13,453 research outputs found
Drying of post-harvest rough rice with silica gel: A preliminary investigation
Rice drying operations can encounter problems of over drying and losses in head rice yield (HRY) through the formation of fissures. Typical rice drying methods also utilize large volumes of expensive fossil fuels to dry the kernels. Drying of rice with a solid desiccant such as silica gel has several potential advantages that avoid some of these problems. Two cultivars of long-grain rough rice, ‘Cheniere’ and ‘Wells’ with harvest moisture contents of 17.8% and 22.0%, respectively, were dried over a 48-h period with various ratios of rough rice-to-silica gel. It was found that an intimate mixture of 3:1 rough rice to silica gel was sufficient to dry these rice lots to 12.5% and 14.3% within 12 h, respectively. Head rice yields of desiccant-dried rice showed no considerable differences from the control. Rough-rice drying curves for all rough rice-to-silica gel mixtures followed exponential relationships
The cAMP sensors, EPAC1 and EPAC2, display distinct subcellular distributions despite sharing a common nuclear pore localisation signal
We have identified a conserved nuclear pore localisation signal (NPLS; amino acids 764–838 of EPAC1) in the catalytic domains of the cAMP-sensors, EPAC1 and EPAC2A. Consequently, EPAC1 is mainly localised to the nuclear pore complex in HEK293T cells where it becomes activated following stimulation with cAMP. In contrast, structural models indicate that the cAMP-binding domain of EPAC2A (CNBD1) blocks access to the conserved NPLS in EPAC2A, reducing its ability to interact with nuclear binding sites. Consequently, a naturally occurring EPAC2 isoform, EPAC2B, which lacks CNBD1 is enriched in nuclear fractions, similar to EPAC1. Structural differences in EPAC isoforms may therefore determine their intracellular location and their response to elevations in intracellular cAMP
A sharp estimate for the Hardy-Littlewood maximal function
The best constant in the usual Lp norm inequality for the centered
Hardy-Littlewood maximal function on R1 is obtained for the class of all
``peak-shaped'' functions. A positive function on the line is called
``peak-shaped'' if it is positive and convex except at one point. The
techniques we use include convexity and an adaptation of the standard
Euler-Langrange variational method.Comment: Also available at http://www.math.missouri.edu/~stephen/preprints
Absolute linear instability in laminar and turbulent gas/liquid two-layer channel flow
We study two-phase stratified flow where the bottom layer is a thin laminar
liquid and the upper layer is a fully-developed gas flow. The gas flow can be
laminar or turbulent. To determine the boundary between convective and absolute
instability, we use Orr--Sommerfeld stability theory, and a combination of
linear modal analysis and ray analysis. For turbulent gas flow, and for the
density ratio r=1000, we find large regions of parameter space that produce
absolute instability. These parameter regimes involve viscosity ratios of
direct relevance to oil/gas flows. If, instead, the gas layer is laminar,
absolute instability persists for the density ratio r=1000, although the
convective/absolute stability boundary occurs at a viscosity ratio that is an
order of magnitude smaller than in the turbulent case. Two further unstable
temporal modes exist in both the laminar and the turbulent cases, one of which
can exclude absolute instability. We compare our results with an
experimentally-determined flow-regime map, and discuss the potential
application of the present method to non-linear analyses.Comment: 33 pages, 20 figure
WMTrace : a lightweight memory allocation tracker and analysis framework
The diverging gap between processor and memory performance has been a well discussed aspect of computer architecture literature for some years. The use of multi-core processor designs has, however, brought new problems to the design of memory architectures - increased core density without matched improvement in memory capacity is reduc- ing the available memory per parallel process. Multiple cores accessing memory simultaneously degrades performance as a result of resource con- tention for memory channels and physical DIMMs. These issues combine to ensure that memory remains an on-going challenge in the design of parallel algorithms which scale. In this paper we present WMTrace, a lightweight tool to trace and analyse memory allocation events in parallel applications. This tool is able to dynamically link to pre-existing application binaries requiring no source code modification or recompilation. A post-execution analysis stage enables in-depth analysis of traces to be performed allowing memory allocations to be analysed by time, size or function. The second half of this paper features a case study in which we apply WMTrace to five parallel scientific applications and benchmarks, demonstrating its effectiveness at recording high-water mark memory consumption as well as memory use per-function over time. An in-depth analysis is provided for an unstructured mesh benchmark which reveals significant memory allocation imbalance across its participating processes
N=1 super Yang-Mills on a (3+1) dimensional transverse lattice with one exact supersymmetry
We formulate =1 super Yang-Mills theory in 3+1 dimensions on a two
dimensional transverse lattice using supersymmetric discrete light cone
quantization in the large- limit. This formulation is free of fermion
species doubling. We are able to preserve one supersymmetry. We find a rich,
non-trivial behavior of the mass spectrum as a function of the coupling
, and see some sort of "transition" in the structure of a bound
state as we go from the weak coupling to the strong coupling. Using a toy model
we give an interpretation of the rich behavior of the mass spectrum. We present
the mass spectrum as a function of the winding number for those states whose
color flux winds all the way around in one of the transverse directions. We use
two fits to the mass spectrum and the one that has a string theory
justification appears preferable. For those states whose color flux is
localized we present an extrapolated value for for some low energy bound
states in the limit where the numerical resolution goes to infinity.Comment: 23(+2 for v3) pages, 19 figures; v2: a footnote added; v3: an
appendix, comments, references added. The version to appear PR
Effectiveness of the development of internal auditing in the Victorian Public Service (1982-1987)
The selection of an inappropriate regime by policy makers can thwart the effective implementation of public policy and lead to implementation failure. Competing values in the implementation process have a significant impact on the results of implementation, and the regime selected for implementation implies the choice of one value over another. Stoker has argued that on the one hand central leadership is valued for consistency, benefits of scale, co-ordination and cost sharing (instrumental model); and on the other, diffuse authority is valued as knowledge is particular and situational, and the task of analysis is to understand the problems, perspectives and interactions of implementation participants at the contact point between public programs and their clients (accommodation model). This study examines the implementation regime chosen by the Victorian Government for the introduction of a modern internal auditing function into the Victorian Public Service, using the Bureau of Internal Audit within its Department of Management and Budget. The selection of the Department of Management and Budget for the introduction of Internal Audit as a managerial accountability mechanism indicates that the instrumental model was held by the Victorian Government to be the most important in implementation. It is argued that use of a top-down central agency leadership approach resulted in implementation failure. Three propositions suggesting the mechanisms by which this result is brought about are examined: that lack of co-ordinated planning at the outset will result in inadequate definition of client needs as part of policy formulation; that intraorganisational conflict during the implementation success, as individual participants are likely to exercise their veto; and the increasing the number of participants contributes to complexity, so that they should only be involved in implementation when their presence is absolutely required. It is argued that the essential task of implementation is to create an environment where participants are likely to co-operate to achieve predetermined public policy goals; and that the introduction of a modern internal auditing approach into the Victorian Public Service required a more participatory implementation regime in order to facilitate policy outcomes and prevent implementation failure. It is also argued that the dominance of economic reform over accountability in Victoria restricted the ability of the Bureau of Internal Audit to implement change to internal audit practices within Victorian Government departments. The selection of an instrumental model of implementation by the Department of Management and Budget is examined in the context of the environment that existed in Victoria between 1982-1987; and while some of the values which Stoker associates with the top-down approach to policy making were observed, an alternative view to the development of internal auditing in the Victorian Public Service can be sustained
Genome Empowerment for the Puerto Rican Parrot – Amazona vittata
A unique community-funded project in Puerto Rico has launched whole-genome sequencing of the critically endangered Puerto Rican Parrot (Amazona vittata), with interpretation by genome bioinformaticians and students, and deposition into public online databases. This is the first article that focuses on the whole genome of a parrot species, one endemic to the USA and recently threatened with extinction. It provides invaluable conservation tools and a vivid example of hopeful prospects for future genome assessment of so many new species. It also demonstrates inventive ways for smaller institutions to contribute to a field largely considered the domain of large sequencing centers
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