scholarly journals The longevity response to warm temperature is neurally controlled via regulation of collagen genes

2021 ◽  
Author(s):  
Sankara Naynar Palani ◽  
Durai Sellegounder ◽  
Yiyong Liu
Keyword(s):  
Reaction Rates ◽  
Warm Temperature ◽  
Extended Lifespan ◽  
Effects Of Temperature ◽  
Negative Impacts ◽  
Response To Temperature ◽  
Increasing Temperature ◽  
Collagen Genes ◽  
The Relationship ◽  
Living Theory

ABSTRACTLower temperatures have been associated with longer lifespan, while higher temperatures with shorter lifespan. These inverse effects of temperature on longevity were traditionally explained by the “rate of living theory”, which posits that higher temperatures increase chemical reaction rates, thus speeding up the aging process. Recent studies have identified specific molecules and cells that mediate the longevity response to temperature, suggesting that the temperature effects on aging are not simply thermodynamic but regulated processes. However, the mechanisms underlying such regulation are not well understood. In the current study, we found that Caenorhabditis elegans lacking NPR-8, a neuronal GPCR related to the mammalian neuropeptide Y receptors, exhibited extended lifespan at warm temperature. Such lifespan extension can be suppressed by re-expression of NPR-8 in the amphid sensory neurons AWB and AWC or by inactivation of NPR-8-regulated collagen genes. These results suggest that the warm temperature effect on longevity is regulated by the nervous system through controlling collagen gene expression. Our study potentially provides mechanistic insights into understanding the relationship between temperature and longevity, which could prove useful in mitigating negative impacts of increasing temperature due to global warming.

Influence of humidity and temperature during exposure on SO2-induced leaf necrosis of Virginia pine and river birch

1987 ◽  
Vol 17 (10) ◽  
pp. 1213-1218 ◽  
Author(s):  
D. M. Umbach ◽  
D. D. Davis
Keyword(s):  
Vapor Pressure ◽  
Vapor Pressure Deficit ◽  
Leaf Conductance ◽  
Negative Slope ◽  
Pine Seedlings ◽  
Temperature And Humidity ◽  
Leaf Necrosis ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
The Relationship

River birch and Virginia pine seedlings were exposed to 0.8 or 1.0 ppm SO2 (approximately 2100 and 2600 μg m−3, respectively) for 4 h at temperatures of 16, 24, and 32 °C and at relative humidities of 60, 75, and 90%, in all combinations. Virginia pine seedlings exhibited increased SO2-induced leaf necrosis with increasing temperature and with increasing humidity. For greenhouse-grown Virginia pine seedlings, the relationship between leaf necrosis and vapor pressure deficit was linear with a common negative slope but with different intercepts for each temperature. For Virginia pine seedlings grown outdoors, the relationship between leaf necrosis and vapor pressure deficit was also linear, but both slope and intercept changed with temperature. For river birch, temperature did not greatly affect the overall level of injury; instead, the response to humidity was negligible, linear, or quadratic, depending on temperature and on the conditions under which seedlings were grown. The effects of temperature and humidity on injury to Virginia pine are consistent with an explanation based on changes in leaf conductance; however, such an explanation cannot easily account for the observed response of river birch.

scholarly journals Effects of temperature on the metabolic stoichiometry of Arctic zooplankton

2013 ◽  
Vol 10 (2) ◽  
pp. 689-697 ◽  
Author(s):  
M. Alcaraz ◽  
R. Almeda ◽  
E. Saiz ◽  
A. Calbet ◽  
C. M. Duarte ◽  
...  
Keyword(s):  
Nutrient Pool ◽  
Marine Food Web ◽  
Carbon Biomass ◽  
Metabolic Products ◽  
Natural Temperature ◽  
Effects Of Temperature ◽  
Excretion Rates ◽  
Increasing Temperature ◽  
The Relationship

Abstract. We assessed the relationship between zooplankton metabolism (respiration and inorganic N and P excretion) and "in situ" temperature through a grid of stations representing a range of natural temperature variation during the ATOS-Arctic cruise (July 2007). The objective was to explore not only the direct effects of temperature on zooplankton carbon respiratory losses (hereafter CR) and NH4-N and PO4-P excretion rates (hereafter NE and PE, respectively), but also to investigate whether these metabolic pathways responded similarly to temperature, and so how temperature could affect the stoichiometry of the metabolic products. Metabolic rates, normalised to per unit of zooplankton carbon biomass, increased with increasing temperature following the Arrhenius equation. However, the activation energy differed for the various metabolic processes considered. Respiration, CR, was the metabolic activity least affected by temperature, followed by NE and PE, and as a consequence the values of the CR : NE, CR : PE and NE : PE atomic quotients were inversely related to temperature. The effects of temperature on the stoichiometry of the excreted N and P products would contribute to modifying the nutrient pool available for phytoplankton and induce qualitative and quantitative shifts in the size, community structure and chemical composition of primary producers that could possibly translate to the whole Arctic marine food web.

scholarly journals Inequality, policy polarization and the income gap in turnout

2021 ◽  
pp. 135406882110119
Author(s):  
Matthew Polacko
Keyword(s):  
Income Inequality ◽  
Low Income ◽  
Party Systems ◽  
Individual Level ◽  
Income Gap ◽  
Income Groups ◽  
Logistic Regressions ◽  
Negative Impacts ◽  
The Impact ◽  
The Relationship

Previous research into the relationship between income inequality and turnout inequality has produced mixed results, as consensus is lacking whether inequality reduces turnout for all income groups, low-income earners, or no one. Therefore, this paper builds on this literature by introducing supply-side logic, through the first individual-level test of the impact that income inequality (moderated by policy manifesto positions) has on turnout. It does so through multilevel logistic regressions utilizing mixed effects, on a sample of 30 advanced democracies in 102 elections from 1996 to 2016. It finds that higher levels of income inequality significantly reduce turnout and widen the turnout gap between rich and poor. However, it also finds that when party systems are more polarized, low-income earners are mobilized the greatest extent coupled with higher inequality, resulting in a significantly reduced income gap in turnout. The findings magnify the negative impacts income inequality can exert on political behavior and contribute to the study of policy offerings as a key moderating mechanism in the relationship.

Survival of Endocronartium harknessii teliospores in a simulated airborne state

1989 ◽  
Vol 67 (3) ◽  
pp. 928-932 ◽  
Author(s):  
Kan-Fa Chang ◽  
P. V. Blenis
Keyword(s):  
Relative Humidity ◽  
Liquid Nitrogen ◽  
Long Distance ◽  
Spider Webs ◽  
Considerable Potential ◽  
Good Ability ◽  
Endocronartium Harknessii ◽  
Spore Longevity ◽  
Effects Of Temperature ◽  
Increasing Temperature

The effects of temperature and relative humidity (RH) on the survival of Endocronartium harknessii teliospores and the longevity of these spores out of doors during daylight hours were studied. In one experiment, fresh and liquid-nitrogen-stored spores of E. harknessii were impacted onto spider webs or plastic threads and incubated in darkness at temperatures of 6, 15, and 24 °C and RHs of 39 and 98%. Survival was measured after 1, 2, 4, 8, and 16 days. Spore longevity decreased with increasing temperature and was lower at 98 than at 39% RH. In a second experiment, spores were impacted onto spider webs and placed out of doors on clear days. Viability decreased linearly with time and averaged 33% after 12 h. The data suggest that E. harknessii has relatively good ability to survive in an airborne state and thus would have considerable potential for long distance spread.

Effects of light, temperature and population variability on the germination of seven Spanish pines

2002 ◽  
Vol 12 (4) ◽  
pp. 261-271 ◽  
Author(s):  
A. Escudero ◽  
F. Pérez-García ◽  
A. L. Luzuriaga
Keyword(s):  
Habitat Preferences ◽  
Population Variability ◽  
Nested Models ◽  
Germination Response ◽  
Germination Characteristics ◽  
Different Populations ◽  
Effects Of Temperature ◽  
Germination Traits ◽  
The Relationship ◽  
Pine Species

AbstractMost Pinus species are obligate seeders. Thus, knowledge of germination characteristics can help in the understanding, prediction and manipulation of the regeneration and dynamics of pine forests. Seven pine species with contrasting habitat preferences and different genetic pairwise distances are present in the Iberian Peninsula and the Canary Islands: P. halepensis, P. nigra, P. pinaster, P. pinea, P. sylvestris, P. uncinata and P. canariensis. These seven pine species comprise an exceptional experimental set to test some questions related to germination traits, such as: (1) What are the effects of light and temperature on germination, taking into account interpopulation variability? (2) Is there any association of germination traits with habitat (montane versus lowland) preferences? and (3) What is the relationship between germination traits and the genetic distance between pine species? P. nigra, P. sylvestris and P. uncinata seeds showed faster germination rates. Seeds of P. nigra and P. sylvestris reached high total germination percentages in every temperature and light treatment, suggesting an opportunistic germination strategy. Unlike montane pines, lowland pines did show significant effects of temperature on germination response: final germination was higher between 15°C and 20°C than at warmer and alternating temperatures. Relatively low temperatures associated with the winter rainy season would favour germination of most of these species. Nested models showed that population variability was the main source of variation in germination response. Thus, there is no phylogenetic control of the germination response and, surprisingly, germination traits were not related to habitat preferences. As a consequence, we believe that studies of the germination characteristics of a pine species should consider different populations.

Effects of Temperature on Leaf Expansion in Sunflower

1982 ◽  
Vol 9 (2) ◽  
pp. 209 ◽  
Author(s):  
HM Rawson ◽  
JH Hindmarsh
Keyword(s):  
Field Studies ◽  
Leaf Expansion ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Leaf Position ◽  
Leaf Emergence ◽  
Temperature Regimes ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Relative Change

Five commercial cultivars of sunflower were grown in cabinets at three temperature regimes, 32/22, 27/17 and 22/12°C, and with 15-h and 11-h photoperiods, and expansion of leaves 5-15 was followed. Leaves appeared faster with increasing temperature (0.022 leaves day-1 °C-1) and with increasing daylength. Areas of individual leaves increased linearly up the plant profile and, although final area per leaf (Amax) decreased with increasing temperature, the relative change was similar for each leaf position. Cultivars maintained their ranking for Amax across temperatures, and these rankings agreed with those in previous field studies. Within each temperature regime, both the expansion rate of leaves and the duration of expansion increased with leaf position. As temperature increased, leaves grew for shorter periods with a change of 1.04 days °C-1, but under the photon flux density used (500 �mol m-2 s-1, or about 25% full sunlight) expansion rates were greatest at the lowest temperature. Expansion rates were only one-third of those in field studies at comparable temperatures, but durations were similar. Cultivars that achieved the largest Amax did so via faster rates of expansion and not via longer durations: only one cultivar differed from the mean (20 days) duration of leaf expansion. All cultivars reached floral initiation progressively earlier with extension of photoperiod from 10 to 15 h, with the change for the most sensitive cultivars being 8 days and for the least sensitive 5 days. Rates of leaf emergence were linked with this sensitivity.

Production of quicklime from Ashaka limestone through calcination process

2021 ◽  
Vol 1 (2) ◽  
pp. 041-048
Author(s):  
Benson Chinweuba Udeh
Keyword(s):  
Particle Size ◽  
Critical Value ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Particle Sizes ◽  
Calcination Process ◽  
Process Effects ◽  
Effects Of Temperature ◽  
The Difference ◽  
The Relationship

This study is on the production of quicklime from Ashaka limestone through calcination process. Effects of temperature, particle size and time on quicklime yield were determined. The experiment was carried out at temperatures of 800, 900, 1000, 1100 and 1200 0C, particle sizes of 80mm, 90mm, 100mm, 300mm and 425mm and times of 0.5hr, 1hr, 2hrs, 3hrs and 4hrs. Analyses of the results showed that quicklime was successfully produced from Ashaka limestone through the calcination process. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. Recorded model F-value of 134.35 implies that the model is significant. The predicted R² of 0.9597 is in reasonable agreement with the adjusted R² of 0.9844; the difference is less than the critical value of 0.2. Optimum yield of 73.48% was obtained at optima operating conditions; temperature of 1000 0C, particle size of 90 µm and time of 3 hrs.

Exploring the Relationship Between Organizational Politic and Knowledge Sharing in Brazilian Modular Consortium

2021 ◽  
Vol 17 (4) ◽  
pp. 76-92
Author(s):  
Indira Arias Rodriguez ◽  
Jorge Muniz Jr. ◽  
Timothy P. Munyon
Keyword(s):  
Knowledge Sharing ◽  
Interpersonal Communication ◽  
Cultural Influences ◽  
Organizational Politics ◽  
Shop Floor ◽  
Future Research ◽  
Assembly Lines ◽  
Perceptions Of Organizational Politics ◽  
Negative Impacts ◽  
The Relationship

This research aimed to explore the relationship between employees' perceptions of organizational politics (POPS) and their predisposition to involve in knowledge sharing (KS) behaviors at individuals and workgroups level in the Brazilian automotive Modular Consortium. The sample included 144 shop floor employees of Modular Consortium (six connected companies in assembly lines). The POPS-KS relationship was analyzed using different referents, seeking to understand how individuals and groups respond to the presence of organizational politics, and POPS and KS were tested in a Brazilian context, shedding new light on potential cultural influences impacting this relationship. The results evidenced that positive interpersonal communication can contribute to KS, and in turn, KS can counteract the negative impacts of POPS. There was a positive relationship between POPS-KS, indicating that POPS may have functional effects in facilitating KS of individuals and workgroups. Key findings and implications for future research were discussed.

Modeling the Growth of Salmonella in Cut Red Round Tomatoes as a Function of Temperature

2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Mathematical Model ◽  
Growth Rates ◽  
Low Temperatures ◽  
Safety Concern ◽  
Time Intervals ◽  
Salmonella Serotypes ◽  
Increasing Temperature ◽  
Incubation Temperatures ◽  
Raw Poultry ◽  
The Relationship

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.

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