Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

/pdf/climate-change-2007-the-physical-science-basis-1x93ttz9jt.pdf

Climate Change 2007: The Physical Science Basis.

Climate change 2014 - Synthesis Report

Beginning with Emlen (1966) and MacArthur and Pianka (1966) and extending through the last ten years, several authors have sought to predict the foraging behavior of animals by means of mathematical models. These models are very similar,in that they all assume that the fitness of a foraging animal is a function of the efficiency of foraging measured in terms of some "currency" (Schoener, 1971) -usually energy- and that natural selection has resulted in animals that forage so as to maximize this fitness. As a result of these similarities, the models have become known as "optimal foraging models"; and the theory that embodies them, "optimal foraging theory." The situations to which optimal foraging theory has been applied, with the exception of a few recent studies, can be divided into the following four categories: (1) choice by an animal of which food types to eat (i.e., optimal diet); (2) choice of which patch type to feed in (i.e., optimal patch choice); (3) optimal allocation of time to different patches; and (4) optimal patterns and speed of movements. In this review we discuss each of these categories separately, dealing with both the theoretical developments and the data that permit tests of the predictions. The review is selective in the sense that we emphasize studies that either develop testable predictions or that attempt to test predictions in a precise quantitative manner. We also discuss what we see to be some of the future developments in the area of optimal foraging theory and how this theory can be related to other areas of biology. Our general conclusion is that the simple models so far formulated are supported are supported reasonably well by available data and that we are optimistic about the value both now and in the future of optimal foraging theory. We argue, however, that these simple models will requre much modification, espicially to deal with situations that either cannot easily be put into one or another of the above four categories or entail currencies more complicated that just energy.

Citation classic - optimal foraging - a selective review of theory and tests

Anaerobic digestion of energy crops, residues, and wastes is of increasing interest in order to reduce the greenhouse gas emissions and to facilitate a sustainable development of energy supply. Production of biogas provides a versatile carrier of renewable energy, as methane can be used for replacement of fossil fuels in both heat and power generation and as a vehicle fuel. For biogas production, various process types are applied which can be classified in wet and dry fermentation systems. Most often applied are wet digester systems using vertical stirred tank digester with different stirrer types dependent on the origin of the feedstock. Biogas is mainly utilized in engine-based combined heat and power plants, whereas microgas turbines and fuel cells are expensive alternatives which need further development work for reducing the costs and increasing their reliability. Gas upgrading and utilization as renewable vehicle fuel or injection into the natural gas grid is of increasing interest because the gas can be used in a more efficient way. The digestate from anaerobic fermentation is a valuable fertilizer due to the increased availability of nitrogen and the better short-term fertilization effect. Anaerobic treatment minimizes the survival of pathogens which is important for using the digested residue as fertilizer. This paper reviews the current state and perspectives of biogas production, including the biochemical parameters and feedstocks which influence the efficiency and reliability of the microbial conversion and gas yield.

Biogas production: current state and perspectives

Framework Convention on Climate Change

Six ruminally cannulated steers were used in a replicated 3 × 3 Latin square with 2 wk for adaptation and 1 wk for measurements to study the effects of Propionibacterium P15 (P15) alone or in combination with Enterococcus faecium EF212 (PE) on acute phase response. Treatments were: (i) carrier (control), (ii) P15, and (iii) PE. The bacterial treatments [109 colony forming units (CFU) d-1] mixed in whey powder (carrier), or whey powder alone for control animals, were top-dressed once daily at the time of feeding (10 g steer-1 d-1). Blood samples were obtained from jugular veins on the last day of each period at 0, 6, and 12 h after feeding of bacteria and serum amyloid A (SAA), haptoglobin, lipopolysaccharide de-binding protein (LBP) were measured by ELISA and alpha1-acid glycoprotein (α1-AGP) by radial immunodiffusion. Results indicate that feeding P15 alone increased SAA and lowered plasma haptoglobin, whereas, feeding PE elevated concentrations of SAA, but had no effect on plasma haptoglobin. No signifi...

Feeding a combination of lactate-utilizing and lactate producing bacteria modulates acute phase response in feedlot steers

/pdf/effects-of-sustainable-agronomic-intensification-in-a-forage-1lrrif5g.pdf

Effects of sustainable agronomic intensification in a forage production system of perennial grass and silage corn on nutritive value and predicted milk production of dairy cattle.

http://www.journalofdairyscience.org/article/S0022030222005902/pdf

Karen A. Beauchemin

Papers

Feeding a combination of lactate-utilizing and lactate producing bacteria modulates acute phase response in feedlot steers

Effects of sustainable agronomic intensification in a forage production system of perennial grass and silage corn on nutritive value and predicted milk production of dairy cattle.

Estimates of daily oxygen consumption, carbon dioxide and methane emissions, and heat production for beef and dairy cattle using spot gas sampling.

068 Environmental impacts from cattle consuming tannin-containing hays

1658 Synergism of cattle and bison inoculum on ruminal fermentation and bacterial communities in an artificial rumen (Rusitec) fed barley straw