SBS 0909+532: A New Double Gravitational Lens or Binary Quasar?

The z=1.377, B=17.0 mag quasar SBS 0909+532 A, B is a double with two images separated by 1.107 +/- 0.006 arcsec. Because the faint image has an emission line at the same wavelength as the MgII 2798 A emission line of the quasar, and lacks the broad MgIb absoption feature expected for a star with the same colors (a K star), we conclude that image B is a quasar with similar redshift to image A. The relative probabilities that the double is the smallest separation (4.8/h kpc for \Omega_0=1) correlated quasar pair or a gravitational lens are \sim 1:10^6. If the object is a lens, the mean lens redshift is $=0.5$ with 90% confidence bounds of 0.18 < z_l < 0.83 for \Omega_0=1. If the lens is an elliptical galaxy, we expect it to be brighter than I < 19.5 mag. The broad band flux ratio varies with wavelength, with \Delta I=0.31, \Delta R=0.58, and \Delta B=1.29 magnitudes, which is difficult to reconcile with the lensing hypothesis.Comment: 19 pages, 6 figures, ApJ in pres

A global meta-analysis on the monetary valuation of dryland ecosystem services : The role of socio-economic, environmental and methodological indicators

Monetary valuation of dryland ecosystem services may help to increase the salience of drylands in decision making. Yet, there is no comprehensive assessment of the indicators that determine the estimated monetary values for dryland ecosystem services (hereafter: dryland value). Having compiled a database consisting of 559 observations from 66 valuation studies in drylands worldwide, this study analyzes the relative importance of local socio-economic, environmental and methodological indicators in explaining the monetary value estimates for nine dryland ecosystem services by means of a multiple regression analysis. By explicitly quantifying the effect sizes of the indicators of dryland value, we shed new light on the driving forces behind monetary valuation of dryland ecosystem services. Our results show that local socio-economic and environmental conditions are marginal in explaining dryland value, indicating that local dryland conditions are not sufficiently captured with current valuation approaches. Simultaneously, we find that methodological factors, including valuation method and study extent, heavily influence dryland value, suggesting that monetary valuation outcomes are largely determined by the selected methodology. This emphasizes the need to improve monetary valuation methods so that they better capture local dryland conditions in order to be able to serve as a meaningful tool for decision making.</p

A global meta-analysis on the monetary valuation of dryland ecosystem services : The role of socio-economic, environmental and methodological indicators

Monetary valuation of dryland ecosystem services may help to increase the salience of drylands in decision making. Yet, there is no comprehensive assessment of the indicators that determine the estimated monetary values for dryland ecosystem services (hereafter: dryland value). Having compiled a database consisting of 559 observations from 66 valuation studies in drylands worldwide, this study analyzes the relative importance of local socio-economic, environmental and methodological indicators in explaining the monetary value estimates for nine dryland ecosystem services by means of a multiple regression analysis. By explicitly quantifying the effect sizes of the indicators of dryland value, we shed new light on the driving forces behind monetary valuation of dryland ecosystem services. Our results show that local socio-economic and environmental conditions are marginal in explaining dryland value, indicating that local dryland conditions are not sufficiently captured with current valuation approaches. Simultaneously, we find that methodological factors, including valuation method and study extent, heavily influence dryland value, suggesting that monetary valuation outcomes are largely determined by the selected methodology. This emphasizes the need to improve monetary valuation methods so that they better capture local dryland conditions in order to be able to serve as a meaningful tool for decision making.</p

Pharmacological profile of BIBN4096BS, the first selective small molecule CGRP antagonist

Calcitonin gene-related peptide (CGRP) is one of the most potent endogenous vasodilators known. This peptide is increased during migraine attacks and has been implicated in the pathogenesis of migraine headache. Here we report on the first small molecule selective CGRP antagonist: BIBN4096BS. In vitro, this compound is extremely potent at primate CGRP receptors exhibiting an affinity (K(i)) for human CGRP receptors of 14.4±6.3 (n=4) pM. In an in vivo model, BIBN4096BS in doses between 1 and 30 μg kg(−1) (i.v.) inhibited the effects of CGRP, released by stimulation of the trigeminal ganglion, on facial blood flow in marmoset monkeys. It is concluded that BIBN4096BS is a potent and selective CGRP antagonist

Evaluation of five radiation schedules and prognostic factors for metastatic spinal cord compression

To study five radiotherapy (RT) schedules and potential prognostic factors for functional outcome in metastatic spinal cord compression (MSCC). One thousand three hundred four patients who were irradiated from January 1992 to December 2003 were included in this retrospective review. The schedules of 1 x 8 Gy in 1 day (n = 261), 5 x 4 Gy in 1 week (n = 279), 10 x 3 Gy in 2 weeks (n = 274), 15 x 2.5 Gy in 3 weeks (n = 233), and 20 x 2 Gy in 4 weeks (n = 257) were compared for motor function, ambulatory status, and in-field recurrences. The following potential prognostic factors were investigated: age, sex, performance status, histology, number of involved vertebra, interval from cancer diagnosis to MSCC, pretreatment ambulatory status, and time of developing motor deficits before RT. A multivariate analysis was performed with the ordered logit model. Motor function improved in 26% (1 x 8 Gy), 28% (5 x 4 Gy), 27% (10 x 3 Gy), 31% (15 x 2.5 Gy), and 28% (20 x 2 Gy); and posttreatment ambulatory rates were 69%, 68%, 63%, 66%, and 74% (P = .578), respectively. On multivariate analysis, age, performance status, primary tumor, involved vertebra, interval from cancer diagnosis to MSCC, pretreatment ambulatory status, and time of developing motor deficits were significantly associated with functional outcome, whereas the RT schedule was not. Acute toxicity was mild, and late toxicity was not observed. In-field recurrence rates at 2 years were 24% (1 x 8 Gy), 26% (5 x 4 Gy), 14% (10 x 3 Gy), 9% (15 x 2.5 Gy), and 7% (20 x 2 Gy) (P <.001). Neither the difference between 1 x 8 Gy and 5 x 4 Gy (P = .44) nor between 10 x 3 Gy, 15 x 2.5 Gy, and 20 x 2 Gy (P = .71) was significant. The five RT schedules provided similar functional outcome. The three more protracted schedules seemed to result in fewer in-field recurrences. To minimize treatment time, the following two schedules are recommended: 1 x 8 Gy for patients with poor predicted survival and 10 x 3 Gy for other patients. Results should be confirmed in a prospective randomized tria

Yeast adapts to a changing stressful environment by evolving cross-protection and anticipatory gene regulation

Organisms can protect themselves against future environmental change. An example is cross-protection, where physiological adaptation against a present environmental stressor can protect an organism against a future stressor. Another is anticipation, where an organism uses information about its present environment to trigger gene expression and other physiological changes adaptive in future environments. “Predictive” abilities like this exist in organisms that have been exposed to periodic changes in environments. It is unknown how readily they can evolve. To answer this question, we carried out laboratory evolution experiments in the yeast Saccharomyces cerevisiae. Specifically, we exposed three replicate populations of yeast to environments that varied cyclically between two stressors, salt stress and oxidative stress, every 10 generations, for a total of 300 generations. We evolved six replicate control populations in only one of these stressors for the same amount of time. We analyzed fitness changes and genome-scale expression changes in all these evolved populations. Our populations evolved asymmetric cross protection, where oxidative stress protects against salt stress but not vice versa. Gene expression data also suggest the evolution of anticipation and basal gene expression changes that occur uniquely in cyclic environments. Our study shows that highly complex physiological states that are adaptive in future environments can evolve on very short evolutionary time scales