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1.
Reg Environ Change ; 23(1): 32, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36741241

RESUMO

The 2018-2019 Central European drought was probably the most extreme in Germany since the early sixteenth century. We assess the multiple consequences of the drought for natural systems, the economy and human health in the German part of the Elbe River basin, an area of 97,175 km2 including the cities of Berlin and Hamburg and contributing about 18% to the German GDP. We employ meteorological, hydrological and socio-economic data to build a comprehensive picture of the drought severity, its multiple effects and cross-sectoral consequences in the basin. Time series of different drought indices illustrate the severity of the 2018-2019 drought and how it progressed from meteorological water deficits via soil water depletion towards low groundwater levels and river runoff, and losses in vegetation productivity. The event resulted in severe production losses in agriculture (minus 20-40% for staple crops) and forestry (especially through forced logging of damaged wood: 25.1 million tons in 2018-2020 compared to only 3.4 million tons in 2015-2017), while other economic sectors remained largely unaffected. However, there is no guarantee that this socio-economic stability will be sustained in future drought events; this is discussed in the light of 2022, another dry year holding the potential for a compound crisis. Given the increased probability for more intense and long-lasting droughts in most parts of Europe, this example of actual cross-sectoral drought impacts will be relevant for drought awareness and preparation planning in other regions. Supplementary Information: The online version contains supplementary material available at 10.1007/s10113-023-02032-3.

2.
Eur J Nutr ; 56(4): 1621-1628, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27029919

RESUMO

PURPOSE: Obesity increases the risk of cardiovascular disease, type 2 diabetes mellitus and cancer development. Autophagy and apoptosis are critical processes for development and homeostasis in multicellular organisms and have been linked to a variety of disorders. We aimed to investigate whether the quantity and quality of dietary fat can influence these processes in the adipose tissue of obese people. METHODS: A randomized, controlled trial within the LIPGENE study assigned 39 obese people with metabolic syndrome to 1 of 4 diets: (a) a high-saturated fatty acid diet, (b) a high-monounsaturated fatty acid (HMUFA) diet, and (c, d) two low-fat, high-complex carbohydrate diets supplemented with long-chain n-3 polyunsaturated fatty acids (LFHCC n-3) or placebo (LFHCC), for 12 weeks each. RESULTS: We found an increase in the expression of autophagy-related BECN1 and ATG7 genes after the long-term consumption of the HMUFA diet (p = 0.001 and p = 0.004, respectively) and an increase in the expression of the apoptosis-related CASP3 gene after the long-term consumption of the LFHCC and LFHCC n-3 diets (p = 0.001 and p = 0.029, respectively). CASP3 and CASP7 gene expression changes correlated with HOMA index. CONCLUSION: Our results suggest that the processes of autophagy and apoptosis in adipose tissue may be modified by diet and that the consumption of a diet rich in monounsaturated fat may contribute to adipose tissue homeostasis by increasing autophagy. They also reinforce the notion that apoptosis in adipose tissue is linked to insulin resistance. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT00429195.


Assuntos
Adipócitos/citologia , Tecido Adiposo/fisiopatologia , Apoptose , Autofagia , Gorduras na Dieta/administração & dosagem , Adulto , Idoso , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Glicemia/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Caspase 7/genética , Caspase 7/metabolismo , Dieta com Restrição de Gorduras , Dieta Hiperlipídica , Ácidos Graxos/administração & dosagem , Ácidos Graxos Monoinsaturados/administração & dosagem , Ácidos Graxos Ômega-3/administração & dosagem , Feminino , Regulação da Expressão Gênica , Homeostase , Humanos , Resistência à Insulina , Masculino , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Método Simples-Cego
3.
Opt Express ; 24(4): 3790-805, 2016 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-27333621

RESUMO

NOMAD is a suite of three spectrometers that will be launched in 2016 as part of the joint ESA-Roscosmos ExoMars Trace Gas Orbiter mission. The instrument contains three channels that cover the IR and UV spectral ranges and can perform solar occultation, nadir and limb observations, to detect and map a wide variety of Martian atmospheric gases and trace species. Part I of this work described the models of the UVIS channel; in this second part, we present the optical models representing the two IR channels, SO (Solar Occultation) and LNO (Limb, Nadir and Occultation), and use them to determine signal to noise ratios (SNRs) for many expected observational cases. In solar occultation mode, both the SO and LNO channel exhibit very high SNRs >5000. SNRs of around 100 were found for the LNO channel in nadir mode, depending on the atmospheric conditions, Martian surface properties, and observation geometry.

4.
Cardiovasc Diabetol ; 15: 68, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27095446

RESUMO

BACKGROUND/AIMS: Previous evidences have shown the presence of a prolonged and exaggerated postprandial response in type 2 diabetes mellitus (T2DM) and its relation with an increase of cardiovascular risk. However, the response in prediabetes population has not been established. The objective was to analyze the degree of postprandial lipemia response in the CORDIOPREV clinical trial (NCT00924937) according to the diabetic status. METHODS: 1002 patients were submitted to an oral fat load test meal (OFTT) with 0.7 g fat/kg body weight [12 % saturated fatty acids (SFA), 10 % polyunsaturated fatty acids (PUFA), 43 % monounsaturated fatty acids (MUFA), 10 % protein and 25 % carbohydrates]. Serial blood test analyzing lipid fractions were drawn at 0, 1, 2, 3 and 4 h during postprandial state. Postprandial triglycerides (TG) concentration at any point >2.5 mmol/L (220 mg/dL) has been established as undesirable response. We explored the dynamic response in 57 non-diabetic, 364 prediabetic and 581 type 2 diabetic patients. Additionally, the postprandial response was evaluated according to basal insulin resistance subgroups in patients non-diabetic and diabetic without pharmacological treatment (N = 642). RESULTS: Prevalence of undesirable postprandial TG was 35 % in non-diabetic, 48 % in prediabetic and 59 % in diabetic subgroup, respectively (p < 0.001). Interestingly, prediabetic patients displayed higher plasma TG and large triacylglycerol-rich lipoproteins (TRLs-TG) postprandial response compared with those non-diabetic patients (p < 0.001 and p = 0.003 respectively). Moreover, the area under the curve (AUC) of TG and AUC of TRLs-TG was greater in the prediabetic group compared with non-diabetic patients (p < 0.001 and p < 0.005 respectively). Patients with liver insulin resistance (liver-IR) showed higher postprandial response of TG compared with those patients with muscle-IR or without any insulin-resistance respectively (p < 0.001). CONCLUSIONS: Our findings demonstrate that prediabetic patients show a lower phenotypic flexibility after external aggression, such as OFTT compared with nondiabetic patients. The postprandial response increases progressively according to non-diabetic, prediabetic and type 2 diabetic state and it is higher in patients with liver insulin-resistance. To identify this subgroup of patients is important to treat more intensively in order to avoid future cardiometabolic complications.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Hipertrigliceridemia/metabolismo , Resistência à Insulina/fisiologia , Lipídeos/sangue , Fígado/metabolismo , Obesidade/metabolismo , Estado Pré-Diabético/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Feminino , Humanos , Hipertrigliceridemia/complicações , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Período Pós-Prandial/fisiologia , Estado Pré-Diabético/complicações , Fatores de Risco , Triglicerídeos/sangue
5.
Sci Rep ; 12(1): 18328, 2022 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-36316348

RESUMO

In mountain areas, the phenology and productivity of grassland are closely related to snow dynamics. However, the influence that snow melt timing has on grassland growing still needs further attention for a full understanding, particularly at high spatial resolution. Aiming to reduce this knowledge gap, this work exploits 1 m resolution snow depth and Normalized Difference Vegetation Index observations acquired with an Unmanned Aerial Vehicle at a sub-alpine site in the Pyrenees. During two snow seasons (2019-2020 and 2020-2021), 14 NDVI and 17 snow depth distributions were acquired over 48 ha. Despite the snow dynamics being different in the two seasons, the response of grasslands greening to snow melt-out exhibited a very similar pattern in both. The NDVI temporal evolution in areas with distinct melt-out dates reveals that sectors where the melt-out date occurs in late April or early May (optimum melt-out) reach the maximum vegetation productivity. Zones with an earlier or a later melt-out rarely reach peak NDVI values. The results obtained in this study area, suggest that knowledge about snow depth distribution is not needed to understand NDVI grassland dynamics. The analysis did not reveal a clear link between the spatial variability in snow duration and the diversity and richness of grassland communities within the study area.


Assuntos
Pradaria , Neve , Estações do Ano , Temperatura
6.
J Geophys Res Planets ; 127(5): e2021JE007083, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35865508

RESUMO

The Nadir and Occultation for MArs Discovery (NOMAD) instrument suite aboard ExoMars/Trace Gas Orbiter spacecraft is mainly conceived for the study of minor atmospheric species, but it also offers the opportunity to investigate surface composition and aerosols properties. We investigate the information content of the Limb, Nadir, and Occultation (LNO) infrared channel of NOMAD and demonstrate how spectral orders 169, 189, and 190 can be exploited to detect surface CO2 ice. We study the strong CO2 ice absorption band at 2.7 µm and the shallower band at 2.35 µm taking advantage of observations across Martian Years 34 and 35 (March 2018 to February 2020), straddling a global dust storm. We obtain latitudinal-seasonal maps for CO2 ice in both polar regions, in overall agreement with predictions by a general climate model and with the Mars Express/OMEGA spectrometer Martian Years 27 and 28 observations. We find that the narrow 2.35 µm absorption band, spectrally well covered by LNO order 189, offers the most promising potential for the retrieval of CO2 ice microphysical properties. Occurrences of CO2 ice spectra are also detected at low latitudes and we discuss about their interpretation as daytime high altitude CO2 ice clouds as opposed to surface frost. We find that the clouds hypothesis is preferable on the basis of surface temperature, local time and grain size considerations, resulting in the first detection of CO2 ice clouds through the study of this spectral range. Through radiative transfer considerations on these detections we find that the 2.35 µm absorption feature of CO2 ice clouds is possibly sensitive to nm-sized ice grains.

7.
Transl Psychiatry ; 12(1): 146, 2022 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-35393390

RESUMO

Alcohol is part of the usual diet of millions of individuals worldwide. However, not all individuals who drink alcohol experience the same effects, nor will everyone develop an alcohol use disorder. Here we propose that the intestinal microbiota (IMB) helps explain the different consumption patterns of alcohol among individuals. 507 humans participated in this study and alcohol consumption and IMB composition were analyzed. On the other hand, in 80 adult male Wistar rats, behavioral tests, alcohol intoxication, fecal transplantation, administration of antibiotics and collection of fecal samples were performed. For identification and relative quantification of bacterial taxa was used the bacterial 16 S ribosomal RNA gene. In humans, we found that heavy episodic drinking is associated with a specific stool type phenotype (type 1, according to Bristol Stool Scale; p < 0.05) and with an increase in the abundance of Actinobacteria (p < 0.05). Next, using rats, we demonstrate that the transfer of IMB from alcohol-intoxicated animals causes an increase in voluntary alcohol consumption in transplant-recipient animals (p < 0.001). The relative quantification data indicate that the genus Porphyromonas could be associated with the effect on voluntary alcohol consumption. We also show that gut microbiota depletion by antibiotics administration causes a reduction in alcohol consumption (p < 0.001) and altered the relative abundance of relevant phyla such as Firmicutes, Bacteroidetes or Cyanobacteria (p < 0.05), among others. Benjamini-Hochberg false discovery rate (FDR) correction was performed for multiple comparisons. These studies reveal some of the consequences of alcohol on the IMB and provide evidence that manipulation of IMB may alter voluntary alcohol consumption.


Assuntos
Microbioma Gastrointestinal , Consumo de Bebidas Alcoólicas , Animais , Antibacterianos/farmacologia , Bactérias , Transplante de Microbiota Fecal , Masculino , Ratos , Ratos Wistar
8.
J Geophys Res Planets ; 127(9): e2022JE007231, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36583097

RESUMO

We present water vapor vertical distributions on Mars retrieved from 3.5 years of solar occultation measurements by Nadir and Occultation for Mars Discovery onboard the ExoMars Trace Gas Orbiter, which reveal a strong contrast between aphelion and perihelion water climates. In equinox periods, most of water vapor is confined into the low-middle latitudes. In aphelion periods, water vapor sublimated from the northern polar cap is confined into very low altitudes-water vapor mixing ratios observed at the 0-5 km lower boundary of measurement decrease by an order of magnitude at the approximate altitudes of 15 and 30 km for the latitudes higher than 50°N and 30-50°N, respectively. The vertical confinement of water vapor at northern middle latitudes around aphelion is more pronounced in the morning terminators than evening, perhaps controlled by the diurnal cycle of cloud formation. Water vapor is also observed over the low latitude regions in the aphelion southern hemisphere (0-30°S) mostly below 10-20 km, which suggests north-south transport of water still occurs. In perihelion periods, water vapor sublimated from the southern polar cap directly reaches high altitudes (>80 km) over high southern latitudes, suggesting more effective transport by the meridional circulation without condensation. We show that heating during perihelion, sporadic global dust storms, and regional dust storms occurring annually around 330° of solar longitude (L S) are the main events to supply water vapor to the upper atmosphere above 70 km.

9.
Nature ; 438(7069): 785-91, 2005 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-16319827

RESUMO

On the basis of previous ground-based and fly-by information, we knew that Titan's atmosphere was mainly nitrogen, with some methane, but its temperature and pressure profiles were poorly constrained because of uncertainties in the detailed composition. The extent of atmospheric electricity ('lightning') was also hitherto unknown. Here we report the temperature and density profiles, as determined by the Huygens Atmospheric Structure Instrument (HASI), from an altitude of 1,400 km down to the surface. In the upper part of the atmosphere, the temperature and density were both higher than expected. There is a lower ionospheric layer between 140 km and 40 km, with electrical conductivity peaking near 60 km. We may also have seen the signature of lightning. At the surface, the temperature was 93.65 +/- 0.25 K, and the pressure was 1,467 +/- 1 hPa.

10.
Sci Total Environ ; 769: 144702, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33736257

RESUMO

We analyzed the impacts of drought severity on a variety of sectors in a topographically complex basin (the upper Aragón basin 2181 km2) in the Central Spanish Pyrenees. Using diverse data sources including meteorological and hydrological observations, remote sensing and tree rings, we analyze the possible hydrological implications of drought occurrence and severity on water availability in various sectors, including downstream impacts on irrigation water supply for crop production. Results suggest varying responses in forest activity, secondary growth, plant phenology, and crop yield to drought impacts. Specifically, meteorological droughts have distinct impacts downstream, mainly due to water partitioning between streamflow and irrigation channels that transport water to crop producing areas. This implies that drought severity can extend beyond the physical boundaries of the basin, with impacts on crop productivity. This complex response to drought impacts makes it difficult to develop objective basin-scale operational definitions for monitoring drought severity. Moreover, given the high spatial variability in responses to drought across sectors, it is difficult to establish reliable drought thresholds from indices that are relevant across all socio-economic sectors. The anthropogenic impacts (e.g. water regulation projects, ecosystem services, land cover and land use changes) pose further challenges to assessing the response of different systems to drought severity. This study stresses the need to consider the seasonality of drought impacts and appropriate drought time scales to adequately assess and understand their complexity.

11.
Behav Brain Res ; 381: 112441, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-31863847

RESUMO

Although the genetic influence on global stopping has been extensively investigated, little is known about the genetic contribution to other more complex forms of inhibitory control such as selective stopping. The selectivity of inhibitory control can be assessed by using the stimulus-selective stop-signal task. Notably, recent behavioural and neural evidence indicates that individuals can adopt selective but also non-selective stopping strategies to solve it. This study aimed to investigate for the first time the influence of two relevant dopaminergic polymorphisms (in COMT and DRD2 genes) on stimulus-selective stopping in a sample of 529 adults. Results showed that although none of these polymorphisms (neither individually nor in combination) modulate the latency of the stop process in each strategy (the stop-signal reaction time), the choice of strategy was influenced by their interaction. These results suggest that dopaminergic polymorphisms might influence strategy adoption in selective stopping paradigms, which constitutes a novel finding.


Assuntos
Catecol O-Metiltransferase/genética , Inibição Psicológica , Receptores de Dopamina D2/genética , Adolescente , Feminino , Genética Comportamental , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Tempo de Reação/genética , Adulto Jovem
12.
Neuroscience ; 158(2): 465-73, 2009 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-18977415

RESUMO

The endocannabinoid system is a neuromodulatory system which controls the release of multiple neurotransmitters, including glutamate and both, the endocannabinoid and glutamatergic systems, have been implicated in alcohol relapse. Cannabinoid agonists induce an increase in relapse-like drinking whereas glutamate receptor antagonists could prevent it. Here we hypothesize that cannabinoid-induced increases in relapse-like alcohol drinking could be mediated by glutamatergic N-methyl-d-aspartate (NMDA) receptors. To test this hypothesis, Wistar rats with a background of alcohol operant self-administration were treated with the cannabinoid receptor agonist (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl), pyrrolo [1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate (WIN 55.212-2, WIN) (2.0 mg/kg) during periods of alcohol deprivation. For five consecutive days, 30 min before the reintroduction of alcohol, rats were injected with the NMDA/glycine receptor antagonist 7-chloro-4-hydroxy-3-(3-phenoxy)phenylquinolin-2-[1H]-one (L-701) (1.25-5.0 mg/kg) and alcohol reinforcement was evaluated. Our results clearly show that L-701 prevented the cannabinoid-induced increase in relapse-like drinking in a dose-dependent manner, whereas L-701 alone, in the absence of WIN treatment, did not significantly alter alcohol intake. The potentiation of relapse-like drinking induced by WIN is not caused by nonspecific anxiogenic effects, since no effect was observed in the elevated-plus maze test. These alcohol-related behaviors are linked to differential changes in CNR1 and NR1 subunit mRNA transcripts. In WIN-treated rats, an increase in CNR1 transcript levels was observed in the hypothalamus and striatum, whereas in the amygdala and anterior cingulate cortex, brain regions involved in emotional processing, a decrease was observed. Interestingly, such changes were blocked after L-701 treatment. Finally, WIN treatment also caused a reduction in NR1 mRNA levels in the amygdala. In conclusion, pharmacological inactivation of the glycine-binding site of NMDA receptors may control cannabinoid-induced relapse-like drinking, which is associated with altered expression of CNR1 and NR1 gene expression as observed after WIN treatment.


Assuntos
Consumo de Bebidas Alcoólicas/prevenção & controle , Alcoolismo/fisiopatologia , Canabinoides/efeitos adversos , Glicina/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Síndrome de Abstinência a Substâncias/prevenção & controle , Consumo de Bebidas Alcoólicas/fisiopatologia , Alcoolismo/metabolismo , Animais , Benzoxazinas/farmacologia , Sítios de Ligação/efeitos dos fármacos , Canabinoides/agonistas , Condicionamento Operante/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Etanol/administração & dosagem , Etanol/efeitos adversos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Morfolinas/farmacologia , Naftalenos/farmacologia , Quinolonas/farmacologia , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/genética , Receptor CB1 de Canabinoide/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Autoadministração , Síndrome de Abstinência a Substâncias/fisiopatologia
13.
Psychopharmacology (Berl) ; 236(4): 1187-1197, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30470859

RESUMO

RATIONALE: Only in Europe it can be estimated that more than 20 million of people would be affected by hypothyroidism in some moment of their life. Given that ethanol consumption is so frequent, it would be reasonable to ask what the consequences of ethanol consumption in those individuals affected by hypothyroidism are. OBJECTIVES: To study the interaction between hypothyroidism and ethanol consumption. METHODS: We study ethanol consumption in a rat model of methyl-mercaptoimidazole-induced-adult-onset hypothyroidism and thyroid T4/T3 hormone supplementation. Also, we studied the effects of ethanol on motor activity, memory, and anxiety. RESULTS: We found that hypothyroidism increased the voluntary ethanol consumption and that this was enhanced by thyroid hormone supplementation. Hypothyroidism was associated with motor hyperactivity which was prevented either by T4/T3 supplementation or ethanol. The relationship between hypothyroidism, ethanol, and anxiety was more complex. In an anxiogenic context, hypothyroidism and T4/T3 supplementation would increase immobility, an anxiety-like behavior, while in a less anxiogenic context would decrease rearing, a behavior related to anxiety. Regarding memory, acute ethanol administration did not alter episodic-like memory in hypothyroid rats. Gene expression of enzymes involved in the metabolism of ethanol, i.e., Adh1 and Aldh2, were altered by hypothyroidism and T4/T3 supplementation. CONCLUSIONS: Our results suggest that hypothyroid patients would need personalized attention in terms of ethanol consumption. In addition, they point that it would be useful to embrace the thyroid axis in the study of ethanol addiction, including as a possible therapeutic target for the treatment of alcoholism and its comorbid disorders.


Assuntos
Consumo de Bebidas Alcoólicas/sangue , Etanol/administração & dosagem , Hipotireoidismo/sangue , Fatores Etários , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/psicologia , Aldeído-Desidrogenase Mitocondrial/sangue , Animais , Ansiedade/sangue , Ansiedade/psicologia , Humanos , Hipotireoidismo/complicações , Hipotireoidismo/psicologia , Masculino , Ratos , Ratos Wistar , Hormônios Tireóideos/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue
14.
Sci Total Environ ; 579: 272-282, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27890413

RESUMO

In this study, we investigate changes in the glaciated surface and the formation of lakes in the headwater of the Querococha watershed in Cordillera Blanca (Peru) using 24 Landsat images from 1975 to 2014. Information of glacier retreat was integrated with available climate data, the first survey of recent depositional dynamics in proglacial Yanamarey Lake (4600m a.s.l.), and a relatively short hydrological record (2002-2014) at the outlet of Yanamarey Lake. A statistically significant temperature warming (0.21°C decade-1 for mean annual temperature) has been detected in the region, and it caused a reduction of the glacierized area since 1975 from 3.5 to 1.4km-2. New small lakes formed in the deglaciated areas, increasing the flooded area from1.8ha in 1976 to 2.8ha in 2014. A positive correlation between annual rates of glacier recession and runoff was found. Sediment cores revealed a high sedimentation rate (>1cmyr-1) and two contrasted facies, suggesting a shift toward a reduction of meltwater inputs and higher hydrological variability likely due to an increasing role of precipitation on runoff during the last decades. Despite the age control uncertainties, the main transition likely occurred around 1998-2000, correlating with the end of the phase with maximum warming rates and glacier retreat during the 1980s and 1990s, and the slowing down of expansion of surface lake-covered surface. With this hydrological - paleolimnological approach we have documented the association between recent climate variability and glacier recession and the rapid transfer of hydroclimate signal to depositional and geochemical processes in high elevation Andean environments. This, study also alerts about water quality risks as proglacial lakes act as secondary reservoirs that trap trace and minor elements in high altitude basins.

15.
Science ; 355(6332): 1392-1395, 2017 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-28325842

RESUMO

The Rosetta spacecraft spent ~2 years orbiting comet 67P/Churyumov-Gerasimenko, most of it at distances that allowed surface characterization and monitoring at submeter scales. From December 2014 to June 2016, numerous localized changes were observed, which we attribute to cometary-specific weathering, erosion, and transient events driven by exposure to sunlight and other processes. While the localized changes suggest compositional or physical heterogeneity, their scale has not resulted in substantial alterations to the comet's landscape. This suggests that most of the major landforms were created early in the comet's current orbital configuration. They may even date from earlier if the comet had a larger volatile inventory, particularly of CO or CO2 ices, or contained amorphous ice, which could have triggered activity at greater distances from the Sun.

16.
Hypertension ; 7(6 Pt 1): 1017-22, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-2416684

RESUMO

To study the significance of the increased activity of the kallikrein-kinin system described in patients with Bartter's syndrome, we investigated the pressor response to infused angiotensin II in four patients with the syndrome receiving no treatment and during the administration of aprotinin and of indomethacin. Five normal subjects served as controls. Aprotinin is a proteolytic enzyme that inhibits the formation of kinins by inhibiting plasma and glandular kallikrein. Indomethacin, a prostaglandin-synthesis inhibitor, can also inhibit the kallikrein-kinin system and normalizes vascular responsiveness to angiotensin II in Bartter's syndrome. All patients had increased urinary kallikrein and prostaglandin E2 concentrations. Aprotinin significantly decreased the dose of infused angiotensin II required to induce a 20 mm Hg increase in diastolic blood pressure, from 11 +/- 4 ng/kg/min to 7.0 +/- 2.0 ng/kg/min (mean +/- SD; p less than 0.05) in normal subjects and from 135 +/- 57 ng/kg/min to 70 +/- 26 ng/kg/min (p less than 0.05) in the patients with Bartter's syndrome, without significantly changing plasma renin activity, mean control blood pressure, or urinary prostaglandin E2 concentration. Indomethacin normalized the pressor response to angiotensin II in three patients who had been pretreated for 4 days (pressor dose, 10 ng/kg/min) but not in one patient who received a single oral dose of indomethacin 5 hours before the test. Our results suggest that inhibition of the kallikrein-kinin system alone accounts for approximately a 50% decrease in vascular resistance to the pressor effect of angiotensin II in Bartter's syndrome, while additional suppression of prostaglandins entirely normalizes the vascular response to angiotensin II.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Síndrome de Bartter/fisiopatologia , Hiperaldosteronismo/fisiopatologia , Calicreínas/fisiologia , Cininas/fisiologia , Adulto , Angiotensina II , Aprotinina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Criança , Pré-Escolar , Feminino , Humanos , Indometacina/farmacologia , Masculino , Resistência Vascular/efeitos dos fármacos
17.
J Clin Endocrinol Metab ; 66(2): 349-54, 1988 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3276723

RESUMO

The function of the adrenal zona glomerulosa was studied in two pubertal siblings with the hypertensive virilizing form of congenital adrenal hyperplasia who had never been treated. Initially, their plasma 11-deoxycortisol and 11-deoxycorticosterone (DOC) levels were very high, PRA was suppressed, and plasma aldosterone and 18-hydroxycorticosterone (18-OHB) were undetectable. To selectively study zona glomerulosa function, the patients and five normal subjects were given dexamethasone (2 mg/day; thus suppressing zona fasciculata function), and their sodium intake was restricted to 10 mmol/day. After 3-5 days, the zona glomerulosa was stimulated with either angiotensin II or potassium chloride. The same protocol was repeated in the patients at various intervals up to 39 months after beginning maintenance therapy with dexamethasone (0.25 mg twice daily). PRA, plasma aldosterone, and 18-OHB remained low during the first 6 months of treatment. After the first year, PRA recovered, and the zona glomerulosa began to respond. Plasma aldosterone and 18-OHB levels reached normal basal and stimulated values in one of the patients after 2 yr of treatment, but remained subnormal after 39 months of treatment in the other patient. Both patients, however, had persistently elevated plasma DOC concentrations, suggesting slight but definite impairment of 11 beta-hydroxylation in the zona glomerulosa. We conclude that in spite of a severe and persistent 11 beta-/18-hydroxylation deficiency in the zona fasciculata, the zona glomerulosa can recover almost completely after prolonged treatment. Appropriate stimulation, however, discloses a minor 11 beta-hydroxylation impairment also in the zona glomerulosa. In addition, the lack of parallelism in zona glomerulosa 11 beta- and 18-hydroxylation of DOC provides evidence for the concept of different 18-hydroxylating systems in the adrenal cortex.


Assuntos
Córtex Suprarrenal/fisiopatologia , Hiperplasia Suprarrenal Congênita/fisiopatologia , Hipertensão/complicações , 18-Hidroxicorticosterona/sangue , Adolescente , Córtex Suprarrenal/enzimologia , Hiperplasia Suprarrenal Congênita/complicações , Aldosterona/sangue , Angiotensina II , Criança , Cortodoxona/sangue , Citocromo P-450 CYP11B2 , Desoxicorticosterona/análogos & derivados , Desoxicorticosterona/sangue , Feminino , Humanos , Masculino , Cloreto de Potássio , Renina/sangue , Esteroide 11-beta-Hidroxilase/análise , Esteroide Hidroxilases/metabolismo
18.
Neuropharmacology ; 47(7): 1036-44, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15555637

RESUMO

Tobacco and alcohol are highly co-abused by humans. Most experimental studies have evaluated ethanol consumption in animals exposed concomitantly to nicotine. However, little is known regarding the effects of nicotine administered during periods of alcohol deprivation. In the present study, adult male Wistar rats with an extended background of operant self-administration of ethanol were alcohol-deprived and treated with nicotine (0.1, 0.2, 0.4 and 0.8 mg/kg) or saline during five consecutive days in one chamber of a place conditioning apparatus. Nicotine-induced changes in locomotion were monitored daily, whereas the expression of place conditioning was studied the day after the last nicotine injection. Forty-eight hours after testing for conditioning, the animals resumed operant self-administration of ethanol and their alcohol intake was evaluated during the next 14 days. We observed that alcohol consumption was increased in animals treated with nicotine at doses of 0.2, 0.4 and 0.8 mg/kg but not in animals treated with the dose of 0.1 mg/kg or saline. Additionally, the dose of 0.8 mg/kg of nicotine not only induced persistent changes in alcohol self-administration but also produced conditioned place aversion and depressed locomotor activity. These results indicate that nicotine administration during the ethanol deprivation period can exacerbate the maintenance of alcohol consumption.


Assuntos
Depressores do Sistema Nervoso Central/farmacologia , Condicionamento Operante/efeitos dos fármacos , Etanol/farmacologia , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Animais , Relação Dose-Resposta a Droga , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Wistar , Reforço Psicológico , Recompensa , Autoadministração , Síndrome de Abstinência a Substâncias/psicologia
19.
Medicina (B Aires) ; 52(1): 37-40, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1302290

RESUMO

Serum osteocalcin (OC) was serially measured along an ovulatory menstrual cycle in 4 healthy unmedicated volunteers (age 33-38 years). During the study the women maintained their normal diet and daily physical activity. Starting at days 4-5 of the cycle, blood samples were taken between 09-11 AM every 2 or 3 days for OC, FSH, LH, E2 and P determinations. Daily ultrasound assessment of ovulation was performed in all subjects between days 7-18 of the cycle. Hormone determinations and OC were performed by RIA. While blood levels of FSH, LH, E2 and P changed during the cycle, according to the expected ovulatory pattern, serum OC concentrations remained stable during the cycle in each subject. In conclusion, serum OC is independent of the gonadotropin and ovarian steroid variations during the normal menstrual cycle.


Assuntos
Ciclo Menstrual/sangue , Osteocalcina/sangue , Adulto , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Fósforo/sangue , Radioimunoensaio
20.
Rev Neurol ; 25(143): 1081-3, 1997 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-9280640

RESUMO

INTRODUCTION: The combination of subarachnoid hemorrhage (SAH) and subhyaloid hemorrhage is known as 'Terson syndrome'. Retinal hemorrhage is commonly observed clinically in the optic fundi of patients with SAH, however, subhyaloid hemorrhage of the globe in the setting of SAH has been rarely on CT of the brain. Several mechanisms of subhyaloid hemorrhage have been proposed: a. A sudden increase in intracranial pressure (ICP) forces blood from the subarachnoid space directly into the preretinal space. b. A sudden rise in ICP is thought to decrease venous return to the cavernous sinus from the veins draining the globe. The increased retinal venous pressure results in stasis followed by vessel rupture. c. A sudden rise in ICP obstructs both the retinochoroidal anastomoses and the central retinal vein due to a rapid effusion of CSF through the communication of the subarachnoid space with the optic nerve sheat. This produces an acute decrease in venous drainage from the retina and results in stasis and hemorrhage. CLINICAL CASE: A 35 year old man, with a history of a non controlled arterial hypertension, dilated cardiopathy and 'agitation episodes'. He had a spontaneous intracranial hemorrhage, consistent in a parenchymal hematoma ruptured into ventricles and subarachnoid space. The CT showed through optic nerve sheath this hemorrhage extended to subhyaloid space. The patient came in coma 'dépassé' and brain death. CONCLUSIONS: We report a case of Terson syndrome demonstrated by CT. This CT allow see the blood from the subarachnoid space erupt directly into the preretinal space through optic nerve sheath, confirming one the proposed mechanism for this syndrome.


Assuntos
Hemorragia Retiniana/complicações , Hemorragia Subaracnóidea/complicações , Adulto , Encéfalo/patologia , Coma/diagnóstico , Coma/etiologia , Escala de Coma de Glasgow , Hematoma/patologia , Humanos , Pressão Intracraniana , Masculino , Hemorragia Retiniana/diagnóstico , Hemorragia Subaracnóidea/diagnóstico , Síndrome , Tomografia Computadorizada por Raios X
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