Improving ice core interpretation using in situ and reanalysis data

Back trajectory analysis, provided by the British Atmospheric Data Centre using meteorological parameters from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis ERA-40 (1980-2001) and operational analysis (2002-2006), is used to investigate transport pathways and source regions of climate proxies preserved in a new ice core (Gomez) from the southwestern Antarctic Peninsula. The ECMWF data are compared with automatic weather station data and ice core annual accumulation records to demonstrate that the ECMWF data capture a large proportion of the annual and subseasonal precipitation variability at the site. The back trajectories reveal that precipitation preserved in the ice core accumulation record, and hence climate proxies contained therein, originate from the low-pressure systems from the Bellingshausen Sea transported via circumpolar westerly winds. Hence, precipitation-dependent ice core proxies, such as isotopic composition, will be influenced by both localized sea ice extent and large-scale circulation changes, such as the Southern Annular Mode. Sea ice proxies from the ice core are expected to be dominated by sea ice extent in the Bellingshausen Sea but also influenced by sea ice in the Weddell Sea, with a small proportion of air mass trajectories originating from this region during the summer. Comparison with other ice core sites reveals a stronger influence of easterly transport at more northerly locations, thus explaining the observed differences in snow accumulation records between ice cores and the poor correlation with instrumental records at these sites

Diquat Derivatives: Highly Active, Two-Dimensional Nonlinear Optical Chromophores with Potential Redox Switchability

In this article, we present a detailed study of structure−activity relationships in diquaternized 2,2′-bipyridyl (diquat) derivatives. Sixteen new chromophores have been synthesized, with variations in the amino electron donor substituents, π-conjugated bridge, and alkyl diquaternizing unit. Our aim is to combine very large, two-dimensional (2D) quadratic nonlinear optical (NLO) responses with reversible redox chemistry. The chromophores have been characterized as their PF_6^− salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Their visible absorption spectra are dominated by intense π → π^* intramolecular charge-transfer (ICT) bands, and all show two reversible diquat-based reductions. First hyperpolarizabilities β have been measured by using hyper-Rayleigh scattering with an 800 nm laser, and Stark spectroscopy of the ICT bands affords estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large and increase with the extent of π-conjugation and electron donor strength. Extending the quaternizing alkyl linkage always increases the ICT energy and decreases the E_(1/2) values for diquat reduction, but a compensating increase in the ICT intensity prevents significant decreases in Stark-based β_0 responses. Nine single-crystal X-ray structures have also been obtained. Time-dependent density functional theory clarifies the molecular electronic/optical properties, and finite field calculations agree with polarized HRS data in that the NLO responses of the disubstituted species are dominated by ‘off-diagonal’ β_(zyy) components. The most significant findings of these studies are: (i) β_0 values as much as 6 times that of the chromophore in the technologically important material (E)-4′-(dimethylamino)-N-methyl-4-stilbazolium tosylate; (ii) reversible electrochemistry that offers potential for redox-switching of optical properties over multiple states; (iii) strongly 2D NLO responses that may be exploited for novel practical applications; (iv) a new polar material, suitable for bulk NLO behavior

Recombinant Human Adenovirus with Rat MIP-2 Gene Insertion Causes Prolonged PMN Recruitment to the Murine Brain

Single injections of recombinant cytokines/chemokines into tissue have provided insights into their possible roles during the inflammatory response. Adenoviral technology may allow us to mimic the in vivo situation more closely, with protein generated in a continuous but transient fashion. Replication-deficient human type 5 adenovirus containing a rat macrophage inflammatory protein-2 ( MIP-2 ) gene insertion and cytomegalovirus promoter was injected into the mouse brain to investigate the inflammatory response to continuous overproduction of MIP-2. Adenovirus with a LacZ gene insertion expressing Β-galactosidase was used as a control. At doses of 10 4 to 10 7 plaque-forming units, a minimal inflammatory response was detected to the LacZ virus, with leukocyte recruitment that was restricted to the injection site. A dose of 10 7 plaque-forming units of both the LacZ and the MIP-2 vector produced extensive transgene product expression that persisted for at least 7 days. Astrocytes, recognized by their morphology, were the predominant cell type expressing MIP-2 and Β-galactosidase. A dose of 10 7 plaque-forming units of MIP-2 vector caused dramatic polymorphonuclear leukocyte (PMN) recruitment to the brain parenchyma after 2 days. PMN recruitment was still observed after 4 and 7 days, but had become more localized to the injection site and was associated with numerous foam-like macrophages. At both 2 and 7 days the blood-brain barrier was breached in the region of leukocyte recruitment. Despite the extent of leukocyte recruitment there were no overt signs of neuronal degeneration or demyelination. Our findings demonstrate that continuous production of MIP-2 in the CNS results in persistent PMN recruitment to the brain parenchyma with no evidence of tachyphylaxis. The lack of PMN recruitment to the brain parenchyma following CNS injury may be a result of deficient production of PMN chemoattractants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75633/1/j.1460-9568.1996.tb01324.x.pd

Technological collaboration : bridging the innovation gap between small and large firms

This paper analyzes how technological collaboration acts as an input to the innovation process and allows small and medium-sized entetprises to bridge the innovation gap with their bigger counterparts. Based on a large longitudinal sample of Spanish manufacturing firms, the results show that though technological collaboration is a useful mechanism for firms of all sizes to improve innovativeness, it is a critical factor for the smallest firms. The impact on this collaboration varies depending on innovation output and type of partner. Specifically, the impact of collaboration in small and medium-sized firms is more significant for product than process innovations. Regarding type of partner, vertical collaboration-with suppliers and clients-has the greatest impact on firm innovativeness, though (his effect is clearer lor medium-sized entetprises than for the smallest firmsThis study has been finaneially supported by projeets SEC]2007-67582-C02-02/ECON and CCG08-UC3M/HUM-4152Publicad

Identifying sources of strength: resilience from the perspective of older people receiving long-term community care

This study seeks to explore the sources of strength giving rise to resilience among older people. Twenty-nine in-depth interviews were conducted with older people who receive long-term community care. The interviews were subjected to a thematic content analysis. The findings suggest that the main sources of strength identified among older people were constituted on three domains of analysis; the individual-, interactional and contextual domain. The individual domain refers to the qualities within older people and comprises of three sub-domains, namely beliefs about one’s competence, efforts to exert control and the capacity to analyse and understand ones situation. Within these subdomains a variety of sources of strength were found like pride about ones personality, acceptance and openness about ones vulnerability, the anticipation on future losses, mastery by practising skills, the acceptance of help and support, having a balanced vision on life, not adapting the role of a victim and carpe-diem. The interactional domain is defined as the way older people cooperate and interact with others to achieve their personal goals. Sources of strength on this domain were empowering (in)formal relationships and the power of giving. Lastly, the contextual domain refers to a broader political-societal level and includes sources of strength like the accessibility of care, the availability of material resources and social policy. The three domains were found to be inherently linked to each other. The results can be used for the development of positive, proactive interventions aimed at helping older people build on the positive aspects of their lives

Global patterns of care in advanced stage mycosis fungoides/Sezary syndrome: a multicenter retrospective follow-up study from the Cutaneous Lymphoma International Consortium

ABSTRACT Background Advanced-stage mycosis fungoides (MF)/Sezary syndrome (SS) patients are weighted by an unfavorable prognosis and share an unmet clinical need of effective treatments. International guidelines are available detailing treatment options for the different stages but without recommending treatments in any particular order due to lack of comparative trials. The aims of this second CLIC study were to retrospectively analyze the pattern of care worldwide for advanced-stage MF/SS patients, the distribution of treatments according to geographical areas (USA versus non-USA), and whether the heterogeneity of approaches has potential impact on survival. Patients and methods This study included 853 patients from 21 specialist centers (14 European, 4 USA, 1 each Australian, Brazilian, and Japanese). Results Heterogeneity of treatment approaches was found, with up to 24 different modalities or combinations used as first-line and 36% of patients receiving four or more treatments. Stage IIB disease was most frequently treated by total-skin-electron-beam radiotherapy, bexarotene and gemcitabine; erythrodermic and SS patients by extracorporeal photochemotherapy, and stage IVA2 by polychemotherapy. Significant differences were found between USA and non-USA centers, with bexarotene, photopheresis and histone deacetylase inhibitors most frequently prescribed for first-line treatment in USA while phototherapy, interferon, chlorambucil and gemcitabine in non-USA centers. These differences did not significantly impact on survival. However, when considering death and therapy change as competing risk events and the impact of first treatment line on both events, both monochemotherapy (SHR = 2.07) and polychemotherapy (SHR = 1.69) showed elevated relative risks. Conclusion This large multicenter retrospective study shows that there exist a large treatment heterogeneity in advanced MF/SS and differences between USA and non-USA centers but these were not related to survival, while our data reveal that chemotherapy as first treatment is associated with a higher risk of death and/or change of therapy and thus other therapeutic options should be preferable as first treatment approach

Assessing fitness-to-practice of overseas-trained health practitioners by Australian registration & accreditation bodies

Assessment of fitness-to-practice of health professionals trained overseas and who wish to practice in Australia is undertaken by a range of organisations. These organisations conduct assessments using a range of methods. However there is very little published about how these organisations conduct their assessments. The purpose of the current paper is to investigate the methods of assessment used by these organisations and the issues associated with conducting these assessments