Heavy metals and trace elements analysis in groundwater around Mahaoya hot water springs

Groundwater in and around Mahaoya thermal springs found in the Precambrian highgrade metamorphic terrain of Sri Lanka were investigated to assess their geochemical properties with compared to normal regional groundwater of particular area and to produce a data set to develop a model of identification of thermal springs or mixing of thermal and non-thermal ground water. The main objective is this study is to compare the geochemical parameters of thermal springs with nearby cold ground water and interprets the geochemical relationships among them.Samples of low temperature (<35 °C) groundwater from nearby springs, piezometers and open wells were also collected for comparison. All samples were analyzed for their major and trace element compositions using Atomic Absorption Spectrophotometer and standard methods.These waters showed low concentrations of selected trace elements and were comparable to that of geothermal groundwater. Major cation and anion concentrations of thermal springs are similar to nearby cold springs. Close matches of geochemical data from geothermal and dug wells waters confirm the hypothesis of a common source

Obtención de hidrolizado de aceite de macauba y su aplicación en la producción de ésteres metílicos

This work aimed to obtain a hydrolyzate rich in free fatty acids (FFA) from the hydrolysis of macauba oil for subsequent esterification and obtaining of methyl esters. To determine the conditions that maximize FFA yield in the hydrolysis step, the effects of buffer solution percentage and catalyst concentration (Lipozyme®&nbsp;RM IM) were determined at 55 ºC and 6 h. From the results, it was verified that both variables evaluated in the experimental range had an influence on the reaction and their increase favored the production of FFA. Additional experiments were carried out to assess the influence of reaction time with a progressive increase up to 8 h. Hydrolyzate with ~92 wt % FFA was obtained and its use in the enzymatic esterification step using Novozym® 435 as catalyst resulted in ~95 % FFA conversion. Regarding the reuse of enzymes at each stage, a ~50 % reduction in FFA yield was found and only 98 % FFA conversion.Este trabajo tuvo como objetivo obtener un hidrolizado rico en ácidos grasos libres (AGL) a partir de la hidrólisis del aceite de frutos de macauba, para su posterior esterificación y obtención de ésteres metílicos. Para determinar las condiciones que maximizan el rendimiento de AGL en la etapa de hidrólisis, se determinaron los efectos del porcentaje de solución amortiguadora y la concentración de catalizador (Lipozyme® RM IM) a 55 ºC y 6 h. De los resultados se verificó que ambas variables, en el rango experimental evaluado, tienen influencia en la reacción y su incremento favorece la producción de AGL. Se llevaron a cabo experimentos adicionales para evaluar la influencia del tiempo de reacción, observándose un aumento progresivo hasta las 8 h. Se obtuvo un hidrolizado con ~92 % en peso de FFA y su uso en el paso de esterificación enzimática, usando Novozym® 435 como catalizador, resultó en ~95 % de conversión de FFA. Al investigar la reutilización de enzimas, en cada etapa, se encontró una reducción de ~50 % en el rendimiento de FFA y solo un 98 % en la conversión de FFA

Exploring Tourist Flow Patterns through Geotagged Social Media Data: A Case Study from Sri Lanka

Tourism studies often rely on conventional methods such as interviews and site-specific surveys to collect data on tourist behaviour, mobility patterns, and preferences. However, these methods can be expensive, time-consuming, and limited in scope. Additionally, accurately tracing tourist travel paths can be challenging due to recall bias. Recently, user generated content on social media platforms have emerged as an alternative data source in tourism studies. In this study, we used geotagged posts on Flickr to understand the dominant paths taken by inbound tourists in Sri Lanka. The methodology consisted of three steps. First, geotagged photographs were collected from the Flickr API spanning a ten-year period, from 2012 to 2022. These photographs included metadata such as user ID, the timestamp of photo capture, and geo coordinates indicating where the photo was taken. Second, a density-based clustering algorithm was utilized to identify tourist hotspots. Finally, the Markov Chain model was employed to calculate transition probabilities among different attractions, revealing dominant travel routes within the country. Study’s findings indicate that Cultural heritage attractions were the most popular, comprising 55% of all attractions identified by the algorithm, and are particularly popular in districts such as Anuradhapura, Polonnaruwa, Matale, Kandy, and Galle. Nature-based attractions, constituting 37% of the total, were mainly located in Nuwara Eliya and Badulla Districts, as well as Yala National Park in Hambantota District. For coastal tourism, Galle and Matara Districts were the top preferences. The analysis confirms dominant travel patterns between North Central, Central, and Southwest coast regions. Notably, Galle, Kandy, Matale, Matara, Nuwara Eliya, and Colombo attract tourists from a more diverse array of regions compared to other districts in the country, showcasing their significance as tourist hubs. The study findings highlight opportunities in Jaffna for cultural-heritage tourism, the Eastern coast for coastal tourism, and the central highlands for tea tourism. It also emphasizes the need to develop the less-visited natural sites to ease pressure on popular National Parks. This research's significance lies in its contribution to informed decision-making and the sustainable management of tourist destinations. By understanding tourist mobility patterns and identifying popular attractions through social media data, policymakers can effectively manipulate visitor flows and mitigate excessive tourist pressure, while preserving the authenticity and allure of these destinations. &nbsp; Keywords: Sustainable tourism, Geotagged photographs, Social media, Tourist mobility, Flick

Teste rápido de aglutinação utilizando partículas de látex para a detecção de anticorpos anti-cisticercos em amostras de líquido cefalorraquidiano (LCR)

Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. In this article, we present the preliminary results obtained with a latex agglutination test (LAT) for diagnosing neurocysticercosis by detection of antibodies in CSF. A total of 43 CSF samples were assayed by the LAT: 19 CSF samples from patients with neurocysticercosis and 24 CSF samples from patients with other neurologic disorders (neurosyphilis, n = 8; neurotoxoplasmosis, n = 3; viral meningitis, n = 4, chronic headache, n = 9). The LAT exhibited 89.5% sensitivity and 75% specificity. The use of LAT seems to be an additional approach for the screening of neurocysticercosis with advantage of simplicity and rapidity. Further studies could be performed using purified antigens and serum samples.Testes diagnósticos simples e rápidos baseados na aglutinação de partículas de látex têm sido utilizados para a pequisa de antígenos ou anticorpos específicos em muitas doenças. No presente trabalho, é descrito um teste de aglutinação em lâmina para a pesquisa de anticorpos contra cisticercos de Taenia solium, utilizando partículas de látex revestidas com um extrato bruto do parasita. Anticorpos anti-cisticercos foram pesquisados em 19 amostras de LCR de pacientes com neurocisticercose e em 24 amostras de LCR de pacientes com outros problemas neurológicos (neurosífilis, n = 8; neurotoxoplasmose, n = 3; meningite viral, n = 4; cefaléia crônica, n = 9). O teste de aglutinação apresentou sensibilidade e especificidade de 89,5% e 75%, respectivamente. O teste de aglutinação para cisticercose idealizado é simples, rápido e barato. Essas características tornam o teste um meio promissor de expansão e simplificação do imunodiagnósico da neurocisticercose. Estudos futuros poderiam testar a sensibilização das partículas de látex com antígenos de cisticercos purificados e a pesquisa de anticorpos em amostras de soros

Theory of a magnetic microscope with nanometer resolution

We propose a theory for a type of apertureless scanning near field microscopy that is intended to allow the measurement of magnetism on a nanometer length scale. A scanning probe, for example a scanning tunneling microscope (STM) tip, is used to scan a magnetic substrate while a laser is focused on it. The electric field between the tip and substrate is enhanced in such a way that the circular polarization due to the Kerr effect, which is normally of order 0.1% is increased by up to two orders of magnitude for the case of a Ag or W tip and an Fe sample. Apart from this there is a large background of circular polarization which is non-magnetic in origin. This circular polarization is produced by light scattered from the STM tip and substrate. A detailed retarded calculation for this light-in-light-out experiment is presented.Comment: 17 pages, 8 figure

Câncer de colo de útero: barreiras preventivas no século 21 / Cervical cancer: preventive barriers in the 21st century

Introdução: No Brasil, o câncer de colo de útero é o segundo tipo de câncer ginecológico mais comum, ficando atrás apenas do câncer de mama. Apesar da alta incidência e mortalidade, se configura como um câncer com possibilidade de prevenção, e com estratégias de prevenção consolidadas nas políticas de atenção a saúde. Objetivos: Especificar as barreiras na prevenção ao câncer de colo de útero, especialmente no Brasil. Métodos: Trata-se de uma revisão sistemática de literatura. Para a pesquisa as bases de dados consultadas foram: Lilacs e PubMed, usando os descritores: “Cervical Cancer”,”HPV”, “Prevention”. Resultados: O câncer de colo irá surgir quando houver a infecção persistente pelo vírus HPV oncogênico, associado a fatores de risco. Devido ao contágio pelo HPV ser uma infecção sexualmente transmissível, o carcinoma passa a ter caráter preventivo, ou seja, medidas podem ser tomadas para que se diagnostique a infecção e suas alterações primárias antes que ocorra a evolução para lesão carcinomatosa. A prevenção primária envolve o uso de condoms e a vacinação para HPV, associada a ações de promoção em saúde. Enquanto a prevenção secundária envolve a detecção precoce, ou seja, o diagnóstico precoce a partir do exame citopatológico, conhecido como Papanicolau. Conclusões: De forma geral, a educação sexual é um passo fundamental nas barreiras preventivas atualmente enfrentadas pelo Brasil no combate ao câncer de colo de útero

Longitudinal changes in wellbeing amongst breastfeeding women in Australia and New Zealand during the COVID-19 pandemic

The COVID-19 pandemic has impacted new mothers’ wellbeing and breastfeeding experience. Women have experienced changes in birth and postnatal care and restricted access to their support network. It is unclear how these impacts may have changed over time with shifting rates of infection and policies restricting movement and access to services in Australia and New Zealand. This study investigated the longitudinal effect of the COVID-19 pandemic on breastfeeding and maternal wellbeing in Australia and New Zealand. Mothers (n = 246) completed an online survey every 4 weeks for 6 months that examined feeding methods, maternal mental wellbeing, worries, challenges, and positive experiences during the pandemic. Mothers maintained high full breastfeeding rates at 4 months (81%) which decreased to 37% at 6 months. Perceived low milk supply contributed to the earlier cessation of full breastfeeding. Poor infant sleep was associated with stress, perinatal anxiety, mental wellbeing, and breastfeeding status. Although mothers initially reported that lockdowns helped with family bonding and less pressure, prolonged lockdowns appeared to have adverse effects on access to social networks and extended family support. Conclusion: The results highlight the changing dynamic of the pandemic and the need for adaptable perinatal services which allow mothers access to in-person services and their support network even in lockdowns. Similarly, access to continuous education and clinical care remains critical for women experiencing concerns about their milk supply, infant sleep, and their own wellbeing

Homogeneous Fermion Superfluid with Unequal Spin Populations

For decades, the conventional view is that an s-wave BCS superfluid can not support uniform spin polarization due to a gap $\Delta$ in the quasiparticle excitation spectrum. We show that this is an artifact of the dismissal of quasiparticle interactions $V_{qp}^{}$ in the conventional approach at the outset. Such interactions can cause triplet fluctuations in the ground state and hence non-zero spin polarization at "magnetic field" $h<\Delta$. The resulting ground state is a pairing state of quasiparticles on the ``BCS vacuum". For sufficiently large $V_{qp}$, the spin polarization of at unitarity has the simple form $m\propto \mu^{1/2}$. Our study is motivated by the recent experiments at Rice which found evidence of a homogenous superfluid state with uniform spin polarization.Comment: 4 pages, 3 figure