532 research outputs found
Quantitative Untersuchungen ĂŒber experimentellen Hermaphroditismus : [vĂ€itekiri]
http://tartu.ester.ee/record=b1558769~S1*es
Cybersecurity in Power Grids: Challenges and Opportunities
Increasing volatilities within power transmission and distribution force power grid operators to amplify their use of communication infrastructure to monitor and control their grid. The resulting increase in communication creates a larger attack surface for malicious actors. Indeed, cyber attacks on power grids have already succeeded in causing temporary, large-scale blackouts in the recent past. In this paper, we analyze the communication infrastructure of power grids to derive resulting fundamental challenges of power grids with respect to cybersecurity. Based on these challenges, we identify a broad set of resulting attack vectors and attack scenarios that threaten the security of power grids. To address these challenges, we propose to rely on a defense-in-depth strategy, which encompasses measures for (i) device and application security, (ii) network security, and (iii) physical security, as well as (iv) policies, procedures, and awareness. For each of these categories, we distill and discuss a comprehensive set of state-of-the art approaches, as well as identify further opportunities to strengthen cybersecurity in interconnected power grids
Prophylactic Application of Nebulized Liposomal Amphotericin B in Hematologic Patients with Neutropenia
Background: Pulmonary invasive fungal infections (IFI) are well-recognized complications with high morbiditiy and mortality in patients with hematologic malignancies. Patients and Methods: Aerosolized liposomal amphotericin B (lipAmB) was evaluated as an antifungal prophylaxis in patients with an expected neutropenia of more than 10 days due to intensive chemotherapy or stem cell transplantation, in a prospective phase II trial. Results: 98 treatment episodes were included in the study and compared to 105 historical control patients. Inhalation was performed between 0 and 103 days. No severe side effects of therapy occurred. 40 patients considered inhalations as unpleasant, 2 as very unpleasant, mostly due to bad taste or cough. Few cases of definite or probable IFI were recorded, whereas a large number of patients were treated with systemic antifungal therapy for pneumonia or fever of unknown origin without a significant difference between study patients and controls. In a predefined subgroup analysis of 48 patients with newly diagnosed acute myeloid leukemia (AML), significantly more patients survived for 1 year in the AmB prophylaxis than in the control group (80% vs. 54%, p < 0.01). Conclusions: Inhalations of lipAmB are feasible and safe. Results in the subgroup of patients with AML together with data from other trials suggest further evaluation of effectiveness
Photodisintegration of three- and four- nucleon systems
Three- and four-nucleon photodisintegration processes are quite efficiently
treated by means of effective two-body integral equations in momentum space. We
recall some aspects of their derivation, present previous and most recent
results obtained within this framework, and discuss general features, trends
and effects observed in these investigations: At low energies final-state
interaction plays an important role. Even more pronounced is the effect of
meson exchange currents. A considerable potential dependence shows up in the
low-energy peak region. The different peak heights are found to be closely
correlated with the corresponding binding energies. Above the peak region only
the difference between potentials with or without p-wave contributions remains
relevant. In the differential cross sections the electric quadrupole
contributions have to be taken into account. The remarkable agreement between
theory and experiment in - radiative capture is achieved only when
incorporating this contribution, together with most of the above-mentioned
effects. In the final part of this report we briefly review also methods
developed, and results achieved in three- and four- nucleon
electrodisintegration. We, in particular, compare them with a recent access to
this problem, based on the construction of nucleon-nucleus potentials via
Marchenko inversion theory.Comment: 20 pages LaTeX and 22 postscript figures included, uses epsfig.sty
and espcrc1.sty. Invited talk at the XVth International Conference on
Few-Body Problems in Physics (22-26 July, 1997, Groningen, The Netherlands).
To be published in the conference proceedings in Nucl. Phys.
Abnormal brain tryptophan metabolism and clinical correlates in Tourette syndrome
Symptoms in Tourette syndrome (TS) are likely related to abnormalities involving multiple neurotransmitter systems in striatal-thalamo-cortical circuitry. Although prior studies have found abnormal levels of tryptophan, serotonin, and their metabolites in blood, cerebrospinal fluid and brain tissue of TS patients, understanding of focal brain disturbances and their relationship to clinical phenotype remains poor. We used Î-[ 11 C]methyl- L -tryptophan (AMT) positron emission tomography (PET) to assess global and focal brain abnormalities of tryptophan metabolism and their relationship to behavioral phenotype in 26 children with TS and nine controls. Group comparisons on regional cortical and subcortical AMT uptake revealed decreased AMT uptake in bilateral dorsolateral prefrontal cortical and bilaterally increased uptake in the thalamus ( P = 0.001) in TS children. The ratio of AMT uptake in subcortical structures to dorsolateral prefrontal cortex was significantly increased bilaterally ( P < 0.01) in TS patients also. Behaviorally defined subgroups within the TS sample revealed differences in the pattern of AMT uptake in the fronto-striatal-thalamic circuit. This study demonstrates cortical and subcortical abnormalities of tryptophan metabolism in TS and provides neuroimaging evidence for a role of serotonergic mechanisms in the pathophysiology of TS. © 2007 Movement Disorder SocietyPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57523/1/21712_ftp.pd
Comment on 'Nonreciprocal light propagation in a silicon photonic circuit'
We show that the structure demonstrated by Feng et al. (Reports, 5 August 2011, p. 729) cannot enable optical isolation because it possesses a symmetric scattering matrix. Moreover, one cannot construct an optical isolator by incorporating this structure into any system as long as the system is linear and time-independent and is described by materials with a scalar dielectric function
The impact of emotional well-being on long-term recovery and survival in physical illness: a meta-analysis
This meta-analysis synthesized studies on emotional well-being as predictor of the prognosis of physical illness, while in addition evaluating the impact of putative moderators, namely constructs of well-being, health-related outcome, year of publication, follow-up time and methodological quality of the included studies. The search in reference lists and electronic databases (Medline and PsycInfo) identified 17 eligible studies examining the impact of general well-being, positive affect and life satisfaction on recovery and survival in physically ill patients. Meta-analytically combining these studies revealed a Likelihood Ratio of 1.14, indicating a small but significant effect. Higher levels of emotional well-being are beneficial for recovery and survival in physically ill patients. The findings show that emotional well-being predicts long-term prognosis of physical illness. This suggests that enhancement of emotional well-being may improve the prognosis of physical illness, which should be investigated by future research
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