scholarly journals Low costs of adaptation to dietary restriction

2020 ◽  
Vol 16 (3) ◽  
pp. 20200008
Author(s):  
Roy Z. Moger-Reischer ◽  
Elizabeth V. Snider ◽  
Kelsey L. McKenzie ◽  
Jay T. Lennon
Keyword(s):  
Dietary Restriction ◽  
Low Cost ◽  
Reproductive Fitness ◽  
Life Extension ◽  
Restricted Diet ◽  
Contrast Adaptation ◽  
Term Evolution ◽  
Trade Offs ◽  
Low Costs

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.

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
Keyword(s):  
Dietary Restriction ◽  
Low Cost ◽  
Reproductive Fitness ◽  
Life Extension ◽  
Evolutionary Explanation ◽  
Restricted Diet ◽  
Contrast Adaptation ◽  
Term Evolution ◽  
Low Costs

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.

scholarly journals Transgenerational fitness effects of lifespan extension by dietary restriction in Caenorhabditis elegans

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
Edward R. Ivimey-Cook ◽  
Kris Sales ◽  
Hanne Carlsson ◽  
Simone Immler ◽  
Tracey Chapman ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Dietary Restriction ◽  
Mortality Risk ◽  
Lifespan Extension ◽  
Dietary Interventions ◽  
Negative Effects ◽  
Trade Offs ◽  
Wide Range ◽  
Broad Variety

Dietary restriction (DR) increases lifespan in a broad variety of organisms and improves health in humans. However, long-term transgenerational consequences of dietary interventions are poorly understood. Here, we investigated the effect of DR by temporary fasting (TF) on mortality risk, age-specific reproduction and fitness across three generations of descendants in Caenorhabditis elegans . We show that while TF robustly reduces mortality risk and improves late-life reproduction of the individuals subject to TF (P 0 ), it has a wide range of both positive and negative effects on their descendants (F 1 –F 3 ). Remarkably, great-grandparental exposure to TF in early life reduces fitness and increases mortality risk of F 3 descendants to such an extent that TF no longer promotes a lifespan extension. These findings reveal that transgenerational trade-offs accompany the instant benefits of DR, underscoring the need to consider fitness of future generations in pursuit of healthy ageing.

scholarly journals Transgenerational fitness effects of lifespan extension by dietary restriction in Caenorhabditis elegans

2020 ◽  
Author(s):  
Edward R. Ivimey-Cook ◽  
Kris Sales ◽  
Hanne Carlsson ◽  
Simone Immler ◽  
Tracey Chapman ◽  
...  
Keyword(s):  
Dietary Restriction ◽  
Mortality Risk ◽  
Future Generations ◽  
Lifespan Extension ◽  
Dietary Interventions ◽  
C Elegans ◽  
Trade Offs ◽  
Wide Range ◽  
Broad Variety

AbstractDietary restriction increases lifespan in a broad variety of organisms and improves health in humans. However, long-term transgenerational consequences of dietary interventions are poorly understood. Here we investigated the effect of dietary restriction by temporary fasting (TF) on mortality risk, age-specific reproduction and fitness across three generations of descendants in C. elegans. We show that while TF robustly reduces mortality risk and improves late-life reproduction in the parental generation (P0), it has a wide range of both positive and deleterious effects on future generations (F1-F3). Remarkably, great-grandparental exposure to TF in early-life reduces fitness and increases mortality risk of F3 descendants to such an extent that TF no longer promotes a lifespan extension. These findings reveal that transgenerational trade-offs accompany the instant benefits of dietary restriction underscoring the need to consider fitness of future generations in pursuit of healthy ageing.

scholarly journals Priority-Based Machine-To-Machine Overlay Network over LTE for a Smart City

2018 ◽  
Vol 7 (3) ◽  
pp. 27 ◽  
Author(s):  
Nargis Khan ◽  
Jelena Mišić ◽  
Vojislav Mišić
Keyword(s):  
Smart City ◽  
Overlay Network ◽  
Long Term Evolution ◽  
City Development ◽  
Machine To Machine ◽  
Crowd Sensing ◽  
Term Evolution ◽  
Trade Offs ◽  
Access Channel

Long-Term Evolution (LTE) and its improvement, Long-Term Evolution-Advanced (LTE-A), are attractive choices for Machine-to-Machine (M2M) communication due to their ubiquitous coverage and high bandwidth. However, the focus of LTE design was high performance connection-based communications between human-operated devices (also known as human-to-human, or H2H traffic), which was initially established over the Physical Random Access Channel (PRACH). On the other hand, M2M traffic is mostly based on contention-based transmission of short messages and does not need connection establishment. As a result, M2M traffic transmitted over LTE PRACH has to use the inefficient four-way handshake and compete for resources with H2H traffic. When a large number of M2M devices attempts to access the PRACH, an outage condition may occur; furthermore, traffic prioritization is regulated only through age-based power ramping, which drives the network even faster towards the outage condition. In this article, we describe an overlay network that allows a massive number of M2M devices to coexist with H2H traffic and access the network without going through the full LTE handshake. The overlay network is patterned after IEEE 802.15.6 to support multiple priority classes of M2M traffic. We analyse the performance of the joint M2M and H2H system and investigate the trade-offs needed to keep satisfactory performance and reliability for M2M traffic in the presence of H2H traffic of known intensity. Our results confirm the validity of this approach for applications in crowd sensing, monitoring and others utilized in smart city development.

scholarly journals Priority-Based Machine-To-Machine Overlay Network over LTE for a Smart City

2021 ◽  
Author(s):  
Nargis Khan ◽  
Jelena Mišić ◽  
Vojislav B. Mišić
Keyword(s):  
Smart City ◽  
Overlay Network ◽  
Long Term Evolution ◽  
City Development ◽  
Machine To Machine ◽  
Crowd Sensing ◽  
Term Evolution ◽  
Trade Offs ◽  
Access Channel

Long-Term Evolution (LTE) and its improvement, Long-Term Evolution-Advanced (LTE-A), are attractive choices for Machine-to-Machine (M2M) communication due to their ubiquitous coverage and high bandwidth. However, the focus of LTE design was high performance connection-based communications between human-operated devices (also known as human-to-human, or H2H traffic), which was initially established over the Physical Random Access Channel (PRACH). On the other hand, M2M traffic is mostly based on contention-based transmission of short messages and does not need connection establishment. As a result, M2M traffic transmitted over LTE PRACH has to use the inefficient four-way handshake and compete for resources with H2H traffic. When a large number of M2M devices attempts to access the PRACH, an outage condition may occur; furthermore, traffic prioritization is regulated only through age-based power ramping, which drives the network even faster towards the outage condition. In this article, we describe an overlay network that allows a massive number of M2M devices to coexist with H2H traffic and access the network without going through the full LTE handshake. The overlay network is patterned after IEEE 802.15.6 to support multiple priority classes of M2M traffic. We analyse the performance of the joint M2M and H2H system and investigate the trade-offs needed to keep satisfactory performance and reliability for M2M traffic in the presence of H2H traffic of known intensity. Our results confirm the validity of this approach for applications in crowd sensing, monitoring and others utilized in smart city development.

Radio Resource Management for Green 3GPP Long Term Evolution Cellular Networks: Review and Trade-offs

2013 ◽  
Vol 30 (3) ◽  
pp. 257 ◽  
Author(s):  
MustafaIsmael Salman ◽  
MuntadherQasim Abdulhasan ◽  
CheeKyun Ng ◽  
NorKamariah Noordin ◽  
Aduwati Sali ◽  
...  
Keyword(s):  
Resource Management ◽  
Cellular Networks ◽  
Radio Resource Management ◽  
Long Term Evolution ◽  
Radio Resource ◽  
Term Evolution ◽  
Trade Offs ◽  
3Gpp Long Term Evolution

Standard-Phase-height measurements over Europe during 60 years of measurements – Long-term variability and trends of the mesosphere

2020 ◽  
Author(s):  
Dieter H.W. Peters ◽  
Günter Entzian
Keyword(s):  
Global Warming ◽  
Solar Cycle ◽  
Decadal Variability ◽  
Low Frequency ◽  
Radio Waves ◽  
Northern Germany ◽  
Term Evolution ◽  
Low Costs ◽  
Photo Ionization

<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>

scholarly journals Priority-Based Machine-To-Machine Overlay Network over LTE for a Smart City

2021 ◽  
Author(s):  
Nargis Khan ◽  
Jelena Mišić ◽  
Vojislav B. Mišić
Keyword(s):  
Smart City ◽  
Overlay Network ◽  
Long Term Evolution ◽  
City Development ◽  
Machine To Machine ◽  
Crowd Sensing ◽  
Term Evolution ◽  
Trade Offs ◽  
Access Channel

Long-Term Evolution (LTE) and its improvement, Long-Term Evolution-Advanced (LTE-A), are attractive choices for Machine-to-Machine (M2M) communication due to their ubiquitous coverage and high bandwidth. However, the focus of LTE design was high performance connection-based communications between human-operated devices (also known as human-to-human, or H2H traffic), which was initially established over the Physical Random Access Channel (PRACH). On the other hand, M2M traffic is mostly based on contention-based transmission of short messages and does not need connection establishment. As a result, M2M traffic transmitted over LTE PRACH has to use the inefficient four-way handshake and compete for resources with H2H traffic. When a large number of M2M devices attempts to access the PRACH, an outage condition may occur; furthermore, traffic prioritization is regulated only through age-based power ramping, which drives the network even faster towards the outage condition. In this article, we describe an overlay network that allows a massive number of M2M devices to coexist with H2H traffic and access the network without going through the full LTE handshake. The overlay network is patterned after IEEE 802.15.6 to support multiple priority classes of M2M traffic. We analyse the performance of the joint M2M and H2H system and investigate the trade-offs needed to keep satisfactory performance and reliability for M2M traffic in the presence of H2H traffic of known intensity. Our results confirm the validity of this approach for applications in crowd sensing, monitoring and others utilized in smart city development.

scholarly journals Progress on Electrolytes Development in Dye-Sensitized Solar Cells

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1998 ◽  
Author(s):  
Haider Iftikhar ◽  
Gabriela Gava Sonai ◽  
Syed Ghufran Hashmi ◽  
Ana Flávia Nogueira ◽  
Peter David Lund
Keyword(s):  
Solar Cells ◽  
Low Cost ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Scale Production ◽  
Dye Sensitized ◽  
Trade Offs ◽  
Redox Shuttles ◽  
Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) have been intensely researched for more than two decades. Electrolyte formulations are one of the bottlenecks to their successful commercialization, since these result in trade-offs between the photovoltaic performance and long-term performance stability. The corrosive nature of the redox shuttles in the electrolytes is an additional limitation for industrial-scale production of DSSCs, especially with low cost metallic electrodes. Numerous electrolyte formulations have been developed and tested in various DSSC configurations to address the aforementioned challenges. Here, we comprehensively review the progress on the development and application of electrolytes for DSSCs. We particularly focus on the improvements that have been made in different types of electrolytes, which result in enhanced photovoltaic performance and long-term device stability of DSSCs. Several recently introduced electrolyte materials are reviewed, and the role of electrolytes in different DSSC device designs is critically assessed. To sum up, we provide an overview of recent trends in research on electrolytes for DSSCs and highlight the advantages and limitations of recently reported novel electrolyte compositions for producing low-cost and industrially scalable solar cell technology.

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