Rare k-decays

This article reviews the current situation in the field of rare K decays: the relevant phenomenology, the present experimental situation, and prospects for the near future. Study of rare K decays can make a significant contribution in a number of different frontier areas of research in high-energy physics. In the area of CP violation, study of such rare decays as K(L)0 --> pi0e+e-, K(L)0 --> pi0mu+mu-, K(L)0 --> pi0nunuBAR, and muon polarization in K(L)0 --> mu+mu- can provide important complementary information to what has been learned from the decay K(L)0 --> pipi. Even though experiments with sufficient accuracy to make a meaningful study of CP violation are still a few years away, significant progress has been made in this general area during the last decade. A second major area of interest in the field of rare K decays is the search for processes forbidden in the Standard Model, e.g., K(L)0 --> mue and K+ --> pi+mu+e-. Various extensions of the Standard Model predict that these processes will occur with branching fractions in the range of 10(-10) to 10(-15). Experiments of the last decade have pushed the limits into the 10(-10) to 10(-11) range, and further improvements in sensitivity of one to two orders of magnitude can be expected in the next few years. K decays allow one also to study higher-order weak-interaction processes such as K(L)0 --> mu+mu-, K(L)0 --> e+e-, K+ --> pi+nunuBAR, which are forbidden to first order in the Standard Model. Because of strong suppression, these decay modes offer potential windows on new physics; in addition, they may offer the most reliable measurement of V(td), one of the elements of the weak mixing matrix in the quark sector. The studies of the mu+mu- channel have achieved data samples of close to 1000 events; the other two modes should be observed for the first time in the next few years. Finally, as a byproduct of these studies, one has been able to look simultaneously for new light particles into which the K meson could decay. Limits obtained for various hypothetical particles are summarized.Physic

The Doppler Spectra of Medium Grazing Angle Sea Clutter; Part 1: Characterisation

This paper is concerned with the characterisation of Doppler spectra from high range resolution X-band radar sea clutter observed from an airborne platform over the range of grazing angles, 15° to 45°. It is observed that when looking up or down wind there is a strong correlation between mean Doppler shift and local spectrum intensity. When combined with random fluctuations of spectrum width, these characteristics give the spectra a temporal and spatial variability. This behaviour has previously been observed in low grazing angle data and these results confirm the wider applicability of the models developed using that data. The modelling method is also extended here to capture the bimodal behaviour observed with high intensity returns from breaking waves looking up or down-wind

Why (and how) Superman hides behind glasses: the difficulties of face matching

As a mild-mannered reporter, Clark Kent is able to blend into human society without drawing much attention to himself. Although he utilises several methods of disguise (clothing, posture, hair style), perhaps his most famous is a simple pair of glasses (see Figure 1). We know that wearing glasses can make you look more educated and intelligent (e.g., Hellström & Tekle, 1994), but for Superman, the goal is primarily to hide his true identity. Of course, one of the cornerstones of enjoying superhero fiction is that we suspend our disbelief and try to ignore the obvious questions (for example, how useful or plausible is it that Squirrel Girl can communicate with and understand squirrels?!). However, the scientist inside us sometimes breaks through and we are given the opportunity to investigate. Here, we tackle the question that comic book fans have been asking for decades – could Superman really hide his identity using a pair of glasses

The Doppler Spectra of Medium Grazing Angle Sea Clutter; Part 2: Model Assessment and Simulation

This paper is concerned with the assessment of models of Doppler spectra, derived from high range resolution X-band radar sea clutter observed from an airborne platform over the range of grazing angles, 15 to 45. When looking up or downwind these models represent the strong correlation between mean Doppler shift and local spectrum intensity. When combined with random fluctuations of spectrum width, these characteristics give the spectra a temporal and spatial variability. The models are used to predict clutter spectrum statistics as a function of Doppler frequency and these are compared with statistics derived from the original data. It is also shown how realistic range-varying coherent clutter returns can be simulated using the models

Designing prevention programmes to reduce incidence of dementia: prospective cohort study of modifiable risk factors

Objective To estimate the percentage reduction in incidence of dementia that would be obtained if specific risk factors were eliminated

Viewers extract the mean from images of the same person: a route to face learning

Research on ensemble encoding has found that viewers extract summary information from sets of similar items. When shown a set of four faces of different people, viewers merge identity information from the exemplars into a representation of the set average. Here, we presented sets containing unconstrained images of the same identity. In response to a subsequent probe, viewers recognized the exemplars accurately. However, they also reported having seen a merged average of these images. Importantly, viewers reported seeing the matching average of the set (the average of the four presented images) more often than a nonmatching average (an average of four other images of the same identity). These results were consistent for both simultaneous and sequential presentation of the sets. Our findings support previous research suggesting that viewers form representations of both the exemplars and the set average. Given the unconstrained nature of the photographs, we also provide further evidence that the average representation is invariant to several high-level characteristics

Audit of domperidone use as a galactogogue at an Australian tertiary teaching hospital

BACKGROUND: Domperidone is often used to promote lactation among women who have difficulty breastfeeding. OBJECTIVE: To examine prescribing and dispensing practices of domperidone at the Women's and Children's Hospital (WCH), Adelaide. METHODS: A retrospective audit of domperidone dispensing among women with singleton pregnancies who delivered at the WCH between January 2000 and July 2010 was undertaken. Women dispensed domperidone were identified using WCH pharmacy dispensing records. Maternal and infant clinical data were obtained from the WCH Perinatal Statistics Collection. An audit of paper-based medical records was undertaken for a random sample of 261 mother-child pairs to collect prescribing and additional clinical data. RESULTS: From 2000 to 2010, 1605 women were dispensed domperidone. There was a steady increase in the percentage of women dispensed domperidone, from 5% of total WCH pregnancies in 2010. Among women dispensed domperidone, the percentage of women who received > 1 dispensing remained consistent (20%) over time, as did the median number of days (12) from delivery to first dispensing. Multiparous women were more likely to receive domperidone within 3 days following delivery compared to primiparous women (8% vs 4%; P < .01). Most women (80%) received directions to take domperidone according to a standard tapering dosing regimen over 12 days. Notably, 60% of women had no documentation of being assessed by a lactation consultant. CONCLUSION: From 2000 to 2010, there was a considerable increase in domperidone dispensing. With a lack of clinical evidence to guide use, current practice appears to be based on anecdotal evidence.Luke E. Grzeskowiak, Sze Wen Lim, Alicia E. Thomas, Usha Ritchie and Andrea L. Gordo