Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 136
Filtrar
1.
Int J Ment Health Syst ; 16(1): 57, 2022 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-36527036

RESUMO

BACKGROUND: International estimates suggest around a third of students arrives at university with symptoms indicative of a common mental disorder, many in late adolescence at a developmentally high-risk period for the emergence of mental disorder. Universities, as settings, represent an opportunity to contribute to the improvement of population mental health. We sought to understand what is known about the management of student mental health, and asked: (1) What proportion of students use mental health services when experiencing psychological distress? (2) Does use by students differ across health service types? METHODS: A systematic review was conducted following PRISMA guidelines using a Context, Condition, Population framework (CoCoPop) with a protocol preregistered on Prospero (CRD42021238273). Electronic database searches in Medline, Embase, PsycINFO, ERIC and CINAHL Plus, key authors were contacted, citation searches were conducted, and the reference list of the WHO World Mental Health International College Student Initiative (WMH-ICS) was searched. Data extraction was performed using a pre-defined framework, and quality appraisal using the Joanna Briggs Institute tool. Data were synthesised narratively and meta-analyses at both the study and estimate level. RESULTS: 7789 records were identified through the search strategies, with a total of 44 studies meeting inclusion criteria. The majority of included studies from the USA (n = 36), with remaining studies from Bangladesh, Brazil, Canada, China, Ethiopia and Italy. Overall, studies contained 123 estimates of mental health service use associated with a heterogeneous range of services, taking highly variable numbers of students across a variety of settings. DISCUSSION: This is the first systematic quantitative survey of student mental health service use. The empirical literature to date is very limited in terms of a small number of international studies outside of the USA; studies of how services link together, and of student access. The significant variation we found in the proportions of students using services within and between studies across different settings and populations suggests the current services described in the literature are not meeting the needs of all students.

2.
SSM Ment Health ; 2: 100175, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37916032

RESUMO

Background: When experiencing mental distress, many university students seek support from their peers. In schools and mental health services, formalised peer support interventions have demonstrated some success but implementation challenges have been reported. This study aimed to assess the feasibility, acceptability and safety of a novel manualized peer support intervention and associated data collection processes. Methods: A longitudinal mixed methods study was conducted following the pilot of a peer support intervention at a large London university between June 2021 and May 2022. The study utilised data routinely recorded on all students who booked a peer support session, focus groups with nine peer workers and five staff members implementing the intervention, pre-post intervention surveys with 13 students and qualitative interviews with 10 of those students. Results: 169 bookings were made during the pilot, of which 130 (77%) were attended, with November the peak month. Staff and peer workers described strong motivation and commitment to implement the intervention, noting that the peer support model and peer worker role addressed previously unmet needs at the university. However, students described implementation problems relating to the coherence of the intervention and the burden of participation. While students mostly described acceptable experiences, there were examples where acceptability was lower. No adverse events were reported during the pilot. Conclusion: The training and supervision of peer workers, and the provision of one-to-one peer support to students was found to be feasible, mostly acceptable, and safe. However, sustained implementation difficulties were observed. These pose challenges to the scalability of peer support in universities. We make recommendations to improve implementation of peer support including improving reach, greater clarity about the intervention, and fuller involvement of students throughout.

3.
Scand J Rheumatol ; 51(4): 323-328, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34232106

RESUMO

OBJECTIVE: Systemic sclerosis (SSc) is a complex, heterogeneous connective tissue disease with multiorgan dysfunction. This study aimed to compare healthcare utilization among incident cases of SSc versus age- and gender-matched comparators. METHOD: A population-based cohort of physician-diagnosed patients with SSc in Olmsted County, MN, USA, from 1 January 1988 to 31 December 2016 was assembled. A 2:1 cohort of age- and gender-matched non-SSc subjects was randomly selected for comparison. Patients were followed until death, migration from Olmsted County, or 31 December 2017. Outpatient utilization data were obtained beginning 12 months before the SSc incidence/index date and compared using negative binomial and multinomial models. Services were summarized as visit-days to avoid overestimation of services provided. RESULTS: The study included 69 incident SSc cases and 138 non-SSc comparators (mean ± sd age 57 ± 16 years at diagnosis/index, 90% female). Patients with SSc had higher utilization of outpatient physician, laboratory, and combined radiology visit-days annually for the year before and for each of the first 5 years after diagnosis than comparators. Among patients with SSc, healthcare utilization was highest during the year of SSc diagnosis. Rate ratios comparing utilization in patients with and without SSc ranged from 1.8 to 3.0 for all comparisons. CONCLUSION: Higher utilization of outpatient physician, laboratory, and radiology visit-days was observed among patients with SSc compared to non-SSc subjects throughout 5 years of disease duration, indicating high and continued care needs in this patient population. The highest utilization of services among SSc patients occurred during the year of SSc diagnosis.


Assuntos
Pacientes Ambulatoriais , Escleroderma Sistêmico , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde , Escleroderma Sistêmico/epidemiologia , Escleroderma Sistêmico/terapia
4.
Intensive care med ; 43(3)Mar. 2017.
Artigo em Inglês | BIGG - guias GRADE | ID: biblio-948600

RESUMO

OBJECTIVE: To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012". DESIGN: A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy wasdeveloped at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroupsand among the entire committee served as an integral part of the development. METHODS: The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable. RESULTS: The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions. CONCLUSIONS: Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.(AU)


Assuntos
Humanos , Choque Séptico/tratamento farmacológico , Sepse/tratamento farmacológico , Planejamento de Assistência ao Paciente , Respiração Artificial , Vasoconstritores/uso terapêutico , Calcitonina/uso terapêutico , Avaliação Nutricional , Doença Crônica/tratamento farmacológico , Terapia de Substituição Renal , Hidratação/métodos , Antibacterianos/administração & dosagem
5.
Lupus ; 26(3): 240-247, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27365370

RESUMO

In 2012, the Systemic Lupus International Collaborating Clinics (SLICC) group published a new set of classification criteria for systemic lupus erythematosus (SLE). Studies applying these criteria to real-life scenarios have found either equal or greater sensitivity and equal or lower specificity to the 1997 ACR classification criteria (ACR 97). Nonetheless, there are no studies that have used the SLICC 12 criteria to investigate the incidence of lupus. We used the resource of the Rochester Epidemiology Project to identify incident SLE patients in Olmsted County, Minnesota, from 1993 to 2005, who fulfilled the ACR 97 or SLICC 12 criteria. A total of 58 patients met criteria by SLICC 12 and 44 patients met criteria by ACR 97. The adjusted incidence of 4.9 per 100,000 person-years by SLICC 12 was higher than that by ACR 97 (3.7 per 100,000 person-years, p = 0.04). The median duration from the appearance of first criterion to fulfillment of the criteria was shorter for the SLICC 12 than for ACR 97 (3.9 months vs 8.1 months). The higher incidence by SLICC 12 criteria came primarily from the ability to classify patients with renal-limited disease, the expansion of the immunologic criteria and the expansion of neurologic criteria.


Assuntos
Lúpus Eritematoso Sistêmico/classificação , Lúpus Eritematoso Sistêmico/epidemiologia , Reumatologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Minnesota/epidemiologia , Análise de Regressão , Índice de Gravidade de Doença , Sociedades Médicas , Adulto Jovem
6.
Int J Oral Maxillofac Surg ; 45(8): 1023-6, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27066740

RESUMO

Spontaneous herniation of the condylar head into the external auditory canal (EAC) through the foramen of Huschke is extremely rare, with approximately 30 cases reported in the international literature. The typical presentation is a constellation of non-specific symptoms including otalgia, temporomandibular joint (TMJ) pain, malocclusion, otorrhea, tinnitus while chewing, and hearing loss. Clinical examination may reveal pain, granulation tissue in the EAC, or the exposed mandibular condyle with the mouth closed. With mouth opening, the tissue or exposed bone retracts anteriorly leaving an often normal-appearing EAC. Having the patient open and close the mouth while performing otoscopy will show the displacement of tissue, which is critical for diagnosis of the condition. Radiographic examination with a computed tomography scan typically reveals a discontinuous anterior wall of the EAC with visible soft tissue in the protruding in the EAC. A case of spontaneous TMJ herniation into the EAC in a 54-year-old male patient with a history of otalgia and malocclusion is reported here. Total joint replacement therapy for the treatment of this rare condition is reported, and its importance in providing a posterior mechanical stop to prevent joint relapse is discussed.


Assuntos
Artroplastia de Substituição/métodos , Meato Acústico Externo , Fáscia/transplante , Hérnia/terapia , Herniorrafia/métodos , Côndilo Mandibular , Retalhos Cirúrgicos/transplante , Transtornos da Articulação Temporomandibular/cirurgia , Articulação Temporomandibular/cirurgia , Hérnia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos da Articulação Temporomandibular/etiologia
7.
Mol Neurobiol ; 53(8): 5161-77, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26399642

RESUMO

It has been uncertain whether specific disease-relevant biomarker phenotypes can be found using sporadic Parkinson's disease (PD) patient-derived samples, as it has been proposed that there may be a plethora of underlying causes and pathological mechanisms. Fibroblasts derived from familial PD patients harboring leucine-rich repeat kinase 2 (LRRK2), PTEN-induced putative kinase 1 (PINK1), and Parkin mutations show clear disease-relevant mitochondrial phenotypes, which are exacerbated under conditions of pharmacological stress. We utilized fibroblasts derived from non-familial sporadic PD patients (without LRRK2 mutations) or LRRK2 mutation carriers to directly compare the cellular phenotypes during and after mitochondrial stress. We then determined the effects of pharmacological LRRK2 kinase inhibition using LRRK2-in-1. We found that there were two distinct populations of sporadic PD patient-derived fibroblast lines. One group of sporadic PD lines was highly susceptible to valinomycin-induced mitochondrial depolarization, emulating the mutant LRRK2 phenotype. These lines showed elevated mitochondrial superoxide/ nitric oxide levels, displayed increased mitochondrial and lysosome co-localization, and an increased rate of mitochondrial collapse, which corresponded with changes in mitochondrial fission and fusion proteins. The application of LRRK2-in-1 reversed decreased levels of mitochondrial and lysosome co-localization and partially restored mitochondrial network associated proteins and the mitochondrial membrane potential in the fibroblasts. This study identifies novel mitochondrial biomarkers in sporadic PD patient-derived fibroblast lines, which could be used as preclinical tools in which to test novel and known neuroprotective compounds.


Assuntos
Biomarcadores/metabolismo , Fibroblastos/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/antagonistas & inibidores , Doença de Parkinson/enzimologia , Benzodiazepinonas/farmacologia , Linhagem Celular , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos , Doença de Parkinson/patologia , Proteínas Quinases/metabolismo , Pirimidinas/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Ubiquitina-Proteína Ligases/metabolismo , Valinomicina/farmacologia
8.
J Chem Phys ; 141(10): 104702, 2014 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-25217942

RESUMO

A combined wet and dry cleaning process for GaN(0001) has been investigated with XPS and DFT-MD modeling to determine the molecular-level mechanisms for cleaning and the subsequent nucleation of gate oxide atomic layer deposition (ALD). In situ XPS studies show that for the wet sulfur treatment on GaN(0001), sulfur desorbs at room temperature in vacuum prior to gate oxide deposition. Angle resolved depth profiling XPS post-ALD deposition shows that the a-Al2O3 gate oxide bonds directly to the GaN substrate leaving both the gallium surface atoms and the oxide interfacial atoms with XPS chemical shifts consistent with bulk-like charge. These results are in agreement with DFT calculations that predict the oxide/GaN(0001) interface will have bulk-like charges and a low density of band gap states. This passivation is consistent with the oxide restoring the surface gallium atoms to tetrahedral bonding by eliminating the gallium empty dangling bonds on bulk terminated GaN(0001).

9.
BJOG ; 120(6): 695-704; discussion 704-6, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23398859

RESUMO

OBJECTIVE: To investigate the influence of menses on the vaginal microbiota and determine whether tampons that differ in material composition influence these bacterial communities in different ways. DESIGN: A single-centre trial with randomised, complete block design. SETTING: Procter & Gamble facility. SAMPLE: Seven self-declared healthy, female volunteers of reproductive age. METHODS: Volunteers used a pad and two types of tampons during the study, one product exclusively each month for three sequential menstrual cycles. During menses and once each mid-cycle, vaginal bacterial community composition was characterised by cultivation-independent methods based on pyrosequencing of V1-V2 variable regions of 16S ribosomal RNA genes. MAIN OUTCOME MEASURES: Changes in the species composition, abundance and diversity in vaginal bacterial communities over time and between treatments. RESULTS: The vaginal microbiotas of all seven women were dominated by Lactobacillus spp. at mid-cycle, and the compositions of those communities were largely consistent between cycles. Community dynamic patterns during menses varied considerably and were more or less individualised. In three of the seven women the community diversity during pad use was significantly different from at least one tampon cycle. CONCLUSIONS: Changes in the composition of the vaginal microbiota during menses were common, but the magnitude of change varied between women. Despite these changes, most communities were capable of resuming a composition similar to previous mid-cycle sampling times following menstruation. Overall we conclude that the two tampons tested do not significantly impact the vaginal microbiota in different ways; however, larger studies should be performed to confirm these findings.


Assuntos
Bactérias/classificação , Produtos de Higiene Menstrual , Menstruação , Metagenoma , Vagina/microbiologia , Adolescente , Adulto , Bactérias/genética , Bactérias/isolamento & purificação , Feminino , Humanos , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Adulto Jovem
10.
Intensive care med ; 39(2)Feb. 2013. ilus, tab
Artigo em Inglês | BIGG - guias GRADE | ID: biblio-947114

RESUMO

Objective: To provide an update to the "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," last published in 2008. Design: A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict of interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independent of any industry funding. A stand-alone meeting was held for all subgroup heads, co- and vice-chairs, and selected individuals. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development. Methods: The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations as strong (1) or weak (2). The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Recommendations were classified into three groups: (1) those directly targeting severe sepsis; (2) those targeting general care of the critically ill patient and considered high priority in severe sepsis; and (3) pediatric considerations. Results: Key recommendations and suggestions, listed by category, include: early quantitative resuscitation of the septic patient during the first 6 h after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm a potential source of infection (UG); administration of broad-spectrum antimicrobials therapy within 1 h of the recognition of septic shock (1B) and severe sepsis without septic shock (1C) as the goal of therapy; reassessment of antimicrobial therapy daily for de-escalation, when appropriate (1B); infection source control with attention to the balance of risks and benefits of the chosen method within 12 h of diagnosis (1C); initial fluid resuscitation with crystalloid (1B) and consideration of the addition of albumin in patients who continue to require substantial amounts of crystalloid to maintain adequate mean arterial pressure (2C) and the avoidance of hetastarch formulations (1B); initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspicion of hypovolemia to achieve a minimum of 30 mL/kg of crystalloids (more rapid administration and greater amounts of fluid may be needed in some patients (1C); fluid challenge technique continued as long as hemodynamic improvement is based on either dynamic or static variables (UG); norepinephrine as the first-choice vasopressor to maintain mean arterial pressure ≥65 mmHg (1B); epinephrine when an additional agent is needed to maintain adequate blood pressure (2B); vasopressin (0.03 U/min) can be added to norepinephrine to either raise mean arterial pressure to target or to decrease norepinephrine dose but should not be used as the initial vasopressor (UG); dopamine is not recommended except in highly selected circumstances (2C); dobutamine infusion administered or added to vasopressor in the presence of (a) myocardial dysfunction as suggested by elevated cardiac filling pressures and low cardiac output, or (b) ongoing signs of hypoperfusion despite achieving adequate intravascular volume and adequate mean arterial pressure (1C); avoiding use of intravenous hydrocortisone in adult septic shock patients if adequate fluid resuscitation and vasopressor therapy are able to restore hemodynamic stability (2C); hemoglobin target of 7­9 g/dL in the absence of tissue hypoperfusion, ischemic coronary artery disease, or acute hemorrhage (1B); low tidal volume (1A) and limitation of inspiratory plateau pressure (1B) for acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure (PEEP) in ARDS (1B); higher rather than lower level of PEEP for patients with sepsis-induced moderate or severe ARDS (2C); recruitment maneuvers in sepsis patients with severe refractory hypoxemia due to ARDS (2C); prone positioning in sepsis-induced ARDS patients with a PaO 2/FiO 2 ratio of ≤100 mm Hg in facilities that have experience with such practices (2C); head-of-bed elevation in mechanically ventilated patients unless contraindicated (1B); a conservative fluid strategy for patients with established ARDS who do not have evidence of tissue hypoperfusion (1C); protocols for weaning and sedation (1A); minimizing use of either intermittent bolus sedation or continuous infusion sedation targeting specific titration endpoints (1B); avoidance of neuromuscular blockers if possible in the septic patient without ARDS (1C); a short course of neuromuscular blocker (no longer than 48 h) for patients with early ARDS and a PaO 2/FI O 2<150 mm Hg (2C); a protocolized approach to blood glucose management commencing insulin dosing when two consecutive blood glucose levels are >180 mg/dL, targeting an upper blood glucose ≤180 mg/dL (1A); equivalency of continuous veno-venous hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1B); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding in patients with bleeding risk factors (1B); oral or enteral (if necessary) feedings, as tolerated, rather than either complete fasting or provision of only intravenous glucose within the first 48 h after a diagnosis of severe sepsis/septic shock (2C); and addressing goals of care, including treatment plans and end-of-life planning (as appropriate) (1B), as early as feasible, but within 72 h of intensive care unit admission (2C). Recommendations specific to pediatric severe sepsis include: therapy with face mask oxygen, high flow nasal cannula oxygen, or nasopharyngeal continuous PEEP in the presence of respiratory distress and hypoxemia (2C), use of physical examination therapeutic endpoints such as capillary refill (2C); for septic shock associated with hypovolemia, the use of crystalloids or albumin to deliver a bolus of 20 mL/kg of crystalloids (or albumin equivalent) over 5­10 min (2C); more common use of inotropes and vasodilators for low cardiac output septic shock associated with elevated systemic vascular resistance (2C); and use of hydrocortisone only in children with suspected or proven "absolute"' adrenal insufficiency (2C). Conclusions: Strong agreement existed among a large cohort of international experts regarding many level 1 recommendations for the best care of patients with severe sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for this important group of critically ill patients.


Assuntos
Humanos , Sepse/diagnóstico , Sepse/terapia , Choque Séptico/diagnóstico , Choque Séptico/terapia , Índice de Gravidade de Doença
11.
Psychooncology ; 17(10): 1039-47, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18318453

RESUMO

OBJECTIVE: To identify factors associated with psychological functioning in adolescent children of early-stage breast cancer patients. METHOD: Adolescents' self-reported psychological functioning using the Child Behaviour Checklist (YSR), Mental Health subscale of the Child Health Questionnaire (CHQ-MH) and Child Impact of Events (C-IES) scale. The Family Assessment Device (FAD) and the Family Environment Scale (FES cohesion subscale) assessed family functioning. Maternal depression was assessed on the Beck Depression Inventory (BDI) and quality of life using the SF8. Using a cross-sectional within-groups design, assessments were obtained for 56 adolescents of 11-17 years . RESULTS: High rates of stress were found (C-IES) in 33% males and 45% females. Thirty percent of adolescents reported psychological problems (YSR) (28% males and 32% females) when compared with published norms. Poor family functioning was linked with YSR internalising and externalising problems; poor family cohesion with higher externalising and total YSR psychological problems. Maternal depression was linked with adolescent-reported internalising problems. CONCLUSIONS: When mothers have breast cancer, a substantial minority of their adolescent children have psychological and stress response-related problems linked with poor family functioning. These results argue in favour of a family-oriented approach to psychological support of breast cancer patients.


Assuntos
Comportamento do Adolescente/psicologia , Neoplasias da Mama/epidemiologia , Filho de Pais com Deficiência/estatística & dados numéricos , Depressão/epidemiologia , Depressão/psicologia , Família/psicologia , Pais , Estresse Psicológico/diagnóstico , Estresse Psicológico/psicologia , Adolescente , Adulto , Criança , Estudos Transversais , Depressão/diagnóstico , Humanos , Pessoa de Meia-Idade , Mães/estatística & dados numéricos , Meio Social , Inquéritos e Questionários , Adulto Jovem
12.
Theor Appl Genet ; 115(6): 859-67, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17676305

RESUMO

In a previous study, we showed that the genetic variation present in the Medicago sativa subsp. sativa Peruvian and M. sativa subsp. falcata WISFAL germplasms could be used to improve forage yields when favorable alleles were recombined and used in hybrid combination with cultivated alfalfa. In this paper, we present testcross forage yield and fall growth data for two seasons of a C0 population generated after intermating the Peruvian x WISFAL population for several generations. In addition, we conducted marker-trait association analysis as an attempt to identify Peruvian and WISFAL genomics regions affecting the targeted traits. Five and seven genomic regions were found significantly associated with forage yield and fall growth, respectively. In the case of fall growth, alleles from both accessions were positively associated with plant height. However, more alleles from WISFAL were positively associated with forage yield than from Peruvian. WISFAL is known for its winter hardiness and genomic regions with large effects on winter survival may have masked the effect of forage yield from Peruvian. The fact that most of the genomic regions discovered in this study have been previously associated with traits involved in winter hardiness validates our findings and suggests that associations between DNA fragments and agronomic traits can be detected without the necessity of developing bi-parental mapping populations.


Assuntos
Cruzamentos Genéticos , Medicago sativa/genética , Alelos , Cruzamento , Mapeamento Cromossômico , Marcadores Genéticos , Hibridização Genética , Medicago sativa/crescimento & desenvolvimento , Fenótipo
13.
Philos Trans A Math Phys Eng Sci ; 363(1831): 1329-58, 2005 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16191653

RESUMO

Within the framework of a Tyndall Centre research project, sea level and wave changes around the UK and in the North Sea have been analysed. This paper integrates the results of this project. Many aspects of the contribution of the North Atlantic Oscillation (NAO) to sea level and wave height have been resolved. The NAO is a major forcing parameter for sea-level variability. Strong positive response to increasing NAO was observed in the shallow parts of the North Sea, while slightly negative response was found in the southwest part of the UK. The cause of the strong positive response is mainly the increased westerly winds. The NAO increase during the last decades has affected both the mean sea level and the extreme sea levels in the North Sea. The derived spatial distribution of the NAO-related variability of sea level allows the development of scenarios for future sea level and wave height in the region. Because the response of sea level to the NAO is found to be variable in time across all frequency bands, there is some inherent uncertainty in the use of the empirical relationships to develop scenarios of future sea level. Nevertheless, as it remains uncertain whether the multi-decadal NAO variability is related to climate change, the use of the empirical relationships in developing scenarios is justified. The resulting scenarios demonstrate: (i) that the use of regional estimates of sea level increase the projected range of sea-level change by 50% and (ii) that the contribution of the NAO to winter sea-level variability increases the range of uncertainty by a further 10-20cm. On the assumption that the general circulation models have some skill in simulating the future NAO change, then the NAO contribution to sea-level change around the UK is expected to be very small (<4cm) by 2080. Wave heights are also sensitive to the NAO changes, especially in the western coasts of the UK. Under the same scenarios for future NAO changes, the projected significant wave-height changes in the northeast Atlantic will exceed 0.4m. In addition, wave-direction changes of around 20 degrees per unit NAO index have been documented for one location. Such changes raise the possibility of consequential alteration of coastal erosion.


Assuntos
Clima , Planejamento em Desastres/métodos , Desastres , Modelos Estatísticos , Oceanografia/métodos , Reologia/métodos , Medição de Risco/métodos , Simulação por Computador , Europa (Continente) , Mar do Norte , Fatores de Risco , Reino Unido
14.
Theor Appl Genet ; 109(4): 775-82, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15300381

RESUMO

Although unadapted germplasms have been used to improve disease and insect resistance in alfalfa, there has been little effort to use these for improving forage yield. We evaluated genetic diversity and combining ability among two unadapted germplasms ( Medicago sativa ssp. sativa Peruvian and M. sativa ssp. falcata WISFAL) and three Northern U.S. adapted alfalfa cultivars. Population structure analyses indicated that the WISFAL and Peruvian germplasms were genetically distinct from the cultivars, although Peruvian was relatively closer to the cultivars. Peruvian and WISFAL germplasms were intermated to generate a novel hybrid population. This population was crossed to the three cultivars as testers, and the testcross progenies were evaluated for forage yield along with the hybrid population, the original germplasms (Peruvian, WISFAL and cultivars), testcrosses of Peruvian and WISFAL to the three cultivars and a three-way hybrid of the cultivars. The experiment was carried out in the field in Temuco, Chile and Arlington, Wisconsin, USA, and forage was harvested during two seasons. Results from these evaluations showed that hybrids between the Peruvian x WISFAL population and the cultivar testers yielded as much as the cultivar testers. Heterosis was observed between Peruvian and WISFAL, and between these germplasms and the cultivar testers, suggesting that each germplasm may contain different favorable alleles. If Peruvian and WISFAL populations contain alleles at different loci that complement cultivar testers, then combining and enriching these alleles in a single population could result in improved combining ability with alfalfa cultivars.


Assuntos
Biomassa , Variação Genética , Genética Populacional , Medicago sativa/genética , Teorema de Bayes , Cruzamento/métodos , Chile , Cruzamentos Genéticos , Medicago sativa/crescimento & desenvolvimento , Repetições Minissatélites/genética , Peru , Polimorfismo de Fragmento de Restrição , Análise de Componente Principal , Estados Unidos
15.
Theor Appl Genet ; 108(7): 1378-84, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-14727029

RESUMO

Dwarf genes have been valuable for improving harvestable yield of several crop plants and may be useful in oilseed Brassica. We evaluated a dwarf gene, dwf2, from Brassica rapa in order to determine its phenotypic effects and genetic characteristics. The dwf2 mutant was insensitive to exogenous GA(3) for both plant height and flowering time, suggesting that it is not a mutation in the gibberellin biosynthesis pathway. The dwarf phenotype was controlled by a semidominant allele at a single locus. Near-isogenic lines that were homozygous or heterozygous for dwf2 had 47.4% or 30.0% reduction in plant height, respectively, compared to the tall wild-type line, and the reduction was due to reduced internode length and number of nodes. The dwf2 homozygous and heterozygous lines had the same or significantly higher numbers of primary branches than the wild-type line, but did not differ in flowering time. The DWF2 gene was mapped to the bottom of linkage group R6, in a region having homology to the top of Arabidopsis thaliana chromosome 2. The map position of DWF2 in comparison to markers in A. thaliana suggests it is a homolog of RGA ( repressor of ga1-3), which is a homolog of the wheat "Green Revolution" gene. This dwarf gene could be used to gain more insight on the gibberellin pathway and to reduce lodging problems in hybrid oilseed Brassica cultivars.


Assuntos
Brassica rapa/genética , Giberelinas/metabolismo , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Arabidopsis/genética , Southern Blotting , Brassica rapa/crescimento & desenvolvimento , Brassica rapa/metabolismo , Mapeamento Cromossômico , Cruzamentos Genéticos , Modelos Lineares , Polimorfismo de Fragmento de Restrição
16.
Plant Dis ; 88(9): 1033-1039, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30812218

RESUMO

A petiole inoculation technique was adapted for evaluating resistance of oilseed Brassica napus seedlings to Sclerotinia sclerotiorum. In the first of four experiments, four isolates of S. sclerotiorum were tested, two originating from soybean and two from B. napus. In all, 10 to 47 B. napus accessions were inoculated in the seedling stage and responses to isolates were evaluated using days to wilt (DW) and a lesion phenotype index (LP). There were no significant differences in virulence among the four isolates for DW and only slight differences for LP. However, significant differences (P < 0.0001) were observed among the B. napus accessions for DW and LP in this experiment and in subsequent experiments using one isolate. The responses of accessions were consistent among experiments and among evaluation criteria. Higher levels of resistance were found among winter-type than spring-type accessions, and among rapeseed-quality compared with canola-quality accessions. The most resistant accessions identified also were the most resistant when inoculated at the flowering stage. Terminal stems were inoculated immediately below the lowest flower and stem lesion length (SLL) was used to characterize the interaction phenotype of each accession. The petiole inoculation technique can be used successfully to differentiate oilseed B. napus germ plasm for response to S. sclerotiorum. This inoculation technique and the sources of resistance identified in this study may be used to determine inheritance resistance to S. sclerotiorum and for improving oilseed B. napus cultivars for resistance to this important pathogen.

17.
Genome ; 45(1): 22-7, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11908664

RESUMO

Genes for resistance to white rust (Albugo candida) in oilseed Brassica rapa were mapped using a recombinant inbred (RI) population and a genetic linkage map consisting of 144 restriction fragment length polymorphism (RFLP) markers and 3 phenotypic markers. Young seedlings were evaluated by inoculating cotyledons with A. candida race 2 (AC2) and race 7 (AC7) and scoring the interaction phenotype (IP) on a 0-9 scale. The IP of each line was nearly identical for the two races and the population showed bimodal distributions, suggesting that a single major gene (or tightly linked genes) controlled resistance to the two races. The IP scores were converted to categorical resistant and susceptible scores, and these data were used to map a single Mendelian gene controlling resistance to both races on linkage group 4 where resistance to race 2 had been mapped previously. A quantitative trait loci (QTL) mapping approach using the IP scores detected the same major resistance locus for both races, plus a second minor QTL effect for AC2 on linkage group 2. These results indicate that either a dominant allele at a single locus (Acal) or two tightly linked loci control seedling resistance to both races of white rust in the biennial turnip rape cultivar Per. The map positions of white rust resistance genes in B. rapa and Brassica napus were compared and the results indicate where additional loci that have not been mapped may be located. Alignment of these maps to the physical map of the Arabidopsis genome identified regions to target for comparative fine mapping using this model organism.


Assuntos
Arabidopsis/genética , Brassica napus/genética , Brassica rapa/genética , Oomicetos/fisiologia , Arabidopsis/microbiologia , Brassica napus/microbiologia , Brassica rapa/microbiologia , Mapeamento Cromossômico , Genes Dominantes , Marcadores Genéticos , Alinhamento de Sequência , Análise de Sequência de DNA
18.
Science ; 292(5517): 662-7, 2001 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-11326088

RESUMO

Knowledge of past climate variability is crucial for understanding and modeling current and future climate trends. This article reviews present knowledge of changes in temperatures and two major circulation features-El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO)-over much of the last 1000 years, mainly on the basis of high-resolution paleoclimate records. Average temperatures during the last three decades were likely the warmest of the last millennium, about 0.2 degrees C warmer than during warm periods in the 11th and 12th centuries. The 20th century experienced the strongest warming trend of the millennium (about 0.6 degrees C per century). Some recent changes in ENSO may have been unique since 1800, whereas the recent trend to more positive NAO values may have occurred several times since 1500. Uncertainties will only be reduced through more extensive spatial sampling of diverse proxy climatic records.


Assuntos
Clima , Animais , Cnidários , Sedimentos Geológicos , Gelo , Temperatura , Tempo , Árvores
19.
Genome Biol ; 2(3): REVIEWS1011, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11276431

RESUMO

Those studying the genus Brassica will be among the early beneficiaries of the now-completed Arabidopsis sequence. The remarkable morphological diversity of Brassica species and their relatives offers valuable opportunities to advance our knowledge of plant growth and development, and our understanding of rapid phenotypic evolution.


Assuntos
Arabidopsis/genética , Brassica/genética , Genoma de Planta , Genômica , Arabidopsis/fisiologia , Brassica/economia , Brassica/fisiologia , Biologia Computacional , Produtos Agrícolas/economia , Produtos Agrícolas/genética , Produtos Agrícolas/fisiologia , Evolução Molecular
20.
J Hered ; 91(3): 242-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10833052

RESUMO

Recent molecular data using resynthesized polyploids of Brassica napus established that genome changes can occur rapidly after polyploid formation. In this study we present data that de novo phenotypic variation for flowering time also occurs rapidly after polyploidization. Two initial polyploid plants were developed by reciprocal crosses of B. rapa and B. oleracea followed by chromosome doubling to establish two lineages, each of which was expected to be homozygous and homogeneous. Several sublineages of each lineage were advanced by self-pollination. The range in days to flower of the sixth generation plants was 39-75 and 43-64 for the two lineages. Analysis of seventh generation progeny indicated that the variation was heritable. Lines were selected and self-pollinated to the eighth generation and also testcrossed to a natural B. napus cultivar; the testcross plants were then self-pollinated. Differences in flowering time were also inherited in these advanced generations. Days to flower was significantly correlated with leaf number in each generation. The rapid evolution of new phenotypic variation, like that observed in this model system, may have contributed to the success and diversification of natural polyploid organisms.


Assuntos
Brassica/genética , Poliploidia , Brassica/crescimento & desenvolvimento , Cruzamentos Genéticos , Hibridização Genética , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...