1,720,988 research outputs found
Nitrogen utilization pattern and degradation capability of some plant secondary metabolites by agelastica alni l. (coleoptera: chrysomelidae)
No full textWOS: 000268194600001An oligophagous leaf beetle, Agelastica alni (L., 1758) (Coleoptera: Chrysomelidae), often occurs in outbreak densities and utilizes both alders and willows in Europe. It was reported on alder and hazel in Turkey and its outbreaks on alder occur almost every year in the middle and eastern Black Sea regions of the country where hazel plantations cover huge areas. Nitrogen utilization, and degradation of some plant secondary metabolites by A. alni larvae fed with leaves of alder (Alnus glutinosa (L.) Gaertn. ssp. glutinosa), babylon willow (Salix babylonica L.) and hazel (Corylus avellana L.) with varying nutritional status were investigated. Larvae of this species were fed leaves of these plants that had been fertilized (NPK) and not been fertilized. Larval nitrogen utilization was determined to calculate the nitrogen utilization efficiency (NUE). The effects of some secondary metabolites of leaves of the plants on the digestion efficiency of A. alni larvae were tested. It was determined that A. alni larvae balanced its nitrogen utilization to some degree, despite the increase of nitrogen content of the leaves. Although the nitrogen content changed from 2,97% to 4,33 in hazel, from 2,47 % to 3,68 in babylon willow, from 4,27 % to 5,34 in young alder, from 4,04 % to 4,66 in older alder, the efficiency of nitrogen utilization of larvae changed from 16,54% to 12,77, from 11,92 % to 13,86, 22,72 % to 24,53, and 21,09 % to 23,71, respectively. In addition, the correlation between the changed N content of the treated leaves and the nitrogen utilization of the larvae that fed on them was negative (except from the larvae fed on unfertilized leaves of C. avellana) in all plants and treatments. The statistical analysis indicated that the approximate digestibility (AD) of the larvae was not affected by these secondary compounds (r(2)<0.7, P < 0.05). On the other hand, the degradation ratio of proanthocyanidin (condensed tannin) and total phenolics by A. alni larvae was determined as 3381 %. These results lead to the interpretation that metabolites had no measurable effects on A. alni larvae, or alternatively, the larvae utilized regulatory mechanisms to overcome the undesirable effects of these compounds. This study also indicated that larvae of A. alni have developed nitrogen homeostasis, which may involves a decrease of predation risk
The Socio-Economic Structure of Giresun Fishermen
No full textWOS: 000444528000041This study aims that determining the Turkish province of Giresun's fishing and social-economic state. 630 boats from across the province were categorized according to their lengths as well as densities: those smaller than 8 m, 8 - 11.9 m, 12 - 29.9 m, those larger than 30m. 167 boats were surveyed using the layered exemplification technique, and took a look at the fishing vessels in question's owners, the socio-economic characteristics of the crew, current problems, and solutions to those problems. Consequently, the socio-economic structures of Giresun fishermen are not at the desired level that they should or could be
Assessment of mercuric chloride toxicity on rainbow trouts (Oncorhynchus mykiss) and chubs (Alburnoides bipunctatus)
No full textPubMed: 19070058Acute toxicity of mercury-II chloride (HgCl2), one of most toxic pollutants for aquatic ecosystems, in chub (Alburnoides bipunctatus) and rainbow trout (Oncorhynchus mykiss) was investigated in the present study. Actual concentration of HgCl2 was ranged from 0.10 to 8.00 mg L -1. Concentrations of HgCl2 that killed 50% of the chub and rainbow trout within 96 h (96 h LC50) were estimated as 0.205 and 0.814 mg L-1, respectively. Acute toxicity tests were evaluated by the Finney's Probit Analysis. Chub (Alburnoides bipunctatus) was appeared to be more sensitive than trouts (Oncorhynchus mykiss) to HgCl2. © 2007 Asian Network for Scientific Information
The trace element analysis in freshwater fish species, water and sediment in Iyidere stream (Rize-Turkey)
Get PDFPubMed: 24171246Many environmental problems like dam construction, agricultural debris, flooding and industrial establishments threaten Iyidere stream (Rize, Turkey) on the southeastern coast of the Black Sea (Turkey). The trace element concentrations in water, fish and sediments in Iyidere stream (Rize, Turkey) were investigated in this study. The concentration of six different elements in ten freshwater fish species and sediment was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of fish and sediments. Water samples for trace metals were analyzed using standard spectrophotometry methods. A qualitative analysis of spectral peaks showed that ten different freshwater fish samples (Chondrostoma colchicum, Chalcalburnus chalcoides, Salmo trutta labrax, Alburnoides bipunctatus, Leuciscus cephalus, Barbus taurus escherichia, Capoeta tinea, Neogobius kessleri, Rutilus frisii, Lampetra lanceolata) and sediment contained phosphorus (P), sulphur (S), chlorine (Cl), potassium (K), calcium (Ca) and titanium (Ti). Heavy metals as toxic elements for biota (Pb, Cd, Hg, Zn and Mn etc.) were not detected in fish, water and sediments. Thus, It can be declared that freshwater fish of Iyidere does not contains health risks for consumers in terms of metal pollution. © 2012 Asian Network for Scientific Information
Age, growth, and gonadosomatic index (gsi) of mediterranean horse mackerel (trachurus mediterraneus steindachner, 1868) in the eastern black sea
No full textWOS: 000265870500005The aim of this study was to calculate the basic population parameters of Trachurus mediterraneus off the coast of the Eastern Black Sea. Average total length was estimated as 13.52 +/- 1.884 cm for the entire population, 13.08 +/- 1.594 cm for males, and 13.62 +/- 1.804 for females. Average weight was 20.27 +/- 8.819 g for the entire population, 18.65 +/- 7.626 g for males, and 2131 +/- 9.184 g for females. Age of the fish ranged between 0 and 5 years. Length-weight, age-length, and age-weight relationships were estimated for the population, where W = 0.0089 x L-2.9552: L-t = 26.09 (1 - e(-0.125(t + 4.002))); and W-t = 136.56 (1 - e(-0.125(t + 4.002))) Total mortality rates were Z = 3.73 year(-1) and M = 0.29 year for natural deaths. and F = 3.44 year(-1) for fishing mortality.Scientific Research Fund of Karadeniz Technical UniversityThis study was financially supported by the Scientific Research Fund of Karadeniz Technical University. We would also like to thank Prof. Dr. Ertug Duzgunes for his invaluable comments about this study
Comparison of metal concentrations in tissues of blue crab, callinectes sapidus from mediterranean lagoons
No full textTurkmen, Aysun/0000-0001-7461-4038; Turkmen, Mustafa/0000-0001-6700-5947; TEPE, Yalcin/0000-0002-8415-3754; TEPE, Banu/0000-0002-3428-8167WOS: 000293852900015PubMed: 21755288This study was performed to investigate the metal concentrations in muscle and gill of blue crab, Callinectes sapidus from Dortyol Lake, Akyatan Lagoon, Paradeniz Lagoon and CamlA +/- k Lagoon from the northeastern coastal area of Mediterranean Sea. So, the levels of cadmium, chromium, copper, iron, manganese, nickel, aluminum and zinc in tissues of specimens from the lagoons were determined by inductively coupled plasma optical emission spectrometer. The metal concentrations found in muscle tissue varied for Cd: 0.03-0.08, Cr: 0.05-0.13, Cu: 5.38-11.7, Fe: 21.1-38.2, Mn: 0.15-2.98, Ni: 0.24-0.45, Zn: 13.9-20.1 and Al: 1.2-13.7 mg/kg wet weight. Iron showed the highest levels in both tissues, and generally followed by zinc except gills. On the other hand, cadmium showed the lowest levels from all sites. Followed cadmium; chromium had the second lowest levels. The differences between mean metal concentrations from different sampling sites were statistically significant. Regional changes in metal concentration were observed in the tissues of the crabs, but these variations may not influence consumption advisories
THE STOCK PARAMETER OF ANCHOVY (Engraulis encrasicolus) POPULATION ON THE COASTS OF THE EASTERN BLACK SEA: REASON AND IMPLICATIONS IN DECLINING OF ANCHOVY POPULATION DURING THE 2004-2005 AND 2005-2006 FISHING SEASONS
Get PDFAkin, Senol/0000-0002-3851-4360WOS: 000264011400003Some basic characteristics of anchovy (Engraulis encrasicolus) population in the Eastern Black Sea coasts were estimated in order to explain the differences seen in the catch of anchovy during the fishing seasons of 2004-2005 and 2005-2006. The samplings were carried out from October to April in both fishing seasons on board of commercial fishing vessels. A total of 1499 and 1485 individuals were examined during 2004-2005 and 2005-2006 fishing seasons. respectively. Weight- length relationship and von Bertalanffy growth equations were calculated as W = 0.0101 L-2.7948 and L-t = 16.114 (1 - e(-0.2919) ((t + 2.56262))) and W = 0.0055 L (3.0125) and L-t = 15.272 (1 - e(-0.284 (t +3.530))) for the 2004-2005 and 2005-2006 fishing seasons, respectively. Total (Z), natural (M) and fishing mortality rates (F) of 2004-2005 fishing season were calculated as Z = 0.99 year(-1), M = 0.45 year(-1), and F = 0.54 year(-1), respectively. Corresponding rates for 2005-2006 scason. on the other hand, were calculated as Z =1.56 year(-1), M =0.54 year(-1) and F =1.02 year(-1). There were remarkable differences in some growth parameters including weight (9.27 vs. 6.80), length (11.36 vs. 10.05), percentage of fish having a length less than 9 cm (4.39 vs. 34.08), percentage of immature individuals (4 vs. 16) and condition factor (1.02 vs. 0.49) between 2004-2005 and 2005-2006 fishing season, respectively. The changes in these parameters suggested that environmental or biological factors could not be suitable for anchovy especially during the 2005-2006 fishing season. The results of higher natural mortality rate, lower weight. length. and condition factor for the 2005-2006 fishing season and higher catches of bonito during this fishing season (12 times greater than previous season) suggested that bonito, one of the natural enemies of anchovy, could affect anchovy through predation or by preventing anchovy to freely forage in feeding areas (i.e.. anti-predator behavior). In addition to the effect due to presence of bonito, extreme changes in the other biological and physical conditions could have operated together with bonito causing population parameters of anchovy to decline during the 2005-2006 fishing season
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Giresun Ar Yeti tiricili inde Antibiyotik Dirençlili i ve Ballardaki Antibiyotik Kal nt Düzeyinin Ara t r lmas
No full textTez (Yüksek lisans) -- Giresun Üniversitesi. Kaynakça var.v , 47 s. ; 28 cm.Demirba : 006350
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