253 research outputs found
VLSI implementation of the SIFT algorithm for pitch detection
Speech voicing classification and pitch detection are
fundamental techniques in speech analysis. Voicing information provides valuable insights into the nature of the excitation source used in speech production, and the pitch information is useful to many speech processing
applications. In 1972 John Markel developed a technique which combines the benefits of inverse linear predictive (LPC) analysis and simple short-time autocorrelation to extract essential speech parameters. The research resulted
in the simplified inverse filter tracking (SIFT) algorithm to make voiced/unvoiced classification of speech signals and determine the pitch period. Up until now this algorithm was used in various software algorithms only. However, this paper describes a real-time CMOS hardware implementation of this algorithm small enough to be implemented into various mobile communications equipment
Locus of Heat Resistance (LHR) in Meat-Borne \u3ci\u3eEscherichia coli\u3c/i\u3e: Screening and Genetic Characterization
Microbial resistance to processing treatments poses a food safety concern, as treatment tolerant pathogens can emerge. Occasional foodborne outbreaks caused by pathogenic Escherichia coli have led to human and economic losses. Therefore, this study screened for the extreme heat resistance (XHR) phenotype as well as one known genetic marker, the locus of heat resistance (LHR), in 4,123 E. coli isolates from diverse meat animals at different processing stages. The prevalences of XHR and LHR among the meat-borne E. coli were found to be 10.3% and 11.4%, respectively, with 19% agreement between the two. Finished meat products showed the highest LHR prevalence (24.3%) compared to other processing stages (0 to 0.6%). None of the LHR1 E. coli in this study would be considered pathogens based on screening for virulence genes. Four high-quality genomes were generated by whole-genome sequencing of representative LHR+ isolates. Nine horizontally acquired LHRs were identified and characterized, four plasmid-borne and five chromosomal. Nine newly identified LHRs belong to ClpK1 LHR or ClpK2 LHR variants sharing 61 to 68% nucleotide sequence identity, while one LHR appears to be a hybrid. Our observations suggest positive correlation between the number of LHR regions present in isolates and the extent of heat resistance. The isolate exhibiting the highest degree of heat resistance possessed four LHRs belonging to three different variant groups. Maintenance of as many as four LHRs in a single genome emphasizes the benefits of the LHR in bacterial physiology and stress response. IMPORTANCE Currently, a âmultiple-hurdleâ approach based on a combination of different antimicrobial interventions, including heat, is being utilized during meat processing to control the burden of spoilage and pathogenic bacteria. Our recent study (M. Guragain, G. E. Smith, D. A. King, and J. M. Bosilevac, J Food Prot 83:1438â1443, 2020, https://doi.org/10.4315/JFP-20-103) suggests that U.S. beef cattle harbor Escherichia coli that possess the locus of heat resistance (LHR). LHR seemingly contributes to the global stress tolerance in bacteria and hence poses a food safety concern. Therefore, it is important to understand the distribution of the LHRs among meat-borne bacteria identified at different stages of different meat processing systems. Complete genome sequencing and comparative analysis of selected heat-resistant bacteria provide a clearer understanding of stress and heat resistance mechanisms. Further, sequencing data may offer a platform to gain further insights into the genetic background that provides optimal bacterial tolerance against heat and other processing treatments
Preliminary Characterization of Voltage-Activated Whole-Cell Currents in Developing Human Vestibular Hair Cells and Calyx Afferent Terminals
We present preliminary functional data from human vestibular hair cells and primary afferent calyx terminals during fetal development. Whole-cell recordings were obtained from hair cells or calyx terminals in semi-intact cristae prepared from human fetuses aged between 11 and 18Â weeks gestation (WG). During early fetal development (11â14 WG), hair cells expressed whole-cell conductances that were qualitatively similar but quantitatively smaller than those observed previously in mature rodent type II hair cells. As development progressed (15â18 WG), peak outward conductances increased in putative type II hair cells but did not reach amplitudes observed in adult human hair cells. Type I hair cells express a specific low-voltage activating conductance, G(K,L). A similar current was first observed at 15 WG but remained relatively small, even at 18 WG. The presence of a âcollapsingâ tail current indicates a maturing type I hair cell phenotype and suggests the presence of a surrounding calyx afferent terminal. We were also able to record from calyx afferent terminals in 15â18 WG cristae. In voltage clamp, these terminals exhibited fast inactivating inward as well as slower outward conductances, and in current clamp, discharged a single action potential during depolarizing steps. Together, these data suggest the major functional characteristics of type I and type II hair cells and calyx terminals are present by 18 WG. Our study also describes a new preparation for the functional investigation of key events that occur during maturation of human vestibular organs
Heterogeneous Responses to Antioxidants in Noradrenergic Neurons of the Locus Coeruleus Indicate Differing Susceptibility to Free Radical Content
The present study investigated the effects of the antioxidants trolox and dithiothreitol (DTT) on mouse Locus coeruleus (LC) neurons. Electrophysiological measurement of action potential discharge and whole cell current responses in the presence of each antioxidant suggested that there are three neuronal subpopulations within the LC. In current clamp experiments, most neurons (55%; 6/11) did not respond to the antioxidants. The remaining neurons exhibited either hyperpolarization and decreased firing rate (27%; 3/11) or depolarization and increased firing rate (18%; 2/11). Calcium and JC-1 imaging demonstrated that these effects did not change intracellular Ca2+ concentration but may influence mitochondrial function as both antioxidant treatments modulated mitochondrial membrane potential. These suggest that the antioxidant-sensitive subpopulations of LC neurons may be more susceptible to oxidative stress (e.g., due to ATP depletion and/or overactivation of Ca2+-dependent pathways). Indeed it may be that this subpopulation of LC neurons is preferentially destroyed in neurological pathologies such as Parkinson's disease. If this is the case, there may be a protective role for antioxidant therapies
Heterogeneous Responses to Antioxidants in Noradrenergic Neurons of the Locus Coeruleus Indicate Differing Susceptibility to Free Radical Content
The present study investigated the effects of the antioxidants trolox and dithiothreitol (DTT) on mouse Locus coeruleus (LC) neurons. Electrophysiological measurement of action potential discharge and whole cell current responses in the presence of each antioxidant suggested that there are three neuronal subpopulations within the LC. In current clamp experiments, most neurons (55%; 6/11) did not respond to the antioxidants. The remaining neurons exhibited either hyperpolarization and decreased firing rate (27%; 3/11) or depolarization and increased firing rate (18%; 2/11). Calcium and JC-1 imaging demonstrated that these effects did not change intracellular Ca2+ concentration but may influence mitochondrial function as both antioxidant treatments modulated mitochondrial membrane potential. These suggest that the antioxidant-sensitive subpopulations of LC neurons may be more susceptible to oxidative stress (e.g., due to ATP depletion and/or overactivation of Ca2+-dependent pathways). Indeed it may be that this subpopulation of LC neurons is preferentially destroyed in neurological pathologies such as Parkinson's disease. If this is the case, there may be a protective role for antioxidant therapies
High Harmonic Spectroscopy of the Cooper Minimum in Molecules
The Cooper minimum (CM) has been studied using high harmonic generation solely in atoms. Here, we present detailed experimental and theoretical studies on the CM in molecules probed by high harmonic generation using a range of near-infrared light pulses from λ = 1.3 to 1.8 ”m. We demonstrate the CM to occur in CSâ and CClâ at ~42 and ~40 eV, respectively, by comparing the high harmonic spectra with the known partial photoionization cross sections of different molecular orbitals, confirmed by theoretical calculations of harmonic spectra. We use CM to probe electron localization in Cl-containing molecules (CClâ, CHâClâ, and trans-CâHâClâ) and show that the position of the minimum is influenced by the molecular environment
Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit juices
[EN] A comparative study of the analytical performance of enzyme-linked immunosorbent assays (ELISAs), based on monoclonal and recombinant antibodies, for the determination of fungicide residues in fruit juices has been carried out. To this aim, three murine hybridoma cell lines secreting specific monoclonal antibodies against (RS)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetrafluoroethyl ether (tetraconazole), 2-(4-triazolyl)benzimidazole (thiabendazole), and (RS)-1-(beta-allyloxy-2,4-dichlorophenylethyl)imidazole (imazalil) were used as a source of immunoglobulin gene fragments for the production of single-chain variable fragment (scFv) and fusion scFv-pIII recombinant antibodies in Escherichia coli. Selected recombinant antibodies displayed cross-reactivity profiles very similar to those of the parent monoclonal antibodies. Imazalil and tetraconazole recombinant antibodies showed one order of magnitude lower affinity than their respective monoclonal antibodies, whereas the thiabendazole recombinant antibodies showed an affinity similar to that of their parent monoclonal antibody. On the other hand, scFv-pIII fusion fragments showed similar analytical properties as, and occasionally better than, scFv recombinant antibodies. Finally, ELISAs developed from each antibody type showed similar analytical performance when applied to the analysis of the target fungicides in fruit juices.This work was funded by Ministerio de Educacion y Ciencia (MEC, Spain, Project AGL2002-03266). E. P. was the recipient of a doctoral fellowship from Conselleria d'Educacio (Generalitat Valenciana, Spain).Moreno Tamarit, MJ.; Plana Andani, E.; Manclus Ciscar, JJ.; Montoya Baides, Ă. (2014). Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit juices. Food Analytical Methods. 7(2):481-489. https://doi.org/10.1007/s12161-013-9655-zS48148972Abad A, ManclĂșs JJ, Moreno M, Montoya A (2001) J AOAC Int 84:1â6Alcocer MJC, Doyen C, Lee HA, Morgan MRA (2000) J Agric Food Chem 48:4053â4059Brichta J, Vesela H, Franek M (2003) Vet Med 48:237â247Brichta J, Hnilova M, Viskovic T (2005) Vet Med 50:231â252Charlton K, Harris WJ, Potter AJ (2001) Biosens Bioelec 16:639â646EU Pesticide Database (2013) Pesticide EU-MRLs. http://ec.europa.eu/sanco_pesticides/public/index.cfm . Accessed Jan 2013Ferrer C, MartĂnez-Bueno MJ, Lozano A, FernĂĄndez-Alba AR (2011) Talanta 83:1552â1561Garret SD, Appleford DJA, Wyatt GM, Lee HA, Morgan MRA (1997) J Agric Food Chem 45:4183â4189Graham BM, Porter AJ, Harris WJ (1995) J Chem Technol Biotech 63:279â289Hiemstra M, de Kok A (2007) J Chromatog A 1154:3â25Kipriyanov SM, Moldenhauer G, Little M (1997) J Immunol Meth 200:69â77Kramer K, Hock B (2007) Recombinant antibodies for agrochemicals: Evolutionary optimization. In: Kennedy IR, Solomon KR, Gee SJ, Crossan AN, Wang S, SĂĄnchez-Bayo F (eds) Rational environmental management of agrochemicals: Risk assessment, monitoring, and remedial action. ACS Symposium Series, vol. 966, pp 155â170Krebber A, Bornhauser S, Burmester J, Honegger A, Willuda J, Bosshard HR, PlĂŒckthun A (1997) J Immunol Meth 201:35â55Leong SSJ, Chen WN (2008) Chem Engin Sci 63:1401â1414Li T, Zhang Q, Liu Y, Chen D, Hu B, Blake DA, Liu F (2006) J Agric Food Chem 54:9085â9091ManclĂșs JJ, Moreno M, Plana E, Montoya A (2008) J Agric Food Chem 56:8790â8800Markus V, Janne L, Urpo L (2011) Trends Anal Chem 30:219â226Mersmann M, Schmidt A, Tesar M, Schöneberg A, Welschof M, Kipriyanov S, Terness P, Little M, Pfizenmaier K, Moosmayer D (1998) J Immunol Meth 220:51â58Moreno M, Plana E, Montoya A, Caputo P, ManclĂșs JJ (2007) Food Addit Contam 24:704â712Morozova VS, Levashova AI, Eremin SA (2005) J Anal Chem 60:202â217Nishi K, Imajuku Y, Nakata M, Ohde K, Miyake S, Morimune K, Kawata M, Ohkawa H (2003) J Pest Sci 28:301â309Nishi K, Ishiuchi M, Morimune K, Ohkawa H (2005) J Agric Food Chem 53:5096â5104Scholthof KB, Whang G, Karu AE (1997) J Agric Food Chem 45:1509â1517Sheedy C, MacKenzie CR, Hall JC (2007) Biotech Adv 25:25333â25352Tout NL, Yau KYF, Trevors JT, Lee H, Hall JC (2001) J Agric Food Chem 49:3628â3637Webb SR, Lee H, Hall JC (1997) J Agric Food Chem 45:535â541Yau KYF, Tout NL, Trevors JT, Lee H, Hall JC (1998) J Agric Food Chem 46:4457â4463Yoshioka N, Akiyama Y, Matsuoka T, Mitsuhashi T (2010) Food Control 21:212â21
Dopamine metabolism by a monoamine oxidase mitochondrial shuttle activates the electron transport chain
Genetic and expression studies of SMN2 gene in Russian patients with spinal muscular atrophy type II and III
<p>Abstract</p> <p>Background</p> <p>Spinal muscular atrophy (SMA type I, II and III) is an autosomal recessive neuromuscular disorder caused by mutations in the survival motor neuron gene (<it>SMN1</it>). <it>SMN2 </it>is a centromeric copy gene that has been characterized as a major modifier of SMA severity. SMA type I patients have one or two <it>SMN2 </it>copies while most SMA type II patients carry three <it>SMN2 </it>copies and SMA III patients have three or four <it>SMN2 </it>copies. The <it>SMN1 </it>gene produces a full-length transcript (FL-SMN) while <it>SMN2 </it>is only able to produce a small portion of the FL-SMN because of a splice mutation which results in the production of abnormal SMNÎ7 mRNA.</p> <p>Methods</p> <p>In this study we performed quantification of the <it>SMN2 </it>gene copy number in Russian patients affected by SMA type II and III (42 and 19 patients, respectively) by means of real-time PCR. Moreover, we present two families consisting of asymptomatic carriers of a homozygous absence of the <it>SMN1 </it>gene. We also developed a novel RT-qPCR-based assay to determine the FL-SMN/SMNÎ7 mRNA ratio as SMA biomarker.</p> <p>Results</p> <p>Comparison of the <it>SMN2 </it>copy number and clinical features revealed a significant correlation between mild clinical phenotype (SMA type III) and presence of four copies of the <it>SMN2 </it>gene. In both asymptomatic cases we found an increased number of <it>SMN2 </it>copies in the healthy carriers and a biallelic <it>SMN1 </it>absence. Furthermore, the novel assay revealed a difference between SMA patients and healthy controls.</p> <p>Conclusions</p> <p>We suggest that the <it>SMN2 </it>gene copy quantification in SMA patients could be used as a prognostic tool for discrimination between the SMA type II and SMA type III diagnoses, whereas the FL-SMN/SMNÎ7 mRNA ratio could be a useful biomarker for detecting changes during SMA pharmacotherapy.</p
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