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PubMed2001

The use of the Index of Orthodontic Treatment need (IOTN) in a school population and referred population.

The aim of this study is to assess the need for orthodontic treatment in a Turkish school population and a group of population referred for orthodontic treatment. The study groups were 250 school children, 11-14 years of age, and 250 patients, 11-14 years of age, referred to the department of orthodontics. The Index of Orthodontic Treatment Need (IOTN) was used by two examiner in order to estimate the treatment need. The differences between the IOTN values for the boys and girls were also not statistically significant in both groups. When the dental health component of IOTN is considered, 38.8 per cent of Turkish school population showed great need treatment, 24.0 per cent moderate need treatment and slight or no need was 37.2 per cent. On the other hand, the referred population represented an 83.2 per cent great need treatment, 12.0 per cent moderate need treatment, 4.8 per cent no need treatment according to the DHC. The AC of IOTN in school population resulted in 4.8 per cent great need, 4.8 per cent moderate need, 90.4 per cent no need. These percentage were 36.8 per cent great need, 17.6 per cent moderate need, 45.2 per cent no need in referred population. Grade 8 was 28.8 per cent out of the 36.8 per cent great need percentage in referred population. Therefore, it can be concluded that the ectopic canines were the driving factor for the referred population.

Adolescent↗
PubMedDate not supplied

Teaching nurses to focus on the health needs of populations: a Master's Degree Program in Population Health Nursing.

Responding to the mandate to prepare nurses for practice in population-based healthcare, the faculty at Cleveland State University (CSU) developed a unique Master of Science in Nursing program to prepare Population Health Nurse Experts. The program prepares nurses to examine the health status of populations and to design, implement, and evaluate nursing interventions accounting for the varied factors impacting on the health of a defined group. The speciality of population health nursing is practiced by nurses who can use population sciences (epidemiology, demography, population projections, and population behavioral theories) along with post-baccalaureate nursing competencies to work with defined populations across care environments. The authors discuss a curriculum that prepares nurses for this emerging speciality.

Community Health Planning↗
PubMed2006

Prevalence and correlations of lower urinary tract symptoms, erectile dysfunction and incontinence in men from a multiethnic Asian population: Results of a regional population-based survey and comparison with industrialized nations.

OBJECTIVE: To determine, in a population-based survey, the prevalence of lower urinary tract symptoms (LUTS), erectile dysfunction (ED) and incontinence in community-dwelling men in multiethnic Malaysia, as currently available Western demographic data might not be applicable in the Asian population. SUBJECTS AND METHODS: A cross-sectional population-based survey was carried out in the State of Penang, Malaysia, with a target population of men aged > or = 40 years. Using a multistage study design, random systematic sampling was used to represent the target population, who were weighted based on ethnicity and rural-urban ratios so as to represent the general population distribution. Trained field-workers conducted direct interviews and administered the American Urological Association Symptom Index (AUA-SI), the International Index of Erectile Function (IIEF-5) questionnaire and questions on incontinence based on the International Continence Society 2002 definition. RESULTS: In all, 418 men aged > or = 40 years were interviewed, of whom 353 completed the AUA-SI questionnaire (84.5% response rate). The prevalence of mild, moderate and severe LUTS was 80.6%, 6% and 0.3%, respectively. The prevalent symptoms were frequency and nocturia. There was moderate and severe ED in 45.9% of men, whereas incontinence was reported by 8.2%. The AUA-SI correlated strongly with age (R = 0.291, P < 0.001), IIEF-5 (R = - 0.265, P < 0.001) and diabetes mellitus. CONCLUSION: The prevalence and severity of LUTS, ED and incontinence increased with age in this multiethnic Asian population, in which ED correlated strongly with LUTS. Compared to the Western population, the prevalence of LUTS was significantly lower, while the prevalence of ED and incontinence were comparable.

Adult↗
PubMed1998

Performance of screening instruments for identifying alcohol dependence in the general population, compared with clinical populations.

Screening instruments for problem drinking have been developed in clinical populations, and little is known of their performance in the general population. Sensitivity and specificity of the CAGE and the TWEAK for ICD-10 and/or DSM-IV criteria for alcohol dependence are compared among those sampled from the southern region in the 1995 National Alcohol Survey (n = 776), and from emergency room (ER) (n = 1327) and primary care clinic (n = 767) samples in Jackson, MS. Sensitivity of the CAGE was higher in both the ER (85%) and primary care (82%) samples than in the general population (75%), although differences were not significant, and this held for males and females alike. Sensitivity of the TWEAK was lower in the general population sample (83%) than in the ER sample (89%), but higher than in the primary care sample (75%). In the general population, sensitivity of both screeners was better (although not significantly so) among those making an ER or primary care visit during the last year than among those not doing so, with the largest difference found for the CAGE (85% vs. 65%, respectively). In a merged sample of the three sites, the interaction of site by screening instrument was not a significant predictor of alcohol dependence for either the CAGE or TWEAK. Data suggest that screening instruments may not perform as well in the general population as in some clinical populations, with more variation apparent across groups for some screeners than for others. Although further analysis is necessary to explore this issue further, attention should be given to selection of the best instrument for use in a given population.

Adolescent↗
PubMed2000

A population pharmacokinetic model for vancomycin in pediatric patients and its predictive value in a naive population.

The objectives of this study were to (i) construct a population pharmacokinetic (PK) model able to describe vancomycin (VAN) concentrations in serum in pediatric patients, (ii) determine VAN PK parameters in this population, and (iii) validate the predictive ability of this model in a naive pediatric population. Data used in this study were obtained from 78 pediatric patients (under 18 years old). PK analyses were performed using compartmental methods. The most appropriate model was chosen based on the evaluation of pertinent graphics and calculation of the Akaike information criterion test. The population PK analysis was performed using an iterative two-stage method. A two-compartment PK model using age, sex, weight, and serum creatinine as covariates was determined to be the most appropriate one to describe serum VAN concentrations. The quality of fit was very good, and the distribution of weighted residuals was found to be homoscedastic (Wilcoxon signed rank test). Fitted population PK parameters (mean +/- standard deviation) were as follows: central clearance (0.1 +/- 0.05 liter/h/kg), central volume of distribution (0.27 +/- 0.07 liter/kg), peripheral volume of distribution (0.16 +/- 0.07 liter/kg), and distributional clearance (0.16 +/- 0.07 liter/kg). The predictive ability of the developed model (including the above-mentioned covariates) was evaluated in a naive population of 19 pediatric patients. The predictability was very good. Precision (+/-95% confidence interval [CI]) (peak, 4.1 [+/-1.4], and trough, 2.2 [+/-0.7]) and bias (+/-95% CI) (peak, -0.58 [+/-2.2], and trough, 0.63 [+/-1.1] mg/liter) were significantly (P < 0.05) superior to those obtained using a conventional method (precision [+/-95% CI]: peak, 8.03 [+/-2. 46], and trough, 2.7 [+/-0.74]; bias: peak, -7.1 [+/-2.9], and trough, -1.35 [+/-1.2] mg/liter). We propose the use of this population PK model to optimize VAN clinical therapies in our institution and others with similar patient population characteristics.he object

Adolescent↗
PubMed2005

Population coding of self-motion: applying bayesian analysis to a population of visual interneurons in the fly.

Coding of sensory information often involves the activity of neuronal populations. We demonstrate how the accuracy of a population code depends on integration time, the size of the population, and noise correlation between the participating neurons. The population we study consists of 10 identified visual interneurons in the blowfly Calliphora vicina involved in optic flow processing. These neurons are assumed to encode the animal's head or body rotations around horizontal axes by means of graded potential changes. From electrophysiological experiments we obtain parameters for modeling the neurons' responses. From applying a Bayesian analysis on the modeled population response we draw three major conclusions. First, integration of neuronal activities over a time period of only 5 ms after response onset is sufficient to decode accurately the rotation axis. Second, noise correlation between neurons has only little impact on the population's performance. And third, although a population of only two neurons would be sufficient to encode any horizontal rotation axis, the population of 10 vertical system neurons is advantageous if the available integration time is short. For the fly, short integration times to decode neuronal responses are important when controlling rapid flight maneuvers.

Animals↗
PubMed2006

[Population genetic variation and structure analysis on five populations of mirror carp Cyprinus carpio L. using microsatellites].

In this paper, population genetic variability and genetic structure of five populations of an important cultivation species, mirror carp (Cyprinus carpio L.) were analyzed using 30 microsatellite loci. The observed (Ho) and expected (He) heterozygosity values, polymorphic information content (PIC) and number of effective alleles (Ae) were all determined. The genetic similarity coefficient and Nei's standard genetic distance were computed based on the allele frequencies. The Hardy-Weinberg equilibrium was checked by chi2 test. Genetic differentiation and hierarchical partition of genetic diversity were evaluated by FST and Nm. A dendrogram was constructed based on UPGMA methods using PHYLIP software package supported by a bootstrap value of 91.0%. Totally 7,083 fragments were procured. Their lengths were from 102 bp to 446 bp. For each locus, 1-16 alleles were amplified, adding up to 356 alleles in all the 5 populations. We found the genetic variability level was relatively high in all five populations, as shown by Ae = 1.07-2.30, He= 0.70-0.78 and PIC=0.69-0.75, respectively. The genetic similarity coefficients were all above 0.52, indicating their close genetic relationships. The UPGMA phylogenetic tree showed mirror carps sampled from Donggang, Fengcheng and Liaozhong were clustered into one group and the other two populations, both collected from Songpu, were grouped together. There were obvious relations between genetic distances and geographical distributions of the five populations. No fragments were amplified from some loci of EST-SSRs, which may suggest the loss of these loci in mirror carp genome or sequence divergence at the primer binding sites. These null alleles may result from selection because functional genes are under more selection pressure than non-encoding loci. Overall, population genetic variation is high for each of the five mirror carp, and the differentiations are also significant among populations.

Alleles↗
PubMed2000

Understanding population history for conservation purposes: population genetics of Saxifraga aizoides (Saxifragaceae) in the lowlands and lower mountains north of the Alps.

Several alpine species have outlying populations in the lowlands and lower mountains north of the Alps. These small, isolated populations are usually described as either (1) glacial relics, (2) descendants from populations living on forelands and moraines during the ice ages, or (3) populations founded by long-distance dispersal after glaciation. A floristic survey of the historic and present distributions and an allozyme investigation were performed on one of these relic species, Saxifraga aizoides. The species was historically more abundant and had more stations in more regions of northeastern Switzerland. The former population structures within regions, nowadays destroyed, were still reflected in distinct and high regional genetic diversity and variation. There was weak evidence of increased inbreeding in outlying populations, but populations did not deviate from Hardy-Weinberg equilibrium. No geographic pattern of genetic variation above the regional scale (>10 km) was found. Based on the spatial and genetic structures found, it was not possible to discriminate between the abovementioned hypotheses. Nevertheless, the study shows how a thorough evaluation of distribution and abundance data aids the interpretation of genetic data with respect to population history, biogeography, and conservation biology.

Journal Article↗
PubMed2003

Distinct populations of forebrain neural stem and progenitor cells can be isolated using side-population analysis.

The absence of stem cell-specific markers has posed challenges to the identification and isolation of stem cells. We report the isolation of a discrete and highly enriched population of neural stem cells from clonally derived colonies of neural stem cell and progenitor cells (neurospheres) after exposure to the fluorescent DNA binding dye Hoeschst 33342 and subsequent analysis via dual wavelength flow cytometry. The low fluorescent side population comprised only 3.6% of all live cells sorted yet contained >99% of all the neural stem cells as assayed by the formation of neurospheres in culture. Most neurosphere-derived cells are progenitor cells, and these are found within the higher fluorescence (non-side population) fraction. The isolation of a highly enriched population of self-renewing, multipotential neural stem cells was seen from both adult- and embryonic-derived neurospheres; however, the relative percentage of cells comprising the side-population and the mechanism of dye efflux varied between adult and embryonic donor tissue. Combining the side-population analysis with markers recently shown to enrich for neural stem cells afforded no further enrichment in the case of peanut agglutinin expression and size criteria; however, when the side-population analysis was combined with Lewis X (LeX) expression, a slight enrichment was seen over side-population analysis alone.

Animals↗
PubMed2004

Comparison between the Polish population and European populations on the basis of mitochondrial morphs and haplogroups.

Polymorphisms in mitochondrial DNA (mtDNA) were analyzed in 152 samples from the Polish population using restriction enzymes AvaI, BamHI, HaeII, HpaI and PstI. Additionally, each sample was classified into the appropriate haplogroup. When required, appropriate fragments were sequenced to establish the exact polymorphic sites. We found one new morph for PstI and six new morphs for AvaII. Some detected morphs have previously been described as population specific morphs in different regions of the world. All polymorphisms were classified into 31 different haplotypes. 21 of them were detected in single individuals. The Polish population was compared with other populations from different regions. Moreover, we have obtained evidence for mutation hot spots in the mtDNA coding region. Our results indicate that AvaII morph and haplogroup composition of the Polish population is similar to other European populations and has a distribution typical for this part of the world. However, statistically significant differences in haplogroup composition were found between the Polish population and Italian and Finnish populations.

DNA, Mitochondrial↗
PubMed1985

[Population genetics of taiga hunters-deer breeders. Characteristics of the prevalence of HLA system markers among the native population of Central Siberia].

The postulated peculiarities of distribution of the HLA antigens in the Evenk population of the Central Siberia indicate this population to be, on the whole, Mongoloid. Prolonged isolated existence of small inbred populations of the Evenks resulted in the number of specific HLA-complex features, such as poor antigen diversity, low level of heterozygosity. Non-homogeneity of gene frequencies was noted, the prevailing genes being A9, B40 with frequencies reaching 50%. Of the remaining alleles found in the Evenks A2, Aw19 in A locus, B5, B15, B17, B27, Bw35 in B locus and Cw2, Cw3, Cw4-in C locus are only widely spread. Similar heterozygosis levels and the HLA-system profiles draw the Evenks and the populations of American Indians and Eskimos closer to one another. On the basis of the fact that significant positive correlation exists between genetic and geographic distances determined for the Evenks and the native populations of America, genetic resemblance of these populations may be considered as evidence for their original relationship. Postulated closeness of native Central-Siberian populations to Americanoids, as regards HLA-system, makes it possible to consider formation of specific complex of HLA-system peculiarities in native American population in the light of their Siberian origin, for the first time.

Animal Husbandry↗
PubMed1995

Population genetics of dinucleotide (dC-dA)n.(dG-dT)n polymorphisms in world populations.

We have characterized eight dinucleotide (dC-dA)n.(dG-dT)n repeat loci located on human chromosome 13q in eight human populations and in a sample of chimpanzees. Even though there is substantial variation in allele frequencies at each locus, at a given locus the most frequent alleles are shared by all human populations. The level of heterozygosity is reduced in isolated or small populations, such as the Pehuenche Indians of Chile, the Dogrib of Canada, and the New Guinea highlanders. On the other hand, larger average heterozygosities are observed in large and cosmopolitan populations, such as the Sokoto population from Nigeria and German Caucasians. Conformity with Hardy-Weinberg equilibrium is generally observed at these loci, unless (a) a population is isolated or small or (b) the repeat motif of the locus is not perfect (e.g., D13S197). Multilocus genotype probabilities at these microsatellite loci do not show departure from the independence rule, unless the loci are closely linked. The allele size distributions at these (CA)n loci do not follow a strict single-step stepwise-mutation model. However, this features does not compromise the ability to detect population affinities, when these loci are used simultaneously. The microsatellite loci examined here are present and, with the exception of the locus D13S197, are polymorphic in the chimpanzees, showing an overlapping distribution of allele sizes with those observed in human populations.

Alleles↗
PubMed1996

Population data on the loci LDLR, GYPA, HBGG, D7S8, and GC in three southwest European populations.

Three Southwest European populations: Galicia (NW Spain), a mixed Spanish population from the rest of Spain (outside Galicia), and a population sample from the Coimbra area (Centre of Portugal) have been studied for the Low Density Lipoprotein Receptor (LDLR), Glycophorin A (GYPA), Hemoglobin G Gammaglobin (HBGG), D7S8 and Group Specific Component (GC). The allele and genotype frequencies found have been compared with other previously published data. All loci meet Hardy-Weinberg expectations in the three sampled populations. There was no evidence of association in any of the three population samples, between the five loci studied. No significant differences were found with Caucasian populations, nevertheless, significant differences were observed between our three population studies and the US SW Hispanic and African populations. The AmpliType PM DNA test greatly facilitates DNA testing in forensic laboratories, providing quick results and a good discrimination power from a single test.

DNA↗
PubMed1997

Study of a trimeric tandem repeat locus (SBMA) in the Basque population: comparison with other populations.

Microsatellites can be highly unstable and show a high level of polymorphism between individuals. Here we present the analysis of the CAG trinucleotide repeat polymorphism at the SBMA locus in 57 phenotypically normal individuals rigorously assigned to the Spanish Basque population. Results are compared with 100 Spanish non-Basque individuals who were already analyzed by us (175 alleles). This is the first study undertaken in these populations for this marker. In addition, we compared our results with those published for other populations. Relative allele frequencies showed differences between the samples and no unimodal distribution. The expected heterozygosity in the Basque sample was slightly lower than in the non-Basque sample. Conformity with Hardy-Weinberg equilibrium was verified by three tests. When compared with published data, the predominant alleles appear to be the same in the various populations. There are more differences between Basques and other Caucasoid samples than between non-Basques and Caucasoid samples. Population relationships were also examined by dendrograms based on genetic distances. The results obtained showed some peculiarities in the Basque population. The high degree of similarity with other dendrograms based on different markers and the efficiency of this STR marker in differentiating closely related populations, support the potential usefulness of microsatellites as tools for human population studies.

Ethnicity↗
PubMed2003

Multiple paternity and population genetic structure in natural populations of the poeciliid fish, Heterandria formosa.

Heterandria formosa Agassiz, exhibits internal fertilization, internal brooding of embryos, sperm storage and an extreme level of superfetation. In this study we used microsatellite markers to examine variation among seven populations that exhibited significant variance in their histories of population density. We found that the populations were genetically distinct and that the heterozygosity increased as population density increased. We also examined paternity in three of those populations and found that the number of sires per female and the number of sires per brood increased with population density. Overall, the rates of multiple paternity are quite low relative to other species. The correlations with population density suggest that contact rates play a critical role in the breeding system in this species but the low rates of multiple paternity suggest that females may exert control over fertilization of their ova.

Animals↗
PubMed2004

Heterozygote excess in small populations and the heterozygote-excess effective population size.

It has been proposed that effective size could be estimated in small dioecious population by considering the heterozygote excess observed at neutral markers. When the number of breeders is small, allelic frequencies in males and females will slightly differ due to binomial sampling error. However, this excess of heterozygotes is not generated by dioecy but by the absence of individuals produced through selfing. Consequently, the approach can also be applied to self-incompatible monoecious species. Some inaccuracies in earlier equations expressing effective size as function of the heterozygote excess are also corrected in this paper. The approach is then extended to subdivided populations, where time of sampling becomes crucial. When adults are sampled, the effective size of the entire population can be estimated, whereas when juveniles are sampled, the average effective number of breeders per subpopulations can be estimated. The main limitation of the heterozygote excess method is that it will only perform satisfactorily for populations with a small number of reproducing individuals. While this situation is unlikely to happen frequently at the scale of the entire population, structured populations with small subpopulations are likely to be common. The estimation of the average number of breeders per subpopulations is thus expected to be applicable to many natural populations. The approach is straightforward to compute and independent of equilibrium assumptions. Applications to simulated data suggest the estimation of the number of breeders to be robust to mutation and migration rates, and to specificities of the mating system.

Biological Evolution↗
PubMed1999

Stable stroke occurrence despite incidence reduction in an aging population: stroke trends in the danish monitoring trends and determinants in cardiovascular disease (MONICA) population.

BACKGROUND AND PURPOSE: A stroke register was established at the Glostrup Population Studies in 1982 with the objective to monitor stroke occurrence in the population continuously during a 10-year period and contribute data to the WHO Monitoring Trends and Determinants in Cardiovascular Disease (MONICA) Project. The purpose of the current analysis was to estimate temporal trends in stroke occurrence. METHODS: All stroke events in the study population were ascertained and validated according to standardized criteria outlined by the WHO MONICA Project. The study population comprised all subjects > or = 25 years of age. Stroke was defined by the clinical presentation. A total of 5262 stroke events in >2 million person-years were analyzed. Age-adjusted rates for first-ever stroke and for all stroke events were calculated and temporal trends estimated by means of Poisson regression. RESULTS: The overall annual stroke attack rate per 100,000 person-years in the age range > or = 25 years was 272 in men and 226 in women. Age-adjusted stroke attack rates decreased among men by 3.9% per year and by 4.1% among women. Age-adjusted stroke incidence rates declined by 2.9% in men and by 3. 1% in women. The trends were statistically significant in both sexes. However, the proportion of elderly people in the study population increased during the time period of the study. Hence the numbers of stroke victims in the population remained largely unaltered. CONCLUSIONS: Decreasing age-adjusted stroke incidence rates point to a reduction of stroke risk during the time period of the study. Cardiovascular prevention, in particular improved hypertension control, is believed to have contributed to the incidence reduction. However, the burden of stroke on the healthcare system did not substantially diminish. The gain likely achieved from reduction of preventable risk factors was almost counterbalanced by population aging.

Adult↗
PubMed1997

Population control II: The population establishment today.

Although population assistance represents a relatively small share of official development assistance, it influences many other aspects of development planning. The organizations that comprise the population establishment have a common purpose--the reduction of population growth in the Third World--but they are not homogeneous and sometimes have conflicting goals and strategies. National governments, multilateral agencies, nongovernmental organizations, foundations, academic centers, and pressure groups all contribute to creating and sustaining what has become a virtual population control industry. Through scholarships, travel grants, awards, and favorable publicity, Third World elites have been encouraged to join the population establishment. The World Bank, the U.S. Agency for International Development, and the U.N. Fund for Population Activities have pursued explicit strategies for pressuring Third World governments to design and implement population policies, most recently in Africa.

Coercion↗