Many-body approach to the nonlinear interaction of charged particles with an interacting free electron gas

We report various many-body theoretical approaches to the nonlinear decay rate and energy loss of charged particles moving in an interacting free electron gas. These include perturbative formulations of the scattering matrix, the self-energy, and the induced electron density. Explicit expressions for these quantities are obtained, with inclusion of exchange and correlation effects.Comment: 11 pages, 5 figures. To appear in Journal of Physics

Assessing the feeding ecology of three sympatric squids Illex argentinus, Doryteuthis gahi and Onykia ingens off the Patagonian by combining stomach content and stable isotopic analysis

The Ommastrephidae Illex argentinus, the Loliginidae Doryteuthis gahi and the Onychoteuthidae Onikya ingens are squid species coexisting in the south part of the Patagonian Shelf, interacting for similar feeding resources. In the present study, we analyzed the feeding ecology, trophic position and trophic relationships of these three species by combining stomach content and stable isotopic approximations. In particular, stomach content and isotopic analysis were carried out on 20 D. gahi, 20 I. argentinus and 21 O. ingens collected from May 6th and 8th 2013 at depths between 147 and 220 m. The results indicated that the feeding habits of small and larger squids were different in the three species. The two main prey species for small D. gahi individuals were the euphausid Euphausia sp. and the amphipod Eutemisto gaudichaudi, and the main prey for larger D. gahi individuals were a fish and the Munididae Munida subrugosa. The main prey group of small I. argentinus individuals was the amphipod E. gaudichaudi and the myctophid fish, and the main prey for larger size I. argentinus individuals were the paralepididae Arctozenus risso and the Notothenidae Patagonotothen ramsayi, secondly by the squid group. Small O. ingens individuals fed on Micromesistius australis and Notophysis marginata while larger O. ingens individuals fed on Lampanyctus australis and Notoscopelus sp. D. gahi showed higher δ15N values than the other two species and small and larger D. gahi individuals showed similar isotopic values. The δ15N values of I. argentinus and O. ingens were higher for larger individuals. Finally, D. gahi differed in its δ13C values from I. argentinus and O. ingens and the less depleted δ13C values were found in the larger in D. gahi individuals. The results indicate that the three squid species preyed on organisms with similar trophic position, but due to their voracity and their active predation on similar trophic resources, small size individuals segregate their trophic niche from the larger ones. It is important to note that the δ13C values revealed that larger D. gahi individuals had a different distribution in the water column, which probably is a response of the reproductive activity of mature squid near to the surface water.Universidad Nacional Autónoma de Méxic

Modeling GHG emissions, N and C dynamics in Spanish agricultural soils.

To date, only few initiatives have been carried out in Spain in order to use mathematical models (e.g. DNDC, DayCent, FASSET y SIMSNIC) to estimate nitrogen (N) and carbon (C) dynamics as well as greenhouse gases (GHG) in Spanish agrosystems. Modeling at this level may allow to gain insight on both the complex relationships between biological and physicochemical processes, controlling the processes leading to GHG production and consumption in soils (e.g. nitrification, denitrification, decomposing, etc.), and the interactions between C and N cycles within the different components of the continuum plant-soil-environment. Additionally, these models can simulate the processes behind production, consumition and transport of GHG (e.g. nitrous oxide, N2O, and carbon dioxide, CO2) in the short and medium term and at different scales. Other sources of potential pollution from soils can be identified and quantified using these process-based models (e.g. NO3 y NH3)

LIGHT/HVEM/LTβR Interaction as a Target for the Modulation of the Allogeneic Immune Response in Transplantation

[EN] The exchange of information during interactions of T cells with dendritic cells, B cells or other T cells regulates the course of T, B and DC-cell activation and their differentiation into effector cells. The tumor necrosis factor superfamily member LIGHT (homologous to lymphotoxin, exhibits inducible expression and competes with HSV glycoprotein D for binding to herpesvirus entry mediator, a receptor expressed on T lymphocytes) is transiently expressed upon T cell activation and modulates CD8 T cell-mediated alloreactive responses upon herpes virus entry mediator (HVEM) and lymphotoxin β receptor (LTβR) engagement. LIGHT-deficient mice, or WT mice treated with LIGHT-targeting decoy receptors HVEM-Ig, LTβR-Ig or sDcR3-Ig, exhibit prolonged graft survival compared to untreated controls, suggesting that LIGHT modulates the course and severity of graft rejection. Therefore, targeting the interaction of LIGHT with HVEM and/or LTβR using recombinant soluble decoy receptors or monoclonal antibodies represent an innovative therapeutic strategy for the prevention and treatment of allograft rejection and for the promotion of donor-specific tolerance. This review discusses how targeting the interaction of LIGHT with HVEM and/or LTbR using recombinant soluble decoy receptors or monoclonal antibodies may represent an innovative therapeutic intervention for the prevention and treatment of allograft rejection and promotion of donor-specific tolerance. © 2013 The American Society of Transplantation and the American Society of Transplant SurgeonsSIThis work has been supported by grants FIS reference # PI10/01039 from Ministry of Health and Department of Education from Junta of Castilla and Leon reference # LE007A10-2 (to JIRB), and by the Swiss National Science Foundation (to PS

Therapeutic implications of NK cell regulation of allogeneic CD8 T cell-mediated immune responses stimulated through the direct pathway of antigen presentation in transplantation

[EN]Natural killer (NK) cells are a population of innate type I lymphoid cells essential for early anti-viral responses and are known to modulate the course of humoral and cellular-mediated T cell responses. We assessed the role of NK cells in allogeneic CD8 T cell-mediated responses in an immunocompetent mouse model across an MHC class I histocompatibility barrier to determine its impact in therapeutic clinical interventions with polyclonal or monoclonal antibodies (mAbs) targeting lymphoid cells in transplantation. The administration of an NK cell depleting antibody to either CD8 T cell replete or CD8 T cell-depleted naïve C57BL/6 immunocompetent mice accelerated graft rejection. This accelerated rejection response was associated with an in vivo increased cytotoxic activity of CD8 T cells against bm1 allogeneic hematopoietic cells and bm1 skin allografts. These findings show that NK cells were impli-cated in the control host anti-donor cytotoxic responses, likely by competing for common cell growth factors in both CD8 T cell replete and CD8 T cell-depleted mice, the latter reconstituting in response to lymphopenia. Our data calls for precaution in solid organ transplantation under tolerogenic protocols involving extensive depletion of lymphocytes. These pharmacological biologics with depleting proper-ties over NK cells may accelerate graft rejection and promote aggressive CD8 T cell cytotoxic allore-sponses refractory to current immunosuppression.SIThis work has been supported by grant FIS PI# 1300029 (Fondo de Investigaciones Sanitarias, Ministry of Health, Spanish Government and co-funded by European Union ERDF/ESF, “Investing in your future”), LE093U13 and Unit of Excellence Research UIC #012 (Department of Education of the Regional Government, Junta de Castilla y Leon) and Gerencia Regional de Salud (BIO/01/15) to JIRB, and by Miguel Servet National Grant (Health National Organization Research) CP12/03063, CPII17/00002 and FIS PI16/00002 (Instituto de Salud Carlos III and co-funded by European Union ERDF/ESF, “Investing in your future”), and Gerencia Regional de Salud GRS963/A/2014, GRS1142/A/2015 and GRS 1505/A/2017 to M.L.R.G.This work has been partially funded by the National Network CIBER-ONC (oncology research) CB16/12/00480. P.S. is funded by grant 31003A-17-6256 of the Swiss National Science Foundation. We thank University of Leon for providing funding to cover publication expenses

Optimizing omnidirectional reflection by multilayer mirrors

Periodic layered media can reflect strongly for all incident angles and polarizations in a given frequency range. Quarter-wave stacks at normal incidence are commonplace in the design of such omnidirectional reflectors. We discuss alternative design criteria to optimize these systems.Comment: 9 pages, 6 figures. To be published in J. Opt. A: Pure and Applied Optic

Eosinophilic esophagitis, celiac disease, and immunoglobulin E–mediated allergy in a 2-year-old child

This communication was presented at XXVI National Congress of SEAIC, Spanish Society of Allergology and Clinical Immunology, Bilbao, Spain, 2008Celiac disease, eosinophilic esophagitis, and urticaria are 3 manifestations of food allergy with different pathogenic mechanisms. We report the case of a 2-year-old child with digestive symptoms, slow growth, and severe asthma. The results of skin prick tests were positive to several foods. Endoscopy revealed eosinophilic esophagitis and celiac disease. Treatment consisted of a gluten-free diet and a 1-month course of oral corticosteroids. Endoscopy and biopsy fi ndings were normal at 5 years of age. A gluten-free diet is the basis of treatment of celiac disease, but the role of an elimination diet in eosinophilic esophagitis is not well established. Our patient also developed urticaria when exposed to milk and egg. We present, to our knowledge, the fi rst report of a patient with celiac disease, eosinophilic esophagitis, and immediate-type immunoglobulin E–mediated food allergyEnfermedad celíaca, esofagitis eosinofílica y urticaria son tres manifestaciones clínicas de alergia a alimentos con diferente etiopatogénesis. Describimos el caso de una niña de 2 años de edad con síntomas digestivos, retraso del desarrollo póndero-estatural y asma persistente. Las pruebas cutáneas fueron positivas a varios alimentos. La endoscopia digestiva y biopsias mostraron signos de esofagitis eosinofílica y enfermedad celíaca. Realizó dieta exenta de gluten y de los alimentos a los que estaba sensibilizada y siguió tratamiento con corticoides orales un mes. A los 5 años de edad, la endoscopia digestiva alta y biopsias esofágicas fueron normales. Una dieta exenta de gluten es la base del tratamiento de la enfermedad celiaca. Sin embargo, el papel de las dietas de eliminación en la esofagitis eosinofílica no ha sido totalmente establecido. La paciente desarrolló además urticaria tras contacto con leche y huevo. Presentamos el primer caso de enfermedad celiaca, esofagitis eosinofi lica y alergia alimentaria mediada por IgE en el mismo pacient

Preliminary study of the adaptation of Senegalese sole Solea senegalensis Kaup, 1858 to different salinities

Osmoregulatory and metabolic effects of adaptation to different water salinities (5, 15, 25, 42 and 55) were assessed during a period of 14 days in juveniles of Senegalese sole Solea senegalensis Kaup, 1858. The results showed a good capacity to adapt within the range of water salinities tested. Gill Na+,K+-ATPase activity showed a direct lineal relationship with regard to water salinity, whereas kidney Na+,K+-ATPase activity did not change. Plasma osmolality and ions levels did not present differences among the groups. Plasma cortisol, glucose and lactate were higher in the group maintained in the highest water salinity.El crecimiento del lenguado senegalés Solea senegalensis Kaup, 1858 está influido por diferentes variables, y una de ellas es la salinidad ambiental. En este trabajo, se estudian los efectos osmorreguladores y metabólicos de la aclimatación a distintas salinidades (5, 15, 25, 42 y 55) durante un periodo de 14 días en juveniles de esta especie. La actividad Na+,K+-ATPasa branquial presentó una relación lineal directa respecto a la salinidad ambiental, mientras que la actividad Na+,K+-ATPasa renal no experimentó variación alguna. Ni la osmolalidad ni los niveles de iones plasmáticos analizados mostraron diferencias significativas entre los diferentes grupos. El cortisol y los niveles de glucosa y lactato plasmático aumentaron en los ejemplares adaptados a la mayor salinidad. Los resultados mostraron una buena capacidad de aclimatación en el rango de salinidades ambientales analizado.Instituto Español de Oceanografí

Experimental Observation of Differences in the Dynamic Response of Newtonian and Viscoelastic Fluids

In this paper we present an experimental study of the dynamic responses of a Newtonian fluid and a Maxwellian fluid under an oscillating pressure gradient. We use laser Doppler anemometry in order to determine the velocity of each fluid inside a cylindrical tube. In the case of the Newtonian fluid, the dissipative nature is observed and the response obeys the Zhou and Sheng universality (PRB 39, 12027 (1989)). In the dynamic response of the Maxwellian fluid an enhancement at the frequencies predicted by the corresponding theory (PRE 58, 6323 (1998)) is observed.Comment: 5 pages, 4 Figures, paper to be published in Phys. Rev.