is a major cause of morbidity and mortality in chronically infected cystic fibrosis patients. Novel biofilm models which reliably predict the therapeutic success of antimicrobial therapies against biofilm bacteria should be implemented. The activity of fosfomycin, tobramycin, and the fosfomycin-tobramycin combination against 6 susceptible strains isolated from respiratory samples from cystic fibrosis patients was tested by using two biofilm models: a closed system (Calgary device) and an open model based on microfluidics (BioFlux). All but one of the isolates formed biofilms. The fosfomycin and tobramycin minimal biofilm inhibitory concentrations (MBIC) were 1,024 to>1,024 μg/ml and 8 to 32 μg/ml, respectively. According to fractional inhibitory concentration analysis, the combination behaved synergistically against all the isolates except the ATCC 27853 strain. The dynamic formation of the biofilm was also studied with the BioFlux system, and the MIC and MBIC of each antibiotic were tested. For the combination, the lowest tobramycin concentration that was synergistic with fosfomycin was used. The captured images were analyzed by measuring the intensity of the colored pixels, which was proportional to the biofilm biomass. A statistically significant difference was found when the intensity of the inoculum was compared with the intensity of the microchannel in which the MBIC of tobramycin, fosfomycin, or their combination was used ( < 0.01) but not when the MIC was applied ( > 0.01). Fosfomycin-tobramycin was demonstrated to be synergistic against cystic fibrosis strains in the biofilm models when both the Calgary and the microfluidic BioFlux systems were tested. These results support the clinical use of this combination.

There is a striking contrast between the significance of Harold Hotelling's contribution to industrial economics and the fact that his location model was invalid, unrealistic and nonrobust. It is difficult to make sense of the explanatory value of Hotelling's model based on philosophical accounts that emphasize logical validity, representational adequacy, and robustness as determinants of explanatory value. However, these accounts are misleading because they overlook the context within which the explanatory value added of a model is apprehensible. We present Hotelling's model in its historical context and show why it is an important and explanatory model despite its apparent deficiencies.

Turkey has been experiencing a mall boom since the end of the 1990s. This boom"s impacts are obvious on the construction, real estate and shopping sectors. However, surprisingly, this boom encouraged significant enlargement of the movie sector as well. This enlargement affects the cultural life of people, in addition to creating urbanization economies. In this paper, for the first time in the literature, effects of shopping mall expansion on the movie sector are studied. We construct a theoretical model and support our theoretical findings empirically, by employing a dynamic panel data estimation method and utilizing a unique dataset from Turkey. We show that without the mall boom, the recent fast expansion in the movie sector in Turkey would not be possible. Our findings may apply to similar metropolitan development booms in other emerging markets. (Note 1)

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ÖzetBu çalışma Türkiye' de internet erişiminin ve kullanımının belirleyicilerini araştırmaktadır. Çalışmada TUİK'in 2014 yılı Hanehalkı Bilişim Teknolojileri Kullanım Araştırmasının veri setini kullanarak aşamalı bir regresyon analizi kullanılmaktadır. İlk aşamada hanehalklarının internet erişim sahibi olmalarında etkili olan sosyoekonomik, demografik ve bölgesel faktörler tahmin edilmiş, sonraki aşamada ise bu faktörlerin, bireylerin internet kullanımını nasıl etkilediği araştırılmıştır. Var olan literatürü destekler nitelikte, gelir, eğitim, cinsiyet, yaş gibi değişkenlerin hem internet erişiminde hem de kullanımında etkili olduğu görülmüştür. Ayrıca, hanedeki ilkokul çağındaki çocuk sayısının internet erişiminde etkili olduğu; gelir, yaş ve eğitim seviyelerinin internet kullanımında farklılık yarattığı ortaya konmuştur.Anahtar kelimeler: İnternet erişimi, İnternet kullanımı, aşamalı regresyon. JEL Sınıflaması: O10, O31, O32 WHO USES THE INTERNET IN TURKEY AND FOR WHAT PURPOSES?Abstract This paper investigates the determinants of internet access and usage in Turkey. The 2014 ICT Household Survey of TURKSTAT is employed through a multistage regression analysis. In the first stage, the factors which determine the internet adoption are identified, then in the second stage, the effects of those factors on internet usage are examined. The results are consistent with the earlier studies: income, education, gender, age matter both in internet adoption and usage. Besides, this study emphasizes that the number of children in primary school significantly increases the probability of internet adoption, while income, age and education level creates differences in the type of internet usage.