scholarly journals Genetic and thermal variation influences adaptation to fluctuating temperature in the seed beetle, Callosobruchus maculatus

2021 ◽  
Author(s):  
Edward R Ivimey-Cook ◽  
Claudio Piani ◽  
Wei-Tse Hung ◽  
Elena C Berg
Keyword(s):  
Environmental Conditions ◽  
Callosobruchus Maculatus ◽  
Experimental Studies ◽  
Thermal Adaptation ◽  
Central India ◽  
Control Treatment ◽  
Long Term Effects ◽  
Seed Beetle ◽  
Constant Control ◽  
Southern Central

The impacts of climate change on biological systems are notoriously difficult to measure, and laboratory studies often do not realistically represent natural fluctuations in environmental conditions. To date, most experimental studies of thermal adaptation test populations at constant temperatures, or they make incremental changes to an otherwise constant mean background state. To address this, we examined the long-term effects of stressful fluctuating daily temperature on several key life history traits in two laboratory populations of the seed beetle, Callosobruchus maculatus. These populations were kept for 19 generations at either a constant control temperature, T=29C, or at a fluctuating daily cycle with Tmean=33C, Tmax=40C, and Tmin=26C. The latter being a simple representation of daily temperatures in southern central India in May, where this species originally evolved. We found that beetles that had evolved in stressful environments were smaller in body size when switched to a constant 29C and had far greater reproductive fitness in comparison to beetles from both the constant control and continuously stressful 33C environments. This suggests that beetles raised in environments with stressful fluctuating temperatures were more phenotypically plastic and had greater genetic variability than control treatment beetles and indicates that populations that experience fluctuations in temperature may be better able to respond to short-term changes in environmental conditions.

scholarly journals Associations between Nature Exposure and Health: A Review of the Evidence

2021 ◽  
Vol 18 (9) ◽  
pp. 4790
Author(s):  
Marcia P. Jimenez ◽  
Nicole V. DeVille ◽  
Elise G. Elliott ◽  
Jessica E. Schiff ◽  
Grete E. Wilt ◽  
...  
Keyword(s):  
Mental Health ◽  
Physical Activity ◽  
Cognitive Function ◽  
Observational Studies ◽  
Green Space ◽  
Current Knowledge ◽  
Experimental Studies ◽  
Empirical Literature ◽  
Protective Effects ◽  
Long Term Effects

There is extensive empirical literature on the association between exposure to nature and health. In this narrative review, we discuss the strength of evidence from recent (i.e., the last decade) experimental and observational studies on nature exposure and health, highlighting research on children and youth where possible. We found evidence for associations between nature exposure and improved cognitive function, brain activity, blood pressure, mental health, physical activity, and sleep. Results from experimental studies provide evidence of protective effects of exposure to natural environments on mental health outcomes and cognitive function. Cross-sectional observational studies provide evidence of positive associations between nature exposure and increased levels of physical activity and decreased risk of cardiovascular disease, and longitudinal observational studies are beginning to assess long-term effects of nature exposure on depression, anxiety, cognitive function, and chronic disease. Limitations of current knowledge include inconsistent measures of exposure to nature, the impacts of the type and quality of green space, and health effects of duration and frequency of exposure. Future directions include incorporation of more rigorous study designs, investigation of the underlying mechanisms of the association between green space and health, advancement of exposure assessment, and evaluation of sensitive periods in the early life-course.

Predator and prey detection in two species of water bear (Tardigrada)

2019 ◽  
Vol 188 (3) ◽  
pp. 860-864 ◽  
Author(s):  
Harry A Meyer ◽  
Hannah E Larsen ◽  
Nézira O Akobi ◽  
Garret Broussard
Keyword(s):  
Environmental Conditions ◽  
The Other ◽  
Physical Contact ◽  
Nutrient Agar ◽  
Control Treatment ◽  
Prey Detection ◽  
Potential Prey ◽  
Predator Prey ◽  
Petri Dishes

Abstract Tardigrade behavioural studies have focused on responses to abiotic environmental conditions. Predator–prey interactions have received some attention, but not how predators and prey might detect one another. Here, we investigate whether a predatory tardigrade species is attracted to, and a potential prey tardigrade avoids, areas previously occupied by the other. In our experiments, Milnesium lagniappe was the predator and Macrobiotus acadianus the prey. Petri dishes with non-nutrient agar were used as experimental arenas. In one treatment, we allowed Macrobiotus to roam over half of the agar for 20 h, while leaving the other half free of Macrobiotus. We then removed the prey and introduced the predator. In the control treatment, no prey were added. Results indicated that Milnesium individuals were significantly concentrated in the area previously occupied by Macrobiotus, whereas no such concentration was evident when Macrobiotus had not been present. A similar protocol was used to test whether Macrobiotus avoided areas previously occupied by the predator. As expected, Macrobiotus were significantly concentrated in the area never occupied by Milnesium, unlike the control treatment. These results suggest that both species can detect the other without physical contact and react accordingly. Given that the experiments were conducted in darkness, detection is probably olfactory.

scholarly journals LONG-TERM EFFECTS OF GRAIN LEGUMES ON RAINY-SEASON SORGHUM PRODUCTIVITY IN A SEMI-ARID TROPICAL VERTISOL

2000 ◽  
Vol 36 (2) ◽  
pp. 205-221 ◽  
Author(s):  
T. J. REGO ◽  
V. NAGESWARA RAO
Keyword(s):  
Grain Yield ◽  
Rainy Season ◽  
Central India ◽  
Fertilizer Application ◽  
Carthamus Tinctorius ◽  
Grain Legumes ◽  
Long Term Effects ◽  
Total N ◽  
Sorghum Grain

In southern and central India, farmers crop Vertisols only in the post-rainy season, to avoid land management problems in the rainy season. In 1983 ICRISAT established a long-term trial seeking to intensify cropping. The trial included intercrops, sequential crops and appropriate Vertisol management technology to allow consecutive rainy-season and post-rainy season crops to be grown. Benefits provided by legumes to succeeding rainy-season sorghum (Sorghum bicolor) were analysed in relation to a non-legume system of sorghum + safflower (Carthamus tinctorius). Rainy-season sorghum grain yield production was sustained at about 2.7 t ha−1 over 12 years within a continuous sorghum–pigeonpea (Cajanus cajan) intercrop system. With a cowpea–pigeonpea intercrop system, succeeding sorghum benefitted each year by about 40 kg N ha−1 (fertilizer nitrogen (N) equivalent). Without N fertilizer application the sorghum grain yield was around 3.3 t ha−1. Legume benefits were less marked in the chickpea (Cicer arietinum)-based rotation than in the pigeonpea system, in which a 12-year build up of soil total N (about 125 μg g−1) was observed. Although sorghum benefitted from this system, pigeonpea yields declined over time due to soil-borne fungi and nematodes. Wider rotations of crops with pigeonpea may help to overcome these problems, while sustaining sorghum production.

Development of Upper Extremity Finite Element Model for Elderly Female: Validated Against Dynamic Loading Conditions

2017 ◽  
Author(s):  
Anand Hammad ◽  
Anil Kalra ◽  
Prashant Khandelwal ◽  
Xin Jin ◽  
King H. Yang
Keyword(s):  
Finite Element ◽  
Upper Extremity ◽  
Injury Risk ◽  
Experimental Studies ◽  
Upper Extremities ◽  
Whole Body ◽  
Crash Test ◽  
Fe Model ◽  
Long Term Effects ◽  
Elderly Female

Injuries to the upper extremities that are caused by dynamic impacts in crashes, including contact with internal instrument panels, has been a major concern, especially for smaller female occupants, and the problem worsens with increasing age due to reduced strength of the bones. From the analysis of 1988–2010 CDS unweighted data, it was found that risk of AIS ≥ 2 level for the arm was 58.2±20.6 percent higher in females than males, and the injury risk for a 75-year-old female occupant relative to a 21-year-old subjected to a similar physical insult was 4.2 times higher. Although injuries to upper extremities are typically not fatal, they can have long-term effects on overall quality of life. Therefore, it is important to minimize risks of injuries related to upper extremities, especially for elderly females, who are most at risk. Current anthropomorphic surrogates, like crash-test dummies, cannot be directly used to study injury limits, as these dummies were developed mainly to represent the younger population. The current study is focused on the development of a finite element (FE) model representing the upper extremity of an elderly female. This can be further used to analyze the injury mechanisms and tolerance limits for this vulnerable population. The FE mesh was developed through Computer Tomography (CT) scanned images of an elderly female cadaver, and the data included for validation of the developed model were taken from the experimental studies published in scientific literature, but only the data directly representing elderly females were used. It was found that the developed model could predict fractures in the long bones of elderly female specimens and could be further used for analyzing injury tolerances for this population. Further, it was determined that the developed segmental model could be integrated with the whole body FE model of the elderly female.

scholarly journals Stagewise resolution of temperature-dependent embryonic and postembryonic development in the cowpea seed beetle Callosobruchus maculatus (F.)

BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Dmitry Kutcherov
Keyword(s):  
Callosobruchus Maculatus ◽  
Thermal Sensitivity ◽  
Postembryonic Development ◽  
Confocal Imaging ◽  
Temperature Dependent ◽  
Destructive Sampling ◽  
Thermal Thresholds ◽  
Seed Beetle ◽  
Thermal Plasticity ◽  
Cowpea Seed

Abstract Background The thermal plasticity of life-history traits receives wide attention in the recent biological literature. Of all the temperature-dependent traits studied, developmental rates of ectotherms are especially often addressed, and yet surprisingly little is known about embryonic responses to temperature, including changes in the thermal thresholds and thermal sensitivity during early development. Even postembryonic development of many cryptically living species is understood superficially at best. Results This study is the first to estimate the exact durations of developmental stages in the cowpea seed beetle C. maculatus from oviposition to adult emergence at five permissive constant temperatures from 20 to 32 °C. Early embryonic development was tracked and documented by means of destructive sampling and subsequent confocal imaging of fluorescently stained specimens. Late embryonic and early larval development was studied with the use of destructive sampling and light microscopy. Well-resolved temporal series based on thousands of embryos allowed precise timing of the following developmental events: formation of the blastoderm; formation, elongation, and retraction of the germ band; dorsal closure; the onset and completion of sclerotization of the cuticle; hatching, and penetration of the first-instar larva into the cowpea seed. Pupation and adult eclosion were observed directly through an incision in the seed coat. The thermal phenotype of C. maculatus was found to vary in the course of ontogeny and different stages scaled disproportionately with temperature, but pitfalls and caveats associated with analyses of relative durations of individual stages are also briefly discussed. Conclusion Disproportionate changes in developmental durations with temperature may have important implications when study design requires a high degree of synchronization among experimental embryos or when the occurrence of particular stages in the field is of interest, as well as in any other cases when development times need to be estimated with precision. This work provides one of the first examples of integration of embryological techniques with ecophysiological concepts and will hopefully motivate similar projects in the future. While experiments with Drosophila continue to be the main source of information on animal development, knowledge on other model species is instrumental to building a broader picture of developmental phenomena.

scholarly journals Sexual conflict and correlated evolution between male persistence and female resistance traits in the seed beetle Callosobruchus maculatus

2017 ◽  
Vol 284 (1855) ◽  
pp. 20170132 ◽  
Author(s):  
Liam R. Dougherty ◽  
Emile van Lieshout ◽  
Kathryn B. McNamara ◽  
Joe A. Moschilla ◽  
Göran Arnqvist ◽  
...  
Keyword(s):  
Sexual Conflict ◽  
Male Genitalia ◽  
Callosobruchus Maculatus ◽  
Negative Relationship ◽  
Female Reproductive Tract ◽  
Female Resistance ◽  
Correlated Evolution ◽  
Male And Female ◽  
Seed Beetle ◽  
Trade Offs

Traumatic mating (or copulatory wounding) is an extreme form of sexual conflict whereby male genitalia physically harm females during mating. In such species females are expected to evolve counter-adaptations to reduce male-induced harm. Importantly, female counter-adaptations may include both genital and non-genital traits. In this study, we examine evolutionary associations between harmful male genital morphology and female reproductive tract morphology and immune function across 13 populations of the seed beetle Callosobruchus maculatus . We detected positive correlated evolution between the injuriousness of male genitalia and putative female resistance adaptations across populations. Moreover, we found evidence for a negative relationship between female immunity and population productivity, which suggests that investment in female resistance may be costly due to the resource trade-offs that are predicted between immunity and reproduction. Finally, the degree of female tract scarring (harm to females) was greater in those populations with both longer aedeagal spines and a thinner female tract lining. Our results are thus consistent with a sexual arms race, which is only apparent when both male and female traits are taken into account. Importantly, our study provides rare evidence for sexually antagonistic coevolution of male and female traits at the within-species level.

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