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1.
Phys Chem Chem Phys ; 26(17): 13316-13326, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38639914

RESUMO

In this article we present a quantitative analysis of the second positive system of molecular nitrogen and the first negative system of the molecular nitrogen cation excited in the presence of ionizing radiation. Optical emission spectra of atmospheric air and nitrogen surrounding 210Po sources were measured from 250 to 400 nm. Multi-Boltzmann and non-Boltzmann vibrational distribution spectral models were used to determine the vibrational temperature and vibrational distribution function of the emitting N2(C3Πu) and N2+(B2Σ+u) states. A zero-dimensional kinetic model, based on the electron energy distribution function (EEDF) and steady-state excitation and de-excitation of N2(X1Σ+g), N2+(B2Σ+u), N2+(X2Σ+g), N4+, O2+, and N2(C3Πu, v), was developed for the prediction of the relative spectral intensity of both the N2+(B2Σ+u → X2Σ+g) emission band and the vibrational bands of N2(C3Πu → B3Πg) for comparison with the experimental data.

2.
BMC Geriatr ; 24(1): 334, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609852

RESUMO

BACKGROUND: Outcomes following proximal humeral fracture (PHF) may be impacted by a range of clinical, fracture and premorbid factors. The aim of this study was to examine factors impacting hospital admission; length of stay (LOS) and new discharge destination for patients presenting to hospital with PHF. METHODS: Retrospective audit conducted at a tertiary health service. Data was collected from adult patients presenting to hospital with a PHF over a 54-month period. Fractures that were pathological or sustained during admission were excluded. Univariable and multivariable logistic and negative binomial regression were used to explore factors associated with hospital admission, LOS and new discharge destination. RESULTS: Data were analyzed from 701 participants (age 70 years (IQR 60, 81); 72.8% female); 276 (39.4%) participants required a hospital admission. New discharge destination was required for 109 (15.5%) participants, of whom 49 (45%) changed from home alone to home with family/friend(s). Greater comorbidities, as indicated by the Charlson Comorbidity Index score, were associated with hospital admission, longer LOS and new discharge destination. Premorbid living situations of home with family/friend(s) or from an external care facility were associated with a decreased likelihood of hospital admission, shorter LOS and reduced risk of a new discharge destination. Surgical treatment was associated with shorter LOS. Older age and dementia diagnosis were associated with a new discharge destination. CONCLUSIONS: Many factors potentially impact on the likelihood or risk of hospitalization, LOS and new discharge destination post PHF. Patients with greater comorbidities are more likely to have negative outcomes, while patients who had premorbid living situations of home with family/friend(s) or from an external care facility are more likely to have positive outcomes. Early identification of factors that may impact patient outcomes may assist timely decision making in hospital settings. Further research should focus on developing tools to predict hospital outcomes in the PHF population.


Assuntos
Alta do Paciente , Fraturas do Ombro , Humanos , Feminino , Idoso , Masculino , Tempo de Internação , Estudos Retrospectivos , Hospitalização , Fraturas do Ombro/epidemiologia , Fraturas do Ombro/terapia , Hospitais
3.
Breast Cancer Res Treat ; 190(2): 287-293, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34515905

RESUMO

PURPOSE: Older cancer survivors required medical care during the COVID-19 pandemic, but there are limited data on medical care in this age group. METHODS: We evaluated care disruptions in a longitudinal cohort of non-metastatic breast cancer survivors aged 60-98 from five US regions (n = 321). Survivors completed a web-based or telephone survey from May 27, 2020 to September 11, 2020. Care disruptions included interruptions in seeing or speaking to doctors, receiving medical treatment or supportive therapies, or filling prescriptions since the pandemic began. Logistic regression models evaluated associations between care disruptions and education, medical, psychosocial, and COVID-19-related factors. Multivariate models included age, county COVID-19 death rates, comorbidity, and post-diagnosis time. RESULTS: There was a high response rate (n = 262, 81.6%). Survivors were 32.2 months post-diagnosis (SD 17.5, range 4-73). Nearly half (48%) reported a medical disruption. The unadjusted odds of care disruptions were higher with each year of education (OR 1.22, 95% CI 1.08-1.37, p = < 0.001) and increased depression by CES-D score (OR 1.04, CI 1.003-1.08, p = 0.033) while increased tangible support decreased the odds of disruptions (OR 0.99, 95% CI 0.97-0.99, p = 0.012). There was a trend between disruptions and comorbidities (unadjusted OR 1.13 per comorbidity, 95% CI 0.99-1.29, p = 0.07). Adjusting for covariates, higher education years (OR1.23, 95% CI 1.09-1.39, p = 0.001) and tangible social support (OR 0.98 95% CI 0.97-1.00, p = 0.006) remained significantly associated with having care disruptions. CONCLUSION: Older breast cancer survivors reported high rates of medical care disruptions during the COVID-19 pandemic and psychosocial factors were associated with care disruptions. CLINICALTRIALS. GOV IDENTIFIER: NCT03451383.


Assuntos
Neoplasias da Mama , COVID-19 , Sobreviventes de Câncer , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2
4.
Persoonia ; 46: 116-128, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35935891

RESUMO

Several plant pathogenic Parastagonospora species have been identified infecting wheat and other cereals over the past 50 years. As new lineages were discovered, naming conventions grew unwieldy and the relationships with previously recognized species remained unclear. We used genome sequencing to clarify relationships among these species and provided new names for most of these species. Six of the nine described Parastagonospora species were recovered from wheat, with five of these species coming from Iran. Genome sequences revealed that three strains thought to be hybrids between P. nodorum and P. pseudonodorum were not actually hybrids, but rather represented rare gene introgressions between those species. Our data are consistent with the hypothesis that P. nodorum originated as a pathogen of wild grasses in the Fertile Crescent, then emerged as a wheat pathogen via host-tracking during the domestication of wheat in the same region. The discovery of a diverse array of Parastagonospora species infecting wheat in Iran suggests that new wheat pathogens could emerge from this region in the future. Citation: Croll D, Crous PW, Pereira D, et al. 2021. Genome-scale phylogenies reveal relationships among Parastagonospora species infecting domesticated and wild grasses. Persoonia 46: 116-128. https://doi.org/10.3767/persoonia.2021.46.04.

5.
Biochim Biophys Acta ; 1862(7): 1337-44, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27085070

RESUMO

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease is now the leading liver disease in North America. The progression of non-alcoholic fatty liver disease to the inflammatory condition, non-alcoholic steatohepatitis is complex and currently not well understood. Intestinal microbial dysbiosis has been implicated in the development of non-alcoholic fatty liver disease and progression of non-alcoholic steatohepatitis. Volatile organic compounds are byproducts of microbial metabolism in the gut that may enter portal circulation and have hepatotoxic effects contributing to the pathogenesis of non-alcoholic steatohepatitis. To test this hypothesis, we measured volatile organic compounds in cecal luminal contents and portal venous blood in a mouse model of non-alcoholic steatohepatitis. METHODS: Gas chromatography-mass spectrometry analysis was conducted on cecal content and portal vein blood for volatile organic compound detection from mice fed a methionine and choline deficient diet, which induces non-alcoholic steatohepatitis. The colonic microbiome was studied by 16S rRNA gene amplification using the Illumina MiSeq platform. RESULTS: Sixty-eight volatile organic compounds were detected in cecal luminal content, a subset of which was also present in portal venous blood. Importantly, differences in portal venous volatile organic compounds were associated with diet-induced steatohepatitis establishing a biochemical link between gut microbiota-derived volatile organic compounds and increased susceptibility to non-alcoholic steatohepatitis. CONCLUSION: Our model creates a novel tool to further study the role of gut-derived volatile organic compounds in the pathogenesis of non-alcoholic steatohepatitis.


Assuntos
Inflamação/microbiologia , Fígado/irrigação sanguínea , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/microbiologia , Veia Porta/microbiologia , Compostos Orgânicos Voláteis/análise , Animais , Bactérias/isolamento & purificação , Células Cultivadas , Modelos Animais de Doenças , Inflamação/patologia , Mediadores da Inflamação/análise , Fígado/microbiologia , Fígado/patologia , Macrófagos/microbiologia , Macrófagos/patologia , Masculino , Camundongos Endogâmicos C57BL , Microbiota , Hepatopatia Gordurosa não Alcoólica/patologia , Veia Porta/patologia
8.
Clin Exp Dermatol ; 42(7): 771-773, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28597964

RESUMO

Inflammatory bowel disease (IBD) can be divided into Crohn disease, ulcerative colitis and inflammatory bowel disease unclassified (IBDU). In most patients, these disorders present in adolescence or early adulthood. Patients with infantile IBD can have an associated underlying immunodeficiency disorder caused by a mutation in interleukin (IL)-10 or its receptor. We describe a child presenting with intractable bloody diarrhoea since 2 weeks of age and with severe nappy ulceration, who was ultimately diagnosed as having inflammatory bowel disease (IBD) due to an immunodeficiency in the IL-10 receptor. This report highlights the importance of considering this rare immunodeficiency in patients with infantile IBD presenting with severe perianal disease to a dermatologist.


Assuntos
Doenças Inflamatórias Intestinais/genética , Interleucina-10/genética , Mutação , Úlcera Cutânea/genética , Evolução Fatal , Transplante de Células-Tronco Hematopoéticas , Humanos , Lactente , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/terapia , Masculino , Úlcera Cutânea/complicações , Úlcera Cutânea/terapia
9.
J Intellect Disabil Res ; 61(2): 181-195, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27561217

RESUMO

BACKGROUND: Executive function (EF) plays a critical role in academic outcomes in typically developing children, but the contribution of EF to academic performance in Down syndrome (DS) is less well understood. This study evaluated differences in early academic foundations between primary school aged children with DS and non-verbal mental-age matched typically developing (TD) children. Additionally, the contribution of EF domains to academic outcomes was evaluated in each group. METHOD: Participants with DS (n = 29) and mental-age matched TD participants (n = 23) were administered the Woodcock Johnson- III NU Tests of Academic Achievement, as well as a laboratory-based EF battery, including measures of working memory, shifting, inhibition and object-planning. RESULTS: Findings indicated a difference in early academic foundations profile between children with DS and mental-age matched TD children. Patterns of EF contributions towards academic outcomes were also observed across groups. CONCLUSIONS: Aspects of EF are critical to academic achievement in DS but differentially so relative to typical development. Implications for educational instruction are discussed.


Assuntos
Sucesso Acadêmico , Síndrome de Down/fisiopatologia , Função Executiva/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino
10.
Matern Child Nutr ; 13(3)2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-27460693

RESUMO

Vitamin D deficiency has adverse health effects in young children. Our aims were to determine predictors of vitamin D status and then to use these factors to develop a practical tool to predict low 25(OH)D concentrations in preschool New Zealand children. A cross-sectional sample of 1329 children aged 2 to <5 years were enrolled from throughout New Zealand in late-winter to spring 2012. 25-Hydroxyvitamin D (25(OH)D) was measured on dried blood spot (DBS) samples collected using finger-prick sampling. Caregivers completed a questionnaire. Mean (SD) DBS 25(OH)D concentration was 52(19)nmol/L. 25(OH)D < 25 nmol/L was present in 86(7%), 25(OH)D < 50 nmol/L in 642(48%), 25(OH)D 50- < 75 nmol/L in 541(41%) and 25(OH)D > 75 nmol/L in 146(11%) of children. Factors independently associated with the risk of 25(OH)D < 25 nmol/L were female gender (OR 1.92,95%CI 1.17-3.14), other non-European ethnicities (not including Maori or Pacific) (3.51,1.89-6.50), had olive-dark skin colour (4.52,2.22-9.16), did not take vitamin D supplements (2.56,1.06-6.18), had mothers with less than secondary-school qualifications (5.00,2.44-10.21) and lived in more deprived households (1.27,1.06-1.53). Children who drank toddler milk (vitamin D fortified cow's milk formula marketed to young children) had a zero risk of 25(OH)D < 25 nmol/L. The predictive tool identified children at risk of 25(OH)D < 25 nmol/L with sensitivity 42%, specificity 97% and ROC area-under-curve 0.76(95%CI 0.67-0.86, p < 0.001). Predictors of low vitamin D status were consistent with those identified in previous studies of New Zealand children. The tool had insufficient predictive ability for use in clinical situations, and suggests a need to promote safe, inexpensive testing to determine vitamin D status in preschool children.


Assuntos
Alimentos Fortificados , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia , Vitamina D/administração & dosagem , Vitamina D/sangue , Animais , Pré-Escolar , Estudos Transversais , Suplementos Nutricionais , Feminino , Humanos , Masculino , Leite/química , Nova Zelândia/epidemiologia , Estado Nutricional , Instituições Acadêmicas , Estações do Ano , Pigmentação da Pele
11.
Mol Psychiatry ; 20(10): 1197-204, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25385369

RESUMO

Memory impairment is the cardinal early feature of Alzheimer's disease, a highly prevalent disorder whose causes remain only partially understood. To identify novel genetic predictors, we used an integrative genomics approach to perform the largest study to date of human memory (n=14 781). Using a genome-wide screen, we discovered a novel association of a polymorphism in the pro-apoptotic gene FASTKD2 (fas-activated serine/threonine kinase domains 2; rs7594645-G) with better memory performance and replicated this finding in independent samples. Consistent with a neuroprotective effect, rs7594645-G carriers exhibited increased hippocampal volume and gray matter density and decreased cerebrospinal fluid levels of apoptotic mediators. The MTOR (mechanistic target of rapamycin) gene and pathways related to endocytosis, cholinergic neurotransmission, epidermal growth factor receptor signaling and immune regulation, among others, also displayed association with memory. These findings nominate FASTKD2 as a target for modulating neurodegeneration and suggest potential mechanisms for therapies to combat memory loss in normal cognitive aging and dementia.


Assuntos
Hipocampo/fisiologia , Memória/fisiologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Feminino , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Humanos , Estudos Longitudinais , Masculino , Transtornos da Memória/genética , Transtornos da Memória/metabolismo , Polimorfismo de Nucleotídeo Único , Relação Estrutura-Atividade
12.
Heredity (Edinb) ; 116(4): 384-94, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26758189

RESUMO

Different thermal environments impose strong, differential selection on populations, leading to local adaptation, but the genetic basis of thermal adaptation is poorly understood. We used quantitative trait locus (QTL) mapping in the fungal wheat pathogen Zymoseptoria tritici to study the genetic architecture of thermal adaptation and identify candidate genes. Four wild-type strains originating from the same thermal environment were crossed to generate two mapping populations with 263 (cross 1) and 261 (cross 2) progeny. Restriction site-associated DNA sequencing was used to genotype 9745 (cross 1) and 7333 (cross 2) single-nucleotide polymorphism markers segregating within the mapping population. Temperature sensitivity was assessed using digital image analysis of colonies growing at two different temperatures. We identified four QTLs for temperature sensitivity, with unique QTLs found in each cross. One QTL had a logarithm of odds score >11 and contained only six candidate genes, including PBS2, encoding a mitogen-activated protein kinase kinase associated with low temperature tolerance in Saccharomyces cerevisiae. This and other QTLs showed evidence for pleiotropy among growth rate, melanization and growth morphology, suggesting that many traits can be correlated with thermal adaptation in fungi. Higher temperatures were highly correlated with a shift to filamentous growth among the progeny in both crosses. We show that thermal adaptation has a complex genetic architecture, with natural populations of Z. tritici harboring significant genetic variation for this trait. We conclude that Z. tritici populations have the potential to adapt rapidly to climate change and expand into new climatic zones.


Assuntos
Aclimatação/genética , Ascomicetos/genética , Locos de Características Quantitativas , Temperatura , Ascomicetos/fisiologia , Mapeamento Cromossômico , Cruzamentos Genéticos , DNA Fúngico/genética , Pleiotropia Genética , Genótipo , Fenótipo , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Triticum/microbiologia
14.
Clin Exp Dermatol ; 41(1): 45-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26033316

RESUMO

Biological therapies may provide the breakthrough in treating moderate to severe atopic eczema (AE) that is unresponsive to standard therapy. Rituximab has been shown to benefit some patients in published case series, and so we treated three consecutive patients with severe AE with rituximab. Despite achieving low/absent peripheral blood CD19 +  B-cell numbers following rituximab administration, this was not associated with clinical benefit as there was no major change in pre- and post-treatment Eczema Area and Severity Index (34, 64.4 and 42.2 compared with 33.2, 66 and 56.4, respectively). We would therefore recommend that that there is a compelling need for a formal, double-blind, placebo-controlled study to demonstrate efficacy of rituximab as a treatment of moderate to severe AE.


Assuntos
Dermatite Atópica/tratamento farmacológico , Fatores Imunológicos/uso terapêutico , Rituximab/uso terapêutico , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Falha de Tratamento
15.
Persoonia ; 37: 199-216, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-28232765

RESUMO

Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice pathogen and in the last 30 years emerged as an important wheat pathogen in southern Brazil. We conducted phylogenetic analyses using 10 housekeeping loci for 128 isolates of P. oryzae sampled from sympatric populations of wheat, rice, and grasses growing in or near wheat fields. Phylogenetic analyses grouped the isolates into three major clades. Clade 1 comprised isolates associated only with rice and corresponds to the previously described rice blast pathogen P. oryzae pathotype Oryza (PoO). Clade 2 comprised isolates associated almost exclusively with wheat and corresponds to the previously described wheat blast pathogen P. oryzae pathotype Triticum (PoT). Clade 3 contained isolates obtained from wheat as well as other Poaceae hosts. We found that Clade 3 is distinct from P. oryzae and represents a new species, Pyricularia graminis-tritici (Pgt). No morphological differences were observed among these species, but a distinctive pathogenicity spectrum was observed. Pgt and PoT were pathogenic and highly aggressive on Triticum aestivum (wheat), Hordeum vulgare (barley), Urochloa brizantha (signal grass), and Avena sativa (oats). PoO was highly virulent on the original rice host (Oryza sativa), and also on wheat, barley, and oats, but not on signal grass. We conclude that blast disease on wheat and its associated Poaceae hosts in Brazil is caused by multiple Pyricularia species. Pyricularia graminis-tritici was recently found causing wheat blast in Bangladesh. This indicates that P. graminis-tritici represents a serious threat to wheat cultivation globally.

16.
Water Sci Technol ; 71(5): 734-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25768220

RESUMO

A two-stage process consisting of anaerobic fermentation followed by sub-critical wet oxidation was used to generate acetic acid from sewage sludge at pilot scale. Volatile fatty acids, dominated by propionic acid, were produced over 4-6 days in the 2,000 L fermentation reactor, which also achieved 31% solids reduction. Approximately 96% of the carbon was retained in solution over the fermentation stage. Using a 200 L wet oxidation reactor operating in batch mode, the second stage achieved 98% volatile suspended solids (VSS) destruction and 67% total chemical oxygen demand (tCOD) destruction. Acetic acid produced in this stage was recalcitrant to further degradation and was retained in solution. The gross yield from VSS was 16% for acetic acid and 21% for volatile fatty acids across the process, higher than reported yields for wet oxidation alone. The pilot plant results showed that 72% of the incoming phosphorus was retained in the solids, 94% of the nitrogen became concentrated in solution and 41% of the carbon was converted to a soluble state, in a more degradable form. Acetic acid produced from the process has the potential to be used to offset ethanol requirements in biological nutrient removal plants.


Assuntos
Ácido Acético/metabolismo , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Carbono/metabolismo , Ácidos Graxos Voláteis/metabolismo , Fermentação , Nitrogênio/metabolismo , Oxirredução , Fósforo/metabolismo , Projetos Piloto , Propionatos/metabolismo , Esgotos , Eliminação de Resíduos Líquidos/instrumentação
17.
Mol Psychiatry ; 18(7): 781-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23608917

RESUMO

Whole-exome sequencing of individuals with mild cognitive impairment, combined with genotype imputation, was used to identify coding variants other than the apolipoprotein E (APOE) ε4 allele associated with rate of hippocampal volume loss using an extreme trait design. Matched unrelated APOE ε3 homozygous male Caucasian participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) were selected at the extremes of the 2-year longitudinal change distribution of hippocampal volume (eight subjects with rapid rates of atrophy and eight with slow/stable rates of atrophy). We identified 57 non-synonymous single nucleotide variants (SNVs) which were found exclusively in at least 4 of 8 subjects in the rapid atrophy group, but not in any of the 8 subjects in the slow atrophy group. Among these SNVs, the variants that accounted for the greatest group difference and were predicted in silico as 'probably damaging' missense variants were rs9610775 (CARD10) and rs1136410 (PARP1). To further investigate and extend the exome findings in a larger sample, we conducted quantitative trait analysis including whole-brain search in the remaining ADNI APOE ε3/ε3 group (N=315). Genetic variation within PARP1 and CARD10 was associated with rate of hippocampal neurodegeneration in APOE ε3/ε3. Meta-analysis across five independent cross sectional cohorts indicated that rs1136410 is also significantly associated with hippocampal volume in APOE ε3/ε3 individuals (N=923). Larger sequencing studies and longitudinal follow-up are needed for confirmation. The combination of next-generation sequencing and quantitative imaging phenotypes holds significant promise for discovery of variants involved in neurodegeneration.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/genética , Disfunção Cognitiva/genética , Exoma/genética , Predisposição Genética para Doença/genética , Hipocampo/patologia , Poli(ADP-Ribose) Polimerases/genética , Doença de Alzheimer/complicações , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Doença de Alzheimer/psicologia , Apolipoproteína E3/genética , Atrofia/patologia , Disfunção Cognitiva/complicações , Disfunção Cognitiva/patologia , Estudos de Coortes , Estudo de Associação Genômica Ampla , Humanos , Masculino , Neuroimagem , Poli(ADP-Ribose) Polimerase-1 , Polimorfismo de Nucleotídeo Único , População Branca/genética
19.
Plant Dis ; 97(11): 1511, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30708482

RESUMO

The G143A mutation in cytb (cytochrome b gene) is associated with high levels of resistance to quinone outside inhibitor (QoI or strobilurin) fungicides that disrupt electron transport during cellular respiration (1). The G143A mutation in Zymoseptoria tritici (synonyms: Mycosphaerella graminicola and Septoria tritici), the causal agent of septoria tritici blotch of wheat (Triticum aestivum), was first reported in Europe in 2001 (1). Although Z. tritici has a global distribution (3), G143A mutants of Z. tritici have not been reported outside of Europe. We used PCR-RFLP (4) to estimate the frequencies of G143A mutants in Z. tritici populations at two locations in the Willamette Valley of western Oregon: the Hyslop Crop Science Field Research Laboratory (Hyslop Farm, HF), Benton County (44°37'52.85″ N, 123°11'55.19″ W) and research plots planted in a commercial wheat field in Washington County (45°33'58.53″ N, 123°00'11.78″ W) (North Valley Farm, NVF). Isolates originated from flag leaf collections from two cultivars ('Bobtail' and 'Tubbs 06') made in April and June of 2012 from plants in a replicated fungicide-treatment experiment, with isolates collected from both sprayed and unsprayed plots. Sixteen of the 169 isolates (9.5%) from HF possessed the G143A mutation (7 of 132 isolates from plots not receiving a QoI fungicide and 9 of 37 isolates collected from plots receiving two applications of the QoI azoxystrobin). One hundred forty six of the 175 isolates (83.4%) from NVF were G143A mutants (101 of 129 isolates from plots receiving no QoI fungicide and 45 of 46 isolates from plots receiving two applications of azoxystrobin). Results of phenotypic assays of a subset of 10 isolates from each location (5 mutants, 5 wild types from each location; 20 isolates altogether) supported a high level of resistance to azoxystrobin only in the G143A mutants. All 10 G143A mutants developed colonies after 8 days of growth on YMA plates amended with SHAM (2) and 1 ppm or 10 ppm azoxystrobin, with nine and eight G143A mutant isolates developing colonies on plates amended with 1 ppm and 10 ppm azoxystrobin, respectively. None of the wild-type isolates developed colonies on plates amended with SHAM and 1 ppm azoxystrobin, nor on plates amended with SHAM and 10 ppm azoxystrobin. All 20 isolates developed colonies on YMA plates lacking azoxystrobin, and treatments produced identical results across three replicates. These results are consistent with findings of higher levels of azoxystrobin resistance in G143A mutants compared to wild types in European populations (1). Isolates from HF and NVF differ in their previous exposure to QoI fungicides. The majority of the wheat area at HF is planted to breeding plots that are not sprayed with fungicide. Plots at NVF were planted in a commercial wheat field in a county where most wheat fields were treated with two to three applications of strobilurins each year over the past 4 years. Future monitoring for G143A mutants of Z. tritici throughout its range in North America will be necessary to assess whether strobilurin resistance will spread via wind-dispersal of ascospores or emerge de novo in treated fields. In Europe, stobilurins were first applied to wheat in 1996. G143A mutants of Z. tritici emerged de novo several times (4) and were widespread by 2007. References: (1) B. A. Fraaje et al. Phytopathology 95:933, 2005. (2) J. A. LaMondia. Tob. Sci. 49:1, 2012. (3) E. S. Orton et al. Mol. Plant Pathol. 12:413, 2011. (4) S. F. F. Torriani et al. Pest Manag. Sci. 65:155, 2008.

20.
Oecologia ; 169(2): 395-406, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22139429

RESUMO

Identifying individuals' foraging strategies is critical to understanding the ecology of a species, and can provide the means to predict possible ecological responses to environmental change. Our study combines stable isotope analysis and satellite telemetry to study the variability in individual foraging strategies of adult female southern elephant seals (Mirounga leonina). Our hypothesis is that female elephant seals from the Western Antarctica Peninsula (WAP) display individual specialization in their diets. We captured adult female elephant seals (n = 56, 2005-2009) at Livingston Island (Antarctica), and instrumented them with SMRU-CTD satellite tags. We collected blood, fur, and vibrissae samples for δ(13)C and δ(15)N analyses. The mean values for all vibrissae were -21.0 ± 0.7‰ for δ(13)C, and 10.4 ± 0.8‰, for δ(15)N. The individual variability of δ(13)C (60%) was more important than the within-individual variability (40%) in explaining the total variance observed in our data. For δ(15)N, the results showed the opposite trend, with the within-individual variability (64%) contributing more to the total variance than the individual variability (36%), likely associated with the effect that the fasting periods have on δ(15)N values. Most individuals were specialists, as inferred from the low intra-individual variability of δ(13)C values with respect to the population variability, with half the individuals utilizing 31% or less of their available niche. We found eight different foraging strategies for these animals. Female elephant seals from the WAP are a diverse group of predators with individuals utilizing only a small portion of the total available niche, with the consequent potential to expand their foraging habits to exploit other resources or environments in the Southern Ocean.


Assuntos
Isótopos de Carbono/análise , Comportamento Alimentar/fisiologia , Isótopos de Nitrogênio/análise , Focas Verdadeiras/fisiologia , Animais , Regiões Antárticas , Análise por Conglomerados , Ecossistema , Feminino , Cabelo/química , Comportamento Predatório/fisiologia
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