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Estudo dos centenários de Ribeirão Preto - Brasil / Ribeirão Preto - Brazil, centenarians studyPaulo de Oliveira Duarte 10 November 2015 (has links)
Introdução: Centenários são indivíduos que atingiram um século de vida, ou seja, viveram cerca de 20 anos a mais do que a expectativa de vida média da população de países desenvolvidos e 25 anos a mais do que em países em desenvolvimento, como o Brasil. Eles fazem parte do segmento populacional que mais cresce no mundo, sendo estimados aproximadamente 3,8 milhões de idosos nessa faixa etária até a metade deste século. O entendimento das bases da longevidade e do envelhecimento saudável ainda permanece como grande desafio das ciências biológicas no século 21. Objetivos: 1) Conhecimento das características físicas, cognitivas, psíquicas, funcionais e nutricionais da população de centenários presentes na cidade de Ribeirão Preto-SP. 2) Comparar os diversos resultados obtidos entre os centenários com e sem síndrome demencial, desnutridos e não-desnutridos e com independência ou dependência funcional para Atividades Básicas de Vida Diária (ABVDs) pela escala de KATZ. 3) Analisar a expressão gênica transcricional (por qPCR em tempo real) dos genes de interesse IGF1, IGF2, IGF1R, APOE-4, FOXO1 e FOXO3, em linfócitos de sangue periférico dos idosos centenários. Casuística e Métodos: Trata-se de um estudo transversal de base populacional com idosos centenários residentes em Ribeirão Preto, São Paulo, Brasil. Foram obtidas as medidas de peso, altura e pressão arterial, bem como a bioimpedância elétrica. Foi realizada avaliação geriátrica global, por meio de diversas escalas consagradas e análise do desempenho físico e do risco nutricional desses centenários. Numa segunda oportunidade, os pacientes receberam a visita, em jejum, para a coleta de exames laboratoriais, que foram enviados para análise da expressão genética dos genes de interesse. Resultados e Conclusões: Dos 59 centenários residentes na cidade, foram avaliados 33, com média de idade de 101 anos, sendo 27 (81,8%) do sexo feminino, 12 deles (36%) com capacidade cognitiva preservada, assim como independência para ABVDs. Quatorze (58,3%) dos pacientes que responderam a Escala de Depressão Geriátrica não apresentaram sintomas de depressão e demonstraram autopercepção de saúde satisfatória. Do ponto de vista nutricional, 33,3% deles puderam ser classificados como desnutrição instalada, por meio da Mini Avaliação Nutricional (MAN), aumentando para 84,8%, se somados aqueles em risco nutricional. O desempenho físico dos idosos, medido por meio da Short Physical Performance Battery, está significativamente correlacionado, de maneira inversa, ao Fator de Necrose Tumoral, à Interleucina-6, PCR ultra sensível, alfa 1 glicoproteína ácida, velocidade de hemossedimentação e Homocisteína, assim como, de maneira direta, à albumina e ao HDL Colesterol. Os centenários apresentaram elevadas taxas de deficiência de vitamina D e aumento de Homocisteína. Os resultados mostraram que na população estudada não houve diferença significativa na expressão dos genes IGF1R, IGF1, FOXO1, FOXO3 e APOE-4 na comparação entre os grupos demência e não-demência, entre os grupos independência e dependência para ABVDs e entre os desnutridos e não-desnutridos. Houve tendência de diferença na expressão do gene IGF1 entre os grupos demência e não-demência (p=0.07) / Introduction: Centenarians are individuals who have reached one century of life. They live about 20 years longer than the population average life expectancy of developed countries and 25 years longer than developing countries like Brazil. They are part of the fastest growing population segment in the world and it is estimated about 3.8 million seniors in this age group by mid-century. Understanding the longevity basis and the healthy aging remain as great challenges of life sciences in the 21st century. Objectives: 1) The knowledge of physical, cognitive, psychological, functional and nutritional status of Ribeirão Preto centenarians. 2) Compare results between centenarians with and without dementia, malnourished or not, and independent for basic activities daily living (BADL) or not. 3) Analyze the transcriptional gene expression (by real-time PCR) of genes IGF1, IGF2, IGF1R, APOE-4, FOXO1 and FOXO3 in peripheral blood lymphocytes of centenarians. Casuistic and Methods: This is a cross-sectional population-based study of community-dwelling centenarians living in Ribeirão Preto, São Paulo, Brazil. Ages were confirmed by birth certificate. Weight, height and blood pressure measurements were obtained, as well the bioimpedance, the global geriatric assessment through various consecrated scales, the physical performance and nutritional risk of centenarians. A second chance, patients received one visit for the collection of fasting laboratory tests and sending the genetic material for analysis of gene expression. Results and Conclusions: Thirty three centenarians with an average age of 101 years, 27 (81.8%) of them were females, 12 (36%) of them with no dementia and independent for BADLs. Fourteen (58.3%) of volunteers who responded the Geriatric Depression Scale showed no symptoms of depression and 14 had the same self-perception of satisfactory health. Regarding nutrition state, 33.3% of patients could be classified as installed malnutrition by the Mini Nutritional Assessment, rising to 84.8% if we add those at nutritional risk. The performance measured by Short Physical Performance Battery was inversely correlated to the Tumor Necrosis Factor, Interleukin-6, ultra sensitive PCR, alpha-1 acid glycoprotein, ESR and homocysteine, and as a direct manner correlated to albumin and HDL Cholesterol. The centenarians showed high levels of vitamin D deficiency and hyperhomocysteinemia. The results showed no significant difference in the IGF1R, IGF1, FOXO1, FOXO3 and APOE-4 expression between Dementia and No dementia groups, between Independent and Dependent groups for BADL and between Malnourished and no malnourished groups. There is a tendency of difference in the expression of IGF1 gene between Dementia and No dementia groups (p=0.07)
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Fenomén dlouhověkosti / Phenomenon of longevityKrejná, Anna January 2015 (has links)
Thesis entitled Phenomenon of longevity aims to describe and define very actual today Thema longevity. There is also mentioned particularly contemporary view of the phenomenon and its historical development. This work also touches demographics and life expectancy, which is closely linked to longevity. Great attention is paid to the problem spots in the lives of very old people, especially their disadvantaged status. On this chapter is followed also the care and support of life, that is in such high age necessary. Part of the work are also two research projects that enable an insight into the past lives of long-lived seniors in their health and functional status, and especially trying to uncover the causes of longevity.
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Dinâmica populacional e Atherinella brasiliensis (Quoy & Gaimard, 1824) da praia de Itamambuca, Ubatuba (SP) / Populacional dynamic of the Atherinella brasiliensis (Quoy & Gaimard, 1824) from Itamambuca beach, Ubatuba (SP)Fernandez, Wellington Silva 26 June 2007 (has links)
O presente estudo analisou aspectos do ciclo de vida e níveis de metais em Atherinella brasiliensis da praia de Itamambuca, Ubatuba (SP). As coletas foram mensais, nos períodos diurno e noturno, de setembro de 2003 a fevereiro de 2005, em quatro estações na praia e uma no rio Itamambuca, utilizando-se picaré. Os indivíduos migram diariamente para dentro do rio no período noturno. O melhor ajuste ao modelo de von Bertalanffy (CT= 164,85*(1-e-2,16(t+0,0038))) e à longevidade (A0,95= 1,378 ano) foi obtido pelo método de Ford-Walford. O índice de performance de crescimento e a mortalidade variaram de 2,77 a 2,91 e 1,64 a 1,82 ano-1, respectivamente. O valor de L50 estimado para sexos agrupados foi 86,6 mm, e os de RGS, DK e a freqüência de desovantes sugerem desova durante todo o ano, com maior intensidade do final da primavera até início do outono. A desova é parcelada, com alta freqüência e em pequenos lotes. Altas concentrações de Cr, Fe e Zn foram detectadas na musculatura, sendo maiores em indivíduos jovens e na alta temporada turística. Pode-se concluir que o peixe-rei passa todo seu ciclo de vida na praia de Itamambuca, apresenta altas taxas de crescimento e mortalidade natural, e desova ao longo de todo o ano. / The present study analyzed the life history and metal levels of Atherinella brasiliensis from Itamambuca beach, Ubatuba (SP). Surveys were conducted monthly, in diurnal and nocturnal periods, between September 2003 and February 2005, in four stations at the beach and one at the Itamambuca river, using beach seine. Individuals showed daily migration into the river at nocturnal period. The better adjustment to von Bertalanffy?s model (Lt = 164.85*(1-e-2.16(t+0.0038))) and to longevity (A0.95= 1.378 year) was obtained through Ford-Walford method. The value of estimated L50 for grouped gender was 86.6 mm, and the GSR, the DK and the spawning frequency suggest spawning during all year around, with higher intensity in late spring until middle autumn. The high frequency of spawning and the low batch fecundity indicate that the species is a batch spawner. High concentrations of Cr, Fe and Zn were detected in musculature, being higher among young individuals, and during tourist high season. In conclusion, the Brazilian silverside spends its life cycle on the Itamambuca beach, shows high growth and natural mortality rates, and spawning throughout the year.
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Genetic evaluation of functional longevity in South African Holstein cattle using a proportional hazards modelImbayarwo-Chikosi, Venancio Edward 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Improvement and selection of superior animals for longevity is a viable complimentary strategy for increasing functional longevity of Holstein dairy cattle. Genetic evaluation of animals for functional longevity is a prerequisite for improvement of the trait. This study was carried out to determine non-genetic factors that influence functional longevity in South African Holstein cattle, as well as to estimate genetic parameters for functional longevity, estimate sire breeding values, and to establish the contribution of conformation traits to the risk of cows being culled from dairy herds. Analyses were carried out using records of 166 222 daughters of 2 051 sires from 1 545 herds in six regions of South Africa. The regions were the Western Cape, Eastern Cape, Northern Cape, Free State, Kwa-Zulu Natal and the combined Gauteng & North Western Provinces. Data were analysed using a piecewise Weibull sire-maternal grandsire model in which the baseline hazard was assumed to change at 270 and 380 days in milk as well as at drying-off. The fixed effects model comprised of the time-independent effect of age at first calving, the combined time-dependent effects of region x year of calving, number of lactations x within-herd milk production class, year of calving x within-herd protein and year of calving x fat percentage production class. Model also had the combined time-dependent effect of herd size x annual herd size change. The random herd-year and sire effects were later included in the model for the estimation of sire and herd-year variance components. Analyses indicated a decline in the survival function, an indicator of functional longevity, among cows that calved for the first time in 2000, 2004 and 2008. Cows that delivered their first calf in 2000 had better survival functions that those that calved for the first time in 2004 and 2008. All fitted effects significantly contributed to the risk of a cow being culled from a herd. Within-herd milk production made the largest contribution to the risk of a cow being culled from a herd. Survival was best in the Northern Cape and worst in Eastern Cape. The risk of being culled was the highest for cows in the second stage of lactation (271- 380 days), when the entire lactation period was considered. High producing cows were more likely not to be culled from a herd than poor producing cows. Cows were more likely to be culled for low protein production percentage than within-herd fat production percentage. The risk of being culled was low for heifers calving at 20 to 25 months of age. The higher risk of culling among cows with multiple lactations indicated the culling policy of dairy farmers to retain a higher number of younger cows than older cows in herds. A decrease in herd size was indicative of a high culling rate. Effective heritability was 0.109. Breeding values ranged from 2.12 for the best cows to -4.80 for the worst cows. This implied that the best and the worst cows were 2.12 times and 4.80 more likely to be culled from herds than the average cow respectively. Genetic trends for functional longevity indicated a marginal decline in sire estimated breeding values. This corresponded with the phenotypic decline in the survivor function observed in cows that calved in 200, 2004 and 2008. All udder, rump, body, feet and leg type traits, with the exception of rear leg side, significantly influenced functional longevity. Farmers culled cows mainly of extremely poor type with a tendency to retain animals with poor to very good structure. Udder traits contributed the most to the risk of a cow being culled. Cows were more likely to be culled for poor scores received for rear teat placement, rear udder height and fore udder attachment, than for any of the other conformation type traits. The contribution of angularity to the risk of being culled was also high, indicating a preference for highly angular bodied cows. Conformation type traits can therefore be used as indicator traits for functional longevity in Holstein cattle, especially when selection and culling is done based on very poor scores for udder traits. The study indicated that genetic improvement in functional longevity can be achieved with the evaluation and selection of dairy sires. There is therefore a wide scope for including functional longevity in the selection objectives for South African Holstein cattle. There is a need to develop appropriate models to ensure that the national dairy industry can benefit from using a Weibull piecewise model. / AFRIKAANSE OPSOMMING: Die verbetering en seleksie van voortreflike diere vir langlewendheid is 'n lewensvatbare en aanvullende strategie vir die verhoging van die funksionele langlewendheid van Holstein melkbeeste. Die genetiese evaluasie van melkproduserende diere ten opsigte van hierdie eienskap is ʼn voorvereiste om verbetering in die eienskap moontlik te maak. Die studie is uitgevoer om nie-genetiese faktore wat die funksionele langlewendheid van Suid-Afrikaanse Holsteins beïnvloed te bepaal, om genetiese parameters vir langlewendheid en vaar teeltwaardes vir dié eienskap te bepaal en ook om die bydrae van bouvorm eienskappe tot die waarskynlikheid van koeie om uitgeskot te word, te bepaal. ʼn Databasis bestaande uit rekords van 166 222 dogters van 2 051 vaars, wat in ses streke in Suid-Afrika (Wes-Kaap, Oos-Kaap, Noord-Kaap, Vrystaat, KwaZulu-Natal en die gekombineerde Gauteng en Noord-Wes Provinsies) voorgekom het, is vir die studie gebruik. Data is ontleed met behulp van 'n stuksgewyse Weibull vader-moeder grootvader model, waarin die basislyn risiko aanvaar is om te verander op 270, 380 dae na kalwing en by afdroog van die melkkoeie. Die vaste effek model het die tyd-onafhanklike effek van ouderdom met eerste kalwing en die tyd-afhanklike effekte van streek en jaar van kalwing, aantal laktasies en binne-kudde melkproduksie klas, binne-kudde proteïen en vet persent produksie klasse volgens jaar van kalwing, asook die gekombineerde tyd-afhanklike effek van kuddegrootte en jaarlikse verandering in kudde grootte, ingesluit. Die ewekansige trop-jaar en vaar effekte is later opgeneem in die model vir bepaling van die vaar- en kudde-jaar variansie komponente. Ontledings het aangedui dat daar 'n algemene afname in die oorlewingsfunksie, wat ʼn aanduiding van funksionele langlewendheid is, was in koeie wat vir die eerste keer in 2000, 2004 en 2008 gekalf het. Koeie wat vir die eerste keer in 2000 gekalf het, het ʼn hoër waarde vir die oorlewingsfunksie gehad as koeie wat onderskeidelik in 2004 en 2008 gekalf het. Alle vaste effekte het betekenisvol tot die waarskynlikheid van ʼn koei om uitgeskot te word, bygedra. Binne-kudde melkproduksie het die grootste bydrae tot die waarskynlikheid van ʼn koei om uitgeskot te word, gemaak. Wanneer die totale laktasieperiode in ag geneem is, was daar gevind dat koeie wat in die tweede fase van laktasie (271-380 dae) die hoogste risiko ervaar het om uitgeskot te word. Hoë produseerders, wanneer hulle met lae produseerders vergelyk is, was minder geneig om uitgeskot te word. Koeie was meer geneig om uitgeskot te word vir lae proteïen produksie persentasie as binne-kudde vet produksie persentasie. Die waarskynlikheid om uitgeskot te word, was laag vir verse wat op ʼn ouderdom van 20 tot 25 maande gekalf het. Die hoër risiko van uitskot van koeie met veelvuldige laktasies het aangedui dat melkboere geneig was om meer jonger koeie te behou en ouer koeie uit te skot. ʼn Afname in kuddegrootte was aanduidend van ʼn hoë uitskotpersentasie. Die effektiewe oorerflikheid was 0.109, met teelwaardes wat van 2.12 vir die hoogste produserende koeie tot -4.80 vir die laagste produserende koeie, gewissel het. Hierdie waardes het dus aangedui dat hoë produseerders en swak produseerders onderskeidelik ʼn 2.12 en 4.80 groter kans gehad het om uitgeskot te kan word. Genetiese tendense vir funksionele langlewendheid het aangedui dat daar 'n marginale afname in vaar beraamde teelwaardes vir funksionele langlewendheid was. Dit het ooreengestem met die waargenome fenotipiese afname in die oorlewingsfunksie wat in 2000, 2004 en 2008 gekalf het. Alle bou-tipe eienskappe (uier, agterkwart, liggaam, voet en been), met die uitsondering van die agterbeen kant, het funksionele langlewendheid betekenisvol beïnvloed. Boere het koeie hoofsaaklik op uiters swak boutipe uitgeskot, met 'n neiging om diere wat as ʼn swak tot uiters goeie bouvorm geklassifiseer is, te behou. Uier eienskappe het die meeste tot die waarskynlikheid van ʼn koei om uitgeskot te word, bygedra. Koeie met ʼn lae gradering vir agterste speen plasing, agter-uier hoogte en voor-uier aanhegting se waarskynlikheid om uitgeskot te word, was groter. Die bydrae van hoekigheid tot die waarskynlikheid van ʼn koei om uitgeskot te word was hoog, wat ʼn aanduiding van ʼn voorkeur vir 'n baie growwe hoekigheid was. Bouvorm tipe eienskappe kan dus gebruik word as indikator eienskappe vir funksionele langlewendheid in Holstein melkbeeste, veral wanneer in ag geneem word dat die meeste melkboere seleksie op grond van swak gradering van uier eienskappe doen. Die studie het aangedui dat genetiese verbetering in funksionele langlewendheid teweeg gebring kan word met die evaluering en seleksie van Holstein vaars. Daar is dus ʼn geleentheid vir die insluiting van funksionele langlewendheid in die seleksie doelwitte vir Suid-Afrikaanse Holstein beeste. Daar is ʼn behoefte om toepaslike modelle te ontwikkel wat met die toepassing daarvan, sal verseker dat die plaaslike melkbedryf sal kan voordeel trek deur die gebruik van 'n stuksgewyse Weibull model benadering.
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Longevity and oviposition of Mediterranean fruit fly (Ceratitis capitata) (Diptera : Tephritidae) fed on a predominantly sugar and a predominantly protein dietVan der Merwe, Cornelia 03 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Experiments using the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), were conducted
to determine the mortality of males and females and the ovipositing ability of females fed on
two diets. The sugar diet consisted of 5: 1 sugar:protein and the protein diet consisted of 5:1
protein: sugar. Dilutions of 80%, 60%, 40%, 20% and 10% with water of both diets were also
provided to the flies. Female longevity was shorter than male longevity. There was no difference
in female longevity between fruit flies fed on the two diets. However, males fed on the sugar
diet lived longer than those fed on the protein diet. More eggs per female per day were laid by
those fed the sugar diet than by those fed the protein diet. There were no differences m
oviposition between flies fed on the different concentrations of the two diets. / AFRIKAANSE OPSOMMING: Proewe met die Mediterreense vrugtevlieg, Ceratitis capitata (Wiedemann), is uitgevoer om die
mortaliteit van die mannetjies en wyfies, asook eierlegging van wyfies wat met twee
verskillende diëte voorsien is, te bepaal. Die onderskeie diëte het uit 'n mengsel van proteïen en
suiker (5 dele suiker en 1 deel proteïen) en (5 dele proteïen en 1 deel suiker) bestaan.
Verdunnings van 80%, 60%, 40%, 20% en 10% is van die onderskeie diëte gemaak en aan die
vlieë voorsien. Daar was geen verskil in die lewensduur van wyfies wat op die twee diëte
gevoed is nie. Mannetjies wat op die oorwegende suiker dieët gevoed is, het langer as dié wat op
die proteïen dieët gevoed is, geleef. Vlieë wat op die suiker dieët gevoed het, het regdeur 'n hoër
gemiddelde daaglikse eierlegging per wyfie as dié wat op die proteïen dieët gevoed het, getoon.
Geen noemenswaardige verskil in eierlegging vir vlieë wat op verskillende konsentrasies van
die twee diëte gevoed het, is gevind nie.
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An examination of the mentoring strategies and match quality indices that effect both a child’s change in social competency and a mentor’s sense of sufficiencyCollins, Sarah Margaret, 1977- 30 September 2010 (has links)
Much of the recent literature in mentoring centers on the effectiveness of volunteers who donate their time to relationships with children in need of a positive adult role model (DuBois & Karcher, 2005). Because mentors generally take on a great deal of responsibility with youth who are often at-risk either personally or academically (Commonwealth Fund, 1998; McLearn, Colasanto & Schoen, 1998; McLearn et al., 1999), researchers want to identify those variables and practices that increase the chance of a successful and beneficial relationship (Nakkula & Harris, 2005). This study examined the benefits of adult-child mentoring and looked for connections between the mentees’ growth in social competence and the relationship length, match quality, and specific mentoring strategies employed. The mentors’ perceptions of sufficiency about the match, the mentee’s additional resources, and their own abilities were also examined. A survey was distributed electronically to 890 Austin, Texas mentors about their relationships, and a separate school level survey was distributed to the 90 mentor contacts located in each school that utilizes mentors. School demographic data was also collected from the Texas Education Agency. The results indicate that longer and more high-quality matches, an increased importance placed on getting the mentee to care more about others, and spending more time with the mentee’s teachers all predict higher levels of growth in specific social competencies. The strength of the match was also a positive predictor of the mentors’ sense of sufficiency about themselves and about the impact of mentoring with their mentee. The results suggest a need for increased training in the specific caring and teacher-involvement mentor strategies, and for more discussion with mentors about the importance of committing to long-term, high-quality matches. / text
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Perceived benefits of, barriers and helpful cues to physical activity among tertiary institution students in Rwanda.Tumusiime, David Kabagema January 2004 (has links)
According to literature, particularly from data obtained from the World Health Organisation, physical inactivity or sedentarism is one of the leading causes of the major non-communicable diseases, which contributes substantially to the global burden of diseases, death and disability. The burden of mortality, morbidity and disability attributable to non-communicable diseases is currently greatest and is continuing to grow in the developing countries. Most declines in physical activity are during the transition from high school to college or university. The aim of the study was to ascertain perceptions of physical activity, specifically / perceived benefits of, perceived barriers and perceived helpful motivational factors to physical activity among tertiary institution students in Rwanda, and to find out whether demographic and background characteristics have an influence on these perceptions.
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An Analysis of the Effect of ß-Hydroxy-ß-Methylbutyrate on the Flight Ability and Lifespan of Drosophila melanogasterBeattie, Alexandra Elizabeth 01 January 2014 (has links)
As muscle function deteriorates with age, the discovery of new ways to enhance the quality of human life by stunting inevitable aging processes, such as sarcopenia, is a subject of great interest to aging populations, to health care professionals and to nutritional companies. β-hydroxy-β-methylbutyrate (HMB) enhances muscle strength in humans and attenuates disease-induced and disuse-dependent atrophy in rodents. We investigated the feasibility of utilizing Drosophila as a model organism to study the biological effects of HMB in aging muscle. Using flight ability as an index of muscle function and monitoring the lifespan of flies, we found that normal food supplemented with 10 mg/mL HMB, supplied from eclosion through adulthood, attenuates the age-dependent decline in flight ability and enhances longevity of flies.
To further discern the dietary optimization of HMB supplementation, we examined the effect of 10 mg/mL HMB supplementation from the larval stages throughout adulthood under various dietary conditions. As dietary restriction without malnutrition and HMB supplementation independently increase longevity in flies, we investigated the relationship between dietary restriction and HMB supplementation. Flies were subject to non-restricted, reduced yeast (protein), or intermittently cycled feeding regimens, with or without HMB.
Both modes of dietary restriction improved flight ability, while only cycling flies on and off food increased lifespan and improved survivorship of the flies. HMB supplementation increased flight ability later in life in all groups, but had differential effects on lifespan; HMB improved the survivorship of females fed a reduced yeast diet, but decreased the survivorship of both non-restricted and intermittently fed flies. This not only suggests that HMB may act via different pathways to influence fly flight and survivorship, but that these mechanisms may differ under various dietary conditions, in different sexes. Because HMB supplemented dietary restriction had different effects on flight ability and survival than dietary restriction alone, HMB likely acts via different mechanisms than dietary restriction. Sex specific effects were found, suggesting that future HMB and dietary restriction studies should make distinctions between effects in males and females.
As the flight ability and longevity of D. melanogaster was affected by HMB supplementation under various dietary conditions, future studies may use D. melanogaster as a model organism to explore the effects of HMB on age-related muscle deterioration and to help uncover the biological mechanisms of such observations, as well as potential treatments for age-associated muscle dysfunction and disease.
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Molecular mechanisms of premature ageing in a worm model of human Werner syndromeLees, Hayley Diane January 2014 (has links)
Investigating the biological basis of ageing is both fascinating and medically relevant, as we strive to understand both how organisms age, and how our knowledge might be put to good use in an increasingly long-lived human population. Despite the complexity of ageing biology, it is very striking that longevity, in a wide variety of organisms, can be modified by manipulating single genes. In this thesis, I investigate phenotypes associated with mutations in C. elegans homologues of human WRN, the gene mutated in the progeroid Werner syndrome (WS). Mutant phenotypes in the worm recapitulate aspects of the pathophysiology observed in WS patients, including premature ageing, genomic instability, and sensitivity to DNA damaging agents. wrn-1 overexpression, on the other hand, appears to enhance longevity, suggesting that wrn-1 acts as a bona fide anti-gerontogene. The combination of wrn-1 mutations with mutation in the worm p53 homologue, cep-1, unexpectedly triggers a novel and very striking enhanced lifespan and healthspan phenotype, termed synthetic super-viability (SSV). The SSV phenotype is modulated by various environmental inputs such as temperature stress. The data presented here can be incorporated into a model in which stress sensing (involving p53) is the crucial determinant of longevity outcomes. Several theories of ageing incorporate the idea that 'that which does not kill us, makes us stronger' - encapsulated in a biological sense in the idea of hormesis, a physiological shift in response to stress. Here, this hypothesis is expanded to include the notion that intrinsic <strong>responses</strong> to stress may themselves act to limit lifespan - too much of a good thing can be bad.
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Stochastické modelování vývoje úmrtnosti / Stochastic modelling of mortality developmentŠkerlík, Peter January 2013 (has links)
In the presented diploma thesis we study possibilities of forecasting mortality rates and we explain the most used models to measure it. The longevity and mortality risk are characterized and options for transfer of risks to other subjects are suggested. Further we applied LifeMetrics tool to predict mortality and quantify longevity risk in our data set, also possibilities of its usage are described in more details. The aim of the work is to provide the reader with sufficient amount of theoretical information about the used stochastic models for mortality prediction. Also the work may be helpful to gain deeper knowledge about longevity risk.
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