187 research outputs found
Opportunistic Secrecy with a Strict Delay Constraint
Full text linkWe investigate the delay limited secrecy capacity of the flat fading channel
under two different assumptions on the available transmitter channel state
information (CSI). The first scenario assumes perfect prior knowledge of both
the main and eavesdropper channel gains. Here, upper and lower bounds on the
delay limited secrecy capacity are derived, and shown to be tight in the high
signal-to-noise ratio (SNR) regime. In the second scenario, only the main
channel CSI is assumed to be available at the transmitter where, remarkably, we
establish the achievability of a non-zero delay-limited secure rate, for a wide
class of channel distributions, with a high probability. In the two cases, our
achievability arguments are based on a novel two-stage key-sharing approach
that overcomes the secrecy outage phenomenon observed in earlier works.Comment: Submitted to IEEE Transactions on Information Theor
Subclinical pulmonary pathogenic infection in camels slaughtered in Cairo, Egypt
Get PDFIntroduction: Camels migrate between the open boundaries of Sudan and Egypt
either for grazing or for slaughtering. Bad hygiene and stress is often
related to pulmonary diseases in camels. This study investigated whether
camels slaughtered in Cairo carried pulmonary infections. Methodology: Five
hundred lung tissues of slaughtered camels were examined and 100 samples
suspected for pulmonary infection were subjected to microbial identification
and histopathology. Results: A total of 70 lung tissues revealed 97 bacterial
isolates of 8 species, including Staphylococcus aureus (37.14%), Escherichia
coli (27.14%), Klebsiella pneumoniae (26.71%), Bacillus spp. (25.72%),
Streptococcus pyogenes (10%), Corynebacterium spp. (8.85 %), Pasteurella spp.
(2.85%), and Arcanobacterium pyogenes (1.4%). Some of these species were
earlier reported to be associated with pulmonary infection. Histopathology
revealed different types of pneumonia in 50% of the investigated lungs.
Conclusions: A considerable number of apparently healthy camels carry
pathogenic agents in their lower respiratory tracts. Immunosuppression and
stressful conditions might influence these pathogens to induce respiratory
diseases in camels. Thus, the infected camels might act as reservoir of these
infections agents. If adequate care is not taken, this might be a threat to
abattoir workers and may spread infections to humans
On the Delay Limited Secrecy Capacity of Fading Channels
Full text linkIn this paper, the delay limited secrecy capacity of the flat fading channel
is investigated under two different assumptions on the available transmitter
channel state information (CSI). The first scenario assumes perfect prior
knowledge of both the main and eavesdropper channel gains. Here, upper and
lower bounds on the secure delay limited capacity are derived and shown to be
tight in the high signal-to-noise ratio (SNR) regime (for a wide class of
channel distributions). In the second scenario, only the main channel CSI is
assumed to be available at the transmitter. Remarkably, under this assumption,
we establish the achievability of non-zero secure rate (for a wide class of
channel distributions) under a strict delay constraint. In the two cases, our
achievability arguments are based on a novel two-stage approach that overcomes
the secrecy outage phenomenon observed in earlier works.Comment: Proceedings of the 2009 IEEE International Symposium on Information
Theory (ISIT 2009), Seoul, Korea, June 28-July 3, 200
Recurrent Pneumonia in Children Admitted to Assiut University Children Hospital. Magnitude of the Problem and Possible Risk Factors
Get PDFBackground: Incidence data indicate that recurrent pneumonia occurs in 7.7–9% of all children withcommunity acquired pneumonia. We aim by this study to assess the prevalence of recurrent pneumoniaamong the admissions with diagnosis of pneumonia in Assiut university children hospital for one year andto try to define the possible related risk factors. Patients and methods: This is a prospective hospital basedstudy in Assiut University Children’s Hospital. Children younger than 16 years admitted with a hospitaldiagnosis of pneumonia to Assiut University Children’s Hospital for one year from 1 February 2017 to 31January 2018 were included.Results: Approximately 1 in 12 children with pneumonia in our locality have recurrent pneumonia with percentageof 12.61%. Cardiac diseases especially congenital heart diseases was the cause among 25.45%of the cases, immunodeficiency diseases represented 20.9% of the cases ,while bronchial asthma wasthe cause of recurrent pneumonia among 16.36% of the cases. As regard to risk factors in studied group,prematurity was detected among 7.27 % of the cases while more than 50% were formula fed and more than60% exposed to pollution. Father smoking was detected among 36.36% of cases. Patients aged > 6 yearsshowed significantly higher frequency in risk factors as obesity, indoor and outdoor pollution and use ofsteroids in comparison to other age groups. However, patients aged 0-3 years exhibited significantly higher% frequency of having heart disease, oro-motor in coordination /swallowing dysfunction, gastro esophagealreflux and under nutrition as risk factors for recurrent pneumonia in comparison to other age groups.Conclusions: The most frequent underlying cause for recurrent pneumonia in Assiut University Children’sHospital which presents the largest referral pediatric hospital in Upper Egypt for one year according to ourstudy was cardiac diseases; the second most frequent cause was immunodeficiency diseases, followedby bronchial asthma. Risk factors for recurrent pneumonia include socio-economic status of studiedcases, prematurity, exposure to passive smoking and in or outdoor pollution, obesity, under nutrition, lackof breast feeding, gastro esophageal reflux and steroids usage
New norfloxacin/nitric oxide donor hybrids: Synthesis and nitric oxide release measurement using a modified Griess colorimetric method
Get PDFOximes and nitrate esters are considered as important nitric oxide (NO) donors with diverse biological activities. Herein, we report the synthesis and characterization of new oxime and nitrate ester derivatives of norfloxacin as potential NO donor hybrids with expected synergistic antimicrobial activity. The release of NO from those hybrids was measured by a modified Griess method in which p-nitroaniline was employed instead of sulfanilamide. The increased electrophilicity of the intermediate 4-nitroaniline diazonium salt accelerated the coupling process and shortened the overall assessment time. The improved detection limits and enhanced sensitivity would pave the way for the future application of this method in nitrite determination in biological or non-biological systems
A Security-by-Design Decision-Making Model for Risk Management in Autonomous Vehicles
Get PDFAutonomous/self-driving vehicles have gained significant attention these days, as one of the intelligent transportation systems. However, those vehicles have risks related to their physical implementation and security against cyber threats. Therefore, this study proposes a new security-by-design model for estimating the uncertainty of autonomous vehicles and measuring cyber risks; thus it assists decision-makers in addressing the risks of the physical design and their attack surfaces. The proposed model is developed using neutrosophic sets that efficiently tackle multi-criteria decision-making (MCDM) problems with extensive conflicting criteria and alternatives. The proposed model integrates MCDM, Analytic Hierarchy Process (AHP), Multi-Attributive Border Approximation Area Comparison (MABAC), and Preference Ranking Organization Method for Enrichment Evaluations II (PROMETHEE II), along with single-valued neutrosophic sets (SVNSs). An illustrative case considering ten risks in self-driving vehicles is used to validate the feasibility of the proposed model. Compared to the state-of-the-art methods, the proposed model is considered consistent and reliable to deal with and represent uncertainty and incomplete risk information using neutrosophic sets
Comparative study between aortic valve replacement through full sternotomy versus mini-sternotomy
Get PDFBackground: The superiority of minimally invasive aortic valve replacement (AVR) over the standard approach is the subject of ongoing research. The aim of this study was to compare the outcomes of AVR through full sternotomy versus mini-sternotomy.
Methods: We included 60 patients who had AVR; 30 patients underwent AVR through J- or T-shaped mini-sternotomy, and 30 patients had a full sternotomy. We included patients who had isolated AVR and excluded patients who had a concomitant cardiac procedure, redo surgery, or those who needed annular dilatation. All patients had aortic and right atrial cannulation for cardiopulmonary bypass. Study endpoints were operative times, postoperative complications and duration of ICU and hospital stays.
Results: There were no differences between the two groups preoperatively. Cardiopulmonary bypass time was longer in the mini-sternotomy group (median: 100 (range: 65- 170) vs. 85 (55-160) min, respectively; p= 0.024). Operative time was non-significantly longer in the mini-sternotomy group 5 (4-6) hours vs. 4.5 (4-6) hours in the full sternotomy group (p=0.62). Ventilation time was 10 (4- 50) hours in the mini-sternotomy group vs. 14 (8- 45) hours in the full sternotomy group (p<0.001). ICU stay was shorter in the mini-sternotomy group (2 (1-6.5) vs. 2.5 (1-7) days, respectively, p= 0.014). The total mediastinal drainage was 100 (50 400) ml in the mini-sternotomy group vs. 275 (50- 1000) ml in the full sternotomy group (p= <0.001). There was no difference in wound infection (p= 0.35), tamponade (p˃0.99), and hemothorax (p˃0.99) between both groups.
Conclusion: Mini-sternotomy AVR had longer cardiopulmonary bypass times; however, there were no differences in the postoperative complications compared to the full sternotomy approach. Mini-sternotomy could be a safe alternative approach to the full median sternotomy for aortic valve replacement
Correlation of polycystic ovary syndrome and recurrent miscarriage
Get PDFBackground: Numerous studies have investigated the association between polycystic ovary syndrome (PCOS) and recurrent miscarriage (RM). Increased rates of PCOS have been reported for women with RM. However, the actual prevalence is controversially discussed by the scientific community and remains unclear, since a wide range of rates from 8–82% can be found in the literature. Objective: To assess the relation between polycystic ovary syndrome and recurrent miscarriage and to evaluate the prevalence of polycystic ovarian syndrome within the recurrent miscarriage population. Patients and method: It is a cross sectional conducted at the infertility clinic in the outpatient department of University Hospital from March 2019 to March 2020. Patient sample was 47 participant. Hormonal profile FSH, LH, TSH, TSH, assessment of glycemic status and insulin resistance and ultrasonography for diagnosis of polycystic ovaries were done to every patients. Result: There was high statistically significant relation between the PCO and total number of follicles, number of follicles ≥ 18 mm and endometrial thickness. There was high statistically significant relation between the PCO and testosterone hormones and statistically significant relation between the PCO and FSH and LH. There was no statistically significant relation between the PCO and insulin resistance. Conclusion: In this study we concluded that the prevalence of PCOS seems slightly increased in women with recurrent miscarriage, PCOS on the other hand showed a rather high prevalence compared to the general population
Neural substrates and potential treatments for levodopa-induced dyskinesias in Parkinson's disease
Get PDFParkinson’s disease (PD) is primarily a motor disorder that involves the gradual loss of motor function. Symptoms are observed initially in the extremities, such as hands and arms, while advanced stages of the disease can effect blinking, swallowing, speaking, and breathing. PD is a neurodegenerative disease, with dopaminergic neuronal loss occurring in the substantia nigra pars compacta, thus disrupting basal ganglia functions. This leads to downstream effects on other neurotransmitter systems such as glutamate, γ-aminobutyric acid, and serotonin. To date, one of the main treatments for PD is levodopa. While it is generally very effective, prolonged treatments lead to levodopa-induced dyskinesia (LID). LID encompasses a family of symptoms ranging from uncontrolled repetitive movements to sustained muscle contractions. In many cases, the symptoms of LID can cause more grief than PD itself. The purpose of this review is to discuss the possible clinical features, cognitive correlates, neural substrates, as well as potential psychopharmacological and surgical (including nondopaminergic and deep brain stimulation) treatments of LID
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