Modelling trade offs between public and private conservation policies

To reduce global biodiversity loss, there is an urgent need to determine the most efficient allocation of conservation resources. Recently, there has been a growing trend for many governments to supplement public ownership and management of reserves with incentive programs for conservation on private land. At the same time, policies to promote conservation on private land are rarely evaluated in terms of their ecological consequences. This raises important questions, such as the extent to which private land conservation can improve conservation outcomes, and how it should be mixed with more traditional public land conservation. We address these questions, using a general framework for modelling environmental policies and a case study examining the conservation of endangered native grasslands to the west of Melbourne, Australia. Specifically, we examine three policies that involve: i) spending all resources on creating public conservation areas; ii) spending all resources on an ongoing incentive program where private landholders are paid to manage vegetation on their property with 5-year contracts; and iii) splitting resources between these two approaches. The performance of each strategy is quantified with a vegetation condition change model that predicts future changes in grassland quality. Of the policies tested, no one policy was always best and policy performance depended on the objectives of those enacting the policy. This work demonstrates a general method for evaluating environmental policies and highlights the utility of a model which combines ecological and socioeconomic processes.Comment: 20 pages, 5 figure

Intertrial unconditioned stimuli differentially impact trace conditioning

Three experiments assessed how appetitive conditioning in rats changes over the duration of a trace conditioned stimulus (CS) when unsignaled unconditioned stimuli (USs) are introduced into the intertrial interval. In Experiment 1, a target US occurred at a fixed time either shortly before (embedded), shortly after (trace), or at the same time (delay) as the offset of a 120-s CS. During the CS, responding was most suppressed by intertrial USs in the trace group, less so in the delay group, and least in the embedded group. Unreinforced probe trials revealed a bell-shaped curve centered on the normal US arrival time during the trace interval, suggesting that temporally-specific learning occurred both with and without intertrial USs. Experiments 2a and 2b confirmed that the bulk of the trace CS became inhibitory when intertrial USs were scheduled, as measured by summation and retardation tests, even though CS offset evoked a temporally precise conditioned response. Thus, an inhibitory CS may give rise to new stimuli specifically linked to its termination, which were excitatory. A modification to the micostimulus temporal difference model is offered to account for the data

Demonstration of an online tool to assist managed care formulary evidence-based decision making: meta-analysis of topical prostaglandin analog efficacy

BACKGROUND: The purpose of this paper was to demonstrate the use of an online service for conducting a systematic review and meta-analysis of the efficacy of topical prostaglandin analogs in reducing intraocular pressure (IOP) in glaucoma and ocular hypertension. METHODS: An online service provider (Doctor Evidence) reviewed and extracted data from the peer-reviewed literature through September 2009. Randomized controlled studies of at least three months’ duration assessing at least two prostaglandin analogs in patients with primary open-angle glaucoma, ocular hypertension, or normal-tension glaucoma were included. The primary endpoint was mean IOP. Summary estimates were created using random-effects models. The Q Chi-square test was used to assess statistical heterogeneity. RESULTS: Sixteen studies satisfied the inclusion criteria and were analyzed. On average, greater IOP-lowering was seen with bimatoprost relative to latanoprost (1 mmHg, P = 0.025) and travoprost (0.8 mmHg, P = 0.033) based on mean IOP after 12–26 weeks of treatment. No statistical difference was observed in IOP-lowering between latanoprost and travoprost (P = 0.841). Findings were similar to previously published meta-analyses of topical prostaglandin analogs. CONCLUSION: Systematic reviews relying on meta-analytic techniques to create summary statistics are considered to be the “gold standard” for synthesizing evidence to support clinical decision-making. However, the process is time-consuming, labor-intensive, and outside the capability of most formulary managers. We have demonstrated the effectiveness of a commercial service that facilitates the process of conducting such reviews

Inactivation of rabbit muscle glycogen phosphorylase b by peroxynitrite revisited: does the nitration of Tyr613 in the allosteric inhibition site control enzymatic function?

There is increasing evidence that sequence-specific formation of 3-nitrotyrosine (3-NT) may cause functional changes in target proteins. Recently, the nitration of Tyr residues in glycogen phosphorylase b (Ph-b) was implicated in the age-associated decline of protein function (Sharov et al., Exp. Gerontol. 41, 407–416; 2006); in another report, the nitration of one specific residue, Tyr613, located in the allosteric inhibition site was hypothesized as a rationale for peroxynitrite inactivation (Dairou et al., J. Mol. Biol. 372, 1009–1021; 2007). In the present study, we have optimized the analysis of in-gel Ph-b digests by high performance liquid chromatography-electro spray ionization-tandem mass spectrometry, in order to achieve a quantitative analysis of nitration of individual Tyr residues at a high coverage of Tyr-containing sequences (92%). Our data do not confirm the role of Tyr613 nitration in the control of enzymatic function. Furthermore, we show here that the enzymatic activity of Ph-b does not directly correlate with the protein nitration levels, and that the modification of Cys and, potentially, other amino acid residues can better rationalize Ph-b inactivation by peroxynitrite

High-Frequency Density Oscillations from a Plasma Source Used for Simulating Low-Earth Orbit Plasma Environment

We present data from ground-based, vacuum-chamber tests demonstrating the ability to modulate the output of a plasma source capable of producing a low-Earth orbit (LEO) type plasma. We obtained plasma oscillations up to 2.5 kHz impingent on stationary test equipment, which corresponds to meter-level ionospheric structures in LEO. This plasma source is, therefore, suitable for developing scientific instruments that measure the LEO plasma environment, in situ, with meter-level spatial resolution. Measurements were made using a fixed-bias collector and an electrometer sampling at 40 kHz. A mechanical aperture was established at the output of the plasma source via two concentric grids. The outer grid was free to rotate in the azimuthal direction with respect to the fixed inner grid. An identical, alternating hole pattern in the two grids resulted in a variable aperture that cycles through 90 open/close cycles per revolution. The frequency of the plasma oscillations is limited by the mechanism used to spin the grids and the bearing assembly on which the grids rotate. Higher frequencies are obtainable by upgrading the drive mechanism, allowing the possibility of centimeter-level spatial resolution

Decreases in Plasma Membrane Ca2+-ATPase in Brain Synaptic Membrane Rafts from Aged Rats

Precise regulation of free intracellular Ca2+ concentrations [Ca2+]i is critical for normal neuronal function, and alterations in Ca2+ homeostasis are associated with brain aging and neurodegenerative diseases. One of the most important proteins controlling [Ca2+]i is the plasma membrane Ca2+-ATPase (PMCA), the high affinity transporter that fine tunes the cytosolic nanomolar levels of Ca2+. We previously found that PMCA protein in synaptic plasma membranes (SPMs) is decreased with advancing age and the decrease in enzyme activity is much greater than that in protein levels. In the present study, we isolated raft and non-raft fractions from rat brain SPMs and used quantitative mass spectrometry to show that the specialized lipid microdomains in SPMs, the rafts, contain 60% of total PMCA, comprised of all four isoforms. The raft PMCA pool had the highest specific activity and this decreased progressively with age. The reduction in PMCA protein could not account for the dramatic activity loss. Addition of excess CaM to the assay did not restore PMCA activity to that in young brains. Analysis of the major raft lipids revealed a slight age-related increase in cholesterol levels and such increases might enhance membrane lipid order and prevent further loss of PMCA activity

I-Domain-Antigen Conjugate (IDAC) for Delivering Antigenic Peptides to APC: Synthesis, Characterization, and in vivo EAE Suppression

The objectives of this work are to characterize the identity of I-domain-antigen conjugate (IDAC) and to evaluate the in vivo efficacy of IDAC in suppressing experimental autoimmune encephalomyelitis (EAE) in mouse model. The hypothesis is that the I-domain delivers PLP139-151 peptides to antigen-presenting cells (APC) and alters the immune system by simultaneously binding to ICAM-1 and MHC-II, blocking immunological synapse formation. IDAC was synthesized by derivatizing the lysine residues with maleimide groups followed by conjugation with PLP-Cys-OH peptide. Conjugation with PLP peptide does not alter the secondary structure of the protein as determined by CD. IDAC suppresses the progression of EAE while I-domain and GMB-I-domain could only delay the onset of EAE. As a positive control, Ac-PLP-BPI-NH2-2 can effectively suppress the progress of EAE. The number of conjugation sites and the sites of conjugations in IDAC were determined using tryptic digest followed by LC-MS analysis. In conclusion, conjugation of I-domain with an antigenic peptide (PLP) resulted in an active molecule to suppress EAE in vivo

The impact of the Self-Determined Learning Model of Instruction on student self-determination

This is the publisher's version, also found here: http://cec.metapress.com/content/c5n78j60w945vk2x/?p=9b7820f03e7c4a37be218efe08d17483&pi=0Promoting self-determination has become a best practice in special education. There remains, however, a paucity of causal evidence for interventions to promote self-determination. This article presents the results of a group-randomized, modified equivalent control group design study of the efficacy of the Self Determined Learning Model of Instruction (SDLMI, Wehmeyer, Palmer, Agran, Mithaug, & Martin, 2000) to promote self-determination. The authors used data on self-determination using multiple measures collected with 312 high school students with cognitive disabilities in both a control and a treatment group to examine the relationship between the SDLMI and self-determination. After determining strong measurement invariance for each latent construct, they found significant differences in latent means across measurement occasions and differential effects attributable to the SDLMI. This was true across disability category, though there was variance across disability populations

MR Molecular Imaging of Aortic Angiogenesis

ObjectivesThe objectives of this study were to use magnetic resonance (MR) molecular imaging to 1) characterize the aortic neovascular development in a rat model of atherosclerosis and 2) monitor the effects of an appetite suppressant on vascular angiogenesis progression.BackgroundThe James C. Russell:LA corpulent rat strain (JCR:LA-cp) is a model of metabolic syndrome characterized by obesity, insulin resistance, hyperlipidemia, and vasculopathy, although plaque neovascularity has not been reported in this strain. MR molecular imaging with ανβ3-targeted nanoparticles can serially map angiogenesis in the aortic wall and monitor the progression of atherosclerosis.MethodsSix-week old JCR:LA-cp (+/?; lean, n = 5) and JCR:LA-cp (cp/cp; obese, n = 5) rats received standard chow, and 6 obese rats were fed the appetite suppressant benfluorex over 16 weeks. Body weight and food consumption were recorded at baseline and weeks 4, 8, 12, and 16. MR molecular imaging with ανβ3-targeted paramagnetic nanoparticles was performed at weeks 0, 8, and 16. Fasted plasma triglyceride, cholesterol, and glucose were measured immediately before MR scans. Plasma insulin and leptin levels were assayed at weeks 8 and 16.ResultsBenfluorex reduced food consumption (p < 0.05) to the same rate as lean animals, but had no effect on serum cholesterol or triglyceride levels. MR (3-T) aortic signal enhancement with ανβ3-targeted nanoparticles was initially equivalent between groups, but increased (p < 0.05) in the untreated obese animals over 16 weeks. No signal change (p > 0.05) was observed in the benfluorex-treated or lean rat groups. MR differences paralleled adventitial microvessel counts, which increased (p < 0.05) among the obese rats and were equivalently low in the lean and benfluorex-treated animals (p > 0.05). Body weight, insulin, and leptin were decreased (p < 0.05) from the untreated obese animals by benfluorex, but not to the lean control levels (p < 0.05).ConclusionsNeovascular expansion is a prominent feature of the JCR:LA-cp model. MR imaging with ανβ3-targeted nanoparticles provided a noninvasive assessment of angiogenesis in untreated obese rats, which was suppressed by benfluorex