PUBLIC POLICY IN VERTICALLY RELATED MARKETS: A COURNOT OLIGOPOLY-OLIGOPSONY MODEL

We use a partial equilibrium two-country model, with two vertically related markets, with perfect competition in the primary good sector and with a fixed number of processing firms in each country, characterized by a Cournot behavior upstream and downstream. In the first stage of the game, the government of the exporting country chooses the level of price instruments on both goods. The targeting principle is used to characterize optimal intervention in presence of a minimum revenue constraint towards primary producers. Keywords: vertically related markets, imperfectvertically related markets, imperfect competition, Industrial Organization, International Relations/Trade, F1, H2, L1, Q1,

Seasonal density estimates of common large herbivores in Hwange National Park, Zimbabwe

The monitoring of ecosystem processes and states is a critical step in the management of protected areas. It allows for the assessment of the success or failure of practices ranging from ‘laissez-faire’ to strong hands-on policies. Much effort is for instance devoted to the monitoring of wildlife abundance, particularly when associated with large ecological influence or socio-economical values (Gordon, Hester & Festa-Bianchet, 2004). In Africa, the diversity of large herbivores represents both a major asset of protected areas and a global conservation target as a consequence of the dramatic decline of wildlife populations under other land uses. In addition to the local importance of such monitoring data, collation of data from multiple sites ultimately allows general patterns to be revealed (e.g. Fritz & Duncan, 1994). Here, we contribute to the general knowledge on large African herbivores by reporting on their seasonal abundance, using road transect counts, in Hwange National Park (thereafter HNP), north-western Zimbabwe

Comparative study of lipids and fatty acids in the liver, muscle, and eggs of wild and captive common snook broodstock

In this study, the lipid composition of wild and captive common snook broodstock were investigated to identify potential nutritional deficiencies and formulate suitable diets for captive stocks. Results showed captive snook incorporated significantly more lipid than their wild counterparts. However, cholesterol and arachidonic acid (ARA) levels were significantly lower compared to wild fish, which may impact steroid and prostaglandin production, reproductive behavior and gametogenesis. In eggs obtained from captive broodstock, high docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels, associated with low ARA contents were found. As a result, ARA/EPA ratio in captive eggs was less than half of that in wild eggs with the potential for negative consequences on embryo and larval development. In conclusion, large differences were noticed between wild and captive broodstock that may contribute to the reproductive dysfunctions observed in captive snook broodstock (e.g. incomplete oocyte maturation, low milt production and highly variable egg and larval quality). The wild snook survey also identified the presence of hydrocarbons in the liver, which should be further studied to identify a potential impact on the reproductive performances of a vulnerable population like common snook

Functional limb muscle innervation prior to cholinergic transmitter specification during early metamorphosis in Xenopus

In vertebrates, functional motoneurons are defined as differentiated neurons that are connected to a central premotor network and activate peripheral muscle using acetylcholine. Generally, motoneurons and muscles develop simultaneously during embryogenesis. However, during Xenopus metamorphosis, developing limb motoneurons must reach their target muscles through the already established larval cholinergic axial neuromuscular system. Here, we demonstrate that at metamorphosis onset, spinal neurons retrogradely labeled from the emerging hindlimbs initially express neither choline acetyltransferase nor vesicular acetylcholine transporter. Nevertheless, they are positive for the motoneuronal transcription factor Islet1/2 and exhibit intrinsic and axial locomotor-driven electrophysiological activity. Moreover, the early appendicular motoneurons activate developing limb muscles via nicotinic antagonist-resistant, glutamate antagonist-sensitive, neuromuscular synapses. Coincidently, the hindlimb muscles transiently express glutamate, but not nicotinic receptors. Subsequently, both pre- and postsynaptic neuromuscular partners switch definitively to typical cholinergic transmitter signaling. Thus, our results demonstrate a novel context-dependent re-specification of neurotransmitter phenotype during neuromuscular system development

The archaeological potential of Wogan Cavern (Pembroke, UK):Results of the first fieldwork season

Funding Information: Acknowledgements Many thanks are due to numerous people for their help with our work on Wogan Cavern, including (but not limited to) Jon Williams and the staff at Pembroke Castle, Sian Williams, several colleagues at Dyfed Archaeological Trust, Mark Lewis and Eloise Chapman at Tenby Museum, and Louise Mees at Cadw. We are also grateful to the reviewers for a careful reading of this article and for providing some insightful comments, and to David Lowe, whose comments and advice benefitted the final version of the Paper. The work described here and that planned for the future is funded by the Natural History Museum’s Human Origins Research Fund, the BCRA’s CSTRF scheme, and the Prehistoric Society. ELJ acknowledges the Belspo-ICHIE project for funding her contribution to this research.Peer reviewedPublisher PD

Evolution of antibiotic treatments for healthcare-associated infections caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae in France

BACKGROUND: Infections caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLE) remain a public health challenge. AIM: We traced the evolution of antibiotics prescribed for patients with ESBLE-healthcare associated infections (ESBLE-HAI) between 2012 and 2017, with a specific focus on treatments for lower urinary tract infections (LUTI). METHODS: We used the 2012 and 2017 French point prevalence survey data. Patients with ESBLE-HAI were defined as those diagnosed with at least one Enterobacteriaceae with ESBL production. Patients with LUTI caused by ESBLE (ESBLE-LUTI) were defined as those with LUTI as the reported infection site and diagnosed with ESBLE. We only analysed treatments intended for HAI. RESULTS: In 2017, more than half of treatments for ESBLE-HAIs were β-lactams. While from 2012 to 2017 the proportion of carbapenem treatments decreased from 30% to 25%, penicillin treatments doubled. Among patients treated for ESBLE-LUTI, a larger proportion received a single antibiotic in 2017. The most frequently prescribed antibiotics for these infections were amoxicillin/clavulanic acid, nitrofurantoin and ofloxacin. More than one out of six treatments lasted for more than 7 days. Carbapenem use was halved between 2012 and 2017, and decreases were likewise observed for aminoglycosides. CONCLUSION: In accordance with French recommendations, comparison of the two most recent French point prevalence surveys showed an evolution in ESBLE-HAI treatment, especially for ESBLE-LUTI. However, treatment durations remained longer than recommended. Data from the 2022 survey should provide insights on the future evolution of prescription trends

Quantitative nanohistology of aging dermal collagen

The skin is the largest organ in the body and is essential for protecting us from environmental stressors such as UV radiation, pollution, and pathogens. As we age, our skin undergoes complex changes that can affect its function, appearance, and health. These changes result from intrinsic (chronological) and extrinsic (environmental) factors that can cause damage to the skin’s cells and extracellular matrix. As higher-resolution microscopical techniques, such as Atomic Force Microscopy (AFM), are being deployed to support histology, it is possible to explore the biophysical properties of the dermal scaffold’s constituents, such as the collagen network. In this study, we demonstrate the use of our AFM-based quantitative nanohistology, performed directly on unfixed cryosections of 30 donors (female, Caucasian), to differentiate between dermal collagen from different age groups and anatomical sites. The initial 420 (10 × 10 μm2) Atomic Force Microscopy images were segmented into 42,000 (1 × 1 μm2) images before being classified according to four pre-defined empirical collagen structural biomarkers to quantify the structural heterogeneity of the dermal collagen. These markers include interfibrillar gap formation, undefined collagen structure, and registered or unregistered dense collagen fibrillar network with evident D-banding. The structural analysis was also complemented by extensive nanoindentation (∼1,000 curves) performed on individual fibrils from each section, yielding 30,000 indentation curves for this study. Principal Component Analysis was used to reduce the complexity of high-dimensional datasets. The % prevalence of the empirical collagen structural biomarkers between the papillary and reticular dermis for each section proves determinant in differentiating between the donors as a function of their age or the anatomical site (cheek or breast). A case of abnormal biological aging validated our markers and nanohistology approach. This case also highlighted the difference between chronological and biological aging regarding dermal collagen phenotyping. However, quantifying the impact of chronic and pathological conditions on the structure and function of collagen at the sub-micron level remains challenging and lengthy. By employing tools such as the Atomic Force Microscope as presented here, it is possible to start evaluating the complexity of the dermal matrix at the nanoscale and start identifying relevant collagen morphology which could be used toward histopathology standards

Genetic landscape of a large cohort of Primary Ovarian Insufficiency : New genes and pathways and implications for personalized medicine

Background Primary Ovarian Insufficiency (POI), a public health problem, affects 1-3.7% of women under 40 yield-ing infertility and a shorter lifespan. Most causes are unknown. Recently, genetic causes were identified, mostly in single families. We studied an unprecedented large cohort of POI to unravel its molecular pathophysiology.Methods 375 patients with 70 families were studied using targeted (88 genes) or whole exome sequencing with pathogenic/likely-pathogenic variant selection. Mitomycin-induced chromosome breakages were studied in patients' lymphocytes if necessary. Findings A high-yield of 29.3% supports a clinical genetic diagnosis of POI. In addition, we found strong evidence of pathogenicity for nine genes not previously related to a Mendelian phenotype or POI: ELAVL2, NLRP11, CENPE, SPATA33, CCDC150, CCDC185, including DNA repair genes: C17orf53(HROB), HELQ, SWI5 yielding high chromo-somal fragility. We confirmed the causal role of BRCA2, FANCM, BNC1, ERCC6, MSH4, BMPR1A, BMPR1B, BMPR2, ESR2, CAV1, SPIDR, RCBTB1 and ATG7 previously reported in isolated patients/families. In 8.5% of cases, POI is the only symptom of a multi-organ genetic disease. New pathways were identified: NF-kB, post-translational regulation, and mitophagy (mitochondrial autophagy), providing future therapeutic targets. Three new genes have been shown to affect the age of natural menopause supporting a genetic link.Interpretation We have developed high-performance genetic diagnostic of POI, dissecting the molecular pathogene-sis of POI and enabling personalized medicine to i) prevent/cure comorbidities for tumour/cancer susceptibility genes that could affect life-expectancy (37.4% of cases), or for genetically-revealed syndromic POI (8.5% of cases), ii) predict residual ovarian reserve (60.5% of cases). Genetic diagnosis could help to identify patients who may benefit from the promising in vitro activation-IVA technique in the near future, greatly improving its success in treating infertility.Funding Universite? Paris Saclay, Agence Nationale de Biome?decine.Copyright (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Peer reviewe

Low loss coatings for the VIRGO large mirrors

présentée par L. PinardThe goal of the VIRGO program is to build a giant Michelson type interferometer (3 kilometer long arms) to detect gravitational waves. Large optical components (350 mm in diameter), having extremely low loss at 1064 nm, are needed. Today, the Ion beam Sputtering is the only deposition technique able to produce optical components with such performances. Consequently, a large ion beam sputtering deposition system was built to coat large optics up to 700 mm in diameter. The performances of this coater are described in term of layer uniformity on large scale and optical losses (absorption and scattering characterization). The VIRGO interferometer needs six main mirrors. The first set was ready in June 2002 and its installation is in progress on the VIRGO site (Italy). The optical performances of this first set are discussed. The requirements at 1064 nm are all satisfied. Indeed, the absorption level is close to 1 ppm (part per million), the scattering is lower than 5 ppm and the R.M.S. wavefront of these optics is lower than 8 nm on 150 mm in diameter. Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the mirrors (thermal noise reduction)

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta