scholarly journals Inter‐Specific and Inter‐Population Variation in Individual Diet Specialization: Do Environmental Factors Have a Role?

2020 ◽  
Vol 101 (3) ◽  
Author(s):  
Enrico Lunghi ◽  
Raoul Manenti ◽  
Fabio Cianferoni ◽  
Filippo Ceccolini ◽  
Michael Veith ◽  
...  
2017 ◽  
Author(s):  
Juliane Meyer ◽  
Claudia Wrozyna ◽  
Albrecht Leis ◽  
Werner Piller

Abstract. Isotopic signatures of ostracod shells became common proxies for the reconstruction of paleo-environmental conditions. Their isotopic composition is the result of the composition of their host water and the phenology and ecology of the target species. The sum of spatial and temporal variations from environmental factors in the species habitat defines the maximum isotopic variation of a population during the time of their shell formation. Here we present isotopic signatures (δ18O, δ13C) of living Cytheridella ilosvayi (Ostracoda) and chemical and isotopic compositions of 14 simultaneously sampled freshwater habitats in South Florida and instrumental data of the region. The chemical and isotopic compositions of the selected sites characterize the different habitats and show the influence of the source water, biological activity and the duration of exposure to the surface. Isotopic signatures of C. ilosvayi shells correlate well with the isotopic composition of their host waters. Within-sample variability of repeated isotopic measurements of ostracod shells reflect habitat dependent ranges and indicate temperature and the δ18O composition of precipitation (δ18Oprec) as regional environmental factors responsible for the population variation. Instrumental data of water temperature and δ18Oprec were used to calculate the monthly variation of a theoretical calcite in rivers of Florida showing distinct seasonal variations in values and ranges. Different configurations of the theoretical calcite were compared to the within-sample variability to identify possible calcification periods of C. ilosvayi. For a plausible calcification period the ostracod isotopic range has to correlate with mean values of the theoretical calcite with a slight positive offset (vital effect) and the extension of the theoretical calcite range. The tested model suggests a seasonal calcification period of C. ilosvayi in early spring. The surprising seasonality of a tropical ostracod life cycle is probably coupled to the hydrologic cycle of Florida. The results of this study contribute to the application of ostracod isotopes in modern calibration studies and their potential use in paleontology.


Author(s):  
Lisa-ann Gershwin

While it is generally assumed that jellyfishes (Cnidaria: Scyphozoa) are stably tetramerous, variation in symmetry (i.e. unimerous to octamerous) can be observed in most populations at a rate of approximately 2%, but sometimes as high as 10%. This type of variation has been observed among clonemates during strobilation in five taxa, namely Aurelia aurita, A. labiata, Chrysaora fuscescens, Pelagia colorata, and Phacellophora camtschatica. It is currently unclear whether the symmetry variation is caused by genetic, environmental, or developmental factors, or some combination. Although hexamerous lineages were not bred successfully, lineages were raised with rates of variation higher than normal. Thus, there may be some genetic component to the variation. In one lineage observed over 4.5 months, the rate of non-tetramery declined substantially from an initial high of 88.9% to a final cumulative low of 29%. Apparently this lineage was able to stabilize tetramery over time, possibly indicating some self-correcting developmental mechanism. Furthermore, no difference was found in variation rates between stressed and unstressed polyps, indicating that environmental factors may not play an important role in symmetry determination in these animals. These results indicate stabilizing selection in controlling the expression of variable symmetry.


Ecology ◽  
2020 ◽  
Vol 101 (8) ◽  
Author(s):  
Enrico Lunghi ◽  
Raoul Manenti ◽  
Fabio Cianferoni ◽  
Filippo Ceccolini ◽  
Michael Veith ◽  
...  

2006 ◽  
Vol 84 (6) ◽  
pp. 817-822 ◽  
Author(s):  
T. Mizuta

Within-population variation in the timing of breeding in the insectivorous Madagascar paradise flycatcher, Terpsiphone mutata (L., 1766), was investigated in a dry forest of northwestern Madagascar. The study area was divided into two sites (namely, A and B) based on the distance from the waterside. An examination was conducted to determine whether the date of egg laying varies between the two sites, and if it does vary, what are the environmental factors that affect the variation. The females started egg laying significantly earlier at site B than at site A. The two sites are located in a continuous forest; hence, photoperiod and precipitation would not differ between them. The number of insects was higher at site B than at site A. The difference in the temperature was not considered to be the cause of the variation in the date of egg laying. Age structure of the females was not likely to differ between the sites. Therefore, the variation in the date of egg laying is considered to be caused by the difference in food abundance that is associated with the relative distance from the waterside.


2019 ◽  
Vol 42 ◽  
Author(s):  
Nicole M. Baran

AbstractReductionist thinking in neuroscience is manifest in the widespread use of animal models of neuropsychiatric disorders. Broader investigations of diverse behaviors in non-model organisms and longer-term study of the mechanisms of plasticity will yield fundamental insights into the neurobiological, developmental, genetic, and environmental factors contributing to the “massively multifactorial system networks” which go awry in mental disorders.


2020 ◽  
Vol 134 (18) ◽  
pp. 2447-2451
Author(s):  
Anissa Viveiros ◽  
Gavin Y. Oudit

Abstract The global prevalence of obesity has been rising at an alarming rate, accompanied by an increase in both childhood and maternal obesity. The concept of metabolic programming is highly topical, and in this context, describes a predisposition of offspring of obese mothers to the development of obesity independent of environmental factors. Research published in this issue of Clinical Science conducted by Litzenburger and colleagues (Clin. Sci. (Lond.) (2020) 134, 921–939) have identified sex-dependent differences in metabolic programming and identify putative signaling pathways involved in the differential phenotype of adipose tissue between males and females. Delineating the distinction between metabolically healthy and unhealthy obesity is a topic of emerging interest, and the precise nature of adipocytes are key to pathogenesis, independent of adipose tissue volume.


2016 ◽  
Vol 1 (12) ◽  
pp. 83-93 ◽  
Author(s):  
Mary Blake Huer ◽  
Travis T. Threats

The World Health Organization's (WHO's) 2001 International Classification of Functioning Disability and Health (ICF) has as one of its central tenets the full inclusion of persons with disabilities in society. It acknowledges the need for medical and rehabilitation intervention in its biopscychosocial framework. However, the WHO realizes that society must do its part to facilitate this full participation and empowerment. Persons with complex communication needs (PWCCN) often need augmentative and alternative communication (AAC) in order to express themselves. However, in order to access and successfully use AAC, PWCCN need access to the necessary AAC devices and services, as well as a willing society to interact with them as full contributing members of society. The factors outside of a person's specific physical and/or cognitive functional limitations are addressed in the ICF via the Personal and Environmental Factors. Personal Factors include the individual's personality traits, lifestyle, experiences, social/educational/professional background, race, gender, and age. Environmental Factors include community support systems, social service agencies, governments, social networks, and those persons that interact with the PWCCN. This article addresses the sociopolitical influences on PWCCN and their functioning from a human rights perspective. The necessary introspective role of speech-language pathologists in this process is explored.


2004 ◽  
Vol 171 (4S) ◽  
pp. 99-99
Author(s):  
Vincenzo Serretta ◽  
Vincenzo Altieri ◽  
Giuseppe Morgia ◽  
Rosalinda Allegro ◽  
Alessandra Di Lallo ◽  
...  

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