Magnetic Behavior of Diluted Magnetic Semiconductors

The magnetic characteristics of Diluted Magnetic Semiconductors are reviewed and related to the exchange interactions and mechanisms. The relevance of the long-range interactions in II–VI DMS is emphasized. An analytical expression for the radial dependence is derived from the freezing temperature and compared with theoretical predictions. The magnetic properties of Fe-DMS are summarized and interpreted on the basis of the dominant crystal field splitting effects. Recent studies on IV–VI Mn DMS are presented with the emphasis on the new phenomena of carrier induced ferromagnetism

Thermal limits of wild and laboratory strains of two African malaria vector species, <it>Anopheles arabiensis</it> and <it>Anopheles funestus</it>

<p>Abstract</p> <p>Background</p> <p>Malaria affects large parts of the developing world and is responsible for almost 800,000 deaths annually. As climates change, concerns have arisen as to how this vector-borne disease will be impacted by changing rainfall patterns and warming temperatures. Despite the importance and controversy surrounding the impact of climate change on the potential spread of this disease, little information exists on the tolerances of several of the vector species themselves.</p> <p>Methods</p> <p>Using a ramping protocol (to assess critical thermal limits - CT) and plunge protocol (to assess lethal temperature limits - LT) information on the thermal tolerance of two of Africa’s important malaria vectors, <it>Anopheles arabiensis</it> and <it>Anopheles funestus</it> was collected. The effects of age, thermal acclimation treatment, sex and strain (laboratory <it>versus</it> wild adults) were investigated for CT determinations for each species. The effects of age and sex for adults and life stage (larvae, pupae, adults) were investigated for LT determinations.</p> <p>Results</p> <p>In both species, females are more tolerant to low and high temperatures than males; larvae and pupae have higher upper lethal limits than do adults. Thermal acclimation of adults has large effects in some instances but small effects in others. Younger adults tend to be more tolerant of low or high temperatures than older age groups. Long-standing laboratory colonies are sufficiently similar in thermal tolerance to field-collected animals to provide reasonable surrogates when making inferences about wild population responses. Differences between these two vectors in their thermal tolerances, especially in larvae and pupae, are plausibly a consequence of different habitat utilization.</p> <p>Conclusions</p> <p>Limited plasticity is characteristic of the adults of these vector species relative to others examined to date, suggesting limited scope for within-generation change in thermal tolerance. These findings and the greater tolerance of females to thermal extremes may have significant implications for future malaria transmission, especially in areas of current seasonal transmission and in areas on the boundaries of current vector distribution.</p

The immuno-oncological challenge of COVID-19

International audienceCoronavirus disease 2019 (COVID-19) and its causative virus, SARS-CoV-2, pose considerable challenges for the management of oncology patients. COVID-19 presents as a particularly severe respiratory and systemic infection in aging and immunosuppressed individuals, including patients with cancer. Moreover, severe COVID-19 is linked to an inflammatory burst and lymphopenia, which may aggravate cancer prognosis. Here we discuss why those with cancer are at higher risk of severe COVID-19, describe immune responses that confer protective or adverse reactions to this disease and indicate which antineoplastic therapies may either increase COVID-19 vulnerability or have a dual therapeutic effect on cancer and COVID-19. Zitvogel and colleagues discuss the interplay between cancer and COVID-19 with respect to patient risk and prognosis, immune responses and potential therapies