Recombinant Production and Biochemical Characterization of Thermostable Arabinofuranosidase from Acidothermophilic Alicyclobacillus Acidocaldarius

The complete enzymatic degradation of lignocellulosic biomass requires the cooperative action of cellulosic, hemicellulosic, and lignolytic enzymes such as cellulase, xylanase, laccase, galactosidase, and arabinofuranosidase. Arabinofuranosidases (E.C 3.2.1.55), which belong to the glycoside hydrolase family of enzymes, hydrolyze the 1,3- and 1,5-α-arabinosyl bonds in L-arabinose- containing molecules. L-arabinoses are present in hemicellulosic part of lignocellulosic biomass. Arabinofuranosidases also play an important role in the complete hydrolysis of arabinoxylans. Analysis of the genome project and CAZY database revealed two putative arabinofuranosidase genes in the A. acidocaldarius genome. The aim of the study was cloning, heterologous expression, purification and biochemical characterization of the arabinofuranosidase enzyme encoded in A. acidocaldarius genome. For this purpose, the AbfA gene of the arabinofuranosidase protein was cloned into the pQE-40 vector, heterologously expressed in E. coli BL21 GOLD (DE3) and successfully purified using His-Tag. Biochemical characterization of the purified enzyme revealed that A. acidocaldarius arabinofuranosidase exhibited activity over a wide pH and temperature range with optimum activity at 45 ºC and pH 6.5 in phosphate buffer towards 4-nitrophenyl-α-L-arabinofuranoside as the substrate. In addition, the enzyme is highly stable over wide range of temperature and maintaining 60% of its activity after 90 min of incubation at 80 ºC. Through the bioinformatics studies, the homology model of A. acidocaldarius arabinofuranosidase was generated and the substrate binding site and residues located in this site were identified. Further molecular docking analysis revealed that the substrate located in the catalytically active pose and, residues N174, E175, and E294 have direct interaction with 4-nitrophenyl-α-L-arabinofuranoside. Moreover, based on phylogenetic analysis, A. acidocaldarius arabinofuranosidase exists in the sub-group of intracellular arabinofuranosidases, and G. stearothermophilus and B.subtilis arabinofuranosidases are close relatives of A. acidocaldarius arabinofuranosidase. This is the first study to report the gene cloning, recombinant expression and biochemical and bioinformatic characterization of an auxiliary GH51 arabinofuranosidase from an acidothermophilic bacterium A. acidocaldarius. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature

Diagnostic performance and interobserver agreement of CO-RADS: evaluation of classification in radiology practice

PURPOSEWe aimed to evaluate the use of the COVID-19 reporting and data system (CO-RADS) among radiologists and the diagnostic performance of this system.METHODSFour radiologists retrospectively evaluated the chest CT examinations of 178 patients. The study included 143 patients with positive reverse transcriptase-polymerase chain reaction (RT-PCR) test results and 35 patients whose RT-PCR tests were negative but whose clinical and/or radiological findings were consistent with COVID-19. Fleiss’ kappa (κ) values were calculated, and individual observers’ scores were compared. To investigate diagnostic efficiency, receiver operating characteristic (ROC) curves were calculated for each interpreter.RESULTSThe interpreters were in full agreement on 574 of 712 (80.6%) evaluations. The common Fleiss’ κ value of all the radiologists combined was 0.712 (95% confidence interval [CI] 0.692–0.769). A reliable prediction on the basis of RT-PCR and clinical findings indicated the mean area under the curve (AUC) of Fleiss’ κ value as 0.89 (95% CI 0.708–0.990). General interpreter agreement was found to range from moderate to good.CONCLUSIONThe interpreter agreement for CO-RADS categories 1 and 5 was reasonably good. We conclude that this scoring system will make a valuable contribution to efforts in COVID-19 diagnosis. CO-RADS can also be of significant value for the diagnosis and treatment of the disease in cases with false-negative PCR results

Ulusaldan Küresele: Popülizm, Demokrasi, Güvenlik Konferansı

Öngörülmesi giderek güçleşen, sarsıntılı ve savrulmalı zamanlardan geçiyoruz. İkinci Dünya Savaşı ve Soğuk Savaş ortak deneyimleri sonrasında 1950’lerden ve 1990’lardan itibaren demokratik sistemlerin peş peşe dalgalarla meşrulaşacağı, yaygınlaşacağı ve güçleneceği öngörüsü hakimdi. Ancak son yıllarda yaşanan bazı gelişmelerle demokrasilerin geleceği tekrar sorgulanmaya başladı. Gerek 11 Eylül ile başlayan ve IŞİD ile devam eden ve şiddet içeren İslamcı radikalizm, gerek Batı demokrasilerinde popülist radikal sağ hareketlerin ve beyaz ırkçı grupların yükselişi ve iktidara gelişi, bir yandan güvenlik-özgürlük ikileminin demokrasi dengesini bozdu, bir yandan da hem demokratik sistemlerin hem dünya barışının geleceğini bizi tekrar sorgular, sorgulatır hale getirdi. Demokrasileri bildiğimizi zannediyoruz, ama demokrasiler ile ilgili daha öğrenmemiz gereken çok şey var. Demokrasi kaderimiz de geleceğimiz de olmak zorunda değil belki de. Ya da belki yanlış yerden soru sormaya başlıyoruz, belki demokrasi yerine yeni bir referansa ihtiyacımız var. Aslında demokrasileri çantada keklik görmeyip, sabırla büyütüp yeşertmek, geliştirmek, korumak, ileri safhalara taşımak ve bizden sonraki nesillere aktarmak bir sorumluluk, ve bu sorumluluk bizlere ait. Popülizm, demokrasi, güvenlik kavramlarının her biri bugün sıkça ve yaygın olarak kullandığımız kavramlar olarak gündelik sohbetlerimizin içine kadar girmiş durumda. Bu yaygın kullanımlarına rağmen her bir kavram, üzerine düşünmeye, tartışmaya ve değerlendirmeye tekrar tekrar olanak verecek derinlikte. Her bir tartışma bir diğerini açarken, farklı gibi görünen bu kavramların birbirleriyle kesiştikleri zeminler bulmak mümkün. Popülist liderlerin politikaları bütün siyaset yapma biçimlerini kendine çeken ya da kendinden uzaklaştıran eksenler yaratarak her ikisini de aynı anda besleyebiliyor. Popülist politikaya angaje olan liderler ve grupların yanında bu politikaya karşı mücadele eden kişiler ve kitleler de yok değil, ancak kimi zaman bu kitleler eleştirdiği bu siyaset biçiminin kurucu öznesi haline de gelebiliyor. Bunun karşısında tabandan gelen demokratikleşme talepleri ve popülist siyasetle beraber kurumsallaşan diğer politika yapma biçimleri, demokrasi anlayışımızı farklı yönlere çekebiliyor. Bu demokratikleşme talepleri kimi zaman olumlu karşılıklar alsa da, kimi zaman devletlerin güvenlik politikaları ile etkisizleştirilmeye ve bastırılmaya çalışılıyor. Güvenlik politikalarının alanı günümüz teknolojisi sebebiyle o kadar genişledi ki, bu politikanın nesnesi haline gelmemiş varlık ve alan bulmak neredeyse mümkün değil. Ulusaldan Küresele: Popülizm, Demokrasi, Güvenlik konferansımız bu alanların kendine özgülüklerini göz önünde bulundururken, aralarındaki kesişimleri de ortaya koyan pek çok değerli sunuma ev sahipliği yaptı. Konferansın düzenlenmesinde emeği geçen herkese, ve bu bildiri kitabında tam metinleri ve özetleri bulunan bütün katılımcılarımıza çok teşekkür ederiz.Publisher's Versio

Tekstil sanayinde kullanılan sentetik polimer mamullerin biyoaktif bileşiklerle modifikasyonu

Bu çalışmada, tekstil sanayinde kullanılan çeşitli sentetik polimerlerden yapılmış kumaşların enzimatik ve kimyasal olarak modifikasyonu ile özelliklerinin iyileştirilmesi ve/veya fonksiyonelleştirilmesi amaçlandı. Modifikasyon işlemleriyle fonksiyonel grup eklenerek reaksiyona yatkın hale getirilen sentetik kumaşlara biyoaktif bileşik olarak trombin immobilize edildi. Bu amaçla, sentetik kumaş olarak PET, PP ve PAN kumaşlar seçildi ve öncelikle Trametes versicolor (ATCC 11235), Pseudomonas fluorescens (DSM 6521) Pseudomonas putida (DSM 548), Abortiporus biennis, Trametes trogii, Trametes versicolor (İ-1), Trametes versicolor (İ-2), Pleurotus ostreatus (İ-1), Pleurotus citrinopileatus, Gloeophyllum sepiarium, Ganoderma carnosum, Laetiporus sulphureus ve Pleurotus ostreatus mikroorganizmaları kullanarak seçilen sentetik kumaşların mikrobiyal modifikasyonu yapıldı. Mikrobiyal modifikasyonun derecesi dinamik temas açısı ölçümü yoluyla saptandı. En düşük temas açısına sahip kumaş, en fazla modifiye olan kumaş olduğundan, sentetik kumaşların temas açısını mikrobiyal modifikasyondan sonra en çok düşüren mikroorganizmalar belirlendi. PET kumaşın mikrobiyal modifikasyonu sonucu en düşük temas açısı Trametes trogii, PP kumaşın mikrobiyal modifikasyonu sonucu en düşük temas açısı Trametes versicolor (ATCC_ 1235) ve PAN kumaşın mikrobiyal modifikasyonu sonucu en düşük temas açısı Pseudomonas putida (DSM 548) ile elde edildi. Belirlenen mikroorganizmalar ile sentetik kumaşların inkübasyonu sırasında lignin peroksidaz, MnP, lakkaz ve nitrilaz enzimlerinin aktiviteleri izlendi. PET, PAN ve PP'nin modifikasyonlarında sırasıyla lakkaz, nitrilaz ve MnP enzimlerinin aktivitelerinin diğer enzimlere göre daha yüksek olduğu belirlendi. Modifikasyonlar sonucu, PET ve PAN kumaşlarda karboksil gruplarının oluştuğu ATR-FTIR yöntemiyle belirlendi. Kimyasal modifikasyon, UV-indüklü aşı polimerizasyonu ile yapıldı. Foto-başlatıcı olarak BP ve aşı monomeri olarak MAA'nın kullanıldığı tek adımlı aşı polimerizasyonu, PET, PP ve PAN kumaşlara yapıldı. Sentetik kumaşların fonksiyonelleştirilmesinde model biyoaktif bileşik olarak trombin seçildi. Enzimatik olarak modifiye edilen ve aşı polimerizasyonu yöntemi ile modifiye edilen PET, PP ve PAN kumaşlara EDC kullanarak trombin optimize edilen koşullarda immobilize edildi. Trombin immobilize edilmiş materyal in vitro koşullarda, kanın rekalsifikasyon zamanına etkisi ölçülerek test edildi. Trombin immobilize materyaller arasında en iyi sonuç rekalsifikasyon süresinin %49'a indirildiği TI-PET-2 ile alındı. Geliştirilen ürün in vivo olarak Cavia porcellus kullanılarak test edildi ve kanama süresini %24,6'ya düşürdüğü belirlendi. Veriler istatistiksel olarak değerlendirildi ve sonuçlar istatistiksel olarak anlamlı bulundu. Sonuç olarak, hem enzimatik hem de kimyasal olarak modifiye edilen sentetik kumaşların model biyoaktif bileşik olarak trombinin kullanılmasıyla fonksiyonel medikal tekstil ürünü elde edildi

Covalent Immobilization of Urease to Modified Ethyl Cellulose

WOS: 000314077800004Graft polymerization technology is a good way to modify polymers. New functional groups are added to polymer structure using graft polymerization. Enzyme immobilization could be done from these added functional groups. Ethyl cellulose was selected as a support for enzyme immobilization and no many studies has been conducted about it. It is insoluble in water and suitable for reuse. In this study, methacrylic acid was graft polymerized to ethyl cellulose using benzophenone. In graft polymerization studies, optimum amounts of methacrylic acid and benzophenone were determined as 60 mmol and 0.6 g, respectively. Percentage of graft polymerization was maximum in toluene as solvent and optimum graft polymerization time was found as 3 hours. The graft polymerization percentage was 225.7 % at optimum conditions. This value was very good for UV-induced graft polymerization technique. FT-IR spectra of ethyl cellulose and methacrylic acid graft polymerized ethyl cellulose showed that graft polymerization was carried out successfully. -COOH groups were added to ethyl cellulose structure after graft polymerization. Then, urease was immobilized to methacrylic acid graft polymerized ethyl cellulose using 1-ethyl-3-(3-dimetylaminopropyl)-carbodiimide as the condensing agent which accelerates the reaction between -COOH from methacrylic acid graft polymerized ethyl cellulose and -NH2 from urease. Optimization studies were also performed for the immobilization of urease. Optimized values for urease immobilization; optimum amount of 1-ethyl-3-(3-dimetylaminopropyl)-carbodiimide was found as 5 mg, temperature was determined as 37 degrees C, 2 hours were selected as optimum time, pH and amount of urease were found to be pH 7 and 10 mg, respectively. Remained activity of immobilized urease was 1.74 % before optimization studies. After optimization of immobilization studies, this ratio has increased to 29.85 %. The immobilized urease activity was increased 17.2 times

Effects Of Low Energy Architecture On Building Cost Within The Scope Of Economic Feasibility Studies

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1996Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 1996Ekolojik dengeyi korama ve doğal kaynaklan hesaplı tüketme zorunluluğu, yapının tasarlanma ve inşaası aşamalarında karar vericileri yeni tedbirler almaya yöneltmektedir. Bu amaç için yapının ekonomik ve teknolojik olarak yapılabilirliğinin mümkün olması gerekir. Bu çalışmada, özellikle petrol krizi sonrası, dünyada artan bir ivmeyle kabul gören Düşük Enerji Mimarlığı Yaklaşımının ekonomik yapılabilirlik çalışmaları kapsamında maliyete etkileri irdelenmektedir. Ekonomik Yapılabilirlik Çalışmaları Kapsamında Düşük Enerji Mimarlığı Yaklaşımının Maliyete Etkisi konusu; Giriş, Düşük Enerji Mimarlığı, Fizibilite ve Düşük Enerji Mimarlığı Yaklaşımının Bina Maliyetine Etkileri olmak üzere dört bölümde incelenmiştir. Giriş Bölümü'nde problemin tanımı yapılmış ve araştırma metodolojisi özetlenmiştir. Düşük Enerji Mimarlığı Bölümü'nde, kuramsal ve tarihi gelişim ile araştırma kapsamında, yerleşim ölçeğinden malzeme seçimine dek dizayn ve imalat kriterleri tariflenmiştir. Fizibilite Bölümü'nde, kuramsal ve tarihi gelişim ile Fizibilite kapsamında yapılan çalışmalar teknik, örgütsel ve ekonomik değerlendirme bazında ve herbirinin alt açılımlarından bahsedilmek suretiyle tariflenmiştir. Dördüncü Bölüm olan, Düşük Enerji Mimarlığı Yaklaşımının Bina Maliyetine Etkileri, ikinci ve üçüncü bölümlerde tariflenen konuların çakışma noktasında, ve araştırmanın amacı doğrultusunda yer verilen değerlendirmelerden oluşmaktadır.The value to the user of any building resides its ability to promote well-being and encourage people to perform at their best. For designers to meet this challenge requires a proper response to the findings of many studies. Architecture is a process; the art and science of designing buildings and also a product; the buildings that this design process creates. Architecture therefore embraces the design process, the construction process, the building as it is intended to be used, and the building as it actually performs and used in practice. All buildings require energy inputs at various points in their life cycle. The amount, type and uses of energy vary across buildings, regions and countries. In general, combustible fuels and electricity are supplied for lighting and equipment, cooking, hot water, heating and cooling, and mechanised access. Other energy inputs are derived as incidental heat gains from these services, from the sun and from people. Solar radiation in particular can make significant contributions to heating, cooling and lighting loads. In "low energy buildings" designed to minimise energy consumption, these incidental gains can meet %70 of the total energy needed. Energy efficient design embraces the design and building process, the building as it is intended to be used, and the building as it is actually used. Energy efficient design therefore priorities' energy efficiency for human factors, the environment, economics, architecture, building elements, solar applications and monitoring. Energy efficient design demands an exchange of energy conscious information among designers, building managers and users. This exchange can occur at two levels; Short- term feedback at local level, and long-term feedback at global level. VIII One of the main functions of a building is to create an environment that is less varied and therefore more usable than that outside. Energy efficient design enables this system to be controlled from the perspective of energy efficiency. It gives buildings the ability to control energy gains, losses and demands, and gives users the ability to control energy gains, losses and demands, and give users the ability to control the building and its technology. Energy efficiency is also affected by the characteristics of the services within the building. The technology selected for these services should be appropriate for context, cost, function and use, and should be capable of being installed, operated and maintained without undue difficulty. In terms of an overall strategy, energy efficient design also provides a feedback loop for designers to understand and act upon the consequences of design decisions, and to design in more control. An energy efficient design strategy therefore embraces the whole project, including design and construction process, intended use and actual use, all within a responsive and functionally appropriate environment. Through energy efficient design, economic savings are made in the energy consumed during a building's life. Because running costs are lower than for a conventional building, after a period of time any extra design and construction costs are recovered. Savings are than made in running costs for the rest of the buildings life. A short payback period therefore means greater cost effectiveness. New buildings should only be constructed where there is sufficient purpose. More energy can be consumed as a result of building location and operation. Free solar energy is relatively easy to obtain, even at northern latitudes. The problem for designers is to make sensible use of it inside the building. A building should not waste energy by being over-sized or inefficient in the use of space. In addition energy savings may be provided by controlling the design of the building fabric, materials and elements. Running costs for services can be reduced by using efficient systems and good control equipment which is conveniently located, easy to understand and not too complex can repay its costs within a few years. Management can be effective in new and existing buildings. Installing control equipment and providing user training in its use can produce savings of over 25%. For example, a reduction of 1°C in the average temperature levels can often save 5% of the midwinter heating cost and up to 10% of the annual heating cost. IX The most important factors influencing energy-efficient design are, the location of the building, positioning on site, the direction it faces, arrangement of internal rooms, building size, building type, building function, the primary structure, construction methods, material specification, the building in use and legal obligations for the designer and building. Each of the above parameters are explained from the perspective of energy-efficient design to allow new designs to be explored and existing designs to be verified for energy efficiency. The design of individual components and building details may then be undertaken with a full understanding of the larger energy efficiency framework. Capital is needed to design and builds a building. Energy efficient buildings often cost more to design and build. The size of this overcost differs between countries, buildings and designs. In general, overcosts average 10% of design and construction costs within a range of 1 0-15%, and are lower for designs using conventional construction, materials and technology. Finance of overcosts may come from a number of sources. Building clients and designers may bear overcosts, governments at all levels may finance overcosts, particularly for programmes such as the use of insulation. Professional Institutions may finance designs which promote the profession. Private sector manufacturers and commercial interests may finance overcosts where designs demonstrate the value of their products or services. Such as private patrons, financial institutions, charities and development agencies may finance the over costs. In addition to the finance one of the most important item for the feasibility of the building is the payback period. The payback period is the time it takes for the overcosts of enrgy-efficient design to be repaid as reduced running costs. For long- life measures, such as increased insulation, a payback period of 10-20 years may be considered reasonable. Shorter life measures such as mechanized shading devices, need to pay for themselves more quickly. The most important running costs are energy, maintenance and improvement, life expectancy and added value. The amount and cost of energy consumed is the main determinant of running costs. Lower energy consumption and rising energy prices means relatively lower running costs compared with conventional buildings, and therefore shorter payback periods. Designs for conventional construction, materials and technology, such as exploiting orientation for solar radiation and light, require less attention. Complex technology İs often less successful; for example, mechanical ventilation systems with heat recovery and movable shutters can lessen energy efficiency or fall if badly maintained. As many energy-efficient buildings are experimental or one-off designs, allowance must be made for higher maintenance levels and improvements. The payback period should usually be less than half the expected overall life of the measure. High replacement costs of building elements and solar applications also add to running costs and mean longer payback periods. Positive factors which cannot be easily costed should also be considered; for example, sunspaces raise internal quality, amenity and property value. Feasibility studies represent a decision making approach with a long history. Through the techniques still require refinement they offer a systematic approach to establish the likely outcome of decisions and the costs involved. Through these predictions about the future are by no means certain, their usefulness lies in the hope that the results may be nearer to expectations if they are based on an objective assessment of the costs and benefits of a scheme rather than if decisions are based purely on intuition, then the exercise may be said to be worthwhile undertaking. Moreover using cost benefit analysis, it's possible to relate detailed analyses of building costs to complex notional costs which might only arise in the far distant future. With the increasing awareness of environmental and ecological problems that are accumulating in the world at an alarming rate, it is likely that building projects with expected useful lives of 50 to 100 years must begin to anticipate some of these future implications, especially those relating to energy use and pollution as well as the consumption of diminishing raw material resources. In this thesis not only the economic feasibility but also all design levels and prefeasibility of probable subsystem alternatives to build a low energy building has discussed. The main structure of the investigation consists of four chapters, named introduction, the definition of low energy building, feasibility studies and economic feasibility of low energy buildings. XI At first chapter the problem undertaken in the thesis is defined. Then the early studies carried on Turkey and at abroad about the problem is briefly explained and the objectives of the research are stated with its scope and limitations. In addition to the definition of the problem, the method of investigation is explained. The investigation results are based on scanning literature, lessons of the construction management programme of ITÜ, Architecture Faculty, practice at design and construction of low energy buildings at Frankfurt in Germany, interviews with the specialists working both at Turkey and Germany and examining the world-wide publications. The second chapter is devoted to a full analysis of the Low Energy Building's aspects, design criterias, building materials and subsystems. At the third chapter the history and the limitations of Feasibility Studies are defined. The subject is observed in three sections; Technical analysis, Organizational analysis and economical analysis. The fourth chapter; Effects of Low Energy Architecture Approach on Building Cost expresses the importance of energy expences on building investments and the prefeasibility studies and sampling the world-wide applied Low Energy Buildings within the scope of building performance. As a result of the thesis, an approach have been stated which could be used as a check-list during the design prossesses and feasibility studies. According to this statement the 15% additional cost used to promote the performance of a building can provide 70% energy saving which could also be paid back by the reduction of maintenance and running costs.Yüksek LisansM.Sc

THROMBIN IMMOBILIZATION TO METHACRYLIC ACID GRAFTED POLY(3-HYDROXYBUTYRATE) AND ITS IN VITRO APPLICATION

WOS: 000312186100004PubMed ID: 23215654Poly(3-hydroxybutyrate) is nontoxic and biodegradable, with good biocompatibility and potential support for long-term implants. For this reason, it is a good support for enzyme immobilization. Enzyme immobilization could not be done directly because poly(3-hydroxybutyrate) has no functional groups. Therefore, modification should be done for enzyme immobilization. In this study, methacrylic acid was graft polymerized to poly(3-hydroxybutyrate) and thrombin was immobilized to polymethacrylic acid grafted poly(3-hydroxybutyrate). In fact, graft polymerization of methacrylic acid to poly(3-hydroxybutyrate) and thrombin immobilization was a model study. Biomolecule immobilized poly(3-hydroxybutyrate) could be used as an implant. Thrombin was selected as a biomolecule for this model study and it was immobilized to methacrylic acid grafted poly(3-hydroxybutyrate). Then the developed product was used to stop bleeding

The realion between public expenditures and economic growth comparison of developed and developing countries

İktisat tarihini incelediğimizde klasik iktisadi düşüncenin sınırlı devleti, yani devletin sadece belli hizmetleri gerçekleştirmesi gerektiğini savunduğunu, modern iktisadi düşünce sisteminin ise devlete ilave yükler yüklediğini görürüz. Dolayısıyla klasik iktisatçılar devletin sınırlı kamu harcamaları yapması gerektiği savunurken, modern iktisatçılar ise devletin daha geniş kapsamda kamu harcaması yapması gerektiğini savunurlar. Kamu harcamalarıyla ilgili tarihsel sürece baktığımızda bu alanda önemli çalışmaların 19. yüzyıldan itibaren yapılmaya başlandığını görürüz. Alman İktisatçı A. Wagner birçok ülkeyi kapsayan çalışmalarında kamu harcamalarının sürekli olarak arttığını tespit etmiştir. Bu artışın genel bir nitelik taşıdığı kabul edilerek Wagner kanunu olarak tanımlanmıştır. Daha sonra birçok bilim adamı bu konuda çalışmalar yapmıştır. Kamu harcamalarının sürekli olarak büyümesi bu artışın reel bir büyümemi yoksa rakamsal bir büyümemi olduğu sorusunu akla getirmiştir. Reel olarak kamu harcamalarının artmasına gerçekte artış rakamsal olarak artmasına ise görünüşte artış denilmektedir. Kamu harcamaları, devletin ekonomiye müdahale araçlarından biridir. İktisatçılar bu aracın ne kadar kullanılması gerektiğini sürekli olarak sorgulamışlardır. İktisatçılar bu sorgulamalarda kamu harcamalarıyla ekonomik büyüme arasında bir ilişkinin olduğunu tespit etmişlerdir Ekonomik büyüme topluma sunulan mal ve hizmet kalitesini artıran, ülkeyi sosyal ve ekonomik açıdan güçlendiren bir olgudur. Bu artışın gerçekte veya görünüşte olması ekonomik büyüme üzerinde farklı etkiler meydana getirecektir. Bu çalışmanın amacı kamu harcamaları ve ekonomik büyüme kavramlarını teorik çerçevede ortaya koymak, gelişmiş ve gelişmekte olan ülkeler bakımından kamu harcamalarının etkilerini analiz etmektir. Çalışmamızda yüksek gelirli, orta üst gelirli ve düşük orta gelirli ülkeler için kamu harcamaları ve ekonomik büyüme arasındaki ilişki incelenmiştir. Çalışmada ARDL (Autoregresive Distribute Log) yaklaşımı kullanılarak bu ülkeler bakımından kamu harcamaları ve ekonomik büyüme arasındaki ilişki test edilmiştir.When we examine the history of economics, we observe that classical economics advocate limited state, i.e. state’s delivering only certain services, while modern economic thought puts additional burdens to the state. Thus, while classical economists advocate limited public spending, modern economists argue for more extensive public spending. When we look at the historical process related with public spending, we see that significant studies in this field started to be engaged in 19th century. German economist A. Wagner, in his studies that cover several countries, confirmed that public spendings have increased on a regular base. Assuming that this increase a general fact, this increase is defined as Wagner’s Law. Later, a lot of scientist engaged in studies on this topic. Constant increase of public spending raised a question of whether this increase is real or numeric. Real increase in the public spending is called increase in real, numeric increase is called as increase in appearence. Public spending is one of the tools of state intervention. Economists, on a constant base, have been questioning the extent of usage of this tool. Economists, in their studies, detected relation between public spending and economic growth. Economic growth is a phenomenon that promotes higher quality of goods and services provided to society, and strenghtens country in economic and social terms. The real increase and increase in appearence have different impacts on economic growth. The goal of the study is to put concepts of public spending and economic growth in a theoretical context, and to analyze the effects of public spendings in developed and developing countries. In our study, the relation between public spending and economic growth in high income, middle income and low income countries. In the study, the relation between public spending and economic growth is tested and concluded through adoption of Autoregresive Distribute Log approach