11 research outputs found
Les tétras-lyres des vallons de Salèse et Mollières, parc national du Mercantour. Domaine vital et influence du tourisme
The home ranges of 4 male and 2 female Black Grouses in the Mercantour National Park, south-east France, were studied by radiotelemetry. The areas ranged from 69.5 to 236 ha for males, and from 98 to 130 ha for females. These home ranges overlapped broadly, and all were included within park limits.
Tourism is a potential disturbing factor for Black Grouse in the Mercantour National Park. The percentage occurence of these birds was indeed low within a 50 m wide strip on each side of the two paths studied. However, beyond this 50 m limit, the distribution of the birds was mostly influenced by the structure of the vegetation.Houard Thierry, Mure Michel. Les tétras-lyres des vallons de Salèse et Mollières, parc national du Mercantour. Domaine vital et influence du tourisme . In: Revue d'Écologie. Supplément n°4, 1987. pp. 165-171
Chapitre II. Le mouflon de Corse
Bon Richard, Cugnasse Jean-Marc, Dubray Dominique, Rigaux Pierre, Gibert P., Houard Thierry. Chapitre II. Le mouflon de Corse . In: Revue d'Écologie. Supplément n°6, 1991. pp. 67-110
Occurrence of a lost fishing net within the marine area of the Port-Cros national Park (Provence, northwestern Mediterranean Sea). Sci. Rep. Port-Cros natl. Park, 26 : 109-118.
Sci. Rep. Port-Cros natl. Park, 26 : 109-118.not availabl
Metallogels: a novel approach for the nanostructuration of single-chain magnets
International audienceIn this study we demonstrate that single-chain magnets (SCMs) can be assembled in gel phase and transferred intact on surface. We take advantage of a family of SCMs based on Tb(III) ions and nitronyl-nitroxides radicals functionalized with short alkyl chains known to form crystalline supramolecular nanotubes interacting with heptane acting as crystallizing solvent. When the radicals are functionalized with long aliphatic chains a robust gel is formed with similar structural and functional properties respect to its crystalline parent. Indeed, a small-angle X-ray scattering (SAXS) study unambiguously demonstrates that the gel is made of supramolecular nanotubes: the high stability of the gel allows the determination from SAXS data of precise nanotube metrics such as diameter, helical pitch and monoclinic cell of the folded 2D crystal lattice along the tube direction. Additionally, static and dynamic magnetic investigations show the persistence of the SCM behavior in the metallogel. Last, on-surface gelation provides thick films as well as sub-monolayer deposits of supramolecular nanotubes on surface as evidenced by atomic force microscopy (AFM) observations. This paves the road toward magnetic materials and devices made of SCMs profiting of their isolation on surface as individual chains
Single-chain magnet behavior in a finite linear hexanuclear molecule
International audienceThe careful monitoring of crystallization conditions of a mixture made of a Tb building block and a substituted nitronyl-nitroxide that typically provides infinite coordination polymers (), affords a remarkably stable linear hexanuclear molecule made of six Tb ions and five NIT radicals. The are double-bridged by water molecules but calculations demonstrate that this bridge is inefficient in mediating any magnetic interaction other than a small dipolar antiferromagnetic coupling. Surprisingly the , despite being finite molecules, show a single-chain magnet (SCM) behavior. This results in a magnetic hysteresis at low temperature whose coercive field is almost doubled when compared to the . We thus demonstrate that finite linear molecules can display SCM magnetic relaxation, which is a strong asset for molecular data storage purposes because 1D magnetic relaxation is more robust than the relaxation mechanisms observed in single-molecule magnets (SMMs) where under-barrier magnetic relaxation can operate
Chiral supramolecular nanotubes of single-chain magnets
International audienceWe report a Single-Chain Magnet (SCM) made of a Terbium(III) building block and a nitronyl-nitroxide radical (NIT) functionalized with an aliphatic chain. This substitution is targeted to induce a long range distortion of the polymeric chain and accordingly it gives rise to chains that are curled with almost 20 nm helical pitch. They self-organize as a chiral tubular superstructure made of 11 chains wound around each other. The supramolecular tubes have a 4.5 nm internal diameter. Overall, this forms a porous chiral network with almost 44% porosity. Ab-initio calculations highlight that each Tb III ion possesses high magnetic anisotropy. Indeed, notwithstanding the supramolecular arrangement each chain behaves as a SCM. Magnetic relaxation with both finite and infinite-size regimes is observed and confirms the validity of the Ising approximation. This is associated with quite strong coercive field and magnetic remanence (Hc = 2400 Oe MR = 2.09 µB at 0.5 K) for this class of compounds
Investigation and control of metallogel formation for the deposition of supramolecular nanotubes of single-chain magnets
International audienceMetallogels are versatile and intriguing objects that can be used as media for the deposition of extended molecular architectures on surfaces. In this work, we investigate the thermodynamic and kinetics conditions that induce robust metallogel formation from supramolecular nanotubes of single-chain magnets (SCM). These latter are made of woven chains that alternate Tb and nitronyl-nitroxide radical building blocks. By tailoring the size of the alkyl chain grafted on the radical (NITPhOCn, with n = 6, 10, or 18) we show that long alkyl chains induce delicate gelation conditions but provide gels with improved stability against crystallization and enhanced deposition ability while preserving the overall SCM behaviour of the molecular nanotubes
The Candidate Blood-stage Malaria Vaccine P27A Induces a Robust Humoral Response in a Fast Track to the Field Phase 1 Trial in Exposed and Nonexposed Volunteers.
P27A is an unstructured 104mer synthetic peptide from Plasmodium falciparum trophozoite exported protein 1 (TEX1), the target of human antibodies inhibiting parasite growth. The present project aimed at evaluating the safety and immunogenicity of P27A peptide vaccine in malaria-nonexposed European and malaria-exposed African adults.
This study was designed as a staggered, fast-track, randomized, antigen and adjuvant dose-finding, multicenter phase 1a/1b trial, conducted in Switzerland and Tanzania. P27A antigen (10 or 50 μg), adjuvanted with Alhydrogel or glucopyranosil lipid adjuvant stable emulsion (GLA-SE; 2.5 or 5 μg), or control rabies vaccine (Verorab) were administered intramuscularly to 16 malaria-nonexposed and 40 malaria-exposed subjects on days 0, 28, and 56. Local and systemic adverse events (AEs) as well as humoral and cellular immune responses were assessed after each injection and during the 34-week follow-up.
Most AEs were mild to moderate and resolved completely within 48 hours. Systemic AEs were more frequent in the formulation with alum as compared to GLA-SE, whereas local AEs were more frequent after GLA-SE. No serious AEs occurred. Supported by a mixed Th1/Th2 cell-mediated immunity, P27A induced a marked specific antibody response able to recognize TEX1 in infected erythrocytes and to inhibit parasite growth through an antibody-dependent cellular inhibition mechanism. Incidence of AEs and antibody responses were significantly lower in malaria-exposed Tanzanian subjects than in nonexposed European subjects.
The candidate vaccine P27A was safe and induced a particularly robust immunogenic response in combination with GLA-SE. This formulation should be considered for future efficacy trials.
NCT01949909, PACTR201310000683408
High Risk of Anal and Rectal Cancer in Patients With Anal and/or Perianal Crohn’s Disease
International audienceBackground & AimsLittle is known about the magnitude of the risk of anal and rectal cancer in patients with anal and/or perineal Crohn’s disease. We aimed to assess the risk of anal and rectal cancer in patients with Crohn’s perianal disease followed up in the Cancers Et Surrisque Associé aux Maladies Inflammatoires Intestinales En France (CESAME) cohort.MethodsWe collected data from 19,486 patients with inflammatory bowel disease (IBD) enrolled in the observational CESAME study in France, from May 2004 through June 2005; 14.9% of participants had past or current anal and/or perianal Crohn’s disease. Subjects were followed up for a median time of 35 months (interquartile range, 29–40 mo). To identify risk factors for anal cancer in the total CESAME population, we performed a case-control study in which participants were matched for age and sex.ResultsAmong the total IBD population, 8 patients developed anal cancer and 14 patients developed rectal cancer. In the subgroup of 2911 patients with past or current anal and/or perianal Crohn’s lesions at cohort entry, 2 developed anal squamous-cell carcinoma, 3 developed perianal fistula–related adenocarcinoma, and 6 developed rectal cancer. The corresponding incidence rates were 0.26 per 1000 patient-years for anal squamous-cell carcinoma, 0.38 per 1000 patient-years for perianal fistula–related adenocarcinoma, and 0.77 per 1000 patient-years for rectal cancer. Among the 16,575 patients with ulcerative colitis or Crohn’s disease without anal or perianal lesions, the incidence rate of anal cancer was 0.08 per 1000 patient-years and of rectal cancer was 0.21 per 1000 patient-years. Among factors tested by univariate conditional regression (IBD subtype, disease duration, exposure to immune-suppressive therapy, presence of past or current anal and/or perianal lesions), the presence of past or current anal and/or perianal lesions at cohort entry was the only factor significantly associated with development of anal cancer (odds ratio, 11.2; 95% CI, 1.18-551.51; P = .03).ConclusionsIn an analysis of data from the CESAME cohort in France, patients with anal and/or perianal Crohn’s disease have a high risk of anal cancer, including perianal fistula–related cancer, and a high risk of rectal cancer