Global and regional probabilities of major nuclear reactor accidents.

The continued and extended use of nuclear power is often considered and discussed as a viable energy policy option to meet energy demands while also meeting national CO2 emission reduction goals. A central issue in energy policy for sustainability is the question of nuclear reactor safety. However, studies on nuclear reactor safety often run up against the problem of estimating the probability of a major accident from patchy and limited empirical data. Here, we describe a simple probabilistic model of catastrophic nuclear reactor accidents based on a set of four assumptions. The model treats the accident probability in each of n reactors as a variable and returns the probability of a major accident in the reactor fleet. We find that, at 99.5% reactor safety, the probability of another Chernobyl- or Fukushima-sized event is 49% for the global fleet, and that safety would have to be 99.96% in order to bring that probability below 5%. We discuss our findings in light of the debate on energy policy for sustainability.

Open and endoscopic excision of calvarial dermoid and epidermoid cysts: a single center experience on 128 consecutive cases.

OBJECTIVE: Dermoid and epidermoid cysts rank among the most common pediatric tumors. We analyzed the outcomes of surgical excision of dermal and epidermal inclusion cysts in a large consecutive series of children. METHODS: We retrospectively reviewed 128 consecutive children who underwent calvarial inclusion cyst resection between 2000 and 2010 at NYU Langone Medical Center. Demographic information, neurological exam, lesion location, lesion diameter, type of treatment, extent of resection, time of follow-up, and recurrence were collected. RESULTS: The cohort includes 67 girls (52.3 %) and 61 boys (47.7 %). Age at diagnosis ranged from birth to 6.5 years (mean of 1.2 years) with surgical intervention between 1 month and 20 years of age (1.5 ± 2.1). Of the 128 patients, 107 underwent open resection. Surgical approach was determined by the senior surgeon. Location, postoperative cosmesis, and family preference were the determining factors. Endoscopic resection was favored with supraorbital and glabellar lesions (75 % endoscopic versus 25 % open) using a rigid scope via a single incision. Erosion of the outer table and involvement of the inner table was noted in 20 patients (15 %), 14 of which were reconstructed using a split thickness calvarial graft. These lesions were noted to be significantly larger than lesions where cranioplasty was not used (1.9 ± 2.81 cm versus 1.23 ± 0.98 cm, p = 0.022). Gross total resection was achieved in all cases. DISCUSSION: Complete removal and cure from dermoid and epidermoid inclusion cysts are possible. Complications are few. Endoscopic approaches are useful to improve cosmesis and limit tissue damage for lesions near the orbits.

Use of intraoperative fluoroscopy for the safe placement of C2 laminar screws: technical note.

INTRODUCTION: Rigid fixation of the atlantoaxial joint can be quite challenging due to complex anatomic variants. Numerous techniques have evolved over time, improving the surgeon's adaptability. The recent advent of C2 laminar screws adds to the surgeon's armamentarium, but is not without its own set of limitations. Risk of ventral laminar breach with possible spinal cord injury, CSF leak, or poor bony fixation have led some to recommend prefabricated models or expensive intraoperative spinal navigation to aid screw placement. The purpose of this report is to detail how the use of intraoperative fluoroscopy can be used to aid in the safe placement of C2 laminar screws. METHODS: One patient with rheumatoid arthritis and progressive cervical myelopathy from C1-2 instability underwent C1-2 fixation using C2 laminar screws. Intraoperative fluoroscopy was used to guide and confirm safe laminar screw placement. RESULTS: Immediate and 6-month postoperative imaging demonstrated excellent placement of C2 laminar screws without ventral breach. At 6 months, the patient noted significant improvement of her preoperative symptoms. CONCLUSION: Use of intraoperative fluoroscopy is an easy and safe method for the placement of C2 laminar screws. Given its use of readily available equipment, this method can be implemented without significant pre-planning, or as an impromptu salvage maneuver.

A novel approach to the lumbar sympathetic chain: lateral access.

Plantar hyperhydrosis is a disabling condition of excessive, symmetric, focal sweating of the feet with social, psychological, and medical implications. Treatment options include topical agents, iontophoresis, botulinum toxin injection, and surgical disruption of the lumbar sympathetic chain. Surgical corridors include transperitoneal and retroperitoneal approaches. We report our technique with a novel minimally invasive lateral retroperitoneal approach commonly used for lateral interbody fusions. The lateral approach for sectioning of the sympathetic chain in the treatment of hyperhydrosis appears safe. The approach may be advantageous for the patient and surgeons familiar with lateral interbody fusion. Further studies may elucidate the long term efficacy and safety of the lateral approach. The video can be found here: http://youtu.be/Q82SGpmAXng.

Tipping points ahead? How laypeople respond to linear versus nonlinear climate change predictions.

We investigate whether communication strategies that portray climate change as a nonlinear phenomenon provoke increases in laypeople's climate change risk perceptions. In a high-powered, preregistered online experiment, participants were exposed to linear or nonlinear predictions of future temperature increases that would be expected if global greenhouse gas emissions were not reduced. We hypothesized that the type of climate change portrayal would impact perceptions of qualitative risk characteristics (catastrophic potential, controllability of consequences) which would, in turn, affect laypeople's holistic risk perceptions. The results of the study indicate that the type of climate change portrayal did not affect perceptions of risk or other social-cognitive variables such as efficacy beliefs. While participants who were exposed to a nonlinear portrayal of climate change perceived abrupt changes in the climate system as more likely, they did not perceive the consequences of climate change as less controllable or more catastrophic. Notably, however, participants who had been exposed to a linear or nonlinear portrayal of climate change were willing to donate more money to environmental organizations than participants who had not been presented with a climate-related message. Limitations of the present study and directions for future research are discussed.

The coronavirus pandemic as an analogy for future sustainability challenges.

The current coronavirus outbreak may provide an illustrative analogy for sustainability challenges, exemplifying how challenges such as climate change may become wicked problems demanding novel and drastic solution attempts.

Navigating cognition biases in the search of sustainability.

We provide a conceptual review of the available knowledge on the role of human cognition biases for sustainability and sustainable behavior. Human cognition biases are defined as any deviation in decision making from the standard framework of rational choice. We distinguish between biases in individual decision making and biases in group decision making, and highlight the relevance of each for sustainable behavior. We find that while both categories may contribute to unsustainable behavior, human cognition biases in group settings might be central to understanding many of the current sustainability issues. Moreover, we argue that the effects of group-related biases may outweigh those on the individual level in driving unsustainable behavior, and that biases that have been discussed under various labels in the literature can be interpreted as manifestations of human cognition biases in group settings.

Surgical management of penetrating spinal cord injury primarily due to shrapnel and its effect on neurological outcome: a literature review and meta-analysis.

OBJECTIVE This study was performed to determine whether decompression of penetrating spinal cord injury (SCI) due to explosive shrapnel leads to greater neurological recovery than conservative management. METHODS In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive literature search using PubMed/MEDLINE, Web of Science, Google Scholar, and the Defense Technical Information Center public site was conducted on May 2, 2016. Studies that described penetrating SCI with shrapnel as an etiology, included surgical and/or conservative management, and demonstrated admission and follow-up neurological status were eligible for inclusion in this study. Odds ratios were calculated for the overall effect of surgical treatment on neurological recovery. Funnel plots were used to evaluate publication bias. RESULTS Five case series (Level IV evidence) met the study criteria, and 2 of them had estimable odds ratios for use in the Forest plot analysis. Among the patients from all 5 studies, 65% were injured by shrapnel, 25% by high-velocity bullet, 8% by low-velocity bullet, and 2% by an unknown cause. A total of 288 patients were included in the overall odds ratio calculations. Patients were stratified by complete and incomplete SCI. The meta-analysis showed no significant difference in outcomes between surgical and conservative management in the complete SCI cohort or the incomplete SCI cohort. Overall rates of improvement for complete SCI were 25% with surgery and 27% with conservative treatment (OR 1.07, 95% CI 0.44-2.61, p = 0.88); for incomplete SCI, 70% with surgery and 81% with conservative treatment (OR 1.67, 95% CI 0.68-4.05, p = 0.26). CONCLUSIONS This study demonstrates no clear benefit to surgical decompression of penetrating SCI due predominantly to shrapnel. There is a considerable need for nonrandomized prospective cohort studies examining decompression and stabilization surgery for secondary and tertiary blast injuries.

Posterior Spinal Artery Aneurysm Presenting with Leukocytoclastic Vasculitis.

Rupture of isolated posterior spinal artery (PSA) aneurysms is a rare cause of subarachnoid hemorrhage (SAH) that presents unique diagnostic challenges owing to a nuanced clinical presentation. Here, we report on the diagnosis and management of the first known case of an isolated PSA aneurysm in the context of leukocytoclastic vasculitis. A 53-year-old male presented to an outside institution with acute bilateral lower extremity paralysis 9 days after admission for recurrent cellulitis. Early magnetic resonance imaging was read as negative and repeat imaging 15 days after presentation revealed SAH and a compressive spinal subdural hematoma. Angiography identified a PSA aneurysm at T9, as well as other areas suspicious for inflammatory or post-hemorrhagic reactive changes. The patient underwent a multilevel laminectomy for clot evacuation and aneurysm resection to prevent future hemorrhage and to establish a diagnosis. The postoperative course was complicated by medical issues and led to the diagnosis of leukocytoclastic vasculitis that may have predisposed the patient to aneurysm development. Literature review reveals greater mortality for cervical lesions than thoracolumbar lesions and that the presence of meningitic symptoms portents better functional outcome than symptoms of cord compression. The outcome obtained in this case is consistent with outcomes reported in the literature.

The dynamic turnover and functional roles of alpha-actinin in dendritic spines.

Excitatory synapses are located on actin-rich protrusions known as dendritic spines. alpha-Actinin is an actin binding protein enriched in the postsynaptic density (PSD) of excitatory synapses. Because it also binds to NMDA receptors and other PSD components, alpha-actinin has been proposed to link NMDA receptors and the PSD to the underlying actin cytoskeleton of the dendritic spine. Although alpha-actinin has been implicated in modulation of NMDA receptor activity, the cell biological function of alpha-actinin in neurons is unknown. We report here that alpha-actinin is concentrated in spines. Both the actin binding domain and the spectrin repeat region (which interacts with NMDA receptors) of alpha-actinin2 are required for spine targeting. In live imaging experiments, Venus-tagged alpha-actinin2 in dendritic spines showed faster turnover than PSD-95, as determined by fluorescent recovery after photobleaching (FRAP), and individual spines often showed marked fluctuations in alpha-actinin content over a time-scale of minutes. Overexpression of alpha-actinin2 increased the length and density of dendritic protrusions in cultured hippocampal neurons, an effect that requires the actin binding domain and the spectrin repeats of alpha-actinin. These results suggest that alpha-actinin regulates spine morphology and density.