509 research outputs found

    La dimensión afectiva olvidada del conocimiento didáctico del contenido de los profesores de ciencias

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    Shulman se refería al paradigma olvidado de la investigación sobre el profesor el que no se hubiese considerado el contenido de la materia específica, lo que le llevó a desarrollar el Conocimiento Didáctico del Contenido (CDC). Sin embargo la dimensión afectiva y emocional podemos considerarla la parte olvidada del CDC. Shulman consideraba que el CDC es una forma de razonamiento y de acción didáctica por medio de la cual los profesores transforman el contenido en representaciones comprensibles a los estudiantes. Investigaciones recientes indican que no hay acción humana, sin una emoción que la haga posible. Desde esta perspectiva es indudable que las emociones del profesor formarían parte del CDC. En el simposio mostraremos la relación entre lo cognitivo y lo afectivo del profesor y la necesidad de incluir la dimensión afectiva en el CDC de los profesores de ciencias

    Site-selective enzymatic chemistry for polymer conjugation to protein lysine residues: PEGylation of G-CSF at lysine-41

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    Microbial transglutaminase (mTGase) is an enzyme that catalyzes site-specific protein derivatization at specific glutamines and lysines

    Seroprevalence of Toxoplasma gondii among stray cats using different serological techniques in Erbil City: Kurdistan Region/Iraq

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    Background: The causative agent of toxoplasmosis is Toxoplasma gondii which is an intracellular protozoan. Felines including cats are the only definitive hosts for T. gondii and they play a significant role in spreading the oocysts in the environment. It has been estimated that T. gondii infects about one-third of the human population. This study was performed to estimate the seroprevalence rate of Anti-T. gondii IgG Abs in 100 strays by using different serological techniques.Methods: Hundred stray cats of both sexes (50 males and 50 females) from different ages (one month to 48 months) were hunted by trap cage and shooting tranquilizer gun in Erbil city and used for detecting T. gondii antibodies.Results: The seroprevalence rates obtained were: 22%, 20% and 11% by MAT, ELISA and LAT respectively. Male cats showed higher seroprevalence than females (13% versus7%). According to the agreement between MAT titers and ELISA IgG (cutoff ELISA≥1) in stray cat’s sera, the percent of positive results in ELISA (cutoff≥1) method were exactly matched with the MAT titer (≥1:50) while the overall agreement and negative percent agreement were elevated by increasing MAT titers and the positive percent agreement was stable in all titers. The overall agreement results were 96% and 100% for MAT titers ≥1:25 and ≥1:50, respectively and negative percent agreement results were 97.4% and 100% for MAT titers ≥1:25 and ≥1:50 respectively.Conclusions: Exactly matched between MAT technique titer (≥1:50) and ELISA technique. Index (cutoff≥1). Therefore, MAT could be used for detecting IgG Abs of Toxoplasma gondii instead of ELISA technique

    The steric influence of extra-framework cations on framework flexibility:An LTA case study

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    The theoretical extent of framework flexibility of Zeolite A (LTA) in response to the steric and geometric effects of different Si/Al compositions and extra-framework cation content has been explored using GASP software. Flexibility windows and compression mechanisms for siliceous LTA and aluminosilicate Na-LTA, Ca-LTA and K-LTA have been modelled. As expected, relatively small cations in the zeolite pores have little effect on the range of flexibility observed. Aluminosilicate LTA, Na-LTA and Ca-LTA frameworks exhibit identical flexibility windows and these frameworks also follow the same compression mechanisms. The introduction of larger K+ ions, however, results in greater steric hindrance. This restricts the flexibility of the framework and alters the compression mechanism to accommodate these larger cations. It is shown that the limits of the flexibility window of Zeolite A are dependent on framework aluminium content and extra-framework cation size.</p

    Determination of Lipids and Glucose Content in Hydatid Cysts of Echinococcus Granulosus Isolated from Different Intermediate Hosts (Sheep, Goats, Cattle And Human) Tissues

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    This study included comparative biochemical composition of hydatid fluid, protoscolices, infected and non-infected tissues isolated from liver and lungs of infected sheep, goats, and cattle slaughtered in Duhok abattoirs during the period from Nov. 2009 to Apr. 2010. Also hydatid fluid of cysts surgically removed from humans in Azadi Teaching Hospital, Duhok during the period from Mar. 2010 to Jul. 2010. Protoscolices contained higher levels of Lipids, triglycerides and cholesterol with the highest being in cattle liver (63.81±1.434 mg/100g, 38.28±1.277 mgs/100gs and 28.85±0.795 mgs/100gs, respectively) and infected cattle liver and lung tissues (57.78±1.3 mgs/100gs and 51.91±1.299 mgs/100gs, respectively). Hydatid fluid contained high levels of glucose with the highest in hydatid fluid of sheep cysts (Liver: 37.41±0.384 mgs/dl and Lung: 38.98±0.424 mgs/dl) and infected sheep Lung tissues (48.12±0.475 mg/100g)

    Determination of Ions and Iron Content in Hydatid Cysts of Echinococcus Granulosus Isolated From Different Intermediate Hosts (Sheep, Goats, Cattle and Human) Tissues

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    This study included comparative biochemical composition of hydatid fluid, protoscolices, infected and non-infected tissues isolated from liver and lungs of infected sheep, goats, and cattle in Duhok abattoirs during the period from Nov. 2009 to Apr. 2010. Also hydatid fluid of cysts surgically removed from humans in Azadi Teaching Hospital, Duhok during the period from Mar. 2010 to Jul. 2010.Hydatid cysts and host tissues were analyzed for Ions (Na+, K+, Ca++, and Mg++) and Fe++. Among Ions, Na+ exhibited high levels in hydatid fluid of the studied hosts with the highest being in hydatid fluid of sheep liver cyst (356±8.207 mg/dl); furthermore, infected tissues showed higher Na+ levels with the highest being in sheep liver and lung tissues (196±7.461 and 178±5.868 mg/100g respectively). Protoscolices of both liver and lungs showed high K+ levels, among tissues, infected tissue contained high K+ levels with the highest being in infected lung tissues (Ranged from 63.46±0.597 mg/100g to 77.39±0.729 mg/100g). Nearly similar levels of Ca++ were detected in hydatid fluid and protoscolices of all cysts with the highest level being in goats cysts protoscolices (Liver: 9.212±0.081 mg/100g, Lungs: 9.044±0.072 mg/100g) and the lowest in cattle cysts fluid (Liver: 6.954±0.061 mg/dl, Lungs: 6.826±0.054 mg/dl). The level of Mg++ was low in hydatid cysts and tissues of all hosts (Ranged from 0.746±0.016 mg/100g to 0.952±0.015). Small quantities of iron were detected in hydatid cysts of all hosts which were higher in cattle liver cysts (Hydatid fluid 0.0882±0.003 mg/dl and protoscolices 0.0838±0.003 mg/100g) and infected liver tissues (0.2293±0.008 mg/100g)

    Choice of sprint start performance measure affects the performance-based ranking within a group of sprinters: which is the most appropriate measure?

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    Sprint start performance has previously been quantified using several different measures. This study aimed to identify whether different measures could influence the performance-based ranking within a group of 12 sprinters, and if so, to identify the most appropriate measure. None of the 10 performance measures ranked all sprinters in the same order; Spearman's rho correlations between different block phase measures ranged from 0.50 to 0.94, and between block phase measures and those obtained beyond block exit from 0.66 to 0.85. Based on the consideration of what each measure quantifies, normalised average horizontal external power was identified as the most appropriate, incorporating both block velocity and the time spent producing this velocity. The accuracy with which these data could be obtained in an externally valid field setting was assessed against force platform criterion data. For an athlete producing 678 ± 40 W of block power, a carefully set-up manual high-speed video analysis protocol produced systematic and random errors of +5 W and ± 24 W, respectively. Since the choice of performance measure could affect the conclusions drawn from a technique analysis, for example the success of an intervention, it is proposed that external power is used to quantify start performance

    Cortisol is related to acute leukocytosis in maximal but not in hypertrophic dynamic resistance exercise

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    Introduction. Exercise induces immune changes that are multifactorial and include neuroendocrine factors. Acute resistance exercise is followed by marked increases in adrenaline, cortisol, growth hormone, and other factors that have immunomodulatory effects. The purpose of the present study was to investigate the relationship between leukocytosis and hormone responses to two different resistance exercises, low volume high load (gains in maximal strength, MAX) and high volume medium load (gains in muscle mass, HYP). Methods. Using a cross-over design twelve healthy men participated in bilateral leg press exercise consisting of 5 sets of 10 RM and 15 sets of 1 RM. The inter-set rest period was 3 minutes for MAX and 2 minutes for HYP. Venous blood samples were taken at baseline, immediately after (P0) and 15 (P15) and 30 (P30) minutes after the exercise. Basic blood count was analyzed using Sysmex KX-21N (TOA Medical Electronics Co., Ltd., Kobe, Japan). Serum cortisol (COR), testosterone (TES), and growth hormone (GH) concentrations were analyzed by an immunometric chemiluminence method (Immunlite R 1000, DPC, Los Angeles, USA) Results. Both exercises induced significant acute leukocytosis (p\u3c0.001). Leukocytosis was significantly higher after HYP (p\u3c0.01). COR and TES increased significantly after HYP (p\u3c0.01) but not in MAX. GH increased significantly (p\u3c0.05) in both exercises and stayed elevated at P30 in HYP. There was a significant negative correlation between acute leukocytosis and cortisol at P0 in MAX (R=-0.622, p=0.031) but not in HYP r=0.287 (p=0.366). Significant correlations between TES, GH and leukocytes were not observed. Conclusions. Clearly, manipulation of the rest period and load in resistance exercise alters endocrinal as well as immunological responses. Hypertrophic resistance exercise triggered significantly stronger immunological as well as endocrinal responses. In line with the previous studies (e.g. Kraemer et al. 1996) cortisol did not correlate with leukocytes nor with leukocyte subgroups in HYP. It might be that cortisol acts as an anti-inflammatory agent in MAX, however in HYP leukocytosis appears to be related to additional physiological mechanisms e.g. muscle damage and metabolic demands, which might explain why we did not observe the same in HYP. When considering recovery from resistance exercise the immune system should be monitored in addition to hormones
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