9,888 research outputs found
Is emamectin benzoate effective against the different stages of Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae)?
peer-reviewedThis work was partially supported by the Spanish Ministry of Science and Innovation (project AGL 2007-66130-C03-02 to P. Medina). F. Amor and P. Bengochea acknowledge the ministry of Education
and Culture and the Technical University of Madrid (UPM) for the doctoral fellowships. Special thanks to Syngenta Agro S.A. for their support.The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae), is a major
polyphagous pest in greenhouses and open fields worldwide and also a main problem
in sweet pepper greenhouses. The effectiveness of the pesticide emamectin benzoate was tested in the laboratory on different stages of S. exigua using different concentrations and uptake routes. After dipping young (48-h-old) S. exigua eggs in emamectin benzoate at 0.5, 1 and 1.5 mg/L a.i. the chemical did not exhibit any ovicidal activity. There was, however, progressive neonate mortality at all concentrations,
culminating at 72 hours after hatching, when 100% of the larvae from the treated young
eggs died. Second and fourth instar S. exigua larvae did not exhibit significant mortality when exposed to the inert surfaces which were treated. In contrast, ingesting a diet contaminated with 0.5 mg/L a.i. of emamectin benzoate caused 100% mortality in L2 and L4 larvae 24 and 72 hours after ingestion, respectively. The LC50 value of the compound against L4 larvae that fed on sprayed sweet pepper leaves for 24 hours was 0.81 mg/L a.i..
When adults were fed on a solution of 0.5 mg/L a.i., there was a reduction in the female and male lifespan of 29.3% and 55.3%, respectively. Fecundity was reduced by more than 99%. These data suggest that emamectin benzoate is not only a useful insecticide when ingested by beet armyworm larvae but it also has ovolarvicidal and adult activity.Spanish Ministry of Science and Innovatio
Spotting the differences between active and non-active twin galaxies on kpc-scales. A pilot study
We present a pilot study aimed to identify large-scale galaxy properties that
could play a role in activating a quiescent nucleus. To do so, we compare the
properties of two isolated nearby active galaxies and their non-active twins
selected from the Calar Alto Legacy Integral Field Area (CALIFA) survey. This
pilot sample includes two barred and two unbarred galaxies. We characterise the
stellar and ionised gas kinematics and also their stellar content. We obtain
simple kinematic models by fitting the full stellar and ionised gas velocity
fields and just the approaching/receding sides. We find that the analysed
active galaxies present lopsided disks and higher values of the global stellar
angular momentum () than their non-active twins. This could be
indicating that the stellar disks of the AGN gained angular momentum from the
inflowing gas that triggered the nuclear activity. The inflow of gas could have
been produced by a twisted disk instability in the case of the unbarred AGN,
and by the bar in the case of the barred AGN. In addition, we find that the
central regions of the studied active galaxies show older stellar populations
than their non-active twins. The next step is to statistically explore these
galaxy properties in a larger sample of twin galaxies.Comment: 24 pages, 24 figures. Accepted by MNRA
The potential of hematopoietic growth factors for treatment of Alzheimer's disease: a mini-review
There are no effective interventions that significantly forestall or reverse neurodegeneration and cognitive decline in Alzheimer's disease. In the past decade, the generation of new neurons has been recognized to continue throughout adult life in the brain's neurogenic zones. A major challenge has been to find ways to harness the potential of the brain's own neural stem cells to repair or replace injured and dying neurons. The administration of hematopoietic growth factors or cytokines has been shown to promote brain repair by a number of mechanisms, including increased neurogenesis, anti-apoptosis and increased mobilization of bone marrow-derived microglia into brain. In this light, cytokine treatments may provide a new therapeutic approach for many brain disorders, including neurodegenerative diseases like Alzheimer's disease. In addition, neuronal hematopoietic growth factor receptors provide novel targets for the discovery of peptide-mimetic drugs that can forestall or reverse the pathological progression of Alzheimer's disease
Improved methods for detection of β-galactosidase (lacZ) activity in hard tissue
The ß-galactosidase gene (lacZ) of Escherichia coli is widely used as a reporter gene. The expression of lacZ can be detected by enzyme-based histochemical staining using chromogenic substrates such as 5-bromo-4-chloro-3-indolyl-ß-D: -galactoside (X-gal). Because the enzymatic activity of lacZ is vulnerable to high temperatures and acid treatment for demineralization, detection of lacZ on paraffinized sections is difficult, especially for hard tissues, which require demineralization before sectioning in paraffin. To circumvent this problem, whole-mount X-gal staining before sectioning is performed. However, detection of lacZ activity in the center of larger portions of hard whole adult tissues is challenging. In this study, focusing on fixation procedures, we determined the conditions conducive to improved detection of lacZ activity in deeper areas of whole tissues. We used an annexin a5 (Anxa5)-lacZ reporter mouse model in which the Anxa5 expression in hard tissue is indicated by lacZ activity. We found that lacZ activity could be detected throughout the periodontal ligament of adult mice when fixed in 100% acetone, whereas it was not detected in the periodontal ligament around the root apex fixed in glutaraldehyde and paraformaldehyde. This staining could not be detected in wild-type mice. Acetone maintains the lacZ activity within 48 h of fixation at both 4°C and at room temperature. In conclusion, acetone is the optimal fixative to improve permeability for staining of lacZ activity in large volumes of adult hard tissues
Pharmacokinetics evaluation of nimotuzumab in combination with doxorubicin and cyclophosphamide in patients with advanced breast cancer
EGFr (Epidermal growth factor receptor) overexpression has been detected in many tumors of epithelial origin, specifically in breast cancer and it is often associated with tumor growth advantages and poor prognosis. The nimotuzumab is a genetically engineered humanized MAb (monoclonal antibody) that recognizes an epitope located in the extracellular domain of human EGFr. The aim of this study was to assess the pharmacokinetics of nimotuzumab in patients with locally advanced breast cancer who are receiving neoadyuvant therapy combined with the AC chemotherapy regimen (i.e., 60 mg/m2 of Doxorubicin and 600 mg/m2 of Cyclophosphamide in 4 cycles every 21 days). A single center, non-controlled, open Phase I clinical trial, with histopathological diagnosis of locally advanced stage III breast cancer, was conducted in 12 female patients. Three patients were enrolled at each of the following fixed dose levels: 50, 100, 200 and 400 mg/week. Multiple intermittent short-term intravenous infusions of nimotuzumab were administered weekly, except on weeks 1 and 10, when blood samples were drawn for pharmacokinetic assessments. Nimotuzumab showed dose-dependent kinetics. No anti-idiotypic response against nimotuzumab was detected in blood samples of participants. There was not interaction between the administration of nimotuzumab and chemotherapy at the dose levels studied. The optimal biological doses ranging were estimated to be 200 mg/weekly to 400 mg/weekly
Spinor-Vector Duality in Heterotic String Orbifolds
The three generation heterotic-string models in the free fermionic
formulation are among the most realistic string vacua constructed to date,
which motivated their detailed investigation. The classification of free
fermion heterotic string vacua has revealed a duality under the exchange of
spinor and vector representations of the SO(10) GUT symmetry over the space of
models. We demonstrate the existence of the spinor-vector duality using
orbifold techniques, and elaborate on the relation of these vacua to free
fermionic models.Comment: 20 pages. v2 minor corrections. Version to appear on JHEP. v3
misprints correcte
Nuevos fármacos antiepilépticos en PediatrÃa
Se estima que unos 70 millones de personas padecen epilepsia a nivel mundial de los cuales más de la mitad son niños, en los que la prevalencia estimada se sitúa en torno al 0,5-0,8%. Aunque existen diversas terapias, el tratamiento de la epilepsia se basa mayoritariamente en fármacos, que en función de su año de comercialización se clasifican como de primera, segunda o tercera generación. En el presente artÃculo se revisan las principales caracterÃsticas de los fármacos antiepilépticos de última generación (lacosamida, acetato de eslicarbazepina, brivaracetam, perampanel, retigabina, everolimus y cannabidiol) que, con excepción de la retigabina (ya no está comercializada), se consideran seguros y efectivos en población pediátrica. El everolimus y el cannabidiol tienen indicaciones muy concretas (esclerosis tuberosa, sÃndrome de Dravet y sÃndrome de Lennox Gastaut) mientras que el resto están indicados en el manejo de crisis de origen focal en niños a partir de 4 años. Estas nuevas moléculas han sido desarrolladas para aportar un perfil farmacocinético y de tolerancia superior a los fármacos previamente disponibles y es previsible que a medida que aumente su uso, se vaya perfilando y ampliando su verdadero potencial. Además, por primera vez en epileptologÃa pediátrica, se ha utilizado la extrapolación de datos de efectividad en adultos (junto con estudios de seguridad y farmacocinética especÃficos en población pediátrica), para acelerar la aprobación de uso en población infantil.It is estimated that about 70 million people all over the world suffer from epilepsy, half of which are children, in whom the prevalence is around 0.5 to 0.8%. Although there are several therapies, the treatment of epilepsy is based mainly on drugs, which, depending on the year of coming onto the market are classified as first, second, or third generation. In this article, a description is presented on the main characteristics of the latest generation of antiepileptic drugs (lacosamide, eslicarbazepine acetate, brivaracetam, perampanel, retigabine, everolimus and cannabidiol). These, with the exception of retigabine (is not yet on the market), are considered safe and effective in the paediatric population. Everolimus and cannabidiol have very specific indications (tuberous sclerosis, Dravet syndrome, and Lennox Gastaut syndrome), while the rest are indicated in the management of seizures of focal origin in children from 4 years-old. These new molecules have been developed in order to provide a pharmaceutical profile and tolerance superior to the previously available drugs, and it is forecast that as their use increases, their true potential and profile will widen. Furthermore, for the first time in Paediatric Epileptology,the extrapolation ofthe efficacy data in adults have been used (together with specific safety and pharmacokinetic studies in the paediatric population), in order to speed up their approval for use in the child population
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