cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of Temperature on Tether Extraction, Surface Protrusion, and Cortical Tension of Human Neutrophils

Neutrophil rolling on endothelial cells, the initial stage of its migrational journey to a site of inflammation, is facilitated by tether extraction and surface protrusion. Both phenomena have been studied extensively at room temperature, which is considerably lower than human body temperature. It is known that temperature greatly affects cellular mechanical properties such as viscosity. Therefore, we carried out tether extraction, surface protrusion, and cortical tension experiments at 37°C with the micropipette aspiration technique. The experimental temperature was elevated using a custom-designed microscope chamber for the micropipette aspiration technique. To evaluate the constant temperature assumption in our experiments, the temperature distribution in the whole chamber was computed with finite element simulation. Our simulation results showed that temperature variation around the location where our experiments were performed was less than 0.2°C. For tether extraction at 37°C, the threshold force required to pull a tether (40 pN) was not statistically different from the value at room temperature (51 pN), whereas the effective viscosity (0.75 pN·s/μm) decreased significantly from the value at room temperature (1.5 pN·s/μm). Surface protrusion, which was modeled as a linear deformation, had a slightly smaller spring constant at 37°C (40 pN/μm) than it did at room temperature (56 pN/μm). However, the cortical tension at 37°C (5.7 ± 2.2 pN/μm) was substantially smaller than that at room temperature (23 ± 8 pN/μm). These data clearly suggest that neutrophils roll differently at body temperature than they do at room temperature by having distinct mechanical responses to shear stress of blood flow.
Extrinsic Mortality Effects on Reproductive Strategies in a Caribbean Community

Extrinsic mortality is a key influence on organisms’ life history strategies, especially on age at maturity. This historical longitudinal study of 125 women in rural Domenica examines effects of extrinsic mortality on human age at maturity and pace of reproduction. Extrinsic mortality is indicated by local population infant mortality rates during infancy and at maturity between the years 1925 and 2000. Extrinsic mortality shows effects on age at first birth and pace of reproduction among these women. Parish death records show huge historical variation in age-specific mortality rates. The infant mortality rate (IMR) in the early 1920s was low, increased dramatically beginning in 1929, and reached a maximum in the 1950s, at which point IMR declined steadily to its present low rate. The mortality rate early in life showed a quadratic association with age at first birth. Women who experienced conditions of low IMR early in life reproduced relatively late in life. Those born into moderately high levels of infant mortality tended to reproduce earlier than those born at low levels. At very high infant mortality levels early in life, women went on to delay reproduction until relatively late, possibly as a result of somatic depletion and energetic stress associated with the conditions that lead to high IMR. Population mortality rates at age of maturity also showed a quadratic association with age at first birth. The pace of reproduction, estimated as number of surviving offspring controlled for maternal age, showed a similar quadratic effect. There were complex interactions between population mortality rates in infancy and at maturity. When extrinsic mortality was high during infancy, extrinsic mortality later in life had little effect on timing of first birth. When extrinsic mortality was low to moderate in infancy, extrinsic mortality later in life had significant effects on adult reproduction. I speculate that these effects are mediated through development of personality facets associated with reproduction.
EARLY ANEMIA IN INFANTS WITH SICKLE CELL DISEASE - RELATIONSHIP TO A VULNERABLE POPULATION OF RED CELLS

Hematological parameters were studied in 33 infants with sickle cell disease from birth to 2 years of age. The hemoglobin was below normal for age as early as 6 weeks and remained low thereafter (average 8.7 gm %). Significant reticulocytosis was noticed as early as one month of age, and by three monthsfit averaged 7.6%. Hb F concentration in these infants declined more slowly than in normal infants and at 6 months of age averaged 25.6%; at 1 year the Hb F concentration was about 20%. The intracellular distribution of the Hb F (by the Betke-Kleihauer technique) was heterogeneous at all ages. Even in infants less than 3 weeks of age, “ghost” cells containing no Hb F (presumably therefore containing only Hb S) were seen. Our data indicate that in newborn infants with Hb S (as in those with Hb A) a population of cells containing little or no Hb F is present even when there is a high concentration of Hb F in the blood. In infants with Hb S, sickling and hemolysis of this vulnerable cell population would explain the uniform early development of hemolytic anemia by 6 weeks of age.
A reduced order thermal model with application to multi-fin field effect transistor structure

A reduced order model based on proper orthogonal decomposition (POD) has been applied to a multi-fin SOI field effective transistor (FinFET) to develop a compact thermal model. The approach projects the simulation domain onto a function space in order to reduce the numerical degrees of freedom (DOF). The approach does not require any assumption about the physical geometry, dimensions, or heat flow paths, as needed in other compact thermal models. The POD models created using periodic and synchronized random power pulse excitations have been examined using excitations with time shifts, width variations and amplitude modulations. In addition, a simulation structure has been proposed to account for realistic boundary conditions for the developed POD model. It has been shown that the developed POD models provide accurate thermal solutions as detailed as the direct numerical simulation (DNS) with a reduction in numerical DOF by 5 to 6 orders of magnitude.
Monitoring water stress in buffelgrass using hand-held radiometers

Abstract Hand-held MARK-II radiometric measurements were used to monitor levels of water stress in buffelgrass (Cenchrus ciliaris L.) plots. Three levels of irrigation treatments were applied: dry, medium and wet. The radiometric RED (630 to 690 nm) and NIR (760 to 900 nm) measurements obtained from the plots were converted to reflectance factors and to perpendicular and normalized difference vegetation indices (PVI and NDVI respectively). Reflectance and vegetation indices were monitored over the growing season to trace buffelgrass development and response to rainfall and irrigation treatments. Higher than normal rainfall in 1986 moderated the water stress effects. However, we found that a range manager, using a hand-held radiometer, could detect (1) initial plant cover development due to increases in chlorophyll amounts at first of season in RED band, (2) continuing plant structure development in the NIR band, (3) maximum biomass in both RED and NIR bands, (4) initial onset of water stress due to plant ...
Thermal Model for Some Continental Margin Sedimentary Basins and Uplift Zones

The process of sea-floor spreading has caused some fragments of continental material to be separated from the main continental mass. The heat production in the fragments is greater than that in the surrounding oceanic or transitional crust; consequently, the rate of crustal cooling with time is diminished, and the rate of subsidence of the crust is retarded near the continental fragment. Such dislocated fragments will exhibit sustained topographic prominence over geologic time. A numerical thermal model applied to the Ocala Uplift in northern Florida compares well with the observed elevations of the pre-Cretaceous surface. Other available geophysical data support the existence of zones of anomalous crust north and south of the uplift.
SPLENIC ABSCESS AS COMPLICATION OF PERINEPHRIC ABSCESS

Retroperitoneal extension of perinephric abscess with fistulization to intra-abdominal and intrathoracic structures has been well documented in the literature. Intraperitoneal rupture is much less common, and exceptionally may not present as an acute abdominal condition. We describe herein 1 such case involving the spleen. Since the extent of the disease may not be apparent radiologically, and often is only ascertained at the time of surgery, we recommend an aggressive approach to renal calculi as the most effective means of preventing complicated perinephritis.
Risk of hospitalizations after spinal cord injury: relationship with biographical, injury, educational, and behavioral factors.

Study design:Cross-sectional survey.Objectives:To assess the risk factors associated with hospitalization and the relationship of individual health behaviors with hospitalizations after spinal cord injury (SCI).Setting:A large specialty hospital in the southeastern USA.Methods:Persons with SCI responded (n=1386) to a mail survey assessing various aspects of their health, including health behaviors and number of hospitalizations in the past year. Logistic regression was used to assess the relationships between biographical, injury, educational, and health behavior factors with hospitalization in the past year.Results:Overall, 36.6% of participants were hospitalized on at least one occasion during the earlier year. Two biographical and injury characteristics were associated with hospitalization: race and SCI severity. Specifically, minorities and persons with non-ambulatory high cervical or non-cervical SCI were more likely to be hospitalized. Three behavioral factors were significantly associated with hospitalization after controlling for biographical and injury characteristics. Persons who used prescription medications, those who engaged more in smoking behaviors, and persons who reported more SCI-specific health behaviors were more likely to be hospitalized.Conclusion:Specific health behaviors are associated with an increased hospitalization among persons with SCI. Future research is needed to assess the time sequence of these relationships. Language: en
Analysis of excess Gibbs energy of electrolyte solutions: a new model for aqueous solutions.

This paper presents an analysis of the excess Gibbs free energy of aqueous electrolytes. The analysis of experimental data leads to the conclusion that the equilibrium state for dilute univalent electrolytes in water involves an intercalation of water and ionic liquid crystal domains. Excess free energy of the solution is determined by the Madelung energy of hydrated ion-pair liquid crystals, and the energy associated with a shift in the structural equilibrium of water. The data that point to such a model include: molecular orbital-molecular dynamics applied to electrolyte water systems; Raman spectra; infrared spectra; magnetic resonance spectra of ions; the apparent density of water; and the excess free energy of electrolytes in aqueous solutions. Molecular orbital-molecular dynamics calculations of relatively large water clusters containing a molecule of sodium iodide show that the solvent separated ion pair exists in a substantial potential well compared to other possible structures. Raman spectra of univalent electrolyte solutions as a function of concentration can be quantitatively modeled using only the spectra of pure water and electrolyte solution at the concentration of the solvent separated ion pair. The other observations are consistent with the structures proposed from the Raman spectral study. The new model provides a satisfactory account of the fact that the excess free energy of dilute (<0.2 mol/l) solutions is generally more negative than anticipated on the basis of Debye-Huckel theory, and that the equilibrium evidence points to the same functional behavior at very low concentrations as is seen at 0.05 mol/l. We present a testable hypothesis that the excess free energy, and other thermodynamic properties of the solutions do not follow the Debye-Huckel limiting law. The tests of this hypothesis must involve only equilibrium measurements at concentrations between 0.05 and 0.0005 mol/l. This hypothesis concerning the structure of aqueous electrolyte solutions is not in conflict in any way with the Debye-Huckel-Onsager theory of electrical conductivity.
Chemically Mediated Foraging Preference of Black Bears (Ursus americanus)

The role of chemical constituents in the foraging behavior of black bears ( Ursus americanas ) was investigated using two field studies. Vascular tissue samples were collected from Douglas-fir ( Pseudotsuga menziesii ) trees recently foraged by black bears. Samples were extracted and analyzed by liquid and gas chromatography to determine carbohydrates and terpenes, respectively. Chemical data were subjected to correlation analyses and multiple regression to examine if they adequately describe observed foraging preferences. Free-ranging black bears also were offered a choice of four test diets that differed in content of carbohydrates and terpenes. Results indicated that forage preferences were based in part on chemical constituents in the forage. Black bears maximized intake of carbohydrates and minimized intake of terpenes. In multiple choice tests, free-ranging bears preferred a low-terpene diet to a high-terpene diet with identical carbohydrate content. Bears also preferred a high-carbohydrate diet to a low-carbohydrate diet with identical terpene content.
Phosphorolysis of adenosine diphosphoribose.

Abstract The phosphorolysis of ADPR to ADP and R-5-P by a soluble enzyme from Euglena gracilis is reported. The enzyme was partially purified and was present in cells that were grown either heterotrophically or autotrophically. The reaction appears to be irreversible and probably proceeds via a “ping-pong” type of mechanism. The enzyme also catalyzes an exchange reaction between ADP and Pi. Some exchange activity was observed with IDP; CDP, UDP, and GDP were inactive. The apparent Michaelis constants were: ADPR, 4 × 10−5M; ADP, 6 × 10−4M; Pi, 4 × 10−4M. Neither the exchange nor the phosphorolytic activity appears to require the presence of a metal. PCMB inhibits the exchange activity and the inhibition is reversed by cysteine. The exchange reaction is completely reversible, but the phosphorolytic reaction proceeds to completion.
The impact of formulary replacement of sildenafil by vardenafil at a local VA hospital

The National Veterans Administration (VA) changed its formulary agent for the treatment of erectile dysfunction from sildenafil to vardenafil in January 2006 for economic reasons. The objective of this study was to assess the impact of this formulary change on the patients at a local VA hospital. All non-formulary requests for sildenafil between January 2006 and September 2006 were reviewed. A total of 169 non-formulary requests were made for sildenafil while 7657 patients filled vardenafil prescriptions. Overall, the formulary change from sildenafil to vardenafil appeared to be well tolerated by the vast majority of patients at this local VA hospital. The substantial cost savings to the VA seem to be justified by the minimal adverse effects on men treated for erectile dysfunction.
Comparative Evaluation of Public–Private Partnerships in Roadway Preservation

In a bid to reduce overall costs, manage risks, and attract private capital, highway agencies worldwide strive to increase private-sector participation in road infrastructure development, particularly at the developmental phases of construction and preservation. A common mechanism for private-sector participation is the concept of a public-private partnership (PPP). As agencies grapple with the decision about whether to adopt a specific PPP or the traditional contracting approach for a specific project, they lack a rational decision-support structure. In addressing this major gap in PPP-related literature, this paper presents a framework by which an agency may assess the performance (relative benefits) of different PPP contracting approaches for highway preservation. For the purposes of this paper, performance is expressed in relation to the likelihood and intensity of cost savings calculated with data from domestic (U.S.) and international projects. In addition, the influence of project and contract attr...
Local market socialism: Local corporatism in action in rural China

Since the rural reform was launched in China in 1978, its growth and success, along with its problems, have received much research attention.1 Conceptualizing the reform process and experience beyond descriptive materials has also gained momentum. Two theoretical perspectives are of particular current saliency: market transition theory, as advanced by Nee2 and local state corporatism, as recently proposed by Oi.3 Both perspectives focus on the economic dynamics and analyze institutional consequences. This essay builds on these perspectives and proposes a perspective underlining the sociocultural forces that allow the simultaneous and coordinated incorporation of market and collective mechanisms. To be emphasized is the embeddedness of these forces in the local networks that lend enduring institutions and functioning to the transformation.
An evolutionary model of debt

Abstract We study the emergence of institutions that facilitate lending within the context of a reputational model of debt. Taking an evolutionary perspective, we examine a game played between randomly matched players, and ask whether debt can be supported in the long run when lenders are given the option of joining an information-sharing coalition. Despite the fact that players are assumed to be unsophisticated, and follow simple adaptive rules, we observe steady states with widespread lending. The game also has steady states with no borrowing or lending, and these can persist in the long run. Using a mix of analytical and computational methods, we identify stable outcomes and provide an explanation for our results. The findings are shown to have broad implications for the study of institutional change and the feasibility of collective action through voluntary association.
Can Hospitals “Game the System” by Avoiding High-Risk Patients?

Background It has been suggested that implementation of quality-improvement benchmarking programs can lead to risk-avoidance behaviors in some physicians and hospitals in an attempt to improve their rankings, potentially denying patients needed treatment. We hypothesize that avoidance of high-risk patients will not change risk-adjusted rankings. Study Design We conducted a simulation analysis of 6 complex operations in the Nationwide Inpatient Sample, including abdominal aortic aneurysm repair, aortic valve replacement, coronary artery bypass grafting, percutaneous coronary intervention, esophagectomy, and pancreatic resection. Primary outcomes included in-hospital mortality. Hospitals were ranked into quintiles based on observed-to-expected (O/E) mortality ratios, with their expected mortalities calculated based on models generated from the previous 3 years. Half of the hospitals were then randomly selected to undergo risk avoidance by avoiding 25% of patients with higher than median risks (ie, Charlson, Elixhauser, age, minority, or uninsured status). Their new O/E ratios and hospital-rank categories were compared with their original values. Results A total of 2,235,298 patients were analyzed, with an overall observed mortality rate of 1.9%. Median change in O/E ratios across all simulations was zero, and O/E ratios did not change in 97.5% to 99.3% of the hospitals, depending on the risk definitions. Additionally, 70.5% to 98.0% of hospital rankings remained unchanged, 1.3% to 13.1% of hospital rankings improved, and 0.7% to 14.3% of hospital rankings worsened after risk avoidance. Conclusions Risk-adjusted rankings of hospitals likely cannot be changed by simply avoiding high-risk patients. In the minority of scenarios in which risk-adjusted rankings changed, they were as likely to improve as worsen after risk avoidance.
Analysis of impurity-related blue emission in Zn-doped GaN/InGaN/AlGaN double heterostructure

GaN/In 0.05 Ga 0.95 N/Al 0.15 Ga 0.85 N double heterostructures doped with Zn and Si, used in Nichia LEDs, are investigated. Electrical, electroluminescent and photoluminescent properties are presented and discussed. Blue photoluminescence (PL) is analyzed to obtain optical transition parameters (phonon coupling strength and zero-phonon line position) involved in formation of the impurity-related emission band. With a minor modification of parameters for Zn centers in GaN, a satisfactory fit is achieved for PL spectra.
Correlation Between the Molting Period of Cryptocercus and Sexuality in its Protozoa

SUMMARY. The various sexual processes in each of ten genera of protozoa of Cryptocercus have been correlated with the molting period of their host in days beginning with 50 days before ecdysis and ending 3 days after ecdysis. Some genera begin the gametogenesis portion of their sexual cycle much earlier in the molting period than others. Gametogenesis in some genera is haploid, in others it is diploid; in some it is a short process, requiring only a few hours for completion; in others it requires several days for completion. Not counting Leptospironympka and Macrospironympha, meiosis occurs after ecdysis in 6 genera and before in two. The fertilization process in some genera is too involved to make possible a simple summary. The time when gametogenesis, fertilization, and meiosis occur in the molting period of the host seems to be determined by the nature of the various genera of protozoan parasites themselves rather than by their host, although the host, in each case, is always responsible for the initiation of the sexual process as well as for carrying it to completion.
Conducting science inquiry in primary classrooms: Case studies of two preservice teachers’ inquiry-based practices

This study examined the impact of an intervention designed to promote inquiry-based instruction among early childhood/elementary preservice teachers in Earth science. Preservice teachers participated in training sessions and community-based internships to deepen Earth science content knowledge and develop inquiry-based practices. Analyses of Earth science content knowledge pre- and posttests reveal mixed results: four of the eight participants’ posttest scores increased over the duration of the study, two participants’ posttest scores remained the same, and two participants’ posttest scores decreased. Results of the Science Teacher Inquiry Rubric (STIR) (Bodzin & Beerer, 2003) also show mixed results with four participants who exhibited student-centered practices and four participants who engaged in teacher-centered practices. Two preservice teachers with different profiles were selected for in-depth case studies. Findings reveal the importance of preservice teachers’ conceptions of science inquiry and the school environment. We concluded that appropriate conceptions and supportive environments are prerequisite to sustaining prospective teachers’ inquiry-based practices.
Stable chlorine intramolecular kinetic isotope effects from the abiotic dehydrochlorination of DDT.

Intention, Goal, Scope, Background. Identifying different sources and following reaction pathways of chlorinated organic contaminants in the environment can be challenging, especially when only their concentrations are available. Compoundspecific stable chlorine measurements of some contaminants have recently been shown to provide additional information and an increased understanding of their biogeochemistry. These studies, however, have been generally limited to volatile molecules. Here, the stable chlorine isotope ratios of the semi-volatile pesticide, 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)ethane (DDT) were investigated. Specifically, the intramolecular stable chlorine isotopic compositions of DDT and the kinetic isotope effect (KIE) for the abiotic dehydrochlorination of DDT to 2, 2-bis(p-chloro-phenyl)-1, 1-dichloroethene (DDE) were determined. Selective chemical oxidation of DDT to dichlorobenzo-phenone (DCBP) and analysis of each compound was used to calculate the stable chlorine isotope ratios of the alkyl and aromatic chlorines in DDT. To determine the KIE for dehydrochlorination, DDT was reacted in a basic solution to yield DDE at 52°C, 60°C, and 72°C for 3, 5, and 5 days, respectively. Significant intramolecular stable chlorine isotopic differences were observed in one sample of DDT where the alkyl and aromatic δ37C1 values were −5.76 ± 0.45 and −2.21 ± 0.24%‰, respectively. Dehydrochlorination of DDT to DDE in basic solutions at 52, 60, and 70°C resulted in a substantial intramolecular KIE where the alkyl chlorines of DDE shifted by ∼3%‰ relative to the alkyl chlorines in DDT. However, no temperature dependence was observed. The KIE, calculated by an iterative program, was 1.009. Intramolecular differences in the stable chlorine isotope ratios were observed in DDT and this is the first such finding. Dehydrochlorination of DDT yields a measurable and distinct intramolecular stable chlorine KIE. The results of this study demonstrate the existence of significant intramolecular differences in chlorinated organic compounds. Many other chlorinated semi-volatile and volatile organic contaminants are synthesized from multiple sources of chlorine, and we recommend that similar studies be performed on many such molecules in order to attain a clear understanding of their intramolecular chlorine isotopic differences. The existence of a measurable KIE for the dehydrochlorination of DDT to DDE shows the potential strength of using isotopic measurements to investigate the biogeochemistry of these important compounds. For example, the isotopically depleted aqueous chloride produced by dehydrochlorination of DDT to DDE may be a useful tracer of these reactions in freshwater environments.
Assessing Whether an Allele Can Account in Part for a Linkage Signal: The Genotype-IBD Sharing Test (GIST)

To fine map genes, investigators often test for disease-marker association in chromosomal regions with evidence for linkage. Given a marker allele tentatively associated with disease, one would ask if this allele, or one in linkage disequilibrium (LD) with it, could account in part for the observed linkage signal. This question can be addressed by determining if families selected on the basis of the presence of the tentatively associated allele show stronger evidence of linkage as measured by increased allele sharing identical by descent (IBD) by affected family members. However, common selection strategies can be biased for or against linkage in the marker region, even given no disease-marker association. We define unbiased selection schemes and extend the definition to allow weighted selection on the basis of all genotyped family members. For affected-sibship data, we describe three genotype-based weight variables, corresponding to dominant, recessive, and additive models. We then introduce a test for association of a family weight variable with excess IBD sharing. This test allows us to determine if the linkage signal in a region can be attributed in part to the presence of a marker allele, either because of direct involvement in disease etiology or because of LD with a predisposing genetic variant. For samples of 500 affected sib pairs, the tests are powerful in detection of genotype-IBD sharing association, even for disease models with sib relative risk as low as λS=1.1, or when evidence for linkage is absent because of sampling variation. This makes our method a new tool for detecting linkage as well as association, especially in regions harboring a candidate gene. We have implemented these methods in the software package GIST (Genotype-IBD Sharing Test).
Modeling of arrayed waveguide grating for wavelength interrogation application

We have proposed and discussed a design of arrayed waveguide grating (AWG) for the application of wavelength interrogation. The spectral responses of a silica-based 16 channel AWG with channel spacing 1.6 nm have been simulated when different receiver waveguide spacing are used. It was found that the 3-dB bandwidth is reduced about 50% as the receiver waveguide spacing increasing from 20 μm to 30 μm. The effect of bandwidth of the spectral response on wavelength resolution of AWG based interrogator has been estimated and discussed.
Measurement of Teacher Attitudes Toward Sanction Activities

(1970). Measurement of Teacher Attitudes Toward Sanction Activities. The Journal of Educational Research: Vol. 63, No. 5, pp. 219-221.
Individual differences in source selection behavior: Profile analyses via multidimensional scaling

The study aims to understand how undergraduate students perceive and use different information sources. The study will examine: (1) how students perceive and use different sources, (2) how the perception and the use of information sources are related, and (3) how the user characteristics and source use behaviors are related. Their relationships will be examined through correlations and profile analyses via multidimensional scaling.
Corrections to the Impulse Approximation for High-Energy Neutron Scattering from Liquid Helium

Corrections to the impulse approximation for scattering from a many-body system are derived in the form of a series in inverse powers of the momentum transfer $k$. The coefficients in this series are written in terms of the two-body interaction potential and the particle-density matrices. Application is made to the case of high-energy neutron scattering from liquid helium. Evaluation of correction terms corresponding to a single helium-helium collision during the neutron-helium interaction time indicates (a) a shift in the peak of the incoherent-scattering cross section toward lower energy by a constant amount, and (b) an asymmetry of the cross section with respect to neutron energy loss about its peak value. Numerical estimates are given for these two effects for $k=14.3$ ${\mathrm{\AA{}}}^{\ensuremath{-}1}$. Evaluation of condensate broadening due to multiple He-He collisions shows that the condensate-scattering contribution has a width proportional to ${k}^{\frac{1}{2}}$, and is thus distinguishable from the main noncondensate peak whose width is proportional to $k$. Estimates are given for requirements on experimental-resolution functions necessary to preserve this evidence of a distinct condensate contribution.
Summer low flows in New England during the 20th century

High springtime river flows came earlier by one to two weeks in large parts of northern New England during the 20th Century. In this study it was hypothesized that late spring/early summer recessional flows and late summer/early fall low flows could also be occurring earlier. This could result in a longer period of low flow recession and a decrease in the magnitude of low flows. To test this hypothesis, variations over time in the magnitude and timing of low flows were analyzed. To help understand the relation between low flows and climatic variables in New England, low flows were correlated with air temperatures and precipitation. Analysis of data from 23 rural, unregulated rivers across New Eng- land indicated little evidence of consistent changes in the timing or magnitude of late summer/early fall low flows during the 20th Cen- tury. The interannual variability in the timing and magnitude of the low flows in northern New England was explained much more by the interannual variability in precipitation than by the interan- nual variability of air temperatures. The highest correlation between the magnitude of the low flows and air temperatures was with May through November temperatures (r = -0.37, p = 0.0017), while the highest correlation with precipitation was with July through August precipitation (r = 0.67, p < 0.0001). (KEY TERMS: climatic variability and change; seasonal stream- flow; low flows; hydroclimatology; temporal trends; New England.)
Agential obligation as non-agential personal obligation plus agency

Abstract I explore various ways of integrating the framework for predeterminism, agency, and ability in [P. McNamara, Nordic J. Philos. Logic 5 (2) (2000) 135] with a framework for obligations. However, the agential obligation operator explored here is defined in terms of a non-agential yet personal obligation operator and a non-deontic (and non-normal) agency operator. This is contrary to the main current trend, which assumes statements of personal obligation always take agential complements. Instead, I take the basic form to be an agent's being obligated to be such that p . I sketch some logics for agential obligation based on personal obligation and agency, first in a fairly familiar context that rules out conflicting personal obligations (and derivatively, conflicting agential obligations), and then in contexts that do allow for conflicts (of both sorts). Finally, a solution to van Fraassen's puzzle is sketched, and an important theorem is proved.
Comparison of push-out bond strengths of Resilon with three different sealers.

Abstract Introduction The purpose of this study was to evaluate the push-out bond strengths of different obturating materials. Methods Forty single-rooted human extracted teeth were used in this study. The teeth were instrumented and irrigated by using 5.25% NaOCl, 15% ethylenediaminetetraacetic acid, and sterile water. The teeth were then filled with Resilon/RealSeal, Resilon/RealSeal SE, Resilon/MetaSeal , or gutta-percha/Kerr EWT sealer. The roots were then sectioned into 1-mm-thick slices and subjected to vertical loading to displace the obturating material toward the coronal side of the slice. The bond strength was then calculated and subjected to statistical analysis. Slices were examined by using a stereomicroscope at 30× to determine the mode of failure. Results The mean push-out bond strengths were as follows: Resilon/RealSeal, 1.45 ± 0.99 MPa; RealSeal SE, 0.88 ± 0.49 MPa; Resilon/MetaSeal, 2.41 ± 1.7 MPa; and gutta-percha/Kerr EWT sealer, 2.32 ± 0.74 MPa. Conclusions The push-out bond strengths of Resilon/MetaSeal and gutta-percha/Kerr EWT were significantly (P
Stem cell plasticity

The central dogma in stem cell biology has been that cells isolated from a particular tissue can renew and differentiate into lineages of the tissue it resides in. Several studies have challenged this idea by demonstrating that tissue specific cell have considerable plasticity and can cross-lineage restriction boundary and give rise to cell types of other lineages. However, the lack of a clear definition for plasticity has led to confusion with several reports failing to demonstrate that a single cell can indeed differentiate into multiple lineages at significant levels. Further, differences between results obtained in different labs has cast doubt on some results and several studies still await independent confirmation. In this review, we critically evaluate studies that report stem cell plasticity using three rigid criteria to define stem cell plasticity; differentiation of a single cell into multiple cell lineages, functionality of differentiated cells in vitro and in vivo, robust and persistent engraft of transplanted cells.
Probability-based LRFD for engineered wood construction

The newly developed load and resistance factor design (LRFD) specification for engineered wood construction in the United States uses probabilistic methods as the technical basis for selecting design strength requirements, load combinations and load factors. Special characteristics of wood and wood products as structural materials are considered. The strength of wood structural products depends on the rate of application and duration of the loads. LRFD criteria for the ultimate limit states account for this dependence by means of a time effect factor. The apparent increase in strength of wood structural systems comprised of several nominally identical and repetitively used members is taken into account with a system factor. Serviceability limit states of deflection and vibration are addressed with some general code guidelines and a nonmandatory commentary.
HOT-ELECTRON INSTABILITY IN SUPERCONDUCTORS

High flux velocities in a superconductor can distort the quasiparticle distribution function and elevate the electronic temperature. Close to Tc, a non-thermal distribution function shrinks the vortex core producing the well-known Larkin-Ovchinnikov flux instability. In the present work we consider the opposite limit of low temperatures, where electron-electron scattering is more rapid than electron-phonon, resulting in an electronic temperature rise with a thermal-like distribution function. This produces a different kind of flux instability, due to a reduction in condensate and expansion of the vortex core. Measurements in YBCO films confirm the distinct predictions ofthis mechanism.
Symptoms in Patients With Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction: Is It All About Diastole?

Although it has been ≈50 years since Ross and Braunwald1 reported the malignant natural history of aortic stenosis (AS) after the onset of angina, syncope, or heart failure, the pathophysiologic underpinnings of these classic symptoms remain incompletely delineated. We appreciate that angina may occur in the absence of epicardial coronary disease with both increased demand and impaired supply, contributing to imbalance of the supply–demand relationship. Exertional syncope reflecting the inability to maintain cerebral perfusion is attributed to an inability to increase cardiac output in combination with, at times, paradoxically reduced systemic vascular resistance. Although we attribute the low-output symptoms of heart failure to the same inability to increase cardiac output, we still have an incomplete understanding of the changes that restrict stroke volume augmentation. Similarly, although the dyspnea of heart failure is typically linked to elevated pulmonary capillary pressures, which of the multiple pathways leading to elevated pulmonary pressures is/are operative in the symptomatic patient with AS? Although afterload mismatch and attendant left ventricular (LV) systolic dysfunction provide a substrate for symptoms in some patients, understanding the basis for symptoms in patients with preserved LV ejection fraction (EF) is particularly challenging because measures of AS severity alone predict the onset of but correlate imperfectly with the presence of symptoms.2 Article see p 142 In this issue of Circulation: Cardiovascular Imaging , Dahl et al3 provide hypothesis-generating data that argue an important role for LV remodeling and diastolic dysfunction in the pathogenesis of symptoms in patients AS and preserved (≥50%) LVEF. They compared echocardiographic parameters in 139 asymptomatic patients assessed in an outpatient clinic and 99 symptomatic patients referred for surgical intervention. Although the symptomatic patients were surprisingly younger, had less atrial fibrillation, hypertension, and chronic lung disease than did the asymptomatic cohort, higher LV mass index and …
Multi-objective optimization of PM AC machines using computationally efficient - FEA and differential evolution

A total of eleven independent stator and rotor variables are simultaneously employed for the optimization of a generic example IPM motor design. The multi-objective criterion maximizes efficiency, while minimizing torque ripple at the rated output condition. A Pareto-based differential evolution (DE) algorithm with 100 generations, each with a population of 100 individuals, is presented. Computationally efficient FEA (CE-FEA), which is based on a reduced number of magnetostatic solutions for a motor model in the abc reference frame, is employed. As a result, a total of 10,000 candidate motor designs, which are included in the comprehensive study, are evaluated in a record short time on a typical PC-based workstation. The paper includes an engineering trade-off discussion based on a typical-reference motor, two optimum designs in terms of average torque and torque ripple, and a best-compromise solution. For the case-study, an order of magnitude reduction of the rated-load torque ripple and open-circuit cogging torque has been achieved. This is while, at the same time, the specific torque output has been increased by as much thirty seven percent.
Generation and instability of spiral wakes in sheared electron flows

Images of the electron density of a magnetized electron column illustrate the dynamics of intense vortices moving in a weaker background vorticity. A moving retrograde clump of vorticity generates a spiral wake that then evolves into many long-lived holes, contributing to the late time fluctuations.
Murine Guanylate Cyclase C Regulates Colonic Injury and Inflammation

Guanylate cyclase C (GUCY2C or GC-C) and its ligands, guanylin (GUCA2A or Gn) and uroguanylin (GUCA2B or Ugn), are expressed in intestinal epithelial cells and regulate ion secretion, intestinal barrier function, and epithelial monolayer homeostasis via cGMP-dependent signaling pathways. The aim of this study was to determine whether GC-C and its ligands direct the course of intestinal inflammation. In this article, we show that dextran sodium sulfate (DSS)-induced clinical disease and histological damage to the colonic mucosa were significantly less severe in GC-C−/− mice and moderately reduced in Gn−/− animals. Relative to wild-type controls, GC-C−/− and Gn−/− mice had reduced apoptosis and increased proliferation of intestinal epithelial cells during DSS colitis. Basal and DSS-induced production of resistin-like molecule β (RELMβ) was substantially diminished in GC-C−/− mice. RELMβ is thought to stimulate cytokine production in macrophages in this disease model and, consistent with this, TNF-α and IFN-γ production was minimal in GC-C−/− animals. RELMβ and cytokine levels were similar to wild-type in Gn−/− mice, however. Colonic instillation of recombinant RELMβ by enema into GC-C−/− mice restores sensitivity to DSS-mediated mucosal injury. These findings demonstrate a novel role for GC-C signaling in facilitating mucosal wounding and inflammation, and further suggest that this may be mediated, in part, through control of RELMβ production.
Poset boxicity of graphs

Abstract A t-box representation of a graph encodes each vertex as a box in t -space determined by the (integer) coordinates of its lower and upper corner, such that vertices are adjacent if and only if the corresponding boxes intersect. The boxicity of a graph G is the minimum t for which this can be done; equivalently, it is the minimum t such that G can be expressed as the intersection graph of intervals in the t -dimensional poset that is the product of t chains. Scheinerman defined the poset boxicity of a graph G to be the minimum t such that G is the intersection graph of intervals in some t -dimensional poset. In this paper, a special class of posets is used to show that the poset boxicity of a graph on n points is at most O(log log n ). Furthermore, Ramsey's theorem is used to show the existence of graphs with arbitrarily large poset boxicity.
The Dynamics of Agenda Convergence and the Paradox of Competitiveness in Presidential Campaigns

The mass media’s representation of campaign discourse influences whether voters have the opportunity to scrutinize the candidates’ issue priorities and policy proposals. But it is not clear whether candidate and media issue emphases are more or less similar at an election’s most consequential moments—when it is competitive. In a study of the 1992 and 1996 presidential campaigns, the author finds that as the polls narrow, the media are less likely to reflect candidate discourse. Paradoxically, voters are deprived of an accurate representation of candidate dialogue when they need it most, with media behavior making it difficult for citizens to cast informed ballots in close contests. The results also show that whether the media serve as a conduit for, or filter of, candidate messages depends on a variety of factors, especially electoral context.
Robust Self-Incompatibility in the Absence of a Functional ARC1 Gene in Arabidopsis thaliana

Self-incompatibility (SI) is the primary determinant of the outbreeding mode of sexual reproduction in the Brassicaceae. All Arabidopsis thaliana accessions analyzed to date carry mutations that disrupt SI functions by inactivating the SI specificity-determining S locus or SI modifier loci. S-locus genes isolated from self-incompatible close relatives of A. thaliana restore robust SI in several accessions that harbor only S-locus mutations and confer transient SI in accessions that additionally harbor mutations at modifier loci. Self-incompatible transgenic A. thaliana plants have proved to be valuable for analysis of the recognition and signaling events that underlie SI in the Brassicaceae. Here, we review results demonstrating that S-locus genes are necessary and sufficient for SI signaling and for restoration of a strong and developmentally stable SI phenotype in several accessions of A. thaliana. The data indicate that introduction of a functional E3 ligase-encoding ARC1 gene, which is deleted in all accessions that have been analyzed to date, is not required for SI signaling leading to inhibition of self pollen or for reversion of A. thaliana to its fully self-incompatible ancestral state.
Glutamine Transport in Mouse Cerebral Astrocytes

We measured initial influx and exchange of [14C]glutamine in primary astrocyte cultures in the presence and absence of Na+. Kinetic analysis of transport in Na+ -free solution indicated two saturable Na+ -independent components, one of which was identifiable functionally as system L1 transport. In the presence of Na+, multiple hyperbolic components were not resolvable from the kinetic data. Nevertheless, other evidence supported participation by at least three Na+ -dependent neutral amino acid transporters (systems A, ASC, and N). System A transport of glutamine was usually absent or minimal, based on lack of inhibition by alpha-(methylamino) isobutyric acid. However, vigorous system A-mediated transport emerged after derepression by substrate deprivation. Participation by system ASC was indicated by trans-acceleration of Na+ -dependent uptake, preferential inhibition of an Li+ -intolerant component of uptake by cysteine, and inhibition by cysteine of a component resistant to inhibition by histidine and alpha-(methylamino) isobutyric acid. Because nonsaturable transport of glutamine appeared negligible, and system L transport of glutamine was suppressed in the presence of Na+, low-affinity system ASC transport may be the major route of export of glutamine from astrocytes. At 700 microM glutamine, the primary uptake route was system N transport, identified on the basis of selective inhibition by histidine and asparagine, pH sensitivity, and tolerance of Li+ in place of Na+.
Electromagnetic scattering by high-density meteor trails

The discussion first concerns itself with establishing limits on the validity of the low-density approximation. These depend not only on the electron line density (as has sometimes been loosely stated) but also on the wavelength of observation and on the altitude of the trail. Next, a model is developed for scattering by a supercritical density distribution of electrons, based on the idea that the process can still be viewed as a superposition of individual Compton effects, but with the wave incident on the electron attenuated because of refraction (in analogy to the skin effect). Results of this model are compared with those obtained by the usual approach of replacing the electron distribution by a metallic scatterer whose surface is the critical density contour. Some calculations with nonGaussian electron distributions help to clarify the physical interpretation.
The nursing home as a discursive anchor for the ageing body

The nursing home has become a paramount site for the care and custody of old people, but it also affects how we think and talk about the ageing body. In this article, narrative and ethnographic material drawn from a variety of care-related settings is used to illustrate how and where the nursing home serves as a discursive anchor for embodiment. Circumstantial, local cultural, and organisational mediations are considered, featuring institutionalisation to be as much a descriptive phenomenon, as it is a residential relocation.