616 research outputs found
Capacity Requirements of Traffic Handling Schemes in Multi-Service Networks
Cataloged from PDF version of article.This paper deals with the impact of traffic handling mechanisms on capacity for different network architectures. Three traffic handling
models are considered: per-flow, class-based and best-effort (BE). These models can be used to meet service guarantees, the major
differences being in their complexity of implementations and in the quantity of network resources that must be provided. In this study, the
performance is fixed and the required capacity determined for various combinations of traffic handling architectures for edge-core networks.
This study provides a comparison of different QoS architectures. One key result of this work is that on the basis of capacity requirements,
there is no significant difference between semi-aggregate traffic handling and per-flow traffic handling. However, best-effort handling
requires significantly more capacity as compared to the other methods.
(C) 2004 Elsevier B.V. All rights reserve
Effects of milk, pasteurized milk, and milk replacer on health and productivity of dairy calves
Dairy Research, 2014 is known as Dairy Day, 2014Our objectives were to determine the health and blood parameters before, during, and
after weaning of 114 Holstein heifers fed either accelerated milk replacer (MR; 28%
CP, 18% fat) or non-saleable milk (3.59 ± 0.28% true protein; 4.12 ± 0.37% fat) that
was either pasteurized (PM) or raw (RM; refrigerated and fed <24 h after collection).
Calves were randomly assigned to feeding treatments at birth. Colostrum (1 L) was fed
less than 14 hours after birth (MR and PM = pasteurized colostrum; RM = raw colostrum).
All calves were bottle-fed 1.8 ± 0.20 L, 3 times daily; all calves were provided
fresh water and grain ad libitum throughout the experiment. Calves began step-down
weaning at age 5 weeks and completed weaning at age 6 weeks. Blood samples were collected
at ages 3, 5, and 7 weeks and were analyzed for complete blood counts (CBC) using
a Procyte Idexx Analyzer (IDEXX Laboratories, Inc., Westbrook, ME). Fecal scores
were observed twice daily, on a 1 to 3 scale (FS1 = normal, FS2 = loose, FS3 = scours).
Results showed that MR-fed calves had more (P < 0.01) observations (%obs) with
FS > 2 than the PM- and RM-fed calves (2.3 vs. 1.6 and 1.7 ± 0.2 %obs, respectively).
In addition, there were no differences in body weight or shoulder or hip height between
treatments, but a treatment × week interaction (P = 0.05) occurred for grain consumed,
with a noticeably higher increase between 6 and 7 weeks of age for MR calves.
When CBC was considered, there were no differences in blood cell types, but MR-fed
calves had greater mean corpuscular volume (MCV) than the other calves (P < 0.01),
leading to higher resistance for iron deficiency anemia. In conclusion, these findings
suggest that calf performance and feed intake are not affected by the administration of
raw milk, pasteurized milk, or milk replacer. Moreover, CBC health parameters showed
no significant changes due to administration of the different types of milk sources
Alternating seismic uplift and subsidence in the late Holocene at Madang, Papua New Guinea: Evidence from raised reefs
Reduction of Maternal Mortality with Highly Active Antiretroviral Therapy in a Large Cohort of HIV-Infected Pregnant Women in Malawi and Mozambique
Background: HIV infection is a major contributor to maternal mortality in resource-limited settings. The Drug Resource Enhancement Against AIDS and Malnutrition Programme has been promoting HAART use during pregnancy and postpartum for Prevention-of-mother-to-child-HIV transmission (PMTCT) irrespective of maternal CD4 cell counts since 2002. Methods: Records for all HIV+ pregnancies followed in Mozambique and Malawi from 6/2002 to 6/2010 were reviewed. The cohort was comprised by pregnancies where women were referred for PMTCT and started HAART during prenatal care (n = 8172, group 1) and pregnancies where women were referred on established HAART (n = 1978, group 2). Results: 10,150 pregnancies were followed. Median (IQR) baseline values were age 26 years (IQR:23-30), CD4 count 392 cells/mm(3) (IQR:258-563), Viral Load log(10) 3.9 (IQR:3.2-4.4), BMI 23.4 (IQR:21.5-25.7), Hemoglobin 10.0 (IQR:9.0-11.0). 101 maternal deaths (0.99%) occurred during pregnancy to 6 weeks postpartum: 87 (1.1%) in group 1 and 14 (0.7%) in group 2. Mortality was 1.3% in women with <than 350 CD4 cells/mm(3) and 0.7% in women with greater than 350 CD4s cells/mm(3) [OR = 1.9 (CL 1.3-2.9) p = 0.001]. Mortality was higher in patients with shorter antenatal HAART: 22/991 (2.2%) if less than 30 days and 79/9159 (0.9%) if 31 days or greater [OR = 2.6 (CL 1.6-4.2) p<0.001]. By multivariate analysis, shorter antenatal HAART (p, 0.001), baseline values for CD4 cell count (p = 0.012), hemoglobin (p = 0.02), and BMI (p<0.001) were associated with mortality. Four years later, survival was 92% for women with shorter antenatal HAART and 98% for women on established therapy prior to pregnancy, p = 0.001. Conclusions: Antiretrovirals for PMTCT purposes have significant impact on maternal mortality as do CD4 counts and nutritional status. In resource-limited settings, PMTCT programs should provide universal HAART to all HIV+ pregnant women given its impact in prevention of maternal death
Whole-genome characterisation of G12P[6] rotavirus strains possessing two distinct genotype constellations co-circulating in Blantyre, Malawi, 2008
Reinforcement versus Fluidization in Cytoskeletal Mechanoresponsiveness
Every adherent eukaryotic cell exerts appreciable traction forces upon its substrate. Moreover, every resident cell within the heart, great vessels, bladder, gut or lung routinely experiences large periodic stretches. As an acute response to such stretches the cytoskeleton can stiffen, increase traction forces and reinforce, as reported by some, or can soften and fluidize, as reported more recently by our laboratory, but in any given circumstance it remains unknown which response might prevail or why. Using a novel nanotechnology, we show here that in loading conditions expected in most physiological circumstances the localized reinforcement response fails to scale up to the level of homogeneous cell stretch; fluidization trumps reinforcement. Whereas the reinforcement response is known to be mediated by upstream mechanosensing and downstream signaling, results presented here show the fluidization response to be altogether novel: it is a direct physical effect of mechanical force acting upon a structural lattice that is soft and fragile. Cytoskeletal softness and fragility, we argue, is consistent with early evolutionary adaptations of the eukaryotic cell to material properties of a soft inert microenvironment
Should female health providers be involved in medical male circumcision? Narratives of newly circumcised men in Malawi
Background: The Malawi government has endorsed voluntary medical male circumcision (VMMC) as a biomedical strategy for HIV prevention after a decade of debating its effectiveness in the local setting. The “policy” recommends that male circumcision (MC) should be clinically based, as opposed to the alternative of traditional male circumcision (TMC). Limited finances, acceptability concerns, and the health system’s limited capacity to meet demand are among the challenges threatening the mass rollout of VMMC. In terms of acceptability, the gender of clinicians conducting the operations may particularly influence health facility-based circumcision. This study explored the acceptability, by male clients, of female clinicians taking part in the circumcision procedure.Methods: Six focus group discussions (FGDs) were conducted, with a total of 47 newly circumcised men from non-circumcising ethnic groups in Malawiparticipating in this study. The men had been circumcised at three health facilities in Lilongwe District in 2010. Data were audio recorded and transcribed verbatim. Data were analysed using narrative analysis.Results: Participants in the FGDs indicated that they were not comfortable with women clinicians being part of the circumcising team. While few mentioned that they were not entirely opposed to female health providers’ participation, arguing that their involvement was similar to male clinicians’ involvement in child delivery, most of them opposed to female involvement, arguing that MC was not an illness that necessitates the involvement of clinicians regardless of their gender. Most of the participants said that it was not negotiable for females to be involved, as they could wait until an all-male clinician team could be available. Thematically, the arguments against female clinicians’ involvement include sexual undertones and the influences of traditional male circumcision practices, among others.Conclusion: Men preferred that VMMC should be conducted by male health providers only. Traditionally, male circumcision has been a male-only affair shrouded in secrecy and rituals. Although being medical, this study strongly suggested that it may be difficult for VMMC to immediately move to a public space where female health providers can participate, even for men coming from traditionally non-circumcising background
Improving a Ka-Band Integrated Balanced Power Amplifier Performance by Compensating Quadrature Hybrid Mismatch Effects
Abstract
This article presents an integrated quadrature balanced power amplifier (PA) operating at a 26-GHz frequency range and techniques to mitigate the frequency-dependent amplitude response of quadrature hybrids used in the balanced amplifier design. The overall structure consists of two stacked pseudo-differential PAs and transformer-based quadrature hybrids designed with 22-nm CMOS FDSOI. Two techniques to compensate frequency-dependent amplitude response of the quadrature hybrid when operating away from the center frequency are proposed. The first one involves a dual input drive and the second one involves asymmetric biasing. With distortion contribution analysis, it is shown that asymmetric biasing compensates quadrature hybrid asymmetry but also produces mutually compensating third-order nonlinearity, resulting in improved linearity. Measurements with continuous wave (CW) and high dynamic range fifth generation (5G) modulated signal demonstrate that the described techniques improve output power that can be reached within the linearity specifications when operating away from the center frequency.Abstract
This article presents an integrated quadrature balanced power amplifier (PA) operating at a 26-GHz frequency range and techniques to mitigate the frequency-dependent amplitude response of quadrature hybrids used in the balanced amplifier design. The overall structure consists of two stacked pseudo-differential PAs and transformer-based quadrature hybrids designed with 22-nm CMOS FDSOI. Two techniques to compensate frequency-dependent amplitude response of the quadrature hybrid when operating away from the center frequency are proposed. The first one involves a dual input drive and the second one involves asymmetric biasing. With distortion contribution analysis, it is shown that asymmetric biasing compensates quadrature hybrid asymmetry but also produces mutually compensating third-order nonlinearity, resulting in improved linearity. Measurements with continuous wave (CW) and high dynamic range fifth generation (5G) modulated signal demonstrate that the described techniques improve output power that can be reached within the linearity specifications when operating away from the center frequency
Ka-Band Dual Input Stacked 22 nm CMOS FDSOI Power Amplifier with Transformer-Based Power Combiner
AbstractA Ka-band dual input, three stack power amplifier (PA) is designed and fabricated using 22nm CMOS FDSOI. The PA output matching is implemented with a transformer-based combiner, which allows tuning the load with bias and input drive settings. The PA shows maximum output power, gain, one dB output power compression point (P 1dB ) and power added efficiency (PAE) of 19.5dBm, 11.5dB, 14.1dBm and 17%, respectively, measured at 29.5 GHz. Measured amplitude to phase modulation (AM-PM) stays at very low level, below 0.7° up to P1dB and below 2.6° up to P3dB. With a 100 MHz 64-QAM OFDM signal the PA achieves 8% error vector magnitude (EVM) and -28dBc adjacent channel leakage ratio (ACLR) at 6.3dBm and 7.6dBm output channel power, respectively.Abstract
A Ka-band dual input, three stack power amplifier (PA) is designed and fabricated using 22nm CMOS FDSOI. The PA output matching is implemented with a transformer-based combiner, which allows tuning the load with bias and input drive settings. The PA shows maximum output power, gain, one dB output power compression point (P 1dB ) and power added efficiency (PAE) of 19.5dBm, 11.5dB, 14.1dBm and 17%, respectively, measured at 29.5 GHz. Measured amplitude to phase modulation (AM-PM) stays at very low level, below 0.7° up to P1dB and below 2.6° up to P3dB. With a 100 MHz 64-QAM OFDM signal the PA achieves 8% error vector magnitude (EVM) and -28dBc adjacent channel leakage ratio (ACLR) at 6.3dBm and 7.6dBm output channel power, respectively
Compensating Quadrature Hybrid Mismatch Effects in Integrated Balanced Power Amplifier
Abstract
This paper presents techniques to mitigate frequency dependent amplitude response of quadrature hybrid in an integrated quadrature balanced power amplifier (PA). The studied structure consists of stacked pseudo-differential power amplifiers and transformer-based quadrature hybrids designed with 22 nm CMOS FDSOI operating at 26 GHz. We propose two techniques to compensate frequency-dependent amplitude response of the quadrature hybrid when operating away from the center frequency. First one involves dual input drive and second asymmetric biasing. Measurements with continuous wave (CW) and high dynamic range fifth generation (5G) modulated signals demonstrate that the described techniques improve output power that can be reached within the linearity specifications when operating away from the center frequency.Abstract
This paper presents techniques to mitigate frequency dependent amplitude response of quadrature hybrid in an integrated quadrature balanced power amplifier (PA). The studied structure consists of stacked pseudo-differential power amplifiers and transformer-based quadrature hybrids designed with 22 nm CMOS FDSOI operating at 26 GHz. We propose two techniques to compensate frequency-dependent amplitude response of the quadrature hybrid when operating away from the center frequency. First one involves dual input drive and second asymmetric biasing. Measurements with continuous wave (CW) and high dynamic range fifth generation (5G) modulated signals demonstrate that the described techniques improve output power that can be reached within the linearity specifications when operating away from the center frequency
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