399 research outputs found
A Dynamically Configurable Log-based Distributed Security Event Detection Methodology using Simple Event Correlator
Log event correlation is an effective means of detecting system faults and security breaches encountered in information technology environments. Centralized, database-driven log event correlation is common, but suffers from flaws such as high network bandwidth utilization, significant requirements for system resources, and difficulty in detecting certain suspicious behaviors. This research presents a distributed event correlation system which performs security event detection, and compares it with a centralized alternative. The comparison measures the value in distributed event correlation by considering network bandwidth utilization, detection capability and database query efficiency, as well as through the implementation of remote configuration scripts and correlation of multiple log sources. These capabilities produce a configuration which allows a 99% reduction of network syslog traffic in the low-accountability case, and a significant decrease in database execution time through context-addition in the high-accountability case. In addition, the system detects every implemented malicious use case, with a low false positive rate
Pulsed Plasma Thruster Contamination
Pulsed Plasma Thrusters (PPT's) are currently baselined for the Air Force Mightysat II.1 flight in 1999 and are under consideration for a number of other missions for primary propulsion, precision positioning, and attitude control functions. In this work, PPT plumes were characterized to assess their contamination characteristics. Diagnostics included planar and cylindrical Langmuir probes and a large number of collimated quartz contamination sensors. Measurements were made using a LES 8/9 flight PPT at 0.24, 0.39, 0.55, and 1.2 m from the thruster, as well as in the backflow region behind the thruster. Plasma measurements revealed a peak centerline ion density and velocity of approx. 6 x 10(exp 12) cm(exp -3) and 42,000 m/s, respectively. Optical transmittance measurements of the quartz sensors after 2 x 10(exp 5) pulses showed a rapid decrease in plume contamination with increasing angle from the plume axis, with a barely measurable transmittance decrease in the ultraviolet at 90 deg. No change in optical properties was detected for sensors in the backflow region
Patient characteristics of the Accident and Emergency Department of Kenyatta National Hospital, Nairobi, Kenya: a cross-sectional, prospective analysis
Background Resource-limited settings are increasingly experiencing a ‘triple burden’ of disease, composed of trauma, non-communicable diseases (NCDs) and known communicable disease patterns. However, the epidemiology of acute and emergency care is not well characterised and this limits efforts to further develop emergency care capacity. Objective To define the burden of disease by describing the patient population presenting to the Accident and Emergency Department (A&E) at Kenyatta National Hospital (KNH) in Kenya. Methods We completed a prospective descriptive assessment of patients in KNH’s A&E obtained via systematic sampling over 3 months. Research assistants collected data directly from patients and their charts. Chief complaint and diagnosis codes were grouped for analysis. Patient demographic characteristics were described using the mean and SD for age and n and percentages for categorical variables. International Classification of Disease 10 codes were categorised by 2013 Global Burden of Disease Study methods. Results Data were collected prospectively on 402 patients with an average age of 36 years (SD 19), and of whom, 50% were female. Patients were most likely to arrive by taxi or bus (39%), walking (28%) or ambulance (17%). Thirty-five per cent of patients were diagnosed with NCDs, 24% with injuries and 16% with communicable diseases, maternal and neonatal conditions. Overall, head injury was the single most common final diagnosis and occurred in 32 (8%) patients. The most common patient-reported mechanism for head injury was road traffic accident (39%). Conclusion This study estimates the characteristics of the A&E population at a tertiary centre in Kenya and highlights the triple burden of disease. Our findings emphasise the need for further development of emergency care resources and training to better address patient needs in resource-limited settings, such as KNH
Bubbling AdS Black Holes
We explore the non-BPS analog of `AdS bubbles', which are regular spherically
symmetric 1/2 BPS geometries in type IIB supergravity. They have regular
horizons and can be thought of as bubbling generalizations of non-extremal AdS
black hole solutions in five-dimensional gauged supergravity. Due to the
appearance of the Heun equation even at the linearized level, various
approximation and numerical methods are needed in order to extract information
about this system. We study how the vacuum expectation value and mass of a
particular dimension two chiral primary operator depend on the temperature and
chemical potential of the thermal Yang-Mills theory. In addition, the mass of
the bubbling AdS black holes is computed. As is shown numerically, there are
also non-BPS solitonic bubbles which are completely regular and arise from
continuous deformations of BPS AdS bubbles.Comment: 37 pages, 2 figure
New supersymmetric solutions of N=2, D=5 gauged supergravity with hyperscalars
We construct new supersymmetric solutions, including AdS bubbles, in an N=2
truncation of five-dimensional N=8 gauged supergravity. This particular
truncation is given by N=2 gauged supergravity coupled to two vector multiples
and three incomplete hypermultiplets, and was originally investigated in the
context of obtaining regular AdS bubble geometries with multiple active
R-charges. We focus on cohomogeneity-one solutions corresponding to objects
with two equal angular momenta and up to three independent R-charges.
Curiously, we find a new set of zero and negative mass solitons asymptotic to
AdS_5/Z_k, for k \ge 3, which are everywhere regular without closed timelike
curves.Comment: Latex 3 times, 42 page
Specific Subpopulations of Hypothalamic Leptin Receptor-Expressing Neurons Mediate the Effects of Early Developmental Leptin Receptor Deletion on Energy Balance
ACKNOWLEDGEMENTS We thank MedImmune, Inc. and James Trevaskis, PhD and Christopher Rhodes, PhD for the gift of leptin. We thank members of the Myers and Olson labs for helpful discussions. Research support was provided by the Michigan Diabetes Research Center (NIH P3 0 DK020572, including the Molecular Genetics, Animal Phenotyping, and Clinical Cores), the American Diabetes Association (MGM), the Marilyn H. Vincent Foundation (MGM), the NIH (MGM: D K05673 1; ACR:DK071212; MBA: DK097861), the BBSRC (LKH: BB/NO17838/1) and WellcomeTrust (LKH: 098012).Peer reviewedPublisher PD
Continuity, Deconfinement, and (Super) Yang-Mills Theory
We study the phase diagram of SU(2) Yang-Mills theory with one adjoint Weyl
fermion on R^3xS^1 as a function of the fermion mass m and the compactification
scale L. This theory reduces to thermal pure gauge theory as m->infinity and to
circle-compactified (non-thermal) supersymmetric gluodynamics in the limit
m->0. In the m-L plane, there is a line of center symmetry changing phase
transitions. In the limit m->infinity, this transition takes place at
L_c=1/T_c, where T_c is the critical temperature of the deconfinement
transition in pure Yang-Mills theory. We show that near m=0, the critical
compactification scale L_c can be computed using semi-classical methods and
that the transition is of second order. This suggests that the deconfining
phase transition in pure Yang-Mills theory is continuously connected to a
transition that can be studied at weak coupling. The center symmetry changing
phase transition arises from the competition of perturbative contributions and
monopole-instantons that destabilize the center, and topological molecules
(neutral bions) that stabilize the center. The contribution of molecules can be
computed using supersymmetry in the limit m=0, and via the
Bogomolnyi--Zinn-Justin (BZJ) prescription in the non-supersymmetric gauge
theory. Finally, we also give a detailed discussion of an issue that has not
received proper attention in the context of N=1 theories---the non-cancellation
of nonzero-mode determinants around supersymmetric BPS and KK
monopole-instanton backgrounds on R^3xS^1. We explain why the non-cancellation
is required for consistency with holomorphy and supersymmetry and perform an
explicit calculation of the one-loop determinant ratio.Comment: A discussion of the non-cancellation of the nonzero mode determinants
around supersymmetric monopole-instantons in N=1 SYM on R^3xS^1 is added,
including an explicit calculation. The non-cancellation is, in fact, required
by supersymmetry and holomorphy in order for the affine-Toda superpotential
to be reproduced. References have also been adde
Recommended from our members
Ichthyosporidium weissii n. sp. (Microsporidia) Infecting the Arrow Goby (Clevelandia ios)
Gonadal infections by a novel microsporidium were discovered in 34% (13/38) of arrow gobies, Clevelandia ios, sampled over a 3-yr period from Morro Bay Marina in Morro Bay, California. Gonadal tumors had been reported in arrow gobies from this geographic area. The infected gonads, found primarily in females, typically appeared grossly as large, white-gray firm and lobulated masses. Histological examination revealed large, multilobate xenomas within the ovaries and no evidence of neoplasia. Typical of the genus Ichthyosporidium, the large xenomas were filled with developmental stages and pleomorphic spores. Wet mount preparations showed two general spore types: microspores with mean length of 6.2 (7.04.9, SD=0.6, N=20) mu m and mean width of 4.3 (5.32.9, SD=0.8) mu m; and less numerous macrospores with mean length of 8.5 (10.17.1, SD=1.0, N=10) mu m and mean width of 5.5 (6.24.8, SD=0.5) mu m. Transmission electron microscopy demonstrated stages consistent with the genus and 3550 turns of the polar filament. Small subunit rDNA gene sequence analysis revealed that the parasite from arrow gobies was most closely related to, but distinct from Ichthyosporidium sp. based on sequences available in GenBank. We conclude that this microsporidium represents a new species of Ichthyosporidium, the first species of this genus described from a member of the family Gobiidae and from the Pacific Ocean.This is the publisher’s final pdf. The published article is copyrighted by Wiley and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1550-7408Keywords: Parasite, Gonads, Phylogeny, Neoplasia, Electron microscopy, New specie
- …