229 resultados para PP-MA
Resumo:
We conducted a genome-wide scan using variance components linkage analysis to localize quantitative-trait loci (QTLs) influencing triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol, and total cholesterol (TC) levels in 3,071 subjects from 459 families with atherogenic dyslipidemia. The most significant evidence for linkage to TG levels was found in a subset of Turkish families at 11q22 [logarithm of the odds ratio (LOD)=3.34] and at 17q12 (LOD=3.44). We performed sequential oligogenic linkage analysis to examine whether multiple QTLs jointly influence TG levels in the Turkish families. These analyses revealed loci at 20q13 that showed strong epistatic effects with 11q22 (conditional LOD=3.15) and at 7q36 that showed strong epistatic effects with 17q12 (conditional LOD=3.21). We also found linkage on the 8p21 region for TG in the entire group of families (LOD=3.08). For HDL-C levels, evidence of linkage was identified on chromosome 15 in the Turkish families (LOD=3.05) and on chromosome 5 in the entire group of families (LOD=2.83). Linkage to QTLs for TC was found at 8p23 in the entire group of families (LOD=4.05) and at 5q13 in a subset of Turkish and Mediterranean families (LOD=3.72). These QTLs provide important clues for the further investigation of genes responsible for these complex lipid phenotypes. These data also indicate that a large proportion of the variance of TG levels in the Turkish population is explained by the interaction of multiple genetic loci.
Resumo:
To constrain the age of strike-slip shear, related granitic magmatism, and cooling along the Insubric line, 29 size fractions of monazite and xenotime were dated by the U-Pb method, and a series of 25 Rb-Sr and Ar-40/Ar-39 ages were measured on different size fractions of muscovite and biotite. The three pegmatitic intrusions analyzed truncate high-grade metamorphic mylonite gneisses of the Simplon shear zone, a major Alpine structure produced in association with dextral strike-slip movements along the southern edge of the European plate, after collision with its Adriatic indenter. Pegmatites and aplites were produced between 29 and 25 Ma in direct relation to right-lateral shear along the Insubric line, by melting of continental crust having Sr-87/Sr-86 between 0.7199 and 0.7244 at the time of melting. High-temperature dextral strike-slip shear was active at 29.2 +/- 0.2 (2 sigma) Ma, and it terminated before 26.4 +/- 0.1 Ma. During dike injection, temperatures in the country rocks of the Isorno-Orselina and Monte Rosa structural units did not exceed approximate to 500 degrees C, leading to fast initial cooling, followed by slower cooling to approximate to 350 degrees C within several million years. In one case, initial cooling to approximate to 500 degrees C was significantly delayed by about 4 m.y., with final cooling to approximate to 300 degrees C at 20-19 Ma in all units. For the period between 29 and 19 Ma, cooling of the three sample localities was non-uniform in space and time, with significant variations on the kilometre scale. These differences are most likely due to strongly varying heat flow, and/or heterogeneous distribution of unroofing rates within the continuously deforming Insubric line. If entirely ascribed to differences in unroofing, corresponding rates would vary between 0.5 and 2.5 mm/y, for a thermal gradient of 30 degrees/km.
Resumo:
The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence variants linked to human disease, and can thereby guide interpretation of this variation. Overall, the project provides new insights into the organization and regulation of our genes and genome, and is an expansive resource of functional annotations for biomedical research.
Resumo:
A combined Ar-40/Ar-39, K/Ar, Rb/Sr and stable isotope study has been made of white micas from the Gummfluh klippe (Brianconnais domain of the Prealpes), Switzerland. The klippe consists mainly of Mesozoic to early Tertiary carbonate rocks metamorphosed from anchizonal to epizonal conditions. At the base of the klippe is a 10-50 m thick, ductilely deformed marble mylonite containing deformed authigenic quartz segregations. Stable isotope measurements of the coexisting calcite (deltaO-18SMOW=24.5) and quartz (deltaO-18SMOW=28.4) from the mylonite indicate relatively low temperatures (< 300-degreesC) during mylonitization. Analyses of white mica separates of varying size fractions from the mylonitic rocks by K/Ar and Rb/Sr techniques yield ages between 57 and 103 Ma. This variation is correlated with two parameters, the size of the mineral fraction, and the proportion of 2M1 (more phengitic) to 1M (more muscovitic) polytype in the sample. The K/Ar and Rb/Sr ages are generally younger in the smaller size fractions, which also containless 2M1 phengite. High precision Ar-40/Ar-39 age spectra from different size fractions of these micas record three distinct components, a small Hercynian component (ca. 200-300 Ma), a significant Eoalpine component (64-80 Ma) forming Ar-40/Ar-39 age plateaus, and a very minor Tertiary component (ca. 20-40 Ma). Characterization of the samples by SEM indicates the presence of two white mica populations, a coarser grained, deformed, detrital mica that probably corresponds to the 2M1 phengite and a finer grained neoformed 1M mica. Collectively these observations suggest that the Gummfluh samples contain a mixture of detrital phengites of Hercynian age together with neocrystallized muscovites grown during the late Eoalpine metamorphic event followed by minor argon loss during the Tertiary. The main geologic episode recorded in the Ar-40/Ar-39 age spectra of white micas in the mylonite is of Late Cretaceous/Early Tertiary age (64-80 Ma), representing the first reliable Eoalpine ages ever to be reported from the Prealpes. Contrary to tectonic models, the marble mylonite at the base of the Gummfluh klippe appears to be a Cretaceous thrust plane and not the thrust surface formed during transport of the klippe into its present position from the Penninic Alps during the Tertiary. The late Cretaceous thrust developed during marine sedimentation at a depth of 800 m below the seafloor at temperatures of approximately 280-degrees-C, facilitated by warm fluids along the tectonic discontinuity.
Resumo:
We describe a device made of artificial muscle for the treatment of end-stage heart failure as an alternative to current heart assist devices. The key component is a matrix of nitinol wires and aramidic fibers called Biometal muscle (BM). When heated electrically, it produces a motorless, smooth, and lifelike motion. The BM is connected to a carbon fiber scaffold, tightening the heart and providing simultaneous assistance to the left and right ventricles. A pacemaker-like microprocessor drives the contraction of the BM. We tested the device in a dedicated bench model of diseased heart. It generated a systolic pressure of 75 mm Hg and ejected a maximum of 330 ml/min, with an ejection fraction of 12%. The device required a power supply of 6 V, 250 mA. This could be the beginning of an era in which BMs integrate or replace the mechanical function of natural muscles.
Resumo:
The northeastern portion of the Mont Blanc massif in western Switzerland is predominantly comprised of the granitic rocks of the Mont Blanc intrusive suit, and the Mont Blanc basement gneisses. Within these metamorphic rocks are a variety of sub-economic Fe skarns. The mineral assemblages and fluid inclusions from these rocks have been used to derive age, pressure, temperature and fluid composition constraints for two Variscan events. Metamorphic hornblendes within the assemblages from the basement amphibolites and iron sk:lms have been dated using Ar-40/Ar-39, and indicate that these metamorphic events have a minimum age of approximately 334 Ma. Garnet-hornblende-plagioclase thermobarometry and stable isotope data obtained from the basement amphibolites are consistent with metamorphic temperatures in the range 515 to 580 degrees C, and pressures ranging from 5 to 8 kbar. Garnet-hornblende-magnetite thermobarometry and fluid inclusion studies indicate that the iron skarns formed at slightly lower temperatures, ranging from 400 to 500 degrees C in the presence of saline fluids at formational pressures similar to those experienced by the basement amphibolites. Late Paleozoic minimum uplift rates and geothermal gradients calculated using these data and the presence of Ladinien ichnofossils are on the order of 0.32 mm/year and 20 degrees C/km respectively. These uplift rates and geothermal gradients differ from those obtained from the neighbouring Aiguilles Rouges massif and indicate that these two massifs experienced different metamorphic conditions during the Carboniferous and Permian periods. During the early to late Carboniferous period the relative depths of the two massifs were reversed with the Aiguilles Rouges being initially unroofed at a much greater rate than the Mont Blanc, but experiencing relatively slower uplift rates near the termination of the Variscan orogeny.
Resumo:
BACKGROUND: Microalbuminuria (MA) has been shown to be an early biomarker of renal damage. It is postulated that MA is the early result of hyperfiltration, which could evolve into glomerular sclerosis and renal failure if hyperfiltration is left untreated. We hypothesized that MA is a good indicator of hyperfiltration in children with kidney disorders, obviating the need to calculate the filtration fraction (FF). METHODS: A total of 155 children or young adults were prospectively included [42 single kidney (SK), 61 vesico-ureteral reflux, 23 obstructive uropathies, 29 other kidney diseases]. We measured inulin, para-aminohippuric acid clearances, FF and MA. Prediction of hyperfiltration was explored by studying the association between the FF and other variables such as urinary albumin (Alb), urinary albumin-creatinine ratio (ACR) and creatinine clearance. RESULTS: A significant but weak association between urinary Alb or ACR and FF was found in subjects with an SK (Spearman correlation coefficients 0.32 and 0.19, respectively). Multivariate analysis also showed that urinary Alb and ACR significantly predict FF only in subjects with an SK (r(2) = 0.17, P = 0.01 and r(2) = 0.13, P = 0.02, respectively). This holds true only in subjects with an SK and inulin clearance >90 mL/min/1.73 m(2) (r(2) = 0.41, P < 0.001). There was no association between creatinine clearance and FF. CONCLUSIONS: MA is not associated with FF in our subjects with nephro-urological disorders, except in those with an SK, where the association is weak, indicating that MA is due to other mechanisms than high FF and cannot predict hyperfiltration in such groups.
Resumo:
Chronic atrial fibrillation affects millions of people worldwide. Its surgical treatment often fails to restore the transport function of the atrium. This study first introduces the concept of an atrial assist device (AAD) to restore the pump function of the atrium. The AAD is developed to be totally implantable in the human body with a transcutaneous energy transfer system to recharge the implanted battery. The ADD consists of a motorless pump based on artificial muscle technology, positioned on the external surface of the atrium to compress it and restore its muscular activity. A bench model reproduces the function of a fibrillating atrium to assess the circulatory support that this pump can provide. Atripump (Nanopowers SA, Switzerland) is a dome-shaped silicone-coated nitinol actuator 5 mm high, sutured on the external surface of the atrium. A pacemaker-like control unit drives the actuator that compresses the atrium, providing the mechanical support to the blood circulation. Electrical characteristics: the system is composed of one actuator that needs a minimal tension of 15 V and has a maximum current of 1.5 A with a 50% duty cycle. The implantable rechargeable battery is made of a cell having the following specifications: nominal tension of a cell: 4.1 V, tension after 90% of discharge: 3.5 V, nominal capacity of a cell: 163 mA h. The bench model consists of an open circuit made of latex bladder 60 mm in diameter filled with water. The bladder is connected to a vertically positioned tube that is filled to different levels, reproducing changes in cardiac preload. The Atripump is placed on the outer surface of the bladder. Pressure, volume and temperature changes were recorded. The contraction rate was 1 Hz with a power supply of 12 V, 400 mA for 200 ms. Preload ranged from 15 to 21 cm H(2)O. Maximal silicone membrane temperature was 55 degrees C and maximal temperature of the liquid environment was 35 degrees C. The pump produced a maximal work of 16 x 10(-3) J. Maximal volume pumped was 492 ml min(-1). This artificial muscle pump is compact, follows the Starling law and reproduces the hemodynamic performances of a normal atrium. It could represent a new tool to restore the atrial kick in persistent atrial fibrillation.
Resumo:
The Huqf Supergroup in Oman contains an exceptionally well-preserved and complete sedimentary record of the Middle to Late Neoproterozoic Era. Outcrops of the Huqf Supergroup in northern and central Oman are now well documented, but their correlation with a key succession in the Mirbat area of southern Oman, containing a sedimentary record of two Neoproterozoic glaciations, is poorly understood. Integration of lithostratigraphic, chemostratigraphic and new U-Pb detrital zircon data suggests that the Mirbat Group is best placed within the Cryogenian (c. 850-635 Ma) part of the Huqf Supergroup. The c. I km thick marine deposits of the Arkahawl and Marsham Formations of the Mirbat Group are thought to represent a stratigraphic interval between older Cryogenian and younger Cryogenian glaciations that is not preserved elsewhere in Oman. The bulk of detrital zircons in the Huqf Supergroup originate from Neoproterozoic parent rocks. However, older Mesoproterozoic, Palaeoproterozoic and even Archaean zircons can be recognized in the detrital population from the upper Mahara Group (Fiq Formation) and Nafun Group, suggesting the tapping of exotic sources, probably from the Arabian-Nubian Shield.
Resumo:
The results of Ar-40/Ar-39 dating integrated with calcareous plankton biostratigraphical data performed on two volcaniclastic layers (VLs) interbedded in Burdigalian to Lower Langhian outer shelf carbonate sediments cropping out in Monferrato (NW Italy) are presented. The investigated VLs, named Villadeati and Varengo, are thick sedimentary bodies with scarce lateral continuity. They are composed of prevalent volcanogenic material (about 87 up to 90% by volume) consisting of glass shards and volcanic phenocrysts (plagioclase, biotite, quartz, amphibole, sanidine and magnetite) and minor extrabasinal and intrabasinal components. On the basis of their composition and sedimentological features, the VLs have been interpreted as distal shelf turbidites deposited below storm wave base. However, compositional characteristics evidence the rapid resedimentation of the volcanic detritus after its primary deposition and hence the VL sediments can be considered penecontemporaneous to the encasing deposits. Biostratigraphical analyses were carried out on the basis of a quantitative study of calcareous nannofossil and planktonic foraminifer associations, whilst Ar-40/Ar-39 dating were performed on biotite at Villadeati and on homeblende at Varengo. The data resulting from the Villadeati section have permitted to estimate an age of 18.7 +/- 0.1 Ma for the last common occurrence (LCO) of Sphenolithus belemnos whereas those from Varengo allowed to extrapolate an age of 16.4 Ma +/-0.1 Ma for the first occurrence (FO) of Praeorbulina sicana. This latter biovent is commonly used to approximate the base of the Langhian stage, that corresponds to the Early-Middle Miocene boundary.
Resumo:
A government would like to subsidize an indivisible good. Consumers' valuations of the good vary according to their wealth and benefits from the good. A subsidy scheme may be based on consumers' wealth or benefit information. We translate a wealth-based policy to a benefit-based policy, and vice versa, and give a necessary and sufficient condition for the pair of policies to implement the same assignment: consumers choose to purchase the good under the wealth-based policy if and only if they choose to do so under the translated benefit-based policy. General taxation allows equivalent policies to require the same budget.
Resumo:
The therapeutic efficacy of anticancer chemotherapies may depend on dendritic cells (DCs), which present antigens from dying cancer cells to prime tumor-specific interferon-gamma (IFN-gamma)-producing T lymphocytes. Here we show that dying tumor cells release ATP, which then acts on P2X(7) purinergic receptors from DCs and triggers the NOD-like receptor family, pyrin domain containing-3 protein (NLRP3)-dependent caspase-1 activation complex ('inflammasome'), allowing for the secretion of interleukin-1beta (IL-1beta). The priming of IFN-gamma-producing CD8+ T cells by dying tumor cells fails in the absence of a functional IL-1 receptor 1 and in Nlpr3-deficient (Nlrp3(-/-)) or caspase-1-deficient (Casp-1(-/-)) mice unless exogenous IL-1beta is provided. Accordingly, anticancer chemotherapy turned out to be inefficient against tumors established in purinergic receptor P2rx7(-/-) or Nlrp3(-/-) or Casp1(-/-) hosts. Anthracycline-treated individuals with breast cancer carrying a loss-of-function allele of P2RX7 developed metastatic disease more rapidly than individuals bearing the normal allele. These results indicate that the NLRP3 inflammasome links the innate and adaptive immune responses against dying tumor cells.