Background: Essential tremor (ET) is reported to have a bimodal distribution of age at onset (AAO) with phenotypic variability based on the AAO. This study aims to explore the distribution of AAO based on mathematical modeling and ascertain the differences, if any, in the clinical features of groups.
Methods: A chart review was conducted for 252 patients with ET diagnosed based on the Consensus statement of the Movement Disorder Society on Tremor. Finite mixture modeling was performed to identify groups of the cohort based on the AAO.
Results: Three groups were defined: early onset (EO): AAO ≤ 22 years, n = 63, intermediate onset (IO): 23 ≤ AAO ≤ 35 years, n = 43, and late onset (LO): AAO ≥ 36 years, n = 146. There were no significant differences related to family history or responsiveness to alcohol. The EO group had significantly higher prevalence of upper limb and lower limb tremor. Head tremor and voice tremor was more prevalent in the IO and LO groups. Cerebellar signs showed a significant increase with an increase in AAO.
Conclusions: ET shows significant phenotypic variability based on the AAO. Patients with an early AAO are more likely to develop an appendicular tremor, whereas the probability of axial tremor and cerebellar signs increases with increasing AAO.
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http://dx.doi.org/10.1017/cjn.2018.384 | DOI Listing |
Translocating individuals from multiple source populations is one way to bolster genetic variation and avoid inbreeding in newly established populations. However, mixing isolated populations, especially from islands, can potentially lead to outbreeding depression and/or assortative mating, which may limit interbreeding between source populations. Here, we investigated genetic consequences of mixing individuals from two island populations of the dibbler () in an island translocation.
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Aquatic Botany and Microbial Ecology Research Group, Hungarian Research Network (HUN-REN) Balaton Limnological Research Institute, Tihany, Hungary.
Common reed () is a cosmopolitan species, though its dieback is a worldwide phenomenon. In order to assess the evolutionary role of phenotypic plasticity in a successful plant, the values and plasticity of photophysiological traits of were investigated in the Lake Fertő wetlands at 5 sites with different degrees of reed degradation and along a seasonal sequence. On the one hand, along the established ecological degradation gradient, photophysiological traits of changed significantly, affecting plant productivity, although no consistent gradient-type trends were observed.
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Institute of Crop Science, College of Agriculture and Food Science, University of the Philippines Los Baños, Philippines.
Abaca ( Nee) is the primary source of manila hemp fiber, a vital industrial product for the country. Previous studies have relied on molecular markers designed for other species or distant genera like rice, limiting accurate genetic characterization and germplasm conservation. To address this, we developed 50 genome-specific molecular markers based on the recently released whole genome sequence assembly of Abaca var.
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Department of Zoology, Fisheries, Hydrobiology and Apiculture, Faculty of Agronomy Mendel University in Brno Brno Czech Republic.
This study evaluates the response of ground beetle (Coleoptera: Carabidae) assemblage to forest management practices by integrating species composition, body traits, wing morphology and developmental instability. Traditional approaches that rely on averaged identity-based descriptors often overlook phenotypic plasticity and functional trait variability, potentially masking species-specific responses to environmental changes. To address this, we applied a three-layered analytical approach to address this gap, utilising ground beetle occurrence and morphological trait data from Podyjí National Park, Czech Republic.
View Article and Find Full Text PDFAll species must partition resources among the processes that underly growth, survival, and reproduction. The resulting demographic trade-offs constrain the range of viable life-history strategies and are hypothesized to promote local coexistence. Tropical forests pose ideal systems to study demographic trade-offs as they have a high diversity of coexisting tree species whose life-history strategies tend to align along two orthogonal axes of variation: a growth-survival trade-off that separates species with fast growth from species with high survival and a stature-recruitment trade-off that separates species that achieve large stature from species with high recruitment.
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