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Sagittal spinopelvic malalignment in Parkinson disease: prevalence and associations with disease severity.
No full textStudy designProspective study.ObjectiveOur objectives were to evaluate the prevalence of sagittal spinopelvic malalignment in a consecutive series of patients with Parkinson disease (PD) and to identify factors associated with sagittal spinopelvic deformity in this population.Summary of background dataPD is a degenerative neurological condition characterized by tremor, rigidity, bradykinesia, and loss of postural reflexes. The prevalence of spinal deformity in PD is higher than that of age-matched adults without PD.MethodsThis study was a prospective assessment of consecutive patients with PD presenting to a neurology clinic during 12 months. Inclusion criteria included age more than 21 years and diagnosis of PD. Age- and sex-matched control group was selected from patients with cervical spondylosis. Clinical and demographic factors were collected including Unified Parkinson Disease Rating Scale score and Hoehn and Yahr stage. Full-length standing spine radiographs were assessed. Patients were grouped into either low C7 sagittal vertical axis (SVA) (10°) pelvic incidence (PI)-lumbar lordosis.ResultsEighty-nine patients met criteria (41 males/48 females), including 52 with low C7 SVA and 37 with high C7 SVA. Significantly higher prevalence of high C7 SVA was found in PD (41.6 vs. 16.8%; P ConclusionPatients with PD have a high prevalence of sagittal spinopelvic malalignment than control group patients. Greater severity of PD is associated with sagittal spinopelvic malalignment.Level of evidence3
An Intracortical Implantable Brain-Computer Interface for Telemetric Real-Time Recording and Manipulation of Neuronal Circuits for Closed-Loop Intervention.
No full textRecording and manipulating neuronal ensemble activity is a key requirement in advanced neuromodulatory and behavior studies. Devices capable of both recording and manipulating neuronal activity brain-computer interfaces (BCIs) should ideally operate un-tethered and allow chronic longitudinal manipulations in the freely moving animal. In this study, we designed a new intracortical BCI feasible of telemetric recording and stimulating local gray and white matter of visual neural circuit after irradiation exposure. To increase the translational reliance, we put forward a Göttingen minipig model. The animal was stereotactically irradiated at the level of the visual cortex upon defining the target by a fused cerebral MRI and CT scan. A fully implantable neural telemetry system consisting of a 64 channel intracortical multielectrode array, a telemetry capsule, and an inductive rechargeable battery was then implanted into the visual cortex to record and manipulate local field potentials, and multi-unit activity. We achieved a 3-month stability of the functionality of the un-tethered BCI in terms of telemetric radio-communication, inductive battery charging, and device biocompatibility for 3 months. Finally, we could reliably record the local signature of sub- and suprathreshold neuronal activity in the visual cortex with high bandwidth without complications. The ability to wireless induction charging combined with the entirely implantable design, the rather high recording bandwidth, and the ability to record and stimulate simultaneously put forward a wireless BCI capable of long-term un-tethered real-time communication for causal preclinical circuit-based closed-loop interventions
Histoarchitecture of the fibrillary matrix of human fetal posterior tibial tendons.
No full textAdult tendons are highly differentiated. In mature individuals, tendon healing after an injury occurs through fibrotic tissue formation. Understanding the intrinsic reparative properties of fetal tendons would help to understand the maturation tissue process and tendon tissue repair. The present study evaluated the evolution of histoarchitecture, cellularity and the distribution of collagens I, III and V in the posterior tibial tendon in human fetuses at different gestational ages. Morphological profiles were assessed in nine fresh spontaneously aborted fetuses (Group I: five fetuses aged between 22 and 28 weeks of gestation; Group II: four fetuses aged between 32 and 38 weeks of gestation), characterized by a combination of histology, fluorescence and immunohistochemistry. In Group I, the posterior tibial tendon showed statistically significant greater cellularity and presence of collagen III and V than in Group II tendon, which showed a predominance of collagenous I and a better organization of the extracellular matrix compared with Group I tendons. In addition, a statistically significant higher rate of CD90, a marker of mesenchymal cells, was found in Group I tendons. In fetuses with gestational age between 22 and 28 weeks, the posterior tibialis tendons showed a thin and disorganized fibrillar structure, with an increase in collagen III and V fibers and mesenchymal cells. In the posterior tibialis tendons of fetuses with gestational age between 32 and 38 weeks, the fibrillar structure was thicker with a statistically significant increase in type I collagen and decreased cellularity
How well can we predict climate migration? A review of forecasting models
No full textClimate change will have significant impacts on all aspects of human society, including population movements. In some cases, populations will be displaced by natural disasters and sudden-onset climate events, such as tropical storms. In other cases, climate change will gradually influence the economic, social, and political realities of a place, which will in turn influence how and where people migrate. Planning for the wide spectrum of future climate-related mobility is a key challenge facing development planners and policy makers. This article reviews the state of climate-related migration forecasting models, based on an analysis of thirty recent models. We present the key characteristics, strengths, and weaknesses of different modeling approaches, including gravity, radiation, agent-based, systems dynamics and statistical extrapolation models, and consider five illustrative models in depth. We show why, at this stage of development, forecasting models are not yet able to provide reliable numerical estimates of future climate-related migration. Rather, models are best used as tools to consider a range of possible futures, to explore systems dynamics, to test theories or potential policy effects. We consider the policy and research implications of our findings, including the need for improved migration data collection, enhanced interdisciplinary collaboration, and scenarios-based planning
Credit and Classification: The Impact of Industry Boundaries in 19th Century America
No full textIn this article, we examine how issues of multi-category membership (hybridity) were handled during the evolution of one of the first general systems of industrial classification in the United States, the credit rating schema of R. G. Dun and Company. Drawing on a repeated cross-sectional study of credit evaluations during the post bellum period (1870-1900), our empirical analyses suggest that organizational membership in multiple categories need not be problematic when classification systems themselves are emergent or in flux and when organizations avoid rare combinations or identities involving ambiguous components. As Dun's schema became institutionalized, boundaries between industries were more clearly defined and boundary violations became subject to increased attention and penalty by credit reporters. Our perspective highlights the utility of an evolutionary perspective and tests its implications for the salience of distinct mechanisms of hybridity. © 2009 by Johnson Graduate School, Cornell University
Mesoscopic Anderson box: Connecting weak to strong coupling
No full textWe study the Anderson impurity problem in a mesoscopic setting, namely the "Anderson box," in which the impurity is coupled to finite reservoir having a discrete spectrum and large sample-to-sample mesoscopic fluctuations. Note that both the weakly coupled and strong coupling Anderson impurity problems are characterized by a Fermi-liquid theory with weakly interacting quasiparticles. We study how the statistical fluctuations in these two problems are connected, using random matrix theory and the slave boson mean-field approximation (SBMFA). First, for a resonant level model such as results from the SBMFA, we find the joint distribution of energy levels with and without the resonant level present. Second, if only energy levels within the Kondo resonance are considered, the distributions of perturbed levels collapse to universal forms for both orthogonal and unitary ensembles for all values of the coupling. These universal curves are described well by a simple Wigner-surmise-type toy model. Third, we study the fluctuations of the mean-field parameters in the SBMFA, finding that they are small. Finally, the change in the intensity of an eigenfunction at an arbitrary point is studied, such as is relevant in conductance measurements. We find that the introduction of the strongly coupled impurity considerably changes the wave function but that a substantial correlation remains. © 2012 American Physical Society
Gestational and perinatal exposure to diazinon causes long-lasting neurobehavioral consequences in the rat.
No full textDiazinon is a widely-used organophosphate pesticide. Pulsatile exposure to diazinon during neonatal development has previously been shown cause long-term neurobehavioral impairments in rats. However, the effects of chronic low concentration exposures during perinatal development remain unclear. This experiment evaluated such effects in Sprague-Dawley rats by implanting osmotic pumps in breeder females prior to conception (N = 13-15 litters per condition) which then delivered chronic, zero order kinetic low-level infusions of 0, 114 or 228 ug/day of diazinon throughout pregnancy. One male and one female from each litter was assessed with a battery of behavioral tests that continued from four weeks of age into adulthood. Litter was used as the unit of variance for the analysis of variance test of significance, with sex as a within litter factor. Diazinon treatment condition was the between subjects factor and time or sessions were repeated measures. Chronic diazinon exposure from pre-mating until the neonatal period caused a significant (p < 0.05) increase in percent of time spent on the open arms of the elevated plus maze, an index of risk-taking behavior. Gestational and lactational diazinon exposure also caused a significant (p < 0.05) degree of hyperactivity in the Figure-8 apparatus during adolescence, specifically affecting the early part of the hour-long test session. This effect had dissipated by the time the rats reached adulthood. Diazinon exposure also caused a significant impairment in novel object recognition, a test of cognitive function. Offspring exposed to 228 ug/day diazinon (p < 0.05) showed significantly less preference for the novel vs. familiar object than controls during the first five minutes of the novel object recognition test
National Trends in Emergency Department Care Processes for Acute Myocardial Infarction in the United States, 2005 to 2015.
No full textBackground Despite investments to improve quality of emergency care for patients with acute myocardial infarction (AMI), few studies have described national, real-world trends in AMI care in the emergency department (ED). We aimed to describe trends in the epidemiology and quality of AMI care in US EDs over a recent 11-year period, from 2005 to 2015. Methods and Results We conducted an observational study of ED visits for AMI using the National Hospital Ambulatory Medical Care Survey, a nationally representative probability sample of US EDs. AMI visits were classified as ST-segment-elevation myocardial infarction (STEMI) and non-STEMI. Outcomes included annual incidence of AMI, median ED length of stay, ED disposition type, and ED administration of evidence-based medications. Annual ED visits for AMI decreased from 1 493 145 in 2005 to 581 924 in 2015. Estimated yearly incidence of ED visits for STEMI decreased from 1 402 768 to 315 813. The proportion of STEMI sent for immediate, same-hospital catheterization increased from 12% to 37%. Among patients with STEMI sent directly for catheterization, median ED length of stay decreased from 62 to 37 minutes. ED administration of antithrombotic and nonaspirin antiplatelet agents rose for STEMI (23%-31% and 10%-27%, respectively). Conclusions National, real-world trends in the epidemiology of AMI in the ED parallel those of clinical registries, with decreases in AMI incidence and STEMI proportion. ED care processes for STEMI mirror evolving guidelines that favor high-intensity antiplatelet therapy, early invasive strategies, and regionalization of care
Laboratory Experiments to Evaluate the Potential Mobilization of Contaminants from Hard Rock Lithium Mining
No full textHard rock mining of lithium is projected to increase significantly over the next decade due to the demand for lithium in renewable energy. The potential impacts of lithium mine tailings and waste rock from a pegmatite source on water quality are not fully documented. Chemical interactions of lithium mine tailings and waste rock with meteoric water can promote leaching of contaminants from the residual rocks and potentially contaminate associated water. This study utilizes the Leaching Environmental Assessment Framework (LEAF) methods used by the US Environmental Protection Agency (EPA) to assess the potential of contaminants leaching from lithium tailings and possible impacts on water quality. Groundwater, surface water and waste rock samples from an undisclosed hard rock lithium mine site in North Carolina were collected. The results were compared to ecological and drinking water standards set by the EPA, US Geological Survey (USGS) and World Health Organization (WHO) as well as to the quality of effluents extracted from coal ash through the LEAF methodology. Results of the leaching experiments indicate that interactions between water and lithium tailings can cause the mobilization of metals and impact water quality. In all leaching scenarios, low liquid-solid (L/S) ratios caused higher mobilization of trace elements. The experimental acidity conditions affected mobilization of trace elements as well; under acidic conditions (lower than pH 4), the mobilization of beryllium, manganese, nickel, and cobalt are promoted, whereas under both acidic (lower than pH 4) and alkaline (greater than pH 10.5) conditions, zinc, lead, iron, aluminum, chromium, lithium, and uranium are mobilized into the effluents. Uranium in one sample leached 40.62% in pH 2, below the detection limit in pH 7 and 60.9% in pH 13 in comparison to the concentration of the bulk solid. Lead showed a similar pattern with one sample leaching 6.77% in initial pH of 2, below the detection limit in pH 7 and 3.54% in pH 12. These results highlight the dependence of ambient acidity conditions on the mobilization of contaminants from lithium tailings solids. The LEAF tests indicated that the lithium waste rock samples all had a buffer capacity between pH 6-10 in testing conditions between pH 4-10.5 and produced slightly to moderately alkaline effluent between a pH of 7-10 in deionized water. Both the alkaline effluent and high buffering capacity observed in the LEAF tests suggests that the formation of acidic effluent and the potential for acid rock drainage is low. Alkaline water observed in the two samples taken on-site, i.e., one surface water sample and one groundwater sample, supports this finding. A comparison to the effluent chemistry generated from a LEAF experiment of coal ash reveals that industrial effluent from a lithium mine will have less of an impact on water quality than coal ash residuals. Under expected moderately alkaline conditions (pH 9) of both coal ash and lithium residual rock effluent, results showed that concentrations of coal ash effluent exceeded lithium rock effluent concentrations by a factor of 19 for antimony, 130 for chromium and 440 for selenium. This study highlights the need to monitor and manage the conditions at tailings and waste rock storage areas. There were L/S and acidity conditions in the lab setting where contaminants of concern including chromium, lead, uranium, beryllium, cadmium, antimony and thallium mobilized. Although the results of this study cannot be directly applied to field conditions, environmental managers should be aware of the conditions in which contaminants of concern mobilized in the lab setting. The main conclusions are that acid rock drainage is unlikely to occur given that the lithium residual rock samples all produced alkaline effluent, the buffer capacity of the lithium residual rock can reduce the risk of contamination associated with highly alkaline conditions, and lithium residual rock effluent in expected moderately alkaline conditions will have less of an impact than coal ash effluent on water quality