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1.
BMC Health Serv Res ; 23(1): 294, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36978125

RESUMO

BACKGROUND: Heart failure is a chronic heart condition. Persons with heart failure often have limited physical capability, cognitive impairments, and low health literacy. These challenges can be barriers to healthcare service co-design with family members and professionals. Experience-Based Co-Design is a participatory healthcare quality improvement approach drawing on patients', family members' and professionals' experiences to improve healthcare. The overall aim of this study was to use Experience-Based Co-Design to identify experiences of heart failure and its care in a Swedish cardiac care setting, and to understand how these experiences can translate into heart failure care improvements for persons with heart failure and their families. METHODS: A convenience sample of 17 persons with heart failure and four family members participated in this single case study as a part of an improvement initiative within cardiac care. In line with Experienced-Based Co-Design methodology, field notes from observations of healthcare consultations, individual interviews and meeting minutes from stakeholders' feedback events, were used to gather participants' experiences of heart failure and its care. Reflexive thematic analysis was used to develop themes from data. RESULTS: Twelve service touchpoints, organized within five overarching themes emerged. The themes told a story about persons with heart failure and family members struggling in everyday life due to a poor quality of life, lack of support networks, and difficulties understanding and applying information about heart failure and its care. To be recognized by professionals was reported to be a key to good quality care. Opportunities to be involved in healthcare varied, Further, participants' experiences translated into proposed changes to heart failure care such as improved information about heart failure, continuity of care, improved relations, and communication, and being invited to be involved in healthcare. CONCLUSIONS: Our study findings offer knowledge about experiences of life with heart failure and its care, translated into heart failure service touchpoints. Further research is warranted to explore how these touchpoints can be addressed to improve life and care for persons with heart failure and other chronic conditions.


Assuntos
Insuficiência Cardíaca , Qualidade de Vida , Humanos , Família/psicologia , Qualidade da Assistência à Saúde , Insuficiência Cardíaca/terapia , Instalações de Saúde , Pesquisa Qualitativa
3.
Glob Chang Biol ; 26(10): 5365-5370, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32816359

RESUMO

The growth of the global terrestrial sink of carbon dioxide has puzzled scientists for decades. We propose that the role of land management practices-from intensive forestry to allowing passive afforestation of abandoned lands-have played a major role in the growth of the terrestrial carbon sink in the decades since the mid twentieth century. The Forest Transition, a historic transition from shrinking to expanding forests, and from sparser to denser forests, has seen an increase of biomass and carbon across large regions of the globe. We propose that the contribution of Forest Transitions to the terrestrial carbon sink has been underestimated. Because forest growth is slow and incremental, changes in the carbon density in forest biomass and soils often elude detection. Measurement technologies that rely on changes in two-dimensional ground cover can miss changes in forest density. In contrast, changes from abrupt and total losses of biomass in land clearing, forest fires and clear cuts are easy to measure. Land management improves over time providing important present contributions and future potential to climate change mitigation. Appreciating the contributions of Forest Transitions to the sequestering of atmospheric carbon will enable its potential to aid in climate change mitigation.


Assuntos
Florestas , Árvores , Biomassa , Sequestro de Carbono , Agricultura Florestal
4.
J Water Health ; 18(3): 375-382, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32589622

RESUMO

Soil-transmitted helminths (STH) are intestinal worms that infect 24% of the world's population. Stopping the spread of STH is difficult, as the eggs are resilient (can withstand high pH) and persistent (can remain viable in soils for several years). To ensure that new sanitation systems can inactivate STH, a better understanding of their resilience is required. This study assessed the inactivation of Ascaris eggs under various conditions, in terms of moisture content (MC) (<20 to >90%), temperature (20-50 °C) and pH (7-12.5). The results highlight that the exposure of Ascaris eggs to elevated pH (10.5-12.5) at temperatures ≤27.5 °C for >70 days had no effect on egg viability. Compounding effects of alkaline pH (≥10.5) or decreasing MC (<20%) was observed at 35 °C, with pH having more of an effect than decreasing MC. To accelerate the inactivation of STH, an increase in the treatment temperature is more effective than pH increase. Alkaline pH alone did not inactivate the eggs but can enhance the effect of ammonia, which is likely to be present in organic wastes.


Assuntos
Ascaris , Helmintíase , Animais , Concentração de Íons de Hidrogênio , Óvulo , Solo , Temperatura
5.
BMC Health Serv Res ; 20(1): 107, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32046710

RESUMO

BACKGROUND: Clinical practice improvements based on quality-register data are influenced by multiple factors. Although there is agreement that information from quality registers is valuable for quality improvement, practical ways of organising register use have been notoriously difficult to realise. The present study sought to investigate the mechanisms that lead various clinicians to use quality registers for improvement. METHODS: This research involves studying individuals' decisions in response to a Swedish programme focusing on increasing the use of quality registers. Through a case study, we focused on heart failure care and its corresponding register: the Swedish Heart Failure Register. The empirical data consisted of a purposive sample collected longitudinally by qualitative methods between 2013 and 2015. In total, 18 semi-structured interviews were carried out. We used realist evaluation to identify contexts, mechanisms, and outcomes. RESULTS: We identified four contexts - registration, use of output data, governance, and improvement projects - that provide conditions for the initiation of specific mechanisms. Given a professional theoretical perspective, we further showed that mechanisms are based on the logics of either organisational improvement or clinical practice. The two logics offer insights into the ways in which clinicians choose to embrace or reject certain registers' initiatives. CONCLUSIONS: We identified a strong path dependence, as registers have historically been tightly linked to the medical profession's competence. Few new initiatives in the studied programme reach the clinical context. We explain this through the lack of an organisational improvement logic and its corresponding mechanisms in the context of the medical profession. Implementation programmes must understand the logic of clinical practice; that is, be integrated with the ways in which work is carried out in everyday practice. Programmes need to be better at helping core health professionals to reach the highest standards of patient care.


Assuntos
Lógica , Melhoria de Qualidade , Sistema de Registros , Pesquisa sobre Serviços de Saúde , Humanos , Suécia
6.
Glob Chang Biol ; 25(9): 2900-2914, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31166650

RESUMO

There is evidence that anthropogenic nitrogen (N) deposition enhances carbon (C) sequestration in boreal forest soils. However, it is unclear how free-living saprotrophs (bacteria and fungi, SAP) and ectomycorrhizal (EM) fungi responses to N addition impact soil C dynamics. Our aim was to investigate how SAP and EM communities are impacted by N enrichment and to estimate whether these changes influence decay of litter and humus. We conducted a long-term experiment in northern Sweden, maintained since 2004, consisting of ambient, low N additions (0, 3, 6, and 12 kg N ha-1  year-1 ) simulating current N deposition rates in the boreal region, as well as a high N addition (50 kg N ha-1  year-1 ). Our data showed that long-term N enrichment impeded mass loss of litter, but not of humus, and only in response to the highest N addition treatment. Furthermore, our data showed that EM fungi reduced the mass of N and P in both substrates during the incubation period compared to when only SAP organisms were present. Low N additions had no effect on microbial community structure, while the high N addition decreased fungal and bacterial biomasses and altered EM fungi and SAP community composition. Actinomycetes were the only bacterial SAP to show increased biomass in response to the highest N addition. These results provide a mechanistic understanding of how anthropogenic N enrichment can influence soil C accumulation rates and suggest that current N deposition rates in the boreal region (≤12 kg N ha-1  year-1 ) are likely to have a minor impact on the soil microbial community and the decomposition of humus and litter.


Assuntos
Micorrizas , Nitrogênio , Carbono , Solo , Microbiologia do Solo , Suécia
7.
Health Expect ; 22(6): 1240-1250, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31433546

RESUMO

BACKGROUND: An improvement initiative sought to improve care for atrial fibrillation (AF) patients; many felt insecure about how to cope with AF. OBJECTIVE: To reveal AF patients' and professionals' experiences of pilot-testing a Learning Café group education programme, aimed at increasing the patients' sense of security in everyday life. DESIGN: Using an organizational case study design, we combined quantitative data (patients' sense of security) and qualitative data (project documentation; focus group interviews with five patients and five professionals) analysed using inductive qualitative content analysis. SETTING: AF patients and a multiprofessional team at a cardiac care unit in a Swedish district hospital. IMPROVEMENT ACTIVITIES: Two registered nurses invited AF patients and partners to four 2.5-hour Learning Café sessions. In the first session, they solicited participants' questions about life with AF. A physician, a registered nurse and a physiotherapist were invited to address these questions in the remaining sessions. RESULTS: AF patients reported gaining a greater sense of security in everyday life and anticipating a future shift from emergency care to planned care. Professionals reported enhanced professional development, learning more about person-centredness and gaining greater control of their own work situation. The organization gained knowledge about patient and family involvement. CONCLUSIONS: The Learning Café pilot test-exemplifying movement towards co-production through patient-professional collaboration-generated positive outcomes for patients (sense of security), professionals (work satisfaction; learning) and the organization (better care) in line with contemporary models for quality improvement and with Self-Determination Theory. This approach merits further testing and evaluation in other contexts.


Assuntos
Atividades Cotidianas/psicologia , Fibrilação Atrial/psicologia , Educação de Pacientes como Assunto/métodos , Adaptação Psicológica , Idoso , Idoso de 80 Anos ou mais , Feminino , Grupos Focais , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Autoimagem
8.
J Environ Manage ; 210: 1-9, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29329003

RESUMO

We evaluated the long-term implications from modifying rotation lengths in production forests for four forest-reliant species with different habitat requirements. By combining simulations of forest development with habitat models, and accounting both for stand and landscape scale influences, we projected habitat availability over 150 years in a large Swedish landscape, using rotation lengths which are longer (+22% and +50%) and shorter (-22%) compared to current practices. In terms of mean habitat availability through time, species requiring older forest were affected positively by extended rotations, and negatively by shortened rotations. For example, the mean habitat area for the treecreeper Certhia familiaris (a bird preferring forest with larger trees) increased by 31% when rotations were increased by 22%, at a 5% cost to net present value (NPV) and a 7% decrease in harvested volume. Extending rotation lengths by 50% provided more habitat for this species compared to a 22% extension, but at a much higher marginal cost. In contrast, the beetle Hadreule elongatula, which is dependent on sun-exposed dead wood, benefited from shortened rather than prolonged rotations. Due to an uneven distribution of stand-ages within the landscape, the relative amounts of habitat provided by different rotation length scenarios for a given species were not always consistent through time during the simulation period. If implemented as a conservation measure, prolonging rotations will require long-term strategic planning to avoid future bottlenecks in habitat availability, and will need to be accompanied by complementary measures accounting for the diversity of habitats necessary for the conservation of forest biodiversity.


Assuntos
Conservação dos Recursos Naturais , Agricultura Florestal , Animais , Ecossistema , Florestas , Suécia , Árvores
9.
Am J Hum Genet ; 94(1): 47-61, 2014 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-24387989

RESUMO

In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci.


Assuntos
Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 3/genética , Loci Gênicos , Predisposição Genética para Doença , Escleroderma Sistêmico/genética , Alelos , Proteína 5 Relacionada à Autofagia , Proteínas de Transporte/genética , Estudos de Casos e Controles , RNA Helicases DEAD-box/genética , Endodesoxirribonucleases/genética , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Antígenos HLA/genética , Humanos , Subunidade p35 da Interleucina-12/genética , Desequilíbrio de Ligação , Modelos Logísticos , Masculino , Procedimentos Analíticos em Microchip , Proteínas Associadas aos Microtúbulos/genética , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas/genética , Fatores de Risco , População Branca/genética
10.
Ecol Appl ; 27(6): 1838-1851, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28464423

RESUMO

We report results from long-term simulated external nitrogen (N) input experiments in three northern Pinus sylvestris forests, two of moderately high and one of moderately low productivity, assessing effects on annual net primary production (NPP) of woody mass and its interannual variation in response to variability in weather conditions. A sigmoidal response of wood NPP to external N inputs was observed in the both higher and lower productivity stands, reaching a maximum of ~65% enhancement regardless of the native site productivity, saturating at an external N input of 4-5 g N·m-2 ·yr-1 . The rate of increase in wood NPP and the N response efficiency (REN , increase in wood NPP per external N input) were maximized at an external N input of ~3 g N·m-2 ·yr-1 , regardless of site productivity. The maximum REN was greater in the higher productivity than the lower productivity stand (~20 vs. ~14 g C/g N). The N-induced enhancement of wood NPP and its REN were, however, markedly contingent on climatic variables. In both of the higher and lower productivity stands, wood NPP increased with growing season precipitation (P), but only up to ~400 mm. The sensitivity of the response to P increased with increasing external N inputs. Increasing growing season temperature (T) somewhat increased the N-induced drought effect, whereas decreasing T reduced the drought effect. These responses of wood NPP infused a large temporal variation to REN , making the use of a fixed value unadvisable. Based on these results, we suggest that regional climate conditions and future climate scenarios should be considered when modeling carbon sequestration in response to N deposition in boreal P. sylvestris, and possibly other forests.


Assuntos
Sequestro de Carbono , Clima , Florestas , Nitrogênio/metabolismo , Pinus sylvestris/metabolismo , Noruega , Estações do Ano , Suécia , Árvores/metabolismo , Madeira/química , Madeira/metabolismo
11.
J Environ Manage ; 197: 404-414, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28411568

RESUMO

A variety of modeling approaches can be used to project the future development of forest systems, and help to assess the implications of different management alternatives for biodiversity and ecosystem services. This diversity of approaches does however present both an opportunity and an obstacle for those trying to decide which modeling technique to apply, and interpreting the management implications of model output. Furthermore, the breadth of issues relevant to addressing key questions related to forest ecology, conservation biology, silviculture, economics, requires insights stemming from a number of distinct scientific disciplines. As forest planners, conservation ecologists, ecological economists and silviculturalists, experienced with modeling trade-offs and synergies between biodiversity and wood biomass production, we identified fifteen key considerations relevant to assessing the pros and cons of alternative modeling approaches. Specifically we identified key considerations linked to study question formulation, modeling forest dynamics, forest processes, study landscapes, spatial and temporal aspects, and the key response metrics - biodiversity and wood biomass production, as well as dealing with trade-offs and uncertainties. We also provide illustrative examples from the modeling literature stemming from the key considerations assessed. We use our findings to reiterate the need for explicitly addressing and conveying the limitations and uncertainties of any modeling approach taken, and the need for interdisciplinary research efforts when addressing the conservation of biodiversity and sustainable use of environmental resources.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Florestas , Ecossistema , Madeira
12.
Glob Chang Biol ; 21(8): 3169-80, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25711504

RESUMO

It is proposed that carbon (C) sequestration in response to reactive nitrogen (Nr ) deposition in boreal forests accounts for a large portion of the terrestrial sink for anthropogenic CO2 emissions. While studies have helped clarify the magnitude by which Nr deposition enhances C sequestration by forest vegetation, there remains a paucity of long-term experimental studies evaluating how soil C pools respond. We conducted a long-term experiment, maintained since 1996, consisting of three N addition levels (0, 12.5, and 50 kg N ha(-1) yr(-1) ) in the boreal zone of northern Sweden to understand how atmospheric Nr deposition affects soil C accumulation, soil microbial communities, and soil respiration. We hypothesized that soil C sequestration will increase, and soil microbial biomass and soil respiration will decrease, with disproportionately large changes expected compared to low levels of N addition. Our data showed that the low N addition treatment caused a non-significant increase in the organic horizon C pool of ~15% and a significant increase of ~30% in response to the high N treatment relative to the control. The relationship between C sequestration and N addition in the organic horizon was linear, with a slope of 10 kg C kg(-1) N. We also found a concomitant decrease in total microbial and fungal biomasses and a ~11% reduction in soil respiration in response to the high N treatment. Our data complement previous data from the same study system describing aboveground C sequestration, indicating a total ecosystem sequestration rate of 26 kg C kg(-1) N. These estimates are far lower than suggested by some previous modeling studies, and thus will help improve and validate current modeling efforts aimed at separating the effect of multiple global change factors on the C balance of the boreal region.


Assuntos
Sequestro de Carbono , Carbono/análise , Nitrogênio/análise , Taiga , Ecossistema , Solo/química , Microbiologia do Solo , Suécia
14.
J Environ Manage ; 154: 284-92, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25745845

RESUMO

Over previous decades new environmental measures have been implemented in forestry. In Fennoscandia, forest management practices were modified to set aside conservation areas and to retain trees at final felling. In this study we simulated the long-term effects of set-aside establishment and tree retention practices on the future availability of large trees and dead wood, two forest structures of documented importance to biodiversity conservation. Using a forest decision support system (Heureka), we projected the amounts of these structures over 200 years in two managed north Swedish landscapes, under management scenarios with and without set-asides and tree retention. In line with common best practice, we simulated set-asides covering 5% of the productive area with priority to older stands, as well as ∼5% green-tree retention (solitary trees and forest patches) including high-stump creation at final felling. We found that only tree retention contributed to substantial increases in the future density of large (DBH ≥35 cm) deciduous trees, while both measures made significant contributions to the availability of large conifers. It took more than half a century to observe stronger increases in the densities of large deciduous trees as an effect of tree retention. The mean landscape-scale volumes of hard dead wood fluctuated widely, but the conservation measures yielded values which were, on average over the entire simulation period, about 2.5 times as high as for scenarios without these measures. While the density of large conifers increased with time in the landscape initially dominated by younger forest, best practice conservation measures did not avert a long-term decrease in large conifer density in the landscape initially comprised of more old forest. Our results highlight the needs to adopt a long temporal perspective and to consider initial landscape conditions when evaluating the large-scale effects of conservation measures on forest biodiversity.


Assuntos
Biodiversidade , Agricultura Florestal/métodos , Árvores , Conservação dos Recursos Naturais , Ecossistema , Humanos , Suécia , Madeira
15.
Water Sci Technol ; 72(12): 2112-21, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26675998

RESUMO

The effect of a two-step process on the concentration of pathogens and indicator microorganisms in black water (0.9-1% total solids) was studied. The treatment combined auto-thermal aerobic digestion (ATAD) and ammonia sanitisation. First, the temperature of the black water was increased through ATAD and when a targeted temperature was reached (33, 41 and 45.5 °C studied), urea was added to a 0.5% concentration (total ammonia nitrogen >2.9 g L⁻¹). Escherichia coli and Salmonella spp. were reduced to non-detectable levels within 3 days following urea addition at temperatures above 40 °C, whereas when urea was added at 33 °C E. coli was still present after 8 days. By adding urea at temperatures of 40 °C and above, a 5 log10 reduction in Enterococcus spp. and a 3 log10 reduction in Ascaris suum eggs was achieved 1 week after the addition. With combined ATAD and ammonia treatment using 0.5% ww urea added at an aerobic digestion temperature >40 °C, black water was sanitised regarding the pathogens studied in 2 weeks of total treatment time.


Assuntos
Amônia/metabolismo , Fezes , Microbiologia da Água , Purificação da Água/métodos , Água/normas , Aerobiose , Amônia/administração & dosagem , Animais , Ascaris suum/efeitos dos fármacos , Ascaris suum/fisiologia , Bacteriófagos/efeitos dos fármacos , Bacteriófagos/crescimento & desenvolvimento , Bacteriófagos/isolamento & purificação , Enterococcus/efeitos dos fármacos , Enterococcus/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Fezes/química , Fezes/microbiologia , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Salmonella/efeitos dos fármacos , Salmonella/crescimento & desenvolvimento , Salmonella/isolamento & purificação , Ureia/administração & dosagem , Ureia/química , Água/química , Água/parasitologia , Purificação da Água/instrumentação , Purificação da Água/normas
16.
Hum Mol Genet ; 21(4): 926-33, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22076442

RESUMO

A single-nucleotide polymorphism (SNP) at the IL12RB2 locus showed a suggestive association signal in a previously published genome-wide association study (GWAS) in systemic sclerosis (SSc). Aiming to reveal the possible implication of the IL12RB2 gene in SSc, we conducted a follow-up study of this locus in different Caucasian cohorts. We analyzed 10 GWAS-genotyped SNPs in the IL12RB2 region (2309 SSc patients and 5161 controls). We then selected three SNPs (rs3790567, rs3790566 and rs924080) based on their significance level in the GWAS, for follow-up in an independent European cohort comprising 3344 SSc and 3848 controls. The most-associated SNP (rs3790567) was further tested in an independent cohort comprising 597 SSc patients and 1139 controls from the USA. After conditional logistic regression analysis of the GWAS data, we selected rs3790567 [P(MH)= 1.92 × 10(-5) odds ratio (OR) = 1.19] as the genetic variant with the firmest independent association observed in the analyzed GWAS peak of association. After the first follow-up phase, only the association of rs3790567 was consistent (P(MH)= 4.84 × 10(-3) OR = 1.12). The second follow-up phase confirmed this finding (P(χ2) = 2.82 × 10(-4) OR = 1.34). After performing overall pooled-analysis of all the cohorts included in the present study, the association found for the rs3790567 SNP in the IL12RB2 gene region reached GWAS-level significant association (P(MH)= 2.82 × 10(-9) OR = 1.17). Our data clearly support the IL12RB2 genetic association with SSc, and suggest a relevant role of the interleukin 12 signaling pathway in SSc pathogenesis.


Assuntos
Predisposição Genética para Doença/genética , Receptores de Interleucina-12/genética , Escleroderma Sistêmico/genética , População Branca/genética , Europa (Continente)/etnologia , Seguimentos , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo Único/genética , Estados Unidos/etnologia
17.
Glob Chang Biol ; 20(1): 276-86, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24115224

RESUMO

It is proposed that increases in anthropogenic reactive nitrogen (Nr ) deposition may cause temperate and boreal forests to sequester a globally significant quantity of carbon (C); however, long-term data from boreal forests describing how C sequestration responds to realistic levels of chronic Nr deposition are scarce. Using a long-term (14-year) stand-scale (0.1 ha) N addition experiment (three levels: 0, 12.5, and 50 kg N ha(-1)  yr(-1) ) in the boreal zone of northern Sweden, we evaluated how chronic N additions altered N uptake and biomass of understory communities, and whether changes in understory communities explained N uptake and C sequestration by trees. We hypothesized that understory communities (i.e. mosses and shrubs) serve as important sinks for low-level N additions, with the strength of these sinks weakening as chronic N addition rates increase, due to shifts in species composition. We further hypothesized that trees would exhibit nonlinear increases in N acquisition, and subsequent C sequestration as N addition rates increased, due to a weakening understory N sink. Our data showed that understory biomass was reduced by 50% in response to the high N addition treatment, mainly due to reduced moss biomass. A (15) N labeling experiment showed that feather mosses acquired the largest fraction of applied label, with this fraction decreasing as the chronic N addition level increased. Contrary to our hypothesis, the proportion of label taken up by trees was equal (ca. 8%) across all three N addition treatments. The relationship between N addition and C sequestration in all vegetation pools combined was linear, and had a slope of 16 kg C kg(-1)  N. While canopy retention of Nr deposition may cause C sequestration rates to be slightly different than this estimate, our data suggest that a minor quantity of annual anthropogenic CO2 emissions are sequestered into boreal forests as a result of Nr deposition.


Assuntos
Sequestro de Carbono , Nitrogênio/metabolismo , Árvores/metabolismo , Biomassa , Briófitas/crescimento & desenvolvimento , Briófitas/metabolismo , Atividades Humanas , Picea/crescimento & desenvolvimento , Picea/metabolismo , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo , Solo/química , Suécia , Árvores/crescimento & desenvolvimento , Vaccinium myrtillus/crescimento & desenvolvimento , Vaccinium myrtillus/metabolismo
18.
Oecologia ; 175(2): 457-70, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24705693

RESUMO

Boreal coniferous forests are characterized by fairly open canopies where understory vegetation is an important component of ecosystem C and N cycling. We used an ecophysiological approach to study the effects of N additions on uptake and partitioning of C and N in two dominant understory shrubs: deciduous Vaccinium myrtillus in a Picea abies stand and evergreen Vaccinium vitis-idaea in a Pinus sylvestris stand in northern Sweden. N was added to these stands for 16 and 8 years, respectively, at rates of 0, 12.5, and 50 kg N ha(-1) year(-1). N addition at the highest rate increased foliar N and chlorophyll concentrations in both understory species. Canopy cover of P. abies also increased, decreasing light availability and leaf mass per area of V. myrtillus. Among leaves of either shrub, foliar N content did not explain variation in light-saturated CO2 exchange rates. Instead photosynthetic capacity varied with stomatal conductance possibly reflecting plant hydraulic properties and within-site variation in water availability. Moreover, likely due to increased shading under P. abies and due to water limitations in the sandy soil under P. sylvestris, individuals of the two shrubs did not increase their biomass or shift their allocation between above- and belowground parts in response to N additions. Altogether, our results indicate that the understory shrubs in these systems show little response to N additions in terms of photosynthetic physiology or growth and that changes in their performance are mostly associated with responses of the tree canopy.


Assuntos
Carbono/análise , Nitrogênio/metabolismo , Fotossíntese/fisiologia , Árvores/fisiologia , Abies , Biomassa , Clorofila , Ecossistema , Luz , Pinus/fisiologia , Pinus sylvestris , Folhas de Planta/fisiologia , Solo , Suécia , Vaccinium myrtillus
19.
PLoS Genet ; 7(7): e1002178, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21779181

RESUMO

The aim of this study was to determine, through a genome-wide association study (GWAS), the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc). We considered limited (lcSSc) and diffuse (dcSSc) cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA), and anti-topoisomerase I (ATA). Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32×10(-12), OR = 0.75). Also, rs12540874 in GRB10 gene (P = 1.27 × 10(-6), OR = 1.15) and rs11047102 in SOX5 gene (P = 1.39×10(-7), OR = 1.36) showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79×10(-61), OR = 2.48), in the HLA-DPA1/B1 loci with ATA (P = 4.57×10(-76), OR = 8.84), and in NOTCH4 with ACA P = 8.84×10(-21), OR = 0.55) and ATA (P = 1.14×10(-8), OR = 0.54). We have identified three new non-HLA genes (IRF8, GRB10, and SOX5) associated with SSc clinical and auto-antibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc.


Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Escleroderma Sistêmico/genética , Alelos , Autoanticorpos/imunologia , Feminino , Loci Gênicos/genética , Marcadores Genéticos , Antígenos HLA/genética , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Escleroderma Sistêmico/classificação , Escleroderma Sistêmico/imunologia
20.
Sci Total Environ ; 918: 170741, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38325494

RESUMO

Anthropogenic nitrogen (N) deposition and fertilization in boreal forests frequently reduces decomposition and soil respiration and enhances C storage in the topsoil. This enhancement of the C sink can be as strong as the aboveground biomass response to N additions and has implications for the global C cycle, but the mechanisms remain elusive. We hypothesized that this effect would be associated with a shift in the microbial community and its activity, and particularly by fungal taxa reported to be capable of lignin degradation and organic N acquisition. We sampled the organic layer below the intact litter of a Norway spruce (Picea abies (L.) Karst) forest in northern Sweden after 20 years of annual N additions at low (12.5 kg N ha-1 yr-1) and high (50 kg N ha-1 yr-1) rates. We measured microbial biomass using phospholipid fatty-acid analysis (PLFA) and ergosterol measurements and used ITS metagenomics to profile the fungal community of soil and fine-roots. We probed the metabolic activity of the soil community by measuring the activity of extracellular enzymes and evaluated its relationships with the most N responsive soil fungal species. Nitrogen addition decreased the abundance of fungal PLFA markers and changed the fungal community in humus and fine-roots. Specifically, the humus community changed in part due to a shift from Oidiodendron pilicola, Cenococcum geophilum, and Cortinarius caperatus to Tylospora fibrillosa and Russula griseascens. These microbial community changes were associated with decreased activity of Mn-peroxidase and peptidase, and an increase in the activity of C acquiring enzymes. Our results show that the rapid accumulation of C in the humus layer frequently observed in areas with high N deposition is consistent with a shift in microbial metabolism, where decomposition associated with organic N acquisition is downregulated when inorganic N forms are readily available.


Assuntos
Microbiota , Nitrogênio , Nitrogênio/análise , Solo , Carbono , Florestas , Microbiologia do Solo
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