Contextual Pandora's Box

Pandora's Box is a fundamental stochastic optimization problem, where the decision-maker must find a good alternative while minimizing the search cost of exploring the value of each alternative. In the original formulation, it is assumed that accurate distributions are given for the values of all the alternatives, while recent work studies the online variant of Pandora's Box where the distributions are originally unknown. In this work, we study Pandora's Box in the online setting, while incorporating context. At every round, we are presented with a number of alternatives each having a context, an exploration cost and an unknown value drawn from an unknown distribution that may change at every round. Our main result is a no-regret algorithm that performs comparably well to the optimal algorithm which knows all prior distributions exactly. Our algorithm works even in the bandit setting where the algorithm never learns the values of the alternatives that were not explored. The key technique that enables our result is a novel modification of the realizability condition in contextual bandits that connects a context to a sufficient statistic of each alternative's distribution (its "reservation value") rather than its mean

Spontaneous regression of a true splenic cyst: a case report and review of the literature

Splenic cysts are rare clinical findings, detected due to derivative symptoms or as a random discovery in abdominal imaging. Although there still remains controversy as to their optimal treatment, bigger secondary cysts should be treated surgically. However, spontaneous regression may be observed in cysts with a diameter smaller than 4 cm. In these cases, expectant treatment is preferable. We report, herein, a single case of a splenic cyst in an adult woman, who reported minor symptoms despite the size of the lesion and who demonstrated a possible almost total regression of the cyst within a ten-year period, accompanying with review of the most recent literature

Diffuse anorectal melanoma; review of the current diagnostic and treatment aspects based on a case report

Primary anorectal melanoma is a rare and aggressive disease. Patients commonly complain for changes in bowel habits and rectal bleeding, and proctoscopically they mostly appear as non pigmented or lightly pigmented polypoid lesions. Such a lesion should always raise a high index of suspicion in any gastroenterologist or surgeon to prompt surgery, since early radical excision is the only treatment option

The Relationship between Student Science Teachers’ Views on Nature of Science and Classroom Practice: Is There Any?

The present study investigated the relationship between student science teachers’ views on Nature of Science and their views on the importance of teaching Nature of Science. It is a case study in which qualitative methods and descriptive statistics are used. The sample consisted of 23 student science teachers who attended a faculty course on Didactics of Physics and participated voluntarily. Preliminary findings showed a moderate relationship between students’ views on Nature of Science issues and their classroom practice, particularly regarding “tenets” such as the tentative character of science and sociocultural milieu. When it comes to more epistemological issues, such as the difference between a theory and a law, then student teachers have considerable conceptual difficulties and they also find the particular “tenets” less important for a school science context

Epididymal Adenomatoid Tumor: A Very Rare Paratesticular Tumor of Childhood

Adenomatoid tumor is an uncommon benign mesothelial neoplasm, usually localized in the epididymis. It is the most common paratesticular tumor of middle-aged patients (average age of clinical presentation: 36 years). However, these tumors in pediatric and pubertal patients are extremely rare. Due to their rarity, we present a case of adenomatoid tumor of the tail of the epididymis in a 16-year-old patient. After systematic research of the current literature, we did not find another case report of epididymal adenomatoid tumor in a male patient aged 16 years old or less. This notice and our concern, as well, about the patient’s surveillance protocol during the postoperative period were the motive for this case study

Integrated primary health care in Greece, a missing issue in the current health policy agenda: a systematic review

Background: Over the past years, Greece has undergone several endeavors aimed at modernizing and improving national health care services with a focus on PHC. However, the extent to which integrated primary health care has been achieved is still questioned. <br><br> Purpose: This paper explores the extent to which integrated primary health care (PHC) is an issue in the current agenda of policy makers in Greece, reporting constraints and opportunities and highlighting the need for a policy perspective in developing integrated PHC in this Southern European country. <br><br> Methods: A systematic review in PubMed/Medline and SCOPUS, along with a hand search in selected Greek biomedical journals was undertaken to identify key papers, reports, editorials or opinion letters relevant to integrated health care. <br><br> Results: Our systematic review identified 198 papers and 161 out of them were derived from electronic search. Fifty-three papers in total served the scope of this review and are shortly reported. A key finding is that the long-standing dominance of medical perspectives in Greek health policy has been paving the way towards vertical integration, pushing aside any discussions about horizontal or comprehensive integration of care. <br><br> Conclusion: Establishment of integrated PHC in Greece is still at its infancy, requiring major restructuring of the current national health system, as well as organizational culture changes. Moving towards a new policy-based model would bring this missing issue on the discussion table, facilitating further development

Smoking status in relation to serum folate and dietary vitamin intake

Objective Cigarette smoke itself is an abundant source of free radicals and a major cause of oxidative stress, to which plasma antioxidants function as a vital protective and counterbalancing mechanism. The objective of this study was to investigate into the relationship between smoking status and serum and dietary micronutrient concentrations. Design Cross-sectional study Subjects ' Setting 502 farmers from the Valley of Messara in Crete were randomly selected and examined. Complete three-day and 24-hr recall questionnaires were collected along with anthropometrical, physical activity and clinical data from all participating subjects. Results After adjusting for age, gender and number of fasting days adhered to per year, current smokers were found to have a lower dietary intake of vitamin C (112.1 mg vs. 136.4 mg, p = 0.03), fibre (16.6 g vs. 19.1 g, p = 0.006) and fruits and vegetables (339 g vs. 412 g, p = 0.014), while dietary vitamin B1 intake was found to be higher (1.7 mg vs. 1.4 mg, p = 0.02) in comparison to non/ex smokers. Dietary intake of meat, folate and vitami A, E, B2, B6 and B12 did not differ between the groups. Controlling age, gender, fasting days and dietary micronutrient intake, serum folate levels were found to be lower among smokers (geometric mean 15.3 nmol/L vs. 17.7 nmol/L, p = 0.023), while serum iron and vitamin B12 levels were not affected by smoking status. Conclusion Current smoking status affects dietary nutrient intake as well as plasma folate levels. The above coherence between antioxidant depletion and reduced antioxidant intake may predispose smokers to the premature development of tobacco related mortality and morbidity

Lipid accumulation product in relation to 10-year cardiovascular disease incidence in Caucasian adults: The ATTICA study

Background and aims The lipid accumulation product (LAP) is an index describing lipid over-accumulation based on waist circumference (WC) and fasting triglycerides, and can outperform the body mass index (BMI) in recognizing cardiovascular disease (CVD) risk. We aimed to explore the association of LAP with long-term CVD risk and compare its CVD-predictive value against common anthropometric indices/ratios of obesity. Methods ATTICA is a prospective, population-based cohort that recruited 3042 adults without pre-existing CVD from the Greek general population (age 18–89 years; 1514 men). The 10-year study follow-up (2011–2012) captured the fatal/non-fatal CVD incidence in 2020 participants (50% men). Baseline LAP (cm⋅mmol/L) was calculated and analyzed in relation to the 10-year CVD incidence. Results In total, 317 CVD cases (15.7%) were documented during the follow-up. Baseline LAP showed a significant positive association with the 10-year CVD incidence, even after adjusting for hypertension, diabetes, hypercholesterolemia, smoking, physical activity, Mediterranean diet adherence, and key pro-inflammatory biomarkers (Hazard Ratios per 10 cm mmol/L of LAP ranging from 1.1 to 1.21, p = 0.04). Moreover, LAP predicted the 10-year CVD study incidence better than common obesity indices (BMI, WC, waist-to-hip, waist-to-height ratio). Conclusions These findings support and independent positive association between LAP and long-term CVD incidence in CVD-free Caucasian adults from the general population

Nonresectable Hepatocellular Carcinoma: Long-term Toxicity in Patients Treated with Transarterial Chemoembolization - Single-Center Experience

Purpose: To determine the toxicity profile of transarterial chemoembolization (TACE) at 6 months and 1 year after treatment in patients with hepatocellular carcinoma (HCC) in a standardized oncology protocol so that TACE could be compared with systemic chemotherapeutic regimens for liver cancer. Materials and Methods: The study was authorized by the institutional review board. Between January 2002 and January 2007, 190 patients (155 men, 35 women; median age, 65 years; age range, 18 – 84 years) with HCC who underwent TACE treatment were identified from a prospectively collected database. Clinical records of complete blood cell counts and chemical profiles at baseline and at 6 and 12 months after treatment were studied retrospectively. Toxicity was graded according to the common terminology criteria for adverse events (CTCAE). A transition (survival) analysis perspective was used to estimate the distribution of toxicity grades. Patient survival from the first TACE session was calculated with Kaplan-Meier analysis. Results: Grade 3 or 4 toxicity 6 and 12 months, respectively, after treatment included leukocytopenia (7% and 19%); anemia (9% and 19%); thromobocytopenia (13% and 23%); prolonged activated partial thromboplastin time (8% and 18%); elevated aspartate aminotransferase (15% and 18%), alanine aminotransferase (10% and 18%), and alkaline phosphatase (8% and 18%) levels; hypoalbuminemia (10% and 19%); hyperbilirubinemia (10% and 22%); and alopecia (18%). The cumulative survival rate was 58% at 1 year, 39% at 2 years, and 29% at 3 years. These toxicity rates were considerably lower than those reported after treatment with currently used systemic chemotherapeutic agents. Conclusion: Study results show that TACE has a favorable long-term toxicity profile in patients with HCC. Data clearly support the role of TACE in the treatment of patients with nonresectable HHC