Evaluation of Siderophores Generated by Pseudomonas Bacteria and Their Possible Application as Fe Biofertilizers.

The application of synthetic iron chelates to overcome iron deficiency in crops is leading to a high impact on the environment, making it necessary to find more friendly fertilizers. A promising alternative is the application of biodegradable iron chelates, such as those based on siderophores. In the present work, seven bacterial strains of the genus Pseudomonas were selected for their ability to secrete pyoverdine, a siderophore with a high affinity for iron, which could be used as a biofertilizer. The concentration of siderophores secreted by each bacterium expressed as desferrioxamine B equivalents, and the pyoverdine concentration was determined. Their potential as Fe biofertilizers was determined based on their capacity to complex Fe, determining the maximum iron complexation capacity at alkaline pH and selecting the RMC4 strain. The biostimulant capacity of the RMC4 strain was evaluated through the secretion of organic acids such as the hormone Indol-3-acetic acid or glutamic acid, among others, in a kinetic assay. Finally, the genome of RMC4 was determined, and the strain was identified as Pseudomonas monsensis. The annotated genome was screened for genes and gene clusters implicated in biofertilization and plant growth promotion. Besides iron mobilization, genes related to phosphorus solubilization, production of phytohormones and biological control, among others, were observed, indicating the suitability of RMC4 as an inoculant. In conclusion, RMC4 and its siderophores are promising sources for Fe biofertilization in agriculture.

Mitigation of yield-scaled nitrous oxide emissions and global warming potential in an oilseed rape crop through N source management.

Enhanced-efficiency nitrogen (N) fertilizers, such as those containing nitrification or urease inhibitors, can mitigate the carbon (C) footprint linked to the production of bioenergy crops through a reduction in direct nitrous oxide (N2O) emissions and indirect N2O losses. These indirect emissions are derived from ammonia (NH3) volatilization, which also have important environmental and health implications. The evaluation of the global warming potential (GWP) of different N sources using site-specific data of yield and direct and indirect emissions is needed for oilseed rape under rainfed semi-arid conditions, especially when meteorological variability is taken into account. Using urea as a N source, the N2O mitigation efficacy of the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) alone or combined with the nitrification inhibitor 2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture (DMPSA) was evaluated under field conditions in a rainfed oilseed rape (Brassica napus L.) crop. Two additional N sources from calcium ammonium nitrate (CAN), with and without DMPSA, were included. The GWP of the treatments was estimated considering the emissions from inputs, operations and other direct and indirect emissions of greenhouse gases (GHGs), such as methane (CH4) and the volatilization of NH3. We also measured the abundance of key genes involved in nitrification and denitrification to improve the understanding of N2O emissions on a biochemical basis under the conditions of our study. The results show that due to the intense rainfall after fertilization and a rewetting event, N2O losses from fertilizers without inhibitors were greater than those previously reported under Mediterranean conditions, while NH3 losses were low and not affected by the urease inhibitor. The cumulative N2O emissions (which were greatly influenced by a rewetting peak three months after fertilization) from the urea fertilization were significantly higher than those from CAN. The presence of NBPT significantly reduced N2O losses by an average of 71%, with respect to urea. The use of DMPSA with CAN resulted in an abatement of N2O emissions (by 57%) and a significant increase in oil yield in comparison with CAN alone. All inhibitor-based treatments were effective in abating N2O emissions during the rewetting peak. The abundances of the nitrifier and denitrifier communities, especially ammonia-oxidizing bacteria (AOB), significantly decreased relative to the urea or CAN treatments as inhibitors were applied. Under the conditions of our study, the sustainability of a bioenergy crop such as oilseed rape can be improved by using inhibitors because they mitigated N2O emissions and/or enhanced the oil yield.

"Just Carbon": Ideas About Graphene Risks by Graphene Researchers and Innovation Advisors.

Graphene is a nanomaterial with many promising and innovative applications, yet early studies indicate that graphene may pose risks to humans and the environment. According to ideas of responsible research and innovation, all relevant actors should strive to reduce risks related to technological innovations. Through semi-structured interviews, we investigated the idea of graphene as a risk (or not) held by two types of key actors: graphene researchers and innovation advisors at universities, where the latter are facilitating the movement of graphene from the laboratory to the marketplace. The most common idea found is that graphene is not a risk due to, e.g., low toxicity, low amounts produced/used, and its similarity to harmless materials (being "just carbon"). However, some researchers and advisors also say that graphene is a risk, e.g., under certain conditions or due to a lack of risk-related information. We explain the co-existence of these seemingly contradictory ideas through (1) the semantic ambiguity of the word risk and (2) a risk/no-risk rhetoric, where risks are mentioned rhetorically only to be disregarded as manageable or negligible. We suggest that some of the ideas held by the researchers and innovation advisors constitute a challenge to responsible research and innovation regarding graphene. At the same time, we acknowledge the dilemma that the discourse of responsible innovation creates for the actors: denying graphene risks makes them irresponsible due to a lack of risk awareness, while affirming graphene risks makes them irresponsible due to their everyday engagement in graphene development. We therefore recommend more research into what researchers and innovation advisors should do in practice in order to qualify as responsible.

ß2-Adrenergic receptor activation mobilizes intracellular calcium via a non-canonical cAMP-independent signaling pathway.

Beta adrenergic receptors (ßARs) are G-protein-coupled receptors essential for physiological responses to the hormones/neurotransmitters epinephrine and norepinephrine which are found in the nervous system and throughout the body. They are the targets of numerous widely used drugs, especially in the case of the most extensively studied ßAR, ß2AR, whose ligands are used for asthma and cardiovascular disease. ßARs signal through Gαs G-proteins and via activation of adenylyl cyclase and cAMP-dependent protein kinase, but some alternative downstream pathways have also been proposed that could be important for understanding normal physiological functioning of ßAR signaling and its disruption in disease. Using fluorescence-based Ca2+ flux assays combined with pharmacology and gene knock-out methods, we discovered a previously unrecognized endogenous pathway in HEK-293 cells whereby ß2AR activation leads to robust Ca2+ mobilization from intracellular stores via activation of phospholipase C and opening of inositol trisphosphate (InsP3) receptors. This pathway did not involve cAMP, Gαs, or Gαi or the participation of the other members of the canonical ß2AR signaling cascade and, therefore, constitutes a novel signaling mechanism for this receptor. This newly uncovered mechanism for Ca2+ mobilization by ß2AR has broad implications for adrenergic signaling, cross-talk with other signaling pathways, and the effects of ßAR-directed drugs.

Rendimiento diagnóstico de la cápsula endoscópica y su impacto en la evolución clínica. Experiencia en el Hospital Rebagliati de Lima / Diagnostic yield of capsule endoscopy and its impact on clinical outcome. Experience in the Hospital of Lima Rebagliati

La cápsula endoscópica (CE) es un método diagnóstico relativamente nuevo que evalúa el tracto gastrointestinal en toda su extensión Es seguro, no invasivo, muy bien tolerado si se utiliza correctamente. La CE es un elemento importante en el diagnóstico de enfermedades del intestino delgado, especialmente en el diagnóstico de sangrado gastrointestinal oscuro. OBJETIVO: Evaluar el rendimiento diagnóstico de la CE y la evolución clínica después de ser realizada en los pacientes del HNERM (Lima-Perú). Materiales y métodos: Se trata de un estudio retrospectivo, descriptivo, observacional, se recolectó información requerida a través de una ficha de datos de todos los pacientes que se sometieron a CE en el período comprendido entre Enero del 2004 y Enero del 2007. El procesamiento de datos se realizó a través del programa EPI-INFO versión 6.04B. Se empleó la prueba de chi cuadrado. Resultados: Se obtuvieron 45 casos, fueron excluidos 4 de ellos. El género predominante fue el masculino con 56 por ciento (23/41), la edad media fue 58.8 años. El sangrado de origen gastrointestinal de origen oscuro representa la primera indicación para el uso de CE con un 85.4 por ciento (35/41), seguida de diarrea crónica asociada a anemia con 7.3 por ciento (3/41), diarrea crónica con 4.9 por ciento (2/41) y dolor abdominal con 2.4 por ciento (1/41). La duración media de síntomas y signos antes de realizar la CE fue de 20.8 meses Dentro de los hallazgos de cápsula los más frecuentes fueron flebectasias, sangrado activo, erosiones, parásitos, úlceras, y angiodisplasias. El 29 por ciento (12/41) fue diagnóstico confirmado, así como diagnóstico sospechado, siendo el rendimiento diagnóstico global de 58.5 por ciento (24/41)...

Capsule endoscopy (CE) is a promising diagnostic method that evaluates gastrointestinal tract in all extension. If it is used in the correct patient, it is safe, noninvasive, tolerated very well. The CE is an important element in the diagnostic of diseases of the small bowel, specially in diagnostic of obscure gastrointestinal bleeding. Objective: To evaluate the diagnostic yield and clinical outcome after CE in HNERM (Lima, Peru). Methods: It is a retrospective study between January 2004 and January 2007. We reviewed specific interventions before and after CE and were noted. Results: Forty five CE were obtained, were excluded 4 from them. Fifty six percent (23/41). * Departamento del Aparato Digestivo, Hospital Nacional Edgardo Rebagliati Martins (EsSALUD), Lima-Perú. Universidad Peruana Cayetano Heredia.350 The first indication to CE was obscure gastrointestinal bleeding with 85.4 per cent (35/41), followed by diarrhea plus anemia 7.3 per cent (3/41), chronic diarrhea with 4.9 per cent (2/41) abdominal pain with2.4 per cent (1/41). The average duration of symptoms and signs before making the CE was of 20.8 months. The most frequent findings were: flebectasias, active bleeding, erosions,parasites, ulcers, and angiodisplasias. Positive findings were 29 per cent (12/41), suspicious findings were 29 per cent, too. Overall diagnostic yield was 58.5 per cent (24/41). The diagnostic yield of each indication was: obscure overt gastrointestinal bleeding 65 per cent (13/20), obscure occult gastrointestinal bleeding 60 per cent (9/15), abdominal pain 0 per cent (0/1) and diarrea 50 per cent (1/2). The best evolution was in positive CE (75 per cent vs 33 per cent p=0.03). Conclusions: The overall diagnostic yield was 59 per cent and the evolution was better when we obtain some result in theCE. The prospective following is necessary to evaluate long term outcome of the patients after the obtained result and of the established treatment.

[Diagnostic yield of the endoscopic capsule and their impact in the clinical outcome]. / Rendimiento diagnóstico de la célula endoscópica y su impacto en la evolución clínica: experiencia en el Hospital Rebagliati de Lima.

UNLABELLED: Capsule endoscopy (CE) is a promising diagnostic method that evaluates gastrointestinal tract in all extension. If it is used in the correct patient, it is safe, noninvasive, tolerated very well. The CE is an important element in the diagnostic of diseases of the small bowel, specially in diagnostic of obscure gastrointestinal bleeding. OBJECTIVE: To evaluate the diagnostic yield and clinical outcome after CE in HNERM (Lima, Peru). METHODS: It is a retrospective study between January 2004 and January 2007. We reviewed specific interventions before and after CE and were noted. RESULTS: Forty five CE were obtained, were excluded 4 from them. Fifty six percent (23/41). The first indication to CE was obscure gastrointestinal bleeding with 85.4% (35/41), followed by diarrhea plus anemia 7.3% (3/41),chronic diarrhea with 4.9% (2/41) abdominal pain with 2.4% (1/41). The average duration of symptoms and signs before making the CE was of 20.8 months. The most frequent findings were: flebectasias, active bleeding, erosions, parasites, ulcers, and angiodisplasias. Positive findings were 29% (12/41), suspicious findings were 29%, too. Overall diagnostic yield was 58.5% (24/41). The diagnostic yield of each indication was: obscure overt gastrointestinal bleeding 65% (13/20), obscure occult gastrointestinal bleeding 60% (9/15), abdominal pain 0% (0/1) and diarrea 50% (1/2). The best evolution was in positive CE (75% vs 33% p=0.03). CONCLUSIONS: The overall diagnostic yield was 59% and the evolution was better when we obtain some result in the CE. The prospective following is necessary to evaluate long term outcome of the patients after the obtained result and of the established treatment.

Elementos de análisis para la estructuración de un programa docente asistencial. Vereda el Zancudo (Fredonia, Antioquia), 1998. I Parte: Estado de Salud Bucal de Población / Elements of analysis for the design and implementation of a teaching assistance program, in the communities of El Zancudo y Fredonia in Colombia. Part I: Oral health status of the population

En este estudio se describe el estado de salud bucal de la población de la vereda el Zancudo (Fredonia- Antioquia). Se realizó examen clínico bucal a una muestra de 150 personas para determinar los niveles de caries dental, enfermedad periodontal y las necesidades de prótesis. En términos generales puede afirmarse que la situación de salud bucal de la población estudiada es un nivel aceptable principalmente en la población joven. Las personas menores de 20 años tienen alto grado de conservación dentaria, baja historia de caries dental y buena salud gingival. En los mayores de 20 años hay un deterioro evidente de estas condiciones pero los indicadores de enfermedad son más bajos que los reportados en el último estudio Nacional de salud bucal. Con base en estos resultados puede afirmarse que el programa docente asistencial debe estructurarse para responder a tres retos: -Mantener los buenos niveles de salud bucal encontrados en la población escolar, -Reformular programas educativos y de mercadeo social que tengan efectos sobre las conductas, hábitos y comportamiento de la población y -Garantizar actividades de recuperación de la salud para todos los grupos de edad...