524 research outputs found
Characterization of protein-flavor interactions using inverse gas chromatography
No full textIn this research, we investigated the retention/release mechanism of selected flavor compounds on or from protein matrices by establishing quantitative design principles for these interactions. Thermodynamic parameters (partition coefficient Kp, free energy of adsorption ∆Gs and the enthalpy of adsorption ∆Hs) of the interaction between selected flavor compounds (hexane, hexanal, hexanol and d-limonene) and protein systems (soy protein isolate and zein) were determined by using inverse gas chromatography under different temperatures and relatively humid conditions. The inverse gas chromatography system was fitted with an additional humidification system that could maintain the relative humidity of the carrier gas, thus enabling the evaluation of the effect of relative humidity on the measured quantities. Increasing temperature and relative humidity led to less favorable interaction between selected flavors and proteins. Flavor retention at high relative humidity was less than at low relative humidity or at dry conditions. This suggests that flavor compounds and water molecules might be competing to bind to the available sides of the protein. Quantitative characterization of the mechanism and thermodynamics of flavor binding and release in protein matrices will benefit the food industry to efficiently develop flavored foods.M.S.Includes bibliographical referencesby Ozlem Dol
Risk-averse control of undiscounted transient Markov models
No full textThe classical optimal control problems for discrete-time, transient Markov processes are infinite horizon, undiscounted expected total cost or reward models. Some examples of these models are optimal stopping problems and stochastic shortest or longest path problems, which may have applications in health-care, finance, and maintenance. However, such expected value models implicitly assume the decision maker is risk-neutral, so they may not be appropriate for several real-life problems. In this study, we use Markov risk measures to formulate a risk-averse version of the optimal control problem for transient Markov processes with general state and compact control spaces. We derive risk-averse dynamic programming equations and show that they have a unique solution which is also the optimal value of the Markov control problem. Furthermore, it is shown that a randomized policy may be strictly better than deterministic policies, when risk measures are employed. We suggest two algorithms, value iteration and policy iteration methods, for solving the dynamic programming equations and show their convergence. In general, each policy evaluation step of the policy iteration algorithm requires solving a system of nonsmooth equations. We use a version of nonsmooth Newton method to solve these equations and show its global convergence. We further consider a risk-averse finite horizon Markov control problem under randomized policies and derive a value iteration method for its solution. Finally, we work on asset selling, organ transplant, and credit card examples to illustrate the theory for infinite horizon problem, and present numerical results.Ph. D.Includes bibliographical referencesIncludes vitaby Ozlem Cavu
Modeling traveler behavior via day-to-day learning dynamics
No full textTravel behavior lies at the core of analysis and evaluation of transportation related measures aiming to improve urban mobility, environmental quality and a wide variety of social objectives. A better understanding of travel behavior will improve travel demand forecasting and the assessment of emerging transport policies, and will improve our means to increase road safety. The day-to-day models reflect the travelers’ learning and forecasting mechanisms. These models predict travelers’ choices for any given day based on their experienced choices in the previous days. Day-to-day approaches allow the use of wide range of behavioral rules, and levels of aggregation, and capture the heterogeneity in users’ learning and adaptation processes, and behavioral characteristics. This thesis aims to develop a novel framework to model the interdependence between travelers’ choice decisions, learning and adaptation behavior and the day-to-day update mechanism of traffic flows. The novelty of this thesis is that the proposed approach combines traveler heterogeneity and rationality in a single framework to predict travelers’ day-to-day departure time and route decisions, and develops a novel day-to-day dynamic traffic assignment approach. The empirical results obtained from real transportation network, New Jersey Turnpike, confirm that the proposed day-to-day learning and dynamic traffic assignment framework model can successfully capture the significant learning dynamics, demonstrating the possibility of developing a psychological framework (i.e., learning models) as a viable approach to represent travel behavior. The other contributions of this thesis include a novel route choice set generation approach based on stochastic integer programming approach. The proposed methodology takes into account travel time variability and reliability in the transportation network. The path relevance criteria are directly incorporated into the optimization model by minimizing mean travel time, travel time variability and path overlap. Unlike previous approaches in the literature, proposed methodology eliminates the filtering step from the choice set generation and generates paths sets at desired dissimilarity level while minimizing the travel time and variability of these paths. Several case studies show the applicability of the proposed methodology on real transportation networks.Ph.D.Includes bibliographical referencesIncludes vitaby Ozlem Yanmaz-Tuze
Aza-peptide Aldehydes and Ketones: A New Class of Inhibitors for Proteases
Full text linkProteases are enzymes that catalyze the hydrolysis of specific peptide bonds in proteins, a process referred to as proteolysis. Proteases are largely responsible for processes such as apoptosis, immune response, protein turnover, digestion, blood coagulation and wound healing, fertilization, cell differentiation and growth, and cell signaling among other processes. Thus, uncontrolled proteolysis can lead to many disease states, such as cancer, neurological disorders, viral infections, inflammation, and arthritis. Aza-peptide aldehydes and ketones are a new class of inhibitors designed to inhibit the proteasome and the clan CD cysteine proteases for the potential treatment of cancer and neurodegenerative disorders. These compounds are designed starting with the structure of a good target protease substrate structure. The α-carbon of the P1 amino acid residue is replaced with a nitrogen atom to make an Aza-amino acid residue and the scissile peptide bond is replaced with an aldehyde or ketone moiety. Aza-peptides are more rigid than their peptide analogs due to the inability of the N-CO bond at the P1 site to rotate. We hypothesize that the rigidity of aza-peptides makes these inhibitors more selective, as other proteases will be unable to accommodate this rigidity while the proteasome and the clan CD cysteine proteases will be able to. Here I will present the synthesis and the kinetic inhibition study of the first examples of the proteasome and the clan CD cysteine protease specific aza-peptide aldehyde and ketone inhibitors.No embargoAcademic Major: Chemistr
Corrigendum to “The status of depression and anxiety in infertile Turkish couples” [Iran J Reprod Med 2011; 9: 99-104]
Full text linkThe publisher has been informed of an error that occurred on page 99 in which the second authors name must be changed to Ozlem Kayacik Gunday. On behalf of the author, the publisher wishes to apologize for this error. The online version of article has been updated on 31 August 2023 and can be found at https://doi.org/10.18502/ijrm.v9i2.104
The Beliefs of Teachers, Students, and Parents on the Importance of Learning Second Language at a Young Age
Full text linkThere are so many factors which affect the learners when learning second language. Age, motivation of the learners, the ability to acquire language, cognitive development as the factors affect learning second language. When learners start at a young age the other factors are affected positively. The researcher aimed to search the importance of age when learning foreign language. She made a questionnaire with 52 volunteers; 26 of them are students at Foreign Language Department in Uludag University, 26 of them are parents. And she also interviewed with teachers. She carried out this study by collecting the qualitative and quantitative data. The research has shown that “Age” is important factor when learning second language. Person who learned second language at a young age has a lot of advantages in long term. The researcher chose this subject because she thought that learning second language at a young age is easier inasmuch as language acquisition is available. She wanted to learn thoughts of parents, students in Foreign Language Departments, teachers. She revealed the thought of “the younger the better” by making interview with teachers and making a questionnaire with parents and students in Foreign Language Departments. The researcher corroborate her theory by looking at these results
Blepharoptosis and hypertrophic osteoarthropathy: A case report
No full textA 52-year-old male patient presented to our hospital with a history of secondary hypertrophic osteoarthropathy (HOA) associated with an abdominal neoplasia and blepharoptosis. He had finger clubbing, hyperhidrosis, and hypertrichosis. He also had a recent history of extensive abdominal surgery with a pathology report of myelolipoma. Routine blood work was unremarkable. Upper eyelid reconstruction with blepharoplasty, upper eyelid wedge resection, and brow suspension was performed to address his eyelid concerns. By this case report, we would like to attract notice that the eyelid involvement may be a part of HOA and to emphasize the importance of systemic and pathologic evaluation in failed blepharoptosis surgery
Evaluation of ABO/Rh Blood Group Distributions and Clinical Characteristics in Patients with Adrenal Incidentaloma: A Case-Control Study
Full text linkAim:Studies examining the relationship between endocrine organ diseases and ABO and Rh blood groups have been conducted, and some studies have shown that endocrine organ diseases may be associated with ABO/Rh blood groups. The aim of this study was to evaluate the ABO/Rh blood group distribution in patients with adrenal incidentaloma (AI) and its relationship with the clinical features of the patients.Methods:The study was conducted as a retrospective case-control study. Patients with AI who were followed up in the outpatient clinic of a single tertiary center between 2019 and 2023 were included in the study. The clinical (age, gender), radiological (diagnostic method, radiological features, adenoma size, localization), and biochemical (catecholamines, cortisol, aldosterone, and plasma-renin activity) characteristics of the patients were determined. The ABO and Rh blood group distributions of the patients were compared with those of the healthy control group.Results:The number of patients included in the study was 356 and the number of people in the healthy control group was 2,809,237. Adrenal incidentaloma was detected by computed tomography in 237 (67.1%) patients and was more often detected in the left adrenal gland (51.1%). The median size of the adrenal mass was 20 mm. Because of the hormonal evaluation, functional hormone production was detected in 16 (4.5%) patients. After further investigations, it was found that three (0.8%) patients had adrenal carcinoma and three (0.8%) patients had cancer metastases. ABO blood group distributions in the patients (42.7% A, 13.5% B, 9.6% AB, 34.3% O) and control groups (42% A, 16% B, 8% AB, 34% O) were found to be similar (p=0.9). Similar results were found in terms of the Rh factor (p=0.9). There was no statistically significant relationship between the distribution of ABO and Rh blood groups and clinical features such as age, gender, functional hormone release, mass size, and accompanying endocrine diseases.Conclusion:The ABO/Rh blood group was not found to be a risk factor in patients with AI. In addition, no relationship was found between clinical features and the ABO/Rh blood group in patients with AI
Proceedings: 3rd International Conference on Food and Agricultural Economics: DEMOGRAFIC TRANSITION IN TURKEY, RURAL POPULATION AND ANALYSING OF DEMOGRAFIC PROJECTION OF 2080
Full text linkTurkey has a total population of 82 million 3 thousand 882 in 2018. Rural population is 6 million 337 thousand 385 and 7.7% of our population. Contribution to the agricultural economy and rural population in Turkey's economy plays a primary role. Demographic projection is a method to help us prepare prudential economic and social policies. These projections provide useful predictions about, current population structure, it’s vocations and also helps us to determine if the current behaviour of the population keeps having the same vocation, what kind of population would appear in near future, population density, migrations, sex and age pattern of the population and sociocultural changes. Demographic Projections not only suggest that Turkey’s young and constantly growing population pattern is changing but it also shows that it's fertility rates and structures showing some changes as well. Changes through Low Death and Fertilty Rates from higher rates ,what we can define as “Demographic Change Process”, affects on population’s age structure as well. What we gathered from recent projection researchs indicates that there will be constant fall on young population levels, there will be rise in the number of population in working till 2040 but then there will be fall on the number in the same population group afterwards. Based on these informations, elderly population in Turkey constantly growing. These changes on both age and demographic structures makes impact in direct or indirect ways on both Social and Ekonomic live in Turkey. Demographic changes brought some positive outcomes(having a peak on population in working age level) along with the risks that Turkey never have been faced before(aging population). This situation requires taking measures for many sectors, especially the agricultural economy. Therefore, our study of the demographic transformation of Turkey, the rural population and population projections to 2080 are analyzed
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