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In this paper, we introduce and study the Tricomi continuants, a family of tridiagonal determinants forming a Sheffer sequence closely related to the Tricomi polynomials and the Laguerre polynomials. Specifically, we obtain the main umbral operators associated with these continuants and establish some of their basic relations. Then, we obtain a Turan-like inequality, some congruences, some binomial identities (including a Carlitz-like identity), and some relations with the Cayley continuants. Furthermore, we show that the infinite Hankel matrix generated by the Tricomi continuants has an LDU-Sheffer factorization, while the infinite Hankel matrix generated by the shifted Tricomi continuants has an LTU-Sheffer factorization. Finally, by the first factorization, we obtain the linearization formula for the Tricomi continuants and its inverse.

Abstract Background The COVID-19 pandemic and the lockdown period lasted from March to May 2020, resulted in a highly stressful situation yielding different negative health consequences, including the worsening of smoking habit. Methods A web-based cross-sectional study on a convenient sample of 1013 Italian ever smokers aged 18 years or more was conducted. Data were derived from surveys compiled by three different groups of people: subjects belonging to Smoking Cessation Services, Healthcare Providers and Nursing Sciences’ students. All institutions were from Northern Italy. The primary outcome self-reported worsening (relapse or increase) or improvement (quit or reduce) of smoking habit during lockdown period. Multiple unconditional (for worsening) and multinomial (for improving) logistic regressions were carried out. Results Among 962 participants, 56.0% were ex-smokers. Overall, 13.2% of ex-smokers before lockdown reported relapsing and 32.7% of current smokers increasing cigarette intake. Among current smokers before lockdown, 10.1% quit smoking and 13.5% decreased cigarette intake. Out of 7 selected stressors related to COVID-19, four were significantly related to relapse (OR for the highest vs. the lowest tertile ranging between 2.24 and 3.62): fear of being infected and getting sick; fear of dying due to the virus; anxiety in listening to news of the epidemic; sense of powerlessness in protecting oneself from contagion. In addition to these stressors, even the other 3 stressors were related with increasing cigarette intensity (OR ranging between 1.90 and 4.18): sense of powerlessness in protecting loved ones from contagion; fear of losing loved ones due to virus; fear of infecting other. Conclusion The lockdown during the COVID-19 pandemic was associated with both self-reported relapse or increase smoking habit and also quitting or reduction of it.

ABSTRACT: Family farmers preserve the tradition of cultivating maize landrace varieties because these plants have characteristics that hybrids lack. The greatest challenge in conserving in situ on-farm genetic diversity is avoiding gene flow and genetic introgression of transgenes to landrace varieties. Thus, farmers are obliged to change sowing times to guarantee temporal isolation since most farms are small, making spatial isolation impossible. The objective of the present work was to evaluate the behavior of maize landrace varieties submitted to different sowing times and densities in an agroecological system. The test was conducted in sub-sub-divided plots, where the main plot was represented by the sowing time, the sub-plot by the genotype, and the sub-sub-plot by the density, with three replications, for two consecutive years. The results demonstrate the effect of sowing time and density on the characteristics evaluated. In western Santa Catarina, the best time to sow seeds of maize landrace varieties in an agroecological system is in September, which is when the varieties expressed the greatest potential at densities from 45,000 to 50,000 pl.ha-1 , but it will not avoid transgene contamination.

Dear Editor, The recent and explosive worldwide outbreak of Covid-19 leads many scientists and clinicians to identify the most responsible triggering risk factors in individuals without comorbidities, as well as potential prognostic factors. A notable field of research has been conducted on the role of smoking, which has been initially hypothesized as being a protective factor for Covid-19....

O artigo apresenta uma reflexão sobre a experiencia do Curso de Especialização (Lato Sensu) em educação do Campo e Desenvolvimento Sustentável com Base na agroecologia (Residência Agraria), realizado em Santa Catarina, por meio da parceria entre INCRA/PRONERA, UFSC, CNPQ e MST. Tem como objetivo analisar a experiencia desenvolvida no curso que teve como centralidade a formação interdisciplinar. A partir do estudo e análise realizada durante o curso, buscamos refletir sobre os aspectos organizativos, o qual foi desenvolvido a partir da Pedagogia da Alternância; bem como, analisamos a pesquisa como elemento central na formação dos trabalhadores. Por fim, discorremos sobre os limites e possibilidades que a interdisciplinaridade trouxe neste curso para a formação de educadores do campo.

Abstract Background Tobacco use and the Western diet are two of the most important and investigated topics in relation to adolescents’ health. In addition, air pollution is a crucial subject for future generations. School is a key social environment that should promote healthy behaviors in children and adolescents. In this field many different programs have been conducted, with mixed results and effectiveness. Research data suggest that comprehensive and multicomponent approaches may have a greater effect on tobacco use and diet, especially when integrated into a community-wide approach. Methods The present work describes a multi-area pilot study called “La Scuola della Salute” (the School of Health) with a focus on the methodological aspects of the intervention. In our study we assessed different web-based and practical experiences related to adolescents’ smoking and dietary behaviors and awareness of smoke-related air pollution. Furthermore, to make adolescents more conscious of smoking and dietary behaviors, we conducted experiential workshops that addressed smoking and environmental pollution, food education, and lifestyle. Teachers and school administrators were involved in the project. Results At baseline we investigated dietary habits, tobacco use, and individual and social characteristics by means of lifestyle questionnaires. In addition, we collected anthropometric parameters and performance indicators such as exhaled carbon monoxide and urinary fructose to assess smoking and nutrition habits. At the end of the intervention lifestyle questionnaire and biological markers were collected again: knowledge about these topics was significantly improved, and the urinary fructose was able to estimate the levels of obesity in the classes. Conclusions The integrated approach, combined with the use of biological markers, could be an innovative approach to the promotion of healthy lifestyles among adolescents, but further research is needed.

In this paper, we introduce and study the Tricomi continuants, a family of tridiagonal determinants forming a Sheffer sequence closely related to the Tricomi polynomials and the Laguerre polynomials. Specifically, we obtain the main umbral operators associated with these continuants and establish some of their basic relations. Then, we obtain a Turan-like inequality, some congruences, some binomial identities (including a Carlitz-like identity), and some relations with the Cayley continuants. Furthermore, we show that the infinite Hankel matrix generated by the Tricomi continuants has an LDU-Sheffer factorization, while the infinite Hankel matrix generated by the shifted Tricomi continuants has an LTU-Sheffer factorization. Finally, by the first factorization, we obtain the linearization formula for the Tricomi continuants and its inverse. [ABSTRACT FROM AUTHOR]

Abstract Patients with long-standing ulcerative colitis (UC) have an increased colorectal cancer (CRC) risk. In this pilot study we evaluated the effect of Eicosapentaenoic acid as free fatty acid (EPA-FFA) supplementation on mucosal disease activity, colonic differentiation markers and microbiota composition in UC patients. Twenty long-standing UC patients in stable clinical remission and with fecal calprotectin (FC) > 150 µg/g were enrolled (T0) and supplemented with EPA-FFA 2 g/daily for 90 days (T3). Endoscopic and histologic disease activities were measured by Mayo and Geboes scores, respectively. HES1, KLF4, STAT3, IL-10 and SOCS3 levels were determined using western blotting and qRT-PCR, while phospho-STAT3 levels were assessed by western blotting. Goblet cells were stained by Alcian blue. Microbiota analyses were performed on both fecal and colonic samples. Nineteen patients completed the study; seventeen (89.5%) were compliant. EPA-FFA treatment reduced FC levels at T3. Patients with FC > 150 µg/g at T3 (n = 2) were assumed as non-responders. EPA-FFA improved endoscopic and histological inflammation and induced IL-10, SOCS3, HES1 and KLF4 in compliant and responder patients. Importantly, long-term UC-driven microbiota composition was partially redressed by EPA-FFA. In conclusion, EPA-FFA supplementation reduced mucosal inflammation, promoted goblet cells differentiation and modulated intestinal microbiota composition in long-standing UC patients.

Objectives: Unhealthy dietary patterns have been associated with colorectal cancer (CRC) onset while Mediterranean Diet (MD) has been proposed for CRC prevention. This study evaluated the effect of a Mediterranean Diet Mix (MD-MIX) on colonic tumors development in A/J mice fed a low-fat (LFD) or a high-fat western diet (HFWD), and injected with the procarcinogen azoxymethane (AOM).Materials and Methods: Forty A/J male mice were randomly assigned into four feeding arms (10 mice/arm; LFD, LFD-MD-MIX, HFWD, HFWD-MD-MIX) to be treated with AOM. Ten mice were exposed to the diets alone (Healthy LFD and Healthy HFWD) to be used as control. Tumor incidence and multiplicity were evaluated at sacrifice. Mucosal fatty acid content and urinary phenolic compounds were assayed by mass spectrometry. Apoptosis was evaluated by TUNEL assay and gene expression markers. Cell proliferation was evaluated by Ki67 immunohistochemistry. Microbiota composition was assessed at different time points by 16S RNA sequencing.Results: A tumor incidence of 100% was obtained in AOM-treated mice. The MD-MIX supplementation was able to reduce the number of colonic lesions in both LFD and HFWD-fed mice and to induce apoptosis, in particular in the LFD-MD-MIX arm. Moreover, a preventive effect on low-grade dysplasia and macroscopical lesions (>1 mm) development was found in HFWD-fed mice together with a regulation of the AOM-driven intestinal dysbiosis.Conclusions: MD-MIX was able to counteract CRC development in mice under different dietary backgrounds through the regulation of apoptosis and gut microbiota.

Background: Docosahexaenoic acid (DHA) is a major constituent of neuronal and retinal membranes and plays a crucial role in brain and visual development within the first months of life. Dietary intakes are fundamental to provide neonates with adequate DHA supply; hence, maternal supplementation might represent a useful strategy to implement DHA contents in breast milk (BM), with possible benefits on neonatal neurodevelopment. Antarctic krill is a small crustacean rich in highly available phospholipid-bound DHA. This pilot study aimed to evaluate whether maternal supplementation with krill oil during breastfeeding increases long-chain polyunsaturated fatty acids (LCPUFAs) BM contents.Methods: Mothers of infants admitted to the Neonatal Intensive Care Unit were enrolled in this open, randomized-controlled study between 4 and 6 weeks after delivery and randomly allocated in 2 groups. Group 1 received an oral krill oil-based supplement providing 250 mg/day of DHA and 70 mg/day of eicosapentaenoic acid (EPA) for 30 days; group 2 served as control. BM samples from both groups were collected at baseline (T0) and day 30 (T1) and underwent a qualitative analysis of LCPUFAs composition by gas chromatography/mass spectrometry.Results: Sixteen breastfeeding women were included. Of these, 8 received krill-oil supplementation and 8 were randomized to the control group. Baseline percentage values of DHA (%DHA), arachidonic acid (%AA), and EPA (%EPA) did not differ between groups. A significant increase in %DHA (T0: median 0.23% [IQR 0.19;0.38], T1:0.42% [0.32;0.49], p 0.012) and %EPA (T0: median 0.10% [IQR 0.04;0.11], T1:0.11% [0.04;0.15], p 0.036) and a significant reduction in %AA (T0: median 0.48% [IQR 0.42;0.75], T1:0.43% [0.38;0.61], p 0.017) between T0 and T1 occurred in Group 1, whereas no difference was seen in Group 2. Consistently, a significant between-group difference was observed in percentage changes from baseline of DHA (Δ%DHA, group 1: median 64.2% [IQR 27.5;134.6], group 2: −7.8% [−12.1;−3.13], p 0.025) and EPA (Δ%EPA, group 1: median 39% [IQR 15.7;73.4]; group 2: −25.62% [−32.7;−3.4], p 0.035).Conclusions: Oral krill oil supplementation effectively increases DHA and EPA contents in BM. Potential benefits of this strategy on brain and visual development in breastfed preterm neonates deserve further evaluation in targeted studies.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03583502.