124 research outputs found
Combining dental and skeletal evidence in age classification: Pilot study in a sample of Italian sub-adults
Background: Dental and skeletal maturation have proved to be reliable evidence for estimating age of children and prior studies and internationally accredited guidelines recommend to evaluate both evidence in the same subject to reduce error in age prediction. Nevertheless the ethical and legal justification of procedures that imply a double exposition of children stands as a relevant issue. This study aims to evaluate the accuracy of age estimation provided by a combination of skeletal and dental methods applied in the same sample of children. / Materials and methods: The sample consisted of 274 orthopantomographies and left hand-wrist X-rays of Italian children, (aged between 6 and 17 years) taken on the same day. Greulich and Pyle’s (GP), Tanner-Whitehouse’s version 3 (TW3) and Willems’ (W) and the Demirjian’s (D) methods were respectively applied for estimating skeletal and dental age. A combination of skeletal and dental age estimates through Linear Discriminant Analysis (LDA) is proposed to obtain a classifier respect to an age threshold. / Results: The combination of D and TW3 obtained an improvement of accuracy in classifying female subjects respect to the 12 years threshold respect to the original methods (from about 77% using either original methods to 83.3% combining TW3 + D) as well as a consistent reduction of false positives rate (from 17% to 21% for original methods to 5.6% with TW3 + D). For males the LDA classifier (based on TW3 and W) enable a small improvement in accuracy, whilst the decreasing of false positives was as noticeable as for females (from 17.6 to 14.1% for original methods to 6.2% combining TW3 + W). / Conclusions: Although the study is influenced by the limited size and the uneven age distribution of the sample, the present findings support the conclusion that age assessment procedures based on both dental and skeletal age estimation can improve the accuracy and reduce the occurrence of false positives
Fluid geochemistry of the Los Humeros geothermal field (LHGF - Puebla, Mexico): New constraints for the conceptual model
Geothermal power in Mexico is mainly produced in four geothermal fields operated by the Comision Federal de Electricidad (CFE): Cerro Prieto, Los Azufres, Los Humeros, and Las Tres Virgenes. The Los Humeros Geothermal Field (LHGF) is ranked third in terms of generated capacity, and in the last decade its installed capacity has doubled (up to 95.0 MW). Further increases in the geothermal power generation capacity in Mexico are planned, and thus the LHGF warrants further examination. The development and growth phases of any geothermal project must start from an awareness of the conceptual model of the natural system studied. The recharge mechanism, feeding zones, and fluid flow-path must be identified, along with the estimation of the temperature at the productive level and of phase separation (liquid - steam). To accomplish this, detailed fluid geochemical surveys were carried out in June 2017 and March 2018, in which 57 and 87 samples were collected, respectively, from cold and thermal springs, water wells and maar lakes located around and inside the LHGF. Samples from fumaroles inside the producing area were also collected for the first time, together with fluid from re-injection wells. The presence of a meteoric component, which plays an important role at the regional scale, is confirmed by the chemical and isotope data, and its contribution in terms of recharge may be higher than previously assumed. The Sierra Madre Oriental, on the west side of the LHGF, is characterized by widespread outcrops of limestone belonging to the same geological formation as those at the bottom of the LHGF. The isotope composition (delta D and delta O-18, respectively -77.3 parts per thousand and -10.50 parts per thousand for the hypothetical Infiltration Water IW) is similar to that observed in cold springs located in the Sierra Madre Oriental, and from this the evolution of isotopes in the liquid-rock-steam system during water-rock interaction and phase separation processes can be modelled. Thus, the experimental data obtained for natural gas emissions (fumarolic condensates) and for geothermal fluids can be reproduced. These findings suggest that geothermal fluids in the LHGF are likely to be derived from meteoric water infiltrating (IW) the limestone outcrops of the Sierra Madre Oriental. During their flow-path, the infiltrating waters exchange isotopes at a high temperature with the crustal rocks, which have a much higher O-18/O-16 ratio, resulting in a shift towards higher delta O-18 (-4.35 parts per thousand +/- 1) as the water O exchanges with rock O. The vapor phase can be separated from this deep water (DW) and it is discharged from the fumarolic effluents of Loma Blanca. Single Step Vapor Separation (SSVS) and Continuous Steam Separation processes (CSS) were modelled using stable isotopes of water. The results of geochemical modeling agree with available data for geothermal liquids discharged from several geothermal wells, suggesting that steam separation may be interpreted either as SSVS or CSS. Other processes can affect the chemistry and isotope composition of geothermal fluids (e.g. phase segregation, gas exchange, contributions from magmatic-volcanic deep fluids and re-injection fluids). The proposed conceptual model is consistent with both the geochemical data and the geological setting, and provides a useful point of reference for examining the fluid flow-path and geochemical processes active in the LHGF, at least at a general level.An involvement of magmatic-volcanic deep fluids in the feeding mechanism of the geothermal system cannot be excluded at priori, but the regional meteoric end-member is supported by the data and it seems the most important component
A Highly Intensified ART Regimen Induces Long-Term Viral Suppression and Restriction of the Viral Reservoir in a Simian AIDS Model
Stably suppressed viremia during ART is essential for establishing reliable simian models for HIV/AIDS. We tested the efficacy of a multidrug ART (highly intensified ART) in a wide range of viremic conditions (103–107 viral RNA copies/mL) in SIVmac251-infected rhesus macaques, and its impact on the viral reservoir. Eleven macaques in the pre-AIDS stage of the disease were treated with a multidrug combination (highly intensified ART) consisting of two nucleosidic/nucleotidic reverse transcriptase inhibitors (emtricitabine and tenofovir), an integrase inhibitor (raltegravir), a protease inhibitor (ritonavir-boosted darunavir) and the CCR5 blocker maraviroc. All animals stably displayed viral loads below the limit of detection of the assay (i.e. <40 RNA copies/mL) after starting highly intensified ART. By increasing the sensitivity of the assay to 3 RNA copies/mL, viral load was still below the limit of detection in all subjects tested. Importantly, viral DNA resulted below the assay detection limit (<2 copies of DNA/5*105 cells) in PBMCs and rectal biopsies of all animals at the end of the follow-up, and in lymph node biopsies from the majority of the study subjects. Moreover, highly intensified ART decreased central/transitional memory, effector memory and activated (HLA-DR+) effector memory CD4+ T-cells in vivo, in line with the role of these subsets as the main cell subpopulations harbouring the virus. Finally, treatment with highly intensified ART at viral load rebound following suspension of a previous anti-reservoir therapy eventually improved the spontaneous containment of viral load following suspension of the second therapeutic cycle, thus leading to a persistent suppression of viremia in the absence of ART. In conclusion, we show, for the first time, complete suppression of viral load by highly intensified ART and a likely associated restriction of the viral reservoir in the macaque AIDS model, making it a useful platform for testing potential cures for AIDS
Diversity arrays technology (DArT) markers in apple for genetic linkage maps
Diversity Arrays Technology (DArT) provides a high-throughput whole-genome genotyping platform for the detection and scoring of hundreds of polymorphic loci without any need for prior sequence information. The work presented here details the development and performance of a DArT genotyping array for apple. This is the first paper on DArT in horticultural trees. Genetic mapping of DArT markers in two mapping populations and their integration with other marker types showed that DArT is a powerful high-throughput method for obtaining accurate and reproducible marker data, despite the low cost per data point. This method appears to be suitable for aligning the genetic maps of different segregating populations. The standard complexity reduction method, based on the methylation-sensitive PstI restriction enzyme, resulted in a high frequency of markers, although there was 52–54% redundancy due to the repeated sampling of highly similar sequences. Sequencing of the marker clones showed that they are significantly enriched for low-copy, genic regions. The genome coverage using the standard method was 55–76%. For improved genome coverage, an alternative complexity reduction method was examined, which resulted in less redundancy and additional segregating markers. The DArT markers proved to be of high quality and were very suitable for genetic mapping at low cost for the apple, providing moderate genome coverage
Erwinia amylovora Novel Plasmid pEI70: Complete Sequence, Biogeography, and Role in Aggressiveness in the Fire Blight Phytopathogen
Comparative genomics of several strains of Erwinia amylovora, a plant pathogenic bacterium causal agent of fire blight disease, revealed that its diversity is primarily attributable to the flexible genome comprised of plasmids. We recently identified and sequenced in full a novel 65.8 kb plasmid, called pEI70. Annotation revealed a lack of known virulence-related genes, but found evidence for a unique integrative conjugative element related to that of other plant and human pathogens. Comparative analyses using BLASTN showed that pEI70 is almost entirely included in plasmid pEB102 from E. billingiae, an epiphytic Erwinia of pome fruits, with sequence identities superior to 98%. A duplex PCR assay was developed to survey the prevalence of plasmid pEI70 and also that of pEA29, which had previously been described in several E. amylovora strains. Plasmid pEI70 was found widely dispersed across Europe with frequencies of 5–92%, but it was absent in E. amylovora analyzed populations from outside of Europe. Restriction analysis and hybridization demonstrated that this plasmid was identical in at least 13 strains. Curing E. amylovora strains of pEI70 reduced their aggressiveness on pear, and introducing pEI70 into low-aggressiveness strains lacking this plasmid increased symptoms development in this host. Discovery of this novel plasmid offers new insights into the biogeography, evolution and virulence determinants in E. amylovora
J Clin Immunol
We report a longitudinal analysis of the immune response associated with a fatal case of COVID-19 in Europe. This patient exhibited a rapid evolution towards multiorgan failure. SARS-CoV-2 was detected in multiple nasopharyngeal, blood, and pleural samples, despite antiviral and immunomodulator treatment. Clinical evolution in the blood was marked by an increase (2–3-fold) in differentiated effector T cells expressing exhaustion (PD-1) and senescence (CD57) markers, an expansion of antibody-secreting cells, a 15-fold increase in γδ T cell and proliferating NK-cell populations, and the total disappearance of monocytes, suggesting lung trafficking. In the serum, waves of a pro-inflammatory cytokine storm, Th1 and Th2 activation, and markers of T cell exhaustion, apoptosis, cell cytotoxicity, and endothelial activation were observed until the fatal outcome. This case underscores the need for well-designed studies to investigate complementary approaches to control viral replication, the source of the hyperinflammatory status, and immunomodulation to target the pathophysiological response. The investigation was conducted as part of an overall French clinical cohort assessing patients with COVID-19 and registered in clinicaltrials.gov under the following number: NCT04262921
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