bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Autonomous Selfing in Gesneria citrina (Gesneriaceae), a Specialized Hummingbird Pollinated Species with Variable Expression of Herkogamy
Authors: Chen Xin‐Sheng , Martén‐Rodríguez Silvana , Li Qing‐Jun , Fenster Charles B.
Published: September 2009

Species with mixed mating systems often demonstrate variable expression of breeding system characteristics and thus represent the opportunity to understand the factors and mechanisms that promote both outcrossed and selfed seed production. Here, we investigate variation in levels of herkogamy (variation in stigma‐anther separation distance) in a Puerto Rican population of hummingbird pollinated Gesneria citrina Urban. There is significant variation in herkogamy levels among individuals of this species and stigma‐anther separation is negatively associated with the ability to set fruits and seeds in the absence of pollinators. The variation in levels of herkogamy may represent a mechanism to ensure the production of some self‐fertilized progeny in the absence of hummingbird pollinators. We also describe a novel breeding system in G. citrina, where stamens elongate over time to reach stigma height, but stamen elongation is accelerated by pollination. These results suggest that once the flowers are pollinated, stamen elongation may favor increased pollen removal and siring success, while the reduction in stigma‐anther distance no longer imposes the risk of interference between male and female functions. We discuss our findings of breeding system variation in the context of pollination system evolution in an island setting (Antillean islands).
STORAGE TIME STUDY OF SUGAR‐FREE AND REDUCED CALORIE MILK CHOCOLATES
Authors: DE MELO LAURO LUÍS MARTINS MEDEIROS , BOLINI HELENA MARIA ANDRÉ , EFRAIM PRISCILLA
Published: September 2009

In order to study storage time, sensory properties and acceptability among consumers, regular, free‐sugar (sucralose [Sucra] or stevioside [Ste]) and free‐sugar/reduced calorie (Sucra or Ste], with whey protein concentrate as fat replacer) milk chocolates were evaluated over storage (0, 3, 6 and 9 months). Quantitative descriptive analysis showed that sensory properties do not change throughout the studied storage period. These results were confirmed by acceptability data. No significant changes (P ≥ 0.05) were observed on acceptability means for appearance, aroma, flavor, texture and overall liking. These results show that sugar‐free and reduced calorie milk chocolates prepared with high‐intensity sweeteners, Sucra and Ste, with partial fat replacement with whey protein concentrate had a similar storage time behavior as compared with regular chocolates.

PRACTICAL APPLICATIONS

This research aims to study sensory storage time of regular, sugar‐free and sugar‐free/reduced calorie milk chocolates. It can help food industries to understand storage time of these products as sensory properties for highly stable food products, such as chocolate, usually define shelf life.
SELECTION OF A SENSORY MARKER TO PREDICT THE SENSORY SHELF LIFE OF A FLUID HUMAN MILK REPLACEMENT FORMULA
Authors: CURIA ANA V. , HOUGH GUILLERMO E.
Published: September 2009

Human milk replacement formulas (HMRFs) are foods designed for babies in their early months of age. An accelerated storage test showed that dark color increased at a higher rate than oxidized flavor. Additionally, a survey among mothers who were giving HMRFs to their babies showed that mothers rarely tasted the product. Thus, the salient sensory attribute they would pay attention to when preparing their babies' bottles was color. If a portion was rejected by the babies, mothers attributed the rejection to stomach trouble and not to an inappropriate flavor. Thus, as a result of the color having increased at a higher rate than flavor changes and being the salient attribute that mothers would pay attention to, it was chosen as the critical shelf life descriptor.

The sensory cutoff point was determined from the correlation between mothers' acceptability scores for samples with increasing color and the dark color of the same samples measured by a trained panel. A high correlation was obtained between dark color measurements from a trained panel and CIE‐LAB values (L*, a* and b*).

The cutoff point was used to determine shelf life based on sensory attributes of a commercial HMRF stored at 25, 37 and 45C, resulting in 150, 43 and 21 days, respectively. Activation energy is calculated.

PRACTICAL APPLICATIONS

Sensory shelf life determination in foods for babies is not an easy task. This work offers a methodological practice to develop a decision criterion for when the end user cannot be consulted directly.
GEOCHEMICAL CHARACTERIZATION OF A BIODEGRADED CRUDE OIL, ASSRAN FIELD, CENTRAL GULF OF SUEZ
Authors: Hegazi A. H. , El‐Gayar M. Sh.
Published: September 2009

A crude oil sample from the Assran field in the Central Gulf of Suez (Egypt) was analysed geochemically and characterized in terms of a variety of source and maturity dependent biomarkers. Biodegradation was indicated by increasing concentration ratios of Pr/n‐C17 and Ph/n‐C18. However, biodegradation was only slight as GC‐MS analyses of the saturate and aromatic fractions showed that hopanes, steranes, aromatic steroids and polycyclic aromatic compounds including sulphur heterocycles remained intact. The sterane and hopane distributions showed a predominance of C27 steranes, a low diasterane index, an abundance of gammacerane, a high homohopane index and an oleanane index < 0.2. The results indicate that the Assran‐10 crude oil was derived from a marine carbonate source deposited in a highly reducing saline environment with a high bacterial contribution, consistent with the Upper Cretaceous Brown Limestone or Lower Eocene Thebes Formation containing Type IIS kerogen. Maturity parameters based on changes in the stereochemistry at chirality centres in hopane and sterane nuclei, such as C30βα/(βα+αβ) and C31 22S/(22S+22R) hopanes and C29ββ/(ββ+αα) and C29 20S/(20S+20R) steranes, together with triaromatic sterane cracking ratios, indicate that the oil sample was marginally mature. The results also suggest that biodegradation is probably due to sulphate‐reducing anaerobic bacteria.
PETROPHYSICAL CHARACTERISTICS OF SOURCE AND RESERVOIR ROCKS IN THE HISTRIA BASIN, WESTERN BLACK SEA
Authors: Cranganu C. , Villa M. A. , Saramet M. , Zakharova N.
Published: September 2009

The petroleum system in the Histria Basin, Western Black Sea, includes Oligocene source rocks and Upper Cretaceous — Eocene reservoir rocks. Here we report on the petrophysical characteristics of these source and reservoir rocks using mercury intrusion porosimetry data from 14 core samples collected from five wells drilled on the East Lebada, West Lebada and Pescarus structures. Samples were in general dominated by carbonate lithologies with minor shales. Petrophysical parameters analyzed were: median pore‐throat radius, average pore‐throat radius, apparent porosity, pore‐throat size distribution, pore‐throat type, pore‐throat sorting, maximum threshold entry radius, pore‐throat radius at 35% mercury saturation (R35), and air permeability. Reservoir rock quality was estimated using a permeability / porosity / pore‐throat type plot.

The Oligocene samples showed little petrophysical variation. Samples were relatively homogenous and had the same pore‐throat type (nano), were well sorted, had unimodal pore‐throat distribution (suggesting the existence of a single fluid phase), had similar values for median and average pore‐throat radius, and similar values for R35 and maximum threshold entry radius. Upper Cretaceous – Eocene samples were more heterogeneous in terms of petrophysical properties, and reservoir quality was in general higher than in the Oligocene interval. Average porosity and calculated air‐permeability values were 18.4% and 0.37 mD, respectively for Upper Cretaceous samples; and 11.8% and 27.11 mD, respectively for Eocene samples. A case study of Oligocene and Cretaceous – Eocene samples from well West Lebada 817 is presented.

This paper represents the first petrophysical study of source and reservoir rocks in the Histria Basin, Western Black Sea. The results will help to establish the links between petrophysical characteristics, age and depositional environment for source and reservoir rocks in other basins bordering the Black Sea.
GEOCHEMICAL CHARACTERIZATION OF CENTRAL NIGER DELTA OILS
Authors: Akinlua A. , Ajayi T. R.
Published: September 2009

Oil samples from six oilfields in the Central Niger Delta were analyzed for normal alkanes, aliphatic isoprenoid hydrocarbons, aromatic hydrocarbons and biomarkers using gas chromatography (GC) and gas chromatography‐mass spectrometry (GC‐MS). The study was carried out with the aim of assessing the origin and thermal maturity of the oils and the depositional environment of the organic matter from which they were derived, and to evaluate similarities (or differences) among the oils from the Central Niger Delta in comparison to those from other parts of the Delta. The ratios of n‐alkanes and aliphatic isoprenoids showed that Pr/nC17 ranged from 0.56 to 0.86 while Ph/nC18 ranged from 0.22 to 0.31 indicating that the oils were derived from organic matter of both terrestrial and marine origin. Pristane/phytane ratios ranged from 2.67 to 3.50, suggesting that the organic matter was deposited in generally oxidizing environments. The oleanane index, which ranged from 0.07 to 1.39, and other biomarker data also indicate contributions from both marine and terrestrial organic matter. Both saturated and aromatic hydrocarbon biomarker data indicate that the oils are thermally mature. The study showed that the Central Niger Delta oils have organic geochemical characteristics similar to those of oils from other parts of the Delta. However, there is a striking difference in the distribution of aromatic hydrocarbons, and this may in future be used as a tool with which oils from different parts of the Delta can be differentiated.
God and the Natural World in the Seventeenth Century: Space, Time, and Causality
Authors: Gorham Geoffrey
Published: September 2009

The employment by seventeenth‐century natural philosophers of stock theological notions like creation, immensity, and eternity in the articulation and justification of emerging physical programs disrupted a delicate but longstanding balance between transcendent and immanent conceptions of God. By playing a prominent (if not always leading) role in many of the major scientific developments of the period, God became more intimately involved with natural processes than at any time since antiquity. In this discussion, I am particularly concerned with the causal and spatio‐temporal relations between God and nature in the seventeenth century as recent scholarship has revealed how dramatically traditional conceptions of these relations were transformed by philosophers and scientists like Descartes, Malebranche, More, and Newton.
Cartesian Sensations
Authors: De Rosa Raffaella
Published: September 2009

Descartes maintained that sensations of color and the like misrepresent the material world in normal circumstances. Some prominent scholars have argued that, to explain this Cartesian view, we must attribute to Descartes a causal account of sensory representation. I contend that neither the arguments motivating this reading nor the textual evidence offered in its support is sufficient to justify such attribution. Both textual and theoretical reasons point in the direction of an (at least partial) internalist account of Descartes’ views on sensory representation.
Exercise Preference Patterns, Resources, and Environment Among Rural Breast Cancer Survivors
Authors: Rogers Laura Q. , Markwell Stephen J. , Courneya Kerry S. , McAuley Edward , Verhulst Steven
Published: September 2009

ABSTRACT: 
Context:

Rural breast cancer survivors may be at increased risk for inadequate exercise participation. Purpose: To determine for rural breast cancer survivors: (1) exercise preference “patterns,” (2) exercise resources and associated factors, and (3) exercise environment. Methods: A mail survey was sent to rural breast cancer survivors identified through a state cancer registry, and 483 (30%) responded. Findings: The majority (96%) were white, with mean education of 13 (±2.5) years and mean 39.0 (±21.5) months since diagnosis. Most participants (67%) preferred face‐to‐face counseling from an exercise specialist (27%) or other individual (40%). A third (31%) preferred home‐based exercise with non face‐to‐face counseling from someone other than an exercise specialist. Participants preferring face‐to‐face counseling were more apt to prefer supervised exercise (38% vs 9%, P < 0.001) at a health club (32% vs 8%, P < 0.001). Home exercise equipment was reported by 63%, with 97% reporting home telephone and 67% reporting Internet access. Age, education, self‐efficacy, treatment status, and exercise behavior were associated with exercise resources. The physical environment was often not conducive to exercise but a low crime rate and high trust in neighbors was reported. Conclusions: Rural health education programs encouraging exercise should offer multiple programming options while considering the physical environment and capitalizing on available resources and beneficial social environmental characteristics.
Physician Assistants and Nurse Practitioners as a Usual Source of Care
Authors: Everett Christine M. , Schumacher Jessica R. , Wright Alexandra , Smith Maureen A.
Published: September 2009

ABSTRACT: Purpose:To identify characteristics and outcomes of patients who use physician assistants and nurse practitioners (PA/NPs) as a usual source of care.Methods:Cross sectional analysis using the telephone and mail surveys of the Wisconsin Longitudinal Study (WLS), a prospective cohort study of Wisconsin high school graduates and selected siblings (n = 6,803).Findings:Individuals from metropolitan (OR = 0.40, 95% CI = 0.29‐0.54) and micropolitan (OR = 0.65, 95% CI = 0.44‐0.95) areas were less likely to utilize PA/NPs than participants from rural locations. Participants without insurance or with public insurance other than Medicare were more likely than those with private insurance to utilize PA/NPs (OR = 1.71, 95% CI = 1.02‐2.86). Patients of PA/NPs were more likely to be women (OR = 1.77, 95% CI = 1.34‐2.34), younger (OR = 0.95, 95% CI = 0.92‐0.98) and have lower extroversion scores (OR = 0.81, 95% CI = 0.68‐0.96). Participants utilizing PA/NPs reported lower perceived access (β=−0.22, 95% CI =−0.35‐0.09) than those utilizing doctors. PA/NP utilization was associated with an increased likelihood of chiropractor visits (OR = 1.57, 95% CI = 1.15‐2.15) and decreased likelihood of a complete health exams (OR = 0.74, 95% CI = 0.55‐0.99) or mammograms (OR = 0.65, 95% CI = 0.45‐0.93). There were no significant differences in self‐rated health or difficulties/delays in receiving care.Conclusions:Populations served by PA/NPs and doctors differ demographically but not in complexity. Though perceived access to care was lower for patients of PA/NPs, there were few differences in utilization and no differences in difficulties/delays in care or outcomes. This suggests that PA/NPs are acting as primary care providers to underserved patients with a range of disease severity, findings which have important implications for policy, including clinician workforce and reimbursement issues.
Actions Can Speak as Loud as Words: Measuring Behavior in Psychological Science
Authors: Lewandowski Jr Gary W. , Strohmetz David B.
Published: September 2009

It has been argued that there is a growing trend in personality and social psychological science concerning the preference of self‐report measures over the use of direct observations of behavior for the outcome variables of interest. Augmenting the use of self‐reports with measures of behavior helps achieve methodological pluralism that allows researchers to triangulate on the phenomenon of interest and have increased confidence in understanding the phenomenon. To facilitate this process, we discuss a sample of social psychological and personality studies published during APA’s ‘Decade of Behavior’ that use straightforward and innovative ways of measuring behavioral outcome variables. Specifically, we identify three different strategies for incorporating behavior in a study: behavioral traces, behavioral observations, and behavioral choice. In each case, we show how measures of behavior complement self‐report measures. By making a conscientious effort to include more behavior measures in our research, we can broaden the appeal of psychological science by enhancing our understanding of the causes and antecedents of human behavior.
Does deprivation index modify the acute effect of black smoke on cardiorespiratory mortality?
Authors: Carder M , McNamee R , Beverland I , Elton R , Cohen G R , Boyd J , Van Tongeren M , Agius R M
Published: September 2009

Objectives

To investigate whether deprivation index modifies the acute effect of black smoke on cardiorespiratory mortality.

Methods

Generalised linear Poisson regression models were used to investigate whether deprivation index (as measured by the Carstairs deprivation index) modified the acute effect of black smoke on mortality in two largest Scottish cities (Glasgow and Edinburgh) between January 1981 and December 2001. Lag periods of up to 1 month were assumed for the effects of black smoke.

Results

Deprivation index significantly modified the effect of black smoke on mortality, with black smoke effects generally increasing as level of deprivation increased. The interaction coefficient from a parametric model assuming a linear interaction between black smoke (μg/m−3) and deprivation in their effect on mortality—equivalent to a test of ‘linear trend’ across Carstairs categories—was significant for all mortality outcomes. In a model where black smoke effects were estimated independently for each deprivation category, the estimated increase in respiratory mortality over the ensuing 1-month period associated with a 10 μg/m3increase in the mean black smoke concentration was 8.0% (95% CI 5.1 to 10.9) for subjects residing in the ‘most’ deprived category (Carstairs category 7) compared to 3.7% (95% CI −0.7 to 8.4) for subjects residing in the ‘least’ deprived category (Carstairs category 1).

Conclusions

The results suggest a stronger effect of black smoke on mortality among people living in more deprived areas. The effect was greatest for respiratory mortality, although significant trends were also seen for other groups. If corroborated, these findings could have important public health implications.
Pneumoconiosis among underground bituminous coal miners in the United States: is silicosis becoming more frequent?
Authors: Laney A Scott , Petsonk Edward L , Attfield Michael D
Published: September 2009

Objectives

Epidemiological reports since 2000 have documented increased prevalence and rapid progression of pneumoconiosis among underground coal miners in the United States. To investigate a possible role of silica exposure in the increase, we examined chest x-rays (CXRs) for specific abnormalities (r-type small opacities) known to be associated with silicosis lung pathology.

Methods

Underground coal miners are offered CXRs every 5 years. Abnormalities consistent with pneumoconiosis are recorded by National Institute for Occupational Safety and Health (NIOSH) B Readers using the International Labour Organization Classification of Radiographs of Pneumoconioses. CXRs from 1980 to 2008 of 90 973 participating miners were studied, focussing on reporting of r-type opacities (small rounded opacities 3–10 mm in diameter). Log binomial regression was used to calculate prevalence ratios adjusted for miner age and profusion category.

Results

Among miners from Kentucky, Virginia and West Virginia, the proportion of radiographs showing r-type opacities increased during the 1990s (prevalence ratio (PR) 2.5; 95% CI 1.7 to 3.7) and after 1999 (PR 4.1; 95% CI 3.0 to 5.6), compared to the 1980s (adjusted for profusion category and miner age). The prevalence of progressive massive fibrosis in 2000–2008 was also elevated compared to the 1980s (PR 4.4; 95% CI 3.1 to 6.3) and 1990s (PR 3.8; 95% CI 2.1 to 6.8) in miners from Kentucky, Virginia and West Virginia.

Conclusions

The increasing prevalence of pneumoconiosis over the past decade and the change in the epidemiology and disease profile documented in this and other recent studies imply that US coal miners are being exposed to excessive amounts of respirable crystalline silica.
Ranking of Feeding Positions by Drift-Feeding Arctic Grayling (Thymallus arcticus) in Dominance Hierarchies
Authors: Hughes Nicholas F.
Published: September 2009

Field experiments in the pools of a mountain stream demonstrate that Arctic grayling (Thymallus arcticus) rank feeding positions according to desirability and that competition sorts fish so that the dominance rank of each individual matches the rank desirability of its position. Groups containing the same number of fish always occupied the same set of positions, and positions were added (in reverse order of desirability) as group size was increased; these results show that fish ranked positions. There was an almost perfect correlation between the dominance rank (measured as fish length) of each fish and the rank desirability of its position, suggesting that competition sorts fish among positions. This conclusion was strengthened by the results of sequential removal experiments in which the dominant fish was removed at the end of each day. After each removal the remaining fish almost always moved into the positions previously occupied by fish immediately above them in the dominance hierarchy.
Selection of Positions by Drift-Feeding Salmonids in Dominance Hierarchies: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska
Authors: Hughes Nicholas F.
Published: September 2009

In this work I describe a model to predict position choice by each individual in a dominance hierarchy of drift-feeding stream salmonids. This is an adaptation of Hughes and Dill's model (1990. Can. J. Fish. Aquat. Sci. 47: 2039–2048) of position choice by solitary fish. I have included the effect that prey consumption, lateral diffusion of drifting invertebrates, and entry of invertebrates into the drift have on the density of prey downstream of feeding fish and the restrictions that dominant fish place on freedom of choice by their subordinates. l assume that each fish chooses the most profitable position that its rank in the hierarchy will allow. There was an encouraging match between the distribution patterns predicted by the model and the distribution patterns actually adopted by Arctic grayling (Thymallus arcticus) in two pools of a mountain stream. This result suggests that Arctic grayling locate and rank positions based on their profitability. The predictions of reduced models, and the location of positions in relation to bottom topography and current flow, suggest that the physical habitat forms the template for distribution patterns by determining the location and ranking of the most profitable positions.
Top-Down Effects of Brook Trout (Salvelinus fontinalis) in a Boreal Forest Stream
Authors: Bechara José A. , Moreau Guy , Planas Dolors
Published: September 2009

The impact of fish predation on epibenthic organisms at different trophic levels was studied in a series of replicated experimental outdoor channels fed by a boreal forest stream (Québec, Canada). Brook trout (Salvelinus fontinalis) were introduced into five of 10 channels according to a randomized block experimental design. Periphyton biomass (expressed as total chlorophyll a and total organic matter) and macroinvertebrate biomass were measured four times during the summer. The biomass of small insects such as Chironomidae was always higher in the presence than in the absence of fish, while the biomass of larger invertebrates such as Baetis (Ephemeroptera) and Psychoglypha subborealis (Trichoptera) was reduced in the presence of fish. Periphyton biomass was significantly greater in channels with fish on the first sampling date after fish introduction but not at later dates. Complementary cage experiments, involving both the inclusion and exclusion of selected invertebrates from periphyton-covered surfaces, demonstrated that the presence of Baetis can reduce the periphytic biomass, while the presence of P. subborealis can reduce the biomass of Chironomidae. Overall, these results suggest that size-selective predation by brook trout can cause profound changes in the structure of epibenthic communities at primary as well as secondary trophic levels.
Fertility and Sperm Quality of Virgin and Repeat-Spawning Atlantic Cod (Gadus morhua) and Associated Hatching Success
Authors: Trippel Edward A. , Neilson John D.
Published: September 2009

Sperm performance of virgin and repeat spawners of Atlantic cod (Gadus morhua) was compared. Our results indicate that sperm extracted from either virgin or repeat-spawning male cod exhibit a high capacity (usually >95%) to fertilize eggs at semen:seawater dilutions ranging from 1:1 to 1:100. Fertilization rates at higher dilutions, however, decreased to averages of 47 and 53% at 1:1000, with no statistically significant differences occurring betwen the two types of spawners. Spermatocrit and proportion of sperm cells exhibiting progressive forward motion together accounted for, at most, 14% of the total variability in success of fertilization at semen:seawater dilutions of 1:250, 1:500, and 1:1000. Individuals of both spawner types had immotile sperm, sometimes at high prevalence levels, but these individuals achieved fertiliztion rates comparable with those with high sperm motility. Hatching success of eggs fertilized by virgin males was more variable but, based on mean values, was almost identical to that of repeat spawners. Use of a video camera to record enlarged images of sperm with a haemacytometer grid pattern in the background has permitted the first documented measurements of sperm swimming speeds of a marine teleost fish; the fastest recorded speed was 1000 μm∙30 s−1.
Aquatic Insects as Bioindicators of Trace Element Contamination in Cobble-Bottom Rivers and Streams
Authors: Cain Daniel J. , Luoma Samuel N. , Carter James L. , Fend Steven V.
Published: September 2009

Trace element bioaccumulation was studied in immature benthic insects from two contaminated river systems to develop these animals as bioindicators. In one river, Cu, Cd, Pb, and Zn were analysed in insects and in fine bed sediments over a 381-km reach downstream of a large copper mining complex. In the other river, As contamination from a gold mine was assessed in insects and bed sediments over a 40-km reach. All insect taxa collected in contaminated river reaches had elevated whole-body trace element concentrations. However, direct comparisons of contamination using a single, common species among stations were limited because few species were distributed throughout the study reaches. Comparisons of contamination at taxomic levels higher than species were complicated by element-specific differences in bioaccumulation among taxa. These differences appeared to be governed by biological and hydrogeochemical factors. The variation in element concentrations among species of the caddisfly Hydropsyche was slightly greater than within individual species. If this genus is representative of others, comparisons of contamination within genera may be a practical alternative for biomonitoring studies when single species are not available.
Factors Affecting the Vulnerability of Juvenile Coho (Oncothynchus kisutch) and Chinook Salmon (O. tshawytscha) in a Saltwater Sport Fishery
Authors: Holtby L. Blair , Kadowaki Ronald K. , Simpson Kent S.
Published: September 2009

The fork length, origin (hatchery or wild), and sex and age composition of sport- and seine-caught juvenile (no sea winter annulus) coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) were compared in Saanich Inlet, British Columbia. Sport-caught coho and chinook were larger and had a higher proportion of males than seine-caught fish. The sport fishery was strongly size- selective for both species, resulting in the overrepresentation of jack coho and freshwater age 1 juvenile chinook in the sport catch. Marked coho and chinook were overrepresented in the sport catch, indicating that hatchery fish were more vulnerable to the sport fishery than wild fish. For both species, the higher vulnerability of hatchery fish to the sport fishery could not be fully explained on the basis of size, sex, or freshwater age. Relative to older fish, juvenile coho and chinook were more vulnerable to fishing methods that used light gear at shallow depths (<30 m), such as trolling and casting. Assumptions by managers that vulnerability of coho and chinook does not vary with size, sex, freshwater age, or origin need to be reexamined in light of these findings.
COMPOSITIONALITY AND REACHABILITY WITH CONDITIONS ON PATH LENGTHS
Authors: FELSCHER INGO , THOMAS WOLFGANG
Published: September 2009

In model-checking the systems under investigation often arise in the form of products. The compositional method, developed by Feferman and Vaught in 1959, fits to this situation and can be used to deduce the truth of a formula in the product from information in the factors. Building on earlier work of Wöhrle and Thomas (2004), we study first-order logic with reachability predicates over finitely synchronized products (i.e. synchronized products with a finite number of synchronization transitions). We extend the reachability predicates by conditions on the length of the corresponding paths, formulated in Presburger arithmetic. For finitely synchronized products with these enhanced reachability predicates we prove a composition theorem and then show that severe limitations exist for generalisations of this result.
THE COMPLEXITY OF SATISFIABILITY FOR FRAGMENTS OF CTL AND CTL⋆
Authors: MEIER ARNE , THOMAS MICHAEL , VOLLMER HERIBERT , MUNDHENK MARTIN
Published: September 2009

The satisfiability problems for [Formula: see text] and [Formula: see text] are known to be EXPTIME-complete, resp. 2EXPTIME-complete (Fischer and Ladner (1979), Vardi and Stockmeyer (1985)). For fragments that use less temporal or propositional operators, the complexity may decrease. This paper undertakes a systematic study of satisfiability for [Formula: see text]-and [Formula: see text]-formulae over restricted sets of propositional and temporal operators. We show that restricting the temporal operators yields satisfiability problems complete for 2EXPTIME, EXPTIME, PSPACE, and NP. Restricting the propositional operators either does not change the complexity (as determined by the temporal operators), or yields very low complexity like NC1, TC0, or NLOGTIME.
A RIGOROUS TREATMENT OF THE PERTURBATION THEORY FOR MANY-ELECTRON SYSTEMS
Authors: KASHIMA YOHEI
Published: September 2009

Four point correlation functions for many electrons at finite temperature in periodic lattice of dimension d (≥1) are analyzed by the perturbation theory with respect to the coupling constant. The correlation functions are characterized as a limit of finite dimensional Grassmann integrals. A lower bound on the radius of convergence and an upper bound on the perturbation series are obtained by evaluating the Taylor expansion of logarithm of the finite dimensional Grassmann Gaussian integrals. The perturbation series up to second-order is numerically implemented along with the volume-independent upper bounds on the sum of the higher order terms in the 2-dimensional case.
THE GROUNDSTATES AND PHASES OF THE TWO-DIMENSIONAL FULLY FRUSTRATED XY MODEL
Authors: MINNHAGEN PETTER , BERNHARDSSON SEBASTIAN , KIM BEOM JUN
Published: September 2009

The 2D Fully Frustrated XY(FFXY) class of models is shown to contain a new groundstate in addition to the checkerboard groundstate of the standard 2D XY model. The spin configuration of this additional groundstate is obtained and its connection to a broken Z2-symmetry explained. This means that the class of 2D FFXY models belongs within a U(1) ⊗ Z2 ⊗ Z2-symmetry phase-transition representation. The phase diagram is reviewed and the central charges of the four multicritical points described. The implications for the standard 2D FFXY-model are discussed and elucidated, in particular with respect to the long standing controversy concerning the phase transitions of the standard 2D FFXY-model.
ERGODICITY AND CHAOS IN A SYSTEM OF HARMONIC OSCILLATORS
Authors: LEE M. HOWARD
Published: September 2009

In recent years the term ergodicity has come into scientific vogue in various physical problems. In particular when a system exibits chaotic behavior, it is often said to be ergodic. Is it a correct usage of the term ergodicity? Does it not mean that the time and ensemble averages of a variable are equal? Are they really related one to one? We examine this issue via simple models of harmonic oscilators by means of the theorems of Birkhoff and Khinchin and also by our own physical theory of ergometry. This study also considers the chaotic behavior in the logistic map.
TOPOLOGICAL PHASE TRANSITIONS IN STRONGLY CORRELATED FERMI SYSTEMS
Authors: CLARK J. W. , KHODEL V. A. , ZVEREV M. V.
Published: September 2009

Opportunities for topological phase transitions in strongly correlated Fermi systems near a quantum critical point are explored as an alternative to collective scenarios for experimentally observed departures from standard Fermi-liquid behavior. Attention is focused on a quantum critical point at which the effective mass is divergent due to vanishing of the quasiparticle group velocity at the Fermi surface. Working within the original Landau quasiparticle theory, it is demonstrated that the quasiparticle picture can remain meaningful beyond the quantum critical point through rearrangements of the unstable normal Fermi surface and quasiparticle spectrum. Two possibilities emerge at zero temperature, depending on whether the quasiparticle interaction is regular or singular at zero momentum transfer. In the regular case, one type of topological phase transformation leads to a state with a multiconnected Fermi surface. In the singular case, another type of topological phase transition leads to an exceptional state containing a fermion condensate – the Fermi surface swells into a volume in momentum space, within which partial occupation prevails and quasiparticle energies are pinned to the chemical potential. As the temperature increases from zero to a characteristic value Tm, a crossover can occur from the state with multiple Fermi surfaces to that containing a fermion condensate.
AN INFORMATIVE METHOD FOR THE DIAGNOSTICS OF SUPERCONDUCTORS
Authors: ROSTAMI KHALIL
Published: September 2009

A method is proposed to measure the thermodynamic field of a superconductor; this method allows for the high-precision measurement of the first thermodynamic critical magnetic fields of the sample and its crystallites and subcrystallites. The first thermodynamic critical magnetic fields are used to estimate the critical current density of the sample, crystallites, and subcrystallites. The role of the demagnetizing fields of crystallites in HTSC samples is studied. An increase in the crystallite size is shown to suppress the intra-and intercrystalline critical currents of the sample in lower fields.
NON-LINEAR DYNAMICS, ENTANGLEMENT AND THE QUANTUM-CLASSICAL CROSSOVER OF TWO COUPLED SQUID RINGS
Authors: EVERITT M. J.
Published: September 2009

We explore the quantum-classical crossover of two coupled, identical, superconducting quantum interference device (SQUID) rings. We note that the motivation for this work is based on a study of a similar system comprising two coupled Duffing oscillators. In that work we showed that the entanglement characteristics of chaotic and periodic (entrained) solutions differed significantly and that in the classical limit entanglement was preserved only in the chaotic-like solutions. However, Duffing oscillators are a highly idealised toy model. Motivated by a wish to explore more experimentally realisable systems we now extend our work to an analysis of two coupled SQUID rings. We observe some differences in behaviour between the system that is based on SQUID rings rather than on Duffing oscillators. However, we show that the two systems share a common feature. That is, even when the SQUID ring's trajectories appear to follow (semi) classical orbits entanglement persists.
ELECTROSTATIC FIELD IN SUPERCONDUCTORS I: OPEN QUESTIONS
Authors: KOLÁČEK JAN , LIPAVSKÝ PAVEL
Published: September 2009

The electrostatic field in superconductors in the equilibrium diamagnetic state is discussed. On recent experimental data we demonstrate that the electrostatic field in superconductors is still far from being understood. Then we present the elementary ideas based on the balance of forces.
ELECTROSTATIC FIELD IN SUPERCONDUCTORS AT EQUILIBRIUM
Authors: LIPAVSKÝ PAVEL , KOLÁČEK JAN
Published: September 2009

The theory of electrostatic fields in superconductors at equilibrium is reviewed. We start from the simple Bernoulli potential balancing the Lorentz and inertial forces. Then we add interaction of superconducting and normal electrons and forces due to gradients of the condensation energy. Nonlocal relation between perturbing forces and the induced electrostatic field is formulated within the extended Ginzburg-Landau theory.
The Functional Specialization of the Planum Temporale
Authors: Zheng Zane Z.
Published: September 2009

The planum temporale (PT) is an anatomically heterogeneous area with several architectonic subdivisions and extensive connections with other parts of the brain. Here I review a functional MRI study investigating the role of a functionally defined area (Spt) within the left PT in speech motor processing and discuss the functional properties of PT regions in the context of findings from recent neurophysiological and neuroimaging studies.
Identification of Candidate Biomarkers of Therapeutic Response to Docetaxel by Proteomic Profiling
Authors: Zhao Liangli , Lee Brian Y. , Brown David A. , Molloy Mark P. , Marx Gavin M. , Pavlakis Nick , Boyer Michael J. , Stockler Martin R. , Kaplan Warren , Breit Samuel N. , Sutherland Robert L. , Henshall Susan M. , Horvath Lisa G.
Published: September 2009

Docetaxel chemotherapy improves symptoms and survival in men with metastatic hormone-refractory prostate cancer (HRPC). However, ∼50% of patients do not respond to Docetaxel and are exposed to significant toxicity without direct benefit. This study aimed to identify novel therapeutic targets and predictive biomarkers of Docetaxel resistance in HRPC. We used iTRAQ-mass spectrometry analysis to identify proteins associated with the development of Docetaxel resistance using Docetaxel-sensitive PC3 cells and Docetaxel-resistant PC3-Rx cells developed by Docetaxel dose escalation. Functional validation experiments were performed using recombinant protein treatment and siRNA knockdown experiments. Serum/plasma levels of the targets in patient samples were measured by ELISA. The IC50 for Docetaxel in the PC3-Rx cells was 13-fold greater than the parent PC-3 cell line (P = 0.004). Protein profiling identified MIC-1 and AGR2 as respectively up-regulated and down-regulated in Docetaxel-resistant cells. PC-3 cells treated with recombinant MIC-1 also became resistant to Docetaxel (P = 0.03). Conversely, treating PC3-Rx cells with MIC-1 siRNA restored sensitivity to Docetaxel (P = 0.02). Knockdown of AGR2 expression in PC3 cells resulted in Docetaxel resistance (P = 0.007). Furthermore, increased serum/plasma levels of MIC-1 after cycle one of chemotherapy were associated with progression of the cancer (P = 0.006) and shorter survival after treatment (P = 0.002). These results suggest that both AGR2 and MIC-1 play a role in Docetaxel resistance in HRPC. In addition, an increase in serum/plasma MIC-1 level after cycle one of Docetaxel may be an indication to abandon further treatment. Further investigation of MIC-1 as a biomarker and therapeutic target for Docetaxel resistance in HRPC is warranted. [Cancer Res 2009;69(19):7696–7703]
[18F]Fluoromethyl-[1,2-2H4]-Choline: A Novel Radiotracer for Imaging Choline Metabolism in Tumors by Positron Emission Tomography
Authors: Leyton Julius , Smith Graham , Zhao Yongjun , Perumal Meg , Nguyen Quang-De , Robins Edward , Årstad Erik , Aboagye Eric O.
Published: September 2009

Current radiotracers for positron emission tomography imaging of choline metabolism have poor systemic metabolic stability in vivo. We describe a novel radiotracer, [18F]fluoromethyl-[1,2-2H4]-choline (D4-FCH), that employs deuterium isotope effect to improve metabolic stability. D4-FCH proved more resistant to oxidation than its nondeuterated analogue, [18F]fluoromethylcholine, in plasma, kidneys, liver, and tumor, while retaining phosphorylation potential. Tumor radiotracer levels, a determinant of sensitivity in imaging studies, were improved by deuterium substitution; tumor uptake values expressed as percent injected dose per voxel at 60 min were 7.43 ± 0.47 and 5.50 ± 0.49 for D4-FCH and [18F]fluoromethylcholine, respectively (P = 0.04). D4-FCH was also found to be a useful response biomarker. Treatment with the mitogenic extracellular kinase inhibitor PD0325901 resulted in a reduction in tumor radiotracer uptake that occurred in parallel with reductions in choline kinase A expression. In conclusion, D4-FCH is a very promising metabolically stable radiotracer for imaging choline metabolism in tumors. [Cancer Res 2009;69(19):7721–8]
Ambulatory Monitoring Detects Sorafenib-Induced Blood Pressure Elevations on the First Day of Treatment
Authors: Maitland Michael L. , Kasza Kristen E. , Karrison Theodore , Moshier Kristin , Sit Laura , Black Henry R. , Undevia Samir D. , Stadler Walter M. , Elliott William J. , Ratain Mark J.
Published: September 2009

Purpose: Hypertension is a mechanism-based toxicity of sorafenib and other cancer therapeutics that inhibit the vascular endothelial growth factor (VEGF) signaling pathway. This prospective, single-center, cohort study characterized ambulatory blood pressure monitoring as an early pharmacodynamic biomarker of VEGF signaling pathway inhibition by sorafenib.

Experimental Design: Fifty-four normotensive advanced cancer patients underwent 24-hour ambulatory blood pressure monitoring before and between days 6 and 10 of sorafenib therapy. After blood pressure changes were detected among the first cohort within 10 days, ambulatory blood pressure monitoring was done during the first 24 hours of treatment for the second cohort.

Results: For the entire patient population, the blood pressure increase [mean systolic, +10.8 mm Hg; 95% confidence interval (95% CI), 8.6-13.0; range, −5.2 to +28.7 mm Hg; mean diastolic, +8.0 mm Hg; 95% CI, 6.3-9.7; range, −4.4 to +27.1 mm Hg] was detected between days 6 and 10 (P < 0.0001 for both) and plateaued thereafter. Variability in blood pressure change did not associate with: age, body size, sex, self-reported race, baseline blood pressure, or steady-state sorafenib plasma concentrations. In the second cohort, the blood pressure elevation was detected during the first 24 hours (mean systolic, +8.2 mm Hg; 95% CI, 5.0-11.3; mean diastolic, +6.5 mm Hg; 95% CI, 4.7-8.3; P < 0.0001 for both).

Conclusions: Ambulatory blood pressure monitoring detects the blood pressure response to VEGF signaling pathway inhibition by sorafenib during the first 24 hours of treatment. The magnitude of blood pressure elevation is highly variable and unpredictable but could be important in optimizing the therapeutic index of VEGF signaling pathway inhibitor therapy. (Clin Cancer Res 2009;15(19):6250–7)
Habitual Physical Activity and Physical Fitness in Older Japanese Adults: The Nakanojo Study
Authors: Aoyagi Yukitoshi , Park Hyuntae , Watanabe Eiji , Park Sungjin , Shephard Roy J.
Published: September 2009

Background: Optimal patterns of habitual physical activity to ensure healthy aging remain unclear because of measurement limitations; most investigators have used either subjective questionnaires, or accelerometer or pedometer measurements limited to a single week, despite evidence of both the limited reliability/validity of questionnaires and seasonal changes in activity patterns. Objective: This study explored possible associations between indicators of physical fitness (walking ability, upper- and lower-extremity isometric strength, and static and dynamic balance) and yearlong pedometer/accelerometer assessments of the quantity and quality of habitual physical activity in ostensibly healthy older adults. Methods: Subjects were 76 male and 94 female Japanese aged 65–84 years. Each participant wore a pedometer/accelerometer for 1 year; measurements included the average number of steps taken each day and the duration of activity at an intensity of >3 metabolic equivalents (METs). Compliance was good, the instrument being removed for intervals of >3 h on <5% of days; data for such intervals were excluded from analysis. At the year’s end, traditional laboratory techniques assessed preferred and maximal walking speeds, peak handgrip force, peak knee extension torque, total body sway, and maximal functional reach. Results: After controlling data for age and/or sex, lower-extremity function (walking speeds and knee extension torque) showed significant positive relationships with the daily step count and daily duration of activity at >3 METs, especially in individuals ≥75 years of age. On the other hand, handgrip force and body sway were unrelated to pedometer/accelerometer measurements. Linear and exponential regressions showed positive associations between walking speeds and pedometer/accelerometer scores up to the observed maxima of 13,700 steps/day and 62 min/day at >3 METs. However, when data were categorized into quartiles, walking speeds were not significantly greater in persons exceeding 7,000–8,000 steps/day and/or 15–20 min/day at >3 METs. With a few exceptions, subjects meeting these levels of habitual activity had walking speeds above the threshold predicting the development of functional dependence. Conclusion: The present data suggest that fitness is well maintained in elderly people who take >7,000–8,000 steps/day and/or spend >15–20 min/day at >3 METs. Nevertheless, the direction of this association merits exploration by longitudinal prospective studies and/or randomized controlled trials.
A ‘Desaturase Hypothesis’ for Atherosclerosis: Janus-Faced Enzymes in ω–6 and ω–3 Polyunsaturated Fatty Acid Metabolism
Authors: Martinelli Nicola , Consoli Letizia , Olivieri Oliviero
Published: September 2009

The delta-5 and delta-6 desaturases are key enzymes in the metabolism of omega-3 (ω–3) and omega-6 (ω–6) polyunsaturated fatty acids (PUFA), which in turn influence cellular functions by regulating several metabolic pathways with well-known effects on the cardiovascular system. At present, data about desaturase activity and cardiovascular risk remain inconclusive. In this short review we propose a ‘desaturase hypothesis’ of atherosclerosis, providing suggestions for the Janus-faced role of desaturases, with both more favorable (mainly related to ω–3 long-chain fatty acids) and more harmful (mainly related to ω–6 long-chain fatty acids) cardiovascular effects than those obtained in subjects with lower desaturase activity. In particular in populations eating a Western diet rich in ω–6 PUFA, a high desaturase activity may promote an increased bioavailability of arachidonic acid with prevailing synthesis of arachidonic acid-derived proinflammatory eicosanoids, finally favoring atherosclerotic vascular damage. In contrast, high desaturase activity in subjects consuming a diet rich in ω–3 PUFA or receiving ω–3 PUFA supplementation could result in the opposite situation with a preferential synthesis of anti-inflammatory eicosanoids. For these reasons, carriers of specific FADS haplotypes may be predisposed to more pronounced vascular inflammatory damage, but also to an increased beneficial effect with ω–3 PUFA supplementation.