Femtosecond wavepacket interferometry using the rotational dynamics of a trapped cold molecular ion

A Ramsey-type interferometer is suggested, employing a cold trapped ion and two time-delayed off-resonant femtosecond laser pulses. The laser light couples to the molecular polarization anisotropy, inducing rotational wavepacket dynamics. An interferogram is obtained from the delay dependent populations of the final field-free rotational states. Current experimental capabilities for cooling and preparation of the initial state are found to yield an interferogram visibility of more than 80\%. The interferograms can be used to determine the polarizability anisotropy with an accuracy of about $\pm 2\%$, respectively $\pm 5\%$, provided the uncertainty in the initial populations and measurement errors are confined to within the same limits

Tropical Periods for Calabi-Yau Hypersurfaces in non--Fano Toric Varieties

We consider multi-polytopes to describe non-Fano toric varieties and their associated anticanonical Calabi-Yau hypersurfaces. From the periods of the mirror manifold the $\widehat{\Gamma}$-conjecture is shown to hold for examples of Calabi-Yau hypersurfaces in non-Fano ambient spaces, extending earlier work by Abouzaid et al by employing a generalized Duistermaat-Heckman measure.Comment: 43 pages, 6 figures. References added and minor edits to section

Carbon and Nitrogen Isotopic Ratio of the Water-Insoluble Fraction in Air Filter Particulate Matter

Particulate matter samples were collected during two episodes of thermal inversion (14.01-2.3.2006) and at four different air monitoring stations in Krakow (Agro: urban background site, Indu: industrial site at Nowa Huta, Poly: domestic coal heating district, Traffic: traffic site) and from the Zakopane sub-urban mountain site (Zakopane), dominated by domestic coal heating. The carbon and nitrogen isotopic compositions of aerosol particles collected in the city of Krakow were measured in 2006 as part of the JRC-IES Krakow project, for which the samples were taken. A total of 42 samples (including 24 source samples) was analysed by Isotope Ratio Mass Spectrometry (IRMS) for isotopic ratios of N and C. The results for samples from different locations show clear grouping of related samples. The leftover of samples provided within the Krakow project were stored in the refrigerator. After one year of cool storage the EA-IRMS measurement was repeated and water extraction was applied. The aim of this experiment was to get more isotopic data for source apportionment. The results showed that the isotopic values of some source samples obtained in 2007 are different from these measured in 2006. However, these differences were not observed for ambient air samples. The possible explanation could be improper storage condtions causing continued reactions between products adsorbed on the filter during storage in the refrigerator. The water extraction removed water soluble inorganic and organic nitrogen-containing compounds and caused the changes in delta15N vs. Air. In this study it is difficult to make a link between sources and ambient air samples after application of water extraction because of the problem with instability of isotopic compositions of the original sources samples.JRC.D.4-Isotope measurement

Determination by Isotope Ratio Mass Spectrometry of the Absolute Isotope Amount Fractions of Oxygen and Nitrogen in Nitrous Oxide

A measurement procedure for the complete isotope characterisation of atmospheric nitrous oxide sample has been developed and applied to establish a first Reference Material for this gas. The whole work has been based on the peculiar instrumental capabilites of "Avogadro" MAT 271IRMS. Additional hardware and software improvement has been done for this mass spectrometer to apply the proposed method.JRC.D.4-Isotope measurement

Intrinsic symmetry groups of links with 8 and fewer crossings

We present an elementary derivation of the "intrinsic" symmetry groups for knots and links of 8 or fewer crossings. The standard symmetry group for a link is the mapping class group \MCG(S^3,L) or \Sym(L) of the pair $(S^3,L)$. Elements in this symmetry group can (and often do) fix the link and act nontrivially only on its complement. We ignore such elements and focus on the "intrinsic" symmetry group of a link, defined to be the image $\Sigma(L)$ of the natural homomorphism \MCG(S^3,L) \rightarrow \MCG(S^3) \cross \MCG(L). This different symmetry group, first defined by Whitten in 1969, records directly whether $L$ is isotopic to a link $L'$ obtained from $L$ by permuting components or reversing orientations. For hyperbolic links both \Sym(L) and $\Sigma(L)$ can be obtained using the output of \texttt{SnapPea}, but this proof does not give any hints about how to actually construct isotopies realizing $\Sigma(L)$. We show that standard invariants are enough to rule out all the isotopies outside $\Sigma(L)$ for all links except $7^2_6$, $8^2_{13}$ and $8^3_5$ where an additional construction is needed to use the Jones polynomial to rule out "component exchange" symmetries. On the other hand, we present explicit isotopies starting with the positions in Cerf's table of oriented links which generate $\Sigma(L)$ for each link in our table. Our approach gives a constructive proof of the $\Sigma(L)$ groups.Comment: 72 pages, 66 figures. This version expands the original introduction into three sections; other minor changes made for improved readabilit

Social differences in lung cancer management and survival in South East England: a cohort study

OBJECTIVE: To examine possible social variations in lung cancer survival and assess if any such gradients can be attributed to social differences in comorbidity, stage at diagnosis or treatment. DESIGN: Population-based cohort identified in the Thames Cancer Registry. SETTING: South East England. PARTICIPANTS: 15 582 lung cancer patients diagnosed between 2006 and 2008. MAIN OUTCOME MEASURES: Stage at diagnosis, surgery, radiotherapy, chemotherapy and survival. RESULTS: The likelihood of being diagnosed as having early-stage disease did not vary by socioeconomic quintiles (p=0.58). In early-stage non-small-cell lung cancer, the likelihood of undergoing surgery was lowest in the most deprived group. There were no socioeconomic differences in the likelihood of receiving radiotherapy in stage III disease, while in advanced disease and in small-cell lung cancer, receipt of chemotherapy differed over socioeconomic quintiles (p<0.01). In early-stage disease and following adjustment for confounders, the HR between the most deprived and the most affluent group was 1.24 (95% CI 0.98 to 1.56). Corresponding estimates in stage III and advanced disease or small-cell lung cancer were 1.16 (95% CI 1.01 to 1.34) and 1.12 (95% CI 1.05 to 1.20), respectively. In early-stage disease, the crude HR between the most deprived and the most affluent group was approximately 1.4 and constant through follow-up, while in patients with advanced disease or small-cell lung cancer, no difference was detectable after 3 months. CONCLUSION: We observed socioeconomic variations in management and survival in patients diagnosed as having lung cancer in South East England between 2006 and 2008, differences which could not fully be explained by social differences in stage at diagnosis, co-morbidity and treatment. The survival observed in the most affluent group should set the target for what is achievable for all lung cancer patients, managed in the same healthcare system

Source Apportionment of Nitrate Pollution in Surface Water Using Stable Isotopes of N and O in Nitrate and B: A Case Study in Flanders (Belgium)

Excess application to fields of animal manure or mineral fertilizers is generally assumed to be the major source of nitrate pollution in surface and groundwater in agricultural areas in Flanders (Belgium). The Flemish Environment Agency (VMM) suspects, but could not prove, that discharges of untreated domestic sewage or discharges containing mineral fertilizers from hydroculture in greenhouses are also contributing to the nitrate pollution observed in some of the agricultural areas. The objective of this study was to investigate, using stable isotope data of dissolved nitrate and boron, if these suspected sources significantly contribute to the nitrate pollution observed in selected surface water monitoring points in Flanders.JRC.D.4-Isotope measurement

Aspects of (0,2) Orbifolds and Mirror Symmetry

We study orbifolds of (0,2) models and their relation to (0,2) mirror symmetry. In the Landau-Ginzburg phase of a (0,2) model the superpotential features a whole bunch of discrete symmetries, which by quotient action lead to a variety of consistent (0,2) vacua. We study a few examples in very much detail. Furthermore, we comment on the application of (0,2) mirror symmetry to the calculation of Yukawa couplings in the space-time superpotential.Comment: 13 pages, TeX (harvmac, big) with 4 enclosed PostScript figures, one reference adde