Convergence of the mass-transport steepest descent scheme for the sub-critical Patlak-Keller-Segel model

Variational steepest descent approximation schemes for the modified Patlak-Keller-Segel equation with a logarithmic interaction kernel in any dimension are considered. We prove the convergence of the suitably interpolated in time implicit Euler scheme, defined in terms of the Euclidean Wasserstein distance, associated to this equation for sub-critical masses. As a consequence, we recover the recent result about the global in time existence of weak-solutions to the modified Patlak-Keller-Segel equation for the logarithmic interaction kernel in any dimension in the sub-critical case. Moreover, we show how this method performs numerically in one dimension. In this particular case, this numerical scheme corresponds to a standard implicit Euler method for the pseudo-inverse of the cumulative distribution function. We demonstrate its capabilities to reproduce easily without the need of mesh-refinement the blow-up of solutions for super-critical masses.

On the critical periods of perturbed isochronous centers

"Vegeu el resum a l'inici del document del fitxer adjunt."

Microbial spoilage and quality of marinated dark, firm, dry meat

Estudi elaborat a partir d’una estada al Royal Veterinary and Agricultural University of Denmark entre els mesos de Març a Juny del 2006. S’ha investigat l’efecte dels envasats amb atmosferes modificades (MAP), així com la marinació amb vi tint, sobre l’evolució de la contaminació bacteriològica de carns fosques, dures i seques (DFD). Les carns DFD es troben a les canals d’animals que, abans del sacrifici, han estat exposades a activitats musculars prolongades o estrès. Les carns DFD impliquen importants pèrdues econòmiques degut a la contaminació bacteriològica i als problemes tecnològics relacionats amb la alta capacitat de retenció d’aigua. A més a més, és crític per la indústria investigar la diversitat de la contaminació bacteriana, identificar les espècies bacterianes i controlar-les. Però és difícil degut a la inhabilitat per detectar algunes bactèries en medis coneguts, les interaccions entre elles, la complexitat dels tipus de contaminació com són aigua, terra, femtes i l’ambient. La Polymerasa chain reaction- Denaturating Electrophoresis Gel (PCR-DGEE ) pot sobrepassar aquests problemes reflectint la diversitat microbial i les espècies bacterianes. Els resultants han indicat que la varietat bacteriana de la carn incrementava amb els dies d’envasat independentment del mètode d’envasat, però decreixia significativament amb el tractament de marinació amb vi tint. La DGEE ha mostrat diferències en les espècies trobades, indicant canvis en la contaminació bacteriana i les seves característiques en la carn DFD sota els diferents tractaments. Tot i que la marinació és una bona alternativa i solució a la comercialització de carn DFD , estudis de seqüenciació són necessaris per identificar les diferents tipus de bactèries.

The Ideas Debate in International and European Studies: Towards a Cartography and Critical Assessment

The appeal to ideas as causal variables and/or constitutive features of political processes increasingly characterises political analysis. Yet, perhaps because of the pace of this ideational intrusion, too often ideas have simply been grafted onto pre-existing explanatory theories at precisely the point at which they seem to get into difficulties, with little or no consideration either of the status of such ideational variables or of the character or consistency of the resulting theoretical hybrid. This is particularly problematic for ideas are far from innocent variables – and can rarely, if ever, be incorporated seamlessly within existing explanatory and/or constitutive theories without ontological and epistemological consequence. We contend that this tendency along with the limitations of the prevailing Humean conception of causality, and associated epistemological polemic between causal and constitutive logics, continue to plague almost all of the literature that strives to accord an explanatory role to ideas. In trying to move beyond the current vogue for epistemological polemic, we argue that the incommensurability thesis between causal and constitutive logics is only credible in the context of a narrow, Humean, conception of causation. If we reject this in favour of a more inclusive (and ontologically realist) understanding then it is perfectly possible to chart the causal significance of constitutive processes and reconstrue the explanatory role of ideas as causally constitutive.

Teaching clinical anatomy of the female pelvic floor to undergraduate students: A critical review of nevralgic points

Pelvic floor anatomy is complex and its three-dimensional organization is often difficult to understand for both undergrad- uate and postgraduate students. Here, we focused on several critical points that need to be considered when teaching the perineum. We have to deal with a mixed population of students and with a variety of interest. Yet, a perfect knowledge of the pelvic floor is the basis for any gynecologist and for any surgical intervention. Our objectives are several-fold; i) to estab- lish the objectives and the best way of teaching, ii) to identify and localize areas in the female pelvic floor that are suscepti- ble to generate problems in understanding the three-dimensional organization, iii) to create novel approaches by respecting the anatomical surroundings, and iv) prospectively, to identify elements that may create problems during surgery i.e. to have a closer look at nerve trajectories and on compression sites that may cause neuralgia or postoperative pain. A feedback from students concludes that they have difficulties to assimilate this much information, especially the different imaging tech- niques. Eventually, this will lead to a severe selection of what has to be taught and included in lectures or practicals. Another consequence is that more time to study prosected pelves needs to be given.

Critical evaluation of outcome scales to assess outcome after lateral ankle ligament repair

Introduction: Several scores are commonly used to evaluate patients' postoperative satisfaction after lateral ankle ligament repair, including: AOFAS, FAAM, CAIT and CAIS. Comparing published studies in the literature is difficult, as the same patient can have markedly different results depending on which scoring system is used. The current study aims to address this gap in the literature by developing a system to compare these tests, to allow better analysis and comparison of published studies. Patients and methods: This is a retrospective cohort study of 47 patients following lateral ankle ligament repair using a modified Broström-Gould technique. All patients were operated between 2005 and 2010 by a single surgeon and followed the same post operative rehabilitation protocol. Six patients were excluded from the study because of concomitant surgery. Patients were assessed by an independent observer. We used the Pearson correlation coefficient to analyse the concordance of the scores, as well as scatter plots to assess the linear relationship between them. Results: A linear distribution between the scores was found when the results were analysed using scatter plots. We were thus able to use the Pearson correlation coefficient to evaluate the relationship between each of the different postoperative scores. The correlation was found to be above 0.5 in all cases except for the comparison between the CAIT and the FAAM for the activities of daily living (0.39). We were, therefore, able to compare the results obtained and assess the relative concordance of the scoring systems. The results showed that the more specific the scale is, the worst the score is and inversely. So the CAIT and the CAIS appeared to be more severe than the AOFAS and the FAAM measuring the activities of daily living. The sports subscale of the FAAM demonstrated intermediate results. Conclusion: This study outlines a system to compare different postoperative scores commonly used to evaluate outcome after ankle stabilization surgery. The impact of this study is that it makes comparison of published studies easier, even though they use a variety of different clinical scores, thus facilitating better outcome analysis of operative techniques.

Critical mass for a Patlak-Keller-Segel model with degenerate diffusion in higher dimensions

"Vegeu el resum a l'inici del document del fitxer adjunt."

Pharmacokinetics and safety of panobacumab: specific adjunctive immunotherapy in critical patients with nosocomial Pseudomonas aeruginosa O11 pneumonia.

Objectives Nosocomial Pseudomonas aeruginosa pneumonia remains a major concern in critically ill patients. We explored the potential impact of microorganism-targeted adjunctive immunotherapy in such patients. Patients and methods This multicentre, open pilot Phase 2a clinical trial (NCT00851435) prospectively evaluated the safety, pharmacokinetics and potential efficacy of three doses of 1.2 mg/kg panobacumab, a fully human monoclonal anti-lipopolysaccharide IgM, given every 72 h in 18 patients developing nosocomial P. aeruginosa (serotype O11) pneumonia. Results Seventeen out of 18 patients were included in the pharmacokinetic analysis. In 13 patients receiving three doses, the maximal concentration after the third infusion was 33.9 ± 8.0 μg/mL, total area under the serum concentration-time curve was 5397 ± 1993 μg h/mL and elimination half-life was 102.3 ± 47.8 h. Panobacumab was well tolerated, induced no immunogenicity and was detected in respiratory samples. In contrast to Acute Physiology and Chronic Health Evaluation II (APACHE II) prediction, all 13 patients receiving three doses survived, with a mean clinical resolution in 9.0 ± 2.7 days. Two patients suffered a recurrence at days 17 and 20. Conclusions These data suggest that panobacumab is safe, with a pharmacokinetic profile similar to that in healthy volunteers. It was associated with high clinical cure and survival rates in patients developing nosocomial P. aeruginosa O11 pneumonia. We concluded that these promising results warrant further trials.

Development and current use of parenteral nutrition in critical care - an opinion paper.

Critically ill patients depend on artificial nutrition for the maintenance of their metabolic functions and lean body mass, as well as for limiting underfeeding-related complications. Current guidelines recommend enteral nutrition (EN), possibly within the first 48 hours, as the best way to provide the nutrients and prevent infections. EN may be difficult to realize or may be contraindicated in some patients, such as those presenting anatomic intestinal continuity problems or splanchnic ischemia. A series of contradictory trials regarding the best route and timing for feeding have left the medical community with great uncertainty regarding the place of parenteral nutrition (PN) in critically ill patients. Many of the deleterious effects attributed to PN result from inadequate indications, or from overfeeding. The latter is due firstly to the easier delivery of nutrients by PN compared with EN increasing the risk of overfeeding, and secondly to the use of approximate energy targets, generally based on predictive equations: these equations are static and inaccurate in about 70% of patients. Such high uncertainty about requirements compromises attempts at conducting nutrition trials without indirect calorimetry support because the results cannot be trusted; indeed, both underfeeding and overfeeding are equally deleterious. An individualized therapy is required. A pragmatic approach to feeding is proposed: at first to attempt EN whenever and as early as possible, then to use indirect calorimetry if available, and to monitor delivery and response to feeding, and finally to consider the option of combining EN with PN in case of insufficient EN from day 4 onwards.

Are there two species of Pygmy Shrews (Sorex)? Revisiting the question using DNA sequence data

Pygmy Shrews in North America have variously been considered to be one species (Sorex hoyi) or two species (S. hoyi and S. thompsoni). Currently, only S. hoyi is recognized. In this study, we examine mitochondrial DNA sequence data for the cytochrome b gene to evaluate the level of differentiation and phylogeographic relationships among eleven samples of Pygmy Shrews from across Canada. Pygmy Shrews from eastern Canada (i.e., Ontario, Quebec, New Brunswick, Nova Scotia, and Prince Edward Island) are distinct from Pygmy Shrews from western Canada (Alberta, Yukon) and Alaska. The average level of sequence divergence between these clades (3.3%) falls within the range of values for other recognized pairs of sister species of shrews. A molecular clock based on third position transversion substitutions suggests that these two lineages diverged between 0.44 and 1.67 million years ago. These molecular phylogenetic data. combined with a reinterpretation of previously published morphological data, are suggestive of separate species status for S. hoyi and S. thompsoni as has been previously argued by others. Further analysis of specimens from geographically intermediate areas (e.g., Manitoba. northern Ontario) is required to determine if there is secondary contact and/or introgression between these two putative species.

Representation of motor habit in a sequence of repetitive reach and grasp movements performed by macaque monkeys: evidence for a contribution of the dorsolateral prefrontal cortex.

In the context of an autologous cell transplantation study, a unilateral biopsy of cortical tissue was surgically performed from the right dorsolateral prefrontal cortex (dlPFC) in two intact adult macaque monkeys (dlPFC lesioned group), together with the implantation of a chronic chamber providing access to the left motor cortex. Three other monkeys were subjected to the same chronic chamber implantation, but without dlPFC biopsy (control group). All monkeys were initially trained to perform sequential manual dexterity tasks, requiring precision grip. The motor performance and the prehension's sequence (temporal order to grasp pellets from different spatial locations) were analysed for each hand. Following the surgery, transient and moderate deficits of manual dexterity per se occurred in both groups, indicating that they were not due to the dlPFC lesion (most likely related to the recording chamber implantation and/or general anaesthesia/medication). In contrast, changes of motor habit were observed for the sequential order of grasping in the two monkeys with dlPFC lesion only. The changes were more prominent in the monkey subjected to the largest lesion, supporting the notion of a specific effect of the dlPFC lesion on the motor habit of the monkeys. These observations are reminiscent of previous studies using conditional tasks with delay that have proposed a specialization of the dlPFC for visuo-spatial working memory, except that this is in a different context of "free-will", non-conditional manual dexterity task, without a component of working memory.

Characterization of a Trypanosoma cruzi genomic fragment complementary to several species-specific mRNAs but different from the spliced leader sequence

We have isolated a clone of Trypanosoma cruzi genimic DNA, lambda 3b2-5, which contains sequences that are reiterated in the genome. Northtern blot analysis showed that clone 3b2-5 hybridizes to 1,200-5,000 bases different mRNA species. The number of mRNAs species hybridized to clone 3b2-5 exceeds its coding capacity showing that this clone carries sequences that are common to several mRNAs species and conserved in the poly A(+) RNA. These sequences are not homologous to the T. cruzi spliced leader sequence, since clone 3b2-5 hybridize to a synthetic 20 nucleotice complementary to the spliced leader sequence. Clone 3b2-5 does not hybridize to DNA and RNA from several genera of Trypanosomatidae and other Trypanosoma species indicating that it carries T. cruzi species-specific sequences.

MFGE8 does not influence chorio-retinal homeostasis or choroidal neovascularization in vivo.

PURPOSE: Milk fat globule-epidermal growth factor-factor VIII (MFGE8) is necessary for diurnal outer segment phagocytosis and promotes VEGF-dependent neovascularization. The prevalence of two single nucleotide polymorphisms (SNP) in MFGE8 was studied in two exsudative or "wet" Age-related Macular Degeneration (AMD) groups and two corresponding control groups. We studied the effect of MFGE8 deficiency on retinal homeostasis with age and on choroidal neovascularization (CNV) in mice. METHODS: The distribution of the SNP (rs4945 and rs1878326) of MFGE8 was analyzed in two groups of patients with "wet" AMD and their age-matched controls from Germany and France. MFGE8-expressing cells were identified in Mfge8(+/-) mice expressing ß-galactosidase. Aged Mfge8(+/-) and Mfge8(-/-) mice were studied by funduscopy, histology, electron microscopy, scanning electron microscopy of vascular corrosion casts of the choroid, and after laser-induced CNV. RESULTS: rs1878326 was associated with AMD in the French and German group. The Mfge8 promoter is highly active in photoreceptors but not in retinal pigment epithelium cells. Mfge8(-/-) mice did not differ from controls in terms of fundus appearance, photoreceptor cell layers, choroidal architecture or laser-induced CNV. In contrast, the Bruch's membrane (BM) was slightly but significantly thicker in Mfge8(-/-) mice as compared to controls. CONCLUSIONS: Despite a reproducible minor increase of rs1878326 in AMD patients and a very modest increase in BM in Mfge8(-/-) mice, our data suggests that MFGE8 dysfunction does not play a critical role in the pathogenesis of AMD.

Evaluation of a summary score of cognitive performance for use in trials in perioperative and critical care.

Background/Aims: Cognitive dysfunction after medical treatment is increasingly being recognized. Studies on this topic require repeated cognitive testing within a short time. However, with repeated testing, practice effects must be expected. We quantified practice effects in a demographically corrected summary score of a neuropsychological test battery repeatedly administered to healthy elderly volunteers. Methods: The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Neuropsychological Assessment Battery (for which a demographically corrected summary score was developed), phonemic fluency tests, and trail-making tests were administered in healthy volunteers aged 65 years or older on days 0, 7, and 90. This battery allows calculation of a demographically adjusted continuous summary score. Results: Significant practice effects were observed in the CERAD total score and in the word list (learning and recall) subtest. Based on these volunteer data, we developed a threshold for diagnosis of postoperative cognitive dysfunction (POCD) with the CERAD total score. Conclusion: Practice effects with repeated administration of neuropsychological tests must be accounted for in the interpretation of such tests. Ignoring practice effects may lead to an underestimation of POCD. The usefulness of the proposed demographically adjusted continuous score for cognitive function will have to be tested prospectively in patients.