Geochemical evidence for possible natural migration of Marcellus Formation brine to shallow aquifers in Pennsylvania

The debate surrounding the safety of shale gas development in the Appalachian Basin has generated increased awareness of drinking water quality in rural communities. Concerns include the potential for migration of stray gas, metal-rich formation brines, and hydraulic fracturing and/or flowback fluids to drinking water aquifers. A critical question common to these environmental risks is the hydraulic connectivity between the shale gas formations and the overlying shallow drinking water aquifers. We present geochemical evidence from northeastern Pennsylvania showing that pathways, unrelated to recent drilling activities, exist in some locations between deep underlying formations and shallow drinking water aquifers. Integration of chemical data (Br, Cl, Na, Ba, Sr, and Li) and isotopic ratios ((87)Sr/(86)Sr, (2)H/H, (18)O/(16)O, and (228)Ra/(226)Ra) from this and previous studies in 426 shallow groundwater samples and 83 northern Appalachian brine samples suggest that mixing relationships between shallow ground water and a deep formation brine causes groundwater salinization in some locations. The strong geochemical fingerprint in the salinized (Cl > 20 mg/L) groundwater sampled from the Alluvium, Catskill, and Lock Haven aquifers suggests possible migration of Marcellus brine through naturally occurring pathways. The occurrences of saline water do not correlate with the location of shale-gas wells and are consistent with reported data before rapid shale-gas development in the region; however, the presence of these fluids suggests conductive pathways and specific geostructural and/or hydrodynamic regimes in northeastern Pennsylvania that are at increased risk for contamination of shallow drinking water resources, particularly by fugitive gases, because of natural hydraulic connections to deeper formations.     

Moving towards universal health coverage: health insurance reforms in nine developing countries in Africa and Asia

We analyse nine low-income and lower-middle-income countries in Africa and Asia that have implemented national health insurance reforms designed to move towards universal health coverage. Using the functions-of-health-systems framework, we describe these countries' approaches to raising prepaid revenues, pooling risk, and purchasing services. Then, using the coverage-box framework, we assess their progress across three dimensions of coverage: who, what services, and what proportion of health costs are covered. We identify some patterns in the structure of these countries' reforms, such as use of tax revenues to subsidise target populations, steps towards broader risk pools, and emphasis on purchasing services through demand-side financing mechanisms. However, none of the reforms purely conform to common health-system archetypes, nor are they identical to each other. We report some trends in these countries' progress towards universal coverage, such as increasing enrolment in government health insurance, a movement towards expanded benefits packages, and decreasing out-of-pocket spending accompanied by increasing government share of spending on health. Common, comparable indicators of progress towards universal coverage are needed to enable countries undergoing reforms to assess outcomes and make midcourse corrections in policy and implementation.     

Relationships Between Eight Measures of Suspect Effort

Previous studies have recommended that multiple measures be employed concurrently to provide converging evidence regarding the presence of suspect effort during neuropsychological assessment. However, if the tests are highly correlated they do not represent independent sources of information. To date, no study has examined correspondence between effort tests. The present study assessed the relationships between eight measures which can be used to assess effort (Rey 15-item, Rey Dot Counting Test, Rey Word Recognition Test, RAVLT recognition trial, Rey-Osterrieth Complex Figure Test effort equation, Digit Span, Warrington Recognition Memory Test-Words, and “b” Test) in a sample of 105 patients in litigation or attempting to obtain/maintain disability compensation and who displayed noncredible symptoms based on psychometric performance and behavioral criteria. Modest to moderate correlations were observed between test summary scores with only two measures sharing more than 50% score variance (Digit Span and Dot Counting). Moderate correlations were also observed between individual test scores reflecting indices of response time, free recall, recognition, and false positive errors, providing possible evidence that patients may use specific strategies when producing noncredible performances. Overall the results suggest that the use of these various tests generally provides nonredundant data regarding patient credibility in neuropsychological evaluations.     

A new EEG biomarker of neurobehavioural impairment and sleepiness in sleep apnea patients and controls during extended wakefulness

ObjectiveTo explore the use of detrended fluctuation analysis (DFA) scaling exponent of the awake electroencephalogram (EEG) as a new alternative biomarker of neurobehavioural impairment and sleepiness in obstructive sleep apnea (OSA).MethodsEight patients with moderate–severe OSA and nine non-OSA controls underwent a 40-h extended wakefulness challenge with resting awake EEG, neurobehavioural performance (driving simulator and psychomotor vigilance task) and subjective sleepiness recorded every 2-h. The DFA scaling exponent and power spectra of the EEG were calculated at each time point and their correlation with sleepiness and performance were quantified.ResultsDFA scaling exponent and power spectra biomarkers significantly correlated with simultaneously tested performance and self-rated sleepiness across the testing period in OSA patients and controls. Baseline (8am) DFA scaling exponent but not power spectra were markers of impaired simulated driving after 24-h extended wakefulness in OSA (r = 0.738, p = 0.037). OSA patients had a higher scaling exponent and delta power during wakefulness than controls.ConclusionsThe DFA scaling exponent of the awake EEG performed as well as conventional power spectra as a marker of impaired performance and sleepiness resulting from sleep loss.SignificanceDFA may potentially identify patients at risk of neurobehavioural impairment and assess treatment effectiveness.     

Self-Report of Psychological Function Among OEF/OIF Personnel Who Also Report Combat-Related Concussion

MMPI-2 RF profiles of 128 U.S. soldiers and veterans with history of concussion were examined. Participants evaluated in forensic (n?=?42) and clinical (n?=?43) settings showed significantly higher validity and clinical elevations relative to a research group (n?=?43). In the full sample, a multivariate GLM identified main effects for disability claim status and Axis I diagnosis across numerous MMPI-2 RF scales. Participants with co-morbid PTSD and concussion showed significant Restructured Clinical and Specific Problem scale elevations relative to those without Axis I diagnosis. Participants with PTSD and active disability claims were especially prone to elevate on FBS/FBS-r and RBS. Implications for neuropsychologists who routinely administer the MMPI-2/RF in the context of combat-related concussion are discussed.