local distribution
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2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Alastair Fitter ◽  
Martin Hammond ◽  
Meg Huby ◽  
Kevin Walker ◽  
Phillip Whelpdale

Gingerbread or Elongated Sedge Carex elongata L. is a rare plant in eastern England and the Yorkshire populations are isolated from the main distribution. It has only ever naturally occurred at five sites and is extant at two of them, one of which probably results from a recent colonisation event. It has been re-introduced near another of its historic sites. At its principal site, Askham Bog near York, the plant has expanded its population considerably over the last 40 years. Its local distribution appears to be strictly limited by topography and winter flooding. Its ability to colonise new sites and to expand populations show that earlier concern about seed viability was misplaced.


Author(s):  
T. N. Naumova

Data on the local distribution of capelin in the eastern part of the Sea of Okhotsk in 2000–2019 are very limited. Maps of the distribution were made based on results of complex pelagic surveys in 2000–2019. It is demonstrated, that spring distribution of capelin in the Eastern Sea of Okhotsk varied depending temperature conditions in each particular year. Major aggregations of capelin were observed within Shelikhov Gulf in spring. In the “cold” years these aggregations were in the south-western part of the West Kamchatkan shelf, and in the “warm” years – in the north-western part. In sense of bathymetric distribution the main body of the capelin aggregations was observed in the upper part of the shelf at the depth <125 m at the temperatures bit lower zero.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Luca Vecchioni ◽  
Marco Arculeo ◽  
Federico Marrone

Biological invasions are known to be among the most important threats to the long-term conservation of native biota, and their effects might be even more difficult to contrast when they are cryptic, i.e., when the non-native invaders cannot be easily recognised based on morphology, and can thus be confused with native taxa. Such cryptic invasions are known to widely occur in the cladoceran genus Daphnia O.F. Müller, 1785, so that the actual distribution and status of most species and lineages need to be checked with a genetic approach. In the frame of this work, we investigated if the Sicilian populations of D. (Daphnia) pulex Leydig, 1860 belonged to the allochthonous North American lineage, which is known to occur in several regions of the Palearctic and Afrotropical biogeographical regions, or rather to the autochthonous European lineage of the species. The molecular results obtained, based on a fragment of the mitochondrial gene encoding for NADH subunit dehydrogenase 5 (ND5), allowed us to rule out the allochthonous status of the species, confirming the presence of autochthonous relictual lineages of D. pulex in Sicily. The native status of these populations is in agreement with their local distribution, limited to natural and poorly-impacted water bodies mostly located in wooded areas at medium and high altitudes. The current local distribution of D. pulex in Sicily is possibly linked to the end of the last glacial maximum and the onset of warmer climatic conditions in the early Holocene, which led the species to take refuge in colder microthermal refugia located at high altitudes, determining their current relictual distribution. 


2021 ◽  
Author(s):  
PU TIAN

Molecular simulation is a mature and versatile tool set widely utilized in many subjects with more than 30,000 publications each year. However, its methodology development has been struggling with a tradeoff between accuracy/resolution and speed, significant improvement of both beyond present state of the art is necessary to reliably substitute many expensive and laborious experiments in molecular biology, materials science and nanotechnology. Previously, the ubiquitous issue regarding severe wasting of computational resources in all forms of molecular simulations due to repetitive local sampling was raised, and the local free energy landscape approach was proposed to address it. This approach is derived from a simple idea of first learning local distributions, and followed by dynamic assembly of which to infer global joint distribution of a target molecular system. When compared with conventional explicit solvent molecular dynamics simulations, a simple and approximate implementation of this theory in protein structural refinement harvested acceleration of about six orders of magnitude without loss of accuracy. While this initial test revealed tremendous benefits for addressing repetitive local sampling, there are some implicit assumptions need to be articulated. Here, I present a more thorough discussion of repetitive local sampling; potential options for learning local distributions; a more general formulation with potential extension to simulation of near equilibrium molecular systems; the prospect of developing computation driven molecular science; the connection to mainstream residue pair distance distribution based protein structure prediction/refinement; and the fundamental difference of utilizing averaging from conventional molecular simulation framework based on potential of mean force. This more general development is termed the local distribution theory to release the limitation of strict thermodynamic equilibrium in its potential wide application in general soft condensed molecular systems.


Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 911
Author(s):  
Jūratė Lynikienė ◽  
Vytautas Tamutis ◽  
Artūras Gedminas ◽  
Adas Marčiulynas ◽  
Audrius Menkis

Tetropium gabrieli is a longhorn beetle that usually attacks weakened larch trees. During prolonged summer droughts, T. gabrieli can form outbreaks, causing damages to larch stands. Although it is known in several European countries, in Lithuania it was detected for the first time in 2019. The detection of T. gabrieli indicates potential secondary damages to European larch and other larch species growing in the area.Abstract: Tetropium gabrieli is known to be native to the Alps in Europe where it breeds in European larch (Larix decidua), but it has spread to other areas and was reported in Poland, Sweden, Denmark and Belorussia. Although T. gabrieli is considered an important secondary pest of Larix spp., it can be particularly harmful to trees subjected to abiotic stress. Here we report that in Lithuania, T. gabrieli was for the first time captured in 2019 using sticky traps attached to Larix spp. trees. Two adult beetles were trapped at two different sites in central Lithuania, and this was in the period between 10th of May and 5th of June. Regarding potential threats caused by this insect pest, this new finding requires special attention, particularly on its biology, ecology, and local distribution.


2021 ◽  
pp. 1-12
Author(s):  
Chunyan She ◽  
Shaohua Zeng

Outlier detection is a hot issue in data mining, which has plenty of real-world applications. LOF (Local Outlier Factor) can capture the abnormal degree of objects in the dataset with different density levels, and many extended algorithms have been proposed in recent years. However, the LOF needs to search the nearest neighborhood of each object on the whole dataset, which greatly increases the time cost. Most of these extended algorithms only consider the distance between an object and its neighborhood, but ignore the local distribution of an object within its neighborhood, resulting in a high false-positive rate. To improve the running speed, a rough clustering based on triple fusion is proposed, which divides a dataset into several subsets and outlier detection is performed only on each subset. Then, considering the local distribution of an object within its neighborhood, a new local outlier factor is constructed to estimate the abnormal degree of each object. Finally, the experimental results indicate that the proposed algorithm has better performance and lower running time than the others.


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