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31.
Biological invasions can have severe and widespread impacts on ecological communities. A few species of ants have become particularly
damaging invaders but quantitative data of their impacts on many taxa is still lacking. We provide experimental evidence using
artificial nests baited with quail eggs that the invasive Argentine ant (Linepithema humile) can be a significant avian nest predator – Argentine ants recruited to more nests and in higher abundance than the native
ant species they displace. However, at a site invaded by Argentine ants, we monitored over 400 nests of a ground-nesting species,
the Dark-eyed Junco (Junco hyemalis), and found that less than 2% of nests failed as a result of Argentine ant predation/infestation. A review of the literature
also suggests that Argentine ants may not be a serious threat to bird nests relative to other predators or parasites. However,
invasive ants with the capability of overwhelming prey though stinging (specifically the red-imported fire ant, Solenopsis invicta), may have a higher impact on avian nesting success.
Received 14 January 2005; revised 28 April 2005; accepted 12 May 2005. 相似文献
32.
Chiu-Chung Young Ta-Chen Lin Mao-Song Yeh Fo-Ting Shen Jo-Shu Chang 《World journal of microbiology & biotechnology》2005,21(8-9):1409-1414
Summary An indigenous strain Gordonia alkanivorans CC-JG39 was isolated from oil-contaminated sludge of a local gas station located in central Taiwan. The bacterial isolate
was able to grow on diesel-containing Bushnell–Haas medium and also tolerate various chemical additives frequently used in
petroleum products (e.g. BETX, methyl-tert-butyl ether, and naphthalene). Kinetics of diesel-limited cell growth and biodegradation
of diesel followed a Monod-type model. The kinetic constants for cell growth (μmax and KS,G) were 0.158 h−1 and 3196 mg/l, respectively, while those for biodegradation of diesel (vmax, diesel and KS,D) were 3.59 mg/h/mg cell and 2874 mg/l, respectively. G. alkanivorans CC-JG39 produced extracellular surface-active material, leading to a low surface tension of nearly 33 mN/m. The CC-JG39 strain
also possessed the ability to float towards the oil/water interface. These features might play some roles in enhancing the
mass transfer efficiency between oil substrate and the bacterial cells. Therefore, G. alkanivorans CC-JG39 may have potential applications in bioremediation of oil pollution sites. 相似文献
33.
Abstract Post-construction avifauna investigations were undertaken at Project West Wind, Meridian Energy Limited's 62-turbine wind farm on the Wellington south coast. These investigations were required in accordance with the resource consent conditions to quantify the level of avian mortalities occurring at the wind farm, particularly in regard to New Zealand falcon (Falco novaeseelandiae), kākā (Nestor meridionalis) and kererū (Hemiphaga novaeseelandiae). This is the first comprehensive study at a New Zealand operating wind farm. The methods included three field components necessary to calculate annual estimates of mortalities across the wind farm site: routine turbine searches; carcass detection trials; and carcass removal trials. Results from years 1 and 2 of a three-year programme are presented. To date, mortalities have been recorded for 17 taxa at 18 of the 24 study turbines. There have been no recorded mortalities of falcon, kākā or kererū. Australasian harrier (Circus approximans) has been the species for which the most mortalities have been recorded. Overall estimated annual mortality rates for years 1 and 2 were calculated to be approximately six and five birds per turbine respectively. 相似文献
34.
Li Liu T. Kevin Hitchens Qing Ye Yijen Wu Brent Barbe Devin E. Prior Wendy F. Li Fang-Cheng Yeh Lesley M. Foley Daniel J. Bain Chien Ho 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Background
Superparamagnetic iron-oxide nanoparticles are useful as contrast agents for anatomical, functional and cellular MRI, drug delivery agents, and diagnostic biosensors. Nanoparticles are generally cleared by the reticuloendothelial system (RES), in particular taken up by Kupffer cells in the liver, limiting particle bioavailability and in-vivo applications. Strategies that decrease the RES clearance and prolong the circulation residence time of particles can improve the in-vivo targeting efficiency.Methods
Intralipid 20.0%, an FDA approved nutritional supplement, was intravenously administered in rats at the clinical dose (2 g/kg) 1 h before intravenous injection of ultra-small superparamagnetic iron-oxide (USPIO) or micron-sized paramagnetic iron-oxide (MPIO) particles. Blood half-life, monocyte labeling efficiency, and particle biodistribution were assessed by magnetic resonance relaxometry, flow cytometry, inductively-coupled plasma MS, and histology.Results
Pre-treatment with Intralipid resulted in a 3.1-fold increase in USPIO blood half-life and a 2-fold increase in USPIO-labeled monocytes. A 2.5-fold increase in MPIO blood half-life and a 5-fold increase in MPIO-labeled monocytes were observed following Intralipid pre-treatment, with a 3.2-fold increase in mean iron content up to 2.60 pg Fe/monocyte. With Intralipid, there was a 49.2% and 45.1% reduction in liver uptake vs. untreated controls at 48 h for USPIO and MPIO, respectively.Conclusions
Intralipid pre-treatment significantly decreases initial RES uptake and increases in-vivo circulation and blood monocyte labeling efficiency for nano- and micron-sized superparamagnetic iron-oxide particles.General significance
Our findings can have broad applications for imaging and drug delivery applications, increasing the bioavailability of nano- and micron-sized particles for target sites other than the liver. 相似文献35.
36.
37.
Dror Kolodkin-Gal Sandrine L. Hulot Birgit Korioth-Schmitz Randi B. Gombos Yi Zheng Joshua Owuor Michelle A. Lifton Christian Ayeni Robert M. Najarian Wendy W. Yeh Mohammed Asmal Gideon Zamir Norman L. Letvin 《Journal of virology》2013,87(24):13589-13597
Effective strategies are needed to block mucosal transmission of human immunodeficiency virus type 1 (HIV-1). Here, we address a crucial question in HIV-1 pathogenesis: whether infected donor mononuclear cells or cell-free virus plays the more important role in initiating mucosal infection by HIV-1. This distinction is critical, as effective strategies for blocking cell-free and cell-associated virus transmission may be different. We describe a novel ex vivo model system that utilizes sealed human colonic mucosa explants and demonstrate in both the ex vivo model and in vivo using the rectal challenge model in rhesus monkeys that HIV-1-infected lymphocytes can transmit infection across the mucosa more efficiently than cell-free virus. These findings may have significant implications for our understanding of the pathogenesis of mucosal transmission of HIV-1 and for the development of strategies to prevent HIV-1 transmission. 相似文献
38.
Shu-Chun Tsai Sue-Jane Lin Cheau-Jye Lin Ya-Ching Chou Jiun-Han Lin Te-Huei Yeh Mei-Ru Chen Li-Min Huang Meng-You Lu Ya-Chi Huang Huan-Yun Chen Ching-Hwa Tsai 《Journal of virology》2013,87(16):9041-9052
Epstein-Barr virus (EBV) alters the regulation and expression of a variety of cytokines in its host cells to modulate host immune surveillance and facilitate viral persistence. Using cytokine antibody arrays, we found that, in addition to the cytokines reported previously, two chemotactic cytokines, CCL3 and CCL4, were induced in EBV-infected B cells and were expressed at high levels in all EBV-immortalized lymphoblastoid cell lines (LCLs). Furthermore, EBV latent membrane protein 1 (LMP1)-mediated Jun N-terminal protein kinase activation was responsible for upregulation of CCL3 and CCL4. Inhibition of CCL3 and CCL4 in LCLs using a short hairpin RNA approach or by neutralizing antibodies suppressed cell proliferation and caused apoptosis, indicating that autocrine CCL3 and CCL4 are required for LCL survival and growth. Importantly, significant amounts of CCL3 were detected in EBV-positive plasma from immunocompromised patients, suggesting that EBV modulates this chemokine in vivo. This study reveals the regulatory mechanism and a novel function of CCL3 and CCL4 in EBV-infected B cells. CCL3 might be useful as a therapeutic target in EBV-associated lymphoproliferative diseases and malignancies. 相似文献
39.
Absence of CXCL10 Aggravates Herpes Stromal Keratitis with Reduced Primary Neutrophil Influx in Mice
Fang-Hsiu Shen Shainn-Wei Wang Trai-Ming Yeh Yuk-Ying Tung Sheng-Min Hsu Shun-Hua Chen 《Journal of virology》2013,87(15):8502-8510
Herpes simplex virus 1 (HSV-1) replication initiates inflammation and angiogenesis responses in the cornea to result in herpetic stromal keratitis (HSK), which is a leading cause of infection-induced vision impairment. Chemokines are secreted to modulate HSK by recruiting leukocytes, which affect virus growth, and by influencing angiogenesis. The present study used a murine infection model to investigate the significance of the chemokine CXC chemokine ligand 10 (CXCL10; gamma interferon-inducible protein 10 [IP-10]) in HSK. Here, we show that HSV-1 infection of the cornea induced CXCL10 protein expression in epithelial cells. The corneas of mice with a targeted disruption of the gene encoding CXCL10 displayed decreases in levels of neutrophil-attracting cytokine (interleukin-6), primary neutrophil influx, and viral clearance 2 or 3 days postinfection. Subsequently, absence of CXCL10 aggravated HSK with elevated levels of interleukin-6, chemokines for CD4+ T cells and/or neutrophils (macrophage inflammatory protein-1α and macrophage inflammatory protein-2), angiogenic factor (vascular endothelial growth factor A), and secondary neutrophil influx, as well as infiltration of CD4+ T cells to exacerbate opacity and angiogenesis in the cornea at 14 and up to 28 days postinfection. Our results collectively show that endogenous CXCL10 contributes to recruit the primary neutrophil influx and to affect the expression of cytokines, chemokines, and angiogenic factors as well as to reduce the viral titer and HSK severity. 相似文献
40.
The intracellular ice formation (IIF) behavior of Haliotis diversicolor (small abalone) eggs is investigated in this study, in relation to controlling the cooling rate and the concentration of dimethyl sulfoxide (DMSO). The IIF phenomena are monitored under a self-developed thermoelectric cooling (TEC) cryomicroscope system which can achieve accurate temperature control without the use of liquid nitrogen. The accuracy of the isothermal and ramp control is within ±0.5 °C. The IIF results indicate that the IIF of small abalone eggs is well suppressed at cooling rates of 1.5, 3, 7 and 12 °C/min with 2.0, 2.5, 3.0 and 4.0 M DMSO in sea water. As 2.0 M DMSO in sea water is the minimum concentration that has sufficient IIF suppression, it is selected as the suspension solution for the cryopreservation of small abalone eggs in order to consider the solution’s toxicity effect. Moreover, IIF characteristics of the cumulative probability of IIF temperature distribution are shown to be well fitted by the Weibull probabilistic distribution. According to our IIF results and the Weibull distribution parameters, we conclude that cooling at 1.5 °C/min from 20 to −50 °C with 2.0 M DMSO in sea water is more feasible than other combinations of cooling rates and DMSO concentrations in our experiments. Applying this protocol and observing the subsequent osmotic activity, 48.8% of small abalone eggs are osmotically active after thawing. In addition, the higher the cooling rate, the less chance of osmotically active eggs. A separate fertility test experiment, with a cryopreservation protocol of 1.5 °C/min cooling rate and 2.0 M DMSO in sea water, achieves a hatching rate of 23.7%. This study is the first to characterize the IIF behavior of small abalone eggs in regard to the cooling rate and the DMSO concentration. The Weibull probabilistic model fitting in this study is an approach that can be applied by other researchers for effective cryopreservation variability estimation and analysis. 相似文献