2,343 research outputs found
Designating market maker behaviour in Limit Order Book markets
Financial exchanges provide incentives for limit order book (LOB) liquidity
provision to certain market participants, termed designated market makers or
designated sponsors. While quoting requirements typically enforce the activity
of these participants for a certain portion of the day, we argue that liquidity
demand throughout the trading day is far from uniformly distributed, and thus
this liquidity provision may not be calibrated to the demand. We propose that
quoting obligations also include requirements about the speed of liquidity
replenishment, and we recommend use of the Threshold Exceedance Duration (TED)
for this purpose. We present a comprehensive regression modelling approach
using GLM and GAMLSS models to relate the TED to the state of the LOB and
identify the regression structures that are best suited to modelling the TED.
Such an approach can be used by exchanges to set target levels of liquidity
replenishment for designated market makers
Hemophilia : a disease on the move
peer reviewedOver the last hundred years, the treatment of hemophilia has evolved considerably. To date, its principle is still to prevent the occurrence of hemorrhages by regular intravenous injections of factor VIII or IX concentrate. It allows to reach a life expectancy similar to the general population. The quality of life is constantly improving despite the constraint imposed by the modality and frequency of injections. The main complication remains the development of antibodies that inhibit the administered factors. Concentrates of long-acting factors are now available allowing to limit for example the frequency of injections. A bispecific monoclonal antibody reproducing the action of factor VIII and injectable subcutaneously has recently become available to hemophilia A patients, with the advantage of being effective even in the presence of inhibitors. Other non-substitute products are being studied offering interesting leads. Finally, gene therapy shows promising results, giving hope for access to this therapeutic option in a relatively near future. These advances are, however, a challenge for clinical laboratories, which must adapt their measurement techniques to ensure optimal monitoring. The future is on its way for hemophilia. Treatment remains expensive but it is worth the price.Depuis un siècle, le traitement de l’hémophilie a considérablement évolué. À ce jour, son principe est toujours de prévenir la survenue d’hémorragies par injections intraveineuses régulières de concentré de facteur VIII ou IX. Il permet d’atteindre une espérance de vie similaire à la population générale. La qualité de vie est en constante amélioration, malgré la contrainte imposée par les modalités et la fréquence des injections. La complication principale reste le développement d’anticorps inhibant les facteurs administrés. Des concentrés de facteurs à action prolongée sont, maintenant, disponibles et permettent, notamment, de limiter la fréquence des injections. Un anticorps monoclonal bispécifique reproduisant l’action du facteur VIII et injectable par voie sous-cutanée est, depuis peu, à la disposition des patients hémophiles A, avec l’avantage d’être efficace même en présence d’inhibiteurs. D’autres produits non substitutifs sont à l’étude offrant des pistes intéressantes. Enfin, la thérapie génique montre des résultats prometteurs, laissant espérer un accès à cette option thérapeutique dans un futur relativement proche. Ces avancées sont cependant un défi pour les laboratoires d’analyse qui doivent adapter leurs techniques de mesure pour assurer un suivi optimal. Le futur est en marche pour l’hémophilie. Le traitement reste coûteux, mais il en vaut le prix
New frontiers in healthcare environmental hygiene:thoughts from the 2022 healthcare cleaning forum
Healthcare environmental hygiene (HEH) has become recognized as being increasingly important for patient safety and the prevention of healthcare-associated infections. At the 2022 Healthcare Cleaning Forum at Interclean in Amsterdam, the academic lectures focused on a series of main areas of interest. These areas are indicative of some of the main trends and avenues for research in the coming years. Both industry and academia need to take steps to continue the momentum of HEH as we transition out of the acute phase of the Covid-19 pandemic. There is a need for new ways to facilitate collaboration between the academic and private sectors. The Clean Hospitals® network was presented in the context of the need for both cross-disciplinarity and evidence-based interventions in HEH. Governmental bodies have also become more involved in the field, and both the German DIN 13603 standard and the UK NHS Cleaning Standards were analyzed and compared. The challenge of environmental pathogens was explored through the example of how P. aeruginosa persists in the healthcare environment. New innovations in HEH were presented, from digitalization to tracking, and automated disinfection to antimicrobial surfaces. The need for sustainability in HEH was also explored, focusing on the burden of waste, the need for a circular economy, and trends towards increasingly local provision of goods and services. The continued focus on and expansion of these areas of HEH will result in safer patient care and contribute to better health systems
Metformin-associated lactic acidosis in an intensive care unit
International audienceIntroduction Metformin-associated lactic acidosis (MALA) is aclassic side effect of metformin and is known to be a severedisease with a high mortality rate. The treatment of MALA withdialysis is controversial and is the subject of many case reportsin the literature. We aimed to assess the prevalence of MALA ina 16-bed, university-affiliated, intensive care unit (ICU), and theeffect of dialysis on patient outcome.Methods Over a five-year period, we retrospectively identifiedall patients who were either admitted to the ICU with metforminas a usual medication, or who attempted suicide by metforminingestion. Within this population, we selected patientspresenting with lactic acidosis, thus defining MALA, anddescribed their clinical and biological features.Results MALA accounted for 0.84% of all admissions duringthe study period (30 MALA admissions over five years) and wasassociated with a 30% mortality rate. The only factorsassociated with a fatal outcome were the reason for admissionin the ICU and the initial prothrombin time. Although patientswho went on to haemodialysis had higher illness severity scores,as compared with those who were not dialysed, the mortalityrates were similar between the two groups (31.3% versus28.6%).Conclusions MALA can be encountered in the ICU severaltimes a year and still remains a life-threatening condition.Treatment is restricted mostly to supportive measures, althoughhaemodialysis may possess a protective effect
Staphylococcal Small Colony Variants Have Novel Mechanisms for Antibiotic Resistance
Over the past 4 years, a variant subpopulation of Staphylococcus aureus has been characterized that is defective in electron transport. These organisms grow slowly and are typical of the previously described small colony variants (SCVs). Indeed, many earlier papers included data that are consistent with defective respiratory activity in SCVs. We present a hypothesis that serves as biochemical basis for the development of SCVs. These variants are particularly interesting because they have been associated with very persistent infections, and they are more resistant to many antibiotics than normal S. aureus. Because of their slow growth, atypical colonial morphology, and unusual biochemical profile, they are easily missed or misidentified in the clinical laboratory. This is of some significance, as this subpopulation is more resistant to antibiotics than the parent population from which they arose. When an infection is particularly resistant to therapy, persists for a long period, or fails to respond to apparently adequate antimicrobial therapy, clinicians and clinical laboratory personnel should consider special efforts to search for SCV
Bloodstream Infections Caused by Small-Colony Variants of Coagulase-Negative Staphylococci Following Pacemaker Implantation
Small-colony variants (SCVs) of Staphylococcus aureus cause persistent and relapsing infections. Relatively little is known regarding infections caused by SCVs of coagulase-negative staphylococci. We report two cases of pacemaker electrode infections due to SCVs of Staphylococcus epidermidis and Staphylococcus capitis. Sequence analysis of a portion of the 16S rRNA gene (16S rDNA) confirmed the identity of the staphylococcal species as S. capitis and S. epidermidis. Isolates from cultures of blood obtained over at least a 2-week interval were compared by pulsed-field gel electrophoresis and found to be clonal even though the colony morphology was very different. Analysis for auxotrophism revealed hemin dependencies for all isolated SCVs. The two cases have several clinical and laboratory characteristics (which are also seen with S. aureus SCV infections) and strongly suggest that SCVs of coagulase-negative staphylococci must be actively sought, because they grow very slowly and can be easily misse
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