New Limit on the Permanent Electric Dipole Moment of ^{129}Xe Using ^{3}He Comagnetometry and SQUID Detection

We report results of a new technique to measure the electric dipole moment of ^{129}Xe with ^{3}He comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred to a measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result from a one week measurement campaign in 2017 and a 2.5 week campaign in 2018, combined with detailed study of systematic effects, is d_{A}(^{129}Xe)=(1.4±6.6_{stat}±2.0_{syst})×10^{-28}  e cm. This corresponds to an upper limit of |d_{A}(^{129}Xe)|<1.4×10^{-27}  e cm (95% C.L.), a factor of 5 more sensitive than the limit set in 2001.

A magnetically shielded room with ultra low residual field and gradient

A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.

Test of Lorentz invariance with spin precession of ultracold neutrons

A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and 199Hg atoms, is reported. No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field b perpendicular < 2 x 10(-20) eV (95% C.L.). This is the first limit for the free neutron. This result is also interpreted as a direct limit on the gravitational dipole moment of the neutron |gn| < 0.3 eV/c2 m from a spin-dependent interaction with the Sun. Analyzing the gravitational interaction with the Earth, based on previous data, yields a more stringent limit |gn| < 3 x 10(-4) eV/c2 m.

Surface plasmons in terahertz metamaterials

We characterize terahertz metamaterials by applying apertureless near-field microscopy with a bandwidth that covers the entire spectral response of the structures. The observations agree with the interpretation of the fundamental mode of the metamaterial. But the high frequency resonance shows properties that deviate from the common interpretation. We show that the high frequency response is governed by surface Plasmon excitations, which have a comparable oscillator strength as the fundamental mode.

Mistakes were made: misperception as a barrier to reducing overweight

OBJECTIVE

To examine the agreement between individuals' weight status as measured by their body mass index (BMI) and their perceptions of their weight status in the US population.

DESIGN

Data from the third National Health and Nutrition Examination Survey, 1988-94 (NHANES III), were used to cross-tabulate actual weight status and self-assessed weight status, identifying population proportions that underassessed or overassessed weight status. The study accounts for gender and socioeconomic and demographic variables to identify subpopulations in which relatively large numbers of individuals misperceive their weight status.

MEASUREMENTS

Survey data included clinically measured height and weight. BMI was categorized (overweight, healthy weight, or underweight) following conventional cutpoints. In addition, each surveyed individual was asked to assess their own (categorical) weight status.

SUBJECTS

NHANES III is representative of the US population. The sample included 7758 males and 8451 females aged 20 y or above after excluding women who were pregnant or breastfeeding.

RESULTS

We show that large segments of the US population misperceive their weight status. The mix of misperceptions differs by gender, with men who are obese or overweight more likely than obese or overweight women to underassess their weight status. Women who are healthy weight/underweight are more likely than men to believe they are overweight. In addition to the gender differences, underassessors are more frequently found among those aged 65 y and over, individuals with relatively low education levels, lower income levels, and among non-Hispanic black subjects. Overassessors are more frequently found among women less than 65 y old (between the ages of 35 and 64 y for men), individuals with higher education levels, higher income levels, and among non-Hispanic white subjects.

CONCLUSIONS

Information programs linking overweight and obesity with health risks might fail to induce diet and lifestyle changes if individuals fail to recognize they are overweight or obese. While there are large number of individuals who fail to recognize their overweight or obese status, there are indicator variables that can help identify this subpopulation. Thus, it is possible to first target a message that would attempt to correct misperceptions. If successful, the size of the population susceptible to a weight-health risk information program could increase.

The influence of individual choices and attitudes on adiposity

OBJECTIVE

To determine which dietary and lifestyle choices and which attitudes toward diet and health most contribute to adiposity and whether those factors differ by gender.

METHODS

Multiple regression was used to estimate the effect of energy intake, energy expenditure, resources, demographics, and attitudes toward diet and health on self-reported body mass index (BMI) in a nationally representative sample of the US population.

SAMPLE

This study used secondary data from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII) and its telephone follow-up, the Diet and Health Knowledge Survey (DHKS). CSFII is a nationally representative survey of individuals which obtained 24 h recalls of all food intake on two nonconsecutive days. The DHKS data set obtained information on knowledge and attitudes toward dietary guidance and health from individuals 20 y of age and over, who participated in the CSFII. Our sample consisted of responses from 5512 individuals.

RESULTS

We found that many of the variables previously found to or hypothesized to influence body weight do so. Our analysis shows that choices and attitudes do matter for adiposity. Moreover, the analysis shows that the choices males and females make often have quite different effects on BMI. For females all the variables we constructed to represent energy intake, energy expenditure, and financial and human resources are significant. Most of the variables that characterize attitudes toward diet and health are significant. For males, far fewer variables are significant. Our tests for gender-related differences show that whether or not males believe their weight is predetermined has no influence on BMI. In contrast, women who do not believe that their weight is predetermined have lower BMI values than those who believe weight is genetically determined.

DISCUSSION

While our qualitative conclusion--choices and attitudes affect BMI--is unsurprising, the quantitative aspects are important. The analysis shows that factors affecting BMI differ systematically by gender. Understanding these systematic differences is critical to the design of information campaigns. Our analysis suggests that entirely different campaigns are necessary to communicate the importance of diet and lifestyle choices to men and to women.

Strategies for promoting equity: experience with community financing in three African countries

Although the need for a pro-poor health reform agenda in low and middle income countries is increasingly clear, implementing such policy change is always difficult. This paper seeks to contribute to thinking about how to take forward such an agenda by reflection on the community financing activities of the UNICEF/WHO Bamako Initiative. It presents findings from a three-country study, undertaken in Benin, Kenya and Zambia in 1994/95, which was initiated in order to better understand the nature of the equity impact of community financing activities as well as the factors underlying this impact. The sustained relative affordability gains achieved in Benin emphasise the importance of ensuring that financing change is used as a policy lever for strengthening health service management in support of quality of care improvements. All countries, however, failed in protecting the most poor from the burden of payment, benefiting this group preferentially and ensuring that their views were heard in decision-making. Tackling these problems requires, amongst other things, an appropriate balance between central and local-level decision-making as well as the creation of local decision-making structures which have representation from civil society groups that can voice the needs of the most poor. Leadership, strategy and tactics are also always important in securing any kind of equity gain-such as establishing equity goals to drive implementation. In the experiences examined, the dominance of the goal of financial sustainability contributed to their equity failures. Further research is required to understand what equity goals communities themselves would prefer to guide financing policy.

The equity impacts of community financing activities in three African countries

Although the Bamako Initiative from its very beginning was caught up in wider debates about the potential equity impact of any form of user financing, to date there has been little empirical investigation of this impact. This three-country study, undertaken in Benin, Kenya and Zambia in 1994/95, was initiated to add to the body of relevant evidence. It sought to understand not only what had been the equity impacts of community financing activities in these countries but also how they had been brought about. As a result, it investigated equity primarily through consideration of the design of these financing activities and through the perceptions of different actors, within a limited number of purposively selected geographical areas in each country, about their strengths and weaknesses. Additional data on utilization were either collected during the course of the study (Kenya) or drawn from other available studies (Benin and Zambia). Key issues considered in the studies' assessment of equity were the extent to which both relative and absolute affordability gains were achieved, as well as as an influence over both the distributional and procedural justice of the financing activities, the pattern of decision-making. Across countries there was evidence of relative affordability gains in Benin and Kenya, but Kenyan gains were not sustained over time and no such gains were identified in Zambia. In addition, no country had given attention either to the issue of absolute affordability, through the implementation of effective exemption mechanisms to protect the poorest from the burden of payment, or to the establishment of community decision-making bodies that effectively represented the interests of all groups including the poorest. Overall, therefore, although the Benin Bamako Initiative programme might be judged as successful in terms of what appear to be its own equity objectives, the other two countries' schemes had clear equity problems even in these terms. The experience across countries also highlights the unresolved question of whether equity is concerned with the greatest good for the greatest number or with promoting the interests of the most disadvantaged.