The merit of high-frequency data in portfolio allocation

This paper addresses the open debate about the usefulness of high-frequency (HF) data in large-scale portfolio allocation. Daily covariances are estimated based on HF data of the S&P 500 universe employing a blocked realized kernel estimator. We propose forecasting covariance matrices using a multi-scale spectral decomposition where volatilities, correlation eigenvalues and eigenvectors evolve on different frequencies. In an extensive out-of-sample forecasting study, we show that the proposed approach yields less risky and more diversified portfolio allocations as prevailing methods employing daily data. These performance gains hold over longer horizons than previous studies have shown

Structural studies of T4S systems by electron microscopy

Abstract: Type IV secretion (T4S) systems are large dynamic nanomachines that transport DNA and/or proteins through the membranes of bacteria. Analysis of T4S system architecture is an extremely challenging task taking into account their multi protein organisation and lack of overall global symmetry. Nonetheless the last decade demonstrated an amazing progress achieved by X-ray crystallography and cryo-electron microscopy. In this review we present a structural analysis of this dynamic complex based on recent advances in biochemical, biophysical and structural studies

What Is New for an Old Molecule? Systematic Review and Recommendations on the Use of Resveratrol

Stilbenes are naturally occurring phytoalexins that generally exist as their more stable E isomers. The most well known natural stilbene is resveratrol (Res), firstly isolated in 1939 from roots of Veratrum grandiflorum (white hellebore) (1) and since then found in various edible plants, notably in Vitis vinifera L. (Vitaceae) (2). The therapeutic potential of Res covers a wide range of diseases, and multiple beneficial effects on human health such as antioxidant, anti-inflammatory and anti-cancer activities have been suggested based on several in vitro and animal studies (3). In particular, Res has been reported to be an inhibitor of carcinogenesis at multiple stages via its ability to inhibit cyclooxygenase, and is an anticancer agent with a role in antiangiogenesis (4). Moreover, both in vitro and in vivo studies showed that Res induces cell cycle arrest and apoptosis in tumor cells (4). However, clinical studies in humans evidenced that Res is rapidly absorbed after oral intake, and that the low level observed in the blood stream is caused by a fast conversion into metabolites that are readily excreted from the body (5). Thus, considerable efforts have gone in the design and synthesis of Res analogues with enhanced metabolic stability. Considering that reduced Res (dihydro- resveratrol, D-Res) conjugates may account for as much as 50% of an oral Res dose (5), and that D-Res has a strong proliferative effect on hormone-sensitive cancer cell lines such as breast cancer cell line MCF7 (6), we recently devoted our synthetic efforts to the preparation of trans-restricted analogues of Res in which the E carbon-carbon double bond is embedded into an imidazole nucleus. To keep the trans geometry, the two aryl rings were linked to the heteroaromatic core in a 1,3 fashion. Based on this design, we successfully prepared a variety of 1,4-, 2,4- and 2,5-diaryl substituted imidazoles including Res analogues 1, 2 and 3, respectively, by procedures that involve transition metal-catalyzed Suzuki-Miyaura cross-coupling reactions and highly selective N-H or C-H direct arylation reactions as key synthetic steps. The anticancer activity of compounds 1–3 was evaluated against the 60 human cancer cell lines panel of the National Cancer Institute (NCI, USA). The obtained results, that will be showed and discussed along with the protocols developed for the preparation of imidazoles 1–3, confirmed that a structural optimization of Res may provide analogues with improved potency in inhibiting the growth of human cancer cell lines in vitro when compared to their natural lead. (1) Takaoka,M.J.Chem.Soc.Jpn.1939,60,1090-1100. (2) Langcake, P.; Pryce, R. J. Physiological. Plant Patology 1976, 9, 77-86. (3) Vang, O.; et al. PLoS ONE 2011, 6, e19881. doi:10.1371/journal.pone.0019881 (4) Kraft, T. E.; et al. Critical Reviews in Food Science and Nutrition 2009, 49, 782-799. (5) Walle, T. Ann. N.Y. Acad. Sci. 2011, 1215, 9-15. doi: 10.1111/j.1749-6632.2010.05842.x (6) Gakh,A.A.;etal.Bioorg.Med.Chem.Lett.2010,20,6149-6151

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial

Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402

Improved Depiction of Pterygopalatine Fossa Anatomy Using Ultrahigh-Resolution Magnetic Resonance Imaging at 7 Tesla

Purpose. To study the anatomy of the pterygopalatine fossa (PPF) using ultrahigh-resolution magnetic resonance imaging. Methods. A human cadaveric tissue block containing the pterygopalatine fossa was examined on a clinical 7-Tesla magnetic resonance imaging system. Subsequently, cryosections of the tissue block were created in a coronal plane. The cryosections were photographed and collected on adhesive tape. The on-tape sections were stained for Mallory-Cason, in order to detail the anatomic structures within the fossa. Magnetic resonance images were compared with surface photos of the tissue block and on-tape sections. Results. High-resolution magnetic resonance images demonstrated the common macroscopic structures in the PPF. Smaller structures, best viewed at the level of the operation microscope, which have previously been obscured on magnetic resonance imaging, could be depicted. Some of the orbital pterygopalatine ganglion branches and the pharyngeal nerve were clearly viewed. Conclusions. In our experience with one human cadaver specimen, magnetic resonance imaging at 7 Tesla seems effective in depicting pterygopalatine fossa anatomy and provides previously unseen details through its demonstration of the pharyngeal nerve and the orbital pterygopalatine ganglion branches. The true viability of depicting the pterygopalatine fossa with ultrahigh-resolution MR will depend on confirmation of our results in larger studies

Hearing sensitivity in adults with a unilateral cleft lip and palate after two-stage palatoplasty

Objective To evaluate long-term hearing and middle ear status in patients treated for a unilateral complete cleft lip and palate (UCLP) by two-stage palatoplasty. Methods Forty-nine UCLP patients aged 17 years and older were included in this retrospective study. Patients were invited for a multidisciplinary long-term follow-up of their treatment at a tertiary center for craniofacial surgery in the Netherlands. ENT assessment included tympanometry and pure-tone audiometry. Medical files were searched for medical and surgical history. Results In total, 19.4% of the patients had significant long-term hearing loss (PTA > 20 dB), comprising conductive hearing loss in 21.5% of the patients. In the majority (70%), this hearing loss was more pronounced at higher frequencies. In 25% the high fletcher index showed hearing thresholds above 20 dB. Ventilation tubes were placed at least once in 78.7% of the patients. The frequency of tube insertion was positively correlated with the incidence of reduced tympanic compliance (tympanogram type B) and the need for a pharyngoplasty. Conclusion The present study reports long-term hearing outcomes in UCLP patients with hard palate closure at 3 years of age. Persistent hearing loss was observed in 19.4% of our patients (PTA > 20 dB), mainly at the higher frequencies. Ventilation tube placement was associated with reduced tympanic compliance and higher risk on hearing loss (PTA air conduction). Our high incidence of velopharyngeal incompetence during early childhood, which is likely associated with Eustachian tube dysfunction, might have contributed to these results

Late detection of cleft palate

Cleft palate only (CPO) is a common congenital malformation, and most patients are diagnosed within the first weeks after birth. Late diagnosis of the cleft palate (CP) could initially result in feeding and growth impairment, and subsequently speech and hearing problems later in life. The purpose of this study is to retrospectively investigate (1) at which age CPO is diagnosed and (2) how the presence of syndromes and other factors relate to the age at diagnosis. The mean age of all children at our centre with CPO included between 1997 and 2014 at diagnosis (n = 271) was 1 year and 4 months. In all, 24.8 % (n = 67) was older than 12 months when diagnosed, and 37.3 % (n = 101) of all children had been diagnosed >30 days. These findings remain valid when a cut-off point of 14 days is used (44.3 % late). Moreover, the grade of the cleft was a determining factor for successful diagnosis; submucous clefts were detected much later on average (89.3 % > 30 days; p = .000). Similar results were found using Kaplan-Meier survival analyses. CONCLUSION: CPO is often diagnosed late. Patients diagnosed ≤30 days after birth more often presented with an associated disorder. Early diagnoses became more frequent as the severity of the cleft increased (grades 1-4). Professionals should perform more thorough intra-oral investigations, including manual palpations and visual inspections of the palate; they should be made more aware of the frequent accompanying symptoms. What is Known: • The presence of cleft palate only (CPO) is known to negatively affect feeding, hearing, speech and (social) development. • Submucous clefts are often underdiagnosed due to their difficulty to detect. As far as we know the literature shows that symptomatic submucous CPs are often diagnosed at an average age of 4.9 years. What is New: • 37.3 % respectively of all children with CPO were diagnosed relatively late (>30 days after birth), 24.8 % was older than 12 months when diagnosed. Mean age of all children with CPO was 1 year and 4 months. • We conclude that midwives and pediatricians should perform more through intra-oral investigations of all new-borns, including both a manual palpation, als well a visual inspection of the palate