918 resultados para History of mathematics in Spain


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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We describe the distribution of tuberculosis-like lesions (TBL) in wild boar (Sus scrofa) and red deer (Cervus elaphus) in Spain. Animals with TBL were confirmed in 84.21% of mixed populations (n = 57) of red deer and wild boar and in 75% of populations of wild boar alone (n = 8) in central and southern Spain (core area). The prevalence of TBL declined towards the periphery of this region. In the core area, the prevalence ranged up to 100% in local populations of wild boar (mean estate prevalence 42.51%) and up to 50% in red deer (mean estate prevalence 13.70%). We carried out exploratory statistical analyses to describe the epidemiology of TBL in both species throughout the core area. Prevalence of TBL increased with age in both species. Wild boar and red deer mean TBL prevalence at the estate level were positively associated, and lesion scores were consistently higher in wild boars than in red deer. The wild boar prevalence of TBL in wild boar did not differ between populations that were or were not cohabiting with red deer. Amongst the wild boars with TBL, 61.19% presented generalized lesions, and the proportion of generalized cases was similar between sex and age classes. In red deer, 57.14% of TBL-positive individuals presented generalized lesions, and the percentage of generalized cases increased with age class, but did not differ between the sexes. These results highlight the potential importance of wild boar and red deer in the maintenance of tuberculosis in south central Spain.

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In this action research study of my mathematics classroom of eighth grade students, I investigated the use of mathematics vocabulary by focusing on improving the usage of this vocabulary in both oral and written communication. I discovered oral communication tended to show more improvements compared to written communication done by the same group of students. As a result of this research, I plan to continue to focus my teaching on the use of mathematics vocabulary in an effort to help my students gain a greater understanding of the daily use of that vocabulary.

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In this action research study of my classroom of eighth grade mathematics, I investigated the use of manipulatives and its impact on student attitude and understanding. I discovered that overall, students enjoy using manipulatives, not necessarily for the benefit of learning, but because it actively engages them in each lesson. I also found that students did perform better on exams when students were asked to solve problems using manipulatives in place of formal written representations of situations. In the course of this investigation, I also uncovered that student attitude toward mathematics improved when greater manipulative use was infused into the lessons. Students felt more confident that they understood the material, which translated into a better attitude regarding math class. As a result of this research, I plan to find ways to implement manipulatives in my teaching on a more regular basis. I intend to create lessons with manipulatives that will engage both hands and minds for the learners.

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Standing at the corner of Tenth and O streets in the city of Lincoln, Nebraska, any week-day morning between 7:30 and 8 o'clock, you may see pass by you from ten to twenty women with little black woolen shawls on their heads. Ask any citizen who they are, and ninety-nine times in one hundred he will tell you they are "Russians" who live down on the bottoms, that they are going out into the offices and homes to wash and scrub and clean house, and that their husbands are street laborers or work for the railroad. He may then grow confidential and tell you that he "has no use for these people", that "they are only half human", and that he "would just as soon see the Chinese come here as those people". As a matter of fact the greater part of his information is incorrect, partly through race prejudice but chiefly through ignorance of their history. These people, of whom there are about 4,000 in the city (Including "beet fielders"), are Germans, not Russians: they are Teutons, not Slavs; they are Lutheran and Reformed, not Greek Catholics. To be sure they and their ancestors lived in Russia for over one hundred years and they came here directly from the realm of the Czar whoso bona fide citizens they were—but they never spoke the Russian language, never embraced the Greek religion, never intermarried with the Russians, and many of their children never saw a Russian until they left their native village for the new home in America. They despise being called "Russians" just as an Italian resents "Dago"; a Jew, "Sheeny"; and a German, "Dutchman". Ask them where they came from and most of the children and not a few of the grown people will say, "Germany". If you pursue your questioning as to what part of Germany, they will tell you "Saratov" or "Samara" - two governments in the eastern part of Russia on the lower course of the Volga river. The misconceptions concerning the desirability of these German-Russians as citizens arise from their unprogressiveness as compared with those Germans who come to us directly from the mother country. During their century's sojourn in Russia they have been out of the main current of civilization, a mere eddy in the stream of progress. They present a concrete example of arrested development, The characteristics which differentiate them from other Germans are not due to an inherent lack of capacity but to different environment. Notwithstanding this, the German- Russians have some admirable qualities. They bring us large stores of physical energy and an almost unlimited capacity for work. The majority of them are literate although the amount of their education is limited. They are thrifty and independent, almost never applying for public aid. They are law abiding, their chief offenses being those which are traceable to their communal life in Russia. They are extremely religious, all their social as well as spiritual life being bound up in the church which they support right royally. To be sure, the saloon gets their vote (the prohibition vote among them is increasing); but "was not the first miracle that Christ performed the turning of water into wine? If they would shut up the shows (theaters), they wouldn't need to shut up the saloons". The object of this paper is to give the historical setting in which the German-Russians have lived as one means to a better understanding and appreciation of them by our own citizens.

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This paper reports the reconstruction of the contamination history of a large South American industrial coastal area (Santos Estuary, Brazil) using linear alkylbenzenes (LABs). Three sediment cores were dated by (137)Cs Concentrations in surficial layers were comparable to the midrange concentrations reported for coastal sediments worldwide LAB concentrations increased towards the surface. indicating increased waste discharges into the estuary in recent decades. The highest concentration values occurred in the early 1970s, a time of intense industrial activity and marked population growth. The decreased LAB concentration, in the late 1970s was assumed to be the result of the world oil crisis Treatment of industrial effluents, which began in 1984, was represented by decreased LAB levels Microbial degradation of LABs may be more intense in the industrial area sediments. The results show that industrial and domestic waste discharges are a historical problem in the area. (C) 2010 Elsevier Ltd. All rights reserved.

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The hydroid Zyzzyzus warreni is usually found in shallow coastal waters forming aggregations of solitary polyps embedded in demosponges. Early life history transformations and settlement responses by the actinulae of this hydroid were studied in the laboratory using 13 species of sponges and 2 species of algae collected in the Sao Sebastiao Channel (Brazil) as substrata. The absence of oral tentacles and mouth in the actinulae and early events of metamorphosis suggest that these larvae are unable to spend long periods in the plankton and attach quickly near conspecifics when a preferred substratum is encountered. The time required for settlement and the number of elicited settlings indicated four settlement responses: (a) frequent and short-time settlement, in actinulae exposed to Halichondria cebimarensis, Mycale angulosa, M. aff. americana, M. laxissima (skeleton) and Tedania ignis; (b) moderate and delayed settlement, in actinulae exposed to Aplysina caissara, A. fulva, Haliclona melana and M. microsigmatosa; (c) no settlement, in actinulae exposed to Suberites aurantiacus and to the algae Hypnea musciformis and Sargassum cymosum; and (d) lethal response, in actinulae exposed to Amphimedon viridis, Aplysilla rosea, Dragmacidon reticulatum and M. laxissima. These responses indicate a considerable degree of species discrimination by the actinulae and are consistent with substrata used by the hydroid in the natural environment.

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Non-myrmecophilous lepidopteran larvae using plants bearing ant attractants such as extrafloral nectaries are good models for studying morphological and behavioural mechanisms against ant predation. Udranomia spitzi (Hesperiidae) is a butterfly whose larvae feed on leaves of Ouratea spectabilis (Ochnaceae), a plant with extrafloral nectaries. We described the early stages of U. spitzi, and used field observations and experiments to investigate the defensive strategies of caterpillars against predatory ants. Larvae pass through five instars and pupation occurs inside larval leaf shelters. Ant-exclusion experiments revealed that the presence of ants did not affect significantly caterpillar survival. Predation experiments showed that vulnerability to ant predation decreased with increase in larval size. The present study showed that predatory ants are not as relevant as demonstrated for other systems, and also illustrates how observational data and field experiments can contribute to a better understanding of the biology and ecology of a species of interest.

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Background-Patients with acute coronary syndromes and history of stroke or transient ischemic attack (TIA) have an increased rate of recurrent cardiac events and intracranial hemorrhages. Methods and Results-We evaluated treatment effects of ticagrelor versus clopidogrel in patients with acute coronary syndrome with and without a history of prior stroke or TIA in the PLATelet inhibition and patient Outcomes (PLATO) trial. Of the 18 624 randomized patients, 1152 (6.2%) had a history of stroke or TIA. Such patients had higher rates of myocardial infarction (11.5% versus 6.0%), death (10.5% versus 4.9%), stroke (3.4% versus 1.2%), and intracranial bleeding (0.8% versus 0.2%) than patients without prior stroke or TIA. Among patients with a history of stroke or TIA, the reduction of the primary composite outcome and total mortality at 1 year with ticagrelor versus clopidogrel was consistent with the overall trial results: 19.0% versus 20.8% (hazard ratio, 0.87; 95% confidence interval, 0.66-1.13; interaction P=0.84) and 7.9% versus 13.0% (hazard ratio, 0.62; 95% confidence interval, 0.42-0.91). The overall PLATO-defined bleeding rates were similar: 14.6% versus 14.9% (hazard ratio, 0.99; 95% confidence interval, 0.71-1.37), and intracranial bleeding occurred infrequently (4 versus 4 cases, respectively). Conclusions-Patients with acute coronary syndrome with a prior history of ischemic stroke or TIA had higher rates of clinical outcomes than patients without prior stroke or TIA. However, the efficacy and bleeding results of ticagrelor in these high-risk patients were consistent with the overall trial population, with a favorable clinical net benefit and associated impact on mortality.

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To evaluate whether a history of falls is directly related to the quadriceps muscular function and body sway, 26 elderly women were divided on the basis of the presence or absence of a history of falls. Evaluation of muscular power and anteroposterior and mediolateral displacements of center of pressure during consecutive stand and sit 5 times were performed. Fallers exhibited higher mediolateral displacement than nonfallers. No differences were observed for quadriceps power and for sit-to-stand time between groups (P<.05). The fall history was not related to the quadriceps muscular function or to the anteroposterior displacement during sit to stand.

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Background: The aim of this study was to investigate the effects of sub-clinical alterations on the amplitudes and slopes of the DPOAE input-output responses from subjects with previous history of middle ear dysfunction. Material/Methods: The study included 15 subjects with and 15 subjects without a history of otitis media in the last 10 years. All participants were assessed with acoustic immittance, pure-tone audiometry, and DPOAEs. For the later, I/O functions and I/O slopes were estimated at 1501, 2002, 3174, 4004 and 6384Hz. Results: No statistically significant differences were found between the 2 groups in terms of behavioral thresholds. The group with a previous history of middle ear dysfunction presented significantly lower mean DPOAE amplitudes at 2002, 3174 and 4004 Hz. In terms of DPOAE slopes, no statistically significant differences were observed at the tested frequencies, except at 3174 Hz. Conclusions: Middle ear pathologies can produce subclinical alterations that are undetectable with traditional pure-tone audiometry. The data from the present study show that reduced amplitude DPOAEs are associated with a previous history of middle ear complications. The corresponding DPOAE slopes were affected at only 1 tested frequency, suggesting that the cochlear non-linearity is preserved. Considering these results, it remains to be elucidated to what degree the DPOAE amplitude attenuation interferes with higher-order auditory tasks.

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The history of the quinine synthesis can be used as a case study to emphasize that science is influenced by social and historical processes. The first efforts toward the synthesis of this substance, which until recently was the only treatment for malaria, were by Perkin in 1856 when, trying to obtain quinine,,. he synthesized mauveine. Since then, the quest for the total synthesis of quinine involved several characters in a web of controversies. A major step in this process was made in 1918 by Rabe and Kindler, who proposed the synthesis of quinine from quinotoxine. Twenty-six years later, after obtaining the total synthesis of quinotoxine, Woodward and Doering announced the total synthesis of quinine. However, the lack of experimental details about Rabe and Kindler's process, associated with Woodward and Doering's failure to reproduce it, raised a series of doubts about the synthesis. Stork and colleagues questioned the veracity of the experimental data and even the scientific reputation of the involved researchers. Doubts remained alive until 2008, when Williams and Smith reported, not without reservations, the reproducibility of Rabe and Kindler's protocol. The scientific knowledge as a social and historical development, its legitimating process, and the absence of neutrality in science constitute aspects that can be discussed from this case study, providing significant contributions to science education, in particular, to the initial or continued training of chemistry teachers.