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Selected AbstractsPrehospital management of diabetic emergencies , a population-based intervention studyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2003A. Holstein Background: Diabetes-related emergencies are frequent and potentially life-threatening. A study was performed to obtain reliable data about the prevalence of diabetic emergencies and to improve the quality of prehospital care of patients with diabetes-related emergencies. Methods: A prospective population-based study in a German emergency medical service district in the period from 1997 to 2000 was conducted. After initial diabetes training for the entire emergency team, a standardized protocol was introduced for prehospital emergency therapy of severe hypoglycaemia (SH) and severe hyperglycaemic disorders. A rapid blood glucose test was performed on all emergency patients with the exception of resuscitations and deaths. Indicators of treatment quality before and after these interventions were compared. Results: A rapid blood glucose test was performed in 6631 (85%) of the 7804 emergencies that occurred during the period investigated. The prevalence of acute diabetic complications was 3.1%, and 213 cases of SH and 29 severe hyperglycaemic disorders were recorded. Education of the emergency team led to a significant improvement in the quality of treatment. Larger volumes of iv 40% glucose solution (50 ± 20 ml (1997,2000) vs. 25 ± 17 ml (1993,96); P < 0.0001) were administered to patients with SH. Insulin-treated patients who were well educated about their diabetes were more often treated only at the emergency scene, after SH (25% vs. 8%; P = 0.007), and without complications. In 50 patients who experienced sulfonylurea-induced SH, the mandatory additional glucose infusions and hospitalization for further observation reduced mortality from 4.9% to 0% (P = 0.2). Conclusion: Training of the emergency team is an effective and efficient intervention to improve quality of treatment and prognosis outcome for patients with diabetic emergencies. Treatment of SH at the emergency scene only was demonstrated to be safe in type 1 diabetic patients who had previously received structured patient education. [source] The Effect of Hemodialysis on Left Ventricular Outflow Tract GradientECHOCARDIOGRAPHY, Issue 6 2010Pawel Petkow Dimitrow M.D. Background: The aim of the study was to assess the effect of hemodialysis (HD) on left ventricular outflow tract gradient (LVOTG) measured both in supine and upright position (provocative maneuver to unload LV cavity by rapid preload reduction). Supine/standing echocardiography was performed immediately before and immediately after HD. For additional verification of the hypothesis about preload-dependence of LVOTG, the echocardiograms after long (2-day delay HD due to weekend) versus short (usual 1-day) pause between HDs were compared. Methods: Forty-one patients on chronic HD (mean age 44 ± 11 years) were examined using a portable hand-carried echocardiograph. In accordance with the prestudy assumption the ultrafiltration volume was significantly greater during HD after a long pause in comparison to HD after a short pause (3707 ± 2826 mL vs. 2665 ± 1152 mL P < 0.05). Results: After a long pause, the mean value of LVOTG at the pre-HD was mildly increased in the supine position and remained at a similar level in the upright position (13.1 ± 6.1 vs. 13.6 ± 9.1 mmHg). Mean LVOTG at the post-HD in the supine position was similar to pre-HD, however the orthostatic stress test induced a significant increase of LVOTG (13.9 ± 15.2 vs. 18.2 ± 19.9 mmHg P < 0.05). After a short pause at the pre-HD the LVOTG in the supine position and after the orthostatic provocation was very similar to measurements after long pause (13.3 ± 9.1 vs. 13.3 ± 10.8 mmHg). At the post-HD the mean value of LVOTG increased during upright posture but the differences were of borderline significance (13.2 ± 6.6 vs. 17.9 ± 18.6 mmHg P = 0.052). Conclusions: HD predisposed to standing-provoked LVOTG especially when a long pause (2 days) between HDs induced a greater weight gain and subsequently a larger volume of ultrafiltration was needed to reduce hypervolemia. (Echocardiography 2010;27:603-607) [source] Conditional gene recombination by adenovirus-driven Cre in the mouse uterusGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 2 2006Haibin Wang Abstract Cre-mediated conditional gene targeting has been shown to be successful in many cell and tissue types. However, gene recombination in the uterus with heterogeneous cell types by Cre activation is not yet well established. Using recombinant adenoviruses expressing a functional Cre (ADV-Cre) and ROSA26 reporter mice, we show here that ADV-Cre infused intraluminally in a small volume (10 ,l) conditionally excises the loxP site, resulting in lacZ expression in uterine luminal epithelial cells without significantly affecting pregnancy. In contrast, a similar intraluminal infusion of ADV-Cre in a larger volume (50 ,l) damages the normal architecture and integrity of the luminal epithelium, inducing gene recombination in the underneath stromal cells, with disruption of pregnancy. Further, decidualizing stromal cells at the implantation sites can be targeted by ADV-Cre after intravenous administration on days 5,6. This route of administration also elicits Cre activity in other tissues, including the liver, spleen, ovary, and, more remarkably, in the adrenal cortex. These findings demonstrate the feasibility of achieving conditional expression or deletion of specific genes in uterine cells at desired times and physiological states. genesis 44:51,56, 2006. © 2006 Wiley-Liss, Inc. [source] Characterization of a Multilayer Aquifer Using Open Well Dilution TestsGROUND WATER, Issue 1 2007L. Jared West An approach to characterization of multilayer aquifer systems using open well borehole dilution is described. The approach involves measuring observation well flow velocities while a nearby extraction well is pumped by introducing a saline tracer into observation wells and collecting dilution vs. depth profiles. Inspection of tracer profile evolution allows discrete permeable layers within the aquifer to be identified. Dilution profiles for well sections between permeable layers are then converted into vertical borehole flow velocities and their evolution, using an analytic solution to the advection-dispersion equation applied to borehole flow. The dilution approach is potentially able to measure much smaller flow velocities that would be detectable using flowmeters. Vertical flow velocity data from the observation wells are then matched to those generated using a hydraulic model of the aquifer system, "shorted" by the observation wells, to yield the hydraulic properties of the constituent layers. Observation well flow monitoring of pumping tests represents a cost-effective alternative or preliminary approach to pump testing each layer of a multilayer aquifer system separately using straddle packers or screened wells and requires no prior knowledge of permeable layer depths and thicknesses. The modification described here, of using tracer dilution rather than flowmeter logging to obtain well flow velocities, allows the approach to be extended to greater well separations, thus characterizing a larger volume of the aquifer. An example of the application of this approach to a multilayer Chalk Aquifer in Yorkshire, Northeast England, is presented. [source] Pharmacokinetics of factors IX, recombinant human activated factor VII and factor XIIIHAEMOPHILIA, Issue 2006M.-C. POON Summary., There is now a volume of literature on the pharmacokinetics (PK) of coagulation factor concentrates, although the majority is on factor VIII (FVIII) and factor IX (FIX). PK of FIX and FVIII are different with FIX having a larger volume of distribution (Vdss), higher elimination clearance (CL), longer mean resident time (MRT) and longer terminal half-life (T1/2,,). Factor IX in vivo recovery (IVR) is also much shorter possibly due to reversible binding of FIX to the endothelium and possibly to platelets. There is considerable FIX PK variability between products (particularly between plasma-derived FIX and recombinant FIX), and between individuals. Important inter-individual factors leading to PK variability include age and body weight because plasma volume as a fraction of body weight decreases with increasing weight and hence age. Thus, IVR increases with body weight and hence age and is consequently lower in children than in adults. Absolute Vdss and CL increase linearly with body weight and age in children and adolescents, becoming stable in adults with more stable weight. Inter-individual variability also likely applies to other clotting factors, particularly to recombinant activated FVII (rFVIIa) but likely also to the less well studied factor XIII (FXIII). The former is known to have an extremely short T1/2,,, large Vdss, high CL, short MRT, whereas the latter has an extremely long T1/2,,, large Vdss, short CL and long MRT. Both are discussed in this article. Understanding of PK of specific clotting factors in individual patients is important in order to make decisions regarding appropriate dosage and dosage intervals to treat patients, and to allow by means of computer modelling the determination of dosage to achieve target trough level at various dosing intervals for patients undergoing prophylaxis. [source] Differential activity in left inferior frontal gyrus for pseudowords and real words: An event-related fMRI study on auditory lexical decisionHUMAN BRAIN MAPPING, Issue 2 2005Zhuangwei Xiao Abstract After Newman and Twieg ([2001]: Hum Brain Mapp 14:39,47) and others, we used a fast event-related functional magnetic resonance imaging (fMRI) design and contrasted the lexical processing of pseudowords and real words. Participants carried out an auditory lexical decision task on a list of randomly intermixed real and pseudo Chinese two-character (or two-syllable) words. The pseudowords were constructed by recombining constituent characters of the real words to control for sublexical code properties. Processing of pseudowords and real words activated a highly comparable network of brain regions, including bilateral inferior frontal gyrus, superior, middle temporal gyrus, calcarine and lingual gyrus, and left supramarginal gyrus. Mirroring a behavioral lexical effect, left inferior frontal gyrus (IFG) was significantly more activated for pseudowords than for real words. This result disconfirms a popular view that this area plays a role in grapheme-to-phoneme conversion, as such a conversion process was unnecessary in our task with auditory stimulus presentation. An alternative view was supported that attributes increased activity in left IFG for pseudowords to general processes in decision making, specifically in making positive versus negative responses. Activation in left supramarginal gyrus was of a much larger volume for real words than for pseudowords, suggesting a role of this region in the representation of phonological or semantic information for two-character Chinese words at the lexical level. Hum Brain Mapp 25:212,221, 2005. © 2005 Wiley-Liss, Inc. [source] Utility of reticulocyte maturation parameters in the differential diagnosis of macrocytic anemiasINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2003A. Torres Gomez Summary The aim of this study was to test the clinical utility of reticulocyte maturation parameters in the differential diagnosis of macrocytic anemias. Using an automated reticulocyte counter, we analyzed immature reticulocyte fraction (IRF), mean reticulocyte volume (MRV) and mean fluorescence index (MFI) in peripheral blood samples from healthy donors (n = 30), patients diagnosed with myelodysplastic syndromes (MDS, n = 35), with megaloblastic anemia (MA, n = 10) and with non-megaloblastic macrocytic anemias (NMMA, n = 30). Macrocytic anemias due to ineffective erythropoiesis (MA and MDS) showed reticulocytes skewed to a more immature fraction. Therefore, they have a larger volume and a greater RNA content than healthy controls. Interestingly, reticulocytes in both low and high risk MDS are significantly larger (127.3 vs. 118.3 fl, P < 0.01) and have a greater RNA content (MFI 20.5 vs. 12.9, P < 0.01 and IRF 22.5 vs. 9.1%, P < 0.01) than NMMA patients. We conclude that measurement of reticulocyte maturation parameters may be a very useful tool in the differential diagnosis of macrocytic anemia. The presence of extremely high values of IRF (>16%), MFI (>18) and MRV (>129 fl), makes the diagnosis of NMMA very unlikely. An underlying MDS should, therefore, be sought. [source] Estimation of number of follicles, volume of colloid and inner follicular surface area in the thyroid gland of ratsJOURNAL OF ANATOMY, Issue 2 2005M. L. Hartoft-Nielsen Abstract Volume is an important variable in assessing the growth and involution of the thyroid gland. The functional unit in the thyroid is the follicle, which consists of thyrocytes surrounding colloid. The size of a follicle depends on the number of cells and the amount of colloid. These are interchangeable and vary according to biological activity. Direct measurements of these variables provide information on structures involved in thyroid hormone synthesis, storage and secretion, and also on changes at the morphological and functional levels. Stereological methods are developed to obtain information on three-dimensional structures from two-dimensional sections and to achieve information on an entire organ by examining a minor part of it. Full-grown male Sprague,Dawley rats were used to develop a set of methods relying on unbiased stereological principles to determine the number of follicles, the total volume of colloid and the inner follicular surface area in the thyroid gland. The total volume of colloid was positively correlated (P < 0.021) with the number of follicles and the inner follicular surface area (P < 0.002) but not to the mean volume of colloid in each follicle. Thus under physiological conditions an increase in the total volume of colloid is associated with an increased number of follicles with a constant size distribution rather than a larger volume of colloid in each follicle. This implies that under physiological conditions there is equilibrium in the size distribution of the volume of colloid in each follicle. [source] Collapse of acrylamide-based polyampholyte hydrogels in waterJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2009Saadet Dogu Abstract The swelling behavior of balanced acrylamide (AAm)-based polyampholyte hydrogels in water and in aqueous salt (NaCl) solutions was investigated. Equimolar ratio of the ionic comonomers 4-vinylpyridine (cationic monomer) and acrylic acid (anionic monomer) were used together with the nonionic monomer AAm in the hydrogel preparation. The variations of the hydrogel volume in response to changes in pH were measured. It was found that the hydrogels are in a collapsed state not only at the pH of the isoelectric point pHIEP but also over a wide range of pH including pHIEP. The width of the collapsed plateau increased and the hydrogels assumed a more compact state as the ionic group content is increased. The antipolyelectrolyte behavior was observed along the collapsed plateau region, where the gel occupies a larger volume in salt solution. The experimental swelling data were compared with the predictions of the Flory-Rehner theory of swelling equilibrium including the ideal Donnan equilibria. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Relative fatigue life estimation of cylindrical hollow rollers in general pure rolling contactLUBRICATION SCIENCE, Issue 1 2008Wisam M. Abu Jadayil Solid and hollow cylindrical rollers in pure rolling contact have been modelled. The two rollers are subjected to a combined normal and tangential loading. The tangential loading is one-third of the normal loading value. The finite element package, ABAQUS, is used to study the stress distribution and the resulting deformations in the bodies of the rollers. Then the Ioannides,Harris fatigue life model for rolling bearings is applied on the ABAQUS numerical results to investigate the fatigue life of the solid and hollow rollers. Using the fatigue life of the solid rollers as the reference fatigue life, the relative fatigue lives of hollow rollers are determined. Four main different hollowness percentages are been studied: 20, 40, 60 and 80%. The hollowness percentage is the ratio of the diameter of the hole to the outer diameter of the cylinder. For each of those hollowness percentages, two cases are studied , when the two rollers in contact are hollow and when one hollow roller is in contact with a solid roller. This study includes two main models: Model 1, where the two cylindrical rollers in contact are of the same size, and Model 2, where the two rollers in contact are not of the same size. The estimated relative fatigue lives of hollow rollers showed a great improvement of the fatigue life compared with solid rollers under the same loading conditions. This was a result of the redistribution of stresses in the contact zone in the case of hollow rollers. Redistribution of stresses over a larger volume of the roller body decreased the peak stress and reduced the volume under risk. Increasing the hollowness percentage from 20 to 60% increased the flexibility of the roller, and better stress distribution was achieved, which resulted in improving the fatigue life. Although 80% of hollowness rollers have more flexibility than 60% of hollowness rollers, the bending stresses (,b) on the inner surface of the rollers tend to decrease the fatigue life. Copyright © 2007 John Wiley & Sons, Ltd. [source] 39Ar- 40Ar dating of the Zagami Martian shergottite and implications for magma origin of excess 40ArMETEORITICS & PLANETARY SCIENCE, Issue 7 2008Donald D. BOGARD 1992, 1999). Like several shergottites, Zagami contains excess 40Ar relative to its formation age. To understand the origin of this excess 40Ar, we made 39Ar- 40Ar analyses on plagioclase and pyroxene minerals from two phases representing different stages in the magma evolution. Surprisingly, all these separates show similar concentrations of excess 40Ar, ,1 × 10,6 cm3/g. We present arguments against this excess 40Ar having been introduced from the Martian atmosphere as impact glass. We also present evidence against excess 40Ar being a partially degassed residue from a basalt that actually formed ,4 Gyr ago. We utilize our experimental data on Ar diffusion in Zagami and evidence that it was shock-heated to only ,70 °C, and we assume this heating occurred during an ejection from Mars ,3 Myr ago. With these constraints, thermal considerations necessitates either that its ejected mass was impossibly large, or that its shock-heating temperature was an order of magnitude higher than that measured. We suggest that this excess 40Ar was inherited from the Zagami magma, and that it was introduced into the magma either by degassing of a larger volume of material or by early assimilation of old, K-rich crustal material. Similar concentrations of excess 40Ar in the analyzed separates imply that this magma maintained a relatively constant 40Ar concentration throughout its crystallization. This likely occurred through volatile degassing as the magma rose toward the surface and lithostatic pressure was released. These concepts have implications for excess 40Ar in other shergottites. [source] Sex differences in songbirds 25 years later: What have we learned and where do we go?MICROSCOPY RESEARCH AND TECHNIQUE, Issue 6 2001Gregory F. Ball Abstract About 25 years ago, Nottebohm and Arnold reported that there are profound male-biased sex differences in volume in selected nuclei in telencephalic portions of the song control system. This review focuses on issues related to the cellular bases of these sex differences in volume and comparative studies that might elucidate the function of this variation between the sexes. Studies utilizing a variety of neurohistological methods in several different species to define the boundaries of two key telencephalic song nuclei HVc and the robust nucleus of the archistriatum (RA) all tend to find a sex difference in volume in agreement with Nissl-defined boundaries. Sex differences in volume in nuclei such as HVc and RA are associated with differences in cell size and cell number. Other attributes of the phenotype of cells in these nuclei are also different in males and females such as the number of cells expressing androgen receptors. Comparative studies have been employed to understand the function of these sex differences in the brain. In some songbird species, females sing rarely or not at all, and the brain nuclei that control song are many times larger volume in males than females. In other species, males and females sing approximately equally, and the brain nuclei that control song are approximately equal between the sexes. Recently, statistical methods have been employed to control for phylogenetic effects while comparing the co-evolution of traits. This analysis indicates that the evolution of sex differences in song has co-evolved with the evolution of sex differences in singing behavior in songbird species. Future studies should focus on the function of the smaller song control nuclei of females and investigate the role these nuclei might play in perception as well as in production. Microsc. Res. Tech. 54:327,334, 2001. © 2001 Wiley-Liss, Inc. [source] Can Comparative Advantage Explain the Growth of us Trade?,THE ECONOMIC JOURNAL, Issue 520 2007Alejandro Cuñat We present a dynamic comparative advantage model in which moderate reductions in import tariffs can generate sizable increases in trade volumes over time. A fall in tariffs has two effects. First, for given factor endowments, it raises the degree of specialisation, leading to a larger volume of trade in the short run. Second, it raises the factor price of each country's abundant factor, leading to diverging paths of relative factor endowments and a rising degree of specialisation. A simulation exercise shows that a fall in tariffs produces a disproportional increase in the trade share of output as in the data. [source] Trading activity in stock index futures markets: The evidence of emerging marketsTHE JOURNAL OF FUTURES MARKETS, Issue 10 2002Yu Chuan Huang This study investigates the trading activity of the Taiwan Futures Exchange (TAIFEX) and Singapore Exchange Derivatives Trading Limited (SGX-DT) Taiwan Stock Index Futures markets by analyzing the intraday patterns of volume and volatility. In addition, the market closure theory, which may explain such patterns, is examined. Overall, the trading pattern appears to be U-shaped for the TAIFEX futures and U+W-shaped for the SGX-DT. For the SGX-DT futures, volatility follows the same pattern as that of the number of price changes. For the TAIFEX futures, however, after the peak at the close of the spot market, the volatility in the TAIFEX futures drops consistently until the end of the day while volatility in the SGX-DT still reaches a smaller peak at the close of the futures market. In addition, a visual inspection of the intraday patterns of these two markets shows that the market closure theory can effectively explain the intraday patterns of these two markets. The empirical results support the market closure theory in that liquidity demand from traders rebalancing their portfolios before and after market closures creates larger volume and volatility at both the open and close. © 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:983,1003, 2002 [source] The ability of breathing system filters to prevent liquid contamination of breathing systems: a laboratory study*ANAESTHESIA, Issue 1 2002APPARATUS The ability of 29 different breathing system filters (five pleated hydrophobic and 24 electrostatic) to prevent the passage of water was assessed. Five, 10 or 20 ml of water was added on to the patient side of the filter during ventilation of a patient model with the filter layer orientated either horizontally or vertically. Water did not pass through the filter layer during any of the 30 tests on the pleated hydrophobic filters. In contrast, water passed through the filter layer in 39 of the 144 tests on the electrostatic filters (27%; 95% CI for difference between the filter types 14,35%; p = 0.0004). For electrostatic filters, a smaller internal volume, a larger volume of water added, and having the filter layer horizontal rather than vertical all significantly increased the probability of water penetration. Although pleated hydrophobic filters would protect the breathing system against liquid contamination, electrostatic filters can also be used, provided the internal volume is chosen appropriately and the filter layer is vertical. [source] Adjuvant and neoadjuvant chemotherapy for Ewing sarcoma family tumors in patients aged between 40 and 60,CANCER, Issue 4 2007Report of 35 cases, comparison of results with 586 younger patients treated with the same protocols in the same years Abstract BACKGROUND. The clinical and pathologic features of 46 patients 40 to 60 years old with Ewing sarcoma family tumor (ESFT) diagnosed at the authors' institute between 1972 and 2000 were reviewed. METHODS. Ten patients with metastatic tumors at presentation went elsewhere for treatment; 35 of 36 remaining cases with localized disease were treated at the authors' institution according to different chemotherapy protocols activated in successive years. In patients with nonmetastatic tumors local treatment was surgery in 9 patients, radiotherapy in 16, and surgery followed by radiotherapy in 10. RESULTS. At follow-up times ranging from 6 and 34 years (mean, 17.8 years), 15 patients (42.9%) remained continuously disease-free, 19 experienced recurrence, and 1 died of chemotherapy-related toxicity. The 5- and 10-year event-free survivals were 42.9% and 35.2%, respectively, and the 5- and 10-year overall survivals were 46.1% and 42.8%, respectively. Comparing this group of patients with 586 cases of younger patients seen in the same period at Rizzoli, the only difference between the 2 groups was a significantly higher rate of tumors located in the soft tissues with a larger volume in the older group. The results achieved were comparable in the 2 groups, although the older group had a lower chemotherapy dose-intensity and a higher rate of WHO grade 4 hematologic toxicity. CONCLUSIONS. For patients with localized disease treated with adjuvant and neoadjuvant chemotherapy the results were essentially comparable in the 2 groups. It is concluded that patients 40 years or older with ESFT should be treated in the same way as younger patients and included in treatment trials for these tumors. Cancer 2007. © 2007 American Cancer Society. [source] When monocytes and platelets compete: The effect of platelet count on the flow cytometric measurement of monocyte CD36,CYTOMETRY, Issue 2 2010W.H. Dzik Abstract Background: Flow cytometric measurement of monocyte surface CD36 is relevant to several conditions including diabetes, cardiovascular disease, lipid disorders, platelet isoimmunization, and susceptibility to P falciparum malaria. CD36 is also strongly expressed on platelets where it is also known as platelet glycoprotein IV. Methods: Whole blood samples, containing identical monocyte concentrations, were adjusted to contain platelets ranging from 20,000/uL to 600,000/uL, were stained with fluorescent-labeled anti-CD36, and analyzed by flow cytometry. Results: CD36 median fluorescent intensity (MFI) observed on monocytes decreased as the platelet concentration in the sample increased with more than a 50% decline in monocyte MFI over the normal range of platelet values. The effect was not abolished by using larger volumes of monoclonal antibody and was observed with different clones of reagent anti-CD36. The findings were most consistent with competition by platelets for the CD36 reagent. Similar findings were observed with antibody to class I HLA. Under defined assay conditions, monocyte CD36 MFI declined with rising platelet concentration in a predictable fashion following an inverse linear relationship. Conclusions: Measurement of CD36 expression on monocytes by flow cytometry in whole blood samples is affected by the sample platelet count. When comparing the monocyte CD36 expression among different individuals, our approach can be used to adjust measured monocyte CD36 expression for the effect of the platelet concentration in the sample. Competition by platelets for monoclonal reagents may occur in other settings when whole blood assays are used and when the target antigen is strongly expressed on both platelets and leukocytes. © 2009 Clinical Cytometry Society [source] Single layer centrifugation of stallion spermatozoa consistently selects the most robust spermatozoa from the rest of the ejaculate in a large sample sizeEQUINE VETERINARY JOURNAL, Issue 7 2010J. M. MORRELL Summary Reasons for performing study: An improvement in sperm quality after single layer centrifugation (SLC) has been seen in previous studies using small sample sizes (for example, n = 10 stallions). There is a need to investigate whether this improvement is repeatable over several breeding seasons with a larger number of stallions (n , 30 stallions). Objective: To make a retrospective analysis of the results of SLC performed on more than 250 sperm samples (176 ejaculates) from 31 stallions in 3 consecutive breeding seasons. Methods: Sperm quality (motility, proportion of morphologically normal spermatozoa and the proportion of spermatozoa with undamaged chromatin) was assessed before and after SLC. Results: All parameters of sperm quality examined were significantly better in sperm samples after SLC than in their unselected counterparts (P<0.001 for each parameter). The yield of spermatozoa obtained after SLC was influenced by the type of extender used and also by the concentration of spermatozoa in the original ejaculate, with fewer spermatozoa being recovered when the loading dose contained a high concentration of spermatozoa. The optimal concentration was approximately 100 × 106/ml. Sperm concentration in the samples loaded on to the colloid influenced the sperm yield while the type of semen extender affected sperm quality and survival. Furthermore, the scaled-up SLC method was found to be suitable for use with a range of ejaculates, with similar sperm kinematics being observed for standard and scaled-up preparations. Conclusions: SLC consistently improved the quality of stallion sperm samples from a large number of ejaculates. The method could be scaled-up, allowing larger volumes of ejaculate to be processed easily from a wide range of stallions. [source] Constructal tree-shaped paths for conduction and convectionINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 4 2003Adrian Bejan Abstract This lecture reviews a series of recent results based on the geometric minimization of the resistance to flow between one point (source, sink) and a volume or an area (an infinity of points). Optimization is achieved by varying the geometric features of the flow path subject to volume constraints. The method is outlined by using the problem of steady volume-point conduction. Optimized first is the smallest elemental volume, which is characterized by volumetric heat generation in a low-conductivity medium, and one-dimensional conduction through a high-conductivity ,channel'. Progressively larger volumes are covered by assemblies of previously optimized constructs. Tree-shaped flow structures spring out of this objective and constraints principle. Analogous problems of fluid flow, and combined heat and fluid flow (convection, trees of fins) are also discussed. The occurrence of similar tree structures in nature may be reasoned based on the same principle (constructal theory) (Bejan, 2000). Copyright © 2003 John Wiley & Sons, Ltd. [source] Effect of heat treatment on Cronobacter spp. in reconstituted, dried infant formula: preparation guidelines for manufacturersLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2009P.-C. Chen Abstract Aim:, To explore safe guidelines for manufacturers and consumers to prepare, handle and store dry infant formula (DIF) to protect infants against Cronobacter spp. Methods and Results:, Selected strains (2.45, FSM 293, ATCC-12868, FSM-271) screened from 68 strains of Cronobacter spp. were used to study growth and survival in commercial DIF. Prototype growth patterns in Enterobacteriaceae enrichment broth (EEB) containing a cocktail comprised of ATCC 12868, ATCC 29004, ATCC 29544 and ATCC 51329 showed a rapid increase in cell count (2·0 log10 to 6·2 log10 CFU ml,1). Infant formula provided a better protective environment for the cells of Cronobacter strains than did buffered peptone water. Experiments on survival in inoculated (104,106 CFU ml,1) reconstituted infant formula (RIF), preparation temperature, the effect of preparation volume (one-serving or two-serving) and effect of storage at room temperature for up to 10 h provided information to develop consumer guidelines for DIF preparation and handling. Conclusions:, Reconstituted DIF in water at >70°C in larger volumes, minimizing storage time before feeding and storing unused reconstituted formulate at <4°C, may reduce the risk of Cronobacter infection in infants. Significance and Impact of the Study:, Meningitis, necrotizing enterocolitis and bacteremia in premature babies has been linked to contaminated milk powder and DIF; better handling practices may improve the safety of these foods for neonates. [source] Sexual dimorphism of vocal control nuclei in budgerigars (Melopsittacus undulatus) revealed with Nissl and NADPH-d stainingTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2005Steven E. Brauth Abstract Nissl staining and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry were used to explore the existence of sexual dimorphism in vocal control nuclei of adult budgerigars (Melopsittacus undulatus), a parrot species capable of lifelong vocal learning. Behavioral studies indicate that adult males possess larger vocal repertoires than adult females and learn new calls more quickly. The results of the present study show that the volumes of all vocal nuclei, as measured using both Nissl-stained and NADPH-d-stained material, as well as the total numbers of NADPH-d neurons, were 35,110% greater in males. Furthermore, all vocal nuclei exhibit conspicuous NADPH-d staining compared to surrounding fields in both adult males and females. Nevertheless, there were no significant gender differences in either the intensity of neuropil staining or the densities of NADPH-d neurons in vocal nuclei. Moreover NADPH-d neuron somal shapes were similar in males and females. Diameters of NADPH-d neurons in vocal nuclei were 8.5,32% larger in males than in females. Greater size of NADPH-d neuronal somata in males may be a general property of this cell type in budgerigars because a similar gender difference was found in a visual nucleus, the entopallium, which is not directly associated with the vocal control system and does not exhibit sexual dimorphism in total volume or total NADPH-d neuron numbers. Taken together, the results of the present study favor the hypothesis that superior lifelong vocal learning ability in male budgerigars rests largely on larger volumes of vocal control nuclei in males rather than on sexual dimorphism in the internal composition of vocal nuclei. J. Comp. Neurol. 484:15,27, 2005. © 2005 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||