bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Hepatitis C Virus Subgenomic Replicon Resistance to Cyclosporine In Vitro
Authors: Robida John M. , Nelson Heather B. , Liu Zhe , Tang Hengli
Published: March 2007

Treatment of hepatitis C virus (HCV) infection has been met with less than satisfactory results due primarily to its resistance to and significant side effects from alpha interferon (IFN-α). New classes of safe and broadly acting treatments are urgently needed. Cyclosporine (CsA), an immunosuppressive and anti-inflammatory drug for organ transplant patients, has recently been shown to be highly effective in suppressing HCV replication through a mechanism that is distinct from the IFN pathway. Here we report the selection and characterization of HCV replicon cells that are resistant to CsA treatment in vitro, taking advantage of our ability to sort live cells that are actively replicating HCV RNA in the presence of drug treatments. This resistance is specific to CsA as the replicon cells most resistant to CsA were still sensitive to IFN-α and a polymerase inhibitor. We demonstrate that the resistant phenotype is not a result of general enhanced replication and, furthermore, that mutations in the coding region of HCV NS5B contribute to the resistance. Interestingly, a point mutation (I432V) isolated from the most resistant replicon was able to rescue a lethal mutation (P540A) in NS5B that disrupts its interaction with its cofactor, cyclophilin B (CypB), even though the I432V mutation is located outside of the reported CypB binding site (amino acids 520 to 591). Our results demonstrate that CsA exerts selective pressure on the HCV genome, leading to the emergence of resistance-conferring mutations in the viral genome despite acting upon a cellular protein.
Distinguishing trophic variation from seasonal and size-based isotopic (δ15N) variation of zooplankton
Authors: Matthews Blake , Mazumder Asit
Published: March 2007

We measured the δ15N of particulate organic matter (POM), Daphnia pulex (D), Holopedium gibberum (H), Leptodiaptomus tyrelli (LT), Epischura nevadensis (E), and Chaoborus trivittatus (C) over an annual cycle in Council Lake, a pristine, oligotrophic, fishless lake. Annual averages of the δ15N of plankton (C, LT, E > D, H > POM) matched expected differences in trophic position, but seasonal patterns differed among species. During midsummer, the δ15N of D, H, and LT increased above the δ15N of E and C, despite little temporal or spatial variation in the δ15N of POM (<41 µm). Larger size fractions of POM (41–200 µm) helped explain some of the temporal variability of zooplankton δ15N. Body size of zooplankton was correlated with δ15N for D, C, and E, which could indicate size-based, trophic-level variation; selective feeding; or physiological differences in 15N enrichment. We propose that detailed time series of δ15N for multiple zooplankton species can help determine the seasonal variability of trophic structure in zooplankton assemblages.
Morphological and swimming stamina differences between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), rainbow trout (Oncorhynchus mykiss), and their hybrids
Authors: Seiler Steven M , Keeley Ernest R
Published: March 2007

We hypothesized that body shape differences between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), rainbow trout (Oncorhynchus mykiss), and their hybrids may influence swimming ability and thus play an important role in the invasion of nonnative rainbow trout and hybrid trout into native cutthroat trout populations. We reared Yellowstone cutthroat trout, rainbow trout, and reciprocal hybrid crosses in a common environment and conducted sustained swimming trials in order to test for genetically based morphological and swimming stamina differences. Linear and geometric morphometric analyses identified differences in body shape, with cutthroat trout having slender bodies and small caudal peduncles and rainbow trout having deep bodies and long caudal peduncles. Hybrid crosses were morphologically intermediate to the parental genotypes, with a considerable maternal effect. Consistent with morphological differences, cutthroat trout had the lowest sustained swimming velocity and rainbow trout had the highest sustained swimming velocity. Sustained swimming ability of hybrid genotypes was not different from that of rainbow trout. Our results suggest that introduced rainbow trout and cutthroat-rainbow trout hybrids potentially out-compete native Yellowstone cutthroat trout through higher sustained swimming ability.
An "experiment" on effort allocation of fishing vessels: the role of interference competition and area specialization
Authors: Poos Jan-Jaap , Rijnsdorp Adriaan D
Published: March 2007

A temporarily closed area established to protect spawning Atlantic cod (Gadus morhua) in the North Sea allowed us to study the response of the Dutch beam trawl fleet exploiting common sole (Solea solea) and plaice (Pleuronectes platessa). A number of vessels left the North Sea 1 month earlier than the normal seasonal pattern. The vessels that continued fishing in the North Sea were concentrated in the remaining open areas. In the first week after the closure, the catch rate decreased by 14%, coinciding with an increase in crowding of 28%. Area specialisation affected the response of individual vessels because vessels without prior experience in the open areas showed a larger decline in catch rate compared with vessels that previously fished in these open areas and were more likely to stop fishing during the closed period. The decrease in catch rate in response to the increase in competitor density allowed us to estimate the strength of the interference competition.
State-dependent life history plasticity in Sacramento River winter-run chinook salmon (Oncorhynchus tshawytscha): interactions among photoperiod and growth modulate smolting and early male maturation
Authors: Beckman Brian R , Gadberry Brad , Parkins Paul , Cooper Kathleen A , Arkush Kristen D
Published: March 2007

An experiment was performed to determine the relative effects of photoperiod at emergence and growth rate on smolting pattern and early male maturation rate in Sacramento River (California, USA) winter-run chinook salmon (Oncorhynchus tshawytscha) (listed as endangered under the US Endangered Species Act). Fry were ponded on the same day but at three different points in the seasonal photoperiod cycle (using artificial lighting) spanning the natural range of emergence timing in this population. Significant increases in gill Na+,K+-ATPase activity and seawater survival were found during March and April in all treatments, similar to yearling smolting patterns found in many salmonids. Fish that emerged early and grew at a relatively high rate also demonstrated signs of smolting in August–November. Male maturation was growth dependent, with HiFeed groups maturing at a rate double that found in LoFeed groups. Male maturation was also photoperiod dependent with a linear relation found between emergence date and rate of male maturation. These results demonstrate that individual life history pattern was variable and dependent on emergence timing and growth rate.
Disease dynamics and the potential role of thermal stress in the sea urchin, Strongylocentrotus purpuratus
Authors: Lester Sarah E , Tobin Elizabeth D , Behrens Michael D
Published: March 2007

Evidence from field and laboratory data indicates that warmer ocean temperatures likely play a critical role in the disease dynamics of intertidal populations of the sea urchin, Strongylocentrotus purpuratus. Urchin populations along the west coast of North America have experienced numerous disease epidemics in the past several decades, and yet little is known about disease transmission, the geographic extent, or contributing factors to these outbreaks. In this study, we examine disease in Pacific Strongylocentrotus urchins over a broad geographic range with repeated sampling. We suggest that what has been assumed to be a single disease might be two distinct diseases presenting two disparate pathologies. Both potential pathologies were extremely rare or absent north of Point Conception, California, in a region associated with strong upwelling and cooler water temperatures but were common at warmer sites in southern California and northern Baja California, Mexico. Furthermore, during the survey period, disease prevalence at some of the study sites was positively correlated with sea surface temperatures as estimated from satellite data, leading us to hypothesize that heat stress may increase urchin susceptibility to disease. In experimentally elevated water temperatures, diseased individuals had significantly larger lesions and a significantly lower gonadal index, which could have important implications for urchin population dynamics.
Nonlinear stability of the near-Earth plasma sheet during substorms: 9 February 1995 event
Authors: Dobias P , Wanliss J A , Samson J C
Published: March 2007

It has been previously demonstrated that several minutes prior to an onset of a magnetospheric substorm the near-Earth plasma sheet becomes unstable to resonance-type perturbations. The next logical step, examined here, is an assumption that the velocity shear in the resonance would lead to a development of a Kelvin–Helmholtz (KH) instability. Using a Grad-Shafranov equilibrium constrained by CANOPUS data, we analyze the stability properties of the near-Earth plasma sheet in the presence of a field-line resonance-generated KH instability at around 10 Earth radii. The results of the analysis are in general agreement with observations and computer modeling of substorms. As a part of the analysis, we discuss the importance of the proper distinction between the stability properties of the magnetotail, and the trigger mechanism responsible for the instability. While these two aspects of a substorm may be (and likely are) related, it is possible that they involve different types of processes that work in a complementary fashion. PACS Nos.: 06.54, 27.40, 27.72, 27.88
Bird declines over 22 years in forest remnants in southeastern Australia: Evidence of faunal relaxation?
Authors: MacHunter Josephine , Wright Wendy , Loyn Richard , Rayment Phil
Published: March 2007

Declines in Australia's forest avifauna are largely attributed to loss of native vegetation. Many studies have examined patches of remnant vegetation, but few have considered changes over many years. In our study, bird data were collected 22 years apart (survey period A (SPA), 1980–1983; survey period B (SPB), 2002–2005) in 20 forest remnants in a rural landscape in southeastern Australia. Initial modelling (SPA) predicted a decline of nine species per patch in the 100 years following fragmentation. Our data showed that average species richness declined by nine species per patch in just 22 years between SPA and SPB, perhaps representing an example of faunal relaxation. Observer variation, changes in climate, changes in land use, and interspecific competition from an aggressive edge-adapted native bird (the noisy miner, Manorina melanocephala (Latham, 1802)) did not appear to be the main drivers of this decline. However, noisy miners were strongly associated with high turnover of forest species where they occurred above a threshold of six birds per count. Revisiting sites after an interval of many years has shed new light on the dynamics of a fragmented ecosystem, and indicates that further bird declines are likely as a result of past habitat loss.
On the analysis of cubic smoothing spline-based stem curve prediction for forest harvesters
Authors: Koskela Laura , Nummi Tapio , Wenzel Simone , Kivinen Veli-Pekka
Published: March 2007

In the cut-to-length (CTL) harvesting system the felling, delimbing, and bucking processes take place at the harvesting site. The optimal cutting points along the stem can be determined if the whole stem curve is known. In practice, however, it is not economically feasible to measure the whole stem first before crosscutting, and hence the first cutting decisions are usually made when only a short part of the stem is known. Predictions are used to determine the cutting pattern to compensate for the unknown part of the stem. In this paper our interest focuses on stem curve prediction in a harvesting situation and we study a modified version of a cubic smoothing spline-based prediction method devised by Nummi and Mottonen (T. Nummi and J. Mottonen. 2004. J. Appl. Stat. 31: 105–114). The method's performance was assessed in five different final felling stands of spruce and pine, collected by harvesters in southern Finland. The results for the spline approach are very promising and show the superiority of the method over the linear mixed-model-based approach of Liski and Nummi (E. Liski and T. Nummi. 1995. Scand. J. Stat. 22: 255–269) and also over the approach based on the variable-exponent taper equation of Kozak (A. Kozak. 1988. Can. J. For. Res. 18: 1363–1368).
Persistence of ground-layer bryophytes in a structural retention experiment: initial effects of level and pattern of overstory retention
Authors: Dovčiak Martin , Halpern Charles B , Saracco James F , Evans Shelley A , Liguori Denise A
Published: March 2007

We examined first-year responses of forest-floor bryophytes to structural retention harvests at four locations in western Washington. Treatments represented a range of retention levels (100%, 75%, 40%, and 15% of original basal area) and spatial patterns (dispersed vs. aggregated in 1 ha patches). Declines in bryophyte cover and species' frequencies were comparably large at 40% and 15% retention. Retention pattern had little effect on the magnitude of decline, although declines in richness tended to be greater in aggregated treatments. Changes in cover were small within forest aggregates (comparable to controls). However, richness declined relative to controls within aggregates at 15% retention; rarer taxa in these exposed patches may be susceptible to edge effects. Declines in species' frequencies and richness were consistently greater in "clear-cut" areas of aggregated treatments than in dispersed retention; liverworts were particularly sensitive to harvest. In cut areas, bryophytes responded positively to cover of understory vegetation and negatively to logging slash. The positive correlation of richness (but not cover) to tree basal area may reflect the contribution of tree boles to persistence of rarer corticolous species. Our results suggest that conservation of bryophytes in forests managed with structural retention will require large retention patches and dispersed trees at levels considerably higher than current retention standards.
Past, current, and future fire frequencies in Quebec's commercial forests: implications for the cumulative effects of harvesting and fire on age-class structure and natural disturbance-based management
Authors: Bergeron Yves , Cyr Dominic , Drever C Ronnie , Flannigan Mike , Gauthier Sylvie , Kneeshaw Daniel , Lauzon Ève , Leduc Alain , Goff Héloïse Le , Lesieur Daniel , Logan Kimberley
Published: March 2007

The past decade has seen an increasing interest in forest management based on historical or natural disturbance dynamics. The rationale is that management that favours landscape compositions and stand structures similar to those found historically should also maintain biodiversity and essential ecological functions. In fire-dominated landscapes, this approach is feasible only if current and future fire frequencies are sufficiently low compared with the preindustrial fire frequency, so a substitution of fire by forest management can occur without elevating the overall frequency of disturbance. We address this question by comparing current and simulated future fire frequency based on 2 × CO2 and 3 × CO2 scenarios to historical reconstructions of fire frequency in the commercial forests of Quebec. For most regions, current and simulated future fire frequencies are lower than the historical fire frequency, suggesting that forest management could potentially be used to maintain or recreate the age-class distribution of fire-dominated preindustrial landscapes. Current even-aged management, however, tends to reduce forest variability by, for example, truncating the natural age-class distribution and eliminating mature and old-growth forests from the landscape. Therefore, in the context of sustainable forest management, silvicultural techniques that retain a spectrum of forest compositions and structures at different scales are necessary to maintain this variability and thereby allow a substitution of fire by harvesting.
Fifty years of forest dynamics following diameter-limit cuttings in balsam fir – yellow birch stands of the Lower St. Lawrence region, Quebec
Authors: Archambault Louis , Delisle Claude , Larocque Guy R , Sirois Luc , Belleau Pierre
Published: March 2007

The long-term effects of high-intensity diameter-limit cuttings conducted in the winter and summer of the 1940s and 1950s on the dynamics of softwood and mixedwood stands in southeastern Quebec were compared. Changes in composition and stand structure over a 50 year period were studied using 18 permanent sample plots located in the Lac-Métis Seigneury observation area measured in 1950, 1960, 1970, and 2003. Winter logging operations were conducted between 1942 and 1949, and summer logging operations were conducted between 1958 and 1960. The interaction between cuttings and the 1950s and 1970s spruce budworm (Choristoneura fumiferana (Clemens)) outbreaks that occurred in the area affected forest dynamics. For the two logging operation types, the most abundant softwood species observed before logging and in 2003 was balsam fir (Abies balsamea (L.) Mill.), whereas white birch (Betula papyrifera Marsh.) and yellow birch (Betula alleghaniensis Britt.) were the most abundant hardwood species. Changes in the overstory composition were more significant in the summer logging operations than in the winter ones. The softwood cover type observed before winter logging was maintained in 2003. Following summer logging, an important increase in the proportion of birch species was observed. The softwood cover type observed before logging had changed to a mixedwood cover type by 2003. Forest dynamics differences between the two types of logging were the result of interactions between the density and composition of advance regeneration, the microsite conditions after logging, and the length and severity of spruce budworm outbreaks.
The influence of forest structure on riparian litterfall in a Pacific Coastal rain forest
Authors: O'Keefe Thomas C , Naiman Robert J
Published: March 2007

Vegetative litter produced from riparian forests associated with alluvial rivers mediates nutrient and carbon cycling and indirectly shapes successional pathways and overall plant community characteristics. We quantified litter inputs at sites along the Queets River, a temperate rain forest river, in Olympic National Park, Washington. Study plots represented a chronosequence from pioneering vegetative patches on recently formed gravel bars to mature riparian forest terraces up to 350 years old. We observed an initial ~100 year linear increase in litter production (0.8–10.2 Mg·ha–1·year–1). Subsequently, we observed a shift to conifer dominance and development of a forest canopy with considerable structural complexity. During this time, litter production declined to ~5 Mg·ha–1·year–1. Empirical models of temporal changes in litter production suggest that the basal area and canopy volume of individual tree species are significant predictors (r2 = 0.60–0.99) of leaf and needle litter derived from that species, and can be used to predict litter production. We conclude that annual litter production is strongly influenced by structural forest characteristics and that litterfall rates can be estimated for a ~350 year chronosequence from stem basal area and canopy volume.
Effect of soil properties and soil disturbance on frost heaving of mineral soil: a laboratory experiment
Authors: Chantal Michelle de , Rita Hannu , Bergsten Urban , Löfvenius Mikaell Ottosson , Grip Harald
Published: March 2007

A laboratory experiment was done to identify the properties that make a substrate susceptible to frost heaving. Tests were carried out on nondisturbed soil cores (fresh and dry) of Ae and B horizons from sand, loamy sand, and sandy loam in a freezing cabinet (–3.5 °C). Cores were continuously supplied with water from below. Freezing tests were repeated after soil disturbance (V-shaped furrow, 50% increase in surface area). The effects of texture, horizon, drying, and disturbance on frost heaving were tested using repeated-measures analysis of variance with soil elements (organic Al, organic Fe, inorganic Al, inorganic Fe, C, and N) and soil fractions (clay, fine silt, coarse silt, fine sand, and coarse sand) as covariates. The effect of horizon was as important as that of texture, and soil disturbance increased frost heaving. Disturbed fresh B horizon from loamy sand and sandy loam heaved the most (soil expansion >5% in height), whereas nondisturbed dry Ae horizon, regardless of texture, and nondisturbed dry B horizon from sand heaved the least (soil expansion <0.8% in height). Soil elements and fractions had an impact on frost heaving, especially organic Al, although it was of a smaller magnitude. Therefore, it is suggested that seedbeds or planting substrates be prepared by exposing the nondisturbed Ae horizon only, that is, without exposing or disturbing the B horizon.
Effect of thinning and prescribed fire restoration treatments on woody debris and snag dynamics in a Sierran old-growth, mixed-conifer forest
Authors: Innes James C , North Malcolm P , Williamson Nathan
Published: March 2007

Forest managers have little information of the effects of common restoration treatments, thinning and burning, on dead woody material (DWM) dynamics in fire-suppressed forests. Fine woody debris (FWD; 0.6–29.9 cm), coarse woody debris (CWD; ≥30.0 cm), and snags (≥5 cm) were inventoried and mapped in eighteen 4 ha plots before and after applying thinning (overstory, understory, and no thinning) and burning (burn and no burn) treatments. The combination of burning and thinning reduced FWD and CWD quantity and mean piece size, removed highly decayed logs, and increased small (5.0–24.9 cm) snag recruitment. In contrast, thin-only treatments produced similar results but increased FWD and did not remove many small snags. There were no differences in DWM response between the two thinning treatments. Log and snag spatial patterns prior to and following treatment were similar. These results indicate that burning in combination with thinning is more effective at reducing surface FWD and CWD, and removing small trees than are burn-only and thin-only treatments. Although large snags and logs were consumed in the burn, long-term recruitment of these habitat structures relies on managers retaining large-diameter trees. Repeated burns need to be conducted after initial restoration treatments to understand natural patterns of DWM.
Calibration and testing of a generalized process-based model for use in Portuguese eucalyptus plantations
Authors: Fontes Luis , Landsberg Joe , Tomé José , Tomé Margarida , Pacheco Carlos A , Soares Paula , Araujo Clara
Published: March 2007

The work described in this paper aimed to establish a single set of parameter values for a process-based model (3-PG), applicable to Eucalyptus globulus Labill. in Portugal. Initial testing was done with parameter values from Australia using climate, biometric, and soils data from an irrigation and fertilization trial and a spacing trial. The model provided good estimates for stem mass and basal area, poor estimates for leaf mass, and reasonable estimates for volume. The fit between simulated and observed values was then improved by tuning parameter values to produce a final set. The calibrated model was tested, and performed well, against data from permanent sample plots (PSPs) at different locations across Portugal. Volume and basal area predictions made by 3-PG for PSPs were then compared with predictions made by the empirical model in use for E. globulus plantations in Portugal. Differences were negligible. Model outputs with the Australian parameter set and the optimum set for Portugal indicated that partitioning of carbohydrates (net primary productivity) was very different in E. globulus grown in Portugal and Australia. The study has confirmed the potential of this process-based model as a practical tool to support forest management decision-making.
A Bayesian approach to evaluating habitat for woodland caribou in north-central British Columbia
Authors: McNay R Scott , Marcot Bruce G , Brumovsky Viktor , Ellis Rick
Published: March 2007

Woodland caribou (Rangifer tarandus caribou (Gmelin)) populations are in decline throughout much of their range. With increasingly rapid industrial, recreational, residential, and agricultural development of caribou habitat, tools are required to make clear, knowledgeable, and explainable management decisions to support effective conservation of caribou and their range. We developed a series of Bayesian belief networks to evaluate conservation policy scenarios applied to caribou seasonal range recovery areas. We demonstrate the utility of the networks to articulate ecological understanding among stakeholders, to clarify and explicitly depict threats to seasonal range. We also show how simulated forecasts of spatially explicit seasonal range can be compared with landscape potential with range under assumed conditions of natural disturbance. These tools have provided opportunities to operationally define and measure conditions for recovery of caribou in north-central British Columbia.
NONCOMMUTATIVE QUANTIZATION FOR NONCOMMUTATIVE FIELD THEORY
Authors: ABE YASUMI
Published: March 2007

We present a new procedure for quantizing field theory models on a noncommutative space–time. Our new quantization scheme depends on the noncommutative parameter explicitly and reduces to the canonical quantization in the commutative limit. It is shown that a quantum field theory constructed by this quantization yields exactly the same correlation functions as those of the commutative field theory, that is, the noncommutative effects disappear completely after the quantization. This implies, for instance, that the noncommutativity may be incorporated in the process of quantization, rather than in the action as conventionally done.
EFFECT OF IMPROPER BALLAST PACKING/TAMPING ON DYNAMIC BEHAVIORS OF ON-TRACK RAILWAY CONCRETE SLEEPER
Authors: KAEWUNRUEN SAKDIRAT , REMENNIKOV ALEX M.
Published: March 2007

Ballasted railway tracks are impaired due to either normal or abnormal operations. One of the problems is the differential settlements along the track. Clearly, there is the need to maintain periodically the track substructures by means of ballast packing/tamping. Inappropriate conducts result in the nonlinear distributions of support stiffness. This study firstly demonstrates the effects of improper ballast packing/tamping on the free vibration behaviors of in situ railway concrete sleepers. The two-dimensional finite element modeling of an in situ concrete sleeper was employed in the parametric studies. This model takes into account the coupled flexural-and-shear deformations of concrete sleepers, elastic displacements of fastening system, and nonlinear dynamic interaction between the sleeper and ballast support. Dynamic interaction between sleepers and ballast was investigated based on the nonlinear distribution of ballast support stiffness underneath the sleeper. Effects of both symmetrical and asymmetrical stiffness distributions on dynamic behaviors of the local in situ concrete sleeper were also highlighted.
NUMERICAL ANALYSIS OF VIBRATION EFFECTS OF METRO TRAINS ON SURROUNDING ENVIRONMENT
Authors: XIA H. , CAO Y. M. , ZHANG N.
Published: March 2007

A finite element approach is extended to study the ground vibrations induced by metro trains and their propagation properties. Two dynamic interaction models are established: the two-dimensional train-track interaction model, which provides the excitation loads of moving trains onto the tunnel structure, and the three-dimensional track-tunnel-ground interaction model, by which the propagation properties of ground accelerations and velocities are analyzed. The results show that there exists a vibration amplifying area in certain distance away from the tunnel center, and the dominant frequencies of the ground vibration concentrate in a certain range. Buildings located in that area with their natural frequencies falling in the specific frequency range will be sensitive to the ground vibrations induced by metro trains.
THE EVOLUTION OF INVENTOR NETWORKS IN THE SILICON VALLEY AND BOSTON REGIONS
Authors: FLEMING LEE , FRENKEN KOEN
Published: March 2007

While networks are widely thought to enhance regional innovative capability, there exist few longitudinal studies of their formation and evolution over time. Based on an analysis of all patenting inventors in the U.S. from 1975 to 2002, we observe dramatic aggregation of the regional inventor network in Silicon Valley around 1989. Based on network statistics, we argue that the sudden rise of giant networks in Silicon Valley can be understood as a phase transition during which small isolated networks form one giant component. By contrast, such a transition in Boston occurred much later and much less dramatically. We do not find convincing evidence that this marked difference between the two regions is due to regional differences in the propensity to collaborate or the involvement of universities in patenting. Interviews with key network players suggest that contingent labor mobility between established firms in Silicon Valley, in particular resulting from IBM's policy as a central player in patenting activity, promoted inter-organizational networking, leading to larger inventor networks.
MAPPING TECHNOLOGICAL TRAJECTORIES AS PATENT CITATION NETWORKS: A STUDY ON THE HISTORY OF FUEL CELL RESEARCH
Authors: VERSPAGEN BART
Published: March 2007

Technological change is argued to be taking place along ordered and selective patterns, shaped jointly by technological and scientific principles, and economic and other societal factors. Historical, descriptive analysis is often used to analyze these "trajectories". Recently, quantitative methods have been proposed to map these trajectories. It is argued that such methods have, so far, not been able to illuminate the engineering side of technological trajectories. In order to fill this gap, a methodology proposed by Hummon and Doreian (1989) is used and extended to undertake a citation analysis of patents in the field of fuel cells.
Slc7a7 disruption causes fetal growth retardation by downregulating Igf1 in the mouse model of lysinuric protein intolerance
Authors: Sperandeo Maria Pia , Annunziata Patrizia , Bozzato Andrea , Piccolo Pasquale , Maiuri Luigi , D'Armiento Maria , Ballabio Andrea , Corso Gaetano , Andria Generoso , Borsani Giuseppe , Sebastio Gianfranco
Published: March 2007

The solute carrier family 7A member 7 gene ( SLC7A7) encodes the light chain of the heterodimeric carrier responsible for cationic amino acid (CAA) transport across the basolateral membranes of epithelial cells in intestine and kidney. Mutations affecting SLC7A7 cause lysinuric protein intolerance (LPI), a multiorgan disorder with clinical symptoms that include visceromegaly, growth retardation, osteoporosis, hyperammonemia, and hyperdibasicaminoaciduria. Here, we describe the consequences of inactivating Slc7a7 in a mouse model of LPI. The Slc7a7 mutation was generated by high-throughput retroviral gene-trapping in embryonic stem cells. The Slc7a7−/− mouse displayed intrauterine growth restriction (IUGR), commonly leading to neonatal lethality. After heavy protein ingestion, the surviving adult animals presented metabolic derangement consistent with that observed in human LPI. IUGR was investigated by examining the expression of main factors controlling fetal growth. Insulin-like growth factor 1, the dominant fetal growth regulator in late gestation, was markedly downregulated as demonstrated by quantitative real-time RT-PCR, immunostaining and Western blot analysis in fetal liver. To further explore the pathophysiology of LPI, gene expression profiling analyses were carried out by DNA microarray technology in intestine and liver of adult Slc7a7−/− mice. Significant upregulation or downregulation (twofold or greater) was observed for 488 transcripts in intestine, and for 521 transcripts in the liver. The largest category of differentially expressed genes corresponds to those involved in transport according to Gene Ontology classification. This mouse model offers new insights into the pathophysiology of LPI and into mechanisms linking CAA metabolic pathways and growth control.
Physical Activity and Colon Cancer Risk among Women in the California Teachers Study
Authors: Mai Phuong L. , Sullivan-Halley Jane , Ursin Giske , Stram Daniel O. , Deapen Dennis , Villaluna Doojduen , Horn-Ross Pamela L. , Clarke Christina A. , Reynolds Peggy , Ross Ronald K. , West Dee W. , Anton-Culver Hoda , Ziogas Argyrios , Bernstein Leslie
Published: March 2007

Background: Existing data suggest that physical activity reduces colon cancer risk, but the association is not consistently observed in women. One potential explanation for this inconsistency is that hormone therapy, which is associated with lower colon cancer risk, acts as a modifier of the physical activity/colon cancer relationship.

Methods: Participants in the California Teachers Study (N = 120,147), a prospective cohort of female teachers and administrators residing in California, ages 22 to 84 years at baseline and with no prior history of colon cancer were eligible for study. Between 1996 and 2002, 395 patients were diagnosed with invasive colon cancer. The relative risks (RR) associated with lifetime (high school through age 54 years or current age) and recent (past 3 years) strenuous and moderate recreational physical activity were estimated using Cox proportional hazards regression models.

Results: Combined lifetime moderate and strenuous recreational physical activity was only modestly associated with colon cancer risk in the cohort [≥4 versus ≤0.5 h/wk/y: RR, 0.75; 95% confidence interval, 0.57-1.00; Ptrend = 0.23]. Lifetime physical activity reduced colon cancer risk among postmenopausal women who had never taken hormone therapy (≥4 versus ≤0.5 h/wk/y: RR, 0.51; 95% confidence interval, 0.31-0.85; Ptrend = 0.02). Postmenopausal women with histories of hormone therapy use had lower colon cancer risk, but their risk was not associated with physical activity. The likelihood ratio test for interaction between hormone use and lifetime moderate plus strenuous physical activity was of borderline statistical significance (P = 0.05). We observed no effect modification by age, body mass index, smoking status, menopausal status, or folate intake.

Conclusions: Lifetime recreational physical activity may protect against colon cancer among postmenopausal women who have never used hormone therapy. Among hormone therapy users, who have lower risk of colon cancer, recreational physical activity does not seem to provide any additional benefit. With declining rates of hormone therapy use, physical activity offers one possible means for reducing women's colon cancer risk. (Cancer Epidemiol Biomarkers Prev 2007;16(3):517–25)
Correlates and Predictors of Colorectal Cancer Screening among Male Automotive Workers
Authors: McQueen Amy , Vernon Sally W. , Myers Ronald E. , Watts Beatty G. , Lee Eun Sul , Tilley Barbara C.
Published: March 2007

Background: Most studies examining factors associated with colorectal cancer (CRC) screening (CRCS) are cross-sectional and thus temporal relationships cannot be determined. Furthermore, less attention has been paid to psychosocial predictors of CRCS. We examined both cross-sectional correlates of prior CRCS and predictors of prospective CRCS initiation and maintenance during The Next Step Trial, a 2-year worksite behavioral intervention to promote regular CRCS and dietary change.

Method: The sample included 2,693 White male automotive workers at increased occupational risk for, but no history of, CRC who completed a baseline survey. Stratified analyses were conducted for three dependent variables (prior CRCS, CRCS initiation, and CRCS maintenance). We also assessed prior CRCS as a moderator in prospective analyses. Multivariable logistic regression analyses with generalized linear mixed models were used to adjust for cluster sampling.

Results: Except for education, cross-sectional correlates of prior CRCS including older age, family history of CRC or polyps, personal history of polyps, self-efficacy, family support, and intention were also significant prospective predictors of increased CRCS during the trial. Despite differences in the patterns of association for CRCS initiation and maintenance in stratified analyses, the only associations with prospective CRCS that were significantly moderated by prior CRCS were family history and CRCS availability.

Conclusions: Correlates of prior CRCS that also were prospective predictors of CRCS may be suitable targets for intervention. Additionally, intervention messages addressing psychosocial constructs may be relevant for both CRCS initiation and maintenance. However, studies with more diverse samples are needed to replicate the results reported here. (Cancer Epidemiol Biomarkers Prev 2007;16(3):500–9)
The Need for Coordinating Municipal, State and National Activities
Authors: Cleveland Frederick A.
Published: March 2007

The customary attitude of the citizen toward the government is one of complaint. Toward the officer, the average citizen as sumes an air of superior wisdom. He is sure that he himself would be able to direct any public office in a very effective manner. While formally deferential, a reported shortcoming or complaint causes the citizen to question the officer's motives, his judgment, his ability.
The Structure of Public Leisure Agencies
Authors: Butler George D.
Published: March 2007

This article discusses governmental responsibility for recreation; describes the properties, services, and programs of several federal agencies; and indicates the state agencies providing recreation, their areas, facilities, and serv ices. A major part deals with local recreation parks, facilities, playgrounds, indoor and community-wide activities, and leadership. It indicates the authori ties responsible for local recreation service and describes co-operative planning methods.
Values for Urban Living
Authors: Mead Margaret
Published: March 2007

Technologic change may take away from the cities of the future all the functions once made necessary by war, poor communications, and the need to concentrate populations for production and consumption. But the unique function of cities in providing for contact among many kinds of human crea tivity will remain, possibly to be met by cities that are centers for the new conference methods of multimodal communication.
Urbanization and the World Community
Authors: Henderson Julia J.
Published: March 2007

The rate of urban growth is now higher in some of the economically underdeveloped countries than it is in the United States. The apparent imbal ance between rates of urban growth and of industrialization is pointed out. Levels of employment, health, education, nutrition, and housing among the masses of rural migrants to the cities in most countries are posing problems which strain overburdened resources of the underdeveloped countries to the breaking point. There is some reason to hope that planned economic develop ment as well as the techniques of regional and city planning may be applied more generally in the solution of these problems in Asia, Latin America, and the Middle East than they have been in North America.
Alcoholism: Nature and Extent of the Problem
Authors: Keller Mark
Published: March 2007

Alcoholism is a behavioral disorder causing some physical, social, or economic disability in over 4 million adults in the United States. Its exact etiology is not established; it may be related to constitutional, psychological, sociologic, and pharmacological factors.
Some Meanings of Aggressive Behavior in Children
Authors: Rexford Eveoleen N.
Published: March 2007

Overactivity and aggressive, destructive behavior in children are often regarded as precursors of juvenile delin quency. This symptomatology is nonspecific for diagnosis or causation. Review of typical cases shows the wide range of meanings such behavior may have and the varied backgrounds, in a causal sense, from which such children may come. If delinquency is to be reduced or prevented, more will have to be learned scientifically about this whole subject. Both clinical workers and the general public will have to revise their atti tudes toward and their ways of dealing with aggressive children.
Program Planning and Development
Authors: Goldschmidt Arthur
Published: March 2007

Program planning and development of technical assistance must take place at the level of the recipient country. Once the resources for technical assistance available to a coun try are determined, the government itself must identify its needs and establish its priorities—whether the assistance is to come from local, international, or bilateral sources. The "country programing" procedures under which the United Nations Expanded Program for Technical Assistance is estab lished annually have helped to strengthen the program plan ning machinery of recipient countries. The single purpose, voluntary nature, and multilateral management of the United Nations program make it peculiarly acceptable as an instru ment for assisting in creating and strengthening local institu tions including ministries and other bodies responsible for planning and programing. The Expanded Program has also been successful in undertaking projects involving several recipient countries in major joint programs. While the United Nations program has an important place in technical assist ance, its financing has not kept pace with growing bilateral programs of the United States, the USSR, and other countries. It may therefore be desirable to emphasize the possible role of the United Nations program in the process of development and co-ordination of other technical assistance activities.
The Government Contract as an Administrative Device
Authors: Reining Henry
Published: March 2007

A considerable fraction of the United States technical assistance program is carried out by contract. Profit contracts are traditional with the government. Contracts with voluntary organizations are rooted in religious missions and war relief. University contracts are new but have quickly reached considerable proportions. The typical university con tract is for a term of three years and is related directly to an institution in the host country with the United States Govern ment acting as a third party. There have been many prob lems with these contracts but many adjustments have been made by the International Cooperation Administration. An Office of Contract Relations has been created, policies adopted, a manual and an illustrative contract published. Within that Office, a basic division has been made in the handling of profit and nonprofit contracts. Security clearance, an unsympathetic Congress, understaffing within the ICA itself, and inadequate opportunity for preparation to enter upon contracts and once in, to study and plan prior to commencing operations, are among the remaining problems. The universities on the whole have done well, but there have been failures. Co-ordination of contract and Mission efforts in the field has been a continu ing problem, but have been considerably ameliorated recently. The balance sheet shows that there has been profit for all concerned. Finally there are presented ten operating assump tions for the newcomer to the field.
Communist Politics in the Western World
Authors: Dallin David J.
Published: March 2007

There is no easy solution to the East-West con flict. The post-World War II period has brought both suc cesses and failures to communism. Events following Stalin's death indicated the disintegration of world communism. But since 1956 the various Communist parties have realized that centralized leadership is necessary to their progress and suc cess—Soviet guidance has now been recognized. The cold war is not a contest between two economic systems—it is a politi cal contest. At the Twentieth Congress of the Communist Party of the Soviet Union in 1956, Mr. Khrushchev set aside the old Communist principle of the inevitability of war. This proclamation, however, did not imply a new Soviet course—it meant that war could be avoided because "the imperialists" would not fight; the superiority of communism has been rec ognized, and the West would retreat. The Berlin crisis is a use of this strategy. Russia has remained a continent-bound great power, and to her the number one political issue is Germany. Caution is necessary in any plan of disengagement in Central Europe, for a weak Germany would permit the ex pansion of Russian power over Germany and France. Con federation is proposed in lieu of the unification of Germany. Russia's long-range aim however is the extension of Commu nism in West Germany. On the solution of the German ques tion depends the future of Europe. It is necessary for the West to assume a courageous and dignified posture in this crisis.—Ed.
The Propaganda Battle in India and Burma
Authors: Trager Frank N.
Published: March 2007

Critically significant in any understanding of the responses of Southern Asia to external propagandas, to politi cal pressures, is the fact of the newly won independence (since World War II) of most of the nations of this area. Western governments and Western peoples have not as yet given either the nationalist struggles or the independence of the area suffi cient weight in their deliberations and, perhaps even more, in their fundamental attitudes about the area. India and Burma will always be found, both at home and abroad, ranged against the theory and practice of imperialism. They are both engaged in major efforts to upgrade their economies through large-scale economic development programs for which they have been will ing to accept aid "without strings" from any quarter. India and Burma have set themselves a great task, but one which can lead to victory over the many problems they face, if we in the United States and in the West would make a supreme effort to understand these countries within their own frame of reference and supply them, "without strings," with the needed goods and services. Then it could be predicted that India and Burma and, in like fashion, the other nations of Southern Asia, would strongly undergird and defend that arc of free Asia from the Pamirs to the Pacific-newly come on independence and freedom.
Prestige
Authors: Hughes Everett Cherrington
Published: March 2007

Indications are that the prestige rankings of various occupations in industrial and urban countries tend to be similar. But this is no guide to the effective choices of occupation by young people. For many occupations include people of a great variety of styles and quality of work; not all of these styles are equally visible to all segments of the popula tion. We require an anatomy of prestige which will take dif ferential visibility and the many images and nuances of reality into account. There are studies of how goals and standards are set and of the probability that young people of given back grounds will enter various kinds of schools and occupations. But much remains to be done before we know just how goals are progressively set and revised in our schools, colleges, and professional institutions. Teachers and people in various occu pations may, in fact, give quite contradictory messages to young people about what kind of work is essential to success and what is most valuable. Students then form their own standards, on the basis of what they come to believe, on the basis of their own experience and their own interpretations of the demands made upon them.