Modulation of adult hippocampal neurogenesis by thyroid hormones: implications in depressive-like behavior

11 pages, 5 figures.-- PMID: 16446739.Hormonal imbalances are involved in many of the age-related pathologies, as neurodegenerative and psychiatric diseases. Specifically, thyroid state alterations in the adult are related to psychological changes and mood disorders as depression. The dentate gyrus of the hippocampal formation undergoes neurogenesis in adult mammals including humans. Recent evidence suggests that depressive disorders and their treatment are tightly related to the number of newly born neurons in the dentate gyrus.We have studied the effect of thyroid hormones (TH) on hippocampal neurogenesis in adult rats in vivo. A short period of adult-onset hypothyroidism impaired normal neurogenesis in the subgranular zone of the dentate gyrus with a 30% reduction in the number of proliferating cells. Hypothyroidism also reduced the number of newborn neuroblasts and immature neurons (doublecortin (DCX) immunopositive cells) which had a severely hypoplastic dendritic arborization. To correlate these changes with hippocampal function, we subjected the rats to the forced swimming and novel object recognition tests. Hypothyroid rats showed normal memory in object recognition, but displayed abnormal behavior in the forced swimming test, indicating a depressive-like disorder. Chronic treatment of hypothyroid rats with TH not only normalized the abnormal behavior but also restored the number of proliferative and DCX-positive cells, and induced growth of their dendritic trees. Therefore, hypothyroidism induced a reversible depressive-like disorder, which correlated to changes in neurogenesis.Our results indicate that TH are essential for adult hippocampal neurogenesis and suggest that mood disorders related to adult-onset hypothyroidism in humans could be due, in part, to impaired neurogenesis.This work was supported by Grants BFI2001-2412 and BFU2004-05944 (A.G.-F), BFI2002-00489 (J.B.), BFI2003-07524 (C.V.) from the Ministry of Science and Technology and FIS, Instituto de Salud Carlos III, Red de Centros RCMN (C03/08). A.M.-P. and I.F.-L. are recipient of a fellowship and A.G.-F. and C.V. of a contract from the Ramón y Cajal Program, all of the Ministry of Science and Technology, Spain.Peer reviewe

Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication

Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication

ICPC 14: what is missing?

O intuito deste estudo é levantar questionamentos sobre a Interpretação Técnica do Comitê de Pronunciamentos Contábeis 14 (ICPC 14) frente às características estatutárias das sociedades cooperativas brasileiras. Não almejamos trazer soluções definitivas, esgotando análises conceituais e alternativas de contabilização que envolvem a reclassificação das cotas de cooperados do patrimônio líquido para o passivo, mas apresentar algumas considerações sobre pontos que não estão explícitos na ICPC 14. A aplicação do conceito de ajuste a valor presente (AVP) é o principal ponto deste estudo e isso não foi levado em conta quando da elaboração da ICPC 14. A análise dos estatutos das cooperativas indica, como característica comum, a obrigatoriedade de pagamento do resgate das cotas de cooperados sempre em período superior a um ano, e isso nos leva a concluir que, para a representação fidedigna do fenômeno, torna-se necessário o reconhecimento do AVP desse passivo reclassificado.The purpose of this study is to raise questions about Technical Interpretation 14 (ICPC 14) from the Accounting Standards Committee with regards to the statutory characteristics of Brazilian cooperative societies. We do not aim to provide definitive solutions by exhausting all conceptual analyses and accounting alternatives involving the reclassification of member shares, or “quotas”, from net equity to liabilities, but rather to present some considerations with regards to points that are not explicit in ICPC 14. Applying the concept of adjustment to present value (APV) is the main point of this study, which was not taken into account when ICPC 14 was elaborated. Analysis of the statutes of cooperatives indicates, as a common characteristic, the obligation to always pay the redemption of members’ quotas in a period of more than one year, and this leads us to conclude that for a reliable representation of the phenomenon it is necessary to recognize the APV of this reclassified liability