scholarly journals A nonlinear relationship between marsh size and sediment trapping capacity compromises salt marshes’ stability

Geology ◽  
2020 ◽  
Vol 48 (10) ◽  
pp. 966-970 ◽  
Author(s):  
Carmine Donatelli ◽  
Xiaohe Zhang ◽  
Neil K. Ganju ◽  
Alfredo L. Aretxabaleta ◽  
Sergio Fagherazzi ◽  
...  

Abstract Global assessments predict the impact of sea-level rise on salt marshes with present-day levels of sediment supply from rivers and the coastal ocean. However, these assessments do not consider that variations in marsh extent and the related reconfiguration of intertidal area affect local sediment dynamics, ultimately controlling the fate of the marshes themselves. We conducted a meta-analysis of six bays along the United States East Coast to show that a reduction in the current salt marsh area decreases the sediment availability in estuarine systems through changes in regional-scale hydrodynamics. This positive feedback between marsh disappearance and the ability of coastal bays to retain sediments reduces the trapping capacity of the whole tidal system and jeopardizes the survival of the remaining marshes. We show that on marsh platforms, the sediment deposition per unit area decreases exponentially with marsh loss. Marsh erosion enlarges tidal prism values and enhances the tendency toward ebb dominance, thus decreasing the overall sediment availability of the system. Our findings highlight that marsh deterioration reduces the sediment stock in back-barrier basins and therefore compromises the resilience of salt marshes.

2021 ◽  
pp. 112070002110126
Author(s):  
Raman Mundi ◽  
Harman Chaudhry ◽  
Seper Ekhtiari ◽  
Prabjit Ajrawat ◽  
Daniel M Tushinski ◽  
...  

Introduction: In the United States, over 1,000,000 total joint arthroplasty (TJA) surgeries are performed annually and has been forecasted that this number will exceed 4,000,000 by the year 2030. Many different types of dressing exist for use in TJA surgery, and it is unclear if any of the newer, hydrofibre dressings are superior to traditional dressings at reducing rates of infections or improving wound healing. Thus, the aim of this systematic review and meta-analysis was to assess the impact of hydrofiber dressings on reducing complications. Methods: A systematic review and meta-analysis was performed using the online databases MEDLINE and the Cochrane Library. Randomized controlled trials (RCTs) comparing hydrofibre dressings to a standard dressing were included. Summary measures are reported as odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs). Our primary outcome was prosthetic joint infection (PJI). Secondary outcomes included blisters, dressing changes and wound irritation. Results: 5 RCTs were included. Hydrofibre dressing had no observable effect on PJI or wound irritation (OR 0.53; 95% CI, 0.14–1.98; p = 0.35). Hydrofibre dressings reduced the rate of blisters (OR 0.36; 95% CI, 0.14–0.90; p = 0.03) and number of dressing changes (MD -1.89; 95% CI, -2.68 to -1.11). Conclusions: In conclusion, evidence suggests hydrofibre dressings have no observable effect on PJI and wound irritation. Evidence for reduction in blisters and number of dressings is modest given wide CIs and biased trial methodologies. Use of hydrofibre dressings should be considered inconclusive for mitigating major complications in light of current best evidence.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S843-S843
Author(s):  
John M McLaughlin ◽  
Farid L Khan ◽  
Heinz-Josef Schmitt ◽  
Yasmeen Agosti ◽  
Luis Jodar ◽  
...  

Abstract Background Understanding the true magnitude of infant respiratory syncytial virus (RSV) burden is critical for determining the potential public-health benefit of RSV prevention strategies. Although global reviews of infant RSV burden exist, none have summarized data from the United States or evaluated how RSV burden estimates are influenced by variations in study design. Methods We performed a systematic literature review and meta-analysis of studies describing RSV-associated hospitalization rates among US infants. We also examined the impact of key study characteristics on these estimates. Results After review of 3058 articles through January 2020, we identified 25 studies with 31 unique estimates of RSV-associated hospitalization rates. Among US infants < 1 year of age, annual rates ranged from 8.4 to 40.8 per 1000 with a pooled rate= 19.4 (95%CI= 17.9–20.9). Study type was associated with RSV hospitalization rates (P =.003), with active surveillance studies having pooled rates per 1000 (11.1; 95%CI: 9.8–12.3) that were half that of studies based on administrative claims (21.4; 95%CI: 19.5–23.3) or modeling approaches (23.2; 95%CI: 20.2–26.2). Conclusion Applying the pooled rates identified in our review to the 2020 US birth cohort suggests that 73,680 to 86,020 RSV-associated infant hospitalizations occur each year. To date, public-health officials have used conservative estimates from active surveillance as the basis for defining US infant RSV burden. The full range of RSV-associated hospitalization rates identified in our review better characterizes the true RSV burden in infants and can better inform future evaluations of RSV prevention strategies. Disclosures John M. McLaughlin, PhD, Pfizer (Employee, Shareholder) Farid L. Khan, MPH, Pfizer (Employee, Shareholder) Heinz-Josef Schmitt, MD, Pfizer (Employee, Shareholder) Yasmeen Agosti, MD, Pfizer (Employee, Shareholder) Luis Jodar, PhD, Pfizer (Employee, Shareholder) Eric Simões, MD, Pfizer (Consultant, Research Grant or Support) David L. Swerdlow, MD, Pfizer (Employee, Shareholder)


2021 ◽  
pp. 152483802199128
Author(s):  
David S. Lapsey ◽  
Bradley A. Campbell ◽  
Bryant T. Plumlee

Sexual assault and case attrition at the arrest stage are serious problems in the United States. Focal concerns have increasingly been used to explain police decision making in sexual assault cases. Because of the popularity of the focal concerns perspective and potential to inform evidence-based training, a systematic review and meta-analysis are needed to condense the literature. In this study, we assess the overall strength of the relationship between focal concerns variables and police decisions to arrest in cases of sexual assault. Our assessment of the effects of focal concerns variables on arrest decision making in sexual assault cases followed the systematic review protocols provided by the Campbell Collaboration of Systematic Reviews. Specifically, we used the Campbell Collaboration recommendations to search empirical literature and used meta-analysis to evaluate the size, direction, and strength of the impact of focal concerns variables on arrest decisions. Our search strategy detected 14 eligible studies and 79 effect sizes. The meta-analysis found several robust and statistically significant correlates of arrest. In fact, each focal concerns concept produced at least one robust arrest correlate. Overall, focal concerns offers a strong approach for explaining police decisions in sexual assault cases. Although practical concerns and resource constraints produced the strongest arrest correlates, results show the importance of additional case characteristics in officers’ decision to arrest.


2018 ◽  
Vol 82 (3) ◽  
pp. 1-24 ◽  
Author(s):  
Alexander Edeling ◽  
Alexander Himme

The impact of market share on financial firm performance is one of the most widely studied relationships in marketing strategy research. However, since the meta-analysis by Szymanski, Bharadwaj, and Varadarajan (1993) , substantial environmental (e.g., digitization) and methodological (e.g., accounting for endogeneity) developments have occurred. The current work presents an updated and extended meta-analysis based on all available 863 elasticities drawn from 89 studies and provides the following new empirical generalizations: (1) The average raw market share–financial performance elasticity is .132, which is substantially lower than the effectiveness of other intermediate marketing metrics. This result challenges a widely used strategy that solely focuses on increasing market share. (2) Elasticities differ significantly between contextual settings. For example, they are lower for business-to-business firms than for business-to-consumer firms, for service firms than for manufacturing firms, and for U.S. markets than for emerging and Western European markets. The authors also observe differences between countries with respect to a general time trend (e.g., lower elasticities in recent times for Western European markets) and recessionary periods (e.g., lower elasticities in the United States, higher elasticities in non-Western economies).


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Aaron E. Maxwell ◽  
Michael P. Strager ◽  
Charles B. Yuill ◽  
J. Todd Petty

Throughout the Central Appalachians of the United States resource extraction primarily from coal mining has contributed to the majority of the forest conversion to barren and reclaimed pasture and grass. The loss of forests in this ecoregion is significantly impacting biodiversity at a regional scale. Since not all forest stands provide equal levels of ecological functions, it is critical to identify and map existing forested resources by the benefits that accrue from their unique spatial patterns, watershed drainage, and landscape positions. We utilized spatial analysis and remote sensing techniques to define critical forest characteristics. The characteristics were defined by applying a forest fragmentation model utilizing morphological image analysis, defining headwater catchments at a 1 : 24,000 scale, and deriving ecological land units (ELUs) from elevation data. Once critical forest values were calculated, it was possible to identify clusters of critical stands using spatial statistics. This spatially explicit method for modeling forest habitat could be implemented as a tool for assessing the impact of resource extraction and aid in the conservation of critical forest habitat throughout a landscape.


2018 ◽  
Vol 59 (4) ◽  
pp. e363-e379 ◽  
Author(s):  
Rebecca N Collins ◽  
Naoko Kishita

Abstract Background and Objectives The application of mindfulness- and acceptance-based interventions (MABIs) for informal caregivers of people with dementia (PwD) is relatively novel, and the current state of the evidence base is unclear. This meta-analysis examined the effectiveness of MABIs on reducing symptoms of depression and burden in informal caregivers of PwD. The quality of included studies was evaluated and moderator variables explored. Research Design and Methods A literature search of six electronic databases (PsycARTICLES, PsycINFO, MEDLINE Complete, SCOPUS, Web of Science, and ProQuest) was conducted from the first available date to 20 December 2016. Inclusion criteria involved studies that quantitatively investigated the impact of MABIs on depression and/or burden in informal caregivers of PwD. Results Twelve studies, providing data on 321 caregivers, were included. Most used mindfulness-based stress reduction and were conducted in the United States. The average attrition among participants was 15.83%. The pre–post effect of MABIs was large for depression and moderate for burden. These effects were largely maintained at follow-up. Significant heterogeneity of effect sizes was observed, with no significant moderators identified. Study quality varied from very poor to moderately good. Discussion and Implications The low attrition and moderate to large effects suggest that MABIs are acceptable and beneficial for informal caregivers of PwD. The lack of significant moderators could advocate services using more cost-effective forms of MABIs. Further higher-quality research is needed to improve the robustness of the evidence base and enable a meta-analysis to thoroughly examine and quantify moderator variables.


2021 ◽  
Vol 64 (1) ◽  
pp. E25-E38
Author(s):  
Brice Batomen ◽  
Lynne Moore ◽  
Mabel Carabali ◽  
Pier-Alexandre Tardif ◽  
Howard Champion

Background: There is a growing trend toward verification of trauma centres, but its impact remains unclear. This systematic review aimed to synthesize available evidence on the effectiveness of trauma centre verification. Methods: We conducted a systematic search of the CINAHL, Embase, HealthStar, MEDLINE and ProQuest databases, as well as the websites of key injury organizations for grey literature, from inception to June 2019, without language restrictions. Our population consisted of injured patients treated at trauma centres. The intervention was trauma centre verification. Comparison groups comprised nonverified trauma centres, or the same centre before it was first verified or re-verified. The primary outcome was in-hospital mortality; secondary outcomes included adverse events, resource use and processes of care. We computed pooled summary estimates using random-effects meta-analysis. Results: Of 5125 citations identified, 29, all conducted in the United States, satisfied our inclusion criteria. Mortality was the most frequently investigated outcome (n = 20), followed by processes of care (n = 12), resource use (n = 12) and adverse events (n = 7). The risk of bias was serious to critical in 22 studies. We observed an imprecise association between verification and decreased mortality (relative risk 0.74, 95% confidence interval 0.52 to 1.06) in severely injured patients. Conclusion: Our review showed mixed and inconsistent associations between verification and processes of care or patient outcomes. The validity of the published literature is limited by the lack of robust controls, as well as any evidence from outside the US, which precludes extrapolation to other health care jurisdictions. Quasiexperimental studies are needed to assess the impact of trauma centre verification. Systematic reviews registration: PROSPERO no. CRD42018107083


Author(s):  
Elif Köse ◽  
Derya Seyman ◽  
Figen Sarigül-Yildirim ◽  
Tennur Yerlisu-Lapa ◽  
Evren Tercan-Kaas

Background: Exercise is believed to play an important role in maintaining functionality in patients with HIV and it is thought that researchers are increasingly interested in this field. We aimed to shed light on the historical development of research on HIV and exercise by utilizing visual mapping method. Methods: Overall, 1051 articles retrieved from Web of Science (WoS) core database were analyzed according to the publication year and language, number of issues, citation, country collaborations, co-citation networks and concept–topic trends by using CiteSpace software. Results: The United States played a key role in country collaborations, and had the highest citation burst. The most cited studies were meta-analysis studies. The studies gathered mainly around the clusters named “physical activity” and “metabolic abnormalities” meanwhile, the recent topics of research were heart failure, metabolism, comorbidity, Ethiopia, muscle, cardiovascular event and drug user. Conclusion: The reason why USA was found to be one of the key actors in the network is supposed to be the financial resources it can allocate for the studies conducted. It appears that the majority of the studies in the field dwell upon the impact of exercise on the physical parameters in HIV patients, whereas there are only a limited number of studies focusing on the impact of exercise on HIV-induced psychological and cognitive problems. Recent studies on neurocognitive impairment, on the other hand, are predictive of possible future popularity of such topics among researchers.


2020 ◽  
Vol 10 (4) ◽  
pp. 385-402
Author(s):  
José Osorio-Antonia ◽  
Lila Margarita Bada-Carbajal ◽  
Luis Arturo Rivas-Tovar

PurposeThe purpose of this paper is twofold. First, the impact of the North American Free Trade Agreement (NAFTA) on the agribusinesses of corn production in Mexico is analyzed, taking into special consideration the policy of encouragement to small producers, productive restructuring and identification of positive and negative effects. Second, the evolution of the US–Mexican maize belts (1994–2017) is analyzed, establishing the economic and political impacts with respect to NAFTA.Design/methodology/approachThe paper opted for a documentary meta-analysis study using data from the United States Department of Agriculture (USDA) and the System of Agricultural and Fishery Information (SIAP) in Mexico. The data were completed with documentary analysis of research on maize productivity.FindingsProvided is the information about the impacts of maize belts in the United States (US) and Mexico, where it was determined that the leading states maintained productive hegemony to a greater and lesser extent and that Mexico experienced a productive reorientation. The findings show that it is a myth that there are losers in the maize agroindustry of Mexico and the United States as it is suggested that after twenty-four years they have become complementary.Research limitations/implicationsSummarized is the state of knowledge from 1994 to 2017, aligned to the databases of the United States and Mexico.Originality/valueA need to study the relation between the productive evolution of maize production and NAFTA is identified.


2015 ◽  
Vol 113 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Nicoletta Leonardi ◽  
Neil K. Ganju ◽  
Sergio Fagherazzi

Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.


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