Search results for "Systematic"
showing 10 items of 7608 documents
No phylogeographic structure in the circumpolar snowy owl (Bubo scandiacus)
2008
The snowy owl (Bubo scandiacus) is a nomadic species with a circumpolar distribution. It has recently declined in the western Palearctic and may thus be worthy of special consideration for conservation. We investigated genetic structure in three well separated geographic regions within the snowy owls’ breeding range. We sequenced two mitochondrial genes; the control region and cytochrome b, and two Z-chromosome introns; VLDLR-9 and BRM-15. We found no phylogeographic structure among the sampled regions, indicating high levels of gene flow in the recent past and possibly still today. Intra-population diversity did not vary between regions for the control region, but for Cyt b, North American…
Phylogeography of a Palaearctic sedentary passerine, the willow tit (Parus montanus)
2001
We analysed variation of the mitochondrial control region from willow tits through its Palaearctic distribution range. Although we found high amount of genetic variation (π=1.114%), there was almost no differentiation between subspecies or geographical localities. This may be because of a combination of several ecological and genetic factors, including a relatively homogenic habitat through the distribution range, lack of geographical barriers, high gene flow and a large long-term effective population size. On the contrary, in the songar tit, which is sometimes considered to be conspecific with the willow tit, the mitochondrial lineages seem to correlate with the geographical locality and a…
Environmental features of deep-sea habitats linked to the genetic population structure of a crustacean species in the Mediterranean Sea
2009
The deep-sea habitat, from 200 to 2000 m depth, has long been thought as an ecosystem where biotic and abiotic factors vary very little and consequently species are not disturbed by processes and phenomena which could promote fast evolutionary mechanisms. Unfortunately, biological information relating to deep water is limited, especially regarding the population genetics of species inhabiting the Mediterranean Sea, and general patterns cannot be inferred. In this study we report data on the population genetic structure of Aristeus antennatus, a deep-sea decapod crustacean species which has been widely studied due to its important economic value. We surveyed and examined the variation in a 3…
Conceptualizing ecosystem tipping points within a physiological framework
2017
Connecting the nonlinear and often counterintuitive physiological effects of multiple environmental drivers to the emergent impacts on ecosystems is a fundamental challenge. Unfortunately, the disconnect between the way “stressors” (e.g., warming) is considered in organismal (physiological) and ecological (community) contexts continues to hamper progress. Environmental drivers typically elicit biphasic physiological responses, where performance declines at levels above and below some optimum. It is also well understood that species exhibit highly variable response surfaces to these changes so that the optimum level of any environmental driver can vary among interacting species. Thus, specie…
The role of in situ species diversification for the evolution of high vascular plant species diversity in the European Alps—A review and interpretati…
2017
Abstract By harbouring ca. 3500 native vascular plant species in an area of ca. 170 000 km2, the European Alps represent a region of very high species diversity. Using the most recently published flora of the area and phylogenetic literature, I here review which proportion of the endemic flora of the Alps is the result of in situ diversification, i.e., of diversification in the area and (largely) restricted to the area. There exist only very few and mostly species-poor species diversifications in the Alps, accounting for ca. 1.2% of the native and for ca. 9% of the endemic flora of the Alps. In contrast to this, ca. 33% of the endemic species of the Alps belong to lineages widespread in the…
Lymphatic vessels of the dura mater: a new discovery?
2015
Aspelund et al. discover the presence of a lymphatic vessel network in the dura mater of the mouse brain and show that these dural lymphatic vessels are important for the clearance of macromolecules from the brain.
<p><strong>A new genus of Phaneropterinae (Orthoptera: Ensifera: Tettigoniidae) </strong><strong>from Central Africa</stro…
2014
The new genus Pseudoplangia is described for Plangia laminifera Karsch, 1896. Its general aspect is similar to that of the genus Plangia Stal, 1873, but it differs remarkably in the vertex width, in the shape of eyes, that are oval and elongate, in the length of mid femora, that are shorter than pronotum length, in the shape of fore and mid legs that are very much laterally compressed, and in the presence of broad-based spines on the hind tibiae.
Zur Bewertung der Blattdornen vonHalimodendron halodendron (Fabaceae)
1979
Halimodendron halodendron is a spiny shrub of north-western Asia. The spines are formed by the rachises of the paripinnate leaves. After abscission of pinnae the rigid rachises remain for several years. In culture these rachis spines do not develop fully.
Intra-Articular Injection of Botulinum Toxin for the Treatment of Knee Osteoarthritis: A Systematic Review of Randomized Controlled Trials
2023
The purpose of the present paper was to review the available evidence on intra-articular botulinum toxin (BTX) injection in the treatment of knee osteoarthritis and to compare it to other conservative treatment options. A systematic review of the literature was performed on the PubMed, Scopus, Cochrane Library, Web of Science, Pedro and Research Gate databases with the following inclusion criteria: (1) randomized controlled trials (RCTs), (2) written in the English language, and (3) published on indexed journals in the last 20 years (2001–2021) dealing with the use of BTX intra-articular injection for the treatment of knee OA. The risk of bias was assessed using the Cochrane Risk of Bias to…
Il fascino dell’intuizione femminile: Marie Trautmann (in Jaëll), pianista, pedagoga e ricercatrice
2020
Over the centuries, the differences between genders have led to strong disparities for the assertion of women’s artistic value. In the history of music, in particular, many women musicians did not get the right recognition because of a cultural context that could not enhance their work. This is the case of Marie Trautmann, better known as Marie Jaëll (1846-1925), wife of the Austrian concert pianist Alfred Jaëll (1832-1882). Trautmann is a 19th century woman-musician and an important figure in the history of music still to be discovered, not only for her activity as concert pianist, composer, pedagogue, but mainly for her empirical research work, which aimed at improving the piano technique…