Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.203
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Mol Ecol ; 33(17): e17472, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39077982

RESUMO

Environmental microbes routinely colonize wildlife body surface microbiota. However, animals experience dynamic environmental shifts throughout their daily routine. Yet, the effect of ecological shifts in wildlife body surface microbiota has been poorly explored. Here, we sequenced the hypervariable region V3-V4 of the 16S rRNA gene to characterize the body surface microbiota of wild Magellanic penguins (Spheniscus magellanicus) under two ecological contexts: (1) Penguins walking along the coast and (2) Penguins sheltered underground in their nest, across three subantarctic breeding colonies in the Magellan Strait, Chile. Despite ecological contexts, our results revealed that Moraxellaceae bacteria were the most predominant and abundant taxa associated with penguin body surfaces. Nevertheless, we detected colony-specific core bacteria associated with penguin bodies. The most abundant were: Deinococcus in the Contramaestre colony, Fusobacterium in the Tuckers 1 colony, and Clostridium sensu stricto 1 in the Tuckers 2 colony. Our results give a new perspective on the niche environmental hypothesis for wild seabirds. First, the ecological characteristics of each colony were associated with the microbial communities from the nest soil and the body surface of penguins inside the nests. For example, in the colonies with heterogenous vegetation cover (i.e. the Tuckers Islets), there was a similar microbial composition between the nest soil and the body surface of penguins. In contrast, on the more arid colony (Contramaestre), we detected differences in the microbial communities between the nest soil and the body surface of penguins.


Assuntos
Bactérias , Microbiota , RNA Ribossômico 16S , Spheniscidae , Animais , Spheniscidae/microbiologia , RNA Ribossômico 16S/genética , Microbiota/genética , Bactérias/classificação , Bactérias/genética , Chile , Cruzamento , Ecossistema
2.
Opt Lett ; 49(16): 4557-4560, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39146102

RESUMO

Herein, an analysis of the optical field emerging from a topological Young's interferometer is conducted. The interferometer consists of two 3D-slit shape curves and is studied by projecting it onto a trihedral reference system. From the projection, Airy, Pearcey, and cusped-type beams emerge. The optical field of these beams is organized around its caustic region. The interference between these types of beams presents interesting physical properties, which can be derived from the interaction between the interference fringes and the caustic regions. One property of the interaction is the irradiance flow, which induces a long-distance interaction between the caustic regions. Another property is the bending of the interference fringes toward the caustic regions, which acts as a sink. Due to the adiabatic features of the caustic regions, the interaction between the fringes-caustic and caustic irradiance is studied using a predator-prey model, which leads to a logistic-type differential equation with nonlinear harvesting. The stability analysis of this equation is in good agreement with the theoretical and experimental results.

3.
Brain Behav Immun ; 121: 192-210, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39032542

RESUMO

Cortical pathology involving inflammatory and neurodegenerative mechanisms is a hallmark of multiple sclerosis and a correlate of disease progression and cognitive decline. Astrocytes play a pivotal role in multiple sclerosis initiation and progression but astrocyte-neuronal network alterations contributing to gray matter pathology remain undefined. Here we unveil deregulation of astrocytic calcium signaling and astrocyte-to-neuron communication as key pathophysiological mechanisms of cortical dysfunction in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Using two-photon imaging ex vivo and fiber photometry in freely behaving mice, we found that acute EAE was associated with the emergence of spontaneously hyperactive cortical astrocytes exhibiting dysfunctional responses to cannabinoid, glutamate and purinoreceptor agonists. Abnormal astrocyte signaling by Gi and Gq protein coupled receptors was observed in the inflamed cortex. This was mirrored by treatments with pro-inflammatory factors both in vitro and ex vivo, suggesting cell-autonomous effects of the cortical neuroinflammatory environment. Finally, deregulated astrocyte calcium activity was associated with an enhancement of glutamatergic gliotransmission and a shift of astrocyte-mediated short-term and long-term plasticity mechanisms towards synaptic potentiation. Overall, our data identify astrocyte-neuronal network dysfunctions as key pathological features of gray matter inflammation in multiple sclerosis and potentially additional neuroimmunological disorders.


Assuntos
Astrócitos , Sinalização do Cálcio , Encefalomielite Autoimune Experimental , Camundongos Endogâmicos C57BL , Esclerose Múltipla , Plasticidade Neuronal , Animais , Astrócitos/metabolismo , Encefalomielite Autoimune Experimental/metabolismo , Camundongos , Plasticidade Neuronal/fisiologia , Esclerose Múltipla/metabolismo , Esclerose Múltipla/patologia , Inflamação/metabolismo , Neurônios/metabolismo , Feminino , Ácido Glutâmico/metabolismo , Substância Cinzenta/metabolismo , Substância Cinzenta/patologia , Cálcio/metabolismo , Córtex Cerebral/metabolismo
4.
Dig Dis Sci ; 69(3): 749-765, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38217680

RESUMO

BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) that contributes in part to irreversible bowel damage and long-term complications, reduced quality of life, invalidity, and economic burden. Suboptimal control of IBD is associated with higher healthcare resource utilization (HCRU), impaired quality of life (QoL), and reduced work productivity. AIMS: The IBD-PODCAST study aimed to assess the proportion of IBD patients with suboptimal control and its associated impact. METHODS: IBD-PODCAST is a cross-sectional, multicenter study that aimed to characterize the CD and UC population with optimal or suboptimal control according to the STRIDE-II criteria and patient- and physician-reported measures. Here we present the results of the Spanish cohort (n = 396). RESULTS: A total of 104/196 (53.1%) CD and 83/200 (41.5%) UC patients were found to have suboptimal disease control. Long-term treatment targets according to STRIDE-II were applied in 172 (87.8%) CD and 181 (90.5%) UC patients. 125 of 172 (72.7%) CD and 74 of 181 (40.9%) UC patients were currently treated with targeted immunomodulators. Patients with CD and UC and suboptimal disease control showed impaired QoL, higher HCRU and direct costs, and also loss of work productivity compared to those with optimal control. CONCLUSION: Despite a high rate of targeted immunomodulator therapy, a substantial proportion of IBD patients show suboptimal disease control according to the STRIDE II criteria. Those patients with suboptimal disease control exhibit impaired QoL, less work productivity, and higher HCRU, suggesting that there is considerable need for better treatment approaches in IBD.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Qualidade de Vida , Espanha/epidemiologia , Estudos Transversais , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/epidemiologia , Doença de Crohn/diagnóstico , Doença de Crohn/tratamento farmacológico , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/tratamento farmacológico , Fatores Imunológicos/uso terapêutico
5.
J Opt Soc Am A Opt Image Sci Vis ; 41(5): 881-891, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38856575

RESUMO

There is a continuous interest in shrinking the dimensions of portable atomic gravimeters. This inevitably ends up truncating the Gaussian wings of the excitation laser beams whose effect has not been properly quantified yet. The diffraction pattern created from this aperture creates ripples in the wavefront in both the phase and the intensity. We calculate the shift in the measured value of an atomic gravimeter introduced by the phase variations in the wavefront. Fortunately, this shift has a Gaussian decay with the aperture size. For extended clouds, we observe a reduction of the effect thanks to an averaging over transverse positions with different values of the shift. Surprisingly, we found that the intensity variations also introduce an important correction to the photon recoil, which contributes at about the same level as the previous shift in the measurement of the gravitational acceleration. Our results should help decide how small an apparatus can be to guarantee a particular accuracy.

6.
Opt Express ; 31(3): 3504-3519, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36785342

RESUMO

Nowadays, atom-based quantum sensors are leaving the laboratory towards field applications requiring compact and robust laser systems. Here we describe the realization of a compact laser system for atomic gravimetry. Starting with a single diode laser operating at 780 nm and adding only one fiber electro-optical modulator, one acousto-optical modulator and one laser amplifier we produce laser beams at all the frequencies required for a Rb-87 atomic gravimeter. Furthermore, we demonstrate that an atomic fountain configuration can also be implemented with our laser system. The modulated system reported here represents a substantial advance in the simplification of the laser source for transportable atom-based quantum sensors that can be adapted to other sensors such as atomic clocks, accelerometers, gyroscopes or magnetometers with minor modifications.

7.
Hum Reprod ; 38(4): 596-608, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-36763673

RESUMO

STUDY QUESTION: Can artificial intelligence (AI) algorithms developed to assist embryologists in evaluating embryo morphokinetics be enriched with multi-centric clinical data to better predict clinical pregnancy outcome? SUMMARY ANSWER: Training algorithms on multi-centric clinical data significantly increased AUC compared to algorithms that only analyzed the time-lapse system (TLS) videos. WHAT IS KNOWN ALREADY: Several AI-based algorithms have been developed to predict pregnancy, most of them based only on analysis of the time-lapse recording of embryo development. It remains unclear, however, whether considering numerous clinical features can improve the predictive performances of time-lapse based embryo evaluation. STUDY DESIGN, SIZE, DURATION: A dataset of 9986 embryos (95.60% known clinical pregnancy outcome, 32.47% frozen transfers) from 5226 patients from 14 European fertility centers (in two countries) recorded with three different TLS was used to train and validate the algorithms. A total of 31 clinical factors were collected. A separate test set (447 videos) was used to compare performances between embryologists and the algorithm. PARTICIPANTS/MATERIALS, SETTING, METHODS: Clinical pregnancy (defined as a pregnancy leading to a fetal heartbeat) outcome was first predicted using a 3D convolutional neural network that analyzed videos of the embryonic development up to 2 or 3 days of development (33% of the database) or up to 5 or 6 days of development (67% of the database). The output video score was then fed as input alongside clinical features to a gradient boosting algorithm that generated a second score corresponding to the hybrid model. AUC was computed across 7-fold of the validation dataset for both models. These predictions were compared to those of 13 senior embryologists made on the test dataset. MAIN RESULTS AND THE ROLE OF CHANCE: The average AUC of the hybrid model across all 7-fold was significantly higher than that of the video model (0.727 versus 0.684, respectively, P = 0.015; Wilcoxon test). A SHapley Additive exPlanations (SHAP) analysis of the hybrid model showed that the six first most important features to predict pregnancy were morphokinetics of the embryo (video score), oocyte age, total gonadotrophin dose intake, number of embryos generated, number of oocytes retrieved, and endometrium thickness. The hybrid model was shown to be superior to embryologists with respect to different metrics, including the balanced accuracy (P ≤ 0.003; Wilcoxon test). The likelihood of pregnancy was linearly linked to the hybrid score, with increasing odds ratio (maximum P-value = 0.001), demonstrating the ranking capacity of the model. Training individual hybrid models did not improve predictive performance. A clinic hold-out experiment was conducted and resulted in AUCs ranging between 0.63 and 0.73. Performance of the hybrid model did not vary between TLS or between subgroups of embryos transferred at different days of embryonic development. The hybrid model did fare better for patients older than 35 years (P < 0.001; Mann-Whitney test), and for fresh transfers (P < 0.001; Mann-Whitney test). LIMITATIONS, REASONS FOR CAUTION: Participant centers were located in two countries, thus limiting the generalization of our conclusion to wider subpopulations of patients. Not all clinical features were available for all embryos, thus limiting the performances of the hybrid model in some instances. WIDER IMPLICATIONS OF THE FINDINGS: Our study suggests that considering clinical data improves pregnancy predictive performances and that there is no need to retrain algorithms at the clinic level unless they follow strikingly different practices. This study characterizes a versatile AI algorithm with similar performance on different time-lapse microscopes and on embryos transferred at different development stages. It can also help with patients of different ages and protocols used but with varying performances, presumably because the task of predicting fetal heartbeat becomes more or less hard depending on the clinical context. This AI model can be made widely available and can help embryologists in a wide range of clinical scenarios to standardize their practices. STUDY FUNDING/COMPETING INTEREST(S): Funding for the study was provided by ImVitro with grant funding received in part from BPIFrance (Bourse French Tech Emergence (DOS0106572/00), Paris Innovation Amorçage (DOS0132841/00), and Aide au Développement DeepTech (DOS0152872/00)). A.B.-C. is a co-owner of, and holds stocks in, ImVitro SAS. A.B.-C. and F.D.M. hold a patent for 'Devices and processes for machine learning prediction of in vitro fertilization' (EP20305914.2). A.D., N.D., M.M.F., and F.D.M. are or have been employees of ImVitro and have been granted stock options. X.P.-V. has been paid as a consultant to ImVitro and has been granted stocks options of ImVitro. L.C.-D. and C.G.-S. have undertaken paid consultancy for ImVitro SAS. The remaining authors have no conflicts to declare. TRIAL REGISTRATION NUMBER: N/A.


Assuntos
Inteligência Artificial , Transferência Embrionária , Feminino , Gravidez , Humanos , Transferência Embrionária/métodos , Frequência Cardíaca Fetal , Imagem com Lapso de Tempo , Fertilização in vitro , Taxa de Gravidez
8.
Vet Ophthalmol ; 26(5): 452-457, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37517078

RESUMO

OBJECTIVE: To describe a case of lipogranulomatous conjunctivitis in a horse. ANIMAL STUDIED: A client-owned 12-year-old Standardbred gelding presenting with chronic conjunctivitis and palpebral masses. METHODS: Complete ophthalmic examination, surgical excision, histopathology, and bacterial culture of biopsy samples were performed. RESULTS: Upper and lower eyelids of both eyes were affected, with multiple yellow-to-white nodules on the palpebral conjunctiva, adjacent to the eyelid margin. Nodule removal was achieved via partial tarsal plate excision. Histopathological examination revealed granulomatous inflammation and large droplets of presumed free lipid in the conjunctival lamina propria. The animal was diagnosed with lipogranulomatous conjunctivitis. No postoperative ocular discomfort was observed for months; however, 3 years later, new conjunctival nodules were noticed, requiring a second surgical procedure on three of the eyelids. Transient entropion in the left lower eyelid was observed 2 months after the second surgery, and no recurrence of conjunctival nodules was observed after 18 months of follow-up. CONCLUSION: To our knowledge, this is the first report of lipogranulomatous conjunctivitis in horses.


Assuntos
Conjuntivite , Entrópio , Doenças dos Cavalos , Cavalos , Masculino , Animais , Pálpebras/cirurgia , Conjuntivite/diagnóstico , Conjuntivite/veterinária , Túnica Conjuntiva/patologia , Entrópio/cirurgia , Entrópio/veterinária , Granuloma/patologia , Granuloma/veterinária , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/cirurgia , Doenças dos Cavalos/patologia
9.
BMC Pregnancy Childbirth ; 22(1): 836, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376827

RESUMO

BACKGROUND: Every woman expresses pain differently during birth since it depends on a multitude of predictive factors. The medical care received, companionship during birth, cultural background and language barriers of the women in labour can influence on the expression of pain. This study aims to evaluate the expression of pain during birth and its associated factors in women treated in a Spanish border town. METHODS: The study included 246 women in labour. The expression of pain during labour was evaluated using the validated ESVADOPA scale. A descriptive analysis and association study were performed between cultural identity and dimensions of the scale. Multiple linear regression models were performed to assess the association between cultural identity, origin, language barrier, and companionship during labour. RESULTS: The women included in the study comprised 68.7% Berbers, 71.5% Muslims and 82.1% were accompanied during labour. An association between cultural identity and greater body expression of pain (p = 0.020; Cramer's V = 0.163) in addition to its verbal expression was found during the latent phase of labour, (p = 0.028; Cramer's V = 0.159). During the active phase of labour, cultural identity was associated with pain expression through greater body response, verbal expression, expression of the facial muscles, anxiety, inability to relax and vegetative symptoms. The different factors studied that had a predictive value were companionship (p = 0.027) during the latent phase of labour and Berber origin (p = 0.000), language barrier (p = 0.014) and companionship (p = 0.005) during the active phase of labour. The models designed predict pain expression in the latent phase by companionship and type of companionship (ß = 1.483; 95%CI = 0.459-2.506, ß = 0.238; 95%CI = 0.029-0. 448, respectively), and in the active phase by background, language barrier and companionship (ß = 0.728; 95%CI = 0.258-1.198, ß = 0.738; 95%CI = 0.150-1.326, ß = 1.888; 95%CI = 0.984-2.791, respectively). CONCLUSION: Culture, origin, language barrier and companionship during labour influences the manner in which women in labour express their pain. An understanding of this may help midwives correctly interpret the signs of pain expression and be able to offer the appropriate assistance depending on a woman's particular characteristics. There is a clear need for new models of maternity care that will take the cultural and language characteristics of women in labour into consideration.


Assuntos
Dor do Parto , Trabalho de Parto , Serviços de Saúde Materna , Tocologia , Feminino , Gravidez , Humanos , Tocologia/métodos , Parto
10.
Opt Express ; 29(4): 5505-5515, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33726086

RESUMO

We describe the synthesis of optical modes whose axial structure follows a random tandem array of Bessel beams of integer order. The array follows fluctuations of Markov-chain type and the amplitude values for each beam are linked to a sequence of random vectors. As a prototype, we describe the synthesis of optical fields for Markov-chain type Ehrenfest. This process models the thermodynamic equilibrium and then it can be related to the evolution and stability of optical systems, in this way, it offers a similitude with partially coherent processes where the coherence degree is now distributed between all the compounds of the resulting random vector. The matrix representation for the stochastic process allows incorporating entropy properties and the calculus of the purity for the optical field. This constitutes the basis to describe the interference between markovian modes. When the set of markovian modes type Ehrenfest reaches a stable configuration they become indistinguishability non-conservative optical field having associated hysteresis features. Computer simulations are presented.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA