Design and characterization of optical heads for interferometric ballistic velocity measurements

The design of optical fiber based heads offering high accuracy and bandwidth for use in VISAR (velocity interferometer system for any reflector) experiments measuring ballistic velocities is described. A new, expanded, model for predicting the distance-dependent collection efficiency of the heads is presented. The model is shown to agree very well with experimental results, both within and outside the "depth of field". Various optical heads are demonstrated, to suit different experimental setups and conditions. Designs offering options for high bandwidths, accurate prealignment, and large stand-off distances are discussed. Results from a typical VISAR experiment are presented, verifying that our designs yield high-quality data.     

Two are Better than One: Combining ZnO and MgF2 Nanoparticles Reduces Streptococcus pneumoniae and Staphylococcus aureus Biofilm Formation on Cochlear Implants

Streptococcus pneumoniae (S. pneumoniae) and Staphylococcus aureus (S.aureus) are considered the most common colonizers of cochlear implants (CI), which have prompted the search for new ways to inhibit their growth and biofilm development. In the current study, CI‐based platforms are prepared and sonochemically coated with ZnO or MgF₂ nanoparticles (NPs), two agents previously shown to possess antibacterial properties. Additionally, a method is developed for coating both ZnO and MgF₂ on the same platform to achieve synergistic activity against both pathogens. Each surface is characterized, and the optimal conditions for the NP homogenous distribution on the surface are determined. The ZnO‐MgF₂ surface significantly reduces the S. pneumoniae and S. aureus biofilm compared with the surfaces coated with either ZnO or MgF₂, even though it contains smaller amounts of each NP type. Importantly, leaching assays show that the NPs remain anchored to the surface for at least 7 d. Finally, biocompatibility studies demonstrate that coating with low concentrations of ZnO‐MgF₂ results in no toxicity toward primary human fibroblasts from the auditory canal. Taken together, these findings underscore the potential of using NP combinations such as the one presented here to efficiently inhibit bacterial colonization and growth on medical devices such as CIs.     

Parental and offspring assessment of driving capability under the influence of drugs or alcohol: Gender and inter-generational differences

The current study set to examine whether there are inter-generational and gender-based differences between family members self-assessing their ability to drive under normal conditions and while under the influence of either alcohol or drugs. Participants were 135 young-adults and both their parents, consisting 45 family triads, who received self-assessment questionnaires relating to their driving skills in various road scenarios. Each family triad was randomly assigned to one of three groups: either requested to base the assessments on normal driving conditions, or under the influence of either drugs or alcohol, thus forming a control group, and two experimental groups (alcohol and drugs), respectively.The findings indicate the assessments of both the alcohol and drugs groups were more severe than those of the control group. The alcohol group assessments were less strict than the drug group assessment (non-significantly). Inter-generational differences indicated that the parents’ driving-skills assessments were lower than those of their offspring, corresponding with previous findings (Elkind, 1967, Finn and Bragg, 1986).A significant within-subject interaction has been found between the respondent's gender and familial relations regarding the self-assessment of driving skills: male respondents assessed better driving skills compared to the self estimates of both parents (which did not significantly differ). In contrast, female respondents’ estimates did not differ from their fathers’ and both fathers’ and daughters’ estimates were significantly higher than that of the mothers in each family.     

Fabrication of coaxial metal nanocables using a self-assembled peptide nanotube scaffold

The design and fabrication of complex nanostructures with specific geometry and composition is one of the main challenges of nanotechnology. Here we demonstrate the devise of metal-insulator-metal, trilayered, coaxial nanocables. Such coaxial geometry may give rise to useful and unique electromagnetic properties. We have fabricated these nanostructures using a scaffold of self-assembled peptide nanotubes. Gold nanoparticles were bound to the surface of peptide nanotubes via a common molecular recognition element that was included in various linker peptides. This enabled us to promote site-specific metal reduction and to create the coaxial nanostructure. Using electron microscopy, 1H NMR spectra, and energy-dispersive X-ray analysis, we monitored the different steps within the process, gaining further understanding of its mechanism.     

Vehicle impoundment regulations as a means for reducing traffic-violations and road accidents in Israel

The vehicle impoundment sanction in Israel is applicable to several violations, and authorizes police officers to impound a vehicle for period of 30 days, in addition to license suspension. This study examined the effects of vehicle impoundment on traffic-violations and road accidents in Israel, using both subjective and objective measures. A telephone survey was administered to 378 impounded drivers, examining their knowledge and support of the impoundment penalty, as well as the impoundment's effect on their daily life and subsequent driving behaviors. Survey results indicated most impounded drivers did not recognize the violations to which impoundment applies. Respondents described the impoundment experience as one, which interfered with a variety of daily life aspects, and eventually lead them to the adoption of safer driving behaviors. Additionally, data analysis of police records was performed on 1549 impounded drivers and 1354 controls with matching violations performed prior to the application of the impoundment regulation, comparing accident and traffic-violations involvement in the subsequent year. Results indicated that impoundment failed to yield a significant effect over subsequent accident involvement, compared to previous sanctions. A comparison of subsequent traffic-violations indicated lower rates of violations following impoundment as compared with previous sanctions. Specifically, drivers whose vehicle was impounded were less likely to commit traffic violations in the following year than drivers subjected to other sanctions. The results are explained according to psychological behavioral theories of punishment effectiveness. These findings provide further support for impoundment as a deterrent for several traffic-violations.     

Impact of <Emphasis Type="Italic">in vivo</Emphasis> glycation of LDL on platelet aggregation and monocyte chemotaxis in diabetic <Emphasis Type="Italic">Psammomys obesus</Emphasis>

Psammomys obesus (sand rat) is an appropriate model to highlight the development of hyperinsulinemia, insulin resistance, obesity, and diabetes. This animal species, with genetically predetermined diabetes, acquires non-insulin dependent diabetes mellitus when exposed to energy-rich diets. In the present study, we explored the possibility that glycation of LDL may occur in diabetes-prone P. obesus and affect platelet and macrophage functions. The glycation of LDL, isolated from diabetic animals, was significantly (P<0.05) higher (40%) than that of control animals. The incubation of platelets with glycated LDL enhanced the reactivity of platelets by 32–44% depending on the aggregating agents (thrombin, collagen, ADP). Furthermore, LDL derived from diabetic rats were chemotactic for normal monocytes and stimulated the incorporation of [¹⁴C]oleate into cellular cholesteryl esters. The enhancement of platelet aggregation and cholesterol esterification in monocytes may contribute toward the accelerated development of atherosclerotic cardiovascular disease in diabetic P. obesus animals. This study also illustrates the relevance of studying atherosclerosis in the P. obesus animal model, as it shows an increased tendency to develop dietinduced diabetes, which is associated with cardiovascular disorders.     

X-ray spectroscopy of astrophysical plasmas

We provide a qualitative review of key X-ray spectral diagnostics of astrophysical plasmas. We begin with a brief discussion of the two major types of equilibria, collisional ionization and photoionization, and then consider the behaviour of hydrogen-like, helium-like, iron L-shell and iron K-shell transitions for these separate cases. Where possible, we discuss explicit examples using high-resolution spectra acquired by the grating instruments on the Chandra and XMM-Newton observatories.     

Recovery of 3D animal motions using cameras and mirrors

We present a system that tracks an articulated body performing 3D movement with occlusions using a combination of cameras and mirrors. By integrating cameras and mirrors we get a simultaneous coverage of almost every point on the target and avoid occlusions. The suggested setup is much simpler and easier to handle compared to the equivalent, camera-based setup. Our tracking algorithm is model-based, and errors in the model are treated using the bundle adjustment procedure. In order to deal with the problem of feature visibility, each feature is set to be valid or invalid based on the model and on its expected appearance; this ensures that the system always tracks a set of distinguishable features. The proposed algorithm was able to track targets in 3D using the Gauss–Newton method to minimize geometric errors. We tested our setup by tracking the chameleon’s eyes. Tracking the eyes of a chameleon can be considered as the estimation of the 3D pose of an articulated body, where the head of the chameleon is considered as a rigid body, and each of the two eyes has additional two degrees of freedom. The algorithm proposed can be easily expanded to cope with more complex objects.     

Scanning and tracking with independent cameras—a biologically motivated approach based on model predictive control

This paper presents a framework for visual scanning and target tracking with a set of independent pan-tilt cameras. The approach is systematic and based on Model Predictive Control (MPC), and was inspired by our understanding of the chameleon visual system. We make use of the most advanced results in the MPC theory in order to design the scanning and tracking controllers. The scanning algorithm combines information about the environment and a model for the motion of the target to perform optimal scanning based on stochastic MPC. The target tracking controller is a switched control combining smooth pursuit and saccades. Min-Max and minimum-time MPC theory is used for the design of the tracking control laws. We make use of the observed chameleon’s behavior to guide the scanning and the tracking controller design procedures, the way they are combined together and their tuning. Finally, simulative and experimental validation of the approach on a robotic chameleon head composed of two independent Pan-Tilt cameras is presented.