380 research outputs found
Improved parallel algorithms for finding connected components
Finding the connected components of a graph is a basic computational problem. In recent years, there were several exciting results in breaking the log2 n-time barrier to finding connected components on parallel machines using shared memory without concurrent-write capability. This paper further presents two new parallel algorithms both using less than log2 n time. The merit of the first algorithm is that it uses only a sublinear number of processors, yet retains the time complexity of the fastest existing algorithm. The second algorithm is slightly slower but its work (i.e., the time-processor product) is closer to optimal than all previous algorithms using less than log2 n time.published_or_final_versio
Peanut allergy ā no longer a life sentence
In this review we provide an overview on the latest knowledge in the prevention and active management of peanut allergy. The rise in incidence of food allergy has generated new challenges in the management of affected individuals. Strategies to counteract the increase in prevalence of peanut allergy can be considered as a pyramid, beginning with primary prevention of those at riskthrough earlier introduction of peanut into the infant diet, to secondary prevention of peanut-sensitised childrenthroughimprovements in the correct diagnosis of peanut allergy and finally to thetreatment of children with proven peanut allergy.Conclusion: With theparadigm shift towards an active management, peanut allergy should no longer be seen as a life sentence
Isolation of Ī“-missulenatoxin-Mb1a, the major vertebrate-active spider Ī“-toxin from the venom of Missulena bradleyi (Actinopodidae)
The present study describes the isolation and pharmacological characterisation of the neurotoxin Ī“-missulenatoxin-Mb1a (Ī“-MSTX-Mb1a) from the venom of the male Australian eastern mouse spider, Missulena bradleyi. This toxin was isolated using reverse-phase high-performance liquid chromatography and was subsequently shown to cause an increase in resting tension, muscle fasciculation and a decrease in indirect twitch tension in a chick biventer cervicis nerve-muscle bioassay. Interestingly, these effects were neutralised by antivenom raised against the venom of the Sydney funnel-web spider Atrax robustus. Subsequent whole-cell patch-clamp electrophysiology on rat dorsal root ganglion neurones revealed that Ī“-MSTX-Mb1a caused a reduction in peak tetrodotoxin (TTX)-sensitive sodium current, a slowing of sodium current inactivation and a hyperpolarising shift in the voltage at half-maximal activation. In addition, Ī“-MSTX-Mb1a failed to affect TTX-resistant sodium currents. Subsequent Edman degradation revealed a 42-residue peptide with unusual N- and C-terminal cysteines and a cysteine triplet (Cys14-16). This toxin was highly homologous to a family of Ī“-atracotoxins (Ī“-ACTX) from Australian funnel-web spiders including conservation of all eight cysteine residues. In addition to actions on sodium channel gating and kinetics to Ī“-ACTX, Ī“-MSTX-Mb1a caused significant insect toxicity at doses up to 2000 pmol/g. Ī“-MSTX-Mb1a therefore provides evidence of a highly conserved spider Ī“-toxin from a phylogenetically distinct spider family that has not undergone significant modification. Ā© 2003 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies
Voltage Synchronisation Techniques for Grid-Connected Power Converters
Standard synchronisation scheme for grid-connected power converters has been known to fail to correctly estimate the instantaneous phase angle of the grid voltages which are unbalanced and corrupted with harmonics. There are other advanced schemes which have been proposed to address this issue but a thorough comparison among the schemes is lacking. This paper presents a detailed review on five advanced grid voltage synchronisation schemes. A coherent investigation is performed to compare their merits and limitations considering a wide range of voltage distortions. This is verified through simulation and practical results
Use of multiple epinephrine doses in anaphylaxis: A systematic review and meta-analysis
Background: Regulatory bodies recommend that all patients at risk of anaphylaxis be prescribed 2 epinephrine autoinjectors, which they should carry at all times. This is in contrast to some guidelines. The proportion of anaphylaxis reactions that are treated with multiple doses of epinephrine has not been systematically evaluated. Objective: Our aim was to undertake a systematic review and meta-analysis of published studies reporting epinephrine treatment for anaphylaxis in which data relating to the number of doses administered were available. Methods: We searched the Medline, Embase, and Cochrane databases for relevant studies reporting at least 10 anaphylaxis events (due to food or venom) from 1946 until January 2020. Data were extracted in duplicate for the meta-analysis, and the risk of bias was assessed. The study was registered under the PROSPERO identifier CRD42017069109. Results: A total of 86 studies (36,557 anaphylaxis events) met the inclusion criteria (20 of the studies [23%] were prospective studies; 64 [74%] reported reactions in the community, and 22 [26%] included food challenge data). Risk of bias was assessed as low in 50 studies. Overall, 7.7% of anaphylaxis events from any cause (95% CI = 6.4-9.1) were treated with multiple doses of epinephrine. When only epinephrine-treated reactions for which subsequent doses were administered by a health care professional were considered, 11.1% of food-induced reactions (95% CI = 9.4-13.2) and 17.1% of venom-induced reactions (95% CI = 11.3-25.0) were treated with at least 1 epinephrine dose. Heterogeneity was moderate to high in the meta-analyses, but at sensitivity analysis it was not affected by study design or anaphylaxis definition. Conclusion: Around 1 in 10 anaphylaxis reactions are treated with at least 1 dose of epinephrine
Evidence for partial melt in the crust beneath Mt. Paektu (Changbaishan), Democratic People's Republic of Korea and China
Mt. Paektu (also known as Changbaishan) is an enigmatic volcano on the border between the Democratic People's Republic of Korea (DPRK) and China. Despite being responsible for one of the largest eruptions in history, comparatively little is known about its magmatic evolution, geochronology, or underlying structure. We present receiver function results from an unprecedented seismic deployment in the DPRK. These are the first estimates of the crustal structure on the DPRK side of the volcano and, indeed, for anywhere beneath the DPRK. The crust 60 km from the volcano has a thickness of 35 km and a bulk / of 1.76, similar to that of the Sino-Korean craton. The / ratio increases ~20 km from the volcano, rising to >1.87 directly beneath the volcano. This shows that a large region of the crust has been modified by magmatism associated with the volcanism. Such high values of / suggest that partial melt is present in the crust beneath Mt. Paektu. This region of melt represents a potential source for magmas erupted in the last few thousand years and may be associated with an episode of volcanic unrest observed between 2002 and 2005.This work was supported by the Richard Lounsbery Foundation. The UK seismic instruments and data management facilities were provided under loan number 976 by SEIS-UK at the University of Leicester. The facilities of SEIS-UK are supported by the NERC under Agreement R8/H10/64. J.O.S.H. was supported by an NERC Fellowship NE/I020342/1
Brucellosis presenting as piriformis myositis: a case report
<p>Abstract</p> <p>Introduction</p> <p>Myositis is a rare bacterial muscle infection. Involvement of the piriformis muscle has been rarely reported in the literature. In this report we describe a case of piriformis myositis due to <it>Brucella melitensis</it>, which to the best of our knowledge is the first such case presented in the literature.</p> <p>Case presentation</p> <p>We report the case of a 19-year-old Caucasian man who presented to our institution with fever and right hip pain. Brucellosis was suspected, but the clinical suspicion was for spondylodiscitis. A pelvic magnetic resonance imaging scan allowed prompt diagnosis of inflammatory involvement of the right piriformis muscle. Blood culture results were positive for <it>B. melitensis</it>. Our patient was treated with antibiotics, and follow-up magnetic resonance imaging scans showed resolution of the inflammation.</p> <p>Conclusion</p> <p>Brucellosis can present as piriformis myositis. The clinical diagnosis of piriformis myositis is difficult, as it can mimic other common entities such as referred back pain from spondylodiscitis. Magnetic resonance imaging is the method of choice for establishing the diagnosis in the early stages of the disease, as late diagnosis can lead to abscess formation and the need for drainage.</p
Cyclic vomiting syndrome in adults
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72300/1/j.1365-2982.2008.01113.x.pd
Relationship between autoantibody clustering and clinical subsets in SLE: cluster and association analyses in Hong Kong Chinese
OBJECTIVE: This study aims to identify the existence of, and relationship between autoantibody clusters and clinical subsets in Chinese SLE patients. METHODS: Data from 1928 SLE patients from Hong Kong were analysed. Using cluster analysis, patients were grouped by autoantibodies into clusters. The frequencies of various clinical manifestations were then compared between each cluster. Separate association analyses between individual autoantibodies and clinical manifestations as well as between clinical manifestations were also performed without any prior clustering. RESULTS: Three separate autoantibody clusters were identified, each with significantly different clinical manifestations. Cluster 1 was characterized by anti-dsDNA and the greatest prevalence of renal disorder but the lowest frequencies of other clinical manifestations. Cluster 2 was represented by the predominance of anti-Smith, anti-RNP and aPL, with greater prevalence of malar rash, oral ulcers, arthritis and serositis. Cluster 3 was characterized by anti-Ro and anti-La with greater prevalence of discoid rash, photosensitivity and haematological involvement. Individual association analysis also revealed similar findings. Patients of clusters 2 and 3 were more closely related, while cluster 1 was more distinct, associated with renal disorder only and negatively associated or not associated with other manifestations. CONCLUSION: We conclude that autoantibody clustering and clinical subsets exist in SLE patients of our locality. These clusters may be viewed as a bipolar spectrum of related autoantibody and clinical manifestations. At one end are patients with over-representation of anti-dsDNA and renal disorder, while at the other end are two distinct autoantibody clusters (anti-Sm/anti-RNP/aPL and anti-Ro/anti-La) with overlapping of other clinical manifestations.postprin
The microRNA-29 family in cartilage homeostasis and osteoarthritis
MicroRNAs have been shown to function in cartilage development and homeostasis, as well as in progression of osteoarthritis. The objective of the current study was to identify microRNAs involved in the onset or early progression of osteoarthritis and characterise their function in chondrocytes. MicroRNA expression in mouse knee joints post-DMM surgery was measured over 7 days. Expression of miR-29b-3p was increased at day 1 and regulated in the opposite direction to its potential targets. In a mouse model of cartilage injury and in end-stage human OA cartilage, the miR-29 family were also regulated. SOX9 repressed expression of miR-29a-3p and miR-29b-3p via the 29a/b1 promoter. TGFĪ²1 decreased expression of miR-29a, b and c (3p) in primary chondrocytes, whilst IL-1Ī² increased (but LPS decreased) their expression. The miR-29 family negatively regulated Smad, NFĪŗB and canonical WNT signalling pathways. Expression profiles revealed regulation of new WNT-related genes. Amongst these, FZD3, FZD5, DVL3, FRAT2, CK2A2 were validated as direct targets of the miR-29 family. These data identify the miR-29 family as microRNAs acting across development and progression of OA. They are regulated by factors which are important in OA and impact on relevant signalling pathways
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