Reproductive biology of blue marlin (Makaira nigricans) in the western Pacific Ocean

The reproductive biology of blue marlin (Makaira nigricans) was assessed from 1001 fish (ranging from 121 to 275 cm in eye-to-fork length; EFL) caught by Taiwanese offshore longliners in the western Pacific Ocean from September 2000 to December 2001 and from 843 gonad samples from these fish, The overall sex ratio of the catch was approximately 1:1 dur ing the sampling period, but blue marlin are sexually dimorphic; females are larger than males. Reproductive activity (assessed by histology), a gonadosomatic index, and the distribution of oocyte diameters, indicated that spawning occurred predominantly from May to September. The estimated sizes-at-maturity (EFL50) were 179.76 ±1.01 cm (mean ±standard error) for females and 130 ±1 cm EFL for males. Blue marlin are multiple spawners and oocytes develop asynchronously. The proportion of mature females with ovaries containing postovulatory follicles (0.41) and hydrated oocytes (0.34) indicated that the blue marlin spawned once every 2–3 days on average. Batch fecundity (BF) for 26 females with the most advanced oocytes (≥1000 μm), but without postovulatory follicles, ranged from 2.11 to 13.50 million eggs (6.94 ± 0.54 million eggs). The relationships between batch fecundity (BF, in millions of eggs) and EFL and round weight (RW, kg) were BF = 3.29 × 10 –12 EFL5.31 (r2 = 0.70) and BF = 1.59 × 10–3 RW 1.73 (r2= 0.67), respectively. The parameters estimated in this study are key information for stock assessments of blue marlin in the western Pacific Ocean and will contribute to the conservation and sustainable yield o

The evaluation of pilots performance and mental workload by eye movement

Pilots make important decisions often using ambiguous information, while under stresses and with very little time. During flight operations detecting the warning light of system failure is a task with real-world application relates to measurement of pilot's performance and eye movement. The demand for a pilot’s visual and situational awareness in multiple tasks can be detrimental during pilots’ mental overload conditions. The purpose of this research is to evaluate the relationship between pilot’s mental workload and operational performance by eye tracking. Collecting eye movement data during flight operations in a virtual reality of flight simulator provided useful information to analysis participants’ cognitive processes. There were 36 pilots participated in this research, the experience of flight hours between 320 and 2,920, the range of age between 26 and 51 years old. The apparatus included Applied Science Laboratories (ASL) eye tracking, IDF flight simulator and NASA_TLX for data collection. The results show that pilots with high SA detecting hydraulic malfunction have shorter total fixation duration on Air Speed Indicator and longer total fixation duration on Altitude Indicator, Vertical Speed Indicator, Right multi-display and Left multi-display compared with pilots without detecting the signal of hydraulic malfunction. Pilots’ total fixation time on Integration Control Panel, Altitude Indicator, Attitude Indicator and Right Multi-display, and pilots’ subjective rating on NASA-TLX effort dimension for the mission of close pattern have significant relationship with pilots’ performance on the operational time for completing the tactic mission. Experienced pilots operate aircraft familiar with monitoring Airspeed Indicator and kinetic maneuvering result in less fuel consumption. This study could provide guidelines for future training design to reduce pilots mental workload and improve situational awareness for enhancing flight safety

Scheduling periodic jobs using imprecise results

One approach to avoid timing faults in hard, real-time systems is to make available intermediate, imprecise results produced by real-time processes. When a result of the desired quality cannot be produced in time, an imprecise result of acceptable quality produced before the deadline can be used. The problem of scheduling periodic jobs to meet deadlines on a system that provides the necessary programming language primitives and run-time support for processes to return imprecise results is discussed. Since the scheduler may choose to terminate a task before it is completed, causing it to produce an acceptable but imprecise result, the amount of processor time assigned to any task in a valid schedule can be less than the amount of time required to complete the task. A meaningful formulation of the scheduling problem must take into account the overall quality of the results. Depending on the different types of undesirable effects caused by errors, jobs are classified as type N or type C. For type N jobs, the effects of errors in results produced in different periods are not cumulative. A reasonable performance measure is the average error over all jobs. Three heuristic algorithms that lead to feasible schedules with small average errors are described. For type C jobs, the undesirable effects of errors produced in different periods are cumulative. Schedulability criteria of type C jobs are discussed

Thermal-flow technique for reducing surface roughness and controlling gap size in polymer microring resonators

QQ factors of microring resonator waveguide devices are primarily limited by the surface-roughness-induced scattering loss. Such surface roughness loss has been observed in waveguides that are fabricated from various types of materials, including semiconductors, dielectrics, and polymers. In this letter, we show that the surface roughness of polymer waveguides can be greatly reduced by a thermal-flow technique, and the effective reduction in waveguide loss was verified experimentally. In addition to smoothing surfaces, this technique can simultaneously shrink the gap distance in the coupling region of polymer microring resonators. This, in turn, provides higher coupling, lessens the difficulty of fabricating submicron gaps, and leads to more compact devices. © 2004 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71218/2/APPLAB-84-14-2479-1.pd

Biochemical sensors based on polymer microrings with sharp asymmetrical resonance

Photonic microresonators have great potential in the application of highly sensitive sensors due to high Q-factor resonances and steep slopes between zero and unity transmission. A microring resonator with increased resonance slopes is proposed by introducing two partially reflecting elements implemented by waveguide offsets. This configuration produces a Fano-resonant line shape and can greatly enhance the sensitivity of the sensor. Polystyrene microring resonators were fabricated by the nanoimprinting technique, and the optical spectra were measured in glucose solutions of different concentrations. The shift in resonant wavelength and variation of the normalized transmitted intensity are linearly related to the concentration of the glucose solution. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69921/2/APPLAB-83-8-1527-1.pd

Spatiomechanical Modulation of EphB4-Ephrin-B2 Signaling in Neural Stem Cell Differentiation.

Interactions between EphB4 receptor tyrosine kinases and their membrane-bound ephrin-B2 ligands on apposed cells play a regulatory role in neural stem cell differentiation. With both receptor and ligand constrained to move within the membranes of their respective cells, this signaling system inevitably experiences spatial confinement and mechanical forces in conjunction with receptor-ligand binding. In this study, we reconstitute the EphB4-ephrin-B2 juxtacrine signaling geometry using a supported-lipid-bilayer system presenting laterally mobile and monomeric ephrin-B2 ligands to live neural stem cells. This experimental platform successfully reconstitutes EphB4-ephrin-B2 binding, lateral clustering, downstream signaling activation, and neuronal differentiation, all in a configuration that preserves the spatiomechanical aspects of the natural juxtacrine signaling geometry. Additionally, the supported bilayer system allows control of lateral movement and clustering of the receptor-ligand complexes through patterns of physical barriers to lateral diffusion fabricated onto the underlying substrate. The results from this study reveal a distinct spatiomechanical effect on the ability of EphB4-ephrin-B2 signaling to induce neuronal differentiation. These observations parallel similar studies of the EphA2-ephrin-A1 system in a very different biological context, suggesting that such spatiomechanical regulation may be a common feature of Eph-ephrin signaling

Ultrasound detection using polymer microring optical resonator

Application of polymer waveguide microring resonators for high-frequency ultrasound detection is presented. The device consists of a microring optical resonator coupled to a straight optical waveguide which serves as input and output ports. Acoustic waves irradiating the ring waveguide induce strain modifying the waveguide cross section. As a consequence, the effective refractive index of optical waves propagating along the ring is modified. The sharp wavelength dependence of the high QQ-factor resonator enhances the optical response to acoustic strain. High sensitivity is demonstrated experimentally in detecting broadband ultrasound pulses from a 10 MHz10 MHz transducer. Methods of extending the technique to form multi-element ultrasonic arrays for imaging applications are proposed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70498/2/APPLAB-85-22-5418-1.pd

Geo-processing in cyberinfrastructure: making the web an easy to use geospatial computational platform

International audienceAccess to data on the web has become routine based upon open standards from IETF and W3C. Access to explicitly geospatial data is routinely done using data access standards from the OGC. Geoprocessing services on the web are now being developed. Processing of data must be done to apply or fuse the data to meet specific applications. Standards and implementations for processing of data on the web are just now becoming established. For geospatial data, the OGC has defined the Web Processing Service (WPS) interface standard. Now is a critical time to bring convergence to WPS profiles that make the web an easy to use geospatial computational service. Access to network accessible processing services is bringing geoprocessing to the cyberinfrastructure

Analog Least Mean Square Loop for Self-Interference Cancellation: A Practical Perspective

Self-interference (SI) is the key issue that prevents in-band full-duplex (IBFD) communications from being practical. Analog multi-tap adaptive filter is an efficient structure to cancel SI since it can capture the nonlinear components and noise in the transmitted signal. Analog least mean square (ALMS) loop is a simple adaptive filter that can be implemented by purely analog means to sufficiently mitigate SI. Comprehensive analyses on the behaviors of the ALMS loop have been published in the literature. This paper proposes a practical structure and presents an implementation of the ALMS loop. By employing off-the-shelf components, a prototype of the ALMS loop including two taps is implemented for an IBFD system operating at the carrier frequency of 2.4 GHz. The prototype is firstly evaluated in a single carrier signaling IBFD system with 20 MHz and 50 MHz bandwidths, respectively. Measured results show that the ALMS loop can provide 39 dB and 33 dB of SI cancellation in the radio frequency domain for the two bandwidths, respectively. Furthermore, the impact of the roll-off factor of the pulse shaping filter on the SI cancellation level provided by the prototype is presented. Finally, the experiment with multicarrier signaling shows that the performance of the ALMS loop is the same as that in the single carrier system. These experimental results validate the theoretical analyses presented in our previous publications on the ALMS loop behaviors