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1.
Proc Natl Acad Sci U S A ; 118(5)2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33495327

RESUMO

A primary goal of ecological restoration is to increase biodiversity in degraded ecosystems. However, the success of restoration ecology is often assessed by measuring the response of a single functional group or trophic level to restoration, without considering how restoration affects multitrophic interactions that shape biodiversity. An ecosystem-wide approach to restoration is therefore necessary to understand whether animal responses to restoration, such as changes in biodiversity, are facilitated by changes in plant communities (plant-driven effects) or disturbance and succession resulting from restoration activities (management-driven effects). Furthermore, most restoration ecology studies focus on how restoration alters taxonomic diversity, while less attention is paid to the response of functional and phylogenetic diversity in restored ecosystems. Here, we compared the strength of plant-driven and management-driven effects of restoration on four animal communities (ground beetles, dung beetles, snakes, and small mammals) in a chronosequence of restored tallgrass prairie, where sites varied in management history (prescribed fire and bison reintroduction). Our analyses indicate that management-driven effects on animal communities were six-times stronger than effects mediated through changes in plant biodiversity. Additionally, we demonstrate that restoration can simultaneously have positive and negative effects on biodiversity through different pathways, which may help reconcile variation in restoration outcomes. Furthermore, animal taxonomic and phylogenetic diversity responded differently to restoration, suggesting that restoration plans might benefit from considering multiple dimensions of animal biodiversity. We conclude that metrics of plant diversity alone may not be adequate to assess the success of restoration in reassembling functional ecosystems.


Assuntos
Biodiversidade , Pradaria , Plantas , Animais , Modelos Teóricos
2.
Proc Natl Acad Sci U S A ; 117(21): 11559-11565, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32393622

RESUMO

Pathogens pose significant threats to pollinator health and food security. Pollinators can transmit diseases during foraging, but the consequences of plant species composition for infection is unknown. In agroecosystems, flowering strips or hedgerows are often used to augment pollinator habitat. We used canola as a focal crop in tents and manipulated flowering strip composition using plant species we had previously shown to result in higher or lower bee infection in short-term trials. We also manipulated initial colony infection to assess impacts on foraging behavior. Flowering strips using high-infection plant species nearly doubled bumble bee colony infection intensity compared to low-infection plant species, with intermediate infection in canola-only tents. Both infection treatment and flowering strips reduced visits to canola, but we saw no evidence that infection treatment shifted foraging preferences. Although high-infection flowering strips increased colony infection intensity, colony reproduction was improved with any flowering strips compared to canola alone. Effects of flowering strips on colony reproduction were explained by nectar availability, but effects of flowering strips on infection intensity were not. Thus, flowering strips benefited colony reproduction by adding floral resources, but certain plant species also come with a risk of increased pathogen infection intensity.


Assuntos
Abelhas , Brassica napus , Flores , Infecções Protozoárias em Animais , Animais , Comportamento Apetitivo/fisiologia , Abelhas/parasitologia , Abelhas/fisiologia , Brassica napus/microbiologia , Brassica napus/parasitologia , Crithidia/patogenicidade , Ecossistema , Flores/parasitologia , Flores/fisiologia , Larva/fisiologia , Polinização/fisiologia , Infecções Protozoárias em Animais/fisiopatologia , Infecções Protozoárias em Animais/transmissão
3.
Ecol Appl ; 31(1): e02217, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32810923

RESUMO

Ecological restoration seeks to reestablish functioning ecosystems, but planning and evaluation often focus on taxonomic community structure and neglect consumers and their functional roles. The functional trait composition of insect assemblages, which make up the majority of animal diversity in many systems, can reveal how they are affected by restoration management and the consequences for ecosystem function. We sampled ground beetle (Coleoptera: Carabidae) assemblages in restored tallgrass prairies varying in management with prescribed fire and reintroduced American bison (Bison bison) to describe their taxonomic and functional trait structure. We also measured seed and arthropod predation to relate management, beetle assemblage characteristics, and function, and to test if function is maximized by trait diversity, dominant trait values, or beetle abundance. Beetle assemblages primarily varied with restoration age, declining over time in richness and both taxonomic and functional diversity, but bison presence also influenced taxonomic composition. Prescribed fire reduced seed predation in summer and arthropod predation in fall. Although seed predation was unrelated to beetle assemblages, arthropod predation was greater in sites with higher abundances of carnivorous ground beetles. The relatively weak impacts of fire and bison on functional assemblage structure is a promising sign that these management disturbances, aimed at supporting a diverse native plant community, are not detrimental to beetle assemblages. The significance of reduced predator function following prescribed fire will depend on the restoration context and whether seed or arthropod predation relates to management goals.


Assuntos
Artrópodes , Besouros , Incêndios , Animais , Biodiversidade , Ecossistema , Pradaria
4.
Oecologia ; 195(4): 1007-1018, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33625579

RESUMO

Introduced ecosystem engineers are expected to have extensive ecological impacts on a broad range of resident biota by altering the physical-chemical structure of ecosystems. Livestock that are potentially important introduced ecosystem engineers in grassland systems could create and/or modify habitats for native plant-dwelling insects. Yet, there is little knowledge of how insects respond to engineering effects of introduced livestock. To bridge this gap, we tested how domestic sheep affects the behavior and abundance of a native grasshopper Euchorthippus unicolor at both low (11.8 ± 0.4 plant species per plot) and high (19.8 ± 0.5 plant species per plot) diversity sites. Results found grasshoppers shifted their resting and feeding locations from the upper to the intermediate or low layers of vegetation, and fed on more plants species following livestock engineering effects. In the low plant diversity habitats, grazing caused grasshoppers to increase switching frequency, spend more time searching for host plants, and reduce time spent feeding, but had opposite effects on all the three behaviors in the high-diversity habitats. Moreover, grazing engineering effects on behavioral changes of grasshoppers were potentially related to their abundance. Overall, this study highlights native insect species' behavior and abundance in responses to introduced ecological engineers, and suggests that ecosystem engineers of non-native species have strong and important impacts extending beyond their often most obvious and frequently documented direct ecological effects.


Assuntos
Ecossistema , Gafanhotos , Animais , Pradaria , Gado , Plantas
6.
Environ Microbiol ; 19(8): 3118-3131, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28474391

RESUMO

Restoration and management of natural ecosystems is a critical strategy in mitigating global biodiversity loss. This is exemplified in the American Midwest by efforts aimed at reclaiming historical grasslands lost to high-yield agriculture. While restorations traditionally take the form of plant reintroduction and management, advances in microbial analyses suggest that soil communities could be indicators restoration success. However, current understanding of key microbial taxa and functional activities in both natural and restored ecosystems is limited. Here, we investigated the impact of nearly 30 years of carefully managed restoration on soil microbial communities at the Nachusa Grasslands in northern Illinois, USA. We characterized bacterial and archaeal communities in a chronosequence of restored tallgrass prairies ranging from 1 to 27 years old across a growing season and compared them to communities in pre-restoration agricultural fields and remnant prairies. Results indicate that older restorations harboured communities statistically distinct from newer restorations. These communities converged toward those in local prairie remnants, suggesting that plant-focussed restoration has yielded soil bacterial communities reflective of a successful restoration. Recovery of microbial clades within the Verrucomicrobia and Acidobacteria are an important feature of this convergence, and these groups could be targeted for future soil-focussed, bottom-up restoration studies.


Assuntos
Archaea/isolamento & purificação , Bactérias/isolamento & purificação , Poaceae/crescimento & desenvolvimento , Microbiologia do Solo , Agricultura , Archaea/classificação , Archaea/genética , Archaea/metabolismo , Bactérias/classificação , Bactérias/genética , Biodiversidade , Ecossistema , Pradaria , Illinois , Poaceae/microbiologia , Solo/química
7.
Ecology ; 96(4): 1052-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26230025

RESUMO

Direct and indirect effects can play a key role in invasions, but experiments evaluating both are rare. We examined the roles of direct competition and apparent competition by exotic Amur honeysuckle (Lonicera maackii) by manipulating (1) L. maackii vegetation, (2) presence of L. maackii fruits, and (3) access to plants by small mammals and deer. Direct competition with L. maackii reduced the abundance and richness of native and exotic species, and native consumers significantly reduced the abundance and richness of native species. Although effects of direct competition and consumption were more pervasive, richness of native plants was also reduced through apparent competition, as small-mammal consumers reduced richness only when L. maackii fruits were present. Our experiment reveals the multiple, interactive pathways that affect the success and impact of an invasive exotic plant: exotic plants may directly benefit from reduced attack by native consumers, may directly exert strong competitive effects on native plants, and may also benefit from apparent competition.


Assuntos
Ecossistema , Herbivoria , Espécies Introduzidas , Lonicera/classificação , Animais , Missouri , Especificidade da Espécie , Vertebrados
8.
Am J Bot ; 101(8): 1314-22, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25156980

RESUMO

UNLABELLED: • PREMISE OF THE STUDY: Floral traits play important roles in pollinator attraction and defense against floral herbivory. However, plants may experience trade-offs between conspicuousness to pollinators and herbivore attraction. Comparative studies provide an excellent framework to examine the role of multiple traits shaping mutualist and antagonist interactions.• METHODS: To assess whether putative defensive and attractive traits predict species interactions, we grew 20 different Cucurbitaceae species and varieties in the field to measure interactions with pollinators and herbivores and in the greenhouse to assess trait variation. Cucurbits are characterized by the production of cucurbitacins, bitter nonvolatile terpenoids that are effective against generalist herbivores but can attract specialist beetles. We determined whether plant traits such as cucurbitacins predict herbivore resistance and pollinator attraction using an information-theoretic approach.• KEY RESULTS: Mutualists and floral antagonists were attracted to the same cucurbit varieties once they flowered. However, rather than cucurbitacin concentration, we found that the size of the flower and volatile emissions of floral sesquiterpenoids explained both pollinator and floral herbivore visitation preference across cucurbit taxa. This pattern held across cucurbit taxa and within the Cucurbita genus.• CONCLUSIONS: Surprisingly, floral sesquiterpenoid volatiles, which are associated with direct defense, indirect defense, and attraction, rather than defense traits such as cucurbitacins, appeared to drive interactions with both pollinators and floral herbivores across cucurbit taxa. Identifying the relevant plant traits for attraction and deterrence is important in this economically valuable crop, particularly if pollinators and floral herbivores use the same plant traits as cues.


Assuntos
Cucurbita/fisiologia , Flores/metabolismo , Herbivoria , Doenças das Plantas , Polinização , Simbiose , Terpenos/metabolismo , Animais , Besouros , Produtos Agrícolas , Cucurbita/metabolismo , Cucurbitaceae , Cucurbitacinas/metabolismo , Ecologia , Fenótipo , Sesquiterpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo
9.
Sociol Health Illn ; 36(5): 703-18, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24641087

RESUMO

Information and communication technology (ICT) is often presented by health policymakers and software designers as a means for reducing clinical risk, leading to safer clinical practice. Studies have challenged this view, showing how technology can produce new or unanticipated risks. Although research seeks to objectively identify these risks, we recognise that technological risks are socially constructed through the interaction of technology and practice. The aim of this article is to explore how technology affords opportunities for the social construction and control of risk in health care settings. Drawing upon a study of the electronic prescription service introduced in the National Health Service in England, we make three arguments. Firstly, as technology interacts with social practice (for example, through policy and the design and use of ICT) it affords opportunities for the construction of risk through its interpretive flexibility, transformative capacity and materiality. Secondly, social actors interpret these risks within and across professional boundaries and cultures. Thirdly, the social construction of risk affords certain implications to policymakers, designers and users of health ICT, specifically a reordering of power and responsibility and a recasting of questions of blame. These, in turn, raise questions concerning the boundaries and bearers of responsibility.


Assuntos
Prescrição Eletrônica , Tecnologia Biomédica , Inglaterra , Política de Saúde , Humanos , Erros de Medicação/prevenção & controle , Erros de Medicação/estatística & dados numéricos , Farmacêuticos , Médicos , Risco , Medicina Estatal/organização & administração
10.
BMC Med Inform Decis Mak ; 14: 16, 2014 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-24612966

RESUMO

BACKGROUND: The Electronic Prescription Service release Two (EPS2) is a new national healthcare information and communication technology in England that aims to deliver effective prescription writing, dispensing and reimbursement service to benefit patients. The aim of the study was to explore initial user experiences of Community Pharmacists (CPs) using EPS2. METHODS: We conducted nonparticipant observations and interviews in eight EPS2 early adopter community pharmacies classified as 'first-of-type' in midlands and northern regions in England. We interviewed eight pharmacists and two dispensers in addition to 56 hours recorded nonparticipant observations as field notes. Line-by-line coding and thematic analysis was conducted on the interview transcripts and field notes. RESULTS: CPs faced two types of challenge. The first was to do with missing electronic prescriptions. This was sometimes very disrupting to work practice, but pharmacists considered it a temporary issue resolvable with minor modifications to the system and user familiarity. The second was to do with long term design-specific issues. Pharmacists could only overcome these by using the system in ways not intended by the developers. Some felt that these issues would not exist had 'real' users been involved in the initial development. The issues were: 1) printing out electronic prescriptions (tokens) to dispense from for safe dispensing practices and to free up monitors for other uses, 2) logging all dispensing activities with one user's Smartcard for convenience and use all human resources in the pharmacy, and, 3) problematic interface causing issues with endorsing prescriptions and claiming reimbursements. CONCLUSIONS: We question if these unintended uses and barriers would have occurred had a more rigorous user-centric principles been applied at the earlier stages of design and implementation of EPS. We conclude that, since modification can occur at the evaluation stage, there is still scope for some of these barriers to be corrected to address the needs, and enhance the experiences, of CPs using the service, and make recommendations on how current challenges could be resolved.


Assuntos
Serviços Comunitários de Farmácia/normas , Prescrição Eletrônica/normas , Sistemas de Informação em Saúde/normas , Programas Nacionais de Saúde/normas , Inglaterra , Humanos , Programas Nacionais de Saúde/organização & administração
11.
Ecology ; 105(1): e4192, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37878728

RESUMO

In the midst of an ongoing biodiversity crisis, much research has focused on species losses and their impacts on ecosystem functioning. The functional consequences (ecosystem response) of shifts in communities are shaped not only by changes in species richness, but also by compositional shifts that result from species losses and gains. Species differ in their contribution to ecosystem functioning, so species identity underlies the consequences of species losses and gains on ecosystem functions. Such research is critical to better predict the impact of disturbances on communities and ecosystems. We used the "Community Assembly and the Functioning of Ecosystems" (CAFE) approach, a modification of the Price equation to understand the functional consequences and relative effects of richness and composition changes in small nonvolant mammal and dung beetle communities as a result of two common disturbances in North American prairie restorations, prescribed fire and the reintroduction of large grazing mammals. Previous research in this system has shown dung beetles are critically important decomposers, while small mammals modulate much energy in prairie food webs. We found that dung beetle communities were more responsive to bison reintroduction and prescribed fires than small nonvolant mammals. Dung beetle richness increased after bison reintroduction, with higher dung beetle community biomass resulting from changes in remaining species (context-dependent component) rather than species turnover (richness components); prescribed fire caused a minor increase in dung beetle biomass for the same reason. For small mammals, bison reintroduction reduced energy transfer through the loss of species, while prescribed fire had little impact on either small mammal richness or energy transfer. The CAFE approach demonstrates how bison reintroduction controls small nonvolant mammal communities by increasing prairie food web complexity, and increases dung beetle populations with possible benefits for soil health through dung mineralization and soil bioturbation. Prescribed fires, however, have little effect on small mammals and dung beetles, suggesting a resilience to fire. These findings illustrate the key role of re-establishing historical disturbance regimes when restoring endangered prairie ecosystems and their ecological function.


Assuntos
Bison , Besouros , Animais , Ecossistema , Pradaria , Bison/fisiologia , Biodiversidade , Besouros/fisiologia , Mamíferos/fisiologia , Solo
12.
Biotechnol J ; 19(1): e2300257, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38038229

RESUMO

Chinese hamster ovary (CHO) cells are widely used for production of biologics including therapeutic monoclonal antibodies. Cell death in CHO cells is a significant factor in biopharmaceutical production, impacting both product yield and quality. Apoptosis has previously been described as the major form of cell death occurring in CHO cells in bioreactors. However, these studies were undertaken when less was known about non-apoptotic cell death pathways. Here, we report the occurrence of non-apoptotic cell death in an industrial antibody-producing CHO cell line during fed-batch culture. Under standard conditions, crucial markers of apoptosis were not observed despite a decrease in viability towards the end of the culture; only by increasing stress within the system did we observe caspase activation indicative of apoptosis. In contrast, markers of parthanatos and ferroptosis were observed during standard fed-batch culture, indicating that these non-apoptotic cell death pathways contribute to viability loss under these conditions. These findings pave the way for targeting non-conventional cell death pathways to improve viability and biologic production in CHO cells.


Assuntos
Técnicas de Cultura Celular por Lotes , Reatores Biológicos , Cricetinae , Animais , Cricetulus , Células CHO , Apoptose
13.
Ecol Appl ; 23(7): 1519-30, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24261037

RESUMO

Agricultural management has profound effects on soil communities. Activities such as fertilizer inputs can modify the composition of arbuscular mycorrhizal fungi (AMF) communities, which form important symbioses with the roots of most crop plants. Intensive conventional agricultural management may select for less mutualistic AMF with reduced benefits to host plants compared to organic management, but these differences are poorly understood. AMF are generally evaluated based on their direct growth effects on plants. However, mycorrhizal colonization also may alter plant traits such as tissue nutrients, defensive chemistry, or floral traits, which mediate important plant-insect interactions like herbivory and pollination. To determine the effect of AMF from different farming practices on plant performance and traits that putatively mediate species interactions, we performed a greenhouse study by inoculating Cucumis sativus (cucumber, Cucurbitaceae) with AMF from conventional farms, organic farms, and a commercial AMF inoculum. We measured growth and a suite of plant traits hypothesized to be important predictors of herbivore resistance and pollinator attraction. Several leaf and root traits and flower production were significantly affected by AMF inoculum. Both conventional and organic AMF reduced leaf P content but increased Na content compared to control and commercial AMF. Leaf defenses were unaffected by AMF treatments, but conventional AMF increased root cucurbitacin C, the primary defensive chemical of C. sativus, compared to organic AMF. These effects may have important consequences for herbivore preference and population dynamics. AMF from both organic and conventional farms decreased flower production relative to commercial and control treatments, which may reduce pollinator attraction and plant reproduction. AMF from both farm types also reduced seed germination, but effects on plant growth were limited. Our results suggest that studies only considering AMF effects on growth may overlook changes in plant traits that have the potential to influence interactions, and hence yield, on farms. Given the effects of AMF on plant traits documented here, and the great importance of both herbivores and pollinators to wild and cultivated plants, we advocate for comprehensive assessments of mycorrhizal effects in complex community contexts, with the aim of incorporating multispecies interactions both above and below the soil surface.


Assuntos
Agricultura/métodos , Cucumis sativus/microbiologia , Insetos/fisiologia , Micorrizas , Animais , Herbivoria , Folhas de Planta/química , Folhas de Planta/fisiologia , Raízes de Plantas/química , Raízes de Plantas/fisiologia , Polinização , Solo/química , Microbiologia do Solo
14.
Proc Natl Acad Sci U S A ; 107(16): 7335-40, 2010 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-20368418

RESUMO

Theory on trophic interactions predicts that predators increase plant biomass by feeding on herbivores, an indirect interaction called a trophic cascade. Theory also predicts that predators feeding on predators, or intraguild predation, will weaken trophic cascades. Although past syntheses have confirmed cascading effects of terrestrial arthropod predators, we lack a comprehensive analysis for vertebrate insectivores-which by virtue of their body size and feeding habits are often top predators in these systems-and of how intraguild predation mediates trophic cascade strength. We report here on a meta-analysis of 113 experiments documenting the effects of insectivorous birds, bats, or lizards on predaceous arthropods, herbivorous arthropods, and plants. Although vertebrate insectivores fed as intraguild predators, strongly reducing predaceous arthropods (38%), they nevertheless suppressed herbivores (39%), indirectly reduced plant damage (40%), and increased plant biomass (14%). Furthermore, effects of vertebrate insectivores on predatory and herbivorous arthropods were positively correlated. Effects were strongest on arthropods and plants in communities with abundant predaceous arthropods and strong intraguild predation, but weak in communities depauperate in arthropod predators and intraguild predation. The naturally occurring ratio of arthropod predators relative to herbivores varied tremendously among the studied communities, and the skew to predators increased with site primary productivity and in trees relative to shrubs. Although intraguild predation among arthropod predators has been shown to weaken herbivore suppression, we find this paradigm does not extend to vertebrate insectivores in these communities. Instead, vertebrate intraguild preda-tion is associated with strengthened trophic cascades, and insectivores function as dominant predators in terrestrial plant-arthropod communities.


Assuntos
Artrópodes/fisiologia , Comportamento Predatório , Animais , Biomassa , Tamanho Corporal , Comportamento Alimentar , Insetos , Plantas , Dinâmica Populacional , Tamanho da Amostra , Transdução de Sinais , Árvores
15.
FEMS Microbiol Ecol ; 99(3)2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36669763

RESUMO

Knowledge of how habitat restoration shapes soil microbial communities often is limited despite their critical roles in ecosystem function. Soil community diversity and composition change after restoration, but the trajectory of these successional changes may be influenced by disturbances imposed for habitat management. We studied soil bacterial communities in a restored tallgrass prairie chronosequence for >6 years to document how diversity and composition changed with age, management through fire, and grazing by reintroduced bison, and in comparison to pre-restoration agricultural fields and remnant prairies. Soil C:N increased with restoration age and bison, and soil pH first increased and then declined with age, although bison weakened this pattern. Bacterial richness and diversity followed a similar hump-shaped pattern as soil pH, such that the oldest restorations approached the low diversity of remnant prairies. ß-diversity patterns indicated that composition in older restorations with bison resembled bison-free sites, but over time they became more distinct. In contrast, younger restorations with bison maintained unique compositions throughout the study, suggesting bison disturbances may cause a different successional trajectory. We used a novel random forest approach to identify taxa that indicate these differences, finding that they were frequently associated with bacteria that respond to grazing in other grasslands.


Assuntos
Bison , Ecossistema , Animais , Solo/química , Pradaria , Biodiversidade , Bactérias/genética , Microbiologia do Solo
16.
FEMS Microbiol Ecol ; 99(11)2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37791391

RESUMO

Restoring ecosystems requires the re-establishment of diverse soil microbial communities that drive critical ecosystem functions. In grasslands, restoration and management require the application of disturbances like fire and grazing. Disturbances can shape microbial taxonomic composition and potentially functional composition as well. We characterized taxonomic and functional gene composition of soil communities using whole genome shotgun metagenomic sequencing to determine how restored soil communities differed from pre-restoration agricultural soils and original remnant soils, how management affects soil microbes, and whether restoration and management affect the number of microbial genes associated with carbohydrate degradation. We found distinct differences in both taxonomic and functional diversity and composition among restored, remnant, and agricultural soils. Remnant soils had low taxonomic and functional richness and diversity, as well as distinct composition, indicating that restoration of agricultural soils does not re-create soil microbial communities that match remnants. Prescribed fire management increased functional diversity, which also was higher in more recently planted restorations. Finally, restored and post-fire soils included high abundances of genes encoding cellulose-degrading enzymes, so restorations and their ongoing management can potentially support functions important in carbon cycling.


Assuntos
Microbiota , Solo , Ecossistema , Pradaria , Microbiologia do Solo , Agricultura , Microbiota/genética
17.
Ecology ; 93(7): 1560-70, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22919903

RESUMO

Herbivores affect plants through direct effects, such as tissue damage, and through indirect effects that alter species interactions. Interactions may be positive or negative, so indirect effects have the potential to enhance or lessen the net impacts of herbivores. Despite the ubiquity of these interactions, the indirect pathways are considerably less understood than the direct effects of herbivores, and multiple indirect pathways are rarely studied simultaneously. We placed herbivore effects in a comprehensive community context by studying how herbivory influences plant interactions with antagonists and mutualists both aboveground and belowground. We manipulated early-season aboveground herbivore damage to Cucumis sativus (cucumber, Cucurbitaceae) and measured interactions with subsequent aboveground herbivores, root-feeding herbivores, pollinators, and arbuscular mycorrhizal fungi (AMF). We quantified plant growth and reproduction and used an enhanced pollination treatment to determine if plants were pollen limited. Increased herbivory reduced interactions with both antagonists and mutualists. Plants with high levels of early herbivory were significantly less likely to suffer leaf damage later in the summer and tended to be less attacked by root herbivores. Herbivory also reduced pollinator visitation, likely due to fewer and smaller flowers, and reduced AMF colonization. The net effect of herbivory on plant growth and reproduction was strongly negative, but lower fruit and seed production were not due to reduced pollinator visits, because reproduction was not pollen limited. Although herbivores influenced interactions between plants and other organisms, these effects appear to be weaker than the direct negative effects of early-season tissue loss.


Assuntos
Cucumis sativus/fisiologia , Herbivoria , Insetos/fisiologia , Animais , Cucumis sativus/microbiologia , Flores , Micorrizas/fisiologia , Polinização/fisiologia , Simbiose
18.
Oecologia ; 170(4): 999-1007, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22644051

RESUMO

Top-down effects of predators can have important consequences for ecosystems. Insectivorous birds frequently have strong predation effects on herbivores and other arthropods, as well as indirect effects on herbivores' host plants. Diet studies have shown that birds in temperate ecosystems consume arthropods in winter as well as in summer, but experimental studies of bird predation effects have not attempted to quantitatively separate winter predation impacts from those in summer. To understand if winter foraging by insectivorous birds has consequences for arthropods or plants, we performed a meta-analysis of published bird exclusion studies in temperate forest and shrubland habitats. We categorized 85 studies from 41 publications by whether birds were excluded year-round or only in summer, and analyzed arthropod and plant response variables. We also performed a manipulative field experiment in which we used a factorial design to exclude birds from Quercus velutina Lam. saplings in winter and summer, and censused arthropods and herbivore damage in the following growing season. In the meta-analysis, birds had stronger negative effects on herbivores in studies that included winter exclusion, and this effect was not due to study duration. However, this greater predation effect did not translate to a greater impact on plant damage or growth. In the field experiment, winter exclusion did not influence herbivore abundance or their impacts on plants. We have shown that winter feeding by temperate insectivorous birds can have important consequences for insect herbivore populations, but the strength of these effects may vary considerably among ecosystems. A full understanding of the ecological roles of insectivorous birds will require explicit consideration of their foraging in the non-growing season, and we make recommendations for how future studies can address this.


Assuntos
Artrópodes , Aves , Cadeia Alimentar , Herbivoria , Animais , Ecossistema , Plantas , Dinâmica Populacional , Estações do Ano
19.
BMC Health Serv Res ; 12: 484, 2012 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-23272770

RESUMO

BACKGROUND: In contrast to the acute hospital sector, there have been relatively few implementations of integrated electronic health record (EHR) systems into specialist mental health settings. The National Programme for Information Technology (NPfIT) in England was the most expensive IT-based transformation of public services ever undertaken, which aimed amongst other things, to implement integrated EHR systems into mental health hospitals. This paper describes the arrival, the process of implementation, stakeholders' experiences and the local consequences of the implementation of an EHR system into a mental health hospital. METHODS: Longitudinal, real-time, case study-based evaluation of the implementation and adoption of an EHR software (RiO) into an English mental health hospital known here as Beta. We conducted 48 in-depth interviews with a wide range of internal and external stakeholders, undertook 26 hours of on-site observations, and obtained 65 sets of relevant documents from various types relating to Beta. Analysis was both inductive and deductive, the latter being informed by the 'sociotechnical changing' theoretical framework. RESULTS: Many interviewees perceived the implementation of the EHR system as challenging and cumbersome. During the early stages of the implementation, some clinicians felt that using the software was time-consuming leading to the conclusion that the EHR was not fit for purpose. Most interviewees considered the chain of deployment of the EHR-which was imposed by NPfIT-as bureaucratic and obstructive, which restricted customization and as a result limited adoption and use. The low IT literacy among users at Beta was a further barrier to the implementation of the EHR. This along with inadequate training in using the EHR software led to resistance to the significant cultural and work environment changes initiated by EHR. Despite the many challenges, Beta achieved some early positive results. These included: the ability to check progress notes and monitor staff activities; improving quality of care as a result of real-time, more accurate and shared patient records across the hospital; and potentially improving the safety of care through increasing the legibility of the clinical record. CONCLUSIONS: Notwithstanding what was seen as a turbulent, painful and troublesome implementation of the EHR system, Beta achieved some early clinical and managerial benefits from implementing EHRs. The 'sociotechnical changing' framework helped us go beyond the dichotomy of success versus failure, when conducting the evaluation and interpreting findings. Given the scope for continued development, there are good reasons, we argue, to scale up the intake of EHR systems by mental health care settings. Software customization and appropriate support are essential to work EHR out in such organizations.


Assuntos
Difusão de Inovações , Registros Eletrônicos de Saúde , Hospitais Psiquiátricos , Inglaterra , Humanos , Estudos de Casos Organizacionais , Estudos Prospectivos , Pesquisa Qualitativa
20.
BMC Health Serv Res ; 12: 105, 2012 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-22545646

RESUMO

BACKGROUND: A commitment to Electronic Health Record (EHR) systems now constitutes a core part of many governments' healthcare reform strategies. The resulting politically-initiated large-scale or national EHR endeavors are challenging because of their ambitious agendas of change, the scale of resources needed to make them work, the (relatively) short timescales set, and the large number of stakeholders involved, all of whom pursue somewhat different interests. These initiatives need to be evaluated to establish if they improve care and represent value for money. METHODS: Critical reflections on these complexities in the light of experience of undertaking the first national, longitudinal, and sociotechnical evaluation of the implementation and adoption of England's National Health Service's Care Records Service (NHS CRS). RESULTS/DISCUSSION: We advance two key arguments. First, national programs for EHR implementations are likely to take place in the shifting sands of evolving sociopolitical and sociotechnical and contexts, which are likely to shape them in significant ways. This poses challenges to conventional evaluation approaches which draw on a model of baseline operations → intervention → changed operations (outcome). Second, evaluation of such programs must account for this changing context by adapting to it. This requires careful and creative choice of ontological, epistemological and methodological assumptions. SUMMARY: New and significant challenges are faced in evaluating national EHR implementation endeavors. Based on experiences from this national evaluation of the implementation and adoption of the NHS CRS in England, we argue for an approach to these evaluations which moves away from seeing EHR systems as Information and Communication Technologies (ICT) projects requiring an essentially outcome-centred assessment towards a more interpretive approach that reflects the situated and evolving nature of EHR seen within multiple specific settings and reflecting a constantly changing milieu of policies, strategies and software, with constant interactions across such boundaries.


Assuntos
Fortalecimento Institucional , Difusão de Inovações , Registros Eletrônicos de Saúde , Implementação de Plano de Saúde , Avaliação de Programas e Projetos de Saúde/métodos , Mudança Social , Redes de Comunicação de Computadores/organização & administração , Prestação Integrada de Cuidados de Saúde , Registros Eletrônicos de Saúde/legislação & jurisprudência , Inglaterra , Política de Saúde , Humanos , Relações Interinstitucionais , Modelos Organizacionais , Programas Nacionais de Saúde
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