Simple relationship between the virial-route hypernetted-chain and the compressibility-route Percus--Yevick values of the fourth virial coefficient

As is well known, approximate integral equations for liquids, such as the hypernetted chain (HNC) and Percus--Yevick (PY) theories, are in general thermodynamically inconsistent in the sense that the macroscopic properties obtained from the spatial correlation functions depend on the route followed. In particular, the values of the fourth virial coefficient $B_4$ predicted by the HNC and PY approximations via the virial route differ from those obtained via the compressibility route. Despite this, it is shown in this paper that the value of $B_4$ obtained from the virial route in the HNC theory is exactly three halves the value obtained from the compressibility route in the PY theory, irrespective of the interaction potential (whether isotropic or not), the number of components, and the dimensionality of the system. This simple relationship is confirmed in one-component systems by analytical results for the one-dimensional penetrable-square-well model and the three-dimensional penetrable-sphere model, as well as by numerical results for the one-dimensional Lennard--Jones model, the one-dimensional Gaussian core model, and the three-dimensional square-well model.Comment: 8 pages; 4 figures; v2: slight change of title; proof extended to multicomponent fluid

Information theory of quantum systems with some hydrogenic applications

The information-theoretic representation of quantum systems, which complements the familiar energy description of the density-functional and wave-function-based theories, is here discussed. According to it, the internal disorder of the quantum-mechanical non-relativistic systems can be quantified by various single (Fisher information, Shannon entropy) and composite (e.g. Cramer-Rao, LMC shape and Fisher-Shannon complexity) functionals of the Schr\"odinger probability density. First, we examine these concepts and its application to quantum systems with central potentials. Then, we calculate these measures for hydrogenic systems, emphasizing their predictive power for various physical phenomena. Finally, some recent open problems are pointed out.Comment: 9 pages, 3 figure

Considering Natural Baselines When Calculating Livestock Impacts Point to a Negligible Role of Grass-Fed Livestock Systems in Climate Change

The use of baselines is common in a variety of academic disciplines, including environmental science, but they are subjected to relativity depending on the geographical or historical reference considered. Such considerations are illustrated by how invasive species are evaluated or what reference baselines are considered in biodiversity assessments. The measurement of livestock effects on climate change has, however, disregarded the use of baselines. Current methodology is based exclusively on greenhouse gas emissions by individual animals, without putting them in their ecological context. As a consequence, current analyses of livestock impacts put grass-fed ruminant systems in the spotlight, because of their high methane emissions. Conversion into intensive, grain-fed chicken and pork systems is recommended to cope with increased meat demand, an approach that is being echoed by media. In this study we reviewed existing literature on baseline greenhouse gas emissions by wild ruminants, with models available for North America and northern Russia. We also considered the potential of termites in filling herbivore niches in an ungulate-free scenario and reviewed the literature for possible consequences of ensuing wildfires. We found consistent evidence for natural baseline scenarios to be of the same order of magnitude as current livestock scenarios. This implies that the current policy recommendations for tackling climate change through the livestock sector are likely to be much less effective than currently thought. Other studies on livestock environmental impacts, such as for water or biodiversity, have also not taken into account natural baseline levels from wild herbivores, hence depicting an exaggerated negative image on grass-fed livestock. Policy recommendations should take baseline levels into account, concentrate on reducing intensive use of fossil fuel and focus on double-win strategies for methane emission reduction, such as the use of manure-fed biogas cooking stoves. This paper uses concepts originally developed at Manzano & White (2019)

Carbon footprint of transhumant sheep farms: accounting for natural baseline emissions in Mediterranean systems

Purpose: Transhumance has rarely been analyzed through LCA approaches, and there is little evidence about its emissions level when conducted under different practices (by truck or on foot) or compared to sedentary livestock systems. Moreover, mobile pastoralism is strongly linked to natural resources by its seasonal grazing patterns, thereby occupying the niche of wild herbivores. Considering natural emission baselines in these ecosystems could have relevant effects when estimating their carbon footprint. Materials and methods: Inventory data of 20 sheep farms was collected to estimate the carbon footprint (CF) of lamb meat produced. Farms were divided into three sub-groups representing typical management practices in the region: (1) sedentary (SED), (2) transhumance by truck (THT), and (3) transhumance on foot (THF). Livestock GHG emissions were modeled according to herd structure and IPCC guidelines. Off-farm emissions from external feeds and fuels were accounted based on existent LCA databases. A natural baseline of wild herbivores was established from the population of red deer reported in a hunting preserve, previously considered to be a reference for the natural carrying capacity in Mediterranean ecosystems. GHG emissions of wild herbivores were estimated through two methods based on (1) IPCC guidelines and (2) allometric regression equations. Results and discussion: Carbon footprint ranged from 16.5 up to 26.9 kgCO2-eq/kg of lamb liveweight (LW). Significant differences were identified among sedentary and transhumant farms, the latter consistently showing lower CF values (SED: 25.1 kg CO2-eq/kg LW, THT: 18.3 kg CO2-eq/kg LW, THF: 18.2 kg CO2-eq/kg LW). Sedentary farms resulted in higher GHG emissions (+ 27%) and higher CO2 and N2O, contributions derived from the consumption of additional feeds. Both methods applied to compute emissions for wild herbivores led to similar results (25.3–26.8 Mg CO2-eq/km2), comparatively lower than estimation for transhumant sheep (47.7 Mg CO2-eq/km2). When considering natural baseline emissions, the CF of transhumant lamb meat is reduced by almost 30%, reaching values quite below those reported for intensive lamb production systems in Spain. Conclusions: From our results, mobility of grazing livestock can be considered as a strategy promoting climate change mitigation. This is achieved mainly by reducing the need of external feeds, while maximizing the use of local forage resources that otherwise would be difficult to valorize. Further reductions in the CF result when considering natural baseline emissions. The application of this new GHG accounting perspective could have relevant implications when aiming at climate neutrality of grazing-based ruminant systems.Purpose: Transhumance has rarely been analyzed through LCA approaches, and there is little evidence about its emissions level when conducted under different practices (by truck or on foot) or compared to sedentary livestock systems. Moreover, mobile pastoralism is strongly linked to natural resources by its seasonal grazing patterns, thereby occupying the niche of wild herbivores. Considering natural emission baselines in these ecosystems could have relevant effects when estimating their carbon footprint. Materials and methods: Inventory data of 20 sheep farms was collected to estimate the carbon footprint (CF) of lamb meat produced. Farms were divided into three sub-groups representing typical management practices in the region: (1) sedentary (SED), (2) transhumance by truck (THT), and (3) transhumance on foot (THF). Livestock GHG emissions were modeled according to herd structure and IPCC guidelines. Off-farm emissions from external feeds and fuels were accounted based on existent LCA databases. A natural baseline of wild herbivores was established from the population of red deer reported in a hunting preserve, previously considered to be a reference for the natural carrying capacity in Mediterranean ecosystems. GHG emissions of wild herbivores were estimated through two methods based on (1) IPCC guidelines and (2) allometric regression equations. Results and discussion: Carbon footprint ranged from 16.5 up to 26.9 kgCO2-eq/kg of lamb liveweight (LW). Significant differences were identified among sedentary and transhumant farms, the latter consistently showing lower CF values (SED: 25.1 kg CO2-eq/kg LW, THT: 18.3 kg CO2-eq/kg LW, THF: 18.2 kg CO2-eq/kg LW). Sedentary farms resulted in higher GHG emissions (+ 27%) and higher CO2 and N2O, contributions derived from the consumption of additional feeds. Both methods applied to compute emissions for wild herbivores led to similar results (25.3–26.8 Mg CO2-eq/km2), comparatively lower than estimation for transhumant sheep (47.7 Mg CO2-eq/km2). When considering natural baseline emissions, the CF of transhumant lamb meat is reduced by almost 30%, reaching values quite below those reported for intensive lamb production systems in Spain. Conclusions: From our results, mobility of grazing livestock can be considered as a strategy promoting climate change mitigation. This is achieved mainly by reducing the need of external feeds, while maximizing the use of local forage resources that otherwise would be difficult to valorize. Further reductions in the CF result when considering natural baseline emissions. The application of this new GHG accounting perspective could have relevant implications when aiming at climate neutrality of grazing-based ruminant systems

Sex differences in constitutive autophagy

Sex bias has been described nowadays in biomedical research on animal models, although sexual dimorphism has been confirmed widely under pathological and physiological conditions. The main objective of our work was to study the sex differences in constitutive autophagy in spinal cord and skeletalmuscle tissue fromwild type mice. To examine the influence of sex on autophagy, mRNA and proteins were extracted from male and female mice tissues.The expressions of microtubule-associated protein 1 light chain 3 (LC3) and sequestosome 1 (p62), markers to monitor autophagy, were analyzed at 40, 60, 90, and 120 days of age.We found significant sex differences in the expression of LC3 and p62 in both tissues at these ages. The results indicated that sex and tissue specific differences exist in constitutive autophagy.These data underlined the need to include both sexes in the experimental groups to minimize any sex bias

Ingestive Behavior of Beef Cattle Fed Either Protein or Energy Supplements under a Rotational Grazing System

Eight Nellore bullocks were assigned to a Tanzânia grass pasture (Panicum maximum Jacq.) under a rotational grazing system, to evaluate the ingestive behavior under two different grazing residues. Stocking rate intensity was used to reach either 1000 kg DM.ha-1 (R1) or 4000 kg DM.ha-1 (R2) as residual targets. Three grazing days followed by 33 days resting period, composed a 36 day grazing cycle. Each grazing plot supported four animals, in a 4x4 Latin square design, within the following supplementation rates and sources: S1 = no supplement; S2 = 2,0 kg DM.day-1 coarsely ground corn - 8 mm sieve; S3 = 2,0 kg DM.day-1 steam flaked corn (360 g/L) and S4 = 0,7 kg DM.day-1 soybean meal. Grazing behavior measurements were taken every 15 days after 9 a day adaptation period, during two consecutive summer grazing cycles. Animal activities were recorded every 5 minutes during day time and 15 minutes during night time throughout a 24 hour period. Supplementation with S2 decreased (P \u3c 0,05) rumination time under a higher grazing residue (R2). Both grazing and rumination time were increased and led to a decreased resting time (P \u3c 0,05) in R2 animals compared with R1

Actividad molusquicida de extractos acuosos vegetales sobre el caracol manzana pomacea canaliculata

En el Ecuador, entre el 40 y 48% de la producción de arroz se pierde a causa del ataque de Pomacea canaliculata, una de las cien especies invasivas más dañinas del mundo que actualmente ha infestado alrededor de 170.000 hectáreas del cultivo en todo el territorio nacional

Relativistic Klein-Gordon charge effects by information-theoretic measures

The charge spreading of ground and excited states of Klein-Gordon particles moving in a Coulomb potential is quantitatively analyzed by means of the ordinary moments and the Heisenberg measure as well as by use of the most relevant information-theoretic measures of global (Shannon entropic power) and local (Fisher's information) types. The dependence of these complementary quantities on the nuclear charge Z and the quantum numbers characterizing the physical states is carefully discussed. The comparison of the relativistic Klein-Gordon and non-relativistic Schrodinger values is made. The non-relativistic limits at large principal quantum number n and for small values of Z are also reached.Comment: Accepted in New Journal of Physic