The Absolute Magnitude of the Sun in Several Filters

This paper presents a table with estimates of the absolute magnitude of the Sun and the conversions from $vegamag$ to the AB and ST systems for several wide-band filters used in ground and space-based observatories. These estimates use the dustless spectral energy distribution (SED) of Vega, calibrated absolutely using the SED of Sirius, to set the $vegamag$ zero-points and a composite spectrum of the Sun that coadds space-based observations from the ultra-violet to the near infrared with models of the Solar atmosphere. The uncertainty of the absolute magnitudes is estimated comparing the synthetic colors with photometric measurements of solar analogs and is found to be $\sim$ 0.02 magnitudes. Combined with the uncertainty of $\sim$ 2% in the calibration of the Vega SED, the errors of these absolute magnitudes are $\sim$ 3--4%. Using these SEDs, for the three of the most utilized filters in extragalactic work the estimated absolute magnitudes of the Sun are $M_B$ = 5.44, $M_V$ = 4.81 and $M_K$ = 3.27 mag in the $vegamag$ system and $M_B$ = 5.31, $M_V$ = 4.80 and $M_K$ = 5.08 mag in AB.Comment: 17 pages, 2 figures, accepted by ApJS. Composite solar spectrum available for download at http://mips.as.arizona.edu/~cnaw/sun.htm

Climate Change: Bees and Orchids Lose Touch

SummarySpring temperature increases could differentially affect flowering times and pollinator flight periods, leading to asynchrony and reduced pollination. A specialist orchid–bee study combining herbarium, museum and field data shows that bee flight dates are advancing faster than orchid flowering, which could lead to significant future uncoupling

Influences of major weight loss in women treated with bariatric surgery on their partners’ and children’s weight and psychosocial functioning

The overall aim of the current PhD thesis was to explore how families of female bariatric surgery patients are affected by the surgery. The focus of the thesis was on differences in weight status in siblings born before and after maternal bariatric surgery, and on changes in weight and psychosocial functioning in partners and children of women undergoing Roux-en-Y gastric bypass (RYGB). Study I explored differences in BMI and prevalence of overweight and obesity at the ages of four, six and 10 in children born before and after maternal bariatric surgery. Results showed that at no age did the children born after surgery have a lower prevalence of overweight or obesity, and that there was no association between differences in maternal BMI at week 10 of the two pregnancies and differences in siblings’ BMI at age four. Study II focused on changes in female RYGB patients’ partners in terms of BMI, waist circumference, sleep quality, body dissatisfaction and symptoms of anxiety and depression. The results showed significant reductions in BMI and waist circumference in the partners. However, psychosocial variables, as measured by questionnaires, remained unchanged in the men. In Study III, differences in weight status, body esteem and self-concept in children of female RYGB patients were explored. It was found that the children had a reduced relative risk of overweight after maternal RYGB. The results also showed that the boys improved their age-adjusted body esteem slightly, whilst the girls did not. Study IV investigated changes in eating behaviour and food choices in female RYGB patients and their families. The women were shown to increase their cognitive restraint, decrease their uncontrolled and emotional eating, and reduce their intake frequency of soft drinks and sweets after surgery. Their partners, however, reported no changes in their eating behaviour and food choices. The boys’ eating behaviour improved following maternal RYGB, but the same was not true for the girls in the sample. The children who were overweight or obese at baseline also improved their eating behaviour in comparison to the normal weight children. In conclusion, this thesis shows that women’s gastric bypass surgery may be associated with positive changes in her partners’ and children’s weight, especially if they are themselves overweight. Changes in psychosocial functioning are smaller and more complex in the current sample, and require further study

Non-equilibrium polymeric complex fluids

Complex fluids are commercially- and industrially-important materials which exhibit ordering on scales much larger than atomic. Their usage is typically in non-equilibrium conditions, however traditional methods for measuring rheology are not appropriate for measuring samples with gradients present, such as temperature and concentration. In this work a safe and easy to use optical tweezer (OT) apparatus has been developed in order to facilitate the investigation of various systems during dilution or drying. In contrast to other OT setups, this equipment is safe to use without laser goggles or interlocked rooms, yet still allows full access to the microscope. Proof-of-concept experiments are performed on aqueous poly (ethylene oxide) (PEO) solutions to demonstrate the changes in viscosity and concentration over time, and the OT is then used in a rheological investigation into a commercially-relevant wormlike micelle (WLM) system, in conjunction with Diffusing Wave Spectroscopy (DWS) and traditional bulk rheology. It is shown for the first time that equimolar (eM) SDS:CAPB WLM samples can be considered ‘model’ systems, and form close approximations of Maxwellian systems on the addition of extra salt or surfactant above 0.1eM. The effect of an uncharged polymer (PEO 4M MW) on this WLM network structure was subsequently investigated; its effects are consistent with current theories of polymer-surfactant interactions

The impact of governmental regulation on small business in Georgia

Issued as Report, Project E-100-90