A discrete epidemic model for bovine babesiosis disease and tick populations

In this paper, we provide and study a discrete model for the transmission of Babesiosis disease in bovine and tick populations. This model supposes a discretization of the continuous-time model developed by us previously. The results, here obtained by discrete methods as opposed to continuous ones, show that similar conclusions can be obtained for the discrete model subject to the assumption of some parametric constraints which were not necessary in the continuous case. We prove that these parametric constraints are not artificial and, in fact, they can be deduced from the biological significance of the model. Finally, some numerical simulations are given to validate the model and verify our theoretical study

Determinación de órganos diana para la multiplicación y persistencia del virus de la enfermedad de linfocistis (LCDV) en dorada (Sparus aurata, L.)

La enfermedad de linfocistis es la única patología de etiología viral descrita en dorada cultivada En la cuenca mediterr nea, la prevalencia es cercana al 100 , ocasionando graves p rdidas económicas debido a la imposibilidad de comercializar los peces afectados En el presente trabajo se ha abordado el estudio de la patog nesis del virus de la enfermedad de linfocistis (LCDV) en dorada, además se han establecido los órganos implicados en la multiplicación vírica Para ello, se ha diseñado un protocolo de hibridación in situ empleando sondas RNA marcadas con digoxigenina dirigidas contra el gen que codifica la proteína principal de la cápside (MCP) viral, y se ha evaluado en poblaciones de dorada. En paralelo, se ha procedido a la cuantificación del número de copias de genoma viral por PCR a tiempo real y cuantificación relativa de la transcripción del gen que codifica la MCP viral mediante qRT-PCR. Los resultados obtenidos indican que el LCDV establece una infección sistémica en alevines de dorada, pudiendo detectarse señal de hibridación tanto en órganos internos (hígado, bazo, riñón) como en músculo y aleta. También se han observado diversos daños histopatológicos en animales enfermos, mientras que en animales recuperados de la enfermedad estos daños parecen revertir, aunque en estos animales la infección persiste, si bien sólo a niveles detectables mediante PCR a tiempo real.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Metal-Controlled Magnetoresistance at Room Temperature in Single-Molecule Devices

The appropriate choice of the transition metal complex and metal surface electronic structure opens the possibility to control the spin of the charge carriers through the resulting hybrid molecule/metal spinterface in a single molecule electrical contact at room temperature. The single molecule conductance of a Au/molecule/Ni junction can be switched by flipping the magnetization direction of the ferromagnetic electrode. The requirements of the molecule include not just the presence of unpaired electrons: the electronic configuration of the metal center has to provide occupied or empty orbitals that strongly interact with the junction metal electrodes and that are close in energy to their Fermi levels for one of the electronic spins only. The key ingredient for the metal surface is to provide an efficient spin texture induced by the spin orbit coupling in the topological surface states that results in an efficient spin-dependent interaction with the orbitals of the molecule. The strong magnetoresistance effect found in this kind of single-molecule wire opens a new approach for the design of room-temperature nanoscale devices based on spin-polarized currents controlled at molecular level

Experimental investigation of a thermal storage system using phase change materials

A home-made heat exchanger (HE), used in the evaluation of the performance of different phase change materials (PCMs), was designed, mounted and operated. The HE unit was used as a heat thermal storage system for recovering the residual energy coming from a hydrogen cycle, which could be in turn used in building air-conditioning facilities. Four PCMs (Rubitherm® RT28, Rubitherm® RT48, Rubitherm® RT55 and Mikrocaps PCM35; the latter supplied as a slurry of microcapsules) was selected for their suitable thermal properties. Water was used as the heat transfer fluid (HTF) while the PCM was tightly stored inside the shell. Among all the studied PCMs, Rubitherm® RT48 presented the best thermal performance since it accumulated the maximum amount of energy. The influence of the HTF flow rate on the thermal performance of the shell and tube HE was also evaluated. Low HTF flow rates led to high values of heat transferred. Finally, different operation modes (watertight and countercurrent PCM flow) were compared by using Mikrocaps PCM35. PCM countercurrent flow system showed to be the best experimental set-up configuration system for energy transfer, reaching values of heat accumulation about 71% higher than that shown by the watertight mode.Se diseñó, montó y operó un intercambiador de calor casero (HE), utilizado en la evaluación del desempeño de diferentes materiales de cambio de fase (PCM). La unidad HE se utilizó como sistema de almacenamiento térmico de calor para recuperar la energía residual procedente de un ciclo de hidrógeno, que a su vez podría utilizarse en la construcción de instalaciones de aire acondicionado. Se seleccionaron cuatro PCM (Rubitherm® RT28, Rubitherm® RT48, Rubitherm® RT55 y Mikrocaps PCM35; este último suministrado como una suspensión de microcápsulas) por sus propiedades térmicas adecuadas. Se usó agua como fluido de transferencia de calor (HTF) mientras que el PCM se almacenó herméticamente dentro de la carcasa. Entre todos los PCM estudiados, Rubitherm® RT48 presentó el mejor desempeño térmico ya que acumuló la máxima cantidad de energía. También se evaluó la influencia del caudal de HTF en el rendimiento térmico de la carcasa y el tubo HE. Las bajas tasas de flujo de HTF condujeron a altos valores de transferencia de calor. Finalmente, se compararon diferentes modos de operación (flujo PCM estanco y contracorriente) utilizando Mikrocaps PCM35. El sistema de flujo a contracorriente PCM demostró ser el mejor sistema de configuración experimental para la transferencia de energía, alcanzando valores de acumulación de calor un 71% superiores a los mostrados por el modo estanco

Essential role of protein tyrosine phosphatase 1B in obesity-induced inflammation and peripheral insulin resistance during aging

Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin signaling and a therapeutic target for type 2 diabetes (T2DM). In this study, we have evaluated the role of PTP1B in the development of aging-associated obesity, inflammation, and peripheral insulin resistance by assessing metabolic parameters at 3 and 16 months in PTP1B) ⁄ ) mice maintained on mixed genetic background (C57Bl ⁄ 6J · 129Sv ⁄ J). Whereas fat mass and adipocyte size were increased in wild-type control mice at 16 months, these parameters did not change with aging in PTP1B) ⁄ ) mice. Increased levels of pro-inflammatory cytokines, crown-like structures, and hypoxia-inducible factor (HIF)-1a wereobserved only in adipose tissue from 16-month-old wild-type mice. Similarly, islet hyperplasia and hyperinsulinemia were observed in wild-type mice with agingassociated obesity, but not in PTP1B) ⁄ ) animals. Leanness in 16- month-old PTP1B) ⁄ ) mice was associated with increased energy expenditure. Whole-body insulin sensitivity decreased in 16- month-old control mice; however, studies with the hyperinsulinemic– euglycemic clamp revealed that PTP1B deficiency prevented this obesity-related decreased peripheral insulin sensitivity. At a molecular level, PTP1B expression and enzymatic activity were upregulated in liver and muscle of 16-month-old wild-type mice as were the activation of stress kinases and the expression of p53. Conversely, insulin receptor-mediated Akt ⁄ Foxo1 signaling was attenuated in these aged control mice. Collectively, these data implicate PTP1B in the development of inflammation and insulin resistance associated with obesity during aging and suggest that inhibition of this phosphatase by therapeutic strategies might protect against age-dependentT2DMThis work was supported by grants from Ministerio de Ciencia e Innovación (Spain) SAF2009-08114 and (to A.M.V.), BFU2008- 04901-C03-02 and 03 (to M.R and J.M.C., respectively), BFU2008-01283 (to M.V), Comunidad de Madrid S2010/BMD- 2423 and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM) (Instituto Salud Carlos III). CBMSO is recipient of institutional aid from Ramón Areces Foundation. We also acknowledge grants NIH-R01 DK080756, ADA 7-07-RA-80, and NIH U24-DK093000 (to J.K.K.) and UMass Mouse Phenotyping Center supported by UMass Diabetes and Endocrinology Research Center Grant (DK32520) and EFSD/Amylin Programme 2011 grant (to A.M.V.)

Alfonso Roque Albanese: Latin American Pioneer of Heart Surgery. Tribute from the Pan American Association of Anatomy

Alfonso Roque Albanese (1906-2005) is considered a pioneer of Latin American heart surgery because of his important contributions. He was founding member of the Pan American Association of Anatomy. Researcher and teacher of anatomy and surgery, joining both disciplines.Asociac Panamer Anat, Mexico City, DF, MexicoAcad Panamer Anat AcPA, Mexico City, DF, MexicoUniv Salvador USAL, Fac Med, Buenos Aires, DF, ArgentinaUniv Costa Rica, Fac Med, San Jose, Costa RicaUniv Fed São Paulo UNIFESP, Fac Med, São Paulo, BrazilUniv Chile UCh, Fac Med, Santiago, ChileUniv São Paulo, ICB, Sao Pablo, BrazilUniv Nacl Autonoma Mexico, Fac Med, Mexico City, DF, MexicoUniv Fed São Paulo UNIFESP, Fac Med, São Paulo, BrazilWeb of Scienc

A multiplex qPCR approach for detection of pfhrp2 and pfhrp3 gene deletions in multiple strain infections of Plasmodium falciparum

The rapid and accurate diagnosis of Plasmodium falciparum malaria infection is an essential factor in malaria control. Currently, malaria diagnosis in the field depends heavily on using rapid diagnostic tests (RDTs) many of which detect circulating parasite-derived histidine-rich protein 2 antigen (PfHRP2) in capillary blood. P. falciparum strains lacking PfHRP2, due to pfhrp2 gene deletions, are an emerging threat to malaria control programs. The novel assay described here, named qHRP2/3-del, is well suited for high-throughput screening of P. falciparum isolates to identify these gene deletions. The qHRP2/3-del assay identified pfhrp2 and pfhrp3 deletion status correctly in 93.4% of samples with parasitemia levels higher than 5 parasites/µL when compared to nested PCR. The qHRP2/3-del assay can correctly identify pfhrp2 and pfhrp3 gene deletions in multiple strain co-infections, particularly prevalent in Sub-Saharan countries. Deployment of this qHRP2/3-del assay will provide rapid insight into the prevalence and potential spread of P. falciparum isolates that escape surveillance by RDTs

A Customized Pigmentation SNP Array Identifies a Novel SNP Associated with Melanoma Predisposition in the SLC45A2 Gene

As the incidence of Malignant Melanoma (MM) reflects an interaction between skin colour and UV exposure, variations in genes implicated in pigmentation and tanning response to UV may be associated with susceptibility to MM. In this study, 363 SNPs in 65 gene regions belonging to the pigmentation pathway have been successfully genotyped using a SNP array. Five hundred and ninety MM cases and 507 controls were analyzed in a discovery phase I. Ten candidate SNPs based on a p-value threshold of 0.01 were identified. Two of them, rs35414 (SLC45A2) and rs2069398 (SILV/CKD2), were statistically significant after conservative Bonferroni correction. The best six SNPs were further tested in an independent Spanish series (624 MM cases and 789 controls). A novel SNP located on the SLC45A2 gene (rs35414) was found to be significantly associated with melanoma in both phase I and phase II (P<0.0001). None of the other five SNPs were replicated in this second phase of the study. However, three SNPs in TYR, SILV/CDK2 and ADAMTS20 genes (rs17793678, rs2069398 and rs1510521 respectively) had an overall p-value<0.05 when considering the whole DNA collection (1214 MM cases and 1296 controls). Both the SLC45A2 and the SILV/CDK2 variants behave as protective alleles, while the TYR and ADAMTS20 variants seem to function as risk alleles. Cumulative effects were detected when these four variants were considered together. Furthermore, individuals carrying two or more mutations in MC1R, a well-known low penetrance melanoma-predisposing gene, had a decreased MM risk if concurrently bearing the SLC45A2 protective variant. To our knowledge, this is the largest study on Spanish sporadic MM cases to date