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Mitochondrial probe SiRPFA was synthesized by attaching a long perfluoroalkyl chain on Si-rhodamine cationic dye. High lipophilicity endowed SiRPFA with mitochondrial membrane potential independent properties. Under stimulated emission depletion microscopy, SiRPFA clearly revealed changes in mitochondrial cristae morphology during autophagy induced by starvation or apoptosis. [ABSTRACT FROM AUTHOR]

In this paper, the operation of MPEG-2 systems is modeled and simulated when an MPEG-2 transport stream is delivered through an ATM network with jitter. End-to-end packet-based analysis is performed for delivery of MPEG-2 transport streams over ATM networks. A novel approach to analyzing the decoder buffer behavior in the presence of network jitter is presented. The probability density function of the interarrival time of the ATM adaptation layer 5 (AAL5) protocol data unit (PDU) is derived from an MPEG-2 video source model and an ATM network jitter model. based on a real-time decoding requirement of the MPEG-2 transport stream (TS) system target decoder (T-STD), the decoder buffer behavior is simulated. In this simulation, the packets' arrivals follow the derived probability density function of the AAL5 PDU interarrival time. The modeling and simulation results show the interactions among packet loss ratio, decoder buffer size, and network jitter level. We found that jitter affects decoder buffer size and packet loss ratio in a significant way. Index Terms - ATM networks, decoder buffer, jitter, MPEG-2.

Due to the explosive growth of the Internet and increasing demand for multimedia information on the web, streaming video over the Internet has received tremendous attention from academia and industry. Transmission of real-time video typically has bandwidth, delay, and loss requirements. However, the current best-effort Internet does not offer any quality of service (QoS) guarantees to streaming video. Furthermore, for video multicast, it is difficult to achieve both efficiency and flexibility. Thus, Internet streaming video poses many challenges. To address these challenges, extensive research has been conducted. This special issue is aimed at dissemination of the contributions in the field of streaming video over the Internet. To introduce this special issue with the necessary background and provide an integral view on this field, we cover six key areas of streaming video. Specifically, we cover video compression, application-layer QoS control, continuous media distribution services, streaming servers, media synchronization mechanisms, and protocols for streaming media. For each area, we address the particular issues and review major approaches and mechanisms. We also discuss the tradeoffs of the approaches and point out future research directions. Index Terms--Application-layer QoS control, continuous media distribution services, Internet, protocol, streaming video, streaming server, synchronization, video compression.

With the success of the Internet and flexibility Of MPEG-4, transporting MPEG-4 video over the Internet is expected to be an important component of many multimedia applications in the near future. Video applications typically have delay and loss requirements, which cannot be adequately supported by the current Internet. Thus, it is a challenging problem to design an efficient MPEG-4 video delivery system that can maximize the perceptual quality while achieving high resource utilization. This paper addresses this problem by presenting an end-to-end architecture for transporting MPEG-4 video over the Internet. We present a framework for transporting MPEG-4 video, which includes source rate adaptation, packetization, feedback control, and error control. The main contributions of this paper are: 1) a feedback control algorithm based on Real Time Protocol (RTP) and Real Time Control Protocol (RTCP); 2) an adaptive source-encoding algorithm for MPEG-4 video which is able to adjust the output rate of MPEG-4 video to the desired rate; and 3) an efficient and robust packetization algorithm for MPEG video bit-streams at the sync layer for Internet transport. Simulation results show that our end-to-end transport architecture achieves good perceptual picture quality for MPEG-4 video under low bit-rate and varying network conditions and efficiently utilizes network resources. Index Terms--Adaptive encoding, feedback control, Internet, MPEG-4, packetization, RTP/RTCP, video object.

Background: Protective effect of roscovitine and deregulation of the p-RB/E2F1 have not been well studied in PD models generated by repeated oral administration of rotenone. Objective: These experiments evaluated the effects of repeated oral gavage of rotenone on the activation of p-RB/E2F1 and the effects of roscovitine on the regulation of dopaminergic neuronal injury and the behavior of PD in mice. Methods: Using 2.5% carboxymethylcellulose and 1.25% chloroform as a vehicle solution, rotenone (30 mg/kg) was administered via oral gavage once daily for 30 days in C57 mice. Behavioral profiles (pole test and traction test) were assessed in these PD models, and oxidative stress levels were evaluated in the midbrain. The immunoreactivities of TH, α-synuclein (α-syn), p-RB, E2F1 and cleaved caspase-3 in the substantia nigra were examined with a laser confocal microscope. Pharmacological inhibition of cyclin-dependent kinase with roscovitine was achieved by intraperitoneal (IP) injection at a dose of 50 mg/kg daily. Results: All rotenone-administered C57 mice showed the typical behavioral features of PD: stiffness, bradykinesia, or hypokinesia. Behavioral testing with the pole test and traction test indicated that the rotenone group, but not the vehicle group, was affected. Spectrophotometric analysis demonstrated that glutathione (GSH) and superoxide dismutase (SOD) activity was decreased, and the generation of malondialdehyde (MDA) was elevated in the midbrain of the rotenone-treated group. After oral administration of rotenone, a loss of nigral tyrosine hydroxylase (TH)-positive neurons was observed. The immune response of α-syn was enhanced in the cytoplasm of dopaminergic neurons from the rotenone-induced neurotoxicity. Rb phosphorylation at serine 780, which affected Rb binding to E2F, was induced after rotenone treatment. The activation of E2F1, which is involved in the regulation of the cell cycle, was also induced from chronic exposure to rotenone. Moreover, administration of the cell cycle inhibitor roscovitine protected against rotenone-induced nigral dopaminergic neuronal injury and inhibited cleaved caspase-3 activation. Roscovitine also markedly ameliorated the behavior of PD mice. Conclusions: Mouse models of Parkinson's disease were established by oral rotenone administration and reproduced some of the features of dopaminergic neuronal degeneration. Roscovitine protects against rotenone-induced parkinsonism. [ABSTRACT FROM AUTHOR]