6,402 research outputs found
Convolutional coded dual header pulse interval modulation for line of sight photonic wireless links.
The analysis and simulation for convolutional coded dual header pulse interval modulation (CC-DH-PIM) scheme using a rate ½ convolutional code with the constraint length of 3 is presented. Decoding is implemented using the Viterbi algorithm with a hard decision. Mathematical analysis for the slot error rate (SER) upper bounds is presented and results are compared with the simulated data for a number of different modulation techniques. The authors show that the coded DH-PIM outperforms the pulse position modulation (PPM) scheme and offers >4 dB code gain at the SER of 10?4 compared to the standard DH-PIM. Results presented show that the CC-DH-PIM with a higher constraint length of 7 offers a code gain of 2 dB at SER of 10?5 compared to the CC-DH-PIM with a constraint length of 3. However, in CC-DH-PIM the improvement in the error performance is achieved at the cost of reduced transmission throughput compared to the standard DH-PIM
Game based cyber security training: are serious games suitable for cyber security training?
Security research and training is attracting a lot of investment and interest from governments and the private sector. Most efforts have focused on physical security, while cyber security or digital security has been given less importance. With recent high-profile attacks it has become clear that training in cyber security is needed. Serious Games have the capability to be effective tools for public engagement and behavioural change and role play games, are already used by security professionals. Thus cyber security seems especially well-suited to Serious Games. This paper investigates whether games can be effective cyber security training tools. The study is conducted by means of a structured literature review supplemented with a general web search. While there are early positive indications there is not yet enough evidence to draw any definite conclusions. There is a clear gap in target audience with almost all products and studies targeting the general public and very little attention given to IT professionals and managers. The products and studies also mostly work over a short period, while it is known that short-term interventions are not particularly effective at affecting behavioural change
Swift J164449.3+573451 event: generation in the collapsing star cluster?
We discuss the multiband energy release in a model of a collapsing galactic
nucleus, and we try to interpret the unique super-long cosmic gamma-ray event
Swift J164449.3+573451 (GRB 110328A by early classification) in this scenario.
Neutron stars and stellar-mass black holes can form evolutionary a compact
self-gravitating subsystem in the galactic center. Collisions and merges of
these stellar remnants during an avalanche contraction and collapse of the
cluster core can produce powerful events in different bands due to several
mechanisms. Collisions of neutron stars and stellar-mass black holes can
generate gamma-ray bursts (GRBs) similar to the ordinary models of short GRB
origin. The bright peaks during the first two days may also be a consequence of
multiple matter supply (due to matter release in the collisions) and accretion
onto the forming supermassive black hole. Numerous smaller peaks and later
quasi-steady radiation can arise from gravitational lensing, late accretion of
gas onto the supermassive black hole, and from particle acceleration by shock
waves. Even if this model will not reproduce exactly all the Swift
J164449.3+573451 properties in future observations, such collapses of galactic
nuclei can be available for detection in other events.Comment: 7 pages, replaced by the final versio
Parenting gifted and talented children: What are the key child behaviour and parenting issues?
Objective: The literature on gifted and talented children is limited. Little is known about the types and nature of difficulties experienced by gifted and talented children, and even less known about parenting issues related to parenting a gifted and talented child. The aim of the present study was to describe children's behavioural and emotional adjustment, and the factors that contribute to children's difficulties, as well as to examine the styles of discipline used by parents of gifted and talented children and their level of confidence in managing specific parenting tasks
Modelling diverse root density dynamics and deep nitrogen uptake — a simple approach
We present a 2-D model for simulation of root density and plant nitrogen (N) uptake for crops grown in agricultural systems, based on a modification of the root density equation originally proposed by Gerwitz and Page in J Appl Ecol 11:773–781, (1974). A root system form parameter was introduced to describe the distribution of root length vertically and horizontally in the soil profile. The form parameter can vary from 0 where root density is evenly distributed through the soil profile, to 8 where practically all roots are found near the surface. The root model has other components describing root features, such as specific root length and plant N uptake kinetics. The same approach is used to distribute root length horizontally, allowing simulation of root growth and plant N uptake in row crops. The rooting depth penetration rate and depth distribution of root density were found to be the most important parameters controlling crop N uptake from deeper soil layers. The validity of the root distribution model was tested with field data for white cabbage, red beet, and leek. The model was able to simulate very different root distributions, but it was not able to simulate increasing root density with depth as seen in the experimental results for white cabbage. The model was able to simulate N depletion in different soil layers in two field studies. One included vegetable crops with very different rooting depths and the other compared effects of spring wheat and winter wheat. In both experiments variation in spring soil N availability and depth distribution was varied by the use of cover crops. This shows the model sensitivity to the form parameter value and the ability of the model to reproduce N depletion in soil layers. This work shows that the relatively simple root model developed, driven by degree days and simulated crop growth, can be used to simulate crop soil N uptake and depletion appropriately in low N input crop production systems, with a requirement of few measured parameters
Genetic Background Can Result in a Marked or Minimal Effect of Gene Knockout (GPR55 and CB2 Receptor) in Experimental Autoimmune Encephalomyelitis Models of Multiple Sclerosis
PMCID: PMC379391
Permeability of phospholipid membrane for small polar molecules determined from osmotic swelling of giant phospholipid vesicles
A method for determining permeability of phospholipid bilayer based on the
osmotic swelling of micrometer-sized giant unilamellar vesicles (GUVs) is
presented as an alternative to the two established techniques, dynamic light
scattering on liposome suspension, and electrical measurements on planar lipid
bilayers. In the described technique, an individual GUV is transferred using a
micropipette from a sucrose/glucose solution into an isomolar solution
containing the solute under investigation. Throughout the experiment, vesicle
cross-section is monitored and recorded using a digital camera mounted on a
phase-contrast microscope. Using a least-squares procedure for circle fitting,
vesicle radius R is computed from the recorded images of vesicle cross-section.
Two methods for determining membrane permeability from the obtained R(t)
dependence are described: the first one uses the slope of R(t) for a spherical
GUV, and the second one the R(t) dependence around the transition point at
which a flaccid vesicle transforms into a spherical one. We demonstrate that
both methods give consistent estimates for membrane permeability.Comment: 40 pages, 8 figures, to appear in Advances in Planar Lipid Membranes
and Liposomes vol. 1
Major depressive disorder, personality disorders and coping strategies are independent risk factors for lower quality of life in non-metastatic breast cancer patients.
International audienceObjective: To identify risk factors for lower quality of life (QOL) in non-metastatic breast cancer patients.Methods: Our study included 120 patients from the University Hospital Centers of Tours and Poitiers. This cross-sectional study was conducted 7 months after patients’ breast cancer diagnosis and assessed QOL (Quality of Life Questionnaire-Core 30 = QLQ-C30), socio-demographic characteristics, coping strategies (Brief-Cope), physiological and biological variables (e.g., initial tumor severity, types of treatment received), the existence of major depressive disorder (Mini International Neuropsychiatric Interview) and pain severity (QDSA). We assessed personality disorders 3 months after diagnosis (VKP questionnaire). We used multiple linear regression models to determine which factors were associated with physical, emotional and global QOL. Results: Lower physical QOL was associated with major depressive disorder, younger age, a more severe initial tumor stage and the use of the behavioral disengagement coping. Lower emotional QOL was associated with major depressive disorder, the existence of a personality disorder, a more severe pain level, higher use of self-blame and lower use of acceptance coping strategies. Lower global QOL was associated with major depressive disorder, the existence of a personality disorder, a more severe pain level, higher use of self-blame and lower use of positive reframing coping strategies and an absence of hormone therapy.Conclusions: Lower QOL scores were more strongly associated to variables related to the individual’s premorbid psychological characteristics and the manner in which this individual copes with the cancer (e.g., depression, personality and coping) than to cancer-related variables (e.g., treatment types, cancer severity)
MIF: Mood Improving/Inhibiting Factor?
Although major depressive disorder imposes a serious public health burden and affects nearly one in six individuals in developed countries over their lifetimes, there is still no consensus on its pathophysiology. Inflammation and cytokines have emerged as a promising new avenue in depression research, and, in particular, macrophage migration inhibitory factor (MIF) has been shown to be significant in depression physiology. In this review we summarize current research on MIF and depression. We highlight the arguments for MIF as a pro- and antidepressant species and discuss the potential implications for therapeutics
Contextualizing the Global Nursing Care Chain: International Migration and the Status of Nursing in Kerala, India
In this article I explore the issue of nursing status in Kerala, India and how over time a colonial discourse of caste‐based pollution has given way to a discourse of sexual pollution under expanding migratory opportunities. Based on survey and qualitative research findings, I caution that the improving occupational status of nursing in India is not directly mapped onto social status, and this is particularly evident in the matrimonial market. In the light of these findings I argue that global nursing care chain (GNCC) analysis must assess more than just workplace contexts in order to conceptualize how global care chains (GCCs) interlock, and how they are differentiated from each other
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