Optimum Tilt Angle at Tropical Region

: One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. Meanwhile, is the rule of thumb, which says that solar collector Equator facing position is the best, is valid for tropical region? Thus, it is required to determine the optimum tilt as for Equator facing and for Pole oriented collectors. In addition, the question that may arise: how many times is reasonable for adjusting collector tilt angle for a definite value of surface azimuth angle? A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle) for the solar collector at any latitude. This model was applied for determining optimum tilt angle and orientation in the tropical zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle) maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of 11% to 18% more than the case of a solar collector fixed on a horizontal surface

Strongly bounded groups and infinite powers of finite groups

We define a group as strongly bounded if every isometric action on a metric space has bounded orbits. This latter property is equivalent to the so-called uncountable strong cofinality, recently introduced by G. Bergman. Our main result is that G^I is strongly bounded when G is a finite, perfect group and I is any set. This strengthens a result of Koppelberg and Tits. We also prove that omega_1-existentially closed groups are strongly bounded.Comment: 10 pages, no figure. Versions 1-3 were entitled "Uncountable groups with Property (FH)". To appear in Comm. Algebr

Šutnja i samoizražavanje u romanu Charlotte Brontë Shirley: Primjena teorije govornih činova Johna Searlea

Despite the “comedic” happy ending of Brontë’s Shirley (1849), its heroine’s taciturn incommunicativeness towards the end of the novel in contrast to her lively former derring-do, has naturally given rise to various speculations about the nature of her transformation. The fact that many of the final exchanges between her and Louis Moore are reported with a temporary shift of point of view in Louis’s personal journal, with an obvious artistic distance between the narrator’s voice and his, merely serves to cast darker shadows over the veracity of his conclusions. The present application of Searle’s speech acts theory to some dialogue samples from Shirley, focuses on the differences of communicational styles in its heroine at three stages of the narrative and concludes that feeling the weight of the “new world” she has entered after her betrothal, Shirley finds that there is a consequent need for her to employ more expressive speech acts to elucidate, fewer assertives for greater self-effacement, and more frequent hedges to give a softer edge to her directives. Shirley’s linguistic technique now relies for its success on her silence and tolerant manner rather than persuasive arguments, and her speech mannerisms might in fact be presumed a “performance.” She thus shifts her style of expression intentionally, and in such a fashion as to empower Louis further and hand the conversational reins over to him.Unatoč sretnom završetku romana Charlotte Brontë Shirley (1849.), vidna suzdržanost i nekomunikativnost junakinje pri kraju romana, suprotna njezinoj ranijoj naglašenoj smjelosti, potaknula je razna nagađanja o prirodi njezine transformacije. Činjenica da su mnogi od posljednjih razgovora između nje i Louisa Moorea priopćeni kroz privremeni pomak narativne perspektive u Louisov osobni dnevnik, s očitom umjetničkom distancom između glasa pripovjedača i Louisova glasa, baca još veću sumnju u vjerodostojnost Louisovih zaključaka. Primjenjujući Searleove teorije govornih činova na nekoliko uzoraka dijaloga iz romana Shirley, ovaj se rad usredotočuje na razlike u komunikacijskim stilovima junakinje u tri faze fabule te ustanovljuje da kroz osjećaj tereta „novog svijeta“, u koji je ušla nakon zaruka, Shirley uviđa nužnost upotrebe izražajnijih govornih činova da bi bila shvaćena, neizricanja vlastitih stavova da bi se što manje isticala te češće uporabe oznaka ograđivanja da bi ublažila oštrinu svojih naredbi. Uspjeh junakinjine lingvističke tehnike sada proizlazi iz njezine nečujnosti i tolerantnog stava, a ne uvjerljive argumentacije, a njezini bi se govorni manirizmi zapravo mogli smatrati „predstavom“. Ona, dakle, namjerno mijenja svoj stil izražavanja, i to na takav način da dodatno osnažuje Louisa, omogućivši mu da preuzme glavnu riječ

A Novel Survey Tool to Quantify the Degree and Duration of STEMI Regionalization Across California.

IntroductionCalifornia has been a global leader in regionalization efforts for time-critical medical conditions. A total of 33 local emergency medical service agencies (LEMSAs) exist, providing an organized EMS framework across the state for almost 40 years. We sought to develop a survey tool to quantify the degree and duration of ST-elevation myocardial infarction (STEMI) regionalization over the last decade in California.MethodsThe project started with the development of an 8-question survey tool via a multi-disciplinary expert consensus process. Next, the survey tool was distributed at the annual meeting of administrators and medical directors of California LEMSAs to get responses valid through December, 2014. The first scoring approach was the Total Regionalization Score (TRS) and used answers from all 8 questions. The second approach was called the Core Score, and it focused on only 4 survey questions by assuming that the designation of STEMI Receiving Centers must have occurred at the beginning of any LEMSA's regionalization effort. Scores were ranked and grouped into tertiles.ResultsAll 33 LEMSAs in California participated in this survey. The TRS ranged from 15 to 162. The Core Score range was much narrower, from 2 to 30. In comparing TRS and Core Score rankings, the top-tertiles were quite similar. More rank variation occurred between mid- and low-tertiles.ConclusionThis study evaluated the degree and duration of STEMI network regionalization from 2004 to 2014 in California, and ranked 33 LEMSAs into tertiles based upon their TRS and their Core Score. Successful application of the 8-item survey and ranking strategies across California suggests that this approach can be used to assess regionalization in other states or countries around the world

Inflammatory myofibroblastic tumor of the bladder: dramatic presentation of an unusual tumor

We report a case of an inflammatory myofibroblastic tumor of the bladder (IMT) in an adult male who presented with recurrent hematuria. He required partial cystectomy which revealed perivesical fat infiltration. In spite of this, the tumor was categorized as benign and the patient remained symptom- and tumor-free 18 months post-operatively.Key Words: Myofibroblastic tumor, bladder, IM

Arylamine N-Acetyltransferase 2 (NAT2) Genetic Diversity and Traditional Subsistence: A Worldwide Population Survey

Arylamine N-acetyltransferase 2 (NAT2) is involved in human physiological responses to a variety of xenobiotic compounds, including common therapeutic drugs and exogenous chemicals present in the diet and the environment. Many questions remain about the evolutionary mechanisms that have led to the high prevalence of slow acetylators in the human species. Evidence from recent surveys of NAT2 gene variation suggests that NAT2 slow-causing variants might have become targets of positive selection as a consequence of the shift in modes of subsistence and lifestyle in human populations in the last 10,000 years. We aimed to test more extensively the hypothesis that slow acetylation prevalence in humans is related to the subsistence strategy adopted by the past populations. To this end, published frequency data on the most relevant genetic variants of NAT2 were collected from 128 population samples (14,679 individuals) representing different subsistence modes and dietary habits, allowing a thorough analysis at both a worldwide and continent scale. A significantly higher prevalence of the slow acetylation phenotype was observed in populations practicing farming (45.4%) and herding (48.2%) as compared to populations mostly relying on hunting and gathering (22.4%) (P = 0.0007). This was closely mirrored by the frequency of the slow 590A variant that was found to occur at a three-fold higher frequency in food producers (25%) as compared to hunter-gatherers (8%). These findings are consistent with the hypothesis that the Neolithic transition to subsistence economies based on agricultural and pastoral resources modified the selective regime affecting the NAT2 acetylation pathway. Furthermore, the vast amount of data collected enabled us to provide a comprehensive and up-to-date description of NAT2 worldwide genetic diversity, thus building up a useful resource of frequency data for further studies interested in epidemiological or anthropological research questions involving NAT2

Comparative Effects of Fentanyl, Medazolam, Lignocaine and Propranolol on Controlling the Hemodynamic Pressor Response during Laryngoscopy and Intubation

Laryngoscopy and tracheal intubation are considered the most invasive stimuli in anesthesia. They provoked cardiovascular responses that include hypertension, tachycardia and dysrhythmias. Various pharmacological approaches have been used to blunt or attenuate such pressor responses. The present study was designed to evaluate the effect of medazolom, lignocaine and propranolol as a valuable adjuvant to fentanyl in attenuating hemodynamic responses to endotracheal intubation in normotensive patients. Thirty two patient with physical status I or II according to the score of American Society of Anesthesiologist (ASA), scheduled for elective surgery under standard general anesthesia, were randomly allocated into four groups (8 patients in each group), assigned as F, M, L and P groups. Each patient in the four groups received 1 µg/kg i.v fentanyl. Patients in groups M, L and P are treated with 0.2 mg/kg i.v medazolam, 1.5mg/kg i.v lignocaine and 0.01mg/kg i.v propranolol respectively. Induction of anesthesia was then accomplished with 2mg/kg thiopental sodium followed by1.5mg/kg succinylcholine. Tracheal intubation was performed 2 minutes after induction of anesthesia. Heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure and rate pressure product were measured before induction, after induction and at 2, 4, 6 and 8 minutes after intubation. The results indicated no significant variation in the hemodynamic pressor response in all four groups with tracheal intubation. In conclusion, a minimum effective dose of i.v pre-medications (fentanyl, medazolom, lignocaine and propranolol) were found to be individually successful in attenuating and providing a reliable control of all hemodynamic response changes accompanied the process of laryngoscopy and intubation. Therefore, all are proved effective premedication and no one being superior. Key words:  fentanyl, medazolom, lignocaine, propranolol, endotracheal intubation, hemodynamic response