Extra-large crystal emulsion detectors for future large-scale experiments

Photographic emulsion is a particle tracking device which features the best spatial resolution among particle detectors. For certain applications, for example muon radiography, large-scale detectors are required. Therefore, a huge surface has to be analyzed by means of automated optical microscopes. An improvement of the readout speed is then a crucial point to make these applications possible and the availability of a new type of photographic emulsions featuring crystals of larger size is a way to pursue this program. This would allow a lower magnification for the microscopes, a consequent larger field of view resulting in a faster data analysis. In this framework, we developed new kinds of emulsion detectors with a crystal size of 600-1000 nm, namely 3-5 times larger than conventional ones, allowing a 25 times faster data readout. The new photographic emulsions have shown a sufficient sensitivity and a good signal to noise ratio. The proposed development opens the way to future large-scale applications of the technology, e.g. 3D imaging of glacier bedrocks or future neutrino experiments.Comment: Version accepted for publication in JINS

Factors Driving the Growth in Fertilizer Consumption in Kenya, 1990-2005: Sustaining the Momentum in Kenya and Lessons for Broader Replicability in Sub-Saharan Africa

The objective of this study is to identify the factors responsible for the impressive growth in fertilizer use in Kenya since market liberalization in the early 1990s. Over the past 10 years, fertilizer consumption has risen by 35%. So far, it is unknown whether smallholder farmers are responsible for this growth or whether it is being driven mainly by the large-scale and/or estate sectors. Moreover, it is important for policy makers to know whether the increased fertilizer consumption is being devoted to smallholder food crops or whether industrial crops such as tea and sugarcane are responsible for this growth. This study addresses these questions using nationwide survey data on smallholder fertilizer use patterns between 1996 and 2004. The study also explores whether the growth in fertilizer use in Kenya is attributed to any particular types of fertilizer delivery supply chains. A better understanding of the types of fertilizer distribution channels fueling the growth in consumption and the sustainability of these delivery systems can be of great help in guiding future policy to replicate successful supply chain models more widely in Kenya. Finally the study is meant to guide discussions on fertilizer marketing policy in Kenya in line with the new Economic Recovery Strategy (ERS).Food Security, Food Policy, Fertilizer Consumption, Kenya, Crop Production/Industries, Q18,

Trends and Patterns in Fertilizer Use by Smallholder Farmers in Kenya, 1997-2007

This study uses nationwide household panel survey data from 1996/97 to 2006/07 to examine trends in fertilizer use on maize by smallholder maize growers. The paper also compares these findings with fertilizer use rates according to other recent surveys in Kenya to assess comparability. We also examine the correlation between household fertilizer use and indicators of welfare such as wealth and landholding size. In addition, we use econometric techniques applied to household survey data to identify the main household and community characteristics associated with fertilizer purchases. Lastly, the study considers alternative policy strategies for maintaining smallholders’ access to fertilizer in the current context of substantially higher world fertilizer prices.Fertilizer, Africa, Malawi, Kenya, Small Holders, Crop Production/Industries, Q13,

The Pathological Roles of Ganglioside Metabolism in Alzheimer's Disease: Effects of Gangliosides on Neurogenesis

Conversion of the soluble, nontoxic amyloid β-protein (Aβ) into an aggregated, toxic form rich in β-sheets is a key step in the onset of Alzheimer's disease (AD). It has been suggested that Aβ induces changes in neuronal membrane fluidity as a result of its interactions with membrane components such as cholesterol, phospholipids, and gangliosides. Gangliosides are known to bind Aβ. A complex of GM1 and Aβ, termed “GAβ”, has been identified in AD brains. Abnormal ganglioside metabolism also may occur in AD brains. We have reported an increase of Chol-1α antigens, GQ1bα and GT1aα, in the brain of transgenic mouse AD model. GQ1bα and GT1aα exhibit high affinities to Aβs. The presence of Chol-1α gangliosides represents evidence for genesis of cholinergic neurons in AD brains. We evaluated the effects of GM1 and Aβ1–40 on mouse neuroepithelial cells. Treatment of these cells simultaneously with GM1 and Aβ1–40 caused a significant reduction of cell number, suggesting that Aβ1–40 and GM1 cooperatively exert a cytotoxic effect on neuroepithelial cells. An understanding of the mechanism on the interaction of GM1 and Aβs in AD may contribute to the development of new neuroregenerative therapies for this disorder

Cytotoxic effects of GM1 ganglioside and amyloid β-peptide on mouse embryonic neural stem cells

AD (Alzheimer’s disease) is a neurodegenerative disease and the most common form of dementia. One of the pathological hallmarks of AD is the aggregation of extracellular Aβs (amyloid β-peptides) in senile plaques in the brain. The process could be initiated by seeding provided by an interaction between GM1 ganglioside and Aβs. Several reports have documented the bifunctional roles of Aβs in NSCs (neural stem cells), but the precise effects of GM1 and Aβ on NSCs have not yet been clarified. We evaluated the effect of GM1 and Aβ-(1–40) on mouse NECs (neuroepithelial cells), which are known to be rich in NSCs. No change of cell number was detected in NECs cultured in the presence of either GM1 or Aβ-(1–40). On the contrary, a decreased number of NECs were cultured in the presence of a combination of GM1 and Aβ-(1–40). The exogenously added GM1 and Aβ-(1–40) were confirmed to incorporate into NECs. The Ras–MAPK (mitogen-activated protein kinase) pathway, important for cell proliferation, was intact in NECs simultaneously treated with GM1 and Aβ-(1–40), but caspase 3 was activated. NECs treated with GM1 and Aβ-(1–40) were positive in the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay, an indicator of cell death. It was found that GM1 and Aβ-(1–40) interacted in the presence of cholesterol and sphingomyelin, components of cell surface microdomains. The cytotoxic effect was found also in NSCs prepared via neurospheres. These results indicate that Aβ-(1–40) and GM1 co-operatively exert a cytotoxic effect on NSCs, likely via incorporation into NEC membranes, where they form a complex for the activation of cell death signalling

Ретроспективный анализ врождённых пороков развития у плодов и новорожденных в Гродненском областном перинатальном центре за период 2003-2007 год

НОВОРОЖДЕННЫЙ, БОЛЕЗНИПЛОДА ДИСТРЕС

Effect of pre-germinated brown rice intake on diabetic neuropathy in streptozotocin-induced diabetic rats

<p>Abstract</p> <p>Background</p> <p>To study the effects of a pre-germinated brown rice diet (PR) on diabetic neuropathy in streptozotocin (STZ)-induced diabetic rats.</p> <p>Methods</p> <p>The effects of a PR diet on diabetic neuropathy in STZ-induced diabetic rats were evaluated and compared with those fed brown rice (BR) or white rice (WR) diets with respect to the following parameters: blood-glucose level, motor-nerve conduction velocity (NCV), sciatic-nerve Na⁺/K⁺-ATPase activity, and serum homocysteine-thiolactonase (HTase) activity.</p> <p>Results</p> <p>Compared with diabetic rats fed BR or WR diets, those fed a PR diet demonstrated significantly lower blood-glucose levels (<it>p </it>< 0.001), improved NCV (1.2- and 1.3-fold higher, respectively), and increased Na⁺/K⁺-ATPase activity (1.6- and 1.7-fold higher, respectively). The PR diet was also able to normalize decreased serum homocysteine levels normally seen in diabetic rats. The increased Na⁺/K⁺-ATPase activity observed in rats fed PR diets was associated with elevations in HTase activity (r = 0.913, <it>p </it>< 0.001). The <it>in vitro </it>effect of the total lipid extract from PR bran (TLp) on the Na⁺/K⁺-ATPase and HTase activity was also examined. Incubation of homocysteine thiolactone (HT) with low-density lipoprotein (LDL) <it>in vitro </it>resulted in generation of HT-modified LDL, which possessed high potency to inhibit Na⁺/K⁺-ATPase activity in the sciatic nerve membrane. The inhibitory effect of HT-modified LDL on Na⁺/K⁺-ATPase activity disappeared when TLp was added to the incubation mixture. Furthermore, TLp directly activated the HTase associated with high-density lipoprotein (HDL).</p> <p>Conclusion</p> <p>PR treatment shows efficacy for protecting diabetic deterioration and for improving physiological parameters of diabetic neuropathy in rats, as compared with a BR or WR diet. This effect may be induced by a mechanism whereby PR intake mitigates diabetic neuropathy by one or more factors in the total lipid fraction. The active lipid fraction is able to protect the Na⁺/K⁺-ATPase of the sciatic-nerve membrane from the toxicity of HT-modified LDL and to directly activate the HTase of HDL.</p

Mechanisms of subcutaneous adipose tissue formation in experimental lymphedema model

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Mechanisms of subcutaneous adipose tissue formation in experimental lymphedema model

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