Increasing Rate (increasing + rate)

Distribution by Scientific Domains


Selected Abstracts


CASE REPORT: Efficacy of Hoodia for weight loss: is there evidence to support the efficacy claims?

JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 5 2010
A. M. Whelan PharmD
Summary Increasing rates of adult obesity and its negative health consequences are likely to become an increasing burden to the Canadian health care system. Consumers are looking for treatment options and often try the natural health products that are heavily promoted as safe, fast and effective. In this case report, MH, a 57-year-old overweight female wanted advice regarding whether she should use the natural product Hoodia to help her attain her weight loss goals. A literature search was conducted using Medline, EMBASE, the Cochrane Library, Natural Medicines Comprehensive Database and IPA from inception to March 2009. The internet, files of the authors and bibliographies of articles were searched for additional references. No published, peer-reviewed randomized controlled trials examining efficacy of Hoodia were found. Unpublished data from two small trials reported promising results with no adverse events. However, this leaves many unanswered questions regarding the use of Hoodia for weight loss such as the appropriate dose and duration, short and long term safety and use in patients with concomitant diseases. Literature suggests that some commercial products may not actually contain Hoodia at all. Additionally, Hoodia is not yet listed in the Canadian Licensed Natural Health Products Database meaning products sold in Canada may not meet Canadian regulatory standards. Upon discussing this information, MH decided not to use Hoodia, and other evidence-based recommendations were discussed. [source]


Secular trend in medical education regarding infectious disease

MEDICAL EDUCATION, Issue 10 2003
Kai Ming Chow
Objective ,The paradigm of global medical health has been re-characterised by a shift in its major focus from infectious disease to chronic illness. Opinions vary as to the declining emphasis on infectious disease. This paper provides clinicians with an understanding of a secular trend in medical education regarding the topic of infectious diseases over a period of 26 years. Methods ,A survey was carried out to evaluate coverage of infectious disease topics within recent general medicine textbooks and journals. Results ,The percentage of content dedicated to infectious disease has remained static in 2 major medical textbooks, whereas a trend towards decreasing coverage was shown in 4 major medical journals. Of 901 original articles published in 2000, 16·4% covered certain aspects of infectious disease, as compared with 20·9% of 790 articles published in 1985. Increasing rates of infectious disease mortality in developing countries were not consistently matched with the trend in coverage of infectious disease topics in either medical textbooks or journals. Conclusions ,Our data demonstrate that coverage of infectious disease topics in publications issued in developed countries was more indicative of global trends in disease mortality rather than those of developing countries. Medical education and knowledge, which are usually delivered by the rich nations where influential medical textbooks and journals are published, place less emphasis on infectious disease relative to the burden infectious disease places on the developing world. [source]


Metropolitan Open-Space Protection with Uncertain Site Availability

CONSERVATION BIOLOGY, Issue 2 2005
ROBERT G. HAIGHT
acceso público; Chicago; modelo de selección de sitio; optimización; representación de especies Abstract:,Urban planners acquire open space to protect natural areas and provide public access to recreation opportunities. Because of limited budgets and dynamic land markets, acquisitions take place sequentially depending on available funds and sites. To address these planning features, we formulated a two-period site selection model with two objectives: maximize the expected number of species represented in protected sites and maximize the expected number of people with access to protected sites. These objectives were both maximized subject to an upper bound on area protected over two periods. The trade-off between species representation and public access was generated by the weighting method of multiobjective programming. Uncertainty was represented with a set of probabilistic scenarios of site availability in a linear-integer formulation. We used data for 27 rare species in 31 candidate sites in western Lake County, near the city of Chicago, to illustrate the model. Each trade-off curve had a concave shape in which species representation dropped at an increasing rate as public accessibility increased, with the trade-off being smaller at higher levels of the area budget. Several sites were included in optimal solutions regardless of objective function weights, and these core sites had high species richness and public access per unit area. The area protected in period one depended on current site availability and on the probabilities of sites being undeveloped and available in the second period. Although the numerical results are specific for our study, the methodology is general and applicable elsewhere. Resumen:,Planificadores urbanos adquieren espacios abiertos para proteger áreas naturales y proporcionar acceso público a oportunidades de recreación. Debido a presupuestos limitados y a la dinámica de los mercados de terrenos, las adquisiciones se llevan a cabo secuencialmente en función de la disponibilidad de fondos y sitios. Para atender estas características de la planificación, formulamos un modelo de selección de sitios de dos períodos con dos objetivos: maximizar el número esperado de especies representado en sitios protegidos y maximizar el número esperado de personas con acceso a sitios protegidos. Ambos objetivos fueron maximizados con un límite superior en la superficie protegida en los dos períodos. El balance entre la representación de especies y el acceso público fue generado por el método de ponderación de programación de multiobjetivos. La incertidumbre fue representada con un conjunto de escenarios probabilísticos de la disponibilidad de sitios en una formulación lineal-integral. Para demostrar el modelo, utilizamos datos para 27 especies raras en 31 sitios potenciales en el oeste del Condado Lake, cerca de la ciudad de Chicago. Cada curva tenía forma cóncava y la representación de especies descendió a medida que incrementó la accesibilidad pública, con un menor equilibrio en niveles altos del presupuesto para el área. Varios sitios fueron incluidos en soluciones óptimas independientemente de las funciones de ponderación de los objetivos, y estos sitios tuvieron alta riqueza de especies y acceso público por unidad de área. La superficie protegida en el período uno dependió de la disponibilidad de sitios y de las probabilidades de que los sitios no fueran desarrollados y de su disponibilidad en el segundo período. Aunque los resultados numéricos son específicos a nuestro estudio, la metodología es general y aplicable en otros sitios. [source]


BACKGROUND MATCHING AND COLOR-CHANGE PLASTICITY IN COLONIZING FRESHWATER SCULPIN POPULATIONS FOLLOWING RAPID DEGLACIATION

EVOLUTION, Issue 6 2009
Andrew R. Whiteley
Anthropogenic-induced change is forcing organisms to shift their distributions and colonize novel habitats at an increasing rate, which leads to complex interactions among evolutionary processes. Coastrange sculpin (Cottus aleuticus) have colonized recently deglaciated streams of Glacier Bay in Alaska within the last 220 years. We examined divergence among populations in background matching coloration and tested the hypothesis that observed variation is due to morphological color plasticity. To examine how color-change plasticity has interacted with other evolutionary processes, we also determined the influence of colonization on neutral genetic diversity. We observed clinal variation in substrate-matching fish color along the chronological continuum of streams. Microsatellites provided little evidence of genetic subdivision among sculpin populations. Fish color was significantly correlated to substrate color, but was not correlated to neutral population genetic structure. Furthermore, a laboratory experiment revealed that morphological color plasticity could explain much, but not all, of the observed fish color divergence. Our study demonstrates that sculpin in Glacier Bay have colonized and adapted to recently deglaciated habitat and suggests that color change plasticity has aided in this process. This research, therefore, highlights the important role phenotypic plasticity may play in the adaptation of species to rapid climate change. [source]


Population genetic structure reveals terrestrial affinities for a headwater stream insect

FRESHWATER BIOLOGY, Issue 10 2007
DEBRA S. FINN
Summary 1. The spatial distribution of stream-dwelling organisms is often considered to be limited primarily according to the hierarchical structure of the hydrologic network, and previous conceptual models of population genetic structure have reflected this generality. Headwater specialists, however, are confined to short upstream sections of the network, and therefore are unlikely to respond in the same way as species with a broader range of habitat tolerance. 2. Here, we propose a model to describe spatial patterns of genetic diversity in headwater specialists with a limited ability for among-stream dispersal. The headwater model predicts a partitioning of genetic variance according to higher-elevation ,islands' of terrestrial habitat that provide required headwater stream conditions. The model therefore expects a geographic pattern of genetic variance similar to that expected for low-dispersal terrestrial species occupying the adjacent habitat. 3. Using a 1032-bp mitochondrial DNA fragment encompassing parts of the COI and COII genes, we demonstrate that Madrean Sky Islands populations of the giant water bug Abedus herberti conform to the proposed headwater model. Furthermore, they exhibit phylogeographic patterns broadly concordant with those shown for several terrestrial species in the region, including a major zone of discontinuity in the Chiricahua mountain range. 4. Overall, populations are highly isolated from one another, and a nested clade analysis suggested that A. herberti population structure, similarly to terrestrial Sky Islands species studied previously, has been influenced by Pleistocene climatic cycles causing expansion and contraction of temperate woodland habitat. 5. Because they have no ability to disperse among present-day mountaintop habitat islands, A. herberti and other headwater species with limited dispersal ability are vulnerable to the projected increasing rate of climatic warming in this region. [source]


Formation processes at the Ohalo II submerged prehistoric campsite, Israel, inferred from soil micromorphology and magnetic susceptibility studies

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2003
Alexander Tsatskin
Soil-geomorphic analysis coupled with micromorphology, SEM/EDS, magnetic susceptibility, and conventional sedimentological studies allowed us to reconstruct the site formation history and validate the archaeologically observed variability of human activities in the prehistoric camp of Ohalo II (19.5 ka B.P.), Sea of Galilee, Israel. The cultural layers rest upon the Late Pleistocene Lake Lisan deposits that accumulated under conditions of changing water supply and increasing rate of sedimentation from deep-water varvelike deposits to basalt-derived, near-shore sandy lacustrine deposits. Intermittent occupation is recorded in some localities, indicating short-term inundation episodes, which led to partial truncation and deformation of the sediments, primarily in the eastern lakeward part of the site. On the elevated, landward positions, incipient soils with strongly bioturbated profiles formed. Micromorphology demonstrates that intentional flooring was applied within the remains of brush huts, where millimeter-sized, horizontally organized burnt and unheated vegetal tissues were likely to have been placed upon the compacted ground. In fireplaces, the cultural deposits in thin sections are composed of strongly mixed, abundant wood charcoal, ashes, and fishbone remains. Post-depositional alterations were controlled by intermittent inundation of the site and salinization, which induced gypsum and pyrite deposition, primarily along decayed roots, and eventual pyrite oxidation. Accumulation of sodium and chlorine in the post-occupation deposits is likely to have occurred because of discharge of saline groundwater. Although only suggestive at this stage of research, the conclusions drawn from magnetic susceptibility parameters of archaeologically related deposits at Ohalo II fit well with the micromorphological reconstructions and provide new information on the Late Pleistocene evolution of the Lake Lisan/Sea of Galilee fluctuating system. © 2003 Wiley Periodicals, Inc. [source]


Public Education Financing Trends and the Gray Peril Hypothesis

GROWTH AND CHANGE, Issue 4 2009
DAYTON M. LAMBERT
ABSTRACT The effects of migrating seniors on the provision of local public services in rural communities is growing in importance because of the large number of retiring baby boomers and the increasing rate at which these retirees are locating outside traditional retirement destinations. Some communities are optimistic about attracting and retaining retirees as an economic development strategy, but others are concerned that inmigrating seniors may be reluctant to support local public services, such as education, bringing with them "Gray Peril." This article attempts to clarify questions regarding the Gray Peril hypothesis and local ability and willingness to fund education in Tennessee, an increasingly popular retirement destination. To this end, county per pupil education expenditure growth is explained by growth trends in local property tax assessment and sales tax revenue, and migration patterns of the retirement-aged population from 1962 to 2002. [source]


Helicobacter pylori Infection may be Implicated in the Topography and Geographic Variation of Upper Gastrointestinal Cancers in the Taihang Mountain High-Risk Region in Northern China

HELICOBACTER, Issue 5 2010
Denggui Wen
Abstract Backgrounds:,Helicobacter pylori infection is prevalent in China. Chronic infection of the bacterial not only causes distal stomach cancer, but also confers risk to gastric cardia adenocarcinoma. Because H. pylori infection is inversely associated with esophageal adenocarcinoma, globally the infection rate is significantly correlated with the ratio of squamous carcinoma to adenocarcinoma of the esophagus. These agree with the topography of upper gastrointestinal cancer observed in the Taihang Mountain high-risk region where both gastric cardia and non-cardia adenocarcinoma coincide with esophageal squamous cancer, but with almost no distal esophageal adenocarcinoma. Moreover, as altitude increases from plain to mountains, we observed progressively increasing incidence rates of gastric adenocarcinomas in recent years in the region. Because H. pylori infection is a definite carcinogen to gastric adenocarcinoma and is more prevalent in the mountain than in plain areas due to undeveloped living conditions, the observation gives the impression as though H. pylori infection is implicated. Aims:, This article aims to note the role of H. pylori infection in upper gastrointestinal cancer in the Taihang Mountain high-risk region in northern China. Materials and Methods:, First the unique topography and geographic variation of upper gastrointestinal cancer in the region is described to indicate a possible role of H. pylori infection, then we review studies on prevalence of H. pylori infection in the high-risk region and describe difference in socioeconomic development and water hygiene between the plains and the mountains as related to the prevalence of H. pylori infection. Results:, Coincidence of gastric cancer in the region and a progressively increasing rate of the cancer from the plain towards the mountains indicate H. pylori infection may be implicated in upper gastrointestinal cancer. Conclusion:, International collaboration is needed to study H. pylori and upper gastrointestinal cancer in the region when rapid industrialization is just beginning. [source]


Firm-specific human capital and compensation organizational tenure profiles: An archival analysis of salary data for it

HUMAN RESOURCE MANAGEMENT, Issue 3 2007
Sandra A. Slaughter
We examine determinants of IT compensation using archival salary data from 2,251 IT professionals in Singapore. Consistent with human capital theory, we find that professionals in IT jobs requiring more firm-specific human capital are paid more than those in jobs requiring less firm-specific human capital. Moreover, compensation increases with organizational tenure at an increasing rate for professionals in higher firm-specific human capital IT jobs, but at a decreasing rate for those in lower firm-specific human capital IT jobs. Our results reveal firm-specific human capital as a primary determinant of compensation and a moderator of IT compensation-organizational tenure profiles. © 2007 Wiley Periodicals, Inc. [source]


Development of the DYNA3D simulation code with automated fracture procedure for brick elements

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 14 2003
Ala Tabiei
Abstract Numerical simulation of cracked structures is an important aspect in structural safety assessment. In recent years, there has been an increasing rate of development of numerical codes for modelling fracture procedure. The subject of this investigation is implementing automated fracture models in the DYNA3D non-linear explicit finite element code to simulate pseudo 3D crack growth procedure. The implemented models have the capabilities of simulating automatic crack propagation without user intervention. The implementation is carried on solid elements. The methodology of implementing fracture models is described. An element deletion-and-replacement remeshing procedure is proposed for updating the explicit geometric description of evolving cracks. Fracture parameters such as stress intensity factors, energy release rates and crack tip opening angle are evaluated. The maximum circumferential stress criterion is used to predict the direction of crack advancement. Seven crack problems are presented to verify the effectiveness of the methodology. Mesh sensitivity and loading rate effects are studied in the validation of the presented procedure. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Are we aware of all complications following body piercing procedures?

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 4 2009
Bogus, aw Antoszewski MD
Background, The popularity of body piercing procedures is increasing around the world. Body piercing, depending on the age and social group, is believed to involve up to 51% of the general population. Complications following piercing procedures are variable. Objective, To present an unusual complication after lower lip piercing , embedding of a stud into the lip , and to determine why it occurred from the side of the mucous membrane and not from the side of the skin. Methods, A 21-year-old man presented to the plastic surgery outpatient clinic with embedding of piercing into the lower lip. Results, In lateral X-ray film, a metallic shadow was observed in the area of the oral soft tissues. The length of the stick was only 8 mm. In this patient, a stick that was too short in relation to the thickness of the lip was used. In this situation, the ends of the stud pressed too strongly on the surrounding tissues. Consequently, this may have caused necrosis of the mucous membrane and embedding of the stud into the lip. Conclusion, The observations described confirm a higher susceptibility to mechanical pressure of the mucous membrane than of the skin. An increasing rate of complications after body piercing reflects a lack of medical knowledge in individuals performing such procedures. [source]


Presentation and therapy of myelolipoma

INTERNATIONAL JOURNAL OF UROLOGY, Issue 3 2005
ANDREAS MEYER
Abstract, Background:, Adrenal myelolipoma is a rare and benign, hormonally inactive tumor frequently discovered incidentally. Because of the increasing rate of detection of adrenal myelolipoma, use of the correct diagnostic examination and treatment, with respect to surgical excision or regular controls, is continually gaining importance. We report herein on the largest series of surgically treated patients with adrenal myelolipoma from a single institute. Methods:, The clinical charts of 12 patients who underwent adrenal surgery for myelolipoma were reviewed. Follow up was carried out by means of re-examination or by personal contact with the primary physician. It was possible to perform a re-examination on eight of the 12 patients 6.9 years after the operation: one patient had died 5.2 years after surgery. Results:, Diagnosis of adrenal myelolipoma was made incidentally in seven patients, and during examination for reasons of unspecific abdominal or flank pain in five patients. A transabdominal approach was taken in five patients, a subcostal approach was taken in three patients and a translumbal approach was taken in four patients. At the follow up, all formerly symptomatic patients were free of symptoms. No recurrence could be seen; however, in one patient a contralateral adrenal myelolipoma had developed. Conclusions:, Symptomatic tumors, growing tumors or tumors larger than 10 cm should be excised surgically by means of an endoscopic or conventional approach, depending on the size. Surgical indication should not be liberalized by the introduction of more gentle operative techniques such as the translumbal or the endoscopic approach. A close follow up should be maintained in the case of patients free of symptoms, and for those with a definite diagnosis from imaging procedures. [source]


ELECTRICAL CONDUCTIVITY OF HEATED CORNSTARCH,WATER MIXTURES

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2009
EDUARDO MORALES-SANCHEZ
ABSTRACT Electrical conductivity (EC) of cornstarch,water mixtures in the range 10:90 to 70:30 (w/w) was studied as a function of temperature. An external resistive heating system equipped with an electronic device capable of monitoring EC in real time was used and EC of the mixtures was measured while heated at a rate of 5C/min. Results showed that EC went through four different temperature-dependent stages (A, B, C and D). Stage B (41C to 64C) showed a lower EC increasing rate when compared with that of Stage A (from 25C to 41C), probably as a result of starch granule swelling. In Stage C (64C to 78C), EC behavior was found to be dependent on water content. When water content was more than 50%, the value for EC increased. On the other side, EC decreased when water content was less than 50%. Stage C was related to starch gelatinization, according to differential scanning calorimetry results obtained in this study. In Stage D (78C to 92C), a steady increase in EC was observed, probably as a result of the total solubilization of starch in water. It was concluded that Stage C in EC graphs corresponded to cornstarch gelatinization, so it might be possible to use EC monitoring as an alternative technique to measure cornstarch thermal characteristics with different contents of water. PRACTICAL APPLICATIONS Electrical conductivity can be used as an adequate technique to monitor gelatinization, granule swelling and phase change of starch as a function of temperature in corn starch,water mixtures with a wide range of water contents. With this technique, it is also possible to calculate important thermal parameters, such as the beginning and end of the gelatinization and the energy activation for the heating process of cornstarch. This can lead to a better design and control of important industrial corn processes such as alkaline cooking. [source]


Treatment recommendations in patients diagnosed with high-risk cutaneous squamous cell carcinoma

JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 5 2005
MJ Veness
Summary Non-melanoma cutaneous cancers occur at an epidemic rate in Australia. With an ageing population, more Australians will develop these cancers and at an increasing rate. In the majority of cases local treatment is highly curative. However, a subset of the population will be diagnosed with a high-risk cutaneous squamous cell carcinoma. These can be defined as patients at risk of having subclinical metastases to regional lymph nodes based on unfavourable primary lesion features (including inadequately excised and recurrent lesions), patients with metastatic squamous cell carcinoma to regional lymph nodes, and squamous cell carcinoma in immunosuppressed patients. The mortality and morbidity associated with high-risk cutaneous squamous cell carcinoma is usually as a consequence of uncontrolled metastatic nodal disease and, to a lesser extent, distant metastases. Radiotherapy has an essential role in treating these patients and in many cases the addition of adjuvant radiotherapy may be life saving. It is therefore important that all clinicians treating skin cancers have an understanding and awareness of the optimal approach to these patients. The aim of this article is to present treatment recommendations based on an overview of the current published literature. [source]


Heterogeneous transport costs and spatial sorting in a model of New Economic Geography,

PAPERS IN REGIONAL SCIENCE, Issue 1 2010
Corey Lang
Economic geography; transport costs; sorting; agglomeration Abstract Transportation costs are of central importance in the New Economic Geography literature, though assumptions about transportation costs continue to be simplistic. This paper begins to address these simplifications by assuming that transportation costs for manufactured goods are heterogeneous. Basic results are consistent with standard models showing dispersion of economic activity for high transport costs and eventual agglomeration as transport costs decline. However, several novel features arise too. Many unstable, dispersed equilibria exist for high average transport costs, but converge to a stable equilibrium path as transport costs decrease. Equilibrium paths smoothly transition from dispersion to agglomeration and do so at an increasing rate. Additionally, transport costs directly influence firms' location decisions and firms spatially sort by transport cost. Resumen Los costos de transporte tienen una importancia capital en la literatura sobre la Nueva Geografía Económica, aunque se siguen asumiendo los costos de transporte de manera simplista. Este artículo empieza a tratar estas simplificaciones, asumiendo que los costos de transporte de bienes manufacturados son heterogéneos. Los resultados básicos son consecuentes con los modelos estándar que muestran la dispersión de la actividad económica para costos de transporte elevados y una eventual aglomeración a medida que los costos de transporte disminuyen. Sin embargo, también aparecen varias características novedosas. Existen muchos equilibrios dispersos, inestables, para costos de transporte promedio elevados, pero convergen en una línea de equilibrio a medida que los costos disminuyen. Las líneas de equilibrio tienen una transición fluida de la dispersión a la aglomeración y lo hacen a una tasa en aumento. Además, los costos de transporte influyen directamente las decisiones de localización de las empresas y estas se ordenan espacialmente de acuerdo a los costos de transporte. [source]


Variables Affecting the Participation in Individual Development

PERFORMANCE IMPROVEMENT QUARTERLY, Issue 4 2001
Janet L. Polach
ABSTRACT Workers across the country are being asked to acquire more information at an increasing rate in response to technological, structural, and new product and process changes occurring in the workplace. Organizations continue to struggle with understanding the capabilities and capacity of their workforce and are making critical investments in building expertise. But how do organizations engage people in this development effort? This paper proposes three critical variables that affect an individual's participation in the development process. Proposed variables are: 1) individual expertise, 2) system stability, and 3) the acceptance for the need for improvement. The paper reviews the theories that support the proposed variables in terms of influencing learning participation, and it concludes by pointing out implications for human development practitioners. It identifies where further research is needed in gaining greater insight into understanding this complex issue. [source]


A Doppler-based study on the prevalence of varicocele in German children and adolescents

ANDROLOGIA, Issue 1 2006
D. Pfeiffer
Summary The prevalence of varicocele was estimated among pupils of forms 4 and 8 in the city of Hamburg and the severity of the associated venous reflux was analysed. In the school year of 1998/99, a genital examination was performed on 2756 children (median age 10.2 years) and 2008 adolescents (14.6 years). The varicocele degree was determined according to the WHO. Venous reflux was proven by CW-Doppler sonography, distinguishing between Valsalva-induced reflux (VR) and continuous reflux (CR). As a result, varicoceles were detected in 18.0% of the children (1.2% bilaterally) and 42.7% of the adolescents (7.2%). High-graded forms (palpable/visible) occurred with increasing rate (from 7% to 22.9%) on the left side. Subtle forms (subclinical/during Valsalva) counted for >90% of all right-sided findings, whilst an age-related shift towards higher degrees was noted left-sided. VR occurred bilaterally, CR was almost only established left-sided. VR was mainly associated with subtle varicoceles, CR was predominantly found in the high-graded forms. These results suggest that even in children varicoceles are not a rare phenomenon. However, adolescence is the main period of manifestation. A major venous malfunction is already evident in maturing boys, which seems to be associated with the formation of high-graded varicoceles. [source]


Spread and impact of introduced conifers in South America: Lessons from other southern hemisphere regions

AUSTRAL ECOLOGY, Issue 5 2010
DANIEL SIMBERLOFF
Abstract The history of conifers introduced earlier elsewhere in the southern hemisphere suggests that recent invasions in Argentina, Brazil, Chile and Uruguay are likely to increase in number and size. In South Africa, New Zealand and Australia, early ornamental introductions and small forestry plantations did not lead to large-scale invasions, while subsequent large plantations were followed with a lag of about 20,30 years by troublesome invasions. Large-scale conifer plantation forestry in South America began about 50,80 years later than in South Africa, Australia and New Zealand, while reports of invasions in South America lagged behind those in the latter nations by a century. Impacts of invading non-native conifers outside South America are varied and include replacement of grassland and shrubland by conifer forest, alteration of fire and hydrological regimes, modification of soil nutrients, and changes in aboveground and belowground biotic communities. Several of these effects have already been detected in various parts of South America undergoing conifer invasion. The sheer amount of area planted in conifers is already very large in Chile and growing rapidly in Argentina and Brazil. This mass of reproductive trees, in turn, produces an enormous propagule pressure that may accelerate ongoing invasions and spark new ones at an increasing rate. Regulations to control conifer invasions, including measures to mitigate spread, were belatedly implemented in New Zealand and South Africa, as well as in certain Australian states, inspired by observations on invasions in those nations. Regulations in South America are weaker and piecemeal, but the existing research base on conifer invasions elsewhere could be useful in fashioning effective regulations in South America. Pressure from foreign customers in South Africa has led most companies there to seek certification through the Forestry Stewardship Council; a similar programme operates in Australia. Such an approach may be promising in South America. [source]


Cost-effective Targeting of Riparian Buffers

CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 1 2004
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]


Transient Cooling of Heat-Generating Materials with Thermoelectric Coolers

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 6 2006
Y. Makino
Abstract The transient cooling of heat-generating materials contacted with a thermoelectric microcooler was discussed, and the operation of a fixed electric current was proposed as an alternative to the conventional operation of a variable electric current to obtain the maximum heat flux of cooling. The changes in temperature of the materials cooled by the thermoelectric cooler were obtained by numerical calculation of the unsteady one-dimensional energy equation. The proposed operation of a fixed current was found to be a useful alternative to the conventional operation. An approximate analysis was made on the basis of the results of the numerical calculation. The results showed that the transient response of cooling of material without heat generation could be expressed by the first-order delay. Comparisons with the numerical calculation indicated that the expression by the first-order delay is also applicable to the cooling of material with heat generation and that the time constant decreases with increasing rate of heat generation from the material. [source]


The relationship between maternal depression and child outcomes in a child welfare sample: implications for treatment and policy

CHILD & FAMILY SOCIAL WORK, Issue 4 2005
Alan W. Leschied
ABSTRACT Maternal depression is an extremely important parenting variable in relation to child general health. This investigation addressed the issue of maternal depression as it relates to the lives of children seen by child welfare authorities. Maternal depression was investigated in the context of the increasing rate of children coming to the attention of the London and Middlesex Children's Aid Society. A variety of child outcomes including those of particular relevance to child welfare, specifically disorders of attachment and neglect and physical abuse, school-related variables, conduct disorder and psychological distress, were investigated. The relative contribution of maternal depression along with measures of socioeconomic status and social isolation to childhood risk was examined. Results indicated that the rate of maternal depression doubled during the years 1995,2001. Maternal depression was related to children entering care through wardship. Additional poor child outcomes such as attention deficit disorder, conduct disorder and emotional adjustment were also related to maternal depression. The findings are discussed in terms of treatment and policies that can lower the risk to children through effective intervention with depressed mothers. [source]


Evaluating the impacts of climate and elevated carbon dioxide on tropical rainforests of the western Amazon basin using ecosystem models and satellite data

GLOBAL CHANGE BIOLOGY, Issue 1 2010
HIROFUMI HASHIMOTO
Abstract Forest inventories from the intact rainforests of the Amazon indicate increasing rates of carbon gain over the past three decades. However, such estimates have been questioned because of the poor spatial representation of the sampling plots and the incomplete understanding of purported mechanisms behind the increases in biomass. Ecosystem models, when used in conjunction with satellite data, are useful in examining the carbon budgets in regions where the observations of carbon flows are sparse. The purpose of this study is to explain observed trends in normalized difference vegetation index (NDVI) using climate observations and ecosystem models of varying complexity in the western Amazon basin for the period of 1984,2002. We first investigated trends in NDVI and found a positive trend during the study period, but the positive trend in NDVI was observed only in the months from August to December. Then, trends in various climate parameters were calculated, and of the climate variables considered, only shortwave radiation was found to have a corresponding significant positive trend. To compare the impact of each climate component, as well as increasing carbon dioxide (CO2) concentrations, on evergreen forests in the Amazon, we ran three ecosystem models (CASA, Biome-BGC, and LPJ), and calculated monthly net primary production by changing a climate component selected from the available climate datasets. As expected, CO2 fertilization effects showed positive trends throughout the year and cannot explain the positive trend in NDVI, which was observed only for the months of August to December. Through these simulations, we demonstrated that the positive trend in shortwave radiation can explain the positive trend in NDVI observed for the period from August to December. We conclude that the positive trend in shortwave radiation is the most likely driver of the increasing trend in NDVI and the corresponding observed increases in forest biomass. [source]


Deliberate self-harm in older adults: a review of the literature from 1995 to 2004

INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 8 2007
Jenifer Chan
Abstract Background The prevention of suicide is a national and international policy priority. Old age is an important predictor of completed suicide. Suicide rates in old age differ markedly from country to country but there is a general trend towards increasing rates with increasing age. In 1996 Draper reviewed critically the evidence on attempted suicide in old age in the 10 years between 1985 and 1994. The review highlighted a need for prospective controlled studies in older people with more representative samples as well as studies examining the interaction of risk factors, precipitants, motivations, psychopathology and response to treatment. The aim of this paper is to update this review and to summarise the advances in our understanding of DSH in later life. Method We have critically reviewed relevant studies published between 1995 and 2004 to summarise the advances in our understanding of factors associated with deliberate self-harm in later life. Results The main advances in understanding have been to clarify the effect of personality and cultural factors, service utilisation pre and post attempt, and the (lesser) impact of socio-economic status and physical illness. Methodological weaknesses continue to include inadequate sample sizes performed on highly selected populations, inconsistent age criteria and lack of informant data on studies relating to role of personality. Conclusions Future studies should include prospective, cross-cultural research with adequate sample sizes and which are population-based. Such approaches might confirm or refute the results generated to date and improve knowledge on factors such as the biological correlates of deliberate self-harm, service utilisation, costs and barriers to health care, and the interaction of these factors. Intervention studies to elucidate the impact of modifying these factors and of specific treatment packages are also needed. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Paradoxical Vasodilation During Lower Body Negative Pressure in Patients with Vasodepressor Carotid Sinus Syndrome

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2003
Arduino A. Mangoni MD
OBJECTIVES: To elucidate the pathophysiological mechanism of the vasodepressor form (VD) of carotid sinus syndrome (CSS) by maneuvers designed to induce generalized sympathetic activation after baroreceptor unloading (lower body negative pressure, LBNP) or direct peripheral adrenoreceptor stimulation via local administration of norepinephrine (NA). DESIGN: Subjects were identified with VD of CSS through diagnostic testing. SETTING: Research laboratory. PARTICIPANTS: Eleven young controls (YC) (mean age ± standard error of mean = 22.8 ± 0.7), eight elderly controls (EC) (72.6 ± 0.6), and eight elderly patients with VD (78.7 ± 1.7). MEASUREMENTS: Forearm arterial blood flow (FABF) was measured in the left and right arms by venous occlusion plethysmography. Measurements were performed during baseline conditions, LBNP (,20 mmHg), and intra-arterial NA infusion in the left brachial artery at three progressively increasing rates (60, 120, and 240 pmol/min). RESULTS: During LBNP, FABF significantly decreased in YC (baseline 3.61 ± 0.30 vs ,20 mmHg 2.96 ± 0.24 mL/100 g/min, P = .030) and EC (4.05 ± 0.74 vs 3.69 ± 0.65 mL/100 g/min, P = .033) but increased in elderly patients with VD (3.65 ± 0.60 vs 4.54 ± 0.80 mL/100 g/min, P = .020). During NA infusion, a significant forearm vasoconstriction occurred in YC (FABF left:right ratio 1.00 ± 0.05 at baseline; 0.81 ± 0.08 at 60 pmol/min, P = .034; 0.81 ± 0.05 at 120 pmol/min, P < .001; 0.72 ± 0.04 at 240 pmol/min, P < .001), whereas no significant FABF changes were observed in EC (1.04 ± 0.06; 0.96 ± 0.07, P = .655; 0.89 ± 0.10, P = .401; 0.94 ± 0.10, P = .590) or elderly patients with VD (1.04 ± 0.06; 1.16 ±0 .10, P = .117; 1.04 ± 0.08, P = .602; 1.11 ± 0.10, P = .305). CONCLUSION: VD of CSS is associated with a paradoxical vasodilatation during LBNP and an impairment of peripheral ,-adrenergic responsiveness, which may be age-related. [source]


Silicon-mediated resistance of sugarcane to Eldana saccharina Walker (Lepidoptera: Pyralidae): effects of silicon source and cultivar

JOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2006
M. G. Keeping
Abstract:, The effects of four silicon sources , a USA calcium silicate, a local (South African) calcium silicate, Slagment® and fly ash , on the resistance of sugarcane cultivars (two resistant and two susceptible) to Eldana saccharina Walker (Lepidoptera: Pyralidae) were studied in a potted sugarcane trial. Silicon sources were applied at 5000 or 10 000 kg/ha for the calcium silicates and Slagment; fly ash was applied at 15 000 or 30 000 kg/ha. The greatest increase in plant silicon content (particularly in stalks) was recorded for plants treated with local calcium silicate. Silicon uptake did not vary significantly between the susceptible and resistant cultivars, although the resistant cultivars had inherently higher silicon content than the susceptible ones. Treatment with silicon significantly reduced borer damage and borer performance at the higher treatment level. In general, borer damage and performance decreased with increasing rates of applied silicon and both variables were inversely related with per cent stalk silicon. On average, the higher silicon rate reduced damage by 34% in the susceptible cultivars and by 26% in the resistant cultivars, supporting the argument that susceptible cultivars benefit more from silicon treatments than resistant ones. We propose that calcium silicate amendments could be employed in the integrated, area-wide management of E. saccharina and in the management of soil acidity, both of which are widespread problems in the South African sugar industry. [source]


Gastro-oesophageal reflux disease in Asia

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2000
Khean-Lee Goh
Abstract Gastro-oesophageal reflux disease (GORD) occurs more frequently in Europe and North America than in Asia but its prevalence is now increasing in many Asian countries. Many reasons have been given for the lower prevalence of GORD in Asia. Low dietary fat and genetically determined factors, such as body mass index and maximal acid output, may be important. Other dietary factors appear to be less relevant. Increased intake of carbonated drinks or aggravating medicines may influence the increasing rates of GORD in some Asian countries but no strong evidence links other factors, such as the age of the population, smoking or alcohol consumption, to GORD. The management of GORD in Asia is similar to that in Europe and North America but the lower incidence of severe oesophagitis in Asia may alter the approach slightly. Also, because Asians tend to develop stomach cancer at an earlier age, endoscopy is used routinely at an earlier stage of investigation. Gastro-oesophageal reflux disease is essentially a motility disorder, so short-term management of the disease can usually be achieved using prokinetic agents (or histamine (H2)-receptor antagonists). More severe and recurrent GORD may require proton pump inhibitors (PPI) or a combination of prokinetic agents and PPI. The choice of long-term treatment may be influenced by the relative costs of prokinetic agents and PPI. © 2000 Blackwell Science Asia Pty Ltd [source]


Comparison of the performance of rapid HIV tests using samples collected for surveillance in Mozambique,

JOURNAL OF MEDICAL VIROLOGY, Issue 12 2009
Josefa Melo
Abstract Mozambique had low HIV prevalence until the mid-1990s, but recent data indicate increasing rates. There is little information on HIV-2. Therefore, HIV seroprevalence was assessed among pregnant women and field-ready HIV diagnostic strategies were evaluated. A total of 6,930 samples collected by three health centers from 2002 to 2005 were tested on site by nurses with two simple/rapid tests, Determine HIV-1/2 (Abbott Laboratories; screening) and Uni-Gold HIV (Trinity Biotech; confirmation), which is the national HIV testing strategy. The prevalence of HIV was 14.0% (2002), 17.8% (2003), 16.5% (2004), and 20.2% (2005). A subset of 888 samples collected 2003 was sent to the Central Microbiology Laboratory, Maputo for evaluation of tests and testing strategies. The assays included for comparison were Capillus HIV-1/HIV-2 (Trinity Biotech), DoubleCheckGold HIV-1&2 (Orgenics) and Enzygnost Anti-HIV-1/2 Plus (Behringwerke, reference ELISA). Confirmation of reactive samples was done by Uni-Gold HIV and ImmunoComb II HIV-1&2 BiSpot (for HIV type differentiation). The Capillus HIV-1/ HIV-2,+,ImmunoComb II HIV-1&2 BiSpot combination was the gold standard. The sensitivity of the rapid/simple screening assays (Determine HIV-1/2, DoubleCheckGold HIV-1&2) was 100% (N,=,160) and their (initial) specificities were 99.6% and 99.7%, respectively. Repeated testing and combinations of assays increased the specificity. Four suspected cases of recent seroconversion were found. Together with the increasing prevalence rates, this may indicate that Mozambique is a high-incidence area, although further studies are needed to confirm this. Testing strategies for on-site screening and confirmation based on the combination of Determine HIV-1/2, Uni-Gold HIV and DoubleCheckGold HIV-1&2 are well suited for local field use. J. Med. Virol. 81:1991,1998, 2009. © 2009 Wiley-Liss, Inc. [source]


REEXAMINING BEST MANAGEMENT PRACTICES FOR IMPROVING WATER QUALITY IN URBAN WATERSHEDS,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2003
Stephen R. Pennington
ABSTRACT: Municipalities will be implementing structural best management practices at increasing rates in their effort to comply with Phase II of the National Pollutant Discharge Elimination System (NPDES). However, there is evidence that structural best management practices (BMPs) by themselves may be insufficient to attain desired water quality standards. This paper reports on an analysis of the median removal efficiencies of structural BMPs and compares them to removal efficiencies estimated as being necessary to attain water quality standards in the Rouge River in Detroit, Michigan. Eight water quality parameters are reviewed using data collected from 1994 to 1999 in the Rouge River. Currently, five of the eight parameters in the Rouge River including bacteria, biochemical oxygen demand, and total suspended solids (TSS) exceed the required water quality standards. The reported analysis of structural BMP efficiencies reveals that structural BMPs appear capable of reducing only some of the pollutants of concern to acceptable levels. [source]


Typhoid and Paratyphoid Fever: A 10-Year Retrospective Study of 41 Cases in a Parisian Hospital

JOURNAL OF TRAVEL MEDICINE, Issue 6 2001
Eric Caumes
Background: Enteric fever remains a major cause of fever in travelers. We evaluated new trends in enteric fever. Methods: We reviewed the epidemiological, clinical, biological, bacteriological data, and outcome of all cases of typhoid and paratyphoid fever seen in our department over the last decade. The inclusion criteria were the presence of signs compatible with enteric fever and isolation of Salmonella typhi or Salmonella paratyphi A, B, or C from blood or stool cultures or any other site. Results: Among the 41 patients, 38 (93%) had travel-associated enteric fever. The main geographic source of contamination was the Indian subcontinent. One patient had been vaccinated with parenteral Vi vaccine 1 year previously. Fever and headaches were the only signs which were present in more than 80% of patients. The Widal test at inclusion was positive in 27%, and a second serological test was found to be positive in 50% of evaluated cases. Blood cultures and stool cultures were positive in 34 cases and 10 cases, respectively. Salmonellae spp were isolated in both hemocultures and stool cultures in 4 cases and in urine in 1 case. Two strains of S. typhi were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole. One strain of S. typhi and one of S. paratyphi B were nalidixic acid resistant. All evaluable patients were cured with the exception of 2 patients (1 failure, 1 relapse). We observed 3 toxic reactions. No patients died. Conclusion: The diagnosis and outcome of enteric fever are hampered by the lack of specificity of clinical and biological signs, the increasing rates of antimicrobial resistance, and the occurrence of toxic reactions during treatment. [source]


Type 2 diabetes, cardiovascular disease, and the evolutionary paradox of the polycystic ovary syndrome: A fertility first hypothesis

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2009
Stephen J. Corbett
Worldwide, the high prevalence of the Polycystic Ovary Syndrome (PCOS), a heritable cause of ovarian infertility, is an evolutionary paradox, which provides insight into the susceptibility of well-fed human populations to cardiovascular disease and diabetes. We propose that PCOS, Type 2 diabetes (T2D) and the Metabolic Syndrome are modern phenotypic expressions of a metabolic genotype attuned to the dietary and energetic conditions of the Pleistocene. This metabolic "Fertility First" rather than "Thrifty" genotype persisted at high prevalence throughout the entire agrarian period,from around 12,000 years ago until 1800 AD,primarily, we contend, because it conferred a fertility advantage in an environment defined by chronic and often severe seasonal food shortage. Conversely, we argue that genetic adaptations to a high carbohydrate, low protein agrarian diet, with increased sensitivity to insulin action, were constrained because these adaptations compromised fertility by raising the lower bound of body weight and energy intake optimal for ovulation and reproduction. After 1800, the progressive attainment of dietary energy sufficiency released human populations from this constraint. This release, through the powerful mechanism of fertility selection, increased, in decades rather than centuries, the prevalence of a genotype better suited to carbohydrate metabolism. This putative mechanism for rapid and recent human evolution can explain the lower susceptibility to T2D of today's Europid populations. This hypothesis predicts that the increasing rates of diabetes and cardiovascular disease, which typically accompany economic development, will be tempered by natural, but particularly fertility, selection against the conserved ancestral genotypes that currently underpin them. Am. J. Hum. Biol. 2009. © 2009 Wiley-Liss, Inc. [source]