Low-Cost Beamforming Concept for the Control of Radiation Patterns of Antenna Arrays Installed onto UAVs.

This paper presents a low-cost architecture that allows for beamforming with antenna arrays installed onto unmanned aerial vehicles (UAVs). Beam switching is proposed to improve the antenna gain towards the ground station with two three-element arrays installed below the wings of the UAV. The electromagnetic modeling of the complete structure (UAV and integrated antennas) was performed with commercial electromagnetic simulator Ansys HFSS. The radiation patterns were synthesized with particle swarm optimization (PSO). By employing lumped surface-mount device (SMD) components and switches, the design of the feeder to deliver proper excitation coefficients to the antennas is presented, and its performance was assessed by simulations. The proposed approach is demonstrated to be very effective with low-cost production.

Characterization of Cerebellum-Specific Ribosomal DNA Epigenetic Modifications in Alzheimer's Disease: Should the Cerebellum Serve as a Control Tissue After All?

Alzheimer's disease (AD) is a neurodegenerative disease, known as the most common form of dementia. In AD onset, abnormal rRNA expression has been reported to be linked in pathogenesis. Although region-specific expression patterns have previously been reported in AD, it is not until recently that the cerebellum has come under the spotlight. Specifically, it is unclear whether DNA methylation is the mechanism involved in rRNA expression regulation in AD. Hence, we sought to explore the rDNA methylation pattern of two different brain regions - auditory cortex and cerebellum - from AD and age-/sex-matched controls. Our results showed differential hypermethylation at an upstream CpG region to the rDNA promoter when comparing cerebellum controls to auditory cortex controls. This suggests a possible regulatory region from rDNA expression regulation. Moreover, when comparing between AD and control cerebellum samples, we observed hypermethylation of the rDNA promoter region as well as an increase in rDNA content. In addition, we also observed increased rRNA levels in AD compared to control cerebellum. Although still considered a pathology-free brain region, there are growing findings that continue to suggest otherwise. Indeed, cerebellum from AD has been recently described as affected by the disease, presenting a unique pattern of molecular alterations. Given that we observed that increased rDNA promoter methylation did not silence rDNA gene expression, we suggest that rDNA promoter hypermethylation is playing a protective role in rDNA genomic stability and, therefore, increasing rRNA levels in AD cerebellum.

Role of histone acetylation in gastric cancer: implications of dietetic compounds and clinical perspectives.

Histone modifications regulate the structural status of chromatin and thereby influence the transcriptional status of genes. These processes are controlled by the recruitment of different enzymes to a specific genomic site. Furthermore, obtaining an understanding of these mechanisms could help delineate alternative treatment and preventive strategies for cancer. For example, in gastric cancer, cholecalciferol, curcumin, resveratrol, quercetin, garcinol and sodium butyrate are natural regulators of acetylation and deacetylation enzyme activity that exert chemopreventive and anticancer effects. Here, we review the recent findings on histone acetylation in gastric cancer and discuss the effects of nutrients and bioactive compounds on histone acetylation and their potential role in the prevention and treatment of this type of cancer.

Analysis of 8q24.21 miRNA cluster expression and copy number variation in gastric cancer.

Aim: To analyze gene expression and copy number of five miRNAs (miR-1204, miR-1205, miR-1206, miR-1207 and miR-1208) localized in this chromosome region in gastric cancer (GC). Materials & methods: 65 paired neoplastic and non-neoplastic specimens collected from GC patients and 20 non-neoplastic gastric tissues from cancer-free individuals were included in this study. The expression levels of the five miRNAs were accessed by real time qPCR and were correlated. Results: MiR-1207-3p, miR-1205, miR-1207-5p and miR-1208 were upregulated in approximately 50% of GC tumors in relation to those of adjacent non-neoplastic tissues. MiR-1205 expression was associated with gain of gene copies and was upregulated in adjacent non-neoplastic samples relative to external controls. Conclusion: The coexpression of the 8q24 miRNAs indicated the role of miR-1205 in the initiation of gastric cancer development.

Relationship of weight gain with infrared temperatures in Nelore and F1 (Nelore × Angus) heifers reared in two forage production systems1.

Intensive production systems require high-yield genetics as obtained in Bos taurus × Bos indicus crossbreeding. Generally, high-producing taurine cattle are more susceptible to parasites and heat stress. This study evaluated animal performance, heat-stress measurement (infrared temperatures), and internal parasite infection with daily weight gain in heifers from 2 genetic groups (Nelore and F1-Nelore × Angus) reared in 2 forage production systems (with or without crop-livestock system) during 1 yr. The main objectives were to determine the relationship between infrared measures and animal performance and whether it differs between genetic groups and environments. Thirty-six heifers were randomly assigned to 2 forage production systems, one considered as high-input system with crop-livestock system and other exclusive livestock system considered as low input. At each 28 d, infrared thermography (IR) temperatures, weight, and internal parasite infection (fecal egg count) were measured. The temperatures of the eye, snout, forehead, dewlap, body, ground and squeeze chute were determined. F1 heifers had higher weight gain than Nelore (P < 0.05) and both did not differ in internal parasite infection (P > 0.05). F1 heifers had higher IR than Nelore (P < 0.05). The main body points that differentiate between genetic groups were dewlap, forehead, and eye. Higher dewlap IR temperature (DW) was associated with higher average daily gain (ADG) during dry season (independently of genetic groups) (ADG = -0.755 + 0.032 × DW; R2 = 0.44). Otherwise, the IR temperatures had a negative relationship with ADG during rainy season and low forehead IR temperature was related to higher average daily gain (ADG = 1.81 - 0.033 × forehead; R2 = 0.12 for F1 animals and ADG = 1.46 - 0.025 × forehead; R2 = 0.07 for Nelore). The infrared temperatures were more related to animal performance during the dry season, which had high temperature and low humidity. The infrared temperatures were able to identify the animal response to the environment challenge. Animals with higher temperatures (dewlap and forehead) had higher daily gain during the dry season.