Inductive reasoning stages presented by mathematics teachers when solving a generalization problem

Se reportan seis fases del razonamiento inductivo que presentaron 19 profesores de matemáticas de secundaria al resolver un problema de generalización de un patrón cuadrático. Los datos se recolectaron mediante sus respuestas escritas y entrevistas. El análisis se realizó con base en el modelo de Cañadas y Castro (2007). Se encontró que, para generalizar de manera correcta, no basta con reconocer las regularidades en varios casos particulares, sino que se precisa de asociar esas regularidades con estructuras matemáticas que describan el patrón de manera general, y se detectaron dificultades en algunas fases que impidieron a los profesores llegar a generalizar.This investigation reports six inductive reasoning stages presented by nineteen middle school mathematics teachers when solving a generalization problem of a quadratic pattern. The data was collected through their written responses and interviews. The analysis was performed based on the model of Cañadas and Castro (2007). It was found that the correct generalization not only needed the recognition of regularities in some particular cases, but an accurate association between those regularities and the mathematical structures that describe the pattern in a general way. Furthermore, several difficulties that prevented the teachers from achieving a generalization were detected

Spray drying and process optimization of sour orange juice

In this study, production of sour orange juice powder utilizing a spray dryer was investigated. To prevent stickiness, maltodextrin DE 12 was used as a drying agent. While feed flow rate, feed temperature, and air flow rate were kept constant, inlet air temperature (120–160 °C) and maltodextrin content (maltodextrin dry solids/100 g feed mixture dry solids; 10–20%, w/w) were selected as the independent variables. Product properties investigated included ascorbic acid, volatile compounds, and moisture content. Ascorbic acid retention, volatiles retention, and moisture content were used in optimization of the process by response surface methodology. The optimum inlet air temperature and maltodextrin content were 156 °C and 20% w/w maltodextrin, respectively. This study revealed that by applying these optimal conditions, sour orange juice powder with 81.5% ascorbic acid retention, 5.5%, w/w moisture content, and 78% volatiles retention was produced

Microencapsulation of the Aroma from Capsicum chinense Jacq. cv. Habanero

An aroma distillate with the odour note described as ‘fresh Habanero chilli pepper’ was obtained from hydrodistillation of the fruit. GC-MS analysis of the volatile constituents from the aroma distillate allowed the identification of 100 compounds, most of them esters followed by aldehydes, alcohols, terpenes, ketones, and acids. Encapsulation process of the aroma distillate by spray drying was optimised using response surface methodology. Independent variables were inlet air temperature (150–200 °C) and carrier (maltodextrin 10 DE and gum arabic in 2:1 ratio) content (10–20% wb), while response variables were powder moisture and volatiles retention. Moisture content of the powder varied inversely proportional to the air temperature, while the volatile retention was directly related. Retention of volatiles in the powder increased when the carrier content increased, while this factor negatively affected moisture content. Based on the optimisation model of the response variables, the powder with the highest flavour quality was obtained with an air inlet temperature of 200 °C and 20% wb carrier content, with 4% moisture content and 88.6% volatiles retention

Case report: Mirror paraclinoid aneurysm associated with mirror clinoidal meningioma

IntroductionClinoidal meningiomas and paraclinoid aneurysms are individually uncommon, with the coexistence of mirror paraclinoid aneurysms and clinoidal meningiomas presenting an even rarer scenario. While the association between meningiomas and aneurysms is documented, the simultaneous presence of mirror lesions for both pathologies is not reported in the literature.Clinical presentationWe report a 62-year-old female with a three-month history of moderate bifrontal headaches. Magnetic Resonance Angiography (MRA) revealed mirror paraclinoid aneurysms, prompting surgical intervention. During the procedure, mirror clinoidal meningiomas were incidentally discovered. The left aneurysm was addressed first due to higher rupture risk, followed by the right aneurysm 3 months later. Both meningiomas were confirmed as Transitional Meningiomas (Grade 1; OMS, 2021). The aneurysms were successfully clipped, and the patient had an excellent postoperative outcome.ConclusionThis case represents a unique occurrence of mirror ophthalmic segment internal carotid artery aneurysms associated with mirror clinoidal meningiomas, a combination not previously reported. Despite the limitations of MRA in detecting small meningiomas, it remains a valuable non-invasive screening tool for neurovascular diseases. The case underscores the need for further research to elucidate the association between cerebral aneurysms and meningiomas

PRIMER REGISTRO DE PROBSTMAYRIA TAPIRI (NEMATODA: ATRACTIDAE) EN TAPYIRUS BAIRDII (GILL, 1865) DE LA SIERRA MADRE DEL ESTADO DE CHIAPAS, MÉXICO

This is a first record of Probstmayria tapiri in Mexico, was found in 60 (41.09%) fecal samples from Baird´s tapir (Tapirus bairdii) in the Biosphera Reserves La Sepultura and El Triunfo in the Sierra Madre de Chiapas, Mexico. Morphological characteristics of small nematode spindle-shaped forms truncated anteriorly and with a long, gradually attenuated, acutely pointed tail. Mouth with tree lips, pharynx elongated, aesophagus with tree portions: Anterior portion, long and slender, posterior portion, shorter, and pyriform portion, with a bulb. The excretory pore is situated near oesophagi bulb and ventral surface of the body. Vulva of female at about the middle of the body. Spicules assymetrical and curved. On the ventral surface of the tail there are nine small postanal papillae. These results allow us to extend their geographic distribution of nematode to Central America and another species of Tapir’s (T. bairdii). Finally we emphasized that the environmental conditions of La Sierra Madre de Chiapas, are optimal for the biological development of this nematode from tapirs of Central and South America.Primer registro de Probstmayria tapiri en México y para la especie de Tapirus bairdii (tapir Centroamericano), en la que se hace una redescripción de este nematodo. Se encontró en 60 (41.09%) muestras de excretas frescas recolectadas en las Reservas de la Biosfera La Sepultura y El Triunfo en la Sierra Madre de Chiapas, México. Las características morfológicas de los especimenes observados son nematodos pequeños con cutícula finamente estriada, fusiforme que gradualmente disminuye su diámetro hacia ambos extremos, terminando en una cola aguda. Boca hexagonal con tres labios bilobulados, faringe alargada, esófago con tres porciones: anterior, larga y delgada, media, corta y estrecha, piriforme, con un bulbo. El poro excretor se encuentra situado cerca del bulbo esofágico y ventral a la superficie del cuerpo. La vulva de la hembra esta cerca de la porción media del cuerpo. Las espículas del macho son asimétricas y curvadas. En la superficie ventral de la cola hay nueve papilas postanales. Estos resultados nos permiten ampliar la distribución geográfica del nematodo a Centroamérica y otra especie de tapir (T. bairdii). Finalmente enfatizamos que las condiciones ambientales de la Sierra Madre son óptimas para el desarrollo biológico de este nematodo de los miembros de la Familia Tapiridae en Centroamérica y Sudaméric

Ensemble Composition and Activity Levels of Insectivorous Bats in Response to Management Intensification in Coffee Agroforestry Systems

Shade coffee plantations have received attention for their role in biodiversity conservation. Bats are among the most diverse mammalian taxa in these systems; however, previous studies of bats in coffee plantations have focused on the largely herbivorous leaf-nosed bats (Phyllostomidae). In contrast, we have virtually no information on how ensembles of aerial insectivorous bats – nearly half the Neotropical bat species – change in response to habitat modification. To evaluate the effects of agroecosystem management on insectivorous bats, we studied their diversity and activity in southern Chiapas, Mexico, a landscape dominated by coffee agroforestry. We used acoustic monitoring and live captures to characterize the insectivorous bat ensemble in forest fragments and coffee plantations differing in the structural and taxonomic complexity of shade trees. We captured bats of 12 non-phyllostomid species; acoustic monitoring revealed the presence of at least 12 more species of aerial insectivores. Richness of forest bats was the same across all land-use types; in contrast, species richness of open-space bats increased in low shade, intensively managed coffee plantations. Conversely, only forest bats demonstrated significant differences in ensemble structure (as measured by similarity indices) across land-use types. Both overall activity and feeding activity of forest bats declined significantly with increasing management intensity, while the overall activity, but not feeding activity, of open-space bats increased. We conclude that diverse shade coffee plantations in our study area serve as valuable foraging and commuting habitat for aerial insectivorous bats, and several species also commute through or forage in low shade coffee monocultures

Digoxin reveals a functional connection between HIV-1 integration preference and T-cell activation

HIV-1 integrates more frequently into transcribed genes, however the biological significance of HIV-1 integration targeting has remained elusive. Using a selective high-throughput chemical screen, we discovered that the cardiac glycoside digoxin inhibits wild-type HIV-1 infection more potently than HIV-1 bearing a single point mutation (N74D) in the capsid protein. We confirmed that digoxin repressed viral gene expression by targeting the cellular Na+/K+ ATPase, but this did not explain its selectivity. Parallel RNAseq and integration mapping in infected cells demonstrated that digoxin inhibited expression of genes involved in T-cell activation and cell metabolism. Analysis of >400,000 unique integration sites showed that WT virus integrated more frequently than N74D mutant within or near genes susceptible to repression by digoxin and involved in T-cell activation and cell metabolism. Two main gene networks down-regulated by the drug were CD40L and CD38. Blocking CD40L by neutralizing antibodies selectively inhibited WT virus infection, phenocopying digoxin. Thus the selectivity of digoxin depends on a combination of integration targeting and repression of specific gene networks. The drug unmasked a functional connection between HIV-1 integration and T-cell activation. Our results suggest that HIV-1 evolved integration site selection to couple its early gene expression with the status of target CD4+ T-cells, which may affect latency and viral reactivation