Beyond a warming fingerprint: individualistic biogeographic responses to heterogeneous climate change in California.

Understanding recent biogeographic responses to climate change is fundamental for improving our predictions of likely future responses and guiding conservation planning at both local and global scales. Studies of observed biogeographic responses to 20th century climate change have principally examined effects related to ubiquitous increases in temperature - collectively termed a warming fingerprint. Although the importance of changes in other aspects of climate - particularly precipitation and water availability - is widely acknowledged from a theoretical standpoint and supported by paleontological evidence, we lack a practical understanding of how these changes interact with temperature to drive biogeographic responses. Further complicating matters, differences in life history and ecological attributes may lead species to respond differently to the same changes in climate. Here, we examine whether recent biogeographic patterns across California are consistent with a warming fingerprint. We describe how various components of climate have changed regionally in California during the 20th century and review empirical evidence of biogeographic responses to these changes, particularly elevational range shifts. Many responses to climate change do not appear to be consistent with a warming fingerprint, with downslope shifts in elevation being as common as upslope shifts across a number of taxa and many demographic and community responses being inconsistent with upslope shifts. We identify a number of potential direct and indirect mechanisms for these responses, including the influence of aspects of climate change other than temperature (e.g., the shifting seasonal balance of energy and water availability), differences in each taxon's sensitivity to climate change, trophic interactions, and land-use change. Finally, we highlight the need to move beyond a warming fingerprint in studies of biogeographic responses by considering a more multifaceted view of climate, emphasizing local-scale effects, and including a priori knowledge of relevant natural history for the taxa and regions under study

Lifetimes of states in 19Ne above the 15 O + alpha breakup threshold

The 15O(alpha,gamma)19Ne reaction plays a role in the ignition of Type I x-ray bursts on accreting neutron stars. The lifetimes of states in 19Ne above the 15O + alpha threshold of 3.53 MeV are important inputs to calculations of the astrophysical reaction rate. These levels in 19Ne were populated in the 3He(20Ne,alpha)19Ne reaction at a 20Ne beam energy of 34 MeV. The lifetimes of six states above the threshold were measured with the Doppler shift attenuation method (DSAM). The present measurements agree with previous determinations of the lifetimes of these states and in some cases are considerably more precise

Bistability of Slow and Fast Traveling Waves in Fluid Mixtures

The appearence of a new type of fast nonlinear traveling wave states in binary fluid convection with increasing Soret effect is elucidated and the parameter range of their bistability with the common slower ones is evaluated numerically. The bifurcation behavior and the significantly different spatiotemporal properties of the different wave states - e.g. frequency, flow structure, and concentration distribution - are determined and related to each other and to a convenient measure of their nonlinearity. This allows to derive a limit for the applicability of small amplitude expansions. Additionally an universal scaling behavior of frequencies and mixing properties is found. PACS: 47.20.-k, 47.10.+g, 47.20.KyComment: 4 pages including 5 Postscript figure

Thermodynamic and Kinetic Analyses of Iron Response Element (IRE)-mRNA Binding to Iron Regulatory Protein, IRP1

Comparison of kinetic and thermodynamic properties of IRP1 (iron regulatory protein1) binding to FRT (ferritin) and ACO2 (aconitase2) IRE-RNAs, with or without Mn2+, revealed differences specific to each IRE-RNA. Conserved among animal mRNAs, IRE-RNA structures are noncoding and bind Fe2+ to regulate biosynthesis rates of the encoded, iron homeostatic proteins. IRP1 protein binds IRERNA, inhibiting mRNA activity; Fe2+ decreases IRE-mRNA/IRP1 binding, increasing encoded protein synthesis. Here, we observed heat, 5 °C to 30 °C, increased IRP1 binding to IRE-RNA 4-fold (FRT IRE-RNA) or 3-fold (ACO2 IRE-RNA), which was enthalpy driven and entropy favorable. Mn2+ (50 μM, 25 °C) increased IRE-RNA/IRP1 binding (Kd) 12-fold (FRT IRE-RNA) or 6-fold (ACO2 IRE-RNA); enthalpic contributions decreased ~61% (FRT) or ~32% (ACO2), and entropic contributions increased ~39% (FRT) or ~68% (ACO2). IRE-RNA/IRP1 binding changed activation energies: FRT IRE-RNA 47.0 ± 2.5 kJ/mol, ACO2 IRE-RNA 35.0 ± 2.0 kJ/mol. Mn2+ (50 μM) decreased the activation energy of RNA-IRP1 binding for both IRE-RNAs. The observations suggest decreased RNA hydrogen bonding and changed RNA conformation upon IRP1 binding and illustrate how small, conserved, sequence differences among IREmRNAs selectively influence thermodynamic and kinetic selectivity of the protein/RNA interactions

The just-noticeable difference in speech-to-noise ratio

Just-noticeable differences (JNDs) have been measured for various features of sounds, but despite its importance to communication, there is no benchmark for what is a just-noticeable—and possibly meaningful—difference in speech-to-noise ratio (SNR). SNR plays a crucial role in speech communication for normal-hearing and hearing-impaired listeners. Difficulty hearing speech in background noise—a poor SNR—often leads to dissatisfaction with hearing-assistance devices. While such devices attempt through various strategies to address this problem, it is not currently known how much improvement in SNR is needed to provide a noticeable benefit. To investigate what is a noticeable benefit, we measured the JND in SNR for both normal-hearing and hearing-impaired listeners. Here, we report the SNR JNDs of 69 participants of varying hearing ability, estimated using either an adaptive or fixed-level procedure. The task was to judge which of the two intervals containing a sentence in speech-spectrum noise presented over headphones was clearer. The level of each interval was roved to reduce the influence of absolute level cues. The results of both procedures showed an average SNR JND of 3 dB that was independent of hearing ability. Further experiments using a subset of normal-hearing listeners showed that level roving does elevate threshold. These results suggest that noise reduction schemes may need to achieve a benefit greater than 3 dB to be reliably discriminable

981-46 Impact of a Comprehensive Management Program on the Hospitalization Rate for Patients with Advanced Heart Failure

Patients with advanced heart failure have a course that is often characterized by frequent hospitalizations and progressive deterioration. These patients are commonly referred to specialized centers for consideration of heart transplantation (Tx). To assess the impact of the changes in therapy made in conjunction with heart transplantation evaluation on patient outcomes, we assessed the hospitalization rate and patient's functional status in the 6 months prior to referral compared to the 6 months after referral. Since 1/91, 214 patients were evaluated, accepted for Tx, and discharged having undergone adjustments in medical therapy and a comprehensive patient education program. At time of referral patients had mean LVEF 0.21, NYHA class 3.3, VO2 max 11.0ml/kg, and had undergone a total of 429 hospitalizations in the previous 6 months. During evaluation patients had their ACE inhibitor dose increased by a mean 91.5mg/day of captopril or the equivalent, were diuresed a mean 4.2 liters, were placed on a flexible regimen of loop diuretics, and were counseled on dietary management and home based progressive aerobic exercise. After 6 months of follow-up there were only 63 hospitalizations required (mean hospitalization rate per patient over the 6 months pre-evaluation 2.00±1.45 vs post-evaluation 0.29±0.53 p<0.00001). Patient's NYHA class improved to 2.4 (p<0.0001) and VO2 max increased to 15.2 (p<0.001). Excluding the 12 elective status Tx, 14 urgent status Tx, and 9 deaths within 6 months yielded similar results (344 pre vs 34 post-evaluation hospitalizations). 64 patients (30%) improved their functional status to the point that transplantation was deferred in favor of sustained medical therapy.Referral to a heart failure specialty program is associated with a dramatic occurred between day 10±1 and 3 month. 4 patients died after hospital discharge (no death directly related to thromboembolic disease). Thus no higher risk of PE can be seen in patients with free floating prox-DVT and anticoagulant therapy should be efficient to prevent recurrent PE in such patient

Catalytic Enantioselective [2,3]-Rearrangements of Allylic Ammonium Ylides: A Mechanistic and Computational Study

The research leading to these results (T. H. W., J. E. T., G. C. L.-J. and A.D.S) has received funding from the ERC under the European Union's Seventh Framework Programme (FP7/2007-2013) / E.R.C. grant agreements n° 279850 and n° 340163. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award. P.H.-Y.C. is the Bert and Emelyn Christensen Professor and gratefully acknowledges financial support from the Stone Family of OSU. Financial support from the National Science Foundation (NSF) (CHE-1352663) is acknowledged. D.M.W. acknowledges the Bruce Graham and Johnson Fellowships of OSU. A.C.B. acknowledges the Johnson Fellowship of OSU. D.M.W., A.C.B., and R.C.J. and P.H.-Y.C. also acknowledge computing infrastructure in part provided by the NSF Phase2 CCI, Center for Sustainable Materials Chemistry (CHE1102637).A mechanistic study of the isothiourea-catalyzed enantioselective [2,3]-rearrangement of allylic ammonium ylides is described. Reaction kinetic analyses using 19F NMR and density functional theory computations have elucidated a reaction profile and allowed identification of the catalyst resting state and turnover-rate limiting step. A catalytically-relevant catalyst-substrate adduct has been observed, and its constitution elucidated unambiguously by 13C and 15N isotopic labeling. Isotopic entrainment has shown the observed catalyst-substrate adduct to be a genuine intermediate on the productive cycle towards catalysis. The influence of HOBt as an additive upon the reaction, catalyst resting state, and turnover-rate limiting step has been examined. Crossover experiments have probed the reversibility of each of the proposed steps of the catalytic cycle. Computations were also used to elucidate the origins of stereocontrol, with a 1,5-S•••O interaction and the catalyst stereodirecting group providing transition structure rigidification and enantioselectivity, while preference for cation-π interactions over C-H•••π is responsible for diastereoselectivity.Publisher PDFPeer reviewe

Measurement of two-halo neutron transfer reaction p(11^{11}Li,9^{9}Li)t at 3AA MeV

The p(\nuc{11}{Li},\nuc{9}{Li})t reaction has been studied for the first time at an incident energy of 3$A$ MeV delivered by the new ISAC-2 facility at TRIUMF. An active target detector MAYA, build at GANIL, was used for the measurement. The differential cross sectionshave been determined for transitions to the \nuc{9}{Li} ground andthe first excited states in a wide range of scattering angles. Multistep transfer calculations using different \nuc{11}{Li} model wave functions, shows that wave functions with strong correlations between the halo neutrons are the most successful in reproducing the observation.Comment: 6 pages, 3 figures, submitted to Physical Review Letter

Rapid kinetics of iron responsive element (IRE) RNA/iron regulatory protein 1 and IRE-RNA/eIF4F complexes respond differently to metal ions

Metal ion binding was previously shown to destabilize IRE-RNA/IRP1 equilibria and enhanced IRE-RNA/eIF4F equilibria. In order to understand the relative importance of kinetics and stability, we now report rapid rates of protein/RNA complex assembly and dissociation for two IRE-RNAs with IRP1, and quantitatively different metal ion response kinetics that coincide with the different iron responses in vivo. kon, for FRT IRE-RNA binding to IRP1 was eight times faster than ACO2 IRE-RNA. Mn2+ decreased kon and increased koff for IRP1 binding to both FRT and ACO2 IRE-RNA, with a larger effect for FRT IRE-RNA. In order to further understand IRE-mRNA regulation in terms of kinetics and stability, eIF4F kinetics with FRT IRE-RNA were determined. kon for eIF4F binding to FRT IRE-RNA in the absence of metal ions was 5-times slower than the IRP1 binding to FRT IRE-RNA. Mn2+ increased the association rate for eIF4F binding to FRT IRE-RNA, so that at 50 µM Mn2+ eIF4F bound more than 3-times faster than IRP1. IRP1/IRE-RNA complex has a much shorter life-time than the eIF4F/IRE-RNA complex, which suggests that both rate of assembly and stability of the complexes are important, and that allows this regulatory system to respond rapidly to change in cellular iron