Full-Service MAC Protocol for Metro-Reach GPONs

“This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”An advanced medium access control protocol is presented demonstrating dynamic bandwidth allocation for long-reach gigabit-capable passive optical networks (GPONs). The protocol enables the optical line terminal to overlap the idle time slots in each packet transmission cycle with a virtual polling cycle to increase the effective transmission bandwidth. Contrasting the new scheme with developed algorithms, network modeling has exhibited significant improvement in channel throughput, mean packet delay, and packet loss rate in the presence of class-of-service and service-level differentiation. In particular, the displayed 34% increase in the overall channel throughput and 30 times reduction in mean packet delay for service-level 1 and service-level 2 optical network units (ONUs) at accustomed 50% ONU load constitutes the highest extended-reach GPON performance reported up to date.Peer reviewe

Access to livelihood assets among youth with and without disabilities in South Africa: Implications for health professional education

Purpose. This study compared access to 5 livelihood assets among disabled and non-disabled youth, to inform health professionals on inequities related to disability and to monitor the transformation agenda aimed at creating an inclusive society. Methods. Fieldworkers interviewed 989 youth (18 - 35 years; 523 (52.9%) disabled youth (DY), 466 (47.1%) non-disabled youth (NDY)) at 9 sites in 5 South African provinces. Descriptive statistics were used to describe demographic characteristics and livelihood assets. Chi-squared and t-tests were used for comparisons. Results. Doctors at hospitals and nurses at clinics are health professionals most frequently seen. Far fewer DY than NDY attended and completed school. Unemployment was markedly more common among DY than among NDY. Barriers to accessing employment for DY were poor health and lack of skills development, and a lack of job opportunities for NDY. Both groups received the same amount of support from immediate household members, but significantly more NDY received support from extended family, friends, partners, and neighbours. They spent significantly more time engaging in all free-time activities. NDY reported more access to bathrooms, phone, and newspapers, as well as public services and the business sector. Participation and access were limited for both groups because of inaccessible public transport. Conclusion. This paper shows that DY have a greater struggle to access livelihood assets than non-disabled peers. The Disability Studies Academic Programme at the University of Cape Town is an initiative that seeks to take specific focused action with disability organisations in order to address the inequities faced by disabled youth to ensure their inclusion in development to the same degree as their non-disabled peers

Stripe order at low temperatures in La{2-x}Sr{x}NiO4 for 1/3 < x < 1/2

Stripe order in La{2-x}Sr{x}NiO4 beyond x = 1/3 was studied with neutron scattering technique. At low temperatures, all the samples exhibit hole stripe order. Incommensurability \epsilon of the stripe order is approximately linear in the hole concentration n_h = x + 2\delta up to x = 1/2, where \delta denotes the off-stoichiometry of oxygen atoms. The charge and spin ordering temperatures exhibit maxima at n_h = 1/3, and both decrease beyond n_h > 1/3. For 1/3 < n_h < 1/2, the stripe ordering consists of the mixture of the \epsilon = 1/3 stripe order and the n_h = 1/2 charge/spin order.Comment: REVTeX, 4 pages, 4 figure

Composición de ácidos grasos, fitoquímicos y potencial antioxidante de las semillas de Capparis spinosa

The present study evaluates the contents in bioactive compounds, antioxidant activity, oil content and fatty acid composition of&nbsp;Capparis spinosa&nbsp;seeds. Samples were collected from 5 different habitats (AH: Ahar; KU: Kurdistan; U1, U2 and U3: Urmia) in Iran. The oil content in the seeds ranged from 16 to 27%. The predominant fatty acid was linoleic acid (45-50%) followed by oleic acid (30-39%), palmitic acid (2-8%) and stearic acid (2-3%). Total phenolic content (TPC) varied from 16.3 to 24.2 mg GAE/ g DW; total flavonoid content (TFC) ranged from 1.48 to 3.05 mg QE/g DW; and the antioxidant activity (DPPH assay) of the seeds was between 35 and 63%. The compounds obtained from different genotypes of&nbsp;C. spinosa&nbsp;seeds had different compositions, great antioxidant capacity and unsaturated fatty acids, and therefore could be a prospective source of natural bioactive molecules for the food and health industry.El presente estudio evaluó el contenido de compuestos bioactivos, actividad antioxidante, contenido de aceite y composición de ácidos grasos de las semillas de&nbsp;C. spinosa. Se recolectaron muestras de cinco hábitats diferentes (AH: Ahar; KU: Kurdistán; U1, U2 y U3: Urmia) en Irán. El contenido de aceite de las semillas osciló entre el 15,66 y el 27,50%. El ácido graso predominante fue el ácido linoleico (45-50%) seguido por el oleico (30-39%), el palmítico (2-8%) y el esteárico (2-3%). El contenido fenólico total varió de 16,3 a 24,2 mg GAE/g DW; el contenido total de flavonoides entre 1,48 y 3,05 mg QE/g DW; la actividad antioxidante de las semillas estuvo entre 34,68 y 62,74%. Los compuestos obtenidos de semillas de&nbsp;C. spinosa&nbsp;tienen gran capacidad antioxidante y ácidos grasos insaturados, por lo que podrían ser una fuente de moléculas bioactivas naturales en la industria alimentaria y de la salud

Las bibliotecas de los hospitales públicos en España. Un análisis económico

ResumenIntroducciónEn el campo de la salud, el constante aumento de la producción científica, el desarrollo de nuevas tecnologías y el incremento en los costes de las publicaciones hacen a las bibliotecas fundamentales en la asistencia, docencia e investigación. En España se perciben deficiencias en las bibliotecas hospitalarias y se desconoce su coste. Por ello, este trabajo analizar el coste de las bibliotecas de hospitales públicos en España y estima el coste de adaptación a estándares internacionales.MétodosEstudio transversal mediante encuesta dirigida a las bibliotecas de los hospitales públicos mayores de 100 camas, o menores con acreditación docente. La información sobre las variables de interés fue recogida mediante un cuestionario enviado a las bibliotecas por correo con seguimiento telefónico. La recogida de datos finalizó en 1996. La información sobre costes se refiere al año 1994. Para examinar el efecto de la imprecisión en las estimaciones y asunciones se realizó un análisis de sensibilidad.ResultadosSe identificaron 314 hospitales, de los cuales 211 (67,2%) tienen biblioteca. El coste de las 211 bibliotecas fue de 3.060 millones de pesetas (coste medio: 14,5 millones de pesetas). Los costes de personal son la partida más importante (38% del total) seguidos del coste de suscripciones (29%). El coste de las bibliotecas hospitalarias supuso el 0,08% del gasto sanitario público nacional. Corregir las infradotaciones, según estándares internacionales, supondría unos 400 millones de pesetas adicionales el primer año (0,01% del gasto sanitario público).ConclusionesEl coste de las bibliotecas hospitalarias supone una pequeña fracción del gasto sanitario público. La corrección de las deficiencias observadas y la relevancia de las bibliotecas en el sistema sanitario requerirían incrementar el gasto hasta casi el 0,1% del gasto sanitario público.SummaryBackgroundThe continuous increase in scientific knowledge in the health field, the development of new technologies and the rising cost of publications means that libraries are essential for patient care, medical education and research. In Spain some deficiencies have been seen in hospital libraries, and their cost is unknown.ObjectiveTo analyze the cost of public hospital libraries in Spain and to estimate the cost of adapting them to international standards.MethodsCross-sectional survey of public hospitals larger than 100 beds, or smaller public hospitals with teaching accreditation. Information on the variables of interest was collected by questionnaire mailed to the libraries and followed up by telephone. Data collection was completed in 1996. The information on costs is for 1994. A sensitivity analysis was done to examine the effects of imprecise estimates and assumptions.ResultsOf the 314 hospitals identified, 211 (67.2%) had libraries. The 1994 cost of the of the 211 libraries was 3,060 million pesetas (mean cost: 14.5 million pesetas). Personnel costs were the most important item (38% of the total), followed by the cost of subscriptions (29%). The cost of hospital libraries represented 0.08% of national public expenditures on health. The cost of correcting inadequacies in accordance with international standards would increase spending by about 400 million pesetas the first year (0.01% of public spending on health).ConclusionsThe cost of hospital libraries represents only a small fraction of public spending on health. Correction of the observed deficiencies and the importance of libraries in the health system would require increasing spending to about 0.1% of public spending on health

Assessment of the corneal collagen organization after chemical burn using second harmonic generation microscopy

The organization of the corneal stoma is modified due to different factors, including pathology, surgery or external damage. Here the changes in the organization of the corneal collagen fibers during natural healing after chemical burn are investigated using second harmonic generation (SHG) imaging. Moreover, the structure tensor (ST) was used as an objective tool for morphological analyses at different time points after burn (up to 6 months). Unlike control corneas that showed a regular distribution, the collagen pattern at 1 month of burn presented a non-organized arrangement. SHG signal levels noticeably decreased and individual fibers were hardly visible. Over time, the healing process led to a progressive re-organization of the fibers that could be quantified through the ST. At 6 months, the stroma distribution reached values similar to those of control eyes and a dominant direction of the fibers re-appeared. The present results show that SHG microscopy imaging combined with the ST method is able to objectively monitor the temporal regeneration of the corneal organization after chemical burn. Future implementations of this approach into clinically adapted devices would help to diagnose and quantify corneal changes, not only due to chemical damages, but also as a result of disease or surgical procedures

Standardized Precipitation Index (SPI) evolution over the Iberian Peninsula during the 21st century

Droughts are important natural hazards that occur worldwide and can have severe and long-lasting impacts on humans and ecosystems. These phenomena are usually quantified by means of the so-called drought indices, which are indirect indicators based on climatic information. The Standardized Precipitation Index (SPI) is one of the most widely used indexes and this study attempts to characterize the occurrence and spatial variability of this index in the Iberian Peninsula (IP) over the 21st century. The SPI was calculated at two time scales (3 and 12 months), using simulations from the EURO-CORDEX project under two future scenarios (Representative Concentration Pathway (RCP) 4.5 and RCP 8.5) to analyze meteorological and hydrological droughts. Meteorological droughts (SPI-3) are expected to be less frequent but more intense and durable in the eastern IP, intensifying throughout the century and for the RCP 8.5 scenario. In the first decades of the 21st century, hydrological droughts (SPI-12) are projected to be more common and severe in the northwestern region of the IP for the RCP 4.5, and less frequent but more lasting in the other regions of IP for the RCP 8.5. As the century passes, the drought frequency and intensity experience a decrease in the RCP 4.5 scenario, and a slight increase in the RCP 8.5 scenario.Xunta de Galicia | Ref. ED431C 2021/44Fundação para a Ciência e a Tecnologia | Ref. SFRH/BD/138755/2018Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Fundação para a Ciência e a Tecnologia | Ref. LA/P/0094/202

Effect of high pressure processing temperature on dry-cured hams with different textural characteristics

High pressure processing is mainly used to eliminate pathogenic microorganisms and extend the shelf-life of dry-cured hams, but it also modifies its texture. These changes might be different depending on the initial textural characteristics. In this study, texture, colour and colour stability were evaluated after pressurization at 600 MPa during 6 min at 7 ºC, 20 ºC and 35 ºC in samples with different textural characteristics (no pastiness, medium and high pastiness groups). HP treatments produced an increase of hardness (F0) and lightness (L*) values and a decrease of softness/pastiness (Y2 and Y90) and redness (a*) values at any processing temperatures. However, the increase of F0 and L* values was more pronounced in non–pasty samples. In samples with high pastiness and softness, HP processing at high temperature (35ºC) reduced the intensity of pastiness. However, texture of hams with non-pasty texture might be negatively affected. Therefore, the optimal temperature of HP processing depends on the textural characteristics of dry-cured hams.info:eu-repo/semantics/acceptedVersio

Age and growth of black seabream Spondyliosoma cantharus (Linnaeus, 1758) (Sparidae) off the Canary Islands

The authors determined the age and growth of black seabream Spondyliosoma cantharus (Linnaeus, 1758) caught off the Canary Islands, using the otolith interpretation method. Annual rings are clear in the otolith cross-sections. Two rings, one associated with fast-growing periods (summer) and the other with slow-growing periods (winter) are deposited each year on the otoliths. The specimens ranged from 9.4 cm - 38.6 cm in total length, with ages of 0-9 years. Individuals grew quickly until the third year of life, at which they had reached more than 50 % of their maximum length. The Von Bertalanffy growth curve parameters were: L∞ = 44.09 cm, K = 0.23 year⁻¹, and t0 = -0.34 years. The growth found for this sample of black seabream is very similar to that reported for the species in other regions.Se determinan la edad y el crecimiento de la chopa Spondyliosoma cantharus (Linnaeus, 1758) de las islas Canarias por interpretación de los anillos visibles en los otolitos. Los anillos de crecimiento anuales se observan con claridad en las secciones transversales de los otolitos. Cada año se forman dos anillos, uno de crecimiento rápido en los meses de verano y otro de crecimiento lento durante el periodo invernal. Los ejemplares, de tallas que oscilan desde 9,4 hasta 38,6 cm de longitud total, presentan edades comprendidas entre 0 y 9 años. El crecimiento de los individuos es rápido durante los primeros años de vida, alcanzando al tercero más de la mitad de su talla máxima. Los parámetros de la curva de crecimiento de Von Bertanlanffy son: L∞ = 44,09 cm, K = 0,23 años⁻¹ y t0 = -0,34 años. El crecimiento de la chopa en las islas Canarias es similar al observado para la misma especie en otras regiones.Instituto Español de Oceanografí

Application of temperature and ultrasound as corrective measures to decrease the adhesiveness in dry-cured ham. Influence on free amino acid and volatile compound profile

The impact of low temperature treatment and its combination with ultrasound has been evaluated in order to correct texture defects in dry-cured hams. A total of 26 dry-cured hams, classified as high proteolysis index (PI>36%), were used. From these hams, ten slices from each ham sample were cut, vacuum packed and submitted to three different treatments: control (without treatment), conventional thermal treatments (CV) and thermal treatment assisted by power ultrasound (US). The impact of these treatments on instrumental adhesiveness, free amino acid and volatile compounds profile were assessed. Statistical analysis showed that both US and CV treatments, significantly (P < .001) decreased the instrumental adhesiveness of dry-cured hams from 85.27 g for CO to 40.59 and 38.68 g for US and CV groups, respectively. The total free amino acid content was significantly (P < .001) affected by both treatments, presenting higher values the samples from the US group (6691.5 vs. 6067.5 vs. 5278.2 mg/100 g dry matter for US, CV and CO groups, respectively). No significant differences were observed between US and CV treatments. All the individual free amino acids were influenced by ultrasound and temperature treatments, showing the highest content in sliced dry-cured ham submitted to ultrasounds at 50 °C, except for isoleucine which presented the highest level in samples from CV group. Similarly, significant differences (P < .05) were also detected in the total volatile compound content between CO and US groups, with a higher concentration in the CO batch (56,662.84 AU × 103/g of dry-cured ham) than in the US treatment (45,848.47 AU × 103/g of dry-cured ham), being the values in the CV treatment intermediate (48,497.25 AU × 103/g of dry-cured ham). Aldehydes, ethers and esters, carboxylic acids and sulphur compounds were more abundant in the CO group, while CV group showed higher concentrations of ketones, alcohols and nitrogen compounds.info:eu-repo/semantics/acceptedVersio