Large-scale dynamics and transport in the stratosphere

Stationary planetary waves in the southern stratosphere display a characteristic seasonal cycle. Previous research based on a one-dimensional model suggests that this behavior is mainly determined by seasonally varying transmission properties of the atmosphere with respect to wave propagation. The issue is investigated with the help of a hemispheric, linear, quasigeostrophic model. It reproduces well some of the observed qualitative features and is internally consistent in the sense that its seasonal wave cycle can be explained in terms of varying wave transmission properties of the mean circulation. On the other hand, the model does not yield the observed seasonal cycle. Despite considerable sensitivity to modifications in the basic state wind and dissipation parametrization, the model could not be reasonably fit to reproduce the observed seasonal cycle

Constrained action selection in children with developmental coordination disorder

The effect of advance (‘precue’) information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n = 10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic

Mesenteric panniculitis: systematic review of cross-sectional imaging findings and risk of subsequent malignancy.

OBJECTIVES: Systematic review to determine any association between imaging features of idiopathic mesenteric panniculitis (MP) and subsequent malignancy. METHODS: Two researchers searched primary literature independently for imaging studies of MP. They extracted data focusing on methodology for unbiased patient accrual and capability to determine a link between MP and subsequent malignancy. They noted imaging features of MP. Data were accrued and meta-analysis intended. RESULTS: Fourteen of 675 articles were eligible; 1,226 patients. Only three (21 %) accrued patients prospectively. Twelve (86 %) studies described CT features. Follow-up varied widely; 1 month to 8 years. Prevalence of MP was influenced by accrual: 0.2 % for keyword search versus 1.7 % for consecutive series. Accrual bias affected nine (64 %) studies. 458 (38 %) of 1,209 patients had malignancy at accrual but varied widely (8-89 %), preventing meta-analysis. Sixty (6.4 %) of 933 patients developed new malignancy subsequently, also varying widely (0-11 %). Of just four studies that determined the proportion of unselected, consecutive patients with MP developing subsequent malignancy, three were retrospective and the fourth excluded patients with lymphadenopathy, likely excluding patients with MP. CONCLUSION: Studies were heterogeneous, with biased accrual. No available study can determine an association between MP and subsequent malignancy with certainty. KEY POINTS: • Our systematic review of mesenteric panniculitis found that imaging studies were biased. • Spectrum and recruitment bias was largely due to retrospective study designs. • No study could confirm a certain link between mesenteric panniculitis and subsequent malignancy. • Excessive methodological heterogeneity precluded meaningful meta-analysis. • High-quality research linking mesenteric panniculitis imaging features and subsequent malignancy is needed

Antiferromagnetic and Orbital Ordering on a Diamond Lattice Near Quantum Criticality

We present neutron scattering measurements on powder samples of the spinel FeSc2S4 that reveal a previously unobserved magnetic ordering transition occurring at 11.8(2)~K. Magnetic ordering occurs subsequent to a subtle cubic-to-tetragonal structural transition which distorts Fe coordinating sulfur tetrahedra lifting the orbital degeneracy. The application of 1~GPa hydrostatic pressure appears to destabilize this N\'eel state, reducing the transition temperature to 8.6(8)~K and redistributing magnetic spectral weight to higher energies. The relative magnitudes of ordered $\langle m \rangle^2\!=\!3.1(2)$ and fluctuating moments $\langle \delta m \rangle^2\!=\!13(1)$ show that the magnetically ordered ground state of FeSc2S4 is drastically renormalized and in proximity to criticality.Comment: 16 pages, 12 figure

The choice and definition of summary measure for meta-analysis of clinical studies with binary outcomes: Effect on clinical interpretation

Many systematic reviews and meta-analyses concern the effect of a healthcare intervention on a binary outcome i.e. occurrence (or not) of a particular event. Usually, the overall effect, pooled across all studies included in the meta-analysis, is summarised using the odds ratio (OR) or the relative risk (RR). Under most circumstances, it is obvious how to identify what should be considered as the event of interest - for example, death or a clinically-important side-effect. However, on occasion it may not be clear in which "direction" the event should be specified - such as attendance ( vs non-attendance) at cancer screening. Usually, this choice is not critical to the overall conclusion of the meta-analysis, but occasionally it can lead to differences in how the included studies are pooled, ultimately affecting the overall meta-analytic result, particularly when using relative risks rather than odds ratios. In this commentary, we will explain this phenomenon in more detail using examples from the literature, and explore how analysts and readers can avoid some potential pitfalls

Anterior segment diseases presented in an interactive videotape format

With the overwhelming amount of information provided in ocular disease courses, it is often useful to have a convenient method for supplementing course material. With this in mind, a videotape has been produced which will serve as a convenient and effective teaching aid for second year students. Rather than a simple presentation of facts, this tape is formatted in a manner that encourages participative learning. The student extracts the relevant facts from the case history, forms her/his own diagnosis, observes the recorded eye condition, makes a differential diagnosis and develops a treatment plan. All of this information is available within the tape itself