418 research outputs found
Factors associated with postharvest ripening heterogeneity of "Hass" avocados (Persea americana Mill)
Indexación: Web of ScienceIntroduction. 'Hass' is the main avocado cultivar commercialized worldwide. The extended flowering period, very low percentage of fruit set and inability to ripen on the tree renders the fruit heterogeneous and unpredictable during postharvest management. The "triggered" and "ready-to-eat" growing markets for 'Hass' avocados are affected by the variable postharvest ripening or ripening heterogeneity which creates severe logistical problems for marketers and inconsistent quality delivery to consumers. Synthesis. The dry matter content, the current avocado harvest index that correlates very well with oil content, has been extensively used to harvest 'Hass' avocados to comply with the minimum standards to guarantee consumer satisfaction. However, previous work and empirical experience demonstrate that dry matter does not correlate on a fruit-to-fruit basis with time to reach edible ripeness. Thus, avocados of very different ages are harvested from individual trees, resulting in heterogeneous postharvest ripening of fruit within a specific batch. Several preharvest factors related to environmental and growing conditions and crop management as well as postharvest technology strategies influence the observed variability of postharvest ripening. Conclusion. Modern approaches based on studying the composition of individual fruits displaying contrasting postharvest ripening behavior, combined with non-destructive phenotyping techniques, seem to offer practical solutions for the fresh supply chain of avocados to sort fruit based on their ripening capacity.http://www.pubhort.org/fruits/2016/5/fruits160045.ht
Neuroprotective effects of EpoL against oxidative stress induced by soluble oligomers of Aβ peptide
Erythropoietin is a glycoproteic hormone that regulates hematopoiesis by acting on its specific receptor (EpoR). The expression of EpoR in the central nervous system (CNS) suggests a role for this hormone in the brain. Recently, we developed a new Epo variant without hematopoietic activity called EpoL, which showed marked neuroprotective effects against oxidative stress in brain ischemia related models. In this study, we have evaluated the neuroprotective effects of EpoL against oxidative stress induced by chronic treatment with Aβ. Our results show that EpoL was neuroprotective against Aβ-induced toxicity by a mechanism that implicates EpoR, reduction in reactive oxygen species, and reduction in astrogliosis. Furthermore, EpoL treatment improved calcium handling and SV2 levels. Interestingly, the neuroprotective effect of EpoL against oxidative stress induced by chronic Aβ treatment was achieved at a concentration 10 times lower than that of Epo. In conclusion, EpoL, a new variant of Epo without hematopoietic activity, is of potential interest for the treatment of diseases related to oxidative stress in the CNS such as Alzheimer disease.Grant Innova-Corfo “13IDL2-18688”; Conicyt Grant “Beca Doctorado Nacional no. 21130386”; Fondecyt Grant “1161078
Interferencia del Herpesvirus equino 1 (EHV-1) en la apoptosis inducida
La apoptosis es un tipo de muerte celular programada que puede ser desencadenada por múltiples factores, tanto internos como externos; dentro de estos últimos se encuentran las infecciones virales.
Algunos alphaherpesvirus han desarrollado diversas estrategias para retardar o inhibir la muerte celular obteniendo, de esta manera, su propio beneficio al poder permanecer durante más tiempo en la célula.
Hasta el momento no se ha identificado ningún mecanismo relacionado con la modulación de la muerte celular durante la infección con Herpesvirus equino tipo 1 (EHV-1). El objetivo del presente trabajo fue describir el efecto producido por la infección con EHV-1 sobre cultivos celulares inducidos a la muerte por apoptosis. La evaluación de la apoptosis se realizó mediante el reconocimiento de la fragmentación en escalera del ADN, la evaluación de la relación Anexina V/ioduro de propidio (IP) y la determinación del clivaje de la citoqueratina 18, utilizando técnicas de inmunofluorescencia. Los resultados indican una posible interferencia del EHV-1 con la muerte por apoptosis hacia la mitad de su ciclo de replicación, que se incrementa hacia el final del mismo.Apoptosis is a programmed cell death that can be triggered by many factors, both internal and external. Viral infections are included among the latter. Some alphaherpesvirus have developed several strategies to retard or inhibit cell death and thus the virus benefits itself by staying longer in the cell. So far, no mechanisms have been identified related to modulation of cell death during infection with equine herpesvirus type 1 (EHV-1). The aim of the present study was to describe the effect produced by the infection with EHV-1 on apoptosis-induced cell cultures. Assessment of apoptosis was performed by DNA laddering, the Annexin V/propidium iodide (PI) determination and the cytokeratin 18 cleavage analysis using immunofluorescence techniques. Results indicate a possible interference of EHV-1 with apoptotic cell death in the middle of its replication cycle, being increased by its end
Características biológicas de cepas de Herpesvirus bovino 1 y 5 utilizando el modelo experimental conejo
Los Herpesvirus bovinos (BoHV) pueden infectar tanto a mustélidos como a conejos y esta última especie ha sido utilizada como modelo de laboratorio para la infección por BoHV-1 y 5. El objetivo de este trabajo fue estudiar la patogenicidad de diferentes cepas argentinas de BoHV-1 y BoHV-5 utilizando el modelo experimental conejo. Se utilizaron conejos de raza neozelandesa que se inocularon por vía intranasal e intravaginal. Los animales inoculados por vía intranasal con cepas de BoHV-5 desarrollaron signos nerviosos en el 83% de los casos, mientras que BoHV-1.1 causó signos nerviosos en el 57% de los animales y BoHV-1.2 no provocó signos clínicos evidentes. El BoHV-5 causó síntomas nerviosos solo en los animales jóvenes mientras que BoHV-1 solo lo hizo ocasionalmente y también en individuos jóvenes. Los conejos inoculados por vía intravaginal no mostraron signos clínicos ni lesiones aparentes en los órganos estudiados; la infección se demostró por seroconversión serológica.
El conejo resultó adecuado para estudiar la sintomatología y las lesiones producidas en los distintos órganos, fundamentalmente en el sistema nervioso central. El modelo resultó de utilidad por ser económico, de muy fácil manejo y permitió reconocer diferencias en el comportamiento biológico de las cepas de BoHV-1 y BoHV-5 estudiadas.Bovine Herpesvirus (BoHV) can infect both rabbits and mustelids. Rabbit has been used as a laboratory model for infection with BoHV-1 and 5. The objective of this research was to study the pathogenicity of different Argentinian BoHV-1 and BoHV-5 strains by using the rabbit experimental model.
New Zealand rabbits were inoculated by intranasal and intravaginal ways. The animals inoculated intranasally with strains of BoHV-5 developed neurological signs in 83% of the cases. BoHV-1.1 caused neurological signs in 57% of the animals and BoHV-1.2 did not cause clear clinical signs.
BoHV-5 caused nervous signs in young animals while BoHV-1 did so occasionally in young rabbits.
Animales inoculated intravaginally showed no apparent clinical signs or apparent lesions in the studied organs. The infection was demonstrated by serological seroconversion. The rabbit was appropriate to study the clinical signs and the lesions produced in the different organs, primarily in the central nervous system. The model was useful for being inexpensive and very easy to use, and it enabled to identify differences in the biological behavior of the studied BoHV-1 and BoHV-5 strains
Correlation effects in MgO and CaO: Cohesive energies and lattice constants
A recently proposed computational scheme based on local increments has been
applied to the calculation of correlation contributions to the cohesive energy
of the CaO crystal. Using ab-initio quantum chemical methods for evaluating
individual increments, we obtain 80% of the difference between the experimental
and Hartree-Fock cohesive energies. Lattice constants corrected for correlation
effects deviate by less than 1% from experimental values, in the case of MgO
and CaO.Comment: LaTeX, 4 figure
Rotating Higher Spin Partition Functions and Extended BMS Symmetries
We evaluate one-loop partition functions of higher-spin fields in thermal
flat space with angular potentials; this computation is performed in arbitrary
space-time dimension, and the result is a simple combination of Poincar\'e
characters. We then focus on dimension three, showing that suitable products of
one-loop partition functions coincide with vacuum characters of higher-spin
asymptotic symmetry algebras at null infinity. These are extensions of the
bms_3 algebra that emerges in pure gravity, and we propose a way to build their
unitary representations and to compute the associated characters. We also
extend our investigations to supergravity and to a class of gauge theories
involving higher-spin fermionic fields.Comment: 58 pages; clarifications and references added; version to be
published in JHE
Glycogen Synthase Kinase (GSK) 3β phosphorylates and protects nuclear myosin 1c from proteasome-mediated degradation to activate rDNA transcription in early G1 cells
Nuclear myosin 1c (NM1) mediates RNA polymerase I (pol I) transcription activation and cell cycle progression by facilitating PCAF-mediated H3K9 acetylation, but the molecular mechanism by which NM1 is regulated remains unclear. Here, we report that at early G1 the glycogen synthase kinase (GSK) 3β phosphorylates and stabilizes NM1, allowing for NM1 association with the chromatin. Genomic analysis by ChIP-Seq showed that this mechanism occurs on the rDNA as active GSK3β selectively occupies the gene. ChIP assays and transmission electron microscopy in GSK3β-/- mouse embryonic fibroblasts indicated that at G1 rRNA synthesis is suppressed due to decreased H3K9 acetylation leading to a chromatin state incompatible with transcription. We found that GSK3β directly phosphorylates the endogenous NM1 on a single serine residue (Ser-1020) located within the NM1 C-terminus. In G1 this phosphorylation event stabilizes NM1 and prevents NM1 polyubiquitination by the E3 ligase UBR5 and proteasome-mediated degradation. We conclude that GSK3β-mediated phosphorylation of NM1 is required for pol I transcription activation
Use of rotary kilns for solar thermal applications: Review of developed studies and analysis of their potential
Rotary kilns have a long history of use in classical industries. They are able to achieve high temperatures with higher thermal efficiencies than other reactor types. Their performance has been widely studied and classified according to different parameters. Since it is a well-known technology, rotary kilns have been selected for high temperature solar processes. This article initially presents a brief review of the rotary kiln technology and it focuses on the employment of these devices for thermal and thermochemical processes conducted by concentrating solar energy. Among the solar devices, a novel rotary kiln prototype for thermochemical processes is presented and compared with a static solar reactor. Finally, some practical conclusions on the design and operation of solar rotary kilns are remarked and an analysis of their main limitations is presented.The authors acknowledge the financial support provided by the
FONDECYT project number 3150026 of CONICYT (Chile), the Education Ministry of Chile Grant PMI ANT 1201, as well as CONICYT/FONDAP/ 15110019 ‘‘Solar Energy Research Center” SERC-Chile.
Also, the second author wish to thank to the Plataforma Solar de
Almería and the University of Almería for the collaboration and
assistance devoted to the development of his Ph.D research
Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF
M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe
- …
