29 research outputs found
The Relationship between Power Bases and Influence Tactics of Program Planners
Asymmetrical power relationship between program planners and their superiors could cause substantial amount of constraints for program planners to execute tasks of planning in a democratic manner. Under such situation, program planners are required to negotiate with their superiors by using influence tactics to counterbalance the lop-sided power relationship with their superior. Program planners would also need to acquire power bases and use them as tools to influence their superiors. The main objective of the study was to determine power bases that predict the use of influence tactics by program planners. Along with this objective, the use of influence tactics by program planners, power bases of program planners, the use of influence tactics with respect to personal ctors of program planers and program planners’ perception of importance of power bases in the influence of superiors were also determined. The dependent variables were influence tactics namely pressuring, counteracting, bargaining, reasoning, consulting, appealing and networking tactics. The independent variables were power bases, which were made up of legitimate power, expert power, information control power, uncertainty and ambiguity-coping power, referent power, interpersonal-linkage power and communication-skill power. This is an ex post facto study where data were collected through survey questionnaires. The samples were made up of 367 program planners randomly chosen from 26 teacher training colleges. A total of 264 sets of questionnaires were collected and analyzed. Descriptive statistic was used to describe data pertaining to the use of influence tactics, power bases of program planners, and program planners’ perception of importance of power bases in the influence of superiors. One-way MANOVA was engaged to compare the use of influence tactics of program planners according to their personal characteristics. Multiple Linear Regression was used to determine power bases that predict the use of influence tactics by program planners. The findings of this study indicate that the three most frequently used influence tactics were consulting, reasoning and appealing tactics. Program planners were found to have high power bases with communication-skill power, interpersonal-linkage power and expert power as the three leading power bases. Expert power and legitimate power were perceived as the two most important power bases to influence superiors. The findings of the use of influence tactics with respect to personal factors indicate that there was significant difference in the use of influence tactics among program planners of different gender and age. However, there was no significant difference in the use of influence tactics among program planners of different race, service tenure, academic qualification and level of management in organization. The findings show that among the power bases, interpersonal-linkage power did no predict the use of any influence tactic. However, communication-skill power, referent power and information-control power were significant power bases that predicted the use of pressuring tactic by program planners. Legitimate power and information-control power were significant power bases that predicted the use of counteracting tactic by program planners. Communication-skill power and information-control power were significant power bases that predicted the use of bargaining tactic by program planners. Expert power was the only significant power base that predicted the use of reasoning tactic by program planners. Uncertainty and ambiguity-coping power was the only significant power bases that predicted the use of consulting tactic by program planners. Uncertainty and ambiguity-coping power and information-control power were significant power bases that predicted the use of appealing tactic by program planners.
Communication-skill power and referent power were significant power bases that predicted the use of networking tactic by program planners
Linear B-cell epitopes in the spike and nucleocapsid proteins as markers of SARS-CoV-2 exposure and disease severity
BACKGROUND
Given the unceasing worldwide surge in COVID-19 cases, there is an imperative need to develop highly specific and sensitive serology assays to define exposure to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).
METHODS
Pooled plasma samples from PCR positive COVID-19 patients were used to identify linear B-cell epitopes from a SARS-CoV-2 peptide library of spike (S), envelope (E), membrane (M), and nucleocapsid (N) structural proteins by peptide-based ELISA. Hit epitopes were further validated with 79 COVID-19 patients with different disease severity status, 13 seasonal human CoV, 20 recovered SARS patients and 22 healthy donors.
FINDINGS
Four immunodominant epitopes, S14P5, S20P2, S21P2 and N4P5, were identified on the S and N viral proteins. IgG responses to all identified epitopes displayed a strong detection profile, with N4P5 achieving the highest level of specificity (100%) and sensitivity (>96%) against SARS-CoV-2. Furthermore, the magnitude of IgG responses to S14P5, S21P2 and N4P5 were strongly associated with disease severity.
INTERPRETATION
IgG responses to the peptide epitopes can serve as useful indicators for the degree of immunopathology in COVID-19 patients, and function as higly specific and sensitive sero-immunosurveillance tools for recent or past SARS-CoV-2 infections. The flexibility of these epitopes to be used alone or in combination will allow for the development of improved point-of-care-tests (POCTs)
Robust Virus-Specific Adaptive Immunity in COVID-19 Patients with SARS-CoV-2 Delta 382 Variant Infection
Data-Driven Analysis of COVID-19 Reveals Persistent Immune Abnormalities in Convalescent Severe Individuals
Severe SARS-CoV-2 infection can trigger uncontrolled innate and adaptive immune responses, which are commonly associated with lymphopenia and increased neutrophil counts. However, whether the immune abnormalities observed in mild to severely infected patients persist into convalescence remains unclear. Herein, comparisons were drawn between the immune responses of COVID-19 infected and convalescent adults. Strikingly, survivors of severe COVID-19 had decreased proportions of NKT and Vδ2 T cells, and increased proportions of low-density neutrophils, IgA+/CD86+/CD123+ non-classical monocytes and hyperactivated HLADR+CD38+ CD8+ T cells, and elevated levels of pro-inflammatory cytokines such as hepatocyte growth factor and vascular endothelial growth factor A, long after virus clearance. Our study suggests potential immune correlates of “long COVID-19”, and defines key cells and cytokines that delineate true and quasi-convalescent states
RF testing of QPSK device
The concepts of RF testing of a QPSK device are introduced and followed by the presentation of the simulation results of a common RF tests involving a Quadrature Phase Shift Keying (QPSK) modulator and demodulator.Master of Science (Communications Engineering
Activation and failure mechanism of La0.6Sr0.4Co0.2Fe0.8O3-δ air electrode in solid oxide electrolyzer cells under high-current electrolysis
This work investigates the activation and delamination of La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) air electrode of solid oxide electrolyzer cells sintered on yttria-stabilized zirconia (YSZ) electrolyte. After polarization with an electrolysis current of 1 A cm−2 for 24 h at 800 °C, the LSCF electrode delaminates accompanied by an increase of ohmic and polarization resistance. Notably, polarization resistance decreases at the beginning. By scanning electron microscopy (SEM), a thin but dense layer is observed at the LSCF–YSZ interface of an as-prepared sample, which is identified as SrZrO3 phase by X-ray diffractometry. This layer causes the initial high polarization resistance due to retarded ionic and electronic conductivity. After the test, SEM reveals that the SrZrO3 layer delaminates from YSZ electrolyte. Moreover, energy dispersive X-ray tests confirm that Co diffuses to the SrZrO3 layer and SrZrO3–YSZ interface. Later, the LSCF electrode with Co-containing SrZrO3 layer is shown to perform better than that with pure SrZrO3 layer. Thus, Co diffusion can be the reason for the initial decrease of polarization resistance and renders the generation of oxygen at SrZrO3–YSZ interface during the electrolysis. Owing to its limited porosity, the SrZrO3 layer traps the generated oxygen. High pressure eventually builds up at the SrZrO3–YSZ interface driving the delamination of SrZrO3 layer, and hence the entire LSCF electrode.NRF (Natl Research Foundation, S’pore
Antimutagenic, Cytoprotective and Antioxidant Properties of Ficus deltoidea Aqueous Extract In Vitro
Ficus deltoidea var. deltoidea is used as traditional medicine for diabetes, inflammation, and nociception. However, the antimutagenic potential and cytoprotective effects of this plant remain unknown. In this study, the mutagenic and antimutagenic activities of F. deltoidea aqueous extract (FDD) on both Salmonella typhimurium TA 98 and TA 100 strains were assessed using Salmonella mutagenicity assay (Ames test). Then, the cytoprotective potential of FDD on menadione-induced oxidative stress was determined in a V79 mouse lung fibroblast cell line. The ferric-reducing antioxidant power (FRAP) assay was conducted to evaluate FDD antioxidant capacity. Results showed that FDD (up to 50 mg/mL) did not exhibit a mutagenic effect on either TA 98 or TA 100 strains. Notably, FDD decreased the revertant colony count induced by 2-aminoanthracene in both strains in the presence of metabolic activation (p < 0.05). Additionally, pretreatment of FDD (50 and 100 µg/mL) demonstrated remarkable protection against menadione-induced oxidative stress in V79 cells significantly by decreasing superoxide anion level (p < 0.05). FDD at all concentrations tested (12.5–100 µg/mL) exhibited antioxidant power, suggesting the cytoprotective effect of FDD could be partly attributed to its antioxidant properties. This report highlights that F. deltoidea may provide a chemopreventive effect on mutagenic and oxidative stress inducers
Genoprotective potential of Macaranga species phytochemical compounds on HT-29 human colorectal adenocarcinoma cell line
Abstract Background The species of genus Macaranga are widely found in Malaysian secondary forests and has been used as an alternative for treating varieties of illness. Studies have shown that the medicinal properties of this genus contain anti-inflammatory, antioxidant, and anti-cancer effects. This study aimed to determine the cytotoxicity of six isolated phytochemicals from Macaranga heynei (M. heynei), Macaranga lowii and Shorea leprosula on HT-29 human colorectal adenocarcinoma cell lines. Results One out of six isolated phytochemical compounds, identified as “Laevifolin A”, showed a cytotoxicity with an IC50 value of 21.2 µM following 48 h treatment as detected using Sulforhodamine B (SRB) assay. Additionally, no induction of apoptosis and oxidative stress were observed on Laevifolin A treated HT-29 cells as determined using Annexin V-FITC/PI assay and dihydroethidine (HE) staining, respectively. Additionally, no damage to the DNA were observed as measured using the Alkaline Comet assay. Further investigation on menadione-induced oxidative DNA damage showed the genoprotective potential of Laevifolin A on HT-29 cells. Conclusions In conclusion, this study indicated that only one compound (Laevifolin A) that extracted from M. heynei has the cytotoxicity potential to be developed as an anticancer agent in human colorectal adenocarcinoma. However, besides exhibiting cytotoxic effect, the compound also exhibits genoprotective capability that warrant further investigation
Vitamin D deficiency during pregnancy and its associated factors among third trimester Malaysian pregnant women
Background: Despite perennial sunshine, vitamin D deficiency is prevalent among Malaysians especially pregnant women. This study determines the vitamin D status and its associated factors among third trimester pregnant women attending government health clinics in Selangor and Kuala Lumpur, Malaysia. Methods: Information on socio-demographic characteristics, obstetrical history, and sun exposure were obtained through face-to-face interviews. Vitamin D intake was assessed using a semi-quantitative food frequency questionnaire (FFQ). Serum 25-hydroxyvitamin D concentration was measured and classified as deficient (< 30 nmol/L), insufficient (30-50 nmol/L), and sufficient (≥ 50 nmol/L). Results: Of the 535 pregnant women recruited, 42.6% were vitamin D deficient. They consumed an average of 8.7 ± 6.7 μg of vitamin D daily. A total of 80.4% of the vitamin D were obtained from the food sources, while 19.6% were from dietary supplements. Fish and fish products showed the highest contribution to vitamin D intake (35.8%). The multivariable generalized linear mixed models, with clinic as a random effect, indicates that higher intake of vitamin D is associated with lower odds of vitamin D deficiency among pregnant women (OR = 0.96; 95% CI = 0.93-0.99). The odds of having vitamin D deficiency was reduced by 87% in non-Malays (OR = 0.14; 95% CI = 0.05-0.41) compared to Malays. No associations were found between age, educational level, monthly household income, work status, gravidity, parity, pre-pregnancy body mass index, total hours of sun exposure, total percentage of body surface area, and sun exposure index per day with vitamin D deficiency. Conclusion: Vitamin D deficiency is prevalent among Malaysian pregnant women. Considering the possible adverse obstetric and fetal outcomes of vitamin D deficiency during pregnancy, future nutrition education should emphasise on vitamin D-fortified foods consumption among pregnant women by taking into consideration ethnic differences
Risk Factors for Mortality in Cardiac Implantable Electronic Device (CIED) Infections: A Systematic Review and Meta-Analysis
10.3390/jcm11113063JOURNAL OF CLINICAL MEDICINE1111complete