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Protection of estrogen in portal hypertension gastropathy: an experimental model
Morgan-Martins, Maria Isabel;Jacques, Simone Iahnig;Hartmann, Renata Minuzzo;Marques, Camila Moraes;Marroni, Cláudio Augusto;Marroni, Norma Possa;
Arquivos de Gastroenterologia , 2011, DOI: 10.1590/S0004-28032011000300011
Abstract: context: portal hypertension is a complication secondary to cirrhosis that is characterized by increased blood flow and/or vascular resistance in the portal system, causing the appearance of a hyperdynamic collateral circulation. partial portal vein ligation is an experimental model used in rats to study the pathophysiological mechanisms involved in pre-hepatic portal hypertension. estrogen e2 is an antioxidant molecule with various physiological actions. objectives: to evaluate the antioxidant activity of endogenous estrogen in an experimental model of partial portal vein ligation by comparing intact with castrated rats. methods: twenty wistar rats, weighing on average 250 g were used and divided into four groups: sham-operated (so); intact (i) with partial portal vein ligation (i + ppvl), castrated (c) and castrated with partial ligation of the vein (c + ppvl). day 1: castration or sham-operation; day 7, ppvl surgery; on day 15 post-ppvl, portal pressure in the mesenteric vein of rats was measured on polygraph letica. lipid peroxidation in the stomach was assessed using the technique of thiobarbituric acid reactive substances and activity of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase. statistical analysis was done with anova - student-newman-keuls (mean ± se), and p<0.05 was considered as significant. results: portal pressure was significantly increased in c + ppvl as compared to the other groups. there was no significant difference in the group of intact rats. tbars showed significant damage in c and c + ppvl in relation to others. antioxidant enzymes were significantly increased in the castrated rats with subsequent ppvl as compared to the other groups. conclusion: we suggest that estrogen e2 plays a protective role in intact compared with castrated rats because it presents hydrophenolic radicals in its molecule, thus acting as an antioxidant in this experimental model.
The Value of Beauty in Theory Pursuit: Kuhn, Duhem, and Decision Theory  [PDF]
Gregory J. Morgan
Open Journal of Philosophy (OJPP) , 2013, DOI: 10.4236/ojpp.2013.31003
Abstract:

Should judgments of beauty play a guiding role in theoretical science even if beauty is not a sign of truth? In this paper I argue that they should in certain cases. If we analyze the rationality of theoretical pursuit using decision theory, a theory’s beauty can influence the utilities of the various options confronting the researcher. After considering the views of Pierre Duhem and Thomas Kuhn on aesthetics in science, I suggest that because we value freedom of inquiry we rightly allow scientists some choice in how they value aesthetic properties of theories and thus some freedom to use beauty to guide their research program.

Student Experience and Ubiquitous Learning in Higher Education: Impact of Wireless and Cloud Applications  [PDF]
Vladlena Benson, Stephanie Morgan
Creative Education (CE) , 2013, DOI: 10.4236/ce.2013.48A001
Abstract:

Mobile learning apps for smartphones and tablet computer devices have entered Higher Education (HE) market. While universities are investing in new technologies, they also look into cost reduction strategies, including cloud computing. We draw upon a case study of a successful migration to mobile virtual environment and effective use of cloud computing at a UK university. Success factors and challenges of these emerging technologies in HE are discussed. The paper concludes with the consideration of student experience implications and research questions which need addressing in the area of ubiquitous learning.



Infarto do miocárdio experimental e aumento do estresse oxidativo em diafragma de ratos
Silva, Fabiano Leichsering;Mazzotti, Nicolle Gollo;Picoral, Marcus;Nascimento, Daniella Meirelles;Martins, Maria Isabel Morgan;Klein, Adriane Belló;
Jornal Brasileiro de Pneumologia , 2005, DOI: 10.1590/S1806-37132005000600008
Abstract: objective: to use an experimental model to evaluate the effect of heart failure on oxidative stress in the rat diaphragm. methods: the model of myocardial infarction was developed through left coronary artery ligation. on day 42 after coronary artery ligation, the animals were killed, after which the diaphragms were collected and homogenized. oxidative stress was evaluated in diaphragm homogenates through measurement of lipid peroxidation and assays of the activity of antioxidant enzymes, including catalase and glutathione peroxidase (enzymes that reduce hydrogen peroxide to water), as well as superoxide dismutase (an antioxidant enzyme that reduces superoxide anions to hydrogen peroxide). results: the coronary artery ligation model was found to be effective in causing heart failure. in the animals submitted to coronary artery ligation, the mean infarcted area of the left ventricle was 39%. lipid peroxidation was 217% greater in the diaphragms of ligated animals than in those of controls. the activity of catalase and glutathione peroxidase was 77% and 20% lower, respectively, in study rats than in control rats. infarction did not modify superoxide dismutase activity. conclusion: the results suggest that left coronary artery ligation results in oxidative stress in the diaphragm.
Team Players and Team Managers: Special Educators Working with Paraeducators to Support Inclusive Classrooms  [PDF]
Betty Y. Ashbaker, Jill Morgan
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.33051
Abstract: This paper summarizes recommendations from a selection of international research literature urging teachers to take the initiative in their own classrooms to invite paraeducators to participate fully as team players in collaborative work. In US classrooms paraeducators (teacher aides/teacher assistants) have long been making valuable contributions in providing education services to students with a variety of needs. The literature documents change in their roles. Legislation has influenced their required qualifications—although legislation still refers to them as paraprofessionals. While some researchers have cast doubt on whether paraeducators are truly effective in their assigned roles, others have warned that the education system is over-reliant on them. In response to this changing perspective, teacher educators must revise programs to better prepare teacher candidates to effectively team with paraeducators. Personnel developers and school administrators must provide inservice training for a generation of teachers who have received little if any training in this area.
Cavitation Detection in Variable Speed Pump by Analyzing the Acoustic and Vibration Spectrums  [PDF]
Ashraf Kotb, Abdulaziz Morgan Abdulaziz
Engineering (ENG) , 2015, DOI: 10.4236/eng.2015.710062
Abstract: Cavitation in pumps must be detected and prevented. The present work is an attempt to use the simultaneous measurements of vibration and sound for variable speed pump to detect cavitation. It is an attempt to declare the relationship between the vibration and sound for the same discharge of 780 L/h and NPSHA of 0.754 at variable speeds of 1476 rpm, 1644 rpm, 1932 rpm, 2190 rpm, 2466 rpm, and 2682 rpm. Results showed that: the occurrence of cavitation depends on the rotational speed, and the sound signals in both no cavitation and cavitation conditions appear in random manner. While, surveying the vibration and sound spectrums at the second, third, and fourth blade passing frequencies reveals no indications or phenomenon associated with the cavitation at variable speeds. It is recommended to survey the vibration spectra at the rotational and blade passing frequencies simultaneously as a detection unique method of cavitation.
Investigating the Validity of Acoustic Spectrum as a Prediction Tool for Pump Cavitation  [PDF]
Ashraf Kotb, Abdulaziz Morgan Abdulaziz
Energy and Power Engineering (EPE) , 2015, DOI: 10.4236/epe.2015.713054
Abstract: Cavitation in pumps causes destructive consequences; it must be detected and prevented. The aim of the present work is investigating the validity of sound spectrum as a prediction tool for pump cavitation. Results showed that; for the discrete frequencies of RF = 47.5 Hz, and BPF = 285 Hz and its second, third, and fourth harmonics of 570 Hz, 855 Hz, and 1140 Hz respectively; there are no great variations in the noise signal for the cavitation and non-cavitation conditions. For the discrete frequency of 147 Hz, there is also no great variation in the noise signal at this frequency. The only apparent result is that; the occurrence of cavitation results high energy noise signals at high frequencies from 1000 Hz to 10000 Hz. The absence of any discrete frequency to be monitored makes the sound spectrum not valid as a prediction tool for cavitation in the pumps.
Models for the recent evolution of protocadherin gene clusters
Morgan,Marcos;
Biocell , 2008,
Abstract: the clustered protocadherins (pcdhs) are single-pass transmembrane proteins that constitute a subfamily within the cadherin superfamily. in mammals, they are arranged in three consecutive clusters named a, b, and g. these proteins are expressed in the nervous system and are targeted to mature synapses. interestingly, different neurons express different subsets of isoforms; however, little is known about the functions and expression of the clustered pcdhs. previous phylogenetic analyses that compared rodent and human clusters postulated the recent occurrence of gene duplication events. using standard phylogenetic methods, i confirmed the prior observations, and i show that duplications are likely to occur through unequal crossing-over events between two, and sometimes three, different pcdh genes. the results are consistent with the fact that these genes undergo gene conversion. recombination events between different clustered pcdh genes appear to underlie concerted evolution through gene conversion and gene duplications through unequal crossing-over. in this work, i provided evidence that the unit of duplication of these genes in both the mouse and the human and within each cluster is the same. the unit of duplication includes the extracellular domain-coding sequence of an isoform and its promoter along with the cytoplasmic domain-coding region of the immediately upstream isoform in the cluster.
Infectious disease risks from dead bodies following natural disasters
Morgan,Oliver;
Revista Panamericana de Salud Pública , 2004, DOI: 10.1590/S1020-49892004000500004
Abstract: objective: to review existing literature to assess the risks of infection from dead bodies after a natural disaster occurs, including who is most at risk, what precautions should be taken, and how to safely dispose of the bodies. methods: disease transmission requires the presence of an infectious agent, exposure to that agent, and a susceptible host. these elements were considered to characterize the infectious disease risk from dead bodies. using the pubmed on-line databases of the national library of medicine of the united states of america, searching was done for relevant literature on the infection risks for public safety workers and funeral workers as well as for guidelines for the management of the dead and prevention of infection. a small but significant literature was also reviewed regarding the disposal of the dead and the contamination of groundwater by cemeteries. results: victims of natural disasters usually die from trauma and are unlikely to have acute or "epidemic-causing" infections. this indicates that the risk that dead bodies pose for the public is extremely small. however, persons who are involved in close contact with the dead-such as military personnel, rescue workers, volunteers, and others-may be exposed to chronic infectious hazards, including hepatitis b virus, hepatitis c virus, hiv, enteric pathogens, and mycobacterium tuberculosis. suitable precautions for these persons include training, use of body bags and disposable gloves, good hygiene practice, and vaccination for hepatitis b and tuberculosis. disposal of bodies should respect local custom and practice where possible. when there are large numbers of victims, burial is likely to be the most appropriate method of disposal. there is little evidence of microbiological contamination of groundwater from burial. conclusions: concern that dead bodies are infectious can be considered a "natural" reaction by persons wanting to protect themselves from disease. however, clear information about
A formalised performance assessment process to improve audit committee performance in South Africa: A conceptual exploration
I Morgan
Southern African Business Review , 2010,
Abstract: There is concern worldwide about corporate governance, director liability, litigations and business failures, the economic recession and the quality of fi nancial reporting. Owing to these factors, new regulations and legislation aff ecting organisations and the related responsibilities imposed on audit committees, it is imperative that the performance of audit committees and individual members be enhanced and sustained. The King III Report and other corporate governance principles specify that the board, its committees and individual members should be evaluated regularly, which was not a requirement for individual committee members in King II. This article examines formal guidelines and requirements to identify the factors aff ecting the audit committee and individual members’ performance, to determine whether their performance could be improved by formalising the assessment process and to develop a framework for measuring their performance. The balanced scorecard as a method of assessment or evaluation is examined and proposed to help audit committees to meet their requirements and improve the quality of their oversight responsibilities. This article should be of value to boards of directors, audit committees and regulators in that the contributions of a more formalised performance assessment process as an internal governance mechanism towards facilitating the professional development of audit committee members are demonstrated.
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