1,341 research outputs found
Salix Babylonica, A Traditional Fodder with Promising Potential
In Bhutan, tree fodders are important for ruminant nutrition, especially during the dry winter season. Salix babylonica is the preferred species for temperate regions. Farmers above 2000 m plant it widely for fodder, fuel, and fencing. Lack of fodder availability during the dry season, and competition with other crops are its main disadvantages. Crude protein content of S. babylonica leaves declined from 25% in May to 11% in October. Voluntary intake was 78 and 85 g dry matter/W0.75 and live weight gain 330 and 64 g day-1 for growing bulls and sheep, respectively. Dry matter disappearance after 48 hours of rumen incubation was 85, 65, and 53% for S. babylonica, Robinia pseudoacacia and Litsea polyantha leaves, respectively
Comment on "Origin of Giant Optical Nonlinearity in Charge-Transfer--Mott Insulators: A New Paradigm for Nonlinear Optics"
Comment on Phys. Rev. Lett. 86, 2086 (2001)Comment: 1 page, 1 eps figur
Soil fertility management for organic rice production in the Lao PDR
Rice is the most important agricultural commodity of the Lao People's Democratic Republic (Lao PDR), produced largely using traditional methods with limited inputs of fertilizers and other chemicals. The country has a wide diversity in rice production systems and rice varieties, with over 3000 different varieties recorded. The rich diversity and the production environment and methods are favorable for organic rice production. Investigations were carried out to describe soil fertility conditions, management practices, opportunities and problems associated with organic production methods for rice. Soils used for rice production are mostly of low fertility, with low organic matter and N-availability. In spite of this, virtually no fertilizer inputs are used for upland rice production. Inorganic fertilizer inputs for lowland rice production have increased rapidly over the past decade, but are still below 20 kg ha−1. The most important nutrient sources are rice straw and manure from buffalo and cattle. Chromolaena odorata plays an important role in nutrient cycling in upland rice systems and is sometimes added to lowland fields. In a range of fertility management studies, yield increase ranged from 2 to 89% for manure, straw or rice husk applied at modest rates (3 t ha−1), 32-156% for modest rates of inorganic fertilizer (60 kg N ha−1) and 36-167% for combined application of manure or crop residues with inorganic fertilizer. The response to locally produced commercial organic fertilizer was poor. The most promising inputs and strategies available to optimize yields in organic rice production systems are (1) optimizing use of locally available nutrients, mostly from manure, crop residues and weed biomass, (2) N addition through green manure and legumes growing in rotation and (3) additions of P through guano or rock-phosphate. The Lao PDR is fortunate to have substantial bat guano deposits in limestone caves. Extensive experience is available on straw and husk management for lowland systems and green manure species for upland production system
Handbook on thermophysical properties of oxygen
Handbook has been compiled by Cryogenic Data Center of National Bureau of Standards. It covers thermodynamic functions, physical properties, and heat transfer data for oxygen. Handbook addresses primarily low temperature regime, but also includes some data above room temperature
Floods, landscape modifications and population dynamics in anthropogenic coastal lowlands: the Polesine (northern Italy) case study
It is widely recognized that the complex relationship between humans, soil, and water has become increasingly complicated due to anthropogenic activities, and is further expected to worsen in the future as a result of population dynamics and climate change. The present study aims at shedding light on the multifaceted links between floods, landscape modifications, and population dynamics in anthropogenic coastal lowlands, using a large flood-prone area (the Polesine Region, northeastern Italy) as a significant case study. Based on the analysis of historical events and the results of hydraulic modeling, it is shown that human interventions on both the landscape and the subsoil have substantially altered the flooding dynamics, exacerbating hydraulic hazard. Furthermore, the combined analysis of people and assets exposure to inundation reveals that flood risk is not properly taken into account in land-use planning, nor it is properly understood by people living in areas subject to low-probability, high-impact flooding events
Integration of microRNA changes in vivo identifies novel molecular features of muscle insulin resistance in type 2 diabetes
Skeletal muscle insulin resistance (IR) is considered a critical component of type II diabetes, yet to date IR has evaded characterization at the global gene expression level in humans. MicroRNAs (miRNAs) are considered fine-scale rheostats of protein-coding gene product abundance. The relative importance and mode of action of miRNAs in human complex diseases remains to be fully elucidated. We produce a global map of coding and non-coding RNAs in human muscle IR with the aim of identifying novel disease biomarkers. We profiled >47,000 mRNA sequences and >500 human miRNAs using gene-chips and 118 subjects (n = 71 patients versus n = 47 controls). A tissue-specific gene-ranking system was developed to stratify thousands of miRNA target-genes, removing false positives, yielding a weighted inhibitor score, which integrated the net impact of both up- and down-regulated miRNAs. Both informatic and protein detection validation was used to verify the predictions of in vivo changes. The muscle mRNA transcriptome is invariant with respect to insulin or glucose homeostasis. In contrast, a third of miRNAs detected in muscle were altered in disease (n = 62), many changing prior to the onset of clinical diabetes. The novel ranking metric identified six canonical pathways with proven links to metabolic disease while the control data demonstrated no enrichment. The Benjamini-Hochberg adjusted Gene Ontology profile of the highest ranked targets was metabolic (P < 7.4 × 10-8), post-translational modification (P < 9.7 × 10-5) and developmental (P < 1.3 × 10-6) processes. Protein profiling of six development-related genes validated the predictions. Brain-derived neurotrophic factor protein was detectable only in muscle satellite cells and was increased in diabetes patients compared with controls, consistent with the observation that global miRNA changes were opposite from those found during myogenic differentiation. We provide evidence that IR in humans may be related to coordinated changes in multiple microRNAs, which act to target relevant signaling pathways. It would appear that miRNAs can produce marked changes in target protein abundance in vivo by working in a combinatorial manner. Thus, miRNA detection represents a new molecular biomarker strategy for insulin resistance, where micrograms of patient material is needed to monitor efficacy during drug or life-style interventions
Isochoric thermal conductivity of solid nitrogen
The isochoric thermal conductivity of solid nitrogen has been investigated on
four samples of different densities in the temperature interval from 20 K to
the onset of melting. In alfa-N2 the isochoric thermal conductivity exhibits a
dependence weaker than 1/T; in beta-N2 it increases slightly with temperature.
The experimental results are discussed within a model in which the heat is
transported by low-frequency phonons or by "diffusive" modes above the mobility
boundary. The growth of the thermal conductivity in beta-N2 is attributed to
the decreasing "rotational" component of the total thermal resistance, which
occurs as the rotational correlations between the neighboring molecules become
weaker.Comment: Postscript 12 pages, 3 figures, 1 table. To be published in 200
Double Exchange Models: Self Consistent Renormalisation
We propose a scheme for constructing classical spin Hamiltonians from Hunds
coupled spin-fermion models in the limit J_H/t \to \infinity. The strong
coupling between fermions and the core spins requires self-consistent
calculation of the effective exchange in the model, either in the presence of
inhomogeneities or with changing temperature. In this paper we establish the
formalism and discuss results mainly on the ``clean'' double exchange model,
with self consistently renormalised couplings, and compare our results with
exact simulations. Our method allows access to system sizes much beyond the
reach of exact simulations, and we can study transport and optical properties
of the model without artificial broadening. The method discussed here forms the
foundation of our papers Phys. Rev. Lett. 91, 246602 (2003), and Phys. Rev.
Lett. 92, 126602 (2004).Comment: 11 pages revtex. Final version, to appear in EPJ
Abnormal interneuron development in disrupted-in-schizophrenia-1 L100P mutant mice
BACKGROUND: Interneuron deficits are one of the most consistent findings in post-mortem studies of schizophrenia patients and are likely important in the cognitive deficits associated with schizophrenia. Disrupted-in-Schizophrenia 1 (DISC1), a strong susceptibility gene for schizophrenia and other mental illnesses, is involved in neurodevelopment, including that of interneurons. However, the mechanism by which DISC1 regulates interneuron development remains unknown. In this study, we analyzed interneuron histology in the Disc1-L100P single point mutation mouse, that was previously shown to have behavioral abnormalities and cortical developmental defects related to schizophrenia. RESULTS: We sought to determine whether a Disc1-L100P point mutation in the mouse would alter interneuron density and location. First, we examined interneuron position in the developing mouse cortex during embryonic days 14–16 as an indicator of interneuron tangential migration, and found striking migration deficits in Disc1-L100P mutants. Further analysis of adult brains revealed that the Disc1-L100P mutants have selective alterations of calbindin- and parvalbumin-expressing interneurons in the cortex and hippocampus, decreased GAD67/PV co-localization and mis-positioned interneurons across the neocortex when compared to wild-type littermates. CONCLUSION: Our results are consistent with the anomalies seen in post-mortem schizophrenia studies and other Disc1 mutant mouse models. Future research is required to determine the specific mechanisms underlying these cellular deficits. Overall, these findings provide further evidence that DISC1 participates in interneuron development and add to our understanding of how DISC1 variants can affect susceptibility to psychiatric illness
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