Comment peut-on qualifier l'offre en logement suivant les territoires ? Approche de la question et proposition d'indicateurs

La problématique de l’étalement et du renouvellement urbain est au cœur des préoccupations actuelles en matière de planification et d’aménagement du territoire. Elle entretient une relation étroite avec l’évaluation de l’attractivité et de l’offre urbaine et la thématique de l’habitat. La multiplicité des indicateurs et des données existantes sur ce thème, nécessite une réflexion préalable importante pour « problématiser » l’observation et sélectionner des indicateurs pertinents pour répondre aux questions sous-jacentes à l’étude de ces phénomènes. Ce document vise donc à proposer une approche possible pour évaluer et qualifier l’offre en logement selon les territoires dans le contexte exposé ci-dessus. L’approche repose sur un découpage de la question selon différents objets d’observation, et présente de façon détaillée les indicateurs qu’il est possible d’utiliser pour y répondre. Chacun d’eux est documenté de façon très précise : liens entretenus avec la question, modes de calculs et sources utilisables, illustrations issues de tests réalisés sur cinq sites expérimentaux, sans oublier les extensions possibles, ainsi que les limites et précautions à prendre en compte pour leur utilisation. Les professionnels de l’observation y trouveront tous les éléments leur permettant de mettre en œuvre les indicateurs proposés sur leurs territoires pour procéder à leurs propres analyses, dès lors qu’ils possèdent localement les données nécessaire

Comment peut-on qualifier l'offre en logement suivant les territoires ? Approche de la question et proposition d'indicateurs

La problématique de l’étalement et du renouvellement urbain est au cœur des préoccupations actuelles en matière de planification et d’aménagement du territoire. Elle entretient une relation étroite avec l’évaluation de l’attractivité et de l’offre urbaine et la thématique de l’habitat. La multiplicité des indicateurs et des données existantes sur ce thème, nécessite une réflexion préalable importante pour « problématiser » l’observation et sélectionner des indicateurs pertinents pour répondre aux questions sous-jacentes à l’étude de ces phénomènes. Ce document vise donc à proposer une approche possible pour évaluer et qualifier l’offre en logement selon les territoires dans le contexte exposé ci-dessus. L’approche repose sur un découpage de la question selon différents objets d’observation, et présente de façon détaillée les indicateurs qu’il est possible d’utiliser pour y répondre. Chacun d’eux est documenté de façon très précise : liens entretenus avec la question, modes de calculs et sources utilisables, illustrations issues de tests réalisés sur cinq sites expérimentaux, sans oublier les extensions possibles, ainsi que les limites et précautions à prendre en compte pour leur utilisation. Les professionnels de l’observation y trouveront tous les éléments leur permettant de mettre en œuvre les indicateurs proposés sur leurs territoires pour procéder à leurs propres analyses, dès lors qu’ils possèdent localement les données nécessaire

Simultaneous reversible addition fragmentation chain transfer and ring-opening polymerization

The simultaneous ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) and 2-hydroxyethyl methacrylate (HEMA) polymerization via reversible addition fragmentation chain transfer (RAFT) chemistry and the possible access to graft copolymers with degradable and nondegradable segments is investigated. HEMA and ε-CL are reacted in the presence of cyanoisopropyl dithiobenzoate (CPDB) and tin(II) 2-ethylhexanoate (Sn(Oct)2) under typical ROP conditions (T > 100°C) using toluene as the solvent in order to lead to the graft copolymer PHEMA-g-PCL. Graft copolymer formation is evidenced by a combination of size-exclusion chromatography (SEC) and NMR analyses as well as confirmed by the hydrolysis of the PCL segments of the copolymer. With targeted copolymers containing at least 10% weight of PHEMA and relatively small PHEMA backbones (ca. 5,000-10,000 g mol-1) the copolymer grafting density is higher than 90%. The ratio of free HEMA-PCL homopolymer produced during the "one-step" process was found to depend on the HEMA concentration, as well as the half-life time of the radical initiator used. © 2008 Wiley Periodicals, Inc

In Situ Formation of Bis(phosphinimino)methanide Rare Earth Alkoxide Initiators for the Ring-Opening Polymerization of e-Caprolactone

series of pentamethylcyclopentadienyl bis(phosphinimino)methanide complexes of yttrium and the lanthanides, [{CH(PPh2NSiMe3)2}Ln(h5-C5Me5)Cl] (Ln = Y (1a), Sm (1b), Yb (1c)), were prepd. by two different synthetic approaches. The compds. can be obtained either from [{CH(PPh2NSiMe3)2}LnCl2]2 (Ln = Y, Sm, Yb) and K(C5Me5) or in a one-pot reaction when K{CH(PPh2NSiMe3)2} is reacted with anhyd. rare earth trichlorides in the presence of K(C5Me5). When 1a-c were combined in situ with 1 equiv. of 2-propanol, an active [Ln]-OiPr initiator was formed that enabled the pseudo-living ring-opening polymn. of e-caprolactone to polymers with controlled mol. features (end groups, .hivin.Mn) and very narrow molar mass distributions

Biodegradable polycarbonate-b-polypeptide and polyester-b-polypeptide block copolymers: Synthesis and nanoparticle formation towards biomaterials

The amino poly(trimethylene carbonate)-NHt-Boc (PTMC-NHt-Boc) and poly(E-caprolactone)-NHt-Boc (PCL-NHt-Boc) were synthesized by ring-opening polymerization (ROP) of TMC or CL and subsequently deprotected into the corresponding PTMC-NH2 and PCL-NH2. These functional homopolymers were used as macroinitiators for the ROP of gamma-benzyl-L-glutamate N-carboxyanhydride (BLG), consequently, giving the respective diblock copolymers PTMC-b-PBLG and PCL-b-PBLG in almost quantitative yields. The (co)polymers have been characterized by NMR and SEC analyses. DSC and IR studies confirmed the block structure of the copolymers and highlighted a phase separation between the rigid peptide (alpha-helix conformation) and the more flexible polyester segments. The self-assembly and the degradation behaviors of the copolymers depended on the nature of the polyester block and on the copolymer composition. Nanoparticles obtained from PBLG block copolymers were twice smaller (R-H < 100 nm) than those formed from PTMC and PCL homopolymers. Finally, their enzymatic degradation revealed that PTMC nanoparticles degraded faster than those made of PCL

Controlling drug release from non-aqueous environments: Moderating delivery from ocular silicone oil drug reservoirs to combat proliferative vitreoretinopathy

In a number of cases of retinal detachment, treatment may require the removal of the vitreous humour within the eye and replacement with silicone oil to aid healing of the retina. The insertion of silicone oil offers the opportunity to also deliver drugs to the inside of the eye; however, drug solubility in silicone oil is poor and release from this hydrophobic drug reservoir is not readily controlled. Here, we have designed a range of statistical graft copolymers that incorporate dimethylsiloxane and ethylene glycol repeat units within the side chains, allowing short chains of oligo(ethylene glycol) to be solubilised within silicone oil and provide hydrogen bond acceptor sites to interact with acid functional drug molecules. Our hypothesis included the potential for such interactions to be able to delay/control drug release and for polymer architecture and composition to play a role in the silicone oil miscibility of the targeted polymers. This strategy has been successfully demonstrated using both ibuprofen and all-trans retinoic acid; drugs with anti-inflammatory and anti-proliferation activity. After the copolymers were shown to be non-toxic to retinal pigment epithelial cells, studies of drug release using radiochemical approaches showed that the presence of 10 v/v% of a linear graft copolymer could extend ibuprofen release over three-fold (from 3 days to > 9 days) whilst the release of all-trans retinoic from the silicone oil phase was extended to > 72 days. These timescales are highly clinically relevant showing the potential to tune drug delivery during the healing process and offer an efficient means to improve patient outcomes

Comment peut-on qualifier l'offre en logement suivant les territoires ? Approche de la question et proposition d'indicateurs

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : RL 491 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Group Release of Sanctuary Chimpanzees (Pan troglodytes) in the Haut Niger National Park, Guinea, West Africa: Ranging Patterns and Lessons So Far

The release of wild or captive-bred mammals within their historical ranges typically aims to reestablish populations in areas where they have become extinct or extirpated, to reinforce natural populations, or to resolve human-wildlife conflicts. Such programs, which also typically in parallel help foster the protection of the release site, concern a wide range of endangered mammalian species, including our closest living relatives: chimpanzees. In June 2008, the Chimpanzee Conservation Center (CCC), which is located in the High Niger National Park (HNNP) in Guinea, released a group of 12 chimpanzees (Pan troglodytes verus) comprised of 6 females and 6 males (8-20 yr old). The selected release site lies 32 km from the sanctuary in the Mafou, a core area of HNNP where wild chimpanzees are also known to occur. The purpose of this release was therefore to reinforce the natural chimpanzee population within the Mafou core area and to promote the protection of the HNNP. Nearly 2 yr postrelease, 9 chimpanzees still remain free-living. Two thirds of the release chimpanzees were equipped with VHF-GPS store-on-board tracking collars. We used data from retrieved collars to explore the release chimpanzees' habitat use, individual day range, and core area use (50% and 80%) during the first year of the release. Males traveled significantly further than females. Although minimum day range did not differ between the sexes or vary seasonally, some release males were active for longer during the day than the females. Males also ranged over larger areas and used a wider network of core areas than the females. Habitat use was similar to that recorded in wild chimpanzees in the HNNP. As of September 2010, 2 males and 3 females form a group at the release site. Two of these females gave birth to healthy offspring respectively 16 and 20 mo postrelease. Another female successfully immigrated into a wild chimpanzee community. We suggest that the success of this chimpanzee release can be attributed to the CCC's lengthy rehabilitation process and the savanna-mosaic habitat of the HNNP. This release demonstrates that under special socioecological circumstances, the release of wild-born adult chimpanzees of both sexes is a viable strategy, which can also function as an effective conservation tool