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1.
Commun Biol ; 7(1): 653, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38806643

RESUMEN

Metabolic rate, the rate of energy use, underpins key ecological traits of organisms, from development and locomotion to interaction rates between individuals. In a warming world, the temperature-dependence of metabolic rate is anticipated to shift predator-prey dynamics. Yet, there is little real-world evidence on the effects of warming on trophic interactions. We measured the respiration rates of aquatic larvae of three insect species from populations experiencing a natural temperature gradient in a large-scale mesocosm experiment. Using a mechanistic model we predicted the effects of warming on these taxa's predator-prey interaction rates. We found that species-specific differences in metabolic plasticity lead to mismatches in the temperature-dependence of their relative velocities, resulting in altered predator-prey interaction rates. This study underscores the role of metabolic plasticity at the species level in modifying trophic interactions and proposes a mechanistic modelling approach that allows an efficient, high-throughput estimation of climate change threats across species pairs.


Asunto(s)
Cambio Climático , Cadena Alimentaria , Conducta Predatoria , Animales , Larva/fisiología , Temperatura , Especificidad de la Especie , Insectos/fisiología
2.
Artículo en Inglés | MEDLINE | ID: mdl-38111841

RESUMEN

Fournier gangrene is a disease characterized by necrotizing fasciitis of the perineal and genital region, resulting from synergistic polymicrobiotic infection. Most infections can be localized to a cutaneous, urethral, or rectal source and can culminate in a fulminant sepsis. Current state of the art is systemic broad-spectrum antibiotics and serial aggressive debridement which result in superficial perineal defect of wide dimensions. We compiled all the cases of Fournier gangrene that required reconstruction after debridement in Centro Hospitalar Universitário Lisboa Central from 2018 to 2022. Inclusion criteria were reconstruction for Fournier defects and patients' age 18 to 90 years old. Exclusion criteria were patients who didn't require reconstruction or didn't complete it due to death or transfer to another healthcare institution. Reconstructive procedures and complication rates are reported as whole numbers and percentages of total. The initial search yielded 32 patients. There were 2 (6.2%) patients with defects that healed by secondary intention, 6 (18.7%) with delayed primary closure, 4 (12.5%) with implantation of the testicle in a medial thigh pocket, 12 (37.5%) with skin grafts, 4 (12.5%) with scrotal advancement flaps, 2 (6.2%) with flaps, and 2 (6.2%) with flaps and skin grafts in combination. Four outcomes were evaluated: number of patients, defect size, method of reconstruction, and wound-healing complications. Most reconstructive techniques provide reliable coverage and protection of testicular function with an acceptable cosmetic result. The reconstructive options need to be patient tailored in order to achieve long lasting results with a minimum of postoperative morbidity.

3.
Int J Surg Case Rep ; 111: 108667, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37716054

RESUMEN

INTRODUCTION AND IMPORTANCE: Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma affects mainly the trunk and proximal limbs. Clinically, it typically presents as an asymptomatic plaque or nodular-like lesion that progresses slowly before entering a rapid growth phase. DFSP exhibits a low potential for metastasis, mainly in cases where fibrosarcomatous transformation occurs, but it has a high rate of local recurrence. Diagnosis of DFSP is often delayed, and it is challenging to establish without performing a biopsy and histologic analysis. The mainstay treatment for DFSP is surgical wide excision with free margins, although this can be challenging depending on the location of the tumor. CASE PRESENTATION: We report a rare presentantion of dermatofibrosarcoma protuberans according to the SCARE guidelines. The patients main concern was the slow evolving mass on the dorsum of the foot that at presentation was 1x1cm. The biopsy showed a dermatofibrosarcoma protuberans. A radical excision involving ray amputation of the 2nd and 3rd finger provided a 1 cm clear margin. CLíNICAL DISCUSSION AND CONCLUSION: This case shows how an inconspicuous nodule in an uncommon area can be the primary manifestation of a serious condition.

4.
Rev Fac Cien Med Univ Nac Cordoba ; 80(2): 156-157, 2023 06 30.
Artículo en Español | MEDLINE | ID: mdl-37402307

RESUMEN

The term pseudoascitis is used in patients who give the false impression of ascites, with abdominal distension but without peritoneal free fluid. The case of a 66-year-old woman, hypertensive and hypothyroid with occasional alcohol consumption, who consults due to progressive abdominal distension of 6 months of evolution and diffuse percussion dullness is presented, in whom a paracentesis is performed with the wrong endorsement of examination ultrasound that reports abundant intrabdominal free fluid (Fig. 1), later finding in the CT scan of the abdomen and pelvis an expansive process of cystic appearance of 295mm x 208mm x 250mm. Left anexectomy is programmed (Fig. 2) with pathological report of mucinous ovarian cystadenoma. The case report refers to the availability of the giant ovarian cyst within the differential diagnosis of ascites. If no symptoms or obvious signs of liver, kidney, heart or malignant disease are found and / or ultrasound does not reveal typical signs of intra-abdominal free fluid (fluid in the bottom of the Morrison or Douglas sac, presence of floating free intestinal handles), a CT scan and / or an RMI should be requested before performing paracentesis, which could have potentially serious consequences.


El término pseudoascitis, se utiliza en los pacientes que dan la falsa impresión de ascitis, con distensión abdominal pero sin líquido libre peritoneal. Se presenta el caso de una mujer de 66 años, hipertensa e hipotiroidea con consumo ocasional de alcohol, que consulta por distensión abdominal progresiva de 6 meses de evolución y matidez difusa a la percusión, en quien se realiza una paracentesis con el aval equivoco de examen ecográfico que informa abundante líquido libre  intrabdominal (Fig. 1), hallando posteriormente en TAC de abdomen y pelvis un proceso expansivo de aspecto quístico de 295mm x 208mm x 250mm. Se programa anexectomia izquierda (Fig. 2) con informe anatomopatológico de cistoadenoma mucinoso de ovario. La comunicación del caso remite a tener disponible el quiste ovárico gigante dentro de los diagnósticos diferenciales de ascitis. Si no se hallan síntomas o signos evidentes de insuficiencia hepática, renal, cardiaca o enfermedad maligna y/o la ecografía no revela signos típicos de líquido libre intrabdominal  (líquido en el fondo de saco de Morrison o de Douglas, presencia de asas intestinales libres flotantes), se debería solicitar una TAC y/o una RMI antes de realizar una paracentesis, la cual podría tener consecuencias potencialmente graves.


Asunto(s)
Cistoadenoma Mucinoso , Quistes Ováricos , Neoplasias Ováricas , Femenino , Humanos , Anciano , Ascitis/diagnóstico por imagen , Ascitis/etiología , Cistoadenoma Mucinoso/diagnóstico , Cistoadenoma Mucinoso/patología , Neoplasias Ováricas/diagnóstico , Quistes Ováricos/diagnóstico , Riñón
5.
Nature ; 619(7969): 317-322, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37438590

RESUMEN

Plastic debris is thought to be widespread in freshwater ecosystems globally1. However, a lack of comprehensive and comparable data makes rigorous assessment of its distribution challenging2,3. Here we present a standardized cross-national survey that assesses the abundance and type of plastic debris (>250 µm) in freshwater ecosystems. We sample surface waters of 38 lakes and reservoirs, distributed across gradients of geographical position and limnological attributes, with the aim to identify factors associated with an increased observation of plastics. We find plastic debris in all studied lakes and reservoirs, suggesting that these ecosystems play a key role in the plastic-pollution cycle. Our results indicate that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes and reservoirs with elevated deposition areas, long water-retention times and high levels of anthropogenic influence. Plastic concentrations vary widely among lakes; in the most polluted, concentrations reach or even exceed those reported in the subtropical oceanic gyres, marine areas collecting large amounts of debris4. Our findings highlight the importance of including lakes and reservoirs when addressing plastic pollution, in the context of pollution management and for the continued provision of lake ecosystem services.


Asunto(s)
Lagos , Plásticos , Contaminación del Agua , Abastecimiento de Agua , Ecosistema , Lagos/química , Plásticos/análisis , Plásticos/clasificación , Contaminación del Agua/análisis , Contaminación del Agua/estadística & datos numéricos , Encuestas y Cuestionarios , Urbanización , Actividades Humanas
6.
J Sci Food Agric ; 103(11): 5242-5252, 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37029992

RESUMEN

BACKGROUND: Protein-pectin conjugates, obtained through a controlled Maillard reaction in blends of precursors, are studied for their contribution to improving the emulsifying and thermal properties of proteins. The objective was to obtain a conjugate between whey protein concentrate (WPC) and non-conventional pectins extracted in acid (acid tomato pectin, ATP) and aqueous medium (water tomato pectin, WTP) from industrialized tomato residues (tomato waste, TW), characterize the conjugates and study their emulsion properties. The Maillard reaction was carried out at 60 °C and 75% relative humidity in blends with 2:1 proportions; 1:1 and 1:2 (mprotein :mpectin ) for 3, 6 and 12 days. Conjugates were compared concerning treated and untreated WPC. RESULTS: The WPC-ATP conjugate showed significant increases in color difference (ΔE). The electrophoresis profile of the conjugates showed diffuse bands of molecular weight between 37 and 250 kDa and a reduction in the intensity of bands characteristic of WPC (α-lactalbumin and ß-lactoglobulin). Thermal analysis showed an increase in the peak temperature and a reduction in the enthalpy change in protein denaturation, associated with the formation of conjugates. The infrared spectroscopy of the conjugates, in the amide III zone (1300-1100 cm-1 ), indicated an increase in the relative peak area associated with the unfolding and exhibition of the hydrophobic zones of the WPC fraction. The emulsions formulated with the conjugates showed a significant increase in the emulsifying stability index (ESI) (P < 0.05) concerning the treated and untreated WPC emulsions. CONCLUSION: The formation of conjugates increased the emulsifying properties and improved the thermal stability of WPC, showing an innovative and alternative food ingredient too. © 2023 Society of Chemical Industry.


Asunto(s)
Pectinas , Solanum lycopersicum , Proteína de Suero de Leche/química , Pectinas/química , Emulsiones/química , Adenosina Trifosfato
8.
Trends Ecol Evol ; 37(5): 440-453, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35058082

RESUMEN

The widespread salinisation of freshwater ecosystems poses a major threat to the biodiversity, functioning, and services that they provide. Human activities promote freshwater salinisation through multiple drivers (e.g., agriculture, resource extraction, urbanisation) that are amplified by climate change. Due to its complexity, we are still far from fully understanding the ecological and evolutionary consequences of freshwater salinisation. Here, we assess current research gaps and present a research agenda to guide future studies. We identified different gaps in taxonomic groups, levels of biological organisation, and geographic regions. We suggest focusing on global- and landscape-scale processes, functional approaches, genetic and molecular levels, and eco-evolutionary dynamics as key future avenues to predict the consequences of freshwater salinisation for ecosystems and human societies.


Asunto(s)
Ecosistema , Agua Dulce , Biodiversidad , Evolución Biológica , Cambio Climático , Humanos
9.
Glob Chang Biol ; 28(4): 1402-1413, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34773676

RESUMEN

A variety of organisms can colonize microplastic surfaces through biofouling processes. Heterotrophic bacteria tend to be the focus of plastisphere research; however, the presence of epiplastic microalgae within the biofilm has been repeatedly documented. Despite the relevance of biofouling in determining the fate and effects of microplastics in aquatic systems, data about this process are still scarce, especially for freshwater ecosystems. Here, our goal was to evaluate the biomass development and species composition of biofilms on different plastic polymers and to investigate whether plastic substrates exert a strong enough selection to drive species sorting, overcoming other niche-defining factors. We added microplastic pellets of high-density polyethylene (HDPE), polyethylene terephthalate (PET), and a mix of the two polymers in 15 lentic mesocosms in five different locations of the Iberian Peninsula, and after one month, we evaluated species composition and biomass of microalgae developed on plastic surfaces. Our results, based on 45 samples, showed that colonization of plastic surfaces occurred in a range of lentic ecosystems covering a wide geographical gradient and different environmental conditions (e.g., nutrient concentration, conductivity, macrophyte coverage). We highlighted that total biomass differed based on the polymer considered, with higher biomass developed on PET substrate compared to HDPE. Microplastics supported the growth of a rich and diversified community of microalgae (242 species), with some cosmopolite species. However, we did not observe species-specificity in the colonization of the different plastic polymers. Local species pool and nutrient concentration rather than polymeric composition seemed to be the determinant factor defying the community diversity. Regardless of specific environmental conditions, we showed that many species could coexist on the surface of relatively small plastic items, highlighting how microplastics may have considerable carrying capacity, with possible consequences on the wider ecological context.


Asunto(s)
Microalgas , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente , Microplásticos , Plásticos , Polímeros/química , Contaminantes Químicos del Agua/análisis
10.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-34607952

RESUMEN

Humans have made such dramatic and permanent changes to Earth's landscapes that much of it is now substantially and irreversibly altered from its preanthropogenic state. Remote islands, until recently isolated from humans, offer insights into how these landscapes evolved in response to human-induced perturbations. However, little is known about when and how remote systems were colonized because archaeological data and historical records are scarce and incomplete. Here, we use a multiproxy approach to reconstruct the initial colonization and subsequent environmental impacts on the Azores Archipelago. Our reconstructions provide unambiguous evidence for widespread human disturbance of this archipelago starting between 700-60+50 and 850-60+60 Common Era (CE), ca. 700 y earlier than historical records suggest the onset of Portuguese settlement of the islands. Settlement proceeded in three phases, during which human pressure on the terrestrial and aquatic ecosystems grew steadily (i.e., through livestock introductions, logging, and fire), resulting in irreversible changes. Our climate models suggest that the initial colonization at the end of the early Middle Ages (500 to 900 CE) occurred in conjunction with anomalous northeasterly winds and warmer Northern Hemisphere temperatures. These climate conditions likely inhibited exploration from southern Europe and facilitated human settlers from the northeast Atlantic. These results are consistent with recent archaeological and genetic data suggesting that the Norse were most likely the earliest settlers on the islands.


Asunto(s)
Ecosistema , Ambiente , Actividades Humanas , Migración Humana , Agricultura , Azores , Cambio Climático , Modelos Climáticos , Heces/química , Humanos
11.
PLoS One ; 13(7): e0200556, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29985956

RESUMEN

[This corrects the article DOI: 10.1371/journal.pone.0197877.].

12.
Rev. esp. enferm. dig ; 110(7): 416-420, jul. 2018. ilus, tab, graf
Artículo en Español | IBECS | ID: ibc-177704

RESUMEN

Introducción: en los intentos de canulación del colédoco durante la colangiopancreatografía retrógrada endoscópica (CPRE) la guía puede entrar en el conducto pancreático. No está definido qué maniobra es más eficaz para canular la vía biliar y prevenir la pancreatitis tras pasar la guía al Wirsung. Objetivo: estudiar la tasa de canulación coledociana y de pancreatitis post-CPRE cuando en la primera ocasión en que la guía pasó al conducto pancreático de forma involuntaria se insertó una prótesis pancreática. Material y métodos: análisis retrospectivo de pacientes a los que se realizó una CPRE para drenaje biliar e incluidos de forma prospectiva en una base de datos. Tras la inserción involuntaria de una guía en el conducto pancreático se insertó una prótesis plástica recta de 5 Fr y 4 cm de longitud, sin topes internos para facilitar su expulsión. El colédoco se intentó canular por encima de la prótesis. En los pacientes mayores de 60 años se realizó una esfinterotomía pancreática antes de insertar la prótesis. Resultados: en un grupo de 154 CPRE se insertaron 46 prótesis pancreáticas (29,8%) y en estos casos el colédoco se canuló en el 95,6% (44/46) de las ocasiones. Se realizaron 21/46 (45,6%) esfinterotomías pancreáticas. Hubo 1/46 (2,17%) pancreatitis leves. La mayoría de las prótesis se expulsaron de forma espontánea. Conclusiones: en este estudio, la inserción de una prótesis pancreática plástica cuando la guía ha pasado al conducto pancreático de forma involuntaria en los intentos de canulación del colédoco ayudó a canular la vía biliar en la mayoría de las ocasiones, sin que la inserción de las prótesis produjera efectos adversos


Introduction: the guidewire (GW) may enter the pancreatic duct during common bile duct (CBD) cannulation attempts in endoscopic retrograde cholangiopancreatography (ERCP). After GW passage into the pancreas, the most effective maneuver for CBD cannulation and pancreatitis prevention has not been determined. Aim: to study CBD cannulation and post-ERCP pancreatitis rates when a pancreatic stent is inserted after an unintentional GW cannulation of the pancreatic duct. Material and methods: a retrospective analysis of patients undergoing ERCP for biliary drainage that were included prospectively into a database. After unintentional GW cannulation of the pancreatic duct, a straight 5-Fr and 4-cm long plastic stent was inserted. The stents had no internal flaps to facilitate expulsion. CBD cannulation attempts were made above the stent. A pancreatic sphincterotomy was performed in patients older than 60 years before stent insertion. Results: a total of 46 pancreatic stents were inserted during 154 ERCP (29.8%) procedures. In the stent group, CBD cannulation was accomplished in 44/46 (95.6%) subjects. A total of 21/46 (45.6%) pancreatic sphincterotomies were performed. Only 1/46 (2.17%) mild pancreatitis cases were observed and most stents were spontaneously expelled. Conclusions: in this study, the CBD was eventually reached with the insertion of a plastic pancreatic stent after an unintentional GW passage into the pancreatic duct while attempting a CBD cannulation. No adverse events were observed following pancreatic stent insertion


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Pancreatitis/etiología , Implantación de Prótesis/métodos , Complicaciones Posoperatorias/prevención & control , Factores de Riesgo , Enfermedad Iatrogénica/prevención & control , Conductos Pancreáticos/cirugía , Estudios Retrospectivos , Drenaje/efectos adversos
13.
PLoS One ; 13(5): e0197877, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29791491

RESUMEN

Understanding what determines species' geographic distributions is crucial for assessing global change threats to biodiversity. Measuring limits on distributions is usually, and necessarily, done with data at large geographic extents and coarse spatial resolution. However, survival of individuals is determined by processes that happen at small spatial scales. The relative abundance of coexisting species (i.e. 'community structure') reflects assembly processes occurring at small scales, and are often available for relatively extensive areas, so could be useful for explaining species distributions. We demonstrate that Bayesian Network Inference (BNI) can overcome several challenges to including community structure into studies of species distributions, despite having been little used to date. We hypothesized that the relative abundance of coexisting species can improve predictions of species distributions. In 1570 assemblages of 68 Mediterranean woody plant species we used BNI to incorporate community structure into Species Distribution Models (SDMs), alongside environmental information. Information on species associations improved SDM predictions of community structure and species distributions moderately, though for some habitat specialists the deviance explained increased by up to 15%. We demonstrate that most species associations (95%) were positive and occurred between species with ecologically similar traits. This suggests that SDM improvement could be because species co-occurrences are a proxy for local ecological processes. Our study shows that Bayesian Networks, when interpreted carefully, can be used to include local conditions into measurements of species' large-scale distributions, and this information can improve the predictions of species distributions.


Asunto(s)
Biodiversidad , Geografía , Plantas , Análisis de Varianza , Teorema de Bayes , Modelos Estadísticos , Análisis Espacial , Madera
14.
Rev Esp Enferm Dig ; 110(7): 416-420, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29685042

RESUMEN

INTRODUCTION: the guidewire (GW) may enter the pancreatic duct during common bile duct (CBD) cannulation attempts in endoscopic retrograde cholangiopancreatography (ERCP). After GW passage into the pancreas, the most effective maneuver for CBD cannulation and pancreatitis prevention has not been determined. AIM: to study CBD cannulation and post-ERCP pancreatitis rates when a pancreatic stent is inserted after an unintentional GW cannulation of the pancreatic duct. MATERIAL AND METHODS: a retrospective analysis of patients undergoing ERCP for biliary drainage that were included prospectively into a database. After unintentional GW cannulation of the pancreatic duct, a straight 5-Fr and 4-cm long plastic stent was inserted. The stents had no internal flaps to facilitate expulsion. CBD cannulation attempts were made above the stent. A pancreatic sphincterotomy was performed in patients older than 60 years before stent insertion. RESULTS: a total of 46 pancreatic stents were inserted during 154 ERCP (29.8%) procedures. In the stent group, CBD cannulation was accomplished in 44/46 (95.6%) subjects. A total of 21/46 (45.6%) pancreatic sphincterotomies were performed. Only 1/46 (2.17%) mild pancreatitis cases were observed and most stents were spontaneously expelled. CONCLUSIONS: in this study, the CBD was eventually reached with the insertion of a plastic pancreatic stent after an unintentional GW passage into the pancreatic duct while attempting a CBD cannulation. No adverse events were observed following pancreatic stent insertion.


Asunto(s)
Cateterismo/efectos adversos , Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Páncreas , Pancreatitis/etiología , Pancreatitis/terapia , Stents , Adulto , Anciano , Anciano de 80 o más Años , Cateterismo/instrumentación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conductos Pancreáticos/lesiones , Estudios Retrospectivos , Esfinterotomía Endoscópica
15.
PeerJ ; 4: e1985, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27168991

RESUMEN

Habitat structure influences the diversity and distribution of organisms, potentially affecting their response to disturbances by either affecting their 'susceptibility' or through the provision of resources that can mitigate impacts of disturbances. Chemical disturbances due to contamination are associated with decreases in diversity and functioning of systems and are also likely to increase due to coastal urbanisation. Understanding how habitat structure interacts with contaminants is essential to predict and therefore manage such effects, minimising their consequences to marine systems. Here, we manipulated two structurally different habitats and exposed them to different types of contaminants. The effects of contamination and habitat structure interacted, affecting species richness. More complex experimental habitats were colonized by a greater diversity of organisms than the less complex habitats. These differences disappeared, however, when habitats were exposed to contaminants, suggesting that contaminants can override effects of habitats structure at small spatial scales. These results provide insight into the complex ways that habitat structure and contamination interact and the need to incorporate evidence of biotic responses from individual disturbances to multiple stressors. Such effects need to be taken into account when designing and planning management and conservation strategies to natural systems.

16.
PLoS One ; 10(11): e0142289, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26554924

RESUMEN

Understanding the consequences of fragmentation of coastal habitats is an important topic of discussion in marine ecology. Research on the effects of fragmentation has revealed complex and context-dependent biotic responses, which prevent generalizations across different habitats or study organisms. The effects of fragmentation in marine environments have been rarely investigated across heterogeneous habitats, since most studies have focused on a single type of habitat or patch. In this study, we assessed the effects of different levels of fragmentation (i.e. decreasing size of patches without overall habitat loss). We measured these effects using assemblages of macro-invertebrates colonizing representative morphological groups of intertidal macroalgae (e.g. encrusting, turf and canopy-forming algae). For this purpose, we constructed artificial assemblages with different combinations of morphological groups and increasing levels of fragmentation by manipulating the amount of bare rock or the spatial arrangement of different species in mixed assemblages. In general, our results showed that 1) fragmentation did not significantly affect the assemblages of macroinvertebrates; 2) at greater levels of fragmentation, there were greater numbers of species in mixed algal assemblages, suggesting that higher habitat complexity promotes species colonization. Our results suggest that predicting the consequences of fragmentation in heterogeneous habitats is dependent on the type and diversity of morphological groups making up those habitats.


Asunto(s)
Ecosistema , Algas Marinas/clasificación , Agua , Biomasa
17.
Trends Ecol Evol ; 30(6): 347-56, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25922148

RESUMEN

Inferring biotic interactions from functional, phylogenetic and geographical proxies remains one great challenge in ecology. We propose a conceptual framework to infer the backbone of biotic interaction networks within regional species pools. First, interacting groups are identified to order links and remove forbidden interactions between species. Second, additional links are removed by examination of the geographical context in which species co-occur. Third, hypotheses are proposed to establish interaction probabilities between species. We illustrate the framework using published food-webs in terrestrial and marine systems. We conclude that preliminary descriptions of the web of life can be made by careful integration of data with theory.


Asunto(s)
Ecosistema , Cadena Alimentaria , Animales , Geografía , Modelos Biológicos , Filogenia , Plantas
18.
PLoS One ; 9(5): e95073, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24797663

RESUMEN

Monocyte exposure to mitochondrial Danger Associated Molecular Patterns (DAMPs), including mitochondrial DNA (mtDNA), induces a transient state in which these cells are refractory to further endotoxin stimulation. In this context, IRAK-M up-regulation and impaired p65 activity were observed. This phenomenon, termed endotoxin tolerance (ET), is characterized by decreased production of cytokines in response to the pro-inflammatory stimulus. We also show that monocytes isolated from patients with myocardial infarction (MI) exhibited high levels of circulating mtDNA, which correlated with ET status. Moreover, a significant incidence of infection was observed in those patients with a strong tolerant phenotype. The present data extend our current understanding of the implications of endotoxin tolerance. Furthermore, our data suggest that the levels of mitochondrial antigens in plasma, such as plasma mtDNA, should be useful as a marker of increased risk of susceptibility to nosocomial infections in MI and in other pathologies involving tissue damage.


Asunto(s)
Infección Hospitalaria/sangre , Citocinas/sangre , ADN Mitocondrial/sangre , Endotoxinas/sangre , Infarto del Miocardio/sangre , Regulación hacia Arriba , Anciano , Endotoxinas/farmacología , Femenino , Humanos , Quinasas Asociadas a Receptores de Interleucina-1/biosíntesis , Masculino , Persona de Mediana Edad , Monocitos/metabolismo , Monocitos/patología , Infarto del Miocardio/patología , Factores de Riesgo
19.
PLoS One ; 8(4): e61349, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23593471

RESUMEN

Despite edges being common features of many natural habitats, there is little general understanding of the ways assemblages respond to them. Every edge between two contrasting habitats has characteristics governed by the composition of adjoining habitats and/or by the nature of any transitions between them. To develop better explanatory theory, we examined the extent to which edges act independently of the composition of the surrounding landscape and to which transitions between different types of habitats affect assemblages. Using experimental landscapes, we measured the responses of assemblages of marine molluscs colonising different experimental landscapes constructed with different compositions (i.e. different types of habitats within the landscape) and different types of transitions between habitats (i.e. sharp vs gradual). Edge effects (i.e. proximity to the edge of the landscape) were independent of the internal composition of experimental landscape; fewer species were found near the edges of landscapes. These reductions may be explained by differences in differential larval settlement between edges and interiors of experimental landscapes. We also found that the sharpness of transitions influenced the magnitude of interactions in the different types of habitats in experimental landscapes, most probably due to the increased number of species in areas of transition between two habitats. Our experiments allowed the effects of composition and transitions between habitats to be disentangled from those of proximity to edges of landscapes. Understanding and making predictions about the responses by species to edges depends on understanding not only the nature of transitions across boundaries, but also the landscape in which the edges are embedded.


Asunto(s)
Ecosistema , Ambiente Controlado , Análisis de Varianza , Animales , Organismos Acuáticos , Moluscos
20.
Nat Commun ; 3: 1234, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23212363

RESUMEN

One of the simplest hypotheses used to explain species coexistence is the competition-colonization trade-off, that is, species can stably coexist in a landscape if they show a trade-off between competitive and colonization abilities. Despite extensive theory, the dynamics predicted to result from competition-colonization trade-offs are largely untested. Landscape change, such as habitat destruction, is thought to greatly influence coexistence under competition-colonization dynamics, although there is no formal test of this prediction. Here we present the first illustration of competition-colonization dynamics that fully transposes theory into a controlled experimental metacommunity of two Pseudomonas bacterial strains. The competition-colonization dynamics were achieved by directly manipulating trade-off strength and colonization rates to generate the full range of coexistence conditions and responses to habitat destruction. Our study successfully generates competition-colonization dynamics matching theoretical predictions, and our results further reveal a negative relationship between diversity and productivity when scaling up to entire metacommunities.


Asunto(s)
Bacterias/crecimiento & desarrollo , Dinámica Poblacional , Ecología , Ecosistema , Modelos Biológicos , Pseudomonas
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