Cayley Transform of Position and Orientation Measurement with Monocular Vision

In monocular vision-based position and attitude measurement, the non-linear iteration method based on feature-point geometric constraints is usually used to obtain results with higher accuracy. However, due to its strict geometric constraints to the feature points of target object and the requirement for highly-accurate initial value by iteration process, this algorithm is relatively poor in reliability. In this paper, Cayley transform is applied to the monocular vision-based position and attitude measurement; through an equivalent transformation from the unit orthogonal rotation matrix to 3D vectors by using Cayley transform, the computational process can be linearized, such that the complicated iterations caused by non-linear feature-point geometric constraints are eliminated, and the number of required feature points is reduced. Test data show that Cayley transform is practical and effective in the monocular vision-based position and attitude measurement. DOI : http://dx.doi.org/10.11591/telkomnika.v12i3.4425

Efficient D2D Discovery Scheme for Channel Measurement of Interference Alignment

Device-to-device (D2D) communications have the potential to improve spectrum efficiency and link capacity by allowing nearby devices to communicate directly with each other on the licensed frequency bands. Hence, co-channel interference (CCI) among D2D users are major issues to be solved when they are utilizing the same frequency bands. Consequently, interference alignment (IA) as an effective interference management approach has been implemented to the D2D communications for the frequency sharing. However, the measurement of channel state information (CSI) between transmitter and receiver of a D2D pair and cross-channel state information (C-CSI) among D2D pairs are the major issues that need to be resolved for the implementation of IA from theory to practical. Therefore, in this paper, we propose an effective D2D discovery scheme to overcome this problem, which can measure the CSI and C-CSI based on the transmission of discovery messages. Simulation results show that, under perfect conditions, even though the proposed D2D discovery scheme increases the needed time slots to establish D2D communications compared with the conventional D2D discovery without considering IA by 6.2%, it increases the throughput up to 50% than the conventional D2D communications without considering IA, i.e., it improves the spectrum efficiency.

The digital divide and cognitive disparities among older adults: community-based cohort study in China

Background: The widespread adoption of information and communication technologies (ICTs) further deepens disparities in resource access, particularly among the aging population. However, the relationship between these factors and their resulting impact on cognitive abilities remains uncertain. Objective: This study aims to investigate the potential impact of the digital divide on individuals’ cognitive function and its association with the development and reversion of mild cognitive impairment (MCI). Methods: This cohort study used data from Beijing Aging Brain Rejuvenation (BABRI) study applying a multistage cluster sampling design between 2008 and 2020. The digital divide was quantified by the frequency of using ICTs. Analysis of covariance (ANCOVA), mixed linear models, and Cox proportional hazards models were used to model the association of digital divide and multidomain cognition. Results: Among the 10098 participants, nearly half (n=4941, 48.9%) faced the digital divide, which was associated with a worse performance in processing speed (F10096=10.67; P<.001; effect size r=0.42), rather than memory, executive function, and language. The model indicated that individuals’ physical and mental health, combined with their educational and occupational prestige, influenced the resources they attained, which ultimately caused the digital divide. Moreover, longitudinal data revealed that older adults who successfully crossed the digital divide during the tracking process and those who had already done so prior to tracking showed significantly slower rates of decline in processing speed (B=–1.98, P<.05; B=–2.62, P<.01) and general cognitive function (B=3.50, P<.001; B=3.13, P<.01). Additionally, overcoming the digital divide was also associated with a lower risk of developing MCI (hazard ratio [HR] 0.5, 95% CI 0.34-0.74; HR 0.43, 95% CI 0.29-0.62) and a greater probability of reversion from MCI to normal cognition (HR 6, 95% CI 3.77-9.56; HR 9.22, 95% CI 5.63-15.11). Conclusions: Overcoming the digital divide was significantly associated with improved cognitive function, a slower aging rate in cognitive performance, a reduced risk of developing MCI, and a higher likelihood of reverting from MCI to normal cognition

Research on Resource Allocation based on Clustering in Femtocell Networks

Aiming at the problem that existing femtocell base station searching the optimal clustering scheme based on the clustering resource allocation algorithm is complex. we propose that building an conflict graph and adjacency matrix before clustering to calculate the number of clusters needed for FBS group by using the adaptive clustering heuristic algorithm. We follow maximization the sum of the FBS distances in the cluster and group the femtocell base stations to narrow the search range to reduce the computational complexity. In order to achieve different business types service, based on the above clustering algorithm, this paper proposes a new method that using the weighted energy efficiency, which including the user interruption and the network spectral efficiency as a fitness function of the power control scheme to solve the problem. The simulation results show that the same rate requirement reduces the complexity, while the same complexity increases the user's average rate

Identification and characterization of two critical sequences in SV40PolyA that activate the green fluorescent protein reporter gene

Alu repeats or Line-1-ORF2 (ORF2) inhibit expression of the green fluorescent protein (GFP) gene when inserted downstream of this gene in the vector pEGFP-C1. In this work, we studied cis-acting elements that eliminated the repression of GFP gene expression induced by Alu and ORF2 and sequence characteristics of these elements. We found that sense and antisense PolyA of simian virus 40 (SV40PolyA, 240 bp) eliminated the repression of GFP gene expression when inserted between the GFP gene and the Alu (283 bp) repeats or ORF2 (3825 bp) in pAlu14 (14 tandem Alu repeats were inserted downstream of the GFP gene in the vector pEGFP-C1) or pORF2. Antisense SV40PolyA (PolyAas) induced stronger gene expression than its sense orientation (PolyA). Of four 60-bp segments of PolyAas (1F1R, 2F2R, 3F3R and 4F4R) inserted independently into pAlu14, only two (2F2R and 3F3R) eliminated the inhibition of GFP gene expression induced by Alu repeats. Deletion analysis revealed that a 17 nucleotide AT repeat (17ntAT; 5′-AAAAAAATGCTTTATTT-3′) in 2F2R and the fragment 3F38d9 (5′-ATAAACAAGTTAACAACA ACAATTGCATT-3′) in 3F3R were critical sequences for activating the GFP gene. Sequence and structural analyses showed that 17ntAT and 3F38d9 included imperfect palindromes and may form a variety of unstable stem-loops. We suggest that the presence of imperfect palindromes and unstable stem-loops in DNA enhancer elements plays an important role in GFP gene activation

CS nerve growth factor regulates sevoflurane anesthesiainduced nerve injury in nerve cells

Purpose: Sevoflurane is the most commonly used anesthetic agent for surgery. However, it is associated with deficiency in learning and memory abilities. The study was aimed at investigating the role of nerve growth factor (NGF) in sevoflurane anesthesia-induced nerve injury.Methods: RT-qPCR assay was applied to measure expressions of NGF, miR-98-5p and other factors related to apoptosis. CCK-8 assay was used for detecting cell viability while luciferase reporter assay was employed to measure binding condition between miR-98-5p and NGF. Expressions of proteins in PI3K/AKT/mTOR signaling pathway was measured with western blot.Results: Sevoflurane reduced cell viability of RGC-5 cells, promoted apoptosis and reduced the expression of NGF. In sevoflurane-induced RGC-5 cells, over-expression of NGF promoted cell viability with reduced apoptosis. Also, there was reduction in the protein expression of PI3K/AKT/mTOR signaling pathway by sevoflurane, while up-regulation of NGF promoted the expressions of these proteins. In the presence of PI3K inhibitor, reduction cell viability was reduced but apoptosis increased. Luciferase reporter assay detected MiR-98-5p as the target gene of NGF and its overexpression restored high cell viability in the over-expressed NGF. The rate of apoptosis and expressions of proteins was also restored with up-regulation of miR-98-5p.Conclusion: Sevoflurane caused damage to nerve cells, while over-expression of NGF reduced the injury through PI3K/AKT/mTOR signaling pathway and suppression of miR-98-5p. Keywords: Nerve growth factor, Sevoflurane, Nerve injury, Anesthesia, miR-98-5

Sunlight penetration dominates the thermal regime and energetics of a shallow ice-covered lake in arid climate

The Mongolian Plateau is characterized by cold and arid winters with very little precipitation (snowfall), strong solar insolation, and dry air, but little is known about the thermal regimes of the ice and ice-covered lakes and their response to the distinct weather and climate in this region. In a typical large, shallow lake, ice and snow processes (cover) and under-ice thermodynamics were monitored for four winters in 2015-2019. Heat transfer at the ice-water interface and lake heat budget were investigated. The results revealed that persistent bare ice of 35-50 cm thickness transmits 20 %-35 % of the incident solar radiation into the water below. This is a dominant source for under-ice energy flows and causes/maintains high water temperature (up to 6-8 degrees C) and high heat flux from water to ice (averages of 20-45 W m(-2)) in mid-winter, as well as higher heat conduction in the ice interior during freezing. The heat balance shows that the transmitted radiation and the heat flux from water to ice are the dominant and highly correlated heat flows in the lake. Both bulk water temperature and temperature structure are sensitive to solar transmittance and occasional snow events. Under-ice convective mixing does not necessarily occur because of stratification of salinity in the water body. In particular, salt exclusion during freezing changes both the bulk salinity and the salinity profile, which plays a major role in the stability and mixing of the water column in this shallow lake.Peer reviewe

The effect of overcoming the digital divide on middle frontal gyrus atrophy in aging adults: large-scale retrospective magnetic resonance imaging cohort study

Background The rapid integration of information technology into daily life has exacerbated the digital divide (DD), particularly among older adults, who often face barriers to technology adoption. Although prior research has linked technology use to cognitive benefits, the long-term neurostructural and cognitive consequences of the DD remain poorly understood. Objective The aim of this study is to use large-scale neuroimaging data to examine how the DD affects long-term brain structure and cognitive aging in older adults. It specifically investigates (1) structural and cognitive differences between older adults with and without DD engagement, (2) predictive relationships between group-distinctive brain regions and cognitive outcomes, and (3) longitudinal impacts of DD exposure on accelerated aging trajectories of neural substrates and cognitive functions. Methods The study included 1280 community-dwelling older adults (aged 65‐90 y) who completed comprehensive cognitive assessments and structural magnetic resonance imaging scans at baseline. Longitudinal data were available for 689 participants (mean follow-up 3.2 y). Participants were classified into the DD (n=640) and overcoming DD (n=640) groups using rigorous propensity score matching to control for age, education, gender, and baseline health conditions. A computational framework using the searchlight technique and cross-validation classification model investigated group differences in structural features and cognitive representation. The aging rate of each voxel’s structural feature was calculated to explore the long-term influence of the DD. Results The DD group showed significant deficits in executive function (t=4.75; P<.001; Cohen d=0.38) and processing speed (t=4.62; P<.001; Cohen d=0.37) compared to the overcoming DD group. Reduced gray matter volume in the DD group spanned the fusiform gyrus, hippocampus, parahippocampal gyrus, and superior temporal sulcus (false discovery rate–corrected P<.05). The computational framework identified the key structural substrates related to executive function and processing speed, excluding the ventro-orbitofrontal lobe (classification accuracy <0.6). Longitudinal findings highlighted the long-term impact of the DD. The DD group exhibited faster gray matter volume decline in the middle frontal gyrus (t=3.95 for the peak voxel in this cluster, false discovery rate–corrected P<.05), which mediated 17% of episodic memory decline (P=.02). Conclusions Older adults who overcome the DD demonstrate preserved gray matter structure and slower cognitive decline, particularly in frontotemporal regions critical for executive function. Our findings underscore that mobile digital interventions should be explored as potential cognitive decline prevention strategies

The structure and function of the global citrus rhizosphere microbiome

Citrus is a globally important, perennial fruit crop whose rhizosphere microbiome is thought to play an important role in promoting citrus growth and health. Here, we report a comprehensive analysis of the structural and functional composition of the citrus rhizosphere microbiome. We use both amplicon and deep shotgun metagenomic sequencing of bulk soil and rhizosphere samples collected across distinct biogeographical regions from six continents. Predominant taxa include Proteobacteria, Actinobacteria, Acidobacteria and Bacteroidetes. The core citrus rhizosphere microbiome comprises Pseudomonas, Agrobacterium, Cupriavidus, Bradyrhizobium, Rhizobium, Mesorhizobium, Burkholderia, Cellvibrio, Sphingomonas, Variovorax and Paraburkholderia, some of which are potential plant beneficial microbes. We also identify over-represented microbial functional traits mediating plant-microbe and microbe-microbe interactions, nutrition acquisition and plant growth promotion in citrus rhizosphere. The results provide valuable information to guide microbial isolation and culturing and, potentially, to harness the power of the microbiome to improve plant production and health