Construction and validation of a questionnaire to assess student satisfaction with mathematics learning materials

Sixth Edition Technological Ecosystems for Enhancing MulticulturalityMathematics is an essential branch for the scientific development and its study is mandatory in most university degrees. However, currently the level of academic performance and motivation of students to learn this science is not the desired one. The students can use different learning tools inside and outside the math classroom, enhancing the quality of the learning materials that are designed essentially to facilitate the learning of mathematics. The present research project aims to determine the validity and reliability of a measurement instrument that allows theassessment of the satisfaction of the students with the availablelearning materials. To fulfill the objectives of this research, the method of survey was used. A study with a quantitative approach was developed, which led to the design and validation of a questionnaire by a group of 7 experts. The validation closed after applying a pilot study with 728 students. It concluded positively, obtaining nine factors that coincide with the revision of the literature: technological quality, quality of content, visual quality, didactic significance, adequacy of content, relationship between theory and practice, involvement, contribution to learning, relevance and interaction between educational actors. The results of this questionnaire provide to the international scientific community with relevant information for the design, selection, and use of study materials in the classrooms, which will contribute to raising the levels of student engagement, and their academic performance in mathematics, secondaril

Behavioral ontogeny in larvae and early juveniles of the giant trevally (Caranx ignobilis) (Pisces: Carangidae)

Behavior of young (8−18 mm SL) giant trevally (Caranx ignobilis), a large coral-reef−associated predator, was observed in the laboratory and the ocean. Size was a better predictor of swimming speed and endurance than was age. Critical speed increased with size from 12 to 40 cm/s at 2.7 cm/s for each mm increase in size. Mean scaled critical speed was 19 body lengths/s and was not size related. Swimming speed in the ocean was 4 to 20 cm/s (about half of critical speed) and varied among areas, but within each area, it increased at 2 cm/s for each mm increase in size. Swimming endurance in the laboratory increased from 5 to 40 km at 5 km for each mm increase in size. Vertical distribution changed ontogenetically: larvae swam shallower, but more variably, and then deeper with growth. Two-thirds of individuals swam directionally with no ontogenetic increase in orientation precision. Larvae swam offshore off open coasts, but not in a bay. In situ observations of C. ignobilis feeding, interacting with pelagic animals, and reacting to reefs are reported. Manus

Effects of Prebiotic and Probiotic Supplementation on Lactase Deficiency and Lactose Intolerance: A Systematic Review of Controlled Trials

Lactose intolerance (LI) is characterized by the presence of primarily gastrointestinal clinical signs resulting from colonic fermentation of lactose, the absorption of which is impaired due to a deficiency in the lactase enzyme. These clinical signs can be modified by several factors, including lactose dose, residual lactase expression, concurrent ingestion of other dietary components, gut-transit time, and enteric microbiome composition. In many of individuals with lactose malabsorption, clinical signs may be absent after consumption of normal amounts of milk or, in particular, dairy products (yogurt and cheese), which contain lactose partially digested by live bacteria. The intestinal microbiota can be modulated by biotic supplementation, which may alleviate the signs and symptoms of LI. This systematic review summarizes the available evidence on the influence of prebiotics and probiotics on lactase deficiency and LI. The literature search was conducted using the MEDLINE (via PUBMED) and SCOPUS databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and included randomized controlled trials. For each study selected, the risk of bias was assessed following the Cochrane Collaboration methodology. Our findings showed varying degrees of efficacy but an overall positive relationship between probiotics and LI in relation to specific strains and concentrations. Limitations regarding the wide heterogeneity between the studies included in this review should be taken into account. Only one study examined the benefits of prebiotic supplementation and LI. So further clinical trials are needed in order to gather more evidence

Acceptance criteria for welds in ASTM A106 grade B steel pipe and plate

Based on the RECERT Program findings, NASA-Langley funded a fatigue study of code-unacceptable welds. Usage curves were developed which were based on the structural integrity of the welds. The details of this study are presented in NASA CR-178114. The information presented is a condensation and reinterpretation of the information in NASA CR-178114. This condensation and reinterpretation generated usage curves for welds having: (1) indications 0.20 -inch deep by 0.40-inch long, and (2) indications 0.195-inch deep by 8.4-inches long. These curves were developed using the procedures used in formulating the design curves in Section VIII, Division 2 of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code

La utilización de estudios prospectivos en la elaboración del plan estratégico en una institución científica tecnológica brasileña.

Projeto: 11.11.11.111

Analysis of acute brain slices by electron microscopy: A correlative light-electron microscopy workflow based on Tokuyasu cryo-sectioning.

Acute brain slices are slices of brain tissue that are kept vital in vitro for further recordings and analyses. This tool is of major importance in neurobiology and allows the study of brain cells such as microglia, astrocytes, neurons and their inter/intracellular communications via ion channels or transporters. In combination with light/fluorescence microscopies, acute brain slices enable the ex vivo analysis of specific cells or groups of cells inside the slice, e.g. astrocytes. To bridge ex vivo knowledge of a cell with its ultrastructure, we developed a correlative microscopy approach for acute brain slices. The workflow begins with sampling of the tissue and precise trimming of a region of interest, which contains GFP-tagged astrocytes that can be visualised by fluorescence microscopy of ultrathin sections. The astrocytes and their surroundings are then analysed by high resolution scanning transmission electron microscopy (STEM). An important aspect of this workflow is the modification of a commercial cryo-ultramicrotome to observe the fluorescent GFP signal during the trimming process. It ensured that sections contained at least one GFP astrocyte. After cryo-sectioning, a map of the GFP-expressing astrocytes is established and transferred to correlation software installed on a focused ion beam scanning electron microscope equipped with a STEM detector. Next, the areas displaying fluorescence are selected for high resolution STEM imaging. An overview area (e.g. a whole mesh of the grid) is imaged with an automated tiling and stitching process. In the final stitched image, the local organisation of the brain tissue can be surveyed or areas of interest can be magnified to observe fine details, e.g. vesicles or gold labels on specific proteins. The robustness of this workflow is contingent on the quality of sample preparation, based on Tokuyasu's protocol. This method results in a reasonable compromise between preservation of morphology and maintenance of antigenicity. Finally, an important feature of this approach is that the fluorescence of the GFP signal is preserved throughout the entire preparation process until the last step before electron microscopy

Stable Determination of the Electromagnetic Coefficients by Boundary Measurements

The goal of this paper is to prove a stable determination of the coefficients for the time-harmonic Maxwell equations, in a Lipschitz domain, by boundary measurements

Utility and safety of draining pleural effusions in mechanically ventilated patients: a systematic review and meta-analysis

Abstract Introduction Pleural effusions are frequently drained in mechanically ventilated patients but the benefits and risks of this procedure are not well established. Methods We performed a literature search of multiple databases (MEDLINE, EMBASE, HEALTHSTAR, CINAHL) up to April 2010 to identify studies reporting clinical or physiological outcomes of mechanically ventilated critically ill patients who underwent drainage of pleural effusions. Studies were adjudicated for inclusion independently and in duplicate. Data on duration of ventilation and other clinical outcomes, oxygenation and lung mechanics, and adverse events were abstracted in duplicate independently. Results Nineteen observational studies (N = 1,124) met selection criteria. The mean PaO2:FiO2 ratio improved by 18% (95% confidence interval (CI) 5% to 33%, I 2 = 53.7%, five studies including 118 patients) after effusion drainage. Reported complication rates were low for pneumothorax (20 events in 14 studies including 965 patients; pooled mean 3.4%, 95% CI 1.7 to 6.5%, I 2 = 52.5%) and hemothorax (4 events in 10 studies including 721 patients; pooled mean 1.6%, 95% CI 0.8 to 3.3%, I 2 = 0%). The use of ultrasound guidance (either real-time or for site marking) was not associated with a statistically significant reduction in the risk of pneumothorax (OR = 0.32; 95% CI 0.08 to 1.19). Studies did not report duration of ventilation, length of stay in the intensive care unit or hospital, or mortality. Conclusions Drainage of pleural effusions in mechanically ventilated patients appears to improve oxygenation and is safe. We found no data to either support or refute claims of beneficial effects on clinically important outcomes such as duration of ventilation or length of stay

Inverse problem for wave equation with sources and observations on disjoint sets

We consider an inverse problem for a hyperbolic partial differential equation on a compact Riemannian manifold. Assuming that $\Gamma_1$ and $\Gamma_2$ are two disjoint open subsets of the boundary of the manifold we define the restricted Dirichlet-to-Neumann operator $\Lambda_{\Gamma_1,\Gamma_2}$. This operator corresponds the boundary measurements when we have smooth sources supported on $\Gamma_1$ and the fields produced by these sources are observed on $\Gamma_2$. We show that when $\Gamma_1$ and $\Gamma_2$ are disjoint but their closures intersect at least at one point, then the restricted Dirichlet-to-Neumann operator $\Lambda_{\Gamma_1,\Gamma_2}$ determines the Riemannian manifold and the metric on it up to an isometry. In the Euclidian space, the result yields that an anisotropic wave speed inside a compact body is determined, up to a natural coordinate transformations, by measurements on the boundary of the body even when wave sources are kept away from receivers. Moreover, we show that if we have three arbitrary non-empty open subsets $\Gamma_1,\Gamma_2$, and $\Gamma_3$ of the boundary, then the restricted Dirichlet-to-Neumann operators $\Lambda_{\Gamma_j,\Gamma_k}$ for $1\leq j<k\leq 3$ determine the Riemannian manifold to an isometry. Similar result is proven also for the finite-time boundary measurements when the hyperbolic equation satisfies an exact controllability condition

Myiasis in domestic cats: A global review

Myiasis is an infestation caused by larvae of Diptera in humans and other vertebrates. In domestic cats, Felis silvestris catus L. (Carnivora: Felidae), four dipteran families have been reported as agents of obligatory and facultative myiasis: Oestridae, Calliphoridae, Sarcophagidae and Muscidae. Among agents of obligatory myiasis, the most frequent genus is Cuterebra Clark (Oestridae) and the most frequent species is Cochliomyia hominivorax (Coquerel) (Calliphoridae). Among the agents of facultative myiasis, the most frequent species is Lucilia sericata (Meigen) (Calliphoridae). A survey of myiasis in cats reported in literature shows that the cases are distributed worldwide and linked to the geographical range of the dipteran species. Factors favouring the occurrence of myiasis in cats are prowling in infested areas, poor hygiene conditions due to diseases and/or neglect, and wounds inflicted during territorial or reproductive competition. The aim of the review is to provide an extended survey of literature on myiasis in cats, as general information and possible development of guidelines for veterinarians, entomologists and other researchers interested in the field