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Fulltext Sealants for preventing dental caries in primary teeth

Ramamurthy P, Rath A, Sidhu P, Fernandes B, Nettem S, Fee PA, et al.

Cochrane Database Syst Rev, 2022 Feb 11;2(2):CD012981.
PMID: 35146744 DOI: 10.1002/14651858.CD012981.pub2

BACKGROUND: Pit and fissure sealants are plastic materials that are used to seal deep pits and fissures on the occlusal surfaces of teeth, where decay occurs most often in children and adolescents. Deep pits and fissures can retain food debris and bacteria, making them difficult to clean, thereby causing them to be more susceptible to dental caries. The application of a pit and fissure sealant, a non-invasive preventive approach, can prevent dental caries by forming a protective barrier that reduces food entrapment and bacterial growth. Though moderate-certainty evidence shows that sealants are effective in preventing caries in permanent teeth, the effectiveness of applying pit and fissure sealants to primary teeth has yet to be established.
OBJECTIVES: To evaluate the effects of sealants compared to no sealant or a different sealant in preventing pit and fissure caries on the occlusal surfaces of primary molars in children and to report the adverse effects and the retention of different types of sealants.
SEARCH METHODS: An information specialist searched four bibliographic databases up to 11 February 2021 and used additional search methods to identify published, unpublished and ongoing studies. Review authors scanned the reference lists of included studies and relevant systematic reviews for further studies.
SELECTION CRITERIA: We included parallel-group and split-mouth randomised controlled trials (RCTs) that compared a sealant with no sealant, or different types of sealants, for the prevention of caries in primary molars, with no restriction on follow-up duration. We included studies in which co-interventions such as oral health preventive measures, oral health education or tooth brushing demonstrations were used, provided that the same adjunct was used with the intervention and comparator. We excluded studies with complex interventions for the prevention of dental caries in primary teeth such as preventive resin restorations, or studies that used sealants in cavitated carious lesions.
DATA COLLECTION AND ANALYSIS: Two review authors independently screened search results, extracted data and assessed risk of bias of included studies. We presented outcomes for the development of new carious lesions on occlusal surfaces of primary molars as odds ratios (OR) with 95% confidence intervals (CIs). Where studies were similar in clinical and methodological characteristics, we planned to pool effect estimates using a random-effects model where appropriate. We used GRADE methodology to assess the certainty of the evidence.
MAIN RESULTS: We included nine studies that randomised 1120 children who ranged in age from 18 months to eight years at the start of the study. One study compared fluoride-releasing resin-based sealant with no sealant (139 tooth pairs in 90 children); two studies compared glass ionomer-based sealant with no sealant (619 children); two studies compared glass ionomer-based sealant with resin-based sealant (278 tooth pairs in 200 children); two studies compared fluoride-releasing resin-based sealant with resin-based sealant (113 tooth pairs in 69 children); one study compared composite with fluoride-releasing resin-based sealant (40 tooth pairs in 40 children); and one study compared autopolymerised sealant with light polymerised sealant (52 tooth pairs in 52 children). Three studies evaluated the effects of sealants versus no sealant and provided data for our primary outcome. Due to differences in study design such as age of participants and duration of follow-up, we elected not to pool the data. At 24 months, there was insufficient evidence of a difference in the development of new caries lesions for the fluoride-releasing sealants or no treatment groups (Becker Balagtas odds ratio (BB OR) 0.76, 95% CI 0.41 to 1.42; 1 study, 85 children, 255 tooth surfaces). For glass ionomer-based sealants, the evidence was equivocal; one study found insufficient evidence of a difference at follow-up between 12 and 30 months (OR 0.97, 95% CI 0.63 to 1.49; 449 children), while another with 12-month follow-up found a large, beneficial effect of sealants (OR 0.03, 95% CI 0.01 to 0.15; 107 children). We judged the certainty of the evidence to be low, downgrading two levels in total for study limitations, imprecision and inconsistency. We included six trials randomising 411 children that directly compared different sealant materials, four of which (221 children) provided data for our primary outcome. Differences in age of the participants and duration of follow-up precluded pooling of the data. The incidence of development of new caries lesions was typically low across the different sealant types evaluated. We judged the certainty of the evidence to be low or very low for the outcome of caries incidence. Only one study assessed and reported adverse events, the nature of which was gag reflex while placing the sealant material.
AUTHORS' CONCLUSIONS: The certainty of the evidence for the comparisons and outcomes in this review was low or very low, reflecting the fragility and uncertainty of the evidence base. The volume of evidence for this review was limited, which typically included small studies where the number of events was low. The majority of studies in this review were of split-mouth design, an efficient study design for this research question; however, there were often shortcomings in the analysis and reporting of results that made synthesising the evidence difficult. An important omission from the included studies was the reporting of adverse events. Given the importance of prevention for maintaining good oral health, there exists an important evidence gap pertaining to the caries-preventive effect and retention of sealants in the primary dentition, which should be addressed through robust RCTs.
The rise of hyperabundant native generalists threatens both humans and nature

Moore JH, Gibson L, Amir Z, Chanthorn W, Ahmad AH, Jansen PA, et al.

Biol Rev Camb Philos Soc, 2023 Oct;98(5):1829-1844.
PMID: 37311559 DOI: 10.1111/brv.12985

In many disturbed terrestrial landscapes, a subset of native generalist vertebrates thrives. The population trends of these disturbance-tolerant species may be driven by multiple factors, including habitat preferences, foraging opportunities (including crop raiding or human refuse), lower mortality when their predators are persecuted (the 'human shield' effect) and reduced competition due to declines of disturbance-sensitive species. A pronounced elevation in the abundance of disturbance-tolerant wildlife can drive numerous cascading impacts on food webs, biodiversity, vegetation structure and people in coupled human-natural systems. There is also concern for increased risk of zoonotic disease transfer to humans and domestic animals from wildlife species with high pathogen loads as their abundance and proximity to humans increases. Here we use field data from 58 landscapes to document a supra-regional phenomenon of the hyperabundance and community dominance of Southeast Asian wild pigs and macaques. These two groups were chosen as prime candidates capable of reaching hyperabundance as they are edge adapted, with gregarious social structure, omnivorous diets, rapid reproduction and high tolerance to human proximity. Compared to intact interior forests, population densities in degraded forests were 148% and 87% higher for wild boar and macaques, respectively. In landscapes with >60% oil palm coverage, wild boar and pig-tailed macaque estimated abundances were 337% and 447% higher than landscapes with <1% oil palm coverage, respectively, suggesting marked demographic benefits accrued by crop raiding on calorie-rich food subsidies. There was extreme community dominance in forest landscapes with >20% oil palm cover where two pig and two macaque species accounted for >80% of independent camera trap detections, leaving <20% for the other 85 mammal species >1 kg considered. Establishing the population trends of pigs and macaques is imperative since they are linked to cascading impacts on the fauna and flora of local forest ecosystems, disease and human health, and economics (i.e., crop losses). The severity of potential negative cascading effects may motivate control efforts to achieve ecosystem integrity, human health and conservation objectives. Our review concludes that the rise of native generalists can be mediated by specific types of degradation, which influences the ecology and conservation of natural areas, creating both positive and detrimental impacts on intact ecosystems and human society.
Fulltext Contrasting effects of defaunation on aboveground carbon storage across the global tropics

Osuri AM, Ratnam J, Varma V, Alvarez-Loayza P, Hurtado Astaiza J, Bradford M, et al.

Nat Commun, 2016 04 25;7:11351.
PMID: 27108957 DOI: 10.1038/ncomms11351

Defaunation is causing declines of large-seeded animal-dispersed trees in tropical forests worldwide, but whether and how these declines will affect carbon storage across this biome is unclear. Here we show, using a pan-tropical data set, that simulated declines of large-seeded animal-dispersed trees have contrasting effects on aboveground carbon stocks across Earth's tropical forests. In our simulations, African, American and South Asian forests, which have high proportions of animal-dispersed species, consistently show carbon losses (2-12%), but Southeast Asian and Australian forests, where there are more abiotically dispersed species, show little to no carbon losses or marginal gains (±1%). These patterns result primarily from changes in wood volume, and are underlain by consistent relationships in our empirical data (∼2,100 species), wherein, large-seeded animal-dispersed species are larger as adults than small-seeded animal-dispersed species, but are smaller than abiotically dispersed species. Thus, floristic differences and distinct dispersal mode-seed size-adult size combinations can drive contrasting regional responses to defaunation.
Fulltext Standardized Assessment of Biodiversity Trends in Tropical Forest Protected Areas: The End Is Not in Sight

Beaudrot L, Ahumada JA, O'Brien T, Alvarez-Loayza P, Boekee K, Campos-Arceiz A, et al.

PLoS Biol, 2016 Jan;14(1):e1002357.
PMID: 26785119 DOI: 10.1371/journal.pbio.1002357

Extinction rates in the Anthropocene are three orders of magnitude higher than background and disproportionately occur in the tropics, home of half the world's species. Despite global efforts to combat tropical species extinctions, lack of high-quality, objective information on tropical biodiversity has hampered quantitative evaluation of conservation strategies. In particular, the scarcity of population-level monitoring in tropical forests has stymied assessment of biodiversity outcomes, such as the status and trends of animal populations in protected areas. Here, we evaluate occupancy trends for 511 populations of terrestrial mammals and birds, representing 244 species from 15 tropical forest protected areas on three continents. For the first time to our knowledge, we use annual surveys from tropical forests worldwide that employ a standardized camera trapping protocol, and we compute data analytics that correct for imperfect detection. We found that occupancy declined in 22%, increased in 17%, and exhibited no change in 22% of populations during the last 3-8 years, while 39% of populations were detected too infrequently to assess occupancy changes. Despite extensive variability in occupancy trends, these 15 tropical protected areas have not exhibited systematic declines in biodiversity (i.e., occupancy, richness, or evenness) at the community level. Our results differ from reports of widespread biodiversity declines based on aggregated secondary data and expert opinion and suggest less extreme deterioration in tropical forest protected areas. We simultaneously fill an important conservation data gap and demonstrate the value of large-scale monitoring infrastructure and powerful analytics, which can be scaled to incorporate additional sites, ecosystems, and monitoring methods. In an era of catastrophic biodiversity loss, robust indicators produced from standardized monitoring infrastructure are critical to accurately assess population outcomes and identify conservation strategies that can avert biodiversity collapse.
Limited carbon and biodiversity co-benefits for tropical forest mammals and birds

Beaudrot L, Kroetz K, Alvarez-Loayza P, Amaral I, Breuer T, Fletcher C, et al.

Ecol Appl, 2016 Jun;26(4):1098-1111.
PMID: 28581662 DOI: 10.1890/15-0935

The conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon stock conservation will provide benefits to biodiversity in part because whether forests that contain high carbon density in their aboveground biomass also contain high animal diversity is unknown. Here, we empirically examined medium to large bodied ground-dwelling mammal and bird (hereafter "wildlife") diversity and carbon stock levels within the tropics using camera trap and vegetation data from a pantropical network of sites. Specifically, we tested whether tropical forests that stored more carbon contained higher wildlife species richness, taxonomic diversity, and trait diversity. We found that carbon stocks were not a significant predictor for any of these three measures of diversity, which suggests that benefits for wildlife diversity will not be maximized unless wildlife diversity is explicitly taken into account; prioritizing carbon stocks alone will not necessarily meet biodiversity conservation goals. We recommend conservation planning that considers both objectives because there is the potential for more wildlife diversity and carbon stock conservation to be achieved for the same total budget if both objectives are pursued in tandem rather than independently. Tropical forests with low elevation variability and low tree density supported significantly higher wildlife diversity. These tropical forest characteristics may provide more affordable proxies of wildlife diversity for future multi-objective conservation planning when fine scale data on wildlife are lacking.
Combining camera trap surveys and IUCN range maps to improve knowledge of species distributions

Chen C, Granados A, Brodie JF, Kays R, Davies TJ, Liu R, et al.

Conserv Biol, 2023 Nov 08.
PMID: 37937455 DOI: 10.1111/cobi.14221

Reliable maps of species distributions are fundamental for biodiversity research and conservation. The International Union for Conservation of Nature (IUCN) range maps are widely recognized as authoritative representations of species' geographic limits, yet they might not always align with actual occurrence data. In recent area of habitat (AOH) maps, areas that are not habitat have been removed from IUCN ranges to reduce commission errors, but their concordance with actual species occurrence also remains untested. We tested concordance between occurrences recorded in camera trap surveys and predicted occurrences from the IUCN and AOH maps for 510 medium- to large-bodied mammalian species in 80 camera trap sampling areas. Across all areas, cameras detected only 39% of species expected to occur based on IUCN ranges and AOH maps; 85% of the IUCN only mismatches occurred within 200 km of range edges. Only 4% of species occurrences were detected by cameras outside IUCN ranges. The probability of mismatches between cameras and the IUCN range was significantly higher for smaller-bodied mammals and habitat specialists in the Neotropics and Indomalaya and in areas with shorter canopy forests. Our findings suggest that range and AOH maps rarely underrepresent areas where species occur, but they may more often overrepresent ranges by including areas where a species may be absent, particularly at range edges. We suggest that combining range maps with data from ground-based biodiversity sensors, such as camera traps, provides a richer knowledge base for conservation mapping and planning.
Standards of Practice in Acute Ischemic Stroke Intervention: International Recommendations

Pierot L, Jayaraman MV, Szikora I, Hirsch JA, Baxter B, Miyachi S, et al.

AJNR Am J Neuroradiol, 2018 11;39(11):E112-E117.
PMID: 30442688 DOI: 10.3174/ajnr.A5853
Mycorrhizal feedbacks influence global forest structure and diversity

Delavaux CS, LaManna JA, Myers JA, Phillips RP, Aguilar S, Allen D, et al.

Commun Biol, 2023 Oct 19;6(1):1066.
PMID: 37857800 DOI: 10.1038/s42003-023-05410-z

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure.
Fulltext Arbuscular mycorrhizal trees influence the latitudinal beta-diversity gradient of tree communities in forests worldwide

Zhong Y, Chu C, Myers JA, Gilbert GS, Lutz JA, Stillhard J, et al.

Nat Commun, 2021 May 25;12(1):3137.
PMID: 34035260 DOI: 10.1038/s41467-021-23236-3

Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) associations are critical for host-tree performance. However, how mycorrhizal associations correlate with the latitudinal tree beta-diversity remains untested. Using a global dataset of 45 forest plots representing 2,804,270 trees across 3840 species, we test how AM and EcM trees contribute to total beta-diversity and its components (turnover and nestedness) of all trees. We find AM rather than EcM trees predominantly contribute to decreasing total beta-diversity and turnover and increasing nestedness with increasing latitude, probably because wide distributions of EcM trees do not generate strong compositional differences among localities. Environmental variables, especially temperature and precipitation, are strongly correlated with beta-diversity patterns for both AM trees and all trees rather than EcM trees. Results support our hypotheses that latitudinal beta-diversity patterns and environmental effects on these patterns are highly dependent on mycorrhizal types. Our findings highlight the importance of AM-dominated forests for conserving global forest biodiversity.
Fulltext An estimate of the number of tropical tree species

Slik JW, Arroyo-Rodríguez V, Aiba S, Alvarez-Loayza P, Alves LF, Ashton P, et al.

Proc Natl Acad Sci U S A, 2015 Jun 16;112(24):7472-7.
PMID: 26034279 DOI: 10.1073/pnas.1423147112

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼ 40,000 and ∼ 53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼ 19,000-25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼ 4,500-6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa.
Mammal responses to global changes in human activity vary by trophic group and landscape

Burton AC, Beirne C, Gaynor KM, Sun C, Granados A, Allen ML, et al.

Nat Ecol Evol, 2024 Mar 18.
PMID: 38499871 DOI: 10.1038/s41559-024-02363-2

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human-wildlife interactions along gradients of human influence.
Fulltext Phylogenetic classification of the world's tropical forests

Slik JWF, Franklin J, Arroyo-Rodríguez V, Field R, Aguilar S, Aguirre N, et al.

Proc Natl Acad Sci U S A, 2018 02 20;115(8):1837-1842.
PMID: 29432167 DOI: 10.1073/pnas.1714977115

Knowledge about the biogeographic affinities of the world's tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world's tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: (i) Indo-Pacific, (ii) Subtropical, (iii) African, (iv) American, and (v) Dry forests. Our results do not support the traditional neo- versus paleotropical forest division but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern-hemisphere forests.
Fulltext Consistent patterns of common species across tropical tree communities

Cooper DLM, Lewis SL, Sullivan MJP, Prado PI, Ter Steege H, Barbier N, et al.

Nature, 2024 Jan;625(7996):728-734.
PMID: 38200314 DOI: 10.1038/s41586-023-06820-z

Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.
Platform presentations

Pereda J, Niimi G, Kaul JM, Mishra S, Pangtey B, Peri D, et al.

Surg Radiol Anat, 2009 Sep;31 Suppl 1:49-93.
PMID: 27392491 DOI: 10.1007/BF03371485
Fulltext Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Klionsky DJ, Abdelmohsen K, Abe A, Abedin MJ, Abeliovich H, Acevedo Arozena A, et al.

Autophagy, 2016;12(1):1-222.
PMID: 26799652 DOI: 10.1080/15548627.2015.1100356
Fulltext Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1

Klionsky DJ, Abdel-Aziz AK, Abdelfatah S, Abdellatif M, Abdoli A, Abel S, et al.

Autophagy, 2021 Jan;17(1):1-382.
PMID: 33634751 DOI: 10.1080/15548627.2020.1797280

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

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