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Search Results: 1 - 10 of 10251 matches for " Frank Frost "
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Wissensmanagement-Vision re: Trends und Strategien
Frost, Ingo,Frank, Kathrin
Open Journal of Knowledge Management , 2012,
Abstract: Die Autoren dieses Artikels gehen der Frage nach, wie Organisationen im Jahr 2020 mit Wissen umgehen werden. Dazu haben sie in einem ersten Schritt nationale und internationale Wissensmanagementkonferenzen, Publikationen und Internetver ffentlichungen analysiert, um Wissensmanagement-Vision re aufzufinden. Dabei sind vier Vision re aufgrund Ihrer Keynotes und ihrer Ver ffentlichungen zu Wissensmanagement-Trends aufgefallen: David Griffiths, Dave Snowden, David Gurteen und Norbert Gronau. Sie werden hier zusammen mit ihren Thesen und Visionen zum Umgang mit Wissen vorgestellt. Am Ende werden diese Thesen gegenübergestellt und diskutiert.
Relative transcript quantification by Quantitative PCR: Roughly right or precisely wrong?
Rasmus Skern, Petter Frost, Frank Nilsen
BMC Molecular Biology , 2005, DOI: 10.1186/1471-2199-6-10
Abstract: Analyses of Q-PCR results from a salmon louse starvation experiment show that, even with apparently good raw data, different analytical approaches [1,2] may lead to opposing biological conclusions.The results emphasise the importance of being cautious when analysing Q-PCR data and indicate that uncritical routine application of an analytical method will eventually result in incorrect conclusions. We do not know the extent of, or have a universal solution to this problem. However, we strongly recommend caution when analysing Q-PCR results e.g. by using two or more analytical approaches to validate conclusions. In our view a common effort should be made to standardise methods for analysis and validation of Q-PCR results.Reverse transcription (RT) followed by quantitative polymerase chain reaction (Q-PCR) is at present the most sensitive method for transcript abundance measurement. However, there are many sources of errors, both when purifying RNA, performing the RT reaction and during the PCR setup [3,4]. Q-PCR utilises optical measurement of generated amplicons to survey PCR amplifications. It is common to derive the initial template concentration from the number of amplification cycles required for a signal to reach a threshold chosen by the investigator [1,2,5]. In relative quantification the expression of a target gene is stated relative to a standard gene, which is assumed to be constitutively and uniformly expressed. One popular approach, the 2-ΔΔCT method, assumes ≈100% efficient target and standard gene PCR reactions given that the results conform to certain criteria [1,5]. In recognition of the fact that PCR efficiencies may vary between runs or between target and standard genes, other numerous methods have emerged that calculate template concentrations using amplification simulations or PCR efficiencies derived from CT values or fluorescence data [2,6-9]. We here present the results of a case study showing that the interpretation of results may vary dramatic
Tay-Sachs and French Canadians: A Case of Gene-Culture Co-evolution?  [PDF]
Peter Frost
Advances in Anthropology (AA) , 2012, DOI: 10.4236/aa.2012.23016
Abstract: Tay-Sachs, an inherited neurological disorder, is unusually common among French Canadians from eastern Quebec. Two alleles are responsible, one being specific to the north shore of the St. Lawrence and the other to the south shore. This pattern of convergent evolution suggests the presence of a selection pressure limited to eastern Quebec. Both alleles probably arose after the British conquest of Quebec in 1759 or at least were uncommon previously. To explain the high incidence of Tay-Sachs among Ashkenazi Jews, some authors have invoked heterozygote advantage, i.e., heterozygous individuals enjoy a higher rate of neuronal growth, and thus greater learning capacity, without the neurological deterioration of homozygous individuals. Such an advantage would have helped Ashkenazim perform the mental effort required for work in trade and crafts. A similar situation may have developed in eastern Quebec, where the relative scarcity of British and American merchants made it easier for French Canadians to enter occupations that required literacy, numeracy, and future time orientation.
The Puzzle of European Hair, Eye, and Skin Color  [PDF]
Peter Frost
Advances in Anthropology (AA) , 2014, DOI: 10.4236/aa.2014.42011

Europeans, particularly northern and eastern Europeans, are unusually colored. Their hair can be not only black but also brown, flaxen, golden, or red, and their eyes not only brown but also blue, gray, hazel, or green. Their skin is pale, almost like an albino’s. This color scheme is more developed in women than in men and seems to have been selected for its visual properties, particularly brightness and novelty. Sexual selection is a likely cause. It favors eye-catching colors and, if strong enough, can produce a color polymorphism, i.e., whenever a visible feature becomes differently colored through mutation, the new color will spread through the population until it loses its novelty value and becomes as frequent as the original one. Such selection is consistent with 1) the many alleles for European hair and eye color; 2) the high ratio of nonsynonymous to synonymous variants; and 3) the relatively short time over which this color diversity developed. Sexual selection will target women if they outnumber men on the mate market. Among early modern humans, such imbalances resulted from 1) a low polygyny rate (because few men could provide for a second wife and her children) and 2) a high risk of early male death (because long hunting distances increased exposure to environmental hazards). Sexual selection of women was stronger at latitudes farther from the equator, where men were less polygynous and more at risk of death while hunting. It was strongest on continental steppe-tundra, where men provided for almost all family food needs by pursuing herds of reindeer and other herbivores over long distances. Although this type of environment is now fragmentary, it covered until 10,000 years ago a much larger territory—the same area where, today, hair and eyes are diversely colored and skin almost milk white.

Evolution of Long Head Hair in Humans  [PDF]
Peter Frost
Advances in Anthropology (AA) , 2015, DOI: 10.4236/aa.2015.54021
Abstract: In many humans, head hair can grow to a much greater length than hair elsewhere on the body. This is a “derived” form that evolved outside Africa and probably in northern Eurasia. The ancestral form, which is frizzier and much shorter, survives in sub-Saharan Africans and in other groups whose ancestors never left the tropics. This original hair form is nonetheless relatively straight and silky during infancy. Head hair thus seems to have lengthened in two stages: 1) retention of the infant hair form at older ages; and 2) further lengthening to mid-back and even waist length. These changes seem to have gone farther in women, whose head hair is thicker and somewhat longer. The most popular evolutionary explanations are: 1) relaxation of selection for short hair; and 2) sexual selection for women with long hair. Neither hypothesis is satisfactory. The first one cannot explain why head hair lengthened so dramatically over so little time. The second hypothesis suffers from the assumption that some populations have remained naturally short-haired because they consider long-haired women undesirable. Almost the opposite is true in traditional African cultures, which have a long history of lengthening and straightening women’s hair. It is argued here that sexual selection produced different outcomes in different populations not because standards of beauty differed but because the intensity of sexual selection differed. In the tropical zone, sexual selection acted more on men than on women and was thus too weak to enhance desirable female characteristics. This situation reversed as ancestral humans spread northward into environments that tended to limit polygyny while increasing male mortality. Because fewer men were available for mating, women faced a more competitive mate market and were selected more severely.
The Hajnal Line and Gene-Culture Coevolution in Northwest Europe  [PDF]
Peter Frost
Advances in Anthropology (AA) , 2017, DOI: 10.4236/aa.2017.73011
Abstract: North and west of a line running from Trieste to St. Petersburg, social relations have long conformed to the Western European Marriage Pattern, i.e., men and women marry relatively late;?many people never marry;?children usually leave the nuclear family to form new households, and households often have non-kin members. This pattern goes back at least to the thirteenth century and perhaps to prehistoric times. I argue that this environment of weaker kinship caused northwest Europeans to create communities based on shared moral rules, rather than shared kinship. Community members enforced these rules by monitoring not only the behavior of other members but also their own behavior and even their own thoughts. Initially, this new mindset did not have a genetic basis. Individuals acquired it within the bounds of phenotypic plasticity. Over time, however, a genetic basis would have developed through the survival and reproduction of individuals who were better at being socially independent, at obeying universal rules, at monitoring other community members, and at self-monitoring, self-judging, and self-punishing. These psychological adaptations—independent social orientation, universal rule adherence, affective empathy, guilt proneness—are moderately to highly heritable. Although they are complex, they required only minor evolutionary changes to evolve out of mechanisms that were already present but limited to specific behavioral contexts. Affective empathy, for instance, is a species-wide trait but usually confined to relations with close kin, particularly between a mother and her young children. An evolutionary scenario is proposed, and two questions discussed. Are these mental traits too complex to have evolved over a span of 30 to 300 generations? Are they too altruistic to be sustainable?
Salmon louse (Lepeophtheirus salmonis) transcriptomes during post molting maturation and egg production, revealed using EST-sequencing and microarray analysis
Christiane Eichner, Petter Frost, Bjarte Dysvik, Inge Jonassen, Bj?rn Kristiansen, Frank Nilsen
BMC Genomics , 2008, DOI: 10.1186/1471-2164-9-126
Abstract: EST sequence analysis shows that 43% of the ESTs have no significant hits in GenBank. Sequenced ESTs assembled into 556 contigs and 1614 singletons and whenever homologous genes were identified no clear correlation with homologous genes from any specific animal group was evident. Sequence comparison of 27 L. salmonis proteins with homologous proteins in humans, zebrafish, insects and crustaceans revealed an almost identical sequence identity with all species.Microarray analysis of maturing female adult salmon lice revealed two major transcription patterns; up-regulation during the final molting followed by down regulation and female specific up regulation during post molting growth and egg production. For a third minor group of ESTs transcription decreased during molting from pre-adult II to immature adults. Genes regulated during molting typically gave hits with cuticula proteins whilst transcripts up regulated during post molting growth were female specific, including two vitellogenins.The copepod L.salmonis contains high a level of novel genes. Among analyzed L.salmonis proteins, sequence identities with homologous proteins in crustaceans are no higher than to homologous proteins in humans. Three distinct processes, molting, post molting growth and egg production correlate with transcriptional regulation of three groups of transcripts; two including genes related to growth, one including genes related to egg production. The function of the regulated transcripts is discussed in relation to post molting morphological changes in adult female salmon louse. There is clear evidence that transcription of the major yolk proteins is not induced before some of the post molting growth of abdomen and the genital segment has occurred. A hallmark for the observed growth is transcription of many putative cuticula proteins prior to the size increase.Copepods are arthropods in the aquatic environment and the extremely abundant free-living species are an essential part of the firs
A trypsin-like protease with apparent dual function in early Lepeophtheirus salmonis (Kr?yer) development
Rasmus Skern-Mauritzen, Petter Frost, Sussie Dalvin, Bj?rn Kvamme, Ingunn Sommerset, Frank Nilsen
BMC Molecular Biology , 2009, DOI: 10.1186/1471-2199-10-44
Abstract: An intronless trypsin-like serine peptidase (LsTryp10) from L., salmonis was identified and characterized. LsTryp10 mRNA is evenly distributed in the ovaries and oocytes, but is located along the ova periphery. LsTryp10 protein is deposited in the oocytes and all embryonic cells. LsTryp10 mRNA translation and concurrent degradation after fertilization was found in the embryos demonstrating that LsTryp10 protein is produced both by the embryo and maternally. The results furthermore indicate that LsTryp10 protein of maternal origin has a distribution pattern different to that of embryonic origin.Based on present data and previous studies of peptidases in oocytes and embryos, we hypothesize that maternally deposited LsTryp10 protein is involved in regulation of the yolk degradome. The function of LsTryp10 produced by the embryonic cells remains unknown. To our knowledge a similar expression pattern has not previously been reported for any protease.Trypsin-like serine peptidases of the S1A subfamily (hereafter referred to as S1A peptidases) are found in all metazoan groups and are involved in a variety of biological processes [1,2]. They are synthesized as inactive zymogens which are activated by proteolytic cleavage at a defined site N-terminal to the proteolytic domain. They may consist of the proteolytic domain only (referred to as single domain peptidases) or may contain one or more additional domains, generally N-terminal to the proteolytic domain (referred to as multi domain peptidases). S1A peptidases are generally extracellular peptidases although some have intracellular functions [2,3]. S1A peptidases involved in digestion commonly consist of a proteolytic domain only, but single domain S1A peptidases may exhibit strict specificity and serve regulatory roles [4-6]. However, regulatory S1A peptidases generally include one or more additional domains [2,5,7]. Trypsins are S1A peptidases with a specific architecture that cleave substrates after Arg and Lys [2]. The
Is keV ion induced pattern formation on Si(001) caused by metal impurities?
Sven Macko,Frank Frost,Bashkim Ziberi,Daniel F. F?rster,Thomas Michely
Physics , 2009, DOI: 10.1088/0957-4484/21/8/085301
Abstract: We present ion beam erosion experiments performed in ultra high vacuum using a differentially pumped ion source and taking care that the ion beam hits the Si(001) sample only. Under these conditions no ion beam patterns form on Si for angles below 45 degrees with respect to the global surface normal using 2 keV Kr ions and fluences of 2 x 10^22 ions/m^2. In fact, the ion beam induces a smoothening of preformed patterns. Simultaneous sputter deposition of stainless steel in this angular range creates a variety of patterns, similar to those previously ascribed to clean ion beam induced destabilization of the surface profile. Only for grazing incidence with incident angles between 60 degrees and 83 degrees pronounced ion beam patterns form. It appears that the angular dependent stability of Si(001) against pattern formation under clean ion beam erosion conditions is related to the angular dependence of the sputtering yield, and not primarily to a curvature dependent yield as invoked frequently in continuum theory models.
Restructuring the Reduced Emissions from Deforestation and Forest Degradation (REDD+) Mechanism for a Post Kyoto Agreement  [PDF]
Kamleshan Pillay, Lisa Frost Ramsay
American Journal of Climate Change (AJCC) , 2015, DOI: 10.4236/ajcc.2015.41007
Abstract: With the possibility of a new climate agreement being formed in 2015 at COP 21 in Paris, there is a vital need to restructure REDD+ for formal inclusion into such an agreement. There are two vital questions that need to be assessed if REDD+ is to be effective as a policy tool within the United Nations Framework Convention on Climate Change (UNFCCC). First, can REDD+ be financially self-sustaining if it remains as a fund based mechanism or will a market based system be more effective? Second, will REDD+ remain primarily a carbon offsetting mechanism or can it also deliver co-benefits (poverty alleviation, biodiversity conservation, and promoting indigenous rights protection)?
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