Clock spectroscopy of interacting bosons in deep optical lattices

We report on high-resolution optical spectroscopy of interacting bosonic $^{174}$Yb atoms in deep optical lattices with negligible tunneling. We prepare Mott insulator phases with singly- and doubly-occupied isolated sites and probe the atoms using an ultra-narrow "clock" transition. Atoms in singly-occupied sites undergo long-lived Rabi oscillations. Atoms in doubly-occupied sites are strongly affected by interatomic interactions, and we measure their inelastic decay rates and energy shifts. We deduce from these measurements all relevant collisional parameters involving both clock states, in particular the intra- and inter-state scattering lengths

Reiter syndrome following protracted symptoms of Cyclospora infection.

Two large outbreaks of diarrheal illness associated with Cyclospora cayetanensis, a coccidian parasite, provided an opportunity to evaluate clinical syndromes associated with this enteric pathogen. Reiter syndrome, a triad of ocular inflammation, inflammatory oligoarthritis, and sterile urethritis, has been associated with enteric infections. We describe the first case of Reiter syndrome following protracted symptoms of Cyclospora infection

Use of a new proximity assay (NanoBRET) to investigate the ligand binding characteristics of three fluorescent ligands to the human β1-adrenoceptor expressed in HEK-293 cells

Previous research has indicated that allosteric interactions across the dimer interface of β1-adrenoceptors may be responsible for a secondary low affinity binding conformation. Here we have investigated the potential for probe dependence, in the determination of antagonist pKi values at the human β1-adenoceptor, which may result from such allosterism interactions. Three fluorescent β1-adrenoceptor ligands were used to investigate this using bioluminescence energy transfer (BRET) between the receptor-bound fluorescent ligand and the N-terminal NanoLuc tag of a human β1-adrenoceptor expressed in HEK 293 cells (NanoBRET). This proximity assay showed high affinity specific binding to the NanoLuc-β1-adrenoceptor with each of the three fluorescent ligands yielding KD values of 87.1 ± 10nM (n=8), 38.1 ± 12nM (n=7), 13.4 ± 2nM (n=14) for propranolol-Peg8-BY630, propranolol-3(Ala-Ala)-BY630 and CGP-12177- TMR respectively. Parallel radioligand-binding studies with 3H-CGP12177 and TIRF microscopy, to monitor NanoLuc bioluminescence, confirmed a high cell surface expression of the NanoLuc- 31-adrenoceptor in HEK 293 cells (circa 1500 fmol.mg protein-1). Following a 1h incubation with fluorescent ligands and β1-adrenoceptor competing antagonists, there were significant differences (p < 0.001) in the pKi values obtained for CGP20712a and CGP 12177 with the different fluorescent ligands and 3H-CGP 12177. However, increasing the incubation time to 2h removed these significant differences. The data obtained show that the NanoBRET assay can be applied successfully to study ligand-receptor interactions at the human β1-adrenoceptor. However, the study also emphasizes the importance of ensuring that both the fluorescent and competing ligands are in true equilibrium before interpretations regarding probe dependence can be made

Probe dependence of allosteric enhancers on the binding affinity of adenosine A1‐receptor agonists at rat and human A1‐receptors measured using NanoBRET

Background and Purpose: Adenosine is a local mediator that regulates a number of physiological and pathological processes via activation of adenosine A1‐receptors. The activity of adenosine can be regulated at the level of its target receptor via drugs that bind to an allosteric site on the A1‐receptor. Here, we have investigated the species and probe dependence of two allosteric modulators on the binding characteristics of fluorescent and nonfluorescent A1‐receptor agonists. Experimental Approach: A Nano‐luciferase (Nluc) BRET (NanoBRET) methodology was used. This used N‐terminal Nluc‐tagged A1‐receptors expressed in HEK293T cells in conjunction with both fluorescent A1‐receptor agonists (adenosine and NECA analogues) and a fluorescent antagonist CA200645.Key Results: PD 81,723 and VCP171 elicited positive allosteric effects on the binding affinity of orthosteric agonists at both the rat and human A1‐receptors that showed clear probe dependence. Thus, the allosteric effect on the highly selective partial agonist capadenoson was much less marked than for the full agonists NECA, adenosine, and CCPA in both species. VCP171 and, to a lesser extent, PD 81,723, also increased the specific binding of three fluorescent A1‐receptor agonists in a species‐dependent manner that involved increases in Bmax and pKD.Conclusions and Implications: These results demonstrate the power of the NanoBRET ligand‐binding approach to study the effect of allosteric ligands on the binding of fluorescent agonists to the adenosine A1‐receptor in intact living cells. Furthermore, our studies suggest that VCP171 and PD 81,723 may switch a proportion of A1‐receptors to an active agonist conformation (R*)

Selection of rice cultivars resistant to some pathogens using seed health testing

Trinta e seis progênies de arroz (Oryza sativa L) irrigado foram testadas, em campo, objetivando-se determinar os fungos mais importantes de sementes e o desempenho das progênies com relação a esses patógenos, dando-se ênfase especial à descoloração e consequente perda de peso de sementes. Observaram-se diferenças significativas entre progênies quanto à presença de sete fungos de sementes. Entretanto, considerando-se a descoloração e a consequente perda de peso de sementes, Rhynchosporium oryzae, Phoma spp., Trichoconis padwickii e Helminthosporium oryzae se apresentaram como patógenos mais nocivos. Em todos os parâmetros analisados, sete progênies suplantaram a cultivar comercial IAC-899, usada como controle. Conclui-se que, apesar de trabalhoso, o teste de sanidade de sementes é um instrumento muito eficaz na seleção de novos germoplasmas de arroz com baixa incidência de fungos de sementes.Thirty-six lowland rice (Oryza sativa L.) progenies have been tested in yield trials aiming at determining the most important seed-borne fungi and the progeny performance as to each of the pathogens found in seeds, with special emphasis on seed discoloration and consequent seed weight loss. Significant progeny differences as to seven seed-born fungi have been found; however, as far as seed discoloration and consequent seed weight loss are concerned, Rhynchosporium oryzae, Phoma spp., Trichoconis padwickii and Helminthosporium oryzae have been the most important pathogens. Seven progenies outperformed IAC-899 (commercial variety used as control) regarding all the parameters analysed. It is concluded that seed health testing is an effective complementary 1001 in selecting rice germplasms with lower seed-borne fungal incidence

Two QTLs govern the resistance to Sclerotinia minor in an interspecific peanut RIL population

Sclerotinia blight is a soilborne disease caused by Sclerotinia minor Jagger and can produce severe decrease in yield. Cultural management strategies and chemical treatment are not completely effective; therefore, growing peanut-resistant varieties is likely to be the most effective control method for this disease. Sclerotinia blight resistance has been identified in wild Arachis species and further transferred to peanut elite cultivars. To identify the genome regions conferring Sclerotinia blight resistance within a tetraploid genetic background, this study evaluated a population of recombinant inbred lines (RIL) with introgressed genes from three wild diploid species: A. cardenasii, A. correntina, and A. batizocoi. Two consistent quantitative trait loci (QTLs), qSbIA04 and qSbIB04 located on chromosomes A04 and B04, respectively, were identified. The QTL qSbIA04 was mapped at 56.39 cM explaining 29% of the phenotypic variance and qSbIB04 was mapped at 13.38 cM explaining 22% of the overall phenotypic variance

Introgression of peanut smut resistance from landraces to elite peanut cultivars (\u3ci\u3eArachis hypogaea\u3c/i\u3e L.)

Smut disease caused by the fungal pathogen Thecaphora frezii Carranza & Lindquist is threatening the peanut production in Argentina. Fungicides commonly used in the peanut crop have shown little or no effect controlling the disease, making it a priority to obtain peanut varieties resistant to smut. In this study, recombinant inbred lines (RILs) were developed from three crosses between three susceptible peanut elite cultivars (Arachis hypogaea L. subsp. hypogaea) and two resistant landraces (Arachis hypogaea L. subsp. fastigiata Waldron). Parents and RILs were evaluated under high inoculum pressure (12000 teliospores g-1 of soil) over three years. Disease resistance parameters showed a broad range of variation with incidence mean values ranging from 1.0 to 35.0% and disease severity index ranging from 0.01 to 0.30. Average heritability (h2) estimates of 0.61 to 0.73 indicated that resistance in the RILs was heritable, with several lines (4 to 7 from each cross) showing a high degree of resistance and stability over three years. Evidence of genetic transfer between genetically distinguishable germplasm (introgression in a broad sense) was further supported by simple-sequence repeats (SSRs) and Insertion/Deletion (InDel) marker genotyping. This is the first report of smut genetic resistance identified in peanut landraces and its introgression into elite peanut cultivars

Identificación de Germoplasma de maní de criadero el Carmen tolerante a la sequia: aspectos bioquímicos y rendimiento

PosterLa sequía estacional es un estrés ambiental que genera pérdidas de rendimiento de alrededor del 30% en el cultivo de maní (Arachis hypogaea) en la Provincia de Córdoba. Una de las estrategias para reducirlas es el desarrollo de nuevas variedades comerciales con mayor tolerancia a la sequía. Desde el año 2016 se está desarrollando un sistema de identificación de materiales tolerantes a sequía provenientes de la colección de germoplasma de Criadero El Carmen, empleando un método estandarizado bajo condiciones controladas, que reduce los tiempos de evaluación al realizarse en etapa vegetativa. Se emplean las respuestas relacionadas al balance osmótico y la fotosíntesis como marcadores fisiológicos que permiten monitorear la tolerancia de los materiales de interés. Previamente, se evaluaron diferentes parámetros bioquímicos registrados en distintos ensayos mediante un análisis de componentes principales (PCA), lo que permitió determinar que los contenidos de prolina, carotenoides y azucares están asociados a una mayor tolerancia a la sequía en estadios tempranos del desarrollo vegetativo. El proyecto tiene como objetivo identificar germoplasma de maní tolerante a la sequía mediante un sistema estandarizado rápido a emplearse en etapas vegetativas bajo condiciones controladas y su validación posterior en la etapa reproductiva.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Guzzo, María Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Posada, G. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Costamagna, C. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Soave, S.J. Criadero El Carmen. Gral. Cabrera, Córdoba; ArgentinaFil: Soave, J.H. Criadero El Carmen. Gral. Cabrera, Córdoba; ArgentinaFil: Buteler, M.I. Criadero El Carmen. Gral. Cabrera, Córdoba; ArgentinaFil: Monteoliva, Mariela Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Monteoliva, Mariela Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); Argentin