The antisteroid action on the pineal gland

The study presents the data gathered along the years on the antisteroid action of the pineal gland. Thus, it was demonstrated that administration of pineal polypeptides to the rabbit lowers the urinary 17-KS both of testicular and adrenal origin. Conversely, pinealectomy caused an increase in the level of these steroid hormones. The same pineal material induced a marked decrease both in the serum and testicular testosterone and in the plasma and adrenal corticosterone in the rat. At the same time administration of pineal polypeptides lowered the cholesterol in the serum, bile, liver, testis and adrenal. Melatonin had no effect on these biochemical indices, which demonstrates that the effects obtained with pineal polypeptides are not mediated by melatonin.     

Satellite remote sensing of tropical forest canopies and their seasonal dynamics

Seasonal patterns of tropical evergreen forest green-up in Amazonia, corresponding to drought and the dry season, have recently been detected by the Enhanced Vegetation Index (EVI) and Leaf Area Index (LAI) products of the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor. These observations provide additional evidence for solar radiation as the primary limiting factor regulating wet-tropical ecosystem processes. However, in situ structural mechanisms for forest canopy green-up are unclear and frequently inconsistent with observations. Here, we investigate the signal of seasonal green-up at several intensively measured sites, applying a rigorous series of filters to minimize error from atmospheric contamination that is common in tropical regions. We find that, while satellite-observed forest seasonality is sensitive to data-quality filtering, statistical noise reduction and spatial averaging, the signal is robust at sites where field observations are available, and in particular for the EVI. For the sites where field data are unavailable, it appears that additional filters to those commonly used to remove cloud effects and aerosols also reduce the seasonal magnitude of the LAI. These findings imply that seasonal tropical evergreen forest green-up remains sensitive to the methodology used in removing seasonal contamination from atmospheric conditions and that further field measurements and comparisons to remote sensing are required to reduce this uncertainty.     

The diversity of retrotransposons in the yeast Cryptococcus neoformans.

We have undertaken an analysis of the retrotransposons in the medically important basidiomycetous fungus Cryptococcus neoformans. Using the data generated by a C. neoformans genome sequencing project at the Stanford Genome Technology Center, 15 distinct families of LTR retrotransposons and several families of non-LTR retrotransposons were identified. Members of at least seven families have transposed recently and are probably still active. For several families, only partial elements could be identified and these are quite diverse in sequence, suggesting that they are ancient components of the C. neoformans genome. Most C. neoformans elements are not closely related to previously identified fungal retrotransposons, suggesting that the diversity of fungal retrotransposons has been only sparsely sampled to date. C. neoformans has fewer distinct retrotransposon families than Candida albicans (37 or more), in particular fewer families represented solely by ancient and inactive elements, but it has considerably more families than either Saccharomyces cerevisiae (five) or Schizosaccharomyces pombe (two). The findings suggest that elimination of retrotransposons is faster in C. neoformans than in C. albicans, but perhaps not as rapid as in S. cerevisiae or Sz. pombe. The identification of the retrotransposons of C. neoformans should assist in the molecular characterization of this important pathogen, and also further our understanding of the role played by retroelements in genome evolution.     

Semantic and syntactic forces in noun phrase production.

Three experiments investigated semantic and syntactic effects in the production of phrases in Dutch. Bilingual participants were presented with English nouns and were asked to produce an adjective + noun phrase in Dutch including the translation of the noun. In 2 experiments, the authors blocked items by either semantic category or grammatical gender. Participants performed the task slower when the target nouns were of the same semantic category than when they were from different categories and faster when the target nouns had the same gender than when they had different genders. In a final experiment, both manipulations were crossed. The authors replicated the results of the first 2 experiments, and no interaction was found. These findings suggest a feedforward flow of activation between lexico-semantic and lexico-syntactic information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental determination of the absorbed dose to water in a scanned proton beam using a water calorimeter and an ionization chamber

The absorbed dose to water is the reference physical quantity for the energy absorbed in tissue when exposed to beams of ionizing radiation in radiotherapy. The SI unit of absorbed dose to water is the gray (Gy = 1 J/kg). Ionization chambers are used as the dosimeters of choice in the clinical environment because they show a high reproducibility and are easy to use. However, ionization chambers have to be calibrated in order to convert the measured electrical charge into absorbed dose to water. In addition, protocols require these conversion factors to be SI traceable to a primary standard of absorbed dose to water. We present experimental results where the ionization chamber used for the dosimetry for the scanned proton beam facility at PSI is compared with the direct determination of absorbed dose to water from the METAS primary standard water calorimeter. The agreement of 3.2% of the dose values measured by the two techniques are within their respective statistical uncertainties.     

Design and optimization of small hydropower systems in water distribution networks under consideration of rehabilitation measures

Small hydro power systems (SHPSs) are increasingly installed in water distribution systems (WDSs). With only minor adaptations in a WDS, pressure surplus can be utilised. In such systems, a water surplus is also often available. In this work, water consumption data of a real Alpine WDS over one year are used as an input for an Epanet2 long-term simulation model to assess such a SHPS. In addition, the combinations of pressure and water surplus devices in a WDS are investigated. For such a specific investigated case, the yearly profit of 1750 € for a single SHPS could be increased to 3550 € when combining two interacting devices. Further, necessary and upcoming rehabilitation measures are investigated concerning their positive impact on the energy production potential and how additional costs (e.g., higher diameters (200 mm instead of 125 mm)) can be compensated by additional profits from energy production (maximum 5250 € per year).     

Yttrium incorporation in Cr2AlC: On the metastable phase formation and decomposition of (Cr,Y)2AlC MAX phase thin films

Herein we report on the synthesis of a metastable (Cr,Y)₂AlC MAX phase solid solution by co-sputtering from a composite Cr–Al–C and elemental Y target, at room temperature, followed by annealing. However, direct high-temperature synthesis resulted in multiphase films, as evidenced by X-ray diffraction analyses, room-temperature depositions, followed by annealing to 760°C led to the formation of phase pure (Cr,Y)₂AlC by diffusion. Higher annealing temperatures caused a decomposition of the metastable phase into Cr₂AlC, Y₅Al₃, and Cr-carbides. In contrast to pure Cr₂AlC, the Y-containing phase crystallizes directly in the MAX phase structure instead of first forming a disordered solid solution. Furthermore, the crystallization temperature was shown to be Y-content dependent and was increased by ∼200°C for 5 at.% Y compared to Cr₂AlC. Calculations predicting the metastable phase formation of (Cr,Y)₂AlC and its decomposition are in excellent agreement with the experimental findings.     

Disruption and mapping of IDI1, the gene for isopentenyl diphosphate isomerase in Saccharomyces cerevisiae.

Isopentenyl diphosphate isomerase catalyses an essential activation step in the isoprene biosynthetic pathway. The Saccharomyces cerevisiae gene for isomerase, IDI1, was recently isolated and characterized (Anderson et al. J. Biol. Chem. 1989a, 264, 19169-19175). Wild-type IDI1 was disrupted with a LEU2 marker, and the resulting DNA was used to transform a yeast leucine auxotroph. Southern blots of EcoRI fragments of chromosomal DNA from the diploid strain showed the expected fragments for intact and disrupted IDI1. Dissection and analysis of tetrads demonstrated that IDI1 is an essential single-copy gene. A CHEF gel and clone grid filter analysis, followed by chromosomal mapping indicated that the gene is located on chromosome XVI approximately 55 kb centromere proximal to PEP4.