scholarly journals Evolution of Human Longevity and the Genetic Complexity Governing Aging Rate

2001 ◽  
Vol 2001 (1) ◽  
Author(s):  
Richard G. Cutler

The genetic complexity of processes governing the aging rate of humans was estimated by determining the maximum rate at which life-span has evolved along the hominid ancestral-descendant sequence. Maximum life-span potential was found to have increased approximately twofold over the past 3 million years, reaching a maximum rate of increase of 14 years per 100,000 years about 100,000 years ago. It is estimated that about 0.6% of the total functional genes have received substitutions leading to one or more adaptive amino acid changes during this 100,000-year time-period. This suggests that aging is not the result of the expression of a large number of independently acting processes. Instead, primary aging processes appear to exist in which only a few genetic changes are necessary to uniformly decrease the aging rate of many different physiological functions. Reproduced by permission. Richard G. Cutler, Evolution of Human Longevity and the Genetic Complexity Governing Aging Rate. Proc. Natl. Acad. Sci. U.S.A. 72 , 4664-4668 (1975).

Author(s):  
S. Pfeiffer

RÉSUMÉLa durée de vie maximale (MLS [Maximum Life Span]) de l'homo sapiens est considérablement plus longue que celle de nos plus proches parents, notamment les primates non-humains. Puisque le mouvement évolutionniste depuis le primate commun ancestral est survenu relativement récemment, les changements génétiques agissant sur le MLS ont done dû également survenir rapidement. L'évolution du MLS s'explique généralement par un effet pleiotropique de substance génétique qui accélère ou renvoie à plus tard toute détérioration cellulaire. Cependant, chez les humains, la notion qu'il pourrait exister une sélection directe visant la longévité semble plausible: chez les hommes, par des mécanismes de santé physique personnelle et chez les femmes, une santé physique équilibrée. Le seul défaut évident retrouvé dans cette ligne de raisonnement est qu'elle est non-falsifiable.


2012 ◽  
pp. 61-83 ◽  
Author(s):  
M. Ershov

According to the latest forecasts, it will take 10 years for the world economy to get back to “decent shape”. Some more critical estimates suggest that the whole western world will have a “colossal mess” within the next 5–10 years. Regulators of some major countries significantly and over a short time‑period changed their forecasts for the worse which means that uncertainty in the outlook for the future persists. Indeed, the intensive anti‑crisis measures have reduced the severity of the past problems, however the problems themselves have not disappeared. Moreover, some of them have become more intense — the eurocrisis, excessive debts, global liquidity glut against the backdrop of its deficit in some of market segments. As was the case prior to the crisis, derivatives and high‑risk operations with “junk” bonds grow; budget problems — “fiscal cliff” in the US — and other problems worsen. All of the above forces the regulators to take unprecedented (in their scope and nature) steps. Will they be able to tackle the problems which emerge?


Author(s):  
Iván Area ◽  
Henrique Lorenzo ◽  
Pedro J. Marcos ◽  
Juan J. Nieto

In this work we look at the past in order to analyze four key variables after one year of the COVID-19 pandemic in Galicia (NW Spain): new infected, hospital admissions, intensive care unit admissions and deceased. The analysis is presented by age group, comparing at each stage the percentage of the corresponding group with its representation in the society. The time period analyzed covers 1 March 2020 to 1 April 2021, and includes the influence of the B.1.1.7 lineage of COVID-19 which in April 2021 was behind 90% of new cases in Galicia. It is numerically shown how the pandemic affects the age groups 80+, 70+ and 60+, and therefore we give information about how the vaccination process could be scheduled and hints at why the pandemic had different effects in different territories.


2021 ◽  
pp. 095792652199215
Author(s):  
Charlotte Taylor

This paper aims to cast light on contemporary migration rhetoric by integrating historical discourse analysis. I focus on continuity and change in conventionalised metaphorical framings of emigration and immigration in the UK-based Times newspaper from 1800 to 2018. The findings show that some metaphors persist throughout the 200-year time period (liquid, object), some are more recent in conventionalised form (animals, invader, weight) while others dropped out of conventionalised use before returning (commodity, guest). Furthermore, we see that the spread of metaphor use goes beyond correlation with migrant naming choices with both emigrants and immigrants occupying similar metaphorical frames historically. However, the analysis also shows that continuity in metaphor use cannot be assumed to correspond to stasis in framing and evaluation as the liquid metaphor is shown to have been more favourable in the past. A dominant frame throughout the period is migrants as an economic resource and the evaluation is determined by the speaker’s perception of control of this resource.


1998 ◽  
Vol 39 (10) ◽  
pp. 1989-1994 ◽  
Author(s):  
Reinald Pamplona ◽  
Manuel Portero-Otín ◽  
David Riba ◽  
Cristina Ruiz ◽  
Joan Prat ◽  
...  

2011 ◽  
Vol 4 (4) ◽  
pp. 4753-4800
Author(s):  
R. Bauer ◽  
A. Rozanov ◽  
C. A. McLinden ◽  
L. L. Gordley ◽  
W. Lotz ◽  
...  

Abstract. The increasing amounts of reactive nitrogen in the stratosphere necessitates accurate global measurements of stratospheric nitrogen dioxide (NO2). Over the past decade, the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) instrument on ENVISAT (European Environmental Satellite) has been providing global coverage of stratospheric NO2 every 6 days, which is otherwise difficult to achieve with other systems (e.g. balloon measurements, solar occultation). In this study, the vertical distributions of NO2 retrieved from limb measurements of the scattered solar light from the SCIAMACHY instrument are validated using NO2 products from three different satellite instruments (SAGE II, HALOE and ACE-FTS). The retrieval approach, as well as the sensitivity of the SCIAMACHY NO2 limb data product are discussed, and the photochemical corrections needed to make this validation feasible, as well as the chosen collocation criteria are described. For each instrument, a time period of two years is analyzed with several hundreds of collocation pairs for each year and instrument. The agreement between SCIAMACHY and each instrument is found to be better than 10 % between 22–24 km and 40 km. Additionally, NO2 amounts in three different latitude regions are validated individually, with considerably better agreements in high and middle latitudes compared to tropics. Differences with SAGE II and ACE-FTS below 20 km are consistent with those expected from the diurnal effect.


2005 ◽  
Vol 79 (1) ◽  
pp. 55-59 ◽  
Author(s):  
N.J. Morley ◽  
M. Crane ◽  
J.W. Lewis

AbstractThe effect of exposingLymnaea stagnalis(Gastropoda: Pulmonata), infected withDiplostomum spathaceum(Trematoda: Diplostomatidae), to 100 μg l−1cadmium for 7 days on survival characteristics (survival, tail loss, decaudized cercarial life-span) of emerged cercariae was investigated. Exposure ofL. stagnalisto cadmium resulted in significantly increasedD. spathaceumcercarial survival and an inhibited tail loss compared to controls. The normal parallel relationship which exists over time between decreasing cercarial survival and increasing tail loss in controls was changed in cercariae from cadmium-exposed hosts with an increased proportion of cercarial deaths occurring without tail loss. The decaudized cercarial life-span over the survival period of the cercarial population did not significantly change. However comparisons between individuals decaudized during the initial 24 h time period with those which were decaudized during the final period of cercarial survival showed a significantly altered life span which did not occur in the control population. As a potential indicator of penetration ‘fitness’ comparisons were also undertaken between control and exposed cercariae decaudized during the initial 24 h time period, which revealed that the decaudized cercarial life-span from the exposed hosts was significantly different from controls. This may have important implications for the ability of cercariae to migrate through the tissues of their target host. The importance and relevance of these results to parasite transmission are discussed.


2006 ◽  
Vol 67 (3) ◽  
pp. 230-239 ◽  
Author(s):  
John M. Budd

Concerns about higher education abound, and these include concerns about productivity. The present study extends two previous examinations of faculty publishing productivity covering the years 1991 to 1993 and 1995 to 1997. Both members of ARL and a group of institutions included in ACRL’s data set are included. For both groups there are some increases in mean total numbers of publications, although the rate of increase has decreased since the second time period. Per capita rates of publication demonstrate an even flatter pattern. In recent years, there have been some changes in the dynamics of universities’ faculties; there are more part-time faculty and more faculty who are not on the tenure track. These factors, coupled with the publishing data, point to activities that all academic librarians should be aware of.


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