Teaching of Energy Issues: A debate proposal for a GLobal Reorientation

The growing awareness of serious difficulties in the learning of energy issues has produced a great deal of research, most of which is focused on specific conceptual aspects. In our opinion, the difficulties pointed out in the literature are interrelated and connected to other aspects (conceptual as well as procedural and axiological), which are not sufficiently taken into account in previous research. This paper aims to carry out a global analysis in order to avoid the more limited approaches that deal only with individual aspects. From this global analysis we have outlined 24 propositions that are put forward for debate to lay the foundations for a profound reorientation of the teaching of energy topics in upper high school courses, in order to facilitate a better scientific understanding of these topics, avoid many students' misconceptions and enhance awareness of the current situation of planetary emergency

Skin as a potential source of infectious foot and mouth disease aerosols

This review examines whether exfoliated, virus-infected animal skin cells could be an important source of infectious foot and mouth disease virus (FMDV) aerosols. Infectious material rafting on skin cell aerosols is an established means of transmitting other diseases. The evidence for a similar mechanism for FMDV is: (i) FMDV is trophic for animal skin and FMDV epidermis titres are high, even in macroscopically normal skin; (ii) estimates for FMDV skin cell aerosol emissions appear consistent with measured aerosol emission rates and are orders of magnitude larger than the minimum infectious dose; (iii) the timing of infectious FMDV aerosol emissions is consistent with the timing of high FMDV skin concentrations; (iv) measured FMDV aerosol sizes are consistent with skin cell aerosols; and (v) FMDV stability in natural aerosols is consistent with that expected for skin cell aerosols. While these findings support the hypothesis, this review is insufficient, in and of itself, to prove the hypothesis and specific follow-on experiments are proposed. If this hypothesis is validated, (i) new FMDV detection, management and decontamination approaches could be developed and (ii) the relevance of skin cells to the spread of viral disease may need to be reassessed as skin cells may protect viruses against otherwise adverse environmental conditions

Prevalência de mineralização aórtica detectada no abate de bovinos no estado de Minas Gerais, Brasil Prevalence of aortic mineralization in slaughtered bovine from the state of Minas Gerais, Brazil

Descreve-se a prevalência da mineralização aórtica em bovinos abatidos em frigorífico de Belo Horizonte, MG. Foram examinados 783 fragmentos de aorta torácica de bovinos de diferentes grupos raciais, sexo e idades. As lesões foram caracterizadas em: grau I, grau II, grau III ou grau IV, baseado na intensidade das alterações macroscópicas. Duzentas e noventa e oito (38,1%) aortas foram classificadas com algum tipo de lesão: 180 com grau I (23,0%), 59 com grau II (7,5%), 35 com grau III (4,5%) e 24 com grau IV (3,1%). Houve diferenças nas freqüências de mineralização aórtica quanto ao sexo, a idade e a raça. Fêmeas e machos castrados (54,6% e 50,7%, P<0,00001 e P<0,0001, respectivamente) comparados a machos inteiros (27,5%), mestiços zebuínos de dupla aptidão e animais sem raça definida (59,3% e 47,8%, P<0,02 e P<0,05, respectivamente) comparados a zebus puros (37,4%) e animais acima de três anos de idade (59,4%, P<0,0001) comparados a animais com 2-3 anos ou menos de dois anos de idade (21,7% e 13,9%) foram mais freqüentemente acometidos por mineralização aórtica.<br>This study describes the prevalence of aortic mineralization in slaughtered bovine in the state of Minas Gerais. Fragments of thoracic aorta from 783 animals from different origin, breed, gender and age were evaluated macroscopically. All lesions were characterized and divided in, grade I, grade II, grade III and grade IV, depending on the severity of the lesions. A total of 298 (38.1%) aortas had lesions, as follow: 180 grade I (23.0%), 59 grade II (7.5%), 35 grade III (4.5%) and 24 grade IV (3.1%). Differences concerning age, breed and sex were observed. Females and castrated males (54.6% and 50.7%, P<0.00001 and P<0.0001, respectively) compared to intact males, zebu-crossbred and mixed bred (59.3% and 47.8%, P<0.02 and P<0.05, respectively) compared to pure zebu (37,4%) and animals older then 3 years (59.4%, P<0.0001) compared to animals 2-3 years or under 2 years of age (21.7% and 13.9%, respectively) were more frequently affected by aortic mineralization