scholarly journals ECOLOGIA DE PEIXES DE RIACHOS DE CAVERNAS E OUTROS HABITAT SUBTERRÂNEOS

2021 ◽  
Vol 25 (02) ◽  
pp. 620-641
Author(s):  
Maria Elina Bichuette ◽  
Keyword(s):  
Population Studies ◽  
Condition Factor ◽  
Sedentary Lifestyle ◽  
Small Populations ◽  
Saturated Zone ◽  
Abiotic Conditions ◽  
Different Types ◽  
Population Sizes ◽  
Threatened Fauna ◽  
Bodies Of Water

Brazil is rich in caves, with more than 20,000 officially registered. In addition to the caves, which develop in different types of rock, there are other subterranean habitats (hypogean) with bodies of water in the form of drainages (level base streams), outcrops of the water table (saturated zone) in flooded caves or in the form of pools and lakes within caves, in addition to upper aquifers formed by infiltration of water in the rock. In some cases, groundwater does not emerge in caves, but in alluviums close to rivers, representing a hyporeic zone. The Brazilian subterranean ichthyofauna is composed of fish restricted to caves and other subterranean habitats (generally categorized as troglobites / stygobites) or species that have well-established populations in these habitats, but which also occur in streams and bodies of water on the surface (categorized as troglophilics). Currently, there are more than 80 species of fish with troglobitic and troglophilic populations in Brazil. Some population studies show estimates of varying population sizes and densities, generally characterized by small populations; a tendency towards a sedentary lifestyle; low condition factor values and life cycle strategies tending to K within the r-K continuum. These characteristics are related to the unique abiotic conditions of these habitats, such as low, infrequent and often unpredictable supply of nutrients, which can represent an accentuated filter. In relation to conservation, subterranean fish are threatened and most of the species formally described are included in lists of threatened fauna in Brazil. Only four species have been included and evaluated globally (Stygichthys typhlops, Pimelodella kronei, Phreatobius cisternarum and Phreatobius sanguijuela).

scholarly journals Recombination Can Evolve in Large Finite Populations Given Selection on Sufficient Loci

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 2249-2258 ◽  
Author(s):  
Mark M Iles ◽  
Kevin Walters ◽  
Chris Cannings
Keyword(s):  
Experimental Evidence ◽  
Genetic Drift ◽  
Finite Population ◽  
Selective Advantage ◽  
Indirect Selection ◽  
Small Populations ◽  
Finite Populations ◽  
Population Sizes ◽  
Population Recombination

AbstractIt is well known that an allele causing increased recombination is expected to proliferate as a result of genetic drift in a finite population undergoing selection, without requiring other mechanisms. This is supported by recent simulations apparently demonstrating that, in small populations, drift is more important than epistasis in increasing recombination, with this effect disappearing in larger finite populations. However, recent experimental evidence finds a greater advantage for recombination in larger populations. These results are reconciled by demonstrating through simulation without epistasis that for m loci recombination has an appreciable selective advantage over a range of population sizes (am, bm). bm increases steadily with m while am remains fairly static. Thus, however large the finite population, if selection acts on sufficiently many loci, an allele that increases recombination is selected for. We show that as selection acts on our finite population, recombination increases the variance in expected log fitness, causing indirect selection on a recombination-modifying locus. This effect is enhanced in those populations with more loci because the variance in phenotypic fitnesses in relation to the possible range will be smaller. Thus fixation of a particular haplotype is less likely to occur, increasing the advantage of recombination.

scholarly journals Number of cases of type 1 and 2 diabetes diagnosed in Amapá between 2007 and 2012

2020 ◽  
pp. 18-26
Author(s):  
Kauê de Melo Souza ◽  
Lucas Facco ◽  
Amanda Alves Fecury ◽  
Maria Helena Mendonça de Araújo ◽  
Euzébio de Oliveira ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Genetic Factors ◽  
Sedentary Lifestyle ◽  
High Rate ◽  
Main Risk Factor ◽  
Food Education ◽  
Different Types

Diabetes mellitus is a succession of different types of disorders in metabolism that are characterized by causing a high rate of blood sugar. Because it is a disease with genetic factors type 1 diabetes has as main risk factor heredity, while type 2 diabetes besides these factors, includes obesity, high blood pressure, poor food education and advancing age. This study aims to show the number of cases of type 1 and 2 diabetes diagnosed in Amapá with the variables gender, age group, sedentary lifestyle, overweight, smoking, between 2007 and 2012. The data for the research were taken from the computer department of SUS, DATASUS (http://datasus.saude.gov.br). Type 1 and 2 diabetes mellitus (DM1 and DM2) are diseases that are tied to disturbances in production or in the efficient use of insulin. Smoking, as well as sedentary lifestyle and overweight are important risk factors for the development of DM2. Type 2 diabetes mellitus provides the development of various organic nerve lesions. In addition, DM2, through its chronicity, enables the development of retinopathies, nephropathies and other conditions negative to the individual’s health.

Sightability as a Factor in Aerial Survey of Bird Species and Communities

1985 ◽  
Vol 12 (1) ◽  
pp. 57 ◽  
Author(s):  
LS Broome
Keyword(s):  
New England ◽  
Water Body ◽  
Bird Species ◽  
Abundant Species ◽  
Common Species ◽  
Aerial Survey ◽  
Flying Height ◽  
South Wales ◽  
Population Sizes ◽  
Bodies Of Water

Experimental aerial and ground censuses of waterbirds were conducted on three small, isolated bodies of water on the New England tablelands of New South Wales. The flying height at which sightability was optimized for the most common species was 30 m. Aerial and ground counts were significantly correlated for most species on the three watar bodies. Black swan, swamphen, coots, musk ducks and maned ducks were counted in equivalent or greater numbers from the air than from the ground on at least one water body. Other species were counted in lower numbers from the air than from the ground. A fairly high precision in the aerial-ground relationship for the most abundant species indicates that aerial survey can be a useful procedure for obtaining indices or estimates of the population sizes of these species. However, differences in sightability between species and between types of water body indicate that indices should be used and interpreted with caution. Other bird species from a variety of habitat types which are also amenable to aerial survey are discussed, and some recommendations for aerial surveys of birds are provided.

scholarly journals Evolution of Drift Robustness in Small Populations

2016 ◽  
Author(s):  
Thomas LaBar ◽  
Christoph Adami
Keyword(s):  
Mathematical Modeling ◽  
Experimental Evolution ◽  
Small Population ◽  
Small Populations ◽  
Mutational Load ◽  
Deleterious Mutations ◽  
Mutational Robustness ◽  
Large Populations ◽  
Slightly Deleterious Mutations ◽  
Population Sizes

AbstractMost mutations are deleterious and cause a reduction in population fitness known as the mutational load. In small populations, weakened selection against slightly-deleterious mutations results in an additional fitness reduction. Many studies have established that populations can evolve a reduced mutational load by evolving mutational robustness, but it is uncertain whether small populations can evolve a reduced susceptibility to drift-related fitness declines. Here, using mathematical modeling and digital experimental evolution, we show that small populations do evolve a reduced vulnerability to drift, or “drift robustness”. We find that, compared to genotypes from large populations, genotypes from small populations have a decreased likelihood of small-effect deleterious mutations, thus causing small-population genotypes to be drift-robust. We further show that drift robustness is not adaptive, but instead arises because small populations preferentially adapt to drift-robust fitness peaks. These results have implications for genome evolution in organisms with small population sizes.

scholarly journals Photochemical treatments (UV/H2O2, UV/O3 and UV/H2O2/O3) and inverse osmosis in wastewater: Systematic review

2021 ◽  
Vol 10 (2) ◽  
pp. 229-240
Author(s):  
Angeles Amaro-Soriano ◽  
Fernando Hernández-Aldana ◽  
Antonio Rivera
Keyword(s):  
Systematic Review ◽  
English Language ◽  
Photochemical Processes ◽  
Frequency Of Use ◽  
Different Types ◽  
Research Opportunity ◽  
Bodies Of Water ◽  
Short Times

Every year, the bodies of water receive millions of cubic meters of wastewater from municipal, industrial, agricultural or livestock discharges, treated in an inadequate way or without treatment. The objective of this study was to carry out a systematic review of the frequency of use and effectiveness of the main photochemical processes and the complementation with other treatments such as it is reverse osmosis, used in different types of wastewater effluents. We searched multiple electronic databases (2010-2021), using a stepwise searching approach, supplemented with hand searching. In vitro or in vivo English language publications, original studies, and reviews were included. The database was made up of a total of 100 articles that met the minimum selection criteria, of which 25 articles the maximum scores for analysis. These articles report the improvement in the elimination of pollutants when the treatments are used together and not individually, in relatively short times ranging from 30 minutes of radiation to 8 minutes of exposure to the treatments. Regarding the type of water that was treated, most of the articles report the decontamination of natural wastewater, that is, from the industry without treatment. The percentages calculated to identify research opportunities or gaps in relation to photochemical processes (UV/H2O2/O3). As proposed some authors, if any value of the percentage of pre-selected articles (PAA %) is less than the value of the percentage of failure (MAPAA %), a research opportunity is revealed not addressed by the literature. Based on the percentage results, it is observed that there are no gaps with respect to the photochemical processes or that there are possibly no updates reported in the literature yet.

scholarly journals Quasi-neutral molecular evolution — When positive and negative selection cancel out

2018 ◽  
Author(s):  
Bingjie Chen ◽  
Zongkun Shi ◽  
Qingjian Chen ◽  
Darryl Shibata ◽  
Haijun Wen ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Negative Selection ◽  
Evolutionary Rate ◽  
Neutral Evolution ◽  
Stem Cell Population ◽  
Small Populations ◽  
Phenotypic Evolution ◽  
Normal Tissues ◽  
Genome Wide ◽  
Population Sizes

AbstractIn the absence of both positive and negative selection, DNA sequences evolve at the neutral rate, R = 1. Due to the prevalence of negative selection, R∼1 is rarely achieved in organismal evolution. However, when R ∼ 1 is observed, it does not necessarily indicate neutral evolution because positive and negative selection could be equally strong but in opposite directions - hereby referred to as quasi-neutrality. We now show that somatic-cell evolution could be the paradigm of quasi-neutral evolution for these reasons: 1) Quasi-neutrality is much more likely in small populations (size N < 50) than in large ones; 2) Stem cell population sizes in single niches of normal tissues, from which tumors likely emerges, have small N’s (usually < 50); 3) the genome-wide evolutionary rate across tissue types is close to R = 1; 4) Relative to the average of R ∼ 1, many genes evolve at a much higher or lower rate, thus hinting both positive and negative selection; 5) When N < 50, selection efficacy decreases rapidly as N decreases even when the selection intensity stays constant; 6) Notably, N is smaller in the small intestine (SmI) than in the colon (CO); hence, the ∼ 70 fold higher rate of phenotypic evolution (observed as cancer risk) in the latter can be explained by the greater efficacy of selection, which then leads to the fixation of more advantageous mutations and fewer deleterious ones in the CO. Under quasineutrality, positive and negative selection can be measured in the same system as the two forces are simultaneously present or absent.

scholarly journals Basking behaviour in some nymphalid butterflies of Bangladesh

2018 ◽  
Vol 4 (1) ◽  
pp. 63-72
Author(s):  
Kamrunnahar ◽  
S Akand ◽  
S Rahman ◽  
HR Khan ◽  
MA Bashar
Keyword(s):  
National Park ◽  
Time Budget ◽  
Winter Season ◽  
Butterfly Species ◽  
Abiotic Conditions ◽  
Botanical Gardens ◽  
Closed Type ◽  
The Family ◽  
Different Types ◽  
The University

A through study was conducted on the basking behaviour of some nymphalid butterflies in the fields of Bhawal national park, Rema-Kalenga, Zoological and Botanical Gardens of the University of Dhaka. The time budget and the wing-posture activities of butterflies during basking period were studied butterfly species under the family Nymphalidae. The experimental species were Junonia atlites, J. almana, J. iphita, Neptis soma, Labadea martha, Ergolis ariadne, Phalantha phalantha, Hypolimnas bolina and Athyma perius. Different types of wing postures (viz. appressed, horizontal, angled and closed type) were also recorded. It is found that butterflies take more time for their basking during winter season. Most of them prefer the month of November and December for their basking. The observations reveal that thermal basking increases the temperature in the butterfly body. It directly implies how thermoregulation associated with behavioural activities in different abiotic conditions. The results also showed the importance of wing postures for thermoregulation.J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(1): 63-72

scholarly journals Evaluation of abundance indexes in open population studies: a comparison in populations of small mammals in southern Brazil

2014 ◽  
Vol 74 (3) ◽  
pp. 553-559 ◽  
Author(s):  
ME Graipel ◽  
MIM Hernández ◽  
C Salvador
Keyword(s):  
Small Mammals ◽  
Population Studies ◽  
Size Estimation ◽  
Southern Brazil ◽  
Open Population ◽  
Different Types ◽  
Minimum Number ◽  
Estimate Population Size ◽  
Animal Communities ◽  
Number Of Individuals

Many manuscripts comparing populations and/or analysing the structure of animal communities use indexes of captures as synonymous of abundance. However, the basic methods more suitable to this assumption - probabilistic estimates based on equal capture probability - have not been considered. In this study, the deviations caused by different types of capture indexes are compared with a common probabilistic population estimator (Cormack-Jolly-Seber). The analyses showed that Minimum Number Known Alive (MNKA) and the number of individuals showed greater association with the population estimator than with non-probabilistic indexes based on recaptures. Therefore, none of the indexes presented the same performance to estimate population size estimation which can lead to ecological misinterpretation. Some recommendations were also described.

scholarly journals Population size impacts host–pathogen coevolution

2021 ◽  
Vol 288 (1965) ◽  
Author(s):  
Andrei Papkou ◽  
Rebecca Schalkowski ◽  
Mike-Christoph Barg ◽  
Svenja Koepper ◽  
Hinrich Schulenburg
Keyword(s):  
Population Size ◽  
Finite Population ◽  
Host Population ◽  
Major Influence ◽  
Small Populations ◽  
Selection Dynamics ◽  
Host Pathogen ◽  
Population Sizes ◽  
Size Limits ◽  
Efficiency Of Selection

Ongoing host–pathogen interactions are characterized by rapid coevolutionary changes forcing species to continuously adapt to each other. The interacting species are often defined by finite population sizes. In theory, finite population size limits genetic diversity and compromises the efficiency of selection owing to genetic drift, in turn constraining any rapid coevolutionary responses. To date, however, experimental evidence for such constraints is scarce. The aim of our study was to assess to what extent population size influences the dynamics of host–pathogen coevolution. We used Caenorhabditus elegans and its pathogen Bacillus thuringiensis as a model for experimental coevolution in small and large host populations, as well as in host populations which were periodically forced through a bottleneck. By carefully controlling host population size for 23 host generations, we found that host adaptation was constrained in small populations and to a lesser extent in the bottlenecked populations. As a result, coevolution in large and small populations gave rise to different selection dynamics and produced different patterns of host–pathogen genotype-by-genotype interactions. Our results demonstrate a major influence of host population size on the ability of the antagonists to co-adapt to each other, thereby shaping the dynamics of antagonistic coevolution.

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