Black holes and the double copy Monteiro, R.; O’Connell, D.; White, C. D.
The journal of high energy physics,
12/2014, Letnik:
2014, Številka:
12
Journal Article
Recenzirano
Odprti dostop
A
bstract
Recently, a perturbative duality between gauge and gravity theories (the double copy) has been discovered, that is believed to hold to all loop orders. In this paper, we examine the ...relationship between classical solutions of non-Abelian gauge theory and gravity. We propose a general class of gauge theory solutions that double copy to gravity, namely those involving stationary Kerr-Schild metrics. The Schwarzschild and Kerr black holes (plus their higher-dimensional equivalents) emerge as special cases. We also discuss plane wave solutions. Furthermore, a recently examined double copy between the self-dual sectors of Yang-Mills theory and gravity can be reinterpreted using a momentum-space generalisation of the Kerr-Schild framework.
•Report on soy protein hydrolysates (SPHs) – galactomannan (GA) mixtures.•Gelation of the SPHs occurred at lower temperature in the presence of the GA.•The positive effect of the GA upon gelation of ...SPH depends on the degree of hydrolysis.•Addition of galactomannan improves emulsifying properties of the SPHs.•Diversity of functionalities by changing size and concentration of both biopolymers.
Soy protein hydrolysates (SPH) with different degrees of hydrolysis (DH 0–16%) were obtained by varying the time of hydrolysis with bromelain. The objective of this study was to evaluate how selected techno-functional properties (gelation, emulsification) of SPH were affected by the presence of a non-gelling polysaccharide. A slight hydrolysis was beneficial to increase gel strength. Also, the emulsifying activity was improved for low DHs, whereas hydrolysis was detrimental for emulsion stability. Under certain conditions the presence of the non-gelling polysaccharide was beneficial to improve SPHs’ functional properties, but the effect was in general complex and strongly dependent on both biopolymers’ concentration and molecular weight. Nevertheless, it was demonstrated that by using SPH and galactomannan mixtures and controlling the biopolymers’ concentration and molecular weight, improved functionalities can be obtained with useful applications in food formulation.
Many
species are found as commensal members of the intestinal microbiota. However, imbalances of the microbiota may lead to certain infections caused by these microorganisms, mainly
,
, and
. In many ...cases, infection recurrence can occur after antibiotics, indicating the need for novel therapeutic options that act on the pathogens and also restore the microbiota. Herein, the in vitro antimicrobial activity and probiotic potential of clinical and reference strains of
and
were investigated against
species. Antimicrobial activity was evaluated by the agar spot test and inhibition of gas production. Then, the probiotic potential of selected strains was assessed by analyzing their coaggregation ability, adhesive properties to host cells and mucin, tolerance to acidic pH and bile salts, and antimicrobial susceptibility profiles.
ATCC 8014 was the most promising strain based on its inhibitory activity against
spp. Also, this strain met criteria to be considered a probiotic based on its coaggregation ability, adhesive properties, and tolerance to harsh pH and bile acid salt conditions. The results indicate that among the studied strains,
ATCC 8014 presents probiotic potential for controlling infections induced by the studied
species and should be further evaluated in in vivo animal models.
Global warming is considered a major threat to Earth's lakes water budgets and quality. However, flow regulation, over-exploitation, lack of hydrological data, and disparate evaluation methods hamper ...comparative global estimates of lake vulnerability to evaporation. We have analyzed the stable isotope composition of 1257 global lakes and we find that most lakes depend on precipitation and groundwater recharge subsequently altered by catchment and lake evaporation processes. Isotope mass-balance modeling shows that ca. 20% of water inflow in global lakes is lost through evaporation and ca. 10% of lakes in arid and temperate zones experience extreme evaporative losses >40 % of the total inflow. Precipitation amount, limnicity, wind speed, relative humidity, and solar radiation are predominant controls on lake isotope composition and evaporation, regardless of the climatic zone. The promotion of systematic global isotopic monitoring of Earth's lakes provides a direct and comparative approach to detect the impacts of climatic and catchment-scale changes on water-balance and evaporation trends.
This paper describes an accelerated HPE-type method based on general Bregman distances for solving convex-concave saddle-point (SP) problems. The algorithm is a special instance of a non-Euclidean ...hybrid proximal extragradient framework introduced by Svaiter and Solodov An inexact hybrid generalized proximal point algorithm and some new results on the theory of Bregman functions, Math. Oper. Res. 25(2) (2000), pp. 214-230 where the prox sub-inclusions are solved using an accelerated gradient method. It generalizes the accelerated HPE algorithm presented in He and Monteiro An accelerated HPE-type algorithm for a class of composite convex-concave saddle-point problems, SIAM J. Optim. 26 (2016), pp. 29-56 in two ways, namely: (a) it deals with general monotone SP problems instead of bilinear structured SPs and (b) it is based on general Bregman distances instead of the Euclidean one. Similar to the algorithm of He and Monteiro An accelerated HPE-type algorithm for a class of composite convex-concave saddle-point problems, SIAM J. Optim. 26 (2016), pp. 29-56, it has the advantage that it works for any constant choice of proximal stepsize. Moreover, a suitable choice of the stepsize yields a method with the best known iteration-complexity for solving monotone SP problems. Computational results show that the new method is superior to Nesterov's Smooth minimization of non-smooth functions, Math. Program. 103(1) (2005), pp. 127-152 smoothing scheme.
Abstract The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), is an important pest in the subtropical region of Brazil. This insect has tritrophic relation ...between wild fruits and parasitoids and is associated with apple (Malus domestica Borkh.) orchards adjacent to the Atlantic Forest in Paraná. We thus investigated the degree of infestation of the fruit fly and natural parasitism in wild and cultivated fruits surrounding apple orchards. For this purpose, we collected fruits of Acca sellowiana (Berg.) Burret, Campomanesia xanthocarpa (Mart), Eugenia uniflora L., Eugenia pyriformis Cambessèdes, Psidium cattleianum Sabine, Psidium guajava (L.), Annona neosericea Rainer and Eriobotrya japonica (Thumb) in apple orchards adjacent to the Atlantic Forest located in Campo do Tenente, Lapa and Porto Amazonas counties. In total, we collected 18,289 fruits during four growing years. The occurrence of A. fraterculus depends on the susceptible period of apple fruits. A. sellowiana and P. cattleianum were considered primary fruit fly multipliers and P. guajava was secondary, all occurring after the apple harvest (IS period). The group of parasitoids with A. fraterculus was Aganaspis pelleranoi (Brèthes, 1924) (Hymenoptera: Figitidae), Opius bellus (Gahan, 1930), Doryctobracon areolatus (Szépligeti, 1911) and Doryctobracon brasiliensis (Szépligeti, 1911) (Hymenoptera: Braconidae) all of which are first records in the Atlantic Forest in Paraná. First record of O. bellus occurring in the State of Paraná, as well as, first record of the tritrophic association between host plant A. neosericea, parasitoids D. areolatus and O. bellus and fruit fly A. fraterculus. The host P. cattleianum stood out among the Myrtaceae species in regard to the high diversity of parasitoid species (81% of parasitoids). The total number of Figitidae species (76.5%) was higher than that of Braconidae species. The influence of climatic events in southern Brazil on wild fruit production should be further studied to understand the association of A. fraterculus with the tritrophic relationship.
Resumo Mosca-das-frutas sul-americana, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), é uma importante praga da região subtropical do Brasil. Este inseto tem relação tritrófico entre frutos silvestres e parasitoides e está associado a pomares de macieiras (Malus domestica Borkh.) adjacentes à Mata Atlântica no Paraná. Assim, investigamos o grau de infestação da mosca-das-frutas e o parasitismo natural em frutas silvestres e cultivadas ao redor de pomares de maçã. Para tanto, foram coletados frutos de Acca sellowiana (Berg.) Burret, Campomanesia xanthocarpa (Mart), Eugenia uniflora L., Eugenia pyriformis Cambessèdes, Psidium cattleianum Sabine, Psidium guajava (L.), Annona neosericea Rainer e Eriobotrya japonica (Thumb) em pomares de maçã adjacentes à Mata Atlântica localizados nos municípios de Campo do Tenente, Lapa e Porto Amazonas. No total, coletamos 18.289 frutos durante quatro anos de cultivo. A ocorrência de A. fraterculus depende do período de suscetibilidade dos frutos da maçã. A. sellowiana e P. cattleianum foram considerados multiplicadores primários de mosca-das-frutas e P. guajava foi secundário, todos ocorrendo após a colheita da maçã (período IS). Os parasitóides a associados a A. fraterculus foram Aganaspis pelleranoi (Brèthes, 1924) (Hymenoptera: Figitidae), Opius bellus (Gahan, 1930), Doryctobracon areolatus (Szépligeti, 1911) e Doryctobracon brasiliensis (Szépligeti, 1911) (Hymenoptera: Braconidae), todos os quais são primeiros registros na Mata Atlântica no Paraná. Primeiro registro de O. bellus ocorrendo no Estado do Paraná, assim como, primeiro registro da associação tritrófica entre o hospedeiro A. neosericea, parasitoides D. areolatus e O. bellus e mosca-das-frutas A. fraterculus. O hospedeiro P. cattleianum se destacou entre as espécies de Myrtaceae pela alta diversidade de parasitóides associados (81% dos parasitóides). O número total de espécies de Figitidae (76,5%) foi superior ao de espécies de Braconidae. A influência de eventos climáticos no sul do Brasil na produção de frutas silvestres deve ser mais estudada para entender a associação de A. fraterculus com a relação tritrófica.
The methods of geometric morphometrics, which combine an explicitly geometric definition of shape with the flexible tools of multivariate statistics, have become established in the past decade as the ..."morphometric synthesis." Here, Klingenberg and Monteiro discuss the considerable efforts now directed at applying these methods in diverse biological contexts.
In natural environments fish are exposed to endocrine disrupting compounds (EDCs) present at low concentrations and with different modes of actions. Here, adult zebrafish of both sexes were exposed ...for 21 days to an estrogenic mixture (Mix) of eleven EDCs previously quantified in Douro River estuary (Portugal) and to 100 ng/L 17α-ethinylestradiol (EE2) as positive control. Vitellogenin mRNA and HSI in males confirmed both exposure regimes as physiologically active. Potential candidates for estrogenic disturbance of steroidogenesis were identified (StAR, 17β-HSD1, cyp19a1), but Mix only affected cyp19a1 in females. Significant differences in the response of FSHβ, cypa19a2, 20β-HSD were observed between EE2 and Mix. Mtf-1 and tfap2c transcription factor binding sites were discovered in the putative promoter regions and corresponding transcription factors were found to be differentially expressed in response to Mix and EE2. The results suggest that “non-classical effects” of estrogenic EDC in fish are mediated via transcription factors.
► Zebrafish were exposed to an estrogenic mixture (Mix) and to EE2 as positive control. ► Both exposure regimes were confirmed as physiologically active. ► Different disturbances on steroidogenesis were observed in males and females. ► A male gene expression pattern suggested a differential interference of Mix and EE2. ► Non-classical effects of Mix seem to be mediated via transcription factors.
An estrogenic mixture revealed different effects on specific transcription factors than EE2, probably due to multiple modes of actions of the chosen compounds.
To evaluate the ability of confocal near-infrared reflectance (NIR) to diagnose retrograde microcystic maculopathy (RMM) in eyes with temporal visual field (VF) loss and optic atrophy from chiasmal ...compression. To compare NIR findings with optical coherence tomography (OCT) findings in the same group of patients. Thirty-four eyes (26 patients) with temporal VF loss from chiasmal compression and 41 healthy eyes (22 controls) underwent NIR fundus photography, and macular OCT scanning. VF loss was estimated and retinal layers thickness were measured on OCT. Two examiners blinded to the diagnosis randomly examined NIR images for the presence of hyporeflective abnormality (HA) and OCT scans for the presence of microcystic macular abnormalities (MMA). The total average and hemi-macular HA area and number of microcysts were determined. The groups were compared and the level of agreement was estimated. The OCT-measured macular retinal nerve fiber and ganglion cell layers were thinner and the inner nuclear layer was thicker in patients compared to controls. HA and MMA were detected in 22 and 12 patient eyes, respectively, and in 0 controls (p<0.001, both comparisons). HA was significantly more frequent than MMA in patients with optic atrophy, and agreement between HA and MMA (both total and hemi-macular) was fair (kappa range: 0.24-0.29). The mean HA area was significantly greater in the nasal than temporal hemi-macula. A re-analysis of the 14 eyes with discrepant findings allowed to confirm RMM in 20 eyes (20/34) indicating that OCT detected RMM in 12 and missed it in 8 eyes. On the other hand, NIR correctly detected 18 out of 20 eyes, overcalled 4 and missed 2. RMM is a frequent finding in eyes with severe VF loss from long-standing chiasmal compression. NIR photography appears to be more sensitive than OCT for detecting RMM and may be useful as screening method for its presence.
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