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At least 19 recordsLinked to original sources
PubMed2007

Stochastic simulation of daily air temperature and precipitation from monthly normals in North America north of Mexico.

A simple, stochastic daily temperature and precipitation generator (TEMPGEN) was developed to generate inputs for the study of the effects of climate change on models driven by daily weather information when climate data are available as monthly summaries. The model uses as input only 11 sets of monthly normal statistics from individual weather stations. It needs no calibration, and was parameterized and validated for use in Canada and the continental United States. Monthly normals needed are: mean and standard deviation of daily minimum and maximum temperature, first and second order autoregressive terms for daily deviations of minimum and maximum temperatures from their daily means, correlation of deviations of daily minimum and maximum temperatures, total precipitation, and the interannual variance of total precipitation. The statistical properties and distributions of daily temperature and precipitation data produced by this generator compared quite favorably with observations from 708 stations throughout North America (north of Mexico). The algorithm generates realistic seasonal patterns, variability and extremes of temperature, precipitation, frost-free periods and hot spells. However, it predicts less accurately the daily probability of precipitation, extreme precipitation events and the duration of extreme droughts.

Air↗
PubMed1994

Siphonaptera of North America north of Mexico: Ischnopsyllidae.

The four genera and 11 species of bat fleas known to occur in North America north of Mexico are reviewed with respect to their distribution and host preferences. All are found on hosts belonging to the bat family Vespertilionidae except Sternopsylla distincta (Rothschild, 1903) and Hormopsylla trux Jordan, 1950, which parasitize species of Molossidae. Keys are provided for the genera and species and their diagnostic characters are illustrated.

Animals↗
PubMed1994

Siphonaptera of North America north of Mexico: Vermipsyllidae and Rhopalopsyllidae.

The six species of Chaetopsylla Kohaut, 1903, two species of Polygenis Jordan, 1939, and one species of Rhopalopsyllus Baker, 1905 known to occur in North America north of Mexico are reviewed with respect to their host preferences and distribution. Keys are provided for the species, and their salient characters are illustrated.

Animals↗
PubMed1994

Siphonaptera of North America north of Mexico: Hystrichopsyllidae s. str.

The three species of Atyphloceras Jordan & Rothschild, 1915 and the four species of Hystrichopsylla Taschenberg, 1880 known to occur in North America north of Mexico are reviewed with respect to their host preferences and distribution. Keys are provided for the species, and their diagnostic characters are illustrated.

Animals↗
PubMed2004

Prevalence, awareness, treatment and control of hypertension in North America, North Africa and Asia.

Results from national surveys of prevalence, awareness, treatment and control provide the most meaningful basis for assessing the burden of hypertension in the community. National surveys conducted in a variety of countries in North America, Europe, Australia, Asia and Africa have identified a strikingly similar relationship between age and blood pressure (BP), with a progressive and steep increase in systolic BP throughout adult life and a less steep increase in diastolic BP from adolescence until the fifth or sixth decade. In most countries surveyed, there was a high prevalence of hypertension. Approximately, one quarter of all adults in the United States and Egypt had hypertension (systolic BP>/=140 mmHg or diastolic BP>/=90 mmHg or use of antihypertensive medication) in national surveys conducted in 1988-1991 and 1991-1993, respectively. The corresponding percentage was somewhat lower (14.4%) for adults surveyed in China during 1991, but temporal trends indicate that the prevalence of hypertension is increasing rapidly in that country. In the 1988-1991 national survey, more than 25% of US adults were unaware of their diagnosis, only 55% were being treated with antihypertensive medication and only 29% were on antihypertensive medication with a systolic/diastolic BP >140/90 mmHg. The situation was much worse in Egypt and China, with only 8% and <5% of adults with hypertension, respectively, being treated with antihypertensive medication and having a systolic/diastolic BP <140/90 mmHg. These survey results underscore the fact that hypertension is highly prevalent, poorly treated and controlled, and an escalating health challenge in economically developing countries.

Africa, Northern↗
PubMed1992

Key characters for identifying Aedes bahamensis and Aedes albopictus in North America, north of Mexico.

Aedes bahamensis, a species recently introduced into southern Florida represents the first member of the subgenus Howardina to be found in the United States. Its separation from all other Nearctic Aedes is the subject of this work, integrating it into the North American mosquito keys (Darsie and Ward 1981). The key revisions presented are expanded to include the other exotic species now found in the United States, Aedes albopictus.

Aedes↗
PubMedDate not supplied

Development of specialist and advanced practice in North America.

North American literature provides interesting ideas about the nature of specialist and advanced practice which are useful in informing British thinking on these subjects. However, the two roles do not have the same meanings as their British counterparts. Clarification of the terminology used and the roles described are essential if we are to understand the concepts. This article presents an overview of the literature about clinical nurse specialist and advanced practitioner roles within North America and identifies differences and similarities between the two.

Career Mobility↗
PubMedDate not supplied

The medical impact of tornadoes in North America.

North America suffers some of the most severe tornado disasters of any location on the planet. Significant injury and economic impact may result from these storms, particularly in rural areas. Tornadic storms present unique problems for prehospital and Emergency Department personnel. Soft tissue injuries seen after tornadoes are contaminated with polymicrobial flora and may require delayed primary closure. Fractures are a frequent cause of hospital admission and head injury is a frequent cause of death. Advanced warning and proper sheltering actions by a population are the most significant factors in reducing morbidity and mortality. This article reviews the pertinent literature on the medical impact of tornadoes and details the mechanisms of injury, nature of injuries, pre-hospital and ED planning points associated with tornadic storms.

Canada↗
PubMed2001

Variation in patient management and outcomes for acute coronary syndromes in Latin America and North America: results from the Platelet IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial.

BACKGROUND: Although more than 9500 patients have been enrolled in major clinical trials in Latin America, practice patterns in this region have rarely been examined. We sought to compare characteristics, resource utilization, and outcomes of patients treated for acute coronary syndromes in Latin America with those in North America. METHODS: The Platelet IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Theraphy Trial (PURSUIT) enrolled 10,948 patients with non-ST-segment elevation acute coronary syndromes, including 585 in Latin America and 4358 in North America. We analyzed regional differences in patient groups, treatment patterns, and outcomes and used logistic regression analysis to identify association of enrollment region and survival. RESULTS: For patients in Latin America, the length of hospital stay was significantly longer (10 [7, 15] days vs 6 [4, 9], P <.001). Angiograms, angioplasty, and bypass surgery were significantly less common in Latin America (46.2%, 17.6%, and 11.3% vs 79.4%, 33.6%, and 19.4%, P <.001). Thirty-day death/myocardial infarction was not significantly higher, although mortality alone was significantly higher (6.8% vs 3.1%, P <.001). After adjustment for baseline characteristics, enrollment in Latin America remained an independent predictor for death at 30 days (odds ratio [OR] [95% confidence interval (CI)] 2.42 [1.60-3.67]) and persisted at 6 months (OR [95% CI] 2.5 [1.8-3.4]). CONCLUSIONS: Latin American patients treated for acute coronary syndromes were managed less invasively and were twice as likely as their North American counterparts to die within 6 months. This mortality difference was not explained by imbalances in baseline risk.

Angina, Unstable↗
PubMed1990

Controlling hepatitis B virus transmission in North America. The North American Regional Study Group.

In the US in 1988, 54,011 cases of viral hepatitis were reported to the Centers for Disease Control (CDC), 42% of which were categorized as hepatitis B. Because of incomplete reporting and subclinical disease, the CDC estimates that approximately 300,000 acute cases of hepatitis B are occurring in the US each year for an annual estimated incidence of 125 cases per 100,000 population. Since 1985, a gradual decrease in the reported incidence of hepatitis B has been observed which may be attributed partly to the availability of new hepatitis B vaccines. Comprehensive control of hepatitis B infection in North America has, however, been impeded by the diversity and mobility of high-risk groups who often are unaware of their potential to infect other individuals. Surveillance studies have indicated that the modes of transmission of hepatitis B may be changing in the US. A larger proportion of cases are seen in parenteral drug abusers and in active heterosexuals. It is believed that hepatitis B vaccine has been administered to only 7% of the population who are at risk of acquiring hepatitis B virus (HBV). To achieve maximum control, universal immunization of infants will therefore be necessary. A first programme, already inaugurated in the US, involves screening of all pregnant women and providing appropriate prophylaxis to neonates of hepatitis B surface antigen-positive mothers and to susceptible household contacts of these individuals. Along with mandatory guidelines, collaboration between the hepatitis community, vaccine manufacturers, the CDC and appropriate medical, legislative and health care organizations should be fostered to achieve successful control of HBV in North America.

Adolescent↗
PubMed2006

An estimation of reproductive performance of farmed elk (Cervus elaphus) in North America.

North American farmed elk (Cervus elaphus) producers were surveyed to determine period specific rates of calving, abortion, and dystocia, and to examine the effect of reproduction-related mortality on the productivity of farmed elk. The overall calving rate was 86.3% and the calving rate for adult cows was found to be significantly higher than that for heifers. Abortions were seen on 7.6% of farms and the overall abortion rate was approximately 0.6%. Dystocia was experienced in 5.9% of births. Neonatal mortality, summer mortality, weaning mortality, and postweaning mortality rates were calculated and compared. Failure to produce a live neonate was responsible for 64% of the total reproductive loss and calf mortalities from birth to 1 year of age accounted for 36%. Failure to produce a live neonate had a more significant effect on productivity than did mortalities from birth to 1 year of age, suggesting that reproduction has a greater economic effect on elk farms than neonatal mortality.

Abortion, Veterinary↗
PubMed2001

BETR North America: a regionally segmented multimedia contaminant fate model for North America.

We present the Berkeley-Trent North American contaminant fate model (BETR North America), a regionally segmented multimedia contaminant fate model based on the fugacity concept. The model is built on a framework that links contaminant fate models of individual regions, and is generally applicable to large, spatially heterogeneous areas. The North American environment is modeled as 24 ecological regions, within each region contaminant fate is described using a 7 compartment multimedia fugacity model including a vertically segmented atmosphere, freshwater, freshwater sediment, soil, coastal water and vegetation compartments. Inter-regional transport of contaminants in the atmosphere, freshwater and coastal water is described using a database of hydrological and meteorological data compiled with Geographical Information Systems (GIS) techniques. Steady-state and dynamic solutions to the 168 mass balance equations that make up the linked model for North America are discussed, and an illustrative case study of toxaphene transport from the southern United States to the Great Lakes Basin is presented. Regionally segmented models such as BETR North America can provide a critical link between evaluative models of long-range transport potential and contaminant concentrations observed in remote regions. The continent-scale mass balance calculated by the model provides a sound basis for evaluating long-range transport potential of organic pollutants, and formulation of continent-scale management and regulatory strategies for chemicals.

Air Movements↗
PubMed1996

Fate of biological control introductions: monitoring an Australian fungal pathogen of grasshoppers in North America.

In North America there are two generally recognized pathotypes (pathotypes 1 and 2) of the fungus Entomophaga grylli which show host-preferential infection of grasshopper subfamilies. Pathotype 3, discovered in Australia, has a broader grasshopper host range and was considered to be a good biocontrol agent. Between 1989 and 1991 pathotype 3 was introduced at two field sites in North Dakota. Since resting spores are morphologically indistinguishable among pathotypes, we used pathotype-specific DNA probes to confirm pathotype identification in E. grylli-infected grasshoppers collected at the release sites in 1992, 1993, and 1994. In 1992, up to 23% of E. grylli-infected grasshoppers of the subfamilies Melanoplinae, Oedipodinae, and Gomphocerinae were infected by pathotype 3, with no infections > 1 km from the release sites. In 1993, pathotype 3 infections declined to 1.7%. In 1994 grasshopper populations were low and no pathotype 3 infections were found. The frequency of pathotype 3 infection has declined to levels where its long-term survival in North America is questionable. Analyses of biocontrol releases are critical to evaluating the environmental risks associated with these ecological manipulations, and molecular probes are powerful tools for monitoring biocontrol releases.

Animals↗
PubMed2004

Management of the nontoxic multinodular goiter in Latin America: comparison with North America and Europe, an electronic survey.

To assess diagnostic and therapeutic approaches to nontoxic multinodular goiter and to compare them with previously reported American Thyroid Association (ATA) and European Thyroid Association (ETA) surveys, an online questionnaire was distributed to Latin American Thyroid Society (LATS) members. An index case was presented (42-yr-old woman with an enlarged, irregular, nontender, 50- to 80-g thyroid and no clinical suspicion of malignancy or dysfunction), and 11 variations were proposed to evaluate how each alteration would affect management. We obtained 148 responses (response rate, 50%). In the index case, the most used blood tests were TSH (96%), antithyroid peroxidase antibodies (76%), and free T(4) (64%); 5% included a calcitonin assay. Nearly 90% would perform ultrasound, and only 16% used scintigraphy. Fine needle biopsy was indicated by 88%, with ultrasound guidance in 75% of times. For treatment, observation was preferred by 39%, surgery by 28%, levothyroxine by 21%, and radioiodine by 7% (60% with recombinant TSH prestimulation). A suppressed TSH level prompted 45% of the respondents to recommend radioiodine, whereas 70-78% indicated surgery in the presence of a large goiter or suspicion of malignancy. In conclusion, no consensus exists concerning the ideal management of nontoxic goiter among LATS members, in agreement with previous ATA and ETA surveys. Levothyroxine therapy is less used by LATS than by ATA or ETA members, and a more aggressive therapeutic strategy is generally preferred by members of LATS and ETA compared with ATA.

Adult↗
PubMed2004

Origin of extant domesticated sunflowers in eastern North America.

Eastern North America is one of at least six regions of the world where agriculture is thought to have arisen wholly independently. The primary evidence for this hypothesis derives from morphological changes in the archaeobotanical record of three important crops--squash, goosefoot and sunflower--as well as an extinct minor cultigen, sumpweed. However, the geographical origins of two of the three primary domesticates--squash and goosefoot--are now debated, and until recently sunflower (Helianthus annuus L.) has been considered the only undisputed eastern North American domesticate. The discovery of 4,000-year-old domesticated sunflower remains from San Andrés, Tabasco, implies an earlier and possibly independent origin of domestication in Mexico and has stimulated a re-examination of the geographical origin of domesticated sunflower. Here we describe the genetic relationships and pattern of genetic drift between extant domesticated strains and wild populations collected from throughout the USA and Mexico. We show that extant domesticates arose in eastern North America, with a substantial genetic bottleneck occurring during domestication.

Agriculture↗
PubMed2001

Meningococcal disease and vaccination in North America.

In North America, meningococcal disease occurs at a rate of I case per 100000 population per year, producing 2725 cases notified in the US in 1998 and 155 laboratory confirmed cases in Canada in the same year. A majority of these cases occur in the winter season and in early childhood, with a case fatality rate of approximately 10%. There has been an increase in the proportion of cases due to serogroup Y meningococci over the past decade: in 1995-98 in the US, 33% of cases were due to serogroup B, 28% were due to serogroup C and 34% were due to serogroup Y; in Canada in 1995-96, 47% of cases were due to serogroup B, 40% were due to serogroup C and 10% were due to serogroup Y. Outbreaks due to serogroup C were more common in the 1990s in the US and a number of outbreaks have occurred in Canada due to organisms from the hypervirulent ET-37 complex. College freshmen in the US in dormitories were found to be at an increased risk of disease. In addition, over the past 10 years, an outbreak of serogroup B disease occurred in the Pacific North-west of the US, with a fourfold increased rate of disease in that region. The explanations for these changes in epidemiology are unknown, but probably reflect the appearance of hypervirulent clones of meningococci and/or changing levels of population immunity. Meningococcal serogroup C polysaccharide-protein conjugate vaccines have been introduced recently in the UK, seem efficacious and offer the potential to reduce the burden of disease in the US and Canada too. Because serogroups other than serogroup C are prevalent in North America, a combination polysaccharide-protein vaccine, including C, Y and possibly W135 serogroups, would be attractive for this population. Although not currently an issue in industrialized nations, inclusion of serogroup A conjugates in any future vaccine policy would be an important decision in driving global prevention of meningococcal disease. A meningococcal conjugate vaccine against serogroup C was licensed in Canada in April 2001.

Adolescent↗