Comparative studies on the structure of an upland African stream ecosystem

Upland stream systems have been extensively investigated in Europe, North America and Australasia and many of the central ideas concerning their function are based on these systems. One central paradigm, the river continuum concept is ultimately derived from those North American streams whose catchments remain forested with native vegetation. Streams of the tropics may or may not fit the model. They have been little studied. The Amani Nature Reserve in the East Usambara Mountains of north-eastern Tanzania offers an opportunity to bring these naturally forested systems to the attention of the ecological community. This article describes a comparison made between two lengths of the River Dodwe in this area. The work was carried out by a group of postgraduate students from eighteen European and African countries with advice from five staff members, as part of a course organised by the Tropical Biology Association. Rigorous efforts were made to standardise techniques, in a situation where equipment and laboratory facilities were very basic, through a management structure and deliberate allocation of work to specialists in each area.The article offers a summary of invertebrate communities found in the stream and its biomass. Crabs seem to be the key organism in both sections of the streams

Zum Nachweis der Ameisensäure im Bienenhonig

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Gigahertz (GHz) hard x-ray imaging using fast scintillators

Gigahertz (GHz) imaging technology will be needed at high-luminosity X-ray and charged particle sources. It is plausible to combine fast scintillators with the latest picosecond detectors and GHz electronics for multi-frame hard Xray imaging and achieve an inter-frame time of less than 10 ns. The time responses and light yield of LYSO, LaBr_3, BaF_2 and ZnO are measured using an MCP-PMT detector. Zinc Oxide (ZnO) is an attractive material for fast hard X-ray imaging based on GEANT4 simulations and previous studies, but the measured light yield from the samples is much lower than expected

The response of Monoterpenes to Different Enzyme Preparations in Gewürztraminer (Vitis vinifera L.) Wines

The α-terpineol, linalool, nerol and geraniol, which are the main aromatic monoterpenes in the grapevine varietyGewürztraminer, were determined in the grapes, must and wine after treatment with six different pectolytic enzymes[Lallzyme-β (‘Lall’); Rohavin VR-C (‘VRX’), Rohapect D5L (‘D5L’), Rohavin MX (‘MX’), Rohapect VRC (‘VRC’),Endozym cultivar A (‘Cult. A’)], and after treatment with β-glucosidase (βG, EC 3.2.1.21). The concentrations ofmonoterpenic compounds were determined by solid-phase microextraction (SPME) and GC-MS. The most abundantmonoterpene in the grapes of Gewürztraminer was geraniol (66.7 μg/L), followed by nerol (13.3 μg/L), α-terpineol(7.8 μg/L) and finally linalool (3.3 μg/L). Gewürztraminer wine from must treated with the Lall enzyme preparationwas the most aromatic, which was also confirmed by chemical and sensory analysis in which the concentrations ofnerol (45.9 μg/L), geraniol (31.8 μg/L), α-terpineol (10.5 μg/L) and linalool (6.1 μg/L) were determined. The winesproduced from must treated chemically with enzymes showed higher concentrations of many of the monoterpenecompounds compared to the control, although the sensorial analysis did not affirm this convincingly

Impact of Alternative Skin Contact Procedures on the Aroma Composition of White Wine

Zelen, Ribolla Gialla and Malvasia Istriana, grapes from the Vitis vinifera (L.) varieties, were subjectedto four processes involving grape skin contact. Fresh and fruity young wines were produced by adding6% or 12% grape berries, respectively, during alcoholic fermentation, freezing the pomace (Fp) and thefreezing whole grapes (Fg). Wine-free volatile aromatic compounds were determined using two extractiontechniques coupled to gas chromatography (GC). These aromatic compounds and wine standard chemicalparameters were compared to control wines produced without skin contact. Esters, higher alcohols,terpenes, volatile phenols and C6 alcohols proved to be the most important sensorial odorants in wines.Both the content of aromatic compounds and the odour activity values showed some positive effects fromskin contact. The freezing of the grapes and addition of 12% grape berries proved most effective forZelen and Malvasia Istriana, producing a more intensive fruity and floral odour, a less intensive solventodour and additional freshness. The same processes resulted only in additional fruitiness or a less intensivesolvent odour in Ribolla Gialla while the lowest concentrations of grape derived terpenes were achieved forthis variety. The three varieties were most affected by freezing processes. During the sensorial evaluation,the wines that had been subjected to skin contact were generally preferred to the control wines

Cervicothoracic Intradural Arachnoid Cyst Misdiagnosed as Motor Neuron Disease

Recognizing syndromes which mimic ALS is crucial both to avoid giving this diagnosis erroneously and since there may be appropriate treatments. We report a 63-year-old woman diagnosed with possible ALS five years ago based on upper and lower motor neuron signs with typical electrophysiology and normal cranial MRI. At reassessment, spinal MRI revealed a cervicothoracic cyst with cord compression that was successfully treated neurosurgically. Histopathology confirmed an arachnoid origin as suspected from MRI. Spinal cysts may mimic ALS and need to be thoroughly excluded by appropriate imaging

A genome-wide association study of anorexia nervosa.

Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome-wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2907 cases with AN from 14 countries (15 sites) and 14 860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery data sets. Seventy-six (72 independent) single nucleotide polymorphisms were taken forward for in silico (two data sets) or de novo (13 data sets) replication genotyping in 2677 independent AN cases and 8629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication data sets comprised 5551 AN cases and 21 080 controls. AN subtype analyses (1606 AN restricting; 1445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01 × 10(-7)) in SOX2OT and rs17030795 (P=5.84 × 10(-6)) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76 × 10(-)(6)) between CUL3 and FAM124B and rs1886797 (P=8.05 × 10(-)(6)) near SPATA13. Comparing discovery with replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4 × 10(-6)), strongly suggesting that true findings exist but our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field