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Helena Cortes Martins, Departamento de Doenças Infeciosas do Instituto Nacional de Saúde Doutor Ricardo Jorge, IP Since 2011, human immunodeficiency virus (HIV) incidence appears unchanged in the European Union/European Economic Area with between 29,000 and 33,000 new cases reported annually up to 2015. Despite evidence that HIV diagnosis is occurring earlier post-infection, the estimated number of people living with HIV (PLHIV) who were unaware of being infected in 2015 was 122,000, or 15% of all PLHIV (n=810,000). This is concerning as such individuals cannot benefit from highly effective treatment and may unknowingly sustain transmission. Members of the ECDC HIV/AIDS Surveillance and Dublin Declaration Monitoring Networks: Portugal: Kamal Mansinho, Helena Cortes Martins, Teresa Melo. info:eu-repo/semantics/publishedVersion

Human immunodeficiency virus (HIV) transmission remains significant in Europe. Rates of acquired immunodeficiency syndrome (AIDS) have declined, but not in all countries. New HIV diagnoses have increased among native and foreign-born men who have sex with men. Median CD4 + T-cell count at diagnosis has increased, but not in all groups, and late diagnosis remains common. HIV infection and AIDS can be eliminated in Europe with resolute prevention measures, early diagnosis and access to effective treatment. © 2015, European Centre for Disease Prevention and Control (ECDC). All rights reserved. 20 47

We use the Terrestrial Ecosystem Model (TEM, Version 4.1) and the land cover data set of the international geosphere–biosphere program to investigate how increasing atmospheric CO2 concentration and climate variability during 1900–1994 affect the carbon storage of terrestrial ecosystems in the conterminous USA, and how carbon storage has been affected by land-use change. The estimates of TEM indicate that over the past 95 years a combination of increasing atmospheric CO2 with historical temperature and precipitation variability causes a 4.2% (4.3 Pg C) decrease in total carbon storage of potential vegetation in the conterminous US, with vegetation carbon decreasing by 7.2% (3.2 Pg C) and soil organic carbon decreasing by 1.9% (1.1 Pg C). Several dry periods including the 1930s and 1950s are responsible for the loss of carbon storage. Our factorial experiments indicate that precipitation variability alone decreases total carbon storage by 9.5%. Temperature variability alone does not significantly affect carbon storage. The effect of CO2 fertilization alone increases total carbon storage by 4.4%. The effects of increasing atmospheric CO2 and climate variability are not additive. Interactions among CO2, temperature and precipitation increase total carbon storage by 1.1%. Our study also shows substantial year-to-year variations in net carbon exchange between the atmosphere and terrestrial ecosystems due to climate variability. Since the 1960s, we estimate these terrestrial ecosystems have acted primarily as a sink of atmospheric CO2 as a result of wetter weather and higher atmospheric CO2 concentrations. For the 1980s, we estimate the natural terrestrial ecosystems, excluding cropland and urban areas, of the conterminous US have accumulated 78.2 Tg C yr−1 because of the combined effect of increasing atmospheric CO2 and climate variability. For the conterminous US, we estimate that the conversion of natural ecosystems to cropland and urban areas has caused a 18.2% (17.7 Pg C) reduction in total carbon storage from that estimated for potential vegetation. The carbon sink capacity of natural terrestrial ecosystems in the conterminous US is about 69% of that estimated for potential vegetation.DOI: 10.1034/j.1600-0889.1999.00021.x

A detailed analysis of the history of land-use change in the Soviet Union that included tree cutting and regrowth, oxidation of woody debris, decay of wood products, and clearing of lands for agricultural expansion showed that the net carbon flux between the USSR and the atmosphere resulting from these activities was approximately zero in 1980; that is, there was only a small net flux of 0.037 x 1015 g carbon from the land to the atmosphere in that year. These results are in contrast with previous analyses that found the USSR to be a net carbon sink. In our analysis, we found that regrowth of forest vegetation following harvest, when considered alone, was responsible for an annual net storage in the USSR of about 0.136 x 1015 g C for the period 1955-1975. a value intermediate between estimates derived from a previous analysis. This storage was balanced by a net release to the atmosphere of about the same amount of carbon from a variety of processes, including the oxidation of woody debris and decay of wood products. In 1980, the carbon flux between the land and the atmosphere due to land-use change throughout the entire northern hemisphere’s temperate and boreal systems was also small, as these systems accumulated only 0.025 x 1015 g C that year.DOI: 10.1111/j.1600-0889.1988.tb00215.x

The intensive land use invariably has several negative effects on the environment and crop production if conservative practices are not adopted. Reduction in soil organic matter (SOM) quantity means gas emission (mainly CO2, CH4, N2O) to the atmosphere and increased global warming. Soil sustainability is also affected, since remaining SOM quality changes. Alterations can be verified, for example, by soil desegregation and changes in structure. The consequences are erosion, reduction in nutrient availability for the plants and lower water retention capacity. These and other factors reflect negatively on crop productivity and sustainability of the soil -plant-atmosphere system. Conversely, adoption of "best management practices", such as conservation tillage, can partly reverse the process - they are aimed at increasing the input of organic matter to the soil and/or decreasing the rates at which soil organic matter decomposes.

Land-use change for human settlement and agricultural purposes, especially pasture establishment, has caused major impacts on the Amazon Basin's environment. Development of strategies for reformation and restoration of already degraded pastures constitutes the main goal of the authors' research work. For some of this work, a homogeneous area of land in terms of soil characteristics was selected at Nova Vida ranch in Rondônia state to conduct a multidisciplinary experiment, which included agronomic, environmental and economic analyses. Since July 2001, the authors have monitored five treatments: control, herbicide, tillage, no-till rice and no-till soybean, arranged in four blocks. Early results on carbon and nitrogen stocks, nitrogen mineralization, trace-gas fluxes, dissolved organic carbon and microbial biomass are briefly presented.