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OBJECTIVE: To evaluate the surgical management of thyroid pathologies at the Reference General Hospital. METHODS: This was a retro-prospective study over 4 years 6 months carried out in the departments of General and Digestive Surgery (GDS) and Otorhinolaryngology and Cervico Facial Surgery (ORL/FCS). It involved 182 patients who underwent thyroid surgery. RESULTS: A frequency of thyroidectomy of 9.46% was found. Females predominated with a sex ratio of 0.1. The average age of patients was 42.85 years, a standard deviation 12.80. 84.06% of patients had consulted for anterior cervical mass. EU-TIRADS score 3 represented 7,14% of cases. Heteromultinodular goiter was the main indication for thyroid surgery (59.34%). Total thyroidectomy was the most commonly performed gesture in general surgery in 88,23% (n = 105), in Otorhinolaryngology, it was in the same proportion as lobo-isthmectomy at 47.61% (n = 30). The first route was video-assisted thyroidectomy 2.2% (n = 4). The recurrent laryngeal nerve was dissected and seen in 159 cases (87.36%) and parathyroid glands were also seen and preserved in 58.24% of cases (n = 106). In immediate postoperative surgery, the main complications were unilateral recurrent paralysis with dysphonia in 3.3% (n = 6) and compressive hematoma in 2.2% (n = 4). No deaths had been recorded. CONCLUSION: Total thyroidectomy was the most performed procedure in department of General and Digestive Surgery. Routine oral calcium and vitamin D supplementation in the general surgery ward, reduces the occurrence of hypocalcemia after total thyroidectomy and allows a safe and early exit. Standardizing protocols will further reduce complications.

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The Miocene was a key time in the evolution of African ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here, we report the first Miocene fossil teeth from the shoulders of the Urema Rift in Gorongosa National Park, Mozambique. We provide the first 1) radiometric ages of the Mazamba Formation, 2) reconstructions of paleovegetation in the region based on pedogenic carbonates and fossil wood, and 3) descriptions of fossil teeth. Gorongosa is unique in the East African Rift in combining marine invertebrates, marine vertebrates, reptiles, terrestrial mammals, and fossil woods in coastal paleoenvironments. The Gorongosa fossil sites offer the first evidence of woodlands and forests on the coastal margins of southeastern Africa during the Miocene, and an exceptional assemblage of fossils including new species.

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We explored hand ownership in teenagers with unilateral cerebral palsy (UCP) compared with typically developing teenagers. Eighteen participants with UCP and 16 control teenagers participated. We used the rubber hand illusion to test hand ownership (HO). Both affected/non-affected hands (UCP) and dominant/non-dominant hands (controls) were tested during synchronous and asynchronous strokes. HO was assessed by measuring the proprioceptive drift toward the fake hand (as a percentage of arm length) and conducting a questionnaire on subjective HO. Both groups had significantly higher proprioceptive drift in the synchronous stroking condition for both hands. Teenagers with UCP showed a significantly higher proprioceptive drift when comparing their paretic hand (median 3.4% arm length) with the non-dominant hand of the controls (median 1.7% arm length). The questionnaires showed that synchronous versus asynchronous stroking generated a robust change in subjective HO in the control teenagers, but not in the teenagers with UCP. Teenagers with UCP have an altered sense of HO and a distorted subjective experience of HO that may arise from the early dysfunction of complex sensory-motor integration related to their brain lesions. HO may influence motor impairment and prove to be a target for early intervention.

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Contaminants of emerging concern (CEC) are a focus in marine protection. Several CECs are released with wastewater effluents to coastal environments and their offshore occurrence has been recently documented. Routine monitoring is key for implementing marine protection acts, however infrastructural, financial, and technical limitations hinder this task along broad spatial transects. Here we show the efficacy of a new infrastructure enabling unmanned sampling of surface water from ships of opportunity in providing reliable and cost-effective routine monitoring of CECs along a Europe-Arctic transect. The distribution and long-range transport of several pharmaceuticals and personal care products, artificial food additives, and stimulants were assessed. Validation of operations through strict procedural and analytical quality criteria is presented. A framework to estimate a compound-specific spatial range (SR) index of marine long-range transport based on monitoring results and information on source spatial distribution, is introduced. Estimated SR values ranged 50-350 km depending on compound, yielding a ranking of long-range transport potential which reflected expectations based on degradation half-lives. SR values were used to calculate prior maps of detection probability that can be used to plan future routine monitoring in the region.

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Dissolved organic matter (DOM) can play a major role in determining availability of pollutants to aquatic biota. Equilibrium dialysis is the most commonly used method to assess the interaction between DOM and organic contaminants. However, results obtained through this method can be affected by confounding factors linked to the diffusion of DOM through the membrane or the interaction of DOM and/or the compounds with the membrane itself. In this study, we propose an improved experimental approach, where highly hydrophilic cellulose-ester membranes with small molecular cut-off (100-500 Da) were used to overcome some of these hindrances. The performance of the method to determine the binding of a commonly used moderately hydrophobic herbicide (Isoproturon - ISU) with natural DOM was critically evaluated through a set of quality assurance criteria, across a range of DOM concentrations and pH conditions. DOM trans-membrane diffusion was prevented by the smaller pore size of the dialysis membrane. Good measurement reproducibility, mass balance closure, and successful trans-membrane equilibrium of ISU were obtained. ISU showed relatively low affinity with DOM (log KDOC 1-2 L g-1), which was significantly influenced by varying pH and DOM concentration. An alternative membrane may be needed for higher pH conditions as the greater adsorption effect blurred the observation of trans-membrane equilibrium and confounding mass balance closure. The paper makes recommendations on how to avoid measurement artefacts, while considering criteria for the expected mass distribution of compounds at equilibrium and for sorption onto the membrane and surfaces of the experimental units.

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Information on how key environmental conditions such as natural dissolved organic matter (DOM) and water pH alter the possible risks posed by pharmaceuticals (PPCPs) is still scarce. In our previous study, the presence of natural DOM at high pH reduced the toxicity of a mix of waterborne PPCPs to algae. DOM-complexation and pH effect on speciation of the more hydrophobic and neutral compounds of the mix was suggested to be driving this behaviour. However, the study design did not allow the verification of this hypothesis. Here, the DOM- PPCPs interaction at different pH was investigated for 6 PPCPs through equilibrium dialysis, under the same conditions of DOM and pH as our previous study. Association with DOM was confirmed for the more hydrophobic PPCPs at high pH. The results suggest the binding was driven by i) the presence of carboxylic groups of PPCPs, ii) high pH shifting the structural configuration of DOM, making it more suited to bind some of the PPCPs. A non-linear change of binding capacity with increasing DOM concentration was also observed among the tested PPCPs.

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Microplastic (plastic particles measuring <5mm) pollution is ubiquitous. Unlike in other well-studied ecosystems, for example, marine and freshwater environments, microplastics in terrestrial systems are relatively understudied. Their potential impacts on terrestrial environments, in particular the risk of causing ecological surprise, must be better understood and quantified. Ecological surprise occurs when ecosystem behavior deviates radically from expectations and generally has negative consequences for ecosystem services. The properties and behavior of microplastics within terrestrial environments may increase their likelihood of causing ecological surprises as they (a) are highly persistent global pollutants that will last for centuries, (b) can interact with the abiotic environment in a complex manner, (c) can impact terrestrial organisms directly or indirectly and (d) interact with other contaminants and can facilitate their transport. Here, we compiled findings of previous research on microplastics in terrestrial environments. We systematically focused on studies addressing different facets of microplastics related to their distribution, dispersion, impact on soil characteristics and functions, levels of biological organization of tested terrestrial biota (single species vs. assemblages), scale of experimental study and corresponding ecotoxicological effects. Our systematic assessment of previous microplastic research revealed that most studies have been conducted on single species under laboratory conditions with short-term exposures; few studies were conducted under more realistic long-term field conditions and/or with multi-species assemblages. Studies targeting multi-species assemblages primarily considered soil bacterial communities and showed that microplastics can alter essential nutrient cycling functions. More ecologically meaningful studies of terrestrial microplastics encompassing multi-species assemblages, critical ecological processes (e.g., biogeochemical cycles and pollination) and interactions with other anthropogenic stressors must be conducted. Addressing these knowledge gaps will provide a better understanding of microplastics as emerging global stressors and should lower the risk of ecological surprise in terrestrial ecosystems.

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Submerged macrophytes are of key importance for the structure and functioning of shallow lakes and can be decisive for maintaining them in a clear water state. The ongoing climate change affects the macrophytes through changes in temperature and precipitation, causing variations in nutrient load, water level and light availability. To investigate how these factors jointly determine macrophyte dominance and growth, we conducted a highly standardized pan-European experiment involving the installation of mesocosms in lakes. The experimental design consisted of mesotrophic and eutrophic nutrient conditions at 1 m (shallow) and 2 m (deep) depth along a latitudinal temperature gradient with average water temperatures ranging from 14.9 to 23.9°C (Sweden to Greece) and a natural drop in water levels in the warmest countries (Greece and Turkey). We determined percent plant volume inhabited (PVI) of submerged macrophytes on a monthly basis for 5 months and dry weight at the end of the experiment. Over the temperature gradient, PVI was highest in the shallow mesotrophic mesocosms followed by intermediate levels in the shallow eutrophic and deep mesotrophic mesocosms, and lowest levels in the deep eutrophic mesocosms. We identified three pathways along which water temperature likely affected PVI, exhibiting (a) a direct positive effect if light was not limiting; (b) an indirect positive effect due to an evaporation-driven water level reduction, causing a nonlinear increase in mean available light; and (c) an indirect negative effect through algal growth and, thus, high light attenuation under eutrophic conditions. We conclude that high temperatures combined with a temperature-mediated water level decrease can counterbalance the negative effects of eutrophic conditions on macrophytes by enhancing the light availability. While a water level reduction can promote macrophyte dominance, an extreme reduction will likely decrease macrophyte biomass and, consequently, their capacity to function as a carbon store and food source.

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The use of discontinuity analysis to assess resilience and alternative regimes of ecosystems has mostly been based on animal size. We so far lack systematic comparisons of size-based and abundance-based approaches necessary for assessing the performance and suitability of the discontinuity analysis across a broader range of organism groups. We used an outdoor mesocosm setup to mimic shallow lake ecosystems with different depths (1.2 m deep, "shallow"; 2.2 m deep, "deep") and trophic status (i.e. low and high nutrient status characteristic of mesotrophic and hypertrophic lakes, respectively). We compared resilience assessments, based on four indicators (cross-scale structure, within-scale structure, aggregation length and gap size) inferred from the size and abundance (biovolume) structure of phytoplankton communities. Our results indicate that resilience assessments based on size and biovolume were largely comparable, which is likely related to similar variability in the size and abundance of phytoplankton as a function of nutrient concentrations. Also, nutrient enrichment rather than water depth influenced resilience, manifested in decreased cross-scale structure and increased aggregation lengths and gap sizes in the high-nutrient treatment. These resilience patterns coupled with decreased phytoplankton diversity and dominance of cyanobacteria in the high nutrient treatment support the use of discontinuity analysis for testing alternative regimes theory. Concordance of size-based and abundance-based results highlights the approach as being potentially robust to infer resilience in organism groups that lack discrete size structures.

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The acquisition of tolerance to an environmental stressor can result in organisms displaying slower growth after stress release. While well-grounded in the theory, empirical evidence of the trade-off between stress tolerance and organism fitness is scarce and blurred by the interaction with different environmental factors. Here, we report the effects of water browning on the responses, tolerance acquisition, and associated trade-offs in a population of microalgae exposed to sublethal concentrations of organic micropollutants over multiple generations. Our results show that dissolved organic matter (DOM) reduces toxic responses and modulates tolerance acquisition by the algae, possibly by complexing micropollutants. Microalgae that acquire tolerance allocate resources to fitness at the cost of reduced cell size. They yield higher productivity than nonadapted ones when grown in the presence of micropollutants but lower in their absence. The net trade-off was positive, indicating that adaptation can result in a higher productivity and fitness in tolerant species in recurrently stressed environments.

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Freshwaters are increasingly exposed to complex mixtures of pharmaceutical and personal care products (PPCPs) from municipal wastewater, which are known to alter freshwater communities' structure and functioning. However, their interaction with other disturbances and whether their combined effects can impact ecological resilience (i.e., the ability of a system to tolerate disturbances without altering the system's original structure and processes) remain unexplored. Using in situ mesocosms in 2 lakes with different nutrient levels (mesotrophic and eutrophic), we assessed whether a pulse exposure to sublethal concentrations of 12 PPCPs affects the ecological resilience of natural phytoplankton communities that experienced an abrupt environmental change involving the destabilization of the water column through mixing. Such mixing events are predicted to increase as the effects of climate change unfold, leading to more frequent storms, which disrupt stratification in lakes and force communities to restructure. We assessed their combined effects on community metrics (biomass, species richness, and composition) and their relative resilience using 4 indicators (cross-scale, within-scale, aggregation length, and gap length), inferred from phytoplankton communities by discontinuity analysis. The mixing disturbance alone had negligible effects on the community metrics, but when combined with chemical contaminants significant changes were measured: reducing total biomass, species richness, and altered community composition of phytoplankton. Once these changes occurred, they persisted until the end of the experiment (day 20), when the communities' structures from the 2 highest exposure levels diverged from the controls. The resilience indicators were not affected by PPCPs but differed significantly between lakes, with lower resilience found in the eutrophic lake. Thus, PPCPs can significantly alter community structures and reinforce mechanisms that maintain ecosystems in a "degraded state." Environ Toxicol Chem 2019;38:2197-2208. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

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The presence of a multitude of bioactive organic pollutants collectively classified as pharmaceuticals and personal care products (PPCPs) in freshwaters is of concern, considering that ecological assessments of their potential impacts on natural systems are still scarce. In this field experiment we tested whether a single pulse exposure to a mixture of 12 pharmaceuticals and personal care products, which are commonly found in European inland waters, can influence the size distributions of natural lake phytoplankton communities. Size is one of the most influential determinants of community structure and functioning, particularly in planktonic communities and food webs. Using an in-situ microcosm approach, phytoplankton communities in two lakes with different nutrient levels (mesotrophic and eutrophic) were exposed to a concentration gradient of the PPCPs mixture at five levels. We tested whether sub-lethal PPCPs doses affect the scaling of organisms' abundances with their size, and the slope of these size spectra, which describe changes in the abundances of small relative to large phytoplankton. Our results showed that a large proportion (approximately 80%) of the dataset followed a power-law distribution, thus suggesting evidence of scale invariance of abundances, as expected in steady state ecosystems. PPCPs were however found to induce significant changes in the size spectra and community structure of natural phytoplankton assemblages. The two highest treatment levels of PPCPs were associated with decreased abundance of the most dominant size class (nano-phytoplankton: 2-5 µm), leading to a flattening of the size spectra slope. These results suggest that a pulse exposure to PPCPs induce changes that potentially lead to unsteady ecosystem states and cascading effects in the aquatic food webs, by favoring larger non-edible algae at the expense of small edible species. We propose higher susceptibility due to higher surface to volume ratio in small species as the likely cause of these structural changes.

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Cervicothoracic cellulitis is a very serious, potentially life-threatening infection of the cervical and thoracic soft tissue. It is a genuine medical and surgical emergency with substantial mortality, and its surgical therapy has not yet been standardized. It spreads through the layers of the cervical fascia and can then disseminate to the mediastinum and the pleural cavities, requiring specific management that includes the thoracic surgeon. We present reports of 3 patients with cervicothoracic cellulitis, all complicated by mediastinitis, with pericardial effusion in 1 case and unilateral or bilateral pyothorax in 2 cases. Combining these cases with a review of the literature enables us to describe the management of these complicated cases as seen by a thoracic surgeon.

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BACKGROUND: This paper aims to identify factors that influence the capacity of women to voice their concerns regarding maternal health services at the local level. METHODS: A secondary analysis was conducted of the data from three studies carried out between 2013 and 2015 in the Democratic Republic of the Congo (DRC) in the context of a WOTRO initiative to improve maternal health services through social accountability mechanisms in the DRC. The data processing and analysis focused on data related to factors that influence the capacity of women to voice their concerns and on the characteristics of women that influence their ability to identify, and address specific problems. Data from 21 interviews and 12 focus group discussions (n = 92) were analysed using an inductive content analysis, and those from one household survey (n = 517) were summarized. RESULTS: The women living in the rural setting were mostly farmers/fisher-women (39.7%) or worked at odd jobs (20.3%). They had not completed secondary school (94.6%). Around one-fifth was younger than 20 years old (21.9%). The majority of women could describe the health service they received but were not able to describe what they should receive as care. They had insufficient knowledge of the health services before their first visit. They were not able to explain the mandate of the health providers. The information they received concerned the types of healthcare they could receive but not the real content of those services, nor their rights and entitlements. They were unaware of their entitlements and rights. They believed that they were laypersons and therefore unable to judge health providers, but when provided with some tools such as a checklist, they reported some abusive and disrespectful treatments. However, community members asserted that the reported actions were not reprehensible acts but actions to encourage a woman and to make her understand the risk of delivery. CONCLUSIONS: Factors influencing the capacity of women to voice their concerns in DRC rural settings are mainly associated with insufficient knowledge and socio-cultural context. These findings suggest that initiatives to implement social accountability have to address community capacity-building, health providers' responsiveness and the socio-cultural norms issues.

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We analyzed phytolith and diatom remains preserved at 45 Miocene and Pliocene localities dated between 8 and 1 Ma in northern Chad (16-17°N). Some of these localities yielded cranial remains, lower jaws, and teeth of the hominin species Australopithecus bahrelghazali (∼3.6 Ma) and Sahelanthropus tchadensis (∼7 Ma). Of the 111 sediment samples analyzed, 41 yielded phytoliths, 20 yielded diatoms, and seven yielded both phytoliths and diatoms. Freshwater planktonic and tychoplanktonic diatom species, indicative of lacustrine conditions, are dominant (>91%) in the samples. The phytolith assemblages indicate an opening of the vegetation and a general trend toward an expansion of grass-dominated environments during the time spanning the two hominin occurrences in Chad. The phytoliths suggest the presence of a mosaic environment, including closed forest patches, palm groves, and mixed/grassland formations, between 7.5 and 7 Ma, the replacement by palm grove-like vegetation at approximately 6.5-5 Ma, and the presence of exclusive grass-dominated formations after 4.5 Ma. The type-locality of S. tchadensis (TM266) was likely similar to modern palm grove formations with an arboreal cover percentage ≥40%. The type locality of A. bahrelghazali (KT12) was a grass-dominated ecosystem (likely savanna) with an unrated percentage of arboreal cover. Furthermore, the grass phytolith data support the existence of a (recurrent) Sahelian-like dry climate in northern Chad since at least 8 Ma. Therefore the local closed vegetation formations in the Djurab region at 7.5-7 Ma were sustained by aquatic systems (such as lakes or related rivers, marshes) rather than by extensive annual precipitation.

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Quantitative approaches to measure and assess resilience are needed to bridge gaps between science, policy and management. In this paper, we revisit definitions of resilience and suggest a quantitative framework for assessing ecological resilience sensu Holling (1973). Ecological resilience as an emergent ecosystem phenomenon can be decomposed into complementary attributes (scales, adaptive capacity, thresholds and alternative regimes) that embrace the complexity inherent to ecosystems. Quantifying these attributes simultaneously provides opportunities to move from the assessment of specific resilience within an ecosystem towards a broader measurement of its general resilience. We provide a framework, based on testable hypotheses, which allows assessment of complementary attributes of ecological resilience. By implementing the framework in adaptive approaches to management, inference and modeling, key uncertainties can be reduced incrementally over time and learning about the general resilience of dynamic ecosystems maximized. Such improvements are needed because uncertainty about global environmental change impacts and their effects on resilience is high. Improved resilience assessments will ultimately facilitate an optimized use of limited resources for management.

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Both the anatase (A) and rutile (R) phases of titanium oxide have shown enhanced antimicrobial and bioactivity levels but the specific A/R phase ratio needed for the best results is still unknown. In this study titanium samples were anodized to produce specific ratios of anatase and rutile phases within the oxide layers. Specific ratios produced included maximum A minimum R, minimum A maximum R, 50% A 50% R, minimum A minimum R, and a non-anodized titanium control group. Samples were characterized for phase distributions within the oxide layers, surface porosity, corrosion resistance, and bioactivity. Results indicated the targeted phase ratios were reproducibly achieved during the anodization process. Samples containing the highest levels of anatase showed the largest individual pore sizes, but a lower overall percent porosity value compared to samples containing higher rutile levels. EBSD examination of the anodized layer cross-sections provided valuable new spatial information on the distribution of anatase and rutile phases within the anodized layers. Highly porous oxide layers showed significantly higher corrosion rates compared to non-anodized titanium, but no significant differences were shown in the icorr values between samples containing primarily anatase phase, samples containing primarily rutile phase, and samples containing an approximate 50:50 mixture of the two phases. Minimum A minimum R samples showed substantially less porosity compared to the other anodization groups, a significantly lower oxide thickness, and comparable corrosion rates to non-anodized titanium. All samples within the study showed apatite production in simulated body fluid within the seven day test period indicating enhanced bioactivity.

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Geomagnetic dipole moment variations associated with polarity reversals and excursions are expressed by large changes of the cosmogenic nuclide beryllium-10 (10Be) production rates. Authigenic 10Be/9Be ratios (proxy of atmospheric 10Be production) from oceanic cores therefore complete the classical information derived from relative paleointensity (RPI) records. This study presents new authigenic 10Be/9Be ratio results obtained from cores MD05-2920 and MD05-2930 collected in the west equatorial Pacific Ocean. Be ratios from cores MD05-2920, MD05-2930 and MD90-0961 have been stacked and averaged. Variations of the authigenic 10Be/9Be ratio are analyzed and compared with the geomagnetic dipole low series reported from global RPI stacks. The largest 10Be overproduction episodes are related to dipole field collapses (below a threshold of 2 × 1022 Am2) associated with the Brunhes/Matuyama reversal, the Laschamp (41 ka) excursion, and the Iceland Basin event (190 ka). Other significant 10Be production peaks are correlated to geomagnetic excursions reported in literature. The record was then calibrated by using absolute dipole moment values drawn from the Geomagia and Pint paleointensity value databases. The 10Be-derived geomagnetic dipole moment record, independent from sedimentary paleomagnetic data, covers the Brunhes-Matuyama transition and the whole Brunhes Chron. It provides new and complementary data on the amplitude and timing of millennial-scale geomagnetic dipole moment variations and particularly on dipole moment collapses triggering polarity instabilities.

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INTRODUCTION: Subcutaneous tumors with extra limbs are very rare, and they are considered either as fetus in fetu or fetiform teratoma. CASE REPORT: We report here the case of a 6-day-old presenting a mass extending at the level of the occipital bone. This mass is developed in the extracranial region and contains two forelimbs including hands with digits. CT shows that the squamous part of the occipital bone is involved with several defects through which a part of the cerebellum herniates. The boy was operated on and the tumor was removed. The herniated region of the cerebellum has also been removed. After surgery, the boy develops normally. CONCLUSION: This type of tumor is extremely rare and is only the second case that has been reported at this exact location. This could be the so-called céphalomélie described by Isidore Geoffroy Saint-Hilaire in a duck in his famous Treatise of Teratology (1836). The cause of this malformation is still a matter for debate.

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Environmental change can cause regime shifts in ecosystems, potentially threatening ecosystem services. It is unclear if the degradation status of ecosystems correlates with their vulnerability to environmental change, and thus the risk of future regime shifts. We assessed resilience in acidified (degraded) and circumneutral (undegraded) lakes with long-term data (1988-2012), using time series modeling. We identified temporal frequencies in invertebrate assemblages, which identifies groups of species whose population dynamics vary at particular temporal scales. We also assessed species with stochastic dynamics, those whose population dynamics vary irregularly and unpredictably over time. We determined the distribution of functional feeding groups of invertebrates within and across the temporal scales identified, and in those species with stochastic dynamics, and assessed attributes hypothesized to contribute to resilience. Three patterns of temporal dynamics, consistent across study lakes, were identified in the invertebrates. The first pattern was one of monotonic change associated with changing abiotic lake conditions. The second and third patterns appeared unrelated to the environmental changes we monitored. Acidified and the circumneutral lakes shared similar levels and patterns of functional richness, evenness, diversity, and redundancy for species within and across the observed temporal scales and for stochastic species groups. These similar resilience characteristics suggest that both lake types did not differ in vulnerability to the environmental changes observed here. Although both lake types appeared equally vulnerable in this study, our approach demonstrates how assessing systemic vulnerability by quantifying ecological resilience can help address uncertainty in predicting ecosystem responses to environmental change across ecosystems.

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