Uludag University Academic Repository
Not a member yet
50710 research outputs found
Sort by
Dietary zinc, manganese and copper combination in sulphate or amino acid chelate forms impacts laying performance and intestinal morphology in late-phase laying hens
Get PDFThis study was designed to evaluate the effect of zinc (Zn), manganese (Mn), copper (Cu) combination supplementation in different forms on laying performance, intestinal morphology and antioxidant capacity of laying hens between 64 and 75 weeks of age. A total of 600 Lohmann White layer hens at 64 weeks of age were assigned into 5 treatment groups, with 3 replicates, consisted of the control diet, control group (no supplementation of Zn, Mn and Cu; CG), supplementation of calcium carbonate (CaCO3) as a carrier of Zn, Mn and Cu sulphate (CCS), sulphate form of Zn, Mn and Cu combination (SF), glycine chelated of Zn, Mn and Cu combination (GC), and Zn + Mn - methionine (Met) chelated, Cu - lysine (Lys) chelated (MLC) group. Hen-day egg production tended to be higher in the GC and MLC groups during experimental period (P < 0.001). It changed between 79.7% and 83.4% in GC and MLC groups between 64 and 75 weeks of age. At 69 and 75 weeks of age, the highest value of egg weight was observed in the GC group with values of 66.8 g and 67.1 g, respectively (P < 0.001). The supplementation of MLC caused an enhancement in villus size, including villus height and surface area, in both duodenum and ileum (P < 0.001). In the duodenum, the villus height was found to be the highest with a value of 2583.2 mu m in the CCS group, whereas the villus width was higher in SF (349.9 mu m) and MLC (391.7 mu m) groups (P < 0.001). In the jejunum, SF caused a stimulation effect for villus efficiency, by increasing villus height (2512.6 mu m), villus apparent surface area (723680 mu m(2)), crypt depth (291.1 mu m), and VH/CD (9.4, P < 0.05). Zn, Mn and Cu combination in glycine chelated and methionine-lysine chelated forms caused an increment in height of villus in the ileum part of small intestine (1421.7 mu m in GC and 1388.0 mu m in MLC) when compared other supplementation groups (P < 0.001). In conclusion, it could be suggested that egg production could be improved by 4.3% with supplementation of Zn + Mn-Met and Cu-Lys chelate compared to the commercial diet
The impact of body mass index on the diagnostic and surgical outcomes in primary hyperparathyroidism
Get PDFOBJECTIVE: The aim of this study was to investigate the influence of body mass index on the diagnostic and surgical outcomes in patients undergoing parathyroidectomy for primary hyperparathyroidism. METHODS: A total of 446 patients with primary hyperparathyroidism were divided into four groups according to their body mass index: normal weight (body mass index= 35 kg/m2) (n=38). Perioperative findings were compared between the groups. RESULTS: The preoperative median parathormone level in the morbidly obese group (204 pg/mL, min:max 72:1,178) was significantly lower than that in the normal-weight (246 pg/mL, min:max 60:4,262) (p=0.026) and obese (251 pg/mL, min:max 74:2,094) (p=0.012) groups. The osteoporosis rate in the normal-weight group (51%) was higher than that in the overweight (35.4%) (p=0.041) and morbidly obese (25%) (p=0.023) groups. The symptomatic hypocalcemia rate in the normal-weight group (10.2%) was significantly higher than that in the obese group (1.8%) (p=0.017). CONCLUSION: Normal-weight patients with primary hyperparathyroidism have higher blood parathormone values, higher rates of osteoporosis, and postoperative symptomatic hypocalcemia compared to patients with higher body mass index. For this reason, the surgeon should consider the possibility of symptomatic hypocalcemia after undergoing parathyroidectomy for primary hyperparathyroidism in normal-weight cases
Optimized multiple regression prediction strategies with applications
Get PDFAs a classical statistical method, multiple regression is widely used for forecasting tasks in power, medicine, finance, and other fields. The rise of machine learning has led to the adoption of neural networks, particularly Long Short-Term Memory (LSTM) models, for handling complex forecasting problems, owing to their strong ability to capture temporal dependencies in sequential data. Nevertheless, the performance of LSTM models is highly sensitive to hyperparameter configuration. Traditional manual tuning methods suffer from inefficiency, excessive reliance on expert experience, and poor generalization. Aiming to address the challenges of complex hyperparameter spaces and the limitations of manual adjustment, an enhanced sparrow search algorithm (ISSA) with adaptive parameter configuration was developed for LSTM-based multivariate regression frameworks, where systematic optimization of hidden layer dimensionality, learning rate scheduling, and iterative training thresholds enhances its model generalization capability. In terms of SSA improvement, first, the population is initialized by the reverse learning strategy to increase the diversity of the population. Second, the mechanism for updating the positions of producer sparrows is improved, and different update formulas are selected based on the sizes of random numbers to avoid convergence to the origin and improve search flexibility. Then, the step factor is dynamically adjusted to improve the accuracy of the solution. To improve the algorithm's global search capability and escape local optima, the sparrow search algorithm's position update mechanism integrates L & eacute;vy flight for detection and early warning. Experimental evaluations using benchmark functions from the CEC2005 test set demonstrated that the ISSA outperforms PSO, the SSA, and other algorithms in optimization performance. Further validation with power load and real estate datasets revealed that the ISSA-LSTM model achieves superior prediction accuracy compared to existing approaches, achieving an RMSE of 83.102 and an R2 of 0.550 during electric load forecasting and an RMSE of 18.822 and an R2 of 0.522 during real estate price prediction. Future research will explore the integration of the ISSA with alternative neural architectures such as GRUs and Transformers to assess its flexibility and effectiveness across different sequence modeling paradigms
Formation of colchicine-incorporated hybrid nanoflower with an intrinsic peroxidase-mimic and enhanced antimicrobial activities
Get PDFWe report the formation of colchicine-Cu-3(PO4)(2) hybrid nanoflowers (Colc-NFs) with intrinsic catalytic and antimicrobial activities with and without hydrogen peroxide (H2O2). While the colchicine molecule, known as a secondary metabolite with anti-inflammatory properties, was used as an organic part of Colc-NFs, the Cu2+ ion acted as an inorganic part of Colc-NFs. The acetamide group in the colchicine structure may react with Cu2+ ions in phosphate-buffered saline to form Colc-NFs. The Colc-NFs exhibited both an intrinsic peroxidase-mimic activity against guaiacol and antimicrobial activities against Escherichia coli, Staphylococcus aureus, and Candida albicans in the presence of H2O2. Both activities of the Colc-NFs rely on a Fenton-like reaction mechanism by producing reactive hydroxyl radicals. In addition to that high surface-to-volume ratio and porous structure of Colc-NFs may contribute to their peroxidase-mimic activities depending on the Fenton-like reaction.Erciyes University
FCD-2018-841
Preliminary experience with a novel titanium macular buckle in the management of myopic maculopathy
No full textThe objective of this study was to report the initial experiences of seven surgeons using a titanium macular buckle (TMB) for the treatment of myopic maculopathy. The records of 11 cases that underwent TMB placement, with or without concomitant vitrectomy, were reviewed. Collected data included demographics, type of maculopathy, preoperative and postoperative ophthalmic findings. The intraoperative utilization of pars plana vitrectomy and any associated complications were also documented. The indications for surgery included posterior pole retinal detachment with maculoschisis, maculoschisis with an epiretinal membrane, myopic macular hole with posterior pole retinal detachment, isolated maculoschisis, and myopic macular hole. Eight of the 11 cases underwent combined titanium macular buckle placement and vitrectomy, while three patients received buckle placement without vitrectomy. Partial or complete resolution of the pathology was achieved in all cases. Best-corrected visual acuity improved in 10 out of 11 cases following surgery. A scleral perforation occurred intraoperatively in one case. The patients were followed up for a mean duration of 6.0 +/- 2.3 months (range: 2 to 10 months). TMB may serve as a valuable adjunct in the surgical repair of myopic maculopathy requiring intervention
Localization of hydrogen peroxide in dormant buds of resistant and susceptible chestnut cultivars: Changes during gall developmental stages induced by the asian chestnut gall wasp (dryocosmus kuriphilus)
No full textAsian chestnut gall wasp (ACGW) (Dryocosmus kuriphilus Yasumatsu), native to China, is an invasive pest that causes significant economic losses in Castanea species. While some cultivars show full resistance by inhibiting insect development in buds, the underlying defense mechanisms remain unclear. In this study, the accumulation and distribution of hydrogen peroxide (H2O2) were investigated in dormant buds of chestnut cultivars that are resistant and susceptible to D. kuriphilus by using the 3,3 '-diaminobenzidine (DAB) staining method. Buds were examined under a stereomicroscope during key stages of pest development, including oviposition, transition from egg to larva, gall induction, and gall development. Baseline levels of H2O2 were detected in all buds; however, these levels varied among cultivars, with resistant cultivars exhibiting lower basal levels. The degree of H2O2 accumulation was found to vary depending on plant-insect interaction, physiological processes, and cultivar-specific traits. Histochemical staining revealed that brown spots indicative of H2O2 accumulation were concentrated in the vascular bundles of leaf primordia and in the apical regions. In resistant hybrid cultivars, the defense response was activated at an earlier stage, while in resistant Castanea sativa Mill. cultivars, the response was delayed but more robust. Although consistently high levels of H2O2 were observed throughout the pest interaction in susceptible cultivars, gall development was not inhibited. During the onset of physiological bud break, increased H2O2 accumulation was observed across all cultivars. This increase was associated with endodormancy in susceptible cultivars and with both defense mechanisms and endodormancy processes in resistant cultivars. These findings highlight the significant role of H2O2 in plant defense responses, while also supporting its function as a multifunctional signaling molecule involved in gall development and the regulation of physiological processes
Augmented reality in engineering education: An application for electronic circuits laboratory
No full textEngineering education faces challenges in effectively conveying complex theoretical knowledge and practical skills. Traditional teaching tools like smart boards, education kits, web pages, and computer-based simulators often fall short in bridging the gap between theory and hands-on application. Augmented reality (AR) has emerged as a promising solution to fill this educational gap by providing immersive and interactive learning experiences. In this study, an AR-based application has been developed for operational amplifiers. Agile methodology and the ADDIE learning development model were used in the system development and instructional design of this application. This application, which requires only a smartphone and a breadboard, detects the circuit marker when users point their smartphone camera at it. After detection, the user can interact with the interface to choose whether the system shows input–output signals for different component values, the output voltage formula, a 3D model, or a brief lecture about the used amplifier. These virtual elements are overlaid onto the real-world breadboard based on the user's selection. This integration of AR technology provides an immersive, interactive learning experience, allowing students to visualize and interact with circuit elements in real time
An exact analysis of fine resolution frequency estimation method from three DFT samples: Windowed data case
Get PDFFrequency estimation for a single complex sinusoid in noise is a fundamental problem in signal processing. A suboptimal but simple frequency estimator, known as Jacobsen estimator, which is based on three discrete Fourier transform (DFT) samples, gives good bias performance without the need to increase the DFT size. Candan has modified the Jacobsen estimator by adding a so-called bias correction factor to further reduce the bias of the estimator. In addition to bias considerations, a number of asymptotic variance expressions of the estimators were performed in the literature. However, these expressions are valid only for signal frequencies located very near a DFT bin index. In this paper, with the use of a simple variance analysis technique, an accurate general variance expression for arbitrary frequency locations is derived for the case of windowed data. A general method for calculating the bias correction factor is also proposed. The variance expression is examined for the cosine-sum window family. An approximate variance formula for sufficiently large data record lengths is also given for windows from this family. Computer simulations are included to validate the theoretical results
Comparison of biomordant and chemical mordant on the color, fastness, and antimicrobial properties of wool fabrics dyed with Juglans regia waste product
No full textNatural dyes are regarded as innovative and sustainable resources in the textile industry, offering not only coloration but also functional properties such as antibacterial activity. In this study, the leaves, dry hard shells (inner shell), and green shells (outer shell) of the walnut species Şebinkarahisar were used as natural resources for dyeing wool fabrics. Aluminum potassium sulfate (KAl(SO4)2) was used as a mordant in the pre-mordanting process, whereas pomegranate peel powder and acorn powder were used as biomordants. This study investigated whether acorn and pomegranate peel powders are alternatives to KAl(SO4)2 as a biomordant. The dyeing process was carried out with a concentration of 50% on mordanting and non-mordanting fabrics. The mordanting materials were used at 4 different concentrations: 1%, 5%, 10%, and 15%. Fastness, color, and antibacterial analyses were performed on the treated samples. The analyses revealed that the use of acorn and pomegranate peel powder can be an alternative to aluminum potassium sulfate, apart from the antibacterial properties
