Gated communities: Definitions, causes and consequences

Gated communities became an 'object of study' in the 1990s as social scientists observed their growth in several cities; they are now a feature of the urban landscape in most cities around the world. The expansion of gated communities has led to prolific research, examining different aspects of this type of residential development and providing evidence from case studies worldwide. This paper reviews how gated communities are conceptualised according to the literature and identifies the main factors influencing their development. It also considers spatial, economic, political and social consequences of the development of gated communities. These elements should be taken into account by planners and policymakers to minimise their negative impacts and maximise the positive consequences of a residential option that is likely to be part of the urban landscape for a long time

Gd(III) complexes intercalated into hydroxy double salts as potential MRI contrast agents

The ion exchange intercalation of two Gd-based magnetic resonance imaging contrast agents into hydroxy double salts (HDSs) is reported. The presence of Gd3+ diethylenetriaminepentaacetate and Gd3+ diethylenetriaminepenta(methylenephosphonate) complexes in the HDS lattice after intercalation was confirmed by microwave plasma-atomic emission spectroscopy. The structural aspects of the HDS-Gd composites were studied by X-ray diffraction, with the intercalates having an interlayer spacing of 14.5–18.6 Å. Infrared spectroscopy confirmed the presence of characteristic vibration peaks associated with the Gd3+ complexes in the intercalation compounds. The proton relaxivities of the Gd3+ complex-loaded composites were 2 to 5-fold higher in longitudinal relaxivity, and up to 10-fold higher in transverse relaxivity, compared to solutions of the pure complexes. These data demonstrate that the new composites reported here are potentially potent MRI contrast agents

Contribución del anillamiento al conocimiento y conservación de las aves en España: pasado, presente y futuro

El anillamiento científico de aves es una técnica de estudio con más de un siglo de historia que, probablemente, ha contribuido como ninguna otra metodología al conocimiento de la biología de este grupo faunístico. A pesar del desarrollo de nuevas tecnologías, el marcaje individual de aves mediante anillamiento sigue siendo una técnica plenamente vigente y necesaria. Aunque la evidencia científica sobre los beneficios de la aplicación del anillamiento en la Ornitología moderna es abrumadora, hoy vivimos un proceso de creciente desinformación que cuestiona el anillamiento de aves y su utilidad. Este dosier se ha elaborado con el fin de ofrecer una visión actualizada de la utilidad del anillamiento científico de aves en España. Ha sido elaborado por un nutrido grupo de expertos asociados a universidades y centros de investigación que abarcan buena parte de las áreas del conocimiento implicadas en el estudio y conservación de las aves. El dosier se divide en cuatro grandes apartados. (1) En primer lugar se hace una introducción sobre el anillamiento como metodología y se resumen las grandes cifras del anillamiento en España donde, hasta la fecha, se han anillado algo más de 10.000.000 de aves y se han registrado 700.000 recuperaciones (en la actualidad se anillan unas 380.000 aves y se obtienen unas 30.000 recuperaciones anualmente). (2) En un segundo bloque se resume la aplicación del anillamiento en diferentes aproximaciones al estudio científico de las aves, que van apoyadas por numerosas referencias bibliográficas sobre trabajos llevados a cabo en España. Gracias al anillamiento se han podido abordar múltiples estudios sobre movimientos y migraciones, reproducción, demografía, enfermedades, morfología, muda e identificación y taxonomía. (3) Un tercer bloque se centra en la utilidad del anillamiento más allá de la investigación básica. Es el caso de la conservación, la gestión de especies cinegéticas y el estudio de los impactos del cambio global sobre las aves, por un lado, y la educación ambiental, formación y ciencia ciudadana, por otro. (4) Finalmente, se abordan algunas ideas sobre los retos actuales y perspectivas de futuro del anillamiento en España

Effect of Rare Earth Ions on the Properties of Composites Composed of Ethylene Vinyl Acetate Copolymer and Layered Double Hydroxides

BACKGROUND: The study on the rare earth (RE)-doped layered double hydroxides (LDHs) has received considerable attention due to their potential applications in catalysts. However, the use of RE-doped LDHs as polymer halogen-free flame retardants was seldom investigated. Furthermore, the effect of rare earth elements on the hydrophobicity of LDHs materials and the compatibility of LDHs/polymer composite has seldom been reported. METHODOLOGY/PRINCIPAL FINDINGS: The stearate sodium surface modified Ni-containing LDHs and RE-doped Ni-containing LDHs were rapidly synthesized by a coprecipitation method coupled with the microwave hydrothermal treatment. The influences of trace amounts of rare earth ions La, Ce and Nd on the amount of water molecules, the crystallinity, the morphology, the hydrophobicity of modified Ni-containing LDHs and the adsorption of modifier in the surface of LDHs were investigated by TGA, XRD, TEM, contact angle and IR, respectively. Moreover, the effects of the rare earth ions on the interfacial compatibility, the flame retardancy and the mechanical properties of ethylene vinyl acetate copolymer (EVA)/LDHs composites were also explored in detail. CONCLUSIONS/SIGNIFICANCE: S-Ni₀.₁MgAl-La displayed more uniform dispersion and better interfacial compatibility in EVA matrix compared with other LDHs. Furthermore, the S-Ni₀.₁MgAl-La/EVA composite showed the best fire retardancy and mechanical properties in all composites

Synthesis of (cinnamate-zinc layered hydroxide) intercalation compound for sunscreen application

Background: Zinc layered hydroxide (ZLH) intercalated with cinnamate, an anionic form of cinnamic acid (CA), an efficient UVA and UVB absorber, have been synthesized by direct method using zinc oxide (ZnO) and cinnamic acid as the precursor. Results: The resulting obtained intercalation compound, ZCA, showed a basal spacing of 23.9 Å as a result of cinnamate intercalated in a bilayer arrangement between the interlayer spaces of ZLH with estimated percentage loading of cinnamate of about 40.4 % w/w. The UV–vis absorption spectrum of the intercalation compound showed excellent UVA and UVB absorption ability. Retention of cinnamate in ZLH interlayers was tested against media usually came across with sunscreen usage to show low release over an extended period of time. MTT assay of the intercalation compound on human dermal fibroblast (HDF) cells showed cytotoxicity of ZCA to be concentration dependent and is overall less toxic than its precursor, ZnO. Conclusions: (Cinnamate-zinc layered hydroxide) intercalation compound is suitable to be used as a safe and effective sunscreen with long UV protection effect

New live screening of plant-nematode interactions in the rhizosphere

Abstract Free living nematodes (FLN) are microscopic worms found in all soils. While many FLN species are beneficial to crops, some species cause significant damage by feeding on roots and vectoring viruses. With the planned legislative removal of traditionally used chemical treatments, identification of new ways to manage FLN populations has become a high priority. For this, more powerful screening systems are required to rapidly assess threats to crops and identify treatments efficiently. Here, we have developed new live assays for testing nematode responses to treatment by combining transparent soil microcosms, a new light sheet imaging technique termed Biospeckle Selective Plane Illumination Microscopy (BSPIM) for fast nematode detection, and Confocal Laser Scanning Microscopy for high resolution imaging. We show that BSPIM increased signal to noise ratios by up to 60 fold and allowed the automatic detection of FLN in transparent soil samples of 1.5 mL. Growing plant root systems were rapidly scanned for nematode abundance and activity, and FLN feeding behaviour and responses to chemical compounds observed in soil-like conditions. This approach could be used for direct monitoring of FLN activity either to develop new compounds that target economically damaging herbivorous nematodes or ensuring that beneficial species are not negatively impacted