Chromosome movements and licensing of synapsis must be tightly regulated during early meiosis to ensure accurate chromosome segregation and avoid aneuploidy, although how these steps are coordinated ...is not fully understood. Here we show that GRAS-1, the worm homolog of mammalian GRASP/Tamalin and CYTIP, coordinates early meiotic events with cytoskeletal forces outside the nucleus. GRAS-1 localizes close to the nuclear envelope (NE) in early prophase I and interacts with NE and cytoskeleton proteins. Delayed homologous chromosome pairing, synaptonemal complex (SC) assembly, and DNA double-strand break repair progression are partially rescued by the expression of human CYTIP in gras-1 mutants, supporting functional conservation. However, Tamalin, Cytip double knockout mice do not exhibit obvious fertility or meiotic defects, suggesting evolutionary differences between mammals. gras-1 mutants show accelerated chromosome movement during early prophase I, implicating GRAS-1 in regulating chromosome dynamics. GRAS-1-mediated regulation of chromosome movement is DHC-1-dependent, placing it acting within the LINC-controlled pathway, and depends on GRAS-1 phosphorylation at a C-terminal S/T cluster. We propose that GRAS-1 coordinates the early steps of homology search and licensing of SC assembly by regulating the pace of chromosome movement in early prophase I.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
It is known that growth hormone (GH) is expressed in immune cells, where it exerts immunomodulatory effects. However, the mechanisms of expression and release of GH in the immune system remain ...unclear. We analyzed the effect of growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), ghrelin (GHRL), and somatostatin (SST) upon GH mRNA expression, intracellular and released GH, Ser133-phosphorylation of CREB (pCREB
), intracellular Ca
levels, as well as B-cell activating factor (BAFF) mRNA expression in bursal B-lymphocytes (BBLs) cell cultures since several GH secretagogues, as well as their corresponding receptors (-R), are expressed in B-lymphocytes of several species. The expression of TRH/TRH-R, ghrelin/GHS-R1a, and SST/SST-Rs (Subtypes 1 to 5) was observed in BBLs by RT-PCR and immunocytochemistry (ICC), whereas GHRH/GHRH-R were absent in these cells. We found that TRH treatment significantly increased local GH mRNA expression and CREB phosphorylation. Conversely, SST decreased GH mRNA expression. Additionally, when added together, SST prevented TRH-induced GH mRNA expression, but no changes were observed in pCREB
levels. Furthermore, TRH stimulated GH release to the culture media, while SST increased the intracellular content of this hormone. Interestingly, SST inhibited TRH-induced GH release in a dose-dependent manner. The coaddition of TRH and SST decreased the intracellular content of GH. After 10 min. of incubation with either TRH or SST, the intracellular calcium levels significantly decreased, but they were increased at 60 min. However, the combined treatment with both peptides maintained the Ca
levels reduced up to 60-min. of incubation. On the other hand, BAFF cytokine mRNA expression was significantly increased by TRH administration. Altogether, our results suggest that TRH and SST are implicated in the regulation of GH expression and release in BBL cultures, which also involve changes in pCREB
and intracellular Ca
concentration. It is likely that TRH, SST, and GH exert autocrine/paracrine immunomodulatory actions and participate in the maturation of chicken BBLs.
Consumers’ perception of different types of food markets in Mexico Escobar‐López, Sttefanie Y.; Espinoza‐Ortega, Angélica; Moctezuma‐Pérez, Sergio ...
International journal of consumer studies,
January 2022, 2022-01-00, 20220101, Letnik:
46, Številka:
1
Journal Article
Recenzirano
Developing countries such as Mexico have diverse food retail channels classified into three main groups: Supermarkets in their diverse variants (hypermarkets, medium and small supermarkets, and ...gourmet supermarkets); traditional food supply channels classified in Traditional markets, Tianguis, and grocery stores and Alternative markets. Despite the wide array of options, there is a lack of information on consumers’ perceptions of these different spaces. Therefore, the objective of the present study was to analyse consumers’ perceptions of Traditional markets, Tianguis, Supermarkets and Alternative markets in central Mexico. A questionnaire was applied with three sections: free word association (FWA), purchase habits and socioeconomic aspects. Four hundred and eighty consumers were surveyed, 120 in each type of market. The words mentioned during the FWA were grouped according to category and dimension and were analysed with a chi‐squared test. The relationship between categories and markets was analysed by multiple correspondence analysis and the remaining variables by descriptive statistics. Supermarkets were related to processed foods and nonfood items and were considered accessible, practical and modern spaces. Traditional markets and Tianguis were perceived as traditional and associated with social commitment and fresh foods but were also perceived as lacking in infrastructure, insecure and impractical. Alternative markets were viewed as innovative spaces offering alternative foods, albeit expensive. The interviewed consumers were mostly women. Those approached in Supermarkets and Alternative markets tended to be millennials, and in Tianguis and Traditional markets tended to belong to Generation X (born between 1965 and 1982). Also, most of those in Alternative markets had university or postgraduate degrees. In conclusion, consumers had a clear perception of the different types of markets as well as their advantages and disadvantages. This study contributes to empirical knowledge on the persistence of traditional markets and the incorporation of alternative markets in developing countries in spite of the growth of Supermarkets.
Demographic changes in contemporary societies has promoted sectors of consumers aware of the food they buy for health reasons, as functional foods, whose demand has grown in diverse countries as ...Mexico, recognized as one of the emergent market with the highest consumption of these products in Latin America. However, there is little knowledge on the attitudes of Mexican consumers toward functional foods. The objective was to explore the perception of functional foods by Mexican urban consumers using the free word association technique. A total of 610 persons were asked the three first words that came to their minds with the stimulus “functional food.” Twenty‐three categories were grouped in nine dimensions, the most important were: Health, Nutrition, and Foods and Nutrients. Differences due to age and schooling level were found in dimensions and categories. Consumers have a clear idea of “functional food” that explains growth in this market. The promotion of functional foods should take into consideration the demands that specific groups of consumers have for these products.
Practical applications
This work is a first approach on the study of the perception of Mexican urban consumers toward functional foods, with results that may be useful for public or private entities. As mentioned in works conducted in other areas of the world, demographic and socio‐economic characteristics are identified as significant determinants; the perception toward functional foods is positively associated with educational achievement, age and women. Taking into consideration the diabetes and overweight problems of the Mexican population, research results indicate an opportunity for producers of functional foods for an adequate development, improvement, and promotion of these products to meet specific perceptions of each target group of consumers.
The purpose of the study was to design a device for the dissolution of fertilizers for agricultural use in an automatic and environmentally sustainable way to facilitate the work of farmers. To ...achieve this goal, an outdated blade design was used, which generates turbulent and laminar flows thanks to the angle of inclination of its blades. In tests, the combination of these two flows gave a better result compared to laminar and turbulent flows separately. The best results were achieved by varying the spin and speed, the time between spins, and the rest time. The time it would take to dissolve the mixture was drastically reduced if it were conducted in the traditional way (manually) or compared with commercial mixers. In conclusion, the technique used for the dissolution of agricultural minerals is more effective and reduces time, energy, and effort. This was able to reduce the time necessary to dissolve the fertilizer by 93 percent compared to doing it manually and by 66 percent compared to using commercial mixers, in a solution of 100 L of water per 100 kg of ammonium sulfate.
YKL-40 increase according to the aging process, and its functions have been associated with tissue remodeling and systemic inflammation. In Rheumatoid Arthritis (RA) it has been proposed as a ...possible biomarker of activity and severity, however; in the field of idiopathic inflammatory myopathies (IIM) the role of YKL-40 in IIM is not clear. Thus, we aimed to evaluate if there is an association between the serum levels and muscle tissue expression of YKL-40 with age, IIM phenotype, muscle strength and myositis disease activity. The main finding was that age is the most important variable that affects the YKL-40 serum levels. In muscle biopsy, we observed that YKL-40 is mainly expressed in infiltrating lymphoid cells than in muscle tissue. Using ANCOVA according to the b-coefficients, YKL-40 serum levels are predicted by inflammatory state, age, and IIM diagnosis.
A proof-of-concept of a microwave imaging system for the fast detection of abdominal aortic aneurysms is shown. This experimental technology seeks to overcome the factors hampering the fast screening ...for these aneurysms with the usual equipment, such as high cost, long-time operation or hazardous exposure to chemical substances. The hardware system is composed of 16 twin antennas mastered by a microcontroller through a switching network, which connects the antennas to the measurement instrument for sequential measurement. The software system is run by a computer, mastering the whole system, automatizing the measurement process and running the signal processing and medical image generation algorithms. Two image generation algorithms are tested: Delay-and-Sum (DAS) and Improved Delay-and-Sum (IDAS). Own-modified versions of these algorithms adapted to the requirements of our system are proposed. The system is carefully calibrated and fine-tuned with known objects placed at known distances. An experimental proof-of-concept is shown with a human torso phantom, including an aorta phantom and an aneurysm phantom placed in different positions. The results show good imaging capabilities with the potential for detecting and locating possible abdominal aortic aneurysms and reporting acceptable errors.
Abstract
We investigate a sample of six Herbig Ae/Be stars belonging to the Orion OB1 association, as well as 73 low-mass objects, members of the
σ
Orionis cluster, in order to explore the angular ...momentum evolution at early stages of evolution, and its possible connection with main-sequence Ap/Bp magnetic stars. Using FIES and HECTOCHELLE spectra, we obtain projected rotational velocities through two independent methods. Individual masses, radii, and ages are computed using evolutionary models, distance, and cluster extinction. Under the assumption that similar physical processes operate in both T Tauri and Herbig Ae/Be stars, we construct snapshots of the protostar’s rotation against mass during the first 10 Myr with the aid of a rotational model that includes a variable disk lifetime, changes in the stellar moment of inertia, a dipolar magnetic field with variable strength, and angular momentum loss through stellar winds powered by accretion. We use these snapshots, as well as the rotational data, to infer a plausible scenario for the angular momentum evolution. We find that magnetic field strengths of a few kilo-Gauss at 3 Myr are required to match the rotational velocities of both groups of stars. Models with masses between 2
M
⊙
and 3
M
⊙
display larger angular momentum values by a factor of ∼3, in comparison to stars of similar spectral types on the main sequence. Even though some quantitative estimates on this dramatic decrease with age for Ap/Bp magnetic main-sequence stars are presented, the results obtained for the angular momentum evolution do not explain their low rotation rates.
This work introduces a microwave-based system able to detect tumours in breast phantoms in a non-invasive way. The data acquisition system is composed of a hardware system which involves ...high-frequency components (antennas, switches and cables), a microcontroller, a vector network analyser used as measurement instrument and a computer devoted to the control and automation of the operation of the system. Concerning the software system, the computer runs a Python script which is in charge of mastering and automatising all the required stages for the data acquisition, from initialisation of the hardware system to performing and saving the measurements. We also report on the design of the high-performance broadband antenna used to carry out the measurements, as well as on the algorithm employed to build the final medical images, based on an adapted version of the so-called Improved Delay-and-Sum (IDAS) algorithm improved by a Hamming window filter and averaging preprocessing. The calibration and start-up of the system are also described. The experimental validation includes the use of different tumour models with different dielectric properties inside the breast phantom. The results show promising tumour detection capabilities, even when there is low dielectric contrast between the tumoural and healthy tissues, as is the usual case for dense breasts in young women.
This work shows a proof of concept of a radar-based microwave imaging (MWI) system for the detection of the brain-shift effect with minimum delay. The system is based on the estimation of the ...variations of both the position and the geometry of the brain in order to detect if remarkable variations have occurred. To that end, the system makes use of 12 twin antennas as sensing elements, which transmit broadband signals toward the patient's head and receive the corresponding reflections. Printed monopole antennas with coplanar feed are considered, featuring a broad bandwidth and an omnidirectional radiation pattern. A signal processing strategy to estimate the detected distances to the target from the reflection seen by each antenna is also shown, as well as a calibration and fine-tuning procedure for accurate distance detection capabilities. To demonstrate the potential of the system, a cranium phantom and several brain phantoms, emulating different brain-shift cases, are fabricated and measured. The results show the effective detection of the brain-shift in all the cases under consideration, thereby demonstrating the potential of MWI systems for effective intraoperative brain-shift detection.
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