scholarly journals Mammalian herbivory exacerbates plant community responses to long-term increased soil nutrients in two Alaskan tundra plant communities

2018 ◽  
Vol 4 (2) ◽  
pp. 153-166 ◽  
Author(s):  
Laura Gough ◽  
David R. Johnson

The interaction between bottom-up and top-down forces in regulating plant communities is a long-standing topic of interest in ecology. Factorial field experiments examining these factors have been relatively few, but recent meta-analyses provide predictions that can be tested in a range of ecosystems. We tested the prediction that added nutrients would reduce species richness and evenness, while herbivore activity would offset those changes in two tundra plant communities after 11 years. In moist acidic tundra (MAT), herbivores reduced richness more in fertilized plots when mammals were present compared with fertilized plots without herbivores. In dry heath (DH), evenness was significantly reduced in fertilized plots only when herbivores were present, also providing evidence that herbivores enhanced community changes caused by greater nutrient availability. The difference in response between MAT and the meta-analysis predictions appears to be driven by Betula nana, the species that dramatically increased with added nutrients in MAT. Unlike in similar studies and in DH, B. nana is not as palatable as most of the species in the community and is generally avoided by herbivores. These results highlight how the effects of herbivory and nutrients differ across communities and can be affected by the traits of the species present.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sandra Lopez-Leon ◽  
Talia Wegman-Ostrosky ◽  
Carol Perelman ◽  
Rosalinda Sepulveda ◽  
Paulina A. Rebolledo ◽  
...  

AbstractCOVID-19 can involve persistence, sequelae, and other medical complications that last weeks to months after initial recovery. This systematic review and meta-analysis aims to identify studies assessing the long-term effects of COVID-19. LitCOVID and Embase were searched to identify articles with original data published before the 1st of January 2021, with a minimum of 100 patients. For effects reported in two or more studies, meta-analyses using a random-effects model were performed using the MetaXL software to estimate the pooled prevalence with 95% CI. PRISMA guidelines were followed. A total of 18,251 publications were identified, of which 15 met the inclusion criteria. The prevalence of 55 long-term effects was estimated, 21 meta-analyses were performed, and 47,910 patients were included (age 17–87 years). The included studies defined long-COVID as ranging from 14 to 110 days post-viral infection. It was estimated that 80% of the infected patients with SARS-CoV-2 developed one or more long-term symptoms. The five most common symptoms were fatigue (58%), headache (44%), attention disorder (27%), hair loss (25%), and dyspnea (24%). Multi-disciplinary teams are crucial to developing preventive measures, rehabilitation techniques, and clinical management strategies with whole-patient perspectives designed to address long COVID-19 care.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chengxin Luo ◽  
Li Wang ◽  
Guixian Wu ◽  
Xiangtao Huang ◽  
Yali Zhang ◽  
...  

Abstract Background Mobilization failure may occur when the conventional hematopoietic stem cells (HSCs) mobilization agent granulocyte colony-stimulating factor (G-CSF) is used alone, new regimens were developed to improve mobilization efficacy. Multiple studies have been performed to investigate the efficacy of these regimens via animal models, but the results are inconsistent. We aim to compare the efficacy of different HSC mobilization regimens and identify new promising regimens with a network meta-analysis of preclinical studies. Methods We searched Medline and Embase databases for the eligible animal studies that compared the efficacy of different HSC mobilization regimens. Primary outcome is the number of total colony-forming cells (CFCs) in per milliliter of peripheral blood (/ml PB), and the secondary outcome is the number of Lin− Sca1+ Kit+ (LSK) cells/ml PB. Bayesian network meta-analyses were performed following the guidelines of the National Institute for Health and Care Excellence Decision Support Unit (NICE DSU) with WinBUGS version 1.4.3. G-CSF-based regimens were classified into the SD (standard dose, 200–250 μg/kg/day) group and the LD (low dose, 100–150 μg/kg/day) group based on doses, and were classified into the short-term (2–3 days) group and the long-term (4–5 days) group based on administration duration. Long-term SD G-CSF was chosen as the reference treatment. Results are presented as the mean differences (MD) with the associated 95% credibility interval (95% CrI) for each regimen. Results We included 95 eligible studies and reviewed the efficacy of 94 mobilization agents. Then 21 studies using the poor mobilizer mice model (C57BL/6 mice) to investigate the efficacy of different mobilization regimens were included for network meta-analysis. Network meta-analyses indicated that compared with long-term SD G-CSF alone, 14 regimens including long-term SD G-CSF + Me6, long-term SD G-CSF + AMD3100 + EP80031, long-term SD G-CSF + AMD3100 + FG-4497, long-term SD G-CSF + ML141, long-term SD G-CSF + desipramine, AMD3100 + meloxicam, long-term SD G-CSF + reboxetine, AMD3100 + VPC01091, long-term SD G-CSF + FG-4497, Me6, long-term SD G-CSF + EP80031, POL5551, long-term SD G-CSF + AMD3100, AMD1300 + EP80031 and long-term LD G-CSF + meloxicam significantly increased the collections of total CFCs. G-CSF + Me6 ranked first among these regimens in consideration of the number of harvested CFCs/ml PB (MD 2168.0, 95% CrI 2062.0−2272.0). In addition, 7 regimens including long-term SD G-CSF + AMD3100, AMD3100 + EP80031, long-term SD G-CSF + EP80031, short-term SD G-CSF + AMD3100 + IL-33, long-term SD G-CSF + ML141, short-term LD G-CSF + ARL67156, and long-term LD G-CSF + meloxicam significantly increased the collections of LSK cells compared with G-CSF alone. Long-term SD G-CSF + AMD3100 ranked first among these regimens in consideration of the number of harvested LSK cells/ml PB (MD 2577.0, 95% CrI 2422.0–2733.0). Conclusions Considering the number of CFC and LSK cells in PB as outcomes, G-CSF plus AMD3100, Me6, EP80031, ML141, FG-4497, IL-33, ARL67156, meloxicam, desipramine, and reboxetine are all promising mobilizing regimens for future investigation.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yu Chen ◽  
Shaobin Wei ◽  
Li Huang ◽  
Mei Luo ◽  
Yang Wu ◽  
...  

Background. Pelvic inflammatory disease (PID) without timely and proper treatment can cause long-term sequelae; meanwhile, patients will be confronted with the antimicrobial resistance and side effects. Chinese patent medicine as a supplement is used to treat PID with satisfactory clinical efficacy. This study evaluated the efficacy and safety of Fuke Qianjin (FKQJ) combined with antibiotics in the treatment of PID. Methods. Eight electronic databases and other resources were searched to make a collection of the randomized controlled trials (RCTs) from 1990 to 2019. The RCTs contrasting the effect of FKQJ combined with antibiotics regimens and antibiotics alone in reproductive women with PID were included. The antibiotics regimens are all recommended by the guidelines. Two reviewers independently screened the studies, extracted the data, and assessed the methodological quality of the included studies. Then, the meta-analyses were performed by RevMan 5. 3 software if appropriate. Results. Twenty-three RCTs (2527 women) were included in this review. The evidence showed that FKQJ combined with antibiotics improved the markedly effective rate compared to antibiotics alone group (RR = 1.38, 95% CI 1.27 to 1.49, I2 = 42%), shortened the improvement time of low abdominal pain (MD = −1.11, 95% CI −1.39 to −0.84, I2 = 38%), and increased the rate of lower abdominal pain improvement (RR = 1.35, 95% CI 1.19 to 1.55, I2 = 0). The implementation of adjuvant reduced the recurrent rate compared with antibiotics alone (RR = 0.27, 95% CI 0.13 to 0.56, I2 = 0%). Conclusions. Based on available evidence, FKQJ combined with antibiotics therapy have certain outcomes on increasing the markedly effective rate, decreasing the recurrent rate compared with antibiotics alone group. This therapy appears to improve lower abdominal pain and curtail the relief time. Due to the low quality and the risk of bias, any high-quality evidence or longer follow-up period should be advisable and necessary in the future.


2016 ◽  
Vol 26 (4) ◽  
pp. 364-368 ◽  
Author(s):  
P. Cuijpers ◽  
E. Weitz ◽  
I. A. Cristea ◽  
J. Twisk

AimsThe standardised mean difference (SMD) is one of the most used effect sizes to indicate the effects of treatments. It indicates the difference between a treatment and comparison group after treatment has ended, in terms of standard deviations. Some meta-analyses, including several highly cited and influential ones, use the pre-post SMD, indicating the difference between baseline and post-test within one (treatment group).MethodsIn this paper, we argue that these pre-post SMDs should be avoided in meta-analyses and we describe the arguments why pre-post SMDs can result in biased outcomes.ResultsOne important reason why pre-post SMDs should be avoided is that the scores on baseline and post-test are not independent of each other. The value for the correlation should be used in the calculation of the SMD, while this value is typically not known. We used data from an ‘individual patient data’ meta-analysis of trials comparing cognitive behaviour therapy and anti-depressive medication, to show that this problem can lead to considerable errors in the estimation of the SMDs. Another even more important reason why pre-post SMDs should be avoided in meta-analyses is that they are influenced by natural processes and characteristics of the patients and settings, and these cannot be discerned from the effects of the intervention. Between-group SMDs are much better because they control for such variables and these variables only affect the between group SMD when they are related to the effects of the intervention.ConclusionsWe conclude that pre-post SMDs should be avoided in meta-analyses as using them probably results in biased outcomes.


2018 ◽  
Vol 23 (5) ◽  
pp. 497-512 ◽  
Author(s):  
Chao Miao ◽  
Ronald H. Humphrey ◽  
Shanshan Qian ◽  
Jeffrey M. Pollack

Purpose The topic of entrepreneurial intention, which refers to a person’s degree of interest in creating a new business venture, has received close scrutiny in the entrepreneurship literature. The empirical results regarding the relation between emotional intelligence (EI) and entrepreneurial intention were nevertheless mixed across studies. Based on fit theory and trait activation theory, the purpose of this paper is to explain the fundamental reason for the mixed findings in the extant literature thus far. Design/methodology/approach Random-effects meta-analyses, based on 12 studies (along with 12 effect sizes), were performed to not only investigate the overall relation between EI and entrepreneurial intention but also to examine the moderators (i.e. individualism (vs collectivism), masculinity (vs femininity), power distance, long-term orientation (vs short-term orientation), uncertainty avoidance, and indulgence (vs restraint)) that influence this relation. Findings The results of this meta-analysis demonstrated that EI is positively related to entrepreneurial intention; the positive relationship between EI and entrepreneurial intention is stronger in long-term-oriented cultures; and the positive relationship between EI and entrepreneurial intention does not significantly differ based on a culture’s level of collectivism, masculinity, power distance, uncertainty avoidance, and indulgence. Originality/value This meta-analysis advances the current understanding of the relation between EI and entrepreneurial intention from cross-cultural perspectives.


Koedoe ◽  
2004 ◽  
Vol 47 (2) ◽  
Author(s):  
G. Cleaver ◽  
L.R. Brown ◽  
G.J. Bredenkamp

The Kammanassie Mountain is a declared mountain catchment area and a Cape mountain zebra Equus zebra zebra population is preserved on the mountain. The high number of springs on the mountain not only provides water for the animal species but also contributes to overall ecosystem functioning. Long-term conservation of viable ecosystems requires a broader understanding of the ecological processes involved. It was therefore decided that a classification, description and mapping of the spring vegetation of the Kammanassie Mountain be undertaken. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 11 major plant communities that could be related to geological origin. Habitat factors associated with differences in vegetation include topography, soil type and grazing. Descriptions of the plant communities include diagnostic species as well as prominent and less conspicuous species of the tree, shrub and herbaceous layers. The results also indicate a high species richness compared to similar regions and the difference between plant communities of wet and dry springs. This data is important for long-term monitoring of the spring ecosystems as well as for the compilation of management plans.


Author(s):  
C Dandurand ◽  
AA Sepehry ◽  
MH Asadi Lari ◽  
R Akagami ◽  
PA Gooderham

Background: The optimal therapeutic approach for adult craniopharyngioma remains controversial. Some advocate for gross total resection (GTR), while others support subtotal resection followed by adjuvant radiotherapy (STR + XRT). Methods: MEDLINE (1946 to July 1st 2016) and EMBASE (1980 to June 30th 2016) were systematically reviewed. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed. At our institution, from 1975 to 2013, 33 patients were treated with initial surgical resection for adult onset craniopharyngioma. 22 patients were included in the present case series. Results: Eligible studies (n=21) were identified from the literature in addition to a case series of our institutional experience. Three groups were available for analysis: GTR, STR + XRT, and STR. The rates of recurrence were 17 %, 27 % and 45%, respectively. This differs from childhood population. The difference in risk of recurrence after GTR vs. STR + XRT did not reach significance (OR: 0.63, 95% confidence interval: 0.33-1.24, P=0.18). This maybe because of low pooled sample size (n=99) who underwent STR+XRT. Conclusions: This is the first and largest meta-analysis examining rate of recurrence in adult craniopharyngioma. Thus, when safe and feasible, a goal of gross total resection should be favored. Each patient should be considered on a case-by-case basis.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xi Ouyang ◽  
Zhiqiang Liu ◽  
Chenglin Gui

Purpose Underpinned by the ability–motivation–opportunity framework, this paper aims to establish a framework of employee creativity antecedents in the hospitality and tourism industries and meta-analytically examine the magnitude of effect sizes as well as the moderating effects of cultural factors. Design/methodology/approach A meta-analysis using data from 82 independent studies was conducted to explore the hypothesized relationships and verify how they were contingent on uncertainty avoidance and long-term orientation. Findings The results supported the majority of hypotheses about the relationships between antecedents and creativity. Furthermore, they showed that the effects of intrinsic motivation, positive affect and climate for innovation on creativity in the hospitality and tourism industries were significantly larger than those reported in previous meta-analyses. It also showed that uncertainty avoidance and long-term orientation could buffer or strengthen some associations. Practical implications This study generates some essential managerial suggestions for organizations in need of innovation. Managers can learn from the results so as to effectively promote the ability, motivation and opportunity for creativity and merge cultural elements with innovation strategy when they operate globally. Originality/value This study provides a theory-based explanation for how employee creativity can be activated. To the best of the authors’ knowledge, this study is a first attempt to meta-analytically test the underlying determinants of employee creativity in the hospitality and tourism industries. Additionally, the search for boundary conditions of the proposed relationships is likely to reconcile existing conflicts and inspire future studies.


Author(s):  
Colin Baigent ◽  
Richard Peto ◽  
Richard Gray ◽  
Natalie Staplin ◽  
Sarah Parish ◽  
...  

Clinical trials generally need to be able to detect or to refute realistically moderate (but still worthwhile) differences between treatments in long-term disease outcome. Large-scale randomized evidence should be able to detect such effects, but medium-sized trials or medium-sized meta-analyses can, and often do, yield false-negative or exaggeratedly positive results. Hundreds of thousands of premature deaths each year could be avoided by seeking appropriately large-scale randomized evidence about various widely practicable treatments for the common causes of death, and by disseminating this evidence appropriately. This chapter takes a look at the use of large-scale randomized evidence—produced from trials and meta-analysis of trials—and how this data should be handled in order to produce accurate result.


Author(s):  
Brigida Barberio ◽  
Christopher J Black ◽  
Edoardo V Savarino ◽  
Alexander C Ford

Abstract Background Despite randomized controlled trials [RCTs] and trial-based meta-analyses, the optimal rescue therapy for patients with acute glucorticosteroid-refractory ulcerative colitis [UC], to avoid colectomy and improve long-term outcomes, remains unclear. We conducted a network meta-analysis examining this issue. Methods We searched MEDLINE, EMBASE, EMBASE Classic and the Cochrane central register up to June 2020. We included RCTs comparing ciclosporin and infliximab, either with each other or with placebo, in patients with glucorticosteroid-refractory UC. Results We identified seven RCTs containing 534 patients [415 in head-to-head trials of ciclosporin vs infliximab]. Risk of colectomy at ≤ 1 month was reduced significantly with both treatments, compared with placebo (relative risk [RR] of colectomy with infliximab vs placebo = 0.37; 95% confidence interval [CI] 0.21–0.65, RR with ciclosporin vs placebo = 0.40; 95% CI 0.21–0.77). In terms of colectomy between > 1 month and < 1 year, both drugs ranked equally [P-score 0.75]. Neither treatment was more effective than placebo in reducing the risk of colectomy at ≥ 1 year. Both ciclosporin and infliximab were significantly more efficacious than placebo in achieving a response. Neither treatment was more effective than placebo in inducing remission, nor more likely to cause serious adverse events than placebo. Conclusions Both ciclosporin and infliximab were superior to placebo in terms of response to therapy and avoiding colectomy up to 1 year, with no significant differences in efficacy or safety between the two. Ciclosporin remains a valid option to treat refractory UC patients, especially those who do not respond to previous treatment with infliximab, or as a bridge to other biological therapies.


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