Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
AIDS Care ; : 1-8, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38771971

RESUMEN

The federal Ending the HIV Epidemic (EHE) initiative was created to reduce new US HIV infections, largely through pre-exposure prophylaxis and HIV treatments that reduce HIV transmissibility to zero. Behavioral health disorders (mental health and substance use) remain significant barriers to achieving EHE goals. Addressing behavioral health (BH) disorders within HIV primary care settings has been promoted as a critical EHE strategy. Implementation of efficacious HIV-BH care integration and its impact on HIV-related health outcomes is not well documented. In a federally-funded, exploratory phase implementation science study, we used the Collective Impact Framework to engage partners in seven EHE jurisdictions about the feasibility, acceptability, and sustainability of implementing HIV-BH integration interventions within local HIV settings. Partners concluded that full integration will remain the exception unless health systems invest in collaborative practice, professional training, appropriate health technology, and inter-system communication. Partners supported smaller incremental improvements including transdiagnostic approaches to reinforce each team member's sense of value in the shared endeavor. This early phase implementation science study identified research and implementation gaps that are critical to fill to end the HIV epidemic. Both the Collective Impact Framework and implementation science show promise for guiding future implementation of evidence-based HIV-BH intervention integration.

2.
Arthroscopy ; 39(10): 2228-2230, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37716794

RESUMEN

It is a great challenge to analyze whether sex difference affects outcome of hip arthroscopy, because the indications, risk factors, and comorbidities are difficult to determine and may be heterogeneous between and within studies. For instance, mental health disorders, namely depression, are associated with worse outcomes following hip arthroscopy, and these disorders tend to be more prevalent in a female population. There are also known bony morphologic differences between men and women. Women tend to have a higher rate of borderline hip dysplasia defined by lateral center-edge angle between 18 and 25°. This is notable because long-term (10 year) survivorship of patients with this morphology undergoing hip arthroscopy is notably lower (79-82.2%) compared with patients undergoing hip arthroscopy without BHD (>90%). These gender differences, although notable within specific cohorts, are more difficult to tease out in large systematic reviews with all comers. In addition, many studies do not have longer-term follow-up required to assess conversion to THA. Perhaps hip arthroscopy outcomes are instead directly linked to independent bony morphologic, psychologic, and soft tissue-based risk factors that may have a gender bias.


Asunto(s)
Artroscopía , Luxación Congénita de la Cadera , Humanos , Femenino , Masculino , Sexismo , Factores de Riesgo
3.
J Hunger Environ Nutr ; 18(5): 651-660, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37727805

RESUMEN

We analyzed the prevalence of farm to school (FTS) programs in K-12 schools in four low-income, high-minority cities in New Jersey before and after implementation of the Healthy Hunger-Free Kids Act (HHFKA), between school years 2010-11 and 2017-18. Multivariable logistic regression was used to model FTS participation and the prevalence of FTS before versus after HHFKA initiation. Schools showed a significant positive trend in FTS participation (OR 1.18; p=.010) over the study period. Nonetheless, 20% of schools participated in FTS for 3+ years over the eight-year study period. Findings underscore the importance of federal legislation in supporting child nutrition initiatives.

4.
Sci Adv ; 8(37): eabq2611, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36103534

RESUMEN

DNA double-strand breaks occur in many acute and long-term neurological conditions, including neurodegeneration, neurotrauma, and stroke. Nonrepaired breaks chronically activate the DNA damage response in neurons, leading to neural dysfunction and apoptosis. Here, we show that targeting of the central ATM-Chk2 pathway regulating the response to double-strand breaks slows neural decline in Drosophila models of chronic neurodegeneration. Inhibitors of ATM-Chk2, but not the parallel ATR-Chk1 pathway, also promote marked, functional recovery after acute central nervous system injury in rats, suggesting that inhibiting nonhomologous end-joining rather than homologous recombination is crucial for neuroprotection. We demonstrate that the Chk2 inhibitor, prexasertib, which has been evaluated in phase 2 clinical trials for cancer, has potent neuroprotective effects and represents a new treatment option to promote functional recovery after spinal cord or optic nerve injury.


Asunto(s)
Daño del ADN , Neuroprotección , Animales , Axones , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Regeneración Nerviosa , Ratas
6.
Cells ; 10(8)2021 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-34440784

RESUMEN

CNS neurons are generally incapable of regenerating their axons after injury due to several intrinsic and extrinsic factors, including the presence of axon growth inhibitory molecules. One such potent inhibitor of CNS axon regeneration is Reticulon (RTN) 4 or Nogo-A. Here, we focused on RTN3 as its contribution to CNS axon regeneration is currently unknown. We found that RTN3 expression correlated with an axon regenerative phenotype in dorsal root ganglion neurons (DRGN) after injury to the dorsal columns, a well-characterised model of spinal cord injury. Overexpression of RTN3 promoted disinhibited DRGN neurite outgrowth in vitro and dorsal column axon regeneration/sprouting and electrophysiological, sensory and locomotor functional recovery after injury in vivo. Knockdown of protrudin, however, ablated RTN3-enhanced neurite outgrowth/axon regeneration in vitro and in vivo. Moreover, overexpression of RTN3 in a second model of CNS injury, the optic nerve crush injury model, enhanced retinal ganglion cell (RGC) survival, disinhibited neurite outgrowth in vitro and survival and axon regeneration in vivo, an effect that was also dependent on protrudin. These results demonstrate that RTN3 enhances neurite outgrowth/axon regeneration in a protrudin-dependent manner after both spinal cord and optic nerve injury.


Asunto(s)
Axones/metabolismo , Proteínas Portadoras/metabolismo , Ganglios Espinales/metabolismo , Regeneración Nerviosa , Proyección Neuronal , Traumatismos del Nervio Óptico/metabolismo , Células Ganglionares de la Retina/metabolismo , Traumatismos de la Médula Espinal/metabolismo , Animales , Axones/patología , Conducta Animal , Proteínas Portadoras/genética , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Ganglios Espinales/patología , Actividad Motora , Traumatismos del Nervio Óptico/genética , Traumatismos del Nervio Óptico/patología , Traumatismos del Nervio Óptico/fisiopatología , Ratas Sprague-Dawley , Células Ganglionares de la Retina/patología , Transducción de Señal , Traumatismos de la Médula Espinal/genética , Traumatismos de la Médula Espinal/patología , Traumatismos de la Médula Espinal/fisiopatología , Regulación hacia Arriba , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
7.
Vaccine ; 39(9): 1445-1451, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33541796

RESUMEN

OBJECTIVE: Vaccine stockouts are prevalent in Africa. Despite the importance of this as a barrier to universal vaccination coverage, rigorous studies looking at ways to reduce vaccine stockouts have been limited. We causally evaluated the effect of Vaccine Direct Delivery (VDD), an intervention to ensure the vaccine stock availability at health facilities, on the reduction of stockouts in Bauchi state, Nigeria. METHODS: Employing the interrupted time-series method, we evaluated the change in the occurrence of vaccine stockouts before and after the introduction of VDD in July 2015. We used health facility level data from January 2013 to December 2018 among 175 facilities in Bauchi state, collected through the District Health Information Software 2 (DHIS2) for monthly information on stockouts and stock balances in all the health facilities in Nigeria. Data were analyzed using Stata 15 SE. To validate the causal relationship between VDD and vaccine stockouts, we conducted two sets of robustness checks. First, we evaluated the effect of VDD on the stockouts of other commodities. Second, we compared the trend of the prevalence of vaccine stockouts among health facilities between Bauchi state where VDD was introduced and another state (Adamawa state) where VDD was never introduced. RESULTS: After the introduction of VDD, vaccine stockouts in Bauchi state decreased by 9 percentage points on average, and they have been decreasing monthly by 0.4 percentage points more than pre-VDD. In Adamawa state, where VDD was never introduced, the prevalence of vaccine stockouts did not change over time. In Bauchi state after VDD introduction, the stock balances of target vaccines all increased, and the number of vaccinations carried out increased in neighboring health facilities. CONCLUSIONS: VDD intervention resulted in a significant reduction of vaccine stockouts as well as in an increase in the number of vaccinations performed. However, we should consider how to improve the system to provide vaccination service to the population in a sustainable way.


Asunto(s)
Vacunas , Instituciones de Salud , Nigeria , Vacunación , Cobertura de Vacunación
8.
Front Artif Intell ; 4: 554017, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35187469

RESUMEN

It is currently estimated that 67% of malaria deaths occur in children under-five years (WHO, 2020). To improve the identification of children at clinical risk for malaria, the WHO developed community (iCCM) and clinic-based (IMCI) protocols for frontline health workers using paper-based forms or digital mobile health (mHealth) platforms. To investigate improving the accuracy of these point-of-care clinical risk assessment protocols for malaria in febrile children, we embedded a malaria rapid diagnostic test (mRDT) workflow into THINKMD's (IMCI) mHealth clinical risk assessment platform. This allowed us to perform a comparative analysis of THINKMD-generated malaria risk assessments with mRDT truth data to guide modification of THINKMD algorithms, as well as develop new supervised machine learning (ML) malaria risk algorithms. We utilized paired clinical data and malaria risk assessments acquired from over 555 children presenting to five health clinics in Kano, Nigeria to train ML algorithms to identify malaria cases using symptom and location data, as well as confirmatory mRDT results. Supervised ML random forest algorithms were generated using 80% of our field-based data as the ML training set and 20% to test our new ML logic. New ML-based malaria algorithms showed an increased sensitivity and specificity of 60 and 79%, and PPV and NPV of 76 and 65%, respectively over THINKD initial IMCI-based algorithms. These results demonstrate that combining mRDT "truth" data with digital mHealth platform clinical assessments and clinical data can improve identification of children with malaria/non-malaria attributable febrile illnesses.

9.
J Opt Soc Am A Opt Image Sci Vis ; 37(9): B93-B105, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32902426

RESUMEN

Metal powder bed fusion (PBF) methods need in-process measurement methods to increase user confidence and encourage further adoption in high-value manufacturing sectors. In this paper, a novel measurement method for PBF systems is proposed that uses multi-view fringe projection to acquire high-resolution surface topography information of the powder bed. Measurements were made using a mock-up of a commercial PBF system to assess the system's accuracy and precision in comparison to conventional single-view fringe projection techniques for the same application. Results show that the multi-view system is more accurate, but less precise, than single-view fringe projection on a point-by-point basis. The multi-view system also achieves a high degree of surface coverage by using alternate views to access areas not measured by a single camera.

10.
Res Sports Med ; 28(2): 217-230, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31257930

RESUMEN

Rates of concussion in soccer are high, especially in female players. The primary aim of this study was to examine differences in self-reported concussion-related symptoms (CRS), balance (BESS), and neurocognitive performance (ImPACT) following an acute bout of soccer heading in a group of female collegiate players with and without a history of concussion. Eighty-seven players with 0 to 3+ previous concussions participated. The measurement variables were assessed before and after heading sessions; including one linear and one rotational bout. Players with concussion histories reported more CRS than their non-concussed teammates both before and after the heading sessions. Balance and neurocognitive scores were generally unaffected. This finding should heighten our awareness to carefully monitor soccer players who have experienced concussions and be aware that they may develop concussion-like symptoms, especially after acute bouts of heading either during practice or in matches. The long-term implications of this finding remain unknown.


Asunto(s)
Traumatismos en Atletas/diagnóstico , Conmoción Encefálica/diagnóstico , Fútbol/lesiones , Adolescente , Femenino , Humanos , Pruebas Neuropsicológicas , Equilibrio Postural , Autoinforme , Encuestas y Cuestionarios , Adulto Joven
11.
Cells ; 8(12)2019 11 26.
Artículo en Inglés | MEDLINE | ID: mdl-31779177

RESUMEN

Closed-globe injury can cause visual loss in military and civilian populations, with retinal cell death, including retinal ganglion cell (RGC) degeneration, leading to irreversible blindness. RGC and optic nerve (ON) degeneration after eye or head injury is termed traumatic optic neuropathy (TON). There are currently no treatments for RGC loss, therefore novel therapeutics to prevent RGC death or promote axonal regeneration are a priority. We investigated necroptotic signaling mechanisms in a rat blunt ocular injury model. After bilateral blunt trauma, protein expression and retinal localization of necroptosis pathway members (receptor interacting protein kinase 1, RIPK1; receptor interacting protein kinase 3, RIPK3; and mixed lineage kinase domain like pseudokinase, MLKL) were assessed by Western blot and immunohistochemistry (IHC), and potent necroptosis inhibitor Necrostatin-1s (Nec-1s) was delivered by intravitreal injection to one eye and vehicle to the contralateral eye. RGC and photoreceptor survival were assessed by cell counting and outer nuclear layer (ONL) thickness measurements on histology. The neuroprotective effects of Nec-1s were assessed in primary retinal culture by ßIII-tubulin+ RGC cell counts. MLKL protein expression were upregulated at 48 h after injury and MLKL immunolocalised to retinal binding protein with multiple splice (RBPMS)+ RGC, inner nuclear cells and ONL cells, specifically at the retinal injury site. RIPK3 expression did not increase but RIPK3 co-immunolocalised with RBPMS+ RGC in intact and injured retinae. In vitro, a Nec-1s concentration of 0.01 pg/µL was RGC neuroprotective. In the blunt ocular injury rat model, Nec-1s prevented RGC death at the center of the impact site but did not protect against ONL thinning or provide functional restitution. RGC degeneration in our blunt ocular injury model is site-specific, with necroptosis driving death at the center of the focal impact site.


Asunto(s)
Lesiones Oculares/etiología , Lesiones Oculares/metabolismo , Necroptosis , Células Ganglionares de la Retina/metabolismo , Animales , Biomarcadores , Supervivencia Celular , Modelos Animales de Enfermedad , Lesiones Oculares/patología , Expresión Génica , Inmunohistoquímica , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Transporte de Proteínas , Ratas , Proteína Serina-Treonina Quinasas de Interacción con Receptores , Células Ganglionares de la Retina/patología , Heridas no Penetrantes
12.
Sensors (Basel) ; 19(19)2019 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-31623312

RESUMEN

Ocean colour is recognised as an Essential Climate Variable (ECV) by the Global Climate Observing System (GCOS); and spectrally-resolved water-leaving radiances (or remote-sensing reflectances) in the visible domain, and chlorophyll-a concentration are identified as required ECV products. Time series of the products at the global scale and at high spatial resolution, derived from ocean-colour data, are key to studying the dynamics of phytoplankton at seasonal and inter-annual scales; their role in marine biogeochemistry; the global carbon cycle; the modulation of how phytoplankton distribute solar-induced heat in the upper layers of the ocean; and the response of the marine ecosystem to climate variability and change. However, generating a long time series of these products from ocean-colour data is not a trivial task: algorithms that are best suited for climate studies have to be selected from a number that are available for atmospheric correction of the satellite signal and for retrieval of chlorophyll-a concentration; since satellites have a finite life span, data from multiple sensors have to be merged to create a single time series, and any uncorrected inter-sensor biases could introduce artefacts in the series, e.g., different sensors monitor radiances at different wavebands such that producing a consistent time series of reflectances is not straightforward. Another requirement is that the products have to be validated against in situ observations. Furthermore, the uncertainties in the products have to be quantified, ideally on a pixel-by-pixel basis, to facilitate applications and interpretations that are consistent with the quality of the data. This paper outlines an approach that was adopted for generating an ocean-colour time series for climate studies, using data from the MERIS (MEdium spectral Resolution Imaging Spectrometer) sensor of the European Space Agency; the SeaWiFS (Sea-viewing Wide-Field-of-view Sensor) and MODIS-Aqua (Moderate-resolution Imaging Spectroradiometer-Aqua) sensors from the National Aeronautics and Space Administration (USA); and VIIRS (Visible and Infrared Imaging Radiometer Suite) from the National Oceanic and Atmospheric Administration (USA). The time series now covers the period from late 1997 to end of 2018. To ensure that the products meet, as well as possible, the requirements of the user community, marine-ecosystem modellers, and remote-sensing scientists were consulted at the outset on their immediate and longer-term requirements as well as on their expectations of ocean-colour data for use in climate research. Taking the user requirements into account, a series of objective criteria were established, against which available algorithms for processing ocean-colour data were evaluated and ranked. The algorithms that performed best with respect to the climate user requirements were selected to process data from the satellite sensors. Remote-sensing reflectance data from MODIS-Aqua, MERIS, and VIIRS were band-shifted to match the wavebands of SeaWiFS. Overlapping data were used to correct for mean biases between sensors at every pixel. The remote-sensing reflectance data derived from the sensors were merged, and the selected in-water algorithm was applied to the merged data to generate maps of chlorophyll concentration, inherent optical properties at SeaWiFS wavelengths, and the diffuse attenuation coefficient at 490 nm. The merged products were validated against in situ observations. The uncertainties established on the basis of comparisons with in situ data were combined with an optical classification of the remote-sensing reflectance data using a fuzzy-logic approach, and were used to generate uncertainties (root mean square difference and bias) for each product at each pixel.

13.
J Ethnobiol Ethnomed ; 15(1): 40, 2019 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-31419986

RESUMEN

BACKGROUND: Traditional medicinal plants are still used today in many Aboriginal communities across Australia. Our research focused on the contemporary use of such plants in the two communities within the Tiwi Islands, Wurrumiyanga and Pirlangimpi. METHODS: This qualitative research project performed a video ethnography, community interviews, and a trial intervention to better understand the extent to which these plants are still used throughout the community and how they may be used more in the future. RESULTS: We found that several plants are still used predominantly as medicinal washes to treat skin disorders and/or as a tea to treat congestion associated with cold and flu. Those plants that are commonly used are found near to the community in large amounts and are recognized as being both safe and effective. CONCLUSIONS: Within the community, it is the elder women who remain most knowledgeable about these plants and continue to make them for their families. However, there are many families who no longer know how to make these traditional medicines though they express a desire to use them. Therefore, it would be beneficial to have a central location or method to produce traditional medicine for the community-a bush pharmacy.


Asunto(s)
Medicina Tradicional/métodos , Fitoterapia/métodos , Plantas Medicinales , Población Rural , Adulto , Anciano , Australia , Etnobotánica , Etnofarmacología/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nativos de Hawái y Otras Islas del Pacífico/estadística & datos numéricos , Investigación Cualitativa
14.
Invest Ophthalmol Vis Sci ; 60(5): 1748-1759, 2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-31022296

RESUMEN

Purpose: We investigate if the BMP4/Smad1 intracellular signaling pathway is neuroprotective and axogenic in adult rodent retinal ganglion cells (RGC) in vivo and in vitro. Methods: Adult retinal cultures were prepared from intact and after optic nerve crush (ONC) injured rats that have been stimulated to survive and regenerate using an intravitreal peripheral nerve (PN) graft. Laser capture microdissection (LCM) then was used to isolate RGC with and without neurites. Quantitative RT-PCR determined changes in BMP4/Smad1 signaling pathway mRNA. Immunohistochemistry confirmed localization of BMP4 and activation of Smad1 in ONC+PN-stimulated RGC in vivo. BMP4 peptide was used to stimulate RGC survival and neurite/axon regeneration in vitro and in vivo. Finally, the rapamycin sensitivity of the effects was determined in BMP4-stimulated RGC in vitro and in vivo. Results: In retinal cultures prepared from intact and ONC+PN-stimulated rats, RGC with neurites had upregulated regeneration-related and BMP4/Smad1 signaling pathway mRNA levels, while low levels of these mRNAs were present in RGC isolated without neurites. An optimal dose of 200 ng/mL BMP4 peptide in vitro promoted approximately 30% RGC survival and disinhibited RGC neurite outgrowth, despite the presence of inhibitory CNS myelin extracts. BMP4 also promoted approximately 30% RGC survival in vivo and stimulated significant RGC axon regeneration at 100, 200, and 400 µm beyond the lesion site. Finally, the response of RGC to BMP4 treatment in vitro and in vivo was rapamycin-insensitive. Conclusions: Activation of the BMP4/Smad1 pathway promotes survival and axon regeneration independent of mTOR and, therefore, may be of therapeutic interest.


Asunto(s)
Axones/fisiología , Proteína Morfogenética Ósea 4/metabolismo , Regeneración Nerviosa/fisiología , Células Ganglionares de la Retina/fisiología , Transducción de Señal/fisiología , Proteína Smad1/metabolismo , Animales , Proteína Morfogenética Ósea 4/farmacología , Supervivencia Celular/fisiología , Células Cultivadas , Femenino , Inmunohistoquímica , Compresión Nerviosa , Traumatismos del Nervio Óptico/fisiopatología , ARN Mensajero/genética , ARN Interferente Pequeño , Ratas , Ratas Endogámicas F344 , Ratas Sprague-Dawley , Reacción en Cadena en Tiempo Real de la Polimerasa , Serina-Treonina Quinasas TOR/metabolismo
15.
Brain Commun ; 1(1): fcz005, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32954257

RESUMEN

DNA double-strand breaks are a feature of many acute and long-term neurological disorders, including neurodegeneration, following neurotrauma and after stroke. Persistent activation of the DNA damage response in response to double-strand breaks contributes to neural dysfunction and pathology as it can force post-mitotic neurons to re-enter the cell cycle leading to senescence or apoptosis. Mature, non-dividing neurons may tolerate low levels of DNA damage, in which case muting the DNA damage response might be neuroprotective. Here, we show that attenuating the DNA damage response by targeting the meiotic recombination 11, Rad50, Nijmegen breakage syndrome 1 complex, which is involved in double-strand break recognition, is neuroprotective in three neurodegeneration models in Drosophila and prevents Aß1-42-induced loss of synapses in embryonic hippocampal neurons. Attenuating the DNA damage response after optic nerve injury is also neuroprotective to retinal ganglion cells and promotes dramatic regeneration of their neurites both in vitro and in vivo. Dorsal root ganglion neurons similarly regenerate when the DNA damage response is targeted in vitro and in vivo and this strategy also induces significant restoration of lost function after spinal cord injury. We conclude that muting the DNA damage response in the nervous system is neuroprotective in multiple neurological disorders. Our results point to new therapies to maintain or repair the nervous system.

16.
Micron ; 118: 43-49, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30583220

RESUMEN

It is well known that damage induced by impinging Ga+ ions during focused ion beam (FIB) milling of transmission electron microscopy (TEM) specimens can obfuscate subsequent TEM characterization, especially in the near-surface region of the TEM foil. Numerous strategies for minimizing this damage have been invoked, with the most common being the deposition of a Pt 'strap' at the area of interest. However, damage can still occur in the near-surface region during this Pt deposition step and the variation in the character and extent of this damage with applied Pt deposition parameter, especially in complex structural alloys, is not well characterized. In this study, the damage induced in an aerospace Al alloy (AA7075-T651) during five different Pt deposition protocols is examined using TEM. Results indicate significant variations in damage character and depth amongst the applied Pt deposition protocols, with damage being effectively eliminated using a combined electron-beam/ion-beam Pt deposition strategy. These experimental results are found to be in good agreement with Monte Carlo-based simulations of ion implantation and the implications of these findings on recent experiments in the fracture mechanics community are explored.

17.
PeerJ ; 6: e5814, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30386705

RESUMEN

BACKGROUND: Accurate time-energy budgets summarise an animal's energy expenditure in a given environment, and are potentially a sensitive indicator of how an animal responds to changing resources. Deriving accurate time-energy budgets requires an estimate of time spent in different activities and of the energetic cost of that activity. Bio-loggers (e.g., accelerometers) may provide a solution for monitoring animals such as fur seals that make long-duration foraging trips. Using low resolution to record behaviour may aid in the transmission of data, negating the need to recover the device. METHODS: This study used controlled captive experiments and previous energetic research to derive time-energy budgets of juvenile Australian fur seals (Arctocephalus pusillus) equipped with tri-axial accelerometers. First, captive fur seals and sea lions were equipped with accelerometers recording at high (20 Hz) and low (1 Hz) resolutions, and their behaviour recorded. Using this data, machine learning models were trained to recognise four states-foraging, grooming, travelling and resting. Next, the energetic cost of each behaviour, as a function of location (land or water), season and digestive state (pre- or post-prandial) was estimated. Then, diving and movement data were collected from nine wild juvenile fur seals wearing accelerometers recording at high- and low- resolutions. Models developed from captive seals were applied to accelerometry data from wild juvenile Australian fur seals and, finally, their time-energy budgets were reconstructed. RESULTS: Behaviour classification models built with low resolution (1 Hz) data correctly classified captive seal behaviours with very high accuracy (up to 90%) and recorded without interruption. Therefore, time-energy budgets of wild fur seals were constructed with these data. The reconstructed time-energy budgets revealed that juvenile fur seals expended the same amount of energy as adults of similar species. No significant differences in daily energy expenditure (DEE) were found across sex or season (winter or summer), but fur seals rested more when their energy expenditure was expected to be higher. Juvenile fur seals used behavioural compensatory techniques to conserve energy during activities that were expected to have high energetic outputs (such as diving). DISCUSSION: As low resolution accelerometry (1 Hz) was able to classify behaviour with very high accuracy, future studies may be able to transmit more data at a lower rate, reducing the need for tag recovery. Reconstructed time-energy budgets demonstrated that juvenile fur seals appear to expend the same amount of energy as their adult counterparts. Through pairing estimates of energy expenditure with behaviour this study demonstrates the potential to understand how fur seals expend energy, and where and how behavioural compensations are made to retain constant energy expenditure over a short (dive) and long (season) period.

18.
Rev Sci Instrum ; 89(10): 10I132, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30399820

RESUMEN

We recently developed a one-dimensional imager of neutrons on the Z facility. The instrument is designed for Magnetized Liner Inertial Fusion (MagLIF) experiments, which produce D-D neutrons yields of ∼3 × 1012. X-ray imaging indicates that the MagLIF stagnation region is a 10-mm long, ∼100-µm diameter column. The small radial extents and present yields precluded useful radial resolution, so a one-dimensional imager was developed. The imaging component is a 100-mm thick tungsten slit; a rolled-edge slit limits variations in the acceptance angle along the source. CR39 was chosen as a detector due to its negligible sensitivity to the bright x-ray environment in Z. A layer of high density poly-ethylene is used to enhance the sensitivity of CR39. We present data from fielding the instrument on Z, demonstrating reliable imaging and track densities consistent with diagnosed yields. For yields ∼3 × 1012, we obtain resolutions of ∼500 µm.

19.
Invest Ophthalmol Vis Sci ; 59(11): 4453-4462, 2018 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-30193318

RESUMEN

Purpose: Ocular trauma is common in civilian and military populations. Among other injuries, closed globe blunt ocular trauma causes acute disruption of photoreceptor outer segments (commotio retinae) and retinal ganglion cell (RGC) death (traumatic optic neuropathy [TON]), both of which permanently impair vision. Caspase-2-dependent cell death is important and evidenced in models of RGC degeneration. We assessed the role of caspase-2 as a mediator of RGC and photoreceptor death in a rat blunt ocular trauma model. Methods: Bilateral ballistic closed globe blunt ocular trauma was induced in female Lister-hooded rats and caspase-2 cleavage and localization assessed by Western blotting and immunohistochemistry. Retinal caspase-2 was knocked down by intravitreal injection of caspase-2 small interfering RNA (siCASP2). In retinal sections, RGC survival was assessed by BRN3A-positive cell counts and photoreceptor survival by outer nuclear layer (ONL) thickness, respectively. Retinal function was assessed by electroretinography (ERG). Results: Raised levels of cleaved caspase-2 were detected in the retina at 5, 24, and 48 hours after injury and localized to RGC but not photoreceptors. Small interfering RNA-mediated caspase-2 knockdown neuroprotected RGC around but not in the center of the injury site. In addition, caspase-2 knockdown increased the amplitude of the ERG photopic negative response (PhNR) at 2 weeks after injury. However, siCASP2 was not protective for photoreceptors, suggesting that photoreceptor degeneration in this model is not mediated by caspase-2. Conclusions: Caspase-2 mediates death in a proportion of RGC but not photoreceptors at the site of blunt ocular trauma. Thus, intravitreally delivered siCASP2 is a possible therapeutic for the effective treatment of RGC death to prevent TON.


Asunto(s)
Muerte Celular , Cisteína Endopeptidasas/fisiología , Lesiones Oculares/patología , Retina/lesiones , Células Ganglionares de la Retina/patología , Heridas no Penetrantes/patología , Animales , Western Blotting , Modelos Animales de Enfermedad , Electrorretinografía , Lesiones Oculares/enzimología , Femenino , Silenciador del Gen/fisiología , Proteínas Fluorescentes Verdes/metabolismo , Inmunohistoquímica , Inyecciones Intravítreas , Células Fotorreceptoras de Vertebrados/patología , ARN Interferente Pequeño/genética , Ratas , Retina/fisiopatología , Células Ganglionares de la Retina/enzimología , Heridas no Penetrantes/enzimología
20.
Vaccine ; 35(17): 2175-2182, 2017 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-28364927

RESUMEN

OBJECTIVE: As part of its vaccine supply chain redesign efforts, Kano state now pushes vaccines directly from 6 state stores to primary health centers equipped with solar refrigerators. Our objective is to describe preliminary results from the first 20months of Kano's direct vaccine delivery operations. METHODS: This is a retrospective review of Kano's direct vaccine delivery program. We analyzed trends in health facility vaccine stock levels, and examined the relationship between stock-out rates and each of cascade vaccine deliveries and timeliness of deliveries. Analysis of vaccination trends was based on administrative data from 27 sentinel health facilities. Costs for both the in-sourced and out-sourced approaches were estimated using a bottoms-up model-based approach. RESULTS: Overall stock adequacy increased from 54% in the first delivery cycle to 68% by cycle 33. Conversely, stock-out rates decreased from 41% to 10% over the same period. Similar trends were observed in the out-sourced and in-sourced programs. Stock-out rates rose incrementally with increasing number of cascade facilities, and delays in vaccine deliveries correlated strongly with stock-out rates. Recognizing that stock availability is one of many factors contributing to vaccinations, we nonetheless compared pre- and post- direct deliveries vaccinations in sentinel facilities, and found statistically significant upward trends for 4 out of 6 antigens. 1 antigen (measles) showed an upward trend that was not statistically significant. Hepatitis b vaccinations declined during the period. Overall, there appeared to be a one-year lag between commencement of direct deliveries and the increase in number of vaccinations. Weighted average cost per delivery is US$29.8 and cost per child immunized is US$0.7 per year. CONCLUSION: Direct vaccine delivery to health facilities in Kano, through a streamlined architecture, has resulted in decreased stock-outs and improved stock adequacy. Concurrent operation of insourced and outsourced programs has enabled Kano build in-house logistics capabilities.


Asunto(s)
Almacenaje de Medicamentos , Programas de Inmunización/organización & administración , Organización y Administración , Refrigeración/métodos , Vacunas/provisión & distribución , Humanos , Nigeria , Estudios Retrospectivos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...