Cryptographic Methods with a Pli Cachete: Towards the Computational Assurance of Integrity

Unreproducibility stemming from a loss of data integrity can be prevented with hash functions, secure sketches, and Benford's Law when combined with the historical practice of a Pli Cacheté where scientific discoveries were archived with a 3rd party to later prove the date of discovery. Including the distinct systems of preregistation and data provenance tracking becomes the starting point for the creation of a complete ontology of scientific documentation. The ultimate goals in such a system--ideally mandated--would rule out several forms of dishonesty, catch computational and database errors, catch honest mistakes, and allow for automated data audits of large collaborative open science projects

Periodization and self-regulation in action sports: Coping with the emotional load

Action sports usually include some danger and personal challenge. The levels of both are often further increased when the sport is placed in a competitive environment. In this paper, we consider the Olympic disciplines of freeskiing and snowboarding in park and pipe. We consider some pertinent theoretical perspectives, then offer some insights on their operation using a range of data from ongoing research and support work. Finally, we offer a number of practical steps which can be taken to optimize performance, both in learning and practicing new tricks and in executing them under the pressures of competition

A Mixed-Mode Examination of the Teaching of Lead Climbing by Adventure Sports Coaches in the UK

Background: We present a unique study of adventure sports coaches teaching lead climbing. Expanding existing work on judgement and decision making, we examine the coaching process and the decision making employed to manage the pedagogical and security needs of climbers when they are being introduced to lead climbing. Research design and data collection: As part of a mixed approach, an Applied Cognitive Task Analysis was initially conducted on a small sample of expert coaches (n=7) before a questionnaire was designed and administered with a larger sample (n=53). Findings: The study identifies that the tuition of lead climbing is built on nine core elements that form a shared mental model which in turn is individualised to meet the needs and demands of the individual learning to lead climb. The existence of this coherent shared mental model displays minor modifications to reflect the coach’s own climbing background. More importantly, the existence of this shared mental model is derived from the instructors’ own experiences of climbing and teaching lead climbing rather than any formalised training. In short, this model is actualised through an informal community of practice. Conclusion: The implication for training instructors is that the skills of adapting these nine core aspects to meet individual needs should also be given due consideration alongside the technical skills of rope work and security

Estimates of future warming-induced methane emissions from hydrate offshore west Svalbard for a range of climate models

Methane hydrate close to the hydrate stability limit in seafloor sediment could represent an important source of methane to the oceans and atmosphere as the oceans warm. We investigate the extent to which patterns of past and future ocean-temperature fluctuations influence hydrate stability in a region offshore West Svalbard where active gas venting has been observed. We model the transient behavior of the gas hydrate stability zone at 400–500 m water depth (mwd) in response to past temperature changes inferred from historical measurements and proxy data and we model future changes predicted by seven climate models and two climate-forcing scenarios (Representative Concentration Pathways RCPs 2.6 and 8.5). We show that over the past 2000 year, a combination of annual and decadal temperature fluctuations could have triggered multiple hydrate-sourced methane emissions from seabed shallower than 400 mwd during episodes when the multidecadal average temperature was similar to that over the last century (∼2.6°C). These temperature fluctuations can explain current methane emissions at 400 mwd, but decades to centuries of ocean warming are required to generate emissions in water deeper than 420 m. In the venting area, future methane emissions are relatively insensitive to the choice of climate model and RCP scenario until 2050 year, but are more sensitive to the RCP scenario after 2050 year. By 2100 CE, we estimate an ocean uptake of 97–1050 TgC from marine Arctic hydrate-sourced methane emissions, which is 0.06–0.67% of the ocean uptake from anthropogenic CO2 emissions for the period 1750–2011

Submersible study of an oceanic megamullion in the central North Atlantic

Author Posting. © American Geophysical Union, 2001. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 106, no. B8 (2001): 16145–16161, doi:10.1029/2001JB000373.Recently discovered megamullions on the seafloor have been interpreted to be the exhumed footwalls of long-lived detachment faults operating near the ends of spreading segments in slow spreading crust. We conducted five submersible dives on one of these features just east of the rift valley in the Mid-Atlantic Ridge at 26°35′N and obtained visual, rock sample, gravity, and heat flow data along a transect from the breakaway zone (where the fault is interpreted to have first nucleated in ∼2.0–2.2 Ma crust) westward to near the termination (∼0.7 Ma). Our observations are consistent with the detachment fault hypothesis and show the following features. In the breakaway zone, faulted and steeply backtilted basaltic blocks suggest rotation above a deeper shear zone; the youngest normal faults in this sequence are interpreted to have evolved into the long-lived detachment fault. In younger crust the interpreted detachment surface rises as monotonously flat seafloor in a pair of broad, gently sloping domes that formed simultaneously along isochrons and are now thinly covered by sediment. The detachment surface is locally littered with basaltic debris that may have been clipped from the hanging wall. The domes coincide with a gravity high that continues along isochrons within the spreading segment. Modeling of on-bottom gravity measurements and recovery of serpentinites imply that mantle rises steeply and is exposed within ∼7 km west of the breakaway but that rocks with intermediate densities prevail farther west. Within ∼5 km of the termination, small volcanic cones appear on the detachment surface, indicating melt input into the footwall. We interpret the megamullion to have developed during a phase of limited magmatism in the spreading segment, with mantle being exhumed by the detachment fault <0.5 m.y. after its initiation. Increasing magmatism may eventually have weakened the lithosphere and facilitated propagation of a rift that terminated slip on the detachment fault progressively between ∼1.3 m.y. and 0.7 m.y. Identifiable but low-amplitude magnetic anomalies over the megamullion indicate that it incorporates a magmatic component. We infer that much of the footwall is composed of variably serpentinized peridotite intruded by plutons and dikes.B. Tucholke's research was supported by NSF grant OCE-9503561 and by an award from the Andrew W. Mellon Foundation Endowed Fund for Innovative Research and the Henry Bryant Bigelow Chair in Oceanography at Woods Hole Oceanographic Institution. G. Hirth acknowledges support by NSF grant OCE-9907244

Environmental contributions to disparities in pregnancy outcomes.

One of the most persistent disparities in American health status is the pronounced difference in birth outcomes between non-Hispanic black and non-Hispanic white women. Poor pregnancy outcomes have a substantial impact on mortality, morbidity, and health care costs. Increasing evidence indicates that environmental exposures are associated with poor birth outcomes. This paper reviews the latest research on how environmental exposures affect pregnancy outcomes and then discusses how these exposures may be embedded within a context of significant social and host factor stress. The analysis suggests that environmental, social, and host factors are cumulatively stressing non-Hispanic black women and that this cumulative stress may be a cause of the persistent disparities in pregnancy outcomes

PI3Kinase signaling in glioblastoma

Glioblastoma (GBM) is the most common primary tumor of the CNS in the adult. It is characterized by exponential growth and diffuse invasiveness. Among many different genetic alterations in GBM, e.g., mutations of PTEN, EGFR, p16/p19 and p53 and their impact on aberrant signaling have been thoroughly characterized. A major barrier to develop a common therapeutic strategy is founded on the fact that each tumor has its individual genetic fingerprint. Nonetheless, the PI3K pathway may represent a common therapeutic target to most GBM due to its central position in the signaling cascade affecting proliferation, apoptosis and migration. The read-out of blocking PI3K alone or in combination with other cancer pathways should mainly focus, besides the cytostatic effect, on cell death induction since sublethal damage may induce selection of more malignant clones. Targeting more than one pathway instead of a single agent approach may be more promising to kill GBM cells

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability