(4S,5S)-2,2-Dimethyl-4,5-bis­(3-methyl-2-thioxo-2,3-dihydro-1H-imidazol-1-yl­meth­yl)-1,3-dioxolane

In the chiral title compound, C15H22N4O2S2, there are two mol­ecules in the asymmetric unit with distinctly different conformations, as quanti­fied by torsion angles. The dihedral angles between the thio­imidazole rings are 81.59 (5) and 67.04 (4)°. One mol­ecule exhibits local twofold rotation symmetry, while the other displays no local symmetry. Inter­molecular C—H⋯O and C—H⋯S inter­actions are observed

Looking for bright spots: a bottom-up approach to encouraging urban exercise

Many journeys in urban environments are short and could be conveniently carried out on foot or bike. However, many people use public transport or cars and this places pressure on urban transport infrastructures. Motivating people to change their transport habits is a wicked problem and challenging to address. We outline our current approach that involves a long term study of FitbBit users to identify the bright spots: the factors that enable people to successfully change their habits in the long term

A model study of corona emission from hydrometeors

The maximum measured electric fields in thunderclouds are an order of magnitude less than the fields required for electric breakdown of the air. One explanation for lightning initiation in these low fields is that electric breakdown first occurs at the surfaces of raindrops where the ambient field is enhanced very locally due to the drop geometry. Laboratory experiments [Crabb & Latham, 1974] indicate that colliding raindrops which coalesce to form elongated water filaments can produce positive corona in ambient fields close to those measured in thunderclouds. We calculate the E-field distribution around a simulated coalesced drop pair and use a numerical model to study the positive corona mechanisms in detail. Our results give good agreement with the laboratory observations. At the altitudes (and thus low pressures) at which lightning initiation is observed, our results show that positive corona can occur at observed in-cloud E-fields.Comment: 13 pages, 9 figures, http://www.geophys.washington.edu/Surface/Atmospheric/ Submitted to: Quarterly Journal of the Royal Meteorological Societ

Four-point bending evaluation of dentin-composite interfaces with various stresses

Fracture properties of composite-dentin beams bonded with a self?etching adhesive were tested following short term pretreatments to simulate potential degradation mechanisms (thermal cycling, immersion in 5% NaOCl, or fatigue cycling). Beams of rectangular cross-section were shaped to a size of ~0.87 x 0.87 x 10 mm and placed in a four-point bending apparatus, with the loading points 1.8 and 7.2 mm apart, with the interface centered between the inner rollers. Testing was performed in Hanks? Balanced Salt Solution at 25 ?C . Solid dentin and solid composite beams [n = 6] had bending strengths of 164.4 and 164.6 MPa, respectively, under monotonically increasing loads. Bonded beams [n = 6] had strengths of 56.3 MPa. Thermo-cycling (5? to 55?C), NaOCl solution immersion, or 105 of pre-fatigue cycles did not decrease the strength. Conclusion: Thermal stress, exposure to NaOCL, or 105 cycles of mechanical stress does not decrease bond strength of composite bonded to dentin as tested in four-point bending

Four-point bending evaluation of dentin-composite interfaces with various stresses

Fracture properties of composite-dentin beams bonded with a self?etching adhesive were tested following short term pretreatments to simulate potential degradation mechanisms (thermal cycling, immersion in 5% NaOCl, or fatigue cycling). Beams of rectangular cross-section were shaped to a size of ~0.87 x 0.87 x 10 mm and placed in a four-point bending apparatus, with the loading points 1.8 and 7.2 mm apart, with the interface centered between the inner rollers. Testing was performed in Hanks? Balanced Salt Solution at 25 ?C . Solid dentin and solid composite beams [n = 6] had bending strengths of 164.4 and 164.6 MPa, respectively, under monotonically increasing loads. Bonded beams [n = 6] had strengths of 56.3 MPa. Thermo-cycling (5? to 55?C), NaOCl solution immersion, or 105 of pre-fatigue cycles did not decrease the strength. Conclusion: Thermal stress, exposure to NaOCL, or 105 cycles of mechanical stress does not decrease bond strength of composite bonded to dentin as tested in four-point bending

Don’t Kick the Habit: The Role of Dependency in Habit Formation Apps

Habit formation apps are intended to help instigate and maintain new behaviors. Prior research has established that these apps mostly do not support the theoretical ‘habit’ construct defined in psychology, yet are generally popular and well reviewed in app stores. This apparent mismatch between theory and ‘in-the-wild’ usage has not been investigated to date. Through an in-depth qualitative study of a popular application Lift, this research establishes that common techniques such as reminders and streaks are effective at supporting repetition of new behaviors, but at the same time create a dependency: on-going app use is often required to achieve lasting change. This dependency introduces fragility in users’ attempts to change their behavior, as they often abandon the app and subsequently disengage with their new behaviors

A radar-based rainfall climatology of Great Britain and Ireland

The Met Office 1km radar-derived precipitation-rate composite over 8 years (2006–2013) is examined to evaluate whether it provides an accurate representation of annual-average precipitation over Great Britain and Ireland over long periods of time. The annual-average precipitation from the radar composite is comparable with gauge measurements, with an average error of +23mmyr−1 over Great Britain and Ireland, +29mmyr−1 (3%) over the United Kingdom and –781mmyr−1 (46%) over the Republic of Ireland. The radar-derived precipitation composite is useful over the United Kingdom including Northern Ireland, but not accurate over the Republic of Ireland, particularly in the south

Ocean Rossby waves as a triggering mechanism for primary Madden-Julian events

The Madden–Julian Oscillation (MJO) is sporadic, with episodes of cyclical activity interspersed with inactive periods. However, it remains unclear what may trigger a Madden–Julian (MJ) event which is not immediately preceded by any MJO activity: a ‘primary’ MJ event. A combination of case-studies and composite analysis is used to examine the extent to which the triggering of primary MJ events might occur in response to ocean dynamics. The case-studies show that such events can be triggered by the arrival of a downwelling oceanic equatorial Rossby wave, which is shown to be associated with a deepening of the mixed layer and positive sea-surface temperature (SST) anomalies of the order of 0.5–1 °C. These SST anomalies are not attributable to forcing by surface fluxes which are weak for the case-studies analysed. Furthermore, composite analysis suggests that such forcing is consistently important for triggering primary events. The relationship is much weaker for successive events, due to the many other triggering mechanisms which operate during periods of cyclical MJO activity. This oceanic feedback mechanism is a viable explanation for the sporadic and broadband nature of the MJO. Additionally, it provides hope for forecasting MJ events during periods of inactivity, when MJO forecasts generally exhibit low skill

Examining the impact of forest protection status on firewood sufficiency in rural Africa

Millions of people living in poverty depend on non-timber forest products (NTFPs), yet forest protection causes displacement, replacement or reduction of NTFP extraction activities, with implications for human welfare. Here, we assess the impact of forest protection on a novel measure of wellbeing that incorporates both objective and subjective components of people's lives. In five villages near forests with mixed protection status in Tanzania, household perceived need for firewood is compared with actual consumption in order to provide a simple metric of firewood sufficiency. Firewood sufficiency varied with forest protection status, with non-compliance inferred by household ability to meet firewood needs despite forest access restrictions. Fuel-efficient stove ownership improved the perceived ability to meet firewood needs; however, actual consumption remained unchanged. Firewood sufficiency was significantly lower for those sourcing firewood outside forests, and increased household awareness of the management authority significantly reduced firewood consumption. In a forest landscape of mixed protection status, pressure will likely be displaced to the forest with the least active management authority, affecting their efficiency as non-extractive reserves. Our findings reinforce the need for a landscape approach to forest management planning that accounts for local needs, to avoid leakage to other less well-protected forests and detriment to household welfare