Nuray Misir

Stem taper functions for Abies nordmanniana subsp. bornmulleriana in Turkey

Abstract In this study, 31 stem taper functions from three model groups (simple polynomial, segmented and variable-form stem taper models) were analysed for Bornmullerian fir (Abies nordmanniana subsp. bornmulleriana Mattf.). Diameter at breast height, total height and diameters outside bark at intervals of 1 m from the stump to the top of the tree were measured on 115 sample trees. Taper functions were fitted with data from 85 trees (76% of total data set) using a non-linear least squares method. Data from the other 30 trees (24% of total data set) were used as the validation data. Four statistical criteria (per cent variation explained, bias, absolute bias and mean squared error) were used to determine model accuracy. Box plots of the residual distributions were also produced to compare statistical accuracy by relative height class. Minimum residuals were obtained with the variable-form stem taper models at all stem parts. When the models were compared within their respective groups, the most accurate simple polynomial, segmented and variable-form models were Demaerschalk-II (1972), Farrar (1987) and Kozak (1988), respectively. Based on the statistical and graphic analysis, the model by Kozak (1988) was recommended for A. nordmanniana subsp. bornmulleriana in the Black Sea region of Turkey. The Demaerschalk-II (1972) model could also be used for practical purposes.

Is there any interaction of resistin and adiponectin levels with protein-energy wasting among patients with chronic kidney disease.

The aim of this study was to evaluate the effects of adipocytokines including adiponectin, leptin, resistin, neuropeptide Y and ghrelin in chronic kidney disease (CKD) patients on appearance of protein‐energy wasting (PEW). One hundred fifty patients with mean age of 45.4 ± 15.9 years, without active infections or chronic inflammatory conditions were recruited into the study. Study groups were control group (consisting of 30 healthy volunteers with normal kidney functions), hemodialysis group, predialysis group, peritoneal dialysis group and kidney transplant group. Fasting morning serum leptin, ghrelin, acylated ghrelin, neuropeptide Y, adiponectin, resistin levels of all of the groups were measured. Anthropometric and nutritional assessments of all patients were obtained. Diagnosis of PEW was made according to definition recommended by the International Society of Renal Nutrition and Metabolism. Presence of PEW in hemodialysis (23.3%) and peritoneal dialysis (26.7%) groups were significantly higher than those of predialysis (3.3%), and transplantation (0%) groups. Adiponectin and resistin levels in predialysis, peritoneal dialysis and hemodialysis patients were significantly higher than control group (p: 0.0001). This study had given significant positive correlations between presence of PEW and serum resistin (r: 0.267, p: 0.001), and serum adiponectin levels (r: 0.349, p: 0.0001). There were no relationship between presence of PEW and ghrelin, acylated‐ghrelin, neuropeptide Y, and leptin levels of the groups. CKD patients except transplant patients had higher adiponectin and resistin levels than control group. PEW was found to be linearly correlated with resistin and adiponectin. High serum resistin and adiponectin levels might have a role in development of PEW among dialysis patients.

Generalized height-diameter models for Populus tremula L. stands

Using permanent sample plot data, selected tree height and diameter functions were evaluated for their predictive abilities for Populus tremula stands in Turkey. Two sets of models were evaluated. The first set included five models for estimating height as a function of individual tree diameter; the second set also included six models for estimating height as a function of individual tree diameter and some standlevel- attributes. The inclusion of the stand-level-attributes (basal area, dominant height, dominant diameter, number of trees) and BAL index (which simultaneously indicates the relative position of a tree and stand density) into the base height-diameter models increased the accuracy of prediction for P. tremula. As a result, the second set models gave high performance than the first models. On average, by including stand level attributes, root mean square values were reduced by 21 cm. In the second set, the best results were obtained by the Schnute’s function. In this function, dominant diameter and dominant height independent variables in addition to tree diameter were found significant at 0.01 significant level (R2= 0.949, 1.226 . = y x S , P < 0.01). Root mean square was reduced 35 cm Schnute’s function alone. Thus, a generalized height-diameter model based on Schnute’s function was developed for P. tremula L. stands in Turkey. Based on the residual plots and fit statistics, the model can be recommended for estimating tree heights for P. tremula L. in Turkey. The model coefficients are documented for future use.

The role of adipocytokines on depressive symptoms of patients with chronic kidney disease

Abstract Objective: The aim of this study is to evaluate depression and anxiety scores among chronic kidney disease (CKD) patients and to search the changes of serum concentrations of adipokines with respect to emotional disturbances of CKD patients. Patients and methods: 150 patients recruited into this cross-sectional analytic study. Study groups were control, hemodialysis, predialysis, peritoneal dialysis and kidney transplantation groups. Fasting morning serum leptin, ghrelin, acylated ghrelin, neuropeptide Y, adiponectin, resistin levels of all of the groups were measured using ELISA (Sandwich) method. A screening interview based on the Structured Clinical Interview for DSM-IV and self-report scales (The Beck Depression [BDI] and The Beck Anxiety Inventory [BAI] and Brief Symptom Inventory [BSI] which is self report scales) were administered and conducted by a trained interviewer. Results: BDI scores were significantly higher in hemodialysis and predialysis groups compared to control group (p = 0.009). Somatization sub scores of BSI were significantly higher in hemodialysis and peritoneal dialysis groups compared to control group (p = 0.041). Also positive symptom distress index scores of BSI were significantly higher in hemodialysis and transplantation groups compared to control group (p = 0.047). BDI score were significantly negatively correlated with duration of education (r = −0.165, p = 0.045), positively correlated with presence of protein energy wasting (r = 0.198, p = 0.016), and resistin levels (r = 0.233, p = 0.004). Conclusion: CKD patients had higher BDI, BSI-somatization, BSI-positive symptom distress index scores compared to control group. High serum resistin levels, presence of protein energy wasting might have a role in development of depressive disorders of patients with chronic kidney disease.