10 research outputs found

    Late-Glacial and Holocene Climatic Effects on Fire and Vegetation Dynamics at the Prairie–Forest Ecotone in South-Central Minnesota

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    1. Treeline ecotones, such as the prairie–forest boundary, represent climatically sensitive regions where the relative abundance of vegetation types is controlled by complex interactions between climate and local factors. Responses of vegetation and fire to climate change may be tightly linked as a result of strong feedbacks among fuel production, vegetation structure and fire frequency/severity, but the importance of these feedbacks for controlling the stability of this ecotone is unclear. 2. In this study, we examined the prairie–forest ecotone in south-central Minnesota using two lake sediment cores to reconstruct independent records of climate, vegetation and fire over the past 12 500 years. Using pollen, charcoal, sediment magnetic analyses and LOI properties, we investigated whether fires were controlled directly by climate or indirectly by fuel production. 3. Sediment magnetic and LOI data suggest four broad climatic periods occurring c. 11 350–8250 BP (cool/humid), c. 8250–4250 BP (warm/dry), c. 4250–2450 BP (warm/humid), and c. 2450–0 BP (cool/humid), indicating that, since the mid-Holocene, climate has shifted towards wetter conditions favouring greater in-lake production and fuel production on the landscape. 4. The area surrounding both lakes was characterized by boreal forest c. 12 500–10 000 BP, changing to an Ulmus-Ostrya forest c. 10 000–9000 BP, changing to a community dominated by prairie (Poaceae-Ambrosia-Artemisia) and deciduous forest taxa c. 8000–4250 BP, and finally shifting to a Quercus-dominated woodland/savanna beginning c. 4250–3000 BP. 5. Charcoal influx increased from an average of 0.11–0.62 mm2 cm−2 year−1 during the early Holocene forest period (c. 11 350–8250 BP) to 1.71–3.36 mm2 cm−2 year−1 during the period of prairie expansion (c. 8250–4250 BP) and again increased to 4.18–4.90 mm2 cm−2 year−1 at the start of the woodland/savanna period (c. 4250 BP). 6. As a result of the influence of climate on community composition and fuel productivity, changes in fire severity may be the result and not the cause of shifts in vegetation

    Late-Glacial and Holocene Climatic Effects on Fire and Vegetation Dynamics at the Prairie–Forest Ecotone in South-Central Minnesota

    No full text
    1. Treeline ecotones, such as the prairie–forest boundary, represent climatically sensitive regions where the relative abundance of vegetation types is controlled by complex interactions between climate and local factors. Responses of vegetation and fire to climate change may be tightly linked as a result of strong feedbacks among fuel production, vegetation structure and fire frequency/severity, but the importance of these feedbacks for controlling the stability of this ecotone is unclear. 2. In this study, we examined the prairie–forest ecotone in south-central Minnesota using two lake sediment cores to reconstruct independent records of climate, vegetation and fire over the past 12 500 years. Using pollen, charcoal, sediment magnetic analyses and LOI properties, we investigated whether fires were controlled directly by climate or indirectly by fuel production. 3. Sediment magnetic and LOI data suggest four broad climatic periods occurring c. 11 350–8250 BP (cool/humid), c. 8250–4250 BP (warm/dry), c. 4250–2450 BP (warm/humid), and c. 2450–0 BP (cool/humid), indicating that, since the mid-Holocene, climate has shifted towards wetter conditions favouring greater in-lake production and fuel production on the landscape. 4. The area surrounding both lakes was characterized by boreal forest c. 12 500–10 000 BP, changing to an Ulmus-Ostrya forest c. 10 000–9000 BP, changing to a community dominated by prairie (Poaceae-Ambrosia-Artemisia) and deciduous forest taxa c. 8000–4250 BP, and finally shifting to a Quercus-dominated woodland/savanna beginning c. 4250–3000 BP. 5. Charcoal influx increased from an average of 0.11–0.62 mm2 cm−2 year−1 during the early Holocene forest period (c. 11 350–8250 BP) to 1.71–3.36 mm2 cm−2 year−1 during the period of prairie expansion (c. 8250–4250 BP) and again increased to 4.18–4.90 mm2 cm−2 year−1 at the start of the woodland/savanna period (c. 4250 BP). 6. As a result of the influence of climate on community composition and fuel productivity, changes in fire severity may be the result and not the cause of shifts in vegetation

    Mutations in Extracellular Matrix Genes NID1 and LAMC1 Cause Autosomal Dominant Dandy-Walker Malformation and Occipital Cephaloceles

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    We performed whole-exome sequencing of a family with autosomal dominant Dandy-Walker malformation and occipital cephaloceles and detected a mutation in the extracellular matrix (ECM) protein-encoding gene NID1. In a second family, protein interaction network analysis identified a mutation in LAMC1, which encodes a NID1-binding partner. Structural modeling of the NID1-LAMC1 complex demonstrated that each mutation disrupts the interaction. These findings implicate the ECM in the pathogenesis of Dandy-Walker spectrum disorders

    Tech & Science @ School. Ein fachpraktisches Handbuch für Technik-Lehrkräfte

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    Kunstgegenstände & Schmuck herzustellen ist ein urmenschliches Bedürfnis. Aus diesem Kernbereich der Schmuckfertigung und des Drechselns sind die vorliegenden Projektideen entstanden. Die in dieser Handreichung vorgestellten Projektideen sind alle von Lehramtsstudierenden im Fach Technik an den Pädagogischen Hochschulen in Schwäbisch Gmünd und Ludwigsburg in offener und selbstgesteuerter Werkstattarbeit seit dem Sommersemester 2021 entstanden. Die Studierenden haben dabei ihre Idee stets fachpraktisch erprobt und fachdidaktisch in den vorliegenden Erklärfilmen und Schritt für Schritt-Anleitungen ausgearbeitet. Der Projektrahmen umfasst das curricular verankerte, handwerklich bedeutsame Arbeiten mit den grundlegenden Werkstoffen Holz, Metall und Kunststoffen sowie den Bereich der Elektrotechnik und des Mikrocontrolling. Die Umsetzung dieser Projektideen soll unterstützend wirken, um individuelle handwerkliche Kompetenzen zu entdecken, erproben und vertiefen sowie technische Interessensbildung und vorberufliche Orientierung in Schulen fördern. Eine Schlüsselrolle für die Anfertigung der Werkstücke nimmt hierbei das Vorführen und Erklären (modellhaftes Vormachen) der notwendigen Fertigungsschritte durch Experten in Form von Erklärfilmen ein. Die zugrundeliegende didaktische Konzeption lehnt sich an die Kognitive Meisterlehre aus der gewerblich-technischen beruflich orientierten Bildung an (Collins et al., 1989). Das Projekt KunstHandWerk wurde durch eine Kooperation zwischen der PH Ludwigsburg und der PH Schwäbisch Gmünd in Zusammenarbeit mit der Gold- und Silberschmiede-Innung Stuttgart-Heilbronn-Reutlingen initiiert und von TRAFO - dem Netzwerk transferorientierter Lehre in Baden-Württemberg gefördert. Die Projektfortsetzung Tech&Science@School mit der Uhland-Realschule Aalen wurde durch die Vector Stiftung gefördert

    Exome sequencing followed by large-scale genotyping fails to identify single rare variants of large effect in idiopathic generalized epilepsy.

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    Idiopathic generalized epilepsy (IGE) is a complex disease with high heritability, but little is known about its genetic architecture. Rare copy-number variants have been found to explain nearly 3% of individuals with IGE; however, it remains unclear whether variants with moderate effect size and frequencies below what are reliably detected with genome-wide association studies contribute significantly to disease risk. In this study, we compare the exome sequences of 118 individuals with IGE and 242 controls of European ancestry by using next-generation sequencing. The exome-sequenced epilepsy cases include study subjects with two forms of IGE, including juvenile myoclonic epilepsy (n = 93) and absence epilepsy (n = 25). However, our discovery strategy did not assume common genetic control between the subtypes of IGE considered. In the sequence data, as expected, no variants were significantly associated with the IGE phenotype or more specific IGE diagnoses. We then selected 3,897 candidate epilepsy-susceptibility variants from the sequence data and genotyped them in a larger set of 878 individuals with IGE and 1,830 controls. Again, no variant achieved statistical significance. However, 1,935 variants were observed exclusively in cases either as heterozygous or homozygous genotypes. It is likely that this set of variants includes real risk factors. The lack of significant association evidence of single variants with disease in this two-stage approach emphasizes the high genetic heterogeneity of epilepsy disorders, suggests that the impact of any individual single-nucleotide variant in this disease is small, and indicates that gene-based approaches might be more successful for future sequencing studies of epilepsy predisposition.Journal ArticleResearch Support, N.I.H. ExtramuralResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

    De novo and inherited variants in ZNF292 underlie a neurodevelopmental disorder with features of autism spectrum disorder

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    International audiencePURPOSE:Intellectual disability (ID) and autism spectrum disorder (ASD) are genetically heterogeneous neurodevelopmental disorders. We sought to delineate the clinical, molecular, and neuroimaging spectrum of a novel neurodevelopmental disorder caused by variants in the zinc finger protein 292 gene (ZNF292).METHODS:We ascertained a cohort of 28 families with ID due to putatively pathogenic ZNF292 variants that were identified via targeted and exome sequencing. Available data were analyzed to characterize the canonical phenotype and examine genotype-phenotype relationships.RESULTS:Probands presented with ID as well as a spectrum of neurodevelopmental features including ASD, among others. All ZNF292 variants were de novo, except in one family with dominant inheritance. ZNF292 encodes a highly conserved zinc finger protein that acts as a transcription factor and is highly expressed in the developing human brain supporting its critical role in neurodevelopment.CONCLUSION:De novo and dominantly inherited variants in ZNF292 are associated with a range of neurodevelopmental features including ID and ASD. The clinical spectrum is broad, and most individuals present with mild to moderate ID with or without other syndromic features. Our results suggest that variants in ZNF292 are likely a recurrent cause of a neurodevelopmental disorder manifesting as ID with or without ASD
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