27 research outputs found

    Internal and external forcing of multidecadal Atlantic climate variability over the past 1,200 years

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    The North Atlantic experiences climate variability on multidecadal scales, which is sometimes referred to as Atlantic multidecadal variability. However, the relative contributions of external forcing such as changes in solar irradiance or volcanic activity and internal dynamics to these variations are unclear. Here we provide evidence for persistent summer Atlantic multidecadal variability from AD 800 to 2010 using a network of annually resolved terrestrial proxy records from the circum-North Atlantic region. We find that large volcanic eruptions and solar irradiance minima induce cool phases of Atlantic multidecadal variability and collectively explain about 30% of the variance in the reconstruction on timescales greater than 30 years. We are then able to isolate the internally generated component of Atlantic multidecadal variability, which we define as the Atlantic multidecadal oscillation. We find that the Atlantic multidecadal oscillation is the largest contributor to Atlantic multidecadal variability over the past 1,200 years. We also identify coherence between the Atlantic multidecadal oscillation and Northern Hemisphere temperature variations, leading us to conclude that the apparent link between Atlantic multidecadal variability and regional to hemispheric climate does not arise solely from a common response to external drivers, and may instead reflect dynamic processes

    Effects of therapy with [177Lu-DOTA0,Tyr3]octreotate on endocrine function

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    Purpose: Peptide receptor radionuclide therapy (PRRT) with radiolabelled somatostatin analogues is a novel therapy for patients with somatostatin receptor-positive tumours. We determined the effects of PRRT with [177Lu-DOTA0,Tyr3]octreotate (177Lu-octreotate) on glucose homeostasis and the pituitary-gonadal, pituitary-thyroid and pituitary-adrenal axes. Methods: Hormone levels were measured and adrenal function assessed at baseline and up to 24 months of follow-up. Results: In 35 men, mean serum inhibin B levels were decreased at 3 months post-therapy (205 ± 16 to 25 ± 4 ng/l, p 550 nmol/l, n = 18). Five patients developed elevated HbA1clevels (> 6.5%). Conclusion: In men177Lu-octreotate therapy induced transient inhibitory effects on spermatogenesis, but non-SHBG-bound T levels remained unaffected. In the long term, gonadotropin levels decreased significantly in postmenopausal women. Only a few patients developed hypothyroidism or elevated levels of HbA1c. Therefore, PRRT with177Lu-octreotate can be regarded as a safe treatment modality with respect to short-and long-term endocrine function
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