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Dive into the research topics where Nurhan Dogan is active.

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Featured researches published by Nurhan Dogan.


Journal of Inequalities and Applications | 2013

Comparison of hierarchical cluster analysis methods by cophenetic correlation

Sinan Saraçli; Nurhan Dogan; İsmet Doğan

PurposeThis study proposes the best clustering method(s) for different distance measures under two different conditions using the cophenetic correlation coefficient.MethodsIn the first one, the data has multivariate standard normal distribution without outliers for n=10,50,100 and the second one is with outliers (5%) for n=10,50,100. The proposed method is applied to simulated multivariate normal data via MATLAB software.ResultsAccording the results of simulation the Average (especially for n=10) and Centroid (especially for n=50 and n=100) methods are recommended at both conditions.ConclusionsThis study hopes to contribute to literature for making better decisions on selection of appropriate cluster methods by using subgroup sizes, variable numbers, subgroup means and variances.


International Urology and Nephrology | 2002

Determination of cut-off values for leucocytes and bacteria for urine flow cytometer (UF-100) in urinary tract infections

Tulay Koken; Orhan Cem Aktepe; Mustafa Serteser; M. Murat Samli; Ahmet Kahraman; Nurhan Dogan

Leucocytes and bacteria in urine are the important indices for diagnosing urinary tract infections. Urine specimens from 260 patientswere examined for leucocytes and bacteria with the UF-100 flow cytometer (Sysmex Corporation, Japan). The results obtained with the UF-100 were compared with those obtained by bacteriologic cultures of the same urine samples. Bacteriologic samples were found to be positive in 48 urine samples. The best detected cut-off value for bacteria is 3800/μL (senstivity = 73%, specificity = 78%) and 25/μL for leucocytes (sensitivity = 73%, specificity = 92%). In addition, comparison of leucocyte count by manually and with UF-100 shows good correlation (r = 0.91). A flow cytometric urinalysis analyzer operates in a time saving manner, increases throughput and decrease microscopy review rates. It also provides a reliable information to clinicians prior to bacteriologic culture results, in terms of leucocyte and bacteria count.


Parasitology Research | 2007

Prevalence of coccidia in beef cattle in western Turkey

Hatice Çiçek; Feride Kırcalı Sevimli; Esma Kozan; Mustafa Köse; Mustafa Eser; Nurhan Dogan

A total of 504 bovine faecal samples collected from intensively managed beef farms in Afyon province of Turkey were examined to determine the types and prevalence of coccidian parasites present. Coccidian oocysts were found in 20.04% of all the samples examined by sucrose-flotation. The species detected and their prevalence were Eimeria bovis (34.55%), E. auburnensis (23.03%), E. canadensis (14.55%), E. brasiliensis (10.91%), E. zuernii (6.67%), E. bukidnonensis (3.03%), E. cylindrica (2.42%), E. ellipsoidalis (1.21%), E. illinoisensis (1.21%), E. alabamensis (1.21%) and Isospora sp. (1.21%). Mixed infections of two to four species were found in 43.6% of the animals. The overall prevalence of coccidial oocysts in faecal samples was 27.23% for calves, 15.65% for cows. Linear regression analysis showed that there is a significant reduction in the OPG (the number of oocysts per gram of feces) levels (P < 0.05) in cows infected with Eimeria. No cases of clinical coccidiosis were observed in this survey.


Acta Orthopaedica et Traumatologica Turcica | 2008

The prevalence of low back pain and risk factors among adult population in Afyon region, Turkey

Levent Altinel; Kamil Cagri Kose; Volkan Ergan; Cengiz Isik; Yusuf Aksoy; Aykut Ozdemir; Dilek Toprak; Nurhan Dogan

OBJECTIVES This study was designed to determine the prevalence of and risk factors for low back pain (LBP) in a sample of Turkish population among adults living in the Afyon region, Turkey. METHODS A field screening investigation was performed in a total of 75 areas including the city center, 18 districts, and 57 associated small municipalities. Adequate sample size was determined as 1,990 and a total of 2,035 individuals (1,194 females, 841 males) were enrolled. Participants were inquired about age, occupation, sex, height, weight, history of LBP, hypertension, diabetes, and smoking. Depression symptoms were evaluated using the Symptom Checklist-90-Revised. RESULTS The prevalence of lifetime LBP was 51%, and the prevalence of chronic LBP was 13.1%. Overall, 63.2% of women and 33.8% of men had LBP at least once in their lives (p=0.001). With regard to occupation, the highest incidence of LBP was seen in housewives (64.2%; p=0.0001), whose age and body mass index (BMI) were also higher compared to employed women. Depression (p=0.016) and increased BMI (p=0.000) were found to increase the risk for LBP, whereas smoking, hypertension, or diabetes were not correlated with the prevalence of LBP. Poverty was found to be the leading cause (39.7%) for not presenting to a physician. CONCLUSION Among risk factors reported for LBP, many are also effective in Turkish population. Special attention should be given to the education of housewives in terms of low back protection, healthy nutrition, and family planning. Poverty seems to be a significant barrier to patient presentation to physicians, requiring extended social security coverage.


Preventive Veterinary Medicine | 2011

Isolation of dermatophytes from dogs and cats with suspected dermatophytosis in Western Turkey

Esra Seker; Nurhan Dogan

The aim of this study was to determine the species of dermatophytes isolated from dogs and cats and their prevalence in the two big provinces of Western Turkey. A total of 362 animals (198 dogs and 164 cats) with skin lesions (alopecia and desquamation) were examined from March 2006 to February 2008. Of the 362 samples examined, 52 (14.4%) were positive for fungal elements by direct microscopic examination, and 70 (19.3%) were culture positive for dermatophytes. The isolation rates of dermatophyte species from dogs and cats were 18.7% and 20.1%, respectively. Microsporum canis (57.1%) was the most common species isolated from dogs and cats. The prevalence of Trichophyton mentagrophytes was five-fold greater in dogs than in cats (odds ratio=5.226; CI=1.152-23.696). No association was detected between prevalence of infection and provinces, and also sex of dogs and cats. The only risk factor found to be significantly associated with infection was age. Dogs and cats younger than one year of age showed a statistically significant higher prevalence of dermatophytes than other age groups (P<0.05). The isolation rate of dermatophytes was relatively high in the spring and winter for dogs, and in the spring, summer and autumn for cats. However, the association of season and prevalence was found not to be significant.


Animal Science Journal | 2010

The possible role of bovine herpesvirus type‐4 infection in cow infertility

Sibel Gur; Nurhan Dogan

Experimental and field studies have proven that the bovine herpesvirus type-4 (BHV-4) infection leads to various reproductive system problems. In this study, the role of BHV-4 infection in repeat breeding was investigated serologically. Eighty-four samples were obtained from repeat-breeding diagnosed cows in two organized dairy herds; an equal number of healthy cows were sampled from the same farms. The rest of the samples (105) were obtained from reproductively normal cows that were breeding in 18 small enterprises as a control group. The seropositivity proportion in repeat-breeding diagnosed cows was found to be significantly higher (69% (58/84)) than other cows (44% (37/84)) on the same farms. The lowest antibody positivity value for BHV-4 was detected as 24.7% (26/105) in the samples from family-type small farms. The odds ratio (OR) value was calculated as 2.834 in repeat-breeding diagnosed and healthy cows on the same farms, while 6.778 was determined in cows with and without reproductive problems on organized farms compared to small farms. As a result, the BHV-4 infection can be considered one of the reasons for repeat breeding besides other reproductive disorders.


The Anatolian journal of cardiology | 2012

Hypertension prevalence and risk factors among adult population in Afyonkarahisar region: a cross-sectional research.

Nurhan Dogan; Dilek Toprak; Serap Demir

OBJECTIVE Hypertension is a major public health problem worldwide with increasing prevalence. The purpose of this study was to examine the prevalence of hypertension and related risk factors among adult population in Afyonkarahisar region. METHODS In this cross-sectional research, regarding the population distribution totally 2035 subjects, randomly selected from 75 different parts of our city, both the urban and the rural areas, were included in this epidemiologic research. After the administration of a questionnaire to the subjects, blood samples were taken and physical examinations were performed. Socio-demographic features, diabetes mellitus (DM), hypertension, family history of hypertension, coronary heart disease (CHD), smoking, and number of births were evaluated as possible risk factors for hypertension. Statistical analysis was performed using Students t-test, Chi-square test and binary logistic regression analysis. RESULTS The overall prevalence of hypertension was 24.2% (31.3% in women, 14.1% in men, p<0.001). Its prevalence increased with age (from 2.2% to 50.4%, p<0.001). Age, gender, DM, family history of hypertension, body mass index (BMI), CHD and income levels were significant risk factors. Diabetic patients had 2.35 times (95%CI 1.70-3.25: p<0.0001) more risk, people who had positive family history 2.23 times (95%CI 1.62-3.07: p<0.0001) more risk and those with high BMI 2.15 times (95%CI 1.66-2.78: p<0.0001) more risk to develop HT than who did not have these factors. In addition, women have 2.74 times (95%CI 2.08-3.62: p<0.0001), more risk than men for HT. We determined CHD and low income as other risk factors for HT (OR=2.32, 95%CI 1.48-3.64: p<0.0001) and OR=1.47, 95%CI 1.08-2.02: p=0.016 respectively). CONCLUSION Hypertension is an important health problem in our region. We think that it is possible to reduce the hypertension prevalence with lifestyle changes and educating people, regarding the risk factors.


Reproduction in Domestic Animals | 2011

The importance of staphylococci and threshold value of somatic cell count for diagnosis of sub-clinical mastitis in Pirlak sheep at mid-lactation.

Erhan Özenç; E Seker; D Baki Acar; Muhammed Kürşad Birdane; Isfendiyar Darbaz; Nurhan Dogan

This study investigated the bacterial agents causing sub-clinical mastitis and the mean somatic cell counts (SCC) of milk in Pirlak sheep at mid-lactation. The percentage of infected udder halves was 11.4% (53/464). The most frequently isolated species were coagulase-negative staphylococci (CNS) (64.2%), followed by Staphylococcus aureus (24.5%) and Escherichia coli (11.3%). Among the CNS, the most common species was Staphylococcus epidermidis (38.2%). The other species isolated from milk samples were Staphylococcus xylosus (17.7%), Staphylococcus chromogenes (14.7%), Staphylococcus simulans (8.8%) and Staphylococcus hyicus (8.8%). The mean SCC for culture positive and negative samples was 1742×10(3) and 161×10(3) cells/ml, respectively. A significant difference (p<0.05) was determined between with and without microbial growth groups in terms of the SCC values. Threshold limit for SCC was 374×10(3) cells/ml for Pirlak sheep. In conclusion, it was considered that SCC is an important predictor of sub-clinical mastitis in Pirlak sheep. This is the first study to describe the bacterial agents causing sub-clinical mastitis and threshold limit for SCC in Pirlak sheep in Turkey.


Asian Pacific Journal of Cancer Prevention | 2014

Female Breast Cancer Mortality Rates in Turkey

Nurhan Dogan; Dilek Toprak

The main objective of this study was to analyze the mortality trends of female breast cancer in Turkey between the years 1987-2008. The rates per 100,000 age-standardized to the European standard population were assessed and time trends presented using joinpoint regression analysis. Average annual percent change (AAPC), anual percent change (APC) and 95% confidence interval (CI) was calculated. Nearly 23,000 breast cancer deaths occurred in Turkey during the period 1987-2008, with the average annual age-standardized mortality rate (ASR) being 11.9 per 100,000 women. In the last five years, significant increases were observed in all age groups, but there was no significant change over the age of 65. In this period, the biggest significant increase was in the 45-54 age group (AAPC=4.3, 95%CI=2.6 to 6.0).


Animal Reproduction Science | 2013

Effect of the stage of estrous cycle on follicular population, oocyte yield and quality, and biochemical composition of serum and follicular fluid in Anatolian water buffalo

Duygu Baki Acar; Muhammed Kürşad Birdane; Nurhan Dogan; Hande Gürler

This study was designed to investigate the effects that the different stages of the estrous cycle had on the number of surface ovarian follicles and oocyte yield and quality of Anatolian water buffalo during peak breeding season. Assessments were made on the basis of ovarian morphology, serum and follicular fluid concentrations of variety of biochemical parameters. Following slaughter, blood samples were collected from each animal. The stage of estrous cycle was classified as either the luteal or follicular phase, and surface ovarian follicles were classified as small, medium, or large. The follicular fluid was aspirated, and oocytes were evaluated microscopically for classification into four categories. No statistical differences (p>0.05) were observed regarding the total number of follicles or quality of oocytes relative to the stage of the estrous cycle. Serum high-density lipoprotein cholesterol (HDL), alkaline phosphatase (ALP) and progesterone (P4) concentrations were significantly higher in the luteal phase than in the follicular phase (P<0.05). Significant correlations were observed in the luteal phase between the total number of oocytes and cholesterol (Cho), HDL, sodium (Na), chloride (Cl); A-quality oocytes and Na, Cl, Mg; C-quality oocytes and Cho, HDL, and Mg in follicular fluid. These results offer new information concerning Anatolian water buffalo reproductive physiology, which may be useful for improving oocyte quality in buffalo. This is the first study to describe the number of ovarian follicles, oocyte yield and quality, and a variety of biochemical parameters in the serum and follicular fluid of Anatolian water buffalo during peak breeding season in Turkey.

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Dilek Toprak

Afyon Kocatepe University

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Tulay Koken

Afyon Kocatepe University

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Ahmet Kahraman

Afyon Kocatepe University

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Esma Kozan

Afyon Kocatepe University

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Cengiz Isik

Abant Izzet Baysal University

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Erhan Özenç

Afyon Kocatepe University

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Esra Seker

Afyon Kocatepe University

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