Taming a non-convex landscape with dynamical long-range order: memcomputing Ising benchmarks

Recent work on quantum annealing has emphasized the role of collective behavior in solving optimization problems. By enabling transitions of clusters of variables, such solvers are able to navigate their state space and locate solutions more efficiently despite having only local connections between elements. However, collective behavior is not exclusive to quantum annealers, and classical solvers that display collective dynamics should also possess an advantage in navigating a non-convex landscape. Here, we give evidence that a benchmark derived from quantum annealing studies is solvable in polynomial time using digital memcomputing machines, which utilize a collection of dynamical components with memory to represent the structure of the underlying optimization problem. To illustrate the role of memory and clarify the structure of these solvers we propose a simple model of these machines that demonstrates the emergence of long-range order. This model, when applied to finding the ground state of the Ising frustrated-loop benchmarks, undergoes a transient phase of avalanches which can span the entire lattice and demonstrates a connection between long-range behavior and their probability of success. These results establish the advantages of computational approaches based on collective dynamics of continuous dynamical systems

Weight-area trade-off study for a flat SNAP-8 radiator

Weight-area tradeoff evaluation of radiator used in SNAP-

The Challenge of Preventing Teen Pregnancy in Texas

A reduction in teen pregnancy and subsequent reduction in teen births correlates to myriad improvements in personal (e.g., high school completion, experience of abuse and neglect, etc); social (e.g., number of children in single parent families, life-long poverty, incarceration rates, etc); and economic (e.g., Medicaid costs, decreased tax revenue, etc) outcomes. In 2005, over 73,000 teen girls in Texas age 15-19 became pregnant, a number significantly higher than any other state. Given the severity of the issue the formation of a statewide organization in Texas devoted to addressing the prevention of teen pregnancy is long overdue. The challenge of reducing teen pregnancy is daunting yet there is momentum and a cadre of committed individuals who have formally put together an organization to provide guidance, oversight and a statewide voice of leadership - all things needed to be successful reducing teen pregnancy in Texas. This commentary provides reactions to proposed strategies and to-date lessons learned

Testing positive for human papillomavirus in routine cervical screening: examination of psychosocial impact

Objective To examine the psychosocial impact of testing positive for high risk human papillomavirus (HPV) among women attending primary cervical screening.Design Cross sectional survey.Measures were taken at baseline and one week after the receipt of HPV and cytology screening results.Setting Well women's clinic in London, UK.Population or Sample Four hundred and twenty-eight women aged 20-64 years.Methods Postal questionnaire survey.Main outcome measures Psychosocial and psychosexual outcomes were anxiety, distress and feelings about current, past and future sexual relationships.Results Women with normal cytology who tested positive for HPV (HPVdivided by) were significantly more anxious and distressed than women who were negative (HPV-) using both a state anxiety measure [F(1,267)=29, P<0.0001] and a screening specific measure of psychological distress [F(1,267)=69, P<0.0001]. Women with an abnormal or unsatisfactory smear result, who tested HPV,. were significantly more distressed than HPV- women with the same smear result [F(1,267)=8.8, P=0.002], but there was no significant difference in state anxiety. Irrespective of cytology result, HPV women reported feeling significantly worse about their sexual relationships. Approximately one-third of women who tested positive reported feeling worse about past and future sexual relationships compared with less than 2% of HPV- women.Conclusion The findings suggest that testing positive for HPV may have an adverse psychosocial impact, with increased anxiety., distress and concern about sexual relationships. Psychosocial outcomes of HPV testing need further investigation and must be considered alongside clinical and economic decisions to include HPV testing in routine cervical screening

Racial Minority Lending Trends at the Farm Service Agency

A binomial logistic framework is used to determine important linkages between the FSA's decision on each loan application and the applicants financial and demographic attributes. Using data on both rejected and accepted FSA loan applications, empirical results indicate loan approval decisions were not significantly influenced by the borrowers' racial class and that, in contrast to the credit risk assessment standards employed by commercial lenders, the collective influence of more stringent and objective credit scoring measures on FSA loan approval decisions is insignificant.Agricultural Finance,

The design of a gamma‐ray burst polarimeter

The study of the polarization properties of the gamma‐ray bursts is the one remaining unexplored avenue of research which may help to answer some of the fundamental problems regarding the nature of these mysterious objects. We have designed an instrument to measure linear polarization in cosmic gamma‐ray bursts at energies ≳50 keV. Here we describe the design of this instrument, which we call the Gamma‐ray Burst Polarimeter Experiment (GRAPE)

Using BATSE to measure gamma-ray burst polarization

We describe a technique for measuring the polarization of hard x-rays from γ-ray bursts based on the angular distribution of that portion of the flux which is scattered off the top of the Earth’s atmosphere. The scattering cross section depends not only on the scatter angle itself, but on the orientation of the scatter angle with respect to the incident polarization vector. Consequently, the distribution of the observed albedo flux will depend on the direction and the polarization properties (i.e., the level of polarization and polarization angle) of the source. Although the BATSE design (with its large field-of-view for each detector) is not optimized for albedo polarimetry, we have nonetheless investigated the feasibility of this technique using BATSE data

Space shuttle electromagnetic environment experiment. Phase A: Definition study

Methods for carrying out measurements of earth electromagnetic environment using the space shuttle as a measurement system platform are herein reported. The goal is to provide means for mapping intentional and nonintentional emitters on earth in the frequency range 0.4 to 40 GHz. A survey was made of known emitters using available data from national and international regulatory agencies, and from industry sources. The spatial distribution of sources, power levels, frequencies, degree of frequency re-use, etc., found in the survey, are here presented. A concept is developed for scanning the earth using a directive antenna whose beam is made to rotate at a fixed angle relative to the nadir; the illuminated area swept by the beam is of the form of cycloidal annulus over a sphere. During the beam's sojourn over a point, the receiver sweeps in frequency over ranges in the order of octave width using sweeping filter bandwidths sufficient to give stable readings

Attitudes to self-sampling for HPV among Indian, Pakistani, African-Caribbean and white British women in Manchester, UK

Objective: To examine attitudes to self-sampling for human papillomavirus (HPV) testing among women from contrasting ethnic groups.Setting: Manchester, UK.Methods: Two hundred women of Indian, Pakistani, African-Caribbean and white British origin were recruited from social and community groups to participate in a questionnaire survey. The questionnaire included items on attitudes to self-sampling and intention to use the test.Results: Willingness to try to use the test was high, and women did not foresee religious or cultural barriers to self-sampling; however, a large proportion of women were concerned about doing the test properly. This concern was greatest in the Indian and African-Caribbean groups.Conclusions: Although women's willingness to try self-sampling for HPV is encouraging, worries about carrying out the procedure correctly must be addressed if women are to feel confident about the results of self-sampling methods and reassured by a negative result