Toxicidade e produção de maçãs no sul do Brasil.

Explora as conexões entre uma polêmica apreensão de maçãs contaminadas no sul do Brasil, em 1989, e as reações da indústria da maçã às notícias da imprensa sobre o uso do agrotóxico nas plantações brasileiras. A problemática está inserida em análise mais ampla da ideia de toxicidade e de ‘perigo’, que começa a invadir os domínios público e privado quanto ao consumo de alimentos mais sadios e à ‘segurança alimentar’. Afirma que as respostas dos pomicultores ao problema seriam mais bem entendidas com a leitura histórica das interações entre a biologia da macieira, a agroecologia dessa monocultura e estruturas, atores e discursos que envolvem coletivos humanos e não humanos na região produtora de maçãs

Overcoming Dormancy in <i>Prunus</i> Species under Conditions of Insufficient Winter Chilling in Israel

The phenomenon of dormancy and the evolutionary causes for its development are presented together with the effects of the climatic factors: temperature and light. Shade and darkness have been found to enhance bud breaking in peach. The effects of various temperatures on chilling accumulation, chilling negation and chilling enhancement are described. The way these are computed in the face of global warming is explained, using the dynamic model. When natural chilling is less than that required, there are ways of compensation, up to a certain level. Various horticultural, physical and chemical means to achieve this are described, including bending branches, reducing vegetative vigor, shading the orchard, sprinkling to reduce daytime temperature and the application of various chemicals to break dormancy. When winter chilling is markedly reduced and temperatures increase considerably, the use of dormancy avoidance is suggested in frost-free places. This technique can induce a new growing cycle by avoiding dormancy altogether. However, the best approach is to breed high-quality cultivars requiring much less chilling. Another aspect discussed in this work, independent of the chilling requirement, is the negative effect of heat spells in winter and spring on the abnormal development of flower buds, leading to a low level of the stone fruit set and a reduced yield

Treatment and Imaging Modalities of Giant Coronary Aneurysms Resulting from Kawasaki Disease and Presenting as Acute Inferior Wall Myocardial Infarction

Giant coronary aneurysms are late sequelae of Kawasaki disease (KD). We describe a 53-year-old patient who presented with acute myocardial infarction and proximal aneurysms of all three coronary arteries. Coronary angiography demonstrated the aneurysms, but CT angiography allowed accurate assessment of the real dimensions of the aneurysms and making the decision on the preferred method of revascularization. The patient underwent coronary bypass surgery and is asymptomatic at follow-up

Probing Water Density and Dynamics in the Chaperonin GroEL Cavity

ATP-dependent binding of the chaperonin GroEL to its cofactor GroES forms a cavity in which encapsulated substrate proteins can fold in isolation from bulk solution. It has been suggested that folding in the cavity may differ from that in bulk solution owing to steric confinement, interactions with the cavity walls, and differences between the properties of cavity-confined and bulk water. However, experimental data regarding the cavity-confined water are lacking. Here, we report measurements of water density and diffusion dynamics in the vicinity of a spin label attached to a cysteine in the Tyr71 → Cys GroES mutant obtained using two magnetic resonance techniques: electron-spin echo envelope modulation and Overhauser dynamic nuclear polarization. Residue 71 in GroES is fully exposed to bulk water in free GroES and to confined water within the cavity of the GroEL–GroES complex. Our data show that water density and translational dynamics in the vicinity of the label do not change upon complex formation, thus indicating that bulk water-exposed and cavity-confined GroES surface water share similar properties. Interestingly, the diffusion dynamics of water near the GroES surface are found to be unusually fast relative to other protein surfaces studied. The implications of these findings for chaperonin-assisted folding mechanisms are discussed