Large Radius Hagedorn Regime in String Gas Cosmology

We calculate the equation of state of a gas of strings at high density in a large toroidal universe, and use it to determine the cosmological evolution of background metric and dilaton fields in the entire large radius Hagedorn regime, (ln S)^{1/d} << R << S^{1/d} (with S the total entropy). The pressure in this regime is not vanishing but of O(1), while the equation of state is proportional to volume, which makes our solutions significantly different from previously published approximate solutions. For example, we are able to calculate the duration of the high-density "Hagedorn" phase, which increases exponentially with increasing entropy, S. We go on to discuss the difficulties of the scenario, quantifying the problems of establishing thermal equilibrium and producing a large but not too weakly-coupled universe.Comment: 12 pages, 4 figures, more details presented in string thermodynamics section, to be published in Physical Review

Characterization of a new laboratory ceramic product from industrial by-products as raw materials and caustic magnesia as additive

Στην εργασία αυτή παρουσιάζεται ένα νέο κεραμικό προϊόν που παράχθηκε από μίξη καυστικής μαγνησίας, που παρασκευάστηκε εργαστηριακά από υψηλής καθαρότητας μαγνησίτη, φυσικού πηλού καθώς και τέφρας πυθμένα και ερυθράς ιλύος, προϊόντα γνωστά για τις δυσμενείς περιβαλλοντικές επιπτώσεις τους. Έπειτα από δοκιμή ποικίλων συνταγών, συμπεράναμε ότι προσθήκη 5% καυστικής μαγνησίας στο κεραμικό προϊόν βελτιώνει τις μηχανικές επιδόσεις του. Αυτό αποδίδεται στο γεγονός ότι το περίκλαστο της καυστικής μαγνησίας σχηματίζει «λαιμούς», οι οποίοι ισχυροποιούν τους δεσμούς στη μικροδομή του κεραμικού, σε συνδυασμό με τον ταυτόχρονο σχηματισμό μικρών ποσοτήτων άμορφου υλικού και την ομοιογενή κατανομή των πόρων, που δημιουργούνται κατά την όπτηση. Με συνδυαστική μελέτη Περιθλασιμετρίας Ακτίνων Χ και Σαρωτικού Ηλεκτρονικού Μικροσκοπίου του κεραμικού υποδείχτηκε η παρουσία αναλλοίωτων φάσεων, προερχόμενων από τις πρώτες ύλες, καθώς και νεοσχηματισμένων κρυστάλλων αλβίτη και μαγνησιοφερρίτη. Τα αποτελέσματα της παρούσας μελέτης δείχνουν ότι η χρήση παραπροϊόντων μπορεί να είναι σημαντική και περιβαλλοντικά φιλική στην παραγωγή φτηνών δομικών κεραμικών.A new ceramic product is introduced by mixing caustic magnesia, produced in the laboratory from pure, high quality magnesite, and natural silt. Bottom ash and red mud, two well known environmentally hazardous industrial by-products, were also added in the mixture. After testing various recipes we concluded that addition of 5% caustic magnesia in the ceramic product greatly enhances its performance. Increase bonding of the ceramic microstructure is attributed to the formation of periclase necks, the concurrent formation of small quantities of amorphous material and the homogeneously distributed pores during the experimental firing of the mixture. Combined X-ray Diffractometry and Scanning Electron Microscopy of the ceramic product revealed the occurrence of unreactive phases, inherited by the raw materials, as well as newly-formed albite and magnesioferrite. Our results show that utilization of by-products may be important and environmental friendly materials in producing low cost ceramic building materials

Voluntary self-poisoning as a cause of admission to a tertiary hospital internal medicine clinic in Piraeus, Greece within a year

BACKGROUND: Out of 1705 patients hospitalised for various reasons in the 3(rd) Internal Medicine Department of the Regional General Hospital of Nikaea, in Piraeus, 146(8,5%) persons were admitted for drug intoxication between November 1999 and November 2000. METHODS: On average, these persons [male 50(34,2%) – female 96(65,8%)] were admitted to the hospital within 3.7 hours after taking the drug. RESULTS: The drugs that were more frequently taken, alone or in combination with other drugs, were sedatives (67.1%), aspirins and analgesics (mainly paracetamol) (43.5%). 38.3% of patients had a mental illness history, 31.5% were in need of psychiatric help and 45.2% had made a previous suicide attempt. No death occurred during the above period and the outcome of the patients' health was normal. After mental state examination, the mental illnesses diagnosed were depression (20.96%), psychosis (15.32%), dysthymic disorder (16,2%), anxiety disorder (22.58%) and personality disorder (8.87%). CONCLUSIONS: Self-poisoning remains a crucial problem. The use of paracetamol and sedatives are particularly important in the population studied. Interpersonal psychiatric therapy may be a valuable treatment after people tried to poison themselves

Self-medication with antibiotics in rural population in Greece: a cross-sectional multicenter study

<p>Abstract</p> <p>Background</p> <p>Self-medication is an important driver of antimicrobial overuse as well as a worldwide problem. The aim of the present study was to estimate the use of antibiotics, without medical prescription, in a sample of rural population presenting in primary care in southern Greece.</p> <p>Methods</p> <p>The study included data from 1,139 randomly selected adults (545 men/594 women, mean age ± SD: 56.2 ± 19.8 years), who visited the 6 rural Health Centres of southern Greece, between November 2009 and January 2010. The eligible participants were sought out on a one-to-one basis and asked to answer an anonymous questionnaire.</p> <p>Results</p> <p>Use of antibiotics within the past 12 months was reported by 888 participants (77.9%). 508 individuals (44.6%) reported that they had received antibiotics without medical prescription at least one time. The major source of self-medication was the pharmacy without prescription (76.2%). The antibiotics most frequently used for self-medication were amoxicillin (18.3%), amoxicillin/clavulanic acid (15.4%), cefaclor (9.7%), cefuroxim (7.9%), cefprozil (4.7%) and ciprofloxacin (2.3%). Fever (41.2%), common cold (32.0%) and sore throat (20.6%) were the most frequent indications for the use of self-medicated antibiotics.</p> <p>Conclusion</p> <p>In Greece, despite the open and rapid access to primary care services, it appears that a high proportion of rural adult population use antibiotics without medical prescription preferably for fever and common cold.</p

Prevalence, and associated risk factors, of self-reported diabetes mellitus in a sample of adult urban population in Greece: MEDICAL Exit Poll Research in Salamis (MEDICAL EXPRESS 2002)

BACKGROUND: The continuous monitoring and future prediction of the growing epidemic of diabetes mellitus worldwide presuppose consistent information about the extent of the problem. The aim of this study was to determine the prevalence of diagnosed diabetes and to identify associated risk factors in a sample of adult urban Greek population. METHODS: A cross-sectional population-based survey was conducted in municipality of Salamis, Greece, during an election day (2002). The study sample consisted of 2805 participants, aged 20–94 years. Data were collected using a standardized short questionnaire that was completed by a face-to-face interview. Multiple regression analyses were performed to evaluate the association of diabetes with potential risk factors. RESULTS: The overall prevalence of diagnosed diabetes was 8.7% (95% CI 7.7–9.8%). After age adjustment for the current adult population (2001 census) of Greece, the projection prevalence was calculated to 8.2%. Multivariate logistic regression analysis identified as independent risk factors: increasing age (odds ratio, OR = 1.07, 95% CI 1.06–1.08), male sex (OR = 1.43, 95% CI 1.04–1.95), overweight and obesity (OR = 1.97, 95% CI 1.29–3.01 and OR = 3.76, 95% CI 2.41–5.86, respectively), family history of diabetes (OR = 6.91, 95% CI 5.11–9.34), hypertension (OR = 2.19, 95% CI 1.60–2.99) and, among women, lower educational level (OR = 2.62, 95% CI 1.22–5.63). The prevalence of overweight and obesity, based on self-reported BMI, were 44.2% and 18.4%, respectively. Moreover, the odds for diabetes in obese subjects with family history were 25-fold higher than those with normal weight and without family history of diabetes, while the odds in overweight subjects with family history of diabetes were 15-fold higher. CONCLUSIONS: Our findings indicated that the prevalence of diabetes is high in Greek population. It is suggested that the main modifiable contributing factor is obesity, whose effect is extremely increased upon positive heredity presence

Adaptive mechanisms of plants against salt stress and salt shock

Salinization process occurs when soil is contaminated with salt, which consequently influences plant growth and development leading to reduction in yield of many food crops. Responding to a higher salt concentration than the normal range can result in plant developing complex physiological traits and activation of stress-related genes and metabolic pathways. Many studies have been carried out by different research groups to understand adaptive mechanism in many plant species towards salinity stress. However, different methods of sodium chloride (NaCl) applications definitely give different responses and adaptive mechanisms towards the increase in salinity. Gradual increase in NaCl application causes the plant to have salt stress or osmotic stress, while single step and high concentration of NaCl may result in salt shock or osmotic shock. Osmotic shock can cause cell plasmolysis and leakage of osmolytes in plant. Also, the gene expression pattern is influenced by the type of methods used in increasing the salinity. Therefore, this chapter discusses the adaptive mechanism in plant responding to both types of salinity increment, which include the morphological changes of plant roots and aerial parts, involvement of signalling molecules in stress perception and regulatory networks and production of osmolyte and osmoprotective proteins