The Relation between Solar Eruption Topologies and Observed Flare Features I: Flare Ribbons

In this paper we present a topological magnetic field investigation of seven two-ribbon flares in sigmoidal active regions observed with Hinode, STEREO, and SDO. We first derive the 3D coronal magnetic field structure of all regions using marginally unstable 3D coronal magnetic field models created with the flux rope insertion method. The unstable models have been shown to be a good model of the flaring magnetic field configurations. Regions are selected based on their pre-flare configurations along with the appearance and observational coverage of flare ribbons, and the model is constrained using pre-flare features observed in extreme ultraviolet and X-ray passbands. We perform a topology analysis of the models by computing the squashing factor, Q, in order to determine the locations of prominent quasi-separatrix layers (QSLs). QSLs from these maps are compared to flare ribbons at their full extents. We show that in all cases the straight segments of the two J-shaped ribbons are matched very well by the flux-rope-related QSLs, and the matches to the hooked segments are less consistent but still good for most cases. In addition, we show that these QSLs overlay ridges in the electric current density maps. This study is the largest sample of regions with QSLs derived from 3D coronal magnetic field models, and it shows that the magnetofrictional modeling technique that we employ gives a very good representation of flaring regions, with the power to predict flare ribbon locations in the event of a flare following the time of the model

Turbulence measurements in a complex plowfield using a crossed hot-wire

Turbulence was quantified in complex axisymmetric, nonreacting, nonswirling flowfields using a crossed hot-wire anemometer. Mean velocity, turbulence intensities, turbulent viscosity, and Reynolds tree were measured in round free jet and confined jet flowfields. The confined jet, a model of an axisymmetric can combustor, had an expansion ratio D/d=2, an expansion angle of 90 deg, and an axial location increments of 0.5 diameters. The confined jet was studied with and without a contraction nozzle. Free jet measurements validated the experimental technique and data reduction. Results show good agreement with those of previous research. Measurements in the confined jet indicate that the cross hot-wire used cannot handle axial flow reversal and the experimental technique is inadequate for measuring time-mean radial velocity. Other quantities show a high level of comparability

Briquetage And Brine: Living And Working At The Classic Maya Salt Works Of Ek Way Nal, Belize

Systematic flotation survey and spatial analysis of artifacts at the submerged salt work of Ek Way Nal reveal evidence of a residence, salt kitchens, and additional activities. Ek Way Nal is one of 110 salt works associated with a Late to Terminal Classic (A.D. 600-900) salt industry known as the Paynes Creek Salt Works. Wooden posts that form the walls of 10 buildings are remarkably preserved in a peat bog below the sea floor providing an opportunity to examine surface artifacts in relation to buildings. Numerous salt kitchens have been located at the Paynes Creek Salt Works by evidence of abundant briquetage - pottery associated with boiling brine over fires to make salt. As one of the largest salt works with 10 buildings, there is an opportunity to examine variability in building use. Systematic flotation survey over the site and flagging and mapping individual artifacts and posts provide evidence that the Ek Way Nal salt makers had a residence near the salt kitchens, along with evidence of salting fish for subsistence or surplus household production. The results are compared with ethnographic evidence from Sacapulas and other salt work

Household salt production by the Late Classic Maya: underwater excavations at Ta\u27ab Nuk Na

Salt is an essential commodity; archaeological remains around the world attest to the importance of its production, exchange and consumption. Often located in coastal locations, many production sites were submerged by rising seas, including the Paynes Creek Salt Works on the southern Belize coast. Survey and excavation of these sites has identified ‘kitchens’ for brine boiling, as well as Terminal Classic residential structures at Ek Way Nal. The authors report the discovery of an earlier residential building alongside salt kitchens at the nearby site of Ta\u27ab Nuk Na. This finding indicates that surplus household production began during the Late Classic, when demand for salt from inland cities was at its peak

A kinetic and theoretical study of the borate catalysed reactions of hydrogen peroxide: the role of dioxaborirane as the catalytic intermediate for a wide range of substrates

Our recent work has provided new insights into the equilibria and species that exist in aqueous solution at different pHs for the boric acid – hydrogen peroxide system, and the role of these species in oxidation reactions. Most recently, (M. C. Durrant, D. M. Davies and M. E. Deary, Org. Biomol. Chem., 2011, 9,7249–7254), we have produced strong theoretical and experimental evidence for the existence of a previously unreported monocyclic three membered peroxide species, dioxaborirane, that is the likely catalytic species in borate mediated electrophilic reactions of hydrogen peroxide in alkaline solution. In the present paper, we extend our study of the borate–peroxide system to look at a wide range of substrates that include substituted dimethyl anilines, methyl-p-tolyl sulfoxide, halides, hydrogen sulfide anion, thiosulfate ,thiocyanate, and hydrazine. The unusual selectivity–reactivity pattern of borate catalysed reactions compared with hydrogen peroxide and inorganic or organic peracids previously observed for theorganic sulfides (D. M. Davies, M. E. Deary, K. Quill and R. A. Smith, Chem.–Eur. J., 2005, 11, 3552–3558) is also seen with substituted dimethyl aniline nucleophiles. This provides evidence that the pattern is not due to any latent electrophilic tendency of the organic sulfides and further supports dioxaborirane being the likely reactive intermediate, thus broadening the applicability of this catalytic system. Moreover, density functional theory calculations on our proposed mechanism involving dioxaborirane are consistent with the experimental results for these substrates. Results obtained at high concentrations of both borate and hydrogen peroxide require the inclusion the diperoxodiborate dianion in the kinetic analysis .A scheme detailing our current understanding of the borate–peroxide system is presented

Development of mental health quality indicators (MHQIs) for inpatient psychiatry based on the interRAI mental health assessment

Abstract Background Outcome quality indicators are rarely used to evaluate mental health services because most jurisdictions lack clinical data systems to construct indicators in a meaningful way across mental health providers. As a result, important information about the effectiveness of health services remains unknown. This study examined the feasibility of developing mental health quality indicators (MHQIs) using the Resident Assessment Instrument - Mental Health (RAI-MH), a clinical assessment system mandated for use in Ontario, Canada as well as many other jurisdictions internationally. Methods Retrospective analyses were performed on two datasets containing RAI-MH assessments for 1,056 patients from 7 facilities and 34,788 patients from 70 facilities in Ontario, Canada. The RAI-MH was completed by clinical staff of each facility at admission and follow-up, typically at discharge. The RAI-MH includes a breadth of information on symptoms, functioning, socio-demographics, and service utilization. Potential MHQIs were derived by examining the empirical patterns of improvement and incidence in depressive symptoms and cognitive performance across facilities in both sets of data. A prevalence indicator was also constructed to compare restraint use. Logistic regression was used to evaluate risk adjustment of MHQIs using patient case-mix index scores derived from the RAI-MH System for Classification of Inpatient Psychiatry. Results Subscales from the RAI-MH, the Depression Severity Index (DSI) and Cognitive Performance Scale (CPS), were found to have good reliability and strong convergent validity. Unadjusted rates of five MHQIs based on the DSI, CPS, and restraints showed substantial variation among facilities in both sets of data. For instance, there was a 29.3% difference between the first and third quartile facility rates of improvement in cognitive performance. The case-mix index score was significantly related to MHQIs for cognitive performance and restraints but had a relatively small impact on adjusted rates/prevalence. Conclusions The RAI-MH is a feasible assessment system for deriving MHQIs. Given the breadth of clinical content on the RAI-MH there is an opportunity to expand the number of MHQIs beyond indicators of depression, cognitive performance, and restraints. Further research is needed to improve risk adjustment of the MHQIs for their use in mental health services report card and benchmarking activities.http://deepblue.lib.umich.edu/bitstream/2027.42/112590/1/12913_2012_Article_2419.pd

Methods to estimate body temperature and energy expenditure dynamics in fed and fasted laboratory mice:effects of sleep deprivation and light exposure

Monitoring body temperature and energy expenditure in freely-moving laboratory mice remains a powerful methodology used widely across a variety of disciplines–including circadian biology, sleep research, metabolic phenotyping, and the study of body temperature regulation. Some of the most pronounced changes in body temperature are observed when small heterothermic species reduce their body temperature during daily torpor. Daily torpor is an energy saving strategy characterized by dramatic reductions in body temperature employed by mice and other species when challenged to meet energetic demands. Typical measurements used to describe daily torpor are the measurement of core body temperature and energy expenditure. These approaches can have drawbacks and developing alternatives for these techniques provides options that can be beneficial both from an animal-welfare and study-complexity perspective. First, this paper presents and assesses a method to estimate core body temperature based on measurements of subcutaneous body temperature, and second, a separate approach to better estimate energy expenditure during daily torpor based on core body temperature. Third, the effects of light exposure during the habitual dark phase and sleep deprivation during the light period on body temperature dynamics were tested preliminary in fed and fasted mice. Together, the here-published approaches and datasets can be used in the future to assess body temperature and metabolism in freely-moving laboratory mice.</p

Stereotypic wheel running decreases cortical activity in mice

Prolonged wakefulness is thought to gradually increase sleep need' and influence subsequent sleep duration and intensity, but the role of specific waking behaviours remains unclear. Here we report the effect of voluntary wheel running during wakefulness on neuronal activity in the motor and somatosensory cortex in mice. We find that stereotypic wheel running is associated with a substantial reduction in firing rates among a large subpopulation of cortical neurons, especially at high speeds. Wheel running also has longer-term effects on spiking activity across periods of wakefulness. Specifically, cortical firing rates are significantly higher towards the end of a spontaneous prolonged waking period. However, this increase is abolished when wakefulness is dominated by running wheel activity. These findings indicate that wake-related changes in firing rates are determined not only by wake duration, but also by specific waking behaviours