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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Statistická analýza výroby / Statistical analysis of production

Kovaříková, Ludmila January 2009 (has links)
The aim of Master's thesis is to apply statistical methods in production process. The assignment of the thesis is to describe and evaluate pressing process which is the part of posistor production. The first theoretical part contains introduction to the mathematical statistics, verifying assumptions about the data, describing the regression analysis, the analysis of variance and the part of the design of experiment. The second practical part is focused on design, performing and interpreting of experiments. The thesis is developed according to requirements of company EPCOS s.r.o. Šumperk. Statistical program MINITAB Rlease 14, which is supported by company, was used for all computations.
222

A Chronic Iron-Deficient/High-Manganese Diet in Rodents Results in Increased Brain Oxidative Stress and Behavioral Deficits in the Morris Water Maze

Fitsanakis, Vanessa A., Thompson, Kimberly N., Deery, Sarah E., Milatovic, Dejan, Shihabi, Zak K., Erikson, Keith M., Brown, Russell W., Aschner, Michael 01 February 2009 (has links)
Iron deficiency (ID) is especially common in pregnant women and may even persist following childbirth. This is of concern in light of reports demonstrating that ID may be sufficient to produce homeostatic dysregulation of other metals, including manganese (Mn). These results are particularly important considering the potential introduction of the Mn-containing gas additive, methyl cyclopentadienyl manganese tricarbonyl (MMT), in various countries around the world. In order to model this potentially vulnerable population, we fed female rats fed either control (35 mg Fe/kg chow; 10 mg Mn/kg chow) or low iron/high-manganese (IDMn; 3.5 mg Fe/kg chow; 100 mg Mn/kg chow) diet, and examined whether these changes had any long-term behavioral effects on the animals' spatial abilities, as tested by the Morris water maze (MWM). We also analyzed behavioral performance on auditory sensorimotor gating utilizing prepulse inhibition (PPI), which may be related to overall cognitive performance. Furthermore, brain and blood metal levels were assessed, as well as regional brain isoprostane production. We found that treated animals were slightly ID, with statistically significant increases in both iron (Fe) and Mn in the hippocampus, but statistically significantly less Fe in the cerebellum. Additionally, isoprostane levels, markers of oxidative stress, were increased in the brain stem of IDMn animals. Although treated animals were indistinguishable from controls in the PPI experiments, they performed less well than controls in the MWM. Taken together, our data suggest that vulnerable ID populations exposed to high levels of Mn may indeed be at risk of potentially dangerous alterations in brain metal levels which could also lead to behavioral deficits.
223

Neonatal Quinpirole Treatment Impairs Morris Water Task Performance in Early Postweanling Rats: Relationship to Increases in Corticosterone and Decreases in Neurotrophic Factors

Brown, Russell W., Flanigan, Timothy J., Thompson, Kimberly N., Thacker, Stephanie K., Schaefer, Tori L., Williams, Michael T. 01 August 2004 (has links)
Background Past studies from this laboratory have shown that quinpirole administration from postnatal day (P) 1–21 produces persistent supersensitization of the dopamine D2 receptor that persists throughout the animal's lifetime. Methods In Experiment 1, both male and female rats were treated with quinpirole or saline from P1–21 and tested on the place and match-to-place versions of the Morris water task (MWT) from P22–28. In Experiment 2, both male and female rats were administered either acute or chronic injections of quinpirole (1 mg/kg) or saline beginning on P1 until analysis for corticosterone (CORT) on P7, 14, or 21. Results Neonatal quinpirole treatment produced deficits on both versions of the MWT compared with saline control. One day after behavioral testing, brain tissue was harvested, and the hippocampus was analyzed for nerve growth factor (NGF) and brain-derived nerve growth factor (BDNF); NGF was found to be significantly decreased by neonatal quinpirole treatment. Acute or chronic quinpirole treatment on P14 produced a larger increase in CORT than controls and produced larger increases in CORT than control rats on P21. Conclusions These results demonstrate that neonatal quinpirole treatment produces cognitive deficits that could be related to decreases in hippocampal NGF and increases in CORT, resulting in abnormalities in hippocampal development.
224

The Effects of Adulthood Nicotine Treatment on D2-Mediated Behavior and Neurotrophins of Rats Neonatally Treated with Quinpirole

Brown, Russell W., Perna, Marla K., Schaefer, Tori L., Williams, Michael T. 01 April 2006 (has links)
This study was designed to analyze the effects of nicotine on yawning behavior and neurotrophin content in the hippocampus and frontal cortex of D2-receptor primed female adult Sprague-Dawley rats. Animals were neonatally treated with quinpirole, a dopamine (DA) D2/D3 agonist, from postnatal day 1-21 (P1-21) and raised to P60 and administered nicotine tartarate (0.3 mg/kg free base) or saline twice daily for 14 days. One day after nicotine treatment had ceased, the number of yawns was recorded for 1 h in response to an acute injection of quinpirole (i.p., 100 microg/kg). Yawning is a D2-receptor mediated event. D2-primed rats demonstrated a significant increase in yawning in response to acute quinpirole compared with that of controls, but nicotine did not alleviate this effect. Neonatal quinpirole treatment produced a significant decrease of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in the hippocampus that was alleviated by adulthood nicotine treatment. Interestingly, nicotine treatment to controls produced a significant increase of NGF in the frontal cortex, but a significant decrease of both NGF and BDNF in the hippocampus and BDNF in the frontal cortex. The decreases shown in NGF and BDNF is contrary to past findings that have shown nicotine to produce significant increases of hippocampal NGF and BDNF, but these past studies utilized male rats or mice or were performed in vitro. This study shows that nicotine has complex interactions with NGF and BDNF in D2-primed and control animals, and emphasizes the importance of gender differences when analyzing nicotine's effects on neurotrophins.
225

Nicotine Sensitization in Adult Male and Female Rats Quinpirole-Primed as Neonates

Perna, Marla K., Cope, Zackary A., Maple, Amanda M., Longacre, Ian D., Correll, Jennifer A., Brown, Russell W. 01 July 2008 (has links)
RATIONALE: Increases in dopamine D2-like receptor function are common in several psychological disorders that demonstrate a four to five fold increase in nicotine abuse compared to the general population.OBJECTIVE: The objective of this study was to analyze the interaction of sex differences and sensitization to nicotine in rats D2 receptor primed as neonates.MATERIALS AND METHODS: A total of 32 male and 32 female Sprague-Dawley rats derived from eight litters were ontogenetically treated with quinpirole (1 mg/kg) or saline from postnatal days (P) 1-21 and raised to adulthood. At P60, all animals were given an acute injection of quinpirole HCl (100 microg/kg) and yawns were counted for 1 h. Yawning has been shown to be a behavioral event mediated by D2-like receptors. Beginning on P61-65, animals were habituated to a locomotor arena and subsequently administered either nicotine (0.5 mg/kg free base) or saline (intraperitoneal) every second day for 3 weeks. Approximately 15 min after each injection, animals were placed into the arena and horizontal activity and vertical rears were recorded.RESULTS: A robust increase of yawning was observed at P60 in D2 primed as compared to saline controls. Priming of D2-like receptors increased the locomotor response to nicotine in horizontal activity in both males and females, but females demonstrated a more robust hypoactive locomotor response to initial nicotine treatment when compared to saline-treated females. Nicotine also produced a significant decrease of vertical rearing in both males and females.CONCLUSIONS: It appears that D2 receptor priming enhances sensitization to nicotine in adult rats, and females may be more behaviorally sensitive to nicotine than males.
226

Quantifying Contributions to the Variance of Permeability and Porosity within the Western Belt Sandstones of the Cypress Formation, Illinois Basin

Dulaney, Nathaniel Frederick 08 June 2020 (has links)
No description available.
227

Investigating Differences in Volunteer Administrator Challenges and Management Practices

Thorne, David 28 May 2021 (has links)
No description available.
228

Laser-Assisted Tubal Anastomosis

Kao, L W., Giles, H. R. 01 August 1995 (has links)
OBJECTIVE: To determine if laser-assisted anastomosis is superior to microsurgical anastomosis and laser welding for tubal reconstruction. STUDY DESIGN: Sixty uterine tubes from 30 rabbits were transected and then anastomosed with a microsurgical technique, laser welding and laser-assisted anastomosis using a microscope. The rabbits were mated one month postoperatively and examined for implantation sites and adhesion formation three to seven days postpartum. RESULTS: The amount of time required to perform laser-assisted anastomosis as well as laser welding was significantly shorter than for microsurgery. All the tubes withstood the distension pressure of pregnancy with the exception of 1 of the 20 laser-welded tubes, which had 30% of its circumference dehisced. There was no difference in the number of implantation sites per tube between the different groups. The anastomotic sites were well healed and were nonidentifiable except for holding stitches and microsurgical sutures. CONCLUSION: Laser-assisted anastomosis and laser welding took less time to perform than microsurgery. Laser-assisted anastomosis resulted in excellent healing, as did microsurgery. With the protection of serum albumin, laser-assisted anastomosis did not cause any thermal damage, and the anastomotic sites could tolerate the distension pressure of pregnancy and parturition without problems. Laser welding without protection of serum albumin could cause thermal damage and dehiscence. The implantation and pregnancy rates were comparable The implantation and pregnancy rates were comparable with all three types of procedure.
229

Long-Term Effects of Strokes on Bone Mass

Hamdy, Ronald C., Moore, S W., Cancellaro, V A., Harvill, L. M. 01 September 1995 (has links)
The purpose of the study was to determine the long-term effects of muscle weakness secondary to strokes on the bone mineral content of the hemiparetic limb. Patients who had experienced single recent strokes were studied. The bone mineral content of each limb was measured by Dual Energy X-ray Absorptiometry using the region of interest analysis program. Muscle strength of each muscle group was ranked using the Oxford scale, and the mean was calculated for each limb. Bone and muscle parameters were measured within seven days after the stroke and repeated thereafter at monthly intervals for up to 6 mo. A repeated measures analysis of variance, Newman-Keuls pair-wise comparisons, and orthogonal contrasts were done for each parameter. Significance levels were set at P < 0.05. Sixteen patients were included in this study. Demineralization was more pronounced in the upper than lower limbs. Demineralization of bones on the paralyzed side started during the first month after the stroke and gradually progressed. By the fourth month, the bone mineral content decreased by a mean of 9.3% (P = 0.01) and 3.7% (P = 0.01) in the upper and lower limbs, respectively, for the 11 patients followed for 4 mo. In the patients we followed for more than 4 mo, there was no further significant mineral loss. No change in bone mineral content was observed in the healthy nonparetic limbs. In conclusion, after a stroke, bone demineralization occurs in the paralyzed side and reaches its maximum within 3 to 4 mo. Arms are affected more than legs.
230

Statistical quality assurance of IGUM : Statistical quality assurance and validation of IGUM in a steady and dynamic gas flow prior to proof of concept

Kornsäter, Elin, Kallenberg, Dagmar January 2022 (has links)
To further support and optimise the production of diving tables for the Armed Forces of Sweden, a research team has developed a new machine called IGUM (Inert Gas UndersökningsMaskin) which aims to measure how inert gas is taken up and exhaled. Due to the new design of machine, the goal of this thesis was to statistically validate its accuracy and verify its reliability.  In the first stage, a quality assurance of the linear position conversion key of IGUM in a steady and known gas flow was conducted. This was done by collecting and analysing data in 29 experiments followed by examination with ordinary least squares, hypothesis testing, analysis of variance, bootstrapping and Bayesian hierarchical modelling. Autocorrelation among the residuals were detected but concluded to not have an impact on the results due to the bootstrap analysis. The results showed an estimated conversion key equal to 1.276 ml/linear position which was statistically significant for all 29 experiments.  In the second stage, it was examined if and how well IGUM could detect small additions of gas in a dynamic flow. The breathing machine ANSTI was used to simulate the sinus pattern of a breathing human in 24 experiments where 3 additions of 30 ml of gas manually was added into the system. The results were analysed through sinusoidal regression where three dummy variables represented the three additions of gas in each experiment. To examine if IGUM detects 30 ml for each input, the previously statistically proven conversion key at 1.276ml/linear position was used. An attempt was made to remove the seasonal trend in the data, something that was not completely successful which could influence the estimations. The results showed that IGUM indeed can detect these small gas additions, where the amount detected showed some differences between dummies and experiments. This is most likely since not enough trend has been removed, rather than IGUM not working properly.

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