Quadratic optimal functional quantization of stochastic processes and numerical applications

In this paper, we present an overview of the recent developments of functional quantization of stochastic processes, with an emphasis on the quadratic case. Functional quantization is a way to approximate a process, viewed as a Hilbert-valued random variable, using a nearest neighbour projection on a finite codebook. A special emphasis is made on the computational aspects and the numerical applications, in particular the pricing of some path-dependent European options.Comment: 41 page

Interventions for intermittent exotropia.

BACKGROUND: The clinical management of intermittent exotropia has been discussed frequently in the literature, but there is a lack of clarity regarding the indications for intervention, the most effective type and if there is a time point at which it should be carried out. OBJECTIVES: The objective of this review was to analyse the effects of various surgical and non-surgical treatments in randomised trials of people with intermittent exotropia, to report intervention criteria and determine the significance of factors such as age with respect to outcome. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (2006, Issue 1), MEDLINE (1966 to March 2006), EMBASE (1980 to March 2006) National Research Register (2006, Issue 1), PubMed (searched on 13 March 2006; last 90 days) and LILACS (Latin American and Caribbean Literature on Health Sciences) (1966 to 2002). We manually searched the British Orthoptic Journal, proceedings of the European Strabismological Association (ESA), International Strabismological Association (ISA) and American Academy of Paediatric Ophthalmology and Strabismus meeting (AAPOS). We contacted researchers who are active in the field for information about further published or unpublished studies. There were no language restrictions in the manual or electronic searches. SELECTION CRITERIA: We included randomised controlled trials of any surgical or non-surgical treatment for intermittent exotropia. DATA COLLECTION AND ANALYSIS: Each review author independently assessed study abstracts identified from the database and manual searches. Author analysis was then compared and full papers for appropriate studies were obtained. MAIN RESULTS: We found one randomised trial that was eligible for inclusion. This trial showed that unilateral surgery was more effective than bilateral surgery for correcting basic intermittent exotropia. AUTHORS' CONCLUSIONS: The available literature consists mainly of retrospective case reviews which are difficult to reliably interpret and analyse. The one randomised trial included found unilateral surgery more effective than bilateral for basic intermittent exotropia but there remains a need for more carefully planned clinical trials to be undertaken to improve the evidence base for the management of this condition

Biotic resistance to invasion along an estuarine gradient

Biotic resistance is the ability of native communities to repel the establishment of invasive species. Predation by native species may confer biotic resistance to communities, but the environmental context under which this form of biotic resistance occurs is not well understood. We evaluated several factors that influence the distribution of invasive Asian mussels (Musculista senhousia) in Mission Bay, a southern California estuary containing an extensive eelgrass (Zostera marina) habitat. Asian mussels exhibit a distinct spatial pattern of invasion, with extremely high densities towards the back of Mission Bay (up to 4,000 m−2) in contrast with near-complete absence at sites towards the front of the bay. We established that recruits arrived at sites where adult mussels were absent and found that dense eelgrass does not appear to preclude Asian mussel growth and survival. Mussel survival and growth were high in predator-exclusion plots throughout the bay, but mussel survival was low in the front of the bay when plots were open to predators. Additional experiments revealed that consumption by spiny lobsters (Panulirus interruptus) and a gastropod (Pteropurpura festiva) likely are the primary factors responsible for resistance to Asian mussel invasion. However, biotic resistance was dependent on location within the estuary (for both species) and also on the availability of a hard substratum (for P. festiva). Our findings indicate that biotic resistance in the form of predation may be conferred by higher order predators, but that the strength of resistance may strongly vary across estuarine gradients and depend on the nature of the locally available habitat

Individual variation in levels of haptoglobin-related protein in children from Gabon

Background: Haptoglobin related protein (Hpr) is a key component of trypanosome lytic factors (TLF), a subset of highdensity lipoproteins (HDL) that form the first line of human defence against African trypanosomes. Hpr, like haptoglobin (Hp) can bind to hemoglobin (Hb) and it is the Hpr-Hb complexes which bind to these parasites allowing uptake of TLF. This unique form of innate immunity is primate-specific. To date, there have been no population studies of plasma levels of Hpr, particularly in relation to hemolysis and a high prevalence of ahaptoglobinemia as found in malaria endemic areas. Methods and Principal Findings: We developed a specific enzyme-linked immunosorbent assay to measure levels of plasma Hpr in Gabonese children sampled during a period of seasonal malaria transmission when acute phase responses (APR), malaria infection and associated hemolysis were prevalent. Median Hpr concentration was 0.28 mg/ml (range 0.03-1.1). This was 5-fold higher than that found in Caucasian children (0.049 mg/ml, range 0.002-0.26) with no evidence of an APR. A general linear model was used to investigate associations between Hpr levels, host polymorphisms, parasitological factors and the acute phase proteins, Hp, C-reactive protein (CRP) and albumin. Levels of Hpr were associated with Hp genotype, decreased with age and were higher in females. Hpr concentration was strongly correlated with that of Hp, but not CRP

Inflammatory Processes in Kawasaki Disease Reach their Peak at the Sixth Day of Fever Onset: Laboratory Profiles According to Duration of Fever

We evaluated the inflammatory indices according to the fever duration in children with Kawasaki disease (KD), and determined duration when the inflammatory processes in KD reach their peak. Children with KD (n=152) were classified into 7 groups according to fever duration: at the third day or earlier (n=20), fourth (n=33), fifth (n=46), sixth (n=15), seventh (n=15), eighth (n=9), and at the ninth day or later after fever onset (n= 14). The levels of various laboratory indices were determined 3 times: before, 24 hr and 7 days after intravenous immunoglobulin administration (2 g/kg). WBC and neutrophil counts, and C-reactive protein level were the highest at the sixth day. Levels of hemoglobin, albumin, and high density lipoprotein cholestrol were the lowest at the sixth day. Although these indices were not significant statistically between groups, the indices showed either bell-shaped or U-shaped distribution of which peak or trench were at the sixth day. These findiugs showed that the inflammatory processes in KD reach peak on the sixth day of fever onset. This finding is important because a higher single-dose intravenous immunoglobulin treatment before the peak day may help reduce the coronary artery lesions in KD

Kestenbaum procedure with posterior fixation suture for anomalous head posture in infantile nystagmus

The purpose of this study was to report the effect of combining the Kestenbaum procedure with posterior fixation suture for infantile horizontal nystagmus with anomalous head posture (AHP) in children. Nine consecutive patients who underwent combined Kestenbaum procedure plus posterior fixation suture to the recessed muscles at the same time were retrospectively studied. All patients were orthotropic before surgery and were followed for at least 6 months. Pre- and postoperative AHP and binocular corrected visual acuity (BCVA), and ocular alignment were assessed. Mean age at surgery was 4.8 ± 1.5 years. The average follow-up was 29.7 months. The average head turn preoperatively was 27.4° and postoperatively 7.2°. The average net change in AHP was 24.8° (P = 0.008). Seven of 9 patients (78%) achieved a residual head turn of 10° or less. The average Log Mar BCVA was 0.33 preoperatively and 0.31 postoperatively (P = 0.68). Only 1 patient needed additional surgery for residual horizontal AHP. No patient developed strabismus. Combined Kestenbaum procedure with posterior fixation suture was an effective and stable procedure in reducing AHP of the range of 20° to 35° in children with infantile nystagmus

Serum amyloid A primes microglia for ATP-dependent interleukin-1\u3b2 release

Acute-phase response is a systemic reaction to environmental/inflammatory insults and involves production of acute-phase proteins, including serum amyloid A (SAA). Interleukin-1\u3b2 (IL-1\u3b2), a master regulator of neuroinflammation produced by activated inflammatory cells of the myeloid lineage, in particular microglia, plays a key role in the pathogenesis of acute and chronic diseases of the peripheral nervous system and CNS. IL-1\u3b2 release is promoted by ATP acting at the purinergic P2X7 receptor (P2X7R) in cells primed with toll-like receptor (TLR) ligands

General Practitioners involvement in enteral tube feeding at home: a qualitative study

<p>Abstract</p> <p>Background</p> <p>Complex medical treatment is moving from hospital to primary care and General Practitioners (GPs) are increasingly asked to undertake new roles. There are now an estimated 19,500 patients being fed in the UK in the community on enteral tube feeding using a variety of different feeding tubes (Percutaneous endoscopic gastrostomy (PEG), Jejunostomy, or nasogastric (NG). The majority of patients are over the age of 65 years when they had artificial feeding initiated and mainly because of dysphagia. The aim of this study was to explore GPs knowledge, attitudes and skills relating to enteral feeding in the community.</p> <p>Methods</p> <p>Semi-structured one-to-one interviews with a convenience sample of GPs in Northern Ireland.</p> <p>Results</p> <p>Twenty-three GPs in three health boards in Northern Ireland participated in the study. Most found dealing with enteral feeding to be a predominantly negative experience. They had little involvement in patient selection for the procedure and poor or no discharge information. GPs felt inadequately trained, there was poor communication between primary and secondary care and little support. There was anger and frustration among GPs about lack of resources (funding and training), and the perception that primary care was used as a dumping ground.</p> <p>Conclusion</p> <p>Moving complex medical treatment from secondary to primary care has major implications for GPs who should be included in the patient selection process, have adequate discharge information about their patients, be adequately resourced and have appropriate support and training.</p

Factors associated with recurrence and survival length following relapse in patients with neuroblastoma

Background: Despite therapeutic advances, survival following relapse for neuroblastoma patients remains poor. We investigated clinical and biological factors associated with length of progression-free and overall survival following relapse in UK neuroblastoma patients. Methods: All cases of relapsed neuroblastoma, diagnosed during 1990-2010, were identified from four Paediatric Oncology principal treatment centres. Kaplan-Meier and Cox regression analyses were used to calculate post-relapse overall survival (PROS), post-relapse progression-free survival (PRPFS) between relapse and further progression, and to investigate influencing factors. Results: One hundred eighty-nine cases were identified from case notes, 159 (84.0%) high risk and 17 (9.0%), unresectable, MYCN non-amplified (non-MNA) intermediate risk (IR). For high-risk patients diagnosed >2000, median PROS was 8.4 months (interquartile range (IQR)=3.0-17.4) and median PRPFS was 4.7 months (IQR=2.1-7.1). For IR, unresectable non-MNA patients, median PROS was 11.8 months (IQR 9.0-51.6) and 5-year PROS was 24% (95% CI 7-45%). MYCN amplified (MNA) disease and bone marrow metastases at diagnosis were independently associated with worse PROS for high-risk cases. Eighty percent of high-risk relapses occurred within 2 years of diagnosis compared with 50% of unresectable non-MNA IR disease. Conclusions: Patients with relapsed HR neuroblastomas should be treatment stratified according to MYCN status and PRPFS should be the primary endpoint in early phase clinical trials. The failure to salvage the majority of IR neuroblastoma is concerning, supporting investigation of intensification of upfront treatment regimens in this group to determine whether their use would diminish likelihood of relapse

Consistency and discrepancy in the atmospheric response to Arctic sea-ice loss across climate models

This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordThe decline of Arctic sea ice is an integral part of anthropogenic climate change. Sea-ice loss is already having a significant impact on Arctic communities and ecosystems. Its role as a cause of climate changes outside of the Arctic has also attracted much scientific interest. Evidence is mounting that Arctic sea-ice loss can affect weather and climate throughout the Northern Hemisphere. The remote impacts of Arctic sea-ice loss can only be properly represented using models that simulate interactions among the ocean, sea ice, land and atmosphere. A synthesis of six such experiments with different models shows consistent hemispheric-wide atmospheric warming, strongest in the mid-to-high-latitude lower troposphere; an intensification of the wintertime Aleutian Low and, in most cases, the Siberian High; a weakening of the Icelandic Low; and a reduction in strength and southward shift of the mid-latitude westerly winds in winter. The atmospheric circulation response seems to be sensitive to the magnitude and geographic pattern of sea-ice loss and, in some cases, to the background climate state. However, it is unclear whether current-generation climate models respond too weakly to sea-ice change. We advocate for coordinated experiments that use different models and observational constraints to quantify the climate response to Arctic sea-ice loss.J.A.S. and R.B. were funded by the Natural Environment Research Council (NE/P006760/1). C.D. acknowledges the National Science Foundation (NSF), which sponsors the National Center for Atmospheric Research. D.M.S. was supported by the Met Office Hadley Centre Climate Programme (GA01101) and the APPLICATE project, which is funded by the European Union’s Horizon 2020 programme. X.Z. was supported by the NSF (ARC#1023592). P.J.K. and K.E.M. were supported by the Canadian Sea Ice and Snow Evolution Network, which is funded by the Natural Science and Engineering Research Council of Canada. T.O. was funded by Environment and Climate Change Canada (GCXE17S038). L.S. was supported by the National Oceanic and Atmospheric Administration’s Climate Program Office