Weekend effect in emergency laparotomy: a propensity score-matched analysis.

BACKGROUND: The 'weekend effect' is the term given to the observed discrepancy regarding patient care and outcomes on weekends compared to weekdays. This study aimed to determine whether the weekend effect exists within Aotearoa New Zealand (AoNZ) for patients undergoing emergency laparotomy (EL), given recent advances in management of EL patients. METHODS: A cohort study was conducted across five hospitals, comparing the outcomes of weekend and weekday acute EL. A propensity-score matched analysis was used to remove potential confounding patient characteristics. RESULTS: Of the 487 patients included, 132 received EL over the weekend. There was no statistically significant difference between patients undergoing EL over the weekend compared to weekdays. Mortality rates were comparable between the weekday and weekend cohorts (P = 0.464). CONCLUSIONS: These results suggest that modern perioperative care practice in New Zealand obviates the 'weekend' effect.

VI3 -a New Layered Ferromagnetic Semiconductor.

2D materials are promising candidates for next-generation electronic devices. In this regime, insulating 2D ferromagnets, which remain rare, are of special importance due to their potential for enabling new device architectures. Here the discovery of ferromagnetism is reported in a layered van der Waals semiconductor, VI3 , which is based on honeycomb vanadium layers separated by an iodine-iodine van der Waals gap. It has a BiI3 -type structure ( R 3 ¯ , No.148) at room temperature, and the experimental evidence suggests that it may undergo a subtle structural phase transition at 78 K. VI3 becomes ferromagnetic at 49 K, below which magneto-optical Kerr effect imaging clearly shows ferromagnetic domains, which can be manipulated by the applied external magnetic field. The optical bandgap determined by reflectance measurements is 0.6 eV, and the material is highly resistive.

Effects of singular and dual task constraints on motor skill variability in childhood.

We examined the effects of singular versus dual task constraints involving upper and lower extremities in typically developing children in young (4-6 years old), middle (7-9 years old), and old (10-13 years old) age groups. The purposes of this study were: 1) to investigate the effects of singular upper and lower extremity and dual upper and lower extremity conditions on motor variability and 2) to examine if variability in children's motor actions would differ according to age (i.e., young, middle, or old). Twenty-four children (M age=8.7; SD=3.7) completed three tasks: finger rotation (upper extremity singular task constraint), obstacle crossing (lower extremity singular task constraint), and box carrying while walking (upper and lower extremity dual task constraint). Compared to the old age group, the young age group displayed more variable rotation strategies during clockwise (χ2(8, N=24)=12.4, p=0.046) and counterclockwise finger rotation (χ2(8, N=24)=12.8, p=0.047). During box carrying, children in the young age group had the most motor variability in their stride length, velocity, the vertical positioning of the box, and minimum and maximum joint excursion (all ps<0.05). Crossing leg frontal plane hip angles were more variable on low versus high obstacles (all ps<0.05). Our results suggest that four- to six-year-old children may still be developing the ability to produce consistent motor actions, especially under dual-task constraints. Examining children in the context of completing tasks with a variety of constraints may be useful in assessing the development of children's motor variability.

Diurnal variation of anterior scleral and conjunctival thickness.

PURPOSE: To examine whether anterior scleral and conjunctival thickness undergoes significant diurnal variation over a 24-h period. METHODS: Nineteen healthy young adults (mean age 22 ± 2 years) with minimal refractive error (mean spherical equivalent refraction -0.08 ± 0.39 D), had measures of anterior scleral and conjunctival thickness collected using anterior segment optical coherence tomography (AS-OCT) at seven measurement sessions over a 24-h period. The thickness of the temporal anterior sclera and conjunctiva were determined at six locations (each separated by 0.5 mm) at varying distances from the scleral spur (SS) for each subject at each measurement session. RESULTS: Both the anterior sclera and conjunctiva were found to undergo significant diurnal variations in thickness over a 24-h period (both p < 0.01). The sclera and conjunctiva exhibited a similar pattern of diurnal change, with a small magnitude thinning observed close to midday, and a larger magnitude thickening observed in the early morning immediately after waking. The amplitude of diurnal thickness change was larger in the conjunctiva (mean amplitude 69 ± 29 µm) compared to the sclera (21 ± 8 µm). The conjunctiva exhibited its smallest magnitude of change at the SS location (mean amplitude 56 ± 17 µm) whereas the sclera exhibited its largest magnitude of change at this location (52 ± 21 µm). CONCLUSIONS: This study provides the first evidence of diurnal variations occurring in the thickness of the anterior sclera and conjunctiva. Studies requiring precise measures of these anatomical layers should therefore take time of day into consideration. The majority of the observed changes occurred in the early morning immediately after waking and were of larger magnitude in the conjunctiva compared to the sclera. Thickness changes at other times of the day were of smaller magnitude and generally not statistically significant.

Joint neuronal tuning for object form and position in the human lateral occipital complex.

A long-standing heuristic in visual neuroscience holds that extrastriate visual cortex is parceled into a dorsal "where" pathway concerned with stimulus position and motion and a ventral "what" pathway concerned with stimulus form. Several recent studies using functional magnetic resonance imaging (fMRI), however, have shown that small changes in the position of a single object can produce reliable changes in activity patterns in object-selective lateral occipital complex (LOC). Although these data demonstrate that information about both object form and position is present at the region level in LOC, the extent to which they reflect joint neuronal tuning to these dimensions is unclear. To measure joint tuning for form and position, we used fMRI to record patterns of activity evoked in LOC and other visual areas while subjects viewed pairs of objects that varied in category content, overall position, and relative object position. Consistent with previous results, multivoxel activity patterns in LOC varied reliably with the category content and position of object pairs. Moreover, activity patterns in the lateral occipital (LO) subregion of LOC varied significantly with the relative positions of objects within pairs, even when absolute pair position was constant. This result provides strong evidence for the existence of neuronal populations in LO which are jointly tuned for both object form (i.e., category) and position.