Prediction Of Environmental Conditions Research Articles

REPRODUÇÃO DE PEIXES DE RIACHO: ESTADO DA ARTE, MÉTODOS E PERSPECTIVAS

Stream fish reproduction is still poorly studied in natural environments, especially in the Neotropical region. In this chapter, we recollect some characteristics of fish reproduction and some questions to guide current research, as: Does sexual dimorphism occur in the species? Which is the mode of reproduction? When and where does the species reproduce? Which environmental factors trigger reproductive events? When does the reproductive life begin? Which is the fecundity? Most of these questions can be answered when we have many specimens available, captured at different periods of the year, measured, weighed and dissected following appropriate protocols. Obtained data represent life history traits that allow to categorize the species in reproductive styles related to parental care and to determine their accordance to models of reproductive strategy associated with the predictability of environmental conditions. We highlight some aspects to be considered in current and future field and lab procedures, such as the recognition of sexual dimorphisms, the importance of naturalistic observation and lab procedures. We draw attention to the advances in studies on reproductive modalities in fish groups well represented in streams, such as inseminating characiforms and viviparous cyprinodontiforms. Finally, we highlight gaps, urgencies, and current perspectives for studies on the reproduction of stream fish, with emphasis on the need for basic studies of species biology, on the importance for building theoretical references and for the conservation of stream habitats in all Brazilian biomes.

Adaptation to environmental stress at different timescales.

Environments are changing rapidly, and to cope with these changes, organisms have to adapt. Adaptation can take many shapes and occur at different speeds, depending on the type of response, the trait, the population, and the environmental conditions. The biodiversity crisis that we are currently facing illustrates that numerous species and populations are not capable of adapting with sufficient speed to ongoing environmental changes. Here, we discuss current knowledge on the ability of animals and plants to adapt to environmental stress on different timescales, mainly focusing on thermal stress and ectotherms. We discuss within-generation responses that can be fast and induced within minutes or hours, evolutionary adaptations that are often slow and take several generations, and mechanisms that lay somewhere in between and that include epigenetic transgenerational effects. To understand and predict the impacts of environmental change and stress on biodiversity, we suggest that future studies should (1) have an increased focus on understanding the type and speed of responses to fast environmental changes; (2) focus on the importance of environmental fluctuations and the predictability of environmental conditions on adaptive capabilities, preferably in field studies encompassing several fitness components; and (3) look at ecosystem responses to environmental stress and their resilience when disturbed.

Circadian Rhythms of Urinary Cortisol Levels Vary Between Individuals in Wild Male Chimpanzees: A Reaction Norm Approach

Investigating the repeatability of trait variation between individuals, that is the amount of individual variation in relation to overall phenotypic variation, indicates an upper level of heritability and reveals whether a given trait may be subject to selection. Labile traits are characterized by high levels of flexibility and consequently low trait repeatability is expected. Indeed, research examining glucocorticoid levels in various non-mammal species found low repeatability scores. However, mammals may be different in this respect as (i) differential maternal care early in life has the potential to prime hypothalamic-pituitary-adrenal axis functioning and (ii) allelic variation affecting hypothalamic-pituitary-adrenal axis functioning has been reported. Individuals often differ from each other in average and/or plastic labile trait expression, two aspects that can be described using a reaction norm approach. Both consistent and flexible reaction norm expression has been argued to serve adaptive purposes, depending on the stability and predictability of environmental conditions. Here we investigated both trait and reaction norm repeatability of urinary cortisol levels in wild adult male chimpanzees. To capture the expression of the circadian urinary cortisol rhythm of individual males over time, urine samples were collected throughout the day. In total data of 30 males collected over a period of 8 years were included in the dataset. No male was sampled over the whole 8-year period however. We found minor levels of trait repeatability but considerable reaction norm repeatability. This implies a minor role of genetic or priming factors on cortisol excretion, but reveals that males differ consistently in average urinary cortisol levels and the shape of the circadian urinary cortisol rhythm. Relating these results to fitness parameters will provide answers to questions on the adaptive value of reaction norm repeatability of this labile hormonal trait in the future.

Ellenberg-type indicator values for the Czech flora

A new dataset of ecological indicator values for species, subspecies and some varieties, hybrids and infrageneric species groups has been compiled for the vascular flora of the Czech Republic. Indicator values for light, temperature, moisture, (soil) reaction, nutrient availability and salinity were assigned to 2275 species and 801 other taxa, using the nine-degree (or 12-degree for moisture and 10-degree for salinity) ordinal scales proposed by Heinz Ellenberg for the flora of Germany. The values are compatible with Ellenberg indicator values, which were used as a baseline, but extensively revised based on our own field observations, literature, comparison with indicator value systems of other countries and an analysis of taxon co-occurrences in vegetation plots from the Czech National Phytosociological Database. Taxa in the Czech flora missing in the original Ellenberg tables were added. Compared with the original Ellenberg's dataset of indicator values, smaller proportions of taxa were classified as extremely basiphilous, extremely oligotrophic or strictly avoiding saline habitats. The revised values were tested by regressing unweighted site mean indicator values against measured environmental variables. In most cases, prediction of environmental conditions was slightly more accurate with the new Czech indicator values than with the original Ellenberg indicator values. The full dataset of indicator values is available in an electronic appendix to this paper.

Model-based predictive control of office window shades

In the automation of interior window shading devices, a control system that relies on a prediction of environmental conditions and a building's thermal response can provide savings to space-conditioning loads beyond what can be achieved using a reactive approach. The development of these control strategies can be difficult because of the uniqueness of each building. A simplified model-based predictive control (MPC) method for window shades is proposed. To this end, a control-oriented model representing the heat transfer problem in a perimeter office space was developed. The parameters of the model were estimated using the ensemble Kalman filter (EnKF). The energy-savings potential of the EnKF-based MPC approach for window shades was investigated using EnergyPlus simulations. This was accomplished by implementing the control-oriented model into the energy management system application of EnergyPlus. Simulations were conducted to assess the energy saving potential of using the EnKF-based MPC for roller blinds in a south-facing perimeter office space in Ottawa, Canada. The simulation-based results indicate the potential for about 35% reduction in electricity usage for space conditioning over manually operated interior roller blinds.

Estructura y daños en las comunidades de octocorales (Octocorallia: Alcyonacea) de la Reserva Ecológica Siboney-Juticí, Santiago de Cuba, Cuba

In the spur-and-groove reefs of the Ecological Reserve Siboney-Juticí (Southeast Cuba) octocorals are one of the predominant components of the sessile fauna. Main objectives of the present paper are characterizing the composition, structure and conservation status of the octocoral communities and assessing on the prevailing environmental conditions in the study area. For data collection, six sampling sites were located every 2-3 km ranging from 12 m to 17 m depth along the spur-and-groove reefs. In each site, 22-26 lm2 quadrants were zigzag arranged every 2 m. The density of colonies was determined per site. The severity degree and predictability of environmental conditions were inferred by using the Heterogeneity and Equitability indexes, respectively. Hydrodynamic stress and the Comparative Pollution Index were also assessed. Current affectations of the octocoral communities were also determined and classified into four main categories: mechanical damage, diseases, predation and invertebrate and macroalgae overgrowth. As a result, 25 species represented by 752 colonies were recorded and Eunicea flexuosa and Gorgonia ventalina were the most abundant. The occurrence of Eunicea succinea forma succinea constituted the first report for Eastern Cuba. Site densities ranged from 3.58 +/- 1.84 to 7.58 +/- 2.16 colonies/m2 and considered from moderate to low. The biggest densities were reported at both sides of the San Juan River mouth. Despite of the composition and structure of the octocoral communities, low to high hydrodynamic stress and low and moderate levels of contamination were inferred, it is likely that these indexes could have been overestimated due to the sensitivity of the indicator species to other factors such as sedimentation. The environmental conditions were mostly favorable and stable. In general, the number of dead colonies was low and mostly caused by the detachment of the substrate and overgrowth of Millepora alcicornis. Injuries were mainly brought about by mechanical damage, followed by coenenchyme loss, predation by Cyphoma gibbosum and macroalgae overgrowth. On the other hand, negative effects by Hermodice carunculata predation, bleaching, Red Band and Black Band Disease were not observed. Among sampled species, G. ventalina colonies were the most severely damaged within the community. As a whole, octocoral communities of spur-and-groove reefs in the Ecological Reserve Siboney-Juticí showed a good conservation status.

Walkability and Safety Around Elementary Schools: Economic and Ethnic Disparities

Children's physical inactivity and obesity are growing public health problems in the U.S., especially among low-income, minority populations. Walking to school may help address these problems. This cross-sectional study examined disparities in the environmental support for walking around 73 public elementary schools in Austin TX. GIS was used to measure the neighborhood-level walkability and safety. Field audits were conducted to assess the street-level walkability. Analyses of variance and regressions were performed to analyze economic and ethnic disparities. For the top-quartile schools with higher poverty or Hispanic student percentages, the surroundings showed higher neighborhood-level walkability with shorter distances to school and more sidewalks compared with the bottom quartile. These areas, however, also had higher crash and crime rates and lower street-level walkability captured by visual quality, physical amenities, maintenance, and perceived safety. In predictions of environmental conditions using poverty and Hispanic student percentages, poverty was associated with many adverse conditions on the street level and with only two favorable situations, shorter distances to school and lower traffic volumes, on the neighborhood level. The Hispanic student percentage did not correlate with most street-level variables, but predicted both increased dangers from traffic and crime and higher neighborhood-level walkability with more sidewalks, greater density, and mixed land uses. Economic and ethnic disparities exist in the environmental support for walking, suggesting the need for tailored interventions in promoting active living. Low-income, Hispanic children are more likely to live in unsafe areas with poor street environments but with some favorable neighborhood-level conditions.

Distorting Gene Pools by Conservation: Assessing the Case of Doomed Turtle Eggs

Sea turtles have a high reproductive output and high mortality at early stages of the life cycle. In particular, many nests are laid below or close to high tide lines, and subsequently large numbers of eggs may be inundated and destroyed. A common conservation procedure is to relocate such doomed eggs to higher ground. This article examines this practice in the light of recent data revealing that some individual turtles tend to nest relatively near the water and others relatively higher up the beach. Discussion is focused on the question of why apparently poor placement of nests has not been selected against. Comparison between the ecology of leatherback and hawksbill turtle nesting beaches suggests that predictability of environmental conditions on the nesting beaches has an important influence on patterns of nest-site selection. Options are outlined for the management of nesting beaches where a high proportion of turtle eggs is subject to destruction by flooding.

New theoretical framework for studies of vapor growth and sublimation of small ice crystals in the atmosphere

We present a new microscopic model of growth and sublimation (g/s) of ice crystals in the atmosphere. This model is based on the assumption that the flux of vapor to the crystal surface is uniform over each flat crystal face. It thus differs fundamentally from the standard “capacitance” model for crystal growth, in which the mixing ratio is assumed uniform at the surface. In the new model the surface influence on growth is calculated self‐consistently in terms of local environmental conditions, again differing sharply from the standard models in which this influence is either ignored or assigned a uniform, externally prescribed value. The new model leads to predictions of the evolution of ice crystal shape as well as mass. We find that predicted g/s rates are generally smaller than those predicted by the earlier models. The general trends both in g/s rates and in crystal hollowing predicted by the model are consistent with field and laboratory observations. The values of certain surface parameters needed for application of our model must be found from experiment. We review and compare the relevant laboratory experiments on ice crystal g/s rates and show their lack of mutual consistency. Therefore the surface parameters inferred from these experiments are necessarily uncertain. We show that the surface parameter values can be inferred from observations of crystal hollowing, since our model allows the prediction of environmental conditions at which hollowing should occur.