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More than half of the world's rivers dry up periodically, but our understanding of the biological communities in dry riverbeds remains limited. Specifically, the roles of dispersal, environmental filtering and biotic interactions in driving biodiversity in dry rivers are poorly understood. Here, we conduct a large-scale coordinated survey of patterns and drivers of biodiversity in dry riverbeds. We focus on eight major taxa, including microorganisms, invertebrates and plants: Algae, Archaea, Bacteria, Fungi, Protozoa, Arthropods, Nematodes and Streptophyta. We use environmental DNA metabarcoding to assess biodiversity in dry sediments collected over a 1-year period from 84 non-perennial rivers across 19 countries on four continents. Both direct factors, such as nutrient and carbon availability, and indirect factors such as climate influence the local biodiversity of most taxa. Limited resource availability and prolonged dry phases favor oligotrophic microbial taxa. Co-variation among taxa, particularly Bacteria, Fungi, Algae and Protozoa, explain more spatial variation in community composition than dispersal or environmental gradients. This finding suggests that biotic interactions or unmeasured ecological and evolutionary factors may strongly influence communities during dry phases, altering biodiversity responses to global changes.
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Biodiversidade , Rios , Rios/microbiologia , Animais , Fungos/classificação , Fungos/genética , Sedimentos Geológicos/microbiologia , Bactérias/classificação , Bactérias/genética , Invertebrados/classificação , Código de Barras de DNA Taxonômico , Plantas/classificação , Archaea/classificação , Archaea/genéticaRESUMO
OBJECTIVE: To evaluate the effectiveness of bone anchored maxillary protraction (BAMP) in the management of class III skeletal malocclusion in children aged 11-14 years compared with an untreated control group in terms of perceived need for orthognathic surgery, skeletal and dental change, and psychological impact. DESIGN: A multicentre two-armed parallel randomised controlled trial. SETTING: Six UK hospital orthodontic units. METHODS: A total of 57 patients were randomly allocated into either the BAMP group (BAMPG) (n = 28) or a no treatment control group (CG) (n = 29). OUTCOMES: Data collection occurred at registration (DC1),18 months (DC2) and 3 years (DC3), where skeletal and dental changes were measured from lateral cephalograms and study models. Oral Aesthetic Subjective Impact Score (OASIS) and Oral Quality of Life (OHQOL) questionnaires were used to assess the psychological impact of treatment. RESULTS: The mean age was 12.9 ± 0.7 years and 12.6 ± 0.9 years in the BAMPG and CG, respectively. At DC2, the BAMPG achieved a class III ANB improvement of +0.6° compared with -0.7° in the CG (P = 0.004). The overjet improvement was +1.4 mm for the BAMPG and -0.2 mm for the CG (P = 0.002). There was no evidence of any other group differences for the other skeletal or dental cephalometric outcomes (P > 0.05) or the questionnaire data (OASIS P = 0.10, OHQOL P = 0.75). At DC2, the 18-month follow-up, 22% of the BAMPG achieved a positive overjet. At the 3-year follow-up (DC3), fewer patients in the BAMPG were perceived to need orthognathic surgery (48%) compared with 75% of patients in the CG (P = 0.04), with an odds ratio of 0.31 (95% confidence interval = 0.10-0.95). CONCLUSION: The BAMP technique did not show any social or psychological benefits; however, the skeletal class III improvement in ANB and the overjet change were sufficient to reduce the perceived need for orthognathic surgery by 27% compared with the CG.
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How people value rivers, wetlands and floodplains influences their attitudes, beliefs and behaviours towards these ecosystems, and can shape policy and management interventions. Better understanding why people value rivers, wetlands and floodplains and their key ecosystem components, such as vegetation, helps to determine what factors underpin the social legitimacy required for effective management of these systems. This study sought to ascertain perspectives on the value of non-woody vegetation in river-floodplain systems via an online survey. The survey found that participants valued non-woody vegetation for their provision of a range of ecosystem functions and services, with strong emphasis on ecological aspects such as regulation functions, habitat provision and biodiversity. However, the inclusion of a question framed to focus on stories or narratives resulted in a different emphasis. Responses indicated that non-woody vegetation, and rivers, wetlands and floodplains were valued for the way they made people feel through lived experiences such as recreational activities, personal interactions with nature, educational and research experiences. This highlights the important role of storytelling in navigating complex natural resource management challenges and ascertaining a deeper understanding of values that moves beyond provision of function to feeling. Improved understanding of the diverse ways people value and interact with river-floodplain systems will help develop narratives and forms of engagement that foster shared understanding, empathy and collaboration. Appreciation of plural values such as the provision of functions and services along with the role of emotional connections and lived experience will likely increase lasting engagement of the general public with management to protect and restore river-floodplain systems.
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Ecossistema , Áreas Alagadas , Humanos , Rios , Biodiversidade , Conservação dos Recursos Naturais/métodosRESUMO
Practitioners of environmental water management (EWM) operate within complex social-ecological systems. We sought to better understand this complexity by investigating the management of environmental water for vegetation outcomes. We conducted an online survey to determine practitioners' perspectives on EWM for non-woody vegetation (NWV) in the Murray-Darling Basin, Australia with regards to: i) desirable outcomes and benefits; ii) influencing factors and risks; iii) challenges of monitoring and evaluation, and iv) improving outcomes. Survey participants indicated that EWM aims to achieve outcomes by improving or maintaining vegetation attributes and the functions and values these provide. Our study reveals that EWM practitioners perceive NWV management in a holistic and highly interconnected way. Numerous influencing factors as well as risks and challenges to achieving outcomes were identified by participants, including many unrelated to water. Survey responses highlighted six areas to improve EWM for NWV outcomes: (1) flow regimes, (2) vegetation attributes, (3) non-flow drivers, (4) management-governance considerations, (5) functions and values, and (6) monitoring, evaluation and research. These suggest a need for more than 'just water' when it comes to the restoration and management of NWV. Our findings indicate more integrated land-water governance and management is urgently required to address the impacts of non-flow drivers such as pest species, land-use change and climate change. The results also indicate that inherent complexity in EWM for ecological outcomes has been poorly addressed, with a need to tackle social-ecological constraints to improve EWM outcomes.
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Conservação dos Recursos Naturais , Água , Humanos , Conservação dos Recursos Naturais/métodos , Austrália , Abastecimento de Água , Ecossistema , RiosRESUMO
Interference competition has the potential to alter avian assemblages at long-lasting arid zone waterholes, particularly in a warming world, as more potentially aggressive species frequent these sites to drink. We used camera traps and observational surveys to investigate interference competition between terrestrial avian species at six long-lasting waterholes across three sampling seasons (two summers and one winter) within the MacDonnell Ranges Bioregion in central Australia. The proportion of individuals drinking for each of four dietary classes (granivores, nectarivores, omnivores, and insectivores) was modelled in relation to their abundance in the immediate waterhole habitat, which informed the potential for competition in each season. We then used the temporal overlap estimators to quantify the degree of competition between species at waterholes with species grouped into families (Meliphagidae, Ptilonorhynchidae, Estrildidae, and Rhipiduridae). We found the proportion of individuals drinking at waterholes was greatest during hot and dry periods, suggesting the potential for interference competition is greatest during these times. This was particularly the case for nectarivores where, in hot and dry conditions, the proportion of drinking individuals increased significantly as their abundance also increased in the waterhole habitat. We predicted that subordinate species would alter their activity periods to avoid competitive interactions with meliphagids (honeyeaters), however, we found there was a high degree of temporal overlap between all families sampled across all seasons. These results suggest subordinate species are unlikely to be excluded from long-lasting waterholes by potentially aggressive species, such as honeyeaters. However, some species may face trade-offs between foraging and accessing waterholes to stay hydrated as they shift their activity to avoid the hottest parts of the day during the summer months. Under global warming, extended hot and dry periods will likely create conditions where balancing energy and hydration requirements becomes increasingly difficult and results in the loss of body condition.
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High concentrations of the most consumed pharmaceuticals, caffeine and paracetamol, have been observed globally in wastewater treatment plant discharge. Here, we assess the potential for photodegradation of caffeine and paracetamol residues at concentrations like those observed in treated wastewater discharges to the environment. Laboratory assays were used to measure rates of photodegradation of these two compounds both in distilled water and in natural river water with leaf litter leachate. When exposed to artificial light simulating natural sunlight, the half-life values of caffeine and paracetamol were significantly shorter than in the dark. The presence of organic matter increased caffeine and paracetamol half-life by lessening the photolytic effect. These results suggest that photolysis is a substantial contributor to the degradation of caffeine and paracetamol. The findings contribute to our understanding of persistence of pharmaceuticals in treated wastewater discharge. PRACTITIONER POINTS: The photodegradation of caffeine and paracetamol residues in surface water was examined. With leaf litter leachate, caffeine and paracetamol were photodegraded in distilled and natural river water in laboratory. Caffeine's half-life ranged from 2.3 to 16.2 days under artificial sunlight andparacetamols from 4.3 to 12.2 days. When incubated in the dark, the half-life for both compounds exceeded 4 weeks. Organic matter decreased the photolytic action of caffeine and paracetamol.
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Poluentes Químicos da Água , Água , Águas Residuárias , Fotólise , Cafeína , Acetaminofen , Luz Solar , Poluentes Químicos da Água/química , Preparações FarmacêuticasRESUMO
Among non-gender conforming populations, there is a subgroup of individuals who experience significant distress associated with their gender incongruity, commonly referred to as gender dysphoria (GD). In the UK, there is a recognised pathway for individuals experiencing GD. This has traditionally been initiated by a referral to the Gender Identity Development Service (GIDS) for children and adolescents or to a Gender Identity Clinic (GIC) for adults. This pathway can potentially involve several specialties and treatment modalities, including the prescription of various hormones. It is important for orthodontists to have an understanding of this field, as well as the potential treatment modalities, so that they can support this often marginalised patient group. Inherent differences between male and female facial features may also lead patients with GD to present to orthodontists, wishing to change their facial appearance. This article highlights the current national pathway for GD and the orthodontic considerations for these individuals.
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Disforia de Gênero , Identidade de Gênero , Criança , Adulto , Adolescente , Humanos , Masculino , Feminino , Disforia de Gênero/terapia , OrtodontistasRESUMO
Aquatic plants share a range of convergent reproductive strategies, such as the ability to reproduce both sexually and asexually through vegetative growth. In dryland river systems, floodplain inundation is infrequent and irregular, and wetlands consist of discrete and unstable habitat patches. In these systems, life history strategies such as long-distance dispersal, seed longevity, self-fertilisation, and reproduction from vegetative propagules are important strategies that allow plants to persist. Using two aquatic plants, Marsilea drummondii and Eleocharis acuta, we investigated the proportions of sexual and asexual reproduction and self-fertilisation by employing next-generation sequencing approaches, and we used this information to understand the population genetic structure of a large inland floodplain in western New South Wales (NSW), Australia. Asexual vegetative reproduction and self-fertilisation were more common in M. drummondii, but both species used sexual reproduction as the main mode of reproduction. This resulted in a highly differentiated genetic structure between wetlands and a similar genetic structure within wetlands. The similarity in genetic structure was influenced by the wetland in the two species, highlighting the influence of the floodplain landscape and hydrology on structuring population genetic structure. The high levels of genetic variation among wetlands and the low variation within wetlands suggests that dispersal and pollination occur within close proximity and that gene flow is restricted. This suggests a reliance on locally sourced (persistent) seed, rather than asexual (clonal) reproduction or recolonisation via dispersal, for the population maintenance of plants in dryland rivers. This highlights the importance of floodplain inundation to promote seed germination, establishment, and reproduction in dryland regions.
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Eleocharis , Marsileaceae , Estruturas Genéticas , Genética Populacional , Plantas , Reprodução/genética , Rios/químicaRESUMO
The biological assessment of rivers i.e., their assessment through use of aquatic assemblages, integrates the effects of multiple-stressors on these systems over time and is essential to evaluate ecosystem condition and establish recovery measures. It has been undertaken in many countries since the 1990s, but not globally. And where national or multi-national monitoring networks have gathered large amounts of data, the poor water body classifications have not necessarily resulted in the rehabilitation of rivers. Thus, here we aimed to identify major gaps in the biological assessment and rehabilitation of rivers worldwide by focusing on the best examples in Asia, Europe, Oceania, and North, Central, and South America. Our study showed that it is not possible so far to draw a world map of the ecological quality of rivers. Biological assessment of rivers and streams is only implemented officially nation-wide and regularly in the European Union, Japan, Republic of Korea, South Africa, and the USA. In Australia, Canada, China, New Zealand, and Singapore it has been implemented officially at the state/province level (in some cases using common protocols) or in major catchments or even only once at the national level to define reference conditions (Australia). In other cases, biological monitoring is driven by a specific problem, impact assessments, water licenses, or the need to rehabilitate a river or a river section (as in Brazil, South Korea, China, Canada, Japan, Australia). In some countries monitoring programs have only been explored by research teams mostly at the catchment or local level (e.g., Brazil, Mexico, Chile, China, India, Malaysia, Thailand, Vietnam) or implemented by citizen science groups (e.g., Southern Africa, Gambia, East Africa, Australia, Brazil, Canada). The existing large-extent assessments show a striking loss of biodiversity in the last 2-3 decades in Japanese and New Zealand rivers (e.g., 42% and 70% of fish species threatened or endangered, respectively). A poor condition (below Good condition) exists in 25% of South Korean rivers, half of the European water bodies, and 44% of USA rivers, while in Australia 30% of the reaches sampled were significantly impaired in 2006. Regarding river rehabilitation, the greatest implementation has occurred in North America, Australia, Northern Europe, Japan, Singapore, and the Republic of Korea. Most rehabilitation measures have been related to improving water quality and river connectivity for fish or the improvement of riparian vegetation. The limited extent of most rehabilitation measures (i.e., not considering the entire catchment) often constrains the improvement of biological condition. Yet, many rehabilitation projects also lack pre-and/or post-monitoring of ecological condition, which prevents assessing the success and shortcomings of the recovery measures. Economic constraints are the most cited limitation for implementing monitoring programs and rehabilitation actions, followed by technical limitations, limited knowledge of the fauna and flora and their life-history traits (especially in Africa, South America and Mexico), and poor awareness by decision-makers. On the other hand, citizen involvement is recognized as key to the success and sustainability of rehabilitation projects. Thus, establishing rehabilitation needs, defining clear goals, tracking progress towards achieving them, and involving local populations and stakeholders are key recommendations for rehabilitation projects (Table 1). Large-extent and long-term monitoring programs are also essential to provide a realistic overview of the condition of rivers worldwide. Soon, the use of DNA biological samples and eDNA to investigate aquatic diversity could contribute to reducing costs and thus increase monitoring efforts and a more complete assessment of biodiversity. Finally, we propose developing transcontinental teams to elaborate and improve technical guidelines for implementing biological monitoring programs and river rehabilitation and establishing common financial and technical frameworks for managing international catchments. We also recommend providing such expert teams through the United Nations Environment Program to aid the extension of biomonitoring, bioassessment, and river rehabilitation knowledge globally.
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Mating strategies in fishes are known to include polygyny, polyandry and monogamy and provide valuable insights regarding powerful evolutionary forces such as sexual selection. Monogamy is a complex of mating systems that has been relatively neglected. Previous work on mating strategies in fishes has often been based on observation and focused on marine species rather than freshwater fishes. SNPs are increasingly being used as a molecular ecology tool in non-model organisms, and methods of probabilistic genetic analysis of such datasets are becoming available for use in the absence of parental genotypes. This approach can be used to infer mating strategies. The long-term pair bonding seen in mammals, reptiles and birds has not been recorded in freshwater fishes-in every other respect an extremely diverse group. This study shows that multi-year pair bonding occurs in an Australian Percichthyid fish that exhibits paternal care of eggs and larvae. Using SNPs, full sibling pairs of larvae were found over multiple years in a three-year study. Stable isotope signatures of the larvae support the genetic inference that full sibling pairs shared a common mother, the ultimate source of that isotopic signature during oogenesis. Spatial and temporal clustering also suggests that the full sibling larvae are unlikely to be false positive identifications of the probabilistic identification of siblings. For the first time, we show multi-year pair bonding in a wild freshwater fish. This will have important conservation and management implications for the species. This approach could provide insights into many behavioural, ecological and evolutionary questions, particularly if this is not a unique case. Our findings are likely to initiate interest in seeking more examples of monogamy and alternative mating strategies in freshwater fishes, particularly if others improve methods of analysis of SNP data for identification of siblings in the absence of parental genotypes.
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Bi-allelic Single Nucleotide Polymorphism (SNP) markers are widely used in population genetic studies. In most studies, sequences either side of the SNPs remain unused, although these sequences contain information beyond that used in population genetic studies. In this study, we show how these sequence tags either side of a single nucleotide polymorphism can be used for comparative genome analysis. We used DArTseq (Diversity Array Technology) derived SNP data for a non-model Australian native freshwater fish, Macquaria ambigua, to identify genes linked to SNP associated sequence tags, and to discover homologies with evolutionarily conserved genes and genomic regions. We concatenated 6,776 SNP sequence tags to create a hypothetical genome (representing 0.1-0.3% of the actual genome), which we used to find sequence homologies with 12 model fish species using the Ensembl genome browser with stringent filtering parameters. We identified sequence homologies for 17 evolutionarily conserved genes (cd9b, plk2b, rhot1b, sh3pxd2aa, si:ch211-148f13.1, si:dkey-166d12.2, zgc:66447, atp8a2, clvs2, lyst, mkln1, mnd1, piga, pik3ca, plagl2, rnf6, sec63) along with an ancestral evolutionarily conserved syntenic block (euteleostomi Block_210). Our analysis also revealed repetitive sequences covering approximately 12% of the hypothetical genome where DNA transposon, LTR and non-LTR retrotransposons were most abundant. A hierarchical pattern of the number of sequence homologies with phylogenetically close species validated the approach for repeatability. This new approach of using SNP associated sequence tags for comparative genome analysis may provide insight into the genome evolution of non-model species where whole genome sequences are unavailable.
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Hibridização Genômica Comparativa/métodos , Peixes/genética , Genética Populacional , Genoma , Genômica/métodos , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA/métodos , Animais , Peixes/classificação , FilogeniaRESUMO
BACKGROUND: Early dental decay or demineralised lesions (DLs, also known as white spot lesions) can appear on teeth during fixed orthodontic (brace) treatment. Fluoride reduces decay in susceptible individuals, including orthodontic patients. This review compared various forms of topical fluoride to prevent the development of DLs during orthodontic treatment. This is the second update of the Cochrane Review first published in 2004 and previously updated in 2013. OBJECTIVES: The primary objective was to evaluate whether topical fluoride reduces the proportion of orthodontic patients with new DLs after fixed appliances. The secondary objectives were to examine the effectiveness of different modes of topical fluoride delivery in reducing the proportions of orthodontic patients with new DLs, as well as the severity of lesions, in terms of number, size and colour. Participant-assessed outcomes, such as perception of DLs, and oral health-related quality of life data were to be included, as would reports of adverse effects. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 1 February 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 1) in the Cochrane Library (searched 1 February 2019), MEDLINE Ovid (1946 to 1 February 2019), and Embase Ovid (1980 to 1 February 2019). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Parallel-group, randomised controlled trials comparing the use of a fluoride-containing product versus a placebo, no treatment or a different type of fluoride treatment, in which the outcome of enamel demineralisation was assessed at the start and at the end of orthodontic treatment. DATA COLLECTION AND ANALYSIS: At least two review authors independently, in duplicate, conducted risk of bias assessments and extracted data. Authors of trials were contacted to obtain missing data or to ask for clarification of aspects of trial methodology. Cochrane's statistical guidelines were followed. MAIN RESULTS: This update includes 10 studies and contains data from nine studies, comparing eight interventions, involving 1798 randomised participants (1580 analysed). One report contained insufficient information and the authors have been contacted. We assessed two studies as at low risk of bias, six at unclear risk of bias, and two at high risk of bias. Two placebo (non-fluoride) controlled studies, at low risk of bias, investigated the professional application of varnish (7700 or 10,000 parts per million (ppm) fluoride (F)), every six weeks and found insufficient evidence of a difference regarding its effectiveness in preventing new DLs (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.14 to 1.93; 405 participants; low-certainty evidence). One placebo (non-fluoride) controlled study, at unclear risk of bias, provides a low level of certainty that fluoride foam (12,300 ppm F), professionally applied every two months, may reduce the incidence of new DLs (12% versus 49%) after fixed orthodontic treatment (RR 0.26, 95% CI 0.11 to 0.57; 95 participants). One study, at unclear risk of bias, also provides a low level of certainty that use of a high-concentration fluoride toothpaste (5000 ppm F) by patients may reduce the incidence of new DLs (18% versus 27%) compared with a conventional fluoride toothpaste (1450 ppm F) (RR 0.68, 95% CI 0.46 to 1.00; 380 participants). There was no evidence for a difference in the proportions of orthodontic patients with new DLs on the teeth after treatment with fixed orthodontic appliances for the following comparisons: - an amine fluoride and stannous fluoride toothpaste/mouthrinse combination versus a sodium fluoride toothpaste/mouthrinse, - an amine fluoride gel versus a non-fluoride placebo applied by participants at home once a week and by professional application every three months, - resin-modified glass ionomer cement versus light-cured composite resin for bonding orthodontic brackets, - a 250 ppm F mouthrinse versus 0 ppm F placebo mouthrinse, - the use of an intraoral fluoride-releasing glass bead device attached to the brace versus a daily fluoride mouthrinse. The last two comparisons involved studies that were assessed at high risk of bias, because a substantial number of participants were lost to follow-up. Unfortunately, although the internal validity and hence the quality of the studies has improved since the first version of the review, they have compared different interventions; therefore, the findings are only considered to provide low level of certainty, because none has been replicated by follow-up studies, in different settings, to confirm external validity. A patient-reported outcome, such as concern about the aesthetics of any DLs, was still not included as an outcome in any study. Reports of adverse effects from topical fluoride applications were rare and unlikely to be significant. One study involving fluoride-containing glass beads reported numerous breakages. AUTHORS' CONCLUSIONS: This review found a low level of certainty that 12,300 ppm F foam applied by a professional every 6 to 8 weeks throughout fixed orthodontic treatment, might be effective in reducing the proportion of orthodontic patients with new DLs. In addition, there is a low level of certainty that the patient use of a high fluoride toothpaste (5000 ppm F) throughout orthodontic treatment, might be more effective than a conventional fluoride toothpaste. These two comparisons were based on single studies. There was insufficient evidence of a difference regarding the professional application of fluoride varnish (7700 or 10,000 ppm F). Further adequately powered, randomised controlled trials are required to increase the certainty of these findings and to determine the best means of preventing DLs in patients undergoing fixed orthodontic treatment. The most accurate means of assessing adherence with the use of fluoride products by patients and any possible adverse effects also need to be considered. Future studies should follow up participants beyond the end of orthodontic treatment to determine the effect of DLs on patient satisfaction with treatment.
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Cariostáticos/uso terapêutico , Cárie Dentária/prevenção & controle , Fluoretos/uso terapêutico , Braquetes Ortodônticos/efeitos adversos , Cariostáticos/administração & dosagem , Fluoretos/administração & dosagem , Humanos , Antissépticos Bucais/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Karyotypic data from Australian native freshwater fishes are scarce, having been described from relatively few species. Golden perch (Macquaria ambigua) and Murray cod (Maccullochella peelii) are two large-bodied freshwater fish species native to Australia with significant indigenous, cultural, recreational and commercial value. The arid landscape over much of these fishes' range, coupled with the boom and bust hydrology of their habitat, means that these species have potential to provide useful evolutionary insights, such as karyotypes and sex chromosome evolution in vertebrates. Here we applied standard and molecular cytogenetic techniques to characterise karyotypes for golden perch and Murray cod. Both species have a diploid chromosome number 2n = 48 and a male heterogametic sex chromosome system (XX/XY). While the karyotype of golden perch is composed exclusively of acrocentric chromosomes, the karyotype of Murray cod consists of two submetacentric and 46 subtelocentric/acrocentric chromosomes. We have identified variable accumulation of repetitive sequences (AAT)10 and (CGG)10 along with diverse methylation patterns, especially on the sex chromosomes in both species. Our study provides a baseline for future cytogenetic analyses of other Australian freshwater fishes, especially species from the family Percichthyidae, to better understand their genome and sex chromosome evolution.
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Água Doce , Cariótipo , Percas/genética , Perciformes/genética , Cromossomos Sexuais/genética , Animais , Bandeamento Cromossômico , Metilação de DNA/genética , Feminino , Geografia , Masculino , Metáfase , Repetições de Microssatélites/genética , Filogenia , Especificidade da Espécie , Telômero/genéticaRESUMO
Climate change and human pressures are changing the global distribution and the extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico-chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56%-98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events.
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Nutrientes/análise , Compostos Orgânicos/análise , Rios/química , Biofilmes/crescimento & desenvolvimento , Disponibilidade Biológica , Clima , Mudança Climática , Sedimentos Geológicos/química , Nitratos/análise , Folhas de Planta/químicaRESUMO
INTRODUCTION: In this study, we aimed to compare the incidence of new demineralized lesions and bond failures between 2 groups of participants wearing fixed orthodontic appliances bonded with either light-cured resin-modified glass ionomer cement or light-cured composite. METHODS: This trial was a multicenter (6 centers: 2 teaching hospitals, 4 specialist orthodontic practices), single-blinded, randomized controlled trial with 2 parallel groups. Patients aged 11 years or older, in the permanent dentition, and about to start fixed orthodontic treatment in these 6 centers were randomly allocated to have either resin-modified glass ionomer cement or light-cured composite for bonding brackets, forward of the first molars. Pretreatment and day-of-debond digital photographic images were taken of the teeth and assessed by up to 5 clinical and 3 lay assessors for the presence or absence of new demineralized lesions and the esthetic impact. The assessors were masked as to group allocation. RESULTS: We randomized 210 participants, and 197 completed the trial. There were 173 with complete before-and after-digital images of the teeth. The incidence of new demineralized lesions was 24%; but when the esthetic impact was taken into account, this was considerably lower (9%). There was no statistically significant difference between the bracket adhesives in the numbers with at least 1 new demineralized lesion (risk ratio,1.25; 95% confidence interval, 0.74-2.13; P = 0.403) or first-time bracket failure (risk ratio,0.88; 95% confidence interval, 0.67-1.16; P = 0.35). There were no adverse effects. CONCLUSIONS: There is no evidence that the use of resin modified glass ionomer cement over light-cured composite for bonding brackets reduces the incidence of new demineralized lesions or bond failures. There might be other reasons for using resin modified glass ionomer cement. REGISTRATION: This trial was registered at ClinicalTrials.govNCT01925924. PROTOCOL: The protocol is available from the corresponding author on request.
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Resinas Compostas , Fluoretos Tópicos/administração & dosagem , Cimentos de Ionômeros de Vidro , Braquetes Ortodônticos , Desmineralização do Dente/prevenção & controle , Adolescente , Criança , Resinas Compostas/efeitos adversos , Colagem Dentária/métodos , Falha de Equipamento , Cimentos de Ionômeros de Vidro/efeitos adversos , Cimentos de Ionômeros de Vidro/química , Humanos , Braquetes Ortodônticos/efeitos adversos , Método Simples-Cego , Desmineralização do Dente/etiologiaRESUMO
The ongoing challenge of maintaining and improving the quality of water that leaves urban stormwater systems is often addressed using technical rather than social solutions. The need for investment in often expensive water infrastructure can be reduced through better investing in promoting human behaviors that protect water quality as part of water-sensitive urban design (WSUD) initiatives. Successfully achieving this requires understanding factors that influence adoption of proenvironmental behaviors. We review past studies examining this topic and identify that factors influencing adoption of proenvironmental behaviors relevant to WSUD commonly fall into four domains: proenvironmental values and norms, awareness and knowledge of environmental problems and the actions that can address them, proximity and place-based identity, and life-stage and lifestyle factors. We propose the VAIL (values, awareness, identify, lifestyle) framework, based on these four domains and able to be contextualized to specific water-quality problems and individual communities, to assist in diagnosing factors influencing adoption of proenvironmental behaviors. We demonstrate the applicability of the framework in a case study examining adoption of gardening practices that support water quality in Canberra, Australia. We developed 22 locally relevant VAIL indicators and surveyed 3,334 residents to understand engagement in four water-friendly gardening behaviors that help improve water quality in local lakes. In regression modeling, the indicators explained a significant amount of variance in these behaviors and suggested avenues for supporting greater adoption of these behaviors. Predictor variables across all four VAIL domains were significant, highlighting the importance of a multidomain framework.
Assuntos
Meio Ambiente , Qualidade da Água , Jardinagem , Humanos , Conhecimento , Estilo de VidaRESUMO
BACKGROUND: The permanent canine tooth in the maxillary (upper) jaw sometimes does not erupt into the mouth correctly. In about 1% to 3% of the population these teeth will be diverted into the roof of the mouth (palatally). It has been suggested that if the primary canine is removed at the right time this palatal eruption might be avoided. This is an update of a Cochrane review first published in 2009. OBJECTIVES: To evaluate the effect of extracting the primary maxillary canine on the eruption of the palatally ectopic maxillary permanent canine. SEARCH METHODS: We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 20 April 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1946 to 20 April 2012) and EMBASE via OVID (1980 to 20 April 2012). There were no restrictions regarding language or date of publication. SELECTION CRITERIA: Trials were selected if they met the following criteria: a randomised or quasi-randomised controlled trial, involving the extraction of the deciduous maxillary canine and assessing eruption/non-eruption of the palatally displaced maxillary permanent canine. DATA COLLECTION AND ANALYSIS: Data extraction was undertaken independently by two review authors. The primary outcome was the reported prevalence of eruption or non-eruption of the ectopic permanent canine into the mouth following observation or intervention. Results were to be expressed as risk ratios for dichotomous outcomes with 95% confidence intervals and mean differences for continuous outcomes. Heterogeneity was to be investigated, including both clinical and methodological factors. Authors of trials were contacted to request unpublished data. MAIN RESULTS: Reports of two randomised controlled trials previously excluded from an earlier version of the review due to "deficiencies in reporting, insufficient data" have now been included. These two trials included approximately 128 children, with more than 150 palatally displaced canine teeth, and both were conducted by the same research group. Data presented in the trial reports are either incomplete or inconsistent. Both trials are at high risk of bias. It must be emphasised that both trials have serious deficiencies in the way they were designed, conducted, and reported, and attempts to contact the authors to obtain detailed information and clarify inconsistencies have been unsuccessful. Allocation to treatment appears to be at the level of the individual, but outcomes of successful treatment relate to included teeth and data are not reported for each treatment group. Adverse effects are not reported. Neither trial provides any evidence to guide clinical decision making. AUTHORS' CONCLUSIONS: There is currently no evidence of the effects of extraction of primary canine teeth in 10-13 year old children with one or two palatally displaced permanent canine teeth.
Assuntos
Dente Canino/cirurgia , Maxila , Erupção Ectópica de Dente/prevenção & controle , Extração Dentária , Dente Decíduo , Dente não Erupcionado/prevenção & controle , Adolescente , Criança , Humanos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Adaptive management is an experimental approach used by water management agencies around the world to manage and restore aquatic ecosystems. The effectiveness of the approach can often be constrained by inflexible institutional arrangements. In this paper we compare two cases where agencies have implemented adaptive management to manage and restore aquatic ecosystems. Our aim was to understand practitioners' perceptions of how institutional flexibility can be created for adaptive management. We interviewed 14 adaptive management practitioners working in the Murray-Darling Basin, Australia and 14 practitioners in Southern Florida, United States of America. We found that in both cases, just enough flexibility was created to enable experimentation, but informal institutional arrangements tended to constrain adaptive management. We also found that adaptive management was effective when an agency adopted collaborative and distributed leadership, but these leadership styles were difficult to sustain, and not always appropriate when attempting to create institutional flexibility. Our results illustrate how agencies, stakeholders and researchers can develop a shared understanding of how to manage and restore aquatic ecosystems, which in turn, helps create institutional flexibility for an agency to manage adaptively.