6,395 research outputs found
Gender Earnings Differentials and Regional Economic Development in Urban China, 1988-97
gender earnings differentials, urban China, transitional economies
The study of consumption patterns and expectations of organic catering consumers in Taiwan
This report was presented at the UK Organic Research 2002 Conference. Organic catering is increasingly provided in public and private food services. In Taiwan, most organic catering is vegetarian and affiliated with organic food stores. These offer diners organic meals to make themselves competitive to attract target markets, and provide related information to improve consumers’ knowledge of organic foods and hopefully increase their consumption. Organic catering consumers’ knowledge of organic foods, attitudes toward consumption, and consumption behavior are all related. Consumption is affected by gender, marital status, age, religion, education, occupation, personal health, family health and expenditure allowance. Regular organic catering customers emphasize “balanced nutrition” and “certification or reliability of organic sources”. The obstacles to consumption for non-regular organic catering consumers are “too expensive” and “difficult to find”. Most organic catering consumers prefer the service styles “health-themed restaurant” and “located inside the organic food stores”
Effects of TIPS Homework on Student Learning
Homework is a teaching tool used to facilitate student learning outside of the classroom. The purpose of this study was to observe if parental homework involvement increased homework effectiveness. By soliciting parental involvement using Teachers Involve Parents in Schoolwork (TIPS) assignments, the study implemented an experimental quantitative design with pre and posttests to measure differences in student learning. Convenience sampling was used to select two random class periods, each with 28 students. One period acted as the control group; whereas, the other served as the intervention group. The intervention group received TIPS homework; whereas, the control group received non-TIPS homework. Data was gathered across a three week study. Independent and paired samples t-tests were conducted to determine if there were statistically significant differences between the means of both groups. Both groups showed an increase in average quiz scores from pretest to posttest; however, the control group had greater and statistically significant growth which rejects the hypothesis that using TIPS homework improved students\u27 comprehension above and beyond their normal instruction. Such findings go against much of the available research. As a result, further research is recommended. Possible factors negatively impacting results include: small sample size and difficulty in soliciting homework completion and turn in
Gender earnings differentials and regional economic development in urban China, 1988 - 97
Gender earnings differentials in urban China by region and their changes during the first decade of economic reform are examined. It is found that the female–male earnings ratio increased during the early stage of reform. The male earnings premium, overall, showed an increasing trend in the later stage of reform. Decomposition of the gender earnings differential reveals that a relatively lower percentage of the differential could be explained by gender differences in productive characteristics in the fast growing regions and in regions with a rapid pace of reform. The cross-sectional results highlight the possible existence of gender discrimination, particularly in the later stages of economic reform and development. Both market competition and the effects of wage decentralization play a role in shaping the gender earnings differentials. Gender earnings differentials varied by region and over time, generally in tandem with the pace of economic reform and development. The decomposition of the over time changes in the earnings gap indicated that improvement in females’ productive characteristics during the reform period constantly enhanced the earnings of females relative to those of males. The over time changes in the returns to females’ characteristics, however, work to counter any narrowing of the gender earnings gap
Molecular Mechanism of RNA-Mediated Gene Silencing in Human Cells: A Dissertation
Small non-coding RNAs regulate gene expression at posttranscriptional level in eukaryotic cells. Two classes of such small (~21-25 nt) RNAs that have been extensively studied in gene silencing are short interfering RNAs (siRNAs) and microRNAs (miRNAs). RNA interference (RNAi) is process whereby double-stranded RNA induces the sequence-specific degradation of homologous mRNA. The RNAi machinery can also be programmed in human cells by introducing 21-nt siRNA duplexes that are assembled into RNA-induced silencing complexes (RISC). In this dissertation, systematic analysis of siRNAs with deletions at the passenger and/or guide strand reveals that a short RNAi trigger, 16-nt siRNA, induces potent RNAi in human cells. The 16-nt siRNA more effectively knocked down mRNA and protein levels than 19-nt siRNA when targeting the endogenous CDK9 gene. In vitro kinetic analysis of human RISC indicates that 16-nt siRNA has a higher RISC-loading capacity than 19-nt siRNA. These results suggest that 16-nt duplexes can be designed as potent triggers for RNAi.
RISC can be programmed by small interfering RNAs (siRISC) to cleave a perfectly complementary target mRNA, or endogenous microRNAs (miRISC) to inhibit translation by binding imperfectly matched sequences in the 3’-untranslated region (3’-UTR) of target mRNA. Both RISCs contain Argonaute2 (Ago2), which localizes to cytoplasmic mRNA processing P-bodies. This dissertation shows that RCK/p54, a DEAD box helicase, interacts with Ago2, in affinity-purified active siRISC or miRISC, facilitates formation of P-bodies. Depletion of RCK/p54 disrupted P-bodies and dispersed Ago2 throughout the cytoplasm, but did not significantly affect siRNA-mediated RNAi. Depleting RCK/p54 releases general and miRNA-induced translational repression. These findings imply that miRISC-mediated translation repression requires RCK/p54, also suggest that location of miRISC to P-bodies is not required for miRNA function, but is the consequence of translation repression.
To elucidate the function of RCK/p54 in miRNA-mediated gene silencing, analysis of a series of YFP-tagged RCK/p54 mutants reveals the motif required for P-body localization, interaction with Ago2, and/or facilitating the miRNA-mediated translation repression. Additionally, rabbit reticulocyte lysate system was used to recapitulate the miRISC function in a cell-free system and confirmed the requirement of RCK/p54 for miRNA function in vitro. Analysis of Ago2 distribution in the polysome profiling in RCK/p54-depleted cells, compared to that in normal cells, revealed that RCK/p54 facilitates miRISC by trapping it at translation initiation complex. These data suggest that interaction of RCK/p54 with Ago2 is involved in the repression of translation initiation of miRNA function
Metabolism of isofenphos and bendiocarb in southern corn rootworms
The toxicity and metabolism of isofenphos and bendiocarb were compared between southern corn rootworm (SCR) adults and larvae. In the toxicity tests, insecticide solutions were applied topically on the ventral abdomen, and the LD(,50) values were determined after mortality was evaluated 48 h posttreatment. Isofenphos and three of its metabolites (isofenphos oxon, des-N-isopropyl isofenphos, and des-N-isopropyl isofenphos oxon) were 2.5 to 3.6 times less toxic to SCR larvae than to adults. The 48-h topical LD(,50) values ranged from 1.7 to 2.7 (mu)g/g for adults, and 5.9 to 8.2 (mu)g/g for larvae. Bendiocarb was approximately seven times less toxic to SCR larvae than to adults. The 48-h topical LD(,50) values of bendiocarb to SCR adults and larvae were 1.3 and 9.1 (mu)g/g, respectively;In the metabolism studies, SCR adults and larvae were analyzed at specific time intervals after treatment with a (\u2714)C-labeled insecticide solution at sublethal dosage levels, at the LD(,10) dosage for isofenphos, and at the 1/10 LD(,50) dosage for bendiocarb. Most of the (\u2714)C was recovered from internal organic extract and container rinse fractions;The proposed major metabolic pathway of isofenphos in SCR included oxidative desulfuration of isofenphos to isofenphos oxon, hydrolysis of isofenphos oxon and/or parent isofenphos to isopropyl salicylate, and conjugation of isopropyl salicylate. Isofenphos penetrated approximately three times faster into larvae than into adults. Less accumulation of toxic compounds inside the larvae, however, resulted from a faster metabolism (1.5x) and rapid elimination of toxic parent isofenphos. Less internal toxic compound in SCR larvae may explain partially the lower isofenphos toxicity for larvae;The proposed major metabolic pathways of bendiocarb in SCR are hydrolysis of the carbamate ester bond to yield bendiocarb phenol and the subsequent conjugation of bendiocarb phenol. The major metabolites from bendiocarb were beniocarb phenol and conjugated compounds for SCR adults and larvae, respectively. For bendiocarb, the ratio of applied dose to internal toxic compound was similar to both adults and larvae. Therefore, the amount of internal toxic dose, affected by the rates of penetration, metabolism, and excretion, was not a determining factor in the selective toxicity of bendiocarb between SCR adults and larvae
PERIORAL BIOMECHANICS, KINEMATICS, AND ELECTROPHYSIOLOGY IN PARKINSON'S DISEASE
This investigation quantitatively characterized the orofacial biomechanics, labial kinematics, and associated electromyography (EMG) patterns in individuals with Parkinson's disease (PD) as a function of anti-PD medication state. Passive perioral stiffness, a clinical correlate of rigidity, was sampled using a face-referenced OroSTIFF system in 10 mildly diagnosed PD and 10 age/sex-matched control elderly. Labial movement amplitudes and velocities were evaluated using a 4-dimensional computerized motion capture system. Associated perioral EMG patterns were sampled to examine the characteristics of perioral muscles and compensatory muscular activation patterns during repetitive syllable productions. This study identified several trends that reflect various characteristics of perioral system differences between PD and control subjects: 1. The presence of high tonic EMG patterns after administration of dopaminergic treatment indicated an up-regulation of the central mechanism, which may serve to regulate orofacial postural control. 2. Multilevel regression modeling showed greater perioral stiffness in PD subjects, confirming the clinical correlate of rigidity in these patients. 3. Similar to the clinical symptoms in the upper and lower limb, a reduction of range of motion (hypokinesia) and velocity (bradykinesia) was evident in the PD orofacial system. Administration of dopaminergic treatment improved hypokinesia and bradykinesia. 4. A significant correlation was found between perioral stiffness and the range of labial movement, indicating these two symptoms may result in part from a common neural substrate. 5. As speech rate increased, PD speakers down-scaled movement amplitude and velocity compared to the control subjects, reflecting a compensatory mechanism to maintain target speech rates. 6. EMG from orbicularis oris inferior (OOIm) and depressor labii inferioris (DLIm) muscles revealed a limited range of muscle activation level in PD speakers, reflecting the underlying changes in motor unit firing behavior due to basal ganglia dysfunction. The results of this investigation provided a quantitative description of the perioral stiffness, labial kinematics, and EMG patterns in PD speakers. These findings indicate that perioral stiffness may provide clinicians a quantitative biomechanical correlate to medication response, movement aberrations, and EMG compensatory patterns in PD. The utilization of these objective assessments will be helpful in diagnosing, assessing, and monitoring the progression of PD to examine the efficacy of pharmacological, neurosurgical, and behavioral interventions
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