DNA fragmentation index (DFI) as a measure of sperm quality and fertility in mice.

Although thousands of genetically modified mouse strains have been cryopreserved by sperm freezing, the likelihood of cryorecovery success cannot be accurately predicted using conventional sperm parameters. The objective of the present study was to assess the extent to which measurement of a sperm DNA fragmentation index (DFI) can predict sperm quality and fertility after cryopreservation. Using a modified TUNEL assay, we measured and correlated the DFI of frozen-thawed sperm from 83 unique mutant mouse strains with sperm count, motility and morphology. We observed a linear inverse correlation between sperm DFI and sperm morphology and motility. Further, sperm DFI was significantly higher from males with low sperm counts compared to males with normal sperm counts (P < 0.0001). Additionally, we found that viable embryos derived using sperm from males with high DFI (62.7 ± 7.2% for IVF and 73.3 ± 8.1% for ICSI) failed to litter after embryo transfer compared to embryos from males with low DFI (20.4 ± 7.9% for IVF and 28.1 ± 10.7 for ICSI). This study reveals that measurement of DFI provides a simple, informative and reliable measure of sperm quality and can accurately predict male mouse fertility

淺析傳統中醫理論中的中和之道

本文从中和观的角度探讨了《周易》哲学对传统中医理论的影响，认为易理和医理都同样强调阴阳和谐的中正之道，要求阴阳当位、守正而用中，以保持事物的平衡和稳定，主张顺从天地之道，与自然界和谐共处，贵生广爱，追求“提挈天地，把握阴阳”的至善境界。《周易》哲学的中和理念实际上贯穿了整个传统中医的理论和临床。This paper has explored the influence of the philosophy of the Harmonious View in the “The Book of Changes” on TCM theories. It suggests that both of them emphasize the balance of Yin and Yang, requires that all things have to keep in balance and stability, and advocates to obeying the law of the nature. The philosophy of Harmonious View in the “The Book of Changes” has run throughout the theories of TCM and clinical practice.published_or_final_versio

A paracasting model for concurrent access to replicated content

We propose a framework to study how to download effectively a copy of the same document from a set of replicated servers. A generalized application-layer anycasting, known as paracasting, has been proposed to advocate concurrent access of a subset of replicated servers to satisfy cooperatively a client's request. Each participating server satisfies the request in part by transmitting a subset of the requested file to the client. The client can recover the complete file when different parts of the file sent from the participating servers are received. This framework allows us to estimate the average time to download a file from the set of homogeneous replicated servers, and the request blocking probability when each server can accept and serve a finite number of concurrent. requests. Our results show that the file download time drops when a request is served concurrently by a larger number of homogeneous replicated servers, although the performance improvement quickly saturates when the number of servers used increases. If the total number of requests that a server can handle simultaneously is finite, the request blocking probability increases with the number of replicated servers used to serve a request concurrently. Therefore, paracasting is effective in using a small number of servers, say, up to four, to serve a request concurrently.published_or_final_versio

A resequencing model for high speed networks

In this paper, we propose a framework to study the resequencing mechanism in high speed networks. This framework allows us to estimate the packet resequencing delay, the total packet delay, and the resequencing buffer occupancy distributions when data traffic is dispersed on multiple disjoint paths. In contrast to most of the existing work, the estimation of the end-to-end path delay distribution is decoupled from the queueing model for resequencing. This leads to a simple yet general model, which can be used with other measurement-based tools for estimating the end-to-end path delay distribution to find an optimal split of traffic. We consider a multiple-node M/M/1 tandem network as a path model. When end-to-end path delays are Gaussian distributed, our results show that the packet resequencing delay, the total packet delay, and the resequencing buffer occupancy drop when the traffic is spread over a larger number of homogeneous paths, although the network performance improvement quickly saturates when the number of paths used increases. We find that the number of paths used in multipath routing should be small, say up to three. Besides, an optimal split of traffic occurs at paths with equal loads.published_or_final_versio

Reducing Memory Controller Transaction Queue Size in Scalable Memory Systems

Scalable memory systems provide scalable bandwidth to the core growth demands in multicores’ and embedded systems’ processors. In these systems, as memory controllers (MCs) are scaled, memory traffic per MC is reduced, therefore transaction queues become shallower. As a consequence, there is an opportunity to explore transaction queue utilization and its impact on energy. In this paper we propose to evaluating the performance and energy-per-bit impact of the number of entries of the transaction queues along the MCs in these systems. Preliminary results show that reducing 50% of the number of entries, bandwidth and energy-per-bit levels are not affected, while if reducing them of 93%, bandwidth is reduced of 91% and energy-per-bit levels are increased of 780%

Insights on Memory Controller Scaling for Multicore Embedded Systems

In recent years, the growth of the number of cores as well as the frequency of cores along different processor generations has proportionally increased bandwidth needs simultaneously in both CPU and GPU systems. In order to address the communication latency between CPU and GPU memories in recent implementation of heterogeneous mobile embedded systems with hard or firm real-time requirements, sharing the same address space adds significant levels of contention. In addition, when heterogeneous cores are simultaneously present in a single system, memory parallelism is significantly restricted by a small amount of memory controllers (MCs). As a strategy to approach these significant levels of memory pressure, it is proposed in this paper evaluations of the impact of scaling MCs up to four to eight units - limited by motherboard size for embedded purposes. Our findings show that performance is enhanced by a factor of 4× when employing only CPU cores, 4.6× when only GPU cores and finally, 2× when both CPU and GPU cores are simultaneously considered

Vehicular Energy Network

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Design and analysis of TCP AIMD in wireless networks

The class of additive-increase/multiplicative-decrease (AIMD) algorithms constitutes a key mechanism for congestion control in modern communication networks, like the current Internet. The algorithmic behaviour may, however, be distorted when wireless links are present. Specifically, spurious window reductions may be triggered due to packet reordering and non-congestive loss. In this paper, we develop a framework for AIMD in TCP to analyze the aforementioned problem. The framework enables a systematic analysis of the existing AIMD-based TCP variants and assists in the design of new TCP variants. It classifies the existing AIMD-based TCP variants into two main streams, known as compensators and differentiators, and develops a generic expression that covers the rate adaptation processes of both approaches. It further identifies a new approach in enhancing the performance of TCP, known as the compensation scheme. A tax-rebate approach is proposed as an approximation of the compensation scheme, and used to enhance the AIMD-based TCP variants to offer unified solutions for effective congestion control, sequencing control, and error control. In traditional wired networks, the new family of TCP variants with the proposed enhancements automatically preserves the same inter-flow fairness and TCP friendliness. We have conducted a series of simulations to examine their performance under various network scenarios. In most scenarios, significant performance gains are attained. © 2013 IEEE.published_or_final_versio

Distributed opportunistic scheduling in multihop wireless ad hoc networks

In this paper, we introduce a framework for distributed opportunistic scheduling in multihop wireless ad hoc networks. With the proposed framework, one can take a scheduling algorithm originally designed for infrastructure-based wireless networks and adapt it to multihop ad hoc networks. The framework includes a wireless link state estimation mechanism, a medium access control (MAC) protocols and a MAC load control mechanism. The proposed link state estimation mechanism accounts for the latest results of packet transmissions on each wireless link. To improve robustness and provide service isolation during channel errors, the MAC protocol should not make any packet retransmissions but only report the transmission result to the scheduler. We modify IEEE 802.11 to fulfill these requirements. The MAC load control mechanism improves the system robustness. With link state information and the modified IEEE 802.11 MAC, we use BGFS-EBA, an opportunistic scheduling algorithm for infrastructured wireless networks, as an example to demonstrate how such an algorithm is converted into its distributed version within the proposed framework. The simulation results show that our proposed method can provide robust outcome fairness in the presence of channel errors. ©2008 IEEE.published_or_final_versio

Investigation on semi-active control of vehicle suspension using adaptive inerter

The analysis of passive control with inerter in suspension system has been well studied in previous work by employing different configurations and optimizing the spring stiffness, damping coefficient and inertance simultaneously. In this paper, we study the suspension performance with semi-active control under the assumption that the inertance may be adjusted in real-time. The suspension system is designed to attenuate the vertical acceleration of the sprung mass. A quarter-car model is considered, and the inerter is installed parallel to the spring and damper. First, an analysis is provided on the influence of a fixed inerter to a given suspension system. Then, a state-feedback H2 controller for active suspension system is designed. The active force is approximated by an inerter with adaptive inertance. Simulation results show that comparing with the passive suspension with a fixed inerter, the designedH2 controller realized by adaptive inerter can achieve good improvement of ride comfort at the sprung mass natural frequency at the expense of a relatively small deterioration at the unsprung mass natural frequency. Copyright © (2014) by the International Institute of Acoustics & Vibration All rights reserved.postprin