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1.
BMC Med Educ ; 24(1): 593, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811980

RESUMO

INTRODUCTION: Global trends towards the professionalization of Health Professions Education (HPE) have catalyzed the proliferation of degree-awarding programmes in HPE. We apply the theoretical lens of threshold concepts to explore the required levels of Master's in HPE (MHPE) learning and teaching, with a view to determining how students might be supported to engage meaningfully with learning. METHODS: Qualitative data were collected with a series of nominal group discussions. The methodology and data analysis followed a consensus building approach. RESULTS: Four threshold concepts were identified: Being in the HPE world, the nature of HPE knowledge, the nature of HPE practice and the nature of HPE scholarship. We also mapped the threshold concepts to the World Federation for Medical Education (WFME) master's level academic skills and the Scottish Quality Assurance Agency (QAA) facets of mastersness. CONCLUSION: It is envisaged that our findings will enhance alignment between the outcomes and assessment in an MHPE programme, form the basis of understanding feedback received from students, and inform teaching and supervisory practices. The findings also complement the WFME and QAA frameworks by clarifying the depth and complexity of academic skills expected at master's level and informing teaching and learning approaches to support the development of the identified threshold concepts.


Assuntos
Ocupações em Saúde , Humanos , Ocupações em Saúde/educação , Pesquisa Qualitativa , Educação de Pós-Graduação , Currículo
2.
Teach Learn Med ; : 1-7, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37553839

RESUMO

Issue: Health professions education (HPE) is intimately linked with teaching and learning in the clinical environment. While the value of authentic clinical experiences is acknowledged, whether learning actually occurs is to a large extent dependent on students' behaviors and attitudes. The kinds of student behaviors and attitudes that are necessary to optimize learning in the clinical environment thus becomes relevant. Evidence: Tips and recommendations to maximize clinical learning in a variety of settings have been well documented. There is, however, a dearth of literature which takes a narrative-based praxis approach focused on resource-constrained environments. We developed this praxis-orientated article as a means to translate the available literature and theory into a simple, practical guide, focused on optimizing clinical learning from a student perspective, remaining cognizant of the particular challenges present in a resource-constrained setting. Implications: Based on the resource-constrained environments our students are exposed to, we outline the following six key aspects: student-driven learning, integration into the community of practice, student engagement, empathy, interprofessional learning opportunities, and feedback for learning. These aspects provide useful pointers for students in general. Furthermore, exploration into what strategies students may utilize in resource-constrained clinical contexts is addressed.

3.
Radiography (Lond) ; 29(5): 898-902, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37437398

RESUMO

INTRODUCTION: Caring is a key part of a radiographers work and the education of student radiographers. Despite recent literature highlighting the importance of putting the patient at the centre of care and being caring, research describing the educational approaches used by radiography educators to facilitate the teaching of caring is lacking. The aim of this paper is to explore the teaching and learning strategies used by radiography educators to facilitate the development of caring in students. METHODS: A qualitative, exploratory research design was used. Purposive sampling was used to select radiography educators (n = 9). This was followed by quota sampling to ensure all four radiography disciplines, namely diagnostic radiography, diagnostic ultrasound, nuclear medicine technology and radiation therapy were represented in the sample. Data was analysed thematically and themes were identified. RESULTS: The findings indicated that radiography educators use teaching strategies such as peer role play, learning through observation and role modelling to facilitate teaching and learning of caring. CONCLUSION: The study suggested that although radiography educators know the teaching strategies that facilitate caring, aspects such as clarification of professional values and the refinement of reflection seems to be lacking. IMPLICATIONS FOR PRACTICE: The teaching and learning approaches that can assist students in developing as caring radiographers can add to the evidence-based pedagogies that shape the teaching of caring in the profession.


Assuntos
Aprendizagem , Estudantes , Humanos , Radiografia , Escolaridade
4.
Sci Total Environ ; 873: 162359, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36822429

RESUMO

Organic and microbial contaminants of emerging concern (CECs), even though not yet regulated, are of great concern in reclaimed water reuse projects. Due to the large number of CECs and their different characteristics, it is useful to include only a limited number of them in monitoring programs. The selection of the most representative CECs is still a current and open question. This study presents a new methodology for this scope, in particular for the evaluation of the performance of a polishing treatment and the assessment of the risk for the environment and the irrigated crops. As to organic CECs, the methodology is based on four criteria (occurrence, persistence, bioaccumulation and toxicity) expressed in terms of surrogates (respectively, concentrations in the secondary effluent, removal achieved in conventional activated sludge systems, Log Kow and predicted-no-effect concentration). It consists of: (i) development of a dataset including the CECs found in the secondary effluent, together with the corresponding values of surrogates found in the literature or by in-field investigations; (ii) normalization step with the assignment of a score between 1 (low environmental impact) and 5 (high environmental impact) to the different criteria based on threshold values set according to the literature and experts' judgement; (iii) CEC ranking according to their final score obtained as the sum of the specific scores; and (iv) selection of the representative CECs for the different needs. Regarding microbial CECs, the selection is based on their occurrence and their highest detection frequency in the secondary effluent and in the receiving water, the antibiotic consumption patterns, and recommendations by national and international organisations. The methodology was applied within the ongoing reuse project SERPIC resulting in a list of 30 indicator CECs, including amoxicillin, bisphenol A, ciprofloxacin, diclofenac, erythromycin, ibuprofen, iopromide, perfluorooctane sulfonate (PFOS), sulfamethoxazole, tetracycline, Escherichia coli, faecal coliform, 16S rRNA, sul1, and sul2.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Água , RNA Ribossômico 16S , Poluentes Químicos da Água/análise , Esgotos , Antibacterianos
5.
Sci Total Environ ; 859(Pt 1): 160254, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36402343

RESUMO

The study evaluated the presence and fate of various contaminants of emerging concern (CECs) from a South African wastewater treatment works (WWTW) and surface waters located around an urban setting. A total of 45 CECs were quantified from nine sampling locations over an 11-month period. Daily loads (g/day) of the target analytes in the WWTW showed persistence of some CECs, along with population-normalised daily loads (mg/day/1000inh) of pharmaceuticals and drugs of abuse (DOA) that were estimated for the first time in the study area. Multiple chemical markers were recorded in river water located upstream of the WWTW discharge throughout the study period, suggesting a high degree of diffuse pollution from urban communities in the study area that are not connected to sewage networks or where sanitation services are limited. The potential of using defined surface water locations to perform community-wide substance use profiling for non-sewered communities was also explored. Environmental risk characterisation for the WWTW effluent and surface waters throughout the study period provided multiple risk quotients (RQ) for the target list of CECs spanning over various sentinel trophic levels. High risk profiles (RQ > 1.0) with a frequency of exceedance (FoE) larger than 75 % were recorded for several CECs in both WWTW effluent and surface water locations that suggest potential long-term ecological health risk impacts of pollution hotspot areas in the river catchment situated around the urban area. We present challenges in surface water quality within the study area that is relatable, or may even present more challenging, in other low- or middle-income country (LMICs) settings. The study also highlighted some challenges and limitations associated with the much-needed application of wastewater-based epidemiology (WBE) intervention in non-sewered communities that can inform on public health and communal substance use profiles of the entire urban setting.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Rios/química , Esgotos
6.
Phys Rev Lett ; 131(24): 245001, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38181162

RESUMO

We describe a simple scheme, truncated-channel injection, to inject electrons directly into the wakefield driven by a high-intensity laser pulse guided in an all-optical plasma channel. We use this approach to generate dark-current-free 1.2 GeV, 4.5% relative energy spread electron bunches with 120 TW laser pulses guided in a 110 mm-long hydrodynamic optical-field-ionized plasma channel. Our experiments and particle-in-cell simulations show that high-quality electron bunches were only obtained when the drive pulse was closely aligned with the channel axis, and was focused close to the density down ramp formed at the channel entrance. Start-to-end simulations of the channel formation, and electron injection and acceleration show that increasing the channel length to 410 mm would yield 3.65 GeV bunches, with a slice energy spread ∼5×10^{-4}.

7.
Radiography (Lond) ; 28(3): 668-673, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35643040

RESUMO

INTRODUCTION: Caring is embedded in professional guidance documents, however the meaning of caring remains unclear. It is important to clarify the meaning of caring and identify caring behaviours because it is an integral part of radiography practice and radiography education. This article aimed to explore how radiography educators understand caring and how caring is demonstrated practically from their perspective. METHODS: A qualitative approach using online semi-structured interviews was used. Radiography educators were purposively selected. This was followed by quota sampling to ensure that participants represented all four disciplines in radiography. Thematic analysis was performed and five themes were identified from the data. Data saturation was achieved when no new themes emerged. RESULTS: This study revealed that radiography educators valued caring behaviours as part of their profession and reasonably understood what caring entails. The ability to demonstrate caring during patient-practitioner encounters was seen as an essential part of a radiographer's role. An interesting finding was that participants viewed technical competency as how caring can be demonstrated. CONCLUSION: There is evidence that points to a shared understanding of the meaning of caring but without clarity of how it looks practically in the radiography profession and by implication the radiography curriculum. IMPLICATIONS FOR PRACTICE: Given the importance of caring, consensus on competence standard requirements for caring is suggested. Radiography educators should emphasis the importance of caring and provide diverse learning opportunities for students to develop the knowledge, skills, and attitudes related to caring to develop it as a strong competence.


Assuntos
Currículo , Aprendizagem , Humanos , Radiografia , Estudantes
8.
Environ Int ; 161: 107143, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35176575

RESUMO

With the advent of the SARS-CoV-2 pandemic, Wastewater-Based Epidemiology (WBE) has been applied to track community infection in cities worldwide and has proven succesful as an early warning system for identification of hotspots and changingprevalence of infections (both symptomatic and asymptomatic) at a city or sub-city level. Wastewater is only one of environmental compartments that requires consideration. In this manuscript, we have critically evaluated the knowledge-base and preparedness for building early warning systems in a rapidly urbanising world, with particular attention to Africa, which experiences rapid population growth and urbanisation. We have proposed a Digital Urban Environment Fingerprinting Platform (DUEF) - a new approach in hazard forecasting and early-warning systems for global health risks and an extension to the existing concept of smart cities. The urban environment (especially wastewater) contains a complex mixture of substances including toxic chemicals, infectious biological agents and human excretion products. DUEF assumes that these specific endo- and exogenous residues, anonymously pooled by communities' wastewater, are indicative of community-wide exposure and the resulting effects. DUEF postulates that the measurement of the substances continuously and anonymously pooled by the receiving environment (sewage, surface water, soils and air), can provide near real-time dynamic information about the quantity and type of physical, biological or chemical stressors to which the surveyed systems are exposed, and can create a risk profile on the potential effects of these exposures. Successful development and utilisation of a DUEF globally requires a tiered approach including: Stage I: network building, capacity building, stakeholder engagement as well as a conceptual model, followed by Stage II: DUEF development, Stage III: implementation, and Stage IV: management and utilization. We have identified four key pillars required for the establishment of a DUEF framework: (1) Environmental fingerprints, (2) Socioeconomic fingerprints, (3) Statistics and modelling and (4) Information systems. This manuscript critically evaluates the current knowledge base within each pillar and provides recommendations for further developments with an aim of laying grounds for successful development of global DUEF platforms.


Assuntos
COVID-19 , Vigilância Epidemiológica Baseada em Águas Residuárias , COVID-19/epidemiologia , Saúde Global , Humanos , Pandemias , SARS-CoV-2 , Águas Residuárias
9.
S Afr Med J ; 111(3): 198-202, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33944737

RESUMO

Recent studies have shown that the detection of SARS-CoV-2 genetic material in wastewater may provide the basis for a surveillance system to track the environmental dissemination of this virus in communities. An effective wastewater-based epidemiology (WBE) system may prove critical in South Africa (SA), where health systems infrastructure, testing capacity, personal protective equipment and human resource capacity are constrained. In this proof-of-concept study, we investigated the potential of SARS-CoV-2 RNA surveillance in untreated wastewater as the basis for a system to monitor COVID-19 prevalence in the population, an early warning system for increased transmission, and a monitoring system to assess the effectiveness of interventions. The laboratory confirmed the presence (qualitative analysis) and determined the RNA copy number of SARS-CoV-2 viral RNA by reverse transcription polymerase chain reaction (quantitative) analysis from 24-hour composite samples collected on 18 June 2020 from five wastewater treatment plants in Western Cape Province, SA. The study has shown that a WBE system for monitoring the status and trends of COVID-19 mass infection in SA is viable, and its development and implementation may facilitate the rapid identification of hotspots for evidence-informed interventions.


Assuntos
RNA Viral/isolamento & purificação , SARS-CoV-2/isolamento & purificação , Águas Residuárias/virologia , COVID-19/epidemiologia , Monitoramento Ambiental , Monitoramento Epidemiológico , Humanos , Pneumonia Viral/epidemiologia , Estudo de Prova de Conceito , África do Sul/epidemiologia
10.
Mar Environ Res ; 141: 88-99, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30115533

RESUMO

Biogenic habitats play important roles in shallow-water ecosystems, but their roles in deeper waters are less well-studied. We quantitatively assessed 19 glass sponge reefs in the Salish Sea for live reef-building sponge cover and biodiversity, explored potential drivers behind variation observed among reefs, and quantified individual and collective roles the reefs play in filtration and carbon removal. The reefs support diverse and abundant communities of invertebrates and fish, with 115 unique taxonomic groups observed. Sponge cover varied widely between reefs: percent live reef-building sponge cover ranged from 0.2 to 17.5% and proportion of live reef habitat category ranged from 0.2 to 92%. These differences were predominantly driven by the seabed terrain characteristics such as seafloor rugosity, curvature, and depth; human pressure measures explored in this study - density of anthropogenic objects and fishing footprint over the past 17 years - did not mask the natural influence of seabed terrain. The difference in sponge cover between the reefs led to wide variation in ecosystem function with individual reefs processing between 465 and 47,300 L/m2 per day. Collectively, each day the 19 reefs filter 1.04 × 1011 L of water which corresponds to 1% of the total water volume in Strait of Georgia and Howe Sound combined. The reefs remove up to 1 g of carbon per m2 per day, comparable to carbon sequestration rates reported for terrestrial old growth forests and to "blue carbon" sequestration rates by marine vegetation. Implications for sponge reef conservation and monitoring are discussed.


Assuntos
Biodiversidade , Ecologia , Ecossistema , Animais , Recifes de Corais , Atividades Humanas , Humanos , Invertebrados
11.
Sci Total Environ ; 625: 792-800, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29306167

RESUMO

The current study is aimed to introduce a wastewater-based epidemiology (WBE) approach for the first time on the African continent where substance abuse data is limited. The study included the quantification of several drugs of abuse (DOA) in raw wastewater samples. Quantification of urinary metabolites as drug target residues (DTR), as well as enantiomeric profiling of chiral DOA was performed to distinguish between consumption and direct disposal into sewage. Monitoring campaigns were undertaken at two South African wastewater treatment works (WWTWs) located within two provinces of the country. The presence of non-racemic 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine, as well as the metabolite of cocaine, benzoylecgonine (BEG), confirmed their consumption within the areas investigated. Enantiomeric profiling further pointed to the abuse of methamphetamine as the primary DOA with use estimates calculated between 181.9 and 1184.8mg·day-1·1000inhabitants-1. Population-normalised mass loads for MDMA and cocaine confirmed their status as secondary DOA within the study sites. Use estimates for the new psychoactive substance (NPS) mephedrone were performed for one WWTW. The minor metabolite of heroin, O-6-monoacetylmorphine (O-6-MAM), was also detected at one WWTW and served as a qualitative indicator for heroin abuse within the area. These findings provide a novel comparison of the WBE approach in a developing-country with other global studies, with the aim to strengthen this approach as a tool to inform drug prevention strategies in countries where substance abuse data is limited due to financial constraints and lack of government structures to facilitate conventional monitoring.


Assuntos
Drogas Ilícitas/análise , Detecção do Abuso de Substâncias , Águas Residuárias/química , Poluentes Químicos da Água/análise , Cocaína/análogos & derivados , Cocaína/análise , Humanos , Metanfetamina/análise , N-Metil-3,4-Metilenodioxianfetamina/análise , África do Sul
12.
13.
Artigo em Inglês | MEDLINE | ID: mdl-28912929

RESUMO

Plants are ubiquitous and found in virtually every ecosystem on Earth, but their biology is often poorly understood, and inaccurate ideas about how plants grow and function abound. Many articles have been published documenting student misconceptions about photosynthesis and respiration, but there are substantially fewer on such topics as plant cell structure and growth; plant genetics, evolution, and classification; plant physiology (beyond energy relations); and plant ecology. The available studies of misconceptions held on those topics show that many are formed at a very young age and persist throughout all educational levels. Our goal is to begin building a central resource of plant biology misconceptions that addresses these underrepresented topics, and here we provide a table of published misconceptions organized by topic. For greater utility, we report the age group(s) in which the misconceptions were found and then map them to the ASPB - BSA Core Concepts and Learning Objectives in Plant Biology for Undergraduates, developed jointly by the American Society of Plant Biologists and the Botanical Society of America.

14.
J Parasitol ; 103(6): 786-790, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28850800

RESUMO

The spread of parasites through a host population is based on the variation in behavior and immune function between individuals and is rarely uniform. We studied the gastrointestinal parasites of common mole-rats ( Cryptomys hottentotus hottentotus, Lesson 1826) from 2 sites and assessed the levels of infection based on host sex, breeding status, and season. Only nematode species were found: Neoheligmonella sp. and Mammalakis macrospiculum (Ortlepp, 1939) and a single specimen of Trichuris sp., all of which have direct life cycles. Parasite burden and species richness was greater in the mesic habitat. The abundance of Neoheligmonella sp. differed significantly between seasons, and the season of peak abundance differed between sites, perhaps due to differences in host densities between sites. In addition, parasite burden did not differ between the sexes, but breeding animals had higher infections of Neoheligmonella sp. and M. macrospiculum than non-breeding animals. This and previous studies thus suggest that the subterranean environment is beneficial in reducing parasite diversity, although the restrictions on movement may lead to certain individuals suffering higher parasite burdens.


Assuntos
Gastroenteropatias/veterinária , Enteropatias Parasitárias/veterinária , Ratos-Toupeira/parasitologia , Doenças dos Roedores/parasitologia , Animais , Ecossistema , Feminino , Gastroenteropatias/epidemiologia , Gastroenteropatias/parasitologia , Trato Gastrointestinal/parasitologia , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Modelos Lineares , Masculino , Prevalência , Doenças dos Roedores/epidemiologia , África do Sul/epidemiologia , Trichostrongyloidea/isolamento & purificação , Tricostrongiloidíase/epidemiologia , Tricostrongiloidíase/parasitologia , Tricostrongiloidíase/veterinária , Trichuris/isolamento & purificação
16.
Scand J Med Sci Sports ; 22(4): e24-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22429265

RESUMO

Non-communicable chronic diseases (NCDs), such as cardiovascular disease, diabetes, and cancer, are currently responsible for 65% of all deaths worldwide and are projected to cause over 75% of all deaths by 2030. A substantial accumulation of epidemiological and experimental evidence has established a causal relationship between NCDs and well-known yet preventable risk factors (e.g., physical inactivity and obesity). Given that physical activity has both direct and indirect effects on the mortality and morbidity of NCDs via other risk factors (e.g., obesity, diabetes, and hypertension), it is now undeniable that sedentary lifestyles are one of the most significant public health problems of the 21st century. In 2007, the American College of Sports Medicine (ACSM) and American Medical Association (AMA) launched the Exercise is Medicine® (EIM) initiative in recognition of the fundamental importance of physical activity to health and well-being. EIM is on the forefront of a global movement to reduce sedentary lifestyles, foster implementation of exercise counseling into clinical practice, and disseminate exercise therapy on a global scale. If the devastating human losses and financial burden of inactivity-induced chronic disease are to be ameliorated, the wide-ranging cost-effective health benefits and financial feasibility of physical activity interventions must be appreciated and promoted.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Terapia por Exercício , Promoção da Saúde , Obesidade/prevenção & controle , Educação de Pacientes como Assunto , Saúde Pública , American Medical Association , Doenças Cardiovasculares/terapia , Doença Crônica , Humanos , Obesidade/terapia , Comportamento Sedentário , Sociedades Médicas , Medicina Esportiva , Estados Unidos
17.
Emerg Med J ; 26(1): 41-2, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19104096

RESUMO

BACKGROUND: Children with simple radial fractures requiring manipulation are conventionally admitted for manipulation under general anaesthesia. On the assumption that children (and their parents) wish to spend as little time in hospital as possible, a study was undertaken to explore the experience of children with distal radial fractures admitted for general anaesthesia. METHODS: A retrospective analysis was performed of the time taken from arrival at the emergency department (ED) to general anaesthesia and the time taken from arrival at the ED to hospital discharge in three centres in south-west England: the Bristol Children's Hospital, Derriford (Plymouth) Hospital and the Royal Devon & Exeter Hospital. RESULTS: The median wait for general anaesthesia was >8 h and the median wait from ED admission to discharge was >21 h. This compares with a typical arrival to discharge time for paediatric procedural sedation of 4-5 h in the ED of the Royal Devon & Exeter Hospital. CONCLUSIONS: Given the assumption that children (and their parents) wish to spend as little time in hospital as possible, there appears to be a role for procedural sedation in the ED for this group of children, with a significantly reduced turnaround time anticipated.


Assuntos
Manipulação Ortopédica/métodos , Fraturas do Rádio/terapia , Listas de Espera , Criança , Humanos , Estudos Retrospectivos
18.
Forensic Sci Int ; 154(1): 62-77, 2005 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-16182950

RESUMO

A single nucleotide polymorphism (SNP) multiplex has been developed to analyse highly degraded and low copy number (LCN) DNA template, i.e. <100 pg, for scenarios including mass disaster identification. The multiplex consists of 20 autosomal non-coding loci plus Amelogenin for sex determination, amplified in a single tube PCR reaction and visualised on the Applied Biosystems 3100 capillary electrophoresis (CE) system. Allele-specific primers tailed with shared universal tag sequences were designed to speed multiplex design and balance the amplification efficiencies of all loci through the use of a single reverse and two differentially labelled allele denoting forward universal primers. As the multiplex is intended for use with samples too degraded for conventional profiling, a computer program was specifically developed to aid interpretation. Critical factors taken into account by the software include empirically determined extremes of heterozygous imbalance (Hb) and the drop-out threshold (Ht) defined as the maximum peak height of a surviving heterozygous allele, where its partner may have dropped out. The discrimination power of the system is estimated at 1 in 4.5 million, using a White Caucasian population database. Comparisons using artificially degraded samples profiled with both the SNP multiplex and AMPFISTR SGM plus (Applied Biosystems) demonstrated a greater likelihood of obtaining a profile using SNPs for certain sample types. Saliva stains degraded for 147 days generated an 81% complete SNP profile whilst short tandem repeats (STRs) were only 18% complete; similarly blood degraded for 243 days produced full SNP profiles but only 9% with STRs. Reproducibility studies showed concordance between SNP profiles for different sample types, such as blood, saliva, semen and hairs, for the same individual, both within and between different DNA extracts.


Assuntos
Impressões Digitais de DNA/métodos , Polimorfismo de Nucleotídeo Único , Amelogenina , Animais , Análise Química do Sangue , Primers do DNA , Proteínas do Esmalte Dentário/genética , Eletroforese Capilar , Feminino , Frequência do Gene , Ligação Genética , Heterozigoto , Homozigoto , Humanos , Masculino , Reação em Cadeia da Polimerase , Grupos Raciais/genética , Saliva/química , Sêmen/química , Análise de Sequência de DNA , Análise para Determinação do Sexo , Especificidade da Espécie , Sequências de Repetição em Tandem
19.
Mycorrhiza ; 15(3): 159-65, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15883853

RESUMO

Arbuscular mycorrhizal (AM) C-costs in grapevines were investigated. Dormant vines rely on stored C for initial growth. Therefore AM colonisation costs would compete with plant growth for available C reserves. One-year-old grapevines, colonised with Glomus etunicatum (Becker and Gerdemann), were cultivated under glasshouse conditions. The C-economy and P utilisation of the symbiosis were sequentially analysed. AM colonisation, during the 0-67 day growth period, used more stem C relative to root C, which resulted in lower shoot growth. The decline in AM colonisation during the period of 67-119 days coincided with stem C replenishment and higher shoot growth. Construction costs of AM plants and root C allocation increased with root P uptake. The efficiency of P utilisation was lower in AM roots. The reliance of AM colonisation on stem C declined with a decrease in colonisation, providing more C for the refilling of stem carbohydrate reserves and shoot growth. Once established, the AM symbiosis increased P uptake at the expense of refilling of root C reserves. Although higher root C allocation increased plant construction costs, AM roots were more efficient at P utilisation.


Assuntos
Micorrizas/fisiologia , Vitis/microbiologia , Agricultura/economia , Custos e Análise de Custo , Fungos/fisiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Vitis/crescimento & desenvolvimento , Vitis/metabolismo
20.
Chem Senses ; 29(7): 555-63, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15337681

RESUMO

Exposure of anestrous ewes to a ram or its odor results in the activation of the luteinizing hormone (LH) secretion leading to reinstatement of cyclicity in most females. Sexual experience and learning have been suggested as important factors to explain the variability of the female responses. In experiment 1, we compared the behavioral and endocrine responses of four groups of anestrous females that differed in age (young or adult) and previous exposure to males [naive (no exposure) or experienced (courtship behavior for young and numerous mating for adults)]. Age did not seem to affect the LH response to males or their odor. In contrast, sexual experience was a critical factor: the proportion of females exhibiting an LH response to male odor was significantly higher in experienced than in naive ewes. Sexual experience affected the response to male odor, but did not have an effect on responses to the male himself. A second experiment investigated whether the LH response to male odor could result from an associative learning process. Accordingly, we tested the effectiveness of a conditioned stimulus (lavender odor) previously associated with the male, in inducing the endocrine response. The results indicate that the odor of lavender activated LH secretion only in ewes that have been previously exposed to scented males. This demonstrates that ewes are able to learn the association between a neutral odor and their sexual partner.


Assuntos
Aprendizagem/fisiologia , Comportamento Sexual Animal/fisiologia , Ovinos/fisiologia , Olfato/fisiologia , Envelhecimento/fisiologia , Animais , Ciclo Estral/fisiologia , Feminino , Lavandula , Hormônio Luteinizante/sangue , Masculino , Óleos Voláteis , Óleos de Plantas
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