Examining the role of culture and cultural perceptions of aging and dementia in the recognition, diagnosis, and treatment of age-related cognitive impairment remains an understudied area of clinical neuropsychology. This paper describes a qualitative study based on a series of key informant group interviews with an Aboriginal Grandmothers Group in the province of Saskatchewan. Thematic analysis was employed in an exploration of Aboriginal perceptions of normal aging and dementia and an investigation of issues related to the development of culturally appropriate assessment techniques. Three related themes were identified that highlighted Aboriginal experiences of aging, caregiving, and dementia within the healthcare system: (1) cognitive and behavioural changes were perceived as a normal expectation of the aging process and a circular conception of the lifespan was identified, with aging seen as going back "back to the baby stage", (2) a "big change in culture" was linked by Grandmothers to Aboriginal health, illness (including dementia), and changes in the normal aging process, and (3) the importance of culturally grounded healthcare both related to review of assessment tools, but also within the context of a more general discussion of experiences with the healthcare system. Themes of sociocultural changes leading to lifestyle changes and disruption of the family unit and community caregiving practices, and viewing memory loss and behavioural changes as a normal part of the aging process were consistent with previous work with ethnic minorities. This research points to the need to understand Aboriginal perceptions of aging and dementia in informing appropriate assessment and treatment of age-related cognitive impairment and dementia in Aboriginal seniors.
Language is the best example of a cultural evolutionary system, able to retain a phylogenetic signal over many thousands of years. The temporal stability (conservatism) of basic vocabulary is relatively well understood, but the stability of the structural properties of language (phonology, morphology, syntax) is still unclear. Here we report an extensive Bayesian phylogenetic investigation of the structural stability of numerous features across many language families and we introduce a novel method for analyzing the relationships between the "stability profiles" of language families. We found that there is a strong universal component across language families, suggesting the existence of universal linguistic, cognitive and genetic constraints. Against this background, however, each language family has a distinct stability profile, and these profiles cluster by geographic area and likely deep genealogical relationships. These stability profiles seem to show, for example, the ancient historical relationships between the Siberian and American language families, presumed to be separated by at least 12,000 years, and possible connections between the Eurasian families. We also found preliminary support for the punctuated evolution of structural features of language across families, types of features and geographic areas. Thus, such higher-level properties of language seen as an evolutionary system might allow the investigation of ancient connections between languages and shed light on the peopling of the world.
Cites: Proc Biol Sci. 2011 Feb 7;278(1704):474-920810441
Cites: Philos Trans R Soc Lond B Biol Sci. 2010 Dec 12;365(1559):3903-1221041214
Cites: Nature. 2011 May 5;473(7345):79-8221490599
Cites: Hum Biol. 2011 Apr;83(2):279-9621615290
Cites: Science. 2011 Oct 21;334(6054):351-322021854
Cites: Science. 2011 Mar 25;331(6024):1599-60321436451
Cites: Science. 2001 Dec 14;294(5550):2310-411743192
Cites: Bioinformatics. 2003 Aug 12;19(12):1572-412912839
Differences in the degree of separate and combined effects of temperature, pH, and heavy metals (zinc, copper) on the trypsin- and chymotrypsin-like proteinase activities have been established in the whole body of some invertebrate animals - potential objects of fish nutrition: pond snail Lymnaeae stagnalis, orb snail Planorbis purpura, zebra mussel Dreissena polymorpha, oligochaetae Tubifex sp. and Lumbriculus sp. in total, chironomid larvae Chironimus sp. and Ch. riparus, as well as crustacean zooplankton. It has been shown that enzymes of the potential victim at a low temperature can compensate low activity of intestinal proteinases of fish bentho- and planktophages.
Disorders of dietary sugar assimilation occur more often among native people of the Arctic then in temperate climate inhabitants.It is hypothesized that the limited variety of natural exogenous sugars in the Arctic, and their low content in the traditional diets of native northerners in accordance with a "protein-lipid" type of metabolism weakened selection, favoring diversity of disaccharidase enzymes.
In the Antarctic, fishes of dominant suborder Notothenioidei have evolved in a unique thermal scenario. Phylogenetically related taxa of the suborder live in a wide range of latitudes, in Antarctic, sub-Antarctic and temperate oceans. Consequently, they offer a remarkable opportunity to study the physiological and biochemical characters gained and, conversely, lost during their evolutionary history. The evolutionary perspective has also been pursued by comparative studies of some features of the heme protein devoted to O(2) transport in fish living in the other polar region, the Arctic. The two polar regions differ by age and isolation. Fish living in each habitat have undergone regional constraints and fit into different evolutionary histories. The aim of this contribution is to survey the current knowledge of molecular structure, functional features, phylogeny and adaptations of the haemoglobins of fish thriving in the Antarctic, sub-Antarctic and Arctic regions (with some excursions in the temperate latitudes), in search of insights into the convergent processes evolved in response to cooling. Current climate change may disturb adaptation, calling for strategies aimed at neutralising threats to biodiversity.
Only model organisms live in a world of endless summer. Fitness at temperate latitudes reflects the ability of organisms in nature to exploit the favorable season, to mitigate the effects of the unfavorable season, and to make the timely switch from one life style to the other. Herein, we define fitness as Ry, the year-long cohort replacement rate across all four seasons, of the mosquito, Wyeomyia smithii, reared in its natural microhabitat in processor-controlled environment rooms. First, we exposed cohorts of W. smithii, from southern, midlatitude, and northern populations (30-50 degrees N) to southern and northern thermal years during which we factored out evolved differences in photoperiodic response. We found clear evidence of evolved differences in heat and cold tolerance among populations. Relative cold tolerance of northern populations became apparent when populations were stressed to the brink of extinction; relative heat tolerance of southern populations became apparent when the adverse effects of heat could accumulate over several generations. Second, we exposed southern, midlatitude, and northern populations to natural, midlatitude day lengths in a thermally benign midlatitude thermal year. We found that evolved differences in photoperiodic response (1) prevented the timely entry of southern populations into diapause resulting in a 74% decline in fitness, and (2) forced northern populations to endure a warm-season diapause resulting in an 88% decline in fitness. We argue that reciprocal transplants across latitudes in nature always confound the effects of the thermal and photic environment on fitness. Yet, to our knowledge, no one has previously held the thermal year constant while varying the photic year. This distinction is crucial in evaluating the potential impact of climate change. Because global warming in the Northern Hemisphere is proceeding faster at northern than at southern latitudes and because this change represents an amelioration of the thermal environment and a concomitant increase in the duration of the growing season, we conclude that there should be more rapid evolution of photoperiodic response than of thermal tolerance as a consequence of global warming among northern, temperate ectotherms.
To identify the ecological and genetic mechanisms of local adaptation requires estimating selection on traits, identifying their genetic basis, and evaluating whether divergence in adaptive traits is due to conditional neutrality or genetic trade-offs. To this end, we conducted field experiments for three years using recombinant inbred lines (RILs) derived from two ecotypes of Arabidopsis thaliana (Italy, Sweden), and at each parental site examined selection on flowering time and mapped quantitative trait loci (QTL). There was strong selection for early flowering in Italy, but weak selection in Sweden. Eleven distinct flowering time QTL were detected, and for each the Italian genotype caused earlier flowering. Twenty-seven candidate genes were identified, two of which (FLC and VIN3) appear under major flowering time QTL in Italy. Seven of eight QTL in Italy with narrow credible intervals colocalized with previously reported fitness QTL, in comparison to three of four in Sweden. The results demonstrate that the magnitude of selection on flowering time differs strikingly between our study populations, that the genetic basis of flowering time variation is multigenic with some QTL of large effect, and suggest that divergence in flowering time between ecotypes is due mainly to conditional neutrality.
Host immune selection pressure influences the development of mutations that allow for HIV escape. Mutation patterns induced in HIV by the human leukocyte antigen (HLA) are HLA-allele specific. As ethnic groups have distinct and characteristic HLA allele frequencies, we can expect divergent viral evolution within ethnicities. Here, we have sequenced and analyzed the HIV pol gene from 1248 subtype B infected, treatment-na?ve individuals in Canada. Phylogenetic analysis showed no separation between pol sequences from five self-identified ethnic groups, yet fixation index (F(ST)) values showed significant divergence between ethnicities. A total of 17 amino acid sites showed an ethnic-specific fixation pattern (0.015
Cites: Science. 2002 May 24;296(5572):1439-4312029127
Cites: AIDS Res Hum Retroviruses. 2002 Mar 1;18(4):295-30711860677
Cites: Bioinformatics. 2004 Jan 22;20(2):289-9014734327
Cites: Nat Med. 2004 Mar;10(3):282-914770175
Cites: Science. 1986 Jun 20;232(4757):1548-533012778