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1.
Mar Environ Res ; 201: 106674, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39168086

RESUMEN

Oceans are increasingly crowded by anthropogenic activities yet the impact on Outer Continental Shelf (OCS) marine life remains largely unquantified. The MAPS (Marine Mammal Acoustic and Spatial Ecology) study of 2019 included passive acoustic and visual vessel surveys over the Mid-Atlantic OCS of the USA to address data gaps in winter/spring for deep-diving cetaceans, including sperm whales. Echolocation clicks were used to derive slant ranges to sperm whales for design- and model-based density estimates. Although more survey effort was realised in the spring, high densities of whales were identified in both winter and spring (10.46 and 8.89 per 1000 km2 respectively). The spring model-based abundance estimate of 1587 whales (CI 946-2663) was considered the most representative figure, in part due to lower coefficients of variation. Modelling suggested that high densities of whales were associated with warm core rings, eddies and edges. As OCS waters provide an important foraging habitat for North Atlantic sperm whales, appropriate mitigation is required to ensure commercial pressures to develop offshore energy do not negatively affect this endangered species.


Asunto(s)
Estaciones del Año , Cachalote , Animales , Cachalote/fisiología , Océano Atlántico , Acústica , Densidad de Población , Ecolocación/fisiología , Monitoreo del Ambiente/métodos , Ecosistema
2.
Opt Express ; 30(25): 45093-45109, 2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36522919

RESUMEN

Coupling quantum emitters and nanostructures, in particular cold atoms and optical waveguides, has recently raised a large interest due to unprecedented possibilities of engineering light-matter interactions. In this work, we propose a new type of periodic dielectric waveguide that provides strong interactions between atoms and guided photons with an unusual dispersion. We design an asymmetric comb waveguide that supports a slow mode with a quartic (instead of quadratic) dispersion and an electric field that extends far into the air cladding for an optimal interaction with atoms. We compute the optical trapping potential formed with two guided modes at frequencies detuned from the atomic transition. We show that cold Rubidium atoms can be trapped as close as 100 nm from the structure in a 1.3-mK-deep potential well. For atoms trapped at this position, the emission into guided photons is largely favored, with a beta factor as high as 0.88 and a radiative decay rate into the slow mode 10 times larger than the free-space decay rate. These figures of merit are obtained at a moderately low group velocity of c/50.

3.
Mar Policy ; 140: 105054, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35399704

RESUMEN

The human response to the COVID-19 pandemic set in motion an unprecedented shift in human activity with unknown long-term effects. The impacts in marine systems are expected to be highly dynamic at local and global scales. However, in comparison to terrestrial ecosystems, we are not well-prepared to document these changes in marine and coastal environments. The problems are two-fold: 1) manual and siloed data collection and processing, and 2) reliance on marine professionals for observation and analysis. These problems are relevant beyond the pandemic and are a barrier to understanding rapidly evolving blue economies, the impacts of climate change, and the many other changes our modern-day oceans are undergoing. The "Our Ocean in COVID-19″ project, which aims to track human-ocean interactions throughout the pandemic, uses the new eOceans platform (eOceans.app) to overcome these barriers. Working at local scales, a global network of ocean scientists and citizen scientists are collaborating to monitor the ocean in near real-time. The purpose of this paper is to bring this project to the attention of the marine conservation community, researchers, and the public wanting to track changes in their area. As our team continues to grow, this project will provide important baselines and temporal patterns for ocean conservation, policy, and innovation as society transitions towards a new normal. It may also provide a proof-of-concept for real-time, collaborative ocean monitoring that breaks down silos between academia, government, and at-sea stakeholders to create a stronger and more democratic blue economy with communities more resilient to ocean and global change.

4.
J Exp Biol ; 223(Pt 11)2020 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-32366692

RESUMEN

Whale sharks (Rhincodon typus) - the largest extant fish species - reside in tropical environments, making them an exception to the general rule that animal size increases with latitude. How this largest fish thrives in tropical environments that promote high metabolism but support less robust zooplankton communities has not been sufficiently explained. We used open-source inertial measurement units (IMU) to log 397 h of whale shark behavior in Yucatán, Mexico, at a site of both active feeding and intense wildlife tourism. Here we show that the strategies employed by whale sharks to compensate for the increased drag of an open mouth are similar to ram feeders five orders of magnitude smaller and one order of magnitude larger. Presumed feeding constituted 20% of the total time budget of four sharks, with individual feeding bouts lasting up to 11 consecutive hours. Compared with normal, sub-surface swimming, three sharks increased their stroke rate and amplitude while surface feeding, while one shark that fed at depth did not demonstrate a greatly increased energetic cost. Additionally, based on time-depth budgets, we estimate that aerial surveys of shark populations should consider including a correction factor of 3 to account for the proportion of daylight hours that sharks are not visible at the surface. With foraging bouts generally lasting several hours, interruptions to foraging during critical feeding periods may represent substantial energetic costs to these endangered species, and this study presents baseline data from which management decisions affecting tourist interactions with whale sharks may be made.


Asunto(s)
Tiburones , Natación , Animales , Especies en Peligro de Extinción , Masculino , México
5.
J Prev Alzheimers Dis ; 6(4): 228-231, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31686093

RESUMEN

The engineered fusion protein NPT088 targets amyloid in vitro and in animal models of Alzheimer's disease. Previous studies showed that NPT088 treatment reduced ß-amyloid plaque and tau aggregate loads in mouse disease models. Here, we present the results from an initial clinical study of NPT088 in patients with mild to moderate Alzheimer's disease. Patients were treated with 4 dose levels of NPT088 for 6 months to evaluate its safety and tolerability. Exploratory measurements included measurement of change in ß-amyloid plaque and tau burden utilizing Positron Emission Tomography imaging as well as measures of Alzheimer's disease symptoms. At endpoint NPT088 was generally safe and well-tolerated with the most prominent finding being infusion reactions in a minority of patients. No effect of NPT088 on brain plaques, tau aggregates or Alzheimer's disease symptoms was observed.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Encéfalo/diagnóstico por imagen , Placa Amiloide/diagnóstico por imagen , Proteínas Recombinantes de Fusión/uso terapéutico , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/psicología , Péptidos beta-Amiloides/metabolismo , Compuestos de Anilina , Bacteriófago M13/genética , Encéfalo/metabolismo , Relación Dosis-Respuesta a Droga , Glicoles de Etileno , Femenino , Humanos , Fragmentos Fc de Inmunoglobulinas/genética , Masculino , Persona de Mediana Edad , Placa Amiloide/metabolismo , Tomografía de Emisión de Positrones , Proteínas tau/metabolismo
6.
Phys Rev Lett ; 120(4): 043601, 2018 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-29437405

RESUMEN

We investigate the quantum entanglement of the three modes associated with the three-photon states obtained by triple-photon generation in a phase-matched third-order nonlinear optical interaction. Although the second-order processes have been extensively dealt with, there is no direct analogy between the second and third-order mechanisms. We show, for example, the absence of quantum entanglement between the quadratures of the three modes in the case of spontaneous parametric triple-photon generation. However, we show robust, seeding-dependent, genuine triple-photon entanglement in the fully seeded case.

7.
Opt Lett ; 41(24): 5628-5631, 2016 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-27973475

RESUMEN

We investigate the basic mechanism of nonlinear mode competition in two semiconductor-coupled nanocavities operating in the laser regime. For this, we study energy transfer between bonding (in-phase) and anti-bonding (out-of-phase) modes of the system formed by two strongly coupled photonic crystal nanolasers. We experimentally observe mode switching from the blue-detuned to the red-detuned mode as the pump power is increased. A semi-classical description in terms of mean-field equations allows us to explain this phenomenon as stimulated scattering due to carrier population oscillations in the cavities at the mode splitting frequency. We predict such asymmetrical mode interaction to be universal in arrays of optically coupled semiconductor micro and nanocavities.

8.
Handb Clin Neurol ; 139: 189-192, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27719838

RESUMEN

The name given to functional neurologic symptoms has evolved over time in the different editions of the International Classification of Diseases (ICD) and the Diagnostic and Statistical Manual of Mental Disorders (DSM), reflecting a gradual move away from an etiologic conception rooted in hysterical conversion to an empiric phenomenologic one, emphasizing the central role of the neurologic examination and testing in demonstrating that the symptoms are incompatible with recognized neurologic disease pathophysiology, or are internally inconsistent.


Asunto(s)
Trastornos de Conversión/clasificación , Enfermedades del Sistema Nervioso/clasificación , Enfermedades del Sistema Nervioso/psicología , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Humanos , Clasificación Internacional de Enfermedades
9.
Sleep Health ; 2(2): 167-174, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27525300

RESUMEN

OBJECTIVES: We conducted a pilot study of a sleep health promotion program for college students. The aims of the study were to 1) determine the feasibility of the program, and 2) explore changes in sleep knowledge and sleep diary parameters. DESIGN: Open trial of a sleep health promotion program for college students. SETTING: A small liberal arts university in southwestern Pennsylvania. PARTICIPANTS: University students (primarily female). INTERVENTION: Active intervention components included individualized email feedback based on each participant's baseline sleep diary and an in-person, group format presentation on sleep health. MEASUREMENTS: Participants completed online questionnaires and sleep diaries before and after the health promotion intervention. Online questionnaires focused on sleep knowledge and attitudes toward sleep, as well as Patient Reported Outcomes Measurement Information System (PROMIS) sleep and psychosocial assessments. RESULTS: Of participants who completed some aspect of the study, 89% completed at least one intervention component (in-person lecture and/or sleep diary). Participants reported significant improvement in sleep knowledge and changes in sleep diary parameters (decreased sleep onset latency and time spent in bed, resulting in greater sleep efficiency). Sleep duration also increased by 30 minutes among short sleepers who obtained <7 hours sleep at baseline. CONCLUSIONS: Preliminary evaluation of a brief program to promote sleep health suggests that it is feasible and acceptable to implement, and that it can favorably alter sleep knowledge and behaviors reported on the sleep diary in college students. Controlled trials are warranted.

10.
Opt Express ; 22(10): 12359-68, 2014 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-24921354

RESUMEN

We demonstrate a large tuning of the coupling strength in Photonic Crystal molecules without changing the inter-cavity distance. The key element for the design is the "photonic barrier engineering", where the "potential barrier" is formed by the air-holes in between the two cavities. This consists in changing the hole radius of the central row in the barrier. As a result we show, both numerically and experimentally, that the wavelength splitting in two evanescently-coupled Photonic Crystal L3 cavities (three holes missing in the ΓK direction of the underlying triangular lattice) can be continuously controlled up to 5× the initial value upon ∼ 30% of hole-size modification in the barrier. Moreover, the sign of the splitting can be reversed in such a way that the fundamental mode can be either the symmetric or the anti-symmetric one without altering neither the cavity geometry nor the inter-cavity distance. Coupling sign inversion is explained in the framework of a Fabry-Perot model with underlying propagating Bloch modes in coupled W1 waveguides.

11.
Opt Express ; 21(13): 15144-54, 2013 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-23842301

RESUMEN

We present a coupler design allowing normally-incident light coupling from free-space into a monomode photonic crystal waveguide operating in the slow-light regime. Numerical three-dimensional calculations show that extraction efficiencies as high as 80% can be achieved for very large group indices up to 100. We demonstrate experimentally the device feasibility by coupling and extracting light from a photonic crystal waveguide over a large group-index range (from 10 to 60). The measurements are in good agreement with theoretical predictions. We also study numerically the impact of various geometrical parameters on the coupler performances.

12.
Opt Express ; 20(24): 27403-10, 2012 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-23187597

RESUMEN

We start from a 2D photonic crystal nanocavity with moderate Q-factor and dynamically increase it by two order of magnitude by the joint action of coherent population oscillations and nonlinear refractive index.


Asunto(s)
Simulación por Computador , Luz , Nanotecnología/instrumentación , Dispositivos Ópticos , Fotones , Refractometría/instrumentación , Dispersión de Radiación , Diseño Asistido por Computadora , Cristalización , Diseño de Equipo , Dinámicas no Lineales
13.
Opt Express ; 20(17): 18876-86, 2012 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-23038527

RESUMEN

We report on far-field measurements of L3 photonic crystal (PhC) cavities with high quality beaming. This is achieved by means of the so-called "band folding" technique, in which a modulation of the radius of specific holes surrounding the cavity is introduced. Far-field patterns are measured from photoluminescence of quantum wells embedded in the PhC. A very good agreement between experimental results and simulated radiation patterns has been found. Laser effect is demonstrated in the beaming cavity with a threshold comparable to the regular one. In addition, free-space input coupling to this cavity has been achieved. In order to fully analyze the coupling efficiency, we generalize the approach developed in S. Fan, et al., [J. Opt. Soc. Am. A 20, 569 (2003)], relaxing the hypothesis of mirror symmetry. The obtained coupling efficiencies are about 15% with quality factors (Q) exceeding 10(4). These results further validate the "folding" technique on L3 cavities for nanocavity realization with efficient free-space coupling and high Q factors.


Asunto(s)
Nanoestructuras/química , Nanotecnología/instrumentación , Resonancia por Plasmón de Superficie/instrumentación , Transductores , Diseño Asistido por Computadora , Cristalización , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Dispersión de Radiación
14.
Phys Rev Lett ; 109(11): 113903, 2012 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-23005630

RESUMEN

Slow light induced by coherent population oscillations and cavity dispersive nonlinear response are combined achieving 2 orders of magnitude enhancement of the group delay and an equivalent decreasing of the spectral linewidth of a L3 two-dimensional photonic crystal nanocavity.

15.
J Affect Disord ; 141(2-3): 484-7, 2012 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-22578889

RESUMEN

BACKGROUND: The pathways to increased cardiovascular risk in bipolar disorder include health behaviors, psychosocial stress and long-term medication exposure. However, the evidence that the association between cardiovascular risk factors and bipolar disorder remains significant after controlling for these co-factors suggests that additional important risk factors have yet to be identified. Our hypothesis is that disturbances in the sleep-wake cycle are an important and under-recognized pathway through which affective disorders lead to increased cardiovascular risk. METHODS: In patients with bipolar disorder type 1 in clinical remission, we: 1) explored whether sleep disturbance predicted the endorsement of NCEP ATP-III criteria for dyslipidemia, independent of other lifestyle factors and 2) tested the association between low HDL (NCEP-ATP III) and sleep duration measured with actigraphy over an eight-day period. RESULTS: Median sleep duration is significantly associated with low HDL. The risk of having low HDL increases by 1.23 with every 30 minutes of reduced sleep time. LIMITATIONS: Since sleep patterns in patients with bipolar disorder are variable and irregular, it is possible that other sleep characteristics, not present during the span of our study, or the variability itself may be what drives the increased cardiovascular risk. CONCLUSIONS: Sleep characteristics of patients with bipolar disorder in clinical remission are associated with cardiovascular risk. More specifically, sleep duration was associated with low HDL. Clinicians should pay special attention to sleep hygiene in treating individuals with bipolar disorder, even when they are in clinical remission.


Asunto(s)
Trastorno Bipolar/etiología , Dislipidemias/complicaciones , Trastornos del Sueño-Vigilia/complicaciones , Actigrafía , Adulto , Anciano , Trastorno Bipolar/terapia , Enfermedades Cardiovasculares/etiología , HDL-Colesterol/sangre , HDL-Colesterol/deficiencia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inducción de Remisión , Factores de Riesgo , Sueño/fisiología , Factores de Tiempo
16.
Opt Lett ; 37(3): 289-91, 2012 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-22297328

RESUMEN

Phase-matched third-harmonic generation is demonstrated in a germanium-doped optical fiber. Green light at 514.4 nm is generated in an LP(03) mode when a pump field at ~1543.3 nm is launched into the fiber in the fundamental LP(01) mode. The phase matching is achieved for a particular combination of the germanium doping concentration and the fiber core diameter.

17.
Psychol Med ; 42(4): 865-73, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21861951

RESUMEN

BACKGROUND: One aim of personalized medicine is to determine which treatment is to be preferred for an individual patient, given all patient information available. Particularly in mental health, however, there is a lack of a single objective, reliable measure of outcome that is sensitive to crucial individual differences among patients. METHOD: We examined the feasibility of quantifying the total clinical value provided by a treatment (measured by both harms and benefits) in a single metric. An expert panel was asked to compare 100 pairs of patients, one from each treatment group, who had participated in a randomized clinical trial (RCT) involving interpersonal psychotherapy (IPT) and escitalopram, selecting the patient with the preferred outcome considering both benefits and harms. RESULTS: From these results, an integrated preference score (IPS) was derived, such that the differences between any two patients' IPSs would predict the clinicians' preferences. This IPS was then computed for all patients in the RCT. A second set of 100 pairs was rated by the panel. Their preferences were highly correlated with the IPS differences (r=0.84). Finally, the IPS was used as the outcome measure comparing IPT and escitalopram. The 95% confidence interval (CI) for the effect size comparing treatments indicated clinical equivalence of the treatments. CONCLUSIONS: A metric that combines benefits and harms of treatments could increase the value of RCTs by making clearer which treatments are preferable and, ultimately, for whom. Such methods result in more precise estimation of effect sizes, without increasing the required sample size.


Asunto(s)
Modelos Estadísticos , Evaluación de Resultado en la Atención de Salud/métodos , Medicina de Precisión , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Adulto , Antidepresivos de Segunda Generación/uso terapéutico , Citalopram/uso terapéutico , Intervalos de Confianza , Interpretación Estadística de Datos , Trastorno Depresivo/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Psicoterapia , Equivalencia Terapéutica
18.
Opt Lett ; 36(15): 3000-2, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21808385

RESUMEN

In this Letter we study spontaneous generation of triple photon states in optical fibers by third order spontaneous downconversion. Using a semiclassical approach we derive an explicit expression for the triple photons generation efficiency as a function of fiber parameters. We show that optical fibers with well suited index profiles and standard outer diameters could be the key component of future triple photons sources.

19.
Opt Express ; 18(25): 25642-8, 2010 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-21164910

RESUMEN

Slow light propagation is demonstrated by implementing Coherent Population Oscillations in a silica fiber doped with erbium ions in a ring surrounding the single mode core. Though only the wings of the mode interact with erbium ions, group velocities around 1360 m/s are obtained without any spatial distortion of the propagating mode.


Asunto(s)
Tecnología de Fibra Óptica , Láseres de Estado Sólido , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Dispersión de Radiación
20.
Opt Express ; 18(4): 3693-9, 2010 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-20389379

RESUMEN

We demonstrate an easy-to-implement scheme for fluorescence enhancement and observation volume reduction using photonic crystals (PhCs) as substrates for microscopy. By normal incidence coupling to slow 2D-PhC guided modes, a 65 fold enhancement in the excitation is achieved in the near field region (100 nm deep and 1 microm wide) of the resonant mode. Such large enhancement together with the high spatial resolution makes this device an excellent substrate for fluorescence microscopies.


Asunto(s)
Medios de Contraste/química , Cristalización/métodos , Colorantes Fluorescentes/química , Aumento de la Imagen/métodos , Microscopía Fluorescente/métodos , Medios de Contraste/análisis , Colorantes Fluorescentes/análisis , Propiedades de Superficie
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