An updated review on cattle thermoregulation: physiological responses,biophysical mechanisms,and heat stress alleviation pathways

Environmental Science and Pollution Research - Heat stress is one of the main obstacles to achieving efficient cattle production systems, and it may have numerous adverse effects on cattle. As the...     

Trophic importance of subtidal metazoan meiofauna: evidence from in situ exclusion experiments on soft and rocky substrates

In coastal marine ecosystems, predation might affect spatial distribution and population dynamics of benthic assemblages. Here, by means of experimental exclusion of potential predators, we compared the effects of epibenthic predation on metazoan meiofaunal assemblages on soft and rocky substrates. Different patterns of abundance were observed in uncaged versus caged plots, across habitats. In caged soft substrates, the abundance of Nematodes, Copepods and Polychaetes increased by 56, 45, 57%, respectively, in the first 3 months. An increase in the number of meiofaunal taxa was also observed. The exclusion of predators from rocky substrates showed less clear patterns. It did not affect the number of taxa while a decrease in meiofaunal abundance was observed. Our results suggest that the exclusion of epibenthic predators had clear effect on total metazoan meiofaunal abundance and on the number of taxa, only in soft bottoms. The different impact of predation across habitats can be potentially explained by differences in terms of spatial variability and substrate complexity. We estimated that, coarsely, more than 75% of total metazoan meiofaunal production can be channeled to higher trophic levels through predation on soft-bottoms. Among meiofaunal taxa, Polychaetes and Nematodes provided the major contribution to benthic energy transfers. These results suggest the trophic relevance of metazoan meiofauna in coastal food webs and claim for the refinement of further experiments for the quantification of its role in different ecological systems.     

Spatial and seasonal variability of dissolved oxygen and nutrients in the Southern Adriatic coastal waters

The main objective of this paper is to present vertical and horizontal patterns of dissolved oxygen and nutrients found during four seasonal surveys (March, June, September and December 2000) in the Southern Adriatic Sea coastal waters. The multivariate technique Principal Component Analysis has been applied to our dataset considering the following parameters: seawater temperature, salinity, dissolved oxygen and nutrients (nitrate, nitrite, phosphate, silicate). The resulting plot shows in a self-explanatory way that a seasonal trend was not observable in the investigated period and that no significant differences occur between the stations sampled in the Taranto Gulf and those along the Adriatic coast. Water column stratification persists in all seasons, except in spring, in the shallowest stations. The surface layer is characterized by a low nutrient content. The influence of the Northern Adriatic Surface Water in the Southern Adriatic sub-basin seems to be very low and can be traced by nitrate and silicate only in spring and winter. Regarding deep waters, nitrate distribution shows an increasing gradient moving from the coast to the open sea, having the lowest concentration in the shelf area and the highest in the most offshore stations of the Otranto Strait. In the Otranto Strait area the vertical distributions of physical and chemical parameters show, at middle depths, the inflow of Levantine Intermediate Water, traced by both the maximum of salinity, nitrate and phosphate and the minimum of oxygen. The LIW signal is lost moving northward. The outflow of Adriatic Dense Water is less evident, being traced only in spring by an oxygen increase at the bottom layer in the shelf area. The N:P ratio is highly variable but in the range already observed in the Southern Adriatic, suggesting a P-limitation, which can both contribute to the low primary productivity of the area and support the N:P ratio anomaly of the Eastern Mediterranean.     

Possible Use of Rna:Dna Ratio for Detecting Oil Induced Disturbance: A Field Report

The effects of oil contamination on the metabolic state of suspended participate and sedimented organic matter were investigated through the analysis of the RNA:DNA ratio on samples collected from January 1991 to January 1992 in the Ligurian Sea (northwestern Mediterranean). the ratio of RNA to DNA appeared to be highly sensitive to hydrocarbon stress since the oil disturbance resulted in an evident decline in the RNA:DNA ratio relative to the pre-pollution conditions. Such a pattern was unusual since it occurred in a period when we would expect a seasonal increase in bacterial activity. Differences are seen when comparing the temporal trend of DNA in suspended particulates and in sediments. However, the effects of oil on the RNA:DNA ratio were similar. Oiled samples showed a RNA:DNA ratio lower than 1 whereas RNA concentrations exceeded DNA content in undisturbed samples. Bacterial DNA accounted for a significant fraction (average 26%) of total DNA in sediments. It is likely that changes in RNA:DNA ratio in oiled sediments are due to the disturbance of bacterial communities. Consistent with the meiofaunal response to oil contamination, the hydrocarbons had only temporary and limited effects and RNA:DNA values recovered to pre-pollution conditions after a few weeks. the possible use of the RNA:DNA ratio in pollution monitoring is discussed.     

Toxic effects of the ingestion of water-soluble elements found in soil under the atmospheric influence of an industrial complex

In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks.     

Framework for high-resolution climate change impact assessment on grapevines at a regional scale

Understanding the impacts of climate change on viticulture is especially essential in those areas producing high-quality wines. In this work, we create an operational framework to investigate climate change impact on viticulture in the Tuscany region (central Italy) the viticulture industry of which relies on producing high-quality wines to compete in a global market. The framework includes (i) statistical downscaling of General Circulation Model (GCM) outputs for the period 1975–2099 to a local scale; (ii) the use of downscaling outputs as driving variables in specific simulation models; (iii) the spatial interpolation of model outputs to feed an economic and (iv) a quality model. The results show that as a consequence of a progressive increase in temperature and a decrease in rainfall, (a) the area potentially suitable for grapevine cultivation increases; (b) the grapevine growth cycle becomes shorter; (c) the final yield is gradually reduced, particularly in those areas characterised by quality cultivation regulation; and d) the premium wine quality production areas shift towards higher elevations. The proposed framework revealed itself to be an effective tool for climate change impact assessment at a very local scale. Additionally, this approach may be easily extended to testing the effect of different adaptation strategies in terms of management practices (e.g. irrigation) and grape varieties (e.g. longer or shorter cycle, advanced or delayed bud burst).     

Spatial and seasonal variability of dissolved oxygen and nutrients in the Southern Adriatic coastal waters

The main objective of this paper is to present vertical and horizontal patterns of dissolved oxygen and nutrients found during four seasonal surveys (March, June, September and December 2000) in the Southern Adriatic Sea coastal waters. The multivariate technique Principal Component Analysis has been applied to our dataset considering the following parameters: seawater temperature, salinity, dissolved oxygen and nutrients (nitrate, nitrite, phosphate, silicate). The resulting plot shows in a self-explanatory way that a seasonal trend was not observable in the investigated period and that no significant differences occur between the stations sampled in the Taranto Gulf and those along the Adriatic coast. Water column stratification persists in all seasons, except in spring, in the shallowest stations. The surface layer is characterized by a low nutrient content. The influence of the Northern Adriatic Surface Water in the Southern Adriatic sub-basin seems to be very low and can be traced by nitrate and silicate only in spring and winter. Regarding deep waters, nitrate distribution shows an increasing gradient moving from the coast to the open sea, having the lowest concentration in the shelf area and the highest in the most offshore stations of the Otranto Strait. In the Otranto Strait area the vertical distributions of physical and chemical parameters show, at middle depths, the inflow of Levantine Intermediate Water, traced by both the maximum of salinity, nitrate and phosphate and the minimum of oxygen. The LIW signal is lost moving northward. The outflow of Adriatic Dense Water is less evident, being traced only in spring by an oxygen increase at the bottom layer in the shelf area. The N:P ratio is highly variable but in the range already observed in the Southern Adriatic, suggesting a P-limitation, which can both contribute to the low primary productivity of the area and support the N:P ratio anomaly of the Eastern Mediterranean.