Dynamical evidence for causality between galactic cosmic rays and interannual variation in global temperature

As early as 1959, it was hypothesized that an indirect link between solar activity and climate could be mediated by mechanisms controlling the flux of galactic cosmic rays (CR) [Ney ER (1959) Nature 183:451–452]. Although the connection between CR and climate remains controversial, a significant body of laboratory evidence has emerged at the European Organization for Nuclear Research [Duplissy J, et al. (2010) Atmos Chem Phys 10:1635–1647; Kirkby J, et al. (2011) Nature 476(7361):429–433] and elsewhere [Svensmark H, Pedersen JOP, Marsh ND, Enghoff MB, Uggerhøj UI (2007) Proc R Soc A 463:385–396; Enghoff MB, Pedersen JOP, Uggerhoj UI, Paling SM, Svensmark H (2011) Geophys Res Lett 38:{"type":"entrez-nucleotide","attrs":{"text":"L09805","term_id":"177519"}}L09805], demonstrating the theoretical mechanism of this link. In this article, we present an analysis based on convergent cross mapping, which uses observational time series data to directly examine the causal link between CR and year-to-year changes in global temperature. Despite a gross correlation, we find no measurable evidence of a causal effect linking CR to the overall 20th-century warming trend. However, on short interannual timescales, we find a significant, although modest, causal effect between CR and short-term, year-to-year variability in global temperature that is consistent with the presence of nonlinearities internal to the system. Thus, although CR do not contribute measurably to the 20th-century global warming trend, they do appear as a nontraditional forcing in the climate system on short interannual timescales.The basic principles behind a possible connection between galactic cosmic rays (CR) and global temperature (GT) are as follows: It has been known since the invention of the cloud chamber in 1911 by Charles Thomson Rees Wilson that ionizing radiation leads to atmospheric cloud nucleation. Although the prime source of ionizing radiation in the global troposphere is CR, the flux of CR reaching the troposphere depends on the solar wind. The solar wind is a stream of ionized gases that blows outward from the Sun, and its intensity varies strongly with the level of surface activity on the Sun. The Earth''s magnetic field shields the planet from much of the solar wind, deflecting that wind like water around the bow of a ship. When solar activity is great, the solar wind is strong, swiping away CR arriving at the top of the atmosphere. These CR are hypothesized to affect cloud formation and cloudiness, and therefore GT. The net radiative effect of cloudiness depends on the difference between incoming solar radiation and outgoing long-wave radiation. Increased cloudiness in the upper troposphere reduces outgoing long-wave radiation, thereby resulting in warming of the planet. Increased cloudiness in the lower troposphere causes less incoming radiation, and therefore cooling of the planet. Data suggest (6) that the amount of CR is positively correlated with the amount of low-level clouds but has no effect on middle- or high-level clouds. Although this is still an open question (7, 8), the reduction in flux in CR in times of high solar activity is hypothesized to result in less cloud nucleation and fewer cloud condensation nuclei, and consequently, reduced low-level cloud amounts. This, in turn, leads to a higher solar radiation flux at the Earth’s surface, and warmer temperatures. Conversely, a weaker solar wind results in cooler temperatures. The actual chemical processes and reactions involved in this problem are complex, but a growing body of experimental and theoretical work has uncovered a chemical pathway by which CR ionization may increase nucleation rates to levels appropriate for cloud condensation nuclei (2–5, 9–11 and references therein). This suggests a superficially simple network linking the Sun, CR, and global climate, with the interaction between the Sun and CR having a potential influence on the climate system. However reasonable this may be, as described in a 2006 review (12), “The suggested mechanisms are, however, too complex to evaluate meaningfully at present.”     

Socio‐economic status predicts drinking patterns but not alcohol‐related consequences independently

Aim To identify independent relationships between socio‐economic status and drinking patterns and related consequences and to identify socio‐economic groups at risk for heavier consumption. Design and setting Three comparable national telephone surveys were utilized: 1995, 2000 and 2004. The respondents were aged 18–65 years. Contextual information includes that a number of liberalized alcohol policy changes occurred over the time of the surveys. Results Educational qualification, income and occupation were associated independently with alcohol consumption. There were indications that the different dimensions of drinking (quantity and frequency) had different relationships with socio‐economic status (SES). For example, lower SES groups drank heavier quantities while higher SES groups drank more frequently. SES, however, did not play a major role predicting drinking consequences once drinking patterns were controlled for, although there were some exceptions. It was the lower‐to‐average SES groups that were at greater risk for drinking heavier quantities compared to other SES groups in the population (as they had sustained increases in the quantities they consumed over time where other SES groups did not). Conclusion Socio‐economic status was related independently to drinking patterns and there were indications that SES interacted differently with the different dimensions of drinking (quantity and frequency). For the most part, socio‐economic status was not related independently to the experience of alcohol‐related consequences once drinking patterns were accounted for. It was the lower‐to‐average SES groups that were at greater risk for drinking heavier quantities compared to other SES groups in the population.     

Second‐line mitoxantrone,etoposide, and cytarabine for acute myeloid leukemia: A single‐center experience

The majority of patients with acute myeloid leukemia (AML) will require second‐line chemotherapy for either relapsed or refractory disease. Currently, only allogeneic hematopoietic cell transplantation (HCT) offers a curative option in this setting and no preferred regimen has been established. The reported efficacy of second‐line regimens is widely disparate, thus limiting informed clinical decision making. A retrospective review of 77 patients receiving therapy between 2001 and 2008 with relapsed, 42, and refractory, 35, AML was performed to determine overall response rate and survival following mitoxantrone (8 mg/m²/day), etoposide (100 mg/m²/day), and cytarabine (1,000 mg/m²/day) chemotherapy administered over 5 days. Among 77 patients (median age of 54 years and 64% intermediate risk karyotype) with median follow‐up of 153 days, 18% achieved a complete response and 8% a morphologic leukemia‐free state. Fifty‐seven (74%) experienced treatment failure, 10 of whom achieved a remission after additional therapy. Median overall survival (OS) was 6.8 months. Among patients achieving a response, 50% received consolidation with allogeneic HCT, autologous HCT (5%), or consolidation chemotherapy alone (45%). A nonsignificant trend in overall response (50%, 27%, and 23.8%) and median OS (8.3, 6.8, and 4.7 months) was observed by cytogenetic stratification into favorable, intermediate, and unfavorable risk. Patients with refractory versus relapsed disease had similar overall responses (20% and 31%, P = 0.41) and median OS (5.3 and 7.6 months, P = 0.36). Despite risk stratification by the European Prognostic Index, our series demonstrates inferior rates of response and survival, illustrating the limited activity of this regimen in our cohort. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.