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BackgroundCognitive training can improve cognition in healthy older adults. ObjectiveThe objectives are to evaluate the implementation of community-based computerized cognitive training (CCT) and its effectiveness on cognition, gait, and balance in healthy older adults. MethodsA single-blind randomized controlled trial with baseline and follow-up assessments was conducted at two community centers in Singapore. Healthy community-dwelling adults aged 55 years and older participated in a 10-week CCT program with 2-hour instructor-led group classes twice a week. Participants used a mobile app to play games targeting attention, memory, decision making, visuospatial abilities, and cognitive flexibility. Implementation was assessed at the participant, provider, and community level (eg, reach, implementation, and facilitators and barriers). Effectiveness measures were the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Color Trails Test 2 (CTT-2), Berg Balance Scale, and GAITRite walkway measures (single and dual task gait speed, dual task cost, and single and dual task gait variability index [GVI]). ResultsA total of 94 healthy community-dwelling adults participated in the CCT program (mean age 68.8 [SD 6.3] years). Implementation measures revealed high reach (125/155, 80.6%) and moderate adherence but poor penetration of sedentary older adults (43/125, 34.4%). The effectiveness data were based on intention-to-treat (ITT) and per-protocol (PP) analysis. In the ITT analysis, single task GVI increased (b=2.32, P=.02, 95% CI [0.30 to 4.35]) and RBANS list recognition subtest deteriorated (b=–0.57, P=.01, 95% CI [–1.00 to –0.14]) in both groups. In the PP analysis, time taken to complete CTT-2 (b=–13.5, P=.01, 95% CI [–23.95 to –3.14]; Cohen d effect size = 0.285) was faster in the intervention group. Single task gait speed was not statistically significantly maintained in the intervention group (b=5.38, P=.06, 95% CI [–0.30 to 11.36]) and declined in the control group (Cohen d effect size = 0.414). PP analyses also showed interaction terms for RBANS list recall subtest (b=–0.36, P=.08, 95% CI [–0.75 to 0.04]) and visuospatial domain (b=0.46, P=.08, 95% CI [–0.05 to 0.96]) that were not statistically significant. ConclusionsCCT can be implemented in community settings to improve attention and executive function among healthy older adults. Findings help to identify suitable healthy aging programs that can be implemented on a larger scale within communities. Trial RegistrationClinicalTrials.gov NCT04439591; https://clinicaltrials.gov/ct2/show/NCT04439591

Examines students' motivations for participating in literacy tasks. Finds that grade five students responded positively when the context was perceived as autonomy supportive, and grade three students reported more intrinsic motivations when they perceived the context to be socially supportive than nonsocial contexts. (CR)

Elementary school teachers (n=68) rated 374 students on aspects of motivation for reading. Qualitative and quantitative results show that teachers perceive higher achievers to be relatively higher in intrinsic reading motivation (individual and topical) than in extrinsic reading motivation (activity-based and autonomy-supported), with lower achievers relatively more motivated by extrinsic factors. (SLD)

A membrane-based electrochemical nanobiosensor sensitive toward whole viral particles is fabricated by forming a submicrometer thick nanoporous alumina membrane over a platinum disk electrode. Antibody probe molecules are physically adsorbed onto the walls of the membrane nanochannels. The sensing signal is based on the monitoring of the electrode's Faradaic current response toward ferrocenemethanol, which is extremely sensitive to the formation of immunocomplex within the nanoporous membrane. This nanobiosensor is demonstrated for the sensing of West Nile virus protein domain III (WNV-DIII) and the inactivated West Nile viral particle, using anti-WNV-DIII immunoglobulin M (IgM) as the biorecognition probe. The detection of the viral protein and the particle are logarithmically linear up to 53 pg [mL.sup.-1] ([R.sup.2] = 0.99) and 50 viral particles per 100 mL ([R.sup.2] = 0.93) in pH 7, with extremely low detection limits of 4 pg [mL.sup.-1] and ca. 2 viral particles per 100 mL, comparable to sensitivities of polymerase chain reaction techniques. The relative standard deviation (RSD) of whole viral particle detection in whole blood serum is 6.9%. In addition, the simple nanobiosensor construction procedure, minimal sample preparation, and short detection time of 30 min are highly attractive properties and demonstrate that the detection of a wide range of proteins and viruses can be achieved.

Teacher perceptions of students' intrinsic motivation for reading were examined from the perspective of self-determination development and reading achievement. A sample of 68 teachers from randomly selected elementary schools that were representative of county characteristics rated 374 students on 6 aspects of motivation for reading, including individual, topical, activity-based, autonomy-supported, socially supported, and writing-related aspects. Quantitative and qualitative results showed that teachers perceived higher achievers to be relatively higher in intrinsic reading motivation (individual and topical) than in extrinsic reading motivation (activity-based and autonomy-supported). In contrast, teachers perceived lower achievers to be relatively more motivated by extrinsic contextual factors than by intrinsic factors. Teachers appear to possess implicit theories that are in accord with the self-determination perspective on the development of motivation and reading achievement.

Abstract Background Dengue virus (DENV) is the causative agent of Dengue fever and the life-threatening Dengue Haemorrhagic fever or Dengue shock syndrome. In the absence of anti-viral agents or vaccine, there is an urgent need to develop an effective anti-viral strategy against this medically important viral pathogen. The initial interplay between DENV and the host cells may represent one of the potential anti-viral targeting sites. Currently the involvements of human membrane trafficking host genes or factors that mediate the infectious cellular entry of dengue virus are not well defined. Results In this study, we have used a targeted small interfering RNA (siRNA) library to identify and profile key cellular genes involved in processes of endocytosis, cytoskeletal dynamics and endosome trafficking that are important and essential for DENV infection. The infectious entry of DENV into Huh7 cells was shown to be potently inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis. The important role of clathrin-mediated endocytosis was confirmed by the expression of well-characterized dominant-negative mutants of genes in this pathway and by using the clathrin endocytosis inhibitor chlorpromazine. Furthermore, DENV infection was shown to be sensitive to the disruption of human genes in regulating the early to late endosomal trafficking as well as the endosomal acidic pH. The importance and involvement of both actin and microtubule dynamics in mediating the infectious entry of DENV was also revealed in this study. Conclusions Together, the findings from this study have provided a detail profiling of the human membrane trafficking cellular genes and the mechanistic insight into the interplay of these host genes with DENV to initiate an infection, hence broadening our understanding on the entry pathway of this medically important viral pathogen. These data may also provide a new potential avenue for development of anti-viral strategies and treatment of DENV infection.

Abstract Chikungunya virus (CHIKV) is a mosquito-borne alphavirus and one of the prevalent re-emerging arbovirus in tropical and subtropical regions of Asia, Africa, and Central and South America. It produces a spectrum of illness ranging from inapparent infection to moderate febrile illness as well as severe arthralgia or arthritis affecting multiple joints. In this study, a quantitative, one-step real-time SYBR Green-based RT-PCR system for the non-structural protein 2 (nsP2) of CHIKV that can quantify a wide range of viral RNA concentrations was developed. Comparisons between the conventional semi-quantitative RT-PCR assay, immunofluorescence detection method and the one-step SYBR Green-based RT-PCR assay in the detection of CHIKV infection revealed much rapid and increase sensitivity of the latter method. Furthermore, this newly developed assay was validated by in vitro experiments in which ribavirin, a well-known RNA virus inhibitor, showed a dose-dependent inhibition of virus replication on cells that was assessed by viral infectivity and viral RNA production. Our results demonstrate the potential of this newly developed one-step SYBR Green I-based RT-PCR assay may be a useful tool in rapid detection of CHIKV and monitoring the extent of viral replication possibly in patients' samples.

Abstract In this study, we provide a comprehensive molecular profiling of the involvement of T- helper (Th) genes during dengue virus infection of different cell types. The Th gene profiles of three human cell types (monocytes, T-cells and hepatocytes) were analyzed simultaneously via array-based RT-PCR upon infection with dengue virus. Differential regulation of 41 Th genes was identified and of which 20 of those genes may contribute to immuno-pathogenesis of dengue virus infection by regulating inflammation, thrombocytopenia and vascular permeability. Among the strongly up-regulated genes were the RANTES, CC-CKR3, IRF4, CLEC2C, IL-6 and TLR6, which are potent inducer of inflammation and vascular permeability. Profiling genes obtained from this study may serve as potential biomarkers and the modulation of Th immune responses during dengue virus infection has important implications in disease outcome.

Leukotriene B4 (LTB4) has been implicated in ischemic stroke pathology. We examined the prognostic significance of LTB4 levels in patients with acute middle cerebral artery (MCA) infarction and their mechanisms in rat stroke models. In ischemic stroke patients with middle cerebral artery infarction, plasma LTB4 levels were found to increase rapidly, roughly doubling within 24 h when compared to initial post-stroke levels. Further analyses indicate that poor functional recovery is associated with early and more sustained increase in LTB4 rather than the peak levels. Results from studies using a rat embolic stroke model showed increased 5-lipoxygenase (5-LOX) expression in the ipsilateral infarcted cortex compared with sham control or respective contralateral regions at 24 h post-stroke with a concomitant increase in LTB4 levels. In addition, neutrophil influx was also observed in the infarcted cortex. Double immunostaining indicated that neutrophils express 5-LOX and leukotriene A4 hydrolase (LTA4H), highlighting the pivotal contributions of neutrophils as a source of LTB4. Importantly, rise in plasma LTB4 levels corresponded with an increase in LTB4 amount in the infarcted cortex, thereby supporting the use of plasma as a surrogate for brain LTB4 levels. Pre-stroke LTB4 loading increased brain infarct volume in tMCAO rats. Conversely, administration of the 5-LOX-activating protein (FLAP) inhibitor BAY-X1005 or B-leukotriene receptor (BLTR) antagonist LY255283 decreased the infarct volume by a similar extent. To conclude, targeted interruption of the LTB4 pathway might be a viable treatment strategy for acute ischemic stroke. [ABSTRACT FROM AUTHOR]