Rodlike Complexes of a Polyelectrolyte (Hyaluronan) and a Protein (Lysozyme) observed by SANS

We study by Small Angle Neutron Scattering (SANS) the structure of Hyaluronan -Lysozyme complexes. Hyaluronan (HA) is a polysaccharide of 9 nm intrinsic persistence length that bears one negative charge per disaccharide monomer (Mmol = 401.3 g/mol); two molecular weights, Mw = 6000 and 500 000 Da were used. The pH was adjusted at 4.7 and 7.4 so that lysozyme has a global charge of +10 and + 8 respectively. The lysozyme concentration was varied from 3 to 40 g/L, at constant HA concentration (10 g/L). At low protein concentration, samples are monophasic and SANS experiments reveal only fluctuations of concentration although, at high protein concentration, clusters are observed by SANS in the dense phase of the diphasic samples. In between, close to the onset of the phase separation, a distinct original scattering is observed. It is characteristic of a rod-like shape, which could characterize "single" complexes involving one or a few polymer chains. For the large molecular weight (500 000) the rodlike rigid domains extend to much larger length scale than the persistence length of the HA chain alone in solution and the range of the SANS investigation. They can be described as a necklace of proteins attached along a backbone of diameter one or a few HA chains. For the short chains (Mw ~ 6000), the rod length of the complexes is close to the chain contour length (~ 15 nm)

Full Stock Payment Marginalization in M&A Transactions

The number of merger and acquisition (M&A) transactions paid fully in stock in the U.S. market declined sharply after 2001, when pooling and goodwill amortization were abolished by the Financial Accounting Standards Board. Did this accounting rule change really have such far-reaching implications? Using a differences-in-differences test and Canada as a counterfactual, this study reveals that it did. We also report several other results confirming the role of pooling abolishment, including (i) that the decrease in full stock payment relates to CEO incentives and (ii) that previously documented determinants of the M&A mode of payment cannot explain the post pooling abolishment pattern. These results are also robust to controls for various factors, such as the Internet bubble, the exclusion of cross-border deals, the presence of Canadian cross-listed firms, the use of a constant sample of acquirers across the pooling and post pooling abolishment periods, the use of Europe as an alternative counterfactual, and controls for the SEC Rule 10b-18 share repurchase safe harbor amendments of 2003

Improved Methods for Detecting Acquirer Skills

Large merger and acquisition (M&A) samples feature the pervasive presence of repetitive acquirers. They offer an attractive empirical context for revealing the presence of acquirer skills (persistent superior performance). But panel data M&A are quite heterogeneous; just a few acquirers undertake many M&As. Does this feature affect statistical inference? To investigate the issue, our study relies on simulations based on real data sets. The results suggest the existence of a bias, such that extant statistical support for the presence of acquirer skills appears compromised. We introduce a new resampling method to detect acquirer skills with attractive statistical properties (size and power) for samples of acquirers that complete at least five acquisitions. The proposed method confirms the presence of acquirer skills but only for a marginal fraction of the acquirer population. This result is robust to endogenous attrition and varying time periods between successive transactions. Claims according to which acquirer skills are a first order factor explaining acquirer cross-­‐sectional cumulated abnormal returns appears overstated

Empirical Evidence of Overbidding in M&A Contests

Surprisingly few papers have attempted to develop a direct empirical test for overbidding in M&A contests. We develop such a test grounded on a necessary condition for profit maximizing bidding behavior. The test is not subject to endogeneity concerns. Our results strongly support the existence of overbidding. We provide evidence that overbidding is related to conflicts of interest, but also some indirect evidence that it arises from failing to fully account for the winner’s curse

PicoLibre : a free collaborative platform to improve students'skills in software engineering

International audienceThe work described in this paper consists in the development of a pedagogical collaborative platform to improve the know-how of our students in software engineering and collaborative work. Its use in a free software context leads to greater commitment of the students and better reusability of their work

Isolation of a Novel Phage with Activity against Streptococcus mutans Biofilms

peer-reviewedStreptococcus mutans is one of the principal agents of caries formation mainly, because of its ability to form biofilms at the tooth surface. Bacteriophages (phages) are promising antimicrobial agents that could be used to prevent or treat caries formation by S. mutans. The aim of this study was to isolate new S. mutans phages and to characterize their antimicrobial properties. A new phage, ɸAPCM01, was isolated from a human saliva sample. Its genome was closely related to the only two other available S. mutans phage genomes, M102 and M102AD. ɸAPCM01 inhibited the growth of S. mutans strain DPC6143 within hours in broth and in artificial saliva at multiplicity of infections as low as 2.5x10-5. In the presence of phage ɸAPCM01 the metabolic activity of a S. mutans biofilm was reduced after 24 h of contact and did not increased again after 48 h, and the live cells in the biofilm decreased by at least 5 log cfu/ml. Despite its narrow host range, this newly isolated S. mutans phage exhibits promising antimicrobial properties

New Concepts in Oxidation Processes

This Special Issue of Catalysts aims to cover the recent progress and novel trends in the field of catalytic oxidation reaction. Topics addressed in this special issue concern the influence of different parameters on catalytic activity at various scales (atomic, laboratory, pilot, or industrial scales), the development of new catalytic materials of environmental or industrial importance, as well as the development of new methods, both microscopic and spectroscopic, to analyze oxidation processes

Novel pathogenic variant in TGFBR2 confirmed by molecular modeling is a rare cause of Loeys-Dietz syndrome

Loeys-Dietz syndrome (LDS) is a connective tissue disorder characterized by vascular findings of aneurysm and/or dissection of cerebral, thoracic, or abdominal arteries and skeletal findings. We report a case of a novel pathogenic variant in TGFBR2 and phenotype consistent with classic LDS. The proband was a 10-year-old presenting to the genetics clinic with an enlarged aortic root (Z-scores 5-6), pectus excavatum, and congenital contractures of the right 2nd and 3rd digit. Molecular testing of TGFBR2 was sent to a commercial laboratory and demonstrated a novel, likely pathogenic, variant in exon 4, c.1061T>C, p.(L354P). Molecular modeling reveals alteration of local protein structure as a result of this pathogenic variant. This pathogenic variant has not been previously reported in LDS and thus expands the pathogenic variant spectrum of this condition

Medulloblastoma has a global impact on health related quality of life: Findings from an international cohort.

BackgroundUnderstanding the global impact of medulloblastoma on health related quality of life (HRQL) is critical to characterizing the broad impact of this disease and realizing the benefits of modern treatments. We evaluated HRQL in an international cohort of pediatric medulloblastoma patients.MethodsSeventy-six patients were selected from 10 sites across North America, Europe, and Asia, who participated in the Medulloblastoma Advanced Genomics International Consortium (MAGIC). The Health Utilities Index (HUI) was administered to patients and/or parents at each site. Responses were used to determine overall HRQL and attributes (ie specific subdomains). The impact of various demographic and medical variables on HRQL was considered-including molecular subgroup.ResultsThe majority of patients reported having moderate or severe overall burden of morbidity for both the HUI2 and HUI3 (HUI2 = 60%; HUI3 = 72.1%) when proxy-assessed. Self-care in the HUI2 was rated as higher (ie better outcome) for patients from Western versus Eastern sites, P = .02. Patients with nonmetastatic status had higher values (ie better outcomes) for the HUI3 hearing, HUI3 pain, and HUI2 pain, all P < .05. Patients treated with a gross total resection also had better outcomes for the HUI3 hearing (P = .04). However, those who underwent a gross total resection reported having worse outcomes on the HUI3 vision (P = .02). No differences in HRQL were evident as a function of subgroup.ConclusionsBy examining an international sample of survivors, we characterized the worldwide impact of medulloblastoma. This is a critical first step in developing global standards for evaluating long-term outcomes