2,233 research outputs found
New organometallic approaches to heterocycles
Several heterocyclic ring systems have been prepared by two new organometallic methods. The first approach involved the mercuration of alkyl aryl acetylenes. This reaction resulted in the formation of mercurated heterocycles. Mercurated benzofurans, isocoumarins, chromones, benzothiophenes and benzopyrans were all prepared by this method. The mercury moiety in these compounds was readily substituted by various functional groups. By making a slight modification in the acetylenic substrate, the intramolecular cyclization was prevented. The reaction then produced the (beta)-acetoxy vinylmercurial which was used to synthesize the coumarin ring system. The second approach involved the intramolecular attack of an oxygen or a nitrogen nucleophile on a (pi)-allylpalladium intermediate. The (pi)-allylpalladium intermediate was generated by the reaction of an organomercurial with a diene or an olefin in the presence of a palladium(II) salt. This method was used for the preparation of lactones, dihydrobenzofurans, dihydroindoles and pyrans
Learning versus stealing : how Important are market-share -- reallocations to India's productivity growth?
Recent trade theory emphasizes the role of market-share reallocations across firms ("stealing") in driving productivity growth, while the older literature focused on average productivity improvements ("learning"). The authors use comprehensive, firm-level data from India's organized manufacturing sector to show that market-share reallocations did play an important role in aggregate productivity gains immediately following the start of India's trade reforms in 1991. However, aggregate productivity gains during the overall period from 1985 to 2004 were driven largely by improvements in average productivity, which can be attributed to India's trade liberalization and FDI reforms.Economic Theory&Research,Industrial Management,E-Business,Labor Policies,Debt Markets
Studies on the immunochemistry and serology of Taenia saginata infection in cattle
The work reported in this thesis fell into three main
sections. The first was a study of the immunochemistry
of a saline extract of T. saginata proglottids (SE) with
particular reference to the antigens involved in the
serological response of cattle to infection with T. saginata.
It was hoped that this information would facilitate the
production of relatively pure and specific T. saginata
antigens for use in serodiagnostic tests for this
infection.The second section was concerned with an investigation
of the potential of certain serological techniques, not
previously used with T. saginata infections in cattle,
for use in serological investigations of experimental and
field infections. In the third and final section these
serological techniques were used to measure the serum
antibody levels in cattle both experimentally and naturally
infected with T. saginata. Where possible, partially
purified saline extracts of T. saginata were used as
antigens in these techniques.The immunochemistry of SE was studied by gel filtration
on Sephadex G200, Sepharose 6B and Sepharose 4B, by ion
exchange chromatography and by immunoadsorption techniques.
It was found that SE consisted of two main groups of
antigenic molecules. The first group were of a molecular
weight equivalent to that of the macroglobulin component
of bovine serum and contained most of the haemagglutinin
activity. The second group were of a molecular weight
equivalent to that of the globulin component of bovine serum
and contained mainly gel precipitin activity. The immunoadsorption studies on this extract showed the method to be
potentially valuable for the purification of these helminth
antigens but much work still remains to be done on this
relatively new approach.The micro immuno- precipitation (MGP) and the indirect
haemagglutination (IDH) techniques had already been used in
bovine cysticercosis research prior to the commencement of
this work and only minor modifications have been made to
these procedures. However, the haemagglutination inhibition
(HI), enzyme -linked immunosorbent assay (ELISA) and the
soluble antigen fluorescent antibody (SAFA) techniques have
each been adapted to the study of the T. saginata system in
cattle for the first time. A comparison of SAFA and ELISA
showed that ELISA was the preferable of the two techniques
for experimental work. The technique also has potential as
a versatile and sensitive tool for studies on naturally
infected cattle. The HI technique proved effective in
detecting haemagglutinin activity in fractions of SE
produced by column chromatography.Studies on cattle experimentally infected with
T. saginata showed that the ELISA technique compared favourably with the IDH and MGP techniques. ELISA could in fact
be used to detect an antibody response to both haemagglutinin
and gel precipitin antigens. In contrast the IDH technique
mainly detected an antibody response to haemagglutinins
and the MGP technique an antibody response to gel precipitin
antigens.A limited study on cattle naturally infected with
T. saginata showed, however, that ELISA is not presently
a reliable test for T. saginata infection in the field.
In particular, further work requires to be done on the
antigens used in serological techniques, although there was
an indication that some, but not all, cross reacting antigens
could be removed by gel filtration and immunoadsorption
Realising the open virtual commissioning of modular automation systems
To address the challenges in the automotive industry posed by the need to rapidly manufacture more
product variants, and the resultant need for more adaptable production systems, radical changes are
now required in the way in which such systems are developed and implemented. In this context, two
enabling approaches for achieving more agile manufacturing, namely modular automation systems
and virtual commissioning, are briefly reviewed in this contribution. Ongoing research conducted at
Loughborough University which aims to provide a modular approach to automation systems design
coupled with a virtual engineering toolset for the (re)configuration of such manufacturing
automation systems is reported. The problems faced in the virtual commissioning of modular
automation systems are outlined. AutomationML - an emerging neutral data format which has
potential to address integration problems is discussed. The paper proposes and illustrates a
collaborative framework in which AutomationML is adopted for the data exchange and data
representation of related models to enable efficient open virtual prototype construction and virtual
commissioning of modular automation systems. A case study is provided to show how to create the
data model based on AutomationML for describing a modular automation system
Eligibility and enrollment in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)--27 states and New York City, 2007-2008.
The national Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides nutrition education, growth monitoring, breastfeeding promotion and support, and food to low-income pregnant or postpartum women, infants, and children aged <5 years. Several studies have linked WIC services with improved maternal and infant health outcomes. Most population-based studies have lacked information needed to identify eligible women who are not receiving WIC services and might be at risk for poor health outcomes. This report uses multistate, population-based 2007-2008 survey data from CDC's Pregnancy Risk Assessment Monitoring System (PRAMS) and California's Maternal and Infant Health Assessment (MIHA) to estimate how many women were eligible but not enrolled in WIC during pregnancy and to describe their characteristics and their prevalence of markers of risk for poor maternal or infant health outcomes. Approximately 17% of all women surveyed were eligible but not enrolled in WIC during pregnancy. The proportion of women eligible for WIC and WIC participation rates varied by state. WIC participants had higher prevalences of markers of risk for poor maternal or infant health outcomes than eligible nonparticipants, but both groups had higher prevalences of risk markers than ineligible women, suggesting that many eligible women and their children might benefit from WIC services. The results of this analysis can help identify the scope of WIC outreach needed to include more eligible nonparticipants in WIC and whom to target
- …