2,779 research outputs found
Managing droughts in the low-rainfall areas of the Middle East and North Africa:
Drought is a recurrent and often devastating threat to the welfare of countries in the Middle East and North Africa (MENA) where three-quarters of the arable land has less than 400 mm of annual rainfall, and the natural grazings, which support a majority of the 290 million ruminant livestock, have less than 200 mm. Its impact has been exacerbated in the last half century by the human population increasing yearly at over 3%, while livestock numbers have risen by 50% over the quinquennium. Virtually no scope exists for further expansion of rainfed farming and very little for irrigation, hence there is competition between mechanized cereal production and grazing in the low rainfall areas, and traditional nomadic systems of drought management through mobility are becoming difficult to maintain. Moreover droughts seem to be increasing in frequency, and their high social, economic, and environmental costs have led governments to intervene with various forms of assistance to farmers and herders, including distribution of subsidized animal feed, rescheduling of loans, investments in water development, and in animal health. In this paper we examine the nature and significance of these measures, both with respect to their immediate benefits and costs to the recipients and to governments, and to their longer term impact on poverty and the environment. We conclude that while they have been valuable in reducing catastrophic losses of livestock and thus alleviating poverty, especially in the low rainfall areas where they are the predominant source of income, continued dependence on these programs has sent inappropriate signals to farmers and herders, leading to moral hazards, unsustainable farming practices, and environmental degradation, while generally benefiting the affluent recipients most.Rainfed farming., Environmental impact analysis., Irrigation., Droughts., Middle East., North Africa.,
Very short-lived bromomethanes measured by the CARIBIC observatory over the North Atlantic, Africa and Southeast Asia during 2009-2013
Short-lived organic brominated compounds make up a significant part of the organic bromine budget in the atmosphere. Emissions of these compounds are highly variable and there are limited measurements, particularly in the extra-tropical upper troposphere/lower stratosphere and tropical troposphere. Measurements of five very short-lived bromomethanes (VSLB) were made in air samples collected on the CARIBIC project aircraft over three flight routes; Germany to Venezuela/Columbia during 2009-2011, Germany to South Africa during 2010 and 2011 and Germany to Thailand/Kuala Lumpur, Malaysia during 2012 and 2013. In the tropical troposphere, as the most important entrance region to the stratosphere, we observe a total mean organic bromine derived from these compounds across all flights at 10-12 km altitude of 3.4 ± 1.5 ppt. Individual mean tropical tropospheric mixing ratios across all flights were 0.43, 0.74, 0.14, 0.23 and 0.11 ppt for CHBr3, CH2Br2, CHBr2Cl, CHBrCl2 and CH2BrCl respectively. The highest levels of VSLB-derived bromine (4.20 ± 0.56 ppt) were observed in flights between Bangkok and Kuala Lumpur indicating that the South China Sea is an important source region for these compounds. Across all routes, CHBr and CHBr2 accounted for 34% (4.7-71) and 48% (14-73) respectively of total bromine derived from the analysed VSLB in the tropical mid-upper troposphere totalling 82% (54-89). In samples collected between Germany and Venezuela/Columbia, we find decreasing mean mixing ratios with increasing potential temperature in the extra-tropics. Tropical mean mixing ratios are higher than extra-tropical values between 340-350 K indicating that rapid uplift is important in determining mixing ratios in the lower tropical tropopause layer in the West Atlantic tropics. O3 was used as a tracer for stratospherically influenced air and we detect rapidly decreasing mixing ratios for all VSLB above ∼100 ppb O3 corresponding to the extra-tropical tropopause layer
Southern hemispheric halon trends and global halon emissions, 1978–2011
The atmospheric records of four halons, H-1211 (CBrClF2), H-1301 (CBrF3), H-2402 (CBrF2CBrF2) and H-1202 (CBr2F2), measured from air collected at Cape Grim, Tasmania, between 1978 and 2011, are reported. Mixing ratios of H-1211, H-2402 and H-1202 began to decline in the early to mid-2000s, but those of H-1301 continue to increase up to mid-2011. These trends are compared to those reported by NOAA (National Oceanic and Atmospheric Administration) and AGAGE (Advanced Global Atmospheric Experiment). The observations suggest that the contribution of the halons to total tropospheric bromine at Cape Grim has begun to decline from a peak in 2008 of about 8.1 ppt. An extrapolation of halon mixing ratios to 2060, based on reported banks and predicted release factors, shows this decline becoming more rapid in the coming decades, with a contribution to total tropospheric bromine of about 3 ppt in 2060. Top-down global annual emissions of the halons were derived using a two-dimensional atmospheric model. The emissions of all four have decreased since peaking in the late 1980s–mid-1990s, but this decline has slowed recently, particularly for H-1301 and H-2402 which have shown no decrease in emissions over the past five years. The UEA (University of East Anglia) top-down model-derived emissions are compared to those reported using a top-down approach by NOAA and AGAGE and the bottom-up estimates of HTOC (Halons Technical Options Committee). The implications of an alternative set of steady-state atmospheric lifetimes are discussed. Using a lifetime of 14 yr or less for H-1211 to calculate top-down emissions estimates would lead to small, or even negative, estimated banks given reported production data. Finally emissions of H-1202, a product of over-bromination during the production process of H-1211, have continued despite reported production of H-1211 ceasing in 2010. This raises questions as to the source of these H-1202 emissions
The effect of neural adaptation of population coding accuracy
Most neurons in the primary visual cortex initially respond vigorously when a
preferred stimulus is presented, but adapt as stimulation continues. The
functional consequences of adaptation are unclear. Typically a reduction of
firing rate would reduce single neuron accuracy as less spikes are available
for decoding, but it has been suggested that on the population level,
adaptation increases coding accuracy. This question requires careful analysis
as adaptation not only changes the firing rates of neurons, but also the neural
variability and correlations between neurons, which affect coding accuracy as
well. We calculate the coding accuracy using a computational model that
implements two forms of adaptation: spike frequency adaptation and synaptic
adaptation in the form of short-term synaptic plasticity. We find that the net
effect of adaptation is subtle and heterogeneous. Depending on adaptation
mechanism and test stimulus, adaptation can either increase or decrease coding
accuracy. We discuss the neurophysiological and psychophysical implications of
the findings and relate it to published experimental data.Comment: 35 pages, 8 figure
What do Speech-Language Pathologists want to know when assessing vocal development in children who are deaf/Hard-of-Hearing?
Abstract
Purpose: Delays in vocal development are an early predictor of ongoing language difficulty for children who are deaf/hard-of-hearing (CDHH). Despite the importance of monitoring early vocal development in clinical practice, there are few suitable tools. This study aimed to identify the clinical decisions that speech-language pathologists (SLPs) most want to make when assessing vocal development and their current barriers to doing so.
Method: 58 SLPs who provide services to CDHH younger than 22 months completed a survey. The first section measured potential barriers to vocal development assessment. The second section asked SLPs to rate the importance of 15 clinical decisions they could make about vocal development.
Results: SLPs believed assessing vocal development was important for other stakeholders, and reported they had the necessary skills and knowledge to assess vocal development. Barriers primarily related to a lack of commercially available tests. SLPs rated all 15 clinical decisions as somewhat or very important. Their top 5 decisions included a variety of assessment purposes that tests are not typically designed to support, including measuring change, differential diagnosis, and goal setting.
Conclusions: SLPs wish to make a number of clinical decisions when assessing vocal development in CDHH but lack access to appropriate tools to do so. Future work is needed to develop tools that are statistically equipped to fulfill these purposes. Understanding SLPs’ assessment purposes will allow future tests to better map onto the clinical decisions that SLPs need to make to support CDHH and their families and facilitate implementation into clinical practice
Usability and Feasibility of a Spoken Language Outcome Monitoring Procedure in a Canadian Early Hearing Detection & Intervention Program: Results of a 1-Year Pilot
Abstract
Purpose: Best practice recommendations for Early Hearing Detection and Intervention (EHDI) programs include routine spoken language outcome monitoring. The present article reports on pilot data that evaluated the usability and feasibility of a spoken language outcome monitoring procedure developed for Ontario’s Infant Hearing Program (IHP). This procedure included both Program-level monitoring using omnibus language tests from birth to 6;0 and individual vulnerability monitoring of key domains of spoken language known to be at risk in children who are deaf/hard-of-hearing.
Methodology: Speech-language pathologists (SLPs) in the IHP piloted the new procedures for one year and provided feedback on the procedure through surveys at the end of the pilot.
Results: Data was suggestive that the Program-level procedure might be sensitive to change over time and known predictors of spoken language outcomes. Some, but not all, Program-level test scores were predicted by the presence of additional developmental factors. None of the test scores were significantly predicted by severity of hearing loss. Depending on the tests and scores used, some aspects of the Program-level procedure to change over time. There was insufficient evidence to support individual vulnerability monitoring. SLPs reported significant concerns about the time involved in implementing both procedures.
Conclusions: This article describes preliminary evidence suggesting that the Program-level procedure might be feasible to implement and useful for evaluating EHDI programs. Future evaluations are needed to determine whether the procedure can be accurately implemented to scale in the IHP, and whether the data that results from the procedure can meaningfully inform stakeholders’ decision-making
A Pilot Programme to Facilitate the Use of Mental Health Treatment Requirements: Professional Stakeholders' Experiences
Mental Health Treatment Requirements (MHTRs) have been available in England and Wales since 2005 but are rarely used, despite high rates of mental health problems amongst offenders. In 2018, a new protocol to facilitate the use of MHTRs was piloted in five sites in England. Aims: Understanding the experiences of professional stakeholders and identify barriers to use MHTRs. Methods: Semi-structured qualitative interviews were conducted with thirty-eight professional stakeholders and thematic analysis applied. Results: Interviewees were positive about the content and implementation of the new protocol. Interviewees described key benefits as increasing options in community sentencing, addressing a gap in service provision and facilitating offenders’ access to other services. Challenges described, included multi-agency working, sustainability of funding and the range and complexity of needs of offenders receiving MHTRs and the variation in their motivation to engage. Success factors described were having a strong steering group, staff dedicated to the project and being able to provide a broad range of support to meet offender needs. Conclusion: The MHTR pilot protocol was generally well-received and appeared to address previous barriers to the use of MHTRs. Future work is needed to evaluate the effectiveness of MHTRs and the experience of offenders who receive them
A comment on test validation: The importance of the clinical perspective
© 2019 American Speech-Language-Hearing Association. Purpose: The misuse of standardized assessments has been a long-standing concern in speech-language pathology and traditionally viewed as an issue of clinician competency and training. The purpose of this article is to consider the contribution of communication breakdowns between test developers and the end users to this issue. Method: We considered the misuse of standardized assessments through the lens of the 2-communities theory, in which standardized tests are viewed as a product developed in 1 community (researchers/test developers) to be used by another community (frontline clinicians). Under this view, optimal test development involves a conversation to which both parties bring unique expertise and perspectives. Results: Consideration of the interpretations that standardized tests are typically validated to support revealed a mismatch between these and the interpretations and decisions that speech-language pathologists typically need to make. Test development using classical test theory, which underpins many of the tests in our field, contributes to this mismatch. Application of item response theory could better equip clinicians with the psychometric evidence to support the interpretations they desire but is not commonly found in the standardized tests used by speech-language pathologists. Conclusions: Advocacy and insistence on the consideration of clinical perspectives and decision making in the test validation process is a necessary part of our role. In improving the nature of the statistical evidence reported in standardized assessments, we can ensure these tools are appropriate to fulfill our professional obligations in a clinically feasible way
Usability and Feasibility of a Spoken Language Outcome Monitoring Procedure in a Canadian Early Hearing Detection & Intervention Program: Results of a 1-Year Pilot
Purpose: Best practice recommendations for Early Hearing Detection and Intervention (EHDI) programs include routine spoken language outcome monitoring. The present article reports on pilot data that evaluated the usability and feasibility of a spoken language outcome monitoring procedure developed for Ontario’s Infant Hearing Program (IHP). This procedure included both Program-level monitoring using omnibus language tests from birth to 6 years of age and individual vulnerability monitoring of key domains of spoken language known to be at risk in children who are deaf or hard of hearing.
Methodology: Speech-language pathologists (SLPs) in the IHP piloted the new procedures for one year and provided feedback on the procedure through surveys at the end of the pilot.
Results: Data was suggestive that the Program-level procedure might be sensitive to change over time and known predictors of spoken language outcomes. Some, but not all, Program-level test scores were predicted by the presence of additional developmental factors. None of the test scores were significantly predicted by severity of hearing loss. Depending on the tests and scores used, some aspects of the Program-level procedure were sensitive to change over time. There was insufficient evidence to support individual vulnerability monitoring. SLPs reported significant concerns about the time involved in implementing both procedures.
Conclusions: This article describes preliminary evidence suggesting that the Program-level procedure might be feasible to implement and useful for evaluating EHDI programs. Future evaluations are needed to determine whether the procedure can be accurately implemented to scale in the IHP, and whether the data that results from the procedure can meaningfully inform stakeholders’ decision-making
Accelerating growth of HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) in the atmosphere
We report the first measurements of 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), a substitute for ozone depleting compounds, in air samples originating from remote regions of the atmosphere and present evidence for its accelerating growth. Observed mixing ratios ranged from below 0.01 ppt in deep firn air to 0.59 ppt in the current northern mid-latitudinal upper troposphere. Firn air samples collected in Greenland were used to reconstruct a history of atmospheric abundance. Year-on-year increases were deduced, with acceleration in the growth rate from 0.029 ppt per year in 2000 to 0.056 ppt per year in 2007. Upper tropospheric air samples provide evidence for a continuing growth until late 2009. Furthermore we calculated a stratospheric lifetime of 370 years from measurements of air samples collected on board high altitude aircraft and balloons. Emission estimates were determined from the reconstructed atmospheric trend and suggest that current "bottom-up" estimates of global emissions for 2005 are too high by a factor of three
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