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Öğe A biological perspective on interpreting interaction effect(Tubitak Scientific & Technological Research Council Turkey, 2022) Genc, Serdar; Mendes, MehmetFactorial experiments are commonly employed in agricultural research as in other branches of applied sciences. In these experiments, inferences related to the interaction are essential. However, many researchers are still unable to analyze this type of experiment and interpret the results in the correct way. This is because researchers focus on interpreting the main effects although there is a significant interaction effect. Of course, meaningful main effects can exist even in the presence of an interaction, especially if interactions do not affect the main effects. Therefore, it is extremely important to understand thoroughly in which situations only the interaction effect(s), in which cases only the main effect(s), and in which cases the interpretation of the main effects will be meaningful although the interaction effect is significant. In this study, evaluating factorial experiments has been discussed in detail, especially in studies related to animal science. It has also been focused on the importance of considering both statistical and practical significance while interpreting the statistical analysis results.Öğe A STUDY ON THE EFFECTS OF WOOD VINEGAR ON WEEDS AND CULTIVATED PLANTS IN THE WHEAT AGRO-ECOSYSTEMS(Parlar Scientific Publications (P S P), 2019) Koc, Ibrahim; Namli, Ayten; Mendes, Mehmet; Pinar, Suleyman Mesut; Cig, Fatih; Yardim, Erdal NecipThis study was conducted to determine the effects on the weeds and cultivated plants in the wheat agro-ecosystems of the wood vinegar in the biopesticide potential obtained from hazelnut shells on certain growth and yield parameters. The study was conducted based on the Randomized Blocks Testing Design with repeated four times. In the experiment, treatments of 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, and 5.0% mL doses of wood vinegar were administered, and only tap water was given to the control group. It was found that the 4% mL dose had positive effects on cultivated plant height and that the 1% mL dose had positive effects on thousand kernel weight and seed per spike compared with the control. It was seen that its effect on weeds dry weight is changed according to the years (P=0.011). In 2015-2016, it was found that 3% mL increased and 0.5%, 1% and %5 mL decreased the weight of dry grass. In the test field; weeds determination is made from 12 families. In 2014-2015, Polygonum bellardii, Eremopoa altaica and Microthlaspi perfoliatum; and in 2015-2016, Eremopoa altaica, Erodium absinthoides, Lactuca serriola and Polygonum bellardii was seen most.Öğe A Study on the Relationships between Some Morphological and Reproductive Traits of the Turkish Crayfish, Astacus leptodactylus Eschscholtz, 1823 (Crustacea: Decapoda)(Taylor & Francis Inc, 2010) Berber, Selcuk; Yildiz, Harun; Ates, A. Suat; Bulut, Musa; Mendes, MehmetThis study was carried out to investigate relationships between some morphological and reproductive traits of the Turkish crayfish, A. leptodactylus, collected from a controlled irrigation lake in the Yenice province (Canakkale, Turkey), between July 2007 and June 2008. For this objective, two multivariate analysis techniques, namely canonical correlation analysis and multivariate multiple linear regression analysis, were used. The results of the canonical correlation analysis have shown that the morphological traits may be used to predict the changes in the reproductive traits. For instance, canonical correlation analysis results suggested that the egg weight and the number of eggs are related to the total length, carapace length, and carapace width. The results of multivariate multiple linear regression analysis, on the other hand, show a slightly different picture. Therefore, it is possible to conclude that both canonical correlation and multivariate regression results can be taken into consideration together when investigating the relations between two variable sets.Öğe According to Canonical Correlation, the Evaluation of Bluefish (Pomatomus saltatrix) Blood Chemistry(Medwell Online, 2010) Bulut, Musa; Gultepe, Nejdet; Mendes, Mehmet; Guroy, Derya; Palaz, MustafaBlood chemistry parameters can provide essential information on the physiological status of the animal and therefore allow accurate evaluations of the general health status. Canonical correlation analysis is a fundamental statistical tool. The goal of canonical correlation analysis is to evaluate the relative contribution of each variable to the derived canonical functions in order to explain nature of the relationships. CCA was used to determining, whether the blood protein parameters are related in any way to the blood lipids, enzymes, minerals. However, a linear association between predictor variables (blood proteins) and dependent variables (lipids, enzymes and minerals) were determining. These analyses results shown that canonical correlation analysis can be using prediction of relationships from blood proteins with other blood chemistry parameters.Öğe Asymmetry measures and allometric growth parameter estimates for investigate effect of early feed restriction on deviation from bilateral symmetry in broiler chickens(Archiv Fur Tierzucht, 2008) Mendes, MehmetThe purpose of this study is to investigate the effect of different feeding programs such as ad libitum feeding (AD), 20% feed restriction based on ad libitum group (FR1) and not fed between 9 a.m. and 3 p.m. (FR2) on deviation from bilateral symmetry or developmental stability in broiler chickens by means of two different approaches namely asymmetry measures and allometric growth model parameters. The weekly left and right sides of shank length, shank width, wing length and face width of chickens were collected from 7 days of age to 42 days of age. Results of this study showed that the deviations from the bilateral symmetry were mostly in fluctuating asymmetry (FA) in the FRI group birds. On the other hand, the deviations from the bilateral symmetry in the birds in group AD and FR2 were mostly in the form of anti-symmetry (AS) and directional asymmetry (DA)respectively. In this study, the deviation from the bilateral symmetry was mostly in FA type for the measured morphological characters for the FR1 group, and the FA level was usually lower indicating higher welfare level and lower developmental instability for these animals than that of the AD and FR2 groups. Allometric growth coefficients for evaluating the effects of the feeding programs on the developmental stability were a little bit different from the findings obtained by the asymmetry measures being taken into account. Allometric growth parameters, therefore, should be taken into consideration, along with asymmetry measures when investigating effect of rearing conditions or environmental conditions on developmental stability. As a conclusion, intensive feeding (AD) and long-term feed restriction (FR2) can be said as an important environmental factor affecting developmental stability and dependently athe animal welfare and performance.Öğe Canonical correlation analysis for studying the relationship between the basic morphological and some soil chemical characteristics of Centaurea mucronifera DC. (Asteraceae)(Chemical Publishing Co., 2008) Çelik, Sezgin; Yücel, Ersin; Mendes, Mehmet; Tug, G. Nilhan; Öztürk, MünirThis aim of this study was to investigate the relationship between the basic morphological features and some soil chemical characteristics in order to enlighten the differentiation in the Centaurea mucronifera populations distributed at 16 different places under varying environmental conditions. For this purpose method of Canonical correlation analysis (CCA) was used. The results revealed that morphological features like length of terminal leaves (Y3), length of capitula (Y4), length of involucrum (Y5) and length of achen (Y6) are affected positively by N (X6) and Ca2+ (X7) in the soil but the length of plant (Y1), length of basal leaves (Y2) and length of pappus (Y7) are affected negatively.Öğe Classification Tree Method for Determining Factors that Affecting Hatchability in Chukar Partridge (Alectoris chukar) Eggs(Kafkas Univ, Veteriner Fakultesi Dergisi, 2010) Karabag, Kemal; Alkan, Sezai; Mendes, MehmetThe study was carried out to investigate the effects of some external egg traits on hatchability using classification tree method (CTM) in Chukar partridge (Alectoris chukar). 1193 eggs were collected from 90 female partridges and 671 chicks were obtained from 847 fertile eggs. Overall hatching, fertility and hatchability of fertile eggs were determined as 56.2%, 79.2%, and 71.0%, respectively. Four variables (egg weight=EW, egg volume=EV, egg length=EL and egg breadth=EB) from external egg traits have a significant effect on hatchability was estimated with 75.6% accuracy by using the CTM. Hatchability (H) was occurred as 80.0% at higher eggs than 18.1 g while H was found as 56.0% at lesser eggs than 18.1 g. When EV and EB were higher than 27.2 and 3.14 cm respectively, H was around 82.1%. But, when EV was higher than 27.2 and EB was lower than 3.14 cm (Node 9) respectively, hatchability was lower than desired. EW greater than 18.1 g hatchability was affected significantly by EV, EL and EB. This situation can be regarded as an indicator for hatching from fertilized eggs. The first report on this subject which the external egg traits of Chukar partridges influenced on hatchability were demonstrated by CTM.Öğe Comparison of ANOVA F and WELCH Tests with Their Respective Permutation Versions in Terms of Type I Error Rates and Test Power(Kafkas Univ, Veteriner Fakultesi Dergisi, 2010) Mendes, Mehmet; Akkartal, ErkutWe compared Analysis of Variance (F) and the Welch test (W) with their respective permutation versions (PF and PW) in terms of Type I error rate (alpha) and test power (1-beta) by Monte Carlo simulation technique. Simulation results showed that when the variances were homogeneous, the permutation versions of F and W tests displayed more reliable results in terms of protecting Type I error rate at nominal level, regardless of distribution shape and sample size. Violation of homogeneity of variances adversely affected all tests. Regardless of sample size and effect size, the PF test was slightly more powerful compared to the F test as long as the variances were homogeneous and the distributions were skewed (chi(2)(3) and Exp [0.75]). The PF and F tests had similar power levels when the distributions were symmetrical (Beta (5.5)). The W test was more powerful with homogenous variances, while the PW test was slightly superior with heterogonous variances except for unbalanced sample sizes (i.e., 5:10:15).Öğe Comparison of ANOVA-F and ANOM tests with regard to type I error rate and test power(Taylor & Francis Ltd, 2013) Mendes, Mehmet; Yigit, SonerA Monte Carlo simulation was conducted to compare the type I error rate and test power of the analysis of means (ANOM) test to the one-way analysis of variance F-test (ANOVA-F). Simulation results showed that as long as the homogeneity of the variance assumption was satisfied, regardless of the shape of the distribution, number of group and the combination of observations, both ANOVA-F and ANOM test have displayed similar type I error rates. However, both tests have been negatively affected from the heterogeneity of the variances. This case became more obvious when the variance ratios increased. The test power values of both tests changed with respect to the effect size (), variance ratio and sample size combinations. As long as the variances are homogeneous, ANOVA-F and ANOM test have similar powers except unbalanced cases. Under unbalanced conditions, the ANOVA-F was observed to be powerful than the ANOM-test. On the other hand, an increase in total number of observations caused the power values of ANOVA-F and ANOM test approach to each other. The relations between effect size () and the variance ratios affected the test power, especially when the sample sizes are not equal. As ANOVA-F has become to be superior in some of the experimental conditions being considered, ANOM is superior in the others. However, generally, when the populations with large mean have larger variances as well, ANOM test has been seen to be superior. On the other hand, when the populations with large mean have small variances, generally, ANOVA-F has observed to be superior. The situation became clearer when the number of the groups is 4 or 5.Öğe Determination of suitable permutation numbers in comparing independent group means: a monte carlo simulation study(Natl Inst Science Communication-Niscair, 2010) Akkartal, Erkut; Mendes, Mehmet; Mendes, EmelIn this study, suitable number of permutations were tried to be determined empirically for permutation test, one of which lalternatively used in analysis of variance (ANOVA). Random numbers were generated from chi(2) (3). distribution by simulation technique, and type 1 error rates were calculated with their standard errors. For k=2, 3 and 4, data were dealt with what is commonly faced in practice. Number of observation (n) in each group were taken to be 5, 10 and 15 (except for k = 2). Number of permutation changes with respect to k and n. For k=2, 3 and 4, required number of permutation was determined to be 15,000, 25,000 and 30,000 respectively. In general, there is great advantage of not allowing number of permutation under 10,000, if permutation tests are to be used in testing significance of differences of means of groups.Öğe Determination of water stress with spectral reflectance on sweet corn (Zea mays L.) using classification tree (CT) analysis(Lithuanian Research Centre Agriculture & Forestry, 2013) Genç, Levent; Nalpulat, Melis; Kızıl, Ünal; Mirik, Mustafa; Smith, Scot E.; Mendes, MehmetWater stress is one of the most important growth limiting factors in crop production. Several methods have been used to detect and evaluate the effect of water stress on plants. The use of remote sensing is deemed particularly and practically suitable for assessing water stress and implementing appropriate management strategies because it presents unique advantages of repeatability, accuracy, and cost-effectiveness over the ground-based surveys for water stress detection. The objectives of this study were to 1) determine the effect of water stress on sweet corn (Zea mays L.) using spectral indices and chlorophyll readings and 2) evaluate the reflectance spectra using the classification tree (CT) method for distinguishing water stress levels/severity. Spectral measurements and chlorophyll readings were taken on sweet corn exposed to four levels of water stress with 0,33,66 and 100 % of pot capacity (PC) before and after each watering time. The results demonstrated that reflectance in the red portion (600-700 mu) of the electromagnetic spectrum decreased and increased in the near infrared (NIR) region (700-900 nm) with the increasing field capacity of water level. Reflectance measured before the irrigation was generally higher than after irrigation in the NW region and lower in the red region. However, when the four levels of PC and before or after irrigation only were compared, reflectance spectra indicated that water stressed corn plants absorbed less light in the visible and more light in the NIR regions of the spectrum than the less water stressed and unstressed plants. There was a similar trend to reflectance behaviour of water stress levels using chlorophyll readings that decreased over time. The CT analysis revealed that water stress can be assessed and differentiated using chlorophyll readings and reflectance data when transformed into spectral vegetation indices.Öğe Determining the Factors Affecting 305-Day Milk Yield of Dairy Cows with Regression Tree(2021) Genc, Serdar; Mendes, MehmetThe purpose of this study was to determine the factors affecting the 305-day milk yield of dairycattle by using Regression Tree Analysis (RTA). The data set of this study consisted of 8 differentcattle breeds grown in Turkey. Breed (B), Province (P), Lactation Length (LL), Service Period (SP),Dry Period (DP), Parity (PR), Calving Year (CY), Calving Age (CA) and Calving Month (CM)were used to predict the 305-day milk yield. Results of RTM showed that the usage of this methodmight be appropriate for determining the important factors that would be able to affect the 305-daymilk yield (R2=71.3%). It was seen that the most important factors affecting the 305-day milk yieldwere the Breed, Lactation Length, Province, and Parity. Therefore, those selected factors were moreefficient than the others in predicting the 305-day milk yield. RTA results also indicated that thelowest milk yield was estimated for Jersey, Jersey Crossbred, and Yerli Kara. Among the highest305-day milk yield cows, the milk yield estimates of the cows in the second, third, fourth, fifth, andthe sixth parities were found significantly higher than that of the cows in the first and seventhparities.Öğe Effect of different feed restriction programs in broilers on parameters of blood biochemistry(Asian Journal Of Chemistry, 2008) Karabayir, Ali; Mendes, MehmetIn the study, the effects of different feeding programs on some blood biochemistry and tonic immobility durations in Ross 308 broilers were investigated. When aged 7 d, 60 chicks were divided into three groups to this end as AD, FR and NF in such a way that each group contained 20 birds. The tonic immobility durations, some parameters of blood biochemistry and the H:L ratios, by utilizing the heterophil and lymphocyte counts were determined. As a result of the analysis of variance carried out, it was observed that the H:L ratios of the birds in group NF were higher than those of the birds in groups AD and FR (p = 0.031). No statistically significant difference existed between the tonic immobility durations of the birds in groups AD and FR (p > 0.05) whereas it was observed that the tonic immobility durations of the birds in group NF were clearly higher than those of the groups AD and FR (p = 0.021). Starting from these findings, it was concluded that increasing the duration of feed restriction caused a serious level of stress on birds.Öğe Effect of Feed Restriction on Some Chemical and Sensory Properties of Chicken Meat(Ankara Univ, Fac Agr, 2014) Dincer, Ecmel; Ulutas Parlak, Sibel; Engin, Burcu; Karagül Yüceer, Yonca; Mendes, MehmetFeed restriction application in the early stage of growth in broiler is common to prevent some health problems. However, feed restriction may affect the quality of meat. The objective of this study was to determine the effects of feed restriction on sensory properties of chicken meat. Total 60 Ross 308 broiler chickens were divided into three groups. The chickens in the first group were fed ad libitum (control group; AD), whereas the chickens in the second and the third group were exposed to two different feed restriction applications. The chickens in the second group (FR) were fed with 20% less food of ad libitum food intake, while the chickens in the third group (NF) were not fed between 9 am-3 pm. Feed restriction in both groups was applied when the chickens were between 7-21 days old. The chickens were slaughtered at week six of the trial and the carcasses were stored at -25 degrees C until chemical and sensory analyses. Descriptive sensory analysis was conducted to determine characteristic descriptive terms for breast and thigh body parts. In addition to sensory characteristics, some chemical properties including titratable acidity, dry matter and fat contents of the meat samples were determined. The data of chemical properties were analyzed by repeated measurement variance analysis, while the data of sensory evaluation were analyzed by multivariate analysis of variance (MANOVA) and multidimensional scaling (MDS). The finding of this study demonstrated that juicy, chicken flavor and umami were leading sensory characteristics of chicken meat. Some undesirable flavor attributes including cardboard, feed, oxidized and organy were also determined at very low intensities. Juiciness and chicken flavor scores of breast meat in AD and NF groups did not show any significant differences. No significant differences were detected between feed regimes in the flavor intensities of thigh meat. Feed restriction did not affect acidity or dry matter, whereas feed restriction affected fat contents of breast and thigh.Öğe EFFECTS OF SELECTION IN TERMS OF MEAT YIELD TRAITS ON LEPTIN RECEPTOR GENE IN JAPANESE QUAIL LINES(Univ Ljubljana, Veterinary Faculty, 2022) Karabag, Kemal; Alkan, Sezai; Karsli, Taki; Ikten, Cengiz; Sahin, Inci; Mendes, MehmetThis study was carried out to investigate the effects of selection on the single nucleotide polymorphisms (SNPs) in coding sequence of leptin receptor (LEPR) gene and possible associations between SNPs' and some meat yield traits of Japanese quail lines. Fifteen generations divergently selected two lines (HBW and LBW) for 5-weeks of age body weight and a control were used as materials for this study. A348-bp part of the LEPR coding region (18th exon) were sequenced in a total of 113 individuals from the three quail lines and shown that the fragments contained four SNPs loci (T490C, C528T, G537A, T571C) and five haplotypes (TTGT, CTGT, TCGT, TCAT, TCAC). T490C replacement caused the missense mutation of phenylalanine to convert to leucine (Phe>Leu). However, other SNPs were synonymous and there were no changes in transcripts. It was determined that the quails with higher phenotypic values were in the TT genotype at the T390C locus. Statistical analyses showed that there were significant differences among the quail lines, SNP alleles and haplotypes in terms of interested phenotypic traits (P<0.05), and also SNP and haplotype distributions changed depending on quail lines (P<0.001). When all results were evaluated together, it was concluded that the fifteen generations of selection caused significant changes in the LEPR gene in terms of economically important traits in Japanese quail lines (C. coturnix japonica).Öğe Effects of some heavy metals on hatching of fertilized eggs in four marine fish species in Aliaga Bay (Eastern Aegean Sea), Turkey(Asian Journal Of Chemistry, 2008) Bulut, Musa; Akbulut, Mehmet; Ates, A. Suat; Mendes, MehmetThe present study was carried out to determine the effects of some heavy metals Such as Cd, Mn, Zn on hatching success of fertilized eggs of four marine fish species, Dicentrarchus labrax (Linnaeus, 1758), Spat-Lis aurata (Linnaeus, 1758), Dentex dentex (Linnaeus, 1758), Lithognathus mormyrus (Linnaeus, 1758) in Aliaga Bay (Eastern Aegean Sea). The relationships between heavy metal concentrations in eggs and their hatching success were determined by multiple linear regression analysis. Results showed that magnitude and type of the effects of the three heavy metals studied in this research on egg hatching ratios differed based on fish species. In terms of the magnitude of the effect, Zn has a greater effect than Cd and Mn on the hatching in D. dentex, while it is smaller in D. labrax. The effects-of Zn on egg hatching are in the same direction and about the same level for S. aurata and L mormyrus.Öğe Growth Curves for Body Weight and Some Body Measurement of Ross 308 Broiler Chickens(Garuda Scientific Publications, 2009) Mendes, MehmetTo investigate the growth characteristics of Ross 308 male broiler chickens 30 male broiler chickens were used. Results of growth curve analyses suggest that the Gompertz growth model fitted the weight-age, shank width-age, shank length-age and body length-age data very well, while the linear growth model fitted the breast bone length-age, breast width-age and breast circumference-age data. The growth rate (b) for body weight (0.04) was found obviously smaller than that of shank width (0.23), shank length (0.18) and body length (0.23). Inflection point (k) for shank width and body length was found similar. For one weak increase in age a 19.49 mm enhancement in breast bone length, 6.41 mm enhancement in breast width and 4.06 cm enhancement in breast circumference are expected. All regression slope estimates (except for breast width) were significant.Öğe Investigation on relations of blood chemistry parameters in Bluefish (Pomatomos saltatrix L. 1758) using multidimensional scaling technique(Asian Journal Of Chemistry, 2008) Bulut, Musa; Mendes, Mehmet; Bilen, Soner; Celik, IhsanThe relationships among various blood chemistry parameters of Bluefish (Pomatomus saltatrix L. 1758) were investigated by multidimensional scaling technique (MDS). The results of the MSD technique showed that blood chemistry parameters were affected by seasonal changes, total number of parameters in the model and the interactions between the parameters. The relationships among various parameters were more apparent in winter with a coefficient of 87.8 %, which was followed by fall with 70.5 % and spring with 69.9 %. The results of the statistical analysis also indicated that direct bilirubin, total bilirubin, albumin, uric acid, total protein and low-density lipoproteins parameters of winter Bluefish were associated or similar with each other. The blood proteins did not seem to be related to any of the blood minerals except for K in winter. It was found that the relationships among Cl, K, Na and creatine and between uric acid and cholesterol were high in the fall caught Bluefish. The relationships among the blood parameters of the spring caught Bluefish suggested that high-density lipoproteins, total proteins and cholesterol parameters were associated with each other. It is concluded that MDS may be a valuable tool to study relationships and interactions between various blood chemistry parameters and exogenous factors.Öğe Prediction of mono and multiphasic growth parameters of broilers(Archiv Fur Tierzucht, 2010) Mendes, MehmetThe main objective of this study was to predict mono and multiphasic growth model parameters of broilers. For this purpose daily body weights-age data of 106 male and female chickens reared under different stocking densities (GR1=11 birds/m(2), GR2=17 birds/m(2) and GR3=25 birds/m(2)) were used. Results of mono and multiphasic (diphasic and triphasic) growth curve analyses showed that defining the growth of birds using multiphasic growth models instead of monophasic growth models, displays more detailed and reliable results. Based on goodness-of-fit criteria, lead to the choice of a triphasic logistic growth function for GR1 and GR2, and diphasic function for GR3 males and females.Öğe Regression tree analysis for predicting slaughter weight in broilers(Taylor & Francis Ltd, 2009) Mendes, Mehmet; Akkartal, ErkutIn this study, Regression Tree Analysis (RTA) was used to predict and to determine the most important variables in predicting the slaughter weight of Ross 308 broiler chickens. Data for this study came from 224 chickens raised during three different seasons, namely spring (n=66), summer (n=66), winter (n=92). Second week body weight, shank length, shank width, breast bone length, breast width, breast circumference and body length were used to predict the slaughter weight. Results of RTA showed that among the seven independent variables only four were selected, namely; body weight, breast bone length, shank width, and breast circumference. These selected independent variables were more efficient than the others in predicting the slaughter weight. RTA indicated that the birds which had values of second week body weight >= 295.95 g, breast bone length >55.82 mm and breast circumference >14.18 cm or that of body weight <= 295.95 g, breast bone length >60.26 mm and shank width >8.32 mm could be expected to have higher slaughter weights.
