Search results for "extinction"

Factors affecting between-lake variation in the occurrence of epidermal papillomatosis in roach,Rutilus rutilus(L.)

2009

The theory of island biogeography predicts that the probability of a species occupying an island depends on a dynamic equilibrium between extinction and colonization. Epidermal papillomatosis is a disease manifesting as skin tumours on fish. We studied the factors affecting the occurrence of the disease in roach, Rutilus rutilus (L.), in 34 lakes. The results of discrimination analysis suggest that maximum depth, percentage of the drainage area of the lake covered by lakes in the vicinity and altitude best identified diseased lakes. Comparison of diseased and non-diseased lakes revealed that lake area could also be regarded as a variable contributing to the occurrence of the disease. The sa…

Alarmist by bad design: Strongly popularized unsubstantiated claims undermine credibility of conservation science

2019

“Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades.” or “Our work reveals dramatic rates of decline that may lead to the extinction of 40% of the world's insect species over the next few decades.” These are verbatim conclusions of the recent paper by Sánchez-Bayoa and Wyckhuys (2019) in Biological Conservation. Because of fundamental methodological flaws, their conclusions are unsubstantiated. Like noted by The Guardian, the conclusions of the paper were set out in unusually forceful terms for a peer-reviewed scientific paper. The current case…

Conodonts versus Triassic Climatic and Eustatic Changes

2015

Kılıç, Ali Murat (Balikesir Author)

Ten principles for conservation translocations of threatened wood-inhabiting fungi

2020

Abstract Unlike for many other organism groups, conservation translocations of fungi are still rare. Encouraged by recent successful translocations, there is a growing interest in applying this conservation tool to threatened wood-inhabiting fungi. When combined with other conservation or restoration measures, translocation can be an effective measure for preventing further population decline in the short term, and species extinctions in the long term. Translocations can be appropriate for rare and specialist fungal species that occur as small local populations in isolated patches across fragmented landscapes, where there is a low likelihood of successful dispersal between distant host tree…

Asymmetric transmission of terahertz radiation through a double grating.

2013

We report on experimental evidence of unidirectional transmission of terahertz waves through a pair of metallic gratings with different periods. The gratings are optimized for a broadband transmission in one direction, accompanied with a high extinction rate in the opposite direction. In contrast to previous studies, we show that the zero-order nonreciprocity cannot be achieved. Nonetheless, we confirm that the structure can be used successfully as an asymmetric filter.

89. Loss of extinction in CA1-NMDA receptor deficient mice: A novel model for PTSD?

2009

THE AVERAGE SIZE AND TEMPERATURE PROFILE OF QUASAR ACCRETION DISKS

2014

We use multi-wavelength microlensing measurements of a sample of 10 image pairs from 8 lensed quasars to study the structure of their accretion disks. By using spectroscopy or narrow band photometry we have been able to remove contamination from the weakly microlensed broad emission lines, extinction and any uncertainties in the large-scale macro magnification of the lens model. We determine a maximum likelihood estimate for the exponent of the size versus wavelength scaling ($r_s\propto \lambda^p$ corresponding to a disk temperature profile of $T\propto r^{-1/p}$) of $p=0.75^{+0.2}_{-0.2}$, and a Bayesian estimate of $p=0.8\pm0.2$, which are significantly smaller than the prediction of thi…

Phylogeographic patterns of steppe species in Eastern Central Europe: a review and the implications for conservation

2016

The phylogeography of species associated with European steppes and extrazonal xeric grasslands is poorly understood. This paper summarizes the results of recent studies on the phylogeography and conservation genetics of animals (20 taxa of beetles, butterflies, reptiles and rodents) and flowering plants (18 taxa) of such, "steppic" habitats in Eastern Central Europe. Most species show a similar phylogeographic pattern: relatively high genetic similarity within regional groups of populations and moderate-to-high genetic distinctiveness of populations from currently isolated regions located in the studied area. This distinctiveness of populations suggests a survival here during glacial maxima…

Disturbance-induced emigration: an overlooked mechanism that reduces metapopulation extinction risk.

2021

Emigration propensity (i.e., the tendency to leave undisturbed patches) is a key life-history trait of organisms in metapopulations with local extinctions and colonizations. Metapopulation models of dispersal evolution typically assume that patch disturbance kills all individuals within the patch, thus causing local extinction. However, individuals may instead be able to leave a patch when it is disturbed, either by fleeing before being killed or simply because the disturbance destroys the patch without causing mortality. This scenario may pertain to a wide range of organisms from horizontally transmitted symbionts, to aquatic insects inhabiting temporary ponds, to vertebrates living in fra…

Dianthus superbus as a critically endangered species in Latvia: evaluation of its growth conditions and conservation possibilities

2021

Abstract Dianthus superbus is one of the most endangered species in Latvia and is on the verge of local extinction. Therefore, the aim of this study was to inventory previously identified populations of D. superbus in Latvia and to develop activities to conserve this species in accordance with the results obtained in situ. Expeditions on 18 previously documented locations, according to the data of Nature Conservation Agency, revealed only three existing D. superbus localities in Latvia with a significant number of specimens located in the Latgale region near Silenieki. In 2020, for the first time, two more new D. superbus localities were found in the vicinity of these three approved locatio…