Öğrencilerin Kimyasal Denge Konusundaki Kavram Yanılgıları

The purpose of this study was to determine students’ misconceptions regarding the concepts of chemical equilibrium. To diagnose students’ misconceptions in this area, a written test was administered to 216 11th grade high school students after their formal class schedule. The original test was developed by Hackling and Garnett, 1984 and translated and adopted into Turkish by the authors. The test included 47 multiple choice and true-false items and its reliability coefficient was found to be 0,87. An interview was also conducted with 20 students to establish their reasons for misconception with the open-ended questions. Analysis of responses revealed widespread misconceptions among students in the areas related to (1) approaches to chemical equilibrium, (2) characteristics of chemical equilibrium, (3) changing chemical equilibrium conditions, and (4) adding a catalyst.Bu çalışmanın temel amacı, öğrencilerin kimyasal denge ile ilgili kavram yanılgılarını belirlemektir. Öğrencilerin bu konudaki yanlış kavramlarını tespit etmek için, hazırlanan bir test, 216 lise üçüncü sınıf öğrencisine, konu sınıfta anlatıldıktan sonra uygulanmıştır. Testin orijinali Hackling and Garnett tarafından 1984 yılında geliştirilmiştir. Bu test Türkçe'ye çevrilmiş ve yeniden gözden geçirilerek Türkiye şartlarına uyarlanmıştır. Test doğru- yanlış ve çoktan seçmeli sorulardan oluşmuş ve güvenirlik katsayısı 0,87 olarak hesaplanmıştır. Ayrıca, öğrencilerin kavram yanılgılarının nedenlerini anlamak için 20 öğrenci ile mülakat yapılmıştır. Cevapların analizi, öğrencilerin şu konularda yaygın olarak yanlış kavramlara sahip olduğunu göstermiştir: (1) Tepkime dengeye gelirken, (2) kimyasal dengenin özellikleri, (3) kimyasal denge koşullarının değiştirilmesi ve (4) katalizör ilavesi

Sip-rtsp Convergence: Rtsp-c

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2008Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2008Bu çalışma ile SIP protokolü iletimde kullanılarak ve RTSP protokolü yetenekleri SIP mesaj gövdesine yerleştirilerek VOIP ağlarında yeni bir medya kontrol modeli öne sürülmüştür. RTSP-C olarak isimlendirilmiş olan bu yeni yakınlaşma modeli sadece SIP ve RTSP protokollerinin bir arada çalışmasını garantilemekle kalmamakta; aynı zamanda medya kontrol isteklerinin asıllanması ve oturum sunum bilgisi (SDP) alış verişindeki bazı açık noktalara çözüm getirmektedir. Bu yeni model RTSP protokolünün NAT geçirimie ait yöntemlere gereksinimini ortadan kaldırmakla beraber, SIP protokolünün NAT geçirim yöntemleri geçerliliğini korumaktadır. Bu modelin sağladığı asıl gelişme medya kontrolü bilgisi ve durum bilgisini SIP protokolüne açık hale getirmesidir. Bu sayede bu model medya yayınına dayalı yeni SIP servislerinin geliştirilmesine olanak sağlamaktadır. Bu proje kapsamında ortaya koyulan yeni modeli örneklendirmek amacıyla bir İsteğe Bağlı Görüntü Yayını (VoD) sistemi geliştirilmiştir. Bu uygulama ile RTSP-C yakınlaştırma modelinin çalışabilirliği doğrolanmıştır. Sonuçlar literatürdeki diğer örnekler ile karşılaştırıldığında modelin daha onceden belirlenen sorunlara uygun çözümleri sağladığı görülmüştür.In this study, using Session Initiation Protocol (SIP) as transport and placing Real Time Streaming Protocol (RTSP) capabilities in the SIP message body, a media control model has been introduced for Voice Over IP (VOIP) networks. This new convergence model does not only guarantee the interoperability of SIP and RTSP protocols but also resolve some open points on media control request authentication and session presentation (SDP) exchange. This new model is also valid for NAT Traversal methods applicable to SIP while it lifts the necessity of NAT Traversal methods for RTSP. The major advancement this model provides is: it makes the media control method/state information available to SIP. By doing that, this model enables the development of new streaming based SIP services. In this project content a Video on Demand (VoD) system is developped to instantiate the new convergence model. The implementation validated the operability of RTSP-C convergence model. The comparison of the results with other models on literature showed that the model provided adequate solutions on the pre-determined problems.Yüksek LisansM.Sc

Intracardiac tumors: Results from a single heart center

Background: This study aims to present the results of surgical treatment of intracardiac tumors in our cardiac surgery center. Methods: Data of 21 patients with intracardiac tumors (15 males, 6 females; median age 60.9 years; range 35 to 87 years) who underwent surgery between April 2006 and May 2015 were retrospectively analyzed. The patients were diagnosed preoperatively by transthoracic echocardiography and computed tomography or magnetic resonance imaging. Results: The mean follow-up was 27.85 months. Of 21 patients, 12 had benign tumors and nine had malignant tumors. Of the benign tumors, nine were myxomas, one was an intramuscular lipoma, one was an interatrial septal lipoma, and one was a papillary fibroelastoma. Of the malignant tumors, eight were metastatic tumors and one was a primary tumor. Median sternotomy was performed in all patients to access the heart. Thrombi due to a cardiac mass were detected intraoperatively in some patients. Conclusion: Our study results suggest a high-degree of diagnostic confusion between intracardiac thrombi and tumors. Therefore, metastatic cardiac tumors should be considered in patients with pleural or pericardial effusion of no other identified cause

Video dizilerinden çoğul biyometrik kimlik doğrulama = combining face and voice modalities for person verification from video sequences

In this paper, a multimodal person verification system is presented. The system is based on face and voice modalities. Fusion of information derived from each modality is performed at the matching swre level using sum rule. For face verification statistical subspace tools are utilized as feature exhactors. For speaker verification, me1 frequency cepstral coefficients are used as features and gaussian mixture models are used for modeling. Various wmbination cases are hied in the experiments and the results show that for each case the wmbined modalities performs betfer than the single modality

Mullerian inhibiting substance expression in papillary thyroid cancer

SummaryObjectiveTo examine the expression of Mullerian inhibiting substance (MIS) in papillary thyroid cancer.Materials and methodsThe MIS expression was examined by studying the immunohistochemistry in deparafinized sections prepared from tissue blocks of patients who were diagnosed with papillary thyroid cancer, as given in the pathology archive records (n = 23).ResultsIn all the cases studied, 50% (n = 10) showed strong staining and 50% showed moderate staining. The percentage of staining was found to be 94.2 ± 3.1% in strongly stained cases and 92.2 ± 2.1% in moderately stained cases. Normal thyroid tissues neighboring the tumor did not display any staining.ConclusionThe MIS expression can be used as a significant tool in differential diagnosis of papillary thyroid cancer and also to shed light on its etiopathogenesis

Parental psychological distress associated with COVID-19 outbreak: A large-scale multicenter survey from Turkey

Aims: Pandemics can cause substantial psychological distress; however, we do not know the impact of the COVID-19 related lockdown and mental health burden on the parents of school age children. We aimed to comparatively examine the COVID-19 related the stress and psychological burden of the parents with different occupational, locational, and mental health status related backgrounds. Methods: A large-scale multicenter online survey was completed by the parents (n = 3,278) of children aged 6 to 18 years, parents with different occupational (health care workers—HCW [18.2%] vs. others), geographical (İstanbul [38.2%] vs. others), and psychiatric (child with a mental disorder [37.8%]) backgrounds. Results: Multivariable logistic regression analysis showed that being a HCW parent (odds ratio 1.79, p <.001), a mother (odds ratio 1.67, p <.001), and a younger parent (odds ratio 0.98, p =.012); living with an adult with a chronic physical illness (odds ratio 1.38, p <.001), having an acquaintance diagnosed with COVID-19 (odds ratio 1.22, p =.043), positive psychiatric history (odds ratio 1.29, p <.001), and living with a child with moderate or high emotional distress (odds ratio 1.29, p <.001; vs. odds ratio 2.61, p <.001) were independently associated with significant parental distress. Conclusions: Parents report significant psychological distress associated with COVID-19 pandemic and further research is needed to investigate its wider impact including on the whole family unit. © The Author(s) 2020

Fairness in examination timetabling: student preferences and extended formulations

Variations of the examination timetabling problem have been investigated by the research community for more than two decades. The common characteristic between all problems is the fact that the definitions and data sets used all originate from actual educational institutions, particularly universities, including specific examination criteria and the students involved. Although much has been achieved and published on the state-of-the-art problem modelling and optimisation, a lack of attention has been focussed on the students involved in the process. This work presents and utilises the results of an extensive survey seeking student preferences with regard to their individual examination timetables, with the aim of producing solutions which satisfy these preferences while still also satisfying all existing benchmark considerations. The study reveals one of the main concerns relates to fairness within the students cohort; i.e. a student considers fairness with respect to the examination timetables of their immediate peers, as highly important. Considerations such as providing an equitable distribution of preparation time between all student cohort examinations, not just a majority, are used to form a measure of fairness. In order to satisfy this requirement, we propose an extension to the state-of-the-art examination timetabling problem models widely used in the scientific literature. Fairness is introduced as a new objective in addition to the standard objectives, creating a multi-objective problem. Several real-world examination data models are extended and the benchmarks for each are used in experimentation to determine the effectiveness of a multi-stage multi-objective approach based on weighted Tchebyceff scalarisation in improving fairness along with the other objectives. The results show that the proposed model and methods allow for the production of high quality timetable solutions while also providing a trade-off between the standard soft constraints and a desired fairness for each student

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic