthropology is “evolutionary.” Anthropologists defending accounts of primate or human biological development and evolution that conflict with mainstream “neo-Darwinian” thinking have sometimes been called “creationists” or have been accused of being “antiscience.” As a result, many cultural anthropologists struggle with an “anti-antievolutionism” dilemma: they are more comfortable opposing the critics of evolutionary biology, broadly conceived, than they are defending mainstream evolutionary views with which they disagree. Evolutionary theory, however, comes in many forms. Relational evolutionary approaches such as Developmental Systems Theory, niche construction, and autopoiesis–natural drift augment mainstream evolutionary thinking in ways that should prove attractive to many anthropologists who wish to affirm evolution but are dissatisfied with current “neo-Darwinian” hegemony. Relational evolutionary thinking moves evolutionary discussion away from reductionism and sterile nature–nurture debates and promises to enable fresh approaches to a range of problems across the subfields of anthropology. [Keywords: evolutionary anthropology, Developmental Systems Theory, niche construction, autopoeisis, natural drift]
Notch and presenilin: a proteolytic mechanism emerges

Presenilins are needed for proteolytic processing of transmembrane proteins of the Notch/Lin-12 family and for cleavage of the amyloid precursor protein. Accumulating evidence now strongly implicates Presenilin as the catalytic core of a multiprotein complex that executes an unusual intramembranous cleavage of its substrates. In the case of amyloid precursor protein, this cleavage contributes to the generation of small, toxic amyloid peptides that trigger the pathological development of Alzheimer's disease. In the Notch/Lin-12 pathway, Presenilin-mediated cleavage of the receptor is a crucial feature of ligand-induced receptor activation and signal transduction. In this pathway, the Presenilins perform a regulated cleavage event that follows additional processing steps during receptor maturation and ligand-induced ectodomain removal.