Changes in atmospheric circulation and evapotranspiration are reducing rainfall in the Brazilian Cerrado.

Here we analyze the trends of rainfall and the frequency of rainy days over the Brazilian Cerrado between 1960 and 2021 in four distinct periods according to the seasonal patterns over the region. We also evaluated trends in evapotranspiration, atmospheric pressure, winds, and atmospheric humidity over the Cerrado to elucidate the possible reasons for the detected trends. We recorded a significant reduction in rainfall and frequency of rainy days in the northern and central Cerrado regions for all periods except at the beginning of the dry season. The most pronounced negative trends were recorded during the dry season and the beginning of the wet season, where we recorded reductions of up to 50% in total rainfall and the number of rainy days. These findings are associated with the intensification of the South Atlantic Subtropical Anticyclone, which has been shifting atmospheric circulation and raising regional subsidence. Moreover, during the dry season and the beginning of the wet season, there was a reduction in regional evapotranspiration, which also potentially contributed to the rainfall reduction. Our results suggest an expansion and intensification of the dry season in the region, potentially bringing broad environmental and social impacts that transcend the Cerrado boundaries.

Land cover and conservation state of a region in the southern limit of the Atlantic forest (river Maquiné basin, Rio Grande do Sul, Brazil).

The state of conservation of Atlantic Forest in the Maquiné river basin was assessed using land cover data obtained from Landsat TM 5 satellite imagery (October 1995). The initial analysis examined the distribution of the relative areas of each land-cover type according to landscape slope classes, potential vegetation zones, and a 90 m riparian buffer. Land-cover classes were then regrouped into categories representing "low", "intermediate", and "high" degree of anthropogenic alteration. Results indicate that about 70% of the land cover of the Maquiné river basin has been highly altered as a consequence of replacement of natural forests by agriculture. Presently, a recovery process seems to be underway, contrasting with the historical trend towards deforestation. There are large areas of secondary vegetation in intermediate (34.8%) and advanced successional stages (20.2%), particularly across the range of the montane forest and of forest formations that occur at elevations higher than 800 m (high-montane dense ombrophilous forest and mixed ombrophilous forest). The geographical location at the southern limit of the Atlantic Forest stricto sensu and comparison of the results with data on the state of conservation of the Atlantic Forest in Rio Grande do Sul indicate that the Maquiné river basin is an important area for conservation. Some points regarding future research and conservation management are also discussed.

Land cover and conservation state of a region in the Southern limit of the Atlantic Forest (river Maquiné basin, Rio Grande do Sul, Brazil)

O estado de conservação da Mata Atlântica na bacia do rio Maquiné foi avaliado com base em dados de uso do solo. As categorias de uso do solo foram identificadas a partir de uma imagem do satélite Landsat TM 5, de outubro de 1995. Inicialmente, a análise considerou a distribuição espacial das áreas relativas de cada tipo de uso do solo em relação às classes de declividade do terreno e às zonas de vegetação potencial em uma faixa ripária de 90 m. Posteriormente, os tipos de uso do solo foram reagrupados em categorias conforme o grau de antropização que representam: alto, intermediário e baixo. Os resultados indicam que cerca de 70% da área da bacia do rio Maquiné está, ou já foi, altamente alterada pela substituição da cobertura florestal por agricultura. Atualmente, parece haver um processo de recuperação da vegetação, uma vez que amplas áreas estão ocupadas por vegetação secundária em estádios sucessionais intermediários (34,8%) ou avançados (20,2%), particularmente na região da Floresta Montana e das florestas situadas acima de 800 m de altitude (Floresta Ombrófila Mista e Formação Alto Montana da Floresta Ombrófila Densa). A localização geográfica no extremo meridional da Mata Atlântica stricto sensu e a comparação com dados sobre o estado de conservação da Mata Atlântica no Rio Grande do Sul indicam que a bacia do rio Maquiné é uma importante área do ponto de vista de conservação. Alguns aspectos referentes à pesquisa científica e ao manejo também são discutidos.

Land cover and conservation state of a region in the Southern limit of the Atlantic Forest (river Maquiné basin, Rio Grande do Sul, Brazil)

The state of conservation of Atlantic Forest in the Maquiné river basin was assessed using land cover data obtained from Landsat TM 5 satellite imagery (October 1995). The initial analysis examined the distribution of the relative areas of each land-cover type according to landscape slope classes, potential vegetation zones, and a 90 m riparian buffer. Land-cover classes were then regrouped into categories representing "low", "intermediate", and "high" degree of anthropogenic alteration. Results indicate that about 70% of the land cover of the Maquiné river basin has been highly altered as a consequence of replacement of natural forests by agriculture. Presently, a recovery process seems to be underway, contrasting with the historical trend towards deforestation. There are large areas of secondary vegetation in intermediate (34.8%) and advanced successional stages (20.2%), particularly across the range of the montane forest and of forest formations that occur at elevations higher than 800 m (high-montane dense ombrophilous forest and mixed ombrophilous forest). The geographical location at the southern limit of the Atlantic Forest stricto sensu and comparison of the results with data on the state of conservation of the Atlantic Forest in Rio Grande do Sul indicate that the Maquiné river basin is an important area for conservation. Some points regarding future research and conservation management are also discussed.

O estado de conservação da Mata Atlântica na bacia do rio Maquiné foi avaliado com base em dados de uso do solo. As categorias de uso do solo foram identificadas a partir de uma imagem do satélite Landsat TM 5, de outubro de 1995. Inicialmente, a análise considerou a distribuição espacial das áreas relativas de cada tipo de uso do solo em relação às classes de declividade do terreno e às zonas de vegetação potencial em uma faixa ripária de 90 m. Posteriormente, os tipos de uso do solo foram reagrupados em categorias conforme o grau de antropização que representam: alto, intermediário e baixo. Os resultados indicam que cerca de 70% da área da bacia do rio Maquiné está, ou já foi, altamente alterada pela substituição da cobertura florestal por agricultura. Atualmente, parece haver um processo de recuperação da vegetação, uma vez que amplas áreas estão ocupadas por vegetação secundária em estádios sucessionais intermediários (34,8%) ou avançados (20,2%), particularmente na região da Floresta Montana e das florestas situadas acima de 800 m de altitude (Floresta Ombrófila Mista e Formação Alto Montana da Floresta Ombrófila Densa). A localização geográfica no extremo meridional da Mata Atlântica stricto sensu e a comparação com dados sobre o estado de conservação da Mata Atlântica no Rio Grande do Sul indicam que a bacia do rio Maquiné é uma importante área do ponto de vista de conservação. Alguns aspectos referentes à pesquisa científica e ao manejo também são discutidos.

Placental transfer of Org 10172, a low-molecular weight heparinoid, in the awake late-pregnant guinea pig.

The placental transfer of Org 10172, a low-molecular weight heparinoid, was determined in 12 awake late-pregnant guinea pigs. Nine animals receiving placebo served as controls. After 5 days i.v. treatment with Org 10172 (2 x 300 anti-Xa U/kg/day), anti-Xa activity in fetal plasma amounted to 2.4% of the maternal concentration. The Org 10172 transfer across the placenta was also evaluated with 3H-labelled Org 10172. One hour after the administration of the latter compound, fetal Org 10172-bound 3H-activity had reached 1.5% of the maternal value. The associated extremely low placental Org 10172 transfer indicates that the Org 10172 transport across the placenta of the guinea pig is membrane-limited and that the placental permeability is negligibly low. Since the hemochorial placenta of the guinea pig closely resembles that of the human, it is likely that similar transplacental transfer properties of Org 10172 apply to man.

Serum levels of 3-keto-desogestrel after oral administration of desogestrel and 3-keto-desogestrel.

In a cross-over study with orally administered desogestrel (0.150 mg) plus ethinyloestradiol (0.030 mg) and 3-keto-desogestrel (0.150 mg) plus ethinyloestradiol (0.030 mg) in ten women under steady-state conditions, the serum levels of 3-keto-desogestrel were monitored by radioimmunoassay. No statistically significant differences between treatment groups were found with respect to the areas under the curve of the serum levels versus time (AUC), peak heights and peak times. The individual AUCs for 3-keto-desogestrel after dosing with desogestrel (plus EE) or 3-keto-desogestrel (plus EE) show a similar degree of variation. The biotransformation of desogestrel into 3-keto-desogestrel is rapid and appears not to be limited by the metabolic capacity of the normal liver.

Metabolism of a new synthetic progestagen, Org 2969, in female volunteers. The distribution and excretion of radioactivity after an oral dose of the labelled drug.

The metabolism of a new synthetic progestagen, Org 2969 was studied in 4 healthy female volunteers. During the first part of the study (Phase I), the volunteers ingested 50 microgram (about 0.1 mCi) of [16-3H5Org 2969 together with 50 microgram of ethinyloestradiol as a single dose. During the second part of the study (Phase II), a 10-day pre-treatment with the same dosage of non-radioactive compound preceded the administration of the radioactive steroid. A peak level of total radioactivity, representing 3.16-5.02% of the dose given/l of serum, was achieved within 2-3 h in Phase I. During Phase II, the corresponding figures were 4.54-5.13% after 1.5-3 h. The difference was mainly due to an increase of freely-extractable steroids during Phase II. The difference can at least partly be explained by assuming a change in the kinetics of the metabolism of Org 2969 by pre-treatment with Org 2969 and ethinyloestradiol. The mean recovery of radio activity in urine and faeces was 83.0%/48.1%/34.9% (total/urine/faeces) of the total dose in Phase I and 76.1%/45.2%/30.9% during Phase II. The differences in the total excretion and in the radioactivity excreted in the faeces were significant.

PIP: Org 2969, a newly synthesized progestin from the laboratory of Organon Int B.V., Oss, the Netherlands, was ingested by women volunteers in an oral, radioactive dose to learn more about the drug's metabolism in humans. 4 female volunteeers were studied. The study was conducted in 2 phases, the first had volunteers ingesting about .1 mCi (50 mcg) of tritiated Org 2969 along with 50 mg of ethinylestradiol (as a single dose), and the second phase was a 10-day treatment with the same (50 mcg) dose of Org 2969 without radiolabel followed by administration of tritiated Org 2969. In Phase 1, peak level of total radioactivity occurred within 2-3 hours; this peak represented 3.16-5.02% of the dose administered per liter of serum. The corresponding figures for Phase 2 were 1.5-3 hours and 4.54-5.13%. Phase 2 samples had increased levels of freely-extractable steroids compared with Phase 1, which explains the difference in measurements. Another aspect of the difference in metabolism of the 2 doses must result from a change in kinetics of the metabolism of Org 2969 by pretreatment with Org 2969 (Phase 2) or simultaneous administration with ethinylestradiol (Phase 1). 1 level was significantly different between Phase 1 and 2 and that was amount of drug excreted in feces. In Phase 1, mean recoveries of radioactivity in urine and feces were 83%/48.1%/34.9% (total/urine/feces) and for Phase 2 the same recoveries were 76.1%/45.2%/30.9%.