An All-Fiber Coupled Multicolor Microspherical Light Source

We present results on the realization of an all-taper coupled, multicolor microspherical light source fabricated from the erbium-doped fluoride glass ZBLALiP. Whispering gallery mode lasing at 1555 nm and fluorescent emissions from the ultraviolet to the infrared (IR) have been observed. A tapered fiber is used to launch 980-nm pump light into the microresonator cavity and to collect the resulting IR lasing. A separate, half-taper fiber is used to outcouple the upconversion spectrum over several hundred nanometers. A number of discrete emissions from 400 to 850 nm have been observed in the upconversion spectrum, indicating the suitability of this scheme as a miniature device with a 450-nm-wide band and reasonable output coupling efficiency.     

Histogram approaches for lossy compression of digital holograms of three-dimensional objects.

We present a novel nonuniform quantization compression technique-histogram quantization-for digital holograms of 3-D real-world objects. We exploit a priori knowledge of the distribution of the values in our data. We compare this technique to another histogram based approach: a modified version of Max's algorithm that has been adapted in a straight-forward manner to complex-valued 2-D signals. We conclude the compression procedure by applying lossless techniques to our quantized data. We demonstrate improvements over previous results obtained by applying uniform and nonuniform quantization techniques to the hologram data.     

Occurrence of α- and β-nortestosterone residues in the urine of injured male cattle

The administration of anabolic steroids, for the purposes of growth promotion, to food-producing animals is banned in the EU. Among the compounds covered by this prohibition is ß-nortestosterone (β-NT). This hormone is known to occur naturally in stallions and boars, and its main bovine metabolite, α-nortestosterone (α-NT), occurs naturally in pregnant cows and neonatal calves. However, neither compound is believed to occur naturally in male cattle. During 2006, the presence of α-NT and, on occasion, β-NT was confirmed in male cattle (bulls and steers) slaughtered in Northern Ireland on welfare grounds, as a result of acute injury. Subsequent investigations revealed no evidence of abuse at any of the farms involved and revealed that the phenomenon also occurred in three other regions of the EU, in similarly injured animals. A hypothetical link to release of the adrenal steroid, dehydroepiandrosterone (DHEA), in response to the stress of the injury was tested. Following the intravenous administration of DHEA to two normal steers, β-NT (but not α-NT) was confirmed in the urine of one steer. Thus, it may be concluded that both β-NT and, by implication, α-NT can occur naturally in male cattle (or a specific cohort thereof) in contrast to previously accepted scientific knowledge.     

The suppression of exciting thoughts.

We examined how the suppression of an exciting thought influences sympathetic arousal as indexed by skin conductance level (SCL). Subjects were asked to think aloud as they followed instructions to think about or not to think about various topics. Experiment 1 showed that trying not to think about sex, like thinking about sex, elevates SCL in comparison to thinking about or not thinking about less exciting topics (e.g., dancing). Experiment 2 revealed that the suppression of the thought of sex yielded SCL elevation whether or not subjects believed their think-aloud reports would be private or public, and it also revealed that the effect dissipated over the course of a few minutes. Experiment 3 found such dissipation again but showed that subsequent intrusions of the suppressed exciting thought are associated with further elevations in SCL over 30 min. Because such an association was not found when subjects were trying to think about the exciting thought, it was suggested that the suppression of exciting thoughts might be involved in the production of chronic emotional responses such as phobias and obsessive preoccupations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Housing and health in an informal settlement upgrade in Cape Town, South Africa

Taking a socio-ecological perspective the World Health Organisation recognizes that housing comprises four interrelated dimensions—the physical structure of the house, the home, the neighbourhood infrastructure and the community. Housing related health vulnerability arises when residents are exposed to poor conditions in any one of these dimensions and augmented when two or more co-exists. Regardless the relationship between housing and health in the global south remains largely under explored; in particular there has been little focus on health outcomes resulting from upgrading of informal settlements. Applying this framework we report from an in situ upgrading of the informal settlement of Imizamo Yethu in Cape Town, South Africa. Data gathered from surveys are used to determine whether differences in each of these dimensions exist between housing type; both formal upgrades and shacks. Results show that whilst no significant differences exist in self-reported physical health, residents of formal housing are less likely to report mental health issues, have a stronger sense of belonging and report greater satisfaction with both neighbourhood and home than shack residents. However, these contested spaces are not easily interpreted and community tension, exclusion and disadvantage highlight the complex interactions between each of the interrelated dimensions and policies regarding housing intervention. The paper highlights the complex relationship between housing and health that is often lost in simplistic measures of housing when outcomes related to the indoor environment alone are considered.     

The response of lif thermoluminescence dosemeters to photon beams in the energy range from 30 kV x rays to 60Co gamma rays

The energy response of standard (TLD-100) and high-sensitivity (TLD-100H) LiF thermoluminescence dosemeters (TLDs) has been studied for photon beams with mean energies from about 25 keV to 1100 keV. Canadian primary standards for air kerma were used to establish the air kerma rates for each of the photon beams. TLDs were mounted in a PMMA holder and the air kerma response was measured as a function of energy. The EGSnrc Monte Carlo code was used to model the TLD holder and calculate the absorbed dose to the TLD chip per unit air kerma for each beam. The measured and calculated results were combined to obtain the intrinsic dose response of the TLD chip. Broadly, our results are consistent with existing data, which show a marked difference in the energy dependence of the two materials. However, the precision of our measurements (standard uncertainty of about 0.6%) has permitted the identification of features that have not been noted before. In particular, the energy dependence of the two materials is quite different in the important energy region delimited by 137Cs and 60Co gamma rays.