1,295 research outputs found
Unit Interval Editing is Fixed-Parameter Tractable
Given a graph~ and integers , , and~, the unit interval
editing problem asks whether can be transformed into a unit interval graph
by at most vertex deletions, edge deletions, and edge
additions. We give an algorithm solving this problem in time , where , and denote respectively
the numbers of vertices and edges of . Therefore, it is fixed-parameter
tractable parameterized by the total number of allowed operations.
Our algorithm implies the fixed-parameter tractability of the unit interval
edge deletion problem, for which we also present a more efficient algorithm
running in time . Another result is an -time algorithm for the unit interval vertex deletion problem,
significantly improving the algorithm of van 't Hof and Villanger, which runs
in time .Comment: An extended abstract of this paper has appeared in the proceedings of
ICALP 2015. Update: The proof of Lemma 4.2 has been completely rewritten; an
appendix is provided for a brief overview of related graph classe
Functional Analysis of Alleged NOGGIN Mutation G92E Disproves Its Pathogenic Relevance
We identified an amino acid change (p.G92E) in the Bone Morphogenetic Protein antagonist NOGGIN in a 22-month-old boy who presented with a unilateral brachydactyly type B phenotype. Brachydactyly type B is a skeletal malformation that has been associated with increased Bone Morphogenetic Protein pathway activation in other patients. Previously, the amino acid change p.G92E in NOGGIN was described as causing fibrodysplasia ossificans progressiva, a rare genetic disorder characterized by limb malformations and progressive heterotopic bone formation in soft tissues that, like Brachydactyly type B, is caused by increased activation of Bone Morphogenetic Protein signaling. To determine whether G92E-NOGGIN shows impaired antagonism that could lead to increased Bone Morphogenetic Protein signaling, we performed functional assays to evaluate inhibition of BMP signaling. Interestingly, wt-NOGGIN shows different inhibition efficacies towards various Bone Morphogenetic Proteins that are known to be essential in limb development. However, comparing the biological activity of G92E-NOGGIN with wt-NOGGIN, we observed that G92E-NOGGIN inhibits activation of bone morphogenetic protein signaling with equal efficiency as wt-NOGGIN, supporting that G92E-NOGGIN does not cause pathological effects. Genetic testing of the child's parents revealed the same amino acid change in the healthy father, further supporting that p.G92E is a neutral amino acid substitution in NOGGIN. We conclude that p.G92E represents a rare polymorphism of the NOGGIN gene - causing neither brachydactyly nor fibrodysplasia ossificans progressiva. This study highlights that a given genetic variation should not be considered pathogenic unless supported by functional analyses
A study of general practitioners' perspectives on electronic medical records systems in NHS Scotland
<b>Background</b> Primary care doctors in NHSScotland have been using electronic medical records within their practices routinely for many years. The Scottish Health Executive eHealth strategy (2008-2011) has recently brought radical changes to the primary care computing landscape in Scotland: an information system (GPASS) which was provided free-of-charge by NHSScotland to a majority of GP practices has now been replaced by systems provided by two approved commercial providers. The transition to new electronic medical records had to be completed nationally across all health-boards by March 2012. <p></p><b>
Methods</b> We carried out 25 in-depth semi-structured interviews with primary care doctors to elucidate GPs' perspectives on their practice information systems and collect more general information on management processes in the patient surgical pathway in NHSScotland. We undertook a thematic analysis of interviewees' responses, using Normalisation Process Theory as the underpinning conceptual framework. <p></p>
<b>Results</b> The majority of GPs' interviewed considered that electronic medical records are an integral and essential element of their work during the consultation, playing a key role in facilitating integrated and continuity of care for patients and making clinical information more accessible. However, GPs expressed a number of reservations about various system functionalities - for example: in relation to usability, system navigation and information visualisation.
<b>Conclusion </b>Our study highlights that while electronic information systems are perceived as having important benefits, there remains substantial scope to improve GPs' interaction and overall satisfaction with these systems. Iterative user-centred improvements combined with additional training in the use of technology would promote an increased understanding, familiarity and command of the range of functionalities of electronic medical records among primary care doctors
The recurrent missense mutation p.(Arg367Trp) in YARS1 causes a distinct neurodevelopmental phenotype
Abstract: Pathogenic variants in aminoacyl-tRNA synthetases (ARS1) cause a diverse spectrum of autosomal recessive disorders. Tyrosyl tRNA synthetase (TyrRS) is encoded by YARS1 (cytosolic, OMIM*603,623) and is responsible of coupling tyrosine to its specific tRNA. Next to the enzymatic domain, TyrRS has two additional functional domains (N-Terminal TyrRSMini and C-terminal EMAP-II-like domain) which confer cytokine-like functions. Mutations in YARS1 have been associated with autosomal-dominant Charcot-Marie-Tooth (CMT) neuropathy type C and a heterogenous group of autosomal recessive, multisystem diseases. We identified 12 individuals from 6 families with the recurrent homozygous missense variant c.1099C > T;p.(Arg367Trp) (NM_003680.3) in YARS1. This variant causes a multisystem disorder with developmental delay, microcephaly, failure to thrive, short stature, muscular hypotonia, ataxia, brain anomalies, microcytic anemia, hepatomegaly, and hypothyroidism. In silico analyses show that the p.(Arg367Trp) does not affect the catalytic domain responsible of enzymatic coupling, but destabilizes the cytokine-like C-terminal domain. The phenotype associated with p.(Arg367Trp) is distinct from the other biallelic pathogenic variants that reside in different functional domains of TyrRS which all show some common, but also divergent clinical signs [(e.g., p.(Phe269Ser)āretinal anomalies, p.(Pro213Leu)/p.(Gly525Arg)āmild ID, p.(Pro167Thr)āhigh fatality)]. The diverse clinical spectrum of ARS1-associated disorders is related to mutations affecting the various non-canonical domains of ARS1, and impaired protein translation is likely not the exclusive disease-causing mechanism of YARS1- and ARS1-associated neurodevelopmental disorders. Key messages: The missense variant p.(Arg367Trp) in YARS1 causes a distinct multisystem disorder.p.(Arg367Trp) affects a non-canonical domain with cytokine-like functions.Phenotypic heterogeneity associates with the different affected YARS1 domains.Impaired protein translation is likely not the exclusive mechanism of ARS1-associated disorders
Effectiveness of Carboplatin and Paclitaxel as First- and Second-Line Treatment in 61 Patients with Metastatic Melanoma
BACKGROUND: Patients with metastatic melanoma have a very unfavorable prognosis with few therapeutic options. Based on previous promising experiences within a clinical trial involving carboplatin and paclitaxel a series of advanced metastatic melanoma patients were treated with this combination. METHODS: Data of all patients with cutaneous metastatic melanoma treated with carboplatin and paclitaxel (CP) at our institution between October 2005 and December 2007 were retrospectively evaluated. For all patients a once-every-3-weeks dose-intensified regimen was used. Overall and progression free survival were calculated using the method of Kaplan and Meier. Tumour response was evaluated according to RECIST criteria. RESULTS: 61 patients with cutaneous metastatic melanoma were treated with CP. 20 patients (85% M1c) received CP as first-line treatment, 41 patients (90.2% M1c) had received at least one prior systemic therapy for metastatic disease. Main toxicities were myelosuppression, fatigue and peripheral neuropathy. Partial responses were noted in 4.9% of patients, stable disease in 23% of patients. No complete response was observed. Median progression free survival was 10 weeks. Median overall survival was 31 weeks. Response, progression-free and overall survival were equivalent in first- and second-line patients. 60 patients of 61 died after a median follow up of 7 months. Median overall survival differed for patients with controlled disease (PR+SD) (49 weeks) compared to patients with progressive disease (18 weeks). CONCLUSIONS: Among patients with metastatic melanoma a subgroup achieved disease control under CP therapy which may be associated with a survival benefit. This potential advantage has to be weighed against considerable toxicity. Since response rates and survival were not improved in previously untreated patients compared to pretreated patients, CP should thus not be applied as first-line treatment
The use of light-emitting diodes to stimulate mitochondrial function and liver regeneration of partially hepatectomized rats
Beyond knowing nature: Contact, emotion, compassion, meaning, and beauty are pathways to nature connection
Feeling connected to nature has been shown to be beneficial to wellbeing and pro-environmental behaviour. General nature contact and knowledge based activities are often used in an attempt to engage people with nature. However the specific routes to nature connectedness have not been examined systematically. Two online surveys (total n = 321) of engagement with, and value of, nature activities structured around the nine values of the Biophila Hypothesis were conducted. Contact, emotion, meaning, and compassion, with the latter mediated by engagement with natural beauty, were predictors of connection with nature, yet knowledge based activities were not. In a third study (n = 72), a walking intervention with activities operationalising the identified predictors, was found to significantly increase connection to nature when compared to walking in nature alone or walking in and engaging with the built environment. The findings indicate that contact, emotion, meaning, compassion, and beauty are pathways for improving nature connectedness. The pathways also provide alternative values and frames to the traditional knowledge and identification routes often used by organisations when engaging the public with nature.N/
Sodium Iodate Selectively Injuries the Posterior Pole of the Retina in a Dose-Dependent Manner: Morphological and Electrophysiological Study
Sequential morphological and functional features of retinal damage in mice exposed to different doses (40 vs. 20Ā mg/kg) of sodium iodate (NaIO3) were analyzed. Retinal morphology, apoptosis (TUNEL assay), and function (electroretinography; ERG) were examined at several time points after NaIO3 administration. The higher dose of NaIO3 caused progressive degeneration of the whole retinal area and total suppression of scotopic and photopic ERG. In contrast, the lower dose induced much less severe degeneration in peripheral part of retina along with a moderate decline of b- and a-wave amplitudes in ERG, corroborating the presence of regions within retina that retain their function. The peak of photoreceptor apoptosis was found on the 3rd day, but the lower dose induced more intense reaction within the central retina than in its peripheral region. In conclusion, these results indicate that peripheral area of the retina reveals better resistance to NaIO3 injury than its central part
A classification method for neurogenic heterotopic ossification of the hip
Background: Existing classifications for heterotopic ossification (HO) do not include all HO types; nor do they consider the anatomy of the involved joint or the neurological injury. Therefore, we performed this study to propose and evaluate a classification according to the location of neurogenic HO and the neurological injury. Materials and methods: We studied the files of 24 patients/33 hips with brain or spinal cord injury and neurogenic HO of the hip treated with excision, indomethacin, and radiation therapy. We classified patients according to the Brooker classification scheme as well as ours. Four types of neurogenic HO were distinguished according to the anatomical location of HO: type 1, anterior; type 2, posterior; type 3, anteromedial; type 4, circumferential. Subtypes of each type were added based on the neurological injury: a, spinal cord; b, brain injury. Mean follow-up was 2.5 years (1-8 years). Results: The Brooker classification scheme was misleading - all hips were class III or IV, corresponding to ankylosis, even though only 14 hips had ankylosis. On the other hand, our classification was straightforward and easy to assign in all cases. It corresponded better to the location of the heterotopic bone, and allowed for preoperative planning of the appropriate surgical approach and evaluation of the prognosis; recurrence of neurogenic HO was significantly higher in patients with brain injury (subtype b), while blood loss was higher for patients with anteromedial (type 3) and circumferential (type 4) neurogenic HO. Conclusions: Our proposed classification may improve the management and evaluation of the prognosis for patients with neurogenic HO
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