Adding Charges to N=4 Dyons

The spectrum of dyons in a class of N=4 supersymmetric string theories has been found for a specific set of electric and magnetic charge vectors. We extend the analysis to more general charge vectors by considering various charge carrying collective excitations of the original system.Comment: LaTeX file, 16 page

A rigorous evaluation of crossover and mutation in genetic programming

The role of crossover and mutation in Genetic Programming (GP) has been the subject of much debate since the emergence of the field. In this paper, we contribute new empirical evidence to this argument using a rigorous and principled experimental method applied to six problems common in the GP literature. The approach tunes the algorithm parameters to enable a fair and objective comparison of two different GP algorithms, the first using a combination of crossover and reproduction, and secondly using a combination of mutation and reproduction. We find that crossover does not significantly outperform mutation on most of the problems examined. In addition, we demonstrate that the use of a straightforward Design of Experiments methodology is effective at tuning GP algorithm parameters

Seed storage proteins ARL2 and its variants from the APA locus of wild tepary bean 255 G40199 confers resistance to Acanthoscellides obtectus when expressed in common beans

Wild tepary beans ( Phaseolus acutifolius ) contain arcelins and arcelin-like (ARL2) proteins that are co-expressed with other proteins of the arcelin, \u3b1-amylase inhibitors and phytohemagglutinins (APA) locus. Arcelin and ARL2 protein from a wild tepary bean accession G40199 were transferred into common bean cultivars ICA Pijao and Rojo. Inbred backcross lines were developed and selected for segregation of the proteins at BC2F2:3 generations. Seeds from homozygous, segregating lines expressing the arcelin and ARL2, plus those without the proteins, were used for screening against resistance to A. obtectus. Significant delay of 63 days for 50% adult emergence and reduced number of emerged F1 of A. obtectus adults were observed in backcross lines with homozygous expression of arcelin and ARL2 tepary bean proteins. Furthermore, a reduction in size and weight of emerged adult insects to almost half was observed. This work demonstrates the superior resistance common bean backcross lines to A. obtectus conferred by the presence of the APA proteins introgressed from tepary bean.Les haricots sauvages tepary ( Phaseolus acutifolius ) contiennent des prot\ue9ines arcelines et les prot\ue9ines semblables aux arcelines (ARL2) co-exprim\ue9es avec d\u2019autres prot\ue9ines arcelines, tels les inhibiteurs \u3b1-amylase and les locus phytoh\ue9magglutinines (APA). Les prot\ue9ines arcelines et ARL2 provenant des accessions de haricots sauvages tepary G40199 \ue9taient transf\ue9r\ue9s dans les cultivars du haricot commun ICA Pijao et Rojo. Des lign\ue9es issues de croisement en retour \ue9taient d\ue9velopp\ue9es et s\ue9lectionn\ue9es pour la s\ue9gr\ue9gation des prot\ue9ines aux g\ue9n\ue9rations BC2F2:3. Des graines des lign\ue9es homozygotes s\ue9gr\ue9gantes exprimant les prot\ue9ines arcelines et ARL2, plus celles sans prot\ue9ines, \ue9taient utilis\ue9es pour la s\ue9lection contre la r\ue9sistance au A. obtectus. Un retard significatif de 63 jours pour 50% de l\u2019\ue9mergence des adultes et un nombre r\ue9duit de F1 \ue9merg\ue9es des adultes A. obtectus \ue9taient observ\ue9s dans le croisement reour avec expression des homozygotes des prot\ue9ines arcelines et ARL2 des haricots tepary. En outre, une r\ue9duction jusqu\u2019\ue0 la moiti\ue9 en taille et poids des insects apparus \ue9tait observ\ue9e. Cette \ue9tude d\ue9montre la r\ue9sistance sup\ue9rieure des lign\ue9es de croisement en retour au A. obtectus conf\ue9r\ue9e par la pr\ue9sence de prot\ue9ines APA introgress\ue9es du haricot tepary

Readiness to adopt a performance measurement system for substance abuse treatment: Findings from the Service Quality Measures initiative

Background. A performance measurement system – the Service Quality Measures (SQM) initiative – has been developed to monitor the quality of South Africa (SA)’s substance abuse treatment services. Identifying factors associated with readiness to adopt this system may inform strategies to facilitate its robust implementation.Objective. To examine factors associated with readiness to adopt a performance measurement system among SA substance abuse treatment providers.Methods. We surveyed 81 treatment providers from 13 treatment sites in the Western Cape, SA. The survey examined awareness, resources, organisational climate, leadership support and readiness to adopt the SQM system. Regression analysis was used to identify factors associated with readiness to adopt this system.Results. Readiness to adopt the SQM initiative was high (M=5.64, standard deviation 1.63). In bivariate analyses, caseload size (F=3.73 (degrees of freedom (df)=3.70), p=0.015), awareness (r=0.78, p<0.0001), leadership support (r=0.70, p<0.0001), resources (r=0.65, p<0.0001), openness to change (r=0.372, p=0.001), and external pressure to change were associated with readiness to adopt the SQM. In multivariate analyses, only awareness of the SQM initiative (B=0.34, standard error (SE) 0.08, t=4.4, p<0.0001) and leadership support (B=0.45, SE 0.11, t=4.0, p<0.0001) were significantly associated with readiness to adopt this system.Conclusion. While treatment providers report high levels of readiness to adopt the SQM system, findings show that the likelihood of adoption can be further increased through improved provider awareness and enhanced leadership support for this health innovation

Occurrence of methicillin-resistant Staphylococcus aureus in surface waters near industrial hog operation spray fields

Industrial hog operations (IHOs) have been identified as a source of antibiotic-resistant Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). However, few studies have investigated the presence of antibiotic-resistant S. aureus in the environment near IHOs, specifically surface waters proximal to spray fields where IHO liquid lagoon waste is sprayed. Surface water samples (n = 179) were collected over the course of approximately one year from nine locations in southeastern North Carolina and analyzed for the presence of presumptive MRSA using CHROMagar MRSA media. Culture-based, biochemical, and molecular tests, as well as matrix-assisted laser desorption/ionization-time of flight mass spectrometry were used to confirm that isolates that grew on CHROMagar MRSA media were S. aureus. Confirmed S. aureus isolates were then tested for susceptibility to 16 antibiotics and screened for molecular markers of MRSA (mecA, mecC) and livestock adaptation (absence of scn). A total of 12 confirmed MRSA were detected in 9 distinct water samples. Nine of 12 MRSA isolates were also multidrug-resistant (MDRSA [i.e., resistant to ≥ 3 antibiotic classes]). All MRSA were scn-positive and most (11/12) belonged to a staphylococcal protein A (spa) type t008, which is commonly associated with humans. Additionally, 12 confirmed S. aureus that were methicillin-susceptible (MSSA) were recovered, 7 of which belonged to spa type t021 and were scn-negative (a marker of livestock-adaptation). This study demonstrated the presence of MSSA, MRSA, and MDRSA in surface waters adjacent to IHO lagoon waste spray fields in southeastern North Carolina. To our knowledge, this is the first report of waterborne S. aureus from surface waters proximal to IHOs

Breeding for specific bioregions: a genotype by environment study of horticultural and nutritional traits integrating breeder and farmer priorities for organic broccoli cultivar improvement

The genotype by environment interaction study of broccoli, amongst others demonstrates that traits of a cultivar are sometimes ranked differently when grown in an organic production system compared to a conventional system. This has strong implications for breeding strategies. The breeders interviewed acknowledged that more attention on abiotic and biotic stress resistance in a broccoli breeding programme is needed which is in accordance with the farmers' varietal requirements. The first findings of the field trials show that cultivar performance is influenced by season and region, and differences in treatment (organic versus conventional management). The field trials showed that there are cultivars with broad adaptation such as "Green Goliath". These cultivars performed across locations, seasons and treatments within the sub-top group, however, organic farmers would benefit more from cultivars specifically adapted to their region and season. The trial results showed a wide range of glucosinolate levels. Glucoraphanin was very genotype dependent, while glucobrassicin and neoglucobrassicin were more influenced by abiotic and biotic environmental factors. Therefore, there are opportunities for nutritional performance enhancement under organic conditions which would provide an added value to the product quality with respect to human and plant health. Further elaboration of the dataset will contribute to the design of regional breeding strategies for improved broccoli cultivars for the organic market

Fuzzy Rings in D6-Branes and Magnetic Field Background

We use the Myers T-dual nonabelin Born-Infeld action to find some new nontrivial solutions for the branes in the background of D6-branes and Melvin magnetic tube field. In the D6-Branes background we can find both of the fuzzy sphere and fuzzy ring solutions, which are formed by the gravitational dielectric effect. We see that the fuzzy ring solution has less energy then that of the fuzzy sphere. Therefore the fuzzy sphere will decay to the fuzzy ring configuration. In the Melvin magnetic tube field background there does not exist fuzzy sphere while the fuzzy ring configuration may be formed by the magnetic dielectric effect. The new solution shows that $D_0$ propagating in the D6-branes and magnetic tube field background may expand into a rotating fuzzy ring. We also use the Dirac-Born-Infeld action to construct the ring configuration from the D-branes.Comment: Latex, 15 pages, detailed comments in section 2, typos correcte

Can inflationary models of cosmic perturbations evade the secondary oscillation test?

We consider the consequences of an observed Cosmic Microwave Background (CMB) temperature anisotropy spectrum containing no secondary oscillations. While such a spectrum is generally considered to be a robust signature of active structure formation, we show that such a spectrum {\em can} be produced by (very unusual) inflationary models or other passive evolution models. However, we show that for all these passive models the characteristic oscillations would show up in other observable spectra. Our work shows that when CMB polarization and matter power spectra are taken into account secondary oscillations are indeed a signature of even these very exotic passive models. We construct a measure of the observability of secondary oscillations in a given experiment, and show that even with foregrounds both the MAP and \pk satellites should be able to distinguish between models with and without oscillations. Thus we conclude that inflationary and other passive models can {\em not} evade the secondary oscillation test.Comment: Final version accepted for publication in PRD. Minor improvements have been made to the discussion and new data has been included. The conclusions are unchagne

Spectropolarimetry of the Deep Impact target comet 9P/Tempel 1 with HiVIS

High resolution spectropolarimetry of the Deep Impact target, comet 9P/ Tempel 1, was performed during the impact event on July 4th, 2005 with the HiVIS Spectropolarimeter and the AEOS 3.67m telescope on Haleakala, Maui. We observed atypical polarization spectra that changed significantly in the few hours after the impact. The polarization of scattered light as a function of wavelength is very sensitive to the size and composition (complex refractive index) of the scattering particles as well as the scattering geometry. As opposed to most observations of cometary dust, which show an increase in the linear polarization with the wavelength (at least in the visible domain and for phase angles greater than about 30%, a red polarization spectrum) observations of 9P/Tempel 1 at a phase angle of 41 degrees beginning 8 minutes after impact and centered at 6:30UT showed a polarization of 4% at 650 nm falling to 3% at 950 nm. The next observation, centered an hour later showed a polarization of 7% at 650 nm falling to 2% at 950nm. This corresponds to a spectropolarimetric gradient, or slope, of -0.9% per 1000 Angstroms 40 minutes after impact, decreasing to a slope of -2.3% per 1000 Angstroms an hour and a half after impact. This is an atypical blue polarization slope, which became more blue 1 hour after impact. The polarization values of 4% and 7% at 650nm are typical for comets at this scattering angle, whereas the low polarization of 2% and 3% at 950nm is not. We compare observations of comet 9P/Tempel 1 to that of a typical comet, C/2004 Machholz, at a phase angle of 30 degrees which showed a typical red slope, rising from 2% at 650nm to 3% at 950nm in two different observations (+1.0 and +0.9% per 1000 Angstroms).Comment: Icarus Deep Impact special issue, accepted Aug 28 200

Time-Dependent Spintronic Transport and Current-Induced Spin Transfer Torque in Magnetic Tunnel Junctions

The responses of the electrical current and the current-induced spin transfer torque (CISTT) to an ac bias in addition to a dc bias in a magnetic tunnel junction are investigated by means of the time-dependent nonquilibrium Green function technique. The time-averaged current (time-averaged CISTT) is formulated in the form of a summation of dc current (dc CISTT) multiplied by products of Bessel functions with the energy levels shifted by $m\hbar \omega _{0}$. The tunneling current can be viewed as to happen between the photonic sidebands of the two ferromagnets. The electrons can pass through the barrier easily under high frequencies but difficultly under low frequencies. The tunnel magnetoresistance almost does not vary with an ac field. It is found that the spin transfer torque, still being proportional to the electrical current under an ac bias, can be changed by varying frequency. Low frequencies could yield a rapid decrease of the spin transfer torque, while a large ac signal leads to both decrease of the electrical current and the spin torque. If only an ac bias is present, the spin transfer torque is sharply enhanced at the particular amplitude and frequency of the ac bias. A nearly linear relation between such an amplitude and frequency is observed.Comment: 13 pages,8 figure