1,866 research outputs found
First phylogenetic analyses of galaxy evolution
The Hubble tuning fork diagram, based on morphology, has always been the
preferred scheme for classification of galaxies and is still the only one
originally built from historical/evolutionary relationships. At the opposite,
biologists have long taken into account the parenthood links of living entities
for classification purposes. Assuming branching evolution of galaxies as a
"descent with modification", we show that the concepts and tools of
phylogenetic systematics widely used in biology can be heuristically transposed
to the case of galaxies. This approach that we call "astrocladistics" has been
first applied to Dwarf Galaxies of the Local Group and provides the first
evolutionary galaxy tree. The cladogram is sufficiently solid to support the
existence of a hierarchical organization in the diversity of galaxies, making
it possible to track ancestral types of galaxies. We also find that morphology
is a summary of more fundamental properties. Astrocladistics applied to
cosmology simulated galaxies can, unsurprisingly, reconstruct the correct
"genealogy". It reveals evolutionary lineages, divergences from common
ancestors, character evolution behaviours and shows how mergers organize galaxy
diversity. Application to real normal galaxies is in progress. Astrocladistics
opens a new way to analyse galaxy evolution and a path towards a new
systematics of galaxies
MicroRNAs as Biomarkers for Predicting Complications Following Aneurysmal Subarachnoid Hemorrhage
Aneurysmal subarachnoid hemorrhage (aSAH) is a high mortality hemorrhagic stroke that affects nearly 30,000 patients annually in the United States. Approximately 30% of aSAH patients die during initial hospitalization and those who survive often carry poor prognosis with one in five having permanent physical and/or cognitive disabilities. The poor outcome of aSAH can be the result of the initial catastrophic event or due to the many acute or delayed neurological complications, such as cerebral ischemia, hydrocephalus, and re-bleeding. Unfortunately, no effective biomarker exists to predict or diagnose these complications at a clinically relevant time point when neurologic injury can be effectively treated and managed. Recently, a number of studies have demonstrated that microRNAs (miRNAs) in extracellular biofluids are highly associated with aSAH and complications. Here we provide an overview of the current research on relevant human studies examining the correlation between miRNAs and aSAH complications and discuss the potential application of using miRNAs as biomarkers in aSAH management
Lymphoepithelial Cyst of the Pancreas: Serum Markers do not Help
We report a case of lymphoepithelial cyst of the
pancreas with non-specific elevation of CA 19.9 and
CEA. Pre-operative diagnosis by conventional means
proved elusive, and only surgical resection and
histopathology revealed the diagnosis. The origin
and diagnosis are discussed by literature review
A Highly Predictive MicroRNA Panel for Determining Delayed Cerebral Vasospasm Risk Following Aneurysmal Subarachnoid Hemorrhage
Approximately one-third of aneurysmal subarachnoid hemorrhage (aSAH) patients develop delayed cerebral vasospasm (DCV) 3–10 days after aneurysm rupture resulting in additional, permanent neurologic disability. Currently, no validated biomarker is available to determine the risk of DCV in aSAH patients. MicroRNAs (miRNAs) have been implicated in virtually all human diseases, including aSAH, and are found in extracellular biofluids including plasma and cerebrospinal fluid (CSF). We used a custom designed TaqMan Low Density Array miRNA panel to examine the levels of 47 selected brain and vasculature injury related miRNAs in CSF and plasma specimens collected from 31 patients with or without DCV at 3 and 7 days after aSAH, as well as from eight healthy controls. The analysis of the first 18-patient cohort revealed a striking differential expression pattern of the selected miRNAs in CSF and plasma of aSAH patients with DCV from those without DCV. Importantly, this differential expression was observed at the early time point (3 days after aSAH), before DCV event occurs. Seven miRNAs were identified as reliable DCV risk predictors along with a prediction model constructed based on an array of additional 19 miRNAs on the panel. These chosen miRNAs were then used to predict the risk of DCV in a separate, testing cohort of 15 patients. The accuracy of DCV risk prediction in the testing cohort reached 87%. The study demonstrates that our novel designed miRNA panel is an effective predictor of DCV risk and has strong applications in clinical management of aSAH patients
Enhanced Support for High Intensity Users of the Criminal Justice System – an evaluation of mental health nurse input into Integrated Offender Management Services in the North East of England
The current UK Government’s focus on the development of services to manage and support offenders with mental health problems has resulted in a number of innovative project developments. This research examines a service development in the North East of England which co-located Mental Health nurses with two Integrated Offender Management teams. While not solving all problems, the benefits of co-location were clear – although such innovations are now at risk from government changes which will make Integrated Offender Management the responsibility of new providers without compelling them to co-operate with health services
Prognostic value and functional consequences of cell cycle inhibitor p27Kip1 loss in medulloblastoma
BACKGROUND: The cyclin-dependent kinase inhibitor p27(Kip1) functions during normal cerebellar development and has demonstrated tumor suppressor functions in mouse models of medulloblastoma. Because P27 loss is associated with increased proliferation, we assessed whether P27 absence in surgical medulloblastoma specimens correlated with response to therapy in pediatric patients enrolled in two large studies. Additionally, we examined the functional consequence of p27(Kip1) loss in the SmoA1 medulloblastoma model to distinguish whether p27(Kip1) reduces tumor initiation or slows tumor progression. FINDINGS: Analysis of 87 well-characterized patient samples identified a threshold of P27 staining at which significant P27 loss correlated with poor patient outcome. The same criteria, applied to a second test set of tissues from 141 patients showed no difference in survival between patients with minimal P27 staining and others, suggesting that P27 levels alone are not a sufficient prognostic indicator for identifying standard-risk patients that may fail standard therapy. These findings were in contrast to prior experiments completed using a mouse medulloblastoma model. Analysis of cerebellar tumor incidence in compound mutant mice carrying the activated Smoothened (SmoA1) allele that were heterozygous or nullizygous for p27(Kip1) revealed that p27(Kip1) loss did not alter the frequency of tumor initiation. Tumors haploinsufficient or nullizygous for p27(Kip1) were, however, more invasive and displayed a higher proliferative index, suggesting p27(Kip1) loss may contribute to SmoA1 medulloblastoma progression. CONCLUSIONS: These studies revealed P27 loss affects medulloblastoma progression rather than initiation and that this putative biomarker should not be used for stratifying children with medulloblastoma to risk-based therapeutic regimens
Advanced Feature Extraction and Dimensionality Reduction for Unmanned Underwater Vehicle Fault Diagnosis
This paper presents a novel approach to the diagnosis of blade faults in an electric thruster motor of unmanned underwater vehicles (UUVs) under stationary operating conditions. The diagnostic approach is based on the use of discrete wavelet transforms (DWT) as a feature extraction tool and a dynamic neural network (DNN) for fault classification. The DNN classifies between healthy and faulty conditions of the trolling motor by analyzing the stator current and vibration signals. To overcome feature redundancy, which affects diagnosis reliability, the Orthogonal Fuzzy Neighbourhood Discriminant Analysis (OFNDA) approach is found to be the most effective. Four faulty conditions were analyzed under laboratory conditions, and the results obtained from experiment demonstrate the effectiveness and reliability of the proposed methodology in classifying the different faults faster and more accurately
Operative Management of Symptomatic, Metachronous Carotid Body Tumors Involving the Skull Base and Its Neurological Sequelae
A 44-year-old morbidly obese woman with a history of right carotid body tumor (CBT) resection presented with a symptomatic, nonfunctional, left Shamblin-III CBT. Abutment of the skull base precluded distal internal carotid artery control for arterial reconstruction, favoring parent vessel sacrifice after an asymptomatic provocative test. She underwent CBT resection with anticipated sacrifice of cranial nerves X and XII and the common carotid artery and its branches, developing baroreceptor failure syndrome and sequelae of cranial nerve sacrifice. When facing a symptomatic, metachronous CBT abutting the skull base, upfront operative intervention with adjuvant radiation for residual tumor optimizes curative resection
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