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61.
A new method for computerized modification of sound signals is presented. With digital signal processing in the time domain it is possible to alter the amplitude, the frequency and the time scale of natural sounds independently. The method can be applied to natural sounds with reasonably pure tonal quality.  相似文献   
62.
The sulfatase from the snail Heli pomatia is widely used for analytical applications. We have investigated the content of sulfatases in H. pomatia, using a biochemical and a molecular approach. A 112-kDa protein from the intestinal juice of H. pomatia comigrated with sulfatase activity when chromatographed on Sephacryl S300 and concanavalin A-Sepharose. The N-terminal amino acid sequence of the protein was similar to one of three sulfatase motifs defined by sequence alignment of known sulfatases. Degenerate primers designed from the motifs and the N-terminal amino acid sequence obtained were used to generate PCR fragments and to isolate both a full-length and a 3'-truncated cDNA encoding H. pomatia sulfatases, designated SULF1 and SULF2. SULF1 consists of 503 amino acids and shows 53-55% identity to the mammalian arylsulfatase B. The amino acid sequence deduced from the 878-bp SULF2 cDNA fragment is 55% identical with SULF1. Both SULF1 and SULF2 contain the cysteine residue conserved in the active site of many sulfatases, which is known to be posttranslationally modified into formylglycine in eukaryotic sulfatases. However, the SULF1 and SULF2 cDNAs do not code for the protein purified. This indicates the presence of at least three sulfatase genes in H. pomatia.  相似文献   
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64.
Objectives : A twin‐based comparative study on the genetic influences in metabolic endophenotypes in two populations of substantial ethnic, environmental, and cultural differences was performed. Design and Methods : Data on 11 metabolic phenotypes including anthropometric measures, blood glucose, and lipids levels as well as blood pressure were available from 756 pairs of Danish twins (309 monozygotic and 447 dizygotic twin pairs) with a mean age of 38 years (range: 18‐67) and from 325 pairs of Chinese twins (183 monozygotic and 142 dizygotic twin pairs) with a mean age of 40.5 years (range: 18‐69). Twin modeling was performed on full and nested models with the best fitting models selected. Results : Heritability estimates were compared between Danish and Chinese samples to identify differential genetic influences on each of the phenotypes. Except for hip circumference, all other body measures exhibited similar heritability patterns in the two samples with body weight showing only a slight difference. Higher genetic influences were estimated for fasting blood glucose level in Chinese twins, whereas the Danish twins showed more genetic regulation over most lipids phenotypes. Systolic blood pressure was more genetically controlled in Danish than in Chinese twins. Conclusions : Metabolic endophenotypes show disparity in their genetic determinants in populations under distinct environmental conditions.  相似文献   
65.

In 2016, an outbreak of anthrax killing thousands of reindeer and affecting dozens of humans occurred on the Yamal peninsula, Northwest Siberia, after 70 years of epidemiological situation without outbreaks. The trigger of the outbreak has been ascribed to the activation of spores due to permafrost thaw that was accelerated during the summer heat wave. The focus of our study is on the dynamics of local environmental factors in connection with the observed anthrax revival. We show that permafrost was thawing rapidly for already 6 years before the outbreak. During 2011–2016, relatively warm years were followed by cold years with a thick snow cover, preventing freezing of the soil. Furthermore, the spread of anthrax was likely intensified by an extremely dry summer of 2016. Concurrent with the long-term decreasing trend in the regional annual precipitation, the rainfall in July 2016 was less than 10% of its 30-year mean value. We conclude that epidemiological situation of anthrax in the previously contaminated Arctic regions requires monitoring of climatic factors such as warming and precipitation extremes.

  相似文献   
66.
The secreted morphogens of the Hedgehog family have important roles in normal development as well as in associated pathologies, including cancer. The Hedgehog signalling pathway has been studied in Drosophila and is thought to be conserved in vertebrates. Hedgehog elicits a signalling response that activates Smoothened (Smo). There is evidence of differences between Drosophila and vertebrates concerning signalling downstream of Smo, as well as in Smo itself. Here, we discuss this evidence and its importance for investigations of the pathway and related biology, as well as for the development of drugs targeting components of the pathway for treatment of associated pathologies.  相似文献   
67.
IFN-gamma-inducible protein 10/CXCL10 is a chemokine associated with type 1 T cell responses, regulating the migration of activated T cells through binding to the CXCR3 receptor. Expression of both CXCL10 and CXCR3 are observed during immunopathological diseases of the CNS, and this receptor/ligand pair is thought to play a central role in regulating T cell-mediated inflammation in this organ site. In this report, we investigated the role of CXCL10 in regulating CD8(+) T cell-mediated inflammation in the virus-infected brain. This was done through analysis of CXCL10-deficient mice infected intracerebrally with lymphocytic choriomeningitis virus, which in normal immunocompetent mice induces a fatal CD8(+) T cell-mediated meningoencephalitis. We found that a normal antiviral CD8(+) T cell response was generated in CXCL10-deficient mice, and that lack of CXCL10 had no influence on the accumulation of mononuclear cells in the cerebrospinal fluid. However, analysis of the susceptibility of CXCL10-deficient mice to lymphocytic choriomeningitis virus-induced meningitis revealed that these mice just like CXCR3-deficient mice were partially resistant to this disease, whereas wild-type mice invariably died. Furthermore, despite marked up-regulation of the two remaining CXCR3 ligands: CXCL9 and 11, we found a reduced accumulation of CD8(+) T cells in the brain parenchyma around the time point when wild-type mice succumb as a result of CD8(+) T cell-mediated inflammation. Thus, taken together these results indicate a central role for CXCL10 in regulating the accumulation of effector T cells at sites of CNS inflammation, with no apparent compensatory effect of other CXCR3 ligands.  相似文献   
68.
The genus Pseudoalteromonas has attracted interest because it has frequently been found in association with eukaryotic hosts, and because many Pseudoalteromonas species produce biologically active compounds. One distinct group of Pseudoalteromonas species is the antifouling subgroup containing Pseudoalteromonas tunicata and Ps. ulvae, which both produce extracellular compounds that inhibit growth and colonization by different marine organisms. PCR primers targeting the 16S rRNA gene of the genus Pseudoalteromonas and the antifouling subgroup were developed and applied in this study. Real-time quantitative PCR (qPCR) was applied to determine the relative bacterial abundance of the genus and the antifouling subgroup, and denaturing gradient gel electrophoresis (DGGE) was applied to study the diversity of the genus in 11 different types of marine samples from Danish coastal waters. The detection of Ps. tunicata that contain the antifouling subgroup was achieved through specific PCR amplification of the antibacterial protein gene (alpP). The Pseudoalteromonas species accounted for 1.6% of the total bacterial abundance across all samples. The Pseudoalteromonas diversity on the three unfouled marine organisms Ciona intestinalis, Ulva lactuca and Ulvaria fusca was found to be low, and Ps. tunicata was only detected on these three hosts, which all contain accessible cellulose polymers in their cell walls.  相似文献   
69.
70.
During the dawn chorus, territorial male songbirds vocalise intensively within signalling range of several conspecific males and can therefore be considered members of a busy communication network. The more or less continuous singing over a long period of time under standardised stimulus conditions makes the dawn song a potentially important information source both for simple receivers and for eavesdroppers. Male blue tits (Parus caeruleus) vary in features of their dawn song, e.g. older males sing longer strophes, and females choose males that sing longer strophes as extra-pair partners. However, so far, dawn song in the blue tit has been investigated separately from other singing behaviour of the same males. In this study, we investigate aspects of blue tit male quality, reflected in dawn song characteristics, and their predictive value for how males behave during singing interactions later in the morning. We acted as simple receivers by recording the singing activity of one male at a time at dawn and compared features of its dawn song, such as onset before sunrise, repertoire size, mean bout length, strophe length and percentage performance time to responses of the same male to a territory intrusion simulated by playback of synthesised songs later during the same morning. We assume that an aggressive response towards an intruder will involve a fast approach to the loudspeaker broadcasting strophes of blue tit song, searching for the intruder (flying around), and a high amount of counter singing and overlapping of the intruders songs. Aspects of vigour of response to the simulated intrusion could be predicted from all five investigated dawn song parameters as well as male age. This is, to our knowledge, the first indication that a simple receiver could extract reliable information from a males dawn singing behaviour about its competitiveness later in the day.Communicated by P.K. McGregor  相似文献   
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