Perda de fósforo por drenagem e evolução do teor em fósforo de um Cambissolo sujeito a produção de suínos ao ar livre

Comunicação oral apresentada no III Congresso Ibérico de Ciência do Solo que decorreu em Évora de 1 a 4 de Julho de 2008.A Suinicultura extensiva, caracterizada por um baixo encabeçamento é considerada uma forma de produção mais amiga do ambiente relativamente à suinicultura intensiva. É objectivo deste trabalho avaliar a influência que a produção de suínos ao ar livre pode ter, em determinadas circunstâncias, sobre o conteúdo em P do solo e sobre as perdas de P por drenagem interna contribuindo deste modo para a poluição difusa, numa unidade experimental de produção de suínos parqueados ao ar livre. Esta unidade experimental situa-se na quinta da Escola Superior Agrária de Castelo Branco – Portugal, consta de uma área total de 2.8 ha e está dividida em 6 parques. Os animais encontram-se distribuídos por estes parques de acordo com a idade, estado fisiológico e sexo. Assim, existe um parque para leitões, quatro para porcas reprodutoras e um parque para varrascos. As raças em estudo são: Alentejana e Bízara O solo onde se instalou a unidade de demonstração é um cambisolo dístrico (FAO, 1998), de textura ligeira, pouco ácido e pobre em matéria orgânica. O declive dos parques varia entre os 5 e os 30 %. Antes da instalação da unidade experimental o solo foi caracterizado nas suas propriedades químicas. Em Fevereiro de 2007 realizou-se uma colheita conjunta de terra e de lixiviados em pontos georeferenciados desta unidade experimental. A água lixiviada foi recolhida em cápsulas de porcelana instaladas a 0,60 m de profundidade. Analisaram-se os seguintes parâmetros nas amostras de terra: Pi, Po, P-Olsen, P-AL e nos lixiviados analisou-se o Pt, Pd. Os resultados obtidos mostram um aumento em P do solo e uma elevada correlação entre o conteúdo em P do solo e a sua concentração nas águas de drenagem interna. Também evidenciam um comportamento distinto no solo entre as formas de Po e Pi. O Po apresenta uma tendência a acumular-se e a homogeneizar-se no solo, enquanto que o Pi tende a sofrer lixiviação, apresentando uma elevada variabilidade. As zonas onde ocorre maior acumulação de P são também, as zonas onde se verifica um maior transporte de P para as águas de drenagem interna. A concentração em Pt dos lixiviados nestas zonas atinge valores superiores a 0,1 mg Pt L-1, valor considerado limite em termos de impactos negativos sobre a qualidade das águas subterrâneas no que diz respeito ao seu potencial eutrofizante para as águas superficiais

Striatal expression of GDNF and differential vulnerability of midbrain dopaminergic cells

Glial cell line-derived neurotrophic factor (GDNF) is a member of the transforming growth factor-beta superfamily that when exogenously administrated exerts a potent trophic action on dopaminergic (DA) cells. Although we know a lot about its signalling mechanisms and pharmacological effects, physiological actions of GDNF on the adult brain remain unclear. Here, we have used morphological and molecular techniques, and an experimental model of Parkinson's disease in rats, to investigate whether GDNF constitutively expressed in the adult mesostriatal system plays a neuroprotective role on midbrain DA cells. We found that although all midbrain DA cells express both receptor components of GDNF (GFRalpha1 and Ret), those in the ventral tegmental area (VTA) and rostromedial substantia nigra (SNrm) also contain GDNF but not GDNFmRNA. The levels of GDNFmRNA are significantly higher in the ventral striatum (vSt), the target region of VTA and SNrm cells, than in the dorsal striatum (dSt), the target region of DA cells in the caudoventral substantia nigra (SNcv). After fluoro-gold injection in striatum, VTA and SNrm DA cells show triple labelling for tyrosine hydroxylase, GDNF and fluoro-gold, and after colchicine injection in the lateral ventricle, they become GDNF-immunonegative, suggesting that GDNF in DA somata comes from their striatal target. As DA cells in VTA and SNrm are more resistant than those in SNcv to intracerebroventricular injection of 6-OHDA, as occurs in Parkinson's disease, we can suggest that the fact that they project to vSt, where GDNF expression is significantly higher than in the dSt, is a neuroprotective factor involved in the differential vulnerability of midbrain DA neurons

Bartolosides E-K from a Marine coccoid cyanobacterium

The glycosylated and halogenated dialkylresorcinol (DAR) compounds bartolosides A-D (1-4) were recently discovered from marine cyanobacteria and represent a novel family of glycolipids, encoded by the brt biosynthetic gene cluster. Here, we report the isolation and NMR- and MS-based structure elucidation of monoglycosylated bartolosides E-K (5-11), obtained from Synechocystis salina LEGE 06099, a strain closely related to the cyanobacterium that produces the diglycosylated 2-4. In addition, a genome region containing orthologues of brt genes was identified in this cyanobacterium. Interestingly, the major bartoloside in S. salina LEGE 06099 was 1 (above 0.5% dry wt), originally isolated from the phylogenetically distant filamentous cyanobacterium Nodosilinea sp. LEGE 06102. Compounds 5-11 are analogues of 1, with different alkyl chain lengths or halogenation patterns. Their structures and the organization of the brt genes suggest that the DAR-forming ketosynthase BrtD can generate structural diversity by accepting fatty acyl-derived substrates of varying length. Compound 9 features a rare midchain gem-dichloro moiety, indicating that the putative halogenase BrtJ is able to act twice on the same midchain carbon. © 2016 The American Chemical Society and American Society of Pharmacognosy.We would like to thank CEMUP for NMR and HRMS analyses, I. Dias, A. Kijoa, and S. Buttachon for optical rotation measurements, and B. Jarrais for IR measurements. This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through grants PTDC/MAR-BIO/2818/2012 and IF/01358/2014 to P.N.L. and partially by project NOVELMAR (NORTE-01-0145-FEDER-000035) supported by the NORTE2020 Program and the European Regional Development Fund

Plasma glial fibrillary acidic protein is raised in progranulin-associated frontotemporal dementia

Background There are few validated fluid biomarkers in frontotemporal dementia (FTD). Glial fibrillary acidic protein (GFAP) is a measure of astrogliosis, a known pathological process of FTD, but has yet to be explored as potential biomarker. Methods Plasma GFAP and neurofilament light chain (NfL) concentration were measured in 469 individuals enrolled in the Genetic FTD Initiative: 114 C9orf72 expansion carriers (74 presymptomatic, 40 symptomatic), 119 GRN mutation carriers (88 presymptomatic, 31 symptomatic), 53 MAPT mutation carriers (34 presymptomatic, 19 symptomatic) and 183 non-carrier controls. Biomarker measures were compared between groups using linear regression models adjusted for age and sex with family membership included as random effect. Participants underwent standardised clinical assessments including the Mini-Mental State Examination (MMSE), Frontotemporal Lobar Degeneration-C linical Dementia Rating scale and MRI. Spearman's correlation coefficient was used to investigate the relationship of plasma GFAP to clinical and imaging measures. Results Plasma GFAP concentration was significantly increased in symptomatic GRN mutation carriers (adjusted mean difference from controls 192.3 pg/mL, 95% CI 126.5 to 445.6), but not in those with C9orf72 expansions (9.0, -61.3 to 54.6), MAPT mutations (12.7, -33.3 to 90.4) or the presymptomatic groups. GFAP concentration was significantly positively correlated with age in both controls and the majority of the disease groups, as well as with NfL concentration. In the presymptomatic period, higher GFAP concentrations were correlated with a lower cognitive score (MMSE) and lower brain volume, while in the symptomatic period, higher concentrations were associated with faster rates of atrophy in the temporal lobe. Conclusions Raised GFAP concentrations appear to be unique to GRN-related FTD, with levels potentially increasing just prior to symptom onset, suggesting that GFAP may be an important marker of proximity to onset, and helpful for forthcoming therapeutic prevention trials