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41.
Sarah E. Gergel Yulia Stange Nicholas C. Coops Kasper Johansen Kathryn R. Kirby 《Ecosystems》2007,10(5):688-702
Riparian areas contain structurally diverse habitats that are challenging to monitor routinely and accurately over broad areas.
As the structural variability within riparian areas is often indiscernible using moderate-scale satellite imagery, new mapping
techniques are needed. We used high spatial resolution satellite imagery from the QuickBird satellite to map harvested and
intact forests in coastal British Columbia, Canada. We distinguished forest structural classes used in riparian restoration
planning, each with different restoration costs. To assess the accuracy of high spatial resolution imagery relative to coarser
imagery, we coarsened the pixel resolution of the image, repeated the classifications, and compared results. Accuracy assessments
produced individual class accuracies ranging from 70 to 90% for most classes; whilst accuracies obtained using coarser scale
imagery were lower. We also examined the implications of map error on riparian restoration budgets derived from our classified
maps. To do so, we modified the confusion matrix to create a cost error matrix quantifying costs associated with misclassification.
High spatial resolution satellite imagery can be useful for riparian mapping; however, errors in restoration budgets attributable
to misclassification error can be significant, even when using highly accurate maps. As the spatial resolution of imagery
increases, it will be used more routinely in ecosystem ecology. Thus, our ability to evaluate map accuracy in practical, meaningful
ways must develop further. The cost error matrix is one method that can be adapted for conservation and planning decisions
in many ecosystems. 相似文献
42.
Molecular Biology Reports - Previous studies have demonstrated that cytosolic phospholipase A2α (cPLA2α) is required for NOX2 NADPH oxidase activation in human and mouse phagocytes.... 相似文献
43.
44.
Yulia Lipovka Hao Chen Josef Vagner Theodore?J. Price Tsu-Shuen Tsao John?P. Konhilas 《Bioscience reports》2015,35(5)
Normal and pathological stressors engage the AMP-activated protein kinase (AMPK) signalling axis to protect the cell from energetic pressures. Sex steroid hormones also play a critical role in energy metabolism and significantly modify pathological progression of cardiac disease, diabetes/obesity and cancer. AMPK is targeted by 17β-oestradiol (E2), the main circulating oestrogen, but the mechanism by which E2 activates AMPK is currently unknown. Using an oestrogen receptor α/β (ERα/β) positive (T47D) breast cancer cell line, we validated E2-dependent activation of AMPK that was mediated through ERα (not ERβ) by using three experimental strategies. A series of co-immunoprecipitation experiments showed that both ERs associated with AMPK in cancer and striated (skeletal and cardiac) muscle cells. We further demonstrated direct binding of ERs to the α-catalytic subunit of AMPK within the βγ-subunit-binding domain. Finally, both ERs interacted with the upstream liver kinase B 1 (LKB1) kinase complex, which is required for E2-dependent activation of AMPK. We conclude that E2 activates AMPK through ERα by direct interaction with the βγ-binding domain of AMPKα. 相似文献
45.
Leonid Fedorenko Sergey Mamykin Oksana Lytvyn Yulia Burlachenko Boris Snopok 《Plasmonics (Norwell, Mass.)》2011,6(2):363-371
The physical mechanisms of metallic nanoparticles formation by laser technology were studied. The system air/Au film/glass
was irradiated by laser at the conditions of surface plasmon resonance. A surface electromagnetic wave was excited in Kretchmann
configuration by the fundamental and second harmonics of the Q-switched YAG/Nd+3 laser with pulse power density close to the threshold of melting. Nanostructuring of Au film was observed only for the second
harmonic (λ = 0.532 μm) irradiation at the surface plasmon polariton resonance (SPR) conditions. Estimations were done using the interference
model of the differently directed plasmon polariton waves excited by a surface electromagnetic wave on the metal surface.
It was shown that a regular pattern of locally heated spots can be formed in a metallic film by pulsed laser irradiation.
The spatial distribution of this pattern is close to the period of interference. The observed effect of laser nanofragmentation
is explained by the self-organization of plasmon polariton subsystem in the process of Au nanoparticles formation at high
laser intensity levels. These methods open new possibilities for nanostructured surfaces formation utilizing simple self-organization
processes. 相似文献
46.
Yulia Makusheva Soo-Hyun Chung Aoi Akitsu Natsumi Maeda Takumi Maruhashi Xiao-Qi Ye Tomonori Kaifu Shinobu Saijo Haiyang Sun Wei Han Ce Tang Yoichiro Iwakura 《Experimental Animals》2022,71(3):288
Clec1A, a member of C-type lectin receptor family, has a carbohydrate recognition domain in its extracellular region, but no known signaling motif in the cytoplasmic domain. Clec1a is highly expressed in endothelial cells and weakly in dendritic cells. Although this molecule was reported to play an important role in the host defense against Aspergillus fumigatus by recognizing 1,8-dihydroxynaphthalene-melanin on the fungal surface, the roles of this molecule in un-infected animals remain to be elucidated. In this study, we found that Clec1a−/− mice develop milder symptoms upon induction of experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. The maximum disease score was significantly lower, and demyelination and inflammation of the spinal cord were much milder in Clec1a−/− mice compared to wild-type mice. No abnormality was detected in the immune cell composition in the draining lymph nodes and spleen on day 10 and 16 after EAE induction. Recall memory T cell proliferation after restimulation with myelin oligodendrocyte glycoprotein peptide (MOG35–55) in vitro was decreased in Clec1a−/− mice, and antigen presenting ability of Clec1a−/− dendritic cells was impaired. Interestingly, RNA-Seq and RT-qPCR analyses clearly showed that the expression of inflammatory cytokines including Il17a, Il6 and Il1b was greatly decreased in Clec1a−/− mice after induction of EAE, suggesting that this reduced cytokine production is responsible for the amelioration of EAE in Clec1a−/− mice. These observations suggest a novel function of Clec1A in the immune system. 相似文献
47.
This study is concerned with long-term anthropometric examinations of children and adolescents aged 3-17 years in Moscow (over 10,500 persons, longitudinal and cross-sectional). Population variability of physical development was analyzed by means of regional estimation tables, which were developed on the basis of a regression analysis (scale of the regression of body mass to body length within a range from M - 1sigmaR to M + 2 sigmaR) and used for individual and group diagnostics taking into account age and sex. Such an approach allowed for the determination of the dynamics of the variability of Moscow schoolchildren from decade to decade (inter-population variability) and variations due to social differences (intra-population variability). 相似文献
48.
Purification and primary structure of two isoforms of arenicin, a novel antimicrobial peptide from marine polychaeta Arenicola marina 总被引:1,自引:0,他引:1
Ovchinnikova TV Aleshina GM Balandin SV Krasnosdembskaya AD Markelov ML Frolova EI Leonova YF Tagaev AA Krasnodembsky EG Kokryakov VN 《FEBS letters》2004,577(1-2):209-214
Two novel 21-residue antimicrobial peptides, arenicin-1 and arenicin-2, exhibiting activity against Gram-positive and Gram-negative bacteria and fungi, were purified from coelomocytes of marine polychaeta Arenicola marina (lugworm) by preparative gel electrophoresis and RP-HPLC. Molecular masses (2758.3 and 2772.3 Da) and complete amino acid sequences (RWCVYAYVRVRGVLVRYRRCW and RWCVYAYVRIRGVLVRYRRCW) were determined for each isoform. Each arenicin has one disulfide bond (Cys3-Cys20). The total RNA was isolated from the lugworm coelomocytes, RT-PCR and cloning were performed, and cDNA was sequenced. A 202-residue preproarenicin contains a putative signal peptide (25 amino acids) and a long prodomain. Arenicins have no structure similarity to any previously identified antimicrobial peptides. 相似文献
49.
Gingis-Velitski S Zetser A Kaplan V Ben-Zaken O Cohen E Levy-Adam F Bashenko Y Flugelman MY Vlodavsky I Ilan N 《The Journal of biological chemistry》2004,279(42):44084-44092
Heparanase is a mammalian endoglycosidase that degrades heparan sulfate (HS) at specific intrachain sites, an activity that is strongly implicated in cell dissemination associated with metastasis and inflammation. In addition to its structural role in extracellular matrix assembly and integrity, HS sequesters a multitude of polypeptides that reside in the extracellular matrix as a reservoir. A variety of growth factors, cytokines, chemokines, and enzymes can be released by heparanase activity and profoundly affect cell and tissue function. Thus, heparanase bioavailability, accessibility, and activity should be kept tightly regulated. We provide evidence that HS is not only a substrate for, but also a regulator of, heparanase. Addition of heparin or xylosides to cell cultures resulted in a pronounced accumulation of, heparanase in the culture medium, whereas sodium chlorate had no such effect. Moreover, cellular uptake of heparanase was markedly reduced in HS-deficient CHO-745 mutant cells, heparan sulfate proteoglycan-deficient HT-29 colon cancer cells, and heparinase-treated cells. We also studied the heparanase biosynthetic route and found that the half-life of the active enzyme is approximately 30 h. This and previous localization studies suggest that heparanase resides in the endosomal/lysosomal compartment for a relatively long period of time and is likely to play a role in the normal turnover of HS. Co-localization studies and cell fractionation following heparanase addition have identified syndecan family members as candidate molecules responsible for heparanase uptake, providing an efficient mechanism that limits extracellular accumulation and function of heparanase. 相似文献
50.
Karamysheva ZN Surovtseva YV Vespa L Shakirov EV Shippen DE 《The Journal of biological chemistry》2004,279(46):47799-47807
Little is known about the protein composition of plant telomeres. We queried the Arabidopsis thaliana genome data base in search of genes with similarity to the human telomere proteins hTRF1 and hTRF2. hTRF1/hTRF2 are distinguished by the presence of a single Myb-like domain in their C terminus that is required for telomeric DNA binding in vitro. Twelve Arabidopsis genes fitting this criterion, dubbed TRF-like (TRFL), fell into two distinct gene families. Notably, TRFL family 1 possessed a highly conserved region C-terminal to the Myb domain called Myb-extension (Myb-ext) that is absent in TRFL family 2 and hTRF1/hTRF2. Immunoprecipitation experiments revealed that recombinant proteins from TRFL family 1, but not those from family 2, formed homodimers and heterodimers in vitro. DNA binding studies with isolated C-terminal fragments from TRFL family 1 proteins, but not family 2, showed specific binding to double-stranded plant telomeric DNA in vitro. Removal of the Myb-ext domain from TRFL1, a family 1 member, abolished DNA binding. However, when the Myb-ext domain was introduced into the corresponding region in TRFL3, a family 2 member, telomeric DNA binding was observed. Thus, Myb-ext is required for binding plant telomeric DNA and defines a novel class of proteins in Arabidopsis. 相似文献