5,728 research outputs found
Automatic Detection of Seizures with Applications
There are an estimated two million people with epilepsy in the United States. Many of these people do not respond to anti-epileptic drug therapy. Two devices can be developed to assist in the treatment of epilepsy. The first is a microcomputer-based system designed to process massive amounts of electroencephalogram (EEG) data collected during long-term monitoring of patients for the purpose of diagnosing seizures, assessing the effectiveness of medical therapy, or selecting patients for epilepsy surgery. Such a device would select and display important EEG events. Currently many such events are missed. A second device could be implanted and would detect seizures and initiate therapy. Both of these devices require a reliable seizure detection algorithm. A new algorithm is described. It is believed to represent an improvement over existing seizure detection algorithms because better signal features were selected and better standardization methods were used
A new pathway in the generation of defective retrovirus DNA.
We used a retrovirus shuttle vector to make molecular clones of circular viral DNA from infected cells. One-third of the molecules examined had deletions that started within or near the U5 domain of the long terminal repeat (LTR) region and extended a variable distance toward the gag gene. We present evidence that some of these deletions arose by cleavage of a single LTR unit, in contrast to the cleavage of tandem LTR units associated with the integration reaction. These results suggest that in the formation of defective circular DNA, the U5 domain can be recognized and cleaved in the absence of an adjacent U3 domain. The cleavage of isolated U5 domains may represent an important mechanism responsible for the generation of certain forms of both defective circular DNA and defective integrated DNA
Transduction of Non-Small Cell Lung Cancer Cells by Adenoviral and Retroviral Vectors
Gene transfer into a panel of non-small cell lung cancer (NSCLC) cells by adenoviral (Ad) and retroviral
(RV) vectors was studied. Indexed to multiplicity of infection (MOI), Ad vectors transduce squamous, adenosquamous,
and malignant mesothelioma cells with greater efficiency than large cells or adenocarcinoma
cells. Transduction-sensitive cells bind the Ad vector with specificity for the Ad fiber knob, and internalize
vector efficiently. Transduction-refractory cells bind and internalize vector by less efficient
pathways. Like Ad vectors, there is heterogeneity in RV transduction efficiencies of different NSCLC subtypes.
With respect to the most common cell type metastatic to the pleural space (adenocarcinoma), amphotropic
retroviral vectors transduce cells of this subtype more efficiently (at a lower MOI) than Ad. RV
transduction is not solely dependent on cellular replication, and both permissive and refractory cell lines
express the mRNA for the amphotropic RV receptor. These observations suggest that neither Ad nor RV
vectors will suffice a priori as the optimal gene transfer vehicle, and successful gene therapy of lung cancer
may require tumor-specific or patient-specific vectors
A Push-Button Molecular Switch
The preparation, characterization, and switching mechanism of a unique single-station mechanically switchable hetero[2]catenane are reported. The facile synthesis utilizing a âthreading-followed-by-clippingâ protocol features Cu^(2+)-catalyzed Eglinton coupling as a mild and efficient route to the tetrathiafulvalene-based catenane in high yield. The resulting mechanically interlocked molecule operates as a perfect molecular switch, most readily described as a âpush-buttonâ switch, whereby two discrete and fully occupied translational states are toggled electrochemically at incredibly high rates. This mechanical switching was probed using a wide variety of experimental techniques as well as quantum-mechanical investigations. The fundamental distinctions between this single-station [2]catenane and other more traditional bi- and multistation molecular switches are significant
High efficiency gene transfer to airways of mice using influenza hemagglutinin pseudotyped lentiviral vectors: HA pseudotyping of lentiviral vectors
A limitation to efficient lentivirus-mediated airway gene transfer is the lack of receptors to commonly used viral envelopes on the luminal surface of airway epithelia. The use of viral envelopes with natural tropism to the airway could be useful for overcoming this limitation
Morally Respectful Listening and its Epistemic Consequences
What does it mean to listen to someone respectfully, that is, insofar as they are due recognition respect? This paper addresses that question and gives the following answer: it is to listen in such a way that you are open to being surprised. A specific interpretation of this openness to surprise is then defended
Psychosis Prevention: A Modified Clinical High Risk Perspective From the Recognition and Prevention (RAP) Program
OBJECTIVE: Early intervention and prevention of psychosis remain a major challenge. Prediction would be greatly advanced with improved ability to identify individuals at true risk, which, at present, is moderate at best. The authors tested a modified strategy to improve prediction by selecting a more homogeneous high-risk sample (attenuated positive symptom criteria only, age range of mid-teens to early 20s) than is currently standard, combined with a systematic selection of neurodevelopmental deficits. METHOD: A sample of 101 treatment-seeking adolescents (mean age, 15.9 years) at clinical high risk for psychosis were followed clinically for up to 5 years (mean follow-up time, 3.0 years, SD=1.6). Adolescents were included only if they exhibited one or more attenuated positive symptoms at moderate to severe, but not psychotic, severity levels. Cox regression was used to derive a risk index. RESULTS: The overall conversion rate to psychosis was 28.3%. The final predictor model, with a positive predictive validity of 81.8%, consisted of four variables: disorganized communication, suspiciousness, verbal memory deficits, and decline in social functioning during follow-up. Significant effects also suggest narrowing the risk age range to 15-22 years. CONCLUSIONS: Clinical high risk criteria that emphasize disorganized communication and suspiciousness while also including compromised verbal memory and declining social functioning have the potential to improve predictive accuracy compared with attenuated positive symptoms used alone. On the resulting risk index (a weighted combination of the predictors), low scores were interpreted as signifying minimal risk, with little treatment necessary, high scores as suggesting aggressive intervention, and intermediate scores, although less informative, as supporting psychosocial treatment
Deglaciation of Fennoscandia
To provide a new reconstruction of the deglaciation of the Fennoscandian Ice Sheet, in the form of calendar-year time-slices, which are particularly useful for ice sheet modelling, we have compiled and synthesized published geomorphological data for eskers, ice-marginal formations, lineations, marginal meltwater channels, striae, ice-dammed lakes, and geochronological data from radiocarbon, varve, optically-stimulated luminescence, and cosmogenic nuclide dating. This 25 is summarized as a deglaciation map of the Fennoscandian Ice Sheet with isochrons marking every 1000 years between 22 and 13 cal kyr BP and every hundred years between 11.6 and final ice decay after 9.7 cal kyr BP. Deglaciation patterns vary across the Fennoscandian Ice Sheet domain, reflecting differences in climatic and geomorphic settings as well as ice sheet basal thermal conditions and terrestrial versus marine margins. For example, the ice sheet margin in the high-precipitation coastal setting of the western sector responded sensitively to climatic variations leaving a detailed record of prominent moraines and ice-marginal deposits in many fjords and coastal valleys. Retreat rates across the southern sector differed between slow retreat of the terrestrial margin in western and southern Sweden and rapid retreat of the calving ice margin in the Baltic Basin. Our reconstruction is consistent with much of the published research. However, the synthesis of a large amount of existing and new data support refined reconstructions in some areas. For example, we locate the LGM extent of the ice sheet in northwestern Russia further east than previously suggested and conclude that it occurred at a later time than the rest of the ice sheet, at around 17-15 cal kyr BP, and propose a slightly different chronology of moraine formation over southern Sweden based on improved correlations of moraine segments using new LiDAR data and tying the timing of moraine formation to Greenland ice core cold stages. Retreat rates vary by as much as an order of magnitude in different sectors of the ice sheet, with the lowest rates on the high-elevation and maritime Norwegian margin. Retreat rates compared to the climatic information provided by the Greenland ice core record show a general correspondence between retreat rate and climatic forcing, although a close match between retreat rate and climate is unlikely because of other controls, such as topography and marine versus terrestrial margins. Overall, the time slice
reconstructions of Fennoscandian Ice Sheet deglaciation from 22 to 9.7 cal kyr BP provide an important dataset for understanding the contexts that underpin spatial and temporal patterns in retreat of the
Fennoscandian Ice Sheet, and are an important resource for testing and refining ice sheet models
pH-dependent Intraluminal Organization of Mucin Granules in Live Human Mucous/Goblet Cells
To study the mechanism of gel-forming mucin packaging within mucin granules, we generated human mucous/goblet cells stably expressing a recombinant MUC5AC domain fused to green fluorescent protein (GFP). The fusion protein, named SHGFP-MUC5AC/CK, accumulated in the granules together with native MUC5AC. Inhibition of protein synthesis or disorganization of the Golgi complex did not result in diminished intragranular SHGFP-MUC5AC/CK signals, consistent with long-term storage of the fusion protein. However, SHGFP-MUC5AC/CK was rapidly discharged from the granules upon incubation of the cells with ATP, an established mucin secretagogue. Several criteria indicated that SHGFP-MUC5AC/CK was not covalently linked to endogenous MUC5AC. Analysis of fluorescence recovery after photobleaching suggested that the intragranular SHGFP-MUC5AC/CK mobile fraction and mobility were significantly lower than in the endoplasmic reticulum lumen. Incubation of the cells with bafilomycin A1, a specific inhibitor of the vacuolar H+-ATPase, did not alter the fusion protein mobility, although it significantly increased (approximately 20%) the intragranular SHGFP-MUC5AC/CK mobile fraction. In addition, the granules in bafilomycin-incubated cells typically exhibited a heterogeneous intraluminal distribution of the fluorescent fusion protein. These results are consistent with a model of mucin granule intraluminal organization with two phases: a mobile phase in which secretory proteins diffuse as in the endoplasmic reticulum lumen but at a lower rate and an immobile phase or matrix in which proteins are immobilized by noncovalent pH-dependent interactions. An intraluminal acidic pH, maintained by the vacuolar H+-ATPase, is one of the critical factors for secretory protein binding to the immobile phase and also for its organization
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