Macro-Economic Determinants of Travel and Leisure Sector: A Co-integration Analysis From Turkey

Macro-economic factors have influence on companies in the economy. It is seen that travel and leisure sector firms take less emphasis when they are compared with the other sectors. The study aims to investigate travel and leisure sector firms with macro-economic factors. The data of the study covers the period 2005-2013. Co-integration framework is employed to analyze the data. Inflation, term structure and domestic consumption are detected as significant macro-economic determinants of Travel and Leisure Sector according to Vector Error Correction (VEC) Model and VEC Granger Causality Tests. The results are consisted with the literature. Negative relationship with inflation can indicate counter-cyclical monetary policy. The term structure finding supports the view that maturity premium tends to low around business cycle peaks. Domestic consumption has different coefficient signs which prove the explanation that sometimes consumers turn risk averse and average stock-owning consumer will require high expected returns. The study presents examples of macro-economic relationships and can help individuals who are related to stock market index variations.[1] Keywords: Travel and Leisure sector, Macro-economic determinants, Borsa Istanbul, Co-integration [1] A different version of this study was presented at the 4 th  INTERNATIONAL CONFERENCE ON MANAGEMENT (4 th  ICM 2014), 16 - 17 JUNE 2014

Resource Leveling of an Industrial Building Using Genetic Algorithm Technique

Construction companies should schedule their projects in a manner that considers theefficient use of limited resources in order to complete a project within estimated budget, onschedule and in compliance with the specifications. In this context, the planning of resourcesbecomes crucial for a construction project, which can be accomplished by resource leveling.Resource leveling - also known as resource smoothing - is a method that attempts to reducethe fluctuations in resource usage in order to make the resource requirements as uniform aspossible while maintaining the original project duration. The studies dealing with resource leveling problems can be classified into two categories, which are; (1) analytical methods and(2) heuristic methods. Analytical methods may give optimal solutions on small-scaledproblems; however, they are inadequate in large-scaled problems. As a result of theweaknesses of analytical methods, many studies have been conducted in order to developmore efficient models by heuristic methods. Genetic algorithm-based resource leveling is oneof these models, which is developed to attain better solutions. The main objective of thisstudy is to handle the resource leveling problem of an industrial building using geneticalgorithms. In this context, a schedule for an industrial building is established using theCritical Path Method (CPM). The information about the logical constraints and the resourcesrequired to carry out activities were obtained through the interviews with civil engineers fromthe company, whose expertise is on industrial buildings. The proposed genetic algorithmbased resource leveling model attempts to improve the schedule. The developed modelprovided a decrease of 20% in the total resource-days required to complete the project. Thestudy is of benefit to participants of construction industry, because it makes them aware of the potential use of the combination of critical path method and genetic algorithms in order to solve the resource leveling problem

Spatial and temporal variations of tintinnids (Ciliata: Protozoa) in the Bay of Mersin, Northeastern Mediterranean Sea

Seasonal variations in species composition and abundance of tintinnids were investigated in the eutrophic coastal and offshore waters of Mersin Bay. Twelve sampling cruises were performed from September 2008 to February 2011. A total of 85 tintinnid taxa were identified. Among the recorded genera, agglutinated Tintinnopsis had the largest number of species (12 species), followed by hyaline loricated Eutintinnius (9 species), and Proplectella (7 species). Stenosemella ventricosa, Tintinnopsis beroidea, T. compressa, Favella azorica, and Helicostemella subulata were the dominant species during the study period. There were clear seasonal variations in species composition and abundance of tintinnids. The highest number of tintinnid species occurred in January 2009 and November 2010 in the entire study area, while the lowest species number occurred in March 2009. Morever, species numbers were higher in offshore stations than coastal stations. Some species were present in the coastal area of the bay, and other species were present offshore. The highest tintinnid abundance values were found in September 2008 (820 ind L-1) and August 2009 (749 ind L-1) at coastal stations. The high abundance values in the coastal stations indicates that an increase of tintinnids is closely related to trophic status of the marine environment. In connection with these results, correlation analysis revealed that chlorophyll-a had an important effect on tintinnid abundance. Tintinnid communities may be used as a potential bio-indicator for assessing the trophic state of the coastal seas and bays.

Synthesis of Graphene on Gold

Here we report chemical vapor deposition of graphene on gold surface at ambient pressure. We studied effects of the growth temperature, pressure and cooling process on the grown graphene layers. The Raman spectroscopy of the samples reveals the essential properties of the graphene grown on gold surface. In order to characterize the electrical properties of the grown graphene layers, we have transferred them on insulating substrates and fabricated field effect transistors. Owing to distinctive properties of gold, the ability to grow graphene layers on gold surface could open new applications of graphene in electrochemistry and spectroscopy.Comment: 8 pages, 4 figure

Pre-operative Serum CEA and CA19-9 Levels in Patients with Gastric Cancer: A Single-Center Experience

Introduction: To evaluate the preoperative CEA and CA19-9 levels and their association with clinicopathologic features and mortality. Methods: This retrospective study was conducted on patients who underwent gastric surgery due to gastric adenocarcinoma from 2008 to 2015. Preoperative serum CEA and CA19-9 levels were compared according to the TNM classification and survival data were compared. Results: A total of 335 patients were included in the study with the mean age of 66.1±11.0 years. CEA and CA19-0 positivity were 29.1% and 28.1%, respectively. According to the CEA groups, T stages of the cases were statistically significant (p = 0.013). The rates of T stage 1 in group 1 (CEA positive) were significantly higher than the group 2 (CEA negative) (p=0.007). According to the CA19-9 positivity; rate of stage 2 was significantly higher in the group 1 (CA19-9 positive) (p=0.001); however, rates of stage 2 and 3 were significantly higher in the group 2 (CA19-9 negative) (p=0.004 and p=0.007, respectively). Mortality information could be accessed for 309 cases and 108 deaths (36%) were observed. The mean survival time was 45.21±2.42 months. No significant difference was observed between the groups (p>0.05). Conclusion: Patients with higher levels of CEA and CA19-9 seem to have higher grades of gastric cancer. However, CEA and CA19-9 level does not seem to be in association in our study population

Türk Boğazlar Sistemi’nde Mesozooplankton Biyokütlesinin İlkbahar ve Sonbahar Mevsimlerindeki Alansal ve Vertikal Dağılımı

Zooplanktonik organizmalar pelajik besin ağının şekillenmesinde ve biyokimyasal döngülerin gerçekleşmesinde anahtar rol oynamaktadır. Zooplankton biyokütlesi ve dağılımı hakkında bilgi sahibi olmak, bu canlıların ekosistemdeki organik madde ve enerji akışına katkılarını tahmin etmek için önem arzetmektedir. 2008 yılının Nisan ve Ekim aylarında Türk Boğazlar Sistemi (TBS)’nde tek hat boyunca belirlenen istasyonlardan WP-2 plankton kepçesi (ağ göz açıklığı 200μm) ile zooplankton örnekleri toplanmıştır. Bu örneklerden ölçülen biyokütle değerlerinin epipelajik bölgedeki alansal ve dikey dağılımı belirlenerek bölgedeki bu konuyla ilgili bilgi eksikliği giderilmeye çalışılmıştır.TBS’de ortalama mesozooplankton mevcut stoğu alansal ve dikey olarak farklılık göstermiştir. Mesozooplankton biyokütlesi genel itibariyle ilkbaharda yüzey karışım tabakasında yoğunlaşmış, derinlik ile birlikte azalmıştır. Sonbahar periyodunda ise geçiş tabakası ortalama mesozooplankton biyokütle değerleri bakımından daha yüksek bulunmuştur. Genel olarak, boğazlarda yüksek olan bu değerler, Marmara Denizi’nin iç bölgelerinde özellikle kuzey batısında oldukça düşmüştür. Bölgedeki biyokütle dağılımında istasyon derinliği, derinlik tabakaları ve oksijen miktarı etkili olmakla birlikte, örnekleme periyodu boyunca gerçekleştiği bildirilen musilaj olayının sıcaklık ve tuzluluk gibi çevresel parametrelerin etkisini büyük ölçüde maskelediği düşünülmektedir

Development of antimicrobial peptides specific to biofilm formation bacteria and binding to catheter surface

Today, the resistance developed by bacteria against antibiotics poses a great difficulty in the prevention and treatment of nosocomial infections. However, antimicrobial peptides (AMPs), which bacteria cannot develop resistance specifically, but can only resist with the proteases or biofilm-forming mechanism in their structure, have become a current area of interest. It is aimed to improve the activities of these peptides by synthetic production. The activities and toxic effects of peptides, which have the same sequence in alpha-helix structure but synthesized by combining 2 different amino acid forms in 4 different ways, were compared. As a result, it was seen that the use of D- and L-form amino acids together increased the antibacterial activity 4-32 times. MIC (Minimum Inhibition Concentration) values also remain in the safe range for IC50 and HC50 values. While the lowest antibacterial activity is seen in the peptide consisting entirely of L-form amino acids, peptide antibacterial activity consisting entirely of D-form amino acids is located in the middle segment between these peptides. For biofilm inhibition, NET3 peptide with D-arginine in its structure showed better activity, while NET1 peptide with D-leucine in its structure showed better activity in removing the biofilm. Thereupon, the CRB MIC experiment was developed in order to find the true biofilm inhibition concentration by real time monitoring. After taking these results, peptides which are expected to bond spontaneously with no chemical or intermediate linker is needed called as self-assembly, since they are amphipathic and alpha-helix structure, showed surface binding though with low efficiency