Search results for "Drift"
showing 10 items of 321 documents
On the verge of extinction: genetics of the critically endangered Iberian plant species, Borderea chouardii (Dioscoreaceae) and implications for cons…
2005
Borderea chouardii is a relictual and dioecious, strictly sexually reproducing, long-living geophyte of the Dioscoreaceae family. Previous biological and demographic studies have indicated the existence of a uniformly distributed panmictic population of this taxon at the southernmost Spanish pre-Pyrenean mountain ranges where it occurs in rather inaccessible crevices of a single limestone cliff. However, individuals of B. chouardii are spatially subdivided into two subpopulations located, respectively, on the upper and lower parts of the cliff, and vertically separated 150 m. Because of its extreme rarity, B. chouardii was the first Iberian taxon to have a specific conservation plan and has…
Inbreeding rate modifies the dynamics of genetic load in small populations
2012
The negative fitness consequences of close inbreeding are widely recognized, but predicting the long-term effects of inbreeding and genetic drift due to limited population size is not straightforward. As the frequency and homozygosity of recessive deleterious alleles increase, selection can remove (purge) them from a population, reducing the genetic load. At the same time, small population size relaxes selection against mildly harmful mutations, which may lead to accumulation of genetic load. The efficiency of purging and the accumulation of mutations both depend on the rate of inbreeding (i.e., population size) and on the nature of mutations. We studied how increasing levels of inbreeding …
Gene flow rates in Yugoslavian populations of the smooth newt Triturus vulgaris
1992
Allozymic variation in 22 loci in several Yugoslavian populations of four subspecies of the smooth newt Triturus vulgaris, has been analyzed. The frequency of private alleles and the coefficient of genetic differentiation, FST, give very different indirect estimates of the effective number of migrants per generation, Nm. However, such Nm estimates, in most cases higher than 1, imply that gene flow between populations is large enough as to prevent differentiation by random drift. In the case of T.v. vulgaris, of which sixteen populations amply distributed through Yugoslavia were sampled, there is evidence that frequent extinction and recolonization processes might be responsible for the obse…
Formation of novel PRDM9 allele by indel events as possible trigger for tarsier-anthropoid split
2016
AbstractPRDM9is currently the sole speciation gene found in vertebrates causing hybrid sterility probably due to incompatible alleles. Its role in defining the double strand break loci during the meiotic prophase I is crucial for proper chromosome segregation. Therefore, the rapid turnover of the loci determining zinc finger array seems to be causative for incompatibilities. We here investigated the zinc finger domain-containing exon ofPRDM9in 23 tarsiers. Tarsiers, the most basal extant haplorhine primates, exhibit two frameshifting indels at the 5’-end of the array. The first mutation event interrupts the reading frame and function while the second compensates both. The fixation of this p…
One coast, two systems: Regional innovation systems and entrepreneurial discovery in Western Norway
2021
This paper introduces an analytical framework for understanding how specialized and diversified regional innovation system (RIS) differ in the way an entrepreneurial discovery process (EDP) is likely to unfold. To analytically explore the proposed framework, we deploy a sequential explanatory design approach, using quantitative data to analyze the regional industry structure of the city regions of Bergen and Stavanger in Western Norway, followed by a qualitative analysis of interviews with key stakeholders in both regions. We find that the city regions face unique challenges that align with an understanding of their respective RIS categorization, providing evidence that the framework propos…
Analysis of good corporate governance at Indonesian telecom industry after privatization: case study at PT Telekom an PT Indosat
2006
Masteroppgave i økonomi og administrasjon, Høgskolen i Agder, Kristiansand The objective of this research is to examine whether there are differences of implementation of good corporate governance of company which privatized using different methods. This is relevant with the change of privatization pattern conducted by the government of Indonesia toward its state-owned companies, from Public Offering to Strategic Sale. One of important decisions taken by the government after the economic crisis is privatization of state-owned companies. It is done because the government finds difficulties to financing its national development programs and economic recovery. From company side, the change of …
Online mass flow prediction in CFB boilers with explicit detection of sudden concept drift
2010
Fuel feeding and inhomogeneity of fuel typically cause fluctuations in the circulating fluidized bed (CFB) process. If control systems fail to compensate the fluctuations, the whole plant will suffer from dynamics that is reinforced by the closed-loop controls. This phenomenon causes reducing efficiency and the lifetime of process components. In this paper we address the problem of online mass flow prediction, which is a part of control. Particularly, we consider the problem of learning an accurate predictor with explicit detection of abrupt concept drift and noise handling mechanisms. We emphasize the importance of having domain knowledge concerning the considered case and constructing the…
Hva, hvem og hvordan? : håndbok i helse-, miljø- og sikkerhetsarbeid
2003
Alt som skjer innenfor en virksomhet skal tilfredsstille lovfestede og forskriftsmessige krav til tilsattes helse, miljø og sikkerhet (HMS). Dette er et viktig satsningsområde innenfor norsk arbeidsliv, og det er regulert av arbeidsmiljøloven med tilhørende forskrift om internkontroll. Imidlertid er det et langt stykke vei å gå fra bestemmelser i lov og forskrift til et funskjonelt og realistisk HMS-opplegg i den enkelte virksomhet. Denne boken er en slags "loggbok" for eget arbeid og egen bevisstgjøring gjennom de siste 6- 7 års arbeid innen HMS-sektoren ved Høgskolen i Agder.
Spin texture motion in antiferromagnetic and ferromagnetic nanowires
2017
We propose a Hamiltonian dynamics formalism for the current and magnetic field driven dynamics of ferromagnetic and antiferromagnetic domain walls in one dimensional systems. To demonstrate the power of this formalism, we derive Hamilton equations of motion via Poisson brackets based on the Landau-Lifshitz-Gilbert phenomenology, and add dissipative dynamics via the evolution of the energy. We use this approach to study current induced domain wall motion and compute the drift velocity. For the antiferromagnetic case, we show that a nonzero magnetic moment is induced in the domain wall, which indicates that an additional application of a magnetic field would influence the antiferromagnetic do…
LOFT - A large observatory for x-ray timing
2010
The high time resolution observations of the X-ray sky hold the key to a number of diagnostics of fundamental physics, some of which are unaccessible to other types of investigations, such as those based on imaging and spectroscopy. Revealing strong gravitational field effects, measuring the mass and spin of black holes and the equation of state of ultradense matter are among the goals of such observations. At present prospects for future, non-focused X-ray timing experiments following the exciting age of RXTE/PCA are uncertain. Technological limitations are unavoidably faced in the conception and development of experiments with effective area of several square meters, as needed in order to…