12 research outputs found
The Relationship of Bristle Worm, Protodorvillea kefersteini (McIntosh, 1869) (Eunicida, Dorvilleidae) Abundance with Environmental Variables in Çardak Lagoon (Turkish Straits) Exposed to domestic Discharge
This study presents the correlations between opportunistic polychatea, Protodorvillea kefersteini (McIntosh, 1869) abundance, and environmental variables in Çardak Lagoon. Samplings were carried out on the bottoms using a 30x30 cm quadrate seasonally between 1 and 1.8 m depths of seven sampling points in October 2018, February, April, and June 2019. A total of 1094 specimens belonging to P. kefersteini were collected. Environmental variables such as gravel content in sediment, pH, and salinity levels in the water had the highest correlations with the abundance through the sampling periods. Considering the sampling points, the highest correlation value was between water salinity and the abundance. Sediment gravel content, pH, salinity, temperature, anionic surfactant levels, and NO2+NO3 were major environmental variables affecting P. kefersteini abundance in the study area spatially and temporally
Hypothalamic-pituitary-gonadal axis hormones and cortisol in both menstrual phases of women with chronic fatigue syndrome and effect of depressive mood on these hormones
BACKGROUND: Chronic fatigue syndrome (CFS) is a disease which defined as medically unexplained, disabling fatigue of 6 months or more duration and often accompanied by several of a long list of physical complaints. We aimed to investigate abnormalities of hypothalamic-pituitary-gonadal (HPG) axis hormones and cortisol concentrations in premenopausal women with CFS and find out effects of depression rate on these hormones. METHODS: We examined follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone and cortisol concentrations in 43 premenopausal women (mean age: 32.86 ± 7.11) with CFS and compared matched 35 healthy controls (mean age: 31.14 ± 6.19). Patients were divided according to menstrual cycle phases (follicular and luteal) and compared with matched phase controls. Depression rate was assessed by Beck Depression Inventory (BDI), and patients with high BDI scores were compared to patients with low BDI scores. RESULTS: There were no significant differences in FSH, LH, estradiol and progesterone levels in both of menstrual phases of patients versus controls. Cortisol levels were significantly lower in patients compared to controls. There were no significant differences in all hormone levels in patients with high depression scores versus patients with low depression scores. CONCLUSION: In spite of high depression rate, low cortisol concentration and normal HPG axis hormones of both menstrual phases are detected in premenopausal women with CFS. There is no differentiation between patients with high and low depression rate in all hormone levels. Depression condition of CFS may be different from classical depression and evaluation of HPG and HPA axis should be performed for understanding of pathophysiology of CFS and planning of treatment
Critical crack size investigation method for a land launcher
Structural integrity evaluation of military systems is vital in such applications as rocket launchers. In safe life design, for a certain operational life the system is ensured to function well and no failure would occur even in the presence of some imperfections or flaws. This paper considers the fracture analysis as part of the safe life design approach that is used in the design of a rocket launcher. A methodology based on sub modelling technique is introduced. It was made sure that unstable crack growth would not occur upto certain crack sizes. Subsequently, after actual manufacturing of the launcher, critical locations of welds in the system were checked for presence of any cracks after repeated firing loads. After these controls no cracks were detected due to operational conditions until the time when this document was prepared
The response of apseudopsis latreillii (Milne-Edwards, 1828) (crustacea, tanaidacea) to environmental variables in the dardanelles [Çanakkale bogazi{dotless}'ndaki çevresel degişkenlere apseudopsis latreillii (Milne- Edwards, 1828) (crustacea, tanaidacea)'nin tepkisi]
The tanaid, Apseudopsis latreilli (Milne- Edwards, 1828) is a common crustacean species on the soft bottoms of the Mediterranean ecosystems and occurs in both clean and polluted environments. This study was aimed to determine the sensitive state of tanaid, A. latreillii to the environmental variables observed on the soft bottoms of the Dardanelles. A. latreillei abundance at the sites was analysed in comparision with the organic matter content in sediment and the environmental variables in the study area. A total of 1406 specimens of A. latreillii was recorded during the study. The highest dominance value (Di=30.37%) was for Kepez Harbour where the amount of organic matter was 25.50±12.09% in the sediment. The highest value of dominance according to the sampling seasons was 56.75% for Autumn 2008 (organic matter=21.7±7.99%). The highest sand rate (99.59%) in the sediment was found at the Eceabat sampling point. The highest positive correlation (r=0.349, P<0.05) was observed between gravel content (%) measured at the sites and total abundance (ind.0.09 m-2). © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey
Temporal and spatial effects of environmental variables on crustacean communities in cardak Lagoon (Turkish Straits System) under the influence of domestic pollution
This study presents the temporal and spatial effects of domestic pollution on crustacean assemblages in a protected area, cardak Lagoon (Turkish Straits System). The samplings were performed from sandy and mud (silt + clay) bottoms between 1 and 1.8 m depths in October 2018, February, April, and June 2019. A total of 6920 specimens and 26 species (1 Isopoda, 1 Tanaidacea, 2 Mysidacea, 3 Cumacea, 5 Decapoda, 14 Amphipoda) belonging to crustaceans was found. Highest crustacea abundances were in autumn and winter. Considering the environmental variables, NO2 + NO3 (mg L- 1) and COD (mg L- 1) levels in the water had the highest correlations with abundance for the sampling periods. According to sampling points, the highest correlation value was found between anionic detergent content in the water and the abundance. Crustacean community structure was modified by environmental variables of anthropogenic origin at a higher level. Oxygen, oxygen reduction potential, NO2 + NO3, total nitrogen, chemical oxygen demand and anionic surfactant levels in water and sediment sand content % were major environmental variables affecting the crustacean abundance in the study area temporally.AcknowledgementsThis paper was prepared within the scope of the COST Action Project supported by TUBITAK coded 117Y510.TUBITAK [117Y510