cssi/SciSciGPT-SciSciNet huggingface dataset:
The Frenkel-Kontorova Model with Nonconvex Interparticle Interactions

We present an analytical and numerical study of a chain of atoms moving in a periodic potential with nonlinear, nonconvex interparticle interactions, described by the Hamiltonian $$ H = \sum\limits_n {\frac{1}{2}u_n^2 + A(u_{n + 1} - u_n )^4 - B(u_{n + 1} - u_n )^2 - cos(u_n ).} $$ The ground state is shown to be homogeneous for B 1/8. The nonconvexity is shown to also play an important role when excitations are considered. In the dimerized phase, we define the staggered order parameter vn = (−l)n un and map the model to the on-site Φ4 problem. In particular we find a localized kink solution, v = tgh(x/d), with a width d varying from infinity at B = 1/8 to zero at B = 3/16, where the interparticle interactions in the ground state cross over from the nonconvex region to the convex one. We also show that at this point the kinks are pinned to the lattice. These results are verified by a direct numerical simulation of the discrete model. Finite temperature effects are discussed in terms of a displacive phase transition at B = 1/8 becoming order disorder transition at B = 3/16. When coupling between the springs is introduced by adding a strain gradient term G(un−1 – 2un + un+l)2 to the Hamiltonian, we observe a crossover from an infinite kink width at B = 1/8 to a finite width for B > 3/16, determined by the competition between the effective double well and the interspring coupling strengths.
Heterogeneity of mitochondrial matrix free ca2+: resolution of Ca2+ dynamics in individual mitochondria in situ.

The role of mitochondria in Ca2+ homeostasis is controversial. We employed the Ca2+-sensitive dye rhod 2 with novel, high temporal and spatial resolution imaging to evaluate changes in the matrix f...
Generating Similar Graphs From Spherical Features

We propose a novel model for generating graphs similar to a given example graph. Unlike standard approaches that compute features of graphs in Euclidean space, our approach obtains features on a surface of a hypersphere. We then utilize a von Mises-Fisher distribution, an exponential family distribution on the surface of a hypersphere, to define a model over possible feature values. While our approach bears similarity to a popular exponential random graph model (ERGM), unlike ERGMs, it does not suffer from degeneracy, a situation when a significant probability mass is placed on unrealistic graphs. We propose a parameter estimation approach for our model, and a procedure for drawing samples from the distribution. We evaluate the performance of our approach both on the small domain of all 8-node graphs as well as larger real-world social networks.
Evaluation of a controlled-temperature furnace atomizer as a sampling device for inductively coupled plasma-atomic emission spectrometry

Abstract This report details the adaptation of the IL655 controlled-temperature furnace atomizer and the evaluation of commercial, modified, and novel furnace cuvettes for inductively coupled plasma (ICP) spectrometry. The operational characteristics including thermal cycle, and carrier and outer argon flow rates are investigated. Preliminary results are also presented for a new carbon tube-platform arrangement. With this arrangement absolute detection limits in aqueous samples (in pg)are Al (0.5), Cd (7.5), Cr (9.0), Cu (1.5), K (1200), Li (1.5), Mn (0.3)and Zn (4.5). Precision in the range of 2.0–3.6% RSD for 5-μl samples is obtained.
Evaluating public opinion polls: designing a model for library instruction

Purpose – The purpose of this paper is to design and describe a model of instruction for librarians to effectively teach evaluation skills for public opinion polls.Design/methodology/approach – The paper show a coherent framework for instruction was identified through a survey of the literature. Learning objectives or essential core questions were identified by looking at codes and standards from five major organizations: National Council on Public Polls, Council of American Survey Research Organizations, World Association of Opinion and Marketing Research, American Association for Public Opinion Research, and the European Society of Marketing and Research. The objectives were incorporated into the aforementioned structure.Findings – The paper finds from nine documents produced by these organizations 15 elements were identified and grouped into nine essential questions: purpose of the poll, sponsor of the poll, polling organization, questions asked, order of the questions, who was polled, how were the int...
Metabolic effects of interventions to increase exercise in adults with type 2 diabetes

The aim of this meta-analysis was to integrate the results of primary research testing the effect of diabetes self-management interventions that included recommendations to increase exercise on metabolic outcomes among adults with type 2 diabetes. Extensive literature searching strategies were used to identify published and unpublished intervention studies that measured glycated haemoglobin outcomes. Primary study results were coded. Fixed- and random-effects meta-analytic procedures included moderator analyses. Data were synthesised across 10,455 subjects from 103 research reports. The overall mean weighted effect size for two-group comparisons was 0.29 (higher mean for treatment than control). This effect size is consistent with a difference in HbA1c means of 0.45% (e.g. 7.38% for treatment subjects vs 7.83% for control subjects). For single-group studies, the overall mean weighted effect size was 0.32–0.34. Control group subjects experienced no improvement in metabolic control during participation in the studies. Interventions that targeted multiple health behaviours resulted in smaller effect size estimates (0.22) than interventions that focused only on exercise behaviours (0.45). Funded studies reported greater improvements in metabolic controls. Studies with a greater proportion of female subjects reported lower effect sizes. Baseline HbA1c and BMI were unrelated to metabolic outcomes. These findings suggest that self-management interventions that include exercise recommendations improve metabolic control, despite considerable heterogeneity in the magnitude of the intervention effect. Interventions that emphasise exercise may be especially effective in improving metabolic control. Primary research testing interventions in randomised trials to confirm causal relationships would be constructive.
Boron neutron capture therapy for the treatment of cerebral gliomas. I. Theoretical evaluation of the efficacy of various neutron beams.

The technique of boronneutron capture therapy in the treatment of cerebral gliomas depends upon the selective loading of the tumor with a 10B‐enriched compound and subsequent irradiation of the brain with low‐energy neutrons. The charged particles produced in the 10B (n,α) 7Li reaction have ranges in tissue of less than 10 μm so that the dose distribution closely follows the 10B distribution even to the cellular level. The effectiveness of this therapy procedure is dependent not only on the 10B compound but on the spectral characteristics of the neutron source as well. Hence, an optimization of these characteristics will increase the chances of therapeutic success. Transport calculations using a neutral particle transport code have been made to determine the dose–depth distributions within a simple head phantom for five different incident neutron beams. Comparison of these beams to determine their relative therapeutic efficacy was made by the use of a maximum useable depth criterion. In particular, with presently available compounds, the MIT reactor (MITR) therapy beam (a) is not inferior to a pure thermal neutron beam, (b) would be marginally improved if its gamma‐ray contamination were eliminated, (c) is superior to a partially 10B‐filtered MITR beam, and (d) produces a maximum useable depth which is strongly dependent upon the tumor‐to‐blood ratio of 10B concentrations and weakly dependent upon the absolute 10B concentration in tumor. A pure epithermal neutron beam with a mean energy of 37 eV is shown to have close to the optimal characteristics for boronneutron capture therapy. Furthermore, these optimal characteristics can be approximated by a judiciously D2O moderated and 10B‐filtered 252Cf neutron source. This tailored 252Cf source would have at least a 1.5 cm greater maximum useable depth than the MITR therapy beam for realistic 10B concentrations. However, at least one gram of 252Cf would be needed to make this a practical therapy source. If the moderated 252Cf source is not 10B filtered, the resultant neutron beam has characteristics similar to those of the MITR beam with no gamma‐ray contamination. For such a beam, 100 mg of 252Cf would produce a flux of 2.4×108 neutrons/(cm2 sec), which is an intensity suitable for therapy applications.
Endoscopic transpapillary catheterization of the gallbladder followed by external shock wave lithotripsy and solvent infusion for the treatment of gallstone disease

Herein we describe the techniques and early results of attempted endoscopic transpapillary catheterization of the gallbladder (ETCG) in combination with external shock wave lithotripsy (ESWL) and solvent infusion in the treatment of 23 consecutive, symptomatic patients with gallstones. Despite anticipated difficulty in advancing wires and catheters through the cystic duct, impeded by tortuosity of its lumen, ETCG was successfully accomplished in 20 of the 23 patients (86.9%). Through an indwelling catheter, obstructed gallbladders were drained in 4 patients and combined treatment with ESWL and infused solvents was carried out in 18 patients. Combined treatment resulted in elimination of gallstones from the gallbladders of 14 of 18 patients (77.7%). Treatment was complicated by mild pancreatitis in only 1 of 20 successfully catheterized patients; there was no mortality.
Automated estimation of breast composition from MR images

We present a simple algorithm for determining the fat fraction in magnetic resonance images of the breast. These computed values are intended to help train neural networks for determining breast composition from x-ray mammograms. The method relies on simple intensity thresholding to form a binary mask followed by morphological dilations and erosions, automated region selection and clustering the tissues within the mask into fat and parenchymal components. Correcting the image intensity nonuniformity due to the spatial sensitivity profile of the breast coil was found to be essential and easily accomplished with homologous filtering. In the absence of large artifacts, the algorithm was able to accurately calculate breast fat fractions.
Intranasal trigeminal detection of chemical vapors by humans

Abstract The majority of 14 human observers lacking olfactory nerve function detected, by nasal inhalation, over one quarter of 31 chemicals commonly used in olfactory research. No major differences were noted between anosmic observers with and without documented anatomic, genetic, or physiologic etiology. Detected compounds differed significantly from nondetected ones on the basis of a number of chemical properties, including water solubility and molecular weight. Detection thresholds of the anosmics, established by a single staircase procedure, were approximately two log volume concentration steps above those of normals for two compounds examined. Exponents of power functions fitted to magnitude estimates of the anosmics did not differ significantly from those fitted to the estimates of matched normal controls. These data indicate the trigeminal nerve may play an important role in human nasal chemoreception and that effective trigeminal stimulants may be predictable on physicochemical grounds.
On limiting the narrative paradigm: Three case studies

While narrative is studied in any number of fields as a form of discourse, only in communication studies has it been claimed that all forms of discourse can be viewed as types of narrative. One way of testing such an all‐encompassing interpretation of narrative is to apply the assumptions of the narrative paradigm to works that traditionalists would not consider to be stories. This essay applies the principles of narrative probability and fidelity to three works—a book attacking religious fundamentalism, a short film attacking Pat Robertson and an allegorical science fiction novel that retells the story of Job—in order to test the paradigm. If all rhetoric can be understood through the narrative paradigm, then the paradigm should be equally applicable to all three works. The analysis of the works, however, reveals that narrative approaches are of little use when applied to discourse that does not tell a story. Additionally, the standards for narrative rationality are difficult to apply and inapplicable to...
Brain-specific differentiation of mouse yolk sac endothelial cells.

Abstract Vascular endothelial cells exhibit diverse functional and biochemical properties that vary among tissues and organs, suggesting that differentiation of endothelial cells is influenced by their microenvironment. In this study, relatively undifferentiated endothelial cells from 9-day embryonic mouse yolk sac were co-cultured with 12-day embryonic mouse brain rudiments. Organ-specific differentiation of the yolk sac endothelial cells was monitored based on the expression and functional activities of two brain-specific endothelial cell markers, glucose transporter 1 (Glut-1) and P-glycoprotein. Immunochemical staining, semi-quantitative reverse transcription–polymerase chain reaction (RT–PCR) and functional assays demonstrated that yolk sac endothelial cells can acquire brain-specific properties after induction by brain rudiments. This result provides support for the hypothesis that endothelial cell heterogeneity is acquired during organogenesis.
Radiolysis of simple quaternary ammonium salt components of Amberlite resin

Abstract The radiation chemical yields of gaseous products, H 2 and CH 4 , in the radiolysis of dry methylammonium chloride, dimethylammonium chloride, trimethylammonium chloride, tetramethylammonium chloride and benzyl trimethylammonium chloride by γ-rays and 5 MeV helium ions have been investigated. Some of these amines are the different components of the quaternary ammonium resin Amberlite, which is a strongly basic anion exchange resin based on a polystyrene divinylbenzene copolymer. Molecular hydrogen yields with γ-radiolysis range from a high of 4.43 molecules per 100 eV for trimethylammonium chloride to 0.07 and 0.05 molecules per 100 eV for tetramethylammonium chloride and benzyl trimethylammonium chloride, respectively. Yields of methane gas are generally negligible except for trimethylammonium chloride and tetramethylammonium chloride, 0.26 and 0.02 molecules per 100 eV, respectively. Isotopic labeling studies suggest that the first step in H 2 production is the breakage of the N H bond followed by abstraction of H atom from the methyl groups. EPR analysis shows the formation of both N and C centered radicals. A comparison is made between the radiolysis of Amberlite and its various components.
Paragenesis of “box-work geodes”, Tampa Bay, Florida

Abstract An unusual suite of silicified rocks was excavated during a recent harbour-deepening project in Tampa Bay, Florida. These rocks, which we have termed “box-work geodes”, are composed of convoluted, intersecting silica walls enclosing cavities which are either voids or filled with relatively pure monoclinic palygorskite. The “box-work geodes” are interpreted as having formed in shallow lagoonal environments, similar to the Coorong Lagoon of South Australia. Synaeresis of syngenetic palygorskite was followed by opal deposition and case hardening of the material. Subsequent chemical deposition of chalcedony, megacrystalline quartz, barite, and calcite on the void facing walls indicates an open chemical system. The existence of opal saturated lagoons, as inferred from the “box-work geodes”, suggests that much of the replacement chert, porcelanite, and silicified fossils in the Tertiary deposits of peninsular Florida formed in the shallow subsurface. Subsequent weathering of carbonates and clays not encapsulated in the box works has resulted in formation of a green montmorillonite residual clay bed.
The Role of Postoperative Analgesia on Outcomes in Colorectal Surgery

High-quality analgesia has become an important goal in current colorectal practice given its impact on operative morbidity and mortality, timeliness of postsurgical recovery, and patient satisfaction. Despite an abundance of anesthetic agents and techniques, clinical evidence that surgical outcomes are tightly associated with optimal analgesia, and a pursuit of accelerating postoperative recovery, comprehensive guidelines about adequate perioperative analgesia have not been implemented in today’s surgical practice. In this article we provide an overview of various analgesia options that can lead to improved postoperative pain control as related to the practice of colon and rectal surgery and the outcomes that they reflect.
Geometrical constraints on the rotational function of the femoral adductors in man

Various authors have ascribed differing roles to the adductor muscles of the thigh in producing rotation of the femur. In the present study, measurements have been made on the changes in distance between origin and insertion of the adductor muscles which occur with rotation of the femur. Increases in distance indicate the muscle cannot produce a particular movement, while a decrease in length supports an argument that the muscle has a particular function. Measurements were made for positions of flexion-extension and adduction-abduction as well as anatomical rest. The adductor magnus was found to decrease in length during internal rotation while the adductor longus decreased in length during external rotation in most of the positions studied.
Practice papers: The evolution of segmentation methods in financial services: Where next?

Over the last few years, the financial services market has seen a proliferation of new players and new channels. Customers have increased expectations of being offered the right products, at the right time and for the right reasons. Demographics and affluence have always been the backbone of segmentation tools, but is this still sufficient to meet the challenges that today's marketers face? This paper is a review of how customer segmentation has evolved within the financial services market and the corresponding demand for consumer information. It assesses whether today's segmentation tools remain sufficiently innovative to provide marketers with the information they require in order to maintain competitive advantage in a highly competitive marketplace.
Long-term changes in pelagic tunicates of the California Current

Abstract This study analyzes interannual variability in springtime carbon biomass of pelagic tunicates (salps, doliolids, pyrosomes, and appendicularians) over the period 1951–2002 from CalCOFI zooplankton samples taken in the southern sector of the California Current System. The results provide evidence for ecosystem changes between 1976 and 1977 and perhaps between 1998 and 1999. A cool-phase group of salps (Salpa maxima, Pegea socia, Cyclosalpa bakeri, and Cyclosalpa affinis) that was present between 1951 and 1976 was nearly undetectable in Southern California waters during the warm phase of the California Current (1977–98). C. bakeri and C. affinis then re-appeared in 2001. A persistent group of salps (Salpa aspera, Salpa fusiformis, Thalia democratica, Ritteriella picteti, Iasis zonaria) was observed throughout the study period. The cool-phase species tend to be distributed in mid-latitudes, while the distributions of the persistent species extend to equatorial waters. The cool-phase species have been reported to show little evidence of diel vertical migration, while most of the persistent species are reported to be diel migrants. No distinct multi-decadal patterns were observed in the dominant doliolid Dolioletta gegenbauri, but the rarer subtropical doliolid Doliolum denticulatum was present predominantly during the warm phase of the California Current. The recurrence patterns and biogeographic distributions of both salps and doliolids suggest that the warm phase of the California Current was accompanied by at least some intervals of anomalous transport “seeding” organisms from the south. Variations in total pyrosome and total appendicularian carbon biomass are not clearly related to long-term trends in the water column, although the highest pyrosome biomass occurred in earlier decades and appendicularian biomass has increased since 1999. Long-term changes in the biomass of pelagic tunicates appear to be chiefly responsible for the previously documented long-term decline in California Current total zooplankton biomass. The pattern of decline appeared to reverse in 1999, with a shift to cooler temperatures, somewhat reduced thermal stratification, and an increase in biomass of total zooplankton and of pelagic tunicates.
CORRELATION BETWEEN SIZE OF THE FRUIT AND THE RESISTANCE OF THE TOMATO SKIN TO PUNCTURE AND ITS RELATION TO INFECTION WITH MACROSPORIUM TOMATO COOKE

That artificial infection with Macrosporium tomato Cooke' from tomato on uninjured tomato fruit can be obtained, provided fruit of a certain maturity as measured by size is used, has been established by one of the writers.2 The question naturally arises as to the cause of this apparent immunity or resistance in the fruit after it reaches a certain maturity. Previous investigations along these lines have been recently reviewed and summarized by Hawkins and Harvey3 as follows: "It is apparent that there is good evidence that some parasitic plants make their way into their host plants by breaking through the tissues mechanically. There is no doubt that some fungi secrete enzymes which break down the cell walls of certain plants and are thus able to make their way through the tissues of their hosts." The same workers from their infection studies with Pythium on potato conclude: "There is considerable evidence that the main factor in this penetration is the growth pressure of the fungus filament, and the resistance of the white McCormick potatoes to this disease is due to cell walls that are more resistant to mechanical puncture than are the cell walls of extremely susceptible varieties." The results obtained by Blackman and Welsford4 in their studies with Botrytis cinerea on Vicia Faba are of special interest. They state that " the piercing of the cuticle is due solely to the mechanical pressure exerted by the germ tube as a whole or by the special outgrowth from it." In the work reported in this paper the evidence obtained shows that: I. While a chemical difference is found in the an*alysis of young and old fruits, this is not the limiting factor in infection with Macrosporium. The
Birth spacing in langur monkeys (Presbytis entellus)

This paper presents 10 years of reproductive data on birth interval length and 5 years of data on reproductive behavior postpartum from a captive colony of gray langur monkeys (Presbytis entellus)housed in Berkeley, California. Birth intervals of females following different pregnancy and nursing schedules are compared. Females whose infants survive to the age of 9 months have a median birth interval of 15.4 months. The experimental separation of mothers from infants for a period of 2 weeks, 6 to 9 months postpartum, had no significant effect on the median birth interval length. Females experiencing a pregnancy failure or the loss of a neonate had median birth intervals of 9.6 and 10.7 months, respectively. These intervals were significantly shorter than the birth intervals of females whose infants survived to 9 months, showing that the presence of a nursing infant delays the female’s time to next conception by approximately 5 to 6 months. Females experienced a median of three estrous periods (two estrous cycles) before conceiving postpartum, regardless of pregnancy outcome or length of infant survival, and females rarely conceived during their first estrous period postpartum. Weaning did not occur until after the mother’s next conception. These data indicate that, in populations of langurs characterized by average birth intervals of 15 to 16 months, the loss of an infant after the age of 5 to 6 months will not accelerate a female’s ability to conceive or shorten the birth interval length. The available data on birth spacing from populations of free-ranging langurs are reviewed. It could not be demonstrated that non-Himalayan populations are characterized by birth intervals which are as long as 20 to 24 months. Rather, it is suggested that female langurs inhabiting seasonally arid sites, such as Jodhpur, Abu, and Dharwar, may be capable of producing infants on the average of every 15 to 16 months. Flexibility in the timing of births and the lack of well-defined birth seasons at these sites may be explained by this species’ dietary and digestive adaptations. Additionally, data on birth spacing and the age of missing infants from the above field sites, where it has been suggested that infanticide following changes in male leadership occurs habitually, do not lend support to the sexual selection hypothesis of infanticide as proposed by S. Hrdy (1974, 1977).
Effects of 5,5'-dithiobis-(2-nitrobenzoic acid) on opiate binding to both the membrane-bound receptor and the partially purified opiate receptor.

: Pretreatment of partially purified opiate receptor from rat brains with 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) decreased opiate agonist binding more effectively than that of antagonist. This agent, at a concentration that inhibits only 3H-agonist binding, increases the IC50 values of agonists but not those of antagonists. We also observed similar effects of DTNB on opiate binding to the membrane-bound receptor that are in good agreement with the published data. Moreover, there was an excellent correlation between the IC50 values of the two different preparations. However, opiate binding to the partially purified receptor was about a thousandfold more sensitive to DTNB than binding to this membrane-bound receptor. Dithiothreitol, a sulfide bond reducing agent, reversed the effects of DTNB on the opiate binding.
Effects of caffeine on session ratings of perceived exertion

This study examined effects of caffeine on session ratings of perceived exertion (RPE) following 30 min constant-load cycling. Individuals (n = 15) of varying aerobic fitness completed a $$ \dot{V}{\text{O}}_{2} $$ max trial and two 30 min cycling bouts (double-blind, counterbalanced) following ingestion of 6 mL/kg of caffeine or matched placebo. RPE overall, legs and breathing were estimated every 5 min and session RPE was estimated 30 min post-exercise using the OMNI pictorial scale. Session RPE for caffeine and placebo trails were compared using paired t test. Between-trial comparisons of HR, RPE overall, RPE legs and RPE breathing were analyzed using an independent 2 (trial) × 6 (time point) repeated measures analysis of variance (ANOVA) for each dependent variable. Caffeine resulted in a significantly lower session RPE (p < 0.05) for caffeine (6.1 ± 2.2) versus placebo (6.8 ± 2.1). Acute perceptual responses were significantly lower for caffeine for RPE overall (15, 20, 25, and 30 min), RPE breathing (15, 20, 25, and 30 min) and RPE legs (20 and 30 min). Survey responses post-exercise revealed greater feelings of nervousness, tremors, restlessness and stomach distress following caffeine versus placebo. Blunted acute RPE and survey responses suggest participants responded to caffeine ingestion. Caffeine decreased acute RPE during exercise which could partially account for lower session RPE responses. However, decreased session RPE could also reveal a latent analgesic affect of caffeine extending into recovery. Extending the understanding of session RPE could benefit coaches in avoiding overtraining when adjusting training programs.
Improvements in automotive fuel economy

Abstract Significant improvements in automotive fuel economy can be obtained by reductions in weight, aerodynamic drag (better streamlining) and rolling resistance (tire improvements), as well as by improvements in engine and powertrain efficiency. As applied to a six-passenger, 3700 lb present-day vehicle powered with a 250 CID six-cylinder engine through an automatic transmission, the improvements in EPA M/H fuel economy for 1% reductions in either weight, aerodynamic drag or rolling resistance are projected to be 0.75, 0.35 and 0.28%, respectively. This is under the constraints of constant performances and equal emissions. The extent to which large changes in these parameters can be obtained, resulting in significant improvements in fuel economy, depends not only upon solving manufacturing and technical problems related to costs but also upon government regulations and customer acceptance in the marketplace. If large reductions in these parameters could be accomplished, along with realistic improvements in engine and powertrain efficiency, significant improvements in fuel economy could be achieved.
Contingent effects of water balance variation on tree cover density in semiarid woodlands

Aim The local distribution of woody vegetation affects most functional aspects of semiarid landscapes, from soil erosion to nutrient cycling. With growing concern about anthropogenic climate change, it has become critical to understand the ecological determinants of woody plant distribution in semiarid landscapes. However, relatively little work has examined the determinants of local variation in woody cover. Here we examine water balance controls associated with patterns of tree cover density in a topographically complex semiarid woodland. Location Los Pinos Mountains, Sevilleta National Wildlife Refuge LTER, New Mexico, USA. Methods To explore the relationship between local water balance variation and tree cover density, we used a combination of high-resolution (1 × 1 m), remotely sensed imagery and quantitative estimates of water balance variation in space and time. Regression tree analysis (RTA) was used to identify the environmental parameters that best predict variation in tree cover density. Results Using six predictor variables, the RTA explains 39% of the deviance in tree cover density over the landscape. The relationship between water balance conditions and tree cover density is highly contingent; that is, similar tree cover densities occur under very different combinations of water balance parameters. Thus, the effect of one environmental parameter on tree cover density depends on the values of other parameters. After tree cover density is adjusted for water balance conditions, residual variation is related to tree cover density in the neighbourhood of a particular location. Conclusion In semiarid landscapes, vegetation structure is largely controlled by water supply and demand. Results presented here indicate that localized feedbacks and site-specific historical processes are critical for understanding the responses of semiarid vegetation to climate change.
Property rights in economic history: Implications for research

Property rights institutions underlie the performance and income distribution in all economies. By defining the parameters for the use of scarce resources and assigning the associated rewards and costs, the prevailing system of property rights establishes incentives and time horizons for investment, production, and exchange. Since property rights define the behavioral norms for the assignment and use of resources, it is possible to predict how differences in property rights affect economic activity. That linkage is critical in research in economic history for understanding variations in growth and welfare across societies and time. The comparative’ statics of assessing the impact of property rights institutions on economic performance are complicated because causality also runs in the opposite direction. Competitive forces tend to erode institutions that no longer support economic growth. Changing market conditions exert pressure for dynamic adjustments in the existing rights structure through refinement of rights and privileges or their transfer to others (voluntarily or through coercion) to facilitate responses to new economic opportunities. Predictions regarding the way in which property rights arrangements respond over time to changing economic opportunities, however, must carefully consider political or equity factors, Distributional conflicts arise when property rights are coercively redistributed by the
The Distribution of Income Across National-Populations: Testing Multiple Paradigms

Abstract In response to recent challenges to modernization theory, this research models variables suggested by three major theories that provide explanations of income distribution across nations: Modernization theory, dependency/world-systems theory, and ecological-evolutionary theory. A base modernization model containing energy consumption per capita, adult literacy, and secondary school enrollment ratios (all circa 1965/1970) is tested against alternative specifications that include the social organization of rural areas, political democracy, export dependency, land inequality, and foreign capital penetration. Strongest support is found for modernization and ecological-evolutionary theories, while the patterns of support for political redistribution and dependency/world-systems theory are more mixed. We conclude that singular claims of theoretical dominance are unwarranted and should be replaced by emphasis on how theories provide complimentary explanations.
ON THE EFFECTS OF THERMAL DEGENERACY IN THE THERMISTOR PROBLEM

We investigate the boundedness of weak solutions to the initial boundary-value problem for the system \begin{eqnarray*} \left\{\begin{array}{ll} \frac{\partial u}{\partial t}-\mbox{div}(K(u)\nabla u)= \sigma(u)|\nabla \varphi|^2,\\ \mbox{div}\left(\sigma(u)\nabla\varphi\right)=0 \end{array}\right. \end{eqnarray*} in the case where $K(u),\sigma(u)$ may both tend to 0 as $u\rightarrow \infty$. In particular, if solutions do blow up, our results impose a condition on the blow-up rates.
Matrix signals in electron-electron double resonance

Abstract The ΔMI= 0, ELDOR spectra of nitroxide radicals in amorphous polystyrene and polypropylene matrices display absorptions at Δv = 13.5 and 27 MHz. The intensities of these signals are decreased by about 35 % in perdeuterated polystyrene. This and the frequency establishes the signals to be matrix ELDOR which results when nonbonded protons interact with the resultant of the external field and the electronic field. The 〈αeβ′H∥↔∥βeα″H〉 forbidden transition then becomes allowed. Rapid-passage results are also consistent with this model.
Circadian genes are expressed during early development in Xenopus laevis.

Background Circadian oscillators are endogenous time-keeping mechanisms that drive twenty four hour rhythmic changes in gene expression, metabolism, hormone levels, and physical activity. We have examined the developmental expression of genes known to regulate circadian rhythms in order to better understand the ontogeny of the circadian clock in a vertebrate. Methodology/Principal Findings In this study, genes known to function together in part of the core circadian oscillator mechanism (xPeriod1, xPeriod2, and xBmal1) as well as a rhythmic, clock-controlled gene (xNocturnin) were analyzed using in situ hybridization in embryos from neurula to late tailbud stages. Each transcript was present in the developing nervous system in the brain, eye, olfactory pit, otic vesicle and at lower levels in the spinal cord. These genes were also expressed in the developing somites and heart, but at different developmental times in peripheral tissues (pronephros, cement gland, and posterior mesoderm). No difference was observed in transcript levels or localization when similarly staged embryos maintained in cyclic light were compared at two times of day (dawn and dusk) by in situ hybridization. Quantitation of xBmal1 expression in embryonic eyes was also performed using qRT-PCR. Eyes were isolated at dawn, midday, dusk, and midnight (cylic light). No difference in expression level between time-points was found in stage 31 eyes (p = 0.176) but stage 40 eyes showed significantly increased levels of xBmal1 expression at midnight (RQ = 1.98+/−0.094) when compared to dawn (RQ = 1+/−0.133; p = 0.0004). Conclusions/Significance We hypothesize that when circadian genes are not co-expressed in the same tissue during development that it may indicate pleiotropic functions of these genes that are separate from the timing of circadian rhythm. Our results show that all circadian genes analyzed thus far are present during early brain and eye development, but rhythmic gene expression in the eye is not observed until after stage 31 of development.
Highlights in clinical autonomic neuroscience: Autonomic correlates of social cognition

Human beings by nature are relational and in relating to others modulate their autonomic responses. Interpersonal relationships may be stressful or calming depending on social contexts, individual temperaments and personality traits. Not only human relationships, but also interactions with affectionate pets and virtual relationships via social networking technology can elicit autonomic responses. These responses range from sympathetic arousal to vagal modulation of cardiovascular activity, and from changes in energy intake and expenditure to modification of physical exercise habits, all of which have potential implications for health and well-being.
Calculation of the knight shift in beryllium

Abstract A non-local pseudopotential theory has been used to calculate the contributions to the Knight shift in beryllium. For the first time, the computed value has both the correct sign and numerical agreement with recent experiments.
Comparison of Perineal Operations with Abdominal Operations for Full-Thickness Rectal Prolapse

We can divide surgery for rectal prolapse into two broad categories: abdominal and perineal. However, few studies compare the long-term outcomes and quality of life among operations for full-thickness rectal prolapse. The purpose of this study was to compare abdominal (AO) versus perineal (PO) procedures for the treatment of full-thickness rectal prolapse regarding recurrence rate, incontinence, constipation, and quality of life. Records of 177 operations from 1995 to 2001 were reviewed retrospectively. A telephone survey was attempted for all. Seventy-five (42%) responded to the Cleveland Clinic Incontinence Score (CCIS), KESS Constipation Score (KESS-CS), and SF-36 Quality of Life Score. Appropriate statistical analysis was performed. For the 122 AO and 55 PO, there were no deaths. Mean follow-up was similar (PO 3.1 vs. AO 3.9 years; P = 0.306). As expected the PO patients were older (mean 69 vs. 55 years) and had higher ASA scores. Those undergoing PO had less procedural blood loss, operative time, hospital stay, and dietary restriction. The PO group also scored worse on the physical component of SF-36 (PO 33 vs. AO 39.6; P = 0.034). However, the rate of recurrent prolapse was significantly higher for the PO (PO 26.5% vs. AO 5.2%; P < 0.001). Complications, CCIS, KESS-CS, and SF-36 mental component were similar in both groups. In full-thickness rectal prolapse, elderly, sick patients are selected for a perineal operation. The morbidity, functional outcomes, and quality of life are acceptable. However, the high recurrence rates make the perineal operation a second-best choice for younger, healthy patients.
Thermocapillary flow effects on convective droplet evaporation

The thermocapillary convection effect on the dynamic behavior of a vaporizing-convecting hydrocarbon droplet is investigated numerically in a laminar, axisymmetric environment. The model predicts that surface-tension gradients along the gas-liquid interface strengthen droplet internal circulation and result in shorter evaporation lifetimes. The relative effect of thermocapillary stresses on overall droplet evaporation rates is nearly independent of Reynolds number. While Nusselt numbers on the droplet surface are little affected, a significant reduction of drag coefficient is observed when thermocapillary convection is taken into account. A substantial enhancement of the corresponding Sherwood numbers is also predicted. The results indicate that the Marangoni stresses cause temporal flow oscillations along the droplet interface at early stages of the droplet evaporation lifetime.
Steps toward passively safe, proliferation-resistant nuclear power☆

After about a 30-year hiatus of construction in the US but not in all involved countries, the designs for an improved water-cooled nuclear reactor will hopefully be developed by a consortium of nuclear reactor builders and users under an agreement with the US Department of Energy (DOE) and review by the Nuclear Regulatory Commission (NRC). The construction of high-temperature, helium-cooled pebble-bed or prismatic reactors may herald the entry of new, safer, and less costly types of reactors to replace the water-cooled reactors of the past and current types. Nuclear breeder reactors hold the promise of limitless energy supplies without the use of fossil fuels or renewables at acceptable costs but this development program has been stalled periodically, especially in the US, when abundant low-cost uranium sources were added to the supply side.
Analog filter banks for sampling: Discretization, polyphase form, and role in compressive sensing

Continuous-time signals arising in many applications can often be modeled as the outputs of analog synthesis-filter banks driven by discrete-time inputs di(n). Such a signal x(t) has a finite innovations rate, although it may not be bandlimited in general. In some applications it is necessary to sample such signals after filtering with an analog sampling-filter-bank, to recover the driving signals di(n): This sampling filter bank is in general not unique, and the theory and design techniques for such analog filter banks are not as well developed as the large body of literature on digital filter banks. In this paper we show that the theoretical as well as design and implementation issues can be formulated in terms of digital filter banks, by taking advantage of the finite innovations rate of x(t): The rich body of knowledge on digital filter banks and polyphase forms can therefore be utilized and furthermore the optimization of the sampling filter bank can be done on a more convenient platform. Applications of this development in the context of compressive sensing are also elaborated.
Primary Cutaneous Nocardia otitidiscaviarum Infection: Case Report and Review

Organisms of the genus Nocardia cause a variety of illnesses in humans and other mammals. Nocardiae normally enter the body via the respiratory tract, but they may also be directly inoculated into the skin, causing primary cutaneous disease. Nocardia otitidiscaviarum is one of the less commonly isolated species of Nocardia, but it can produce localized or disseminated infection. We report a case of primary cutaneous N. otitidiscaviarum infection and review the clinical and microbiological features of other reported cases. Cutaneous N. otitidiscaviarum infection usually occurs in the setting of trauma, most often in otherwise healthy hosts. The manifestations of N. otitidiscaviarum skin infection range from cellulitis and abscess formation to the development of mycetomas. Cutaneous infection by N. otitidiscaviarum can mimic disease caused by more common pyogenic organisms, often leading to delay in diagnosis and treatment. Appropriate antibiotic therapy, usually with a sulfa drug-containing regimen, is generally successful.
Effects of C2H5OH, Na4(aq), N(CH2CH3)+4(aq), and Mg2+(aq) on the thermodynamics of double-helix-to-random-coil transitions of poly(dA)*poly(dT) and poly(dAdT)

Abstract D.s.c. studies in PIPES buffer (pH = 7.0) have been performed on poly(dA)*poly(dT) and poly(dAdT) at different concentration of Na+, N(CH2CH3)+4, Mg2+, and C2H5OH in the 273 K to 373 K temperature range. For poly(dAdT) at all salt and ethanol concentrations, the d.s.c. curves for the double-helix-to-random-coil transition (called melting) are fitted well by a simple two-state model with ΔHm ≈ 26 kJ·mol-1 for dAdT pairs and low cooperativity consistent with an extended hairpin structure. For poly(dA)*poly(dT), the d.s.c. curve has an asymmetric transition region, has greater cooperativity, and ΔHm ≈ 35 kJ·mol-1. We were unable to substantiate ΔHm = 57.3 kJ·mol-1 reported for poly(dA)*poly(dT) for this transition by Herrera and Chaires (Biochemistry1989, 28, 1993), even on a sample supplied by them. Calorimetrically derived Tm values (temperature at maximum in d.s.c. curve in the transition region) vary linearly with lg{c(C+)/(mol·dm-3)}, where C+ denotes a cation, with a slope slightly below that predicted from counterion condensation theory; higher values were obtained for NaCl using activity coefficients. Over the entire temperature and concentration ranges of C2H5OH, ΔHm for the melting transition varied less than 15 per cent for both polymers; but Tm decreased linearly with increasing mass fraction of ethanol in water. The difference in ΔHm of over 8.8 kJ·mol-1 between the two polymers for breaking the hydrogen-bond structure, therefore, is probably due to interactions in the interior of the duplex. Two separate transition regions are present in the d.s.c. curves for poly(dA)*poly(dT), however, at all concentrations of C2H5OH studied when c(NA+) >1.0 mol·dm-3 and in aqueous solution with c (Mg2+) >0.03 mol·dm-3. The sum of the individual ΔHm values for these two transition regions is equal to that for the asymmetric transition at lower c (Na+), and we propose formation of triple-helix structures (disproportionation) as intermediates in the melting process.
Helix versus sheet formation in a small peptide.

Segments with the amino acid sequence EKAYLRT (glutamine-lysine-alanine-tyrosine-leucine-arginine-threonine) appear in naturally occurring proteins both in $\ensuremath{\alpha}$-helices and $\ensuremath{\beta}$-sheets. For this reason, we have used this peptide to study how secondary structure formation in proteins depends on the local environment. Our data rely on multicanonical Monte Carlo simulations where the interactions among all atoms are taken into account. Results in gas phase are compared with that in an implicit solvent. We find that both the solvated molecule and EKAYLRT in gas phase form an $\ensuremath{\alpha}$-helix when not interacting with other molecules. However, in the vicinity of a $\ensuremath{\beta}$-strand, the peptide forms a $\ensuremath{\beta}$-strand. Because of this change in secondary structure our peptide may provide a simple model for the $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\alpha}}\ensuremath{\beta}$ transition that is supposedly related to the outbreak of prion diseases and similar illnesses.
A compact two-stage 120WGaN high power amplifier for SweepSAR radar systems

This work presents the design and measured results of a fully integrated switched power two-stage GaN HEMT high-power amplifier (HPA) achieving 60% power-added efficiency at over 120Woutput power. This high-efficiency GaN HEMT HPA is an enabling technology for L-band SweepSAR interferometric instruments that enable frequent repeat intervals and high-resolution imagery. The L-band HPA was designed using space-qualified state-of-the-art GaN HEMT technology. The amplifier exhibits over 34 dB of power gain at 51 dBm of output power across an 80 MHz bandwidth. The HPA is divided into two stages, an 8 W driver stage and 120 W output stage. The amplifier is designed for pulsed operation, with a high-speed DC drain switch operating at the pulsed-repetition interval and settles within 200 ns. In addition to the electrical design, a thermally optimized package was designed, that allows for direct thermal radiation to maintain low-junction temperatures for the GaN parts maximizing long-term reliability. Lastly, real radar waveforms are characterized and analysis of amplitude and phase stability over temperature demonstrate ultra-stable operation over temperature using integrated bias compensation circuitry allowing less than 0.2 dB amplitude variation and 2° phase variation over a 70°C range.