Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 111
Filtrar
1.
Osteoarthritis Cartilage ; 27(4): 667-675, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30597276

RESUMO

OBJECTIVE: Osteoarthritis (OA) is a major source of knee pain. Mechanisms of OA knee pain are incompletely understood but include synovial pathology. We aimed to identify molecular expression patterns in the synovium associated with symptomatic knee OA. DESIGN: Snap frozen synovia were from people undergoing total knee replacement (TKR) for advanced OA, or from post-mortem (PM) cases who had not sought help for knee pain. Associations with OA symptoms were determined using discovery and validation samples, each comprising TKR and post mortem (PM) cases matched for chondropathy (Symptomatic or Asymptomatic Chondropathy). Associations with OA were determined by comparing age matched TKR and PM control cases. Real-time quantitative PCR for 96 genes involved in inflammation and nerve sensitisation used TaqMan® Array Cards in discovery and validation samples, and protein expression for replicated genes was quantified using Luminex bead assay. RESULTS: Eight genes were differentially expressed between asymptomatic and symptomatic chondropathy cases and replicated between discovery and validation samples (P<0.05 or >3-fold change). Of these, matrix metalloprotease (MMP)-1 was also increased whereas interleukin-1 receptor 1 (IL1R1) and vascular endothelial growth factor (VEGF) were decreased at the protein level in the synovium of symptomatic compared to asymptomatic chondropathy cases. MMP1 protein expression was also increased in OA compared to PM controls. CONCLUSION: Associations of symptomatic OA may suggest roles of MMP1 expression and IL1R1 and VEGF pathways in OA pain. Better understanding of which inflammation-associated molecules mediate OA pain should inform refinement of existing therapies and development of new treatments.


Assuntos
Regulação da Expressão Gênica , Metaloproteinase 1 da Matriz/genética , Osteoartrite do Joelho/genética , Receptores Tipo I de Interleucina-1/genética , Membrana Sinovial/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Idoso , Biomarcadores/metabolismo , Estudos Transversais , Progressão da Doença , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Masculino , Metaloproteinase 1 da Matriz/biossíntese , Pessoa de Meia-Idade , Osteoartrite do Joelho/diagnóstico , Osteoartrite do Joelho/metabolismo , RNA/genética , Receptores Tipo I de Interleucina-1/biossíntese , Estudos Retrospectivos , Índice de Gravidade de Doença , Membrana Sinovial/patologia , Fator A de Crescimento do Endotélio Vascular/biossíntese
2.
Philos Trans A Math Phys Eng Sci ; 374(2077)2016 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-27550771

RESUMO

Measurements of atmospheric electrical and standard meteorological parameters were made at coastal and inland sites in southern England during the 20 March 2015 partial solar eclipse. Clear evidence of a reduction in air temperature resulting from the eclipse was found at both locations, despite one of them being overcast during the entire eclipse. The reduction in temperature was expected to affect the near-surface electric field (potential gradient (PG)) through a reduction in turbulent transfer of space charge. No such effect could be unambiguously confirmed, however, with variability in PG and air-Earth current during the eclipse being comparable to pre- and post-eclipse conditions. The already low solar radiation for this latitude, season and time of day was likely to have contributed to the reduced effect of the eclipse on atmospheric electricity through boundary layer stability. The absence of a reduction in mean PG shortly after time of maximum solar obscuration, as observed during eclipses at lower geomagnetic latitude, implied that there was no significant change in atmospheric ionization from cosmic rays above background variability. This finding was suggested to be due to the relative importance of cosmic rays of solar and galactic origin at geomagnetic mid-latitudes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

3.
Nat Nanotechnol ; 11(10): 857-860, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27428275

RESUMO

Obtaining substantial nonlinear effects at the single-photon level is a considerable challenge that holds great potential for quantum optical measurements and information processing. Of the progress that has been made in recent years one of the most promising methods is to scatter coherent light from quantum emitters, imprinting quantum correlations onto the photons. We report effective interactions between photons, controlled by a single semiconductor quantum dot that is weakly coupled to a monolithic cavity. We show that the nonlinearity of a transition modifies the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and to create polarization-correlated photons from an uncorrelated stream using a single spin. These results pave the way for semiconductor optical switches operated by single quanta of light.

4.
Osteoarthritis Cartilage ; 24(9): 1587-95, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27208420

RESUMO

OBJECTIVE: Nerve growth factor (NGF) has a pivotal role in peripheral hyperalgesia and inflammation; anti-NGF antibodies attenuate pain responses in inflammatory pain models, and in people with osteoarthritis (OA) or low back pain. The aim of this study was to characterise the peripheral mechanisms contributing to the analgesic effects of anti-NGF antibody treatment in an established model of joint pain, which mimics key clinical features of OA. DESIGN: Effects of preventative vs therapeutic treatment with an anti-NGF antibody (monoclonal antibody 911: muMab 911 (10 mg/kg, s.c.)) on pain behaviour (weight bearing asymmetry and hindpaw withdrawal thresholds (PWT)), cartilage damage, synovitis and numbers of subchondral osteoclasts were investigated in the monosodium iodoacetate (MIA) model. Potential direct effects of NGF on receptor activator of nuclear factor kappa-B ligand (RANKL) mediated osteoclastogenesis were investigated in cultured human osteoclasts. RESULTS: Intra-articular MIA injection resulted in significant pain behaviour, cartilage damage, synovitis and increased numbers of subchondral osteoclasts. Both preventative and therapeutic treatment with muMab 911 significantly prevented, or reversed, MIA-induced pain behaviour, but did not alter cartilage or synovial pathology quantified at the end of the treatment period. NGF did not facilitate RANKL driven osteoclast differentiation in vitro, but preventative or therapeutic muMab 911 reduced numbers of TRAP positive osteoclasts in the subchondral bone. CONCLUSIONS: We demonstrate that anti-NGF antibody treatment attenuates OA pain behaviour despite permitting cartilage damage and synovitis. Indirect effects on subchondral bone remodelling may contribute to the analgesic effects of NGF blockade.


Assuntos
Dor , Animais , Modelos Animais de Doenças , Humanos , Fator de Crescimento Neural , Osteoartrite , Osteoclastos , Ratos , Ratos Sprague-Dawley
5.
Neuroscience ; 268: 139-48, 2014 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-24657458

RESUMO

5-Hydroxymethylcytosine (5hmC) is abundant in the brain, suggesting an important role in epigenetic control of neuronal functions. In this paper, we show that 5hmC and 5-methylcytosine (5mC) levels are coordinately distributed in gene promoters of the rhesus macaque prefrontal cortex. Although promoter hydroxymethylation and methylation are overall negatively correlated with expression, a subset of highly expressed genes involved in specific cerebral functions is associated with high levels of 5mC and 5hmC. These relationships were also observed in the mouse cortex. Furthermore, we found that early-life maternal deprivation is associated, in the adult monkey cortex, with DNA hydroxymethylation changes of promoters of genes related to neurological functions and psychological disorders. These results reveal that early social adversity triggers variations in brain DNA hydroxymethylation that could be detected in adulthood.


Assuntos
5-Metilcitosina/metabolismo , Citosina/análogos & derivados , Metilação de DNA , Epigênese Genética , Privação Materna , Córtex Pré-Frontal/metabolismo , Animais , Citosina/metabolismo , Bases de Dados Genéticas , Lobo Frontal/metabolismo , Expressão Gênica , Macaca mulatta , Metilação , Camundongos Endogâmicos C57BL , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas
6.
Nat Commun ; 5: 3316, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24548976

RESUMO

Quantum networks can interconnect remote quantum information processors, allowing interaction between different architectures and increasing net computational power. Fibre-optic telecommunications technology offers a practical platform for routing weakly interacting photonic qubits, allowing quantum correlations and entanglement to be established between distant nodes. Although entangled photons have been produced at telecommunications wavelengths using spontaneous parametric downconversion in nonlinear media, as system complexity increases their inherent excess photon generation will become limiting. Here we demonstrate entangled photon pair generation from a semiconductor quantum dot at a telecommunications wavelength. Emitted photons are intrinsically anti-bunched and violate Bell's inequality by 17 standard deviations High-visibility oscillations of the biphoton polarization reveal the time evolution of the emitted state with exceptional clarity, exposing long coherence times. Furthermore, we introduce a method to evaluate the fidelity to a time-evolving Bell state, revealing entanglement between photons emitted up to 5 ns apart, exceeding the exciton lifetime.

7.
Nat Commun ; 4: 2859, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24300834

RESUMO

Quantum teleportation can transfer information between physical systems, which is essential for engineering quantum networks. Of the many technologies being investigated to host quantum bits, photons have obvious advantages as 'pure' quantum information carriers, but their bandwidth and energy is determined by the quantum system that generates them. Here we show that photons from fundamentally different sources can be used in the optical quantum teleportation protocol. The sources we describe have bandwidth differing by a factor over 100, but we still observe teleportation with average fidelity of 0.77, beating the quantum limit by 10 standard deviations. Furthermore, the dissimilar nature of our sources exposes physics hidden in previous experiments, which we also predict numerically. These phenomena include converting qubits from Poissonian to Fock statistics, quantum interference, beats and teleportation for spectrally non-degenerate photons, and acquisition of evolving character following teleportation of a qubit.

8.
Phys Rev Lett ; 111(4): 045003, 2013 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-23931377

RESUMO

By combining electrostatic measurements of lightning-induced electrostatic field changes with radio frequency lightning location, some field changes from exceptionally distant lightning events are apparent which are inconsistent with the usual inverse cube of distance. Furthermore, by using two measurement sites, a transition zone can be identified beyond which the electric field response reverses polarity. For these severe lightning events, we infer a horizontally extensive charge sheet above a thunderstorm, consistent with a mesospheric halo of several hundred kilometers' extent.

9.
Phys Rev Lett ; 110(1): 016804, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23383823

RESUMO

We electrically control the coherent mixing of the optically bright spin states of excitons confined in InAs/GaAs quantum dot molecules. By tunnel coupling two quantum dots, using a vertical electric field, the exciton fine structure splitting and eigenstate orientation relative to the crystal lattice are tuned. We model the electric field dependent anisotropic electron-hole exchange interaction accurately and propose that the controllable mixing of the spin states will enable electrically controlled quantum operations on exciton spin qubits.

10.
Genes Brain Behav ; 12(3): 353-60, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23331374

RESUMO

Individual variation in serotonergic function is associated with reactivity, risk for affective disorders, as well as an altered response to disease. Our study used a nonhuman primate model to further investigate whether a functional polymorphism in the promoter region for the serotonin transporter gene helps to explain differences in proinflammatory responses. Homology between the human and rhesus monkey polymorphisms provided the opportunity to determine how this genetic variation influences the relationship between a psychosocial stressor and immune responsiveness. Leukocyte numbers in blood and interleukin-6 (IL-6) responses are sensitive to stressful challenges and are indicative of immune status. The neutrophil-to-lymphocyte ratio and cellular IL-6 responses to in vitro lipopolysaccharide stimulation were assessed in 27 juvenile male rhesus monkeys while housed in stable social groups (NLL = 16, NS = 11) and also in 18 animals after relocation to novel housing (NLL = 13, NS = 5). Short allele monkeys had significantly higher neutrophil-to-lymphocyte ratios than homozygous Long allele carriers at baseline [t(25) = 2.18, P = 0.02], indicative of an aroused state even in the absence of disturbance. In addition, following the housing manipulation, IL-6 responses were more inhibited in short allele carriers (F1,16 = 8.59, P = 0.01). The findings confirm that the serotonin transporter gene-linked polymorphism is a distinctive marker of reactivity and inflammatory bias, perhaps in a more consistent manner in monkeys than found in many human studies.


Assuntos
Genótipo , Polimorfismo Genético/imunologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Alelos , Animais , Nível de Alerta , Heterozigoto , Homozigoto , Interleucina-6/sangue , Interleucina-6/imunologia , Leucócitos/imunologia , Lipopolissacarídeos/imunologia , Macaca mulatta , Masculino , Regiões Promotoras Genéticas , Proteínas da Membrana Plasmática de Transporte de Serotonina/imunologia , Estresse Psicológico/genética , Estresse Psicológico/imunologia
11.
Diabetologia ; 56(2): 298-310, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23160641

RESUMO

AIMS/HYPOTHESIS: Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes. METHODS: The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans. RESULTS: Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)). CONCLUSIONS/INTERPRETATION: We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.


Assuntos
Exoma/genética , Polimorfismo Genético/genética , Diabetes Mellitus Tipo 2/genética , Frequência do Gene/genética , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Hipertensão/genética , Polimorfismo de Nucleotídeo Único/genética
12.
Br J Pharmacol ; 170(8): 1449-58, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24528237

RESUMO

The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties from the IUPHAR database. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. This compilation of the major pharmacological targets is divided into seven areas of focus: G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors & Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and GRAC and provides a permanent, citable, point-in-time record that will survive database updates.


Assuntos
Bases de Dados de Produtos Farmacêuticos , Terapia de Alvo Molecular , Farmacologia , Humanos , Ligantes , Preparações Farmacêuticas/química
13.
Br J Pharmacol ; 167(8): 1609-19, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22924700

RESUMO

BACKGROUND AND PURPOSE: The cannabinoid receptor-mediated analgesic effects of 2-arachidonoylglycerol (2-AG) are limited by monoacylglycerol lipase (MAGL). 4-nitrophenyl 4-[bis (1,3-benzodioxol-5-yl) (hydroxy) methyl] piperidine-1-carboxylate (JZL184) is a potent inhibitor of MAGL in the mouse, though potency is reportedly reduced in the rat. Here we have assessed the effects of spinal inhibition of MAGL with JZL184 on nociceptive processing in rats. EXPERIMENTAL APPROACH: In vivo spinal electrophysiological assays in anaesthetized rats were used to determine the effects of spinal administration of JZL184 on spinal nociceptive processing in the presence and absence of hindpaw inflammation. Contributions of CB(1) receptors to these effects was assessed with AM251. Inhibition of 2-oleoylglycerol hydrolytic activity and alterations of 2-AG in the spinal cord after JZL 184 were also assessed. KEY RESULTS: Spinal JZL184 dose-dependently inhibited mechanically evoked responses of wide dynamic range (WDR) neurones in naïve anaesthetized rats, in part via the CB(1) receptor. A single spinal administration of JZL184 abolished inflammation-induced expansion of the receptive fields of spinal WDR neurones. However, neither spinal nor systemic JZL184 altered levels of 2-AG, or 2-oleoylglycerol hydrolytic activity in the spinal cord, although JZL184 displayed robust inhibition of MAGL when incubated with spinal cord tissue in vitro. CONCLUSIONS AND IMPLICATIONS: JZL184 exerted robust anti-nociceptive effects at the level of the spinal cord in vivo and inhibited rat spinal cord MAGL activity in vitro. The discordance between in vivo and in vitro assays suggests that localized sites of action of JZL184 produce these profound functional inhibitory effects. LINKED ARTICLES: This article is part of a themed section on Cannabinoids. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.167.issue-8.


Assuntos
Analgésicos/administração & dosagem , Benzodioxóis/administração & dosagem , Monoacilglicerol Lipases/antagonistas & inibidores , Dor/tratamento farmacológico , Piperidinas/administração & dosagem , Medula Espinal/efeitos dos fármacos , Amidoidrolases/metabolismo , Animais , Anti-Inflamatórios/administração & dosagem , Ácidos Araquidônicos/metabolismo , Carragenina , Sensibilização do Sistema Nervoso Central/efeitos dos fármacos , Vias de Administração de Medicamentos , Endocanabinoides/metabolismo , Etanolaminas/metabolismo , Glicerídeos/metabolismo , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/fisiopatologia , Lipase Lipoproteica/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monoacilglicerol Lipases/genética , Dor/induzido quimicamente , Dor/metabolismo , Dor/fisiopatologia , Alcamidas Poli-Insaturadas/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor CB1 de Canabinoide , Especificidade da Espécie , Medula Espinal/fisiologia
14.
Phys Rev Lett ; 108(4): 040503, 2012 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-22400818

RESUMO

A linear optical quantum computer relies on interference between photonic qubits for logic, and entanglement for near-deterministic operation. Here we measure the interference and entanglement properties of photons emitted by a quantum dot embedded within a light-emitting diode. We show that pairs of simultaneously generated photons are entangled, and indistinguishable from subsequently generated photons. We measure entanglement fidelity of 0.87 and two-photon-interference visibility of 0.60 ± 0.05. The visibility, limited by detector jitter, could be improved by optical cavity designs.

15.
Neuroscience ; 207: 167-81, 2012 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-22305886

RESUMO

Early-life stress has been shown to increase susceptibility to anxiety and substance abuse. Disrupted activity within the anterior insular cortex (AIC) has been shown to play a role in both of these disorders. Altered serotonergic processing is implicated in controlling the activity levels of the associated cognitive networks. We therefore investigated changes in both serotonin receptor expression and glutamatergic synaptic activity in the AIC of alcohol-drinking rhesus monkeys. We studied tissues from male rhesus monkeys raised under two conditions: Male rhesus monkeys (1) "mother reared" (MR) by adult females (n=9) or (2) "Nursery reared" (NR), that is, separated from their mothers and reared as a separate group under surrogate/peer-reared conditions (n=9). The NR condition represents a long-standing and well-validated nonhuman primate model of early life stress. All monkeys were trained to self-administer ethanol (4% w/v) or an isocaloric maltose-dextrin control solution. Subsets from each rearing condition were then given daily access to ethanol, water, or maltose-dextrin for 12 months. Tissues were collected at necropsy and were further analyzed. Using real time RT-PCR we found that ethanol-naive, NR monkeys had lower AIC levels of 5-HT(1A) and 5-HT(2A) receptor mRNA compared with ethanol-naive, MR animals. Although NR monkeys consumed more ethanol over the 12-month period compared with MR animals, both MR and NR animals expressed greater 5-HT(1A) and 5-HT(2A) receptor mRNA levels following chronic alcohol self-administration. The interaction between nursery-rearing conditions and alcohol consumption resulted in a significant enhancement of both 5-HT(1A) and 5-HT(2A) receptor mRNA levels such that lower expression levels observed in nursery-rearing conditions were not found in the alcohol self-administration group. Using voltage clamp recordings in the whole cell configuration we recorded excitatory postsynaptic currents in both ethanol-naive and chronic self-administration groups of NR and MR monkeys. Both groups that self-administered ethanol showed greater glutamatergic activity within the AIC. This AIC hyperactivity in MR alcohol-consuming monkeys was accompanied by an increased sensitivity to regulation by presynaptic 5-HT(1A) receptors that was not apparent in the ethanol-naive, MR group. Our data indicate that chronic alcohol consumption leads to greater AIC activity and may indicate a compensatory upregulation of presynaptic 5-HT(1A) receptors. Our results also indicate that AIC activity may be less effectively regulated by 5-HT in ethanol-naive NR animals than in NR monkeys in response to chronic ethanol self-administration. These data suggest possible mechanisms for increased alcohol seeking and possible addiction potential among young adults who had previously experienced early-life stress that include disruptions in both AIC activity and serotonin system dynamics.


Assuntos
Transtornos do Sistema Nervoso Induzidos por Álcool/fisiopatologia , Córtex Cerebral/fisiopatologia , Ácido Glutâmico/metabolismo , Receptores de Serotonina/fisiologia , Estresse Psicológico/fisiopatologia , Transtornos do Sistema Nervoso Induzidos por Álcool/metabolismo , Alcoolismo/metabolismo , Alcoolismo/fisiopatologia , Animais , Depressores do Sistema Nervoso Central/toxicidade , Córtex Cerebral/metabolismo , Doença Crônica , Modelos Animais de Doenças , Etanol/toxicidade , Feminino , Macaca mulatta , Masculino , Privação Materna , Estresse Psicológico/etiologia , Estresse Psicológico/metabolismo
16.
Dev Psychobiol ; 52(5): 465-74, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20583143

RESUMO

The mother-infant dyad is crucial to early development in a variety of species. The complexity of social groupings in nonhuman primates makes this relationship resilient as well as susceptible to early challenges associated with environmental chaos. Quantitative behavior observations of bonnet monkey mother-infant interactions were collected from 28 mother-infant dyads between one and twelve months of age. Social groups were subjected to several prenatal and/or postnatal housing relocations within a single year resulting in two study groups. One group experienced relocations (ATYPICAL, n = 14) and the second group (TYPICAL, n = 14) was conceived and reared in the same location. Behaviors in the ethogram included mother-infant interactions and infant social interactions with other members of the group. Observations between ages of two to four months were analyzed by a mixed model analysis of variance including fixed effects of per and postnatal history (TYPICAL, ATYPICAL), age, and history by age interaction and random effects of mother and infant nested within mother. A significant effect of relocation history was noted on a number of infant behaviors. ATYPICAL infants were out of direct contact with their mother at an earlier age but remained in her proximity. Control of proximity shifted to offsrping in the ATYPICAL group compared to the TYPICAL group. Furthermore, greater social interactions between two and four months of age with other members of the social group as well as the ir mother were observed in the ATYPICAL group. It is suggested that continuous challenge associated with relocation may affect the infant at later developmental ages due to these early differences in ways that are yet unclear.


Assuntos
Macaca radiata/psicologia , Comportamento Materno/psicologia , Apego ao Objeto , Comportamento Social , Meio Social , Identificação Social , Animais , Nível de Alerta , Feminino , Masculino , Gravidez
17.
Phys Rev Lett ; 100(20): 207405, 2008 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-18518580

RESUMO

We report an electrically driven semiconductor single-photon source capable of emitting photons with a coherence time of up to 400 ps under fixed bias. It is shown that increasing the injection current causes the coherence time to reduce, and this effect is well explained by the fast modulation of a fluctuating environment. Hong-Ou-Mandel-type two-photon interference using a Mach-Zehnder interferometer is demonstrated using this source to test the indistinguishability of individual photons by postselecting events where two photons collide at a beam splitter. Finally, we consider how improvements in our detection system can be used to achieve a higher interference visibility.

18.
Diabetologia ; 51(7): 1153-8, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18478198

RESUMO

AIMS/HYPOTHESIS: Variants in the fat-mass and obesity-associated gene (FTO) influence susceptibility to type 2 diabetes via an effect on adiposity/obesity. Given the important role of obesity in the aetiology of both polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus, our aim was to establish whether FTO variants are also implicated in PCOS susceptibility. METHODS: We performed a genetic association study of FTO variant rs9939609 using case-control analyses, conducted in 463 PCOS patients (geometric mean BMI 27.5 kg/m(2)) and 1,336 female controls (geometric mean BMI 25.3 kg/m(2)) of UK British/Irish origin. We also sought evidence for associations between FTO variation and circulating testosterone levels in 324 UK PCOS patients and 1,000 women from the Northern Finland Birth Cohort of 1966. Outcome measures included FTO rs9939609 genotype frequencies by participant group and androgen measures (testosterone, free androgen index) by genotype. RESULTS: There was a significant association between FTO genotype and PCOS status in the UK case-control analysis, which was attenuated by adjustment for BMI (Cochran-Armitage test, odds ratio [per minor allele copy] 1.30 [95% CI 1.12, 1.51], p = 7.2 x 10(-4) [unadjusted], p = 2.9 x 10(-3) [adjusted]). This association was most evident in obese PCOS patients (PCOS patients below median BMI vs UK controls, p = 0.11; above median BMI vs controls, p = 2.9 x 10(-4)). No relationship between FTO genotype and androgen levels was seen. CONCLUSIONS/INTERPRETATION: We provide the first evidence that variants that predispose to common obesity also result in altered susceptibility to PCOS, confirming the mechanistic link between these conditions. The predominant effect of FTO variants on PCOS susceptibility is probably mediated through adiposity.


Assuntos
Obesidade/epidemiologia , Obesidade/genética , Síndrome do Ovário Policístico/epidemiologia , Síndrome do Ovário Policístico/genética , Proteínas/genética , Tecido Adiposo/patologia , Adulto , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patologia , Feminino , Finlândia/epidemiologia , Frequência do Gene , Predisposição Genética para Doença/epidemiologia , Variação Genética , Genótipo , Humanos , Pessoa de Meia-Idade , Obesidade/patologia , Síndrome do Ovário Policístico/patologia , Fatores de Risco , Reino Unido/epidemiologia
19.
Nanotechnology ; 19(34): 345401, 2008 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-21730647

RESUMO

We have fabricated a single-photon emitting diode based on a quantum dot in a micro-pillar cavity. By temperature tuning the dot emission into resonance with the cavity mode we see an enhancement in the collected photon intensity at 40 K. We perform autocorrelation measurements on the electroluminescence at fixed bias, observing photon anti-bunching. Due to the low resistance and capacitance of our device we can inject current pulses shorter than the lifetime of the quantum state, producing single-photon emission with g((2))(0) = 0.17.

20.
Diabetologia ; 51(1): 82-5, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17994213

RESUMO

AIMS/HYPOTHESIS: The P12A variant in the PPARG gene and the E23K polymorphism in KCNJ11 are both known to influence individual predisposition to type 2 diabetes. If the effect of these variants on insulin secretion and action were to extend to an influence on early growth (which is largely mediated by insulin), it would offer an explanation for observed associations between low birthweight and subsequent diabetes. Since previous studies of the effects of these variants on early growth have been limited and conflicting, we examined these associations in a large, well-characterised birth cohort. METHODS: The P12A and E23K variants were genotyped in (respectively) 5,652 and 5,632 individuals from the Northern Finland Birth Cohort of 1966 and we sought associations with early growth phenotypes. RESULTS: Neither variant was associated with birthweight (P12A, p = 0.42; E23K, p = 0.44, additive models) or other measures of early growth. Although a previous report had suggested that the P12A effect on adult insulin sensitivity was restricted to small babies, we were unable to reproduce this finding (p = 0.40), nor did we confirm a previous report of an association with gestational age (p = 0.23). CONCLUSIONS/INTERPRETATION: Despite a larger sample size than previous studies, we were unable to detect any effect of these variants on early growth. These findings do not support the notion that there are shared genetic determinants of low birthweight and adult diabetes.


Assuntos
Peso Corporal , Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , PPAR gama/genética , Canais de Potássio Corretores do Fluxo de Internalização/genética , Adulto , Estudos de Coortes , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/etiologia , Feminino , Finlândia , Variação Genética , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Insulina/metabolismo , Resistência à Insulina , Secreção de Insulina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA