6,244 research outputs found

    Cell-Mediated Immune Predictors of Vaccine Effect on Viral Load and CD4 Count in a Phase 2 Therapeutic HIV-1 Vaccine Clinical Trial.

    Get PDF
    In a placebo-controlled trial of the peptide-based therapeutic HIV-1 p24 <sup>Gag</sup> vaccine candidate Vacc-4x, participants on combination antiretroviral therapy (cART) received six immunizations over 18weeks, followed by analytical treatment interruption (ATI) between weeks 28 and 52. Cell-mediated immune responses were investigated as predictors of Vacc-4x effect (VE) on viral load (VL) and CD4 count during ATI. All analyses of week 28 responses and fold-changes relative to baseline considered per-protocol participants (Vacc-4x:placebo=72:32) resuming cART after week 40. Linear regression models with interaction tests were used. VE was estimated as the Vacc-4x-placebo difference in log <sub>10</sub> -transformed VL (VE <sup>VL</sup> ) or CD4 count (VE <sup>CD4</sup> ). A lower fold-change of CD4+ T-cell proliferation was associated with VE <sup>CD4</sup> at week 48 (p=0.036, multiplicity adjusted q=0.036) and week 52 (p=0.040, q=0.080). A higher fold-change of IFN-γ in proliferation supernatants was associated with VE <sup>VL</sup> at week 44 (p=0.047, q=0.07). A higher fold-change of TNF-α was associated with VE <sup>VL</sup> at week 44 (p=0.045, q=0.070), week 48 (p=0.028, q=0.070), and week 52 (p=0.037, q=0.074). A higher fold-change of IL-6 was associated with VE <sup>VL</sup> at week 48 (p=0.017, q=0.036). TNF-α levels (>median) were associated with VE <sup>CD4</sup> at week 48 (p=0.009, q=0.009). These exploratory analyses highlight the potential value of investigating biomarkers in T-cell proliferation supernatants for VE in clinical studies

    The prevalence of chronic diseases and major disease risk factors at different ages among 150 000 men and women living in Mexico City: cross-sectional analyses of a prospective study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>While most of the global burden from chronic diseases, and especially vascular diseases, is now borne by low and middle-income countries, few large-scale epidemiological studies of chronic diseases in such countries have been performed.</p> <p>Methods</p> <p>From 1998–2004, 52 584 men and 106 962 women aged ≥35 years were visited in their homes in Mexico City. Self reported diagnoses of chronic diseases and major disease risk factors were ascertained and physical measurements taken. Age- and sex-specific prevalences and means were analysed.</p> <p>Results</p> <p>After about age 50 years, diabetes was extremely common – for example, 23.8% of men and 26.9% of women aged 65–74 reported a diagnosis. By comparison, ischaemic heart disease was reported by 4.8% of men and 3.0% of women aged 65–74, a history of stroke by 2.8% and 2.3%, respectively, and a history of cancer by 1.3% and 2.1%. Cancer history was generally more common among women than men – the excess being largest in middle-age, due to breast and cervical cancer. At older ages, the gap narrowed because of an increasing prevalence of prostate cancer. 51% of men and 25% of women aged 35–54 smoked cigarettes, while 29% of men and 41% of women aged 35–54 were obese (i.e. BMI ≥30 kg/m<sup>2</sup>). The prevalence of treated hypertension or measured blood pressure ≥140/90 mmHg increased about 50% more steeply with age among women than men, to 66% of women and 58% of men aged 65–74. Physical inactivity was highly prevalent but daily alcohol drinking was relatively uncommon.</p> <p>Conclusion</p> <p>Diabetes, obesity and tobacco smoking are highly prevalent among adults living in Mexico City. Long-term follow-up of this and other cohorts will establish the relevance of such factors to the major causes of death and disability in Mexico.</p

    Active Front-End converter applied for the THD reduction in power systems

    Get PDF
    The Active Front-End (AFE) converter topology is generated by modifying a conventional back-to-back converter, from using a single VSC to use pVCS connected in parallel. The AFE configuration improves the capability, efficiency and reliability of energy conversion devices connected to the power system. In this paper, a novel technique to reduce the total harmonic distortion (THD) in an AFE converter topology is proposed and analyzed. The THD reduction is achieved by applying a phase shift angle in the SPWM switching signals of each AFE converter VSC. To verify the functionality and robustness of the proposed methodology, the power system simulation in Matlab-Simulink is analyzed for a type-4 wind turbine converter with total power output of 9MW. The obtained simulation results show a THD reduction up to 2.5 for AFE connected to the power network

    Tidal stream and ocean current energy - the benefits of harvesting lesser energetic flows

    Get PDF
    An optimum utilisation of the energy available in the ocean could meet our global energy demands. The implementation of tidal stream technologies is striving faster compared to other offshore technologies, aside from the offshore wind sector. Highly energetic tidal energy streams with peak flow velocities in the order of 2.5 – 5.0 m/s are limited around the globe and therefore, the sector may be constrained to a few worldwide locations. To overcome this limitation, attention has been drawn to the exploration of complementary flow streams with lesser energetic flows. This work thus intends to compare the feasibility of harvesting hydrokinetic energy using horizontal axis turbines from two different sites: a typical tidal stream site in the North of Scotland and an ocean current site in the Mexican Caribbean, characterised by developing slower but more stable flows. The viability of using ocean currents against tidal stream sites is analysed in terms of annual energy output, capacity factors and an initial estimation of the levelized cost of energy which considers the size of the turbine and rotor characteristics. As expected the annual energy produced by tidal devices is overall greater than that provided by marine currents but the capacity factor achieved with a typical tidal turbine can be in the order of 44% whereas the capacity factor calculated for a turbine operating in the Yucatan current can achieve factors in the order of 77%, giving confidence that the development of marine projects in lesser energetic flows may be the next step forward to advance this sector. This research also proposes the optimal turbine diameter to reduce the levelised cost of energy for a marine converter installed in a tidal or an ocean current site

    Clinical subgroups in bilateral meniere disease

    Get PDF
    Meniere disease (MD) is a heterogeneous clinical condition characterized by sensorineural hearing loss, episodic vestibular symptoms, and tinnitus associated with several comorbidities, such as migraine or autoimmune disorders (AD). The frequency of bilateral involvement may range from 5 to 50%, and it depends on the duration of the disease. We have performed a two-step cluster analysis in 398 patients with bilateral MD (BMD) to identify the best predictors to define clinical subgroups with a potential different etiology to improve the phenotyping of BMD and to develop new treatments. We have defined five clinical variants in BMD. Group 1 is the most frequently found, includes 46% of patients, and is defined by metachronic hearing loss without migraine and without AD. Group 2 is found in 17% of patients, and it is defined by synchronic hearing loss without migraine or AD. Group 3, with 13% of patients, is characterized by familial MD, while group 4, that includes 12% of patients, is associated by the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by AD. This approach can be helpful in selecting patients for genetic and clinical research. However, further studies will be required to improve the phenotyping in these clinical variants for a better understanding of the diverse etiological factors contributing to BMD

    The highly prevalent BRCA2 mutation c.2808_2811del (3036delACAA) is located in a mutational hotspot and has multiple origins

    Get PDF
    BRCA2-c.2808_2811del (3036delACAA) is one of the most reported germ line mutations in non-Ashkenazi breast cancer patients. We investigated its genetic origin in 51 Spanish carrier families that were genotyped with 11 13q polymorphic markers. Three independent associated haplotypes were clearly distinguished accounting for 23 [west Castilla y León (WCL)], 20 [east Castilla y León (ECL)] and 6 (South of Spain) families. Mutation age was estimated with the Disequilibrium Mapping using Likelihood Estimation software in a range of 45–68 and 45–71 generations for WCL and ECL haplotypes, respectively. The most prevalent variants, c.2808_2811del and c.2803G > A, were located in a double-hairpin loop structure (c.2794–c.2825) predicted by Quikfold that was proposed as a mutational hotspot. To check this hypothesis, random mutagenesis was performed over a 923 bp fragment of BRCA2, and 86 DNA variants were characterized. Interestingly, three mutations reported in the mutation databases (c.2680G > A, c.2944del and c.2957dup) were replicated and 20 affected the same position with different nucleotide changes. Moreover, five variants were placed in the same hairpin loop of c.2808_2811del, and one affected the same position (c.2808A > G). In conclusion, our results support that at least three different mutational events occurred to generate c.2808_2811del. Other highly prevalent DNA variants, such as BRCA1-c.68_69delAG, BRCA2- c.5946delT and c.8537delAG, are concentrated in hairpin loops, suggesting that these structures may represent mutational hotspots

    Highlights from the Pierre Auger Observatory

    Full text link
    The Pierre Auger Observatory is the world's largest cosmic ray observatory. Our current exposure reaches nearly 40,000 km2^2 str and provides us with an unprecedented quality data set. The performance and stability of the detectors and their enhancements are described. Data analyses have led to a number of major breakthroughs. Among these we discuss the energy spectrum and the searches for large-scale anisotropies. We present analyses of our Xmax_{max} data and show how it can be interpreted in terms of mass composition. We also describe some new analyses that extract mass sensitive parameters from the 100% duty cycle SD data. A coherent interpretation of all these recent results opens new directions. The consequences regarding the cosmic ray composition and the properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray Conference, Rio de Janeiro 201

    Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

    Get PDF
    We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to 8080^\circ and energies in excess of 4 EeV (4×10184 \times 10^{18} eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding pp-values obtained after accounting for searches blindly performed at several angular scales, are 1.3×1051.3 \times 10^{-5} in the case of the angular power spectrum, and 2.5×1032.5 \times 10^{-3} in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report Numbe

    Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory

    Get PDF
    On September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy above 100 PeV from point-like sources across the sky with equatorial declination from about -65 deg. to +60 deg., and in particular from a fraction of the 90% confidence-level (CL) inferred positions in the sky of GW150914 and GW151226. A targeted search for highly-inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth's crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within ±500\pm 500 s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the non-observation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events.Comment: Published version. Added journal reference and DOI. Added Report Numbe
    corecore