| 1. |
- Bluth, Thomas, et al.
(författare)
-
Effect of Intraoperative High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers vs Low PEEP on Postoperative Pulmonary Complications in Obese Patients : A Randomized Clinical Trial.
- 2019
-
Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 321:23, s. 2292-2305
-
Tidskriftsartikel (refereegranskat)abstract
- Importance: An intraoperative higher level of positive end-expiratory positive pressure (PEEP) with alveolar recruitment maneuvers improves respiratory function in obese patients undergoing surgery, but the effect on clinical outcomes is uncertain.Objective: To determine whether a higher level of PEEP with alveolar recruitment maneuvers decreases postoperative pulmonary complications in obese patients undergoing surgery compared with a lower level of PEEP.Design, Setting, and Participants: Randomized clinical trial of 2013 adults with body mass indices of 35 or greater and substantial risk for postoperative pulmonary complications who were undergoing noncardiac, nonneurological surgery under general anesthesia. The trial was conducted at 77 sites in 23 countries from July 2014-February 2018; final follow-up: May 2018.Interventions: Patients were randomized to the high level of PEEP group (n = 989), consisting of a PEEP level of 12 cm H2O with alveolar recruitment maneuvers (a stepwise increase of tidal volume and eventually PEEP) or to the low level of PEEP group (n = 987), consisting of a PEEP level of 4 cm H2O. All patients received volume-controlled ventilation with a tidal volume of 7 mL/kg of predicted body weight.Main Outcomes and Measures: The primary outcome was a composite of pulmonary complications within the first 5 postoperative days, including respiratory failure, acute respiratory distress syndrome, bronchospasm, new pulmonary infiltrates, pulmonary infection, aspiration pneumonitis, pleural effusion, atelectasis, cardiopulmonary edema, and pneumothorax. Among the 9 prespecified secondary outcomes, 3 were intraoperative complications, including hypoxemia (oxygen desaturation with Spo2 ≤92% for >1 minute).Results: Among 2013 adults who were randomized, 1976 (98.2%) completed the trial (mean age, 48.8 years; 1381 [69.9%] women; 1778 [90.1%] underwent abdominal operations). In the intention-to-treat analysis, the primary outcome occurred in 211 of 989 patients (21.3%) in the high level of PEEP group compared with 233 of 987 patients (23.6%) in the low level of PEEP group (difference, -2.3% [95% CI, -5.9% to 1.4%]; risk ratio, 0.93 [95% CI, 0.83 to 1.04]; P = .23). Among the 9 prespecified secondary outcomes, 6 were not significantly different between the high and low level of PEEP groups, and 3 were significantly different, including fewer patients with hypoxemia (5.0% in the high level of PEEP group vs 13.6% in the low level of PEEP group; difference, -8.6% [95% CI, -11.1% to 6.1%]; P < .001).Conclusions and Relevance: Among obese patients undergoing surgery under general anesthesia, an intraoperative mechanical ventilation strategy with a higher level of PEEP and alveolar recruitment maneuvers, compared with a strategy with a lower level of PEEP, did not reduce postoperative pulmonary complications.Trial Registration: ClinicalTrials.gov Identifier: NCT02148692.
|
|
| 2. |
- Bluth, T., et al.
(författare)
-
Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE) : study protocol for a randomized controlled trial
- 2017
-
Ingår i: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 18
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients.Methods/design: The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index >= 35 kg/m(2) scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH(2)O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH(2)O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint.Discussion: To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs.
|
|
| 3. |
- Brenninkmeijer, C. A. M., et al.
(författare)
-
Civil Aircraft for the regular investigation of the atmosphere based on an instrumented container: The new CARIBIC system
- 2007
-
Ingår i: Atmospheric Chemistry and Physics. - 1680-7324. ; 7:18, s. 4953-4976
-
Tidskriftsartikel (refereegranskat)abstract
- An airfreight container with automated instruments for measurement of atmospheric gases and trace compounds was operated on a monthly basis onboard a Boeing 767-300 ER of LTU International Airways during long-distance flights from 1997 to 2002 (CARIBIC, Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container, http://www.caribic-atmospheric.com). Subsequently a more advanced system has been developed, using a larger capacity container with additional equipment and an improved inlet system. CARIBIC phase #2 was implemented on a new long-range aircraft type Airbus A340-600 of the Lufthansa German Airlines (Star Alliance) in December 2004, creating a powerful flying observatory. The instrument package comprises detectors for the measurement of O-3, total and gaseous H2O, NO and NOy, CO, CO2, O-2, Hg, and number concentrations of sub-micrometer particles (>4 nm, >12 nm, and >18 nm diameter). Furthermore, an optical particle counter (OPC) and a proton transfer mass spectrometer (PTR-MS) are incorporated. Aerosol samples are collected for analysis of elemental composition and particle morphology after flight. Air samples are taken in glass containers for laboratory analyses of hydrocarbons, halocarbons and greenhouse gases (including isotopic composition of CO2) in several laboratories. Absorption tubes collect oxygenated volatile organic compounds. Three differential optical absorption spectrometers (DOAS) with their telescopes mounted in the inlet system measure atmospheric trace gases such as BrO, HONO, and NO2. A video camera mounted in the inlet provides information about clouds along the flight track. The flying observatory, its equipment and examples of measurement results are reported.
|
|
| 4. |
- Martinsson, B., et al.
(författare)
-
Analyzing atmospheric trace gases and aerosols using passenger aircraft
- 2005
-
Ingår i: Eos. - 0096-3941. ; 86:8, s. 77-77
-
Forskningsöversikt (refereegranskat)abstract
- CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) resumed regular measurement flights with an extended scientific payload in December 2004. After an automated measurement container was successfully deployed on intercontinental flights using a Boeing 767 from 1997 to 2002, a far more powerful package now is deployed using a new Airbus A340‐600 made available by Lufthansa German Airlines (Star Alliance). The new CARIBIC system will help address a range of current atmospheric science questions during its projected lifetime of 10 years.European and Japanese scientists are developing a variety of atmospheric chemistry research and monitoring projects based on the use of passenger aircraft. This is a logical approach with a main advantage being that near‐global coverage is obtained, in contrast to limited coverage through research aircraftbased expeditions. Moreover, highly detailed and consistent data sets can be acquired, as compared to satellite observations in general. In addition, even compared to land‐based observatories, operational costs are moderate.
|
|
| 5. |
- Moron, M., et al.
(författare)
-
Gelation Dynamics upon Pressure-Induced Liquid-Liquid Phase Separation in a Water-Lysozyme Solution
- 2022
-
Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 126:22, s. 4160-4167
-
Tidskriftsartikel (refereegranskat)abstract
- Employing X-ray photon correlation spectroscopy, we measure the kinetics and dynamics of a pressure-induced liquid–liquid phase separation (LLPS) in a water–lysozyme solution. Scattering invariants and kinetic information provide evidence that the system reaches the phase boundary upon pressure-induced LLPS with no sign of arrest. The coarsening slows down with increasing quench depths. The g2 functions display a two-step decay with a gradually increasing nonergodicity parameter typical for gelation. We observe fast superdiffusive (γ ≥ 3/2) and slow subdiffusive (γ < 0.6) motion associated with fast viscoelastic fluctuations of the network and a slow viscous coarsening process, respectively. The dynamics age linearly with time τ ∝ tw, and we observe the onset of viscoelastic relaxation for deeper quenches. Our results suggest that the protein solution gels upon reaching the phase boundary.
|
|
| 6. |
- Shabalin, A. G., et al.
(författare)
-
Revealing Three-Dimensional Structure of an Individual Colloidal Crystal Grain by Coherent X-Ray Diffractive Imaging
- 2016
-
Ingår i: Physical Review Letters. - 0031-9007. ; 117:13
-
Tidskriftsartikel (refereegranskat)abstract
- We present results of a coherent x-ray diffractive imaging experiment performed on a single colloidal crystal grain. The full three-dimensional (3D) reciprocal space map measured by an azimuthal rotational scan contained several orders of Bragg reflections together with the coherent interference signal between them. Applying the iterative phase retrieval approach, the 3D structure of the crystal grain was reconstructed and positions of individual colloidal particles were resolved. As a result, an exact stacking sequence of hexagonal close-packed layers including planar and linear defects were identified.
|
|
| 7. |
- Shen, L., et al.
(författare)
-
Interplay between relaxational atomic fluctuations and charge density waves in La2-xSrxCuO4
- 2023
-
Ingår i: Physical Review B. - 2469-9950. ; 108:20
-
Tidskriftsartikel (refereegranskat)abstract
- In the cuprate superconductors, the spatial coherence of the charge density wave (CDW) state grows below a temperature TCDW, the origin of which is debated. Using x-ray photon correlation spectroscopy, we have studied the temporal atomic relaxation dynamics in La1.88Sr0.12CuO4 to shed light on this question. Cooling within an emergent structurally distorted phase, which favors the CDW modulation in symmetry and develops in two stages between 180 and 120 K, we observe a crossover from cooperativelike to incoherentlike relaxation dynamics at TCDW=75(10) K. We argue that, if the CDW is hosted by this distortion, the concomitant relaxational crossover and enhancement of CDW spatial coherence supports the interplay between relaxational atomic fluctuations and CDWs in materials of this class on quasistatic times cales.
|
|
| 8. |
- Martin-Loeches, I, et al.
(författare)
-
Use of early corticosteroid therapy on ICU admission in patients affected by severe pandemic (H1N1)v influenza A infection
- 2011
-
Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 37:2, s. 272-283
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection, although relatively common, remains controversial. METHODS: Prospective, observational, multicenter study from 23 June 2009 through 11 February 2010, reported in the European Society of Intensive Care Medicine (ESICM) H1N1 registry. RESULTS: Two hundred twenty patients admitted to an intensive care unit (ICU) with completed outcome data were analyzed. Invasive mechanical ventilation was used in 155 (70.5%). Sixty-seven (30.5%) of the patients died in ICU and 75 (34.1%) whilst in hospital. One hundred twenty-six (57.3%) patients received corticosteroid therapy on admission to ICU. Patients who received corticosteroids were significantly older and were more likely to have coexisting asthma, chronic obstructive pulmonary disease (COPD), and chronic steroid use. These patients receiving corticosteroids had increased likelihood of developing hospital-acquired pneumonia (HAP) [26.2% versus 13.8%, p < 0.05; odds ratio (OR) 2.2, confidence interval (CI) 1.1-4.5]. Patients who received corticosteroids had significantly higher ICU mortality than patients who did not (46.0% versus 18.1%, p < 0.01; OR 3.8, CI 2.1-7.2). Cox regression analysis adjusted for severity and potential confounding factors identified that early use of corticosteroids was not significantly associated with mortality [hazard ratio (HR) 1.3, 95% CI 0.7-2.4, p = 0.4] but was still associated with an increased rate of HAP (OR 2.2, 95% CI 1.0-4.8, p < 0.05). When only patients developing acute respiratory distress syndrome (ARDS) were analyzed, similar results were observed. CONCLUSIONS: Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection did not result in better outcomes and was associated with increased risk of superinfections.
|
|
| 9. |
|
|
| 10. |
- Slemr, F., et al.
(författare)
-
Gaseous mercury distribution in the upper troposphere and lower stratosphere observed onboard the CARIBIC passenger aircraft
- 2009
-
Ingår i: Atmospheric Chemistry and Physics. - 1680-7324. ; 9:6, s. 1957-1969
-
Tidskriftsartikel (refereegranskat)abstract
- Total gaseous mercury (TGM) was measured onboard a passenger aircraft during monthly CARIBIC flights (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrumented Container) made between May 2005 and March 2007 on the routes Frankfurt-Sao Paulo-Santiago de Chile and back and Frankfurt-Guangzhou-Manila and back. The data provide for the first time an insight into the seasonal distributions of TGM in the upper troposphere and lower stratosphere (UT/LS) of both hemispheres and demonstrate the importance of mercury emissions from biomass burning in the Southern Hemisphere. Numerous plumes were observed in the upper troposphere, the larger of which could be characterized in terms of Hg/CO emission ratios and their probable origins. During the flights to China TGM correlated with CO in the upper troposphere with a seasonally dependent slope reflecting the longer lifetime of elemental mercury when compared to that of CO. A pronounced depletion of TGM was always observed in the extratropical lowermost stratosphere. TGM concentrations there were found to decrease with the increasing concentrations of particles. Combined with the large concentrations of particle bond mercury in the stratosphere observed by others, this finding suggests either a direct conversion of TGM to particle bound mercury or an indirect conversion via a semivolatile bivalent mercury compound. Based on concurrent measurements of SF6 during two flights, the rate of this conversion is estimated to 0.4 ng m(-3) yr(-1). A zero TGM concentration was not observed during some 200 flight hours in the lowermost stratosphere suggesting an equilibrium between the gaseous and particulate mercury.
|
|
| 11. |
- Sprung, C. L., et al.
(författare)
-
Seeking Worldwide Professional Consensus on the Principles of End-of-Life Care for the Critically III The Consensus for Worldwide End-of-Life Practice for Patients in Intensive Care Units (WELPICUS) Study
- 2014
-
Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1073-449X. ; 190:8, s. 855-866
-
Tidskriftsartikel (refereegranskat)abstract
- Great differences in end-of-life practices in treating the critically ill around the world warrant agreement regarding the major ethical principles. This analysis determines the extent of worldwide consensus for end-of-life practices, delineates where there is and is not consensus, and analyzes reasons for lack of consensus. Critical care societies worldwide were invited to participate. Country coordinators were identified and draft statements were developed for major end-of-life issues and translated into six languages. Multidisciplinary responses using a web-based survey assessed agreement or disagreement with definitions and statements linked to anonymous demographic information. Consensus was prospectively defined as >80% agreement. Definitions and statements not obtaining consensus were revised based on comments of respondents, and then translated and redistributed. Of the initial 1,283 responses from 32 countries, consensus was found for 66(81%) of the 81 definitions and statements; 26 (32%) had >90% agreement. With 83 additional responses to the original questionnaire (1,366 total) and 604 responses to the revised statements, consensus could be obtained for another 11 of the 15 statements. Consensus was obtained for informed consent, withholding and withdrawing life-sustaining treatment, legal requirements, intensive care unit therapies, cardiopulmonary resuscitation, shared decision making, medical and nursing consensus, brain death, and palliative care. Consensus was obtained for 77 of 81 (95%) statements. Worldwide consensus could be developed for the majority of definitions and statements about end-of-life practices. Statements achieving consensus provide standards of practice for end-of-life care; statements without consensus identify important areas for future research.
|
|
| 12. |
- A. B. Marçal, L., et al.
(författare)
-
Spatially resolved structural and chemical properties of the white layer in machined Inconel 718 super alloy
- 2024
-
Ingår i: Materials and Design. - 0264-1275. ; 239
-
Tidskriftsartikel (refereegranskat)abstract
- Inconel 718 is one type of nickel-based alloy used for a large range of applications, including gas turbines and aeroengines components. Although mechanical and thermodynamic properties of this material have been deeply studied in the past years, a method able to investigate local properties of the thin white layer formed on the alloy surface after machining remains challenging. Here, a 90 nm X-ray beam is used to probe the local strain, crystal orientation, and chemical composition of grains in the white layer. Data reveals mosaicity induced by the tool during machining. The high spatial resolution, combined with crystal lattice sensitivity, shows that the average grain size is around 30 nm throughout the white layer, while the strain is anisotropic nearest to the surface. Results provide new insights on the basic properties of the white layer in super alloys, revealing important information about the impact of finish machining which might help to explain fatigue and cracking formation on these materials during their usage phase.
|
|
| 13. |
- Ebrahimi, M., et al.
(författare)
-
A Systematic Approach to Automotive Security
- 2023
-
Ingår i: Lecture Notes in Computer Science, vol 14000. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783031274800 ; , s. 598-609
-
Konferensbidrag (refereegranskat)abstract
- We propose a holistic methodology for designing automotive systems that consider security a central concern at every design stage. During the concept design, we model the system architecture and define the security attributes of its components. We perform threat analysis on the system model to identify structural security issues. From that analysis, we derive attack trees that define recipes describing steps to successfully attack the system’s assets and propose threat prevention measures. The attack tree allows us to derive a verification and validation (V &V) plan, which prioritizes the testing effort. In particular, we advocate using learning for testing approaches for the black-box components. It consists of inferring a finite state model of the black-box component from its execution traces. This model can then be used to generate new relevant tests, model check it against requirements, and compare two different implementations of the same protocol. We illustrate the methodology with an automotive infotainment system example. Using the advocated approach, we could also document unexpected and potentially critical behavior in our example systems.
|
|
| 14. |
- Jo, W., et al.
(författare)
-
Nanosecond X-ray photon correlation spectroscopy using pulse time structure of a storage-ring source
- 2021
-
Ingår i: IUCrJ. - : International Union of Crystallography. - 2052-2525. ; 8, s. 124-130
-
Tidskriftsartikel (refereegranskat)abstract
- X-ray photon correlation spectroscopy (XPCS) is a routine technique to study slow dynamics in complex systems at storage-ring sources. Achieving nanosecond time resolution with the conventional XPCS technique is, however, still an experimentally challenging task requiring fast detectors and sufficient photon flux. Here, the result of a nanosecond XPCS study of fast colloidal dynamics is shown by employing an adaptive gain integrating pixel detector (AGIPD) operated at frame rates of the intrinsic pulse structure of the storage ring. Correlation functions from single-pulse speckle patterns with the shortest correlation time of 192 ns have been calculated. These studies provide an important step towards routine fast XPCS studies at storage rings. © 2021.
|
|
| 15. |
- Macucci, M., et al.
(författare)
-
Status and perspectives of nanoscale device modelling
- 2001
-
Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 12:2, s. 136-142
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- During the meetings of the theory and modelling working group, within the MEL-ARI (Microelectronics Advanced Research Initiative) and NID-FET (Nanotechnology Information Devices-Future and Emerging Technologies) initiatives of the European Commission, we have been discussing the current status and the future perspectives of nanoscale device modelling. The outcome of such a discussion is summarized in the present paper, outlining the major challenges for the future, such as the integration of nonequilibrium phenomena and of molecular-scale properties. We believe that modelling has a growing importance in the development of nanoelectronic devices and must therefore make a move from physics to engineering, providing valid design tools, with quantitative predictive capabilities.
|
|
| 16. |
- Perakis, Fivos, et al.
(författare)
-
Diffusive dynamics during the high-to-low density transition in amorphous ice
- 2017
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:31, s. 8193-8198
-
Tidskriftsartikel (refereegranskat)abstract
- Water exists in high- and low-density amorphous ice forms (HDA and LDA), which could correspond to the glassy states of high(HDL) and low-density liquid (LDL) in the metastable part of the phase diagram. However, the nature of both the glass transition and the high-to-low-density transition are debated and new experimental evidence is needed. Here we combine wide-angle X-ray scattering (WAXS) with X-ray photon-correlation spectroscopy (XPCS) in the small-angle X-ray scattering (SAXS) geometry to probe both the structural and dynamical properties during the high-to-low-density transition in amorphous ice at 1 bar. By analyzing the structure factor and the radial distribution function, the coexistence of two structurally distinct domains is observed at T = 125 K. XPCS probes the dynamics in momentum space, which in the SAXS geometry reflects structural relaxation on the nanometer length scale. The dynamics of HDA are characterized by a slow component with a large time constant, arising from viscoelastic relaxation and stress release from nanometer-sized heterogeneities. Above 110 K a faster, strongly temperature-dependent component appears, with momentum transfer dependence pointing toward nanoscale diffusion. This dynamical component slows down after transition into the low-density form at 130 K, but remains diffusive. The diffusive character of both the high- and low-density forms is discussed among different interpretations and the results are most consistent with the hypothesis of a liquid-liquid transition in the ultraviscous regime.
|
|
| 17. |
- Serpa Neto, Ary, et al.
(författare)
-
Protective versus Conventional Ventilation for Surgery : A Systematic Review and Individual Patient Data Meta-analysis
- 2015
-
Ingår i: Anesthesiology. - 0003-3022 .- 1528-1175. ; 123:1, s. 66-78
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent studies show that intraoperative mechanical ventilation using low tidal volumes (VT) can prevent postoperative pulmonary complications (PPCs). The aim of this individual patient data meta-analysis is to evaluate the individual associations between VT size and positive end-expiratory pressure (PEEP) level and occurrence of PPC.METHODS: Randomized controlled trials comparing protective ventilation (low VT with or without high levels of PEEP) and conventional ventilation (high VT with low PEEP) in patients undergoing general surgery. The primary outcome was development of PPC. Predefined prognostic factors were tested using multivariate logistic regression.RESULTS: Fifteen randomized controlled trials were included (2,127 patients). There were 97 cases of PPC in 1,118 patients (8.7%) assigned to protective ventilation and 148 cases in 1,009 patients (14.7%) assigned to conventional ventilation (adjusted relative risk, 0.64; 95% CI, 0.46 to 0.88; P < 0.01). There were 85 cases of PPC in 957 patients (8.9%) assigned to ventilation with low VT and high PEEP levels and 63 cases in 525 patients (12%) assigned to ventilation with low VT and low PEEP levels (adjusted relative risk, 0.93; 95% CI, 0.64 to 1.37; P = 0.72). A dose-response relationship was found between the appearance of PPC and VT size (R = 0.39) but not between the appearance of PPC and PEEP level (R = 0.08).CONCLUSIONS: These data support the beneficial effects of ventilation with use of low VT in patients undergoing surgery. Further trials are necessary to define the role of intraoperative higher PEEP to prevent PPC during nonopen abdominal surgery.
|
|
| 18. |
- Tenore, K. R., et al.
(författare)
-
Characterizing the role benthos plays in large coastal seas and estuaries: A modular approach
- 2006
-
Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier BV. - 0022-0981. ; 330:1, s. 392-402
-
Tidskriftsartikel (refereegranskat)abstract
- Ecologists studying coastal and estuarine benthic communities have long taken a macroecological view, by relating benthic community patterns to environmental factors across several spatial scales. Although many general ecological patterns have been established, often a significant amount of the spatial and temporal variation in soft-sediment communities within and among systems remains unexplained. Here we propose a framework that may aid in unraveling the complex influence of environmental factors associated with the different components of coastal systems (i.e. the terrestrial and benthic landscapes, and the hydrological seascape) on benthic communities, and use this information to assess the role played by benthos in coastal ecosystems. A primary component of the approach is the recognition of system modules (e.g. marshes, dendritic systems, tidal rivers, enclosed basins, open bays, lagoons). The modules may differentially interact with key forcing functions (e.g. temperature, salinity, currents) that influence system processes and in turn benthic responses and functions. Modules may also constrain benthic characteristics and related processes within certain ecological boundaries and help explain their overall spatio-temporal variation. We present an example of how benthic community characteristics are related to the modular structure of 14 coastal seas and estuaries, and show that benthic functional group composition is significantly related to the modular structure of these systems. We also propose a framework for exploring the role of benthic communities in coastal systems using this modular approach and offer predictions of how benthic communities may vary depending on the modular composition and characteristics of a coastal system. (C) 2006 Elsevier B.V. All rights reserved.
|
|
