2,399 research outputs found
Simulation-driven emulation of collaborative algorithms to assess their requirements for a large-scale WSN implementation
Assessing how the performance of a decentralized wireless sensor network (WSN) algorithm's implementation scales, in terms of communication and energy costs, as the network size increases is an essential requirement before its field deployment. Simulations are commonly used for this purpose, especially for large-scale environmental monitoring applications. However, it is difficult to evaluate energy consumption, processing and memory requirements before the algorithm is really ported to a real WSN platform. We propose a method for emulating the operation of collaborative algorithms in large-scale WSNs by re-using a small number of available real sensor nodes. We demonstrate the potential of the proposed simulation-driven WSN emulation approach by using it to estimate how communication and energy costs scale with the network’s size when implementing a collaborative algorithm we developed in for tracking the spatiotemporal evolution of a progressing environmental hazard
A novel familial mutation in the PCSK1 gene that alters the oxyanion hole residue of proprotein convertase 1/3 and impairs its enzymatic activity.
Four siblings presented with congenital diarrhea and various endocrinopathies. Exome sequencing and homozygosity mapping identified five regions, comprising 337 protein-coding genes that were shared by three affected siblings. Exome sequencing identified a novel homozygous N309K mutation in the proprotein convertase subtilisin/kexin type 1 (PCSK1) gene, encoding the neuroendocrine convertase 1 precursor (PC1/3) which was recently reported as a cause of Congenital Diarrhea Disorder (CDD). The PCSK1 mutation affected the oxyanion hole transition state-stabilizing amino acid within the active site, which is critical for appropriate proprotein maturation and enzyme activity. Unexpectedly, the N309K mutant protein exhibited normal, though slowed, prodomain removal and was secreted from both HEK293 and Neuro2A cells. However, the secreted enzyme showed no catalytic activity, and was not processed into the 66 kDa form. We conclude that the N309K enzyme is able to cleave its own propeptide but is catalytically inert against in trans substrates, and that this variant accounts for the enteric and systemic endocrinopathies seen in this large consanguineous kindred
Multi-Modal Courtship in the Peacock Spider, Maratus volans (O.P.-Cambridge, 1874)
The peacock spider, Maratus volans, has one of the most elaborate courtship displays in arthropods. Using regular and high-speed video segments captured in the lab, we provide detailed descriptions of complete male courtship dances. As research on jumping spiders has demonstrated that males of some species produce vibrations concurrently with visual displays, we also used laser vibrometry to uncover such elements for this species. Our recordings reveal and describe for the first time, that M. volans males use vibratory signals in addition to complex body ornaments and motion displays. The peacock spider and other closely related species are outstanding study organisms for testing hypotheses about the evolution and functional significance of complex displays, thus, this descriptive study establishes a new model system for behavioral ecology, one that certainly stands to make important contributions to the field
Pneumatized superior turbinate as a cause of headache
BACKGROUND: A pneumatized superior turbinate is a rare cause of headache. Nasal endoscopy alone, does not provide us with adequate information for this inaccessible area of the superior nasal cavity. A coronal computed tomography (CT) must be obtained to confirm the diagnosis. CASE PRESENTATION: We present a 40-year-old female with migraine-type headache and nasal obstruction. Nasal endoscopy revealed a mild septal deviation, a right middle concha bullosa and a paradoxically curved middle turbinate on the left side. Coronal CT-scan showed also the presence of a superior concha bullosa on the left, which was in close contact with the nasal septum. The patient underwent septoplasty and bilateral endoscopic sinus surgery, including partial removal of both the pneumatized middle turbinates in conjunction with gentle lateralization and resection of the lower half of the left superior turbinate. Prompt relief from headache and nasal symptoms was obtained. CONCLUSION: Pneumatized superior concha causing migrainous headache is a rare finding. Endoscopic surgery may provide permanent relief of symptoms
Miliary tuberculosis with no pulmonary involvement in myelodysplastic syndromes: a curable, yet rarely diagnosed, disease: case report and review of the literature
<p>Abstract</p> <p>Background</p> <p>Although tuberculosis is not uncommon among patients with myelodysplastic syndrome (MDS), only a few reports of such patients suffering from miliary tuberculosis (MT) exist. MT often presents as a fever of unknown origin and it is a curable disease, yet fatal if left untreated.</p> <p>Case presentation</p> <p>We report a case of MT with no clinical or laboratory indications of pulmonary involvement in a patient with MDS, and review the relevant literature. <it>Mycobacterium tuberculosis </it>was isolated from the liquid culture of a bone marrow aspirate.</p> <p>Conclusion</p> <p>Even if the initial diagnostic investigation for a fever of obscure etiology is negative, MT should not be excluded from the differential diagnosis list. Since it is a curable disease, persistent and vigorous diagnostic efforts are warranted. In suspected cases, mycobacterial blood cultures should be collected as soon as possible after hospital admission and early bone marrow aspirate with mycobacterial cultures is advocated.</p
Processing and Transmission of Information
Contains research objectives and reports on four research projects.Lincoln Laboratory, Purchase Order DDL-B222Department of the ArmyDepartment of the NavyDepartment of the Air Force under Contract AF19(122)-45
Identification of Niches for Integration of Brachiaria Grasses in Smallholder Mixed Crop-Livestock Farming Systems in Kenya
Inadequate quantity and quality of feed is the major constraint to livestock productivity in Kenya. Low rainfall, lack of adapted forages and poor management of sown forages are major factors that affect feed resources production. In most of the farming systems, forages are relegated to the less fertile and degraded soils resulting into poor growth. As a result the growth is poor resulting in deficient in minerals content, low crude protein (CP) and energy. The situation in exacerbated by climate variability and frequent drought. On the other hand, feed resources derived from crop residues, particularly cereals are of poor quality and not sufficient to meet animal production (Njarui and Mureithi, 2006).
A research programme was initiated in 2012 to explore superior feed resources and increase availability of high quality forages to increase livestock productivity in East Africa. The program focuses on evaluation of drought and marginal soil adapted improved Brachiaria cultivars from South America. The genus Brachiaria is predominantly an African grass with about 100 species. The Brachiaria grasses are the most widely grown forages in South America (Miles et al., 2004). These grasses produce high biomass, enhance soil fertility and reduce greenhouse gas emission (Peters et al., 2012), are highly nutritious and are known to increase milk (Njarui, pers. comm.) thus suitable for different farming systems of Kenya. However, before integration of these grasses into farming systems, it was imperative to identify suitable niches suitable for growing these grasses. The knowledge gained from the study will facilitate development of suitable approaches for promoting these grasses across diverse production systems of Kenya
Performance of the LHC Pre-Injectors
The LHC pre-injector complex, comprising Linac 2, the PS Booster (PSB) and the PS, has undergone a major upgrade in order to meet the very stringent requirements of the LHC. Whereas bunches with the nominal spacing and transverse beam brightness were already available from the PS in 1999 [1], their length proved to be outside tolerance due to a debunching procedure plagued by microwave instabilities. An alternative scenario was then proposed, based on a series of bunch-splitting steps in the PS. The entire process has recently been implemented successfully, and beams whose longitudinal characteristics are safely inside LHC specifications are now routinely available. Variants of the method also enable bunch trains with gaps of different lengths to be generated. These are of interest for the study and possible cure of electron cloud effects in both the SPS and LHC. The paper summarizes the beam dynamics issues that had to be addressed to produce beams with all the requisite qualities for the LHC
Transverse Performance of the Proton Beam Delivered by the CERN PS Complex for the Future LHC
The performance of the CERN LHC will depend heavily on the high-brightness beam delivered by the injector chain. In 1999, after completion of the programme of hardware upgrades of the PS Complex, a major effort was devoted to producing a proton beam with the nominal transverse characteristics foreseen for LHC operation. This paper focuses on the different beam dynamics issues encountered during the setting up of such a beam, in the Linac2, the PS-Booster (PSB), the PS and the TT2 transfer line to the SPS. During the setting-up, single-particle issues, like stop-band compensation, correction of injection oscillations during the double-batch injection process, and the correction of the high-energy closed orbit in the PS, were addressed. Furthermore, collective effects, such as high-order head-tail instabilities induced by the resistive-wall impedance, were observed and cured. The compensation of these harmful phenomena permitted to achieve the goal, namely the generation of small transverse beam emittances and their conservation along the chain of different machines
Free Fermion Orientifolds
We investigate a class of orientifold models based on tensor products of 18
Ising models. Using the same search criteria as for the comparable case of
Gepner model orientifolds we find that there are no three-family standard model
configurations with tadpole cancellation. Even if we do not impose the latter
requirement, we only find one such configuration in the special case of complex
free fermions. In order to allow a comparison with other approaches we
enumerate the Hodge numbers of the type-IIB theories we obtain. We provide
indications that there are fermionic IIB vacua that are not
orbifolds.Comment: 18 pages + Appendix; references adde
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