This paper addresses the problem of discovering the structure of a fitness function from binary strings to the reals under the assumption of bounded epistasis. Two loci (string positions) are ...epistatically linked if the effect of changing the allele (value) at one locus depends on the allele at the other locus. Similarly, a group of loci are epistatically linked if the effect of changing the allele at one locus depends on the alleles at all other loci of the group. Under the assumption that the size of such groups of loci are bounded, and assuming that the function is given only as a “black box function”, this paper presents and analyzes a randomized algorithm that finds the complete epistatic structure of the function in the form of the Walsh coefficients of the function.
A double-blind, crossover, 8-wk study was conducted to compare effects of the tocotrienol-enriched fraction of palm oil (200 mg palmvitee capsules/day) with those of 300 mg corn oil/d on serum lipids ...of hypercholesterolemic human subjects (serum cholesterol 6.21–8.02 mmol/L). Concentrations of serum total cholesterol (−15%), LDL cholesterol (−8%), Apo B (−10%), thromboxane (−25%), platelet factor 4 (−16%), and glucose (−12%) decreased significantly only in the 15 subjects given palmvitee during the initial 4 wk. The crossover confirmed these actions of palmvitee. There was a carry over effect of palmvitee. Serum cholesterol concentrations of seven hypercholesterolemic subjects (> 7.84 mmol/L) decreased 31% during a 4-wk period in which they were given 200 mg γ-tocotrienol/d. This indicates that γ-tocotrienol may be the most potent cholesterol inhibitor in palmvitee capsules. The results of this pilot study are very encouraging.
Advances in research and technology in recent years in the field of controlled atmosphere (CA) storage have led to the development of many new protocols that recommend lower oxygen (O2) levels than ...those historically deemed "safe". As some of these protocols and technologies have been adopted by commercial CA storage rooms, especially in the apple industry, it is now opportune to review the relationships between O2 levels, respiration, fermentation, and fruit quality retention. Lowering O2 levels during apple storage slows respiration, reduces ethylene biosynthesis, and slows fruit maturation and senescence. In addition, low O2 influences the expression of genes associated with cellular energy consumption.When O2 levels become limiting, aerobic mitochondrial respiration is inhibited and plant tissues engage in the energetically less-efficient fermentation pathway. The accumulation of fermentation-related volatiles may lead to off-flavours and odours. At low levels, or for short durations, fermentation is generally not a problem and may even be commercially beneficial. Plants that are limited in their ability to ferment succumb to low-O2 stress more quickly than those that can readily ferment anaerobically. Increasing market pressure to reduce chemical residues in apple, as well as in all fruits and vegetables, is encouraging researchers, CA system manufacturers and suppliers, and some commercial storage operators to explore alternative methods to improve storage procedures.The future of CA storage may reside in a better understanding of what constitutes the lower O2 limit for metabolism and energy demands, improved product-response sensing capabilities, and the application of more dynamic forms of CA storage technology.
We report the discovery of two Einstein Crosses (ECs) in the footprint of the Kilo-Degree Survey (KiDS): KIDS J232940-340922 and KIDS J122456+005048. Using integral field spectroscopy from MUSE@VLT, ...we confirm their gravitational-lens nature. In both cases, the four spectra of the source clearly show a prominence of absorption features, hence revealing an evolved stellar population with little star formation. The lensing model of the two systems, assuming a singular isothermal ellipsoid (SIE) with external shear, shows that: 1) the two crosses, located at redshift \(z=0.38\) and 0.24, have Einstein radius \(R_{\rm E}=5.2\) kpc and 5.4 kpc, respectively; 2) their projected dark matter fractions inside the half effective radius are 0.60 and 0.56 (Chabrier IMF); 3) the sources are ultra-compact galaxies, \(R_{\rm e}\sim0.9\) kpc (at redshift \(z_{\rm s}=1.59\)) and \(R_{\rm e}\sim0.5\) kpc (\(z_{\rm s}=1.10\)), respectively. These results are unaffected by the underlying mass density assumption. Due to size, blue color and absorption-dominated spectra, corroborated by low specific star-formation rates derived from optical-NIR spectral energy distribution fitting, we argue that the two lensed sources in these ECs are blue nuggets migrating toward their quenching phase.
Disinfection by-products in tap water have been found in some studies to be associated with adverse pregnancy outcomes, but little is known about how water use and consumption might change during ...early pregnancy. Estimating water-related activities only at one time during pregnancy could easily lead to exposure misclassification. To evaluate changes in water use among pregnant women, we used data from a large epidemiologic study in which 1990 women were interviewed around 9 and 20 weeks' gestation. The water variables that were examined included ingestion of cold and hot tap water as well as of bottled water, showering and bathing. Changes were detected between early and mid-pregnancy for ingested cold tap water and showering. Thirty-three percent of the subjects changed cold-water ingestion by > or =1.0 liters/day and 44% changed their time showering by > or =35 min per week during this period. Increases in cold tap water intake were associated with age >35 years, income < $40,000, and non-Hispanic white ethnicity. We also found that the proportion of the total variation due to within-subject variability was 62% for hot tap water ingestion but only 35% for showering and approximately 50% for cold tap water, bottled water and bathing. Limited resources in epidemiologic studies often require a decision between collecting data for a large number of people or collecting multiple measurements for a smaller number of people. The results in this study will be useful to researchers who need to determine where to invest their effort when assessing water-related exposures and should help in evaluation of previously performed studies.
Power of Attorney for Research Heesters, Ann M.; Buchman, Daniel Z.; Anstey, Kyle W. ...
Public health ethics,
04/2017, Letnik:
10, Številka:
1
Journal Article
Recenzirano
A recent article in this journal described practical and conceptual difficulties faced by public health researchers studying scabies outbreaks in British residential care facilities (Head et al., ...2015). Their study population was elderly, decisionally incapacitated residents, many of whom lacked a legally appropriate decision-maker for healthcare decisions. The researchers reported difficulties securing Research Ethics Committee approval. As practicing healthcare ethicists working in a large Canadian research hospital, we are familiar with this challenge and welcomed the authors’ invitation to join the discussion of the ‘outstanding ambiguities and further questions’ (Head et al., 2015: 5) that their experience uncovered. We propose a Power of Attorney for Research as one substantive solution to help address the problems they identified. Although we acknowledge the familiar shortcomings associated with Advance Directives in the clinical context, we believe that Powers of Attorney for Research Participation, accompanied by Advance Research Directives, may increase the likelihood of gaining deeper understandings of potential participant’s values and priorities and how they might apply to foreseeable research opportunities.
Summary
1. The stability of resistance to
Bacillus thuringiensis
Crystal (Cry) toxins in highly and moderately resistant sub‐populations of a
Plutella xylostella
field population (SERD4) was compared ...under laboratory conditions. The relative rate of decrease in resistance was greater in a highly resistant Cry1Ac‐selected population than in moderately resistant Cry1Ab‐ and Cry1Ca‐selected populations.
2. The intrinsic rate of population increase (
r
m
) was similar in all populations tested.
3. These results suggest that there are no obvious overall fitness benefits as the frequency of the resistance alleles is reduced.
PDF
