Europium (III) complexes derived from carboxylic-substituted polychlorotriphenylmethyl radicals

Two europium (III) complexes (3 and 4) have been obtained reacting europium (III) nitrate and two polychlorotriphenylmethyl radicals properly functionalized with one (PTMMC⁻, 1) and six (PTMHC⁶⁻, 2) carboxylate groups, respectively. While complex 3 reveals a lamellar polar-apolar separated ion pair structure alternating PTM-based bilayers with nonaaquaeuropium cations ([Eu(H₂O)₉](PTMMC)₃(PTMMCH)₃ · 7H₂O · 6EtOH), complex 4 shows a one-dimensional chain-like structure with formula [Eu₂(PTMHC)(H₂O)₁₃] · 16H₂O · EtOH. Magnetic properties of both complexes were studied in the 2-300 K range, and show the presence of weak inter-radical antiferromagnetic interactions below 5 K.     

Variation in estimated recombination rates across human populations

Recently it has been reported that recombination hotspots appear to be highly variable between humans and chimpanzees, and there is evidence for between-person variability in hotspots, and evolutionary transience. To understand the nature of variation in human recombination rates, it is important to describe patterns of variability across populations. Direct measurement of recombination rates remains infeasible on a large scale, and population-genetic approaches can be imprecise, and are affected by demographic history. Reports to date have suggested broad similarity in recombination rates at large genomic scales and across human populations. Here, we examine recombination rate estimates at a finer population and genomic scale: 28 worldwide populations and 107 SNPs in a 1 Mb stretch of chromosome 22q. We employ analysis of variance of recombination rate estimates, corrected for differences in effective population size using genome-wide microsatellite mutation rate estimates. We find substantial variation in fine-scale rates between populations, but reduced variation within continental groups. All effects examined (SNP-pair, region, population and interactions) were highly significant. Adjustment for effective population size made little difference to the conclusions. Observed hotspots tended to be conserved across populations, albeit at varying intensities. This holds particularly for populations from the same region, and also to a considerable degree across geographical regions. However, some hotspots appear to be population-specific. Several results from studies on the population history of humans are in accordance with our analysis. Our results suggest that between-population variation in DNA sequences may underly recombination rate variation.     

Environmental decision support systems: A new approach to support the operation and maintenance of horizontal subsurface flow constructed wetlands

This paper describes the development and operation of an Environmental Decision Support System (EDSS) to improve the operation and maintenance of horizontal subsurface-flow constructed wetlands (EDSS-maintenance). Constructed wetlands (CWs) allow wastewater treatment in a sustainable manner since they involve low energy consumption, low construction and functioning costs and low environmental impact. However, operation and maintenance activities are essential to guarantee reliability in CWs performance. The definition of operation and maintenance protocols depends on several quantitative and qualitative aspects such as wastewater treatment plant configuration, CW design, influent characteristics, sensitivity of the receiving media, etc. Bearing this in mind and considering the limited technical knowledge about CWs, the need for a new tool to support CW performance is clear. In this sense, EDSSs offer a new approach because they can tackle problems of complex and uncertain systems. The EDSS-maintenance provides operation and maintenance manuals specifically defined for every CW. To achieve it, the required knowledge was implemented within a rule-based system, which forms the backbone of the EDSS. Several features presented in this paper demonstrate how the EDSS-maintenance provides a proper platform to support the necessary collaborative work in the ecological engineering problem of horizontal subsurface flow CWs operation and maintenance.     

Molecular docking analysis of known flavonoids as duel COX-2 inhibitors in the context of cancer

Cyclooxygenase-2 (COX-2) catalyzed synthesis of prostaglandin E2 and it associates with tumor growth, infiltration, and metastasis in preclinical experiments. Known inhibitors against COX-2 exhibit toxicity. Therefore, it is of interest to screen natural compounds like flavanoids against COX-2. Molecular docking using 12 known flavanoids against COX-2 by FlexX and of ArgusLab were performed. All compounds showed a favourable binding energy of >-10 KJ/mol in FlexX and > -8 kcal/mol in ArgusLab. However, this data requires in vitro and in vivo verification for further consideration.     

Dynamics and mechanical stability of the developing dorsoventral organizer of the wing imaginal disc

Shaping the primordia during development relies on forces and mechanisms able to control cell segregation. In the imaginal discs of Drosophila the cellular populations that will give rise to the dorsal and ventral parts on the wing blade are segregated and do not intermingle. A cellular population that becomes specified by the boundary of the dorsal and ventral cellular domains, the so-called organizer, controls this process. In this paper we study the dynamics and stability of the dorsal-ventral organizer of the wing imaginal disc of Drosophila as cell proliferation advances. Our approach is based on a vertex model to perform in silico experiments that are fully dynamical and take into account the available experimental data such as: cell packing properties, orientation of the cellular divisions, response upon membrane ablation, and robustness to mechanical perturbations induced by fast growing clones. Our results shed light on the complex interplay between the cytoskeleton mechanics, the cell cycle, the cell growth, and the cellular interactions in order to shape the dorsal-ventral organizer as a robust source of positional information and a lineage controller. Specifically, we elucidate the necessary and sufficient ingredients that enforce its functionality: distinctive mechanical properties, including increased tension, longer cell cycle duration, and a cleavage criterion that satisfies the Hertwig rule. Our results provide novel insights into the developmental mechanisms that drive the dynamics of the DV organizer and set a definition of the so-called Notch fence model in quantitative terms.     

An objective scatter index based on double-pass retinal images of a point source to classify cataracts

Purpose

To propose a new objective scatter index (OSI) based in the analysis of double-pass images of a point source to rank and classify cataract patients. This classification scheme is compared with a current subjective system.

Methods

We selected a population including a group of normal young eyes as control and patients diagnosed with cataract (grades NO2, NO3 and NO4) according to the Lens Opacities Classification System (LOCS III). For each eye, we recorded double-pass retinal images of a point source. In each patient, we determined an objective scatter index (OSI) as the ratio of the intensity at an eccentric location in the image and the central part. This index provides information on the relevant forward scatter affecting vision. Since the double-pass retinal images are affected by both ocular aberrations and intraocular scattering, an analysis was performed to show the ranges of contributions of aberrations to the OSI.

Results

We used the OSI values to classify each eye according to the degree of scatter. The young normal eyes of the control group had OSI values below 1, while the OSI for subjects in LOCS grade II were around 1 to 2. The use of the objective index showed some of the weakness of subjective classification schemes. In particular, several subjects initially classified independently as grade NO2 or NO3 had similar OSI values, and in some cases even higher than subjects classified as grade NO4. A new classification scheme based in OSI is proposed.

Conclusions

We introduced an objective index based in the analysis of double-pass retinal images to classify cataract patients. The method is robust and fully based in objective measurements; i.e., not depending on subjective decisions. This procedure could be used in combination with standard current methods to improve cataract patient surgery scheduling.