Acute Effects of Cannabis Smoking on Skills Related to Driving : an fMRI Study

Introduction : Driving is a complex everyday task requiring mechanisms of perception, attention, learning, memory, decision making and action control, thus indicating that involves numerous and varied brain networks. If many data have been accumulated over time about the effects of alcohol consumption on driving capability, much less is known about the role of other psychoactive substances, such as cannabis (Chang et al.2007, Ramaekers et al, 2006). Indeed, the solicited brain areas during safe driving which could be affected by cannabis exposure have not yet been clearly identified. Our aim is to study these brain regions during a tracking task related to driving skills and to evaluate the modulation due to the tolerance of cannabis effects. Methods : Eight non-smoker control subjects participated to an fMRI experiment based on a visuo-motor tracking task, alternating active tracking blocks with passive tracking viewing and rest condition. Half of the active tracking conditions included randomly presented traffic lights as distractors. Subjects were asked to track with a joystick with their right hand and to press a button with their left index at each appearance of a distractor. Four smoking subjects participated to the same fMRI sessions once before and once after smoking cannabis and a placebo in two independent cross-over experiments. We quantified the performance of the subjects by measuring the precision of the behavioural responses (i.e. percentage of time of correct tracking and reaction times to distractors). Functional MRI data were acquired using on a 3.0T Siemens Trio system equipped with a 32-channel head coil. BOLD signals will be obtained with a gradient-echo EPI sequence (TR=2s, TE=30ms, FoV=216mm, FA=90°, matrix size 72×72, 32 slices, thickness 3mm). Preprocessing, single subject analysis and group statistics were conducted on SPM8b. Results were thresholded at p<0.05 (FWE corrected) and at k>30 for spatial extent. Results : Behavioural results showed a significant impairment in task and cognitive test performance of the subjects after cannabis inhalation when comparing their tracking accuracy either to the controls subjects or to their performances before the inhalation or after the placebo inhalation (p<0.001 corrected). In controls, fMRI BOLD analysis of the active tracking condition compared to the passive one revealed networks of polymodal areas in superior frontal and parietal cortex dealing with attention and visuo-spatial coordination. In accordance to what is known of the visual and sensory motor networks we found activations in V4, frontal eye-field, right middle frontal gyrus, intra-parietal sulcus, temporo-parietal junction, premotor and sensory-motor cortex. The presence of distractors added a significant activation in the precuneus. Preliminary results on cannabis smokers in the acute phase, compared either to themselves before the cannabis inhalation or to control subjects, showed a decreased activation in large portions of the frontal and parietal attention network during the simple tracking task, but greater involvement of precuneus, of the superior part of intraparietal sulcus and middle frontal gyrus bilaterally when distractors were present in the task. Conclusions : Our preliminary results suggest that acute cannabis smoking alters performances and brain activity during active tracking tasks, partly reorganizing the recruitment of brain areas of the attention network.

Predicting global change impacts on plant species' distributions: Future challenges

Given the rate of projected environmental change for the 21st century, urgent adaptation and mitigation measures are required to slow down the on-going erosion of biodiversity. Even though increasing evidence shows that recent human-induced environmental changes have already triggered species' range shifts, changes in phenology and species' extinctions, accurate projections of species' responses to future environmental changes are more difficult to ascertain. This is problematic, since there is a growing awareness of the need to adopt proactive conservation planning measures using forecasts of species' responses to future environmental changes. There is a substantial body of literature describing and assessing the impacts of various scenarios of climate and land-use change on species' distributions. Model predictions include a wide range of assumptions and limitations that are widely acknowledged but compromise their use for developing reliable adaptation and mitigation strategies for biodiversity. Indeed, amongst the most used models, few, if any, explicitly deal with migration processes, the dynamics of population at the "trailing edge" of shifting populations, species' interactions and the interaction between the effects of climate and land-use. In this review, we propose two main avenues to progress the understanding and prediction of the different processes A occurring on the leading and trailing edge of the species' distribution in response to any global change phenomena. Deliberately focusing on plant species, we first explore the different ways to incorporate species' migration in the existing modelling approaches, given data and knowledge limitations and the dual effects of climate and land-use factors. Secondly, we explore the mechanisms and processes happening at the trailing edge of a shifting species' distribution and how to implement them into a modelling approach. We finally conclude this review with clear guidelines on how such modelling improvements will benefit conservation strategies in a changing world. (c) 2007 Rubel Foundation, ETH Zurich. Published by Elsevier GrnbH. All rights reserved.

Tax Credit Evaluation Study: Iowa’s Earned Income Tax Credit, February 23007

During the 2005 Legislative Session the Iowa Department of Revenue received an appropriation to establish the Tax Credits Tracking and Analysis Program (TCTAP) to track tax credit awards and claims. In addition, the Department was directed to perform periodic evaluations of tax credit programs. The purpose of these studies is three-fold: (1) To provide a comparison of the Iowa tax credit program to similar federal and other states’ programs (2) To summarize information related to the usage of the Iowa tax credit (3) To evaluate the economic impact of the tax credit program.

Tax Credit Evaluation Study: Iowa’s Biofuel Retailers’ Tax Credits, February 2009

During the 2005 Legislative Session the Iowa Department of Revenue received an appropriation to establish the Tax Credits Tracking and Analysis Program (TCTAP) to track tax credit awards and claims. In addition, the Department was directed to perform periodic evaluations of tax credit programs. The purpose of these studies is three-fold: (1) To provide a comparison of the Iowa tax credit program to similar federal and other states’ programs (2) To summarize information related to the usage of the Iowa tax credit (3) To evaluate the economic impact of the tax credit program.

Tax Credit Evaluation Study: Tax Incentive Programs Used by Biofuel Producers, March 2009

During the 2005 Legislative Session the Iowa Department of Revenue received an appropriation to establish the Tax Credits Tracking and Analysis Program (TCTAP) to track tax credit awards and claims. In addition, the Department was directed to perform periodic evaluations of tax credit programs. The purpose of these studies is three-fold: (1) To provide a comparison of the Iowa tax credit program to similar federal and other states’ programs (2) To summarize information related to the usage of the Iowa tax credit (3) To evaluate the economic impact of the tax credit program.

Tax Credit Evaluation Study: Research Activities Tax Credit, January 2008

During the 2005 Legislative Session the Iowa Department of Revenue received an appropriation to establish the Tax Credits Tracking and Analysis Program (TCTAP) to track tax credit awards and claims. In addition, the Department was directed to perform periodic evaluations of tax credit programs. The purpose of these studies is three-fold: (1) To provide a comparison of the Iowa tax credit program to similar federal and other states’ programs (2) To summarize information related to the usage of the Iowa tax credit (3) To evaluate the economic impact of the tax credit program.

Tax Credits Contingent Liabilities Brief December 8, 2006

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief April 2, 2007

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief July 17, 2007

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief October 3, 2007

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief December 7, 2007

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief April 2, 2008

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief July 31, 2008

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief, October 3, 2008

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.

Tax Credits Contingent Liabilities Brief December 8, 2008

The Tax Credits Contingent Liabilities Report was created by the Tax Research and Program Analysis Section of the Iowa Department of Revenue (IDR) for the benefit of the Revenue Estimating Conference (REC). This report is part of the Tax Credits Tracking and Analysis Program. The goal of the program is to provide a repository for information concerning the awarding, usage, and effectiveness of tax credits. This report forecasts tax credit claims assuming that all available awarded credits are issued and then, along with forecasted credits, are subsequently claimed.