2,362 research outputs found
Preventive and Protective Properties of Pertussis Vaccines: Current Situation and Future Challenges
Pertussis, more commonly known as whooping cough, is a potentially fatal respiratory disease caused by Bordetella pertussis. Two different types of vaccines provide effective protection: killed whole-cell vaccines (wPV) and more recently available acellular vaccines (aPVs) formulated with specific components. Disturbingly, while the vaccines are widely used, the incidence of disease is increasing in several developed countries that have switched from wPV to an aPV. It is suggested that the single most important underlying cause suggested for the resurgence is transmission through asymptomatic infections. While both vaccines protect against disease, a newly developed baboon model has shown that they do not prevent infection. Importantly, wPV-vaccinated animals appeared to clear an infection more rapidly than those vaccinated with aPV, which can relate to the period of possible disease transmission. To ultimately control whooping cough, it is clear that a more effective vaccine is needed that can prevent both disease and transmission. Modifications underway include the elimination of LPS from wPVs to improve their safety profiles and augmentation of aPVs with other bacterium proteins to increase immunogenicity and the longevity of protection. In the interim, vaccinations with aPV during pregnancy appear to protect newborns, the most susceptible to deadly pertussis
Object Manipulation in Virtual Reality Under Increasing Levels of Translational Gain
Room-scale Virtual Reality (VR) has become an affordable consumer reality, with applications ranging from entertainment to productivity. However, the limited physical space available for room-scale VR in the typical home or office environment poses a significant problem. To solve this, physical spaces can be extended by amplifying the mapping of physical to virtual movement (translational gain). Although amplified movement has been used since the earliest days of VR, little is known about how it influences reach-based interactions with virtual objects, now a standard feature of consumer VR. Consequently, this paper explores the picking and placing of virtual objects in VR for the first time, with translational gains of between 1x (a one-to-one mapping of a 3.5m*3.5m virtual space to the same sized physical space) and 3x (10.5m*10.5m virtual mapped to 3.5m*3.5m physical). Results show that reaching accuracy is maintained for up to 2x gain, however going beyond this diminishes accuracy and increases simulator sickness and perceived workload. We suggest gain levels of 1.5x to 1.75x can be utilized without compromising the usability of a VR task, significantly expanding the bounds of interactive room-scale VR
Biogeographical ancestry is associated with socioenvironmental conditions and infections in a Latin American urban population.
Racial inequalities are observed for different diseases and are mainly caused by differences in socioeconomic status between ethnoracial groups. Genetic factors have also been implicated, and recently, several studies have investigated the association between biogeographical ancestry (BGA) and complex diseases. However, the role of BGA as a proxy for non-genetic health determinants has been little investigated. Similarly, studies comparing the association of BGA and self-reported skin colour with these determinants are scarce. Here, we report the association of BGA and self-reported skin colour with socioenvironmental conditions and infections. We studied 1246 children living in a Brazilian urban poor area. The BGA was estimated using 370,539 genome-wide autosomal markers. Standardised questionnaires were administered to the children's guardians to evaluate socioenvironmental conditions. Infection (or pathogen exposure) was defined by the presence of positive serologic test results for IgG to seven pathogens (Toxocara spp, Toxoplasma gondii, Helicobacter pylori, and hepatitis A, herpes simplex, herpes zoster and Epstein-Barr viruses) and the presence of intestinal helminth eggs in stool samples (Ascaris lumbricoides and Trichiuris trichiura). African ancestry was negatively associated with maternal education and household income and positively associated with infections and variables, indicating poorer housing and living conditions. The self-reported skin colour was associated with infections only. In stratified analyses, the proportion of African ancestry was associated with most of the outcomes investigated, particularly among admixed individuals. In conclusion, BGA was associated with socioenvironmental conditions and infections even in a low-income and highly admixed population, capturing differences that self-reported skin colour miss. Importantly, our findings suggest caution in interpreting significant associations between BGA and diseases as indicative of the genetic factors involved
Biological, biochemical and molecular features of Trypanosoma cruzi strains isolated from patients infected through oral transmission during a 2005 outbreak in the state of Santa Catarina, Brazil: its correspondence with the new T. cruzi Taxonomy Consensus (2009)
Influence of the substitutional solute on the mechanical properties of Ti-Nb binary alloys for biomedical use
Contribution of ULF Wave Activity to the Global Recovery of the Outer Radiation Belt During the Passage of a High-Speed Solar Wind Stream Observed in September 2014
Energy coupling between the solar wind and the Earth's magnetosphere can affect the electron population in the outer radiation belt. However, the precise role of different internal and external mechanisms that leads to changes of the relativistic electron population is not entirely known. This paper describes how ultralow frequency (ULF) wave activity during the passage of Alfvénic solar wind streams contributes to the global recovery of the relativistic electron population in the outer radiation belt. To investigate the contribution of the ULF waves, we searched the Van Allen Probes data for a period in which we can clearly distinguish the enhancement of electron fluxes from the background. We found that the global recovery that started on 22 September 2014, which coincides with the corotating interaction region preceding a high-speed stream and the occurrence of persistent substorm activity, provides an excellent scenario to explore the contribution of ULF waves. To support our analyses, we employed ground- and space-based observational data and global magnetohydrodynamic simulations and calculated the ULF wave radial diffusion coefficients employing an empirical model. Observations show a gradual increase of electron fluxes in the outer radiation belt and a concomitant enhancement of ULF activity that spreads from higher to lower L-shells. Magnetohydrodynamic simulation results agree with observed ULF wave activity in the magnetotail, which leads to both fast and Alfvén modes in the magnetospheric nightside sector. The observations agree with the empirical model and are confirmed by phase space density calculations for this global recovery period
Giant hepatic hydatid cyst with sub-fascial extension treated by open minimally invasive surgery: a case report
<p>Abstract</p> <p>Introduction</p> <p>Hepatic hydatid disease can be successfully treated by a variety of modalities.</p> <p>Case Presentation</p> <p>We report a case of a 60 year old male with giant hepatic hydatid disease who presented with a huge cystic mass in the upper abdomen. Diagnosis was confirmed by serology, ultrasonography and CT scan. The patient was treated successfully by open minimally invasive surgery with minimum breaching of the peritoneal cavity using a laparoscopic trocar to evacuate the cyst.</p> <p>Conclusion</p> <p>The use of a laparoscopic trocar through a small abdominal incision in selected patients with hepatic hydatid disease with subfascial extension can be a safe, minimally-invasive option of treatment</p
A synthesis of bacterial and archaeal phenotypic trait data.
A synthesis of phenotypic and quantitative genomic traits is provided for bacteria and archaea, in the form of a scripted, reproducible workflow that standardizes and merges 26 sources. The resulting unified dataset covers 14 phenotypic traits, 5 quantitative genomic traits, and 4 environmental characteristics for approximately 170,000 strain-level and 15,000 species-aggregated records. It spans all habitats including soils, marine and fresh waters and sediments, host-associated and thermal. Trait data can find use in clarifying major dimensions of ecological strategy variation across species. They can also be used in conjunction with species and abundance sampling to characterize trait mixtures in communities and responses of traits along environmental gradients
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