Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Plant Phenomics ; 2020: 8086309, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33313563

RESUMO

Grape berry color is an economically important trait that is controlled by two major genes influencing anthocyanin synthesis in the skin. Color is often described qualitatively using six major categories; however, this is a subjective rating that often fails to describe variation within these six classes. To investigate minor genes influencing berry color, image analysis was used to quantify berry color using different color spaces. An image analysis pipeline was developed and utilized to quantify color in a segregating hybrid wine grape population across two years. Images were collected from grape clusters immediately after harvest and segmented by color to determine the red, green, and blue (RGB); hue, saturation, and intensity (HSI); and lightness, red-green, and blue-yellow values (L∗a∗b∗) of berries. QTL analysis identified known major QTL for color on chromosome 2 along with several previously unreported smaller-effect QTL on chromosomes 1, 5, 6, 7, 10, 15, 18, and 19. This study demonstrated the ability of an image analysis phenotyping system to characterize berry color and to more effectively capture variability within a population and identify genetic regions of interest.

2.
Arch Osteoporos ; 12(1): 21, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28243882

RESUMO

To develop consensus on improving the management of patients, we convened an international workshop involving patients, clinicians, and researchers. Key findings included the diagnostic delay and variability in subsequent management with agreement to develop an international natural history study. We now invite other stakeholders to join the partnership. PURPOSE: The aim of this study was develop a consensus on how to improve the management of patients with fibrous dysplasia and prioritize areas for research METHODS: An international workshop was held over 3 days involving patients, clinicians, and researchers. Each day had a combination of formal presentations and facilitated discussions that focused on clinical pathways and research. RESULTS: The patient workshop day highlighted the variability of patients' experience in getting a diagnosis, the knowledge of general clinical staff, and understanding long-term outcomes. The research workshop prioritized collaborations that improved understanding of the contemporary natural history of fibrous dysplasia/McCune-Albright syndrome (FD/MAS). The clinical workshop outlined the key issues around diagnostics, assessment of severity, treatment and monitoring of patients. CONCLUSIONS: In spite of advances in understanding the genetic and molecular underpinnings of fibrous dysplasia/McCune-Albright syndrome, clinical management remains a challenge. From the workshop, a consensus was reached to create an international, multi-stakeholder partnership to advance research and clinical care in FD/MAS. We invite other stakeholders to join the partnership.


Assuntos
Diagnóstico Tardio , Displasia Fibrosa Poliostótica , Assistência Centrada no Paciente , Adulto , Diagnóstico Tardio/efeitos adversos , Diagnóstico Tardio/prevenção & controle , Gerenciamento Clínico , Feminino , Displasia Fibrosa Poliostótica/diagnóstico , Displasia Fibrosa Poliostótica/epidemiologia , Displasia Fibrosa Poliostótica/terapia , Humanos , Cooperação Internacional , Masculino , Assistência Centrada no Paciente/métodos , Assistência Centrada no Paciente/organização & administração , Melhoria de Qualidade , Índice de Gravidade de Doença , Avaliação de Sintomas/métodos
3.
Rural Remote Health ; 8(1): 827, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18271675

RESUMO

INTRODUCTION: The James Cook University School of Medicine is the only complete medical school in northern Australia, and it has a mission to prepare graduates to meet the unique needs of the region with a particular emphasis on rural, remote, Indigenous and tropical health. Eight-week 'rural internships' have been undertaken by all sixth-year medical students at James Cook University since 2005. Each student had previously completed at least 12 weeks of structured rural placements in years 2 and 4, as well as other core teaching in rural health including the year 2 subject, 'Rural, Remote, Indigenous and Tropical Health'. Students worked in rural hospitals across northern Australia developing and practising clinical skills under the supervision of senior staff. Students undertook full-time inpatient and outpatient responsibilities under supervision, being rostered for after-hours work with appropriate support. Assessment involved a learning portfolio, including multi-source feedback from peers, supervisors and patients, and a population health project and a telephone referral exercise. METHODS: This article describes the development, implementation and assessment of the first years of the program, from 2005 to 2007. Evaluation included student questionnaires, site visits and interviews, and follow-up teleconferences with preceptors. RESULTS: The rural internship provides senior medical students with valuable experience by active participation in the healthcare team. Students reported a rich and varied clinical experience. Students accept limited supervised responsibility and further their ability and confidence to undertake the role of the intern. Importantly, they proved not to be a burden to the system. This rotation therefore appears to meet educational needs without compromising the local workforce (and indeed may add to it). Students felt welcomed by their communities and enjoyed the social and cultural aspects of their attachment, as well as the clinical aspects and the opportunity to further their understanding of rural communities, rural health care and the healthcare team. Preparation of the students, the preceptors and the communities emerged as a key element of success. CONCLUSION: This model extends and enhances the traditional apprenticeship model by its rural focus and distributed nature, and involvement of the entire student cohort. In addition, the contribution to patient care by senior students and junior doctors enables a consultant-registrar-resident model, in which experienced rural doctors function as consultants providing advice, support and tuition rather than predominantly face-to-face patient care. This approach also provides a means to address an emerging paradox: rural preceptors and communities want to teach students, appreciating the long-term workforce implications, but are increasingly constrained by resources, particularly time. Similar innovative approaches should be explored in other settings.


Assuntos
Competência Clínica , Serviços de Saúde do Indígena , Internato e Residência , Serviços de Saúde Rural , Estudantes de Medicina/estatística & dados numéricos , Adulto , Currículo , Feminino , Humanos , Masculino , Modelos Educacionais , Avaliação das Necessidades , Equipe de Assistência ao Paciente/organização & administração , Área de Atuação Profissional , Relações Profissional-Paciente , Avaliação de Programas e Projetos de Saúde , Queensland , Recursos Humanos
4.
Evolution ; 59(12): 2560-72, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16526504

RESUMO

Costly resistance mechanisms have been cited as an explanation for the widespread occurrence of parasitic infections, yet few studies have examined these costs in detail. A malaria-mosquito model has been used to test this concept by making a comparison of the fitness of highly susceptible lines of mosquitoes with lines that are resistant to infection. Malaria infection is known to cause a decrease in fecundity and fertility of mosquitoes; resistant mosquitoes were thus predicted to be fitter than susceptible ones. Anopheles gambiae were selected for refractoriness/resistance or for increased susceptibility to infection by Plasmodium yoelii nigeriensis. Additional lines that acted as controls for inbreeding depression were raised in parallel but not exposed to selection pressure. Selections were made in triplicate so that founder effects could be detected. Resistance mechanisms that were selected included melanotic encapsulation of parasites within 24 h postinfection and the complete disappearance of parasites from the gut. Costs of immune surveillance were assessed after an uninfected feed, and costs of immune deployment were assessed after exposure to infection and to infection and additional stresses. Mosquito survivorship was unaffected by either resistance to infection or by an increased burden of infection when compared with low levels of infection. In most cases reproductive fitness was equally affected by refractoriness or by infection. Resistant mosquitoes did not gain a fitness advantage by eliminating the parasites. Costs were consistently associated with larval production and egg hatch rate but rarely attributed to changes in blood feeding and never to changes in mosquito size. No advantages appeared to be gained by the offspring of resistant mosquitoes. Furthermore, we were unable to select for refractoriness in groups of mosquitoes in which 100% or 50% of the population were exposed to infection every generation for 22 generations. Under these selection pressures, no population had become completely refractory and only one became more resistant. Variations in fitness relative to control lines in different groups were attributed to founder effects. Our conclusion from these findings is that refractoriness to malaria is as costly as tolerance of infection.


Assuntos
Anopheles/parasitologia , Plasmodium yoelii/fisiologia , Animais , Anopheles/imunologia , Tamanho Corporal , Comportamento Alimentar , Feminino , Fertilidade , Interações Hospedeiro-Parasita , Imunidade Inata , Endogamia , Larva , Camundongos , Óvulo , Reprodução , Seleção Genética , Comportamento Sexual Animal , Análise de Sobrevida , Zigoto
5.
Neuron ; 29(2): 509-18, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11239439

RESUMO

We examined the frame of reference of auditory responses in the inferior colliculus in monkeys fixating visual stimuli at different locations. Eye position modulated the level of auditory responses in 33% of the neurons we encountered, but it did not appear to shift their spatial tuning. The effect of eye position on auditory responses was substantial-comparable in magnitude to that of sound location. The eye position signal appeared to interact with the auditory responses in at least a partly multiplicative fashion. We conclude that the representation of sound location in primate IC is distributed and that the frame of reference is intermediate between head- and eye-centered coordinates. The information contained in these neurons appears to be sufficient for later neural stages to calculate the positions of sounds with respect to the eyes.


Assuntos
Movimentos Oculares/fisiologia , Movimentos da Cabeça/fisiologia , Colículos Inferiores/fisiologia , Localização de Som/fisiologia , Estimulação Acústica/métodos , Animais , Feminino , Macaca mulatta , Imageamento por Ressonância Magnética
6.
Chemistry ; 7(22): 4902-12, 2001 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-11763459

RESUMO

The [(M+)x[18]crown-6)] supramolecular cations (SC+), in which M+ and [18]crown-6 are alkali metal ions (M+ = Li+, Na+, and Cs+) and 1,4,7,10,13,16-hexaoxacyclooctadecane, respectively, form ionic channel structures through the regular stacks of [18]crown-6 in [Ni(dmit)2]-based molecular conductors (dmit2+ = 2-thioxo-1,3-dithiole-4,5-dithiolate). In addition to the [Ni(dmit)2] salts that have the ionic channel structures (these salts are abbreviated as type I salts), Li+ and Na+ form dimerized [(M+)2([18]crown-6)2] units in the crystals (type II salts). The K+ and Rb+ are coordinated tightly into the [18]crown-6 cavity to form typical disk-shape SC+ units in the corresponding [Ni(dmit)2] salts (type III salts). The type I, II, and III salts have typical stoichiometries of [(M+)x([18]crown-6)][Ni(dmit)2]2, [(M+)([18]crown-6)(H2O)x(CH3CN)(1.5 - x)][Ni(dmit)2]3 (x = 1 for Li+ or 0.5 for Na+), and [M+([18]crown-6)][Ni(dmit)2]3, respectively: the salts of the same type are isostructural. In agreement with the trimer structures of [Ni(dmit)2] in the type II and III salts, they exhibit semiconducting behavior with electrical conductivities at 300 K (sigma(300 K)) of 0.01-0.1 S cm(-1). Type I salts contain a regular stack of partially oxidized [Ni(dmit)2] units, which form a quasi one-dimensional metallic band within the tight-binding approximation regime. The electrical conductivities at 300 K are 10-30 S cm(-1), and an almost temperature-independent conductivity was observed at higher temperatures. However, the one-dimensional electronic structures in these salts are strongly influenced by the static and dynamic structures of the coexisting ionic channel. The Na+ salt is a semiconductor, whose magnetic behavior is described by the disordered one-dimensional antiferromagnetic chain. On the other hand, the Cs+ salt is a exhibits metallic properties with 2 kF instability at room temperature. The Li+ salt shows a gradual transition from the high-temperature metallic phase to the low-temperature one-dimensional antiferromagnetic semiconductor phase, which was associated with the freezing of Li+ motion at lower temperatures. The preferential crystallization of type I salts was possible by controlling the equilibrium constant (Kc) of the complex formation between M+ ions and the [18]crown-6 molecule. The ionic channel structures were obtained when the KC was low in the electrocrystallization solution, while type II or III salts were formed in the high Kc region.

7.
Inorg Chem ; 39(12): 2645-51, 2000 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-11197021

RESUMO

Monovalent cations (M+ = Na+, K+, Rb+, and NH4+) and 12-crown-4 were assembled to new supramolecular cation (SC+) structures of the M+(12-crown-4)n (n = 1 and 2), which were incorporated into the electrically conducting Ni(dmit)2 salts (dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate). The Na+, K+, and Rb+ salts are isostructural with a stoichiometry of the M+(12-crown-4)2[Ni(dmit)2]4, while the NH4+ salt has a stoichiometry of NH4+(12-crown-4)[Ni(dmit)2]3(CH3CN)2. The electrical conductivities of the Na+, K+, Rb+, and NH4+ salts at room temperature are 7.87, 4.46, 0.78, and 0.14 S cm-1, respectively, with a semiconducting temperature dependence. The SC+ structures of the Na+, K+, and Rb+ salts have an ion-capturing sandwich-type cavity of M+(12-crown-4)2, in which the M+ ion is coordinated by eight oxygen atoms of the two 12-crown-4 molecules. On the other hand, the NH4+ ion is coordinated by four oxygen atoms of the 12-crown-4 molecule. Judging from the M(+)-O distances, thermal parameters of oxygen atoms, and vibration spectra, the thermal fluctuation of the Na+(12-crown-4)2 structure is larger than those of K+(12-crown-4)2 and Rb+(12-crown-4)2. The SC+ unit with the larger alkali metal cation gave a stress to the Ni(dmit)2 column, and the SC+ structure changed the pi-pi overlap mode and electrically conducting behavior.

8.
J Neurosci Res ; 56(5): 518-30, 1999 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10369218

RESUMO

The peripheral nervous system consists of multiple neural lineages derived from the neural crest (NC). Pax-3 is expressed in the NC and when mutated in the splotch mouse (Sp) results in the loss of derivatives from this precursor cell population. We have investigated the role of Pax-3 in regulating the generation of neurons from NC-derived precursor cells in vitro. Pax-3 mRNA in NC cultures is initially expressed in all NC but is subsequently only retained in neurons, suggesting a role in their generation. To determine whether Pax-3 is involved in neuron development, we first examined the generation of sensory-like neurons in NC cultures from Sp mice. Fivefold less sensory-like neurons were generated in NC cultures from Sp homozygous mice as compared to wild-type littermates. The role of Pax-3 in sensory neuron generation was then directly examined in dorsal root ganglia cultures by down-regulating the expression of Pax-3 protein with antisense oligonucleotides. It was found that antisense oligonucleotides inhibited 80-90% of newly generated sensory neurons; however, there was no significant effect on the survival of sensory neurons or the precursor population. These results suggest that Pax-3 has a role in regulating the differentiation of peripheral neurons.


Assuntos
Proteínas de Ligação a DNA/genética , Gânglios Espinais/citologia , Crista Neural/citologia , Neurônios/citologia , Transcrição Gênica , Animais , Diferenciação Celular , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Embrião de Mamíferos , Gânglios Espinais/embriologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Genótipo , Camundongos , Camundongos Endogâmicos CBA , Camundongos Mutantes Neurológicos , Neurônios/fisiologia , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Fator de Transcrição PAX3 , Fatores de Transcrição Box Pareados , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Tionucleotídeos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos
10.
J Inorg Biochem ; 52(2): 139-44, 1993 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-8254334

RESUMO

The preparation and properties of the copper(II) complex Cu(SUP)2.H2O are reported for the anti-inflammatory drug Suprofen (SUP). The diffuse reflectance spectra and magnetic moment are consistent with a dinuclear structure as found for [Cu(aspirinate)2(H2O)]2. The copper(II) complex exhibits an increased superoxide dismutase activity compared with the parent drug molecule in the nitroblue tetrazolium assay.


Assuntos
Cobre/química , Compostos Organometálicos/química , Superóxido Dismutase/metabolismo , Suprofeno/análogos & derivados , Suprofeno/química , Sequestradores de Radicais Livres , Modelos Estruturais , Superóxidos
12.
J Inorg Biochem ; 37(1): 1-5, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2552011

RESUMO

The preparation and properties of the Cu(II) complex Cu(SAS)2.H2O are reported for the antiinflammatory drug Salsalate (SAS). The diffuse reflectance spectra and magnetic moments are consistent with a dinuclear structure as found for [Cu(aspirinate)2(H2O)]2. The Cu(II) complex exhibits an increased superoxide dismutase activity compared with the parent drug molecule in the nitroblue tetrazolium assay.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Cobre/análise , Salicilatos/análise , Fenômenos Químicos , Química , Magnetismo , Superóxido Dismutase/metabolismo , Superóxidos
14.
Nature ; 324(6097): 547-549, 1986 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-29517749

RESUMO

The discovery of a low-temperature superconducting state in organic compounds of the type (TMTSF)2CIO4 (Tc = 1.2 K) and (BEDT-TTF)2AuI2 (TC = 4 K) (where TMTSF is tetramethyltetraselenafulvalene, BEDT-TTF is bis(ethylenedithiolo)tetrathiafalvalene and Tc is the superconducting transition temperature) has stimulated the search for new materials that may show higher values of Tc (refs 1-3). The general problem encountered in molecular charge-transfer salts of this type, which have conduction bands formed by intermolecular overlap of π-electron systems, is that conduction is usually quasi-one-dimensional, with good conduction along the stacking direction. Metals with this one-dimensional character are unstable, and undergo a Peierls transition4 to a semiconducting state at low temperatures. The relatively few exceptions (mentioned above), which remain metallic down to low temperatures, are considered to do so because they show stronger interstack interactions. We report here a new material with inherently two-dimensional interactions between the molecular π-electron systems and which we are able to stabilize as a metal down to low temperatures (1.4 K) under hydrostatic pressure (12 kbar).

16.
Science ; 158(3806): 1273-9, 1967 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-17801850

RESUMO

According to theories of model stellar atmospheres only stars of spectral types from O to about B3 may be expected to be bright in the ultraviolet-wavelength region. Observations of the strong resonance lines between 911.6 and 1900 A will yield new information permitting construction of better models for the outermost layers of OB stars. However, an adequate theory of line-formation, including non-l.t.e. effects, should be used if an accurate physical representation is to result. Already it has been demonstrated beyond doubt that O and B0 supergiants are surrounded by expanding atmospheres.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA