562 research outputs found
Size distribution and waiting times for the avalanches of the Cell Network Model of Fracture
The Cell Network Model is a fracture model recently introduced that resembles
the microscopical structure and drying process of the parenchymatous tissue of
the Bamboo Guadua angustifolia. The model exhibits a power-law distribution of
avalanche sizes, with exponent -3.0 when the breaking thresholds are randomly
distributed with uniform probability density. Hereby we show that the same
exponent also holds when the breaking thresholds obey a broad set of Weibull
distributions, and that the humidity decrements between successive avalanches
(the equivalent to waiting times for this model) follow in all cases an
exponential distribution. Moreover, the fraction of remaining junctures shows
an exponential decay in time. In addition, introducing partial breakings and
cumulative damages induces a crossover behavior between two power-laws in the
avalanche size histograms. This results support the idea that the Cell Network
Model may be in the same universality class as the Random Fuse Model
Wiping DNA Methylation: Wip1 Regulates Genomic Fluidity on Cancer
Wip1 phosphatase plays an important role in cancer by inactivating p53 and INK4a/ARF pathways. In this issue of Cancer Cell, Filipponi and colleagues further connect the oncogenic role of Wip1 with heterochromatin dynamics, transposable element expression, and a mutation-prone environment that may enhance heterogeneity and ultimately contribute to tumor evolution
Using a RGB-D camera for 6DoF SLAM
This paper presents a method for fast calculation of the egomotion done by a robot using visual features. The method is part of a complete system for automatic map building and Simultaneous Localization and Mapping (SLAM). The method uses optical flow in order to determine if the robot has done a movement. If so, some visual features which do not accomplish several criteria (like intersection, unicity, etc,) are deleted, and then the egomotion is calculated. We use a state-of-the-art algorithm (TORO) in order to rectify the map and solve the SLAM problem. The proposed method provides better efficiency that other current methods.These authors want to express their gratitude to Spanish Ministry of Science and Technology (MYCIT) and the Research and Innovation Vice-president Office of the University of Alicante for their financial support through the projects DPI2009-07144 and GRE10-16, respectively
An Overview of the Management of Mansonellosis
Mansonellosis is caused by three filarial parasite species from the genus Mansonella that commonly produce chronic human microfilaraemias: M. ozzardi, M. perstans and M. streptocerca. The disease is widespread in Africa, the Caribbean and South and Central America, and although it is typically asymptomatic it has been associated with mild pathologies including leg-chills, joint-pains, headaches, fevers, and corneal lesions. No robust mansonellosis disease burden estimates have yet been made and the impact the disease has on blood bank stocks and the monitoring of other filarial diseases is not thought to be of sufficient public health importance to justify dedicated disease management interventions. Mansonellosis´s Ceratopogonidae and Simuliidae vectors are not targeted by other control programmes and because of their small size and out-door biting habits are unlikely to be affected by interventions targeting other disease vectors like mosquitoes. The ivermectin and mebendazole-based mass drug administration (iMDA and mMDA) treatment regimens deployed by the WHO´s Elimination of Neglected Tropical Diseases (ESPEN) programme and its forerunners have, however, likely impacted significantly on the mansonellosis disease burden, principally by reducing the transmission of M. streptocerca in Africa. The increasingly popular plan of using iMDA to control malaria could also affect M. ozzardi parasite prevalence and transmission in Latin America in the future. However, a potentially far greater mansonellosis disease burden impact is likely to come from shortcourse curative anti-Wolbachia therapeutics, which are presently being developed for onchocerciasis and lymphatic filariasis treatment. Even if the WHO´s ESPEN programme does not choose to deploy these drugs in MDA interventions, they have the potential to dramatically increase the financial and logistical feasibility of effective mansonellosis management.There is, thus, now a fresh and urgent need to better characterise the disease burden and ecoepidemiology of mansonellosis so that effective management programmes can be designed, advocated for and implemented.We would like to express our special thanks to MarĂa BelĂ©n GarcĂa Fernández for helping us to draw the life-cycle of Mansonella species. JLC and SLBL also gratefully acknowledge support from the Fundação de Amparo Ă Pesquisa do Estado do Amazonas (FAPEAM; 062.01282/2018 and 002.00200/2019). And JLC would like to acknowledge support he receives from a Conselho Nacional de Desenvolvimento CientĂfica e TecnolĂłgico (CNPq) productivity grant. THTT is funded by a Sara Borrell contract from the Instituto de Salud Carlos III.S
Video Endoscopy for Laser Photoresection in Tracheobronchial Pathology: Some Considerations After 9 Years Experience With 2105 Treatments
Between 1984 and 1993 we performed 2105 laser treatments in 1210 patients: 52% of treatments were done for malignant pathology, 45% for benign tracheal stenoses and 3% were in a miscellaneous group. The procedure was carried out with a rigid bronchoscope under general anaesthesia. In patients with malignant tumors, it is a good palliative treatment—safe, well tolerated and with immediate results; it can be repeated as many times as needed with and is well accepted by the patient. In patients without tumors, this method avoids emergency tracheotomies. The long term results are now under evaluation
The biological basis of smoltification in Atlantic salmon
Chile is the second-largest producer of Atlantic salmon in the world, and the Chilean salmon production accounts for 27% of the world’s production. One important step of the productive cycle in freshwater is the smoltification process that prepares the fish for the marine life stage. This review describes the biological basis of smoltification in Atlantic salmon, with particular attention on branchial osmoregulatory adaptations. We also discuss some of the infectious diseases and problems in smoltification (two of the main causes of losses in Chilean aquaculture) that could be related from a physiological point of view
Mansonellosis: current perspectives
Mansonellosis is a filarial disease caused by three species of filarial (nematode) parasites (Mansonella perstans, Mansonella streptocerca, and Mansonella ozzardi) that use humans as their main definitive hosts. These parasites are transmitted from person to person by bloodsucking females from two families of flies (Diptera). Biting midges (Ceratopogonidae) transmit all three species of Mansonella, but blackflies (Simuliidae) are also known to play a role in the transmission of M. ozzardi in parts of Latin America. M. perstans and M. streptocerca are endemic in western, eastern, and central Africa, and M. perstans is also present in the neotropical region from equatorial Brazil to the Caribbean coast. M. ozzardi has a patchy distribution in Latin America and the Caribbean. Mansonellosis infections are thought to have little pathogenicity and to be almost always asymptomatic, but occasionally causing itching, joint pains, enlarged lymph glands, and vague abdominal symptoms. In Brazil, M. ozzardi infections are also associated with corneal lesions. Diagnosis is usually performed by detecting microfilariae in peripheral blood or skin without any periodicity. There is no standard treatment at present for mansonellosis. The combination therapy of diethylcarbamazine plus mebendazole for M. perstans microfilaremia is presently one of the most widely used, but the use of ivermectin has also been proven to be very effective against microfilariae. Recently, doxycycline has shown excellent efficacy and safety when used as an antimicrobial against endosymbiotic Wolbachia bacteria harbored by some strains of M. perstans and M. ozzardi. Diethylcarbamazine and ivermectin have been used effectively to treat M. streptocerca infection. There are at present no estimates of the disease burden caused by mansonellosis, and thus its importance to many global health professionals and policy makers is presently limited to how it can interfere with diagnostic tools used in modern filarial disease control and elimination programs aimed at other species of filariae.S
Enhancing a de novo enzyme activity by computationally-focused ultra-low-throughput screening
Directed evolution has revolutionized protein engineering. Still, enzyme optimization by random library
screening remains sluggish, in large part due to futile probing of mutations that are catalytically neutral
and/or impair stability and folding. FuncLib is a novel approach which uses phylogenetic analysis and
Rosetta design to rank enzyme variants with multiple mutations, on the basis of predicted stability. Here,
we use it to target the active site region of a minimalist-designed, de novo Kemp eliminase. The
similarity between the Michaelis complex and transition state for the enzymatic reaction makes this
system particularly challenging to optimize. Yet, experimental screening of a small number of active-site
variants at the top of the predicted stability ranking leads to catalytic efficiencies and turnover numbers
( 2 104 M 1 s 1 and 102 s 1) for this anthropogenic reaction that compare favorably to those of
modern natural enzymes. This result illustrates the promise of FuncLib as a powerful tool with which to
speed up directed evolution, even on scaffolds that were not originally evolved for those functions, by
guiding screening to regions of the sequence space that encode stable and catalytically diverse
enzymes. Empirical valence bond calculations reproduce the experimental activation energies for the
optimized eliminases to within 2 kcal mol 1 and indicate that the enhanced activity is linked to better
geometric preorganization of the active site. This raises the possibility of further enhancing the stabilityguidance
of FuncLib by computational predictions of catalytic activity, as a generalized approach for
computational enzyme designKnut and Alice Wallenberg Foundation (Wallenberg Academy Fellowship)
2018.0140Human Frontier Science Program
RGP0041/2017FEDER Funds/Spanish Ministry of Science, Innovation and Universities
BIO2015-66426-R
RTI2018-097142-B-100FEDER/Junta de Andalucia - Consejeria de Economia y Conocimiento
E.FQM.113.UGR18Swedish National Infrastructure for computing (SNAC)
2018/2-3
2019/2-
Spanish multicenter real – life registry of retrievable vena cava filters (REFiVeC)
Background
The treatment of venous thromboembolic disease the treatment of choice is systemic anticoagulation. However, the interruption of the inferior vena cava with filters has been recommended when anticoagulation fails or there is a contraindication. Due to the rising inferior vena cava filter (IVCF) complications, physicians are encouraged to retrieve them when there is no longer recommended. In daily practice, it may be a difficult close follow-up of these patients. In this study, the primary objective was to evaluate the IVCF retrieval rate of all implanted filters in a Spanish registry. Secondary objectives were to analyze the causes of failed retrieval, procedure-related complications, and outcomes at a 12-month follow-up.
Results
Three hundred fifty-six vena cava filters were implanted in 355 patients. The types of filter were: Gunther Tulip (Cook Medical) 160 (44.9%), Optease (Cordis) 77 (21.6%), Celect (Cook Medical) 49 (13, 7%), Aegisy (Lifetech Scientific) 33 (9.2%), Option ELITE (Argon Medical devices) 16 (4.4%), Denali filter (BD Bard) 11 (3.08%), ALN filter (ALN) 10 (2.8%).
Removal was achieved in 274/356 (76,9%). eighty-two (23,1%) IVCF were not retrieved due to the following: 41 (11,5%) patients required ongoing filtration, 24 IVCF (6,7%) patients died before retrieval, and 17 (4,7%) impossibility of retrieval because of a tilted and embedded filter apex. There were no major complications observed.
Conclusions
The global retrieval rate of IVCF was achieved in 76.9%, and the adjusted retrieval rate was of 94.15% with no major complications. IVCF tilting was associated with failure of filter removal in less than 5% of cases. This study demonstrates that the retrieval procedure of IVCF is controlled by the clinician and not by the interventional radiologist
Surveillance of imported malaria in Spain: The useful tool of the Semi-Nested Multiplex PCR
The use of a new PCR-based method for the diagnosis of malaria in the Spanish Malaria Reference Laboratory has promoted an increase in confirmed cases of malaria. From August 1997 to July 1998, a total of 192 whole-blood samples and 71 serum samples from 168 patients were received from the hospitals of the Spanish National Health System. Most of the patients came from west-central African countries (85%). This molecular method showed more sensitivity and specificity than microscopy, detecting 12.4% more positive samples than microscopy and 13% of mixed infections undetectable by Giemsa stain. Plasmodium falciparum was the main species detected, with 68% of the total positive malaria cases, followed by Plasmodium malariae (29%), Plasmodium vivax (14%), and Plasmodium ovale (7%), including mixed infections in all cases. This report consists of the first wide, centralized survey of malaria surveillance in Spain. The reference laboratory conducted the analysis of all imported cases in order to detect trends in acquisition. The use of a seminested multiplex PCR permitted confirmation of the origins of the infections and the Plasmodium species involved and confirmation of the effectiveness of drug treatments. This PCR also allowed the detection of the presence in Spain of primaquine-tolerant P. vivax strains from west-central Africa, as well as the detection of a P. falciparum infection induced by transfusion.This work was supported by the Fondo de Investigaciones Sanitarias (FIS) (contract number 96/0216) and the Spanish Agency of International Cooperation (AECI). J. M. Rubio was granted a postdoctoral fellowship from the Comunidad Autónoma de Madrid, Madrid, Spain. J. Alvar was supported by a B.A.E. from the FIS (contract number 99/5038) and by the Christ’s College, University of Cambridge, Cambridge, United Kingdo
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