69 research outputs found
Eine bemerkenswerte Bio- und Lithofazies an der Basis des Unter-Hauterivium Nordwestdeutschlands
Im östlichen Teil des Niedersächsischen Beckens ist das Trans gressionskonglomerat des Unter-Hauterivium-Meeres ("Hilskon- glomerat") in Küsten- und Schwellennähe durch einen hohen, meist organogenen Karbonatgehalt (Biosparit), Biomikrit, Kalk und Mergelstein) sowie Brauneisengeröll- und Quarzsandführung gekennzeichnet. Gleichzeitig weisen diese Basisschichten des Unter-Hauterivium hier einen außergewöhnlichen Fauneninhalt auf ("Sonderfazies”), der im küstenferneren Bereich des östlichen wie auch im Gesamtbereich des mittleren und westlichen Niedersächsischen Beckens bisher nicht beobachtet werden konnte ("Normalfazies"). In der Mikrofauna erscheinen, z.T. im Faunenbild dominierend, Foraminiferen mediterraner Herkunft (Trocholina, Meandrospira Cyclammina u.a.). Auch die Megafauna der "Sonderfazies" ist durch Warm- und Flachwasserformen (Kalkschwämme, Korallen, Bryozoen, Serpuliden, Seelilien) charakterisiert. Da auch in der östlichen Fortsetzung des Norddeutsch-Polnischen Unterkreide-Meeres (Brandenburg, Mecklenburg) u.a. eben falls die Foraminiferen-Gattungen Trocholina und Cyclammina sowie Bryozoen und Seelilien beobachtet werden konnten und im Hauterivium lediglich über die südpolnische Meeresstraße eine Verbindung zum mediterranen Meeresraum bestand, müssen warme Meeresströmungen aus südöstlicher Richtung als Ursache für den Karbonatreichtum der Sedimente und deren Besiedelung durch benthische "Warmwasserformen" angenommen werden. Auch die Ammoniten-Gattung Endemoceras ist nach Untersuchungen von THIERMANN (1963) auf diesem Wege in das Niedersächsische Becken eingewandert. Da die Unterkreide-Transgression mit Konglomerat- und Aufarbeitungshorizonten in einigen küsten- und schwellennahen Bereichen des nordwestdeutschen Unterkreide-Meeres bereits im höheren Valanginium oder aber erst im höheren Unter-Hauteri- vium (z.B. Fallsteingebiet) bzw. tiefem Ober-Hauterivium (z.B. Westerberg b. Alfeld) erfolgte, ist das sog. "Hilskon- glomerat" i.w.S. nicht als synchrone Bildung anzusehen. Allerdings konnten der spezifische petrographische Charakter sowie die typische Fauaenvergesellschaftung der "Sonderfazies" bisher nur im Basiskonglomerat des Unter-Hauterivium und nur im östlichen Teil des Niedersächsischen Beckens beobachtet werden. Daraus ließe sich ableiten, daß nur für einen (im geologischen Maßstab!) enger begrenzten Zeitraum (tieferes Unter- Hauterivium) die zur Entstehung der "Sonderfazies" notwendigen hydrologischen und klimatischen Voraussetzungen gegeben waren. So nimmt der Karbonatgehalt der Sedimente bis zum Unter-Aptium deutlich ab; nur im höheren Ober-Hauterivium steigen die Karbonatgehalte wieder stärker an, um dann im Barremium und Unter- Aptium die im Durchschnitt geringsten Werte der borealen Unterkreide NW-Deutschlands zu erreichen. Erst im Ober-Aptium steigen die Karbonatgehalte wieder an, sinken im Unter-Albium deutlich ab und nehmen vom Mittel-Albium bis Cenomanium kontinuierlich zu. Parallel zum abnehmenden Karbonatgehalt der Sedimente verschwinden bereits im Hauterivium Korallen, Kalkschwämme und Bryozoen, im höchsten Ober-Hauterivium auch die Crinoiden. Erst im höheren Unter-Albium erscheinen wieder Crinoiden im Faunenbild der Bodentier-Vergesellschaftungen. Daraus läßt sich eine deutliche Temperaturabnahme - zumindest im Bodenwasserbereich - infolge fehlender warmer Meeres-Strömungen, verbunden mit einer Zunahme der Wassertiefe im Beckenbereich vom Unter-Barremium bis Unter-Aptium, ableiten. Nach beträchtlicher regionaler Ausweitung der Meeresräume während des Albium kennzeichnen abseits der Küsten- und Schwellenbereiche erstmalig pelagische Faziesverhältnisse das lithologische und faunistische Bild der höheren Unterkreide NW-Deutschlands
De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development
Bosma arhinia microphthalmia syndrome (BAMS) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. We report here that missense mutations in the epigenetic regulator SMCHD1 mapping to the extended ATPase domain of the encoded protein cause BAMS in all 14 cases studied. All mutations were de novo where parental DNA was available. Biochemical tests and in vivo assays in Xenopus laevis embryos suggest that these mutations may behave as gain-of-function alleles. This finding is in contrast to the loss-of-function mutations in SMCHD1 that have been associated with facioscapulohumeral muscular dystrophy (FSHD) type 2. Our results establish SMCHD1 as a key player in nasal development and provide biochemical insight into its enzymatic function that may be exploited for development of therapeutics for FSHD
Differential Expression between Human Dermal Papilla Cells from Balding and Non-Balding Scalps Reveals New Candidate Genes for Androgenetic Alopecia
Agency for Science, Technology and Research (A*STAR). EC is supported by the A*STAR Graduate
Scholarship program
A genome-wide association study for late-onset Alzheimer's disease using DNA pooling
Background: Late-onset Alzheimer's disease (LOAD) is an age related neurodegenerative disease with a high prevalence that places major demands on healthcare resources in societies with increasingly aged populations. The only extensively replicable genetic risk factor for LOAD is the apolipoprotein E gene. In order to identify additional genetic risk loci we have conducted a genome-wide association (GWA) study in a large LOAD case – control sample, reducing costs through the use of DNA pooling. Methods: DNA samples were collected from 1,082 individuals with LOAD and 1,239 control subjects. Age at onset ranged from 60 to 95 and Controls were matched for age (mean = 76.53 years, SD = 33), gender and ethnicity. Equimolar amounts of each DNA sample were added to either a case or control pool. The pools were genotyped using Illumina HumanHap300 and Illumina Sentrix HumanHap240S arrays testing 561,494 SNPs. 114 of our best hit SNPs from the pooling data were identified and then individually genotyped in the case – control sample used to construct the pools. Results: Highly significant association with LOAD was observed at the APOE locus confirming the validity of the pooled genotyping approach. For 109 SNPs outside the APOE locus, we obtained uncorrected p-values ≤ 0.05 for 74 after individual genotyping. To further test these associations, we added control data from 1400 subjects from the 1958 Birth Cohort with the evidence for association increasing to 3.4 × 10-6 for our strongest finding, rs727153. rs727153 lies 13 kb from the start of transcription of lecithin retinol acyltransferase (phosphatidylcholine – retinol O-acyltransferase, LRAT). Five of seven tag SNPs chosen to cover LRAT showed significant association with LOAD with a SNP in intron 2 of LRAT, showing greatest evidence of association (rs201825, p-value = 6.1 × 10-7). Conclusion: We have validated the pooling method for GWA studies by both identifying the APOE locus and by observing a strong enrichment for significantly associated SNPs. We provide evidence for LRAT as a novel candidate gene for LOAD. LRAT plays a prominent role in the Vitamin A cascade, a system that has been previously implicated in LOAD
If Canada and Israel are at War, Who Gets My Support? Challenges of Competing Diaspora Loyalties: Marshall Sklare Award Lecture
Moving knowledge into action for more effective practice, programmes and policy: protocol for a research programme on integrated knowledge translation
Pharmacotherapy of keloid scars
grantor:
University of TorontoKeloid scars arise from exuberant tissue growth; increased extracellular matrix (ECM) production combined with decreased ECM degradation. Darker-skinned people are predisposed to keloid scars formation. The efficacy of triamcinolone, compared to methylprednisolone, and dexamethasone was evaluated by their abilities to prevent inflammation induced in rats, as well as in an athymic mouse model. Surgically excised human keloid scar tissue was subcutaneously implanted into the mice. The glucocorticoids (GC) were injected into the keloid scar tissue. A histological scale was used to determine the efficacies of the GCs in both models. A hydroxyproline (OH-P) assay was done to determine the levels of collagen synthesis in the keloid tissue. No GC treatment showed consistent advantage in prevention or amelioration of Keloid scars in these animal models. Both models are imperfect for solutions to clinical problems and ideally study of novel Keloid scars therapies should be conducted in patients.M.Sc
A Comparison of Salary Structures between Economics and Agricultural Economics Departments
This study is the first to empirically assess the difference between the prevailing salary structures in economics and agricultural economics departments at public institutions in the United States. We find that average salaries in economics departments tend to be higher than salaries in agricultural economics departments. Regression analysis suggest that years since Ph.D. explains a greater proportion of salaries in agricultural economics departments while the tier of school explains a great proportion of salaries structure in economics departments. Regression results also suggest that the returns to publications in top 36 and other economics journals is higher in economics departments while publications in core and regional agricultural economics journals is more highly rewarded in agricultural economics departments
A Comparison of Salary Structures between Economics and Agricultural Economics Departments
This study is the first to empirically assess the difference between the prevailing salary structures in economics and agricultural economics departments at public institutions in the United States. We find that average salaries in economics departments tend to be higher than salaries in agricultural economics departments. Regression analysis suggest that years since Ph.D. explains a greater proportion of salaries in agricultural economics departments while the tier of school explains a great proportion of salaries structure in economics departments. Regression results also suggest that the returns to publications in top 36 and other economics journals is higher in economics departments while publications in core and regional agricultural economics journals is more highly rewarded in agricultural economics departments.Teaching/Communication/Extension/Profession,
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