401 research outputs found
Investigation of antimicrobial resistance in pigeons (Columba livia domestica) using indicator bacteria
ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗThe aim of this study was to determine the prevalence of antibiotic resistance as well as presence of resistance-associated genes in Escherichia coli and Enterococcus spp. strains isolated from pigeons. One hundred and fifty cloacal swabs were collected from apparently healthy pigeons in Hatay, Turkey, between March 2014 and June 2014. Antimicrobial susceptibilities of the isolates were tested with disc diffusion method, and resistance genes were investigated by polymerase chain reaction (PCR). E. coli were isolated from 94.7% (142) of the examined cloacal swab samples. E. coli isolates revealed higher resistance rates to tetracycline (51.4%) and ampicillin (50%), followed bynalidixic acid (19.7%), streptomycin (12.7%), amoxycillin-clavulanic acid (15.5%), trimethoprim-sulfamethoxazole (10.6%), cephalothin (7.0%), ciprofloxacin (6.3%), kanamycin (4.9%), gentamicin (4.2%), tobramycin (4.2%), ceftazidime (4.2%), cefotaxime (4.2%), chloramphenicol (2.8%), aztreonam (2.8%), and cefoxitin (0.7%), respectively. Twentyeight (%19.7) E. coli isolates were susceptible to all tested antimicrobials. A total of 136 (90.7%) Enterococcus spp. were isolated and species distribution of the isolates was determined by species-specific PCR. The isolates were identified as 64 (47.1%) E. hirae, 17 (12.5%) E. faecium, 8 (5.9%) E. faecalis, 4 (2.9%) E. columbea, and 2 (1.5%) E. durans. The rest of the isolates (30.1%) were identified as Enterococcus spp. with the used primers. Enterococcus spp. were resistant to tetracycline (67.6%), erythromycin (23.5%), rifampicin (17.6%), chloramphenicol (6.6%) and ciprofloxacin (5.9%). By contrast, 38 (27.9%) Enterococcus spp. were sensitive to all tested antimicrobials. The data obtained in the study showed that pigeons were carriers of antimicrobial resistant E. coli and Enterococcus spp. in their intestinal microbiota, and may pose public health risk due to not only transmission of these resistant bacteria to humans but also contamination of the environment. The current status of antimicrobial resistance in different animal species should be continuosly monitored and control measures should also be taken
Investigation of vector-borne diseases in dogs
In this study, a total of 186 blood samples were collected from kennel dogs consisting of 104 male and 82 female in five provinces (Mersin, Adana, Hatay, Gaziantep and Batman) of Turkey, and evaluated using molecular methods for the presence of canine vector-borne diseases (CVBDs). Overall, 10.8% of the sampled dogs were found to be infected with one or more CVBD pathogens investigated. Ehrlichia canis (17/186; 9.1%) was the most common CVBD pathogen, followed by Babesia canis vogeli (5/186; 2.7%) and Hepatozoon canis (1/186; 0.5%), respectively. Co-infection of E. canis with B. caniswas detected in 3 (1.6%) dogs. Infection with Rickettsia spp., Coxiella burnetii, Borrelia burgdorferi s.l., Francisella tularensis, Bartonella spp., Leishmania spp., Diroflaria immitis, Diroflaria repens, and Acanthocheilonema reconditum were not detected. No sex association with CVBDs was determined (p>0.05). The result of the study indicates the presence of three CVB pathogens, including the first report of B. canis and H. canis in the studied provinces.Bu çalışmada, Türkiye'nin beş farklı ilindeki (Mersin, Adana, Hatay, Gaziantep ve Batman) köpek barınaklarındanalınan 186 (104'ü erkek ve 82'si dişi) kan örneği vektör kaynaklı nakledilen patojenler yönünden moleküler yöntemlerlearaştırıldı. İncelenen örneklerin %10.8'inin en az bir veya birden fazla patojen ile enfekte olduğu tespit edildi. Ehrlichiacanis (17/186; %9.1) en yaygın vektör aracılı nakledilen patojen olup, bunu sırasıyla Babesia canis vogeli (5/186; %2.7) veHepatozoon canis (1/186; %0.5) izledi. E. canis ve B. canis ortak enfeksiyonu 3 (%1.6) köpekte tespit edildi. Rickettsia spp.,Coxiella burnetii, Borrelia burgdorferi s.l., Francisella tularensis, Bartonella spp., Leishmania spp., Diroflaria immitis,Diroflaria repens ve Acanthocheilonema reconditum enfeksiyonu saptanmadı. Vektör aracılı nakledilen patojenler yönündenpozitif bulunan köpeklerde yaş ve cinsiyet yönünden istatistiksel olarak önemli bir fark belirlenmedi (p> 0.05). Çalışılanillerde köpeklerde vektör aracılı nakledilen patojenlerden üçünün varlığı gösterilmiş ve çalışılan illerde ilk kez B. canis ve H.canis varlığı tespit edilmiştir
Some generalizations for mixed multivalued mappings
[EN] In this paper, we first introduce a new concept of KW-type m-contraction mapping. Then, we obtain some fixed point results for these mappings on M-metric spaces. Thus, we extend many well-known results for both single valued mappings and multivalued mappings such as the main results of Klim and Wardowski [13] and Altun et al. [4]. Also, we provide an interesting example to show the effectiveness of our result.Aslantaş, M.; Sahin, H.; Sadullah, U. (2022). Some generalizations for mixed multivalued mappings. Applied General Topology. 23(1):169-178. https://doi.org/10.4995/agt.2022.15214OJS16917823
Investigation of variation in tool-chip contact length in orthogonal cutting process
The tool-chip contact length has an important effect in view of tool life and tool wear in machining process. An increase in tool-chip contact length may results in a decrease of tool life. Besides the tool-chip contact length is an important element in formation of crater wear. The increasing of tool-chip contact length results in increase of friction forces acting on tool rake face and affects the temperature distributions along the cutting tool. First, in this study, all analytical models proposed to calculate the tool-chip contact length were compared with each other. Second, the tool-chip contact length was calculated using three different models for different workpiece materials and cutting parameters. The experiments were performed in a series of test in order to understand the relationship between tool-chip contact length and cutting velocity, material type and undeformed chip thickness.Takım-talaş temas boyu, işleme prosesinde takım ömrü ve takım aşınması açısından önemli bir etkiye sahiptir.
Takım-talaş temas boyundaki artış takım ömrünün azalmasına neden olabilir. Ayrıca takım-talaş temas boyu,
krater aşınma davranışının önemli bir unsurudur. Takım-talaş temas boyunun artması, takım talaş yüzeyinde
sürtünme kuvvetlerin artmasına neden olmakta ve kesici takım boyunca oluşan sıcaklık dağılımını
etkilemektedir. Öncelikle bu çalışmada takım-talaş temas boyunun hesaplanması için kullanılan bütün analitik
modeller birbirleriyle karşılaştırılmıştır. Daha sonra takım-talaş temas boyu, farklı iş parçası malzemesi ve
kesme parametreleri için üç farklı model kullanılarak hesaplanmıştır. Takım-talaş temas boyu ile kesme hızı,
malzeme tipi ve deforme olmamış talaş kalınlığı arasındaki ilişkinin anlaşılması için tornada bir seri deney
yapılmıştır. Tornalama işlemleri ortagonal kesme koşulları altında ve seramik kesici takım kullanılarak
gerçekleştirilmiştir. Elde edilen sonuçlara göre, artan ilerleme değeri ve malzeme türü takım talaş boyunu önemli
oranda etkilemektedir
The First Balkan Alliance, 1866-1868
The Balkan alliance system of 1912 was one of the most important political developments in the modern Balkan history. Before the Balkan wars, the Balkan states formed the alliances between them (Serbia-Bulgaria, Bulgaria-Greece and Montenegro-Bulgaria-Serbia). They defeated the Ottoman Empire in the First Balkan War with the help of these alliances. This article examines the First Balkan Alliance of 1866-68 which was regarded as a kind of rehearsal or a historical proto-example of the alliance system of 1912, and which was formed by the Serbian Prince Mihail Obrenovich and his minister of foreign affairs Ilija Garasanin. The main goal of alliance system was to eliminate the Ottoman Empire from the Balkans. In this context, Serbia signed the alliance treaties with Montenegro in September 1866 with the Bulgarian Secret Central Committee in January 1867, with Greece in August 1867 and with Romania in January 1868. Although the 1866-68 alliance system was not able to achieve its main goal due to some local, regional and continental reasons, it had remained in the minds of Balkan political leaders. When they found a more suitable political and military atmosphere in 1912, they immediately revitalized the alliance of 1866-68
Finite element modelling of edge radius effect in micro turning process
Micro-turning is very similar to conventional
turning, but is a cutting operation in which the tool geometry
effect is more important. For this reason, the cutting geometry
and cutting parameters used in micro turning must be carefully
selected. In this work, during the machining of the Ti6Al4V alloy
in micro cutting conditions, the effect of different edge radii of
the insert on the cutting forces, tool stresses, and residual stresses
was investigated. The appropriate material model is determined
by comparing the force data obtained from the cutting
experiments with the model results. Numerical solutions have
been made for different edge radii. The cutting speed and depth
of cut were considered as constant. Different feed rate values and
different edge radii were chosen as variables. According to the
results obtained, the increasing edge radius causes an increase in
cutting (especially in the direction of feed) forces. Increasing edge
radius causes a decrease in tool stresses. Most importantly, the
increase of the edge radius causes the residual stresses under the
surface to occur, usually in the form of compression
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