By Location (by + location)

Distribution by Scientific Domains

Selected Abstracts

Effect of location on virgin olive oils of the two main Tunisian olive cultivars

Mokhtar Guerfel
Abstract The olive oil content in phenolic compounds depends on the variety of the fruit used for its extraction as well as on the predominant climate conditions in the tree cultivation area. Here, we report on the characterization of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivars Chemlali and Chétoui, grown in three different Tunisian locations, Zaghouan (North), Sousse (Center) and Sfax (South). Chétoui olive oil samples obtained from fruits of olive trees cultivated in Zaghouan and Chemlali olive oil samples obtained from fruits of olive trees cultivated in Sousse were found to have a higher mean total phenol content (1004 and 330,mg/kg, respectively). Olive oil samples obtained from fruits of both cultivars had different phenolic profiles and a higher content in 3,4-DHPEA-EDA when the olive trees were cultivated in Zaghouan. Both olive cultivars were found to have different responses to environmental conditions. Chétoui olive oil showed decreased oxidative stability when the fruits were obtained from olive trees cultivated in the center of Tunisia (34.8,h) and in Sfax (16.17,h). Furthermore, statistical data showed that the phenolic composition and oxidative stability of Chétoui olive oil varied more by location than those of Chemlali olive oils. [source]

Factors influencing proximal dental contact strengths

Christof E. Dörfer
The aim of this study was to systematically measure proximal contact strength in complete natural dentitions of 30 adults (25.3±3.0 years of age), and to analyze its relationship to tooth type, tooth location, chewing effort and time of day variation. The contact strengths were measured dynamically during removal of a calibrated 0.05-mm-thick metal strip between the proximal contacts of adjacent teeth. Proximal contact strengths were lower in the maxilla (2.51±1.36 N) compared to the mandible (4.26±1.88 N). Within the jaws, the lowest proximal contact strength was measured between canine and first premolar (2.91±1.79 N) and the highest between second premolar and first molar (3.73±1.95 N). Chewing increased the proximal contact strength within the maxilla (before: 2.51±1.36 N, after: 3.02±1.45 N) but it remained unchanged in the mandible (before: 4.26±1.88 N, after: 4.22±1.85 N). The proximal contact strength increased significantly from morning (3.39±1.86 N) to noon (3.61±1.77 N), and then decreased in the afternoon (3.43±1.60 N). It was concluded that proximal contact strength can be significantly influenced by location, tooth type, chewing and time of day variation. Based on the differences in distribution due to the effect of chewing and time of day, it is speculated that proximal contact strength is a physiological entity of multifactorial origin. [source]

Effects of upstream lakes and nutrient limitation on periphytic biomass and nitrogen fixation in oligotrophic, subalpine streams

Summary 1. We conducted bioassays of nutrient limitation to understand how macronutrients and the position of streams relative to lakes control nitrogen (N2) fixation and periphytic biomass in three oligotrophic Rocky Mountain catchments. We measured periphytic chlorophyll- a (chl- a) and nitrogen-fixation responses to nitrogen (N) and phosphorus (P) additions using nutrient-diffusing substrata at 19 stream study sites, located above and below lakes within the study catchments. 2. We found that periphytic chl- a was significantly co-limited by N and P at 13 of the 19 sites, with sole limitation by P observed at another four sites, and no nutrient response at the final two sites. On average, the addition of N, P and N + P stimulated chl- a 35%, 114% and 700% above control values respectively. The addition of P alone stimulated nitrogen fixation by 2500% at five of the 19 sites. The addition of N, either with or without simultaneous P addition, suppressed nitrogen fixation by 73% at nine of the 19 sites. 3. Lake outlet streams were warmer and had higher dissolved organic carbon concentrations than inlet streams and those further upstream, but position relative to lakes did not affect chl- a and nitrogen fixation in the absence of nutrient additions. Chl- a response to nutrient additions did not change along the length of the study streams, but nitrogen fixation was suppressed more strongly by N, and stimulated more strongly by P, at lower altitude sites. The responses of chl- a and nitrogen fixation to nutrients were not affected by location relative to lakes. Some variation in responses to nutrients could be explained by nitrate and/or total N concentration. 4. Periphytic chl- a and nitrogen fixation were affected by nutrient supply, but responses to nutrients were independent of stream position in the landscape relative to lakes. Understanding interactions between nutrient supply, nitrogen fixation and chl- a may help predict periphytic responses to future perturbations of oligotrophic streams, such as the deposition of atmospheric N. [source]

Death and International Travel,The Canadian Experience: 1996 to 2004

Douglas W. MacPherson MD, FRCPC, MSc(CTM)
Background Death during international travel concerns several levels of the travel industry. In addition to the immediate effects for the traveler, their family and friends, the nature of travel-related mortality has important implications for pretravel health advisors and providers of medical care services. Methods The Consular Affairs Bureau, Foreign Affairs Canada provides information and assistance to Canadian civilians abroad. Beginning in 1995, the Consular Management and Operations System tracked Canadian deaths abroad notifications. The annual data for 1996 to 2004 was extracted for sex, age, and cause of death by location for all reports received. Results There were 2,410 reported deaths in Canadians abroad; reported sex was 32% female and 68% male, average age of 61.7 and 60.4 years, respectively. Recorded causes of death: natural (1,762), accidental (450), suicide (92), and murder (106). Country of death reflected the pattern of Canadian international travel for recreation, business, and ancestral linkages. Average age of natural death (66 years) distinguished it from all other causes of death: accidental (45), suicide (41), and murder (43). Conclusion Natural causes and suicide deaths may be anticipated or planned to occur abroad. The risk of death may be mitigated through personal knowledge and medical assessment and prevention strategies. Deaths due to vaccine-preventable diseases, exotic and infectious diseases were rare in this population. Consular services may be able to provide various types of support. Local laws and customs, as well as international regulations in health and quarantine govern other responsibilities such as funeral services and repatriation of the deceased to Canada. [source]

Spatial substituent effects of various fluorinated groups on the 13C chemical shifts in cyclohexanes

Yvan Carcenac
Abstract The effect of introduction of fluorinated groups (CH2F, CHF2, CF3, C2F5, OCF3, SCF3) on the 13C NMR chemical shifts in cyclohexanes is examined. The two main effects are caused by location at the , and , carbon positions. Comparison of the various data allowed the calculation of increments corresponding to the introduction of fluorinated groups at axial or equatorial positions on the cyclohexane ring. The introduction of fluorine atoms in methoxy and thiomethoxy groups has only a slight effect through the heteroatom on the 13C chemical shifts. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Variation of dust endotoxin concentrations by location and time within homes of young children

Dennis R. Ownby
Ownby DR, Peterson EL, Williams LK, Zoratti EM, Wegienka GR, Woodcroft KJ, Joseph CLM, Johnson CC. Variation of dust endotoxin concentrations by location and time within homes of young children. Pediatr Allergy Immunol 2010: 21: 533,540. © 2010 John Wiley & Sons A/S Endotoxin may affect the development of allergic disease in childhood but little is known about endotoxin variation within homes. We sought to determine endotoxin concentration agreement within homes when five locations were each sampled twice 5 months apart. Endotoxin was measured using the recombinant Limulus factor C assay in dust samples from 585 homes of children enrolled in a prospective study and again in 335 homes 5 months later. The five locations sampled in each home were the child's bedroom floor, child's bed, mother's bedroom floor, mother's bed and living room floor. Concentrations of 4 allergens (Can f 1, Fel d 1, Der f 1 and Bla g 2) were also measured from the child's bedroom floor. In pair-wise comparisons, endotoxin concentrations in all locations within each home were significantly different from all other locations (p < 0.001) except for the child's and mother's bedroom floors (p = 0.272). Spearman correlations between endotoxin concentrations from the different locations were all statistically significant (p < 0.05) but of modest magnitude (r = 0.24,0.54). Similarly, correlations at each site over the 5 month observation interval were statistically significant but modest (r = 0.17,0.44). Pets and season of the year did not affect correlations, although correlations were lower if the floor was not carpeted. Endotoxin concentrations at all locations were minimally correlated with allergen concentrations in both negative and positive directions (r = ,0.12 to 0.12). We conclude that a single measurement of endotoxin from a home dust sample provides an imprecise estimate of dust endotoxin concentrations in other locations within the home and over a relatively short observation interval. [source]

Communication of positive newborn screening results for sickle cell disease and sickle cell trait: Variation across states,

Patricia L. Kavanagh
Abstract In the US, all states and the District of Columbia have universal newborn screening (NBS) programs for sickle cell disease (SCD), which also identify sickle cell trait (trait). In this project, we surveyed follow-up coordinators, including one in the District of Columbia and two in Georgia, about protocols for stakeholder notification for SCD and trait. The primary outcomes were total number and type of stakeholder informed of a positive screen. We received 52 completed surveys (100% response). Primary care providers (PCPs) (100%), hematologists (81%), hospitals (73%), and families (40%) were the most commonly notified stakeholders of positive SCD screens, while PCPs (88%), hospitals (63%), and families (37%) were most commonly notified for trait. On average, 3.4 stakeholders were notified for a positive screening for SCD, compared to 2.4 stakeholders for sickle cell trait (P,<,0.001). In multivariate analyses for SCD, we found a 2.9% increase in stakeholders notified for each additional year of universal screening mandated in a state (95% CI: 1.4,4.4%). For trait, we found an 8.5% increase in stakeholders notified for each additional follow-up staff (95% CI: 1.3,15.7%), and a 1.3% increase for each additional percent of black births in the state (95% CI: 0.1,2.5%). Wide variation exists in stakeholder notification by NBS programs of positive screenings for SCD and trait. This variation may alter the effectiveness of NBS programs by location of birth. © 2008 Wiley-Liss, Inc. [source]

Electrophysiological correlates of direct selection by color

Esther Vierck
Abstract We report an experiment using event-related potentials (ERPs) to study selection by color uncontaminated from selection by location. Participants monitored an RSVP sequence for a given target letter that could appear in upper- or lowercase. Prior to the sequence, a cue indicated the most likely color of the target letter. Replicating E. Vierck and J. Miller (2005), upper-/lowercase discrimination accuracy was higher following valid than invalid color cues. Within the ERPs, the target onset produced a negative component between 150 and 350 ms at occipital sites, with shorter latencies following valid than invalid cues. We also found larger amplitude components for valid than invalid color cues at central and parietal sites between 150 and 325 ms. The results not only demonstrate clear effects of color cuing on both behavior and ERPs but also suggest that the observed ERP differences between valid versus invalid trials mediate the behavioral effects. [source]

Rough Terrain: Spatial Variation in Campaign Contributing and Volunteerism

Wendy K. Tam Cho
We examine spatial patterns of mass political participation in the form of volunteering and donating to a major statewide election campaign. While these forms of participation are predictably associated with the political and socioeconomic characteristics of the precincts in which the participants reside, we find that these statistical relationships are spatially nonstationary. High-income neighborhoods, for example, are associated with stronger effects on participation at some locations more than at others. By using geographically weighted regression (GWR) to specify local regression parameters, we are able to capture the heterogeneity of contextual processes that generate the geographically uneven flow of volunteers and contributors into a political campaign. Since spatial nonstationarity may well be a rule rather than an exception in the study of many political phenomena, social scientific analyses should be mindful that relationships may vary by location. [source]

ORIGINAL RESEARCH,BASIC SCIENCE: A Prospective Study Examining the Anatomic Distribution of Nerve Density in the Human Vagina

Rachel Pauls MD
ABSTRACT Introduction., Women possess sufficient vaginal innervation such that tactile stimulation of the vagina can lead to orgasm. However, there are few anatomic studies that have characterized the distribution of nerves throughout the human vagina. Aim., The aim of this prospective study was to better characterize the anatomic distribution of nerves in the adult human vagina. A secondary aim was to assess whether vaginal innervation correlates with the subject's demographic information and sexual function. Methods., Full-thickness biopsies of anterior and posterior vagina (proximal and distal), cuff, and cervix were taken during surgery in a standardized manner. Specimens were prepared with hematoxylin and eosin, and S100 protein immunoperoxidase. The total number of nerves in each specimen was quantified. Enrolled patients completed a validated sexual function questionnaire (Female Sexual Function Index, FSFI) preoperatively. Main Outcome Measures., A description of vaginal innervation by location and an assessment of vaginal innervation in association with the subject's demographic information and sexual function. Results., Twenty-one patients completed this study, yielding 110 biopsy specimens. Vaginal innervation was somewhat regular, with no site consistently demonstrating the highest nerve density. Nerves were located throughout the vagina, including apex and cervix. No significant differences were noted in vaginal innervation based on various demographic factors, including age, vaginal maturation index, stage of prolapse, number of vaginal deliveries, or previous hysterectomy. There were no correlations between vaginal nerve quantity and FSFI domain and overall scores. Fifty-seven percent of the subjects had female sexual dysfunction; when compared to those without dysfunction, there were no significant differences in total or site-specific nerves. Conclusions., In a prospective study, vaginal nerves were located regularly throughout the anterior and posterior vagina, proximally and distally, including apex and cervix. There was no vaginal location with increased nerve density. Vaginal innervation was not associated with demographic information or sexual function. Pauls R, Mutema G, Segal J, Silva WA, Kleeman S, Dryfhout V, and Karram M. A prospective study examining the anatomic distribution of nerve density in the human vagina. J Sex Med 2006;3:979,987. [source]

Expression of resistance to Leptosphaeria maculans in Brassica napus double haploid lines in France and Australia is influenced by location

R. Delourme
Abstract Blackleg, caused by Leptosphaeria maculans, is a major disease of oilseed rape (Brassica napus), worldwide, including Australia and France. The aims of these studies were first, to determine if higher levels of resistance to L. maculans could be generated in double haploid (DH) lines derived from spring-type B. napus cv. Grouse, which has a good level of field resistance to blackleg; and second, to determine whether the resistance to blackleg disease of individual DH lines responds differentially to different L. maculans field populations within and between the two countries. DH lines were extracted from cv. Grouse and tested in field experiments carried out in both France and Australia against natural L. maculans populations. Extracting and screening DH lines were an effective means to select individual lines with greatly improved expression of resistance to blackleg crown canker disease in comparison with the original parental population. However, relative disease resistance rankings for DH lines were not always consistent between sites. The higher level of resistance in France was shown to be because of a high expression level of quantitative resistance in the French growing conditions. Big differences were observed for some DH lines between the 2004 and the 2005 field sites in Australia where the L. maculans populations differed by their virulence on single dominant gene-based resistant lines derived from Brassica rapa ssp. sylvestris. This differential behaviour could not be clearly explained by the specific resistance genes until now identified in these DH lines. This investigation highlights the potential to derive DH lines with superior levels of resistance to L. maculans compared with parental populations. However, in locations with particularly high pathogen diversity, such as in southern Australia, multiyear and multisite evaluations should be performed to screen for the most efficient material in different situations. [source]

Feeling safe in one's neighbourhood: Variation by location among older Australians

Susan Quine
No abstract is available for this article. [source]

In situ effective diffusion coefficient profiles in live biofilms using pulsed-field gradient nuclear magnetic resonance

Ryan S. Renslow
Abstract Diffusive mass transfer in biofilms is characterized by the effective diffusion coefficient. It is well documented that the effective diffusion coefficient can vary by location in a biofilm. The current literature is dominated by effective diffusion coefficient measurements for distinct cell clusters and stratified biofilms showing this spatial variation. Regardless of whether distinct cell clusters or surface-averaging methods are used, position-dependent measurements of the effective diffusion coefficient are currently: (1) invasive to the biofilm, (2) performed under unnatural conditions, (3) lethal to cells, and/or (4) spatially restricted to only certain regions of the biofilm. Invasive measurements can lead to inaccurate results and prohibit further (time-dependent) measurements which are important for the mathematical modeling of biofilms. In this study our goals were to: (1) measure the effective diffusion coefficient for water in live biofilms, (2) monitor how the effective diffusion coefficient changes over time under growth conditions, and (3) correlate the effective diffusion coefficient with depth in the biofilm. We measured in situ two-dimensional effective diffusion coefficient maps within Shewanella oneidensis MR-1 biofilms using pulsed-field gradient nuclear magnetic resonance methods, and used them to calculate surface-averaged relative effective diffusion coefficient (Drs) profiles. We found that (1) Drs decreased from the top of the biofilm to the bottom, (2) Drs profiles differed for biofilms of different ages, (3) Drs profiles changed over time and generally decreased with time, (4) all the biofilms showed very similar Drs profiles near the top of the biofilm, and (5) the Drs profile near the bottom of the biofilm was different for each biofilm. Practically, our results demonstrate that advanced biofilm models should use a variable effective diffusivity which changes with time and location in the biofilm. Biotechnol. Bioeng. 2010;106: 928,937. © 2010 Wiley Periodicals, Inc. [source]

Correlation of polymorphism of MTHFRs and RFC-1 genes with neural tube defects in China

Yali Shang
Abstract BACKGROUND: Maternal periconceptional supplementation of folate reduces the incidence of neonatal Neural Tube Defects, indicating that changes in folate metabolism play a role in formation of NTDs. The mutations on two genes involved in folate metabolism, the C677 of the MTHFR gene and the RFC-1(A80G) gene are potential risk factors of NTDs. METHODS: In this study, we analyzed the genotypic distributions and allele frequencies of MTHFR C677T and RFC-1 A80G polymorphisms in DNA samples from mothers with at least one previous child with NTDs (the NTD group) and controls. RESULTS: Our results indicated that there was a significant difference in the genotype and allele frequencies of RFC-1 80A,G between the NTD group and controls (p = .008 and p = .017, respectively). There was, however, no significant difference in the genotype and allele frequencies of the MTHFR 677C,T polymorphism between the NTD group and controls. The NTD group was further separated into the upper and lower types by location of abnormalities. The frequency of RFC-1 80A/G and 80G/G was significantly higher in the upper group than the control (p = .009 and p = .005, respectively). The frequency of G-alleles was also significantly higher in the upper group than the control (OR 2.42; p = .006; 95% CI: 1.28,4.58). For the MTHFR C677 gene, the frequency of T-alleles was significantly lower in the lower defect type than the control group (OR 0.32; p = .027; 95% CI: 0.11,0.9). CONCLUSIONS: These results suggest that in the Shanxi population RFC-1 polymorphisms may play a role in NTD risk, whereas the impact of MTHFR C677T polymorphisms requires further clarification. Birth Defects Research (Part A) 2008. © 2007 Wiley-Liss, Inc. [source]

Cost-effective Targeting of Riparian Buffers

Wanhong Yang
This paper develops an integrated economic, hydrologic and GIS modeling framework to examine the cost-effective targeting of land retirement for establishing riparian buffers in agricultural watersheds. Previous studies have examined the efficiency of targeting large land parcels for retirement or targeting management practices such as conservation tillage but have not considered narrow variable buffer strips. An empirical application of the framework in the Canagagigue Creek watershed in Ontario shows that average and marginal costs of sediment abatement increase at an increasing rate as the environmental goal becomes more stringent. The locations of the buffer strips vary across the watershed and are not necessarily located on those sites with greatest slope or those adjacent to visible streams. Cost effectiveness is further increased if the targeting is extended to allow for the width of the buffer strip to vary by location rather than assume a uniform width. The modeling results have important policy implications for the design of conservation stewardship programs such as setting appropriate environmental health goals based on marginal abatement costs relative to marginal benefits, and setting physical characteristics of the riparian buffers for selection along the drainage network in targeted sub-catchments. L'auteur propose un modèle intégrant l'économie, l'hydrologie et les SIG pour déterminer l'efficacité du choix des terres retirées de la production en vue de l'aménagement de zones tampon dans les bassins hydrographiques agricoles. D'autres auteurs se sont déjà penchés sur l'efficacité du retrait de vastes parcelles de la production ou sur certaines pratiques de gestion environnementales comme le non-travail du sol, sans toutefois s'intéresser aux étroites bandes tampon aux propriétés variables. L'application empirique du modèle au bassin du ruisseau Canagagigue, en Ontario, révèle que les coûts moyens et marginaux des mesures de lutte contre la sédimentation augmentent à un taux croissant quand l'objectif environnemental se fait de plus en plus rigoureux. L'emplacement des bandes tampon varie le long du bassin hydrographique et ces derniéres ne se situent pas nécessairement là où la pente est la plus raide ni à proximité des cours d'eau visibles. Le rendement augmente quand on laisse la largeur de la bande tampon varier en fonction de l'endroit, au lieu de présumer une largeur uniforme. Les résultats de la modélisation revêtent une grande importance pour l'élaboration de politiques relatives aux programmes de conservation et d'intendance comme l'établissement d'objectifs de protection de l'environnement fondés sur une comparaison des coûts et des avantages marginaux des mesures de lutte, et le choix de zones riveraines tampon selon leurs caracteristiques physiques dans le réseau de drainage des zones de captage secondaires. [source]