445 research outputs found
Improving conversion and enantioselectivity in hydrogenation by combining different monodentate phosphoramidites; a new combinatorial approach in asymmetric catalysis
Improving conversion and enantioselectivity in hydrogenation by combining different monodentate phosphoramidites; a new combinatorial approach in asymmetric catalysis
How to detect late-onset inborn errors of metabolism in patients with movement disorders - A modern diagnostic approach
We propose a modern approach to assist clinicians to recognize and diagnose inborn errors of metabolism (IEMs) in adolescents and adults that present with a movement disorder. IEMs presenting in adults are still largely unexplored. These disorders receive little attention in neurological training and daily practice, and are considered complicated by many neurologists. Adult-onset presentations of IEMs differ from childhood-onset phenotypes, which may lead to considerable diagnostic delay. The identification of adult-onset phenotypes at the earliest stage of the disease is important, since early treatment may prevent or lessen further brain damage. Our approach is based on a systematic review of all papers that concerned movement disorders due to an IEM in patients of 16 years or older. Detailed clinical phenotyping is the diagnostic cornerstone of the approach. An underlying IEM should be suspected in particular in patients with more than one movement disorder, or in patients with additional neurological, psychiatric, or systemic manifestations. As IEMs are all genetic disorders, we recommend next-generation sequencing (NGS) as the first diagnostic approach to confirm an IEM. Biochemical tests remain the first choice in acute-onset or treatable IEMs that require rapid diagnosis, or to confirm the metabolic diagnosis after NGS results. With the use of careful and systematic clinical phenotyping combined with novel diagnostic approaches such as NGS, the diagnostic yield of late-onset IEMs will increase, in particular in patients with mild or unusual phenotypes.</p
Estimating the spatial position of marine mammals based on digital camera recordings
Estimating the spatial position of organisms is essential to quantify interactions between the organism and the characteristics of its surroundings, for example, predator–prey interactions, habitat selection, and social associations. Because marine mammals spend most of their time under water and may appear at the surface only briefly, determining their exact geographic location can be challenging. Here, we developed a photogrammetric method to accurately estimate the spatial position of marine mammals or birds at the sea surface. Digital recordings containing landscape features with known geographic coordinates can be used to estimate the distance and bearing of each sighting relative to the observation point. The method can correct for frame rotation, estimates pixel size based on the reference points, and can be applied to scenarios with and without a visible horizon. A set of R functions was written to process the images and obtain accurate geographic coordinates for each sighting. The method is applied to estimate the spatiotemporal fine-scale distribution of harbour porpoises in a tidal inlet. Video recordings of harbour porpoises were made from land, using a standard digital single-lens reflex (DSLR) camera, positioned at a height of 9.59 m above mean sea level. Porpoises were detected up to a distance of ~3136 m (mean 596 m), with a mean location error of 12 m. The method presented here allows for multiple detections of different individuals within a single video frame and for tracking movements of individuals based on repeated sightings. In comparison with traditional methods, this method only requires a digital camera to provide accurate location estimates. It especially has great potential in regions with ample data on local (a)biotic conditions, to help resolve functional mechanisms underlying habitat selection and other behaviors in marine mammals in coastal areas
Time to improve statin prescription guidelines in low-risk patients?
Background The challenge of the primary prevention of cardiovascular disease (CVD) is to identify patients who would benefit from treatment with statins. Statins are currently prescribed to many patients, even those at a low 10-year risk of CVD. These latter patients may not be eligible for statins according to current guidelines. Design This study investigated the prescription of guideline-consistent (according to guidelines) and guideline-inconsistent (not according to guidelines) lipid-lowering treatment in primary prevention in a large contemporary Dutch cohort study (Lifelines). Methods Lifelines is a large cohort study from the Netherlands. Participants were recruited between 2006 and 2013. They completed questionnaires and underwent a physical examination. Participants with previous CVD were excluded. Statins and ezetimibe were grouped as statin treatment. The Dutch guideline on cardiovascular management was used to assess eligibility for statins. Results Of 147,785 participants, 7092 (4.8%) reported statin treatment. In 4667 (66%) participants, statin treatment was inconsistent with the Dutch guideline. A total of 78% of these participants had a low 10-year predicted CVD risk. Multivariable logistic regression analysis showed that female sex and smoking were strongly associated with guideline-inconsistent treatment. Interestingly, 65% of the these participants had low-density lipoprotein cholesterol levels above the 95(th) percentile, adjusted for age and sex, two or more major risk factors of CVD or a positive family history of premature CVD. Therefore treatment might be reasonable. Conclusions There is a large inconsistency between guideline recommendations and the prescription of statins in clinical practice in the Netherlands. This is especially true for patients with low CVD risk. Many of these patients probably had risk-increasing circumstances justifying treatment
CAG Repeat Size Influences the Progression Rate of Spinocerebellar Ataxia Type 3
Objective: In spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD), the expanded cytosine adenine guanine (CAG) repeat in ATXN3 is the causal mutation, and its length is the main factor in determining the age at onset (AO) of clinical symptoms. However, the contribution of the expanded CAG repeat length to the rate of disease progression after onset has remained a matter of debate, even though an understanding of this factor is crucial for experimental data on disease modifiers and their translation to clinical trials and their design. Methods: Eighty-two Dutch patients with SCA3/MJD were evaluated annually for 15 years using the International Cooperative Ataxia Rating Scale (ICARS). Using linear growth curve models, ICARS progression rates were calculated and tested for their relation to the length of the CAG repeat expansion and to the residual age at onset (RAO): The difference between the observed AO and the AO predicted on the basis of the CAG repeat length. Results: On average, ICARS scores increased 2.57 points/year of disease. The length of the CAG repeat was positively correlated with a more rapid ICARS progression, explaining 30% of the differences between patients. Combining both the length of the CAG repeat and RAO as comodifiers explained up to 47% of the interpatient variation in ICARS progression. Interpretation: Our data imply that the length of the expanded CAG repeat in ATXN3 is a major determinant of clinical decline, which suggests that CAG-dependent molecular mechanisms similar to those responsible for disease onset also contribute to the rate of disease progression in SCA3/MJD. ANN NEUROL 2020
A resting-state fMRI pattern of spinocerebellar ataxia type 3 and comparison with F-18-FDG PET
Spinocerebellar ataxia type 3 (SCA3) is a rare genetic neurodegenerative disease. The neurobiological basis of SCA3 is still poorly understood, and up until now resting-state fMRI (rs-fMRI) has not been used to study this disease. In the current study we investigated (multi-echo) rs-fMRI data from patients with genetically confirmed SCA3 (n = 17) and matched healthy subjects (n = 16). Using independent component analysis (ICA) and subsequent regression with bootstrap resampling, we identified a pattern of differences between patients and healthy subjects, which we coined the fMRI SCA3 related pattern (fSCA3-RP) comprising cerebellum, anterior striatum and various cortical regions. Individual fSCA3-RP scores were highly correlated with a previously published F-18-FDG PET pattern found in the same sample (rho = 0.78, P = 0.0003). Also, a high correlation was found with the Scale for Assessment and Rating of Ataxia scores (r = 0.63, P = 0.007). No correlations were found with neuropsychological test scores, nor with levels of grey matter atrophy. Compared with the F-18-FDG PET pattern, the fSCA3-RP included a more extensive contribution of the mediofrontal cortex, putatively representing changes in default network activity. This rs-fMRI identification of additional regions is proposed to reflect a consequence of the nature of the BOLD technique, enabling measurement of dynamic network activity, compared to the more static F-18-FDG PET methodology. Altogether, our findings shed new light on the neural substrate of SCA3, and encourage further validation of the fSCA3-RP to assess its potential contribution as imaging biomarker for future research and clinical use
Implementing personalized medicine in diabetic kidney disease:Stakeholders' perspectives
The promise of personalized medicine to deliver "the right treatments at the right time to the right person" is the next frontier in healthcare. However, to implement personalized medicine in chronic diseases such as diabetes mellitus and diabetic kidney disease (DKD), a number of different aspects need to be taken into account. Better risk stratification and more precise options for treatment need to be developed and included in clinical practice guidelines. A patient's unique psychological, social and environmental situation also drive disease progression and outcomes. Appraising the cost effectiveness of precision medicines is necessary, not just as the cost of new therapies, but also the cost of diagnosis with novel methodologies and averted complications. As the prevalence of DKD grows worldwide to epidemic proportions, challenges such as global disparities in resources, access to healthcare and prevalence need to be addressed. This review considers these issues to achieve the short and longer-term goals of implementing personalized medicine in clinical practice
CWI and TU Delft at TREC 2013: Contextual Suggestion, Federated Web Search, KBA, and Web Tracks
This paper provides an overview of the work done at the Centrum Wiskunde & Informatica (CWI) and Delft University of Technology (TU Delft) for different tracks of TREC 2013. We participated in the Contextual Suggestion Track, the Federated Web Search Track, the Knowledge Base Acceleration (KBA) Track, and the Web Ad-hoc Track. In the Contextual Suggestion track, we focused on filtering the entire ClueWeb12 collection to generate recommendations according to the provided user profiles and contexts. For the Federated Web Search track, we exploited both categories from ODP and document relevance to merge result lists. In the KBA track, we focused on the Cumulative Citation Recommendation task where we exploited different features to two classification algorithms. For the Web track, we extended an ad-hoc baseline with a proximity model that promotes documents in which the query terms are positioned closer together
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