Pulsed beam diffraction by a perfectly conducting wedge: exactsolution

The new canonical problem of scattering of a collimated pulsed beam (PB) by a perfectly conducting wedge is analyzed and solved exactly. The incident PB is modeled by the so called complex-source PB (CSPB). The authors derive an exact closed-form solution for the scattered field and demonstrate, via extensive numerical examples, the local scattering phenomena as a function of the PB parameters (direction, distance from the edge, spatial collimation, and pulse length): if the PB hits near the edge it generates a toroidal diffracted wavepacket that propagates along Keller's cone as well as transitional shadow boundaries effects. These diffraction phenomena diminish as the distance of the impinging wavepacket from the edge grows     

Prevalences of intimate partner violence in a representative U.S. Air Force sample.

Objective: Intimate partner violence (IPV) is a serious health concern, but little is known about prevalence of IPV in the armed forces, as military members cope with the pressures of long-standing operations. Furthermore, previous prevalence studies have been plagued by definitional issues; most studies have focused on acts of aggression without consideration of impact (clinically significant [CS] IPV). This is the first large-scale study to examine prevalences of IPV, CS-IPV, and clinically significant emotional abuse (CS-EA) for men and women. Method: A United States Air Force-wide anonymous survey was administered across 82 bases in 2006 (N = 42,744) to assess IPV, CS-IPV, and CS-EA. Results: The adjusted prevalence of CS-IPV perpetration was 4.66% for men and 3.54% for women. Prevalences of IPV perpetration were 12.90% for men and 15.14% for women. CS-EA victimization was 6.00% for men and 8.50% for women. Sociodemographic differences in risk for violence were found for gender, race/ethnicity, pay grade, religious faith, marital status, and career type even after controlling for other demographic variables. Conclusions: Partner maltreatment is widespread in military (and civilian) samples. Men were more likely to perpetrate CS-IPV, whereas women were more likely to perpetrate IPV. Specific demographic risk factors were identified for different types of partner maltreatment (e.g., lower rank predicted higher risk for both perpetration and victimization across men and women). Other sociodemographic differences varied across severity (IPV vs. CS-IPV) and across gender. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Adaptive optical transmitter and receiver for space communication through thin clouds

Optical space communication from satellite to ground or air to air consists of clouds as part of communication channels. Propagation of optical pulses through clouds causes widening and deformation in the time domain and attenuation of the pulse radiant power. These effects decrease the received signal and limit the information bandwidth of the communication system. Having dealt with the other effects previously, here we concentrate on pulse broadening in the time domain. We derive a mathematical model of an adaptive optical communication system with a multiscattering channel (atmospheric cloud). We use knowledge about the impulse response function of the cloud to adapt the communication parameters to the transfer function of the cloud. The communication system includes a receiver and a transmitter. We adapted the transmitter to atmospheric conditions by changing the bit error rate. One can adapt the receiver to the atmospheric condition by changing the parameters of the detector and the filter. An example for a practical communication system between a low Earth orbit satellite and a ground station cover by cloud is given. Comparison and analysis of an adaptive and semiadaptive system with cloud channels are presented. Our conclusion is that in some cases only by such adaptive methods is optical communication possible.     

Feeling controlled in marriage: A phenomenon specific to physically aggressive couples?

Spouses in maritally happy nonaggressive (H; n?=?21), distressed nonaggressive (DNA; n?=?16), and distressed aggressive (DA; n?=?20) marriages were interviewed about their perceptions of their spouse as controlling. Four areas of spousal control were assessed: involvement in decision making, relationships with family and friends, freedom to plan activities independently, and sense of competence and self-respect. Overall, as expected, spouses in happy marriages reported feeling less controlled than spouses in the 2 distressed groups. Few gender differences were obtained, with the exception that wives in aggressive marriages were more likely to report that their husbands controlled their sense of competence and self-respect. Differences between the DA and DNA groups depended on the specific area of control. Wives in the aggressive couples were significantly more likely than their husbands to state that their spouse's aggression was an attempt to control them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuroprotective Effect of Glatiramer Acetate on Neurofilament Light Chain Leakage and Glutamate Excess in an Animal Model of Multiple Sclerosis

Axonal and neuronal pathologies are a central constituent of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), induced by the myelin oligodendrocyte glycoprotein (MOG) 35–55 peptide. In this study, we investigated neurodegenerative manifestations in chronic MOG 35–55 induced EAE and the effect of glatiramer acetate (GA) treatment on these manifestations. We report that the neuronal loss seen in this model is not attributed to apoptotic neuronal cell death. In EAE-affected mice, axonal damage prevails from the early disease phase, as revealed by analysis of neurofilament light (NFL) leakage into the sera along the disease duration, as well as by immunohistological examination. Elevation of interstitial glutamate concentrations measured in the cerebrospinal fluid (CSF) implies that glutamate excess plays a role in the damage processes inflicted by this disease. GA applied as a therapeutic regimen to mice with apparent clinical symptoms significantly reduces the pathological manifestations, namely apoptotic cell death, NFL leakage, histological tissue damage, and glutamate excess, thus corroborating the neuroprotective consequences of this treatment.     

Aroma volatile compositions of high- and low-aromatic guava varieties

BACKGROUND: The traditional guava variety cultivated in Israel, ‘Ben Dov’, emits a very strong odour, whereas some newly bred varieties have a mild odour. In this study the aroma profile composition of the high‐aromatic ‘Ben Dov’ variety was compared with those of four new low‐aromatic varieties. RESULTS: Overall, using gas chromatography/mass spectrometry, a total of 30 aroma volatiles were detected in fresh ripe guava fruit: 15 of them were specifically detected only in the high‐aromatic ‘Ben Dov’ variety, 13 were detected in both the high‐ and low‐aromatic varieties and two were detected only in the new low‐aromatic varieties. Interestingly, 11 out of the 15 volatiles specifically detected in ‘Ben Dov’ were esters that contribute sweet, tropical and fruity notes. In contrast, ten out of 13 detected terpenes and two detected aldehydes, contributing green, spicy, herbal and woody notes, were common to both the high‐ and low‐aromatic varieties. CONCLUSION: Based on these findings, it is concluded that accumulation of esters is the main reason why the traditional ‘Ben Dov’ guava variety emits such a strong tropical fruity odour. In contrast, the newly bred low‐aromatic guava varieties did not synthesise esters at all and thus lacked fruity aromatic notes. Overall, the results of this study point out the important role of esters in forming tropical fruity guava odours. Copyright © 2011 Society of Chemical Industry     

Non-line-of-sight optical wireless sensor network operating in multiscattering channel

Networks of sensors are envisaged to be major participants in future data-gathering systems for civilian and military applications, including medical and environmental monitoring and surveillance, home security, agriculture, and industry. Typically, a very large number of miniature sensing and communicating nodes are distributed ad hoc at the location of interest, where they establish a network and wirelessly communicate sensed data either to one another or to a base station using various network topologies. The optical modality is a potential solution for the links, due to the small and lightweight hardware and low power consumption, as well as other special features. Notably, the backscattering of light by molecules and aerosols in the atmosphere can function as a vehicle of communication in a way similar to the deployment of numerous tiny reflecting mirrors. The scattering of light at solar-blind ultraviolet wavelengths is of particular interest since scattering by atmospheric particles is significant and ambient solar interference is minimal. In this paper we derive a mathematical model of a simple and low-cost non-line-of-sight (NLOS) optical wireless sensor network operating in the solar-blind ultraviolet spectral range. The viability and limitations of the internode link are evaluated and found to facilitate miniature operational sensor networks.     

Feasibility of retroreflective transdermal optical wireless communication

There is an increasing demand for transdermal high-data-rate communication for use with in-body devices, such as pacemakers, smart prostheses, neural signals processors at the brain interface, and cameras acting as artificial eyes as well as for collecting signals generated within the human body. Prominent requirements of these communication systems include (1) wireless modality, (2) noise immunity and (3) ultra-low-power consumption for the in-body device. Today, the common wireless methods for transdermal communication are based on communication at radio frequencies, electrical induction, or acoustic waves. In this paper, we will explore another alternative to these methods--optical wireless communication (OWC)--for which modulated light carries the information. The main advantages of OWC in transdermal communication, by comparison to the other methods, are the high data rates and immunity to external interference availed, which combine to make it a promising technology for next-generation systems. In this paper, we present a mathematical model and experimental results of measurements from direct link and retroreflection link configurations with Gallus gallus domesticus derma as the transdermal channel. The main conclusion from this work is that an OWC link is an attractive communication solution in medical applications. For a modulating retroreflective link to become a competitive solution in comparison with a direct link, low-energy-consumption modulating retroreflectors should be developed.