Exclusive decay of Υ\Upsilon into J/ψ+χc0,1,2J/\psi+\chi_{c0,1,2}

We study the $\Upsilon$ exclusive decay into double charmonium, specifically, the $S$-wave charmonium $J/\psi$ plus the $P$-wave charmonium $\chi_{c0,1,2}$ in the NRQCD factorization framework. Three distinct decay mechanisms, i.e., the strong, electromagnetic and radiative decay channels are included and their interference effects are investigated. The decay processes $\Upsilon(1S,2S,3S)\to J/\psi+\chi_{c1,0}$ are predicted to have the branching fractions of order $10^{-6}$, which should be observed in the prospective Super $B$ factory.Comment: 22 pages, 9 figures, 3 table

Politics of a Different Kind: Chinese in Immigration Litigation in the Post White Australia Era

The first mass Chinese immigration to Australia occurred in the 19th century, with approximately 100,000 Chinese arriving between the 1840s and 1901 (Fitzgerald 2007; Ho 2007), during which questions were raised both in relation to the Chinese rights of migration and settlement in Australia, and the validity of the government's actions against the Chinese. The latter question was in fact considered in the colonial courts (Cronin 1993; Lake and Reynolds 2008). Since then, the Chinese in Australia have never shied away from taking various legal actions, although they are normally seen as people who keep to themselves. Australia abandoned its 'White Australia' policy in 1974, and lately Australia has placed more emphasis on skilled and business migration. As a result, many believe that Chinese migrants have come to Australia under its normal skilled, business or family migration programs, which ignores the fact that a high proportion of them have obtained their chance to stay in Australia directly or indirectly through a series of legal battles. This paper contributes to the discussion of the Chinese in Australian political life by looking at how the Chinese have fought in the Courts in the post-White Australia era in past decades, and the key features of their unique experiences. This is a different type of political activism, characterising the lives of many Australian Chinese, their engagement with the Australian political system, and becoming part of the background of their identity, transnationality, socio-political attitudes and behaviour and many other traits

Analysis of the biosynthesis of altertoxins in Alternaria alternata

The filamentous fungus Alternaria alternata is one of the most widespread contaminants of food and feed, and a weak plant pathogen. It produces a great diversity of secondary metabolites, many of which are generally recognized as phytotoxins and mycotoxins, with alternariol and its derivatives as prominent examples. A. alternata is a black mold that produces dihydroxynaphthalene (DHN) melanin in its cell walls of spores and hyphae. The DHN-melanin biosynthetic gene cluster in A. alternata contains only three genes: the polyketide synthase-encoding gene pksA, the 1,3,8-trihydroxynaphthalene (T3HN) reductase-encoding gene brm2, and the transcription factor-encoding gene cmrA. The scytalone dehydratase-encoding gene brm1 is found elsewhere in the genome. Compared to the well-characterized DHN-melanin biosynthetic pathway in Aspergillus fumigatus, the pathway for DHN melanin biosynthesis in A. alternata is less well studied. A. alternata also produces several secondary metabolites of the perylene quinone (PQ) family, such as altertoxins (ATX I-III). Some PQs are phytotoxic but exhibit some anticancer activity. On the other hand, ATX II is a powerful mutagen that causes DNA strand-breaks, and is therefore a serious threat to human health. The biosynthesis route of PQs is still unclear. Here, I show that the DHN-melanin biosynthetic pathway shares most of the enzymes with the pathway for PQs. Intriguingly, DHN-melanin was synthesized mainly in spores and aerial hyphae, whereas PQs were formed in substrate hyphae. A. alternata pksA was heterologously expressed in Aspergillus oryzae, and the heptaketide YWA1, the hexaketide AT4HN and the pentaketide T4HN were identified as products of the enzyme reaction. I characterized two α-hydrolyses, AygA and AygB, required for DHN melanin biosynthesis. PQs biosynthesis was independent of the two enzymes. Promoter-reporter assays showed that aygA and aygB are expressed in spores and aerial hyphae, where DHN melanin is synthesized, but not in substrate hyphae, where PQs are formed. These results suggest that T4HN is probably synthesized directly in substrate hyphae and then used to produce PQs. In spores and aerial hyphae, YWA1 and AT4HN are hydrolyzed to T4HN by AygA and AygB, which boosters the concentration of T4HN for DHN melanin biosynthesis. I also identified a new T4HN reductase, Brm3, catalyzing the formation of scytalone from T4HN. Furthermore, Brm1, Brm2 and Brm3 were required to produce PQs. Next, I performed a feeding experiment to determine the intermediate for PQs formation in the DHN-melanin biosynthetic pathway. When different amounts of 1,8-DHN were fed to the pksA-deletion strain, the production of PQs, altertoxin I (ATX I), altertoxin II (ATX II) and alterperylenol (ALP), was recovered. Melanization of the △pksA strain was also recovered in liquid culture in the presence of 1,8-DHN. 1,8-DHN is hence the last common intermediate for melanin and PQs biosynthesis. Several laccase-encoding genes were deleted separately or in combination using the CRISPR/Cas9 knock-out technology. Four laccases, LccB-D and LccF, were required for DHN melanin production, but not for PQs biosynthesis. The dimerization enzyme catalyzing the reaction of 1,8-DHN to PQs remains to be identified. Depletion of the regulator CmrA resulted in a brownish mutant strain, unlike the pale or pinkish pksA-deletion strain. In fact, the genes pksA, aygB, brm2 and lccD were still expressed. The transcription factor CmrA strictly controls the expression of aygA, brm1, brm3, lccB and lccF. PQs were not detected in the cmrA-deletion strain. Promoter-reporter assays showed that pksA is not expressed in substrate hyphae, suggesting that CmrA controls the production of PQs through controlling the expression of pksA and/or the dimerization enzyme-encoding gene. The PQs biosynthesis pathway in A. alternata is an example of how spatial regulation of gene expression of one biosynthetic pathway can lead to different secondary metabolites

Estimation in semi-parametric regression with non-stationary regressors

In this paper, we consider a partially linear model of the form $Y_t=X_t^{\tau}\theta_0+g(V_t)+\epsilon_t$, $t=1,...,n$, where $\{V_t\}$ is a $\beta$ null recurrent Markov chain, $\{X_t\}$ is a sequence of either strictly stationary or non-stationary regressors and $\{\epsilon_t\}$ is a stationary sequence. We propose to estimate both $\theta_0$ and $g(\cdot)$ by a semi-parametric least-squares (SLS) estimation method. Under certain conditions, we then show that the proposed SLS estimator of $\theta_0$ is still asymptotically normal with the same rate as for the case of stationary time series. In addition, we also establish an asymptotic distribution for the nonparametric estimator of the function $g(\cdot)$. Some numerical examples are provided to show that our theory and estimation method work well in practice.Comment: Published in at http://dx.doi.org/10.3150/10-BEJ344 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

Three Essays in the Economics of Child Health and Development

This dissertation is composed of three independent essays that focus on the economics of child health and development. The first chapter explores whether availability of the SBP has affected maternal labor supply by using variation in the SBP mandates within-state over time to identify the effect. To increase the availability of the School Breakfast Program (SBP), between 1989 and 2012, 21 states passed laws that require schools to provide the SBP if the fraction of students eligible for free or reduced-price breakfast in their school districts exceeds a certain threshold. Using the CPS Food Security Supplement data between 1995 and 2012, I first show that the SBP mandates significantly increase program participation among mothers with a high school degree or below and among single mothers. Then I estimate the effects of mandates on maternal labor supply using March CPS 1990 to 2013 surveys. The findings suggest that among less-educated mothers and single mothers, a mandate that requires all schools to provide the SBP is associated with an increase in the probability of being employed and working full time, and an increase in weekly hours of work. However, weaker mandates do not have the same maternal labor supply effects. The second chapter examines the effects of smoking bans on birth outcomes. Prenatal smoking has serious adverse consequences on infant health. Among the newest policies developed to reduce smoking and second-hand smoke are smoking bans. Using individual-level birth certificate data from the Natality Detail File between 1995 and 2009, which is matched to county-level data on smoking bans, we investigate the impacts of smoking bans in bars, restaurants and workplaces on infant birth weight, gestations, 5-minute APGAR scores and incidences of cleft lip/palate. In general, bans are not associated with changes in birth weight or weeks of gestation. Surprisingly, we find small increases in rates of low birth weight and very low birth weight infants born to young women in counties that adopted at least one type of ban during the study period. We also show that the negative infant health effects associated with smoking bans appear among babies born to mothers who reported not smoking during pregnancy; this suggests that increased exposure to second-hand smoke is likely to be the mechanism. The third chapter examines the impact of a heretofore relatively unexplored input in the educational process—language environment at home—on student academic achievement during early childhood. Using the confidential data from Early Childhood Longitudinal Study-Kindergarten Class (1998-99), we are able to exploit cross-sectional geographic variation in local language environment, augmented with the recently developed instrumental variable strategy in Lewbel (2012), to identify the causal effect. Our results show that speaking a language other than English at home has a sizable, negative impact on reading test scores in both third and fifth grades, but has no effect on math scores in either grade. We find no evidence that speaking a language other than English at home has any effect on the growth rate of test scores from the third to the fifth grade, regardless of the subject

CATALYSIS OF ETHANOL SYNTHESIS FROM SYNGAS

Catalytic synthesis of ethanol and other higher alcohols from CO hydrogenation has been a subject of significant research since the 1980s. The focus of this research is to establish a better fundamental insight into heterogeneous catalysis for CO hydrogenation reactions, in an attempt to design the best catalysts for ethanol synthesis. It has been reported widely that promoted Rh-based catalysts can exhibit high selectivity to C2+ oxygenates during CO hydrogenation. The doubly promoted Rh-La-V/SiO2 catalysts exhibited higher activity and selectivity for ethanol and other C2+ oxygenates than singly promoted catalysts. The better performance appears to be due to a synergistic promoting effect of the combined La and V additions through intimate contact with Rh. The kinetic study carried out in this study shows that, in general, increasing H2 pressure resulted in increased activities while increasing CO partial pressure had an opposite effect. Langmuir-Hinshelwood rate expressions for the formation of methane and of ethanol were derived and compared to the experimentally derived power law parameters. It was found that the addition of different promoters appeared to result in different rate limiting steps. Strong metal-oxide interactions (SMOI) of Rh and vanadium oxide (as a promoter) supported on SiO2 was studied. It was found by SSITKA (steady-state isotopic transient kinetic analysis) that the concentration of surface reaction intermediates decreased on Rh/V/SiO2 as the reduction temperature increased, but the activities of the reaction sites increased. The results suggest that Rh being covered by VOx species is probably the main reason for the decreased overall activity induced by high reduction temperature, but more active sites appear to be formed probably at the Rh-VOx interface. The mechanism of C1 and C2 hydrocarbon and oxygenate formation during CO hydrogenation on Rh/SiO2 was for the first time investigated in detail using multiproduct SSITKA. Based on SSITKA results, methanol and CH4 appeared to be produced on different active sites. It is possible that C2 products share at least one intermediate with CH4, but not with methanol. Moreover, C2 hydrocarbons are not likely to be formed from adsorbed acetaldehyde