12,420 research outputs found
A Benchmark for Image Retrieval using Distributed Systems over the Internet: BIRDS-I
The performance of CBIR algorithms is usually measured on an isolated
workstation. In a real-world environment the algorithms would only constitute a
minor component among the many interacting components. The Internet
dramati-cally changes many of the usual assumptions about measuring CBIR
performance. Any CBIR benchmark should be designed from a networked systems
standpoint. These benchmarks typically introduce communication overhead because
the real systems they model are distributed applications. We present our
implementation of a client/server benchmark called BIRDS-I to measure image
retrieval performance over the Internet. It has been designed with the trend
toward the use of small personalized wireless systems in mind. Web-based CBIR
implies the use of heteroge-neous image sets, imposing certain constraints on
how the images are organized and the type of performance metrics applicable.
BIRDS-I only requires controlled human intervention for the compilation of the
image collection and none for the generation of ground truth in the measurement
of retrieval accuracy. Benchmark image collections need to be evolved
incrementally toward the storage of millions of images and that scaleup can
only be achieved through the use of computer-aided compilation. Finally, our
scoring metric introduces a tightly optimized image-ranking window.Comment: 24 pages, To appear in the Proc. SPIE Internet Imaging Conference
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Successfull Blossom Thinning and Crop Load Regulation for Organic Apple Growing with Potassium-bi-carbonate (Armicarb(R)): Results of Field Experiments over 3 Years and with 11 Cultivars
With field trials over 3 years in a commercial organic orchard in Switzerland we have tested the efficacy of Armicarb® (potassium-bi-carbonate) for flower thinning in organic apple production. Over time, Armicarb was tested on 11 cultivars, at different application periods, in different concentrations, and always in comparison to other agents that are already allowed for thinning in organic fruit production in the European Union as e.g. lime sulphur, molasses, mechanical rope-thinner or combinations of methods. Armicarb proved to be an efficient and reliable thinning agent with an efficacy similar to the now recommended methods with rope device, molasses or lime sulphur but has the advantage to be an environmentally very friendly product. On the other hand, the risk for fruit russeting is comparably elevated especially with cultivars ‘Elstar’, ‘Golden Del.’ ’and ‘Gala’. Finally, we have elaborated cultivar-specific recommendations for the use of Armicarb for thinning purposes, which were the basis for the Swiss Federal approval to use Armicarb for thinning in conventional and organic apple production in 2011/2012
Integrative and systemic approaches for evaluating PPARβ/δ (PPARD) function.
The peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptors that function as transcription factors regulating the expression of genes involved in cellular differentiation, development, metabolism and also tumorigenesis. Three PPAR isotypes (α, β/δ and γ) have been identified, among which PPARβ/δ is the most difficult to functionally examine due to its tissue-specific diversity in cell fate determination, energy metabolism and housekeeping activities. PPARβ/δ acts both in a ligand-dependent and -independent manner. The specific type of regulation, activation or repression, is determined by many factors, among which the type of ligand, the presence/absence of PPARβ/δ-interacting corepressor or coactivator complexes and PPARβ/δ protein post-translational modifications play major roles. Recently, new global approaches to the study of nuclear receptors have made it possible to evaluate their molecular activity in a more systemic fashion, rather than deeply digging into a single pathway/function. This systemic approach is ideally suited for studying PPARβ/δ, due to its ubiquitous expression in various organs and its overlapping and tissue-specific transcriptomic signatures. The aim of the present review is to present in detail the diversity of PPARβ/δ function, focusing on the different information gained at the systemic level, and describing the global and unbiased approaches that combine a systems view with molecular understanding
Water Conservation with Urban Landscape Plants
Water shortages are a common problem in much of the southwest. Increasing urbanization and increasing population places greater demands on dwindling water supplies. Over half of the water used in urban areas of the southwest is used in the irrigation of landscapes. To help cope with increased urban water demands and low water supplies, research was conducted from March 1981 to July 1983 at The Texas Agricultural Experiment Station at Dallas to gain information relative to consumptive water use by native and non-native landscape plants.
Twenty weighing lysimeters were constructed and installed and plants established in the lysimeters and adjacent areas. The lysimeters were made from 0.6 X 0.9 m undisturbed cores of Austin silty clay soil. Plants used in the lysimeter study were buffalograss, St. Augustine grass, cenizo, boxwood and Texas barberry. All plants are native to Texas except boxwood and St. Augustine grass. Four lysimeters were planted to each plant type. This allowed two moisture levels and two replications of each plant type.
There was no difference in water use by St. Augustine grass and buffalo grass during the year of establishment. Daily water use ranged from 0.49 to 0.08 cm per day but was generally 50% class A pan evaporation. St. Augustine grass used 0.03 cm/day more water than buffalo grass during 1982. -Irrigation treatments used in 1982 did not influence water use by either grass type but buffalo grass retained higher quality under dry treatment (irrigated at 0.40 bar moisture tension) than St. Augustine grass. Water use from May to July 1983 was highest (of all treatments) by St. Augustine grass when irrigated at 0.25 bar soil moisture tension at 76 cm depth and lowest (of all treatments) by buffalograss when irrigated at 0.75 bar soil moisture tension at 76 cm depth.
Application of 50% class A pan evaporation each week appears to be an acceptable guideline for irrigation of either turfgrass but research should be conducted over a longer time period to obtain more specific guidelines for each grass species.
Water use by shrubs in lysimeters was variable and not influenced by plant type during the period of establishment (Fall 1981). During 1982 water use was influenced more by plant size than by specie or water level. Cenizo had much faster growth rate than the other shrubs in the study.
Water use by container grown plants indicated that cenizo had higher water use efficiency than boxwood or Indian Hawthorn. Water use was determined for several native shrubs and of the ones compared, Texas barberry appeared to have the most promise for use in water conserving landscapes
Metabolic interactions between vitamin A and conjugated linoleic acid
Lipid-soluble molecules share several aspects of their physiology due to their common adaptations to a hydrophilic environment, and may interact to regulate their action in a tissue-specific manner. Dietary conjugated linoleic acid (CLA) is a fatty acid with a conjugated diene structure that is found in low concentrations in ruminant products and available as a nutritional supplement. CLA has been shown to increase tissue levels of retinol (vitamin A alcohol) and its sole specific circulating carrier protein retinol-binding protein (RBP or RBP4). However, the precise mechanism of this action has not been elucidated yet. Here, we provide a summary of the current knowledge in this specific area of research and speculate that retinol and CLA may compete for catabolic pathways modulated by the activity of PPAR- and RXR heterodimer. We also present preliminary data that may position PPAR- at the crossroads between the metabolism of lipids and vitamin
Elastic properties of hydrogenated graphene
There exist three conformers of hydrogenated graphene, referred to as chair-,
boat-, or washboard-graphane. These systems have a perfect two-dimensional
periodicity mapped onto the graphene scaffold, but they are characterized by a
orbital hybridization, have different crystal symmetry, and otherwise
behave upon loading. By first principles calculations we determine their
structural and phonon properties, as well as we establish their relative
stability. Through continuum elasticity we define a simulation protocol
addressed to measure by a computer experiment their linear and nonlinear
elastic moduli and we actually compute them by first principles. We argue that
all graphane conformers respond to any arbitrarily-oriented extention with a
much smaller lateral contraction than the one calculated for graphene.
Furthermore, we provide evidence that boat-graphane has a small and negative
Poisson ratio along the armchair and zigzag principal directions of the carbon
honeycomb lattice (axially auxetic elastic behavior). Moreover, we show that
chair-graphane admits both softening and hardening hyperelasticity, depending
on the direction of applied load.Comment: submitted on Phys.Rev.
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