1,730 research outputs found
A New Methodology for the Block Maxima Approach in Selecting the Optimal Block Size
The Block Maxima method divides sample data into equal blocks. Predictions are based on the maximum values of the observations. Choosing an efficient and proper block size for the Block Maxima method is an important issue and varies across fields (e.g., flood, rainfall, finance). However, the main problem is deciding which block size is suitable or optimal for the prediction. In the literature, it is a known fact that the selection of a small block size leads to bias, while the selection of a large block size leads to a variance problem. In one respect, this issue is any trade off problem between the bias and the variance. This paper proposes simple and easy computational method to specify the optimal block size selection process for the Block Maxima method
Burnout Levels among Senior Students in Applied Sciences Faculties: An Empirical Analysis in Turkey
Nowadays, the burnout which is one of the most influential concepts of work experience has become an important focus of attention in scientific studies by recognizing the negative effects that it has on organizations and individuals. In the business world, the phenomenon of burnout, which is often seen in employees who are in intensive and constant communication with people, is also felt in university students as well as employees. The aim of this study is to examine the burnout levels of students who graduated from the same faculties as those who pursue undergraduate education in the Applied Sciences Faculties in Turkey and to classify these burnout levels according to certain variables. In other words, the research aims to reveal the differences in the burnout levels of graduates and non-graduates. In the study, the “Maslach Burnout Scale” was used to measure burnout levels. Findings show that those who continue to undergraduate education have higher burnout levels than graduates. The results also indicate that there is generally no difference between graduated and non-graduated students' burnout levels according to gender and employment status, but there are differences in the sub-dimensions of burnout.
The role of diffusion-weighted imaging on 3 tesla magnetic resonance in the clinical staging and pathological grading of clear cell renal carcinoma
Aim: To evaluate the contribution of the apparent diffusion coefficient (ADC) to distinguish between the four
clinical stages and pathological grading in patients with clear cell renal cell carcinoma (RCC) on 3T MRI.
Methods: MRI of 93 patients with histopathological diagnosis of clear cell RCC were evaluated
retrospectively. Clinical stage was evaluated according to American Joint Committee on Cancer and
histopathological examination was evaluated according to the Fuhrman grading system. ADC values were
compared for each clinical stage and pathological grade.
Results: Clinical stages were I in 51 patients (54.8%), II in 14 patients (15%), III in 15 patients (16.1%), and
IV in 13 patients (13.9%). The Fuhrman grade of the patients were I in 8 (8.6%) patients, II in 55 (59.1%)
patients, III in 23 (24.7%) patients and IV in 7 (7.5%) patients. Clinical stage I and Fuhrman grade I had
significantly higher ADC values than all groups (p<0.001). The sensitivity was 81% and the specificity was
80.4% when the optimum cut-off value of ADC was taken as 1.41×10−3 mm2
/s to differentiate between clinical
stage I and other stages (II, III, and IV) (AUC:0.910; 95CI:0.855-0.964; p<0.001). The optimum cutoff value
of ADC was taken as 1.67×10−3 mm2
/s to differentiate between Fuhrman grade I and other grades (II, III and
IV), the sensitivity was 88.2% and the specificity was 100% (AUC: 0.927; 95CI: 0.872- 0.983; p<0.001).
Conclusions: In patients with renal mass suggestive of clear cell RCC in imaging studies; The possibility of
lymph node or distant metastatic lesion should be considered in patients with an ADC of the primary tumor
site less than 1.41×10−3 mm2
/s, and the presence of distant metastasis in patients with an ADC less than
1.22×10−3 mm2
/s
A Detailed Investigation of the Bond Performance of Basalt Fiber-Reinforced Polymer Bars in Geopolymer Concrete
This comprehensive experimental study aimed to determine the bond performance of basalt fiber reinforced polymer (BFRP) bars in geopolymer concrete (GC). The study examined the bond performance of BFRP bars and GC by considering several parameters, including bar diameters of 8, 10, and 12 mm, embedment lengths of 4, 8, and 12 db mm (where db is the diameter of the bar), concrete covers of 20, 40, and 70 mm and compressive strengths of 21.7 and 34.4 MPa. The study also compared the effect of the bar surface and bar type on GC bond performance. Eventually, the results were compared with ordinary concrete (OC). The obtained results indicated that an increase in the BFRP bar diameter results in a decrease in the average bond stress. Similarly, an increase in the length of the bond leads to a reduction in the bond stress. The specimen possessing a short embedment length failed due to bar pullout, while the specimens with a longer embedment length failed as a result of concrete splitting. The outcomes also showed that the strength of bond increases with an increase in compressive strength and cover thickness. Furthermore, the results also indicated that BFRP-reinforced GC has comparable bond performance to steel-reinforced GC and BFRP-reinforced OC and performed better than OC. Last, Comparisons between the existing bond-slip models were offered to demonstrate the best bond stress-slip model for FRP bars and GC for ascending branch up to ultimate bond stress of the bond slip curves and for whole curves
The role of diffusion-weighted imaging on 3 tesla magnetic resonance in the clinical staging and pathological grading of clear cell renal carcinoma
Aim: To evaluate the contribution of the apparent diffusion coefficient (ADC) to distinguish between the four clinical stages and pathological grading in patients with clear cell renal cell carcinoma (RCC) on 3T MRI.
Methods: MRI of 93 patients with histopathological diagnosis of clear cell RCC were evaluated retrospectively. Clinical stage was evaluated according to American Joint Committee on Cancer and histopathological examination was evaluated according to the Fuhrman grading system. ADC values were compared for each clinical stage and pathological grade.
Results: Clinical stages were I in 51 patients (54.8%), II in 14 patients (15%), III in 15 patients (16.1%), and IV in 13 patients (13.9%). The Fuhrman grade of the patients were I in 8 (8.6%) patients, II in 55 (59.1%) patients, III in 23 (24.7%) patients and IV in 7 (7.5%) patients. Clinical stage I and Fuhrman grade I had significantly higher ADC values than all groups (p<0.001). The sensitivity was 81% and the specificity was 80.4% when the optimum cut-off value of ADC was taken as 1.41×10−3 mm2/s to differentiate between clinical stage I and other stages (II, III, and IV) (AUC:0.910; 95CI:0.855-0.964; p<0.001). The optimum cutoff value of ADC was taken as 1.67×10−3 mm2/s to differentiate between Fuhrman grade I and other grades (II, III and IV), the sensitivity was 88.2% and the specificity was 100% (AUC: 0.927; 95CI: 0.872- 0.983; p<0.001).
Conclusions: In patients with renal mass suggestive of clear cell RCC in imaging studies; The possibility of lymph node or distant metastatic lesion should be considered in patients with an ADC of the primary tumor site less than 1.41×10−3 mm2/s, and the presence of distant metastasis in patients with an ADC less than 1.22×10−3 mm2/s
Production of microporous Cu-doped BTC (Cu-BTC) metal-organic framework composite materials, superior adsorbents for the removal of methylene blue (Basic Blue 9)
Cellulosic woven waste was used as a biomass material to prepare a Cu-doped BTC (Cu-BTC) adsorbent, which was then used to remove methylene blue (Basic Blue 9) from wastewater. Cellulosic woven waste was used as a biomass material to prepare a Cu-doped BTC (Cu-BTC) adsorbent, which was then used to remove methylene blue (Basic Blue 9) from wastewater. The Cu-BTC had higher adsorption capacity for methylene blue (BB9) than pure woven waste because it had high specific surface area and electrostatic interaction with cationic methylene blue molecules. The Cu-BTC removed methylene blue from wastewater rapidly and effectively and had an excellent adsorption capacity (197.90 mg/g). In batch process, the adsorption efficiency of the adsorbent for removal of BB9 was evaluated within 20 degrees C-60 degrees C, with initial BB9 concentrations of 50 - 200 mg/L and initial pH of 2 -11. The Cu-BTC activation tailored the topological and textural properties of the obtained adsorbent, leading to a relatively large surface area of 1418.3 m(2)/g and pores with a volume of 0.491 cm(3)/g and an average size of 2.11 nm. The adsorption process fitted well with the Langmuir isotherm and the pseudo-second-order kinetic model. The possible mechanism for methylene blue removal mainly involved electrostatic attraction and micro pores. This study can serve as a guide for value-added utilization of cellulosic woven waste and as a practical method for the removal of methylene blue from wastewater. Adsorption of methylene blue onto the CuBTC is an effective and eco-friendly method for its removal from wastewater
Designing and analyzing park sensor system for efficient and sustainable car park area management
Many problems have been seen in cities because of increasing vehicle density. One of these problems is vehicle density in parking lots. People look for empty parking areas and they spend too much time. While people look for empty parking areas, CO2 (carbon dioxide) emission and energy consumption increase due to density in parking lots. We worked to solve these problems by doing Magnetic Car Park Sensor. Magnetic Car Park Sensor is the system which detects cars in car parks. After cars detected with the system, the system sends information to center server and we can see information data in the system interface. The system helps people to find empty parking lots. As people find empty car park areas fastly, energy consumption and CO2 emission are decreased significantly
Prevalence of tick-borne haemoparasites in small ruminants in Turkey and diagnostic sensitivity of single-PCR and RLB
Background: Tick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are
common in regions of the world where the distributions of host, pathogen and vector overlap. Many of these
diseases threaten livestock production and some also represent a concern to human public health. The primary aim
of this study was to determine the prevalence of the above-mentioned pathogens in a large number of blood
samples (n = 1979) collected from sheep (n = 1727) and goats (n = 252) in Turkey. A secondary aim was to assess
the diagnostic sensitivity of a number of species-specific polymerase chain reaction (PCR) tests and the reverse line
blotting (RLB) assay. DNA samples were screened using species-specific PCR for the presence of Theileria ovis,
Theileria sp. MK, T. lestoquardi, T. uilenbergi, T. luwenshuni, Babesia ovis, Anaplasma ovis and A. phagocytophilum while
RLB was undertaken to test for the presence of all known Theileria, Babesia, Anaplasma and Ehrlichia species. The
diagnostic sensitivity of these two approaches was then compared in terms of their ability to detect single species
and mixed infections.
Results: Overall, 84 and 74.43% of the small ruminants sampled were identified as hosting one or more
pathogen(s) by species-specific PCR and RLB respectively. The presence of Theileria sp. OT1, T. luwenshuni and T.
uilenbergi in Turkey was revealed for the first time while the presence of Babesia motasi, B. crassa and T. separata in
Turkish small ruminants was confirmed using molecular methods. A high prevalence of mixed infection was
evident, with PCR and RLB approaches indicating that 52.24 and 35.42% of animals were co-infected with multiple
species, respectively. More than 80% of the mixed infections contained T. ovis and/or A. ovis. The RLB approach was
found to be capable of detecting mixed infections with species such as Theileria sp. OT1, Theileria sp. OT3, T.
separata, B. crassa and Babesia spp.
Conclusion: The results indicated that pathogens causing TBHDs are highly prevalent in sheep and goats in Turkey.
The diagnostic sensitivity of species-specific single PCR was generally higher than that of RLB. However, the latter
approach was still capable of identifying a high proportion of individuals containing mixed-species infections. The
use of species-specific single PCR is recommended to accurately estimate pathogen prevalence and to identify
co-infected hosts
Loop mediated isothermal amplification (LAMP) of Theileria annulata DNA
In the past three decades, as an alternative to PCR (polymerase chain reaction) new diagnostic techniques like
LAMP (loop mediated isothermal amplification) whereby target DNA can be amplified under isothermal conditions without using
thermocycler have been developed. The LAMP method allows the synthesis of large amounts of DNA in a short time with high
specificity and rapid and easy detection of generated products. In this study, specificity and sensitivity of LAMP method was evaluated
for the detection of T. annulata in acute infected and/or carriers cattle using primer pair specifically designed to amplify merozoite
surface antigen gene (Mero1), 30 kDa major merozoite surface antigen gene (Tams-1) and cytochrome b gene of T.annulata. Primer
pairs with highest sensitivity were used to evaluate the applicability of LAMP to the field samples. Two LAMP primers (CYTOB1 and
CYTOB341) targeting cytochrome b gene specifically amplified DNA of different T. annulata isolates successfully while no
amplification was seen in other species DNAs and BL20. CYTOB1 primers detected T. annulata Ankara / D7 DNA up to 2 fg, however
the detection limit of CYTOB341 was 10 fold lower. The sensitivity of CYTOB1 LAMP assay was same with F3/B3 PCR, however
when compared with that of cytob1 PCR a 10 fold lower sensitivity was found. The LAMP product was confirmed by restriction
digestion and sequencing. Results obtained from this study indicated that none of the designed primer pairs specific to target genes
(Tams-1 and Mero1), except cytochrome b gene was able to specifically and sensitively detect different isolates of T. annulata.
Consequently, it was shown that LAMP method using CYTOB1 primers is less effective than the cytob1 PCR in terms of detecting T.
annulata in the field sample
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