Digital compensation of the side-band-rejection ratio in a fully analog 2SB sub-millimeter receiver

In observational radio astronomy, sideband-separating receivers are preferred, particularly under high atmospheric noise, which is usually the case in the sub-millimeter range. However, obtaining a good rejection ratio between the two sidebands is difficult since, unavoidably, imbalances in the different analog components appear. We describe a method to correct these imbalances without making any change in the analog part of the sideband-separating receiver, specifically, keeping the intermediate-frequency hybrid in place. This opens the possibility of implementing the method in any existing receiver. We have built hardware to demonstrate the validity of the method and tested it on a fully analog receiver operating between 600 and 720GHz. We have tested the stability of calibration and performance vs time and after full resets of the receiver. We have performed an error analysis to compare the digital compensation in two configurations of analog receivers, with and without intermediate frequency (IF) hybrid. An average compensated sideband rejection ratio of 46dB is obtained. Degradation of the compensated sideband rejection ratio on time and after several resets of the receiver is minimal. A receiver with an IF hybrid is more robust to systematic errors. Moreover, we have shown that the intrinsic random errors in calibration have the same impact for configuration without IF hybrid and for a configuration with IF hybrid with analog rejection ratio better than 10dB. Compensated rejection ratios above 40dB are obtained even in the presence of high analog rejection. The method is robust allowing its use under normal operational conditions at any telescope. We also demonstrate that a full analog receiver is more robust against systematic errors. Finally, the error bars associated to the compensated rejection ratio are almost independent of whether IF hybrid is present or not

Profiling the Influence of Gene Variants Related to Folate-Mediated One-Carbon Metabolism on the Outcome of In Vitro Fertilization (IVF) with Donor Oocytes in Recipients Receiving Folic Acid Fortification

Partial funding for open access charge: Universidad de MálagaNutritional status and gene polymorphisms of one-carbon metabolism confer a well-known interaction that in pregnant women may affect embryo viability and the health of the newborn. Folate metabolism directly impacts nucleotide synthesis and methylation, which is of increasing interest in the reproductive medicine field. Studies assessing the genetic influence of folate metabolism on IVF treatments have currently been performed in women using their own oocytes. Most of these patients seeking to have a child or undergoing IVF treatments are advised to preventively intake folate supplies that restore known metabolic imbalances, but the treatments could lead to the promotion of specific enzymes in specific women, depending on their genetic variance. In the present study, we assess the influence of candidate gene variants related to folate metabolism, such as Serine Hydroxymethyltransferase 1 SHMT1 (rs1979276 and rs1979277), Betaine-Homocysteine S-Methyltransferase BHMT (rs3733890), Methionine synthase reductase MTRR (rs1801394), Methylenetetrahydrofolate reductase MTHFR (rs1801131 and rs1801133), methionine synthase MTR (rs12749581), ATP Binding Cassette Subfamily B Member 1 ABCB1 (rs1045642) and folate receptor alpha FOLR1 (rs2071010) on the success of IVF treatment performed in women being recipients of donated oocytes. The implication of such gene variants seems to have no direct impact on pregnancy consecution after IVF; however, several gene variants could influence pregnancy loss events or pregnancy maintenance, as consequence of folic acid fortification.This research was funded by grant PTQ 09–01-00496, Ministerio de Economía y Competitividad (MINECO), Government of Spain, Instituto de Fertilidad Clínica Rincón y Fundación Rincón. AR Palomares and KA Rodriguez-Wallberg are supported by grants from the Swedish Research Council (VR Dnr 2021-06116, Dnr 2020–02230), the Swedish Cancer Society (CAN 2017/704, 20 0170 F) and Karolinska Institutet Research grants

Practical study of optical stellar interferometry

In this work we present an observational technique and a detailed analysis of the stellar interferograms produced by three bright stars: Betelgeuse, Rigel and Sirius. It is shown that the atmospheric turbulence is responsible for the reduction of the long-exposure fringe visibility of the obtained interference patterns. By using different baselines in our interferometer, we are able to distinguish the decay of the visibility with the baseline, how different parameters such us the diameter of the holes in our interferometer or their distribution affects the pattern, and to measure the turbulence with the estimation of the Fried parameter r0. The work and methodology are presented as a method for postgraduate students that targets practical learning of optical interferometry in astronomy and how it is affected by several causes, such as the atmospheric turbulence.Comment: 11 pages, 6 figures, paper submitted and accepted to AJ

Terahertz Computed Tomography of NASA Thermal Protection System Materials

A terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described

Enhanced optical properties of Cd–Mg-co-doped ZnO nanoparticles induced by low crystal structure distortion

The growth of CdxMg0.125-xZn0.875O nanoparticles with yellow-orange luminescence is achieved up to 2.5 at. % Cd via a modified sol–gel process. X-ray diffraction analysis confirmed that all the nanoparticles have the hexagonal wurtzite structure. It is found that Cd doping has a considerable effect on the crystal size, microstrain, band gap, and photoluminescence of the Mg0·125Zn0·875O structure, originating from a preferred crystallographic orientation along the (101) plane of the wurtzite structure. The shift and broadening of the E2(high) mode observed in the Raman spectra due to growth-induced strain corroborates the small distortion observed in the X-ray diffraction data. The optical band gap varies from 3.21 eV to 2.74 eV, being redshifted with increasing Cd concentration (from 0 at. % to 2.5 at. %). The photoluminescence obtained with an excitation wavelength of 325 nm has a broad yellow-orange emission peak at around 640 nm due to transitions related to oxygen vacancies and interstitial oxygen atoms. We located the yellow-orange emission in the chromaticity coordinate diagram in the 2683–2777 K colour temperature region, demonstrating that CdxMg0.125-xZnO0.875 nanoparticles have potential applications in white light-emitting diodes.publishe

Propiedades Psicométricas del Inventario Psicológico de Ejecución Deportiva (IPED) en deportistas peruanos de Alto Rendimiento

To measure athlete's success and his sports performance, it is required to quantify the maximum performance developed during seasons of trainings and championships; using a valid, reliable, and adapted to peruvian context instrument. However, caution is urged when considering there is no psychometric evidence to support the use of any scale related to peruvian high performance athletes' sample. The current study was designed to evaluate the psychometric properties of the Sports Performance Psychological Inventory (IPED) in the mentioned sample. Method: Participated 255 peruvian athletes with ages between 14 and 38 years (N:23; SD: 4.29); who actively represents the country and in sports modalities affiliated with the Peruvian Sports Institute (IPD). For the collection of information, a sociodemographic record, Sports Performance Psychological Inventory (IPED) and the Mental Toughness Questionnaire (MTQ) were used. Results: IPED model demonstrated, that the seven-dimensional model had an acceptable fit (SBx2 = 2243.096 / df = 798; CFI=. 955; SRMR=. 095; RMSEA=. 084 [IC90%:. 080 -. 069] and reliability analyses revealed high internal consistency (ω =. 841 > ω =. 754). In addition, scores correlated positively between IPP and MTQ dimensions (AC=. 678; CAN=. 557; CAT=. 457; CVI=. 328; NM=. 425; CAP=. 641; CAC=. 662) and Control (AC=. 558; CAN=. 733; CAT=. 682; CVI=. 171; NM=. 272; CAP=. 432; CAC=. 563) Conclusion: The IPED provides adequate evidence of validity and reliability to measure sports performanc

Genetics of tibia bone properties of crossbred commercial laying hens in different housing systems

Osteoporosis and bone fractures are a severe problem for the welfare of laying hens, with genetics and environment, such as housing system, each making substantial contributions to bone strength. In this work, we performed genetic analyses of bone strength, bone mineral density, and bone composition, as well as body weight, in 860 commercial crossbred laying hens from 2 different companies, kept in either furnished cages or floor pens. We compared bone traits between housing systems and crossbreds and performed a genome-wide association study of bone properties and body weight. As expected, the 2 housing systems produced a large difference in bone strength, with layers housed in floor pens having stronger bones. These differences were accompanied by differences in bone geometry, mineralization, and chemical composition. Genome scans either combining or independently analyzing the 2 housing systems revealed no genome-wide significant loci for bone breaking strength. We detected 3 loci for body weight that were shared between the housing systems on chromosomes 4, 6, and 27 (either genome-wide significant or suggestive) and these coincide with associations for bone length. In summary, we found substantial differences in bone strength, content, and composition between hens kept in floor pens and furnished cages that could be attributed to greater physical activity in pen housing. We found little evidence for large-effect loci for bone strength in commercial crossbred hens, consistent with a highly polygenic architecture for bone strength in the production environment. The lack of consistent genetic associations between housing systems in combination with the differences in bone phenotypes could be due to gene-by-environment interactions with housing system or a lack of power to detect shared associations for bone strength

Differential transcription profiles inAedes aegyptidetoxification genes after temephos selection

The mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance. Target site alteration in the acetylcholine esterase of this species has not being identified. Instead, we tracked changes in transcription of metabolic detoxification genes using the Ae. aegypti ‘Detox Chip’ microarray during five generations of temephos selection. We selected for temephos resistance in three replicates in each of six collections, five from Mexico, and one from Peru. The response to selection was tracked in terms of lethal concentrations. Uniform upregulation was seen in the epsilon class glutathione-S-transferase (eGST) genes in strains from Mexico prior to laboratory selection, while eGSTs in the Iquitos Peru strain became upregulated after five generations of temephos selection. While expression of many carboxyl/cholinesterase esterase (CCE) genes increased with selection, no single esterase was consistently upregulated and this same pattern was noted in the cytochrome P450 monooxygenase (CYP) genes and in other genes involved in reduction or oxidation of xenobiotics. Bioassays using glutathione-S-transferase (GST), CCE and CYP inhibitors suggest that various CCEs instead of GSTs are the main metabolic mechanism conferring resistance to temephos. We show that temephos-selected strains show no cross resistance to permethrin and that genes associated with temephos selection are largely independent of those selected with permethrin in a previous study