336 research outputs found

    The effect of open air conditions on the properties of wooden material

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    In this study, the impregnation materials of Tanalith-C (CCA) and Protim 230 WR were used as preservative and water repellant. Wooden materials were taken from beech and black pine. The sampleswere made subject to weathering conditions for one year. At the end of this period, changes occurred in the samples’ bending strength, compression strength and physical properties were examined. As a result of this study, it was observed that no significant variations occurred in mechanical values of the impregnated samples; however, severe losses occurred in case of the non-impregnated samples. It was seen that impregnation type provides different protection according to the type of the wooden material.It was observed that discoloration is more significant in the  on-impregnated samples compared with those impregnated. Both of the impregnation materials provide sufficient protection

    New records of Decapod Crustaceans (Decapoda: Pontoniinae and Inachidae) associated with sea anemones in Turkish waters

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    Three anemone-associated decapod crustaceans, two shrimp species, Periclimenes amethysteus and P. aegylios (Caridea: Palaemonidae: Pontoniinae), and the crab Inachus phalangium (Brachyura: Inachidae), all collected from the Dardanelles, are reported for the first time from Turkish coasts. Another inachid crab, Macropodia czernjawskii is also reported for the first time to occur in association with the sea anemone, Anemonia viridis. Periclimenes scriptus was the fifth decapod species recorded associated with sea anemones within the present study, and while this species has already been reported from Turkish waters, this is the first time it is recorded from the Dardanelles (the Turkish Straits System)

    Numerical and optical analysis of weather adaptable solar reactor

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    Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Solar energy is an abundant renewable energy resource that can be used to provide high process heat necessary to run thermo chemical processes for production of various solar fuels and commodities. In a solar reactor, sunlight is concentrated into a receiver through a small opening called the aperture. However, obtaining and maintaining semi-constant high temperatures inside a solar reactor is a challenge. This is because the incident solar radiation can fluctuate depending on the position of the sun and the weather conditions. For fixed aperture size reactors, changes in incident solar flux directly affect the temperature inside the reactor. This paper presents a novel solar reactor with variable aperture mechanism which is designed and manufactured at our lab. Radiation heat transfer analysis of this reactor concept is studied via Monte Carlo (MC) ray tracing. MC ray tracing module is coupled to a steady state onedimensional energy equation solver. Energy equation is solved for the wall and gas, accounting for the absorption, emission, and convection. Incoming direct flux values for a typical day are obtained from National Renewable Energy Lab (NREL) database. Results show that for a perfectly insulated reactor, the average temperature of the working fluid may be kept appreciably constant throughout the day if aperture diameter is varied between 3 cm and 1.5 cm for incoming fluxes starting with 400 W/m2 at 05:12 am in the morning, reaching peak value of 981 W/m2 at noon, and eventually receiving 400 W/m2 at 6:58pm in the evening, which can make the solar reactor run about 13 hours continuously at 1500K semi-constant temperature

    More favorable palmitic acid over palmitoleic acid modification of Wnt3 ensures its localization and activity in plasma membrane domains

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    While the lateral organization of plasma membrane components has been shown to control binding of Wnt ligands to their receptors preferentially in the ordered membrane domains, the role of posttranslational lipid modification of Wnt on this selective binding is unknown. Here, we identify that the canonical Wnt is presumably acylated by palmitic acid, a saturated 16-carbon fatty acid, at a conserved serine residue. Acylation of Wnt3 is dispensable for its secretion and binding to Fz8 while it is essential for Wnt3's proper binding and domain-like diffusion in the ordered membrane domains. We further unravel that non-palmitoylated Wnt3 is unable to activate Wnt/beta-catenin signaling either in zebrafish embryos or in mammalian cells. Based on these results, we propose that the lipidation of canonical Wnt, presumably by a saturated fatty acid, determines its competence in interacting with the receptors in the appropriate domains of the plasma membrane, ultimately keeping the signaling activity under control

    Forested Wetlands of the Southern United States: A Bibliography

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    The term forested wetland covers a variety of forest types including mangroves, cypress/tupelo swamps, bottomland hardwoods, pocosins and Carolina bays, flatwoods, and mountain fens. These forests are dominated by woody species that have morphological features, physiological adaptations, and/or reproductive strategies enabling them to achieve maturity and reproduce in an environment where the soils within the rooting zone may be inundated or saturated for various periods during the growing season. Although alluvial floodplains occur along most streams of the United States, they are most extensive in the Atlantic Coastal Plain, Gulf Coastal Plain, and Mississippi Alluvial Plain. Only about half of the original floodplain forests remained by the 1930s, and conversion to agriculture continued at an accelerated pace during the 1960s and 1970s.The purpose of this bibliography is to provide a detailed listing of references for students and researchers of the varied studies conducted in these forest types

    Reproduction and population structure of the sea cucumber Holothuria tubulosa in the Dardanelles Strait, Turkey

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    This study investigated Holothuria tubulosa, Gmelin 1791 in the Dardanelles Strait from April 2013 to March 2014, in order to outline the morphological characteristics, reproductive patterns and the relationship between population characteristics and environmental parameters. 15 to 30 individuals of this species were sampled monthly at three stations. There was a negative allometry between length and weight, with gutted weight being the most reliable measurement for this species. The reproductive patterns of the species were identiied for the irst time for examples from the Turkish coast. By macroscopic examination of the gonads, the smallest sizes ( gutted length) were measured as 8.4 and 8.1 cm for the female and male, respectively. The sex ratio ( female: male) was calculated as 1: 1.1 with differences between seasons. Reproduction of sea cucumbers occurred between August and September after Gonadosomatic Index ( GSI) values reached their maximum in July. The species was found at up to a 10 m depth with a population density of 0.21 / m(2), which was rather low compared to previously reported values for Mediterranean populations of this species. There was a high positive correlation between population density and GSI of the species. The highest population density was observed where the largest sea grass meadows are found.TUBITAK [113Y003]The authors would like to thank the journal editor (Serge Gofas) and anonymous referees for their valuable comments and suggestions, and give special thanks to Asst. Prof. Dr. Yalcm Isler for his support in data analysis. This study was supported by TUBITAK with project number 113Y003. We would like to thank them for their financial aid

    Ruptured Granulosa Cell Tumor of the Ovary as a Cause of Acute Abdomen in Postmenopausal Woman

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    Acute abdomen with hemoperitoneum is a very rare entity in postmenopausal women due to gynecologic conditions. A 54-year-old, postmenopausal woman was brought to emergency department with severe abdominal pain. Physical examination revealed acute abdomen findings with 15 cm pelvic mass on the right adnexal region. Immediate exploratory laparotomy was performed. During laparotomy 1000 cc of bloodstained fluid, ruptured and actively bleeding large mass arising from right ovary was observed. Right salpingo-oopherectomy was performed in emergency conditions, and pathology report revealed an adult type of granulosa cell tumor. After this result, staging surgery was performed and patient was diagnosed as granulosa cell tumor stage 1 c. Cisplatin, etoposide, and bleomycin chemotherapy was given. Clinicians should be aware of granulosa cell tumors which may occur at any age and prone to rupture. Frozen section will be helpful in order to avoid incomplete surgeries especially in postmenopausal women presented with intra-abdominal bleeding

    Monitoring of trace metals, biochemical composition and growth of Axillary seabream (Pagellus acarne Risso, 1827) in offshore Copper alloy net cage

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    The study was conducted to assess trace metal contents, biochemical composition and growth performance of axillary seabream (Pagellus acarne Risso, 1827) cultured in a copper alloy mesh cage. A total of 400 axillary seabream (initial mean weight: 176.0±14.0 g), a new candidate species for the Mediterranean aquaculture, were stocked into a high-density polyethylene frame gravity cage and fed a commercial seabream diet for a period of 6 months. At the end of the feeding trial, fish reached a final weight of 264.8±16.8 g with a weight increase of 88.8 g and a feed conversion rate of 2.51. Overall, relative growth rate, specific growth rate and feed conversion ratio were satisfactory and comparable to the pelagic fishes such as gilthead seabream or European seabass, which are presently the main fish species for the Mediterranean aquaculture industry. Trace elements in fish grown in copper alloy net cages over a 6-month period showed satisfactory results, as the metal concentrations in fish tissues such as liver, skin, muscle and gills were below the reported upper limits for human consumption, indicating that copper alloy net is an acceptable and safe material for finfish cage aquaculture. Furthermore, from the growth performance data obtained in the present study, it can be concluded that axillary seabream showed potential for cage farming, and thus is a promising new candidate for the Mediterranean aquaculture industry

    On the dynamics of the adenylate energy system: homeorhesis vs homeostasis.

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    Biochemical energy is the fundamental element that maintains both the adequate turnover of the biomolecular structures and the functional metabolic viability of unicellular organisms. The levels of ATP, ADP and AMP reflect roughly the energetic status of the cell, and a precise ratio relating them was proposed by Atkinson as the adenylate energy charge (AEC). Under growth-phase conditions, cells maintain the AEC within narrow physiological values, despite extremely large fluctuations in the adenine nucleotides concentration. Intensive experimental studies have shown that these AEC values are preserved in a wide variety of organisms, both eukaryotes and prokaryotes. Here, to understand some of the functional elements involved in the cellular energy status, we present a computational model conformed by some key essential parts of the adenylate energy system. Specifically, we have considered (I) the main synthesis process of ATP from ADP, (II) the main catalyzed phosphotransfer reaction for interconversion of ATP, ADP and AMP, (III) the enzymatic hydrolysis of ATP yielding ADP, and (IV) the enzymatic hydrolysis of ATP providing AMP. This leads to a dynamic metabolic model (with the form of a delayed differential system) in which the enzymatic rate equations and all the physiological kinetic parameters have been explicitly considered and experimentally tested in vitro. Our central hypothesis is that cells are characterized by changing energy dynamics (homeorhesis). The results show that the AEC presents stable transitions between steady states and periodic oscillations and, in agreement with experimental data these oscillations range within the narrow AEC window. Furthermore, the model shows sustained oscillations in the Gibbs free energy and in the total nucleotide pool. The present study provides a step forward towards the understanding of the fundamental principles and quantitative laws governing the adenylate energy system, which is a fundamental element for unveiling the dynamics of cellular life

    Monitoring of trace metals, biochemical composition and growth of Axillary seabream (Pagellus acarne Risso, 1827) in offshore copper alloy mesh cages

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    The study was conducted to assess trace metal contents, biochemical composition and growth performance of axillary seabream (Pagellus acarne Risso, 1827) cultured in a copper alloy mesh cage. A total of 400 axillary seabream (initial mean weight: 176.0 +/- 14.0 g), a new candidate species for the Mediterranean aquaculture, were stocked into a high-density polyethylene frame gravity cage and fed a commercial seabream diet for a period of 6 months. At the end of the feeding trial, fish reached a final weight of 264.8 +/- 16.8 g with a weight increase of 88.8 g and a feed conversion rate of 2.51. Overall, relative growth rate, specific growth rate and feed conversion ratio were satisfactory and comparable to the pelagic fishes such as gilthead seabream or European seabass, which are presently the main fish species for the Mediterranean aquaculture industry. Trace elements in fish grown in copper alloy net cages over a 6-month period showed satisfactory results, as the metal concentrations in fish tissues such as liver, skin, muscle and gills were below the reported upper limits for human consumption, indicating that copper alloy net is an acceptable and safe material for finfish cage aquaculture. Furthermore, from the growth performance data obtained in the present study, it can be concluded that axillary seabream showed potential for cage farming, and thus is a promising new candidate for the Mediterranean aquaculture industry.International Copper Association (ICA) in NY-USA (Research Project Fund: ICA-TEK) [1049]We are grateful to the International Copper Association (ICA) in NY-USA for the financial support (Research Project Fund: ICA-TEK Project No: 1049) of this study. We would like to express our gratitude to Mr. Hal Stillman (Global Initiative Leader for Technology Development and Transfer) and Mr. Langley Gace (Aquaculture Applications Development Manager) from ICA for valuable advice and discussions during the creation of a small scale research and development farm in the Strait of Canakkale, Turkey, and their technical advice during the study. The Port of Canakkale (Canakkale Kepez Liman A.S.) is also acknowledged for their logistic support with port facilities, crane, forklift, and vessels during the deployment work of the mooring system and cages. Many thanks to Canakkale Onsekiz Mart University, Faculty of Marine Science and Technology for the support of vessels and boats during the study
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