The backward crosstalk effect or response grouping in the psychological refractory period paradigm

Background: In the psychological refractory period paradigm, the second response time is increased as the interval between the first and second stimulus is decreased. The response delay for the second stimulus is called the psychological refractory period. In contrast with these findings, some evidence of the backward crosstalk effect has shown that the first reaction time is affected by the second stimulus. The capacity sharing models, in which multiple stimuli can be processed simultaneously, unlike central bottleneck models, are able to provide some explanations for the changes in the reaction time to the first stimulus. However, sometimes these changes could be arisen from response grouping; the first response remains on the processing buffer until the response to the second stimulus is prepared, then both stimuli are responded simultaneously. The questions of this study were whether the second task difficulty and time interval manipulation would affect the first task response or not and in what extend changes are because of response grouping? Materials and Methods: Detection, discrimination and choice tasks were used as the second task in the psychological refractory period paradigm and the time interval between stimuli was 50, 100, 200, 400, or 1000 ms. Results: The type of the second stimulus and time interval between stimuli had an effect on the second-task and first-task reaction times. Conclusion: In the detection group, the first task response time changes were consistent with grouping between the two responses, but in the discrimination group the changes would arise from capacity limitation and were consistent with the backward crosstalk effect

Dynamics of Anti-S IgG Antibodies Titers after the Second Dose of COVID-19 Vaccines in the Manual and Craft Worker Population of Qatar

There is limited seroepidemiological evidence on the magnitude and long-term durability of antibody titers of mRNA and non-mRNA vaccines in the Qatari population. This study was conducted to generate evidence on long-term anti-S IgG antibody titers and their dynamics in individuals who have completed a primary COVID-19 vaccination schedule. A total of 300 male participants who received any of the following vaccines BNT162b2/Comirnaty, mRNA-1273, ChAdOx1-S/Covishield, COVID-19 Vaccine Janssen/Johnson, or BBIBP-CorV or Covaxin were enrolled in our study. All sera samples were tested by chemiluminescent microparticle immunoassay (CMIA) for the quantitative determination of IgG antibodies to SARS-CoV-2, receptor-binding domain (RBD) of the S1 subunit of the spike protein of SARS-CoV-2. Antibodies against SARS-CoV-2 nucleocapsid (SARS-CoV-2 N-protein IgG) were also determined. Kaplan–Meier survival curves were used to compare the time from the last dose of the primary vaccination schedule to the time by which anti-S IgG antibody titers fell into the lowest quartile (range of values collected) for the mRNA and non-mRNA vaccines. Participants vaccinated with mRNA vaccines had higher median anti-S IgG antibody titers. Participants vaccinated with the mRNA-1273 vaccine had the highest median anti-S-antibody level of 13,720.9 AU/mL (IQR 6426.5 to 30,185.6 AU/mL) followed by BNT162b2 (median, 7570.9 AU/mL; IQR, 3757.9 to 16,577.4 AU/mL); while the median anti-S antibody titer for non-mRNA vaccinated participants was 3759.7 AU/mL (IQR, 2059.7–5693.5 AU/mL). The median time to reach the lowest quartile was 3.53 months (IQR, 2.2–4.5 months) and 7.63 months (IQR, 6.3–8.4 months) for the non-mRNA vaccine recipients and Pfizer vaccine recipients, respectively. However, more than 50% of the Moderna vaccine recipients did not reach the lowest quartile by the end of the follow-up period. This evidence on anti-S IgG antibody titers should be considered for informing decisions on the durability of the neutralizing activity and thus protection against infection after the full course of primary vaccination in individuals receiving different type (mRNA verus non-mRNA) vaccines and those with natural infection.The World Health Organization (WHO) - grant number [2021/1183356-0]

Integrating Remote Sensing with SCS and ICONA Models for Mapping Land Degradation in Fars Province

The objective of the present study was to investigate the performance of some of the extracted information for mapping land degradation using remote sensing and field data in Fras province. Maps of vegetation cover, net primary production, land use, surface slope, water erosion, and surface runoff indicators were extracted from MOD13A3, MOD17A3, Landsat TM, SRTM, ICONA model, and SCS model, respectively. The rain use efficiency index was obtained from the net primary production and rainfall map, which was calculated from meteorological stations. The final land degradation map was prepared by integrating all the mentioned indicators using the weighted overlay method. According to the ICONA model, 5.1, 9, 47.21, 27.91, and 10.73 percent of the study area were classified as very low, low, moderate, severe, and very severe water erosion; respectively. Overlaying the ICONA map with other indicators showed that very high and high classes, moderate, and low and very low classes of land degradation covered 1.3, 18.7, 70, 0.9, and 9.1 percent of the study area, respectively. According to the results, integrating remote sensing with ICONA and SCS models increases the ability to identify land degradation

Psychometrics of the recreation experience preference scale in Iranian elderly

Background: The researches have shown that the motivation to health is an important dimension in leisure satisfaction. The aim of this study was to measure the validity and reliability of the recreation experience preference scale (REP scale) in Iranian elderly. Materials and Methods: A total of 552 elderly participants (347 males, 205 females) aged 60 years or older were randomly selected by the multistage sampling method from 9 provinces of Iran in 2013. Demographic characteristic questionnaire and recreation experience preference scale were used to collect data. Data were analyzed using an exploratory factor analysis with Varimax rotation, confirmatory factor analysis for construct validity, Pearson correlation for internal consistence construct validity, Cronbach's coefficient alpha for reliability and multivariate analysis of variance for construct validity. Results: Results showed that the REP scale had an acceptable factor structure. The matrix table of rotated elements showed five components were capable of factoring and 17 items predicted 71.06 of variance. Confirmatory factor analysis showed that the first- and second-order model at the scale of the study was approved appropriately. Also, the internal consistency of the scale in total and its subscales was acceptable (Cronbach's alpha ranged from 0.70 to 0.92). Moreover, a positive and significant correlation between items and factors, also between factors and total scale showed that these questions assessed the same subject. Conclusion: This study represents acceptable reliability and validity of the REP scale in Iranian elderly. Therefore, it can be used for measuring the REP and motivation in Iranian elderly