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Selected AbstractsSpatial and temporal scaling in habitat utilization by klipspringers (Oreotragus oreotragus) determined using giving-up densitiesAUSTRAL ECOLOGY, Issue 5 2009DAVE J. DRUCE Abstract An animal's pattern of habitat use can reveal how different parts of its environment vary in quality based on the costs (such as predation risk) and benefits (such as food intake) of using each habitat. We studied klipspringer habitat use in Augrabies Falls National Park, South Africa using giving-up densities (GUDs; the amount of food remaining in a resource patch following exploitation) in experimental food patches. We tested hypotheses related to how salient habitat variables might influence klipspringers' perceptions of foraging costs. At small spatial scales (3,4 m), klipspringer GUDs did not vary with cover and open microhabitats, or with the four cardinal aspects (shading) around shrubs. Adding water adjacent to food patches did not influence GUDs, showing that water is not a limiting complementary resource to food. Generally, klipspringers do not appear to be physiologically constrained. There was no difference in GUDs between four daily time periods, or between summer and winter; however, a significant interaction effect of time-of-day with season resulted from GUDs during the midday time period in winter being significantly higher (perceived value lower) than during the same time period in summer. At moderate spatial scales (10,60 m), klipspringer GUDs increased with distance from rocks because of increased predation risk. Based on GUDs collected at the largest scale (two 4.41-ha grids), klipspringers preferred foraging at greater distances from drainage lines and on pebble and cobble substrates. Overall, this study has shown the efficacy of measuring GUDs to determine klipspringers' habitat utilization while foraging. [source] Beta-cell function evaluated by HOMA as a predictor of secondary sulphonylurea failure in Type 2 diabetesDIABETIC MEDICINE, Issue 7 2001M. J Taverna Abstract Background and aims Secondary failure to oral hypoglycaemic agents, a common evolution of long-standing Type 2 diabetes, is usually assessed by non-standardized indices requiring fine clinical assessment, including hyperglycaemia resistant to maximum doses of sulphonylureas despite appropriate diet and follow-up. The goal of this study was to evaluate if HOMA, a modelized plasma insulin/glucose ratio allowing simple evaluation of residual insulin secretion and sensitivity, is a better predictor of the insulin requiring stage than clinical indices. Materials and methods HOMA was measured in 84 Type 2 diabetic patients aged 58 ± sd 6 years, with diabetes duration 11 ± 4 years, hospitalized because of hyperglycaemia resistant to maximal doses of sulphonylureas (e.g. glibenclamide ,,15 mg/day), with no apparent external reason for hyperglycaemia. Despite reinforced appropriate diet recommendations, 62 of these patients remained hyperglycaemic (insulin-requiring group). Results Age, duration of diabetes, body mass index (BMI) and HOMA value for insulin sensitivity (71 ± 6% vs. 76 ± 7%, normal values 59,161%) were comparable in the two groups. HbA1c was higher (10.0 ± 0.2% vs. 8.3 ± 0.3%, P < 0.001) and HOMA insulin secretion values lower (25 ± 2% vs. 43 ± 6%, normal values 70,150%, P < 0.01) in the insulin-requiring group. Of the following potential predictors: HbA1c >,8%, duration of diabetes ,,10 years, HbA1c combined with diabetes duration, insulin sensitivity ,,40%, insulin secretion ,,20%, the latter showed the best positive predictivity (86% patients with low insulin secretion were insulin-requiring). Conclusions (i) HOMA is a simple and good predictor of the insulin-requiring stage in Type 2 diabetes mellitus; (ii) this stage of diabetes is characterized by a further decline of insulin secretion rather than of insulin sensitivity. Diabet. Med. 18, 584,588 (2001) [source] Field-amplified sample injection-micellar electrokinetic capillary chromatography for the analysis of bisphenol A, bisphenol F, and their diglycidyl ethers and derivatives in canned soft drinksELECTROPHORESIS, Issue 9 2010Héctor Gallart-Ayala Abstract Conditions were established for the separation and analysis of bisphenol A, bisphenol F, and their diglycidyl ethers by micellar electrokinetic capillary chromatography (MECC). Good resolution was obtained for all compounds, although in order to achieve the separation of ortho,ortho, ortho,para, and para,para isomers of bisphenol F diglycidyl ether (BFDGE), BFDGE·2H2O and BFDGE·2HCl, it was necessary to use a 25,,m id fused silica capillary. To increase sensitivity, a field-amplified sample injection (FASI)-MECC method was developed using 10,mM SDS solution as injection matrix and a 75,,m id fused silica capillary. Instrumental quality parameters such as LODs (<55,,g/L with standards), linearity (r2>0.999), and run-to-run and day-to-day precisions (RSD values lower than 12.5%) were determined. Finally, the suitability of the FASI-MECC method for the analysis of bisphenol A, bisphenol F, and their diglycidyl ethers in canned soft drinks was evaluated. Quantitation was performed by matrix-matched calibration using a plastic-bottled isotonic drink as matrix. The results showed that FASI-MECC is an economic method for the screening and quantitation of these kinds of compounds in soft drink beverages, with no loss of reproducibility, and effective at concentrations lower than the specific migration level values established by the European Union. [source] Capillary electrophoresis using copolymers of different composition as physical coatings: A comparative studyELECTROPHORESIS, Issue 5-6 2006Guillaume L. Erny Abstract In this work, a comparative study on the use of different polymers as physically adsorbed coatings for CE is presented. It is demonstrated that the use of ad hoc synthesized polymers as coatings allows tailoring the EOF in CE increasing the flexibility of this analytical technique. Namely, different polymers were synthesized at our laboratory using different percentages of ethylpyrrolidine methacrylate (EpyM) and N,N -dimethylacrylamide (DMA). Thus, by modifying the percentage of EpyM and DMA monomers it is possible to manipulate the positive charge of the copolymer, varying the global electrical charge on the capillary wall and with that the EOF. These coated capillaries are obtained by simply flushing a given EpyM,DMA aqueous solution into bare silica capillaries. It is shown that by using these coated capillaries at adequate pHs, faster or more resolved CE separations can be achieved depending on the requirements of each analysis. Moreover, it is demonstrated that these coated capillaries reduce the electrostatic adsorption of basic proteins onto the capillary wall. Furthermore, EpyM,DMA coatings allow the reproducible chiral separation of enantiomers through the partial filling technique (PFT). The EpyM,DMA coated capillaries are demonstrated to provide reproducible EOF values independently of the pH and polymer composition with%RSD values lower than 2% for the same day. It is also demonstrated that the coating procedure is reproducible between capillaries. The compatibility of this coating protocol with CE in microchips is discussed. [source] Allochthonous and autochthonous particulate organic matter in floodplains of the River Danube: the importance of hydrological connectivityFRESHWATER BIOLOGY, Issue 2 2003Thomas Hein SUMMARY 1.,The elemental composition, the proportion of living organic carbon and the carbon stable isotope signatures of particulate organic matter (POM) were determined in a large river floodplain system in order to elucidate the major carbon sources in relation to the hydrological conditions over a 13-month period. 2.,Two floodplain segments and the main channel of the River Danube downstream of Vienna (Austria), were compared on the basis of discharge and water age estimations. The more dynamic floodplain was connected to the main channel for 46% of the study period and drained up to 12% of total discharge at high water. 3.,The mean C : N ratio and ,13C signature of the POM increased from the floodplain site that was more isolated from the river (6.6; ,33,) to the main channel (8.4; ,25,). At the dynamic floodplain site, the C : N ratio and the ,13C signature of the POM increased with hydrological connectivity (expressed as water age). 4.,Only during flood events (4% frequency of occurrence), a considerable input of riverine POM was observed. This input was indicated by a C : N ratio of the POM pool of more than 10, the amount of detrital carbon (>80% of the total POM pool) and a ,13C signature of POM of more than ,25, in the dynamic floodplain. 5.,Plankton derived carbon, indicated by C : N ratios less than eight and ,13C values lower than ,25,, dominated the particulate organic carbon (POC) pool at both floodplain sites, emphasising the importance of local (autochthonous) production. Phytoplankton was the major plankton compartment at the dynamic site, with highest biomasses at medium water ages. 6.,At the dynamic floodplain site, the Danube Restoration Project has enhanced the duration of upstream surface connection with the main channel from 4 to 46% frequency of occurrence. Therefore, the export of living POC to the main channel is now established during phases of maximum phytoplankton production and doubled the estimated total export of non-refractory POM compared with prerestoration conditions. [source] Original article: Apparent thermal diffusivity estimation for the heat transfer modelling of pork loin under air/steam cooking treatmentsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2010Massimiliano Rinaldi Summary Apparent thermal diffusivity linear functions vs. product temperature were estimated for pork cooked under two different treatments (forced convection, FC and forced convection/steam combined, FC/S) at 100, 110, 120 and 140 °C by means of experimental time,temperature data and a developed finite-difference algorithm. Slope and intercept of each function were employed to calculate apparent thermal diffusivity at 40, 55 and 70 °C. Generally, FC/S treatments gave significantly higher apparent thermal diffusivities in comparison with FC conditions. Apparent thermal diffusivities were used to develop a model for cooking time and final core temperature prediction on the basis of oven setting. The model was validated by means of additional cooking tests performed at different temperatures of those employed for model development. Root mean square error values lower than 3.8 °C were obtained comparing predicted and experimental temperature profiles. Percentage errors lower than 3.1% and 3.5% were, respectively, obtained for cooking times and final core temperatures. [source] The utility of the Sysmex XE-2100 analyzer's NEUT-X and NEUT-Y parameters for detecting neutrophil dysplasia in myelodysplastic syndromesINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2010J. R. FURUNDARENA Summary The diagnosis of myelodysplastic syndromes (MDS) is based on morphological changes in the blood and bone marrow. The parameters NEUT-X and NEUT-Y of the Sysmex XE-2100 analyzer could help detect neutrophil dysplasia. A control group of 50 patients, along with 50 postpartum patients, 50 anemias, 50 leukopenias, 50 patients with microscopically visible hypergranulated neutrophils and 50 MDS patients were assessed. The NEUT-X and NEUT-Y values (mean ± SD) for the control group were 1346 ± 28.2 and 420 ± 19.3, respectively, with the anemia and leukopenia groups giving similar values. The postpartum and hypergranulated neutrophils groups presented higher values (P < 0.05), whereas the values in the MDS group were 1286 ± 72.8 and 385 ± 50.9 (P < 0.05), respectively. There were no differences between the morphological MDS types. The NEUT-X and NEUT-Y values in MDS patients with optical hypogranulation were significantly lower than for MDS patients without optical hypogranulation. NEUT-X and NEUT-Y values lower than 1298 and 398, respectively, would have a specificity for detecting MDS of 94% and 91% and would detect 60% and 56% of cases, respectively, whereas they would detect 75% and 74%, respectively, of MDS cases with optical hypogranulation. NEUT-X and NEUT-Y parameters can be used to detect neutrophil dysplasia arising from MDS and chronic myelomonocytic leukemia. [source] Evaluation of Liquid Smoke Treated Ready-to-Eat (RTE) Meat Products for Control of Listeria innocua M1JOURNAL OF FOOD SCIENCE, Issue 4 2008P.J. Milly ABSTRACT:, Liquid smoke fractions (S1, S2, S3, and S4) were applied on ready-to-eat (RTE) meat products to control the growth of inoculated Listeria innocua M1. Turkey rolls and roast beef products were dipped in liquid smoke, surface inoculated with L. innocua M1 (102 CFU/25 cm2 RTE meat surface), vacuum packaged, and stored at 4 °C. Section 8.5 of USDA's detection and isolation procedure for L. monocytogenes was employed in conjunction with a Micro-IDÔ system for L. innocua M1 identification (ID). Products treated with smoke fractions S1, S2, and S3 were negative for L. innocua M1 at 2 and 4 wk during incubation at 4 °C. Products treated with S4 were positive for L. innocua M1 immediately following inoculation and after storage for 2 and 4 wk. Smoke fractions S1, S2, and S3 exhibited pH values lower than 4.6, acidity values higher than 1.5%, and carbonyl concentrations higher than 110 mg/mL. All liquid smoke fractions contained similar phenol concentrations (0.3 to 0.6 mg/mL), suggesting that phenols may have a limited role in the bactericidal effects of liquid smoke fractions against specific microorganisms. [source] Early wheeze as reported by mothers and lung function in 4-year-olds.PEDIATRIC PULMONOLOGY, Issue 9 2010Prospective cohort study in Krakow Abstract The purpose of the study was to check the hypothesis that early wheezing as reported by mothers would be associated with reduced lung function in 4-year olds. Study participants were recruited prenatally, as part of a prospective cohort study on the respiratory health of young children exposed to various ambient air pollutants. After delivery, infants were followed over 4 years and the interviewers visited participants at their home to record respiratory symptoms every 3 months in the child's first 2 years of life and every 6 months in the 3rd and 4th years. In the 4th year of follow-up, children were invited for standard lung function testing by spirometry quantified by forced vital capacity (FVC), forced expiratory volume in 1,sec (FEV1), and forced expiratory volume in 0.5,sec (FEV0.5) levels. Out of 258 children attending spirometry testing 139 performed at least two acceptable exhalation efforts. Cohort children with acceptable spirometric measurements did not differ with respect to wheezing experience and exposure characteristics from those without. The study shows that episodic wheeze was reported in 28.1% of 4-year olds, 6.5% had transient wheeze, and 4.3% had recurrent wheeze. There was an increased frequency of wheezing symptoms and their duration in transient and recurrent wheezers. Adjusted multivariable regression models for gender and height showed that children who reported more than two episodes of wheezing at any point over the follow-up had FVC values lower by 120.5,ml (P,=,0.016) and FEV1 values lower by 98.3,ml (P,=,0.034) compared to those who did not report any wheezing; children experiencing more than 10 wheezing days by age 4 showed FVC deficit of 87.4,ml (P,=,0.034) and FEV1 values of 65.7,ml (P,=,0.066). The ratios of FEV1/FVC%, and FEV0.5/FVC% were neither associated with wheezing episodes nor wheezing days. In recurrent wheezers, lung function decrement amounted to 207,ml of FVC, 175,ml of FEV1, and 104,ml of FEV0.5. In conclusion, our findings show that wheezing experience during early postnatal life may be associated with lung function deficit of restrictive character in preschool children and detailed history of wheeze in early postnatal life, even though not physician-confirmed, may help define the high risk group of children for poor lung function testing. Pediatr. Pulmonol. 2010; 45:919,926. © 2010 Wiley-Liss, Inc. [source] Changes in the natural abundance of 13CO2/12CO2 in breath due to lipopolysacchride-induced acute phase responseRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2009Daniel E. Butz The natural abundance of carbon-13 in blood proteins increases during the cachectic state and may be a biomarker for disease status. We hypothesized a corresponding drop in the relative abundance of 13C in breath CO2. Using the lipopolysacchride (LPS)-induced endotoxemia model of the acute cachectic state, we demonstrated that the acute phase response causes shifts in the stable isotopes of carbon in exhaled CO2 (13CO2/12CO2 delta value) shortly after administration of LPS while glucocorticoid treatment does not. Mice were injected with LPS and stable isotopes of blood amino acids and carbon in exhaled CO2 were monitored. An increase in the relative isotopic mass of serum alanine, proline and threonine was observed at 3,h after LPS injection. Breath delta values began dropping immediately after administration of LPS, and were 4,5 delta values lower than those of the control animals by 2.5,h after injection. A corresponding drop in delta value was not observed with dexamethasone treatment. Thus protein synthesis during the acute phase response probably caused the fractionation of stable isotopes observed in the plasma amino acids and in exhaled breath 13CO2 delta values. The exhaled breath 13CO2 delta value may be a valuable real-time biomarker of cachexia associated with an acute phase response due to endotoxemia. Copyright © 2009 John Wiley & Sons, Ltd. [source] Voltage-dependent and -independent titration of specific residues accounts for complex gating of a ClC chloride channel by extracellular protonsTHE JOURNAL OF PHYSIOLOGY, Issue 7 2009María Isabel Niemeyer The ClC transport protein family comprises both Cl, ion channel and H+/Cl, and H+/NO3, exchanger members. Structural studies on a bacterial ClC transporter reveal a pore obstructed at its external opening by a glutamate side-chain which acts as a gate for Cl, passage and in addition serves as a staging post for H+ exchange. This same conserved glutamate acts as a gate to regulate Cl, flow in ClC channels. The activity of ClC-2, a genuine Cl, channel, has a biphasic response to extracellular pH with activation by moderate acidification followed by abrupt channel closure at pH values lower than ,7. We have now investigated the molecular basis of this complex gating behaviour. First, we identify a sensor that couples extracellular acidification to complete closure of the channel. This is extracellularly-facing histidine 532 at the N-terminus of transmembrane helix Q whose neutralisation leads to channel closure in a cooperative manner. We go on to show that acidification-dependent activation of ClC-2 is voltage dependent and probably mediated by protonation of pore gate glutamate 207. Intracellular Cl, acts as a voltage-independent modulator, as though regulating the pKa of the protonatable residue. Our results suggest that voltage dependence of ClC-2 is given by hyperpolarisation-dependent penetration of protons from the extracellular side to neutralise the glutamate gate deep within the channel, which allows Cl, efflux. This is reminiscent of a partial exchanger cycle, suggesting that the ClC-2 channel evolved from its transporter counterparts. [source] Design of Affinity Tags for One-Step Protein Purification from Immobilized Zinc ColumnsBIOTECHNOLOGY PROGRESS, Issue 1 2000Richard S. Pasquinelli Affinity tags are often used to accomplish recombinant protein purification using immobilized metal affinity chromatography. Success of the tag depends on the chelated metal used and the elution profile of the host cell proteins. Zn(II)-iminodiacetic acid (Zn(II)-IDA) may prove to be superior to either immobilized copper or nickel as a result of its relatively low binding affinity for cellular proteins. For example, almost all Escherichiacoli proteins elute from Zn(II)-IDA columns between pH 7.5 and 7.0 with very little cellular protein emerging at pH values lower than 7.0. Thus, a large portion of the Zn(II)-IDA elution profile may be free of contaminant proteins, which can be exploited for one-step purification of a target protein from raw cell extract. In this paper we have identified several fusion tags that can direct the elution of the target protein to the low background region of the Zn(II)-IDA elution profile. These tags allow targeting of proteins to different regions of the elution profile, facilitating purification under mild conditions. [source] 4354: Relationship between flicker FDF perimetry and standard automated perimetryACTA OPHTHALMOLOGICA, Issue 2010P CALVO PEREZ Purpose To compare the main indices of flicker FDF perimetry (FDF, Heidelberg Engineering, Germany) with standard automated perimetry (SAP). Methods Twenty healthy subjects and twenty-three glaucoma patients were prospectively and consecutively selected. Glaucomatous patients had an intraocular pressure higher than 21 mmHg and glaucomatous optic disc appearance. All of them underwent at least one reliable perimetry with each device. SAPs were performed with a FDF perimeter (24-2 ASTA-Standard test) and Humphrey perimeter (Carl Zeiss (24-2 SITA standard algorithm). The Kolmogorov Smirnov test was applied to check that the data were normally distributed. Only one eye per subject was included in the study. Pearson correlations were calculated between both devices : mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI). Results Mean age was 58.41±12,4 years. MD of SAP was -2.82 ± 4.8 dB, and MD of FDF was -4.47 ± 4.8 dB (p=0.123); PSD of SAP was 3.11 ± 3.1, and PSD of FDF was 3.14 ± 1.4 (p = 0.953). The correlations between MDs were 0.521 (p<0.001) and between PSDs were 0.350 (p<0.001) Conclusion Moderate correlations were found between main visual field indices both devices. Altough no differences were found, FDF tends to present MD values lower than Humphrey. [source] Synthesis and Biological Evaluation of Novel 4-Substituted 1-{[4-(10,15,20-Triphenylporphyrin-5-yl)phenyl]methylidene}thiosemicarbazides as New Class of Potential Antiprotozoal AgentsCHEMISTRY & BIODIVERSITY, Issue 5 2008Abdul Abstract A novel series of 4-substituted 1-{[4-(10,15,20-triphenylporphyrin-5-yl)phenyl]methylidene}thiosemicarbazide, 4a,4n, was synthesized in 9,21% yield by the condensation of 4-(10,15,20-triphenylporphyrin-5-yl)benzaldehyde (3) with various substituted thiosemicarbazides in presence of catalytic amount of AcOH. These compounds were assayed for in vitro antiamoebic activity, and the results showed that out of 14 compounds 9 were found with IC50 values lower than metronidazole corresponding to 1.05- to 4.7-fold increase in activity. MTT Assay showed that all the compounds are nontoxic to human kidney epithelial cell line. 4-(m -Toluidinyl)-1-{[4-(10,15,20-triphenylporphyrin-5-yl)phenyl]methylidene}thiosemicarbazide (4h) showed the highest antiamoebic activity with least cytotoxicity. Some of the compounds were screened for their antimalarial activities and ability to inhibit , -haematin formation, but none of them showed an activity better than chloroquine and quinine. Only one compound out of six showed an activity comparable to standard drug. [source] Noninvasive peripheral perfusion index as a possible tool for screening for critical left heart obstructionACTA PAEDIATRICA, Issue 10 2007A de-Wahl Granelli Abstract Aim: Peripheral perfusion index (PPI) has been suggested as a possible method to detect illness causing circulatory embarrassment. We aimed to establish the normal range of this index in healthy newborns, and compare it with newborns with duct-dependent systemic circulation. Design: We conducted a case,control study. Setting: Our study population comprised 10 000 prospectively recruited newborns from Västra Götaland, Sweden. Patients: A total of 10 000 normal newborns and 9 infants with duct-dependent systemic circulation (left heart obstructive disease [LHOD] group) participated in the study. Methods: We conducted single pre- and postductal measurements of PPI with a new generation pulse oximeter (Masimo Radical SET) before discharge from hospital. Results: PPI values between 1 and 120 h of age show an asymmetrical, non-normal distribution with median PPI value of 1.70 and interquartile range of 1.18,2.50. The 5th percentile = 0.70 and 95th percentile = 4.50. All infants in the LHOD group had either pre- or postductal PPI below the interquartile range, and 5 of 9 (56%) were below the 5th percentile cut-off of 0.70 (p < 0.0001, Fisher's exact test). A PPI value <0.70 gave an odds ratio for LHOD of 23.75 (95% CI 6.36,88.74). Conclusion: PPI values lower than 0.70 may indicate illness and a value <0.50 (1st percentile) indicates definite underperfusion. PPI values might be a useful additional tool for early detection of LHOD. [source] | ||||||||||||||||