The Effects of Oil Well Drill Cuttings on Soil and Rice Plant Development (Oryza sativa) Under Two Redox Conditions

Few studies have focused on the release of toxic elements from oil well drill cuttings and their effect on soil. The present study evaluated these effects using rice growth as the endpoint. Drill cuttings were collected from a Brazilian well and added in doses of 300, 3,000 and 6,000 mg kg^?1 soil, which was maintained at oxidized or reduced conditions. When the redox potential reached approximately ?250 mV, barium concentrations were determined by geochemical fractionation. Overall, doses of 300 and 3,000 mg kg^?1 promoted plant development, while a dose of 6,000 mg kg^?1 inhibited it due to the associated increase in electrical conductivity and exchangeable sodium concentration. In addition, the lower redox potential promoted solubilization of barite from the drill cuttings, which increased barium absorption by plants and translocation to grain, posing a risk to human health.     

Retaining doctors in rural Timor-Leste: a critical appraisal of the opportunities and challenges

Timor-Leste is in the process of addressing a key issue for the country’s health sector: a medical workforce that is too small to provide adequate care. In theory, a bilateral programme of medical cooperation with Cuba created in 2003 could solve this problem. By the end of 2013, nearly 700 new doctors trained in Cuba had been added to Timor-Leste’s medical workforce and by 2017 a further 328 doctors should have been trained in the country by Cuban and local health professionals. A few more doctors who have been trained in Indonesia and elsewhere will also soon enter the workforce. It is expected that the number of physicians in Timor-Leste in 2017 will be more than three times the number present in the country in 2003. Most of the new physicians are expected to work in rural communities and support the national government’s goal of improving health outcomes for the rural majority. Although the massive growth in the medical workforce could change the way health care is delivered and substantially improve health outcomes throughout the country, there are challenges that must be overcome if Timor-Leste is to derive the maximum benefit from such growth. It appears crucial that most of the new doctors be deployed in rural communities and managed carefully to optimize their rural retention.     

Impact of Texting Laws on Motor Vehicular Fatalities in the United States

Using a panel study design, we examined the effects of different types of texting bans on motor vehicular fatalities.We used the Fatality Analysis Reporting System and a difference-in-differences approach to examine the incidence of fatal crashes in 2000 through 2010 in 48 US states with and without texting bans. Age cohorts were constructed to examine the impact of these bans on age-specific traffic fatalities.Primarily enforced laws banning all drivers from texting were significantly associated with a 3% reduction in traffic fatalities in all age groups, and those banning only young drivers from texting had the greatest impact on reducing deaths among those aged 15 to 21 years. Secondarily enforced restrictions were not associated with traffic fatality reductions in any of our analyses.Motor vehicle safety has been described as one of the 10 great public health achievements in the United States in the past decade,1 with car manufacturers and highway engineers making significant improvements to car and roadway safety features.2 Despite these improvements, traffic fatalities remain one of the leading causes of death in the United States,3 with an estimated 32 788 such deaths in 2010.4 Thus, road traffic fatalities continue to be a significant public health concern,5,6 garnering much attention from state lawmakers.In an effort to reduce motor vehicle fatalities, states have enacted restrictions on drunk driving, implemented graduated driver’s license programs, and mandated seatbelt use and special licensing procedures for older adults. Most recently, states have focused on restricting texting while driving.7–9 Generally, states define texting as reading, manual composition, or sending of electronic communications—text messages, instant messages, or e-mails—via a portable electronic device. Portable electronic devices include mobile (i.e., cellular) phones, personal digital assistants, and laptop computers. Texting while driving is a serious threat to road safety,10–13 given that research has shown that mobile phone use is associated with impaired following distance,14 improper lane position,11,15 longer reaction times,11,14,16 and crashes,11,17 which can all lead to significant adverse public health outcomes, including death.18 Unlike talking on a mobile phone while driving, texting poses a unique threat in that it requires drivers to take their eyes off the road for several seconds at a time.14Our current understanding of the impact of texting laws on driving outcomes is limited. To our knowledge, 2 studies have empirically examined the impact of texting laws on adverse motor vehicle outcomes. The first was published by the Highway Loss Data Institute.19 It examined the relationship of collision claim frequency and texting bans in just 4 states (CA, LA, MN, and WA). The authors found that texting bans were associated with increased collision claims. They speculated that this increase might be due to drivers hiding their phones from view to avoid fines and, in so doing, taking their eyes off the road more than they did before the bans. More recently, Abouk and Adams20 published the first national-level study of texting bans’ impacts on traffic fatalities. They examined the impact of texting-while-driving bans on the occurrence of only single-vehicle, single-occupant accidents between 2007 and 2010. Their findings indicated that stronger bans that are applied to all drivers were associated with decreases in single-vehicle, single-occupant accidents.The purpose of this study is to add to the knowledge base concerning the effectiveness of texting laws, particularly by considering the varying stringency levels of these laws. Texting bans can be secondarily enforced (i.e., an officer must have another reason to stop a vehicle before citing a driver for texting while driving) or primarily enforced (i.e., an officer does not have to have another reason for stopping a vehicle). Furthermore, some states ban texting among learner’s permit holders, and some ban texting among all those aged 18 years, 21 years, or younger, and still other states ban all drivers from texting. Some states have no texting laws at all. We consider the impact of each of these policy nuances on traffic fatalities in 48 states over an 11-year period. Moreover, given that younger individuals are more likely to text while driving,21 we examine the impact of texting laws on age-specific traffic fatalities. Overall, this study will be of interest to policymakers, law enforcement personnel, and other stakeholders interested in improving roadway safety and, by extension, public health.     

Designing the epitope flanking regions for optimal generation of CTL epitopes

The flanking amino acids that surround epitopes are critical for effective antigen processing and maintenance of epitope integrity. In the present study, the frequency and characteristics of each amino acid that flanked the peptides generated from the proteasomal degradation of three different subtypes of HIV-1 Gag-p24 were determined. Synthetic flanking regions were designed based on the highest and the lowest frequencies of amino acid with the ideal characteristics at positions upstream and downstream of the proteasomal cleavage site. Peptides were synthesized that contained known CD8+ CTL-epitopes from HIV-1 Gag, CMV pp65, and vaccinia proteins HRP-2, and C16, flanked by amino acid sequences specifically designed to either generate or inhibit the known CD8+ CTL-epitopes. As predicted, the known CD8+ CTL-epitopes were effectively generated from the peptides with synthetic flanking regions specifically designed to promote epitope generation in a proteasome-dependent manner. The majority of the proteasome-generated epitopes were cleaved immediately after the C-terminal amino acid of the specific CTL-epitope. The synthetic peptide sequences containing known CD8+ CTL-epitopes with the flanking regions that promote epitope generation were effectively processed and presented to epitope specific CD8+ T-cells resulting in the production of IFN-γ. These results highlight the importance of flanking regions in promoting efficient antigen processing and presentation. This concept can have important implications in vaccine design and development strategies.     

Rasch analysis of clinical outcome measures in spinal muscular atrophy

Introduction: Trial design for SMA depends on meaningful rating scales to assess outcomes. In this study Rasch methodology was applied to 9 motor scales in spinal muscular atrophy (SMA). Methods: Data from all 3 SMA types were provided by research groups for 9 commonly used scales. Rasch methodology assessed the ordering of response option thresholds, tests of fit, spread of item locations, residual correlations, and person separation index. Results: Each scale had good reliability. However, several issues impacting scale validity were identified, including the extent that items defined clinically meaningful constructs and how well each scale measured performance across the SMA spectrum. Conclusions: The sensitivity and potential utility of each SMA scale as outcome measures for trials could be improved by establishing clear definitions of what is measured, reconsidering items that misfit and items whose response categories have reversed thresholds, and adding new items at the extremes of scale ranges. Muscle Nerve 49 :422–430, 2014     

Quantitative tissue pH measurement during cerebral ischemia using amine and amide concentration-independent detection (AACID) with MRI

Tissue pH is an indicator of altered cellular metabolism in diseases including stroke and cancer. Ischemic tissue often becomes acidic due to increased anaerobic respiration leading to irreversible cellular damage. Chemical exchange saturation transfer (CEST) effects can be used to generate pH-weighted magnetic resonance imaging (MRI) contrast, which has been used to delineate the ischemic penumbra after ischemic stroke. In the current study, a novel MRI ratiometric technique is presented to measure absolute pH using the ratio of CEST-mediated contrast from amine and amide protons: amine/amide concentration-independent detection (AACID). Effects of CEST were observed at 2.75 parts per million (p.p.m.) for amine protons and at 3.50 p.p.m. for amide protons downfield (i.e., higher frequency) from bulk water. Using numerical simulations and in vitro MRI experiments, we showed that pH measured using AACID was independent of tissue relaxation time constants, macromolecular magnetization transfer effects, protein concentration, and temperature within the physiologic range. After in vivo pH calibration using phosphorus (³¹P) magnetic resonance spectroscopy (³¹P-MRS), local acidosis is detected in mouse brain after focal permanent middle cerebral artery occlusion. In summary, our results suggest that AACID represents a noninvasive method to directly measure the spatial distribution of absolute pH in vivo using CEST MRI.