876 resultados para Resistance and human emancipation


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Huntington disease (HD) phenotype is associated with expansion of a trinucleotide repeat in the IT15 gene, which is predicted to encode a 348-kDa protein named huntington. We used polyclonal and monoclonal anti-fusion protein antibodies to identify native huntingtin in rat, monkey, and human. Western blots revealed a protein with the expected molecular weight which is present in the soluble fraction of rat and monkey brain tissues and lymphoblastoid cells from control cases. In lymphoblastoid cell lines from juvenile-onset heterozygote HD cases, both normal and mutant huntingtin are expressed, and increasing repeat expansion leads to lower levels of the mutant protein. Immunocytochemistry indicates that huntingtin is located in neurons throughout the brain, with the highest levels evident in larger neurons. In the human striatum, huntingtin is enriched in a patch-like distribution, potentially corresponding to the first areas affected in HD. Subcellular localization of huntingtin is consistent with a cytosolic protein primarily found in somatodendritic regions. Huntingtin appears to particularly associate with microtubules, although some is also associated with synaptic vesicles. On the basis of the localization of huntingtin in association with microtubules, we speculate that the mutation impairs the cytoskeletal anchoring or transport of mitochondria, vesicles, or other organelles or molecules.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The human genome contains many repeated DNA sequences that vary in complexity of repeating unit from a single nucleotide to a whole gene. The repeat sequences can be widely dispersed or in simple tandem arrays. Arrays of up to 5 or 6 nt are known as simple tandem repeats, and these are widely dispersed and highly polymorphic. Members of one group of the simple tandem repeats, the trinucleotide repeats, can undergo an increase in copy number by a process of dynamic mutation. Dynamic mutations of the CCG trinucleotide give rise to one group of fragile sites on human chromosomes, the rare folate-sensitive group. One member of this group, the fragile X (FRAXA) is responsible for the most common familial form of mental retardation. Another member of the group FRAXE is responsible for a rarer mild form of mental retardation. Similar mutations of AGC repeats give rise to a number of neurological disorders. The expanded repeats are unstable between generations and somatically. The intergenerational instability gives rise to unusual patterns of inheritance--particularly anticipation, the increasing severity and/or earlier age of onset of the disorder in successive generations. Dynamic mutations have been found only in the human species, and possible reasons for this are considered. The mechanism of dynamic mutation is discussed, and a number of observations of simple tandem repeat mutation that could assist in understanding this phenomenon are commented on.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Measuring human capital has been a significant challenge for economists because the main variable of interest is intangible and not directly observable. In the Middle Eastern and Northern African region the task is further complicated by the general scarcity of comparable and reliable data. This study overcomes these challenges by relying on a unique international survey that covers most of the region and by deriving a market-based measure that uses returns to education and various labour market factors as guidance. The results show that private returns to schooling are relatively low in most southern Mediterranean countries (SMC). Israel and Turkey are clear outliers, surpassing even the EU-MED averages. In Algeria and Jordan, the returns are almost flat, implying that earnings do not respond significantly to education levels. Despite high attainment levels, Greece, Spain and Portugal also perform badly; only marginally surpassing some of the bottom-ranked SMC, providing evidence of problems in absorption capacity. The baseline scenarios for 2030 show substantial sensitivity to current estimates on returns to education. In particular, improving attainment levels can produce measurable gains in the future only when the returns to education are already high. Such is the case for Egypt, Morocco and Turkey, which substantially improve their human capital stocks under the baseline scenarios, surpassing several EU-MED countries with little or no room for improvement.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Are there planets beyond our solar system? What may appear quite plausible now had only been a hypothesis until about twenty years ago. The search for exoplanets is driven by the interest in the “habitable” ones among them. Could such planets one day in the far future provide resources or even shelter for humankind? Will we find one day a habitable planet that is even inhabited? These kinds of imaginative speculations drive public interest in the subject. Imagining alien intelligent life in the universe is not at all new. When Ted Peters called for establishing the field of “astrotheology,” he was certainly thinking less of historical precedents than of something analogous to the emerging field of astrobiology. Will astrotheology result in the decentering of humanity in cosmic dimensions? One could also conclude that we are alone, at least for all practical purposes.