Effect Of Different Stages Research Articles

Lactation curve models for estimating gene effects over a timeline

The effects of genes are commonly estimated using random regression models based on test-day data and only give a general gene effect. Alternatively, lactation curve models can be used to estimate biological and environmental effects, or to predict missing test-day data and perform breeding value estimation. This study combines lactation curve models and estimation of gene effects to represent gene effects in different stages of lactation. The lactation curve models used were based on the Wood, Wilmink, and Ali and Schaeffer models. A random regression test-day model was used to compare estimated gene effects with the results of commonly used models. The well-characterized DGAT1 gene with known effects on milk yield, milk fat, and milk protein production was chosen to test this new approach in a Holstein-Friesian dairy cattle population. The K232A polymorphism and the promoter VNTR (variable number of tandem repeats) of the DGAT1 gene were used. All lactation curve models predicted the production curves sufficiently. Nevertheless, for predicting genotype effects, the Wilmink curve indicated the closest fit to the data. This study shows that the characteristic gene effects for DGAT1 genotypes occur after lactation d 40, which might be explained by a link to other genes affecting metabolic traits. Furthermore, allele substitution effects of allele K of the K232A locus showed that the typical effect of low milk and protein yield is due mainly to a lower overall production level, whereas the higher fat and protein content is reached by increased production toward its peak and fat yield is increased because of a higher production after this peak. Predicting gene effects with production curves gives better insight into the timeline of gene effects. This can be used to form genetic groups, in addition to feeding groups, for managing livestock populations in a more effective way.

Callosal atrophy in mild cognitive impairment and Alzheimer's disease: Different effects in different stages

Alzheimer's Disease (AD) is a neurodegenerative disorder that mainly affects grey matter (GM). Nevertheless, a number of investigations have documented white matter (WM) pathology associated with AD. The corpus callosum (CC) is the largest WM fiber bundle in the human brain. It has been shown to be susceptible to atrophy in AD mainly as a correlate of Wallerian degeneration of commissural nerve fibers of the neocortex. The aim of this study was to investigate which callosal regions are affected and whether callosal degeneration is associated with the stage of the disease. For this purpose, we analyzed high-resolution MRI data of patients with amnesic mild cognitive impairment (MCI) (n=20), mild AD (n=20), severe AD (n=10), and of healthy controls (n=20). Callosal morphology was investigated applying two different structural techniques: mesh-based geometrical modeling methods and whole-brain voxel-based analyses. Our findings indicate significant reductions in severe AD patients compared to healthy controls in anterior (genu and anterior body) and posterior (splenium) sections. In contrast, differences between healthy controls and mild AD patients or amnesic MCI patients were less pronounced and did not survive corrections for multiple comparisons. When correlating anterior and posterior WM density of the CC with GM density of the cortex in the severe AD group, we detected significant positive relationships between posterior sections of the CC and the cortex. We conclude that callosal atrophy is present predominantly in the latest stage of AD, where two mechanisms might contribute to WM alterations in severe AD: the Wallerian degeneration in posterior subregions and the myelin breakdown process in anterior subregions.

How Can Education Policy Improve Income Distribution?: An Empirical Analysis of Education Stages and Measures on Income Inequality

This paper examines the individual effects of primary, secondary and higher education on income distribution, using different measures of investment rates in education: enrollment rates, public expenditures and public expenditures per student, in each education stage. The panel data method is utilized in estimating the effects of different stages and measures of investment rates in education on income inequality across countries and among sample splits for developed and less developed countries since 1960. The results reveal that expenditures per student in primary education highly significantly improve income distribution especially globally and for less developed countries. Moreover, secondary education, for enrollment rates, and public expenditures particularly among already developed countries, has statistically significant equalizing effects. These results imply that education policy would improve income distribution by ensuring that expenditures per student in primary school are kept up with increases in student cohorts, and by promoting enrollment in secondary education.

Correlation of electrical resistivity, electrical conductivity and soil parameters at a long‐term fertilization experiment

Geophysical methods are progressive, non‐destructive but indirect techniques for characterization of soil properties and mapping of soil heterogeneities. Geophysical surveys for soil mapping lead generally to ambiguous results since geophysical parameters are influenced by several soil properties, e.g., organic content, clay content and bulk density.The investigations presented here focus on the effect of different stages of organic content on DC‐geoelectrics and electromagnetic induction (EMI) at a long‐term fertilization experiment. This experiment gives, after 105 years running, an excellent opportunity to study the correlations between electrical resistivity, apparent electrical conductivity and soil parameters. Results from DC‐geoelectrical measurements (profile length 80–160 m, electrode distance 0.5 m) twice, in August after harvest and in January during black fallow period, are presented. Additionally electromagnetical investigations were conducted in January.Correlations of resistivity and carbon input into the soil are significant and very strong; especially in January with but contradictive in summer and winter. The analysis of resistivity and apparent electrical conductivity is critical since bulk density and water storage capacity is influenced by fertilization and plant growth. Interpretation of a combination of DC‐geoelectrics and electromagnetical techniques on agricultural areas has to be done with respect to management aspects.

Stage of endometriosis does not affect intrauterine insemination outcome

OBJECTIVE: There is evidence that endometriosis can and does decrease fertility. Treatment options include medical therapy, surgical intervention, and assisted reproduction. The relative value of ART based on the stages of endometriosis, however, is untested. The aim of this study was to evaluate the effects of different stages of endometriosis on the outcome of intrauterine insemination (IUI).DESIGN: Retrospective study.MATERIALS AND METHODS: The study group consisted of 114 women with laparoscopically diagnosed endometriosis undergoing IUI between 2003-2005 and 458 non-endometriosis patients (control group) including tubal, ovulatory, male, cervical and unexplained infertility. A total of 1596 cycles were observed and the number of IUI cycles per patient ranged from 1 to 6. Ovulation induction was done using clomiphine citrate (CC), controlled ovarian hyperstimulation by pure FSH and/or HMG or both CC+FSH. 10,000 IU of hCG was given when the dominant follicle reached maturity. A single IUI was performed 36 h after hCG administration. The primary outcomes were: clinical pregnancy rate, miscarriage rate and the number of cycles needed to achieve pregnancy.RESULTS: Women with endometriosis required significantly higher gonadotropin doses compared with non-endometriosis women p<0.001. Patients with endometriosis showed lower pregnancy rates (10.2% vs. 22.0% per cycle) as well as higher miscarriage rates (30.0% vs. 11.2% per cycle) than non-endometriosis patients (p = 0.001). Mean number of IUI cycles per patient were comparable among the 4 stages in non-endometriosis and endometriosis patients.Table 1Endometriosis and IUI outcomesVariableNon-endometriosisEndometriosisP-valueGonadotropin (days)9.63.3<0.001Cycles/patient (mean)2.812.690.89Cycles/pregnant patient2.872.960.85Pregnancy/patient/per cycle) (%)266/ 458 (58.1 and 22.0%)47/ 114 (41.2 and 14.3%)0.001Miscarriage/ patient/cycle) (%)126/ 458 (27.5 and 11.1%)64/ 114 (56.1% and 30.0%)0.001P<0.05 was considered significant for hCG dose using the Wilcoxon rank sum test and for pregnancy and miscarriage rates per patient using chi-square test. Open table in a new tab OBJECTIVE: There is evidence that endometriosis can and does decrease fertility. Treatment options include medical therapy, surgical intervention, and assisted reproduction. The relative value of ART based on the stages of endometriosis, however, is untested. The aim of this study was to evaluate the effects of different stages of endometriosis on the outcome of intrauterine insemination (IUI). DESIGN: Retrospective study. MATERIALS AND METHODS: The study group consisted of 114 women with laparoscopically diagnosed endometriosis undergoing IUI between 2003-2005 and 458 non-endometriosis patients (control group) including tubal, ovulatory, male, cervical and unexplained infertility. A total of 1596 cycles were observed and the number of IUI cycles per patient ranged from 1 to 6. Ovulation induction was done using clomiphine citrate (CC), controlled ovarian hyperstimulation by pure FSH and/or HMG or both CC+FSH. 10,000 IU of hCG was given when the dominant follicle reached maturity. A single IUI was performed 36 h after hCG administration. The primary outcomes were: clinical pregnancy rate, miscarriage rate and the number of cycles needed to achieve pregnancy. RESULTS: Women with endometriosis required significantly higher gonadotropin doses compared with non-endometriosis women p<0.001. Patients with endometriosis showed lower pregnancy rates (10.2% vs. 22.0% per cycle) as well as higher miscarriage rates (30.0% vs. 11.2% per cycle) than non-endometriosis patients (p = 0.001). Mean number of IUI cycles per patient were comparable among the 4 stages in non-endometriosis and endometriosis patients. P<0.05 was considered significant for hCG dose using the Wilcoxon rank sum test and for pregnancy and miscarriage rates per patient using chi-square test.

Ripening stage and drying method affecting colour and quality attributes of Ziziphus mauritiana fruits in Zimbabwe

Ziziphus mauritiana Lamk. (Ber) fruit is harvested at different stages of ripening in the Zambezi valley of Zimbabwe. We hypothesize that the organoleptic quality attributes of fruits depend on post-harvest drying method and ripening stage at harvest. This study was carried out to evaluate the effect of different stages of ripening on the quality of Z. mauritiana fruits during drying. The fruits were graded into green, yellowish-brown and brown categories and these formed the treatments. Some of these fruits were blanched before drying for 1, 2 and 3 weeks under the solar dryer and the open sun drying methods. The green fruits lost significantly (P<0.001) more weight during drying than the yellowishbrown and brown fruits regardless of the drying methods. The development of browning was more on the brown fruits than the green and yellowish-brown fruits.

Effect of processing stages of apple juice concentrate on patulin levels

The effects of different stages of apple juice concentrate production on patulin levels were investigated. Patulin was detected in all samples analyzed in concentrations ranging from 56 to 653 μg/L. Apple paste resulted from milling process had high levels of patulin. The results of this study indicate that it is possible to reduce patulin level in apple juices. After pasteurization, enzymatic treatment, microfiltration and evaporation processes, the mean loss of patulin was 39.6, 28.3, 20.1 and 28.4%, respectively. When apple juices concentrate were diluted from 69 to 12°Brix to consume, patulin content ranged from 15 to 46 μg/L. Patulin content in all juice samples was lower than the limit of 50 μg/L considered acceptable by the Codex Alimentarius Commission. But if consider the maximum permitted concentration established for apple products intended for infants and young children by The Commission of the European Communities all samples were found to exceed patulin concentration of 10 μg/L.

Professionalization and Its Effect on Health Locus of Control Among Indian Dental Students

The objectives of this study were to assess the effect of different stages of professionalization on the health locus of control of students in an Indian dental school and to describe possible factors that may influence the health locus of control among dental students. The multidimensional health locus of control (MHLC) scale was distributed to 372 undergraduate dental students at one school in India, and 325 students returned completed forms. Comparison of the mean scores for the three MHLC subscales (Internal, Chance, and Powerful Others) from first year to final year showed that the mean Internal score remained unchanged in the first and second year, but decreased in the third year and rose sharply in the final year. The mean score for the Internal subscale was consistently higher, followed by the mean scores for Powerful Others in all the years of study. No significant differences were observed between mean scores of the MHLC subscales when compared with gender, previous treatment histories, and missing appointments. Those with self-perceived oral problems were found to have a lower internal locus of control than those who did not report any. The findings of this study provided credible support for the MHLC model in assessing changing health attitudes and may provide a basis for dental educators to effect changes in the locus of control among students.

Effects of Different Stages of Endometriosis on the Outcome of In Vitro Fertilization

ObjectiveThis study was undertaken to evaluate the effects of different stages of endometriosis on the outcome of treatment in an in vitro fertilization (IVF) program. MethodsThis was a retrospective, matched case-control study in an academic tertiary referral centre. The study group consisted of 87 women with laparoscopically diagnosed endometriosis, and the control group consisted of 87 age-matched women undergoing IVF for different reasons. The primary outcomes were duration of stimulation, total gonadotropin dose requirement, peak serum estradiol level, total number of oocytes retrieved, fertilization rate, embryo quality, implantation rate, and clinical pregnancy rate. The effect of obliteration of the cul-de-sac by endometriosis was also evaluated. ResultsWomen with endometriosis required significantly higher gonadotropin doses than women in the control group (P < 0.01). The fertilization rate was significantly lower for women with endometriosis (P < 0.05), although there was no difference in embryo quality or in the number of embryos transferred. In patients with an obliterated cul-de-sac, fewer oocytes were retrieved than in patients in the control group (P < 0.01). ConclusionThe presence of endometriosis, including stages III and IV, does not affect IVF outcome. However, women with endometriosis require more gonadotropin stimulation than those with no endometriosis. Women with an obliterated cul-de-sac have fewer oocytes retrieved than women without obliteration.

Optimum Conditions for Measuring Dehydrogenase Activity of Aspergillus niger using TTC

The suitability of the triphenyl tetrazolium chloride (TTC) for dehydrogenase activity measurement of the vegetative cells of the fungal species Aspergillus niger was investigated. The triphenyl formazan (TF) yield increased with the increases in TTC concentration, pH, temperature and incubation time within the studied ranges. The effects of individual parameters, as well as the combined effects, on the TF yield were found to follow exponential expressions. The sensitivity analysis showed that the TF yield is more sensitive to changes in temperature followed by pH, TTC concentration and incubation time. Although the rate of increase in the enzyme activity decreased gradually with the increase in temperature, no enzyme denaturation was observer below 55 oC. The optimum TTC-test conditions for measuring the dehydrogenase activity of A. niger vegetative cells are a TTC concentration of 15 g/L, a pH of 9, a temperature of 55 oC and an incubation time of 4 h. Although the procedure has been successfully tested with mycelia of different stages of growth, it would be interesting to test the effects of different stages of growth on TTC reduction under both aerobic and anaerobic conditions.

Soil phosphorus dynamics and phytoavailability from sewage sludge at different stages in a treatment stream

The effect of different stages of sewage sludge treatment on phosphorus (P) dynamics in amended soils was determined using samples of undigested liquid (UL), anaerobically digested liquid (AD) and dewatered anaerobically digested (DC) sludge. Sludges were taken from three points in the same treatment stream and applied to a sandy loam soil in field-based mesocosms at 4, 8 and 16 t ha−1 dry solids. Mesocosms were sown with perennial ryegrass (Lolium perenne cv. Melle), and the sward was harvested after 35 and 70 days to determine yield and foliar P concentration. Soils were also sampled during this period to measure P transformations and the activities of acid phosphomonoesterase and phosphodiesterase. Data show that the AD amended soils had the greatest plant-available and foliar P content up to the second harvest, but the UL amended soils had the greatest enzyme activity. Characterisation of control and 16 t ha−1 soils and sludge using solution 31P nuclear magnetic resonance (NMR) spectroscopy after NaOH–EDTA extraction revealed that P was predominantly in the inorganic pool in all three sludge samples, with the highest proportion (of the total extracted P) as inorganic P in the anaerobically digested liquid sludge. After sludge incorporation, P was immobilised to organic species. The majority of organic P was in monoester-P forms, while the remainder of organic P (diester P and phosphonate P) was more susceptible to transformations through time and showed variation with sludge type. These results show that application of sewage sludge at rates as low as 4 t ha−1 can have a significant nutritional benefit to ryegrass over an initial 35-day growth and subsequent 35-day re-growth periods. Differences in P transformation, and hence nutritional benefit, between sludge types were evident throughout the experiment. Thus, differences in sludge treatment process alter the edaphic mineralisation characteristics of biosolids derived from the same source material.

Iron transporters in rat mammary gland: effects of different stages of lactation and maternal iron status

Mechanisms regulating iron transfer from maternal circulation into milk are yet unknown. Whether intestinal iron transporters, divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1), are present in the mammary gland and are involved in iron transfer into milk are unknown. The objective was to examine DMT1 and FPN1 in rat mammary gland at different stages of lactation and to evaluate the effects of maternal iron status. Rats were fed either 35 mg Fe (control rats) or 8 mg Fe (low-iron rats) per kg diet for 3 wk and were fed the same diet throughout pregnancy and lactation. Mammary gland DMT1, FPN1, transferrin receptor, and ferritin were examined in control rats on days 1, 5, 10, and 20 of lactation and in low-iron rats on days 10 and 20 of lactation. Tissue and milk iron were measured. Milk iron, DMT1, and FPN1 decreased throughout lactation. Iron status was compromised in low-iron rats, whereas milk iron was maintained. On day 10 of lactation, mammary gland iron and ferritin were lower in the low-iron rats. DMT1, FPN1, and transferrin receptor values were unchanged; however, a smaller-size DMT1 protein was observed in the low-iron rats. On day 20, transferrin receptor increased in the low-iron rats, whereas mammary gland iron, ferritin, DMT1, and FPN1 were unchanged. The results show that DMT1 and FPN1 concentrations are higher during early lactation and are possibly involved in iron transfer into milk. Mammary gland regulation of DMT and FPN1 during low iron status appears to be different from that in the intestine.

The effect of different stages of neuromuscular block on the bispectral index and the bispectral index-XP under remifentanil/propofol anesthesia.

Facial electromyographic activity and neuromuscular block could influence bispectral index (BIS) depth of anesthesia monitoring. In this study we examined, in 30 patients undergoing general surgical procedures, the effect of different stages of neuromuscular block on BIS monitoring and compared the conventional A-2000 BIS trade mark (BIS(3.4)) with the new BIS-XP trade mark (BIS(XP)). At deep surgical anesthesia BIS(3.4) of approximately 40, under a propofol 3.61 microg/mL target-controlled infusion and a 0.15-0.3 microg. kg(-1). min(-1) remifentanil infusion, mivacurium 0.15 mg/kg was administered. The onset of neuromuscular block triggered a brief transient odd divergence in response that manifested as a BIS(3.4) increase from 43 +/- 4 to 49 +/- 7 (P = 0.007) and a BIS(XP) decline from 41 +/- 3 to 35 +/- 3 (P = 0.003) at 1 +/- 0.2 min. Then, 2.5 +/- 1 min after mivacurium administration, both monitors returned to baseline values of 43 +/- 5 and 40 +/- 4, respectively. After that, BIS(3.4) and BIS(XP) did not significantly change during complete neuromuscular block or during various levels of neuromuscular recovery. At all phases, BIS(XP) was significantly lower than BIS(3.4). Our study indicated that the BIS(3.4)/BIS(XP) bias and the wide limits of agreement do not allow values given by the two monitors to be used interchangeably.

Effect of different stages of the follicular wave on in vitro developmental competence of bovine oocytes

This study aimed to investigate the developmental competence of ovum pick-up collected oocytes on three stages of the follicular wave: Days 2, 5 and 8. A group of 11 cows was used in successive cycles to perform ovum pick-up on either Day 2, 5 or 8 of an induced follicular wave (three sessions per stage). Follicular waves were initiated by puncturing the dominant follicle and all other follicles sized ≥5 mm at Days 5–7 of the cycle. The plasma progesterone concentrations did not differ between the days of ovum pick-up: 4.0±1.8, 5.1±1.6 and 5.2±1.7 ng/ml for Days 2, 5 and 8, respectively. The proportion of oocytes with three or more layers of non-expanded cumulus cells was higher for Day 5 than Day 8, while Days 2 and 5 did not significantly differ from each other (85, 96 and 68% of 113, 60 and 101 oocytes for Days 2, 5 and 8, respectively). The proportion of oocytes competent to develop a blastocyst in an in vitro production system was higher for Days 2 and 5 than for Day 8: 27, 29 and 15% for the oocytes with fair to good cumulus investment and 23, 27 and 11%, respectively, when all oocytes were taken in account. This indicates that the dominant follicle reduces the developmental competence of oocytes from subordinate follicles at a relatively late stage of dominance. This finding has practical consequences for the handling of cows that undergo ovum pick-up only once or very irregularly. The embryo yield can then be improved by performing the ovum pick-up at Days 2–5 of the cycle or 2–5 days after ablation of the large follicles.

HDL derived from the different phases of conjugated diene formation reduces membrane fluidity and contributes to a decrease in free cholesterol efflux from human THP-1 macrophages

Oxidized HDL (ox-HDL) has been reported to reduce free cholesterol efflux from cells. In this study we investigate the effect of different stages of ox-HDL on macrophage membrane fluidity and its effect on free cholesterol efflux from macrophages as a cell function influenced by ox-HDL. HDL was oxidized by means of conjugated diene production using copper as a prooxidant. Fluidity of HDL and human THP-1 macrophage membranes was evaluated by changes in fluorescence anisotropy ( r) by DPH probe where lower ( r) values give higher fluidity. We found that ox-HDL derived from the propagation phase (PP-HDL) and the decomposition phase (DP-HDL) became less fluid (( r): 0.263±0.001, 0.279±0.002, respectively) than HDL from the lag phase (LP-HDL) and native HDL (nat-HDL) (( r): 0.206±0.001) ( P<0.05). Macrophages incubated with PP-HDL and DP-HDL had less fluid membranes (( r): 0.231±0.001, 0.243±0.002, respectively) than those incubated with LP-HDL and nat-HDL (( r): 0.223±0.001) ( P<0.05). Consequently, fluidity was reduced not only in ox-HDL but also in the cell membranes exposed to ox-HDL. A significant negative correlation was observed between macrophage membrane fluorescence anisotropy ( r) and free cholesterol efflux from these cells (−0.876; P<0.05). Thus, lower membrane fluidity was associated with lower free cholesterol efflux from cells. In conclusion, the increase in the HDL oxidation process leads to a lost of macrophage membrane fluidity that could contribute to an explanation of the reduction of free cholesterol efflux from cells by ox-HDL.

EFFECT OF COMMERCIAL PROCESSING STAGES OF APPLE JUICE ON PATULIN, FUMARIC ACID AND HYDROXYMETHYLFURFURAL (HMF) LEVELS

AbstractThe effects of different stages of commercial apple juice production on the patulin, fumaric acid and hydroxymethylfurfural (HMF) contents of apple juice were investigated. Heat treatment and activated charcoal were effective for the reduction of patulin. The average reduction of patulin were 13.4% and 22.9% for heat treatment and activated charcoal, respectively. Statistical analysis showed no significant differences (P&lt;0.05) in the presence of fumaric acid between different treatments. Filtration and heat treatment caused an apparent increase in the HMF content, while activated charcoal caused a decrease. The average increments of HMF were 40.4% and 38.0% for separation and heat treatment, respectively, while the average reduction of HMF was 23.7% for activated charcoal. Spiking of samples with known amounts of patulin and fumaric acid revealed respective recovery rates of 96.4% and 95.9%.

Mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome): a Y210C mutation causes either altered protein handling or altered protein function of N-acetylgalactosamine 4-sulfatase at multiple points in the vacuolar network.

The lysosomal hydrolase N-acetylgalactosamine 4-sulfatase (4-sulfatase) is required for the degradation of the glycosaminoglycan substrates dermatan and chondroitin sulfate. A 4-sulfatase deficiency results in the accumulation of undegraded substrate and causes the severe lysosomal storage disorder mucopolysaccharidosis type VI (MPS VI) or Maroteaux-Lamy syndrome. A wide variation in clinical severity is observed between MPS VI patients and reflects the number of different 4-sulfatase mutations that can cause the disorder. The most common 4-sulfatase mutation, Y210C, was detected in approximately 10% of MPS VI patients and has been associated with an attenuated clinical phenotype when compared to the archetypical form of MPS VI. To define the molecular defect caused by this mutation, Y210C 4-sulfatase was expressed in Chinese hamster ovary (CHO-K1) cells for protein and cell biological analysis. Biosynthetic studies revealed that Y210C 4-sulfatase was synthesized at a comparable molecular size and amount to wild-type 4-sulfatase, but there was evidence of delayed processing, traffic, and stability of the mutant protein. Thirty-three percent of the intracellular Y210C 4-sulfatase remained as a precursor form, for at least 8 h post labeling and was not processed to the mature lysosomal form. However, unlike other 4-sulfatase mutations causing MPS VI, a significant amount of Y210C 4-sulfatase escaped the endoplasmic reticulum and was either secreted from the expression cells or underwent delayed intracellular traffic. Sixty-seven percent of the intracellular Y210C 4-sulfatase was processed to the mature form (43, 8, and 7 kDa molecular mass forms) by a proteolytic processing step known to occur in endosomes-lysosomes. Treatment of Y210C CHO-K1 cells with the protein stabilizer glycerol resulted in increased amounts of Y210C 4-sulfatase in endosomes, which was eventually trafficked to the lysosome after a long, 24 h chase time. This demonstrated delayed traffic of Y210C 4-sulfatase to the lysosomal compartment. The endosomal Y210C 4-sulfatase had a low specific activity, suggesting that the mutant protein also had problems with stability. Treatment of Y210C CHO-K1 cells with the protease inhibitor ALLM resulted in an increased amount of mature Y210C 4-sulfatase localized in lysosomes, but this protein had a very low level of activity. This indicated that the mutant protein was being inactivated and degraded at an enhanced rate in the lysosomal compartment. Biochemical analysis of Y210C 4-sulfatase revealed a normal pH optimum for the mutant protein but demonstrated a reduced enzyme activity with time, also consistent with a protein stability problem. This study indicated that multiple subcellular and biochemical processes can contribute to the biogenesis of mutant protein and may in turn influence the clinical phenotype of a patient. In MPS VI patients with a Y210C allele, the composite effect of different stages of intracellular processing/handling and environment has been shown to cause a reduced level of Y210C 4-sulfatase protein and activity, resulting in an attenuated clinical phenotype.

Biomechanical evaluation of the elbow using roentgen stereophotogrammetric analysis.

The medial collateral ligament complex is the primary constraint of the elbow to valgus forces and is composed of the anterior bundle, the posterior bundle, and a transverse part. Total and partial ruptures have been described. Clinical and radiologic examinations of medial or valgus instability of the elbow are difficult. The effect of different stages of medial collateral ligament ruptures on ulnohumeral movement in cadavers was determined to rationalize the use of physical and radiologic examinations in different stages of valgus instability in vivo. Using roentgen stereophotogrammetric analysis, motion is determined between the humerus and ulna under valgus load and between the humerus and radius during maximal pronation of the forearm after various dimensions of medial collateral ligament lesions. The increase in distance between the humerus and ulna under a 15 N valgus load varied from 2.7 mm to 9.8 mm. The increase in distance between the humerus and proximal radius with the forearm in pronation in an intact specimen and after transsection of the anterior medial collateral ligament and posterior medial collateral ligament in the anterior direction was 9.7 mm. These results suggest that detection of partial ruptures with clinical and radiologic examinations is difficult. Anterior movement of the radial head can be used as an additional parameter of valgus instability.

Performance of programmed temperature vaporizer, pulsed splitless and on-column injection techniques in analysis of pesticide residues in plant matrices

A programmed temperature vaporizer (PTV) injection technique has been recently implemented in our laboratory. In present paper its performance is compared with other GC injection techniques commonly used in trace analysis of organic contaminants. Twenty-six pesticides representing different chemical classes were selected for the study. This group comprised compounds typically subjected to discrimination in the injection port of the gas chromatograph, e.g., polar organophosphorus pesticides and thermolabile carbamates. In the first set of experiments standards in pure solvent were injected into GC systems employing different types of injection, i.e., (i) on-column, (ii) pulsed splitless, (iii) PTV solvent split, (iv) PTV splitless, and the responses of analytes were compared. Discrimination of troublesome compounds was significantly decreased with the application of PTV solvent split injection. In the second set of experiments repetitive injections of purified wheat samples were performed, with aims to evaluate the long-term stability of responses, as well as matrix effects in different stages of system contamination for each injection technique. The tolerance of the GC system to co-injected matrix components was increased in the order: on-column<pulsed splitless<PTV solvent split technique. As regards matrix effects, these were suppressed considerably with the PTV solvent split technique in comparison with pulsed splitless injection. With the latter technique after 66 injections of wheat samples relative responses (apparent recovery) reached as much as 450% for some compounds, while with the application of PTV matrix effects did not exceed 200% under the same conditions.

Effect of different stages of tensile deformation on micromagnetic parameters in high-strength, low-alloy steel

The influence of tensile deformation on the magnetic Barkhausen emissions (MBE) and hysteresis loop has been studied in a high-strength, low-alloy steel (HSLA) and its weldment. The magnetic measurements were made both in loaded and unloaded conditions for different stress levels. The rootmean-square (RMS) voltage of the MBE has been used for analysis. This study shows that the preyield and postyield deformation can be identified from the change in the the MBE profile. The initial elastic deformation showed a linear increase in the MBE level in the loaded condition, and the MBE level remained constant in the unloaded condition. The microplastic yielding, well below the macroyield stress, significantly reduces the MBE, indicating the operation of grain-boundary dislocation sources below the macroyield stress. This is indicated by the slow increase in the MBE level in the loaded condition and the decrease in the MBE level in the unloaded condition. The macroyielding resulted in a significant increase in the MBE level in the loaded condition and, more clearly, in the unloaded condition. The increase in the MBE level during macroyielding has been attributed to the grain rotation phenomenon, in order to maintain the boundary integrity between adjacent grains, which would preferentially align the magnetic domains along the stress direction. With progressive plastic deformation, the MBE level remains more or less constant in the loaded condition and decreases linearly with strain in the unloaded condition. This constant MBE behavior in the loaded condition is attributed to the opposing effect of applied tensile stress (which tends to align the domains along the stress direction) and the dislocation density (which reduces the domain-wall displacement). The decreasing MBE in the unloaded condition is attributed to the combined effect of compressive residual stress at the surface layers (which tends to align the domain wall perpendicular to the stress direction) and the dislocation density. This study shows that MBE during tensile deformation can be classified into four stages: (1) perfectly elastic, (2) microplastic yielding, (3) macroyielding, and (4) progressive plastic deformation. A multimagnetic parameter approach, combining the hysteresis loop and MBE, has been suggested to evaluate the residual stresses.