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801.
Bonnie J. Holmes Julian G. Pepperell Shane P. Griffiths Fabrice R. A. Jaine Ian R. Tibbetts Mike B. Bennett 《Marine Biology》2014,161(11):2645-2658
Partial migration is considered ubiquitous among vertebrates, but little is known about the movements of oceanodromous apex predators such as sharks, particularly at their range extents. PAT-Mk10 and SPOT5 electronic tags were used to investigate tiger shark (Galeocerdo cuvier) spatial dynamics, site fidelity and habitat use off eastern Australia between April 2007 and May 2013. Of the 18 tags deployed, 15 recorded information on depth and/or temperature, and horizontal movements. Tracking times ranged between four and 408 days, with two recovered pop-up archival tags allowing 63 days of high-resolution archived data to be analysed. Overall mean proportions of time-at-depth revealed that G. cuvier spent the majority of time-at-depths of <20 m, but undertook dives as deep as 920 m. Tagged sharks occupied ambient water temperatures from 29.5 °C at the surface to 5.9 °C at depth. Deep dives (>500 m) occurred mostly around dawn and dusk, but no definitive daily dive patterns were observed. Horizontal movements were characterised by combinations of resident and transient behaviour that coincided with seasonal changes in water temperature. While the majority of movement activity was focused around continental slope waters, large-scale migration was evident with one individual moving from offshore Sydney, Australia, to New Caledonia (c. 1,800 km) in 48 days. Periods of tiger shark residency outside of Australia’s fisheries management zones highlight the potential vulnerability of the species to unregulated fisheries and the importance of cross-jurisdictional arrangements for species’ management and conservation. 相似文献
802.
Anne Marie Power Karen McCrann David McGrath Ruth M. O’ Riordan Christina Simkanin Alan A. Myers 《Marine Biology》2011,158(10):2149-2160
This study examined how the species composition of an intertidal barnacle guild varied according to physical gradients in
the environment at small scales governed by microclimates, medium scales of wave exposure and large scales of latitude. Barnacle
distributions at small and medium scales were sampled in Ireland between 51°29′ and 52°44′N and 6°50′ and 10°08′W. Sampling
on European shores spanned ~18° latitude from 37°05′ to 55°16′N. Barnacle surveys mainly took place in 2003–2004. An index
of wave fetch was calculated along the wave exposure gradient using a digital coastline-based model that was supported by
a biological exposure scale. A ‘dryness’ index was defined according to mean monthly wind speed, fetch along the average wind
direction and mean monthly air or sea surface temperatures for 2 years (January 2001–December 2002) which is the period when
the most recent adults in the barnacle community would have settled and grown to adulthood. The proportion of the dry-loving
barnacle Chthamalus montagui Southward increased within the barnacle guild at all scales as the habitat became warmer and drier. Barnacle densities were
high in all habitats, mean densities ranged from a minimum of 4.16 cm−2 on moderately exposed shores to a maximum of 6.27 cm−2 in sunlit or south-facing microclimates. Percentage cover of barnacles across the gradient of latitudes was usually >70%.
The results suggest that the distribution and abundance of interacting barnacle species on European coasts is strongly controlled
by abiotic factors, most likely temperature and desiccation. 相似文献
803.
Dr. V. Ladewig D. Jungmann H.-R. Köhler O. Licht K.-U. Ludwichowski M. Schirling 《毒物与环境化学》2013,95(4):649-664
The impact of bisphenol A (BPA) on Gammarus fossarum and Lumbriculus variegatus was studied in four artificial indoor streams (0, 5, 50 and 500?µg?L?1 BPA, nominal) over 103 days in a pulse–dose exposure scenario (weekly BPA application). For G. fossarum populations at day 103, the proportions of juveniles and of breeding females from the highest BPA treatment were in tendency reduced. For individually exposed gammarid pairs an EC10 of 17?µg?L?1 BPA (nominal) for the proportion of reproductive females in the fourth brood was determined. During the first three broods, the largest brood size occurred at the highest BPA concentration, whereas in the fourth brood it decreased concentration-dependently (fourth brood EC10?=?5?µg?L?1 BPA, nominal). Effects on L. variegatus were a reduced population growth (103?d-EC10 of 2?µg?L?1 BPA, nominal) and an increase in dry weight and the number of segments in large, complete worms. 相似文献
804.
The effect of white African mineral dye Yombofita (YF) on the activities of alkaline phosphatase (ALP), acid phosphatase (ACP) and malondialdehyde (MDA) levels in the skin, liver, kidney and serum of albino rats was investigated. The chemical analysis of the dye was first carried out using solubility test, pH determination and X-ray fluorescence (XRF) elemental analysis. Six different concentrations (0.05, 0.15, 0.25, 0.5, 0.75 and 1.00%) of the dye were prepared using hydrogen peroxide (30 volume) as solvent. A total of 80 albino rats (Rattus norvegicus) were used for the study. The rats were divided into 8 groups of 10 each and were maintained on commercial feed for the period of the experiment i.e. 30 days. In group 1, the control group, the animals were applied distilled water on their heads, whereas in group 2 the vehicle i.e. hydrogen peroxide was applied. In groups 3 to 8 various concentrations of YF (white) dye ranging from 0.05, 0.15, 0.25, 0.5, 0.75 to 1.00% was applied respectively. At the end of the experiment, blood samples were collected and portions of the selected tissues were excised for the determination of ALP and ACP activities. The MDA level was also determined in the skin of experimental animals. The results revealed a significant decrease (p?0.05) with increasing concentration of the dye in the activities of ALP and ACP in the kidney and skin but not in the liver while the level of MDA in the skin increased significantly (p?0.05) with increasing concentration of the dye. 相似文献
805.
A chemical evaluation of Gnetum africana and Telferia occidentalis was carried out in five randomly selected restaurants in Calabar. The results showed that both Gnetum africana and Telferia occidentalis soups have high caloric values and contain adequate levels of essential minerals, vitamins, amino acids, proteins, and fat, which are needed for a variety of cellular functions in humans, and which would reduce the problem of protein energy malnutrition (PEM). 相似文献
806.
The effect of interaction of alcohol and kola nut on sodium pump activity was studied in Wistar rats. Thirty Wistar rats were divided into six groups of five rats per group. Control received a placebo (4 mL of distilled water). Groups 2–6 were treated for a period of 21 days with 10% (v/v) alcohol, 50 mg caffeine/kg, 50 mg kola nut/kg, or a combination of 10% (v/v) alcohol + 50 mg kola nut/kg, or 10% (v/v) alcohol + 50 mg caffeine/kg, respectively. One day after the final exposure, brains were harvested and several biochemical parameters examined including activities of total ATPase, ouabain-insensitive ATPase, ouabain sensitive ATPase (Na+–K+-ATPase) and levels of nonenzymatic breakdown of ATP and inorganic phosphate (Pi) released. Results showed that the essential enzyme of the brain responsible for neuronal function, Na+–K+-ATPase, was inhibited by alcohol–kola nut co-administration relative to control, resulting in a decreased ATP production, ion transport and action potential, leading to loss of neuronal activities. 相似文献
807.
Various antimalarial drugs have been shown to exert different adverse effects; however, scanty information is available for artemether-induced potential side effects. The present study assessed effects of artemether on lipid profile, sperm count, and histological features of testes in an animal model. The mean total cholesterol, high-density lipoproteins, low-density lipoproteins, triglyceride, and total proteins in mice-administered artemether were higher compared with controls. The mean sperm counts in mice treated with artemether were reduced when compared with controls. In addition, it was observed that artemether affected the histopathology of seminiferous epithelia and Leydig cells. Evidence indicates that artemether exerts adverse effects in mice testes. 相似文献
808.
Effects of artemether administration on liver and selected biochemical parameters were evaluated. Eighty albino mice were divided into four equal groups. Group 1 was given water which served as control, while groups 2, 3, and 4 were given 1.2, 2.4, or 4.8 mg kg?1 body weight artemether intramuscularly for five consecutive days. On day 6 all mice were sacrificed by cervical dislocation and blood was collected for analysis of alanine and aspartate transaminases, alkaline phosphatase, copper, and total proteins. Liver tissues were prepared for histological studies. It was found that the serum alanine and aspartate transaminase and alkaline phosphatase activities were higher in groups treated with artemether compared to control. The serum concentrations of copper and total proteins were lower than control. The histological features of liver tissues after administration of artemether showed histopathological alterations. These findings showed that artemether administration may have reversible adverse effects on mouse hepatocytes. 相似文献
809.
810.
O. Adeyemi G.S. Adenitire O.B. Oloyede A.T. Oladiji O.M. Oluba O. Adeyemi 《毒物与环境化学》2013,95(7):1347-1356
A study was performed to evaluate the effect of contaminated water on the tissues of Rattus novergicus (albino rats). Test rats were given water contaminated with lead (0.015 µg L?1 tap water), phenol (0.05 mL L?1 tap water), and benzene (0.05 mL L?1 tap water), while control rats were given tap water over a period of 65 days after which the activity of selected enzymes of the heart and serum was assayed, and hematological parameters and serum lipid profiles were also determined. Generally, a significant (p < 0.05) drop in the activity of the enzymes was observed in the heart of test rats relative to the control rats. However, the serum activities increased significantly in the test group compared to the control group (p < 0.05). The concentrations of serum cholesterol, low-density lipoprotein (LDL), and triglycerides of the test rats were found to be significantly higher than those of the control rats (p < 0.05). Concentrations of hemoglobin, red blood cell count, and packed cell volume of test rats were observed to be significantly lower than those of the control rats (p < 0.05). The experimental results indicated that consumption of water contaminated with lead, phenol, and benzene may damage the heart, increase the risk of atherosclerosis as reflected by the serum lipid profile, and anemia as suggested by abnormal hematological properties. 相似文献