Research of Quantum Well Laser Diode’s and Heterostructural P-I-N Photodiode’s of Fiber-Optic Modules Radiation Hardness to Gamma-ray and Neutron Irradiation

The paper presents the measurements results of optical and electrical parameters of quantum well laser diodes and heteroepitaxial photodiodes under gamma-ray and neutron irradiation. The testing results of transceiver modules gamma irradiation tolerance are introduced. The most vulnerable elements of module are highlighted. Keywords: laser diode, photodiode, radiation hardness, VCSEL, transceiver modules, fiber-optic communicatio

Small-worlds: How and why

We investigate small-world networks from the point of view of their origin. While the characteristics of small-world networks are now fairly well understood, there is as yet no work on what drives the emergence of such a network architecture. In situations such as neural or transportation networks, where a physical distance between the nodes of the network exists, we study whether the small-world topology arises as a consequence of a tradeoff between maximal connectivity and minimal wiring. Using simulated annealing, we study the properties of a randomly rewired network as the relative tradeoff between wiring and connectivity is varied. When the network seeks to minimize wiring, a regular graph results. At the other extreme, when connectivity is maximized, a near random network is obtained. In the intermediate regime, a small-world network is formed. However, unlike the model of Watts and Strogatz (Nature {\bf 393}, 440 (1998)), we find an alternate route to small-world behaviour through the formation of hubs, small clusters where one vertex is connected to a large number of neighbours.Comment: 20 pages, latex, 9 figure

Study of Gamma-ray Induced Attenuation of Fluorine-doped Single-mode Radiation Hard Optic Fiber

The paper presents the measurements results of optic fiber’s radiation induced attenuation. The approach of optic fiber’s radiation test at negative temperatures is introduced. The results of an investigation of the decay of an optical signal during a pulsed electron. Keywords: radiation hardness, fiber-optic communication, radiation-induced attenuatio

Comparative Study of foF2 Measurements with IRI-2007 Model Predictions During Extended Solar Minimum

The unusually deep and extended solar minimum of cycle 2324 made it very difficult to predict the solar indices 1 or 2 years into the future. Most of the predictions were proven wrong by the actual observed indices. IRI gets its solar, magnetic, and ionospheric indices from an indices file that is updated twice a year. In recent years, due to the unusual solar minimum, predictions had to be corrected downward with every new indices update. In this paper we analyse how much the uncertainties in the predictability of solar activity indices affect the IRI outcome and how the IRI values calculated with predicted and observed indices compared to the actual measurements.Monthly median values of F2 layer critical frequency (foF2) derived from the ionosonde measurements at the mid-latitude ionospheric station Juliusruh were compared with the International Reference Ionosphere (IRI-2007) model predictions. The analysis found that IRIprovides reliable results that compare well with actual measurements, when the definite (observed and adjusted) indices of solar activityare used, while IRI values based on earlier predictions of these indices noticeably overestimated the measurements during the solar minimum.One of the principal objectives of this paper is to direct attention of IRI users to update their solar activity indices files regularly.Use of an older index file can lead to serious IRI overestimations of F-region electron density during the recent extended solar minimum

In Defence of Modest Doxasticism About Delusions

Here I reply to the main points raised by the commentators on the arguments put forward in my Delusions and Other Irrational Beliefs (OUP, 2009). My response is aimed at defending a modest doxastic account of clinical delusions, and is articulated in three sections. First, I consider the view that delusions are in-between perceptual and doxastic states, defended by Jacob Hohwy and Vivek Rajan, and the view that delusions are failed attempts at believing or not-quite-beliefs, proposed by Eric Schwitzgebel and Maura Tumulty. Then, I address the relationship between the doxastic account of delusions and the role, nature, and prospects of folk psychology, which is discussed by Dominic Murphy, Keith Frankish, and Maura Tumulty in their contributions. In the final remarks, I turn to the continuity thesis and suggest that, although there are important differences between clinical delusions and non-pathological beliefs, these differences cannot be characterised satisfactorily in epistemic terms. \u

Robot companion cats for people at home with dementia: a qualitative case study on companotics

The use of robot companion pets for people in care homes has been extensively studied. The results are largely positive, and suggest that they are valuable in enhancing wellbeing, communication and behavioural aspects. However, there has been little research in people’s own homes, possibly due to the cost and complexity of some of the robot pets currently available. As dementia affects people in different ways, this study explores the effects of a robot cat for people in their own homes, without specifically investigating the effects on a particular symptom. We utilised a case study design to investigate the proposition that various factors influence the impact of a robot cat on the person living with dementia and their carer, including acceptability of the robot pet and acceptance of dementia and its symptoms. The qualitative analysis explores the similarities and differences within the data which were gathered during interviews with people with dementia and their families. This analysis revealed four themes: Distraction, Communication, Acceptance and rejection, and Connecting with the cat and connecting with others. These themes were synthesized into two overarching themes: The effect of the cat on mood and behaviour, and The interaction with the cat. We present the acceptability and impact of the robot cat on symptoms of dementia, with data presented across and within the group of participants. Our analysis suggests that benefits of the robot pet were evident, and although this was a small-scale study, where they were accepted, robot pets provided positive outcomes for the participants and their families

Experimental modulation of capsule size in Cryptococcus neoformans

Experimental modulation of capsule size is an important technique for the study of the virulence of the encapsulated pathogen Cryptococcus neoformans. In this paper, we summarize the techniques available for experimental modulation of capsule size in this yeast and describe improved methods to induce capsule size changes. The response of the yeast to the various stimuli is highly dependent on the cryptococcal strain. A high CO(2) atmosphere and a low iron concentration have been used classically to increase capsule size. Unfortunately, these stimuli are not reliable for inducing capsular enlargement in all strains. Recently we have identified new and simpler conditions for inducing capsule enlargement that consistently elicited this effect. Specifically, we noted that mammalian serum or diluted Sabouraud broth in MOPS buffer pH 7.3 efficiently induced capsule growth. Media that slowed the growth rate of the yeast correlated with an increase in capsule size. Finally, we summarize the most commonly used media that induce capsule growth in C. neoformans

The Right Diagnosis: The Role of Pathology in Health System Strengthening

Background: The drive to Universal Health Care coverage, and the need for strengthening health systems, has led to the examination of the role of core elements of the system such as surgery and radiology. Until recently, pathology (which, along with radiology, is key to correct diagnosis and treatment), has been relatively neglected within the global health framework. Resource-constrained governments and patients paying out-ofpocket have tended to underestimate the importance of laboratory testing. International donors have looked to point-of-care tests as a way to overcome the difficult task of strengthening national laboratory networks. Without strong pathology systems, however, there is the danger of development of multi-drug resistance, inaccurate tissue diagnosis and delays in identifying new emerging epidemics. Diagnosis and treatment of cancer and other non-communica