SCANNING ELECTRON MICROSCOPIC STUDY OF QUARTZ SAND SURFACE FEATURES, ASH HOLLOW FORMATION, OGALLALA GROUP, WESTERN NEBRASKA

In field studies of the late Tertiary Ash Hollow Formation of the Ogallala Group in western Nebraska the alluvial deposits are composed of large volumes of sand and gravel up to large cobbles. Because the current understanding of the climate of the region at the time of deposition does not provide for a source for deposits of this character, a scanning electron microscopic study of the surface features on the quartz sand grains from these sediments was undertaken. Nine samples, collected from locations in Banner, Morrill and Keith Counties, were examined to see if they had one or more of 22 surface features. The results were compared with models for glacial, glacio-fluvial and fluvial sand compiled from the work of others. Preliminary results indicate that two of the samples correspond well with the glacial model, five others correspond with the glacio-fluvial model and none corresponds well with the fluvial model. These results indicate the need to look further for corroborating evidence of a glacial source for at least part of the Ash Hollow Formation and to consider the implications for a partial glacial history of the mountain sediment source regions in the late Tertiary

Scanning Electron Microscopic Study of Quartz Sand Surface Features, Ash Hollow Formation, Ogallala Group, Western Nebraska

In field studies of the late Tertiary Ash Hollow Formation of the Ogallala Group in western Nebraska the alluvial deposits are composed of large volumes of sand and gravel up to large cobbles. Because the current understanding of the climate of the region at the time of deposition does not provide for a source for deposits of this character, a scanning electron microscopic study of the surface features on the quartz sand grains from these sediments was undertaken. Nine samples, collected from locations in Banner, Morrill and Keith Counties, were examined to see if they had one or more of 22 surface features. The results were compared with models for glacial, glacio-fluvial and fluvial sand compiled from the work of others. Preliminary results indicate that two of the samples correspond well with the glacial model, five others correspond with the glacio-fluvial model and none corresponds well with the fluvial model. These results indicate the need to look further for corroborating evidence of a glacial source for at least part of the Ash Hollow Formation and to consider the implications for a partial glacial history of the mountain sediment source regions in the late Tertiary

Determining the Mechanism of Yield Stability in Alfalfa

Year-to-year stability of crop yields is important for farmers, and hence is an important goal of plant breeding programs. Especially in perennial crops like alfalfa farmers need to know that they can count on consistent yields over a period of three or more years. Alfalfa varieties are composed of a population of many genetically distinct plants (or genotypes), unlike corn hybrids or soybean lines, which are genetically uniform. Our goal is to determine whether the entire population of plants or single plants within a population determine yield stability of alfalfa. If varietal stability is due to the stability of individual plants in the population, then breeders can select individual plants with stable performance under many environmental conditions to use in the development of stable varieties. Conversely, if yield stability of a variety results from the interaction of many different genotypes, each of which performs better under some conditions than others, then alternative methods for developing stable cultivars must be investigated

Arachnoid cysts do not contain cerebrospinal fluid: A comparative chemical analysis of arachnoid cyst fluid and cerebrospinal fluid in adults

<p>Abstract</p> <p>Background</p> <p>Arachnoid cyst (AC) fluid has not previously been compared with cerebrospinal fluid (CSF) from the same patient. ACs are commonly referred to as containing "CSF-like fluid". The objective of this study was to characterize AC fluid by clinical chemistry and to compare AC fluid to CSF drawn from the same patient. Such comparative analysis can shed further light on the mechanisms for filling and sustaining of ACs.</p> <p>Methods</p> <p>Cyst fluid from 15 adult patients with unilateral temporal AC (9 female, 6 male, age 22-77y) was compared with CSF from the same patients by clinical chemical analysis.</p> <p>Results</p> <p>AC fluid and CSF had the same osmolarity. There were no significant differences in the concentrations of sodium, potassium, chloride, calcium, magnesium or glucose. We found significant elevated concentration of phosphate in AC fluid (0.39 versus 0.35 mmol/L in CSF; <it>p </it>= 0.02), and significantly reduced concentrations of total protein (0.30 versus 0.41 g/L; <it>p </it>= 0.004), of ferritin (7.8 versus 25.5 ug/L; <it>p </it>= 0.001) and of lactate dehydrogenase (17.9 versus 35.6 U/L; <it>p </it>= 0.002) in AC fluid relative to CSF.</p> <p>Conclusions</p> <p>AC fluid is not identical to CSF. The differential composition of AC fluid relative to CSF supports secretion or active transport as the mechanism underlying cyst filling. Oncotic pressure gradients or slit-valves as mechanisms for generating fluid in temporal ACs are not supported by these results.</p

Utslipp av breslam til Holandsfjorden fra Svartisen kraftverk. Spredning av mulige effekter av partikkeltilførselen

Etter at Svartisen kraftverk kom i drift i 1993 er det i perioder blitt observert brunlig vann i store deler av Nordfjord/Holandsfjord. Hovedårsaken har vært en høy tilførsel av partikler til fjorden gjennom kraftverket. Det siste års målinger av suspendert materiale (SPM) i kraftverksvannet viser en markant reduksjon i tilførselen av partikler til fjorden gjennom kraftverket, og bedringene er blitt bekreftet av SPM- og siktedypsmålinger i fjorden. Det er anslått at ca. 30% av den leire og silt som slippes ut gjennom kraftverket transporteres forbi Enganeset, hvor den raskt fortynnes og konsentrasjonen av SPM vil komme ned på "bakgrunnsnivå". Sandfraksjonen vil i hovedsak sedimentere rett utenfor utslippet innerst i Nordfjord. Beregninger foretatt med utgangspunkt i dagens-, og den antatt fremtidige situasjon, indikerer liten negativ påvirkning på livet i fjorden. Lokalt, og i korte perioder, vil påvirkningen kunne være større. For å fortsatt kunne følge utviklingen i fjorden i tiden fremover foreslåes at pågående undersøkelser/målinger, med enkelte tillegg og justeringer, videreføres frem til år 2001-02 da en større etterundersøkelse er planlagt

First-in-human pharmacokinetics of tamoxifen and its metabolites in the milk of a lactating mother. A case study

Background Breast cancer represents the most frequent neoplasm diagnosed in women of childbearing age. When the tumour is oestrogen receptor-positive, tamoxifen is among the recommended endocrine treatments. Lactating women are advised not to breastfeed while receiving tamoxifen. However, information about tamoxifen transfer into breast milk is lacking. Methods We measured the concentration of tamoxifen and its metabolites by liquid chromatography-tandem mass spectrometry in the milk of a nursing mother that was treated for pregnancy-associated breast cancer diagnosed a few months after delivery. She was advised not to breastfeed her child and she collected milk samples for 23 days while the baby was fed with formula. Results Tamoxifen concentrations in milk increased reaching a maximum of 214 nM. The two active metabolitesZ-4-hydroxy-tamoxifen and Z-endoxifen, could not be quantified in milk the first days after tamoxifen intake, but increased over time and reached clinically significant levels after day 18. Conclusion This study demonstrates for the first time in human that tamoxifen and its metabolites transfer into milk. Since tamoxifen has a complete oral bioavailability, a long half-life (&gt;7 days) and may interfere with the normal development of the infant, mothers should not breastfeed during tamoxifen treatment

Tyrosine and phenylalanine supplementation on Diplodus sargus larvae: effect on growth and quality

27 páginas, 3 figuras, 5 tablas. The definitive version is available at www.blackwell-synergy.comPhenylalanine is the precursor of tyrosine, which is involved in the synthesis of several molecules with key roles in the regulation of metabolism and growth, stress response and pigmentation. In this study, three experimental diets were tested: an amino acid (AA) balanced diet supplemented with phenylalanine, another supplemented with phenylalanine and tyrosine and a non-supplemented AA balanced diet. Rotifers were enriched with liposomes encapsulating free AA in order to obtain a balanced AA profile. The experimental diets resulted in similar larval survival, growth, enzyme activities of AA catabolism and nitrogen excretion in all treatments. High levels of skeletal deformities were registered and significant differences were found between the control and the phenylalanine treatment for the percentage of vertebral compressions in the trunk region of the vertebral column (30% in the control and 5% in the phenylalanine group). A significantly higher survival to a temperature stress test was found for larvae fed the diet supplemented with phenylalanine and tyrosine. The results suggest that supplementation of phenylalanine/tyrosine in fish diets may be useful in order to reduce skeletal deformities and mortalities caused by stress. The present study confirms that AA requirements may be sufficient for covering growth and survival but insufficient to cover other metabolic processes.This work was supported by the project POCI/MAR/61623/2004 – SAARGO, financed by the programme POCI 2010 (FCT, Portugal), which is co-financed by FEDER. FEDER and PN Project AGL2004-06669-C02-01 (Ministry of Education and Science, Spain) are co-financed by FEDER and project –‘Tecnologias de Produção Aquícola’– (22-05-01-FBR-00014 – QCA IIII).Peer reviewe