330 research outputs found
Utilisation of intensive foraging zones by female Australian fur seals.
Within a heterogeneous environment, animals must efficiently locate and utilise foraging patches. One way animals can achieve this is by increasing residency times in areas where foraging success is highest (area-restricted search). For air-breathing diving predators, increased patch residency times can be achieved by altering both surface movements and diving patterns. The current study aimed to spatially identify the areas where female Australian fur seals allocated the most foraging effort, while simultaneously determining the behavioural changes that occur when they increase their foraging intensity. To achieve this, foraging behaviour was successfully recorded with a FastLoc GPS logger and dive behaviour recorder from 29 individual females provisioning pups. Females travelled an average of 118 ± 50 km from their colony during foraging trips that lasted 7.3 ± 3.4 days. Comparison of two methods for calculating foraging intensity (first-passage time and first-passage time modified to include diving behaviour) determined that, due to extended surface intervals where individuals did not travel, inclusion of diving behaviour into foraging analyses was important for this species. Foraging intensity 'hot spots' were found to exist in a mosaic of patches within the Bass Basin, primarily to the south-west of the colony. However, the composition of benthic habitat being targeted remains unclear. When increasing their foraging intensity, individuals tended to perform dives around 148 s or greater, with descent/ascent rates of approximately 1.9 m•s-1 or greater and reduced postdive durations. This suggests individuals were maximising their time within the benthic foraging zone. Furthermore, individuals increased tortuosity and decreased travel speeds while at the surface to maximise their time within a foraging location. These results suggest Australian fur seals will modify both surface movements and diving behaviour to maximise their time within a foraging patch
Comparison of De-embedding Methods for Long Millimeter and Sub-Millimeter-Wave Integrated Circuits
National audienceThis paper compares several de-embedding methods over millimeter and sub-millimeter wave frequen-cies in integrated technology. These methods are compared for S-CPW transmission lines considered as device under test. From these comparisons we propose an effective way to de-embed transmission lines. A method called "Half-Thru de-embedding method" is especially discussed. The SCPW transmission line model and results are obtained from Ansys HFSS Simulations in BiCMOS 55-nm integrat-ed technology
Design and characterization of a signal insulation coreless transformer integrated in a CMOS gate driver chip
International audienceWith the development of multi-level, multiphase or network converters requiring the implementation of numerous distinct power transistor gate drivers, the control signal insulation is becoming more and more important in power converters. This paper presents an isolation technique based on a coreless transformer integrated in a CMOS silicon die together with the gate driver and other required functions. The associated demodulation circuit will also be presented, as the control signal must be modulated at a high frequency through the coreless transformer. The chosen design methodology will be explained and experimental results will be shown in order to validate the functionality
Etude et réalisation de réseaux d'adaptation d'impédances accordables linéaires et non linéaires, sur PCB et silicium CMOS, pour des applications en radiofréquences
L objectif de ce travail est d aborder la conception de réseaux d adaptation d impédance accordable (RAA) dans deux contextes bien distincts en radiofréquences : le RAA en faible signal et le RAA en fort signal.Concernant les aspects faible signal, des critères de performance de RAA ont été établis et étudiés. Une nouvelle expression générale de l efficacité d un RAA a été développée. Elle permet de prédire le rendement d un RAA à partir des facteurs de qualité des composants dont on dispose dans une technologie donnée et du rapport de transformation à réaliser. Des abaques de couverture d impédances en fonction des pertes d insertion ont été calculés. Ils mettent en évidence les régions de couverture où le RAA apporte une amélioration à la performance du système, pour diverses topologies de RAA.Un démonstrateur sur PCB a été réalisé. Il est constitué de deux RAA, qui assurent l adaptation simultanée d un amplificateur de puissance sur une large plage d impédances, comprises dans un cercle de l abaque de Smith d équation VSWR < 5 :1. La zone de couverture a été mesurée et présentée en fonction des pertes d insertion, qui mettent en évidence les régions où les RAA contribuent à l amélioration de la performance de l amplificateur et celles où les pertes d insertion du RAA n arrivent pas à compenser le gain du à la réduction des coefficients de réflexion.Dans une seconde partie, la conception de RAA en fort signal a été traitée. L objectif a été de présenter à la sortie d un amplificateur de puissance les impédances qui optimisent son efficacité pour chaque puissance de travail. Un démonstrateur en technologie CMOS SOI 130 nm a été conçu et simulé. Il consiste en un amplificateur de puissance pour le standard WCDMA, fonctionnant à 900 MHz, et un RA accordable par des varactors MOS, capable de générer les impédances optimales correspondant à des puissances de sortie comprises entre 20 et 30 dBm. Les résultats ont mis en évidence le bénéfice apporté par l insertion d un RA accordable par rapport à un RA fixe.The aim of this research was the design of tunable matching networks, in two different contexts: the TMN at low and high signals.Performance criteria of TMN were studied. A general expression has been developed that estimates the TMN efficiency in function of the quality factor of the components used. The impedance coverage of different RAA topologies was plotted in function of the insertion losses.For the small signal, we designed a prototype in PCB, composed by two TMN, which ensure the simultaneous matching of a power amplifier in a wide range of impedances, included in a circle of the Smith chart VSWR < 5: 1. The coverage area was measured and presented in function of the insertion losses, emphasizing the areas where the TMN contribute to improve the amplifier performance and those where insertion losses of the TMN are not able to compensate gain with the reduction of the reflection coefficients.Subsequently, we discussed the design of TMN for the large signal. The objective is to present at the output of a power amplifier, the impedances that optimize efficiency for each power of operation. A 130 nm SOI prototype was designed and simulated, consisting of a power amplifier for WCDMA standard, 900 MHz, and a MN tunable by MOS varactors able to produce the optimal impedances corresponding to an output power between 20 and 30 dBm. The results showed the benefit provided by inserting a tunable MN compared to a fixed one.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF
Genetic variability of lactoferrin content estimated by mid-infrared spectrometry in bovine milk
The effects of lactoferrin (LF) on the immune system
have already been shown by many studies. Unfortunately,
the current methods used to measure LF levels
in milk do not permit the study of the genetic variability
of lactoferrin or the performance of routine genetic evaluations.
The first aim of this research was to derive a
calibration equation permitting the prediction of LF in
milk by mid-infrared spectrometry (MIR). The calibration
with partial least squares on 69 samples showed
a ratio of standard error of cross-validation to standard
deviation equal to 1.98. Based on this value, the calibration
equation was used to establish an LF indicator
trait (predicted LF; pLF) on a large number of milk
samples (n = 7,690). A subsequent study of its variability
was conducted, which confirmed that stage of lactation
and lactation number influence the overall pLF
level. Small differences in mean pLF among 7 dairy
breeds were also observed. The pLF content of Jersey
milk was significantly higher than that in Holstein
milk. Therefore, the choice of breed could change the
expected LF level. Heritability estimated for pLF was
19.7%. The genetic and phenotypic correlations between
somatic cell score and pLF were 0.04 and 0.26,
respectively. As somatic cell score increases in presence
of mastitis, this observation seems to indicate that pLF,
or a function of observed pLF, compared with expected
LF might have potential as an indicator of mastitis.
The negative genetic correlation (−0.36) between milk
yield and pLF could indicate an undesirable effect of
selection for high milk production on the overall LF
level
Transfert isolé des signaux de commande dans le contexte de l'intégration pour les composants actifs d'électronique de puissance
Cet article présente plusieurs solutions originales afin de réaliser un transfert isolé des ordres de commutation pour les semiconducteurs de puissance. Sous la contrainte de l'intégration aussi bien monolithique qu'hétérogène, trois solutions sont présentées de façons théoriques et expérimentales. Le premier mode de réalisation intégrée de l'isolation galvanique est une solution optique intégrée au composant de puissance et/ou au sein de son circuit de commande de type CMOS. Les performances statiques et dynamiques des récepteurs optiques sont tout à fait compatibles avec l'application. Enfin, plusieurs transformateurs sans noyau magnétique sont conçus, analysés et caractérisés via une réalisation CMOS, en prenant un soin particulier aux couplages hautes fréquences et éléments parasites. Ce circuit de transmission électromagnétique des ordres est intégré avec plusieurs fonctions de pilotages et le bon fonctionnement de l'ensemble du driver est démontré aussi bien pour les composants Haute Tension High Side que Low Side
Utilisation of intensive foraging zones by female Australian fur seals
Within a heterogeneous environment, animals must efficiently locate and utilise foraging patches. One way animals can achieve this is by increasing residency times in areas where foraging success is highest (area-restricted search). For air-breathing diving predators, increased patch residency times can be achieved by altering both surface movements and diving patterns. The current study aimed to spatially identify the areas where female Australian fur seals allocated the most foraging effort, while simultaneously determining the behavioural changes that occur when they increase their foraging intensity. To achieve this, foraging behaviour was successfully recorded with a FastLoc GPS logger and dive behaviour recorder from 29 individual females provisioning pups. Females travelled an average of 118 ± 50 km from their colony during foraging trips that lasted 7.3 ± 3.4 days. Comparison of two methods for calculating foraging intensity (first-passage time and first-passage time modified to include diving behaviour) determined that, due to extended surface intervals where individuals did not travel, inclusion of diving behaviour into foraging analyses was important for this species. Foraging intensity \u27hot spots\u27 were found to exist in a mosaic of patches within the Bass Basin, primarily to the south-west of the colony. However, the composition of benthic habitat being targeted remains unclear. When increasing their foraging intensity, individuals tended to perform dives around 148 s or greater, with descent/ascent rates of approximately 1.9 m•s-1 or greater and reduced postdive durations. This suggests individuals were maximising their time within the benthic foraging zone. Furthermore, individuals increased tortuosity and decreased travel speeds while at the surface to maximise their time within a foraging location. These results suggest Australian fur seals will modify both surface movements and diving behaviour to maximise their time within a foraging patch
Incidence, Risk Factors, and Outcomes of Rhegmatogenous Retinal Detachment after Intravitreal Injections of Anti-VEGF for Retinal Diseases: Data from the Fight Retinal Blindness! Registry
PURPOSE
To report the estimated incidence, probability, risk factors, and 1-year outcomes of rhegmatogenous retinal detachment (RRD) in eyes receiving intravitreal injections (IVTs) of VEGF inhibitors for various retinal conditions in routine clinical practice.
DESIGN
Retrospective analysis of data from a prospectively designed observational outcomes registry: the Fight Retinal Blindness!
PROJECT
PARTICIPANTS
Eyes of patients starting IVTs of VEGF inhibitors (ranibizumab, aflibercept, or bevacizumab) for neovascular age-related macular degeneration, diabetic macular edema, or retinal vein occlusion from January 1, 2006, to December 31, 2020. All eyes that developed RRD within 90 days of IVTs were defined as cases with RRD and were matched with control eyes.
METHODS
Estimated incidence, probability, and hazard ratios (HRs) of RRD were measured using Poisson regression, Kaplan-Meier survival curve, and Cox proportional hazards models. Locally weighted scatterplot smoothing curves were used to compare visual acuity (VA) between cases and matched controls.
MAIN OUTCOME MEASURES
Estimated incidence of RRD.
RESULTS
We identified 16 915 eyes of 13 792 patients who collectively received 265 781 IVTs over 14 years. Thirty-six eyes were reported to develop RRD over the study period. The estimated incidence (95% confidence interval [CI]) per year per 1000 patients and per 10 000 injections was 0.77 (0.54-1.07) and 1.36 (0.95-1.89), respectively. The probability of RRD did not significantly increase at each successive injection (PÂ = 0.95) with the time of follow-up. Older patients (HR [95% CI]Â = 1.81 [1.21-3.62] for every decade increase in age, P < 0.01) were at a higher risk of RRD, whereas patients with good presenting VA (HR [95% CI]Â = 0.85 [0.70-0.98] for every 10-letter increase in VA, PÂ = 0.02) were at a lower risk. Neither the type of retinal disease (PÂ = 0.52) nor the VEGF inhibitor (PÂ = 0.09) was significantly associated with RRD risk. Cases with RRD lost 3 lines of vision on average compared with the prior RRD VA and had significantly fewer injections than matched controls over the year after the RRD.
CONCLUSIONS
Rhegmatogenous retinal detachment is a rare complication of VEGF inhibitor IVT in routine clinical practice with poor visual outcomes at 1 year
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