On the Star Formation Rates in Molecular Clouds

In this paper we investigate the level of star formation activity within nearby molecular clouds. We employ a uniform set of infrared extinction maps to provide accurate assessments of cloud mass and structure and compare these with inventories of young stellar objects within the clouds. We present evidence indicating that both the yield and rate of star formation can vary considerably in local clouds, independent of their mass and size. We find that the surface density structure of such clouds appears to be important in controlling both these factors. In particular, we find that the star formation rate (SFR) in molecular clouds is linearly proportional to the cloud mass (M_{0.8}) above an extinction threshold of A_K approximately equal to 0.8 magnitudes, corresponding to a gas surface density threshold of approximaely 116 solar masses per square pc. We argue that this surface density threshold corresponds to a gas volume density threshold which we estimate to be n(H_2) approximately equal to 10^4\cc. Specifically we find SFR (solar masses per yr) = 4.6 +/- 2.6 x 10^{-8} M_{0.8} (solar masses) for the clouds in our sample. This relation between the rate of star formation and the amount of dense gas in molecular clouds appears to be in excellent agreement with previous observations of both galactic and extragalactic star forming activity. It is likely the underlying physical relationship or empirical law that most directly connects star formation activity with interstellar gas over many spatial scales within and between individual galaxies. These results suggest that the key to obtaining a predictive understanding of the star formation rates in molecular clouds and galaxies is to understand those physical factors which give rise to the dense components of these clouds.Comment: accepted for publicaton in the Astrophysical Journal; 22 pages, 4 figure

Dos maus tratos ao bom cuidado

Este trabalho explorou a ideia de que os maus-tratos emergem em contexto relacional de prestação de cuidados e deste modo constituem ou são uma consequência direta de cuidados inadequados. Esta formulação privilegia mais o olhar para os maus tratos como uma prática inadequada de cuidados do que uma forma de violência. Isto não significa que se olhem os maus tratos como não sendo violência. Significa tão só uma estratégia de olhar para o fenómeno que permite identificar mais rapidamente necessidades de formação e de alteração de práticas, que não são práticas apenas para com o recetor de cuidados, mas para com a própria pessoa que presta o cuidado.Este trabalho foi desenvolvido no Centro de Investigação em Psicologia (PSI/01662), Universidade do Minho, e foi financeiramente suportado pela Fundação para a Ciência e Tecnologia e pelo Ministério da Ciência, Tecnologia e Ensino Superior, através de fundos nacionais, e co-financiado pelo FEDER, através do COMPETE2020, no âmbito do acordo Portugal 2020 (POCI-01-0145-FEDER-007653). O primeiro autor foi financiado por uma bolsa da Fundação Portuguesa para a Ciência e Tecnologia - FCT - (PD/BD/105965/2014).info:eu-repo/semantics/publishedVersio

Medial dorsal cutaneous nerve entrapment following inversion ankle sprain

The medial dorsal cutaneous nerve is one of the terminal branches of the superficial peroneal nerve that provides sensory innervation to the dorsum of the foot. It may be prone to injury by direct blow, iatrogenic surgical lesion or in rare situations secondary to ankle sprains. The authors report a case of persistent ankle pain in a female patient caused by a post- traumatic compressive neuropathy of the medial dorsal cutaneous nerve secondary to an ankle sprain which was successfully surgically treated with complete resolution of the symptoms

Pharmacological potential of methylxanthines: Retrospective analysis and future expectations

Methylated xanthines (methylxanthines) are available from a significant number of different botanical species. They are ordinarily included in daily diet, in many extremely common beverages and foods. Caffeine, theophylline and theobromine are the main methylxanthines available from natural sources. The supposedly relatively low toxicity of methylxanthines, combined with the many beneficial effects that have been attributed to these compounds through time, generated a justified attention and a very prolific ground for dedicated scientific reports. Methylxanthines have been widely used as therapeutical tools, in an intriguing range of medicinal scopes. In fact, methylxanthines have been/were medically used as Central Nervous System stimulants, bronchodilators, coronary dilators, diuretics and anti-cancer adjuvant treatments. Other than these applications, methylxanthines have also been hinted to hold other beneficial health effects, namely regarding neurodegenerative diseases, cardioprotection, diabetes and fertility. However, it seems now consensual that toxicity concerns related to methylxanthine consumption and/or therapeutic use should not be dismissed. Taking all the knowledge and expectations on the potential of methylxanthines into account, we propose a systematic look at the past and future of methylxanthine pharmacologic applications, discussing all the promise and anticipating possible constraints. Anyways, methylxanthines will still substantiate considerable meaningful research and discussion for years to come.info:eu-repo/semantics/publishedVersio