531 research outputs found

    A fifty year record of winter glacier melt events in southern Chile, 38°–42°S

    Get PDF
    Little is known about the frequency and potential mass balance impact of winter glacier melt events. In this study, daily atmospheric temperature soundings from the Puerto Montt radiosonde (41.43°S) are used to reconstruct winter melting events at the glacier equilibrium line altitude in the 38°–42°S region of southern Chile, between 1960 and 2010. The representativeness of the radiosonde temperatures to near-surface glacier temperatures is demonstrated using meteorological records from close to the equilibrium line on two glaciers in the region over five winters. Using a degree-day model we estimate an average of 0.28 m of melt and 21 melt days in the 15 June–15 September period each year, with high inter-annual variability. The majority of melt events are associated with midlatitude migratory high pressure systems crossing Chile and northwesterly flows, that force adiabatic compression and warm advection, respectively. There are no trends in the frequency or magnitude of melt events over the period of record, but the annual frequency of winter melt days shows a significant, although rather weak and probably non-linear, relationship to late winter and early spring values of a multivariate El Niño Southern Oscillation Index (MEI)

    The Effect of Browse Species When Fed as a Supplement to Low Quality Native Grass Hay on Animal Performance

    Get PDF
    A pen trial was conducted to measure the impact of some browse species when fed as a supplement on the nitrogen (N) and dry matter intake of cattle receiving low quality native grass hay. There were 8 treatments consisting of a nil-supplement control treatment, a urea supplement control, a green oaten hay control and 5 treatment groups based on browse supplements (Albizia lebbeck, Carissa spp. and Bursaria spp.). Treatment effect on increased native pasture intake was related to the amount of supplementary nitrogen (N), such that there was a significant linear relationship between dry matter intake of native pasture and the intake of supplementary N. Similarly, there was a significant relationship between total dry matter intake and total intake of N

    Controls on advance of tidewater glaciers: results from numerical modeling applied to Columbia Glacier

    Get PDF
    This is the published version, also available here: http://dx.doi.org/10.1029/2006JF000551.A one-dimensional numerical ice flow model is used to study the advance of a tidewater glacier into deep water. Starting with ice-free conditions, the model simulates glacier growth at higher elevations followed by advance on land to the head of the fjord. Once the terminus reaches a bed below sea level, calving is initiated. A series of simulations was carried out with various boundary conditions and parameterizations of the annual mass balance. The results suggest that irrespective of the calving criterion and accumulation rate in the catchment area, it is impossible for the glacier terminus to advance into deeper water (>300 m water depth) unless sedimentation at the glacier front is included. The advance of Columbia Glacier, Alaska, is reproduced by the model by including “conveyor belt” recycling of subglacial sediment and the formation of a sediment bank at the glacier terminus. Results indicate slow advance through the deep fjord and faster advance in shallow waters approaching the terminal moraine shoal and the mouth of the fjord

    Restrictive Atrial Dysfunction in Cardiac Amyloidosis: Differences between Immunoglobulin Light Chain and Transthyretin Cardiac Amyloidosis Patients

    Get PDF
    Background: In cardiac amyloidosis, the prevalence of thromboembolic events and atrial fibrillation is higher in transthyretin amyloidosis compared to immunoglobulin light chain amyloidosis. Therefore, we hypothesize that transthyretin cardiac amyloidosis patients have worse atrial function. Purpose: To explore the left atrial function by conventional ultrasound and strain analysis in immunoglobulin light chain- and transthyretin cardiac amyloidosis patients. Methods: In cardiac amyloidosis patients in our Amyloidosis Expert Center, echocardiographic strain analysis was performed using speckle tracking. Results: The data of 53 cardiac amyloidosis patients (83% male, mean age 70 years) were analyzed. Transthyretin cardiac amyloidosis patients (n = 24, 45%) were older (75 ± 5.6 vs. 65 ± 7.2 years, p < 0.001) and had more left ventricular (LV) hypertrophy than immunoglobulin light chain cardiac amyloidosis patients (n = 29, 55%). However, LV systolic and diastolic function did not differ, nor did left atrial dimensions (LAVI 56(24) vs. 50(31) mL/m 2). Left atrial reservoir strain was markedly lower in transthyretin cardiac amyloidosis (7.4(6.2) vs. 13.6(14.7), p = 0.017). This association was independent of other measurements of the left atrial and ventricular function. Conclusions: Transthyretin cardiac amyloidosis patients had lower left atrial reservoir function compared to immunoglobulin light chain cardiac amyloidosis patients although the left atrial geometry was similar. Interestingly, this association was independent of left atrial- and LV ejection fraction and global longitudinal strain. Further research is warranted to assess the impact of impaired left atrial dysfunction in transthyretin cardiac amyloidosis on atrial fibrillation burden and prognosis

    Acquired resistance of human T cells to sulfasalazine: stability of the resistant phenotype and sensitivity to non-related DMARDs.

    Get PDF
    2.5 weeks) resumption of SSZ resistance and ABCG2 expression as in the original CEM/SSZ cells. CEM/SSZ cells displayed diminished sensitivity to the DMARDs leflunomide (5.1-fold) and methotrexate (1.8-fold), were moderately more sensitive (1.6-2.0 fold) to cyclosporin A and chloroquine, and markedly more sensitive (13-fold) to the glucocorticoid dexamethasone as compared with parental CEM cells. CONCLUSION: The drug efflux pump ABCG2 has a major role in conferring resistance to SSZ. The collateral sensitivity of SSZ resistant cells for some other (non-related) DMARDs may provide a further rationale for sequential mono- or combination therapies with distinct DMARDs upon decreased efficacy of SSZ

    Endomyocardial biopsy with co-localization of a lymphoplasmacytic lymphoma and AL amyloidosis

    Get PDF
    In about 4% of cases, amyloid light chain (AL) amyloidosis is due to an underlying lymphoplasmacytic lymphoma (LPL) or other monoclonal protein forming low-grade B-cell lymphoma, instead of a plasma cell neoplasm. We report an unusual case of a 55-year-old male with co-localization of an IgG positive LPL and AL amyloidosis in his endomyocardial biopsy (EMB). The patient was diagnosed 4 years earlier with a low grade B-cell non Hodgkin lymphoma stage IV, at the time classified as marginal zone lymphoma. He received several lines of treatment for his lymphoma, which had shown progressive disease. Four years after initial diagnosis, he developed increasing dyspnea on exertion. Echocardiography demonstrated left and right ventricular hypertrophy with classical apical sparing, suspicious for cardiac amyloidosis. Bone marrow biopsy revealed massive infiltration by his low grade B-cell lymphoma, which was now reclassified as LPL based on the demonstration of a MYD88 L265P mutation. An EMB confirmed the presence of amyloid, which was typed as AL amyloidosis by the use of immunoelectron microscopy. In addition, mild B-cell infiltrates were present in the EMB, which were shown to be part of his LPL by the demonstration of the MYD88 L265P mutation using the highly sensitive droplet digital polymerase chain reaction technique. This is a rare case of cardiac AL amyloidosis based on an IgG kappa positive LPL, in which not only the amyloid but also the lymphoma itself were present in the EMB. In addition, this case nicely illustrates the use of 2 highly sensitive techniques (immunoelectron microscopy and droplet digital polymerase chain reaction), which both can be performed on small, formalin-fixed paraffin-embedded biopsies

    Web-based self-management for patients with lymphoma:Assessment of the reach of intervention of a randomized controlled trial

    Get PDF
    Background: Randomized controlled trials (RCTs) often provide accurate estimates of the internal validity of an intervention but lack information on external validity (generalizability). We conducted an RCT on the effectiveness of a self-management intervention among patients with lymphoma in a population-based setting. Objective: The objectives of the current study were to describe the proportion of RCT participants compared to all patients invited to participate, and compare sociodemographic and clinical characteristics of RCT participants with all respondents, all patients invited to participate, and all patients selected from the Netherlands Cancer Registry (NCR) to determine the reach of the intervention. An additional objective was to assess differences on RCT outcome variables between RCT and paper respondents. Methods: Patients with lymphoma or chronic lymphocytic leukemia ≥18 years old at diagnosis from 13 hospitals in the Netherlands were selected from the population-based NCR, which routinely collects data on sociodemographic and clinical characteristics. Eligible patients were invited to participate in an RCT and complete a questionnaire. Web-based completion determined RCT enrollment, whereas paper respondents were followed observationally. Results: A total of 1193 patients were selected from the NCR, 892 (74.77%) of whom were invited to participate in the trial by their hematologist after verifying eligibility. Among those invited, 25.4% (227/892) completed the web-based questionnaire and were enrolled in the RCT. The RCT participants were younger and there was a higher proportion of men than nonparticipants (P<.001). In addition, 25.7% (229/892) of those invited opted to participate in the paper-based observational follow-up study. Compared with paper respondents, RCT participants were younger (P<.001), with a higher proportion of men (P=.002), and had higher education levels (P=.02). RCT participants more often wanted to receive all available information on their disease (P<.001), whereas paper respondents reported higher levels of emotional distress (P=.009). Conclusions: From a population-based sample of eligible patients, the participation rate in the RCT was approximately 25%. RCT participants may not be representative of the target population because of different sociodemographic and clinical characteristics. Since RCT participants represent a minority of the target population, RCT results should be interpreted with caution as patients in the RCT may be those least in need of a self-management intervention. Trial Registration: Netherlands Trial Register NTR5953; https://www.trialregister.nl/trial/579
    • …
    corecore