111 research outputs found
Response of the coccolithophore Emiliania huxleyi to increased CO2 and Fe availability within the plankton food web
Ocean acidification due to increased CO2 emissions derived from anthropogenic activities is affecting
marine ecosystems at an unprecedented rate (IPCC 2013). Ocean acidification has the potential to affect the physiological processes due to increasing CO2 levels and lower pH (Riebesell & Tortell 2011). Ocean acidification also impacts trace metal solubility and speciation. Among all trace metals, Fe is the most essential for biological functions of phytoplankton. Coccolithophores is one of the taxa most affected by increased CO2 and the most important coccolithophore is Emiliania huxleyi. This species is responsible for a large fraction of the ocean calcium carbonate production and export to the deep ocean contributing to the regulation of the exchange of CO2 across the ocean-atmosphere interface (Rost & Riebesell 2004). Emiliania huxleyi has been widely studied in many different works, with one or more global change stressors either in laboratory or in natural conditions. However, there is a lack of knowledge on the response to interactive effects of ocean acidification and dissolved Fe at different levels in
this species.
The aim of this thesis is to gain deeper insight in the physiological response of E. huxleyi to increased CO2 and Fe availability within the food web using mesocosms and also under controlled laboratory experiments. For this purpose, two types of experiments were performed: a mesocosm experiment and a laboratory experiment. The mesocosm experiment and manipulated to achieve combinations of ambient and increased pCO2 and dFe to investigate the physiology response of the coccolithophorid Emiliania huxleyi within a natural plankton community.
The experimental work was performed to elucidate the interactive effect of the exposure to UV radiation (UVR) with increased CO2 and/or different Fe levels. Mesocosm experiments showed a higher degree of realism compared to controlled laboratory experiments due to the semi-control conditions.
The most important result was that Fe played the major role controlling the physiological response of Emiliania huxleyi in both systems. Fe also allow coping better the stress condition, increased CO2 and exposure to UV radiation, in mesocosm and laboratory experiment, respectively. The effects of increased CO2 were differential depending on the conditions of the experiment. In the mesocosm system, the effect of increased CO2 was
detrimental in the majority of the physiological processes. But the effect of increased CO2 was differential under controlled cultures depending on each physiological process.
This study demonstrates that Fe concentrations may control phytoplankton community structure in coastal ecosystems. Thus, in areas with high total Fe concentrations (particulate and dissolved Fe), the detrimental effects of increased pCO2 on these strains can be partially mitigated by enhanced dFe, possibly inducing cascading effects on food web dynamics, carbon export, and the rain ratio, finally affecting the exchange of CO2 across the oceanatmosphere interface.
References:
IPCC, 2013. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovern- mental Panel on Climate Change.
Riebesell U, Tortell PD (2011) Effects of ocean acidification on pelagic organisms and ecosystems. In: Ocean
Acidification.
Rost B, Riebesell U (2004) Coccolithophores and the biological pump: responses to environmental changes. In: Coccolithophores: from molecular process to global impact
Satisfaction of patients with mechanical neck disorders attended to by primary care physical therapists
8 p.Objective: To describe the satisfaction and expectations of the patients with neck pain with relation to the physical therapy received and to analyse the relationship between the patient's characteristics and his degree of satisfaction and expectation. Design: This study is performed in the setting of a random clinical trial. Participants: Subjects between 18 and 60 years of age with subacute mechanical neck disorders. Main variables: Patient's expectations and satisfaction with the received treatment (scale similar to Likert's Scale). OTHER VARIABLES: Pain intensity, episodes of previous neck pain, depression and anxiety symptoms (Goldberg Scale), age and gender, physical disability, general state of health, duration of the present episode of neck pain, regular exercise and regular consumption of medicines. Results and conclusions: A total of 90 patients were studied. The mean age was 40.1 years and 88.9% were female. Thirteen per cent of the subjects expected partial relief, 60% expected good recovery and 27% expected complete recovery. Those patients who have not suffered previous episodes of neck pain and those who have a higher score on the Goldberg Scale have a higher expectation of recovering after the treatment. About patients' satisfaction after the intervention, 2% totally unsatisfied, 1% very unsatisfied, 2% somewhat unsatisfied, 2% indifferent, 17% somewhat satisfied, 42% very satisfied and 30% totally satisfied. Those patients who experienced a greater decrease in pain were more satisfied. It would be interesting to study in depth the measurement of patients' satisfaction with the received physical therapy and to extend it to other pathologies.Fondo de Investigación Sanitari
Uso de fungicidas en el manejo postcosecha de limón persa (Citrus Latifolia)
Estudios realizados, han identificado que los hongos responsables que limitan la vida de anaquel de los cítricos son principalmente: Penicillium digitatum (55-80%); Penicillium italicum (2-30%); Alternaria citri y A. alternata (8-15%); Botrytis cinerea (8-20%): Colletotrichum gloesporioides (2.5-6%); Geotrichum candidum (2-3%); Rhizopus stolonifer y R. oryzae (1-3%); Phytophtora citrophtora (2%) (Salvador et al., 2007). El objetivo del experimento Evaluar la efectividad de dos fingicidas para el control de enfermedades provocadas por hongos en limón persa (Citrus latifolia) en postcosecha. El Proyecto se realizó en Cuajilote, Cuitláhuac, Ver. Trasladando las muestras al laboratorio general número 4 de la Facultad de Ciencias Biológicas y Agropecuarias, región Orizaba-Córdoba, de la Universidad Veracruzana. Los tratamientos donde se aplicaron los fungicidas Bankit Gold® (Azoxystrobin + Fludioxonil) y Magnate Sulphate® (Imazalil) en limón persa (Citrus latifolia) en el proceso de postcosecha, no tuvieron presencia de patógenos que provocan daños en el fruto por lo cual los fungicidas cumplieron con su objetivo, sin embargo, el tratamiento 1 (testigo absoluto) tuvo presencia del patógeno Penicillium spp. en su evaluación a los 30 DDA, esto, basándonos en los resultados de los análisis microbiológicos de limón persa (Citrus latifolia), la contaminación por Penicillium spp. probablemente fue en el almacenamiento del limón persa (Citrus latifolia). Respecto a los resultados de las propiedades fisicoquímicas están dentro los parámetros de calidad
GREDIQ-RIMA: The evolution of a teaching project of experimentation in chemistry
Authors of this project belong to the Resources Chemistry Teaching Group (GReDiQ) involved in RIMA (Research and innovation in learning methodologies). The audiovisual and multimedia material productions realized have been grouped into three themes: Basic Techniques of Experimentation in Chemistry, Safety in Chemistry Laboratories and Advanced Techniques of Experimentation in Chemistry. This work has been awarded a prize of the Universitat Politècnica de Catalunya (UPC–BARCELONATECH), one of the Autonomous Region of Catalunya and another one of a State scopePostprint (author’s final draft
La quimiocina RANTES en una población hipertensa venezolana
La hipertensión constituye un problema de Salud Pública, su prevalencia en la población venezolana contribuye con el aumento de la aparición de las enfermedades cardiovas- culares. En los últimos años se ha implicado a los factores in amatorios en la etiología de hipertensión los cuales con- ducen a la disfunción endotelial. Es por ello que es de inte- rés la búsqueda de nuevos biomarcadores que permitan la detección temprana de la disfunción endotelial e in amación periférica asociada a la hipertensión. En el presente estudio se evaluaron los niveles plasmáticos de mediadores in ama- torios tales como el estimulador de colonias de granulocitos y macrófagos (GM-CSF), quimiocinas C-C y moléculas de adhesión solubles, producidas por la interacción de la ad- hesión entre los monocitos y las células endoteliales en un grupo de venezolanos adultos pre-hipertensos e hipertensos. Se examinaron 201 individuos voluntarios, 104 con presión arterial sistólica (PAS) menor de 120 mmHg y/o presión ar- terial diastólica (PAD) menor de 80 mmHg, los cuales eran individuos aparentemente sanos (controles), 61 con valores de PAS entre 120 y 139 mmHg y/o PAD entre 80-89 mmHg (pre-hipertensos) y 36 pacientes que presentaban valores de PAS iguales o superiores a 140 mmHg y/o PAD mayor o igual a 90 mmHg (hipertensos). Se realizó la evaluación clí- nica de los pacientes, y se determinó los niveles plasmáticos de glucosa, colesterol total, colesterol-HDL y triglicéridos por métodos enzimáticos, previo ayuno nocturno. Igualmente, se evaluaron los niveles de citosinas, moléculas de adhesión y quimiocinas mediante el análisis multiplex de microesferas (Bio-Plex). Nuestros hallazgos muestran que los pacientes hipertensos (PAS>140 mmHg y/o PAD>90 mmHg) presenta- ron niveles signi cativamente mayores de RANTES (CCL5), el cual se correlacionó signi cativamente con IL-1ra, -2, -6, -8,-12, MIP1b, FGFb, G-CSF y VEGF. Estos datos indican que de la población venezolana evaluada, en los pacientes hipertensos subyacen alteraciones en las citoquinas in ama- torias, moléculas de adhesión y quimiocinas. 
Morphological changes of the calamus of growing remiges feathers in pigeons
1 recurso en línea (páginas 15-24).Las plumas se han utilizado para estudiar procesos de diferenciación celular y morfogénesis. Existen pocos estudios histológicos en animales adultos que describan de manera secuencial la maduración de los componentes celulares durante el crecimiento; así que el objetivo de este trabajo fue describir las características histológicas de este proceso, abarcando los elementos celulares y sus relaciones anatómicas. Se obtuvieron plumas remeras de palomas, en las que se había inducido un proceso de regeneración, a los
8, 13, 18, 23 y 28 días de crecimiento. Se realizaron cortes histológicos teñidos con diferentes técnicas. Se demostró la presencia de la zona ramogénica, que tiende a disminuir de tamaño del día 8 al 28. En las crestas de la barba se observaron células de la barba, barbulares y de la placa axial, quedando cada cresta delimitada por la placa marginal. Las características celulares variaron de acuerdo con la región de las crestas, mostrando en la placa marginal transiciones de células escamosas a cuboides y nuevamente a escamosas, y, por otro lado, en la placa barbular de células cuboides a columnares y después a fusiformes. Se identificaron las células obscuras de la zona ramogénica, las cuales, por sus características tintoriales, parecen derivar de la papila dérmica. En conclusión, se realizó la caracterización histológica del cálamo y se describió, por primera vez, de manera secuencial en las diferentes etapas del crecimiento.Feathers have been studied in processes of cellular differentiation and morphogenesis; however, only few histological studies in adult animals describe the maturation of the cellular components sequentially. Therefore, the objective of this work was to describe the histological characteristics, covering the cellular elements and their anatomical relationships. Pigeon feathers were withdrawn to induce regeneration, and samples were taken at different times: 8 (sprout time), 13, 18, 23, and 28 days. We prepared histological cuts using different staining techniques. We demonstrated the presence of a very marked ramogenic zone that tends to diminish from day 8 to 28. In the barb ridge, we observed the barb, barbule, and axial plate cells, with the marginal plate delimiting each barb ridge. The cellular characteristics varied according to the ridges region, showing in the marginal plate transitions from squamous to cuboidal and back to squamous cells; and, in the barbular plate, from cuboidal to columnar and then to fusiform cells. Obscure cells from the ramogenic zone were identified as cells derived from the dermal papilla based on their staining. In conclusion, we characterized the histology of the calamus and, for the first time, described the different growth stages sequentially.Bibliografía: páginas 23-24
- …