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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The Accuracy of Prevalence Estimations for Suicide Attempts. How Reliably Do Adolescents and Young Adults Report Their Suicide Attempts?

Christl, Bettina, Wittchen, Hans-Ulrich, Pfister, Hildegard, Lieb, Roselind, Bronisch, Thomas January 2006 (has links)
This study explores the accuracy of prevalence estimations for suicide attempts. Data came from the Early Developmental Stages of Psychopathology (EDSP) Study, a prospective community study (mean follow-up period was 42 months) of 3,021 respondents aged 14 to 24 years at the outset of the study. Suicide attempters are at least 1.6 times more likely to drop out than subjects with no suicide attempts and suicidal ideas. A total of 8% of all suicide attempters answered in the negative the depression-related gate questions of all surveys. One-third of all baseline suicide attempters did not report their suicide attempt again at the four years later assessment. In particular, 80% of all nonreporters were female, and almost 60% were aged 14–17 at baseline.
22

Retrospective epidemiological study of vesivirus prevalence and natural transmission in cattle and horses in the USA / Retrospektiv-epidemiologische Studie zur Prävalenz und natürlichen Übertragung von Vesiviren bei Rindern und Pferden in den USA

Kurth, Andreas 29 June 2004 (has links) (PDF)
Screening of cattle sera: distribution of vesiviruses in terrestrial domestic animals. To broaden the knowledge of vesivirus occurrence and distribution dynamics in domestic livestock, we attempted the first extensive study in cattle to assess the distribution of vesiviruses by examining the seroprevalence. Cattle were chosen to be studied here, because this livestock is well characterized, they are suffering diseases with high percentages of unknown aetiologies and extensive animal data are available. Furthermore, several case reports exist on the isolation of vesiviruses from cattle. The objective was to evaluate the distribution of vesiviruses in cattle, correlate vesivirus infection with disease manifestations and estimate the possible impact on other animals and humans. Roughly seven hundred bovine sera from nine States within the United States were acquired and were tested for antibodies against vesiviruses. The sera tested were drawn from a total population of about 9 million cattle in nine States with a geographical distribution ranging from northern Alaska to tropical Hawaii. Screening of horse sera and tissue: correlation of vesivirus prevalence and mare reproductive loss syndrome (MRLS)? A newly emerged disease in horses was analyzed in the second half of this research project. Since all tests for the common toxic abortogenic agents had failed, a further nationwide investigation was initiated for uncommon and unknown infectious agent(s). Caliciviruses, and vesiviruses in particular, are a well established cause of abortion in swine and seals. Nevertheless, these viruses are not routinely tested for or diagnosed. When the Laboratory for Calicivirus Studies at Oregon State University was asked for specific help in this investigation, pertinent seroepidemiological studies were entrusted to me under the guidance of Professor Dr. Alvin W. Smith. After the first serological examination of equine blood samples from mares that had aborted in 2001 and an equal number of sera from unaffected animals from 2000 were examined, tissue samples from aborted fetuses and two other sets of blood samples from ETC-exposed mares from two experiments were acquired. These have been tested for vesivirus-antibodies and antigen. Furthermore, additional samples of ETC were tested for vesiviruses by RT-PCR.
23

Retrospective epidemiological study of vesivirus prevalence and natural transmission in cattle and horses in the USA

Kurth, Andreas 23 July 2004 (has links)
Screening of cattle sera: distribution of vesiviruses in terrestrial domestic animals. To broaden the knowledge of vesivirus occurrence and distribution dynamics in domestic livestock, we attempted the first extensive study in cattle to assess the distribution of vesiviruses by examining the seroprevalence. Cattle were chosen to be studied here, because this livestock is well characterized, they are suffering diseases with high percentages of unknown aetiologies and extensive animal data are available. Furthermore, several case reports exist on the isolation of vesiviruses from cattle. The objective was to evaluate the distribution of vesiviruses in cattle, correlate vesivirus infection with disease manifestations and estimate the possible impact on other animals and humans. Roughly seven hundred bovine sera from nine States within the United States were acquired and were tested for antibodies against vesiviruses. The sera tested were drawn from a total population of about 9 million cattle in nine States with a geographical distribution ranging from northern Alaska to tropical Hawaii. Screening of horse sera and tissue: correlation of vesivirus prevalence and mare reproductive loss syndrome (MRLS)? A newly emerged disease in horses was analyzed in the second half of this research project. Since all tests for the common toxic abortogenic agents had failed, a further nationwide investigation was initiated for uncommon and unknown infectious agent(s). Caliciviruses, and vesiviruses in particular, are a well established cause of abortion in swine and seals. Nevertheless, these viruses are not routinely tested for or diagnosed. When the Laboratory for Calicivirus Studies at Oregon State University was asked for specific help in this investigation, pertinent seroepidemiological studies were entrusted to me under the guidance of Professor Dr. Alvin W. Smith. After the first serological examination of equine blood samples from mares that had aborted in 2001 and an equal number of sera from unaffected animals from 2000 were examined, tissue samples from aborted fetuses and two other sets of blood samples from ETC-exposed mares from two experiments were acquired. These have been tested for vesivirus-antibodies and antigen. Furthermore, additional samples of ETC were tested for vesiviruses by RT-PCR.
24

Experimental Host-Parasite Co-Evolution in a Changing Environment / Experimentelle Parasit-Wirt Co-Evolution in einer sich verändernden Umwelt

Dusi, Eike 31 March 2016 (has links) (PDF)
Parasites with exclusive vertical transmission from host parent to offspring are an evolutionary puzzle. Any fitness costs for infected hosts risk the selective elimination of these parasites because their fitness is linked to host reproduction. One of the main evolutionary transitions from parasitism towards beneficial or mutualistic associations may therefore encompass a change from horizontal transmission to vertical transmission. In this thesis, the experimental evolution study on Paramecium and Holospora supports this hypothesis. The parasite nearly entirely lost horizontal transmission capacity in a treatment favouring vertical transmission and low virulence. However, many vertically transmitted parasites e.g. Caedibacter taeniospiralis impose detectable costs to their hosts. This endosymbiont imposes context-dependent costs to its host Paramecium tetraurelia. Fitness of infected paramecia was reduced in resource-limited conditions at all experimentally tested temperatures (16-32°C). These universal fitness costs along the temperature gradient necessitate universal cost compensation that can be the ‘killer trait’ that eliminates uninfected competitors. At acute heat stress the loss of infection indicates that cost compensation is impossible, thereby restricting conditions for parasite persistence. Surprisingly, the parasite persists in permanent stress and optimal temperature conditions. Caedibacter was able to adapt to high temperature conditions by increasing its number in the populations but without reducing virulence in high temperature conditions. Acute and intense stress harms the parasite and causes its extinction but the parasite was able to evolve and adapt to stress conditions. Moreover, the parasite reacts exactly in the opposite direction as it was expected. They do not suffer from stressful conditions, they benefit.
25

Prävalenz und Risikofaktoren von Eisenmangel bei jungen Müttern

Wagener, Iris Elisabeth 02 February 2001 (has links)
Lebensqualität und Leistungsfähigkeit werden durch einen unbemerkten Eisenmangel beeinträchtigt. Frauen im gebärfähigen Alter haben einen erhöhten Eisenbedarf, der in der Schwangerschaft noch zunimmt. Ziel der Untersuchung war, die Prävalenz von Eisenmangel bei Müttern unter deutschen Lebensbedingungen zu evaluieren. Der Eisenstatus von 507 Müttern wurde zwischen September 1997 und August 1998 untersucht. Datenquellen waren venöse Blutentnahme und Fragebogen. Neben konventionellen Messgrößen wurde eine erhöhte Konzentration des löslichen Transferrinrezeptors als Leitindikator für einen Eisenmangel verwendet. Bei 9,5 % der Mütter besteht ein zellulärer Eisenmangel, eine Eisenmangelanämie bei nur 2,2 % aller Mütter. Abgesehen von fehlendem Einsetzen der Menstruation ein Jahr post partum, sind rein vegetarische Ernährung, Multiparität und nicht deutsche Nationalität Risikofaktoren für einen Eisenmangel. Assoziiert mit geringen mütterlichen Hämoglobinkonzentrationen sind Body-Mass-Index unter 19,8, Alter unter 25 Jahren, fehlende Berufsausbildung und hohes Geburtsgewicht des Kindes. Alkoholkonsum und Rauchen scheinen vor Eisenmangel und Anämie zu schützen. Kinder von Müttern mit unzureichender Eisenversorgung neigen ebenfalls verstärkt zu einem Eisenmangel. / Qualitiy of life and achievements are impaired by unrecognised iron deficiency. The iron requirement of women during their child-bearing age is high and increases in pregnancy. The aim of this study was to determine the prevalence and risk factors for iron deficiency in young mothers under contemporary German life conditions. Between September 1997 and August 1998 the iron status of 507 mothers of one-year old children was assessed. The data was derived from venous blood and questionnaires. Besides conventional methods, the concentration of soluble transferrin receptor was used as leading indicator of iron status. 9,5 % had cellular iron deficiency and 2,2 % of all mothers had iron deficiency anemia. In addition to absence of menstruation one year postpartum, vegetarian foood, a high number of children and non-German nationality are risk factors for iron deficiency. Associated with low maternal hemoglobin concentration are body mass index below 19,8, age below 25 years, low level of education and high birth weight of the child. In contrast, high alcohol intake and cigarette smoking are associated with a better iron status and higher hemoglobin concentrations. Children of mothers with insufficient iron supply are also at higher risk of iron deficiency.
26

Is the Use of Ecstasy and Hallucinogens Increasing?

Schuster, Peter, Lieb, Roselind, Lamertz, Christina, Wittchen, Hans-Ulrich 22 November 2012 (has links) (PDF)
This report presents findings of a community survey of 3,021 adolescents and young adults aged 14–24 years in Munich, Germany, carried out to determine the prevalence of use and abuse of and dependence on ecstasy, amphetamines and hallucinogens. The response rate was 71%. Results: (1) In 1995, 4% of the male and 2.3% of the female respondents aged 14–24 reported the use of ecstasy. Ecstasy-related substances (amphetamines and chemically related substances) were reported by 3.6% of men and 1.6% of women. Hallucinogens were reported slightly less frequently by 3% of men and about 2% of women (LSD combined with others). (2) Compared to findings from a 1990 survey this constitutes a substantial, at least twofold, increase in consumption rate of both types of substances. (3) Among lifetime users of both ecstasy and related substances as well as hallucinogens about two thirds could be regarded as regular users. (4) The prevalence of DSM-IV abuse and dependence on ecstasy and related substances is about 1%, identical to rates of hallucinogen abuse and dependence. Findings also point to a significant dependence potential for both substances. (5) Furthermore, considerable overlap between the two substances was found. Conclusion: Our study suggests a substantial increase in both the use of ecstasy and related substances as well as hallucinogens. The data further suggest that the increase is strongest in younger age groups, but the risk of first use of these substances continues to be present up to the age of 24 years. The higher proportion of women contributing to this increase is noteworthy.
27

How impaired are children and adolescents by mental health problems? Results of the BELLA study

Wille, Nora, Bettge, Susanne, Wittchen, Hans-Ulrich, Ravens-Sieberer, Ulrike 22 February 2013 (has links) (PDF)
Background: The consideration of impairment plays a crucial role in detecting significant mental health problems in children whose symptoms do not meet diagnostic criteria. The assessment of impairment may be particularly relevant when only short screening instruments are applied in epidemiological surveys. Furthermore, differences between childrens’ and parents’ perceptions of present impairment and impairing symptoms are of interest with respect to treatment-seeking behaviour. Objectives: The objectives were to assess parent- and self-reported impairment due to mental health problems in a representative sample of children and adolescents; to describe the characteristics of highly impaired children with normal symptom scores; and to investigate the associations between symptoms in different problem areas and impairment. Methods: The mental health module of the German Health Interview and Examination Survey for Children and Adolescents (the BELLA study) examined mental health in a representative sub-sample of 2,863 families with children aged 7–17. Self-reported and parent-reported symptoms of mental health problems and associated impairment were identified by the extended version of the strengths and difficulties questionnaire (SDQ) in children 11 years and older. Results: Considerable levels of distress and functional impairment were found with 14.1% of the boys and 9.9% of the girls being severely impaired according to the parental reports. However, self-reported data shows a reversed gender-difference as well as lower levels of severe impairment (6.1% in boys; 10.0% in girls). Six percent of the sampled children suffer from pronounced impairment due to mental health problems but were not detected by screening for overall symptoms. Childrens’ and parents’ reports differed in regard to the association between reported symptom scores and associated impairment with children reporting higher impairment due to emotional problems. Conclusions: The assessment of impairment caused by mental health problems provides important information beyond the knowledge of symptoms and helps to identify an otherwise undetected high risk group. In the assessment of impairment, gender-specific issues have to be taken into account. Regarding the systematic differences between childrens’ and parents’ reports in the assessment of impairment, the child’s perspective should be given special attention.
28

Frequency of albuminuria in primary care: a cross-sectional study

Bramlage, Peter, Pittrow, David, Lehnert, Hendrik, Höfler, Michael, Kirch, Wilhelm, Ritz, Eberhard, Wittchen, Hans-Ulrich 26 February 2013 (has links) (PDF)
Background: We aimed to assess the point prevalence of microalbuminuria (MAU) in a sample of unselected consecutive primary-care attendees, with particular focus on patients with diabetes mellitus (with and without additional concomitant diseases) and those with hypertension. Design: Cross-sectional observational study in a nationwide representative sample of 1912 primary-care practices and a patient population consisting of 39 125 primary-care attendees. Diagnoses for diabetes, hypertension and co-morbidities were provided by the treating physician and complemented by blood pressure (BP) measurements and selected lab tests. Screening for microalbuminuria (>20 and <200 μg/ml) was done with a spot urine dipstick test. Results: The clinical diagnosis of nephropathy was assigned to 7.6% of patients. The point prevalence of MAU was 19.0% in the total sample; the proportion was 33.6% in diabetics whereas the diagnosis was assigned to only 7.1% in the total sample. Amongst diabetic patients with MAU, 92.6% had BP above the target value of < 130/80 mmHg. Frequency rates rose with increasing BP (e.g. 20.6% in diabetic patients with BP< 120/70 mmHg, and 36.3% in diabetic patients with BP > 140/90 mmHg). Of note, patients with MAU had a higher burden of co-morbidity compared to those without MAU. Conclusions: We found a high prevalence of MAU in primary care, particularly in diabetic patients. The frequency of MAU was closely related to the BP level and the degree of co-morbidity. The present study underlines the magnitude of the problem of MAU in primary care, and should serve as a starting point to initiate measures to address this important public health issue.
29

Prevalence and burden of bipolar disorders in European countries

Pini, Stefano, de Queiroz, Valéria, Pagnin, Daniel, Pezawas, Lukas, Angst, Jules, Cassano, Giovanni B., Wittchen, Hans-Ulrich 10 April 2013 (has links) (PDF)
A literature search, supplemented by an expert survey and selected reanalyses of existing data from epidemiological studies was performed to determine the prevalence and associated burden of bipolar I and II disorder in EU countries. Only studies using established diagnostic instruments based on DSM-III-R or DSM-IV, or ICD-10 criteria were considered. Fourteen studies from a total of 10 countries were identified. The majority of studies reported 12-month estimates of approximately 1% (range 0.5–1.1%), with little evidence of a gender difference. The cumulative lifetime incidence (two prospective-longitudinal studies) is slightly higher (1.5–2%); and when the wider range of bipolar spectrum disorders is considered estimates increased to approximately 6%. Few studies have reported separate estimates for bipolar I and II disorders. Age of first onset of bipolar disorder is most frequently reported in late adolescence and early adulthood. A high degree of concurrent and sequential comorbidity with other mental disorders and physical illnesses is common. Most studies suggest equally high or even higher levels of impairments and disabilities of bipolar disorders as compared to major depression and schizophrenia. Few data are available on treatment and health care utilization.
30

Wie stabil sind Drogenkonsum und das Auftreten klinisch-diagnostisch relevanter Mißbrauchs- und Abhängigkeitsstadien bei Jugendlichen? / Stability of cannabis use, abuse and dependence patterns in a community sample of adolescents

Wittchen, Hans-Ulrich, Höfler, Michael, Perkonigg, Axel, Sonntag, Holger, Lieb, Roselind 23 October 2012 (has links) (PDF)
Anhand einer prospektiven epidemiologischen Verlaufsstudie an einer repräsentativen Bevölkerungsstichprobe von ursprünglich 14- bis 17jährigen Jugendlichen (N=1395) werden die Häufigkeit und die Verlaufsmuster des Konsums, des Mißbrauchs und der Abhängigkeit von Cannabis untersucht. Die Jugendlichen wurden persönlich mit Hilfe eines Interviews befragt, wobei als diagnostisches Instrument das M-CIDI mit seinen DSM-IV Algorithmen verwendet wurde. Die Ergebnisse aus der Basiserhebung ergaben, daß 1995 etwa 20% aller 14- bis 17jährigen - in der Mehrzahl wiederholt - Cannabis probiert hatten und 6% der Population einen regelmäßigen Gebrauch aufweisen. Die Einjahres-Inzidenz (= Auftreten neuer Fälle) für den Cannabisgebrauch der nun 15- bis 19jährigen betrug zum Zeitpunkt der Nachuntersuchung 20,1% für die Männer und 16,3% für die Frauen. Für den regelmäßigen Gebrauch wurden Inzidenzraen von 12% (Männer) und 8,4% (Frauen) ermittelt. Die Stabilität des Konsumverhaltens zwischen der Basis- und der Nachuntersuchung war relativ hoch un stieg mit höherem Initialkonsum an. Angesichts der hohen Gebrauchsrate von 32,4% bei den 15- bis 19jährigen bei der Nachuntersuchung ergab sich im Vergleich zu anderen psychotropen Substanzen eine relativ niedrige Prävalenz für Mißbrauch und Abhängigkeit (4%). Das Vorliegen einer Diagnose bei der Erstuntersuchung weist allerdings eine relativ hohe Stabilität über die Nachuntersuchungskette auf. / The paper examines the prevalence, incidence and stability patterns of cannabis use and dependence in a prospective epidemiological study of a random community sample of adolescents, aged 14 to 17 years (N=1395) at time 1. Assesments are based on personal interviews by trained clinical psychologists using the computerized DSM-IV lifetime and 12-month change version of the M-CIDI. Results indicate that in 1995 every fifth person aged 14 to 17 years had used cannabis at least once and 6% reported regular use. The 12-month incidence rates (i.e. proportion of the sample reporting first cannabis use in the last year) among subjects, 15 to 19 years of age at time 2, was high, with 20,1% of males and 16,3% of females reporting first use. The incidence of regular use was 12,0% (males) and 8,4% (females). The stability of consumption patterns from time 1 to time 2 was high. Increasing with higher initial consumption. Given the reexamined samples overall high cannabis consumption rates of 32,4%, the prevalence of clinically manifest DSM-IV abuse and dependence was low in comparison to other psychologic drugs (4%). However there was remarkable diagnostic stability over time in this age group of those with an initial diagnosis at time 1 receiving a diagnosis again at time 2.

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