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1.
Child Care Health Dev ; 40(5): 663-70, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24148012

RESUMO

OBJECTIVES: To examine the quality of transitional care in a paediatric and adult hospital by investigating (i) adherence to national transition guidance and (ii) whether implementation is associated with better patient/carer experiences. METHODS: A cross-sectional study was conducted in a UK paediatric hospital (PH) and neighbouring adult hospital. Clinics completed a questionnaire to determine characteristics of their transitional care provision and invited patients aged 11-21 years and parents/carers to complete a questionnaire ('Mind the Gap') to assess their satisfaction. RESULTS: Twenty-three clinics participated. Fourteen (70%) reported delivering a transition programme, but only 5 (25%) indicated this was holistic (addressing medical, psychosocial and vocational issues). Participants included 457 young people and 330 parents, 71% and 88% respectively attending the PH. Ratings of current care were significantly lower than ratings of best care. These 'gap' scores were not excessive, although some participants were very dissatisfied. Better satisfaction was associated with attending clinics that provided transitional care, especially when defined as 'holistic' and youth-friendly. CONCLUSIONS: Transition programmes that adhere to current guidance are associated with better satisfaction, but variations in provision suggest barriers to implementation. Attention is required to how youth-friendly transitional care is defined with particular reference to the specific clinic model.


Assuntos
Serviços de Saúde do Adolescente/organização & administração , Doença Crônica/reabilitação , Continuidade da Assistência ao Paciente/organização & administração , Fidelidade a Diretrizes/normas , Adolescente , Criança , Doença Crônica/psicologia , Estudos de Coortes , Feminino , Humanos , Masculino , Satisfação do Paciente , Autocuidado/métodos , Inquéritos e Questionários , Reino Unido , Adulto Jovem
2.
J Evol Biol ; 25(8): 1676-85, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22694151

RESUMO

Theoretically, asymmetric gene flow along an environmental gradient can limit species range expansion by keeping peripheral populations from locally adapting. However, few empirical studies have examined this potentially fundamental evolutionary mechanism. We address this possibility in the cricket Allonemobius socius, which exist along a season-length gradient where the probability of producing a single generation per year (univoltinism) increases with latitude. As the probability of univoltinism increases northwards, populations are expected to hedge their bets by producing a greater proportion of diapause eggs when exposed to a mild diapause cue. However, gene flow from southern populations may disrupt local adaptation in the north by reducing the proportion of diapause eggs (expected to be 100% in pure univoltine environments). This may limit range expansion along the northern periphery where A. socius compete with A. fasciatus, a sister species that exhibits an invariant diapause-only egg-laying strategy. To assess the potential for range limitation, we examined diapause incidence (the proportion of diapause eggs produced under diapause conditions), gene flow symmetry and population structure across nine A. socius populations. We found that gene flow was asymmetric and biased northwards towards the periphery. Furthermore, peripheral populations that inhabited pure univoltine environments produced numerous nondiapause eggs (a southern, bivoltine diapause phenotype), which we assume to be a suboptimal phenotype. These patterns suggest that asymmetric gene flow along the gradient constrains adaptation in peripheral populations, potentially constraining species range expansion.


Assuntos
Adaptação Fisiológica/genética , Meio Ambiente , Fluxo Gênico , Gryllidae/genética , Animais , Variação Genética , Genética Populacional
3.
J Evol Biol ; 25(8): 1500-12, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22591212

RESUMO

Understanding the genetic architecture of traits involved in premating isolation between recently diverged lineages can provide valuable insight regarding the mode and tempo of speciation. The repeated coevolution of male courtship song and female preference across the species radiation of Laupala crickets presents an unusual opportunity to compare the genetic basis of divergence across independent evolutionary histories. Previous studies of one pair of species revealed a polygenic basis (including a significant X chromosome contribution) to quantitative differences in male song and female acoustic preference. Here, we studied interspecific crosses between two phenotypically less-diverged species that represents a phylogenetically independent occurrence of intersexual signalling evolution. We found patterns consistent with an additive polygenic basis to differentiation in both song and preference (n(E) = 5.3 and 5.1 genetic factors, respectively), and estimate a moderate contribution of the X chromosome (7.6%) of similar magnitude to that observed for Laupala species with nearly twice the phenotypic divergence. Together, these findings suggest a similar genetic architecture underlying the repeated evolution of sexual characters in this genus and provide a counterexample to prevailing theory predicting an association between early lineage divergence and sex-linked 'major genes'.


Assuntos
Comunicação Animal , Especiação Genética , Gryllidae/genética , Animais , Evolução Biológica , Feminino , Havaí , Masculino , Fenótipo , Comportamento Sexual Animal/fisiologia
4.
J Evol Biol ; 24(5): 1110-9, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21375646

RESUMO

Sexual behaviours often evolve rapidly and are critical for sexual isolation. We suggest that coordinated sexual signals and preferences generate stabilizing selection, favouring the accumulation of many small-effect mutations in sexual communication traits. Rapid radiation of a sexual behaviour used in signalling, song pulse rate, has been observed in the Hawaiian cricket genus Laupala. Using marker-assisted introgression, we isolated five known quantitative trait loci (QTL) influencing species-level differences in pulse rate from one species, L. paranigra, into a closely related species, L. kohalensis. All five QTL were found to have a significant effect on song and appear to be largely additive in backcross introgression lines. Furthermore, all effect sizes were small in magnitude. Our data provide support for the hypothesis that stabilizing selection on sexual signals in Laupala creates genetic conditions favourable to incremental divergence during speciation, through the evolution of alleles of minor rather than major phenotypic effects.


Assuntos
Comunicação Animal , Especiação Genética , Gryllidae/genética , Locos de Características Quantitativas , Comportamento Sexual Animal , Alelos , Animais , Evolução Biológica , Feminino , Frequência do Gene , Genótipo , Masculino
5.
Palliat Med ; 24(3): 317-29, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20156934

RESUMO

The Gold Standards Framework aims to optimize primary palliative care for patients nearing the end of their lives. This paper critically reviews the impact of the Gold Standards Framework since its introduction in 2001 and indicates direction for further research and development. Literature was accessed using specific databases and by contacting subject area specialists. The resultant literature was appraised using an established framework to evaluate healthcare interventions. Fifteen documents were reviewed. The quality of evidence is constrained by methodological limitations, but consistently demonstrates that the Gold Standards Framework improves general practice processes, co-working and the quality of palliative care. However, implementation of the Gold Standards Framework is variable and the direct impact on patients and carers is not known. We conclude that the Gold Standards Framework has considerable potential to improve end-of-life care, but further work is needed to support uptake and consistency of implementation. Additional evidence about patient and carer outcomes will add to existing insights.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Atenção Primária à Saúde/normas , Avaliação de Programas e Projetos de Saúde , Garantia da Qualidade dos Cuidados de Saúde/normas , Assistência Terminal/normas , Enfermagem em Saúde Comunitária , Medicina de Família e Comunidade/organização & administração , Medicina de Família e Comunidade/normas , Fidelidade a Diretrizes , Implementação de Plano de Saúde/organização & administração , Humanos , Relações Interprofissionais , Atenção Primária à Saúde/organização & administração , Literatura de Revisão como Assunto , Assistência Terminal/organização & administração , Carga de Trabalho
6.
Int J Sports Med ; 31(1): 38-43, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19885774

RESUMO

This pilot study compared the energy expenditure required to climb an indoor rock wall, in amputees utilizing five prosthetic configurations. Three experienced climbers (1M age 21 yr, 2F ages 30 and 49 yr) with unilateral transfemoral amputation climbed a 9.14 m indoor rock wall, 5.9 Yosemite Decimal Scale rating, using the following prosthetic configurations: 1. no prosthesis; 2. stubby prosthesis-foot forward; 3. stubby prosthesis-foot backward; 4. articulated prosthesis-knee unlocked; 5. articulated prosthesis-knee locked. Subjects climbed three times with each configuration resulting in 15 climbs per subject. Metabolic data was collected using the COSMED K4b(2) system. VO(2) was 15, 18 and 20% greater in the articulated unlocked condition (mean+/-SE: 20.5+/-0.8 ml.kg (-1).min (-1)), and 11, 13 and 15% greater in the articulated locked condition (19.7+/-0.9 ml.kg (-1).min (-1)), compared to the no prosthesis (17.8+/-0.7 ml.kg (-1).min (-1)), stubby backward (17.4+/-0.7 ml.kg (-1).min (-1)) and stubby forward (17.1+/-0.9 ml.kg (-1).min (-1)) conditions. Participants expended 11-20% more energy using the articulated prostheses than with the stubby and no prosthesis conditions. In persons with transfemoral amputation, use of an articulated prosthesis in indoor rock climbing may be a disadvantage in many aspects including competition, training, rehabilitation and satisfaction with the activity.


Assuntos
Amputados , Membros Artificiais , Montanhismo/fisiologia , Adulto , Metabolismo Energético/fisiologia , Feminino , Fêmur , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Projetos Piloto , Desenho de Prótese , Adulto Jovem
7.
Gene Ther ; 16(8): 998-1008, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19440227

RESUMO

An important goal of gene therapy is to be able to deliver genes, so that they express in a pattern that recapitulates the expression of an endogenous cellular gene. Although tissue-specific promoters confer selectivity, in a vector-based system, their activity may be too weak to mediate detectable levels in gene-expression studies. We have used a two-step transcriptional amplification system to amplify gene expression from lentiviral vectors using the human insulin promoter. In this system, the human insulin promoter drives expression of a potent synthetic transcription activator (the yeast GAL4 DNA-binding domain fused to the activation domain of the Herpes simplex virus-1 VP16 activator), which in turn activates a GAL4-responsive promoter, driving the enhanced green fluorescent protein reporter gene. Vectors carrying the human insulin promoter did not express in non-beta-cell lines, but expressed in murine insulinoma cell lines, indicating that the human insulin promoter was capable of conferring cell specificity of expression. The insulin-amplifiable vector was able to amplify gene expression five to nine times over a standard insulin-promoter vector. In primary human islets, gene expression from the insulin-promoted vectors was coincident with insulin staining. These vectors will be useful in gene-expression studies that require a detectable signal and tissue specificity.


Assuntos
Técnicas de Transferência de Genes , Vetores Genéticos , Células Secretoras de Insulina/metabolismo , Insulina/genética , Lentivirus/genética , Ativação Transcricional/genética , Animais , Linhagem Celular , Expressão Gênica , Proteínas de Fluorescência Verde/genética , Humanos , Ilhotas Pancreáticas/metabolismo , Camundongos , Especificidade de Órgãos , Fosfoglicerato Quinase/genética , Regiões Promotoras Genéticas
8.
Science ; 287(5455): 1060-2, 2000 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-10669421

RESUMO

Eukaryotic genome sizes range over five orders of magnitude. This variation cannot be explained by differences in organismic complexity (the C value paradox). To test the hypothesis that some variation in genome size can be attributed to differences in the patterns of insertion and deletion (indel) mutations among organisms, this study examines the indel spectrum in Laupala crickets, which have a genome size 11 times larger than that of Drosophila. Consistent with the hypothesis, DNA loss is more than 40 times slower in Laupala than in Drosophila.


Assuntos
Drosophila/genética , Evolução Molecular , Genoma , Gryllidae/genética , Mutação , Retroelementos , Animais , DNA/genética , Funções Verossimilhança , Família Multigênica , Filogenia , Reação em Cadeia da Polimerase , Pseudogenes , Deleção de Sequência , Especificidade da Espécie
9.
Rheumatology (Oxford) ; 47(10): 1577-82, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18713769

RESUMO

OBJECTIVE: Effective treatment can only be given during the early stages of RA if patients are seen early. However, many patients delay for prolonged periods before seeking medical advice. This study explores factors influencing the decision to seek medical advice in RA patients. METHODS: In-depth, semi-structured interviews were carried out with 24 patients. Purposive sampling ensured a cross-section in terms of time to presentation, gender, age and ethnic background. Interview transcripts were analysed and themes identified using established methods. RESULTS: Four main themes influenced the decision to seek medical advice: (i) symptom experience: the severity of symptoms and their impact on functional ability; (ii) symptom evaluation: the patient's explanation for their symptoms and recognition of their significance; (iii) knowledge of RA and available therapies; and (iv) experience of and attitudes towards health care providers. A significant and rapid impact of the disease on functional ability characterized those presenting early. Many developed an explanation for their symptoms that related to preceding activities. Recognition that this explanation was inadequate to explain symptom progression frequently prompted a consultation. Only one patient sought advice because she thought that she might have RA. CONCLUSIONS: Symptom evaluation is a key factor influencing how quickly medical advice is sought in other diseases. In contrast to the situation with many cancers where there is widespread association of symptoms and signs with the eventual diagnosis, this was not the case in RA. Our findings should inform strategies to reduce delays in help-seeking in people with early RA.


Assuntos
Artrite Reumatoide/diagnóstico , Tomada de Decisões , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Adulto , Idoso , Artrite Reumatoide/complicações , Artrite Reumatoide/fisiopatologia , Artrite Reumatoide/psicologia , Atitude Frente a Saúde , Diagnóstico Precoce , Inglaterra , Medicina de Família e Comunidade , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Seleção de Pacientes
10.
J Evol Biol ; 26(2): 286-7, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23324009
11.
Pediatr Rheumatol Online J ; 14(1): 57, 2016 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-27756328

RESUMO

BACKGROUND: Taking medicines as intended is difficult for everybody, but young people going through adolescence have greater problems than adults and younger children. One of the most important things that happen during the teenage years is the development of individual identities, which might not remain constant during this time and can be affected deeply by the diagnosis of a long-term condition. The aim of this study was to examine the relationships between identity and medication use among young people with juvenile arthritis. METHODS: A prospective qualitative study was undertaken to collect private online 'blog' style data from young people (aged 11-19 years) with juvenile arthritis, and their parents, to examine their views about their condition, identity, medication and use of health services. Participants were identified from a large paediatric hospital in the UK. RESULTS: Young people (n = 21) with a median age 14 years (range 11-17 years) posted a median (range) of 8 (1-36) blogs and parents (n = 6) posted 4 (1-12) blogs. Young people gave a strong sense of both private and public identity that was intertwined with their arthritis and treatment. It was evident that young people's self-care was intrinsically linked to their attempts to maintain a sense of individually and socially constructed definitions of normality. The act of taking medication, and the consequences (positive or negative) of that act, had an impact both personally and socially. CONCLUSIONS: Young people with juvenile arthritis reflect on their medication as a factor affecting their perception of themselves. Acknowledging the roles of both personal and social identity will be important in any strategies to support optimal medication use. This includes an understanding of the identity transformations that young people can experience and how decision-making may be affected by their attempts to retain pre-diagnosis identities and/or develop new social identities.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Juvenil/psicologia , Atitude Frente a Saúde , Adolescente , Artrite Juvenil/tratamento farmacológico , Criança , Feminino , Humanos , Masculino , Farmacêuticos , Estudos Prospectivos , Pesquisa Qualitativa , Autoimagem , Identificação Social
12.
J Mol Biol ; 279(1): 271-86, 1998 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-9636716

RESUMO

Ribonucleases Sa, Sa2, and Sa3 are three small, extracellular enzymes produced by different strains of Streptomyces aureofaciens with amino acid sequences that are 50% identical. We have studied the unfolding of these enzymes by heat and urea to determine the conformational stability and its dependence on temperature, pH, NaCl, and the disulfide bond. All three of the Sa ribonucleases unfold reversibly by a two-state mechanism with melting temperatures, Tm, at pH 7 of 48.4 degrees C (Sa), 41.1 degrees C (Sa2), and 47.2 degrees C (Sa3). The Tm values are increased in the presence of 0.5 M NaCl by 4.0 deg. C (Sa), 0.1 deg. C (Sa2), and 7.2 deg. C (Sa3). The Tm values are decreased by 20.0 deg. C (Sa), 31.5 deg. C (Sa2), and 27.0 deg. C (Sa3) when the single disulfide bond in the molecules is reduced. We compare these results with similar studies on two other members of the microbial ribonuclease family, RNase T1 and RNase Ba (barnase), and with a member of the mammalian ribonuclease family, RNase A. At pH 7 and 25 degrees C, the conformational stabilities of the ribonucleases are (kcal/mol): 2.9 (Sa2), 5.6 (Sa3), 6.1 (Sa), 6.6 (T1), 8.7 (Ba), and 9.2 (A). Our analysis of the stabilizing forces suggests that the hydrophobic effect contributes from 90 to 110 kcal/mol and that hydrogen bonding contributes from 70 to 105 kcal/mol to the stability of these ribonucleases. Thus, we think that the hydrophobic effect and hydrogen bonding make large but comparable contributions to the conformational stability of these proteins.


Assuntos
Isoenzimas/química , Desnaturação Proteica/efeitos dos fármacos , Dobramento de Proteína , Ribonucleases/química , Streptomyces aureofaciens/química , Sequência de Aminoácidos , Dissulfetos/química , Dados de Sequência Molecular , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Cloreto de Sódio/farmacologia , Temperatura , Termodinâmica , Ureia/farmacologia
13.
Genetics ; 162(3): 1275-82, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12454072

RESUMO

As with many organisms of evolutionary interest, the Hawaiian cricket Laupala genome is not well characterized genetically. Mapping such an unexplored genome therefore presents challenges not often faced in model genetic organisms and not well covered in the literature. We discuss the evolutionary merits of Laupala as a model for speciation studies involving prezygotic change, our choice of marker system for detecting genetic variation, and the initial genetic expectations pertaining to the construction of any unknown genomic map in general and to the Laupala linkage map construction in particular. We used the technique of amplified fragment length polymorphism (AFLP) to develop a linkage map of Laupala. We utilized both EcoRI/MseI- and EcoRI/PstI-digested genomic DNA to generate AFLP bands and identified 309 markers that segregated among F(2) interspecific hybrid individuals. The map is composed of 231 markers distributed over 11 and 7 species-specific autosomal groups together with a number of putative X chromosome linkage groups. The integration of codominant markers enabled the identification of five homologous linkage groups corresponding to five of the seven autosomal chromosomal pairs found in Laupala.


Assuntos
Mapeamento Cromossômico , Gryllidae/genética , Animais , Ligação Genética , Marcadores Genéticos , Cromossomo X
14.
Protein Sci ; 9(7): 1395-8, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10933506

RESUMO

Several recent studies have shown that it is possible to increase protein stability by improving electrostatic interactions among charged groups on the surface of the folded protein. However, the stability increases are considerably smaller than predicted by a simple Coulomb's law calculation, and in some cases, a charge reversal on the surface leads to a decrease in stability when an increase was predicted. These results suggest that favorable charge-charge interactions are important in determining the denatured state ensemble, and that the free energy of the denatured state may be decreased more than that of the native state by reversing the charge of a side chain. We suggest that when the hydrophobic and hydrogen bonding interactions that stabilize the folded state are disrupted, the unfolded polypeptide chain rearranges to compact conformations with favorable long-range electrostatic interactions. These charge-charge interactions in the denatured state will reduce the net contribution of electrostatic interactions to protein stability and will help determine the denatured state ensemble. To support this idea, we show that the denatured state ensemble of ribonuclease Sa is considerably more compact at pH 7 where favorable charge-charge interactions are possible than at pH 3, where unfavorable electrostatic repulsion among the positive charges causes an expansion of the denatured state ensemble. Further support is provided by studies of the ionic strength dependence of the stability of charge-reversal mutants of ribonuclease Sa. These results may have important implications for the mechanism of protein folding.


Assuntos
Desnaturação Proteica , Proteínas/química , Estabilidade Enzimática , Isoenzimas/química , Isoenzimas/genética , Muramidase/química , Muramidase/genética , Mutação , Conformação Proteica , Dobramento de Proteína , Proteínas/genética , Ribonuclease T1/química , Ribonuclease T1/genética , Ribonucleases/química , Ribonucleases/genética , Eletricidade Estática
15.
Protein Sci ; 10(6): 1206-15, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11369859

RESUMO

The net charge and isoelectric pH (pI) of a protein depend on the content of ionizable groups and their pK values. Ribonuclease Sa (RNase Sa) is an acidic protein with a pI = 3.5 that contains no Lys residues. By replacing Asp and Glu residues on the surface of RNase Sa with Lys residues, we have created a 3K variant (D1K, D17K, E41K) with a pI = 6.4 and a 5K variant (3K + D25K, E74K) with a pI = 10.2. We show that pI values estimated using pK values based on model compound data can be in error by >1 pH unit, and suggest how the estimation can be improved. For RNase Sa and the 3K and 5K variants, the solubility, activity, and stability have been measured as a function of pH. We find that the pH of minimum solubility varies with the pI of the protein, but that the pH of maximum activity and the pH of maximum stability do not.


Assuntos
Isoenzimas/química , Ribonucleases/química , Ácido Aspártico/química , Dicroísmo Circular , Escherichia coli/metabolismo , Ácido Glutâmico/química , Concentração de Íons de Hidrogênio , Cinética , Lisina/química , Modelos Moleculares , Mutagênese Sítio-Dirigida , Conformação Proteica , Desnaturação Proteica , Solubilidade , Temperatura , Termodinâmica
16.
Protein Sci ; 8(9): 1843-9, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10493585

RESUMO

It is difficult to increase protein stability by adding hydrogen bonds or burying nonpolar surface. The results described here show that reversing the charge on a side chain on the surface of a protein is a useful way of increasing stability. Ribonuclease T1 is an acidic protein with a pI approximately 3.5 and a net charge of approximately -6 at pH 7. The side chain of Asp49 is hyperexposed, not hydrogen bonded, and 8 A from the nearest charged group. The stability of Asp49Ala is 0.5 kcal/mol greater than wild-type at pH 7 and 0.4 kcal/mol less at pH 2.5. The stability of Asp49His is 1.1 kcal/mol greater than wild-type at pH 6, where the histidine 49 side chain (pKa = 7.2) is positively charged. Similar results were obtained with ribonuclease Sa where Asp25Lys is 0.9 kcal/mol and Glu74Lys is 1.1 kcal/mol more stable than the wild-type enzyme. These results suggest that protein stability can be increased by improving the coulombic interactions among charged groups on the protein surface. In addition, the stability of RNase T1 decreases as more hydrophobic aromatic residues are substituted for Ala49, indicating a reverse hydrophobic effect.


Assuntos
Proteínas/química , Ácido Aspártico/química , Eletroquímica , Histidina/química , Concentração de Íons de Hidrogênio , Conformação Proteica , Desnaturação Proteica/genética , Proteínas/genética , Proteínas Recombinantes/química , Ribonuclease T1/química , Ribonuclease T1/genética , Eletricidade Estática , Termodinâmica , Ureia/química
17.
Evolution ; 54(4): 1303-12, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11005297

RESUMO

Female mating behavior plays a fundamental role in the divergent evolution of mate recognition systems that may lead to speciation. Despite this important role, the phenotypic and genetic bases of female mating behavior remain poorly understood. In this study, I examine the shape of the female acoustic preference function and estimate values for pulse rate preference in two species of Hawaiian crickets, Laupala kohalensis and L. paranigra. In addition, I examine how preference differences are inherited in hybrid crosses between these species. Females expressed unimodal preference functions and were generally more attracted to pulse rates characterizing their own species. Unimodal preference functions also characterized F1 and backcross generations, with hybrid females expressing preferences for intermediate pulse rates. Pulse rate preferences segregated in the backcross generation. Mean pulse rate preference matched mean pulse rate in both parental and hybrid generations. Based on F1 hybrids and segregation patterns in backcross females, I show that changes in both signal and receiver components of the mate recognition system are consistent with a multilocus model of change through incremental steps. The results therefore suggest that ancestors of the current species also expressed unimodal preference functions and that changes in acoustic communication signals occurred through shifts in mean pulse rates and pulse rate preferences among populations.


Assuntos
Evolução Biológica , Gryllidae/fisiologia , Comportamento Sexual Animal , Estimulação Acústica , Animais , Comportamento de Escolha , Cruzamentos Genéticos , Feminino , Gryllidae/genética , Masculino , Fenótipo
18.
Proc Biol Sci ; 267(1443): 577-84, 2000 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-10787161

RESUMO

Female preference functions for different sexual traits can differ significantly, from 'unimodal' to 'open ended'. Through the study of acoustic communication in anurans, several studies have reported an association between static (stereotyped) traits versus dynamic (variable) traits and preference function shape (unimodal versus open ended, respectively). Observing a similar pattern in a phylogenetically independent group would suggest that deterministic forces have caused a relationship between signal variability and preference function shape in acoustic signalling systems. We examined this phenomenon in crickets, another animal characterized by intersexual acoustic communication. We measured the within-male variability for three acoustic features of the male calling song in Laupala cerasina and the corresponding shape of the female preference function for each of these features. We offer support for the generalization that open-ended preference functions correspond to relatively dynamic courtship traits and unimodal preference functions correspond to relatively static courtship traits. We discuss the evolutionary significance of these findings in the context of the natural history of the Laupala species radiation.


Assuntos
Gryllidae/fisiologia , Comportamento Sexual Animal , Estimulação Acústica , Animais , Feminino , Masculino
19.
Int J Parasitol ; 25(3): 381-7, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7601597

RESUMO

This study was designed to investigate whether delaying the age of weaning, or feeding a protein-rich supplement alters the rate at which lambs develop immunity to Haemonchus contortus and whether there is any interaction between nutrition, stress of weaning, and gender and the development of this immunity. Ninety-six Merino lambs were allocated to one of four treatment groups: supplemented-unweaned; supplemented-weaned; unsupplemented-unweaned; unsupplemented-weaned. There were approximately similar numbers of male and female lambs in each group. Supplemented lambs received 80 g/head/day of a protein-rich pellet from 16 to 23 weeks of age. Over the same period the lambs were drenched with 300 H. contortus larvae twice per week. Faecal worm egg counts were determined every week, and PCV and liveweight every 2 weeks for each lamb. Neither weaning nor sex had any effect on PCV (P > 0.05) but from day 50 after the start of infection, the decline in PCV was more pronounced in unsupplemented than in supplemented lambs. Faecal worm egg counts were higher (P < 0.001) in unsupplemented-weaned than in supplemented-weaned lambs and in females when compared with castrates (P < 0.03). There was a weaning x supplementation x age interaction (P < 0.03) with unsupplemented-weaned lambs developing a higher faecal egg count than supplemented-weaned lambs. There was also a significant (P < 0.02) sex x weaning x age interaction with weaned-female lambs having a higher faecal egg count than weaned-castrate lambs; egg counts increased more rapidly in unweaned-female lambs than in weaned-female lambs.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Hemoncose/imunologia , Hemoncose/veterinária , Doenças dos Ovinos/imunologia , Ração Animal , Animais , Peso Corporal , Feminino , Alimentos Fortificados , Hematócrito , Imunidade Ativa , Masculino , Projetos de Pesquisa , Caracteres Sexuais , Ovinos , Fatores de Tempo , Desmame
20.
Arthritis Care Res ; 13(4): 227-36, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14635277

RESUMO

OBJECTIVE: To develop a valid and reliable measure to assess parents' perceived ability to control, or manage, aspects of their children's juvenile idiopathic arthritis (JIA). METHODS: Construction of the Parent's Arthritis Self-Efficacy Scale (PASE) was based on existing knowledge and the results of focus groups with parents of children with JIA, children with JIA, and health professionals. Data for validation of the PASE were collected by self-administered questionnaires completed by 178 parents and 89 children with JIA. RESULTS: Analyses revealed a 2-factor structure for both mothers and fathers. These factors related to parents' self-efficacy for managing children's arthritis-related symptoms and psychosocial health. Taken together, the two factors explained 75.5% and 65.8% of the total variance (mothers' and fathers,' respectively). The PASE demonstrated high internal consistency, concurrent validity, and construct validity, particularly among mothers. CONCLUSION: Preliminary findings suggest that the PASE is worthy of further psychometric testing and may have the potential to help delineate variations in adjustment among parents of children with JIA.


Assuntos
Artrite Juvenil/prevenção & controle , Atitude Frente a Saúde , Pais/psicologia , Autoeficácia , Inquéritos e Questionários/normas , Adaptação Psicológica , Adolescente , Adulto , Análise de Variância , Criança , Escolaridade , Emprego , Análise Fatorial , Feminino , Grupos Focais , Nível de Saúde , Humanos , Controle Interno-Externo , Masculino , Estado Civil , Pais/educação , Psicometria
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