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We evaluate three retransmission policies for transport protocols that support multihoming (e.g. SCTP). The policies dictate whether retransmissions are sent to the same peer IP address as the original transmission, or sent to an alternate peer IP address. Each policy presents tradeoffs based on the paths' bandwidth, delay, loss rate, and IP destination reachability. We find that sending all retransmissions to an alternate peer IP address is useful when the primary IP address becomes unreachable, but often degrades performance in non-failure scenarios. On the other hand, sending all retransmissions to the same peer IP address as the original transmission reverses the tradeoffs. We balance the tradeoffs by proposing a hybrid policy that sends fast retransmissions to the same peer IP address as the original transmission, and sends timeout retransmissions to an alternate peer IP address. We show that even with extensions which we proposed to improve the policies' performance, the hybrid policy is the best performing policy in failure and non-failure scenarios. q

IntroductionCardiovascular events (CE) due to atherosclerosis are preventable. Identification of high-risk patients helps to focus resources on those most likely to benefit from expensive therapy. Atherosclerosis is not considered for patient risk categorization, even though a fraction of CE are predicted by Framingham risk factors. Our objective was to assess the incremental value of combining total plaque area (TPA) with the Framingham risk score (FramSc) using post-test probability (Ptp) in order to categorize risk in patients without CE and identify those at high risk and requiring intensive treatment.Material and methodsA descriptive cross-sectional study was performed in the primary care setting in an Argentine population aged 22–90 years without CE. Both FramSc based on body mass index and Ptp-TPA were employed in 2035 patients for risk stratification and the resulting reclassification was compared. Total plaque area was measured with a high-resolution duplex ultrasound scanner.Results57% male, 35% hypertensive, 27% hypercholesterolemia, 14% diabetes. 20.1% were low, 28.5% moderate, and 51.5% high risk. When patients were reclassified, 36% of them changed status; 24.1% migrated to a higher and 13.6% to a lower risk level (κ index = 0.360, SE κ = 0.16, p < 0.05, FramSc vs. Ptp-TPA). With this reclassification, 19.3% were low, 18.9% moderate and 61.8% high risk.ConclusionsQuantification of Ptp-TPA leads to higher risk estimation than FramSc, suggesting that Ptp-TPA may be more sensitive than FramSc as a screening tool. If our observation is confirmed with a prospective study, this reclassification would improve the long-term benefits related to CE prevention.

Abstract-Using the application of bulk data transfer, we investigate end-to-end failover mechanisms and thresholds for transport protocols that support multihoming (e.g., SCTP). First, we evaluate temporary failovers, and measure the tradeoff between aggressive (i.e., lower) thresholds and spurious failovers. We surprisingly find that spurious failovers do not degrade performance, and often actually improve goodput regardless of the paths' characteristics (bandwidth, delay, and loss rate). A permanent failover mechanism tries to avoid throttling the sending rate by not returning to a primary path when it recovers. We demonstrate that such a mechanism can be beneficial if the sender can estimate each path's RTT and loss rate. We advocate a new approach to end-to-end failover that temporarily redirects traffic to an alternate path on the first sign of a potential failure (i.e., a timeout) on the primary path, but conservatively proceeds with failure detection of the primary path in the background. Résumé-En

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Skin physiology in cats has received little attention. The aim of this study was to evaluate the long-term influence of sex, time and the level of dietary fat and energy on the dynamics and qualities of the hair coat. Twenty-four European short-haired laboratory cats were followed over a 1-year period. They were divided into eight groups of three, according to: sex (12 males and 12 females), sexual status (intact or neutered) and diets [(high energy 4300 kcal/kg as fed, 21% fat) vs. (moderate energy 3500 kcal/kg as fed, 10% fat)]. Both diets were fed for 6 months to all cats following a cross-over design. The following parameters were evaluated throughout the study: thickness of hair coat and hair lengths (neck, rump, lateral, flank), hair regrowth (after periodic clippings of 25 cm 2 areas), and telogen/anagen ratio. The thickness of the hair coat initially varied from 1.2-1.7 cm on the neck, 1-1.4 cm on the rump, 1.8-2.5 cm on the flank, and hair shaft lengths were 1.7-2.5, 3.7-3.9 and 2.5-3.2 cm, respectively. Comparison of values revealed few statistical differences: increase of the thickness of hair coat in neutered cats (male and female) during the study, and increase of the length of lateral hairs in all groups during the study. Over all periods and in all groups, the curve of growth was similar (rapid then slower). Some transient variations were attributed to temporary changes in ambient conditions. In conclusion, neither sex, nutrition or season (in housed cats) influenced the general quality of hair coat, in particular hair regrowth. Funding: Royal Canin. Veterinary Dermatology 2004, 15 (Suppl. 1), 41-69 Ó 2004 ESVD and ACVD 41 Poster Abstracts Poster Abstracts

IntroductionThe hypothesis that relates atherosclerosis to traditional risk factors (TRF) seems to be not as adequate as previously thought; other risk factors (RF) need to be considered to prevent atherosclerosis progression. Although a family medical history of premature cardiovascular events (FHx) has been considered the putative RF for decades, it has not been incorporated routinely into cardiovascular risk evaluation along with another RF. The objective of this study was to investigate whether FHx is associated with a higher atherosclerotic burden, measured as carotid total plaque area (TPA) in a population having no traditional RF.Material and methodsThe study included 4,351 primary care patients in Argentina. After excluding a personal history of cardiovascular disease (CVD) and TRF: hypertension, diabetes mellitus, hypercholesterolemia, smoking history, and body mass index (BMI) > 25 kg/cm2, 34 patients with FHx were identified. Compared to 56 matched controls TPA was 86% higher in FHx patients (p < 0.05). A second analysis performed in hypertensive patients but no other TRF; 32 patients with FHx were identified.ResultsCompared with 44 matched controls, TPA was 77% higher in FHx patients (p < 0.05). A final analysis using a generalized linear model with TPA progression as the response variable suggests that TPA progresses more rapidly in FHx patients compared to controls.ConclusionsThe FHx was associated with increased TPA burden and progression in the absence of other TRF. This supports ultrasound screening in FHx patients in order to detect high-risk patients who may benefit from early intervention.

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