首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Microsatellite variation in the reintroduced Pennsylvania elk herd   总被引:8,自引:0,他引:8  
Relocation programs have restored elk (Cervus elaphus) to portions of its vast historical range. We examine the consequences of these relocation programs by assessing variation at 10 microsatellite loci in three elk herds, a source herd (Yellowstone National Park), a large herd reintroduced from Yellowstone (Custer State Park) and a bottlenecked herd reintroduced from both Yellowstone and Custer (the Pennsylvania herd). Observed single locus heterozygosities ranged from 0.000 to 0.739. Multi-locus heterozygosities ranged from 0.222 to 0.589. Although significant differences were detected among all three herds, the Yellowstone National Park and Custer State Park herds possessed similar levels of variation and heterozygosity, and the genetic distance between these two herds was small. The Pennsylvania herd, on the other hand, experienced a 61.5% decrease in heterozygosity relative to its source herds, possessed no unique and few rare alleles, and the genetic distances between the Pennsylvania herd and its sources were large. Simulations were performed to identify bottleneck scenarios in agreement with levels of variation in the Pennsylvania herd. Our data confirm that the rate of population growth post-relocation may have important genetic consequences and indicate that theoretical predictions regarding the maintenance of genetic variation during relocation events must be viewed with caution when small numbers of a polygynous species are released.  相似文献   

2.

Background

Influenza is a contagious respiratory disease responsible for annual seasonal epidemics in temperate climates. An understanding of how influenza spreads geographically and temporally within regions could result in improved public health prevention programs. The purpose of this study was to summarize the spatial and temporal spread of influenza using data obtained from the Pennsylvania Department of Health''s influenza surveillance system.

Methodology and Findings

We evaluated the spatial and temporal patterns of laboratory-confirmed influenza cases in Pennsylvania, United States from six influenza seasons (2003–2009). Using a test of spatial autocorrelation, local clusters of elevated risk were identified in the South Central region of the state. Multivariable logistic regression indicated that lower monthly precipitation levels during the influenza season (OR = 0.52, 95% CI: 0.28, 0.94), fewer residents over age 64 (OR = 0.27, 95% CI: 0.10, 0.73) and fewer residents with more than a high school education (OR = 0.76, 95% CI: 0.61, 0.95) were significantly associated with membership in this cluster. In addition, time series analysis revealed a temporal lag in the peak timing of the influenza B epidemic compared to the influenza A epidemic.

Conclusions

These findings illustrate a distinct spatial cluster of cases in the South Central region of Pennsylvania. Further examination of the regional transmission dynamics within these clusters may be useful in planning public health influenza prevention programs.  相似文献   

3.
Species belonging to the Carboniferous genera Lepidodendron and Lepidophloios are well known from the coalfields of Pennsylvania (Lower Asturian (Westphalian D) substage of the Pennsylvanian) through the publications of Lesquereux and White. They believed that the lycophyte flora was rather distinct from other contemporaneous coal floras elsewhere due to its isolation. A full revision of the lepidodendroid lycophyte species is given here and this reassessment permitted comparisons with those floras known from the European and Canadian Maritimes coalfields. Differences in species distribution suggest there was a barrier (Arcadian Highlands) to species distribution to and from the coalfields of Pennsylvania. Several species are recognized only from the coalfields of Pennsylvania, although the number has been significantly reduced from the original publications.  相似文献   

4.
IntroductionThe purpose of this study was to examine county and state-level accidental poisoning mortality trends in Pennsylvania from 1979 to 2014.MethodsCrude and age-adjusted death rates were formed for age group, race, sex, and county for accidental poisonings (ICD 10 codes X40-X49) from 1979 to 2014 for ages 15+ using the Mortality and Population Data System housed at the University of Pittsburgh. Rate ratios were calculated comparing rates from 1979 to 2014, overall and by sex, age group, and race. Joinpoint regression was used to detect statistically significant changes in trends of age-adjusted mortality rates.ResultsRate ratios for accidental poisoning mortality in Pennsylvania increased more than 14-fold from 1979 to 2014. The largest rate ratios were among 35–44 year olds, females, and White adults. The highest accidental poisoning mortality rates were found in the counties of Southwestern Pennsylvania, those surrounding Philadelphia, and those in Northeast Pennsylvania near Scranton.ConclusionsThe patterns and locations of accidental poisoning mortality by race, sex, and age group provide direction for interventions and policy makers. In particular, this study found the highest rate ratios in PA among females, whites, and the age group 35–44.  相似文献   

5.
This paper considers the social forces leading to the establishment of pioneering public health education programs in the United States. Schools of Public Health emerged in the United States as the result of a confluence of factors, including the changing nature of higher education, the development of commerce and industry, the rise to prominence of the science of bacteriology, and the urbanization of the nation, all coupled with a pervasive spirit of utility and a desire to be, in a word, useful. Each line leading to the establishment of five public health institutions at the Massachusetts Institute of Technology, Harvard-M.I.T., Yale, Michigan, and Pennsylvania is explored.  相似文献   

6.
Following its inclusion in Appendix II of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the harvest, sale and trade of wild ginseng (Panax quinquefolius) for international commerce has been restricted by law in Pennsylvania since the late 1980s. Since then, exports from the state have declined driving the need to better understand the impact of CITES listing and related state and federal laws. Between 2004 and 2010, we conducted a mixed-methods study in Pennsylvania of stakeholder perspectives on state and federal government conservation efforts and experiences relating to enforcement of harvest and trade restrictions. Results from a survey, key informant interviews, and facilitated group discussions indicate widespread support for ginseng conservation efforts but, not with the CITES driven, top-down regulatory approach. It was widely asserted that ginseng stewardship has been, and will continue to be, governed by personal experience, family teachings, and industry norms and not CITES driven restrictions per se. Moreover, study participants were unable to cite instances where prosecution for ginseng-related “crimes” had occurred within their networks and most believed laws are an ineffective deterrent to “bad behavior.” This emic is externally validated by the fact that agency enforcement is constrained by limited personnel and jurisdictional boundaries, not least of which is an inability to enforce on private lands in the state. These findings suggest that a CITES driven regulatory approach has limitations in actually conserving wild ginseng in Pennsylvania, and suggests that this approach should be complemented by stakeholder supported “bottom-up” partnerships involving greater stakeholder participation, such as government-sponsored or supported ginseng planting programs to counter over-exploitation by collectors and/or extirpation resulting from habitat loss.  相似文献   

7.
A study of the research on postpartum mother-infant bonding shows that results from poorly constructed research programs were published in major journals and became a part of hospital policy because the bonding concept was politically useful in the struggle between advocates of natural childbirth and managers of the medical model of birth. The concept was also uncritically accepted because it was consistent with a longstanding ideology of motherhood that sees women as the prime architects of their children’s personalities. Diane Eyer earned her Ph.D. in developmental psychology from the University of Pennsylvania. She is currently writing a book on the ways in which the concepts of bonding and attachment have affected our understanding of appropriate early childcare.  相似文献   

8.
Prehistoric Cultures of Eastern Pennsylvania. Jay F. Custer. Harrisburg: Commonwealth of Pennsylvania, Pennsylvania Historical and Museum Commission, 1996. 383 pp.  相似文献   

9.
Summary The Southeastern Cancer Study Group conducted a randomized clinical trial in acute myeloblastic leukemia and the blastic phase of chronic myelocytic leukemia to compare: Two induction programs (Schedule A) cytosine arabinoside and 6-thioguanine or (Schedule B) cytosine arabinoside, 6-thioguanine and daunorubicin; two consolidation programs (Schedule C) continuation of induction programs at a reduced dose or (Schedule D) a combination of cyclophosphamide, methotrexate and vincristine; and two maintenance programs — (Schedule E) 1 month of BCG, followed by methotrexate or (Schedule F) methotrexate. Over a 3 year period 372 patients were entered and 295 were judged evaluable. None of 11 patients with blastic phase of chronic myelocytic leukemia responded. There were no significant differences between the schedules in the number of patients with acute myeloblastic leukemia achieving complete remissions (37%, Schedule A vs. 41% Schedule B). The relapse rates on consolidation were similar (43%, Schedule C and 39%, Schedule D). BCG significantly prolonged the duration of first remission following consolidation (P<0.05) from 13.0–23.9 weeks. Survival was not significantly prolonged (92.7 weeks vs. 71.7 weeks). There were no serious complications from BCG therapy. Contributors. The following members of the Southeastern Cancer Study Group participated in this study: John T. Carpenter, John R. Durant, Richard Gams, William J. Hammack, George A. Omura, Gayle Roberts, University of Alabama School of Medicine, Birmingham, Alabama; Harold Silberman, Donald S. Miller, Duke University School of Medicine, Durham, North Carolina; William B. Kremer, Durham Veterans Administration Hospital, Durham, North Carolina; Evert A. Bruckner, Lawrence E. Cooper, Charles C. Corley, Joseph E. Hardison, Charles M. Huguley, Jr., James Keller, Mason G. Robertson, John D. Schmale, Charles Vogel, W. R. Vogler, William H. Whaley, E. F. Winton, Emory University School of Medicine, Atlanta, Georgia; Chan Kon Chin, Guy Faguet, Claude-Starr Wright, Medical College of Georgia, Augusta, Georgia; Y. S. Ahn, Howard E. Lessner, University of Miami School of Medicine, Miami, Florida; Dov Gorshein, Scott Murphy, Presbyterian University of Pennsylvania Medical Center, Philadelphia, Pennsylvania; William E. Barry, Sharon P. Fischer, Rosaline R. Joseph, Richard V. Smalley, Temple University School of Medicine, Philadelphia, Pennsylvania; Virgil Loeb, Jr., Cary Presant, Edward Reinhard, Shabbir H. Safdar, Washington University School of Medicine, St. Louis, Missouri; Norman Maldonado, Enrique Velez-Garcia, University of Puerto Rico School of Medicine, San Juan, Puerto Rico; S. A. Gregory, William H. Knospe, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois; Stephen Krauss, University of Tennessee Memorial Research Center, Knoxville, Tennessee; Karl Tornyos, New Orleans Veterans Hospital, New Orleans, Louisiana; W. B. Forman, R. W. Kellermeyer, A. Rassiga, Case Western Reserve University School of Medicine, Cleveland, Ohio; William R. Arrowsmith, George Porter, Donald M. Samples, Ochsner Clinic, New Orleans, Louisiana; Lois W. Dow, Charles L. Neely, University of Tennessee School of Medicine, Memphis, Tennessee; G. O. Broun, Jr., St. Louis University School of Medicine, St. Louis, Missouri  相似文献   

10.
Intestinal contents of 41 eastern chipmunks (Tamias striatus) from Armstrong County, Pennsylvania, were examined for the presence of Eimeria spp. Three previously named species were identified: E. lateralis (prevalence = 9%), E. ovata (3%), and E. vilasi (74%); 1 new species, Eimeria tamiensis n. sp. (74%), is described here. This report extends the geographic ranges of the named species into Pennsylvania. Sporulated oocysts of E. tamiensis n. sp. are ovoid and 18.6 x 14.5 (16-23 x 12-17) microm, with no micropyle or residuum. Sporocysts are ellipsoid and 8.6 x 5.4 (7-10 x 4-8) microm. with a Stieda body and granular residuum. Prevalences of E. lateralis and E. vilasi were similar to those reported previously. The differences in prevalences may be due to different life-history strategies of high- and low-prevalence Eimeria species.  相似文献   

11.
This paper demonstrates that although modern BMIs in the US have increased, 19th century BMIs in Philadelphia were lower than elsewhere within Pennsylvania, indicating that urbanization and agricultural commercialization were associated with lower BMIs. After controlling for stature, blacks consistently had greater BMI values than mulattos and whites; therefore, there is no evidence of a 19th century mulatto BMI advantage in the industrializing North. Farmers' BMIs were consistently heavier than those of non-farmers.  相似文献   

12.
Stochastic models of human reproduction are beginning to play significant roles in the evaluation of family planning programs. A class of stochastic processes called absorbing, agedependent, semi-Markov processes frequently arises in the construction of such models. The paper begins with a discussion of some technicalities regarding absorbing, age-dependent, semi-Markov processes. Then, an algorithm due to Littman, which makes possible the computerization of this class of stochastic processes, is presented. Briefly, Littman’s algorithm provides an efficient method for numerically solving systems of renewal type integral equations, provided the system does not contain a large number of equations. After setting down a concrete model for a large clinical trial of intrauterine devices conducted in Taiwan, the paper concludes with a discussion of a method for validating the model based on the data collected in the clinical trial. Presented at the Society for Mathematical Biology Meeting, University of Pennsylvania, Philadelphia, August 19–21, 1976.  相似文献   

13.
In the Commonwealth of Pennsylvania, it is required that all children under the age of 4 years be restrained by an infant seat or car seat appropriate for their age and weight. Furthermore, all individuals riding in the front seat must be restrained by a seatbelt. This study examined the relationship between patterns of facial injuries and the use of restraining devices in the pediatric population. A retrospective analysis was performed on motor vehicle collision data submitted to the Pennsylvania Trauma Outcome Study database from 1990 through 1995. Criteria for submission included trauma patients who were admitted to the Intensive Care Unit, those who died during hospitalization, those who were hospitalized for more than 72 hours, or those who were transferred in or out of the receiving hospital. A subset of 412 pediatric patients, 15 years of age or younger, was analyzed for patterns of facial injury and the presence or absence of restraining devices. Restraining devices were categorized as a car seat or a seatbelt. Statistical analysis was performed using chi-square and Fisher's exact tests. Of the 412 pediatric patients, only 17 children were restrained with a car seat and 121 were wearing a seatbelt. A total of 30 children sustained facial fractures, and 50 children suffered facial lacerations. There was a statistically significant increase in the incidence of facial fractures with increasing age of the child (p < 0.001). Of children with facial fractures, 70 percent of those 5 to 12 years old and 90 percent of those 13 to 15 years old were unrestrained (p = 0.166). In conclusion, despite legislation mandating the use of restraints, a large proportion of children involved in motor vehicle collisions were unrestrained. Furthermore, there seems to be a direct relationship between the age of a child and the incidence of facial fractures sustained in motor vehicle collisions.  相似文献   

14.
In recent decades, the Asian tiger mosquito expanded its geographic range throughout the northeastern United States, including Pennsylvania. The establishment of Aedes albopictus in novel areas raises significant public health concerns, since this species is a highly competent vector of several arboviruses, including chikungunya, West Nile, and dengue. In this study, we used geographic information systems (GIS) to examine a decade of colonization by Ae. albopictus throughout Pennsylvania between 2001 and 2010. We examined the spatial and temporal distribution of Ae. albopictus using spatial statistical analysis and examined the risk of dengue virus transmission using a model that captures the probability of transmission. Our findings show that since 2001, the Ae. albopictus population in Pennsylvania has increased, becoming established and expanding in range throughout much of the state. Since 2010, imported cases of dengue fever have been recorded in Pennsylvania. Imported cases of dengue, in combination with summer temperatures conducive for virus transmission, raise the risk of local disease transmission.  相似文献   

15.
We collected grape berry moth, Endopiza viteana (Clemens) (from cultivated and wild Vitis along Lake Erie in Pennsylvania and New York), and measured carbaryl susceptibility in first instars. A model of susceptibility was based on the concentration-mortality curve of laboratory-maintained colonies originating from wild Vitis with no prior history of carbaryl exposure, and a noncommercial vineyard with modest previous exposure to carbaryl. We estimated LC50 and LC90 for susceptible grape berry moth larvae at 45.4 and 2319 microg/ml, respectively. Bioassays on field-collected larvae from commercial vineyards in both states, where grape growers were abiding by current pest management guidelines for carbaryl use, revealed carbaryl resistance ratios from 7 to 71 at the LC50 level. With the loss or restriction of alternative chemical control tactics in the Food Quality Protection Act era, resistance management programs for grape berry moth should be immediately developed and implemented to regain the efficacy of this once effective insecticide and other related chemical compounds.  相似文献   

16.
Giving between generations in American families   总被引:4,自引:0,他引:4  
This paper documents the types and amounts of aid exchanged between adults and their non-coresidential parents. Data for the study are drawn from a representative national sample survey of Americans age 19 and older conducted in 1987–1988. Exchanges of monetary and material resources, childcare, household assistance, and companionship and advice are considered. Patterns of intergenerational exchange are found to differ by gender, family structure, age, ethnicity, and socioeconomic situation. Differences in exchange between males and females and between whites and Mexican-Americans are related to other life-course characteristics, and to the availability and proximity of kin. Blacks and persons living in poverty are shown to be less involved than other groups in intergenerational exchanges. Finally, patterns of prior assistance and the available needs and resources of the respondents and their parents are found to influence current patterns of exchange. Support for this research was provided by NICHD Grant No. 1 R01 HD26070-01, “Intergenerational Exchanges in Families with Children,” Dennis P. Hogan, Principal Investigator. Funds for the computer analysis were provided by the Pennsylvania State University Intercollege Research Programs. David Eggebeen is an Assistant Professor of Human Development in the Department of Human Development and Family Studies and a research associate at the Population Issues Research Center at Pennsylvania State University. He trained in sociology and demography at the University of North Carolina. His current research interests, besides those related to intergenerational relations, are the recent changes in the demographic structure of childhood in America and their implications for children’s social and economic well-being. Dennis P. Hogan is a professor of sociology and the director of the Population Issues Research Center at Pennsylvania State University. His current research interests, besides those related to intergenerational relations, are in the interrelation of social structures and the demographic life course. He is coauthor with David I. Kertzer ofFamily, Political Economy, and Demographic Change: The Transformation of Life in Casalecchio, Italy, 1861–1921, University of Wisconsin Press, 1989.  相似文献   

17.
The northern walkingstick, Diapheromera femorata (Say), is the only stick insect of economic importance native to the United States. Young nymphs feed on various understory shrubs and trees whereas older nymphs and adults prefer oaks and cherries. Occasionally, field populations reach outbreak levels and cause complete tree defoliation. Widespread damage rarely occurs except those reported from Michigan (1930–1960), Wisconsin (1950–1960) and Arkansas and Oklahoma (1960–1975) where thousands to tens of thousands of hectares of trees were affected. The most recent infestations were detected in Arkansas, Maryland, and Pennsylvania with severe damage observed in localized areas. The morphology, life stages, host species, damage, biology, life history, natural enemies and management of this insect were reviewed. Host preference and insect predation were confirmed in Pennsylvania. Other notable stick insects in the United States and economically important species around the world are discussed to raise awareness about the ecological impacts of this understudied group of mostly nocturnal herbivores.  相似文献   

18.
Samples of tongue or diaphragm from 2,056 black bears harvested in Pennsylvania during the 1981-1983 hunting seasons were examined for larvae of Trichinella spiralis by peptic digestion. Sixteen males and 21 females were infected. The overall prevalence of infection was 1.8%. Infected animals were distributed widely throughout the range of the bear in Pennsylvania. In samples from infected bears, the geometric mean density of muscle larvae was 7.8 per g of tissue (LPG). There were neither sex- nor age-related differences in prevalence or intensity of infection. Virtually all bears harvested in Pennsylvania are consumed as food, which often is shared widely among hunters, their friends and relatives. Furthermore, high densities of larvae occurred in some bears (i.e., 300, 348, 465, 512, 555, and 912 LPG). Thus, a basis for potential, single-source outbreaks of severe human trichinosis exists.  相似文献   

19.
In Pennsylvania the production of game and other fish species is a $1.6 billion industry, and loss from depredation can take a serious toll on fish stocks and associated revenues. Following a reintroduction project and natural expansion of native populations, river otters (Lontra canadensis) are now widely distributed throughout Pennsylvania. To determine occurrence and extent of depredation by river otters, we conducted telephone or mail surveys with 156 (80%) of Pennsylvania’s 196 fish-rearing facilities. River otters were reported in the vicinity of 50 (32%) facilities, of which 23 (46%) reported river otter visitation. Of the facilities that reported river otter visitation, most (87%) reported losing <5% of fish stock to otters and 91% reported an annual economic loss of <$500 from river otter depredation. Binary logistic regression determined that greater amounts of tree cover (%), facilities that reared >100,000 fish annually, and private facilities were more likely to experience visitation by river otters. Our results demonstrate that the existence of river otter populations in Pennsylvania does not appear to be a significant economic threat to fish-rearing facilities and physical and landscape characteristics of the facilities are important in determining the likelihood of river otter visitation.  相似文献   

20.
White-tailed deer (Odocoileus virginianus (Zimmermann) shot within 20 km of the zinc smelters in the Palmerton, Pennsylvania area contained extremely high renal concentrations of cadmium (372 ppm dry weight (dw] and zinc (600 ppm dw). The deer with the highest renal zinc concentration was shot 4 km from the smelters and had joint lesions similar to those seen in zinc-poisoned horses from the same area. The highest concentrations of lead in both hard and soft tissues were relatively low, 10.9 ppm dw in a sample of teeth, 17.4 ppm dw in a metacarpus, and 4.9 ppm dw in a kidney.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号