Home About us Contact
|
Home About us Contact | ||
|
|
||
Different Segments (different + segment)
Selected AbstractsShort note: Source geometry identification by simultaneous use of structural index and shape factorGEOPHYSICAL PROSPECTING, Issue 1 2001Lopamudra Roy A cross-plot of the shape factors and the structural indices, determined from gravity anomalies over various idealized sources, namely horizontal/vertical lines and vertical ribbons with various strike lengths and depth extents, forms a closed loop. Different segments of this loop, termed the source geometry identification loop (SGIL), correspond to different source geometries. Combined use of the structural index and the shape factor determined from an isolated gravity anomaly reduces the ambiguity in characterizing the source geometry. A simulated example and three field examples, namely a Cuban chromite anomaly, an Indian example over manganese ore and a sulphide ore from Quebec, have been analysed by the proposed method in order to identify their respective source geometries. [source] Analysis of regulatory elements of E-cadherin with reporter gene constructs in transgenic mouse embryosDEVELOPMENTAL DYNAMICS, Issue 2 2003Marc P. Stemmler Abstract Proper regulation of E-cadherin,mediated cell adhesion is important during early embryonic development and in organogenesis. In mice, E-cadherin is expressed from the fertilized egg onward and becomes down-regulated during gastrulation in mesoderm and its derivatives, but its expression is maintained in all epithelia. E-cadherin promoter analyses led to the identification of binding sites for two transcriptional repressors, Snail and SIP1, which are able to mediate down-regulation in vitro, but little is known about the regulatory elements that govern E-cadherin transcriptional activity in vivo. Here, we compared the developmentally regulated expression of a series of lacZ -reporter transgenes fused to different sequences of the murine E-cadherin gene between ,6 kb, including the promoter, and +16 kb, covering one third of intron 2. Four different segments with distinct regulatory properties were identified. The promoter fragment from +0.1 to ,1.5 kb remains inactive in most cases but occasionally induces ectopic expression in mesodermal tissues, although it contains binding sites for the repressors Snail and SIP1. This promoter fragment also lacks positive elements needed for the activation of transcription in ectoderm and endoderm. Sequences from ,1.5 to ,6 kb harbor regulatory elements for brain-specific expression and, in addition, insulator or silencer elements, because they are consistently inactive in the mesoderm. Only if sequences from +0.1 to +11 kb are combined with the promoter fragments is E-cadherin,specific transgene expression observed in endoderm and certain epithelia. Sequences between +11 and +16 kb contain cis -active elements that generally enhance transcription. Our analyses show that E-cadherin expression is governed by a complex interplay of multiple regulatory regions dispersed throughout large parts of the locus. Developmental Dynamics 227:238,245, 2003. © 2003 Wiley-Liss, Inc. [source] A Comparison of Echocardiographic Techniques in Determination of Arterial Elasticity in the Pediatric PopulationECHOCARDIOGRAPHY, Issue 5 2009Michael Fahey M.D. Background: Many methods are used to measure arterial elasticity in children using echocardiography. There is no data to support the equivalence of the different techniques. The goal of this study was to evaluate the reproducibility of several techniques used to measure arterial elasticity using echocardiography. Methods: Aortic distension in two different sites (arterial distension) through the cardiac cycle was measured by (four) two-dimensional (2D) and M-mode echocardiographic techniques in 20 children without significant structural heart disease. These measurements combined with noninvasive blood pressure measurements were used to calculate arterial elastic indices. Arterial elasticity was expressed in terms of distensibility and stiffness. Data were collected by two sonographers and interpreted by two reviewers. Paired Student's t-test and Pitman's test for equality of variance for correlated observations were used to detect differences between different sonographers, different reviewers, and different techniques. Results: No significant difference in the measured elasticity between sonographers or reviewers was observed. There was a somewhat increased variance in two of the four techniques evaluated. There was no significant difference in elasticity measured using different techniques to evaluate the same arterial site, although a significantly decreased elasticity was noted from measurements taken in the proximal ascending aorta as compared with the distal ascending aorta. Conclusions: Many echocardiographic techniques produce reproducible measurements of arterial elasticity. There may be intrinsic differences in arterial elasticity between different segments of the ascending aorta, which have not been previously described in children with normal cardiac anatomy. Comparisons of data from separate studies must take these differences into account. [source] Bidding behaviour and electricity market simulationEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2007T. Chandarasupsang Abstract To trade effectively and profitably in new electricity market structures, participants need to identify how best to use information available to them. In many cases only incomplete information will be available for short-term planning, trading and decision-making. This paper simulates a group of generators who adapt bidding behaviours in different segments of liberalised electricity markets based on historic market information, observed strategies and their view of other market participants. Results show that even in the incomplete information case efficient bidding strategy for market participants can be identified. Specifically, this paper presents some key findings from an active electricity market and utilises them within an electricity market simulation. The benefit of market simulation for participants is identified and reported. Copyright © 2007 John Wiley & Sons, Ltd. [source] Boundary and border considerations in hydrologyHYDROLOGICAL PROCESSES, Issue 7 2004Ming-ko Woo Abstract This paper examines several issues related to hydrological boundaries and their border zones. In a two-dimensional space, a boundary is a line that separates two domains possessing different hydrological properties or dominated by different hydrological processes, and a border is an area that experiences an edge effect owing to transitions or mixing of processes. Hydrological boundaries may be static, such as drainage divides, or dynamic, such as the edges of a seasonal snow cover. They may be open or closed to the transfer of matter and energy, although most boundaries tend to be perforated, permitting different rates of movement across different segments. Borders may be narrow or the edge effect can affect large areas, as happens to the sensible heat flux over a highly fragmented melting snowfield. The introduction of artificial boundaries, notably the grid patterns of remote sensing pixels, digital elevation models and land surface schemes, gives rise to problems of mismatch with the natural hydrological boundaries. Incorrect demarcation, omission and generalization of boundaries can produce errors that are hard to rectify. Serious biases are involved when point observations are used to calibrate parameters or to validate model outputs integrated over a bounded area. Examples are drawn mainly from cold climate hydrology to illustrate the boundary issues but the questions transcend disciplinary areas. The intent of this presentation is to stimulate discussions that could be a prelude to finding solutions to many boundary problems which have thus far eluded hydrological investigations. Copyright © 2004 John Wiley & Sons, Ltd. [source] GENOMIC FEATURES OF COTESIA PLUTELLAE POLYDNAVIRUSINSECT SCIENCE, Issue 2 2003LIU Cai-ling Abstract Polydnavirus was purified from the calyx fluid of Cotesia plutellae ovary. The genomic features of C. plutellae polydnavirus (CpPDV) were investigated. The viral genome consists of at least 12 different segments and the aggregate genome size is a lower estimate of 80kbp. By partial digestion of CpPDV DNA with Bam HI and subsequent ligation with Bam HI-cut plasmid Bluescript, a representative library of CpPDV genome was obtained. [source] Does the Yield Spread Predict Recessions in the Euro Area?,INTERNATIONAL FINANCE, Issue 2 2005Fabio MonetaArticle first published online: 16 DEC 200 This paper studies the informational content of the slope of the yield curve as a predictor of recessions in the euro area and provides evidence of the potential usefulness of this indicator for monetary policy purposes. In particular, the historical predictive power of ten variations of yield spreads, for different segments of the yield curve, is tested using a probit model. The yield spread between the ten-year government bond rate and the three-month interbank rate outperforms all other spreads in predicting recessions in the euro area. The forecast accuracy of the spread between ten-year and three-month interest rates is also explored in an exercise of out-of-sample forecasting. This yield spread appears to contain information beyond that already available in the history of output, and to outperform other competitor indicators. [source] The Richmond Agitation-Sedation Scale: translation and reliability testing in a Swedish intensive care unitACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2010M. ALMGREN Background: Awareness about adequate sedation in mechanically ventilated patients has increased in recent years. The use of a sedation scale to continually evaluate the patient's response to sedation may promote earlier extubation and may subsequently have a positive effect on the length of stay in the intensive care unit (ICU). The Richmond Agitation-Sedation Scale (RASS) provides 10 well-defined levels divided into two different segments, including criteria for levels of sedation and agitation. Previous studies of the RASS have shown it to have strong reliability and validity. The aim of this study was to translate the RASS into Swedish and to test the inter-rater reliability of the scale in a Swedish ICU. Methods: A translation of the RASS from English into Swedish was carried out, including back-translation, critical review and pilot testing. The inter-rater reliability testing was conducted in a general ICU at a university hospital in the south of Sweden, including 15 patients mechanically ventilated and sedated. Forty in-pair assessments using the Swedish version of the RASS were performed and the inter-rater reliability was tested using weighted , statistics (linear weighting). Result: The translation of the RASS was successful and the Swedish version was found to be satisfactory and applicable in the ICU. When tested for inter-rater reliability, the weighed , value was 0.86. Conclusion: This study indicates that the Swedish version of the RASS is applicable with good inter-rater reliability, suggesting that the RASS can be useful for sedation assessment of patients mechanically ventilated in Swedish general ICUs. [source] Intersegment handover performance in integrated terrestrial satellite systemsINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 6 2002M. Leo Abstract To achieve a global cellular network, integration among segments offering different coverage (indoor, outdoor and global) must be pursued. Of course, the possibility to hold the call switching among different segments must be guaranteed. Hence, efficient algorithms to perform intersegment handover (ISHO) must be implemented. The paper aims at analysing some ISHO procedures developed in the frame of some European projects and other proposed in the literature, in a scenario with satellite and terrestrial segments interworking to achieve a worldwide cellular coverage. Performance evaluation will be carried out for different system configurations utilizing a dynamic satellite constellation simulator in the time domain. The impact of the distance user-gateway on performance will be addressed. For each procedure, the execution delay and its complementary cumulative distribution have been evaluated for different constellation geometries at different distances from the gateway. Copyright © 2002 John Wiley & Sons, Ltd. [source] Lead Firms and Competition in ,Bi-polar' Commodity Chains: Grinders and Branders in the Global Cocoa-chocolate IndustryJOURNAL OF AGRARIAN CHANGE, Issue 2 2002Niels FoldArticle first published online: 16 DEC 200 Like most global agro-industrial commodity chains today, the global cocoa - chocolate industry is buyer-driven. However, the chain is characterized by the lead role of a few transnational companies in two different segments: the grinders (processors of cocoa)and the branders (manufacturers of chocolate), a structural pattern identified in other so-called turn-key industries consisting of contract manufacturers and brand-name firms. The paper examines two important spatial sub-systems of the chain: the national cocoa bean supply system in Ghana and the regional cocoa trading-storing-grinding complex in the Zaanstreek, Amsterdam. The structural patterns and relationships in these sub-systems suggest that the dynamics of ,bi-polar' buyer-driven chains is best comprehended in terms of various types of containment strategies of the leadfirms, i.e. efforts to defend and improve their positions on the global market by creating competition among their suppliers and expanding their customers. [source] Separation between the digestive and the respiratory lumina during the human embryonic period: morphometric study along the tracheo-oesophageal septumJOURNAL OF ANATOMY, Issue 1 2001JOSEP NEBOT-CEGARRA An isolated tracheo-oesophageal fistula could be caused by close proximity of the epithelia of both organs (O'Rahilly & Müller, 1984; Kluth et al. 1987) at certain embryonic stages, the most frequent location being the tracheal bifurcation. Thus the relative position and degree of separation between the digestive and the respiratory tubes throughout their development may be relevant to the origin of this anomaly. The aim of this study was to analyse along the different segments of the tracheo-oesophageal septum (TES) where the closest relationship between both lumina occurred and what degree of separation was present at each segment. Computer imaging techniques were applied on cross sections of a graded series of normal human embryos (Carnegie stages (CS) 13,23). In addition, the differentiation of the primitive TES was also studied (from CS 12) by light microscopy. Between CS 13 and 16 both tubes tended to separate (phase of separation), principally at the proximal segments of the laryngopharyngeal and the tracheo-oesophageal portions of the TES. During this phase the separation between the trachea and oesophagus was wider than between the larynx and pharynx. From CS 17 to CS 23 the digestive and respiratory lumina reached their widest separation at different levels of the laryngopharyngeal portion. Below these levels they tended to come closer together, principally at the proximal segment of the tracheo-oesophageal portion, but also at the distal part of the laryngopharyngeal portion. During this phase of approximation they reached their closest relationship at the proximal (CS 17) and the distal (from CS 18) segments of the tracheo-oesophageal portion. When finally the distal segment of the trachea (which includes the bifurcation) comes closest to the oesophagus, the coats of both organs have already undergone an appreciable differentiation. According to these observations, the origin of the most frequent isolated tracheo-oesophageal fistula at the bifurcation region could not be explained from the normal development of the TES. [source] Vitamin D receptor amounts across different segments of the gastrointestinal tract in Brown Swiss and Holstein Frisean cows of different ageJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3 2008A. Liesegang Summary During different stages of lactation, different requirements of calcium have to be met depending on the milk amount. Vitamin D receptors (VDR) regulate calcium homeostasis by increasing the entry of Ca into blood from bone stores and dietary sources. The purpose of this study was to investigate if age and breed of cows influence VDR amounts across different segments of the gastrointestinal tract. Thirty-six cows were used (18 brown swiss, 18 holstein friesan, both > 5.5 years or < 4.5 years). Tissue specimens of the intestines were collected from the cows. Formaldehyde-fixed and microwave-treated paraffin sections were used for VDR immunohistochemistry employing a biotinylated monoclonal rat antibody and streptavidin peroxidase technique. The results showed that nuclei and cytoplasm of enterocytes stained positively for VDRs. Strongest immunoreactions were observed in intermediate and basal glandular cells. No significant differences were observed between the different groups. Vitamin D receptors immunoreactivities were prominent in duodenal mucosa, lower in jejunum and in colon, decreased further in ileum and were lowest in caecum. Decreases in number of positively marked cells and staining intensities resulted in reduced immunoreactions. The results of this study indicate that VDR are highly expressed at the site of maximal intestinal calcium absorption. No significant influence of age and breed was observed. The animals used were not in a negative Ca balance. The cows were all in the stage of late or mid lactation. During these periods, the Ca requirements are low and the diets are high in Ca concentration; and the animals are adapted to these circumstances. Passive absorption in adult animals seems to dominate when Ca intake is adequate or high. The active absorption may play a considerably more significant role during the peripartal period, when Ca homeostatic mechanisms are challenged because of tremendous Ca demand at the initiation of lactation. [source] When a man hits a woman: moral evaluations and reporting violence to the policeAGGRESSIVE BEHAVIOR, Issue 6 2009Richard B. Felson Abstract We use experimental data from a nationally representative sample to examine whether gender and the victim's relationship to the offender affect attitudes about the seriousness of the offense and whether the offense should be reported to the police. We find that respondents are particularly likely to condemn men's assaults on women, and to favor reporting them. The pattern appears to reflect both greater moral condemnation of men's assaults on women and the belief that the victims of these assaults are in greater danger. In general, moral judgments and attitudes toward reporting do not depend on the gender, age, level of education, or political ideology of the respondent. Condemnation of men's violence against women, and support for police intervention when it occurs, are apparently widespread across different segments of the population. Aggr. Behav. 35:477,488, 2009. © 2009 Wiley-Liss, Inc. [source] The Evolution of the Digital Divide: How Gaps in Internet Access May Impact Electronic CommerceJOURNAL OF COMPUTER-MEDIATED COMMUNICATION, Issue 3 2000Donna L. Hoffman Enthusiasm for the anticipated social dividends of the Internet appears boundless. Indeed, the Internet is expected to do no less than virtually transform society. Yet even as the Internet races ambitiously toward critical mass, some social scientists are beginning to examine carefully the policy implications of current demographic patterns of Internet access and usage. Key demographic variables like income and education drive the policy questions surrounding the Internet because they are the most likely have a differential impact on the consequences of interactive electronic media for different segments in our society. Given these concerns, we set out to conduct a systematic investigation of the differences between whites and African Americans in the United States with respect to computer access, the primary current prerequisite for Internet access, and Web use. We wished to examine whether observed race differences in access and use can be accounted for by differences in income and education, how access influences use, and when race matters in the calculus of equal access. The particular emphasis of this research is on how such differences may be changing over time. We believe our results may be used as a window through which policymakers might view the job of ensuring access to the Internet for the next generation. [source] Strain-encoded (SENC) magnetic resonance imaging to evaluate regional heterogeneity of myocardial strain in healthy volunteers: Comparison with conventional taggingJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2009Mirja Neizel MD Abstract Purpose To evaluate the ability of strain-encoded (SENC) magnetic resonance imaging (MRI) for regional systolic and diastolic strain analysis of the myocardium in healthy volunteers. Materials and Methods Circumferential and longitudinal peak systolic strain values of 75 healthy volunteers (35 women and 40 men, mean age 44 ± 12 years) were measured using SENC at 1.5T. MR tagging was used as the reference standard for measuring regional function. Diastolic function was assessed in the 10 youngest (24 ± 8 years) and 10 oldest (62 ± 5 years) subjects. Results Peak strain values assessed with SENC were comparable to those obtained by MR tagging, showing narrow limits of agreement (limits of agreement ,5.6% to 8.1%). Regional heterogeneity was observed between different segments of the left ventricle (LV) by both techniques (P < 0.001). Longitudinal strain obtained by SENC was also heterogenous (P < 0.001). Interestingly, no age- or gender-specific differences in peak systolic strain were observed, whereas the peak rate of relaxation of circumferential strain rate was decreased in the older group. Conclusion SENC is a reliable tool for accurate and objective quantification of regional myocardial systolic as well as diastolic function. In agreement with tagged MRI, SENC detected slightly heterogeneous myocardial strain within LV segments. J. Magn. Reson. Imaging 2009;29:99,105. © 2008 Wiley-Liss, Inc. [source] Profile of P-glycoprotein distribution in the rat and its possible influence on the salbutamol intestinal absorption processJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2004Belén Valenzuela Abstract The intrinsic absorption of salbutamol in different intestinal segments of the rat was measured and related with the corresponding intestinal P-glycoprotein (P-gp) expression levels. The apparent absorption rate constants (ka, h,1) observed in each fraction by means of the "in situ" rat gut absorption method after perfusion of a 0.29-mM isotonic solution of salbutamol were used as absorption indexes. In a separate series of studies, a semiquantitative analysis of the mRNA expression of P-gp by means of polymerase chain reaction and Western blot with an antibody raised against the P-gp were also performed. The "in situ" ka values determined in the different segments (h,1) showed that the absorption is not homogeneous along the intestinal tract, that is, 0.499,±,0.054 for colon, 0.474,±,0.052 for the proximal segment, 0.345,±,0.014 for the mean, and 0.330,±,0.023 for the distal fraction. Addition of verapamil to the perfusion fluid did provide a better absorption of salbutamol in the distal segment. The analysis of the mRNA expression and levels of P-gp showed that the enzyme content in each section of the intestine was inversely related to salbutamol absorption. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1641,1648, 2004 [source] Standardized T2* map of normal human heart in vivo to correct T2* segmental artefactsNMR IN BIOMEDICINE, Issue 6 2007Vincenzo Positano Abstract A segmental, multislice, multi-echo T2* MRI approach could be useful in heart iron-overloaded patients to account for heterogeneous iron distribution, demonstrated by histological studies. However, segmental T2* assessment in heart can be affected by the presence of geometrical and susceptibility artefacts, which can act on different segments in different ways. The aim of this study was to assess T2* value distribution in the left ventricle and to develop a correction procedure to compensate for artefactual variations in segmental analysis. MRI was performed in four groups of 22 subjects each: healthy subjects (I), controls (II) (thalassemia intermedia patients without iron overload), thalassemia major patients with mild (III) and heavy (IV) iron overload. Three short-axis views (basal, median, and apical) of the left ventricle were obtained and analyzed using custom-written, previously validated software. The myocardium was automatically segmented into a 16-segment standardized heart model, and the mean T2* value for each segment was calculated. Punctual distribution of T2* over the myocardium was assessed, and T2* inhomogeneity maps for the three slices were obtained. In group I, no significant variation in the mean T2* among slices was found. T2* showed a characteristic circumferential variation in all three slices. The effect of susceptibility differences induced by cardiac veins was evident, together with low-scale variations induced by geometrical artefacts. Using the mean segmental deviations as correction factors, an artefact correction map was developed and used to normalize segmental data. The correction procedure was validated on group II. Group IV showed no significant presence of segmental artefacts, confirming the hypothesis that susceptibility artefacts are additive in nature and become negligible for high levels of iron overload. Group III showed a greater variability with respect to normal subjects. The correction map failed to compensate for these variations if both additive and percentage-based corrections were applied. This may reinforce the hypothesis that true inhomogeneity in iron deposition exists. Copyright © 2007 John Wiley & Sons, Ltd. [source] Human capital and per capita product: A comparison of US states,PAPERS IN REGIONAL SCIENCE, Issue 4 2000Saurav Dev Bhatta Human capital; US states; gross regional product; growth accounting Abstract. This article analyzes the extent to which human capital differences can explain the differences in gross state product (GSP) per capita levels between the richer and poorer states of the US. It uses 1990 Census and Bureau of Economic Analysis data on educational attainment, wage levels of different segments of the labor force, and GSP to compare New York , our representative rich state , with the poorest third of the states. The findings indicate that human capital differences explain at least 49% of the observed difference in GSP per capita between New York and each of the poor states. [source] The Influence of Pre- and Post-ovulatory Insemination and Early Pregnancy on the Infiltration by Cells of the Immune System in the Sow OviductREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2006J Jiwakanon Contents The aim of this study was to investigate the influence of pre- and post-ovulatory insemination and early pregnancy on the distribution of immune cells in the oviduct. Eighteen sows were pre-ovulatory and sixteen sows were post-ovulatory inseminated and slaughtered at different times, 5,6 h after insemination, 20,25 h and approximately 70 h after ovulation, day 11 and day 19. Immediately after slaughter, oviductal samples of three different segments (isthmus, ampulla and infundibulum) were fixed, embedded in plastic resin and stained with toluidine blue or cryofixed and stored in a freezer at ,70°C until analysed by immunohistochemistry (pre-ovulatory inseminated sows) with an avidin,biotin peroxidase method. Quantitative and qualitative examinations of oviductal epithelium and subepithelial connective tissue were performed by light microscopy. After pre- or post-ovulatory insemination, neutrophils were not observed in the oviductal epithelium from any of the segments or groups. The numbers of intraepithelial lymphocytes of all sows as well as CD2- and CD3-positive cells of the pre-ovulatory inseminated sows were higher in the infundibulum than in the other segments (p , 0.001). In the subepithelial connective tissue of the pre-ovulatory inseminated sows, significantly higher numbers of lymphocytes (p , 0.001) and plasma cells (p , 0.001) were found in infundibulum than in isthmus. Neutrophils were found mainly in infundibulum, the number approximately 40 h after pre-ovulatory insemination was significantly higher (p , 0.05) than in the other groups and segments. Significantly higher numbers of CD2 than CD3-positive cells were found for all groups and segments. In the subepithelial connective tissue of post-ovulatory inseminated sows, the numbers of lymphocytes was higher (p , 0.001) at day 19 than up to 50 h after insemination and lower (p , 0.001) in isthmus than in ampulla and infundibulum. Neutrophils were found in infundibulum in almost all groups and the number was significantly higher (p , 0.05) in the infundibulum up to 50 h after insemination than in other segments. In the oviductal epithelium, no influence of insemination was found on the presence of phagocytes, i.e. neutrophils and macrophages, but on lymphocytes. In the infundibular connective tissue, pre-ovulatory insemination had an effect on neutrophil distribution, indicating an active immune response to insemination in the upper segment. Post-ovulatory insemination changed the oviductal immune cell pattern. [source] Postovulatory Effect of Intravenous Administration of Lipopolysaccharide (E. coli, O55:B5) on the Contractile Activity of the Oviduct, Ova Transport, Binding of Accessory Spermatozoa to the Zona Pellucida and Embryo Development in SowsREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2002AM Mwanza Contents The effect of lipopolysaccharide (LPS) (E. coli, O55:B5), administered 18 h after ovulation in the second oestrus after weaning, on the contractile activity of the oviduct, ova transport, sperm binding to zona pellucida (ZP) and embryo development, was studied in 14 Swedish crossbred (Landrace Yorkshire) multiparous sows. The endotoxin group (E-group) sows were administered with 300 ng/kg of LPS while the control group (C-group) sows were administered with 5 ml of saline i.v. via an indwelling jugular cannula. Immediately after evidence of standing oestrus, a Millar® pressure transducer was placed intraluminally about 3 cm into the mid-isthmus, via laparotomy. Pressure recordings of the oviduct were collected from all conscious sows until slaughter. After slaughter, the genital tract opposite to the side with the transducer was retrieved, and three equal isthmic segments and the first third of the uterine horn part adjacent to the utero-tubal-junction (UTJ) were flushed separately to recover the ova. The intervals (mean±SD) from ovulation to slaughter (OS) and insemination to ovulation (IO) were not different between the E-group (44.5±5.7 h; 13.3±6.5 h) and the C-group (42.7±5.9 h; 14.8±4.1 h), respectively. Ova recovery rate (RR) in the E-group (80.2±22.9%) did not differ from that in the C-group (85.2±4.5%). The frequency distribution of ova recovered in the different segments did not significantly (p>0.05) differ between the groups. The E-group showed higher cleavage rate than controls. A higher proportion of spermatozoa bound to the ZP was also found in the E-group compared with controls. The isthmic intraluminal pressure slightly increased (p=0.07) 18 h after ovulation and immediately following LPS in the E-group, compared with the C-group. The frequencies of phasic pressure fluctuations were significantly (p<0.05) lower at 30 and 38 h after ovulation in the E- than in the C-group. It can be concluded from the present study that a single i.v. administration of LPS (300 ng/kg body weight) to sows, 18 h after ovulation might be associated with changes in isthmic pressure and the frequency of phasic pressure fluctuations, increased numbers of spermatozoa attached to the ZP and an enhanced embryo development but not with ova transport rates. [source] Ex vivo hypothermic recirculatory adenoviral gene transfer to the transplanted pig heartTHE JOURNAL OF GENE MEDICINE, Issue 7 2006Keiji Oi Abstract Background To facilitate the application of adenoviral gene therapy in clinical heart transplantation, we developed an ex vivo hypothermic recirculatory adenoviral gene transfer method to the transplanted pig heart. Methods Experimental animals were assigned into three groups; controls, 1 × 108 plaque-forming units (pfu)/ml group and 1 × 109 pfu/ml group. During the 30 min gene transfer perfusion, 200 ml of University of Wisconsin solution containing the adenoviral vector was recirculated through the coronary vessels. The myocardial temperature was maintained below 4 °C and the perfusion pressure was adjusted at 50 mmHg. Results Cardiac myocyte transduction efficiencies in the 1 × 108 pfu/ml group were 0.04% and 0.07%, whereas transduction efficiencies in the 1 × 109 pfu/ml group were widely distributed from 0.45% to 22.62%. The gene transduction efficiency increased with the virus titer. Additionally, no difference in the transduction efficiency was observed between different segments of the left ventricle. The current gene transfer method at 1 × 109 pfu/ml of adenovirus titer enabled homogeneous gene transduction into the transplanted pig heart up to a maximum of 22.62%. Conclusions This model can be applied to a large isolated heart and will greatly facilitate the investigation of gene therapy in large animal models of heart transplantation. Copyright © 2006 John Wiley & Sons, Ltd. [source] Movement of the tongue during normal breathing in awake healthy humansTHE JOURNAL OF PHYSIOLOGY, Issue 17 2008S. Cheng Electromyographic (EMG) activity of the airway muscles suggest that genioglossus is the primary upper airway dilator muscle. However, EMG data do not necessarily translate into tissue motion and most imaging modalities are limited to assessment of the surfaces of the upper airway. In this study, we hypothesized that genioglossus moves rhythmically during the respiratory cycle and that the motion within is inhomogeneous. A ,tagged' magnetic resonance imaging technique was used to characterize respiratory-related tissue motions around the human upper airway in quiet breathing. Motion of airway tissues at different segments of the eupnoeic respiratory cycle was imaged in six adult subjects by triggering the scanner at the end of inspiration. Displacements of the ,tags' were analysed using the harmonic phase method (HARP). Respiratory timing was monitored by a band around the upper abdomen. The genioglossus moved during the respiratory cycle. During expiration, the genioglossus moved posteriorly and during inspiration, it moved anteriorly. The degree of motion varied between subjects. The maximal anteroposterior movement of a point tracked on the genioglossus was 1.02 ± 0.54 mm (mean ±s.d.). The genioglossus moved over the geniohyoid muscle, with minimal movement in other muscles surrounding the airway at the level of the soft palate. Local deformation of the tongue was analysed using two-dimensional strain maps. Across the respiratory cycle, positive strains within genioglossus reached peaks of 17.5 ± 9.3% and negative strains reached peaks of ,16.3 ± 9.3% relative to end inspiration. The patterns of strains were consistent with elongation and compression within a constant volume structure. Hence, these data suggest that even during respiration, the tongue behaves as a muscular hydrostat. [source] Mean retention time of digesta in the different segments of the equine hindgutANIMAL SCIENCE JOURNAL, Issue 1 2008Makoto MIYAJI ABSTRACT Six Thoroughbred horses were used to determine the mean retention time (MRT) of digesta in the different segments of the hindgut. The horses were fed timothy hay or silage in equal amounts (1.6% bodyweight [BW]/day) every 3 h/day. Hay or silage labeled with the rare earth elements cerium, dysprosium, neodymium, ytterbium, lanthanum, samarium and praseodymium, were fed to the horses 36, 30, 24, 18, 12, 6 and 3 h before slaughter, respectively. Just after slaughter, digesta samples in the different segments were collected and determined for the contents of the rare earth elements. Using these data, a method to calculate the MRT in the different segments was proposed. There were no significant differences between diets in the MRT of each segment. The averaged MRT of hay and silage in the cecum, right ventral colon, left ventral colon, left dorsal colon, right dorsal colon and small colon was 2.9, 3.1, 5.9, 1.0, 4.0, and 4.0 h, respectively. The dry matter weight of the digesta was related to the MRT in the right ventral colon (r = 0.94, P = 0.005), left ventral colon (r = 0.87, P = 0.03), left dorsal colon (r = 0.98, P < 0.001) and right dorsal colon (r = 0.95, P = 0.004), but it was not related to the MRT in the cecum and small colon. [source] Comment: A biological guide for electromagnetic safety: the stress responseBIOELECTROMAGNETICS, Issue 8 2004Martin Blank Abstract Questions of safety of electromagnetic (EM) fields should be based on relevant biological properties, i.e., specific cellular reactions to potentially harmful stimuli. The stress response is a well documented protective reaction of plant and animal cells to a variety of environmental threats, and it is stimulated by both extremely low frequency (ELF) and radio frequency (RF) EM fields. It involves activation of DNA to initiate synthesis of stress proteins. Thermal and non-thermal stimuli affect different segments of DNA and utilize different biochemical pathways. However, both ELF and RF stimulate the same non-thermal pathway. Since the same biochemical reactions are stimulated in different frequency ranges with very different specific absorption rates (SARs), SAR level is not a valid basis for safety standards. Studies of EM field interactions with DNA and with model systems provide insight into a plausible mechanism that can be effective in ELF and RF ranges. Bioelectromagnetics 25:642,646, 2004. © 2004 Wiley-Liss, Inc. [source] Adrenergic mechanisms in canine nasal venous systemsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2003Min Wang We investigated the adrenergic mechanisms of the two venous systems that drain the nasal mucosa, thereby their exact role in eliciting nasal decongestion. The action of endogenously released noradrenaline and exogenous adrenergic agonists on different segments of the nasal venous systems, i.e. collecting (LCV, SCV) and outflow (SPV) veins of posterior venous system, collecting (ACV) and outflow (DNV) veins of anterior venous system and venous sinusoids of the septal mucosa (SM), were studied. In vitro isometric tension of the vascular segments was measured. Transmural nerve stimulation (TNS) produced constriction in ACV, DNV and SM, primary constriction followed by secondary dilatation in LCV and SCV and dilatation in SPV. Tetrodotoxin (10,6M) abolished all responses. Phentolamine (10,6M), prazosin (10,6M) and rauwolscine (10,7M) inhibited the constriction in all venous vessels. Propranolol (10,6M), atenolol (10,6M) and ICI 118,551 (10,6M) inhibited the relaxation in SPV but not in LCV and SCV. Phenylephrine and clonidine constricted whereas dobutamine and terbutaline relaxed all venous vessels dose-dependently. These results indicate ,1 -, ,2 -, ,1 - and ,2 -adrenoceptors are present in both venous systems. TNS causes constriction of anterior venous system, venous sinusoids and posterior collecting veins primarily via postjunctional ,2 -adrenoceptors but relaxation of posterior outflow vein equally via postjunctional ,1 - and ,2 -adrenoceptors. The combined action of the two adrenergic mechanisms can reduce nasal airway resistance in vivo by decreasing vascular capacitance and enhancing venous drainage via the posterior venous system. British Journal of Pharmacology (2003) 138, 145,155. doi:10.1038/sj.bjp.0705020 [source] | ||||||||||||||||||||||