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71.
Jane A. Godiksen Martin-A. Svenning J. Brian Dempson Maare Marttila Andrea Storm-Suke Michael Power 《Hydrobiologia》2010,650(1):67-77
A species-specific fractionation equation for Arctic charr (Salvelinus alpinus (L.)) was developed experimentally for use in ecological studies of temperature-driven phenologies for the species. Juvenile
Arctic charr were reared in controlled conditions at different temperatures (2–14°C), with three replicates of each temperature.
Otoliths from the fish and water samples from the chambers were analysed for oxygen isotope composition and used to estimate
temperature-dependent fractionation equations relating the isotopic ratio to rearing temperature. A linear and a second order
polynomial relationship were estimated and validated using comparable Arctic charr data from another study. Temperatures predicted
using the polynomial equation were not significantly different from recorded experimental temperatures, whereas with the linear
equation there were significant differences between the predicted and measured temperatures. The polynomial equation also
showed the least bias as measured by mean predictive error. Statistical comparisons of the polynomial fractionation equation
to a similarly estimated equation for brook charr (Salvelinus fontinalis (Mitchill)) indicated significant differences. Results imply the need for species-specific fractionation equations, even
for closely related fish. Results further suggest the polynomial form of the fractionation equation will facilitate more accurate
characterisation of water temperatures suitable for use in ecological studies of temperature-driven phenologies of Arctic
charr. 相似文献
72.
73.
Redmond NE Raleigh J van Soest RW Kelly M Travers SA Bradshaw B Vartia S Stephens KM McCormack GP 《PloS one》2011,6(9):e24344
The systematics of the poriferan Order Haplosclerida (Class Demospongiae) has been under scrutiny for a number of years without resolution. Molecular data suggests that the order needs revision at all taxonomic levels. Here, we provide a comprehensive view of the phylogenetic relationships of the marine Haplosclerida using many species from across the order, and three gene regions. Gene trees generated using 28S rRNA, nad1 and cox1 gene data, under maximum likelihood and Bayesian approaches, are highly congruent and suggest the presence of four clades. Clade A is comprised primarily of species of Haliclona and Callyspongia, and clade B is comprised of H. simulans and H. vansoesti (Family Chalinidae), Amphimedon queenslandica (Family Niphatidae) and Tabulocalyx (Family Phloeodictyidae), Clade C is comprised primarily of members of the Families Petrosiidae and Niphatidae, while Clade D is comprised of Aka species. The polyphletic nature of the suborders, families and genera described in other studies is also found here. 相似文献
74.
Esa Kauppila Esko Vanninen Salla Kaurijoki Leila Karhunen Kirsi H. Pietil?inen Aila Rissanen Jari Tiihonen Ullamari Pesonen Jaakko Kaprio 《PloS one》2013,8(1)
Objective
Serotonin transporter gene polymorphism (5-HTTLPR polymorphism) predicts the degree of structural and functional connectivity in the brain, and less consistently the degree of vulnerability for anxiety and depressive disorders. It is less known how 5-HTTLPR polymorphism influences on the coupling between brain and neuronal cardiovascular control. The present study demonstrates the impact of 5-HTTLPR polymorphism on the relations between heart rate (HR) corrected cardiac repolarization interval (QTc interval) and the brain 5-HTT binding.Material and Methods
Thirty healthy young adults (fifteen monozygotic twin pairs) (mean age 26±1.3 years, 16 females) were imagined with single-photon emission computed tomography (SPECT) using iodine-123 labeled 2β-carbomethoxy-3β-(4-iodophenyl) nortropane (nor-β-CIT). Continuous ECG recording was obtained from each participant at supine rest. Signal averaged QTc interval on continuous ECG was calculated and compared with the brain imaging results.Results
In the two groups [l homozygotes (n = 16, 10 females), s carriers (n = 14, 8 female)] HR and the length of QTc interval were not influenced by 5-HTTLPR polymorphism. There were no significant relations between HR and 5-HTT binding in the brain. There were significant associations between QTc interval and nor-β-CIT binding in the brain in l homozygotes, but not in s carriers (correlations for QTc interval and nor-β-CIT binding of striatum, thalamus and right temporal region were −0.8–−0.9, (p<0.0005), respectively).Conclusion
The finding of longer QTc interval with less 5-HTT binding availability in major serotonergic binding sites in l homozygotes, but not in s carriers, implicate to differentiated control of QTc interval by 5-HTTLPR polymorphism. 相似文献75.
76.
A multivariate calibration procedure for UV/VIS spectrometric monitoring of BHK‐21 cell metabolism and growth 下载免费PDF全文
Letícia de Almeida Parizotto Wagner Antonio Chagas Erica Salla dos Santos Aline Tojeira Prestia Caricati Alexandre Gonçalves de Rezende Bruno Labate Vale da Costa Daniela Cristina Ventini Monteiro Vera Lucia Lopes Boldorini Soraia Attie Calil Jorge Renato Mancini Astray Carlos Augusto Pereira Celso Pereira Caricati Aldo Tonso 《Biotechnology progress》2014,30(1):241-248
Monitoring mammalian cell culture with UV–vis spectroscopy has not been widely explored. The aim of this work was to calibrate Partial Least Squares (PLS) models from off‐line UV–vis spectral data in order to predict some nutrients and metabolites, as well as viable cell concentrations for mammalian cell bioprocess using phenol red in culture medium. The BHK‐21 cell line was used as a mammalian cell model. Spectra of samples taken from batches performed at different dissolved oxygen concentrations (10, 30, 50, and 70% air saturation), in two bioreactor configurations and with two strategies to control pH were used to calibrate and validate PLS models. Glutamine, glutamate, glucose, and lactate concentrations were suitably predicted by means of this strategy. Especially for glutamine and glucose concentrations, the prediction error averages were lower than 0.50 ± 0.10 mM and 2.21 ± 0.16 mM, respectively. These values are comparable with those previously reported using near infrared and Raman spectroscopy in conjunction with PLS. However, viable cell concentration models need to be improved. The present work allows for UV–vis at‐line sensor development, decrease cost related to nutrients and metabolite quantifications and establishment of fed‐batch feeding schemes. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 30:241–248, 2014 相似文献
77.
Genetic changes through allelic loss and nucleic acid or protein modifications are the main contributors to loss of function of tumor suppressor proteins. In particular, epigenetic silencing of genes by promoter hypermethylation is associated with increased tumor severity and poor survival. The RASSF (Ras association domain family) family of proteins consists of 10 members, many of which are tumor suppressor proteins that undergo loss of expression through promoter methylation in numerous types of cancers such as leukemia, melanoma, breast, prostate, neck, lung, brain, colorectal and kidney cancers. In addition to their tumor suppressor function, RASSF proteins act as scaffolding agents in microtubule stability, regulate mitotic cell division, modulate apoptosis, control cell migration and cell adhesion, and modulate NFκB activity and the duration of inflammation. The ubiquitous functions of these proteins highlight their importance in numerous physiological pathways. In this review, we will focus on the biological roles of the RASSF family members and their regulation. 相似文献
78.
Ritika Sethi Jonne Sepp?l? Helena Tossavainen Mikko Ylilauri Salla Ruskamo Olli T. Pentik?inen Ulla Pentik?inen Perttu Permi Jari Yl?nne 《The Journal of biological chemistry》2014,289(12):8588-8598
Immunoglobulin-like (Ig) domains are a widely expanded superfamily that act as interaction motifs or as structural spacers in multidomain proteins. Vertebrate filamins (FLNs), which are multifunctional actin-binding proteins, consist of 24 Ig domains. We have recently discovered that in the C-terminal rod 2 region of FLN, Ig domains interact with each other forming functional domain pairs, where the interaction with signaling and transmembrane proteins is mechanically regulated by weak actomyosin contraction forces. Here, we investigated if there are similar inter-domain interactions around domain 4 in the N-terminal rod 1 region of FLN. Protein crystal structures revealed a new type of domain organization between domains 3, 4, and 5. In this module, domains 4 and 5 interact rather tightly, whereas domain 3 has a partially flexible interface with domain 4. NMR peptide titration experiments showed that within the three-domain module, domain 4 is capable for interaction with a peptide derived from platelet glycoprotein Ib. Crystal structures of FLN domains 4 and 5 in complex with the peptide revealed a typical β sheet augmentation interaction observed for many FLN ligands. Domain 5 was found to stabilize domain 4, and this could provide a mechanism for the regulation of domain 4 interactions. 相似文献
79.
Alakoskela JM Jutila A Simonsen AC Pirneskoski J Pyhäjoki S Turunen R Marttila S Mouritsen OG Goormaghtigh E Kinnunen PK 《Biochemistry》2006,45(45):13447-13453
Recent publications described the formation of millimeter-length fibers by diverse lipid-binding proteins (e.g., histone H1, cytochrome c, indolicidin, and endostatin) when they are mixed with 80:20 phosphatidylcholine/phosphatidylserine vesicles. Further, these fibers displayed amyloid characteristics when stained with Congo Red. In the study presented here, we found by FTIR the amide I absorption band to reveal significant variation in fibers formed by cytochrome c, with some consisting of cytochrome c in a nativelike conformation and some exhibiting strong amyloid (beta-sheet) characteristics. Protein structure also varied from amyloid to nearly native within single fibers. Fibers were frequently blue or bluish and sometimes iridescent, likely due to interference of light in the fibers. The amyloid-type amide I band was observed for blue fibers only. AFM shows that fibers consist of smaller 3-4 nm diameter fibers with 10 nm lateral spacing. 相似文献
80.
Ruskamo S Gilbert R Hofmann G Jiang P Campbell ID Ylänne J Pentikäinen U 《The Biochemical journal》2012,446(2):261-269
Filamins are large proteins that cross-link actin filaments and connect to other cellular components. The C-terminal rod 2 region of FLNa (filamin A) mediates dimerization and interacts with several transmembrane receptors and intracellular signalling adaptors. SAXS (small-angle X-ray scattering) experiments were used to make a model of a six immunoglobulin-like domain fragment of the FLNa rod 2 (domains 16-21). This fragment had a surprising three-branched structural arrangement, where each branch was made of a tightly packed two-domain pair. Peptides derived from transmembrane receptors and intracellular signalling proteins induced a more open structure of the six domain fragment. Mutagenesis studies suggested that these changes are caused by peptides binding to the CD faces on domains 19 and 21 which displace the preceding domain A-strands (18 and 20 respectively), thus opening the individual domain pairs. A single particle cryo-EM map of a nine domain rod 2 fragment (domains 16-24), showed a relatively compact dimeric particle and confirmed the three-branched arrangement as well as the peptide-induced conformation changes. These findings reveal features of filamin structure that are important for its interactions and mechanical properties. 相似文献