7,524 research outputs found

    Essential role for PDGF signaling in ophthalmic trigeminal placode induction

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    Much of the peripheral nervous system of the head is derived from ectodermal thickenings, called placodes, that delaminate or invaginate to form cranial ganglia and sense organs. The trigeminal ganglion, which arises lateral to the midbrain, forms via interactions between the neural tube and adjacent ectoderm. This induction triggers expression of Pax3, ingression of placode cells and their differentiation into neurons. However, the molecular nature of the underlying signals remains unknown. Here, we investigate the role of PDGF signaling in ophthalmic trigeminal placode induction. By in situ hybridization, PDGF receptor β is expressed in the cranial ectoderm at the time of trigeminal placode formation, with the ligand PDGFD expressed in the midbrain neural folds. Blocking PDGF signaling in vitro results in a dose-dependent abrogation of Pax3 expression in recombinants of quail ectoderm with chick neural tube that recapitulate placode induction. In ovo microinjection of PDGF inhibitor causes a similar loss of Pax3 as well as the later placodal marker, CD151, and failure of neuronal differentiation. Conversely, microinjection of exogenous PDGFD increases the number of Pax3+ cells in the trigeminal placode and neurons in the condensing ganglia. Our results provide the first evidence for a signaling pathway involved in ophthalmic (opV) trigeminal placode induction

    The Robber Flies (Diptera: Asilidae) of the Albany Pinebush

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    The Albany Pinebush, a pitch pine-scrub oak sand barrens, was examined for robber flies and the results compared to historical records found in the New York State Museum, Albany. Thirty-six species were recorded of which seventeen were new records. Two species, Cyrtopogon laphriformis and Promachus bastardii, last recorded in 1914 and 1931, respectively, were not located in the survey

    Disk Evolution in Young Binaries: from Observations to Theory

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    The formation of a binary system surrounded by disks is the most common outcome of stellar formation. Hence studying and understanding the formation and the evolution of binary systems and associated disks is a cornerstone of star formation science. Moreover, since the components within binary systems are coeval and the sizes of their disks are fixed by the tidal truncation of their companion, binary systems provide an ideal "laboratory" in which to study disk evolution under well defined boundary conditions. In this paper, we review observations of several inner disk diagnostics in multiple systems, including hydrogen emission lines (indicative of ongoing accretion), K−LK-L and K−NK-N color excesses (evidence of warm inner disks), and polarization (indicative of the relative orientations of the disks around each component). We examine to what degree these properties are correlated within binary systems and how this degree of correlation depends on parameters such as separation and binary mass ratio. These findings will be interpreted both in terms of models that treat each disk as an isolated reservoir and those in which the disks are subject to re-supply from some form of circumbinary reservoir, the observational evidence for which we will also critically review. The planet forming potential of multiple star systems is discussed in terms of the relative lifetimes of disks around single stars, binary primaries and binary secondaries. Finally, we summarize several potentially revealing observational problems and future projects that could provide further insight into disk evolution in the coming decadeComment: 16 pages, 7 figures, chapter in Protostars and Planets

    Older Adults at Risk for Atrial Fibrillation Lack Knowledge and Confidence to Seek Treatment for Signs and Symptoms.

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    Early detection of atrial fibrillation (AF) is crucial for averting AF-related stroke and heart failure, but treatment is delayed when AF is not recognized. The critical need for early detection and treatment requires education to promote AF awareness. Knowledge deficits, attitudes, and beliefs about AF that should be addressed to improve awareness and reduce treatment-seeking delay in older adults at risk for developing AF have not been well documented. The purpose of this study was to describe knowledge, treatment-seeking attitudes, and beliefs about AF in adults ⩾ 65 years old and identify demographic characteristics associated with knowledge, attitudes, and beliefs. Patients with no history of AF recruited from an academic medical center were interviewed using the Knowledge, Attitudes, and Beliefs about Atrial Fibrillation Survey. Data were analyzed using descriptive statistics and independent t tests. Participants (N = 180) were 63% male with a mean age of ±3.± 6.0 years, and 52% held ⩾ 4-year college degree. About one third could not identify common symptoms of AF including palpitations (31%), chest pain (36%), dyspnea (30%), and fatigue (35%). A majority (84%) lacked confidence to recognize AF, and 58% were not sure when they should seek care for AF symptoms. Nearly a third (32%) believed palpitations are always present with AF, and 74% believed that low energy would not be their only symptom of AF. Higher scores for AF Symptom Knowledge (p = .02) were observed in females, and General Knowledge about AF was greater for younger participants (p < .001). Participants lacked knowledge and confidence to aid decision-making for treatment-seeking for symptoms of AF and held inaccurate beliefs about AF that could hinder early treatment-seeking. Programs to promote AF awareness should explain the spectrum of symptoms that may be manifested by AF and include action plans for responding to symptoms

    A new scale to assess the therapeutic relationship in community mental health care: STAR

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    Background. No instrument has been developed specifically for assessing the clinician-patient therapeutic relationship (TR) in community psychiatry. This study aimed to develop a measure of the TR with clinician and patient versions using psychometric principles for test construction. Method. A four-stage prospective study was undertaken, comprising qualitative semi-structured interviews about TRs with clinicians and patients and their assessment of nine established scales for their applicability to community care, administering an amalgamated scale of more than 100 items, followed by Principal Components Analysis (PCA) of these ratings for preliminary scale construction. test-retest reliability of the scale and administering the scale in a new sample to confirm its factorial structure. The sample consisted of patients with severe mental illness and a designated key worker in the care of 17 community mental health teams in England and Sweden. Results. New items not covered by established scales were identified, including clinician helpfulness in accessing services, patient aggression and family interference. The new patient (STAR-P) and clinician scales (STAR-C) each have 12 items comprising three subscales: positive collaboration and positive clinician input in both versions, non-supportive clinician input in the patient version, and emotional difficulties in the clinician version. Test-retest reliability was r = 0(.)76 for STAR-P and r = 0(.)68 for STAR-C. The factorial structure of the new scale was confirmed with a good fit. Conclusions. STAR is a specifically developed, brief scale to assess TRs in community psychiatry with good psychometric properties and is suitable for use in research and routine care

    Mechanical Coupler Testing Report

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    Three styles of Barsplice couplers were tested at the University of Kansas Structural Engineering and Materials Laboratory. The couplers tested and reported include six 8XL-2Y Bargrip XL Swagged (orange), six 8XL-2Y Bargrip XL Part Swagged (red) and eight 8B-2Y Bargrip Swagged (yellow) systems. This report includes the test setup, procedures, results, and evaluation of these testing activities. The summary of results indicates that the three types of No. 8 bar coupler models performed quite well under monotonic, step cyclic, and uniform cyclic loading. No systematic failures were encountered in any coupled assembly under the strength and strain criteria that were set forth in the testing program. The results indicate that these systems can = achieve the levels of ductility typically required of reinforced concrete connections under severe lateral loading
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