Cross-section data, disequilibrium situations and estimated coefficients: evidence from car ownership demand

The objective of this paper is to analyse to what extent the use of cross-section data will distort the estimated elasticities for car ownership demand when the observed variables do not correspond to a state equilibrium for some individuals in the sample. Our proposal consists of approximating the equilibrium values of the observed variables by constructing a pseudo-panel data set which entails averaging individuals observed at different points of time into cohorts. The results show that individual and aggregate data lead to almost the same value for income elasticity, whereas with respect to working adult elasticity the similarity is less pronounced.Cross-section, Pseudo panel, Disequilibrium.

Traffic forecasts under uncertainty and capacity constraints

Traffic forecasts provide essential input for the appraisal of transport investment projects. However, according to recent empirical evidence, long-term predictions are subject to high levels of uncertainty. This paper quantifies uncertainty in traffic forecasts for the tolled motorway network in Spain. Uncertainty is quantified in the form of a confidence interval for the traffic forecast that includes both model uncertainty and input uncertainty. We apply a stochastic simulation process based on bootstrapping techniques. Furthermore, the paper proposes a new methodology to account for capacity constraints in long-term traffic forecasts. Specifically, we suggest a dynamic model in which the speed of adjustment is related to the ratio between the actual traffic flow and the maximum capacity of the motorway. This methodology is applied to a specific public policy that consists of suppressing the toll on a certain motorway section before the concession expires.

Soliton eigenvalue control with optical lattices

We address the dynamics of higher-order solitons in optical lattices, and predict their self-splitting into the set of their single-soliton constituents. The splitting is induced by the potential introduced by the lattice, together with the imprinting of a phase tilt onto the initial multisoliton states. The phenomenon allows the controllable generation of several coherent solitons linked via their Zakharov-Shabat eigenvalues. Application of the scheme to the generation of correlated matter waves in Bose-Einstein condensates is discussed.Comment: 13 pages, 4 figures, to appear in Physical Review Letter

The relationship between zinc intake and serum/plasma zinc concentration in adults: a systematic review and dose–response meta-analysis by the EURRECA Network

Dietary zinc recommendations vary widely across Europe due to the heterogeneity of pproaches used by expert panels. Under the EURRECA consortium a protocol was designed to systematically review and undertake meta-analyses of research data to create a database that includes “best practice” guidelines which can be used as a resource by future panels when setting micronutrient recommendations. As part of this process, the objective of the present study was to undertake a systematic review and meta-analysis of previously published data describing the relationship between zinc intake and status in adults. Searches were performed of literature published up to February 2010 using MEDLINE, Embase, and Cochrane Library. Data extracted included population characteristics, dose of zinc, duration of study, dietary intake of zinc, and mean concentration of zinc in plasma or serum at the end of the intervention period. An intake-status regression coefficient was estimated for each individual study, and pooled meta-analysis undertaken. The overall pooled for zinc supplementation on serum/plasma zinc concentrations from RCTs and observational studies was 0.08 (95% CI 0.05, 0.11; p<0.0001; I2 84.5%). An overall of 0.08 means that for every doubling in zinc intake, the difference in zinc serum or plasma concentration is (20.08 = 1.06), which is 6%. Whether the dose-response relationship, as provided in this paper, could be used as either qualitative or quantitative evidence to substantiate the daily zinc intake dose necessary to achieve normal or optimal levels of biomarkers for zinc status, remains a matter of discussion

Visions of a Martian Future

As we look beyond our terrestrial boundary to a multi-planetary future for humankind, it becomes paramount to anticipate the challenges of various human factors on the most likely scenario for this future: permanent human settlement of Mars. Even if technical hurdles are circumvented to provide adequate resources for basic physiological and psychological needs, Homo sapiens will not survive on an alien planet if a dysfunctional psyche prohibits the utilization of these resources. No matter how far we soar into the stars, our psychologies for future generations will be forever tethered to the totality of our surroundings. By shaping our environment toward survival and welfare during the voyage to Mars and in a Martian colony, we indirectly shape our psyches and prepare them for a mission of unprecedented alienation and duration. Once on Mars, human factors such as leadership structure, social organization and code of conduct, group size, gender balance, developmental cycle, mobility, length of stay and the ecological settings and type and manner of subsistence, will create a novel Martian culture. The degree that settlers are severed from the Earth will affect how radically foreign this culture will be when compared with cultures on Earth

Tracking aid flows for development assistance for health.

BACKGROUND AND OBJECTIVES: The global architecture for providing development assistance for health (DAH) has become increasing complex in the last decade, with many new funding agencies entering the health sector. This study presents a detailed picture of European Union (EU) and EU member state originating DAH between 2006 and 2009; with a specific focus on assessing the extent of complementarity of development assistance sourced from the EU. DESIGN: We use a combination of internal EU reporting systems, OECD-DAC creditor reporting system data and other data sources to estimate DAH flows. Our method uses a line by line project assessment in order to identify and categorise DAH flows. RESULTS AND CONCLUSIONS: Our findings show a complex picture of DAH flows--from source, to channel of assistance, to channel of implementation--that is hard to track at the global level, and rarely comprehensively and regularly tracked at the country level. While the majority of EU DAH is focused on low and lower middle income countries there also remains much disparity between countries; and further analysis is required to better understand whether these imbalances are fair and efficient; or result in overlap. We also recommend investment in quality control of DAH tracking internally within donor agencies, and investment in the development of country based systems in order to enable countries and development partners better harmonise DAH flows

Weak value amplification and Hong Ou Mandel effects for quantum sensing

The use of new states of light (quantum sensing and quantum imaging) has opened the door to new protocols for parameter estimation with enhanced resolution. In this project we study two techniques that allow increasing the resolution of measurements, allowing the detection of extremely small changes in variables. In one case, when resolution is limited by technical noise, the protocol is Weak Value Amplification (WVA). In the second case, we make use of quantum interference and develop a new type of microscope (Quantum Differential Interference Contrast, QDIC) that does phase retrieval based on the Hong-Ou- Mandel effect. We consider phase objects, such as sub-wavelength gratings and cliff-like structures, to show the capabilities and potential of the techniques considered. In this project we will explore how the birefringence induced in the Differential Interference contrast microscopy system can be translated into temporal delays that can be measured with WVA. The Hong Ou Mandel (HOM) effect was demonstrated in 1987 as a way to measure subpicosecond time intervals between two Photons. It is an effect very sensitive to differences between the photons that interfere (polarization, temporal delay, spatial shape...). We will explore in this project how phase differences introduced by objects can be translated into different states of polarization that can be measured with HOM

Novel statistical approaches for non-normal censored immunological data: analysis of cytokine and gene expression data

Background: For several immune-mediated diseases, immunological analysis will become more complex in the future with datasets in which cytokine and gene expression data play a major role. These data have certain characteristics that require sophisticated statistical analysis such as strategies for non-normal distribution and censoring. Additionally, complex and multiple immunological relationships need to be adjusted for potential confounding and interaction effects. Objective: We aimed to introduce and apply different methods for statistical analysis of non-normal censored cytokine and gene expression data. Furthermore, we assessed the performance and accuracy of a novel regression approach in order to allow adjusting for covariates and potential confounding. Methods: For non-normally distributed censored data traditional means such as the Kaplan-Meier method or the generalized Wilcoxon test are described. In order to adjust for covariates the novel approach named Tobit regression on ranks was introduced. Its performance and accuracy for analysis of non-normal censored cytokine/gene expression data was evaluated by a simulation study and a statistical experiment applying permutation and bootstrapping. Results: If adjustment for covariates is not necessary traditional statistical methods are adequate for non-normal censored data. Comparable with these and appropriate if additional adjustment is required, Tobit regression on ranks is a valid method. Its power, type-I error rate and accuracy were comparable to the classical Tobit regression. Conclusion: Non-normally distributed censored immunological data require appropriate statistical methods. Tobit regression on ranks meets these requirements and can be used for adjustment for covariates and potential confounding in large and complex immunological datasets

Deficiency in p53 is required for doxorubicin induced transcriptional activation of NF-кB target genes in human breast cancer

NF-кB has been linked to doxorubicin resistance in breast cancer patients. NF- кB nuclear translocation and DNA binding in doxorubicin treated-breast cancer cells have been extensively examined; however its functional relevance at transcriptional level on NF-кB -dependent genes and the biological consequences are unclear. We studied NF-кB -dependent gene expression induced by doxorubicin in breast cancer cells and fresh human cancer specimens with different genetic backgrounds focusing on their p53 status. NF-кB –dependent signature of doxorubicin was identified by gene expression microarrays in breast cancer cells treated with doxorubicin and the IKKβ-inhibitor MLN120B, and confirmed ex vivo in human cancer samples. The association with p53 was functionally validated. Finally, NF-кB activation and p53 status was determined in a cohort of breast cancer patients treated with adjuvant doxorubicin-based chemotherapy. Doxorubicin treatment in the p53-mutated MDA-MB-231 cells resulted in NF NF- кB driven-gene transcription signature. Modulation of genes related with invasion, metastasis and chemoresistance (ICAM-1, CXCL1, TNFAIP3, IL8) were confirmed in additional doxorubicin-treated cell lines and fresh primary human breast tumors. In both systems, p53-deficient background correlated with the activation of the NF-кB –dependent signature. Furthermore, restoration of p53WT in the mutant p53 MDAMB- 231 cells impaired NF-кB driven transcription induced by doxorubicin. Moreover, a p53 deficient background and nuclear NF-кB /p65 in breast cancer patients correlated with reduced disease free-survival. This study supports that p53 deficiency is necessary for a doxorubicin driven NF-кB -response that limits doxorubicin cytotoxicity in breast cancer and is linked to an aggressive clinical behavior.Financial support: This work was supported by RD12/0036/0051 (J.A.), RD09/0076/0101, RD09/0076/0036, RD12/0036/0054 (A.B), RD12/0036/0070 (A. Ll), PI12/00680 (J.A.), PI12/01552 (F.R.), PI12/01421 (A.Ll.), 2009 SGR 321 (J.A.), FMM 9757/002 (F.R.), and the “Xarxa de Bancs de tumors sponsored by Pla Director d’Oncologia de Catalunya (XBTC). J.A. and F.R. are recipients of intensification program ISCIII/FEDER. We thank Fundació Cellex (Barcelona) for a generous donation to the Hospital del Mar Medical Oncology Service. We thank Millenium for generously providing MLN120B

The Relationship between Zinc Intake and Serum/Plasma Zinc Concentration in Children: A Systematic Review and Dose-Response Meta-Analysis

Recommendations for zinc intake during childhood vary widely across Europe. The EURRECA project attempts to consolidate the basis for the definition of micronutrient requirements, taking into account relationships among intake, status and health outcomes, in order to harmonise these recommendations. Data on zinc intake and biomarkers of zinc status reported in randomised controlled trials (RCTs) can provide estimates of dose-response relationships which may be used for underpinning zinc reference values. This systematic review included all RCTs of apparently healthy children aged 1–17 years published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient was calculated for each individual study and calculated the overall pooled and SE using random effects meta-analysis on a double log scale. The pooled dose-response relationship between zinc intake and zinc status indicated that a doubling of the zinc intake increased the serum/plasma zinc status by 9%. This evidence can be utilised, together with currently used balance studies and repletion/depletion studies, when setting zinc recommendations as a basis for nutrition policies