Adipose tissue plays an important role providing energy to other tissues and functioning as an energy reserve organ. The energy supply is produced by triglycerides stored in a large vacuole ...representing approximately 95% of adipocyte volume. In the fasting period, triglyceride hydrolysis produces glycerol and free fatty acids which are important oxidative fuels for other tissues such as liver, skeletal muscle, kidney and myocardium. Hormone-sensitive lipase (HSL) is the enzyme that hydrolyzes intracellular triacylglycerol and diacylglycerol, and is one of the key molecules controlling lipolysis. Hormones and physiological factors such as dieting, physical exercise and ageing regulate intensively the release of glycerol and free fatty acids from adipocytes. One of the best known mechanisms that activate lipolysis in the adipocyte is the cAMP dependent pathway. cAMP production is modulated by hormone receptors coupled to Gs/Gi family of GTP binding proteins, such as β-adrenergic receptors, whereas cAMP degradation is controlled by modulation of phosphodiesterase activity, increased by insulin receptor signalling. cAMP activates PKA which activates HSL by promoting its phosphorylation. Hormonal control of lipolysis can also be achieved by receptors coupled G proteins of the Gq family, through molecular mechanisms that involve PKC and MAPK, which are currently under investigation. cGMP and PKG have also been found to activate lipolysis in adipocytes. In this review we have compiled data from literature reporting both the classical and the alternative mechanisms of lipolysis.
Climate change is increasingly being implicated in species' range shifts throughout the world, including those of important vector and reservoir species for infectious diseases. In North America ...(México, United States, and Canada), leishmaniasis is a vector-borne disease that is autochthonous in México and Texas and has begun to expand its range northward. Further expansion to the north may be facilitated by climate change as more habitat becomes suitable for vector and reservoir species for leishmaniasis.
The analysis began with the construction of ecological niche models using a maximum entropy algorithm for the distribution of two sand fly vector species (Lutzomyia anthophora and L. diabolica), three confirmed rodent reservoir species (Neotoma albigula, N. floridana, and N. micropus), and one potential rodent reservoir species (N. mexicana) for leishmaniasis in northern México and the United States. As input, these models used species' occurrence records with topographic and climatic parameters as explanatory variables. Models were tested for their ability to predict correctly both a specified fraction of occurrence points set aside for this purpose and occurrence points from an independently derived data set. These models were refined to obtain predicted species' geographical distributions under increasingly strict assumptions about the ability of a species to disperse to suitable habitat and to persist in it, as modulated by its ecological suitability. Models successful at predictions were fitted to the extreme A2 and relatively conservative B2 projected climate scenarios for 2020, 2050, and 2080 using publicly available interpolated climate data from the Third Intergovernmental Panel on Climate Change Assessment Report. Further analyses included estimation of the projected human population that could potentially be exposed to leishmaniasis in 2020, 2050, and 2080 under the A2 and B2 scenarios. All confirmed vector and reservoir species will see an expansion of their potential range towards the north. Thus, leishmaniasis has the potential to expand northwards from México and the southern United States. In the eastern United States its spread is predicted to be limited by the range of L. diabolica; further west, L. anthophora may play the same role. In the east it may even reach the southern boundary of Canada. The risk of spread is greater for the A2 scenario than for the B2 scenario. Even in the latter case, with restrictive (contiguous) models for dispersal of vector and reservoir species, and limiting vector and reservoir species occupancy to only the top 10% of their potential suitable habitat, the expected number of human individuals exposed to leishmaniasis by 2080 will at least double its present value.
These models predict that climate change will exacerbate the ecological risk of human exposure to leishmaniasis in areas outside its present range in the United States and, possibly, in parts of southern Canada. This prediction suggests the adoption of measures such as surveillance for leishmaniasis north of Texas as disease cases spread northwards. Potential vector and reservoir control strategies-besides direct intervention in disease cases-should also be further investigated.
Archaeological cobs from Paredones and Huaca Prieta (Peru) represent some of the oldest maize known to date, yet they present relevant phenotypic traits corresponding to domesticated maize. This ...contrasts with the earliest Mexican macro-specimens from Guila Naquitz and San Marcos, which are phenotypically intermediate for these traits, even though they date more recently in time. To gain insights into the origins of ancient Peruvian maize, we sequenced DNA from three Paredones specimens dating ~6700-5000 calibrated years before present (BP), conducting comparative analyses with two teosinte subspecies (
ssp.
and
) and extant maize, that include highland and lowland landraces from Mesoamerica and South America. We show that Paredones maize originated from the same domestication event as Mexican maize and was domesticated by ~6700 BP, implying rapid dispersal followed by improvement. Paredones maize shows no relevant gene flow from
, smaller than that observed in teosinte
. Thus, Paredones samples represent the only maize without confounding
variation found to date. It also harbors significantly fewer alleles previously found to be adaptive to highlands, but not of alleles adaptive to lowlands, supporting a lowland migration route. Our overall results imply that Paredones maize originated in Mesoamerica, arrived in Peru without
introgression through a rapid lowland migration route, and underwent improvements in both Mesoamerica and South America.
There has been a numerous amount of economic research carried out which has aimed at identifying the factors that could contribute positively to economic growth. The economic literature available on ...this matter appears to acknowledge that entrepreneurship is one of the elements that could positively contribute to this growth. Among other factors, both entrepreneurship and knowledge are generally considered to play an important role regarding this macro-economic goal. Bearing this in mind, the positive bond that exists between both of them, which also contributes to economic growth and improvements in welfare, is increasingly analyzed in the different economic studies available. The goal of this paper is to empirically analyze the existing relationship between economic growth, knowledge and entrepreneurship within the context of Latin American countries during the period 2001-2016. For this purpose, the self-employment variable has been used as an empirical proxy of entrepreneurship. In general, the availability of reliable statistical information on entrepreneurship is quite limited especially in the case of the Latin American countries. Consequently, this is one of the reasons why there is a lack of unanimity as to the application of one dataset or another to measure entrepreneurship in the analysis. Therefore, although it is true that there is certain disagreement regarding the use of the aforementioned empirical proxy, there are, however, several references in favor of the use of self-employment statistics in the analysis of entrepreneurship. In order to do so, first of all we study the existing link between economic growth and certain determining factors such as public expenditure, investment, human capital, knowledge and entrepreneurship. Afterwards, we analyze the effects on entrepreneurship caused by such factors as, for example, unemployment, taxes and education (as a proxy of knowledge).
Mediterranean islands of the European Union (EU) have traditionally suffered from a lack of regularity in supplying public transportation due to the high seasonality of the demand for scheduled ...transport services. The insular fact forces people and goods to be carried either by sea or air, and therefore needs to actively stimulate interest in operating specific routes by proper carriers. As regional economies on insular territories also have a tight dependence on tourism, it is vital to achieve an appropriate balance between the need for effective public transportation and sustainable means of transport. This paper aims to provide an approach to the Public Service Obligation (PSO) system imposed on air routes serving the regional transport needs of the Balearic Islands. This study has analyzed data relating to freight and passenger traffic in the period between 2004 and 2019 from scheduled air services linking Palma de Mallorca with Ibiza and Menorca, as well as those between Menorca and Ibiza, and to their respective short-sea links. Results obtained in the research suggest that PSO impositions, together with significant improvement in the resident subsidy schema (from 50% to 75%), have recently led to a sharp increase in the demand for passenger air services on these routes; thus, avoiding the tender for the award of a public contract. However, it has led to a dramatic fall of freight transport on air routes concerned, as such, public intervention on the air market has only sought to ensure the mobility of passengers.
A practical, integrated and versatile U-4CR-based assembly of 1,4-benzodiazepin-2-ones exhibiting functionally, skeletally, and stereochemically diverse substitution patterns is described. By virtue ...of its convergence, atom economy, and bond-forming efficiency, the methodology documented herein exemplifies the reconciliation of structural complexity and experimental simplicity in the context of medicinal chemistry projects.
Polyanionic and electroactive hybrids based on octasilsesquioxanes bearing metallacarborane units are developed. They show remarkable solubility in organic solvents and outstanding thermal stability. ...The metallacarboranes act as independent units simultaneously undergoing the reversible redox process.
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