1,901 research outputs found
Characterization of Structures of Equivalent Tissue With a Pixel Detector
Research using hybrid pixel detectors in medical physics is on the rise. Timepix detectors have arrays of 256 Ă— 256 pixels with a resolution of 55 ÎĽm. Here, and by using Timepix counts instead of Hounsfield units, we present a calibration curve of a Timepix detector analog to those used for CT calibration. Experimentation consisted of the characterization of electron density in 10 different kinds of tissue equivalent samples from a CIRS 062M phantom (lung, 3 kinds of bones, fat, breast, muscle, water and air). Radiation of the detector was performed using an orthodontic X-ray machine at 70 KeV and .06 second of tube current with a purpose-built aluminum collimator. Data acquisition was performed at 1 frame per second and taking 3 frames per phantom. We were able to find a curve whose behavior was similar to others already published. This will lead to the verification of the usage of Timepix for identification of different tissues in an organ
Prospection and identification of traditional-heritage Peruvian grapevine cultivars (Vitis vinifera L.) from Ica and Cañete valleys
Interest in ancient and autochthonous cultivars has increased in recent years since they are directly related to the historical and cultural values of a region. Ica and Cañete valleys (Peru) have a long history of grapevine cultivation and the aim of this study was to identify phenotypes corresponding to the most used varieties for the local production of Pisco and wine. The 29 samples were collected in 17 vineyards in the Ica and Cañete valleys, and were analyzed using 20 molecular markers and 5 morphological descriptors according to the OIV. Results showed that the 29 collected samples corresponded to 11 genotypes: seven traditional cultivars and four unknown genotypes not registered previously. The known cultivars were 'Muscat of Alexandria', 'Listán Prieto', 'Quebranta', 'Moscatel Rosado', 'Pedro Giménez', 'Muscat Hamburg' and 'Palomino Fino'. The four not registered genotypes are locally known as 'Mollar de Ica', 'Moscatel Rosada de Cañete', 'Prieta Mollar' and 'Torontel'. All of them correspond to offspring of traditional-heritage Peruvian cultivars. We also found a phenotypic variation of 'Listán Prieto' with muscat flavor and identified phenotypic berry color variations in 'Quebranta'. This study increases the knowledge of traditional Peruvian grape varieties and highlight the genetic variability preserved in the traditional vineyards of local producers
Whole-genome association analysis of treatment response in obsessive-compulsive disorder.
Up to 30% of patients with obsessive-compulsive disorder (OCD) exhibit an inadequate response to serotonin reuptake inhibitors (SRIs). To date, genetic predictors of OCD treatment response have not been systematically investigated using genome-wide association study (GWAS). To identify specific genetic variations potentially influencing SRI response, we conducted a GWAS study in 804 OCD patients with information on SRI response. SRI response was classified as 'response' (n=514) or 'non-response' (n=290), based on self-report. We used the more powerful Quasi-Likelihood Score Test (the MQLS test) to conduct a genome-wide association test correcting for relatedness, and then used an adjusted logistic model to evaluate the effect size of the variants in probands. The top single-nucleotide polymorphism (SNP) was rs17162912 (P=1.76 Ă— 10(-8)), which is near the DISP1 gene on 1q41-q42, a microdeletion region implicated in neurological development. The other six SNPs showing suggestive evidence of association (P<10(-5)) were rs9303380, rs12437601, rs16988159, rs7676822, rs1911877 and rs723815. Among them, two SNPs in strong linkage disequilibrium, rs7676822 and rs1911877, located near the PCDH10 gene, gave P-values of 2.86 Ă— 10(-6) and 8.41 Ă— 10(-6), respectively. The other 35 variations with signals of potential significance (P<10(-4)) involve multiple genes expressed in the brain, including GRIN2B, PCDH10 and GPC6. Our enrichment analysis indicated suggestive roles of genes in the glutamatergic neurotransmission system (false discovery rate (FDR)=0.0097) and the serotonergic system (FDR=0.0213). Although the results presented may provide new insights into genetic mechanisms underlying treatment response in OCD, studies with larger sample sizes and detailed information on drug dosage and treatment duration are needed
Recommended from our members
Genome-wide association study in obsessive-compulsive disorder: results from the OCGAS.
Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by intrusive thoughts and urges and repetitive, intentional behaviors that cause significant distress and impair functioning. The OCD Collaborative Genetics Association Study (OCGAS) is comprised of comprehensively assessed OCD patients with an early age of OCD onset. After application of a stringent quality control protocol, a total of 1065 families (containing 1406 patients with OCD), combined with population-based samples (resulting in a total sample of 5061 individuals), were studied. An integrative analyses pipeline was utilized, involving association testing at single-nucleotide polymorphism (SNP) and gene levels (via a hybrid approach that allowed for combined analyses of the family- and population-based data). The smallest P-value was observed for a marker on chromosome 9 (near PTPRD, P=4.13 Ă— 10(-)(7)). Pre-synaptic PTPRD promotes the differentiation of glutamatergic synapses and interacts with SLITRK3. Together, both proteins selectively regulate the development of inhibitory GABAergic synapses. Although no SNPs were identified as associated with OCD at genome-wide significance level, follow-up analyses of genome-wide association study (GWAS) signals from a previously published OCD study identified significant enrichment (P=0.0176). Secondary analyses of high-confidence interaction partners of DLGAP1 and GRIK2 (both showing evidence for association in our follow-up and the original GWAS study) revealed a trend of association (P=0.075) for a set of genes such as NEUROD6, SV2A, GRIA4, SLC1A2 and PTPRD. Analyses at the gene level revealed association of IQCK and C16orf88 (both P<1 Ă— 10(-)(6), experiment-wide significant), as well as OFCC1 (P=6.29 Ă— 10(-)(5)). The suggestive findings in this study await replication in larger samples
Lifetime prevalence, age of risk, and genetic relationships of comorbid psychiatric disorders in Tourette syndrome
IMPORTANCE: Tourette syndrome (TS) is characterized by high rates of psychiatric comorbidity; however, few studies have fully characterized these comorbidities. Furthermore, most studies have included relatively few participants
Molecular and morphological characterization of the grapevine cultivars “Italia” in the Ica and Cañete valleys (Peru)
The denomination of “Uva de Italia” or “Italia” is commonly used by growers to refer to a group of varieties used from the colonial times to making a brandy of Pisco with muscat aroma. Previous work have demonstrated that Uva de Italia corresponds in fact to the variety Muscat of Alexandria, a widely spread variety around the world and in South America. However, the distinction between “Italia Dorada” and “Italia Rosada” is usually made, in allusion to the color variations observed in the berries. Our aim was to characterize 5 samples collected in vineyards from the valleys of Ica and Cañete. The genotypes were identified using 13 molecular markers of nuclear simple sequence repeat, and 23 morphological descriptors according to OIV. Our results showed that four genotypes were identified as Muscat of Alexandria while the other corresponded to variety well-known in Argentina as Moscatel Rosado or Uva Pastilla in Chile respectively. Moscatel Rosado showed functionally female flowers, with variable berries size and color in the range from greenish yellow through pink. This is the first identification of Moscatel Rosado as a variety present in the Peruvian vineyards and would allow its use in the pisco industry with distinctive aromatic characteristics. Keywords: Italia, Muscat of Alexandria, Moscatel Rosado, variety identification, parentage analysis, microsatellites, Pisco
QuinuaSmartApp: A Real-Time Agriculture Precision IoT Cloud Platform to Crops Monitoring
IoT networks, cloud-based applications and the use of artificial intelligence models in precision agriculture present an important opportunity to increase production and optimize the use of water resources, which will allow the development of sustainable and responsible agriculture in the face of global food security. In order to provide real-time remote monitoring of quinoa crops, this article proposes and implements an integrated architecture based on sensor networks, drones with multispectral and Lidar cameras and cloud computing-based applications. The system has hardware and software applications that enable Quinoa crop monitoring during the different stages of its growth. Additionally, it comprises weather stations providing real-time data which permits actualising the predictive models that can be used for local climate change projections. The monitoring of the level of humidity in the crop field through soil stations feeds the training database based on machine learning that allows generating the projection of water demand, which allows more efficient and better-planned use of crop water. Additionally, it implements a service of warning messages, attended by experts who are connected to the system in order to provide technical recommendations to help deal with this issue in order to lessen the impact of pests and diseases in the field.2023-2
Suicide Risk in Military Personnel during the COVID-19 Health Emergency in a Peruvian Region: A Cross-Sectional Study
": Military personnel represent a frontline group exposed to multiple stressors. These factors
have increased during the COVID-19 pandemic, predisposing to the development of suicidal risk
(SR). Given the few studies conducted in this population, we evaluated the prevalence of SR and its
associated factors during the health emergency. A cross-sectional survey study was conducted in
person among 514 participants in Lambayeque, Peru in 2021. The outcome was SR, and the exposures
were depression (PHQ-9), anxiety (GAD-7), PTSD (PCL-C), and other sociodemographic variables.
The prevalence of SR was 14.0% (95% CI: 11.12–17.31%) and was significantly higher in people with
a family history of mental health (PR: 2.16; 95% CI: 1.13–4.15) and in those with moderate clinical
insomnia (PR: 2.21; 95% CI: 1.19–4.12). Military personnel with high resilience had a lower prevalence
of SR (PR: 0.54, CI: 0.31–0.95). Anxiety was associated with a higher prevalence of SR (PR: 3.27;
95% CI: 1.76–6.10). Our findings show that at least 1 out of 10 military personnel are at risk of suicide.
Special attention should be paid to the associated factors to develop interventions and reverse their
consequences. These results may be useful in policy implementation and general statistics of SR in
the local and regional context.
- …