Performance of voice and video conferencing over ATM and gigabit ethernet backbone networks

Gigabit Ethernet and ATM network technologies have been modeled as campus network backbones for the simulation-based comparison of their performance. Real-time voice and video conferencing traffic is used to compare the performance of both backbone technologies in terms of response times and packet end-to-end delays. Simulation results show that Gigabit Ethernet has been able to perform the same and in some cases better than ATM as a backbone network for video and voice conferencing providing network designers with a cheaper solution to meet the growing needs of bandwidth-hungry applications in a campus environment

Replacing sources with sinks: when do populations go down the drain? Restor

Abstract We investigate the scenario in which some amount of higher quality habitat is destroyed and is then replaced by some undetermined amount of lower quality habitat. We examined how much low-quality habitat would need to be created to maintain the equilibrium population abundance in the entire geographic area. Using a source-sink model, we find that (1) the number of hectares of created habitat per hectare of destroyed habitat must equal the ratio of the high-quality habitat's productivity to the low-quality habitat's productivity, however, (2) if the created habitat is a sink, then there is a threshold fraction of destroyed high-quality habitat below which the initial population abundance cannot be maintained through the creation of habitat. We illustrate these results using data on Redwinged Blackbirds (Agelaius phoeniceus) in two different regions where high-quality habitat is being replaced by or converted into lower quality habitat

Hot Disks And Delayed Bar Formation

We present observational evidence for the inhibition of bar formation in dispersion-dominated (dynamically hot) galaxies by studying the relationship between galactic structure and host galaxy kinematics in a sample of 257 galaxies between 0.1 $<$ z $\leq$ 0.84 from the All-Wavelength Extended Groth Strip International Survey (AEGIS) and the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey. We find that bars are preferentially found in galaxies that are massive and dynamically cold (rotation-dominated) and on the stellar Tully-Fisher relationship, as is the case for barred spirals in the local Universe. The data provide at least one explanation for the steep ($\times$3) decline in the overall bar fraction from z=0 to z=0.84 in L$^*$ and brighter disks seen in previous studies. The decline in the bar fraction at high redshift is almost exclusively in the lower mass (10 $<$ log M$_{*}$(\Msun)$<$ 11), later-type and bluer galaxies. A proposed explanation for this "downsizing" of the bar formation / stellar structure formation is that the lower mass galaxies may not form bars because they could be dynamically hotter than more massive systems from the increased turbulence of accreting gas, elevated star formation, and/or increased interaction/merger rate at higher redshifts. The evidence presented here provides observational support for this hypothesis. However, the data also show that not every disk galaxy that is massive and cold has a stellar bar, suggesting that mass and dynamic coldness of a disk are necessary but not sufficient conditions for bar formation -- a secondary process, perhaps the interaction history between the dark matter halo and the baryonic matter, may play an important role in bar formation.Comment: In press, ApJ, 13 pages, 5 figures (3 color

Circulation first – the time has come to question the sequencing of care in the ABCs of trauma; an American Association for the Surgery of Trauma multicenter trial

Background The traditional sequence of trauma care: Airway, Breathing, Circulation (ABC) has been practiced for many years. It became the standard of care despite the lack of scientific evidence. We hypothesized that patients in hypovolemic shock would have comparable outcomes with initiation of bleeding treatment (transfusion) prior to intubation (CAB), compared to those patients treated with the traditional ABC sequence. Methods This study was sponsored by the American Association for the Surgery of Trauma multicenter trials committee. We performed a retrospective analysis of all patients that presented to trauma centers with presumptive hypovolemic shock indicated by pre-hospital or emergency department hypotension and need for intubation from January 1, 2014 to July 1, 2016. Data collected included demographics, timing of intubation, vital signs before and after intubation, timing of the blood transfusion initiation related to intubation, and outcomes. Results From 440 patients that met inclusion criteria, 245 (55.7%) received intravenous blood product resuscitation first (CAB), and 195 (44.3%) were intubated before any resuscitation was started (ABC). There was no difference in ISS, mechanism, or comorbidities. Those intubated prior to receiving transfusion had a lower GCS than those with transfusion initiation prior to intubation (ABC: 4, CAB:9, p = 0.005). Although mortality was high in both groups, there was no statistically significant difference (CAB 47% and ABC 50%). In multivariate analysis, initial SBP and initial GCS were the only independent predictors of death. Conclusion The current study highlights that many trauma centers are already initiating circulation first prior to intubation when treating hypovolemic shock (CAB), even in patients with a low GCS. This practice was not associated with an increased mortality. Further prospective investigation is warranted. Trial registration IRB approval number: HM20006627. Retrospective trial not registered

Targeting Mcl-1 for Radiosensitization of Pancreatic Cancers

AbstractIn order to identify targets whose inhibition may enhance the efficacy of chemoradiation in pancreatic cancer, we previously conducted an RNAi library screen of 8,800 genes. We identified Mcl-1 (myeloid cell leukemia-1), an anti-apoptotic member of the Bcl-2 family, as a target for sensitizing pancreatic cancer cells to chemoradiation. In the present study we investigated Mcl-1 inhibition by either genetic or pharmacological approaches as a radiosensitizing strategy in pancreatic cancer cells. Mcl-1 depletion by siRNA produced significant radiosensitization in BxPC-3 and Panc-1 cells in association with Caspase-3 activation and PARP cleavage, but only minimal radiosensitization in MiaPaCa-2 cells. We next tested the ability of the recently identified, selective, small molecule inhibitor of Mcl-1, UMI77, to radiosensitize in pancreatic cancer cells. UMI77 caused dissociation of Mcl-1 from the pro-apoptotic protein Bak and produced significant radiosensitization in BxPC-3 and Panc-1 cells, but minimal radiosensitization in MiaPaCa-2 cells. Radiosensitization by UMI77 was associated with Caspase-3 activation and PARP cleavage. Importantly, UMI77 did not radiosensitize normal small intestinal cells. In contrast, ABT-737, an established inhibitor of Bcl-2, Bcl-XL, and Bcl-w, failed to radiosensitize pancreatic cancer cells suggesting the unique importance of Mcl-1 relative to other Bcl-2 family members to radiation survival in pancreatic cancer cells. Taken together, these results validate Mcl-1 as a target for radiosensitization of pancreatic cancer cells and demonstrate the ability of small molecules which bind the canonical BH3 groove of Mcl-1, causing displacement of Mcl-1 from Bak, to selectively radiosensitize pancreatic cancer cells

Human Neurospheres as Three-Dimensional Cellular Systems for Developmental Neurotoxicity Testing

Bac k g r o u n d: Developmental neurotoxicity (DNT) of environmental chemicals is a serious threat to human health. Current DNT testing guidelines propose investigations in rodents, which require large numbers of animals. With regard to the “3 Rs ” (reduction, replacement, and refinement) of animal testing and the European regulation of chemicals [Registration, Evaluation, and Authorisation of Chemicals (REACH)], alternative testing strategies are needed in order to refine and reduce animal experiments and allow faster and less expensive screening. Objectives: The goal of this study was to establish a three-dimensional test system for DNT screening based on human fetal brain cells. Met h o d s: We established assays suitable for detecting disturbances in basic processes of brain development by employing human neural progenitor cells (hNPCs), which grow as neurospheres. Furthermore, we assessed effects of mercury and oxidative stress on these cells. Re s u l t s: We found that human neurospheres imitate proliferation, differentiation, and migration in vitro. Exposure to the proapoptotic agent staurosporine further suggests that human neurospheres possess functioning apoptosis machinery. The developmental neurotoxicants methylmercury chloride and mercury chloride decreased migration distance and number of neuronal-like cells in differentiated hNPCs. Furthermore, hNPCs undergo caspase-independent apoptosis when exposed toward high amounts of oxidative stress. Co n c l u s i o n s: Human neurospheres are likely to imitate basic processes of brain development, and these processes can be modulated by developmental neurotoxicants. Thus, this three-dimensional cell system is a promising approach for DNT testing. Key w o r d s: apoptosis, differentiation, DNT, human neurospheres, mercury, migration, proliferation. Environ Health Perspect 117:1131–1138 (2009). doi:10.1289/ehp.0800207 available vi

Cognitive Information Processing

Contains reports on four research projects.National Science Foundation (Grant SED76-81985)Associated Press (Grant)Providence Gravure, Inc. (Grant)Taylor Publishing Company (Grant

Cognitive Information Processing

Contains reports on four research projects.Associated Press (Grant)Providence Gravure, Inc. (Grant)Taylor Publishing Company (Grant