Cold dark matter in brane cosmology scenario

We analyze the dark matter problem in the context of brane cosmology. We investigate the impact of the non-conventional brane cosmology on the relic abundance of non-relativistic stable particles in high and low reheating scenarios. We show that in case of high reheating temperature, the brane cosmology may enhance the dark matter relic density by many order of magnitudes and a stringent lower bound on the five dimensional scale is obtained. We also consider low reheating temperature scenarios with chemical equilibrium and non-equilibrium. We emphasize that in non-equilibrium case, the resulting relic density is very small. While with equilibrium, it is increased by a factor of O(10^2) with respect to the standard thermal production. Therefore, dark matter particles with large cross section, which is favored by detection expirements, can be consistent with the recent relic density observational limits.Comment: 14 pages, 1 figur

Protective immune responses against Schistosoma mansoni infection by immunization with functionally active gut-derived cysteine peptidases alone and in combination with glyceraldehyde 3-phosphate dehydrogenase

© 2017 Tallima et al. Background: Schistosomiasis, a severe disease caused by parasites of the genus Schistosoma, is prevalent in 74 countries, affecting more than 250 million people, particularly children. We have previously shown that the Schistosoma mansoni gut-derived cysteine peptidase, cathepsin B1 (SmCB1), administered without adjuvant, elicits protection (>60%) against challenge infection of S. mansoni or S. haematobium in outbred, CD-1 mice. Here we compare the immunogenicity and protective potential of another gut-derived cysteine peptidase, S. mansoni cathepsin L3 (SmCL3), alone, and in combination with SmCB1. We also examined whether protective responses could be boosted by including a third non-peptidase schistosome secreted molecule, glyceraldehyde 3-phosphate dehydrogenase (SG3PDH), with the two peptidases. Methodology/Principal findings: While adjuvant-free SmCB1 and SmCL3 induced type 2 polarized responses in CD-1 outbred mice those elicited by SmCL3 were far weaker than those induced by SmCB1. Nevertheless, both cysteine peptidases evoked highly significant (P < 0.005) reduction in challenge worm burden (54–65%) as well as worm egg counts and viability. A combination of SmCL3 and SmCB1 did not induce significantly stronger immune responses or higher protection than that achieved using each peptidase alone. However, when the two peptidases were combined with SG3PDH the levels of protection against challenge S. mansoni infection reached 70–76% and were accompanied by highly significant (P < 0.005) decreases in worm egg counts and viability. Similarly, high levels of protection were achieved in hamsters immunized with the cysteine peptidase/SG3PDH-based vaccine. Conclusions/Significance: Gut-derived cysteine peptidases are highly protective against schistosome challenge infection when administered subcutaneously without adjuvant to outbred CD-1 mice and hamsters, and can also act to enhance the efficacy of other schistosome antigens, such as SG3PDH. This cysteine peptidase-based vaccine should now be advanced to experiments in non-human primates and, if shown promise, progressed to Phase 1 safety trials in humans

Magnetic resonance imaging of head and neck vascular anomalies: pearls and pitfalls

Purpose: The aim of this study was to describe typical MRI features of the head and neck vascular anomalies and the possible diagnostic pitfalls.Patients and methods: Patients with extracranial vascular anomalies of the head and neck, who underwent MRI examinations between January 2013 and January 2016, were included in the study. Precontrast and postcontrast T1-WI,T2-WI, with and without fat saturation were acquired. When indicated, a noncontrast MR angiography was performed. Dynamic postcontrast MRI techniques were available in six children.Results: The study included 33 patients (age ranged from 10 to 20 years, mean: 49 months). MRI confirmed the clinical diagnosis in equivocal cases, and provided proper determination of lesion extension and/or associated intracranial anomalies. The study included 10 cases of vascular tumors (hemangioma), whereas the remaining 23 cases had the diagnosis of vascular malformations (one patient with arteriovenous malformation, one with capillary malformation, seven with venous, nine with macrocystic lymphatic, and five with microcystic lymphatic malformations).Conclusion: Vascular anomalies in the head and neck are mostly diagnosed on clinical basis; however, when the history is uncertain or the diagnosis is equivocal, a well-tailored MR examination can be a single valuable diagnostic tool providing structural and functional information.Keywords: children, head and neck, hemangioma, lymphatic malformation, magnetic resonance angiography, venous malformatio

Inflation and late time acceleration in braneworld cosmological models with varying brane tension

Braneworld models with variable brane tension $\lambda$ introduce a new degree of freedom that allows for evolving gravitational and cosmological constants, the latter being a natural candidate for dark energy. We consider a thermodynamic interpretation of the varying brane tension models, by showing that the field equations with variable $\lambda$ can be interpreted as describing matter creation in a cosmological framework. The particle creation rate is determined by the variation rate of the brane tension, as well as by the brane-bulk energy-matter transfer rate. We investigate the effect of a variable brane tension on the cosmological evolution of the Universe, in the framework of a particular model in which the brane tension is an exponentially dependent function of the scale factor. The resulting cosmology shows the presence of an initial inflationary expansion, followed by a decelerating phase, and by a smooth transition towards a late accelerated de Sitter type expansion. The varying brane tension is also responsible for the generation of the matter in the Universe (reheating period). The physical constraints on the model parameters, resulted from the observational cosmological data, are also investigated.Comment: 25 pages, 8 figures, accepted for publication in European Physical Journal

Reheating the Universe in Braneworld Cosmological Models with bulk-brane energy transfer

The emergence of the cosmological composition (the reheating era) after the inflationary period is analyzed in the framework of the braneworld models, in which our Universe is a three-brane embedded in a five-dimensional bulk, by assuming the possibility of the brane-bulk energy exchange. The inflaton field is assumed to decay into normal matter only, while the dark matter is injected into the brane from the bulk. To describe the reheating process we adopt a phenomenological approach, by describing the decay of the inflaton field by a friction term proportional to the energy density of the field. After the radiation dominated epoch the model reduces to the standard four dimensional cosmological model. The modified field equations are analyzed analytically and numerically in both the extra-dimensions dominate reheating phase (when the quadratic terms in energy density dominate the dynamics), and in the general case. The evolution profiles of the matter, of the scalar field and of the scale factor of the universe are obtained for different values of the parameters of the model, and of the equations of state of the normal and dark matter, respectively. The equation describing the time evolution of the ratio of the energy density of the dark and of the normal matter is also obtained. The ratio depends on the rate of the energy flow between the bulk and the brane. The observational constraint of an approximately constant ratio of the dark and of the baryonic matter requires that the dark matter must be non-relativistic (cold). The model predicts a reheating temperature of the order of $3\times 10^6$ GeV, a brane tension of the order of $10^{25}$ GeV$^4$, and the obtained composition of the universe is consistent with the observational data.Comment: 29 pages, 9 figures, accepted for publication in JCA

EFFECT OF BIO-FERTILIZERS AND GAMMA RADIATION ON THE ESSENTIAL OIL OF DILL AT THE VEGETATIVE, FLOWERING, FRUITING STAGES AND THEIR ANTIMICROBIAL ACTIVITIES

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EFFECT OF BIO-FERTILIZERS AND GAMMA RADIATION ON THE ESSENTIAL OIL OF DILL AT THE VEGETATIVE, FLOWERING, FRUITING STAGES AND THEIR ANTIMICROBIAL ACTIVITIES

This study was carried out to investigate the response of dill plants to gamma radiation and bio-fertilizers on the essential oils and their constituents during vegetative, flowering and fruiting stages. The results showed that the most effective treatment on the volatile oil content in the three stages was 2 k-rad + bio-fertilizers. The major compounds were found to be α-phellandrene, limonene, β-phellandrene and p-cymene (vegetative stage). In the flowering stage, p-cymene, carvone, dillether and dillapiole. Whereas, carvone, dillapiole and limonene were major compounds (fruiting stage). The results showed those dill volatile oils at different developing stages exhibited strong and a variable degree of antimicrobial activity

Protection against Schistosoma haematobium infection in hamsters by immunization with Schistosoma mansoni gut-derived cysteine peptidases, SmCB1 and SmCL3

© 2017 Elsevier Ltd We examined the immunogenicity and protective potential of SmCB1 and SmCL3 cysteine peptidases, alone and in combination, in hamsters challenged with S. haematobium. For each of two independent experiments, eight Syrian hamsters were immunized twice with a three week-interval with 0 (controls), 20 µg SmCB1, 20 µg SmCL3, or 10 µg SmCB1 plus 10 µg SmCL3, and then percutaneously exposed eight weeks later to 100 S. haematobium cercariae. Hamsters from each group were assessed for humoral and whole blood culture cytokine responses on day 10 post challenge infection, and examined for parasitological parameters 12 weeks post infection. At day 10 post-infection we found that SmCB1 and SmCL3 elicited low antibody titres and weak but polarized cytokine type 2 responses. Nevertheless, both cysteine peptidases, alone or in combination, evoked reproducible and highly significant reduction in challenge worm burden (>70%, P < 0.02) as well as a significant reduction in worm egg counts and viability. The data support our previous findings and show that S. mansoni cysteine peptidases SmCB1 and SmCL3 are efficacious adjuvant-free vaccines that induce protection in mice and hamsters against both S. mansoni and S. haematobium