A synthetic Escherichia coli predator–prey ecosystem

We have constructed a synthetic ecosystem consisting of two Escherichia coli populations, which communicate bi-directionally through quorum sensing and regulate each other's gene expression and survival via engineered gene circuits. Our synthetic ecosystem resembles canonical predator–prey systems in terms of logic and dynamics. The predator cells kill the prey by inducing expression of a killer protein in the prey, while the prey rescue the predators by eliciting expression of an antidote protein in the predator. Extinction, coexistence and oscillatory dynamics of the predator and prey populations are possible depending on the operating conditions as experimentally validated by long-term culturing of the system in microchemostats. A simple mathematical model is developed to capture these system dynamics. Coherent interplay between experiments and mathematical analysis enables exploration of the dynamics of interacting populations in a predictable manner

Improvement of OMI Ozone Profile Retrievals in the Troposphere and Lower Troposphere by the Use of the Tropopause-Based Ozone Profile Climatology

An advance algorithm based on the optimal estimation technique has beeen developed to derive ozone profile from GOME UV radiances and have adapted it to OMI UV radiances. OMI vertical resolution : 7-11 km in the troposphere and 10-14 km in the stratosphere. Satellite ultraviolet measurements (GOME, OMI) contain little vertical information for the small scale of ozone, especially in the upper troposphere (UT) and lower stratosphere (LS) where the sharp O3 gradient across the tropopause and large ozone variability are observed. Therefore, retrievals depend greatly on the a-priori knowledge in the UTL

NNI-Form Quark Mass Matrix Expressed by the Observable Quantities

It is pointed out that the phase convention of the CKM matrix V affects texture analysis of the quark mass matrices (M_u, M_d) when we try to describe (M_u, M_d) by the observable quantities (quark masses and CKM matrix parameters) only. This is demonstrated for a case of the non-Hermitian Fritzsch-type mass matrix (tilde{M}_u, tilde{M}_d), which is a general expression of quark mass matrix (M_u, M_d) and is described by twelve parameters. We find that we can always choose a phase convention of V which yields tilde{M}_{u32} = 0, so that the remaining ten parameters in (tilde{M}_u, tilde{M}_d) can completely be expressed by the ten observable quantities.Comment: 11 pages (LaTeX); Title was change

The voice of experience: the unmet needs of older people in Barnet.

Between February and July 2008 six focus groups of older people were conducted in six locations across Barnet. The participants in the focus groups were either regular attendees at day centres or older people groups which met regularly. The aim of the study was to identify the unmet needs of older people across the Borough. The focus groups identified that need was felt across many domains of older peoples’ lives, including health and access to health care, exercise and responsibility for one’s own well-being, access to information, companionship, transport and the home environment

International capital mobility in an era of globalisation: adding a political dimension to the 'Feldstein–Horioka Puzzle'

The debate about the scope of feasible policy-making in an era of globalisation continues to be set within the context of an assumption that national capital markets are now perfectly integrated at the international level. However, the empirical evidence on international capital mobility contradicts such an assumption. As a consequence, a significant puzzle remains. Why is it, in a world in which the observed pattern of capital flows is indicative of a far from globalised reality, that public policy continues to be constructed in line with more extreme variants of the globalisation hypothesis? I attempt to solve this puzzle by arguing that ideas about global capital market integration have an independent causal impact on political outcomes which extends beyond that which can be attributed to the extent of their actual integration

Hereditary cataract in the Bengal cat in Poland

Background: This paper reports the significant prevalence of a presumed hereditary cataract in the Bengal cat breed in Poland. The nuclear part of the lens is affected and previous reports from Sweden and France for this type of feline cataract suggest that a recessive mode of inheritance is probably involved. Results: Presumed congenital or neonatal cataract involving the posterior nuclear part of each lens was initially diagnosed in a 12 month old male Bengal cat. As both parents and a sibling were also affected with cataract, a group of 18 related and 11 non-related cats was then subsequently examined. Eight related cats and one non- related cat were found to be similarly affected. A breed survey was then completed using an additional five centres across Poland and a further 190 related cats were examined. A total of 223 cats have been involved in this study, with 75 (33%) being affected with several types of cataract and 67 (30%) being specifically affected with the same or similar nuclear lesions. Eight cats (3.6%) presented with other cataract types and a prominence of the posterior lens suture lines was recorded in 65 cats unaffected with cataract (29%). There were no demonstrable vision problems. Neither age nor coat colour was significantly associated with the nuclear cataract, but the nuclear cataract group had a higher proportion of females than the unaffected group. Pedigree analysis has indicated probable inheritance as a recessive trait. Conclusions: These findings suggest that a presumably inherited nuclear cataract is present in the Bengal cat breed in Poland. It is considered to be either congenital or of very early onset, probably being inherited as a recessive trait. Although the lesion has no noticeable effect on vision, breeders in Poland and worldwide should be aware of the disease and clinical examination of young breeding stock prior to reproduction is advisable

Which Kubo formula gives the exact conductance of a mesoscopic disordered system?

In both research and textbook literature one often finds two ``different'' Kubo formulas for the zero-temperature conductance of a non-interacting Fermi system. They contain a trace of the product of velocity operators and single-particle (retarded and advanced) Green operators: $\text{Tr} (\hat{v}_x \hat{G}^r \hat{v}_x \hat{G}^a)$ or $\text{Tr} (\hat{v}_x \text{Im} \hat{G} \hat{v}_x \text{Im} \hat{G})$. The study investigates the relationship between these expressions, as well as the requirements of current conservation, through exact evaluation of such quantum-mechanical traces for a nanoscale (containing 1000 atoms) mesoscopic disordered conductor. The traces are computed in the semiclassical regime (where disorder is weak) and, more importantly, in the nonperturbative transport regime (including the region around localization-delocalization transition) where concept of mean free path ceases to exist. Since quantum interference effects for such strong disorder are not amenable to diagrammatic or nonlinear $\sigma$-model techniques, the evolution of different Green function terms with disorder strength provides novel insight into the development of an Anderson localized phase.Comment: 7 pages, 5 embedded EPS figures, final published version (note: PRB article has different title due to editorial censorship

Sex differences in the association between dynapenic abdominal obesity and onset of disability in activities of daily living among adults aged ≥50 years: A prospective analysis of the Irish Longitudinal Study on Ageing

Background: Sex differences in the longitudinal relationship between dynapenic abdominal obesity, i.e., impairment in muscle strength and high waist circumference, and disability in activities of daily living have not been investigated to date. Therefore, we aimed to examine sex differences in the longitudinal association between dynapenic abdominal obesity at baseline and the onset of disability in activities of daily living during a four-year follow-up period among Irish adults aged ≥50 years. Methods: Data from Wave 1 (2009–2011) and Wave 3 (2014–2015) of the Irish Longitudinal Study on Ageing survey were analyzed. Dynapenia was defined as handgrip strength of <26 kg for men and <16 kg for women. Abdominal obesity was defined as waist circumference of >88 cm for women and >102 cm for men. Dynapenic abdominal obesity was defined as having both dynapenia and abdominal obesity. Disability was defined as having difficulty with at least one of six activities of daily living (dressing, walking, bathing, eating, getting in or out of bed, using the toilet). Multivariable logistic regression was conducted to assess associations. Results: Data on 4471 individuals aged ≥50 years and free of disability at baseline were analyzed [mean (SD) age 62.3 (8.6) years; 48.3 % males]. In the overall sample, compared to no dynapenia and no abdominal obesity, dynapenic abdominal obesity was associated with 2.15 (95%CI = 1.17–3.93) times higher odds for incident disability at 4-year follow-up. This association was significant among men (OR = 3.78; 95%CI = 1.70–8.38) but not among women (OR = 1.34; 95%CI = 0.60–2.98). Conclusions: Interventions to prevent or address dynapenic abdominal obesity may aid in the prevention of disability, especially among men

Retrieval validation during the European Aqua Thermodynamic Experiment

Atmospheric and surface thermodynamic parameters retrieved with advanced hyperspectral remote sensors aboard Earth observing satellites are critical to weather prediction and scientific research. The retrieval algorithms and retrieved parameters from satellite sounders must be validated to demonstrate the capability and accuracy of both observation and data processing systems. The European Aqua Thermodynamic Experiment (EAQUATE) was conducted not only for validation of the Atmospheric InfraRed Sounder on the Aqua satellite, but also for assessment of validation systems of both ground-based and aircraft-based instruments that will be used for other satellite systems, such as the Infrared Atmospheric Sounding Interferometer on the European MetOp satellite, the Cross-track Infrared Sounder from the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project and the continuing series of NPOESS satellites. Detailed intercomparisons were conducted and presented using different retrieval methodologies: measurements from airborne ultraspectral Fourier transform spectrometers, aircraft in situ instruments, dedicated dropsondes and radiosondes, ground-based Raman lidar, as well as the European Centre for Medium-range Weather Forecasting modelled thermal structures. The results of this study not only illustrate the quality of the measurements and retrieval products, but also demonstrate the capability of the validation systems put in place to validate current and future hyperspectral sounding instruments and their scientific products

A High-Fidelity Benthic Stable Isotope Record of Late Cretaceous-Early Eocene Climate Change and Carbon-Cycling

The Late Cretaceous–Early Paleogene is the most recent period in Earth history that experienced sustained global greenhouse warmth on multimillion year timescales. Yet, knowledge of ambient climate conditions and the complex interplay between various forcing mechanisms are still poorly constrained. Here we present a 14.75 million‐year‐long, high‐resolution, orbitally tuned record of paired climate change and carbon‐cycling for this enigmatic period (~67–52 Ma), which we compare to an up‐to‐date compilation of atmospheric pCO2 records. Our climate and carbon‐cycling records, which are the highest resolution stratigraphically complete records to be constructed from a single marine site in the Atlantic Ocean, feature all major transient warming events (termed “hyperthermals”) known from this time period. We identify eccentricity as the dominant pacemaker of climate and the carbon cycle throughout the Late Maastrichtian to Early Eocene, through the modulation of precession. On average, changes in the carbon cycle lagged changes in climate by ~23,000 years at the long eccentricity (405,000‐year) band, and by ~3,000–4,500 years at the short eccentricity (100,000‐year) band, suggesting that light carbon was released as a positive feedback to warming induced by orbital forcing. Our new record places all known hyperthermals of the Late Maastrichtian–Early Eocene into temporal context with regards to evolving ambient climate of the time. We constrain potential carbon cycle influences of Large Igneous Province volcanism associated with the Deccan Traps and North Atlantic Igneous Province, as well as the sensitivity of climate and the carbon‐cycle to the 2.4 million‐year‐long eccentricity cycle