scholarly journals Effects of Dams on Vertebrate Diversity: A Global Analysis

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 528
Author(s):  
Mauricio Bohada-Murillo ◽  
Gabriel J. Castaño-Villa ◽  
Francisco E. Fontúrbel

Dams are crucial for water supply in human populations and are becoming more common globally for hydroelectric power generation. Dams alter natural habitats and their biodiversity; however, studies are inconclusive about their effects on them. This study aimed to examine the effects of dams on vertebrates and the determinants of changes in global biodiversity and their relationship with critical areas for conservation. We evaluated the effects of dams on vertebrate richness and abundance. We performed a meta-analysis based on 120 case studies. We evaluated the overall effect on richness and abundance and examined these effects regarding taxa, disturbance type, latitudinal zone, zoogeographic zone, biodiversity hotspots, dam size and purpose, and species extinction risk. We conducted an overall analysis that included all species, and then we conducted separate analyses for terrestrial and aquatic species. Dams had a negative effect on vertebrate richness but not on vertebrate abundance. These effects were influenced by larger dams with fragmentation and were more pronounced within hotspots and in countries with a low species extinction risk. Such negative effects were explained by terrestrial vertebrates (particularly birds and mammals) because species richness and the abundance of aquatic vertebrates (fish) were not affected by dams in any case. Our results showed that habitat fragmentation created by large dams changes vertebrate communities, negatively affecting species richness in some areas of conservation concern. We propose implementing reservoirs in areas where they would have a lower impact on biodiversity and avoiding large dams in priority areas for conservation and where endangered species inhabit.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng Gong ◽  
Liangtao Li ◽  
Jan C. Axmarcher ◽  
Zhenrong Yu ◽  
Yunhui Liu

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Rosemond Qian-Xiu Tan ◽  
Wai Tak Victor Li ◽  
Wing-Zi Shum ◽  
Sheung Chit Chu ◽  
Hang-Long Li ◽  
...  

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has caused recurring and major outbreaks in multiple human populations around the world. The plethora of clinical presentations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been described extensively, of which olfactory dysfunction (OD) was established as an important and common extrapulmonary manifestation of COVID-19 infection. The aim of this protocol is to conduct a systematic review and meta-analysis on peer-reviewed articles which described clinical data of OD in COVID-19 patients. Methods This research protocol has been prospectively registered with the Prospective Register of Systematic Reviews (PROSPERO; CRD42020196202). CINAHL, ClinicalTrials.gov, Cochrane Central, EMBASE, MEDLINE and PubMed, as well as Chinese medical databases China National Knowledge Infrastructure (CNKI), VIP and WANFANG, will be searched using keywords including ‘COVID-19’, ‘coronavirus disease’, ‘2019-nCoV’, ‘SARS-CoV-2’, ‘novel coronavirus’, ‘anosmia’, ‘hyposmia’, ‘loss of smell’, and ‘olfactory dysfunction’. Systematic review and meta-analysis will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Meta-analyses Of Observational Studies in Epidemiology (MOOSE) guidelines. Articles will be screened according to pre-specified inclusion and exclusion criteria to extract studies that include new clinical data investigating the effect of COVID-19 on olfactory dysfunction. Included articles will be reviewed in full; data including patient demographics, clinical characteristics of COVID-19-related OD, methods of olfactory assessment and relevant clinical outcomes will be extracted. Statistical analyses will be performed using the Comprehensive Meta-Analysis version 3. Discussion This systematic review and meta-analysis protocol will aim to collate and synthesise all available clinical evidence regarding COVID-19-related OD as an important neurosensory dysfunction of COVID-19 infection. A comprehensive search strategy and screening process will be conducted to incorporate broad clinical data for robust statistical analyses and representation. The outcome of the systematic review and meta-analysis will aim to improve our understanding of the symptomatology and clinical characteristics of COVID-19-related OD and identify knowledge gaps in its disease process, which will guide future research in this specific neurosensory defect. Systematic review registration PROSPERO registration number: CRD42020196202.


2020 ◽  
pp. 1901815
Author(s):  
Thomas A. Wills ◽  
Samir S. Soneji ◽  
Kelvin Choi ◽  
Ilona Jaspers ◽  
Elizabeth K. Tam

BackgroundUse of electronic cigarettes (e-cigarettes) is prevalent among adolescents and young adults but there has been limited knowledge about health consequences in human populations. We conduct a systematic review and meta-analysis of results on respiratory disorder from studies of general-population samples and consider the mapping of these results to findings about biological processes linked to e-cigarettes in controlled laboratory studies.MethodWe conduct a literature search and meta-analysis of epidemiological studies on the association of e-cigarette use with asthma and with chronic obstructive pulmonary disease (COPD). We then discuss findings from laboratory studies about effects of e-cigarettes on four biological processes: cytotoxicity, oxidative stress/inflammation, susceptibility to infection, and genetic expression.ResultsEpidemiological studies, both cross-sectional and longitudinal, show a significant association of e-cigarette use with asthma and COPD, controlling for cigarette smoking and other covariates. For asthma (n=15 studies), the pooled adjusted odds ratio (AOR) was 1.39 (CI 1.28–1.51); for COPD (n=9 studies) the AOR was 1.49 (CI 1.36–1.65). Laboratory studies consistently show an effect of e-cigarettes on biological processes related to respiratory harm and susceptibility to illness, with e-cigarette conditions differing significantly from clean-air controls though sometimes less than for cigarettes.ConclusionsThe evidence from epidemiological studies meets established criteria for consistency, strength of effect, temporality, and in some cases a dose-response gradient. Biological plausibility is indicated by evidence from multiple laboratory studies. We conclude that e-cigarette use has consequences for asthma and COPD, which is of significant concern for respirology and public health.


2021 ◽  
Vol 11 (8) ◽  
pp. 804
Author(s):  
Navid Neyshaburinezhad ◽  
Hengameh Ghasim ◽  
Mohammadreza Rouini ◽  
Youssef Daali ◽  
Yalda H. Ardakani

Genetic polymorphisms in cytochrome P450 genes can cause alteration in metabolic activity of clinically important medicines. Thus, single nucleotide variants (SNVs) and copy number variations (CNVs) in CYP genes are leading factors of drug pharmacokinetics and toxicity and form pharmacogenetics biomarkers for drug dosing, efficacy, and safety. The distribution of cytochrome P450 alleles differs significantly between populations with important implications for personalized drug therapy and healthcare programs. To provide a meta-analysis of CYP allele polymorphisms with clinical importance, we brought together whole-genome and exome sequencing data from 800 unrelated individuals of Iranian population (100 subjects from 8 major ethnics of Iran) and 63,269 unrelated individuals of five major human populations (EUR, AMR, AFR, EAS and SAS). By integrating these datasets with population-specific linkage information, we evolved the frequencies of 140 CYP haplotypes related to 9 important CYP450 isoenzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5) giving a large resource for major genetic determinants of drug metabolism. Furthermore, we evaluated the more frequent Iranian alleles and compared the dataset with the Caucasian race. Finally, the similarity of the Iranian population SNVs with other populations was investigated.


1970 ◽  
Vol 20 (1) ◽  
pp. 32-38
Author(s):  
Sri Suharmini Wahyuningsih ◽  
Tri Darmayanti ◽  
Arifah Bintarti

Online tutorial service was a learning support services provided by the Universitas Terbuka (UT) for its students. In the distance education system, the learning process could be done through the internet. Research on online tutorial learning and services has been done by UT lecturers. This article aimed to map research related to UT's online tutorials, both in the form of research reports and those that have been published in journals. The purpose of mapping was to find out what research topics regarding online tutorials that have been conducted. The research method used was the meta-analysis method, combining various analyzes which then produced a global analysis of online tutorials. The results of this study were online tutorial research could be categorized into five topics, namely a) the relationship between online tutorial values ​​and final exam scores; b) organizing online tutorials; c) the quality of online tutorials; d) online tutorial accessibility; and e) online tutorials as a research tool. Students rated the implementation of online tutorials as good and they were satisfied. The value of online tutorials could contribute to the value of final exam scores. However, the accessibility of online tutorials was still low because it depended on the network and students’ discipline and activeness. Layanan tutorial online merupakan layanan bantuan belajar yang diberikan Universitas Terbuka (UT) untuk para mahasiswanya. Dalam sistem pendidikan jarak jauh proses pembelajaran dapat dilakukan melalui jaringan internet. Penelitian tentang layanan dan pembelajaran tutorial online sudah banyak dilakukan oleh dosen UT. Artikel ini bertujuan untuk memetakan penelitian yang berhubungan dengan tutorial online UT, baik dalam bentuk laporan penelitian maupun yang sudah dipublikasikan di jurnal. Tujuan pemetaan adalah untuk mengetahui apa saja topik penelitian mengenai tutorial online yang sudah dilakukan. Metode penelitian yang digunakan adalah metode meta analisis, menggabungkan berbagai analisis yang kemudian menghasilkan analisis global mengenai tutorial online. Hasil dari penelitian ini adalah penelitian tutorial online dapat dikategorikan menjadi lima topik, yaitu: a) Hubungan nilai tutorial online dengan nilai UAS; b) Penyelenggaraan tutorial online; c) Kualitas tutorial online; d) Aksesibilitas tutorial online; dan e) Tutorial online sebagai sarana atau alat penelitian. Mahasiswa menilai penyelenggaraan tutorial online sudah baik dan mahasiswa merasa puas. Nilai tutorial online dapat berkontribusi terhadap nilai UAS. Namun aksesibilitas tutorial online masih rendah karena bergantung kepada jaringan serta kedisiplinan dan keaktifan mahasiswa.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7333 ◽  
Author(s):  
José Maria Cardoso da Silva ◽  
Alessandro Rapini ◽  
Luis Cláudio F. Barbosa ◽  
Roger R. Torres

In a world where changes in land cover and climate happen faster than ever due to the expansion of human activities, narrowly distributed species are predicted to be the first to go extinct. Studies projecting species extinction in tropical regions consider either habitat loss or climate change as drivers of biodiversity loss but rarely evaluate them together. Here, the contribution of these two factors to the extinction risk of narrowly distributed species (with ranges smaller than 10,000 km2) of seed plants endemic to a fifth-order watershed in Brazil (microendemics) is assessed. We estimated the Regional Climate Change Index (RCCI) of these watersheds (areas with microendemics) and projected three scenarios of land use up to the year 2100 based on the average annual rates of habitat loss in these watersheds from 2000 to 2014. These scenarios correspond to immediate conservation action (scenario 1), long-term conservation action (scenario 2), and no conservation action (scenario 3). In each scenario, areas with microendemics were classified into four classes: (1) areas with low risk, (2) areas threatened by habitat loss, (3) areas threatened by climate change, and (4) areas threatened by climate change and habitat loss. We found 2,354 microendemic species of seed plants in 776 areas that altogether cover 17.5% of Brazil. Almost 70% (1,597) of these species are projected to be under high extinction risk by the end of the century due to habitat loss, climate change, or both, assuming that these areas will not lose habitat in the future due to land use. However, if habitat loss in these areas continues at the prevailing annual rates, the number of threatened species is projected to increase to more than 85% (2,054). The importance of climate change and habitat loss as drivers of species extinction varies across phytogeographic domains, and this variation requires the adoption of retrospective and prospective conservation strategies that are context specific. We suggest that tropical countries, such as Brazil, should integrate biodiversity conservation and climate change policies (both mitigation and adaptation) to achieve win-win social and environmental gains while halting species extinction.


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