Joint Modeling of Multivariate Longitudinal Depressive Symptoms and Survival with Application to an Aging Study

Objective The primary aim in this study was to use a joint analysis approach to examine the association between longitudinal depressive symptoms and survival in Mexican Americans. Methods:  The separate Cox regression and joint modeling were applied to data from the Hispanic Established Population for Epidemiological Study of the Elderly (HEPESE). Depressive symptoms were measured by the Center of Epidemiological Studies Depression Scale (CES-D). The trajectories of CES-D, modeled by random effect, were used as independent variables to fit the mortality curve adjusted by other variables including demographics and physical functioning. Results: The separate Cox regression couldn’t identify association between depressive symptoms and survival. The joint analysis indicated that the  slope of  CES-D score was not associated with mortality in older Mexican-Americans, however the intercept had negative effects on mortality. Conclusion: There was significant association between baseline depression symptoms and mortality, while no association with slope in older Mexican American

Exon Primed, Intron Crossing (EPIC) markers for evolutionary studies of Ficus and other taxa in the fig family (Moraceae)

• Premise of the study: The genus Ficus (fi g trees) comprises ca. 750 species of trees, vines, and stranglers found in tropical forests throughout the world. Fig trees are keystone species in many tropical forests, and their relationship with host-specific wasp pollinators has received much attention, although many questions remain unresolved regarding the levels of host specificity,cospeciation, and the role of hybridization in fig and wasp speciation. We developed exon-primed intron-crossing (EPIC)markers to obtain phylogenetic resolution needed to address these questions. • Methods and Results: Expressed sequence tags (ESTs) from F. elastica were compared to Arabidopsis and Populus genomes to locate introns and to design primers in flanking exons. Primer pairs for 80 EPIC markers were tested in samples from divergent clades within Ficus and the outgroup Poulsenia (Moraceae). • Conclusions: Thirty-one EPIC markers were successfully sequenced across Ficus , and 29 of the markers also amplified in Poulsenia , indicating broad transferability within Moraceae. All of the EPIC markers were polymorphic and showed levels of polymorphism similar to that of the widely used internal transcribed spacer (ITS).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100185/1/Yao2013.pd

Does Exam-targeted Training Help Village Doctors Pass the Certified (Assistant) Physician Exam and Improve Their Practical Skills? A Cross-sectional Analysis of Village Doctors\u27 Perspectives in Changzhou in Eastern China

Background Quality of health care needs to be improved in rural China. The Chinese government, based on the 1999 Law on Physicians, started implementing the Rural Doctor Practice Regulation in 2004 to increase the percentage of certified physicians among village doctors. Special exam-targeted training for rural doctors therefore was launched as a national initiative. This study examined these rural doctors’ perceptions of whether that training helps them pass the exam and whether it improves their skills. Methods Three counties were selected from the 4 counties in Changzhou City in eastern China, and 844 village doctors were surveyed by a questionnaire in July 2012. Chi-square test and Fisher exact test were used to identify differences of attitudes about the exam and training between the rural doctors and certified (assistant) doctors. Longitudinal annual statistics (1980–2014) of village doctors were further analyzed. Results Eight hundred and forty-four village doctors were asked to participate, and 837 (99.17%) responded. Only 14.93% of the respondents had received physician (assistant) certification. Only 49.45% of the village doctors thought that the areas tested by the certification exam were closely related to the healthcare needs of rural populations. The majority (86.19%) felt that the training program was “very helpful” or “helpful” for preparing for the exam. More than half the village doctors (61.46%) attended the “weekly school”. The village doctors considered the most effective method of learning was “continuous training (40.36%)” . The majority of the rural doctors (89.91%) said they would be willing to participate in the training and 96.87% stated that they could afford to pay up to 2000 yuan for it. Conclusions The majority of village doctors in Changzhou City perceived that neither the certification exam nor the training for it are closely related to the actual healthcare needs of rural residents. Policies and programs should focus on providing exam-preparation training for selected rural doctors, reducing training expenditures, and utilizing web-based methods. The training focused on rural practice should be provided to all village doctors, even certified physicians. The government should also adjust the local licensing requirements to attract and recruit new village doctors

Delay-Doppler Reversal for OTFS System in Doubly-selective Fading Channels

The recent proposed orthogonal time frequency space (OTFS) modulation shows signifcant advantages than conventional orthogonal frequency division multiplexing (OFDM) for high mobility wireless communications. However, a challenging problem is the development of effcient receivers for practical OTFS systems with low complexity. In this paper, we propose a novel delay-Doppler reversal (DDR) technology for OTFS system with desired performance and low complexity. We present the DDR technology from a perspective of two-dimensional cascaded channel model, analyze its computational complexity and also analyze its performance gain compared to the direct processing (DP) receiver without DDR. Simulation results demonstrate that our proposed DDR receiver outperforms traditional receivers in doubly-selective fading channels

Single-crystal silver nanowires: Preparation and Surface-enhanced Raman Scattering (SERS) property

Ordered Ag nanowire arrays with high aspect ratio and high density self-supporting Ag nanowire patterns were successfully prepared using potentiostatic electrodeposition within the confined nanochannels of a commercial porous anodic aluminium oxide (AAO) template. X-ray diffraction and selected area electron diffraction analysis show that the as-synthesized samples have preferred (220) orientation. Transmission electron microscopy and scanning electron microscopy investigation reveal that large-area and ordered Ag nanowire arrays with smooth surface and uniform diameter were synthesized. Surface-enhanced Raman Scattering (SERS) spectra show that the Ag nanowire arrays as substrates have high SERS activity.Comment: 5 pages, 4 figure

Analytical solution of the nitracline with the evolution of subsurface chlorophyll maximum in stratified water columns

In a stratified water column, the nitracline is a layer where the nitrate concentration increases below the nutrient-depleted upper layer, exhibiting a strong vertical gradient in the euphotic zone. The subsurface chlorophyll maximum layer (SCML) forms near the bottom of the euphotic zone, acting as a trap to diminish the upward nutrient supply. Depth and steepness of the nitracline are important measurable parameters related to the vertical transport of nitrate into the euphotic zone. The correlation between the SCML and the nitracline has been widely reported in the literature, but the analytic solution for the relationship between them is not well established. By incorporating a piecewise function for the approximate Gaussian vertical profile of chlorophyll, we derive analytical solutions of a specified nutrient-phytoplankton model. The model is well suited to explain basic dependencies between a nitracline and an SCML. The analytical solution shows that the nitracline depth is deeper than the depth of the SCML, shoaling with an increase in the light attenuation coefficient and with a decrease in surface light intensity. The inverse proportional relationship between the light level at the nitracline depth and the maximum rate of new primary production is derived. Analytic solutions also show that a thinner SCML corresponds to a steeper nitracline. The nitracline steepness is positively related to the light attenuation coefficient but independent of surface light intensity. The derived equations of the nitracline in relation to the SCML provide further insight into the important role of the nitracline in marine pelagic ecosystems

Sources and formation of nucleation mode particles in remote tropical marine atmospheres over the South China Sea and the Northwest Paci fic Ocean

Peer reviewe