Aberrations in shift-invariant linear optical imaging systems using partially coherent fields

Here the role and influence of aberrations in optical imaging systems employing partially coherent complex scalar fields is studied. Imaging systems require aberrations to yield contrast in the output image. For linear shift-invariant optical systems, we develop an expression for the output cross-spectral density under the space-frequency formulation of statistically stationary partially coherentfields. We also develop expressions for the output cross{spectral density and associated spectral density for weak-phase, weak-phase-amplitude, and single-material objects in one transverse spatial dimension

Developing corporate communications: insights from the Italian scenario

Purpose - Based on business manager perceptions in large firms, this paper explores the emergence, growth and importance of corporate communications and how it is evolving and creating competitive advantage in Italian firms. Design/methodology/approach - A qualitative approach is deployed, comprising depth interviews with senior managers from corporations from a broad spectrum of industries including: energy, telecommunications, automotive, transport, retail chain, appliances, technology and engineering, private shipping, government-owned holdings, marketing consultancy, and construction. Findings - The paper provides insights of corporate communication (corpcom) practices in the sampled companies. The research shows that corpcoms involves a complex range of activities leading to performances managed and implemented under CEO direction. Practical implications - Corpcoms is perceived as a strategic concept with effective application relative to managing corporate image and reputation. The findings offer insights for communication professionals who deal with corpcoms, branding, and marketing communications. Originality/value - Corpcoms can be viewed via lens of social actors’ perspectives, i.e. via practitioners – including brand managers and senior executives as they possess practical knowledge of contextual business setting and the managerial capacity to design and implement integrated corporate communications

The value and significance of corporate community relations: an Italian SME perspective

Purpose – This paper investigates the link between community of place and small and medium-sized enterprises (SMEs) in Lombard industrial districts in Italy. Design/methodology/approach – A brief literature review of international authors from the stakeholder approach and Corporate Community Relations field is presented. This paper refers to a survey of Lombard industrial districts conducted by ALTIS. The data was collected via a telephone survey from 834 firms. Findings – The main finding is that managing Corporate Community Relations (CCR) is of major importance for company success. The results of the survey show that there are some tools and actions that Italian industrial district SMEs uses to interact with their particular communities of place to develop effective and coherent relationships with their stakeholder groups. Moreover, although the survey shows that though SMEs do implement different CCR activities, they are not able to communicate these effectively through systematic communication strategies. However, the narrow sample includes only a sample of some Lombard districts. Nonetheless, the findings indicate that effective CCR seems to confer competitive advantage based on stakeholder responses and rewards sought. Research limitations/implications – The framework could assist in supporting CCR developments between industrial districts as various players would know how to improve CCR activities. One further suggestion is that University and Research Centres could have a role to play in creating and communicating codified knowledge concerning community relations in industrial districts, while other public players still have to develop specific tasks in improving infrastructures. Originality/value – This study is in line with the main focus of CCR, which is in striving to meet stakeholder and societal needs. However, industrial district SMEs have to learn how to communicate their CCR activities from the examples set by large Italian companies. The paper links the notion of CCR with tools and actions to develop meaningful relationships with both community of place and interest. Moreover, considering the survey results, a new framework for local player roles is proposed

Review: Applications of Bayesian Skyline Plots and Approximate Bayesian Computation for Human Demography

Bayesian methods have been adopted by anthropologists for their utility in resolving complex questions about human history based on genetic data. The main advantages of Bayesian methods include simple model comparison, presenting results as a summary of probability distributions, and the explicit inclusion of prior information into analyses. In the field of anthropological genetics, for example, implementing Bayesian skyline plots and approximate Bayesian computation is becoming ubiquitous as means to analyze genetic data for the purpose of demographic or historic inference. Correspondingly, there is a critical need to better understand the underlying assumptions, proper applications, and limitations of these two methods by the larger anthropological community. Here we present a review of Bayesian skyline plots and approximate Bayesian computation as applied to human demography, as well as provide examples of the application of these methods to anthropological research questions. We also review the two core components of Bayesian demographic analysis: the coalescent and Bayesian inference. Our goal is to describe their basic mechanics in attempt to demystify them

Trends in the availability and usage of electrophysical agents in physiotherapy practices from 1990 to 2010: A review

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Maney PublishingBackground: The use of electrophysical agents has a historically important role in physiotherapy practice. There are anecdotal reports that the availability and usage of electrotherapy modalities are declining, which may have implications for physiotherapy practice. The aim of this literature review was to provide scientific evidence on electrotherapy usage in the last 20 years by identifying trends in availability, use, and non-use of nine electrotherapeutic modalities in physiotherapy practices during 1990s and 2000s. Methods: Review of empirical studies published in the English language from 1990 to 2010 and identified through searching online bibliographic databases, which included: Medline/OvidSP, PubMed Central, CINAHL/EBSCOhost, ScienceDirect, Scopus, ISI Web of Science, and Google Scholar. Findings: In the last 20 years, ultrasound availability and usage show increasing trends in several countries. The availability and use of pulsed shortwave diathermy and laser have shown steady trends. Transcutaneous electrical nerve stimulation, interferential, and biofeedback availability and usage have shown increasing trends in the UK and decreasing trends in Australia and the Republic of Ireland. Trends of continuous shortwave diathermy availability and use are declining irrespective of the country of the study. The availability and usage of microwave diathermy and H-wave show steeply declining trends, while there is a sharp rise in their non-availability over the last several years. Conclusions: The availability and use of electrophysical agents have greatly changed in the last 20 years. Declining trends in the availability and usage along with increasing trend of non-availability of electrotherapy modalities may have implications for electrotherapy education, training, and practice in the coming years.This study was funded by Health & Safety Executive, UK (grant no. 4371/R47.022)

Quantifying errors due to frequency changes and target location uncertainty for radar refractivity retrievals

Radar refractivity retrievals can capture near-surface humidity changes, but noisy phase changes of the ground clutter returns limit the accuracy for both klystron- and magnetron-based systems. Observations with a C-band (5.6 cm) magnetron weather radar indicate that the correction for phase changes introduced by local oscillator frequency changes leads to refractivity errors no larger than 0.25 N units: equivalent to a relative humidity change of only 0.25% at 20°C. Requested stable local oscillator (STALO) frequency changes were accurate to 0.002 ppm based on laboratory measurements. More serious are the random phase change errors introduced when targets are not at the range-gate center and there are changes in the transmitter frequency (ΔfTx) or the refractivity (ΔN). Observations at C band with a 2-μs pulse show an additional 66° of phase change noise for a ΔfTx of 190 kHz (34 ppm); this allows the effect due to ΔN to be predicted. Even at S band with klystron transmitters, significant phase change noise should occur when a large ΔN develops relative to the reference period [e.g., ~55° when ΔN = 60 for the Next Generation Weather Radar (NEXRAD) radars]. At shorter wavelengths (e.g., C and X band) and with magnetron transmitters in particular, refractivity retrievals relative to an earlier reference period are even more difficult, and operational retrievals may be restricted to changes over shorter (e.g., hourly) periods of time. Target location errors can be reduced by using a shorter pulse or identified by a new technique making alternate measurements at two closely spaced frequencies, which could even be achieved with a dual–pulse repetition frequency (PRF) operation of a magnetron transmitter

The Prognostic Value of Brain Extracellular Fluid Nitric Oxide Metabolites After Traumatic Brain Injury.

BACKGROUND: Nitric oxide (NO) is a compound with both protective and damaging effects on neurons. Quantification of NO metabolites in humans is limited by sample contamination with blood. In vivo cerebral microdialysis may offer an alternative approach as sampling of extracellular fluid (ECF) adjacent to neurons becomes possible. We investigate the prognostic value of brain ECF NO metabolites in patients with traumatic brain injury (TBI). METHODS: A prospective case cohort of 195 ECF samples collected from 11 cases over 4 days following TBI was collected. Nitrate and nitrite concentrations ([NO( x )]) were quantified using a vanadium-based colorimetric assay. RESULTS: Early ECF [NO( x )] (<48 h post TBI) were significantly higher in non-survivors (median 59.2 μmol/l, n = 7) compared to survivors (23.3 μmol/l, n = 4) (P = 0.04). Late (48-96 h) ECF [NO( x )] remained higher in non-survivors (47.9 μmol/l) compared to survivors (23.0 μmol/l) but this was not significant (P = 0.29). Receiver operator characteristic analysis shows an optimized cutoff level for ECF [NO( x )] of 26.5 μmol/l measured <48 h post TBI for predicting non-survival (sensitivity 100%, specificity 75%). CONCLUSION: Early ECF NO( x ) concentrations are of prognostic value after TBI. ECF NO( x ) may be a useful biomarker for treatment trials targeted at nitric oxide metabolism