scholarly journals Low costs of adaptation to dietary restriction

2019 ◽  
Author(s):  
Roy Z. Moger-Reischer ◽  
Elizabeth V. Snider ◽  
Kelsey L. McKenzie ◽  
Jay T. Lennon

ABSTRACTDietary restriction (DR) is the most successful and widespread means of extending organismal lifespan. However, the evolutionary basis of life extension under DR remains uncertain. The traditional evolutionary explanation is that when organisms experience DR, they allocate endogenous resources to survival and postpone reproduction until conditions improve. However, this life-extension strategy should be maladaptive if DR continues for multiple generations due to tradeoffs between longevity and reproduction. To test this prediction, we subjected the budding yeast Saccharomyces cerevisiae to 1,800 generations of evolution on restricted (i.e., DR) vs. non-restricted diets. Adaptation to a non-restricted diet improved reproductive fitness by 57% on that diet, but provided a much smaller (14%) advantage on a restricted diet. In contrast, adaptation to DR resulted in an approximately 35% increase in reproductive fitness on both restricted and non-restricted diets. Importantly, the life-extending effect of DR did not decrease following long-term evolution on the restricted diet. Thus, contrary to theoretical expectations, we found no evidence that the life-extending DR response became maladaptive during multigenerational DR. Our results suggest the DR response may have a low cost and that this phenomenon may have evolved for reasons that extend beyond the benefits of postponing reproduction.

2020 ◽  
Vol 16 (3) ◽  
pp. 20200008
Author(s):  
Roy Z. Moger-Reischer ◽  
Elizabeth V. Snider ◽  
Kelsey L. McKenzie ◽  
Jay T. Lennon

Dietary restriction (DR) is the most successful and widespread means of extending organismal lifespan. However, the evolutionary basis of life extension under DR remains uncertain. The traditional evolutionary explanation is that when organisms experience DR, they allocate endogenous resources to survival and postpone reproduction until conditions improve. However, this life-extension strategy should be maladaptive if DR continues for multiple generations due to trade-offs between longevity and reproduction. To test this prediction, we subjected the budding yeast Saccharomyces cerevisiae to 1800 generations of evolution on restricted versus non-restricted diets. Adaptation to a non-restricted diet improved reproductive fitness by 57%, but provided a much smaller (14%) advantage on a restricted diet. By contrast, adaptation to DR resulted in an approximately 35% increase in reproductive fitness on both restricted and non-restricted diets. Importantly, the life-extending effect of DR did not decrease following long-term evolution on the restricted diet. Thus, contrary to theoretical expectations, we found no evidence that the life-extending DR response became maladaptive during multigenerational DR. Together, our results suggest that the DR response has a low cost and that this phenomenon may have evolved as part of a generalist strategy that extends beyond the benefits of postponing reproduction.


2020 ◽  
Author(s):  
Dieter H.W. Peters ◽  
Günter Entzian

<p>Beginning with 1959 that means over more than 60 years, field strength measurements of the broadcasting station, Allouis (Central France), have been carried out at Kühlungsborn (54° N, 12° E, Mecklenburg, Northern Germany. These so-called indirect phase-height measurements of low frequency radio waves (here with a frequency of 162 kHz) are used to examine the long-term evolution and trends of the mesosphere over Europe. The advantages of the method are the low costs and the simplicity of operation. The extended reanalyzed fifth release of standard-phase height (SPH) are presented.</p><p>The SPH-series are anti-correlated to the solar cycle as known because stronger photo-ionization is linked with higher number of electrons, which reduces the SPH. The anti-correlation between SPH and proxies of solar cycle are well established. Furthermore the statistical analysis of the SPH-series shows a significant overall trend in the order of hundred meters per decade induced by a shrinking stratosphere due to global warming. Strong intra-decadal variability is related to QBO like and ENSO like variability. The derived thickness temperature of the mesosphere decreased statistically significant over the period 1959-2019 after pre-whitening with summer means of solar sun spot numbers. The trend value is in the order of about -1 K/ decade if the stratopause trend is excluded. The amount of linear regression is weaker, -0.8 K/ decade for the period of 1963-1985 (2 SCs), but stronger, about -1.6 K/ decade during 1995-2016 (last 2 SCs).</p>


2014 ◽  
Vol 11 (3) ◽  
pp. 465-476
Author(s):  
Darko Grujovic ◽  
Mirjana Simic

This paper analyzes the challenges to realize an infrastructure independent and a low-cost positioning method in cellular networks based on RSS (Received Signal Strength) parameter, auxiliary timing parameter and environment estimation. The proposed algorithm has been evaluated using field measurements collected from GSM (Global System for Mobile Communications) network, but it is technology independent and can be applied in UMTS (Universal Mobile Telecommunication Systems) and LTE (Long-Term Evolution) networks, also.


Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  

Author(s):  
Chaithra. H. U ◽  
Vani H.R

Now a days in Wireless Local Area Networks (WLANs) used in different fields because its well-suited simulator and higher flexibility. The concept of WLAN  with  advanced 5th Generation technologies, related to a Internet-of-Thing (IOT). In this project, representing the Network Simulator (NS-2) used linked-level simulators for Wireless Local Area Networks and still utilized IEEE 802.11g/n/ac with advanced IEEE 802.11ah/af technology. Realization of the whole Wireless Local Area Networking linked-level simulators inspired by the recognized Vienna Long Term Evolution- simulators. As a outcome, this is achieved to link together that simulator to detailed performances of Wireless Local Area Networking with Long Term Evolution, operated in the similar RF bands. From the advanced 5th Generation support cellular networking, such explore is main because different coexistences scenario can arise linking wireless communicating system to the ISM and UHF bands.


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