External Timer Research Articles

Major oscillations in spontaneous home-cage activity in C57BL/6 mice housed under constant conditions.

The mouse is the most important mammalian model in life science research and the behavior of the mouse is a key read-out of experimental interventions and genetic manipulations. To serve this purpose a solid understanding of the mouse normal behavior is a prerequisite. Using 14–19 months of cumulative 24/7 home-cage activity recorded with a non-intrusive technique, evidence is here provided for a highly significant circannual oscillation in spontaneous activity (1–2 SD of the mean, on average 65% higher during peak of highs than lows; P = 7E−50) of male and female C57BL/6 mice held under constant conditions. The periodicity of this hitherto not recognized oscillation is in the range of 2–4 months (average estimate was 97 days across cohorts of cages). It off-sets responses to environmental stimuli and co-varies with the feeding behavior but does not significantly alter the preference for being active during the dark hours. The absence of coordination of this rhythmicity between cages with mice or seasons of the year suggest that the oscillation of physical activity is generated by a free-running intrinsic oscillator devoid of external timer. Due to the magnitude of this rhythmic variation it may be a serious confounder in experiments on mice if left unrecognized.

Modelling of adaptive power management circuit with feedback for self-powered IoT

In general, self-powered sensor networks/Internet of Things (IoT) are equipped with a power management system and use a timer as a reference for the device’s actives time, both using an internal timer and an external timer. The system is less efficient because it requires that there are parts that continue to function when the device is in sleep mode. In addition, the amount of harvested energy also influenced by many factors with an uncertain amount. An IoT self-powered system that uses a timer as an active interval reference will encounter problems when the amount of system energy demand is greater than the harvested energy. This paper presents an adaptive power management system equipped with feedback for self-powered IoT for room temperature and humidity monitoring applications. The power management system can provide adaptive active intervals based on the harvested energy capacity. Microcontrollers send feedback to the power management circuit at the end of each cycle. The power management circuit immediately disconnects the controller circuit from the energy storage’s component (supercapacitor) so that energy used efficiently. Several methods of minimizing the energy consumption of the device are also applied to provide optimal results. The research method begins with system modelling, including an energy harvester circuit, power management, and controller. The research scenarios include energy harvester performance tests, calculating the energy requirements of the power management and controller circuit, and validating research results. Overall, the system can work well, the active interval/data transmission of 14.41 seconds to 22.34 seconds in a room with a light intensity of 800 lux to 1000 lux.

PD17-08 THAWING PROCESS DURING CRYOABLATION WITH HELIUM DISABLES IPHONES AND IWATCHES DEVICES

You have accessJournal of UrologyProstate Cancer: Localized: Ablative Therapy I (PD17)1 Apr 2020PD17-08 THAWING PROCESS DURING CRYOABLATION WITH HELIUM DISABLES IPHONES AND IWATCHES DEVICES Alessandra Pluchino*, Alberto Lopez, Felix Angulo, Pedro Gonzalez, David Cohen, and Fernando Bianco Alessandra Pluchino*Alessandra Pluchino* More articles by this author , Alberto LopezAlberto Lopez More articles by this author , Felix AnguloFelix Angulo More articles by this author , Pedro GonzalezPedro Gonzalez More articles by this author , David CohenDavid Cohen More articles by this author , and Fernando BiancoFernando Bianco More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000860.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: During the fall of 2017, we noted spontaneous shut down (death) of two iPhone 7 devices, both from the technician running the cryoablation machine during prostate cryoablation procedures. A similar event occurred on two iPhones X from a physician and staff member shortly after their launch. The shutdown occurred during the thawing phase of the cryoablation cycle. The devices were tested at two different Apple stores and after thorough testing were replaced. Between 01/2018 and 07/2018, 12 devices (iPhone 7, 8 and X) from 9 different individuals went down requiring replacement. No iPads or android devices exhibited a similar event. On October 13th 2018 we noted a post on reddit.com describing a similar event on a MRI suite. The hypothesis was that leaked helium affected the microprocessor of these devices disabling them, and upon gas dissipation the devices would resume normal function. We decided to test this hypothesis METHODS: We contacted the apple store and secured 10 devices, two IPhone6, one IPhone6 plus, one IPhone7, one IPhone7 plus, two IPhone8, one IPhone8 plus, two iPhone X along with 3 iWatches (gen 1-3). We connected all devices into our WiFi network, then placed each device - on mode - working properly on a freeze resistant zip bag. We called each device and let it ring once. We turned on the timer on each iPhone and delivered helium gas from the cryoablation machine into the bag for 2 seconds, immediately closing the bag. We observed the timer until the phone went down. We pressed the home button or tapped into the screen every 15 seconds to keep it on. We performed the same experiment on 4 android devices of different brands. In addition, the experiment was conducted with the iWatches but using an external timer. RESULTS: All 10 iPhones went dead or disabled within an hour of exposure to helium. We did not measure the concentration of helium. The iWatches remained on at the hour, but would not function properly, one device kept restating until battery ran out and kept restarting after charge. The other 2 had a non-responsive screen. The iPhones X and 8, went disabled within 10 minutes, the 7 within 20 and the 6 version between 30 min. None of the android devices went disabled and all functioned properly after the hour. We observed the IPhones and IWatched over 7 days. All the X and 8, restarted and resumed normal function between 3 and 5 days, the 7plus version between 4 and 5 days and the 6plus and a 6 version by day 6. One iPhone 7 turned on but did not function properly and one iPhone6 remained dead after 7 days. Two of the 3 iWatches resumed normal function during the week CONCLUSIONS: Helium is an inert rapidly expansive gas that can dissipate into any surface. Every smart device uses microelectromechanical systems (MEMS) in their processors. Apple specifically uses SiT512, the smallest quartz oscillators, crystals that vibrate at a specific predictable frequency—generally 32 kHz. Helium caused expansions of MEMS, without these oscillators the CPUs of the devices shuts down Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e372-e372 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alessandra Pluchino* More articles by this author Alberto Lopez More articles by this author Felix Angulo More articles by this author Pedro Gonzalez More articles by this author David Cohen More articles by this author Fernando Bianco More articles by this author Expand All Advertisement PDF downloadLoading ...

A uW Backscatter-Morse-Leaf Sensor for Low-Power Agricultural Wireless Sensor Networks

Nowadays, the monitoring of plant water stress is of high importance in smart agriculture. Instead of the traditional ground soil-moisture measurement, the leaf sensing is a new technology, which is used for the detection of plants needing water. In this paper, a novel, low-cost, and low-power system for leaf sensing using a new plant backscatter sensor node/tag is presented. The latter, can result in the prevention of water waste (water-use efficiency), when is connected to an irrigation system. Specifically, the sensor measures the temperature differential between the leaf and the air, which is directly related to the plant water stress. Next, the tag collects the information from the leaf sensor through an analog-to-digital converter, and then, communicates remotely with a low-cost software-defined radio reader using monostatic backscatter architecture. The tag consists of the sensor board, a microcontroller, an external timer, and an RF front-end for communication. The timer produces a subcarrier frequency for simultaneous access of multiple tags. The proposed work could be scaled and be a part of a large backscatter wireless sensor network. The communication protocol exploits the low-complexity Morse code modulation on a 868 MHz carrier signal. The presented novel proof-of-consent prototype is batteryless and was powered by a flexible solar panel consuming power around $20~\mu \text{W}$ . The performance was validated in an indoors environment where wireless communication was successfully achieved up to 2 m distance.

Hardware-in-the-Loop Simulation of Missile Control System Based on Windows Operation System

A hardware-in-the-loop (HIL) simulation platform in use of windows operation system was successfully established based on general industrial PC combined with an external timer. The following HIL simulation process of missile control system indicated that the novel platform could not only satisfied the real-time requirement of HIL simulation, but also is low-cost and universal, which could provide a convenient new choice in the similar applications.

Fluidic Timers for Time-Dependent, Point-of-Care Assays on Paper

This article describes an integrated approach to tracking the end point of a time-based assay that is conducted on an analytical device made out of paper. The timing mechanism is built directly into a paper-based analytical device and does not require starting, stopping, reset buttons, batteries, or maintenance; the timer simply starts once the sample is added to the device. These "fluidic timers" are composed of paraffin wax and a signaling feature (e.g., a dye). The timing function is made possible by the specific time required for a liquid sample to wick through predefined regions in the device. This time period can be anywhere between 1 min and 2 h and is controlled by the quantity of wax present in the timer. Because both the fluidic timers and paper-based assays depend on the wicking rate of the sample, the fluidic timers automatically calibrate themselves (relative to the assay) to account for differences in wicking rates that are caused by variations in humidity. Fluidic timers are 97% accurate (with respect to the time required for the assay) and provide slightly better accuracy than an external timer when used to track an assay that measured the level of glucose in a sample.

Tight bounds for clock synchronization

We present a novel clock synchronization algorithm and prove tight upper and lower bounds on the worst-case clock skew that may occur between any two participants in any given distributed system. More importantly, the worst-case clock skew between neighboring nodes is (asymptotically) at most a factor of two larger than the best possible bound. While previous results solely focused on the dependency of the skew bounds on the network diameter, we prove that our techniques are optimal also with respect to the maximum clock drift, the uncertainty in message delays, and the imposed bounds on the clock rates. The presented results all hold in a general model where both the clock drifts and the message delays may vary arbitrarily within pre-specified bounds. Furthermore, our algorithm exhibits a number of other highly desirable properties. First, the algorithm ensures that the clock values remain in an affine linear envelope of real time. A better worst-case bound on the accuracy with respect to real time cannot be achieved in the absence of an external timer. Second, the algorithm minimizes the number and size of messages that need to be exchanged in a given time period. Moreover, only a small number of bits must be stored locally for each neighbor. Finally, our algorithm can easily be adapted for a variety of other prominent synchronization models.

Hardware and software for tachistoscopy: how to make accurate measurements on any PC utilizing the Microsoft Windows operating system.

Methods for automated stimulus display and accurate response time measurement with IBM-compatible PCs are of great importance in cognitive research designs. Accurate measurements of reaction times are required to interpolate other measures, such as speed of mental processing. We present a description of hardware and software that displays stimulus images and performs reaction timing that is not dependent on PC performance characteristics. This is accomplished by electronically bypassing timing errors normally inherent to the operation of the computer. A high-precision external timer measures the time between stimulus onset and a subject's push-button response while a video blanking circuit controls the video presented to the monitor screen. Two options for accurately detecting stimulus onset are presented: (1) A photodetector can be used to sense the actual onset of the stimulus on a secondary video monitor screen; (2) the video blanking circuit can provide a signal coincident with the initiation of video to the monitor. Both methods result in a system timing accuracy of 100 microseconds.

Relative determination of W-values for alpha particles in tissue-equivalent and other gases

W (the average energy to form an ion pair) for 5.4 MeV 241Am alpha particles in a Rossi-type tissue-equivalent (TE) gas, argon and methane was determined to an accuracy better than 0.2% using a new automated data handling system. A vibrating reed electrometer and current digitiser were used to measure the current produced by completely stopping the alpha particles in a large cylindrical ionisation chamber. A multichannel analyser, operating in a slow multiscalar mode, was used to store pulses from the current digitiser. The dwell time, of the order of 60 min per channel, was selected with an external timer gate. Current measurements were made at reduced pressures (200 Torr) to reduce ion recombination. The average current, over many repeated measurements, was compared to the current produced in nitrogen and its previously published W-value of 36.39+or-0.04 eV per ion pair.

Lunar cycle and timing of mating season in Serengeti wildebeest

WILDEBEEST (Connochaetes taurinus Thomas) herds numbering nearly 1 million (refs 1, 2) on the Serengeti Plains, Tanzania, produce about 80% of their young during a 3-week period in January or February3. This is short compared with the 2-month birth period of the wildebeest in South Africa4, or to the 3–4-month birth period of buffalo and other grazers in the Serengeti5. A suggested advantage for the closely synchronised wildebeest birth period is that it reduces the probability of hyaena (Crocuta crocuta Erxleben) predation on the young3,6–8. I report here evidence which suggests that the lunar cycle is the external timer for the synchronisation.

Skin-Conductance, Alpha-Activity, and Vigilance

In the typical vigilance-situation, S is required to detect and to respond to slight and infrequent changes in stimulation over long periods of time. The usual finding has been that performance declines markedly after about a half-hour at the task.' Little attention has thus far been paid to the possibility of a relationship between performance in vigilance-tasks and electrophysiological measures of activation, such as skin-conductance and EEG alpha-activity. The present experiment was designed to investigate such a possibility. Method. The apparatus used to record skin-resistance was a Fels Dermohmeter, Model 22A. The zinc-zinc sulphate paste electrodes were attached to the soles of the feet by means of plastic clamps. Readings to the nearest 1000 0 were taken at the end of each minute and later translated into conductance-units. EEG-potentials were recorded from two chlorided silver-disk electrodes secured to the scalp by collodion and placed bilaterally over the occipital lobes about 1 in. above the occipital bulge. Two earlobe-electrodes were used for grounding, and no deflection in amplitude was observed on this channel. Conventional EEG-records were obtained by using a Grass Electroencephalograph, Model 111d. From the later stages of amplification of this instrument, the signal was fed into a band-pass electronic filter, rectified in an integrator preamplifier, Model 5U-IS, integrated in a unit-integrator, Model UI-I, and then further amplified and recorded with a polygraph recorder, Model 5. The characteristics of the filter were as follows: maximal relative transmission at 10 c.p.s., with 50% cut-off points, for sine-wave input at the electroencephalograph, at 7.3 and 12.9 c.p.s. The integrator, which provided mathematical integration (area under the curve), was reset each minute by an external timer. The 1-min. values were read to the nearest millimeter from the graphic record, and mean values later were computed for each 15-min. period. The vigilance-task involved the auditory presentation by tape-recording of a series of digits (1-9) in random order at the rate of 1 per sec. The signal to be detected consisted of a series of three successive odd digits, all of which were different. There were 36 such signals to be detected during the 90-min. session. In