Effects of Gender on Basic Numerical and Arithmetic Skills: Pilot Data From Third to Ninth Grade for a Large-Scale Online Dyscalculia Screener

In this study, we analyzed the development and effects of gender on basic number skills from third to ninth grade in Finland. Because the international comparison studies have shown slightly different developmental trends in mathematical attainment for different language groups in Finland, we added the language of education as a variable in our analysis. Participants were 4,265 students from third to ninth grade in Finland, representing students in two national languages (Finnish, n = 2,833, and Swedish, n = 1,432). Confirmatory factor analyses showed that the subtasks in the dyscalculia screener formed two separate factors, namely, number-processing skills and arithmetic fluency. We found a linear development trend across age cohorts in both the factors. Reliability and validity evidence of the measures supported the use of these tasks in the whole age group from 9 to15 years. In this sample, there was an increasing gender difference in favor of girls and Swedish-speaking students by grade levels in number-processing skills. At the same time, boys showed a better performance and a larger variance in tasks measuring arithmetic fluency. The results indicate that the gender ratio within the group with mathematical learning disabilities depends directly on tasks used to measure their basic number skills.

Developing a Learning Module About Integers for 7th Grade Students through Writing-to-Learn

Previous research shows that seventh-grade students lack a sense of flexibility about numbers, lack comprehension of the effect of the operation on numbers, and lack estimation skills. On the other hand, writing to learn is one of the learning activities where the students actively write to express themselves in learning specific material/topic. This project aims to develop a learning module for students about the integers by utilizing the basic number sense framework: the six strands of number sense (Mcintosh et al., 1997) and combining it using writing to learn mathematics (Burns, 1995). The module developed using the steps proposed by Purwanto (2007) and then validated by the experts and tested to the subjects’ trial. The module was then validated by three experts who are lecturers at Sampoerna University. After validation, the module was then tested on four seventh-grade students, where the data gathered by both observation and group interview. As a result, all participants agree that the learning module is easier than what they taught at school and would recommend the module to their friends.

Second Wave Analysis and Confirmed Forecasts of the SARS-Cov-2 Epidemic Outbreak in São Paulo, Brazil

Objective: A SEIR compartmental model was previously selected to estimate future outcomes to the dynamics of the Covid-19 epidemic breakout in Brazil. Method: Compartments for individuals vaccinated and prevalent SARS-Cov-2 variants were not included. A time-dependent incidence weight on the reproductive basic number accounted for Non Pharmaceutical Interventions (NPI). A first series of published data from March 1st to May 8, 2020 was used to adjust all model parameters aiming to forecast one year of evolutionary outbreak. The cohort study was set as a city population-based analysis. Analysis: A population-based sample of 25,366 confirmed cases on exposed individuals was used during the first study period. The analysis was applied to predict the consequences of NPI enforcements followed by progressive releases, and indicates the appearance of a second wave starting last quarter of 2020. Findings: By March 1st 2021, the number of confirmed cases was predicted to reach 0.47Million (0.24-0.78), and fatalities would account for 21 thousand (12-33), 5 to 95% CRI. A second series of data published from May 9, 2020 to March 1st, 2021 confirms the forecasts previously reported for the evolution of infected people and fatalities. Novelty: By March 1st 2021, the number of confirmed cases reached 527,710 (12% above the predicted average of accumulated cases) and fatalities accounted for 18,769 (10% below the accumulated average of estimated fatalities). After March 1st, new peaks on reported numbers of daily new infected and new fatalities appeared as a combined result to the appearance of the prevalent SARS-CoV-2 P1 variant, and the increased number of vaccinated individuals. Doi: 10.28991/SciMedJ-2021-03-SI-10 Full Text: PDF

Chrysosplenium sangzhiense (Saxifragaceae), a new species from Hunan, China

Chrysosplenium sangzhiense Hong Liu, a new species from Hunan, China, is described and illustrated. The phylogenetic analysis revealed that the new species belongs to subgen. Chrysosplenium and is closely related to C. grayanum, C. nepalense and C. sinicum. The chromosome number of the new species is 2n = 46, indicating a novel basic number x = 23 in Chrysosplenium that is different from other species. This also suggests that C. sangzhiense is probably an allopolyploid derivative of a species with x = 11 and one with x = 12. Morphologically, C. sangzhiense can be easily distinguished from C. grayanum, C. nepalense, C. sinicum and C. cavaleriei, a species not included in our phylogenetic analysis by a suite of characters relating to the sterile shoots, basal leaves, cauline leaves, flowering stem, sepals, disc, capsule and seed. A global conservation assessment is performed, and classifies C. sangzhiense as Least Concern (LC).

SARS-CoV-2 viral dynamics in non-human primates

Non-human primates infected with SARS-CoV-2 exhibit mild clinical signs. Here we used a mathematical model to characterize in detail the viral dynamics in 31 cynomolgus macaques for which nasopharyngeal and tracheal viral load were frequently assessed. We identified that infected cells had a large burst size (>104 virus) and a within-host reproductive basic number of approximately 6 and 4 in nasopharyngeal and tracheal compartment, respectively. After peak viral load, infected cells were rapidly lost with a half-life of 9 hours, with no significant association between cytokine elevation and clearance, leading to a median time to viral clearance of 10 days, consistent with observations in mild human infections. Given these parameter estimates, we predict that a prophylactic treatment blocking 90% of viral production or viral infection could prevent viral growth. In conclusion, our results provide estimates of SARS-CoV-2 viral kinetic parameters in an experimental model of mild infection and they provide means to assess the efficacy of future antiviral treatments.

Aphasia and Math: Deficits with Basic Number Comprehension and in Numerical Activities of Daily Living

Objective: In the present study, we explored numerical problems in individuals with aphasia. We investigate whether numerical deficits, usually accompanying aphasia, can be observed on number comprehension tasks that do not necessarily require an oral response. Method: Individuals with aphasia were classified into anterior, posterior, and global subgroups according to the lesion type. To investigate numerical cognition, we used a relatively recent tool, the Numerical Activities of Daily Living (NADL). Results: The results showed that individuals with aphasia have problems with tasks of basic number comprehension as well as in most NADL. In the formal part of the NADL, anterior aphasic patients made comparatively more errors than the posterior aphasic patients. Global aphasic patients presented an invariably poor performance on almost all tasks. Conclusion: The results provide insight into how numerical deficits may impair an individual with aphasia in activities of daily living. This study is a preliminary attempt to start the validation process of the NADL for the Greek population.

Confirmed forecasts for the expansion of the COVID-19 epidemic in the S. Paulo city, Brazil

An epidemiological compartmental model reported on May, 2020 was previously selected to estimate future outcomes to the dynamics of the Covid-19 epidemic breakout in the city of S. Paulo, Brazil. A time-dependent incidence weight on the reproductive basic number accounted for the Non Pharmaceutical Interventions (NPIs). A first series of official published data from March 1st to May 31st, 2020 was used to adjust the model parameters aiming to forecast one year of the COVID-19 evolutionary outbreak. The cohort study was set as a city population-based analysis. The population-based sample, 25,366 during the study period, was the number of confirmed cases on exposed individuals. The analysis was applied to predict the consequences of releasing the NPIs, and indicated the appearance of a second wave starting last quarter of 2020. By January 31st 2021, the number of confirmed cases was predicted to reach 0.49 Million (0.28-0.77), and fatalities would account for 22 thousand (11-32), 5 to 95% CRI. A second series of official data published from June 1st 2020 to January 31st, 2021 confirms all forecasts previously reported for the evolution of infected people and fatalities associated to this epidemic outbreak in the city of S. Paulo. By January 31st 2021, the official number of confirmed cases reached 469,657 (4 % above predicted average of accumulated cases), and fatalities accounted for 17,333 (19% above accumulated average of fatalities).

Dynamics of the impact of COVID-19 on the economic activity of Peru

Background The COVID-19 virus impacts human health and the world economy, causing in Peru, more than 800 thousand infected and a strong recession expressed in a drop of -12% in its economic growth rate for 2020. In this context, the objective of the study is to analyze the dynamics of the short-term behavior of economic activity, as well as to explain the causal relationships in a Pandemic context based on the basic number of spread (Re) of COVID-19 per day. Methods An Autoregressive Distributed Lags (ARDL) model was used. Results A negative and statistically significant impact of the COVID-19 shock was found on the level of economic activity and a long-term Cointegration relationship with an error correction model (CEM), with the expected sign and statistically significant at 1%. Conclusion The Pandemic has behaved as a systemic shock of supply and aggregate demand at the macroeconomic level, which together have an impact on the recession or level of economic activity. The authors propose changing public health policy from an indiscriminate suppression strategy to a targeted, effective and intelligent mitigation strategy that minimizes the risk of human life costs and socioeconomic costs, in a context of uncertainty about the end of the Pandemic and complemented by economic, fiscal and monetary policies that mitigate the economic recession, considering the underlying structural characteristics of the Peruvian economy.