University of Lausanne

About: University of Lausanne is a education organization based out in Lausanne, Switzerland. It is known for research contribution in the topics: Population & Medicine. The organization has 20508 authors who have published 46458 publications receiving 1996655 citations. The organization is also known as: Université de Lausanne & UNIL.

Blocks, liquidity and corporate control

Abstract: The paper develops a simple model of corporate ownership structure in which costs and benefits of ownership concentration are analyzed The model cornpares the liquidity benefits obtained through dispersed corporate ownership with the benefits from efficient management control achieved by some degree of ownership concentration The paper reexamines the free-rider problem in corporate control in the presence of liquidity trading, derives predictions for the trade and pricing of blocks, and provides criteria for the optimal choice of ownership structure THE RECENT INCOMPLETE CONTRACTING approach in corporate finance has considerably improved our understanding of how small firms determine their capital structure The basic setting considered in this line of research is one where a founder-manager seeks funding from one or several financiers The main premise is that the founder-manager, in her dealings with the financiers, is primarily concerned with maintaining her private benefits of control For small firms these are often quite large relative to the financial returns Thus, for a small firm the problem of determining the financial structure often reduces to the problem of how to obtain fundingr while giving away as little control as possible to the financiers Of course, most financiers insist on some form of protection, so that the final compromise reached in most financial contracts for small firms is one resembling a debt contract (or a venture capital contract), which protects the founder-manager's control as long as the firm is performing adequately' This perspective for small firms does not extend naturally to large firms because the private benefits of control of the managers for large firms are likely to be small relative to the firm's monetary returns, so that protection of these benefits is not an overriding consideration Moreover, large firms

Warming experiments underpredict plant phenological responses to climate change

Abstract: Warming experiments are increasingly relied on to estimate plant responses to global climate change. For experiments to provide meaningful predictions of future responses, they should reflect the empirical record of responses to temperature variability and recent warming, including advances in the timing of flowering and leafing. We compared phenology (the timing of recurring life history events) in observational studies and warming experiments spanning four continents and 1,634 plant species using a common measure of temperature sensitivity (change in days per degree Celsius). We show that warming experiments underpredict advances in the timing of flowering and leafing by 8.5-fold and 4.0-fold, respectively, compared with long-term observations. For species that were common to both study types, the experimental results did not match the observational data in sign or magnitude. The observational data also showed that species that flower earliest in the spring have the highest temperature sensitivities, but this trend was not reflected in the experimental data. These significant mismatches seem to be unrelated to the study length or to the degree of manipulated warming in experiments. The discrepancy between experiments and observations, however, could arise from complex interactions among multiple drivers in the observational data, or it could arise from remediable artefacts in the experiments that result in lower irradiance and drier soils, thus dampening the phenological responses to manipulated warming. Our results introduce uncertainty into ecosystem models that are informed solely by experiments and suggest that responses to climate change that are predicted using such models should be re-evaluated.

Hypertension caused by a truncated epithelial sodium channel γ subunit: genetic heterogeneity of Liddle syndrome

Abstract: Sensitivity of blood pressure to dietary salt is a common feature in subjects with hypertension. These features are exemplified by the mendelian disorder, Liddle's syndrome, previously shown to arise from constitutive activation of the renal epithelial sodium channel due to mutation in the β subunit of this channel. We now demonstrate that this disease can also result from a mutation truncating the carboxy terminus of the γ subunit of this channel; this truncated subunit also activates channel activity. These findings demonstrate genetic heterogeneity of Liddle's syndrome, indicate independent roles of β and γ subunits in the negative regulation of channel activity, and identify a new gene in which mutation causes a salt–sensitive form of human hypertension.

Iridoid Glucosides with Free Radical Scavenging Properties from Fagraea blumei

Abstract: Four new iridoid glucosides 1–4, named blumeosides A–D, were isolated from the methanolic stem-bark extract of Fagraea blumei G. DON. (Loganiaceae). They were accompanied by the benzyl-alcohol derivative di-O-methylcrenatin (5) and the flavone C-glucoside swertisin (6). The structures of 1–4 were established by spectroscopic methods, including FAB-MS, and 1H- and 13C-NMR, and by alkaline hydrolysis. Blumeosides A (1) and C (3) are 10-O-(2,5-dihydroxytercphthalo) adoxosidic acid and 10-O-(2-hydroxyterephthalo)adoxosidic acid, respectively. In blumeosides B (4) and D (2), both carboxylic groups of the terephthalic-acid moiety are esterified by adoxosidic-acid units, Blumeosides A–D (1–4) inhibited bleaching of crocin induced by alkoxyl radicals. Blumeosides A (1) and D (2) also demonstrated scavenging properties towards the 2,2-diphenyl-1-picryl-hvdrazvl (CDPPH) radical in TLC autographic and spectrophotometric assays.

Subgroup-specific structural variation across 1,000 medulloblastoma genomes

Abstract: Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-β signalling in Group 3, and NF-κB signalling in Group 4, suggest future avenues for rational, targeted therapy.