News Article | May 1, 2017
Texas University stabbing: At least one dead and several injured after campus attack in Austin At least one person has been killed and three more possibly seriously injured following a mass stabbing and assault on the University of Texas at Austin campus. Police took one person into custody after the stabbing and warned students and the public via social media channels to stay away from the area. The Austin Police force and the University of Texas at Austin Police Department worked together to respond to the incident. Local emergency responders said that there were three victims who came in as patients and that one of them was in critical condition, local media reported. Warren says Obama does not understand 'lived experience of Americans' Confirmed details about the suspect and their motive were not immediately available after police took them into custody. Students in the nearby Gregory Gym were reportedly evacuated for their safety, according to reports from local news organisations. No further threat to campus safety were reported, the University of Austin Police Department said via Twitter. The university’s campus is loaded just streets from downtown Austin and the Texas capitol building. The school is one of the largest universities in the United States.
Forleo G.B.,University of Rome Tor Vergata |
Di Biase L.,The Texas Institute |
Di Biase L.,University of Foggia |
Di Biase L.,Yeshiva University |
And 11 more authors.
Journal of Interventional Cardiac Electrophysiology | Year: 2013
Purpose: A new four-pole connector system (DF-4) for transvenous high-voltage implantable cardioverter defibrillators (ICD) is currently available in clinical practice. However, no clinical data demonstrating the safety and effectiveness of this complex electromechanical design is available. This study aims to test the safety and effectiveness of this newly designed system compared to the conventional DF-1 leads. Methods: During a 3-year period, 351 consecutive patients were implanted with DF-4 leads as part of an ICD or ICD-cardiac resynchronization therapy system. Patients were matched for age, sex, and follow-up with 154 patients implanted with a standard DF-1 lead. The primary outcome of the study was defibrillation lead failure, defined as the need for lead removal or capping. Operative, electrical, and safety data were obtained at implant and during postoperative follow-up. Results: Implantation success rate in both groups was 100 %. A trend towards shorter procedure time was observed in the DF-4 group but the difference did not reach statistical significance. Handling characteristics of the DF-4 leads were graded better than those of DF-1 models. During a total follow-up of 8,130.5 lead-months, there were nine ICD-lead failures (four system erosion/infections and five electrical lead dysfunctions). The overall incidence of electrical lead failure was 0.64 vs. 0.97 per 100 lead-years, for DF-4 and DF-1 leads, respectively (P = 0.2). Conclusions: This multi-center experience provides strong evidence that the feasibility and safety of this novel technology compare favorably with those of the conventional DF-1 leads. © 2013 Springer Science+Business Media New York.
Petkov V.,Central Michigan University |
Hessel C.M.,University of Austin |
Ovtchinnikoff J.,University of Austin |
Guillaussier A.,University of Austin |
And 3 more authors.
Chemistry of Materials | Year: 2013
High-energy synchrotron X-ray diffraction coupled to atomic pair distribution function analysis and computer simulations is used to determine the atomic-scale structure of silicon (Si) nanoparticles obtained by two different synthetic routes. Results show that Si nanoparticles may have significant structural differences depending on the synthesis route and surface chemistry. In this case, one method produced Si nanoparticles that are highly crystalline but surface oxidized, whereas a different method yields organic ligand-passivated nanoparticles without surface oxide but that are structurally distorted at the atomic scale. Particular structural features of the oxide-free Si nanoparticles such as average first coordination numbers, length of structural coherence, and degree of local distortions are compared to their optical properties such as photoluminescence emission energy, quantum yield, and Raman spectra. A clear structure-properties correlation is observed indicating that the former may need to be taken into account when considering the latter. © 2013 American Chemical Society.
Kwon O.-S.,University of Toronto |
Kim E.,University of Austin |
Orton S.,University of Missouri
Journal of Bridge Engineering | Year: 2011
In this paper, the live load factor in the Strength I Limit State in the AASHTO LRFD Bridge Design Specifications is calibrated based on state-specific traffic environments and bridge configurations. As the initial development of the live load factor in the LRFD specifications was intended to be applied at the national level, state-specific traffic conditions, such as traffic volume, truck load, or bridge configurations, were not considered in the development process. In addition, due to the lack of reliable U.S. truck weight data in the early 1990s, truck data from Ontario, Canada, collected in the 1970s were used for the initial AASHTO calibration. Hence, the application of the live load factor in the LRFD specifications may result in over- or under-designed bridges for a specific state. Through reliability analysis of bridges based on state-specific traffic and bridge conditions, the live load factor can be recalibrated to achieve both reliable and economical bridge design. In this study, the traffic data collected for 5 years at weigh-in-motion stations in Missouri are used to simulate realistic truck loads. In addition, typical bridge configurations identified from statistical analyses of 2007 National Bridge Inventory are used to define representative bridges in Missouri. Reliability analysis results using the weigh-in-motion data and the representative bridge configurations show that most bridges have reliability indexes higher than 3.5. Live load calibration factors for the design of new bridges in Missouri are proposed as a function of the bridge's average daily truck traffic. © 2011 American Society of Civil Engineers.
Closed loop stimulation is effective in improving heart rate and blood pressure response to mental stress: Report of a single-chamber pacemaker study in patients with chronotropic incompetent atrial fibrillation
Proietti R.,Luigi Sacco Hospital |
Manzoni G.,Instituto Auxologico Italiano IRCCS |
Manzoni G.,University of Milan |
Di Biase L.,The Texas Institute |
And 16 more authors.
PACE - Pacing and Clinical Electrophysiology | Year: 2012
Introduction: Closed-loop stimulation (CLS) is a form of rate-adaptive pacing capable of providing an effective pacing rate profile not only during physical exercise but also during mental stress. To test its effectiveness, CLS and accelerometer sensor (AS) rate response were compared intraindividually during a mental stress test (MST). Methods: Thirty-six patients (mean age 78.9 ± 6.4 years) implanted with a pacemaker with the CLS algorithm (Cylos, Biotronik, Berlin, Germany) underwent MSTs in different pacing configurations: nonrate-adaptive mode (VVI), AS mode (VVIR), and CLS mode, respectively. A modified Stroop test was used in order to induce mental stress. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure, and pacing percentage burden were collected for 5 minutes before, during, and 5 minutes after the test. Results: Mean peak-HR during MST was significantly higher in CLS configuration than in VVIR and VVI modes (92.8 ± 12.6 vs 78.9 ± 6.5 vs 77.8 ± 7.5; P ≤ 0.001). The average HR increase during MST was also higher in CLS configuration than in VVIR and VVI modes (22.7 ± 16.7 vs 8.2 ± 8.6 vs 6.6 ± 6.3; P ≤ 0.001). The percentage of pacing beats during MST was higher in CLS configuration than with the other two algorithms (48.4 ± 17.9 vs 27.4 ± 17.5 vs 25.8 ± 17.6; P ≤ 0.001). The average peak-SBP was significantly higher during MST in CLS mode than in VVIR and VVI configurations (172.6 ± 15.5 vs 156.7 ± 12.2 vs 145.5 ± 13.7; P ≤ 0.001). The mean SBP increase showed a similar behavior (51.8 ± 24.7 vs 18.4 ± 13.7 vs 16.4 ± 10.3; P ≤ 0.001). Conclusion: CLS algorithm in a single-chamber device is more effective than AS in detecting an hemodynamic demand due to an emotional stress and supplying a proper HR increase. These results are even more surprising compared to previous data in dual-chamber pacemakers, because they imply that CLS algorithm can provide an appropriate rate-modulation in patients with AF and chronotropic incompetence. (PACE 2012; 35:990-998) © 2012 Wiley Periodicals, Inc.
Proietti R.,Luigi Sacco Hospital |
Proietti R.,McGill University |
Pecoraro V.,IRCCS Orthopedic Institute Galeazzi |
Di Biase L.,The Texas Institute |
And 12 more authors.
Europace | Year: 2013
The aim of this study was to determine the efficacy and safety of remote magnetic navigation (RMN) with open-irrigated catheter vs. manual catheter navigation (MCN) in performing atrial fibrillation (AF) ablation. We searched in PubMed (1948-2013) and EMBASE (1974-2013) studies comparing RMN with MCN. Outcomes considered were AF recurrence (primary outcome), pulmonary vein isolation (PVI), procedural complications, and data on procedure's performance. Odds ratios (OR) and mean difference (MD) were extracted and pooled using a random-effect model. Confidence in the estimates of the obtained effects (quality of evidence) was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. We identified seven controlled trials, six non-randomized and one randomized, including a total of 941 patients. Studies were at high risk of bias. No difference was observed between RMN and MCN on AF recurrence [OR 1.18, 95% confidence interval (CI) 0.85 to 1.65, P = 0.32] or PVI (OR 0.41, 95% CI 0.11-1.47, P = 0.17). Remote magnetic navigation was associated with less peri-procedural complications (Peto OR 0.41, 95% CI 0.19-0.88, P = 0.02). Mean fluoroscopy time was reduced in RMN group (-22.22 min; 95% CI-42.48 to-1.96, P = 0.03), although the overall duration of the procedure was longer (60.91 min; 95% CI 31.17 to 90.65, P < 0.0001). In conclusion, RMN is not superior to MCN in achieving freedom from recurrent AF at mid-term follow-up or PVI. The procedure implies less peri-procedural complications, requires a shorter fluoroscopy time but a longer total procedural time. For the low quality of the available evidence, a proper designed randomized controlled trial could turn the direction and the effect of the dimensions explored. © 2013 The Author.
Gerritsma M.,Technical University of Delft |
Hiemstra R.,University of Austin |
Kreeft J.,Royal Dutch Shell |
Palha A.,Technical University of Delft |
And 2 more authors.
Lecture Notes in Computational Science and Engineering | Year: 2014
The relation between physics, its description in terms of partial differential equations and geometry is explored in this paper. Geometry determines the correct weak formulation in finite element methods and also dictates which basis functions should be employed to obtain discrete well-posedness. © Springer International Publishing Switzerland 2014.
News Article | November 10, 2016
Standing on the roof of the Facebook lab in Woodland Hills, California, I can’t see the airplane I’m looking for. It’s too small and too far away. So I duck under a white tent beside me where a bunch of engineers are watching a live video feed from a nearby camera on a massive flat-panel display. Even at heavy magnification, the aircraft is a tiny spec against the blue sky. Beside the tent, a ten-foot-tall dish antenna is trying to establish a connection with the plane. On the flat-panel, a small red circle shows the precise point in the sky where the rooftop antenna is aiming. The red circle flits around the tiny spec, without quite reaching it. At times, one will zoom away from the other. But after several minutes, they come together. “We got lock!” yells Abhishek Tiwari, a lead engineer at Facebook, as the two connect. And then, just as quickly, the connection breaks. This is one of the first airborne tests of a new wireless technology Facebook is building for use with Aquila, the company’s Boeing-737-sized, solar-powered, long-range drone that’s designed to deliver internet access. Facebook engineers hope this wireless system will one day transport enormous amounts of data from ground stations to dozens of drones in the stratosphere, miles away. The drones will then beam the signal down to ground stations that can serve a city or rural area using more traditional communications—or even send the signal straight to smartphones down below, like a flying cellular antenna. Either way, Facebook’s plan aims to bring the internet (and, of course, a certain social network) to new areas without the need to dig holes, install towers, and stretch expensive wire lines across the planet. But the company has a long way to go before reaching that goal. That plane circling the San Fernando Valley in the distance? It’s not the actual drone but a stand-in, a Cessna that Tiwari and his team have outfitted with an extra bulge of equipment on its belly. The key to the whole idea is an old but suddenly resurgent signaling paradigm called millimeter wave technology. Millimeter waves are smaller than the radio waves that transmit cell phone and Wi-Fi signals, and since this portion of the airwaves is not as widely used as others, Facebook can use it to send much larger about of data. Others have used millimeter wave systems to send data between two distant points, like ground stations and satellites. But it’s always been a bulky, power-hungry setup. Facebook is pushing toward the kind of lightweight, energy efficient applications that have only been contemplated in scientific journals and maybe some secret government labs. “There are a lot of theoretical papers on this,” says Robert Heath, an electrical engineer at the University of Austin. “But there aren’t a lot of people who are actually making it work.” Heath says that Facebook’s millimeter wave team rivals any in the world. The team has already proven that its millimeter wave system can trade data between two fixed points eight miles away from each other at a rate of nearly 20 Gigabits per second. That’s roughly 400 times the speed of your home Internet connection. Facebook believes this is a world record for equipment that’s so light and consumes so little power. But achieving that rate in connection with a moving target—and pushing that data rate even faster—are enormously difficult. First the team has to calibrate the precise orientation of the ground antenna using the position of the Sun. Then the flying antenna must lock in on that ground antenna—while hurtling through the sky at more than a hundred miles an hour, eight miles away, connecting with nothing a millimeter wave beam. It’s is like trying to thread a moving needle from the other side of a room. During the test flight, hours go by: red circle zooming past tiny spec, locking briefly, falling away, the team anxiously waiting for a consistent lock. Tiwari and his team built their first prototype of their wireless system during a Facebook hackathon in January. At the time, engineers at the Woodland Hills lab were already working on laser communication technologies for use with Aquila, but they knew lasers wouldn’t work for getting data from the ground to the sky. For that, they needed a signal that could pass through clouds. That’s where they decided millimeter wave technology would come in. (The lasers will still be handy for sending signals between Aquilas in the stratosphere.) Nine months after the hackathon, they were ready for the test flight. Three hours before he heads up to the roof in Woodland Hills, Tiwari—who worked on millimeter wave tech for Darpa before he came to Facebook—is on his knees inside a hangar at Whiteman Airport, about 20 miles away, helping install a millimeter wave antenna on the underside of the Cessna, a plane typically used for aerial photography. The engineers can’t get one of the screws in, and until they do, the plane can’t take off. The antenna fits into a hole in the belly of the plane. It’s a dish little bigger than your hand, and it sits on a two-axis gimbal that controls its direction. The bulk of the apparatus is made of carbon-fiber to reduce weight. It’s about the size of a basketball, covered with a plastic globe to protect it from the wind, and wires connect the antenna to a Dell laptop and some other equipment in the cockpit. The antenna uses the E band, radio frequencies from about 60-GHz to 90-GHz on the electromagnetic spectrum. Because this band includes so much available spectrum, it’s ideal for what’s called “backhaul”—moving enormous data between two different wireless hubs. Plus, says Hamid Hemmati, who oversees the Woodland Hills lab, the E band isn’t as heavily licensed as other frequencies. That means it’s easier to actually deploy this technology—and that, too, is important for the company’s grand plan. Rather than keep all this technology proprietary, Facebook is open sourcing all its Aquila designs, including its millimeter wave hardware. Meanwhile, other Facebook teams are building terrestrial antennas that can help blanket cities with cellular and Wi-Fi signals or beam a signal from a city to distant rural areas. The company will share all these designs freely through an organization the company calls the Telecom Infrastructure Project. Ultimately, Facebook’s bosses want telecoms, governments, and emergency response organizations to build and deploy this equipment themselves—and improve on it. And for that prospect to become real, Facebook’s Internet drone must be easy to build and operate at low cost. That means sending as much data as possible from an ultra-lightweight payload driven only by power Aquila gets from the sun. “It must be cheaper than any other means of getting communications out there,” Tiwari says. And, of course, it also has to work. After few hours of trying, the Woodland Hills team is finally able to make a consistent connection between the antenna on the lab roof and the flying Cessna. The connection is nowhere near 20 Gigabits a second, but it’s an important step nonetheless. “We want to get this into people’s hands as soon as possible,” Hemmati says. Next step: Replacing that Cessna with one of Facebook’s giant, v-shaped Aquilas.
News Article | November 25, 2015
One of the problems with standard electronics is that the circuits inside aren't really built to deal with the kind of wear and tear the future of the medium intends to put on them. Most things degrade with enough use, of course, but trying to fold or roll electronic circuits, for example, speeds up that process. The solution? Circuits that heal themselves when they break. Guihua Yu, a mechanical engineering assistant professor at the University of Austin's Cockrell School of Engineering, and his team have created a self-healing gel that's reportedly the first of its kind: it doesn't require heat or light to function, which is kind of a big deal when it comes to self-healing applications. "In the last decade," says Yu in a quote at Phys.org, "the self-healing concept has been popularized by people working on different applications, but this is the first time it has been done without external stimuli." This time, the thing can actually self-heal all on its own. In two separate papers in the scientific journal Nano Letters, Yu and his team describe the gel and its properties as well as how they created it. First and foremost, it's actually a combination of two other gels: one that supplies the self-healing properties and another that's a conductor, making the mix a perfect match for electronic circuits. It has a molecular framework that basically uses zinc atoms for glue while also maintaining major conductivity — around 10 times that found in comparable gels. Even so, it's not going to replace every single electronic circuit out there. Instead, Yu sees the gel being used to strengthen junction points where circuits are more likely to break — making those much more difficult to destroy thanks to the self-healing conductive gel. It could also eventually see medical applications — where long-serving rugged electronic circuits are important — and use with batteries.