Seeking to understand the socio-spatial behaviour of the COVID-19 virus in the most impacted area in Brazil, five spatial regression models were analysed to assess the disease distribution in the ...affected territory. Results obtained using the Spearman correlation test provided evidence for the correlation between COVID-19 death incidence and social aspects such as population density, average people per household, and informal urban settlements. More importantly, all analysed models using four selected explanatory variables have proven to represent at least 85 per cent of reported deaths at the district level. Overall, our results have demonstrated that the geographically weighted regression (GWR) model best explains the spatial distribution of COVID-19 in the city of São Paulo, highlighting the spatial aspects of the data. Spatial analysis has shown the spread of COVID-19 in areas with highly vulnerable populations. Our findings corroborate reports from the recent literature, pointing out the need for special attention in peripheral areas and informal settlements.
Summary
Over the past 20 years, portable and relatively affordable spectrophotometers have greatly advanced the study of animal coloration. However, the small size of many colour patches poses ...methodological challenges that have not, to date, been assessed in the literature. Here, we tackle this issue for a reflectance spectrophotometry set‐up widely used in ecology and evolution (the beam method).
We reviewed the literature on animal coloration reporting the use of reflectance spectrophotometry to explore how the minimum measurable size of a colour patch is determined. We then used coloured plastic sheets to create artificial colour patches, and quantify the relationship between colour patch size and distortions induced by resulting chimeric spectra (spectra contaminated by an adjacent colour patch). Finally, we assessed the generality of our findings using natural colour spots in the lizard Podarcis muralis, as a biologically realistic model.
We found a lack of consensus in the literature, frequently resulting in the rejection of valid data or the potential inclusion of unreliable data. As expected, we show that decreasing colour patch size reduces the reliability of reflectance measurements, but also that spectral distortions resulting from chimeric spectra depend on patch/background colour combinations. We found similar results using natural colour spots in P. muralis.
We propose a series of steps to avoid the pitfalls described above. First, we provide guidelines on how to identify chimeric spectra and estimate the minimum size of a measurable colour patch in order to avoid them. Second, we show that reducing the probe‐to‐surface distance allows for more accurate measurements and therefore improves the spectrophotometric assessment of small colour patches. Third, we suggest that, as a general rule of thumb, very small (< 2 mm) colour patches should be avoided when using traditional spectrophotometry methods.
Reseña a: María Dolores García de Paso Carrasco, Trinidad Arcos Pereira, María Elisa Cuyás de Torres, Gregorio Rodríguez Herrera, Los Principios de retórica de Aftonio con anotaciones de Juan de Mal ...Lara. Introducción, edición, traducción y notas, Madrid: Ediciones Clásicas, 2021, 363 páginas. ISBN 978-84-7882-876-0
The confinement of atoms in impenetrable spherical boxes at the Hartree-Fock level was evaluated using a non-uniform fixed-grid variational method defined by a
q
-exponential. Applications from He to ...Ne in the ground state and some of them in excited states demonstrated that the method depends essentially on the boundary conditions to produce results as accurate as those reported in the literature with a relatively low number of integration points. An expression was defined for the virial theorem for atoms confined by spherical boxes and the confinement effect on the virial ratio evaluated. The results showed that the confinement of atoms results in much more significant changes to the kinetic than to the potential energy.
Graphical abstract
Purpose: In the present study, we coined the term 'alveolar dome' and aimed to demonstrate the prevalence of alveolar domes through digital periapical radiographs. Materials and Methods: This study ...examined 800 digital periapical radiographs in regard to the presence of alveolar domes. The periapical radiographs were acquired by a digital system using a photostimulable phosphor (PSP) plate. The ${\chi}^2$ test, with a significance level of 5%, was used to compare the prevalence of alveolar domes in the maxillary posterior teeth and, considering the same teeth, to verify the difference in the prevalence of dome-shaped phenomena between the roots. Results: The prevalence of alveolar domes present in the first pre-molars was statistically lower as compared to the other maxillary posterior teeth (p<0.05). No statistically significant difference was observed in the prevalence of alveolar domes between the maxillary first and second molars. Considering the maxillary first and second molars, it was observed that the palatal root presented a lower prevalence of alveolar domes when compared to the distobuccal and mesiobuccal roots (p<0.05). Conclusion: The present study coined the term 'alveolar dome', referring to the anatomical projection of the root into the floor of the maxillary sinus. The maxillary first and second molars presented a greater prevalence of alveolar domes, especially in the buccal roots, followed by the third molars and second pre-molars. Although the periapical radiograph is a two-dimensional method, it can provide dentists with the auxiliary information necessary to identify alveolar domes, thus improving diagnosis, planning, and treatment.
This study presents the physicochemical and mechanical behavior of incorporating hydroxyapatite (HAp) with polylactic acid (PLA) matrix in 3D printed PLA/HAp composite materials. Effects of powder ...loading to the composition, crystallinity, morphology, and mechanical properties were observed. HAp was synthesized from locally sourced nanoprecipitated calcium carbonate and served as the filler for the PLA matrix. The 0, 5, 10, and 15 wt. % HAp biocomposite filaments were formed using a twin-screw extruder. The resulting filaments were 3D printed in an Ultimaker S5 machine utilizing a fused deposition modeling technology. Successful incorporation of HAp and PLA was observed using infrared spectroscopy and X-ray diffraction (XRD). The mechanical properties of pure PLA had improved on the incorporation of 15% HAp; from 32.7 to 47.3 MPa in terms of tensile strength; and 2.3 to 3.5 GPa for stiffness. Moreover, the preliminary
bioactivity test of the 3D printed PLA/HAp biocomposite samples in simulated body fluid (SBF) indicated varying weight gains and the presence of apatite species' XRD peaks. The HAp particles embedded in the PLA matrix acted as nucleation sites for the deposition of salts and apatite species from the SBF solution.
A Geografia, ciência de diálogos, mantém contatos com as diversas áreas do saber há décadas. Tais contatos são a expressão da inquietude do fluxo criativo na interpretação do espaço geográfico. O ...diálogo com as artes e suas deambulações geográficas, então, se evidenciam como parte da natureza própria da Geografia também ser uma ciência associada às explorações. Nesse sentido, a proposta é pensar o filme como campo das novas aventuras geográficas, produtor de novos olhares para o mundo. Assim, sem negligenciar o que foi produzido até os tempos atuais, visa-se uma renovação da relação Geografia-cinema. Articulando autores contemporâneos e da Geografia Clássica, por meio de uma construção teórica, concebe-se a noção de espraiamento artístico-científico, num avanço da Geografia em direção a arte e desta rumo àquela. Como ponto em comum das duas áreas, a narrativa ganha proeminência, posto que ambas, obra cinematográfica e Geografia, são narrativas do mundo. Conclui-se que as narrativas são essencialmente geográficas e a ideia de percurso auxilia no entrelace Geografia-Cinema, pois os itinerários são vitais para compreender as significações geográficas nos filmes.
Background
Chemotherapy can induce cognitive impairment in cancer patients. The main goal of this longitudinal study was to determine the incidence, characteristics, and duration of cognitive ...dysfunction in patients treated with adjuvant chemotherapy for colon cancer.
Patients and methods
We assessed cognitive function, quality of life, anxiety and depression, fatigue, and hemoglobin levels in colon cancer patients at three assessment points: pre-chemotherapy (
n
= 81), post-chemotherapy (
n
= 73), and after 6-month follow-up (
n
= 54). All patients were treated with oxaliplatin plus 5-fluorouracil/leucovorin (FOLFOX4) for 6 months.
Results
Thirty patients (37 %) had cognitive impairment in the pre-chemotherapy evaluation, mainly in processing speed and psychomotor executive function (Trail Making Test A and B). At the end of treatment, the main domain affected was the verbal memory, with an acute decline detected in 56 % of patients. Fifty-four percent of the patients improved their dysfunction after 6 months of follow-up, whereas 18 (33 %) of them showed worsening in at least one test. Cognitive impairment was most common in older patients and in those with less years of education. Quality of life, anxiety, depression, fatigue, and hemoglobin did not influence the results of the cognitive tests.
Conclusions
Adjuvant FOLFOX4 in patients with colon cancer can have a negative effect on verbal memory. This deterioration is usually mild and transient.
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