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1.
Hosp Pharm ; 59(3): 329-333, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38765001

RESUMO

Purpose: Vancomycin is recommended as first-line treatment of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, dosed by area-under-the-curve (AUC) with an assumed minimum inhibitory concentration (MIC) of 1 mcg/mL via broth microdilution. The purpose of this study was to compare effectiveness of AUC-based and trough-based dosing in MRSA bacteremia with an MIC > 1 mcg/mL via Etest. Methods: This was a retrospective, observational cohort that compared vancomycin dosed by AUC or trough between January 1, 2017 and September 1, 2022. The primary outcome was a composite of treatment failure defined as peristent bacteremia ≥ 7 days, inpatient mortality within 90 days, or microbiologic relapse or readmission within 30 days. Secondary outcomes compared nephrotoxicity, hospital and ICU length of stay, MIC differences, and difference in exposure measured by AUC. Results: Twenty-four patients in each group met inclusion criteria. For the primary outcome, there was no statistical difference in treatment failure between trough and AUC groups, respectively [10 (41.7%) vs 10 (41.7%), P = 1.000]. There was no statistical difference in secondary outcomes, with incidence of nephrotoxicity [3 (12.5%) trough vs 2 (8.33%) AUC, P = 1.000] and median AUC exposure over treatment course [502.9 mcg.h/mL (454.1-599.9) vs 474 mcg.h/mL (435.3-533), P = .312] similar between groups. Conclusion: There was no statistically significant difference in treatment failure for vancomycin by AUC or trough with an Etest MIC > 1 mcg/mL. Overall exposure to vancomycin and incidence of nephrotoxicty were numerically higher in the trough group, suggesting that dosing by AUC may limit exposure without impact on treatment failure.

2.
J Neurochem ; 168(4): 397-413, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37864501

RESUMO

The basal forebrain cholinergic neurons provide acetylcholine to the cortex via large projections. Recent molecular imaging work in humans indicates that the cortical cholinergic innervation is not uniformly distributed, but rather may disproportionately innervate cortical areas relevant to supervisory attention. In this study, we therefore reexamined the spatial relationship between acetylcholinergic modulation and attention in the human cortex using meta-analytic strategies targeting both pharmacological and non-pharmacological neuroimaging studies. We found that pharmaco-modulation of acetylcholine evoked both increased activity in the anterior cingulate and decreased activity in the opercular and insular cortex. In large independent meta-analyses of non-pharmacological neuroimaging research, we demonstrate that during attentional engagement these cortical areas exhibit (1) task-related co-activation with the basal forebrain, (2) task-related co-activation with one another, and (3) spatial overlap with dense cholinergic innervations originating from the basal forebrain, as estimated by multimodal positron emission tomography and magnetic resonance imaging. Finally, we provide meta-analytic evidence that pharmaco-modulation of acetylcholine also induces a speeding of responses to targets with no apparent tradeoff in accuracy. In sum, we demonstrate in humans that acetylcholinergic modulation of midcingulo-insular hubs of the ventral attention/salience network via basal forebrain afferents may coordinate selection of task relevant information, thereby facilitating cognition and behavior.


Assuntos
Acetilcolina , Atenção , Humanos , Cognição/fisiologia , Neuroimagem , Colinérgicos/farmacologia
3.
Int J Sports Physiol Perform ; 19(3): 315-321, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38134892

RESUMO

INTRODUCTION: This case study aimed to describe potential changes in neuromuscular activation and synergies after an 8-day cross-country mountain-bike stage race. METHODS: A peak power output test was performed 5 days before the race. Two days before the start and after 7 days of racing, the athlete performed a power-based Lamberts Submaximal Cycling Test, including surface electromyography, and completed a Daily Analysis of Life Demands of Athletes questionnaire. Neuromuscular activation, in terms of root mean square, timing (onset-offset) of muscle activation, and synergies, was obtained from electromyography recordings. RESULTS: The athlete reported an increase in symptoms of experienced stress after the stage race on the Daily Analysis of Life Demands of Athletes questionnaire. Both biceps femoris and tibialis anterior muscles showed a reduction in normalized amplitude after the stage race. In addition, the number of synergies that was necessary to describe neuromuscular activation increased from 2 to 3. CONCLUSIONS: In this case study, the increase in synergies suggests that, after the stage race, the athlete showed a more complex muscle-recruitment pattern. This may indicate that muscle coordination can change when muscle fatigue occurs; however, further research is needed to confirm these results in a larger sample.


Assuntos
Ciclismo , Músculos Isquiossurais , Humanos , Ciclismo/fisiologia , Músculo Esquelético/fisiologia , Fadiga Muscular/fisiologia , Eletromiografia
4.
Pest Manag Sci ; 79(6): 2163-2171, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36730090

RESUMO

BACKGROUND: The tarnished plant bug Lygus lineolaris (Palisot de Beauvois) is considered the most damaging pest of cotton (Gossypium hirsutum L.) in the mid-southern United States. Previous studies have reported the role of different ratios of volatile metathoracic gland components such as hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal in eliciting low-level attraction of L. lineolaris. In this study, we tested different visual cues (colored sticky cards) in combination with olfactory cues (pheromone blends) to optimize the attraction and capture of L. lineolaris in the field. RESULTS: Red-colored sticky cards were more attractive to L. lineolaris adults than white, blue or yellow cards. Red sticky cards combined with blends of three potential pheromone components attracted significantly more L. lineolaris adults than sticky cards without a blend added. Traps baited with a blend of hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal in 4:10:7 ratio, respectively, caught a significantly higher number of L. lineolaris than those baited with 10:4:2 or 7:10:4 blends or an unbaited control in the first week of the experiment. CONCLUSIONS: Combining visual cues (red color) with olfactory cues (pheromone blends) significantly increased the capture of L. lineolaris in the field. This device or a future iteration could contribute towards sustainable and environmentally appropriate early-season monitoring and management of L. lineolaris in the field. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.


Assuntos
Hemípteros , Heterópteros , Animais , Humanos , Feromônios/farmacologia , Sinais (Psicologia) , Plantas , Gossypium , Butiratos/farmacologia , Butiratos/química
5.
Rev Fish Biol Fish ; 33(2): 349-374, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35968251

RESUMO

Fisheries are highly complex social-ecological systems that often face 'wicked' problems from unsustainable resource management to climate change. Addressing these challenges requires transdisciplinary approaches that integrate perspectives across scientific disciplines and knowledge systems. Despite widespread calls for transdisciplinary fisheries research (TFR), there are still limitations in personal and institutional capacity to conduct and support this work to the highest potential. The viewpoints of early career researchers (ECRs) in this field can illuminate challenges and promote systemic change within fisheries research. This paper presents the perspectives of ECRs from across the globe, gathered through a virtual workshop held during the 2021 World Fisheries Congress, on goals, challenges, and future potential for TFR. Big picture goals for TFR were guided by principles of co-production and included (i) integrating transdisciplinary thinking at all stages of the research process, (ii) ensuring that research is inclusive and equitable, (iii) co-creating knowledge that is credible, relevant, actionable, and impactful, and (iv) consistently communicating with partners. Institutional inertia, lack of recognition of the extra time and labour required for TFR, and lack of skill development opportunities were identified as three key barriers in conducting TFR. Several critical actions were identified to help ECRs, established researchers, and institutions reach these goals. We encourage ECRs to form peer-mentorship networks to guide each other along the way. We suggest that established researchers ensure consistent mentorship while also giving space to ECR voices. Actions for institutions include retooling education programs, developing and implementing new metrics of impact, and critically examining individualism and privilege in academia. We suggest that the opportunities and actions identified here, if widely embraced now, can enable research that addresses complex challenges facing fishery systems contributing to a healthier future for fish and humans alike.

6.
J Appl Entomol ; 146(7): 838-849, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36249719

RESUMO

Botanical insecticides offer an environmentally benign insect pest management option for field crops with reduced impacts on natural enemies of pests and pollinators while botanically rich field margins can augment their abundance. Here, we evaluated the non-target effects on natural enemies and pest control efficacy on bean aphids in Lablab of three neem- and pyrethrum-based botanical insecticides (Pyerin75EC®, Nimbecidine® and Pyeneem 20EC®) and determine the influence of florally rich field margin vegetation on the recovery of beneficial insects after treatment. The botanical insecticides were applied at the early and late vegetative growth stages. Data were collected on aphids (abundance, damage severity and percent incidence) and natural enemy (abundance) both at pre-spraying and post-spraying alongside Lablab bean yield. The efficacy of botanical insecticides was similar to a synthetic pesticide control and reduced aphid abundance by 88% compared with the untreated control. However, the number of natural enemies was 34% higher in botanical insecticide-treated plots than in plots treated with synthetic insecticide indicating that plant-based treatments were less harmful to beneficial insects. The presence of field margin vegetation increased further the number of parasitic wasps and tachinid flies by 16% and 20%, respectively. This indicated that non-crop habitats can enhance recovery in beneficial insect populations and that botanical insecticides integrate effectively with conservation biological control strategies. Higher grain yields of 2.55-3.04 and 2.95-3.23 t/ha were recorded for both botanical insecticide and synthetic insecticide in the presence of florally enhanced field margins in consecutive cropping seasons. Overall, these data demonstrated that commercial botanical insecticides together with florally rich field margins offer an integrated, environmentally benign and sustainable alternative to synthetic insecticides for insect pest management and increased productivity of the orphan crop legume, Lablab.

7.
Open Forum Infect Dis ; 9(9): ofac415, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36147600

RESUMO

Background: The landscape of infectious diseases research by interprofessional teams continues to change in both scope and engagement. Limited information exists regarding publication metrics and factors associated with publication of abstracts presented at professional infectious diseases meetings. Methods: This was a retrospective, observational study evaluating abstracts presented at IDWeek in 2017 and 2018. The primary endpoint was the proportion of abstracts that were subsequently published in peer-reviewed journals. Factors associated with publication were evaluated, and a description of publication metrics was reported. Results: Of the 887 abstracts analyzed from the IDWeek meetings, 236 (26.6%) were published. Significantly more abstracts were published if they were presented as a platform presentation versus poster presentation (35% vs 21%, P < .001). Inclusion of a PhD author significantly increased the likelihood of publication (P = .0014). Prospective studies, greater number of authors, and greater number of study subjects were more common among published abstracts. Median time to publication was 10.9 months, and the majority were published in infectious diseases journals, with an overall average impact factor of 7.7 across all journals. Conclusions: Abstracts from IDWeek presented as oral platforms and those including a PhD author were more likely to be published. Large, diverse authorship teams were common among published abstracts. The high quality of resulting manuscripts is evident by the destination journals and their respective impact factors. These data may be used to inform and motivate clinicians and trainees engaging in infectious diseases-related research.

8.
Insects ; 13(7)2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35886745

RESUMO

Field margins support important ecosystem services including natural pest regulation. We investigated the influence of field margins on the spatial and temporal distribution of natural enemies (NEs) of bean pests in smallholder farming systems. We sampled NEs from high and low plant diversity bean fields using sweep netting and coloured sticky traps, comparing monocropped and intercropped farms. NEs collected from within crops included predatory bugs, lacewings, predatory flies, parasitic flies, parasitic wasps, lady beetles, and a range of other predatory beetles; with the most dominant group being parasitic wasps. Overall, high plant diversity fields had a higher number of NEs than low-diversity fields, regardless of sampling methods. The field margin had a significantly higher number of lacewings, parasitic wasps, predatory bugs, syrphid flies, and other predatory beetles relative to the crop, but beneficial insects were collected throughout the fields. However, we observed marginally higher populations of NEs in intercropping than in monocropping although the effect was not significant in both low and high plant diversity fields. We recommend smallholder farmers protect the field margins for the added benefit of natural pest regulation in their fields.

9.
Plants (Basel) ; 11(7)2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35406877

RESUMO

Flower-rich field margins provide habitats and food resources for natural enemies of pests (NEs), but their potential, particularly in the tropics and on smallholder farms, is poorly understood. We surveyed field margins for plant-NE interactions in bean fields. NEs most often interacted with Bidens pilosa (15.4% of all interactions) and Euphorbia heterophylla (11.3% of all interactions). In cage trials with an aphid-infested bean plant and a single flowering margin plant, the survival of Aphidius colemani, the most abundant parasitoid NE in bean fields, was greater in the presence of Euphorbia heterophylla than Bidens pilosa, Tagetes minuta, and Hyptis suaveolens. UV-fluorescent dye was applied to flowers of specific field margin plant species and NE sampled from within the bean crop and field margins using sweep-netting and pan-traps respectively. Captured insects were examined for the presence of the dye, indicative of a prior visit to the margin. Lady beetles and assassin bugs were most abundant in plots with B. pilosa margins; hoverflies with T. minuta and Parthenium hysterophorus margins; and lacewings with T. minuta and B. pilosa margins. Overall, NE benefitted from field margin plants, and those possessing extra floral nectaries had an added advantage. Field margin plants need careful selection to ensure benefits to different NE groups.

10.
BMC Public Health ; 22(1): 557, 2022 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35313845

RESUMO

BACKGROUND: Adolescent substance use has long been a top public health priority. In Indiana, concerning recent trends show high rates of youth alcohol consumption coupled with increasing use of opioids, synthetic marijuana, and over-the-counter drugs. Based on research indicating that parent-based prevention efforts may be a particularly effective way to target adolescent substance use, and in a direct effort to address Indiana's 2017 Strategic Plan to Address Substance Use, we conducted an applied research study targeting parents' knowledge regarding adolescent substance use in Indiana. METHODS: This community-based applied research study included: (i) a needs assessment of Indiana Extension Educators' concerns regarding adolescent substance use, (ii) creation and dissemination of an evidence-informed parent education program on adolescent substance use in collaboration with Purdue Extension (a key community stakeholder), and (iii) qualitative focus group discussions at the end of each program that assessed the challenges families face regarding adolescent substance use, the types of information and resources they wish they had, and the usefulness of our program. RESULTS: The needs assessment revealed that Indiana communities would most benefit from education regarding ways to spot and monitor substance use in teens, and strategies to communicate with teens about substance use. Additionally, Extension Educators thought that existing resources to tackle substance use largely did not match the needs of Indiana communities. Qualitative analysis of the focus group discussions across 8 pilot programs revealed five important themes: (1) The need for current, evidence-informed information regarding adolescent substance use among parents and youth-involved professionals in Indiana, (2) Concern regarding Indiana adolescents' ease of access to substances and lack of healthy recreational activities, (3) Communicating with teens about substance use is crucial but difficult to implement, (4) Indiana communities' need to prioritize funding for evidence-informed prevention programming, and (5) The need for community-based parent and caregiver support groups. CONCLUSIONS: Overall, the program was well-received and participants indicated that there was a strong need for this programming in their communities, but suggested collaborating with schools or similar local community stakeholders to increase attendance. Findings from this pilot study can inform future community-based adolescent substance use prevention efforts state-wide.


Assuntos
Transtornos Relacionados ao Uso de Substâncias , Adolescente , Grupos Focais , Humanos , Avaliação das Necessidades , Projetos Piloto , Instituições Acadêmicas , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/prevenção & controle
12.
Pest Manag Sci ; 78(3): 1109-1116, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34797017

RESUMO

BACKGROUND: Hymenopteran parasitoids provide key natural pest regulation services and are reared commercially as biological control agents. Therefore, understanding parasitoid community composition in natural populations is important to enable better management for optimized natural pest regulation. We carried out a field study to understand the parasitoid community associated with Aphis fabae on East African smallholder farms. Either common bean (Phaseolus vulgaris) or lablab (Lablab purpureus) sentinel plants were infested with Aphis fabae and deployed in 96 fields across Kenya, Tanzania, and Malawi. RESULTS: A total of 463 parasitoids emerged from sentinel plants of which 424 were identified by mitochondrial cytochrome oxidase I (COI) barcoding. Aphidius colemani was abundant in Kenya, Tanzania and Malawi, while Lysiphlebus testaceipes was only present in Malawi. The identity of Aphidius colemani specimens were confirmed by sequencing LWRh and 16S genes and was selected for further genetic and population analyses. A total of 12 Aphidius colemani haplotypes were identified. Of these, nine were from our East African specimens and three from the Barcode of Life Database (BOLD). CONCLUSION: Aphidius colemani and Lysiphlebus testaceipes are potential targets for conservation biological control in tropical smallholder agro-ecosystems. We hypothesize that high genetic diversity in East African populations of Aphidius colemani suggests that this species originated in East Africa and has spread globally due to its use as a biological control agent. These East African populations could have potential for use as strains in commercial biological control or to improve existing Aphidius colemani strains by selective breeding.


Assuntos
Afídeos , Vespas , Animais , Afídeos/genética , Agentes de Controle Biológico , Ecossistema , Controle Biológico de Vetores
13.
PLoS Genet ; 17(9): e1009787, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34478447

RESUMO

Comparative genomics has enabled the identification of genes that potentially evolved de novo from non-coding sequences. Many such genes are expressed in male reproductive tissues, but their functions remain poorly understood. To address this, we conducted a functional genetic screen of over 40 putative de novo genes with testis-enriched expression in Drosophila melanogaster and identified one gene, atlas, required for male fertility. Detailed genetic and cytological analyses showed that atlas is required for proper chromatin condensation during the final stages of spermatogenesis. Atlas protein is expressed in spermatid nuclei and facilitates the transition from histone- to protamine-based chromatin packaging. Complementary evolutionary analyses revealed the complex evolutionary history of atlas. The protein-coding portion of the gene likely arose at the base of the Drosophila genus on the X chromosome but was unlikely to be essential, as it was then lost in several independent lineages. Within the last ~15 million years, however, the gene moved to an autosome, where it fused with a conserved non-coding RNA and evolved a non-redundant role in male fertility. Altogether, this study provides insight into the integration of novel genes into biological processes, the links between genomic innovation and functional evolution, and the genetic control of a fundamental developmental process, gametogenesis.


Assuntos
Cromatina/metabolismo , Drosophila melanogaster/genética , Evolução Molecular , Espermátides/metabolismo , Animais , Núcleo Celular/metabolismo , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Fertilidade/genética , Masculino , Interferência de RNA , Espermatogênese/genética
14.
Biology (Basel) ; 10(8)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34440037

RESUMO

Common bean (Phaseolus vulgaris) production and storage are limited by numerous constraints. Insect pests are often the most destructive. However, resource-constrained smallholders in sub-Saharan Africa (SSA) often do little to manage pests. Where farmers do use a control strategy, it typically relies on chemical pesticides, which have adverse effects on the wildlife, crop pollinators, natural enemies, mammals, and the development of resistance by pests. Nature-based solutions -in particular, using biological control agents with sustainable approaches that include biopesticides, resistant varieties, and cultural tools-are alternatives to chemical control. However, significant barriers to their adoption in SSA include a lack of field data and knowledge on the natural enemies of pests, safety, efficacy, the spectrum of activities, the availability and costs of biopesticides, the lack of sources of resistance for different cultivars, and spatial and temporal inconsistencies for cultural methods. Here, we critically review the control options for bean pests, particularly the black bean aphid (Aphis fabae) and pod borers (Maruca vitrata). We identified natural pest regulation as the option with the greatest potential for this farming system. We recommend that farmers adapt to using biological control due to its compatibility with other sustainable approaches, such as cultural tools, resistant varieties, and biopesticides for effective management, especially in SSA.

15.
Curr Biol ; 31(18): 4127-4131.e4, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34324835

RESUMO

Caffeine is a widely occurring plant defense chemical1,2 that occurs in the nectar of some plants, e.g., Coffea or Citrus spp., where it may influence pollinator behavior to enhance pollination.3,4 Honey bees fed caffeine form longer lasting olfactory memory associations,5 which could give plants with caffeinated nectar an adaptive advantage by inducing more visits to flowers. Caffeinated free-flying bees show enhanced learning performance6 and are more likely to revisit a caffeinated target feeder or artificial flower,7-9 although it is not clear whether improved memory of the target cues or the perception of caffeine as a reward is the cause. Here, we show that inexperienced bumble bees (Bombus terrestris) locate new food sources emitting a learned floral odor more consistently if they have been fed caffeine. In laboratory arena tests, we fed bees a caffeinated food alongside a floral odor blend (priming) and then used robotic experimental flowers10 to disentangle the effects of caffeine improving memory for learned food-associated cues versus caffeine as a reward. Inexperienced bees primed with caffeine made more initial visits to target robotic flowers emitting the target odor compared to control bees or those primed with odor alone. Caffeine-primed bees tended to improve their floral handling time faster. Although the effects of caffeine were short lived, we show that food-locating behaviors in free-flying bumble bees can be enhanced by caffeine provided in the nest. Consequently, there is potential to redesign commercial colonies to enhance bees' forage focus or even bias bees to forage on a specific crop.


Assuntos
Odorantes , Néctar de Plantas , Animais , Abelhas , Flores , Polinização , Olfato
16.
Sci Rep ; 11(1): 15190, 2021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312457

RESUMO

Beneficial insect communities on farms are influenced by site- and landscape-level factors, with pollinator and natural enemy populations often associated with semi-natural habitat remnants. They provide ecosystem services essential for all agroecosystems. For smallholders, natural pest regulation may be the only affordable and available option to manage pests. We evaluated the beneficial insect community on smallholder bean farms (Phaseolus vulgaris L.) and its relationship with the plant communities in field margins, including margin trees that are not associated with forest fragments. Using traps, botanical surveys and transect walks, we analysed the relationship between the floral diversity/composition of naturally regenerating field margins, and the beneficial insect abundance/diversity on smallholder farms, and the relationship with crop yield. More flower visits by potential pollinators and increased natural enemy abundance measures in fields with higher plant, and particularly tree, species richness, and these fields also saw improved crop yields. Many of the flower visitors to beans and potential natural enemy guilds also made use of non-crop plants, including pesticidal and medicinal plant species. Selective encouragement of plants delivering multiple benefits to farms can contribute to an ecological intensification approach. However, caution must be employed, as many plants in these systems are introduced species.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Ecossistema , Fazendas , Insetos/fisiologia , Árvores , Animais , Biodiversidade , Produção Agrícola/métodos , Flores , Florestas , Malaui , Phaseolus/crescimento & desenvolvimento , Polinização , Simbiose/fisiologia , Tanzânia
17.
PeerJ ; 8: e10102, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33150065

RESUMO

BACKGROUND: Many crops are dependent on pollination by insects. Habitat management in agricultural landscapes can support pollinator services and even augment crop production. Common bean (Phaseolus vulgaris L.) is an important legume for the livelihoods of smallholder farmers in many low-income countries, particularly so in East Africa. While this crop is autogamous, it is frequently visited by pollinating insects that could improve yields. However, the value of pollination services to common beans (Kariasii) yield is not known. METHODS: We carried out pollinator-exclusion experiments to determine the contribution of insect pollinators to bean yields. We also carried out a fluorescent-dye experiment to evaluate the role of field margins as refuge for flower-visitors. RESULTS: Significantly higher yields, based on pods per plant and seeds per pod, were recorded from open-pollinated and hand-pollinated flowers compared to plants from which pollinators had been excluded indicating that flower visitors contribute significantly to bean yields. Similarly, open and hand-pollinated plants recorded the highest mean seed weight. Extrapolation of yield data to field scale indicated a potential increase per hectare from 681 kg in self-pollinated beans to 1,478 kg in open-pollinated beans indicating that flower visitors contributed significantly to crop yield of beans. Our marking study indicated that flower-visiting insects including bees, flies and lepidopterans moved from the field margin flowers into the bean crop. Overall, these results show that insect pollinators are important for optimising bean yields and an important food security consideration on smallholder farms. Field margin vegetation also provides habitat for flower-visiting insects that pollinate beans. Hence, non-crop habitats merit further research focusing on establishing which field margin species are most important and their capacity to support other ecosystem services such as natural pest regulation or even pests.

19.
PeerJ ; 7: e8091, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31799074

RESUMO

BACKGROUND: Field margin and non-crop vegetation in agricultural systems are potential ecosystem services providers because they offer semi-natural habitats for both below and above ground animal groups such as soil organisms, small mammals, birds and arthropods that are service supplying units. They are considered as a target area for enhancing farm biodiversity. METHODOLOGY: To explore the multiple potential benefits of these semi-natural habitats and to identify research trends and knowledge gaps globally, a review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 235 publications from the year 2000 to 2016 in the Scopus and Web of Science databases were reviewed. RESULTS: The literature showed an increasing trend in the number of published articles over time with European studies leading in the proportion of studies conducted, followed by North America, Asia, South America, Africa and Australia. Several functional groups of organisms were studied from field margin and non-crop vegetation around agricultural lands including natural enemies (37%), insect pests (22%), birds (17%), pollinators (16%), soil macro fauna (4%) and small mammals (4%). Ecosystem services derived from the field margin included natural pest regulation, pollination, nutrient cycling and reduced offsite erosion. Some field margin plants were reported to host detrimental crop pests, a major ecosystem dis-service, potentially leading to increased pest infestation in the field. CONCLUSION: The majority of studies revealed the importance of field margin and non-crop vegetation around arable fields in enhancing ecosystem biodiversity. Promotion of field margin plants that selectively enhance the population of beneficial organisms would support sustainable food security rather than simply boosting plant diversity. Our analyses also highlight that agro-ecological studies remain largely overlooked in some regions.

20.
J Chem Ecol ; 45(10): 869-878, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31741191

RESUMO

Most plant species depend upon insect pollination services, including many cash and subsistence crops. Plants compete to attract those insects using visual cues and floral odor which pollinators associate with a reward. The cacao tree, Theobroma cacao, has a highly specialized floral morphology permitting pollination primarily by Ceratopogonid midges. However, these insects do not depend upon cacao flowers for their life cycle, and can use other sugar sources. To understand how floral cues mediate pollination in cacao we developed a method for rearing Ceratopogonidae through several complete lifecycles to provide material for bioassays. We carried out collection and analysis of cacao floral volatiles, and identified a bouquet made up exclusively of saturated and unsaturated, straight-chain hydrocarbons, which is unusual among floral odors. The most abundant components were tridecane, pentadecane, (Z)-7-pentadecene and (Z)-8-heptadecene with a heptadecadiene and heptadecatriene as minor components. We presented adult midges, Forcipomyia sp. (subgen. Forcipomyia), Culicoides paraensis and Dasyhelea borgmeieri, with natural and synthetic cacao flower odors in choice assays. Midges showed weak attraction to the complete natural floral odor in the assay, with no significant evidence of interspecific differences. This suggests that cacao floral volatiles play a role in pollinator behavior. Midges were not attracted to a synthetic blend of the above four major components of cacao flower odor, indicating that a more complete blend is required for attraction. Our findings indicate that cacao pollination is likely facilitated by the volatile blend released by flowers, and that the system involves a generalized odor response common to different species of Ceratopogonidae.


Assuntos
Cacau/química , Ceratopogonidae/fisiologia , Compostos Orgânicos Voláteis/química , Animais , Cacau/metabolismo , Ceratopogonidae/efeitos dos fármacos , Flores/química , Flores/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Pólen/química , Pólen/metabolismo , Polinização/efeitos dos fármacos , Olfato , Compostos Orgânicos Voláteis/farmacologia
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