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1.
Mycorrhiza ; 30(4): 513-527, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32500441

RESUMEN

The composition of arbuscular mycorrhizal fungal (AMF) communities should reflect not only responses to host and soil environments, but also differences in functional roles and costs vs. benefits among arbuscular mycorrhizal fungi. The coffee agroecosystem allows exploration of the effects of both light and soil fertility on AMF communities, because of the variation in shade and soil nutrients farmers generate through field management. We used high-throughput ITS2 sequencing to characterize the AMF communities of coffee roots in 25 fields in Costa Rica that ranged from organic management with high shade and no chemical fertilizers to conventionally managed fields with minimal shade and high N fertilization, and examined relationships between AMF communities and soil and shade parameters with partial correlations, NMDS, PERMANOVA, and partial least squares analysis. Gigasporaceae and Acaulosporaceae dominated coffee AMF communities in terms of relative abundance and richness, respectively. Gigasporaceae richness was greatest in conventionally managed fields, while Glomeraceae richness was greatest in organic fields. While total AMF richness and root colonization did not differ between organic and conventionally managed fields, AMF community composition did; these differences were correlated with soil nitrate and shade. OTUs differing in relative abundance between conventionally managed and organic fields segregated into four groups: Gigasporaceae associated with high light and nitrate availability, Acaulosporaceae with high light and low nitrate availability, Acaulosporaceae and a single relative of Rhizophagus fasciculatus with shade and low nitrate availability, and Claroideoglomus/Glomus with conventionally managed fields but uncorrelated with shade and soil variables. The association of closely related taxa with similar shade and light availabilities is consistent with phylogenetic trait conservatism in AM fungi.


Asunto(s)
Micobioma , Micorrizas , Café , Costa Rica , Nitrógeno , Filogenia , Raíces de Plantas , Suelo , Microbiología del Suelo
2.
Appl Environ Microbiol ; 86(11)2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32220838

RESUMEN

The structure and function of fungal communities in the coffee rhizosphere are influenced by crop environment. Because coffee can be grown along a management continuum from conventional application of pesticides and fertilizers in full sun to organic management in a shaded understory, we used coffee fields to hold host constant while comparing rhizosphere fungal communities under markedly different environmental conditions with regard to shade and inputs. We characterized the shade and soil environment in 25 fields under conventional, organic, or transitional management in two regions of Costa Rica. We amplified the internal transcribed spacer 2 (ITS2) region of fungal DNA from coffee roots in these fields and characterized the rhizosphere fungal community via high-throughput sequencing. Sequences were assigned to guilds to determine differences in functional diversity and trophic structure among coffee field environments. Organic fields had more shade, a greater richness of shade tree species, and more leaf litter and were less acidic, with lower soil nitrate availability and higher soil copper, calcium, and magnesium availability than conventionally managed fields, although differences between organic and conventionally managed fields in shade and calcium and magnesium availability depended on region. Differences in richness and community composition of rhizosphere fungi between organic and conventionally managed fields were also correlated with shade, soil acidity, and nitrate and copper availability. Trophic structure differed with coffee field management. Saprotrophs, plant pathogens, and mycoparasites were more diverse, and plant pathogens were more abundant, in organic than in conventionally managed fields, while saprotroph-plant pathogens were more abundant in conventionally managed fields. These differences reflected environmental differences and depended on region.IMPORTANCE Rhizosphere fungi play key roles in ecosystems as nutrient cyclers, pathogens, and mutualists, yet little is currently known about which environmental factors and how agricultural management may influence rhizosphere fungal communities and their functional diversity. This field study of the coffee agroecosystem suggests that organic management not only fosters a greater overall diversity of fungi, but it also maintains a greater richness of saprotrophic, plant-pathogenic, and mycoparasitic fungi that has implications for the efficiency of nutrient cycling and regulation of plant pathogen populations in agricultural systems. As well as influencing community composition and richness of rhizosphere fungi, shade management and use of fungicides and synthetic fertilizers altered the trophic structure of the coffee agroecosystem.


Asunto(s)
Coffea/microbiología , Hongos/aislamiento & purificación , Micobioma , Agricultura Orgánica , Raíces de Plantas/microbiología , Rizosfera , Costa Rica , Hongos/clasificación , Hongos/fisiología
3.
Physiother Theory Pract ; 36(3): 432-443, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29944029

RESUMEN

Persons with subacromial impingement syndrome (SIS) have an imbalance in scapular muscle recruitment. To avoid humeral head compression against the coracoacromial arch during the early stages of rehabilitation, physical therapists recommend movements targeting scapular retraction, shoulder depression, and arm extension such as the inverted row (IR) exercise. The purposes of this study were to describe: (1) scapular balance ratios during an IR and (2) the magnitudes of recruitment of spinal stabilizer muscles. Scapular muscle balance ratios from 26 healthy participants were calculated from electromyographic (EMG) activity of the upper trapezius (UTP), lower trapezius (LTP), middle trapezius (MTP), serratus anterior (SA), posterior deltoid (PD), latissimus dorsi (LD), and biceps brachii (BB) during an IR on stable and unstable support surfaces. Balance ratios were obtained by dividing normalized EMG activity of the UTP by the normalized EMG values from each of the other six muscles. Four median scapular balance ratios (UTP/MTP, UTP/PD, UTP/LD, and UTP/BB) ranged from 0.9 to 2.2, whereas the UTP/LTP ratio ranged from 1.6 to 2.2 and the UTP/SA ratio ranged from 1 to 4.7. Activation of seven muscles promoted safe containment of the humeral head within the glenoid fossa during the IR in healthy persons and potentially people with the tendency for development of SIS. Four spinal stabilizer muscles were examined: longissimus thoracis (LT), multifidus (MF), rectus abdominis (RA), and external oblique (EO). Spinal stabilizer EMG activation values ranged from 34% to 40% maximum voluntary isometric contraction (MVIC) for the RA and EO and from 54% to 66% MVIC for the LT and MF.


Asunto(s)
Músculo Esquelético/fisiología , Escápula/fisiología , Hombro/fisiología , Adulto , Estudios Transversales , Electromiografía , Femenino , Voluntarios Sanos , Humanos , Contracción Isométrica , Masculino
5.
Midwifery ; 27(3): 308-15, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21129828

RESUMEN

OBJECTIVE: This paper uses comparisons and contrasts identified during an assessment of pre-service education for midwives in three countries in sub-Saharan Africa. The purpose of the paper is to stimulate discussion about issues that must be carefully considered in the context of midwifery educational programming and the expansion of the midwifery workforce. DESIGN AND SETTING: A mixed qualitative and quantitative participatory assessment was conducted in Ethiopia, Ghana and Malawi, in the context of a final review of outcomes of a USAID-funded global project (ACCESS). Quantitative surveys were distributed. Individual and focus group interviews were conducted. PARTICIPANTS: Participants included key informants at donor, government and policy-making levels, representatives of collaborating and supporting agencies, midwives and students in education programmes, and midwives in clinical practice. FINDINGS: Information is presented concerning the challenges encountered by those responsible for midwifery pre-service education related to issues in programming including: pathways to midwifery, student recruitment and admission, midwifery curricula, preparation of faculty to engage in academic teaching and clinical mentorship, modes of curriculum dissemination and teaching/learning strategies, programme accreditation, qualifications for entry-into practice and the assessment of continued competence. KEY CONCLUSIONS: Quality issues must be carefully considered when designing and implementing midwifery pre-service education programmes, and planning for the integration of new graduates into the health workforce. These issues, such as the availability of qualified tutors and clinical teachers, and measures for the implementation of competency-based teaching and learner-assessment strategies, are particularly relevant in countries that experience health manpower shortages. IMPLICATIONS FOR PRACTICE: This review highlights important strategic choices that can be made to enhance the quality of pre-service midwifery education. The deployment, appropriate utilisation and increased number of highly qualified midwifery graduates can improve the quality of maternal and newborn health-care service, and reduce maternal and newborn mortality.


Asunto(s)
Educación Basada en Competencias/estadística & datos numéricos , Bachillerato en Enfermería/normas , Partería/educación , Facultades de Enfermería/organización & administración , Gestión de la Calidad Total/normas , Selección de Profesión , Curriculum/normas , Etiopía , Grupos Focales , Ghana , Humanos , Malaui , Partería/organización & administración , Modelos Educacionales , Programas Nacionales de Salud/normas , Investigación en Educación de Enfermería , Evaluación de Programas y Proyectos de Salud
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