918 research outputs found
Post-Glitch RXTE-PCA Observations of the Vela Pulsar
We report the results of analysis of observations of the Vela Pulsar by PCA
on RXTE. Our data consists of two parts. The first part contains observations
at 1, 4, and 9 days after the glitch in 1996 and has 27000 sec. total exposure
time. The second part of observations were performed three months after this
glitch and have a total exposure time of 93000 sec. We found pulsations in both
sets. The observed spectrum is a power-law with no apparent change in flux or
count rate. The theoretical expectations of increase in flux due to internal
heating after a glitch are smaller than the uncertainty of the observations.Comment: 6 pages, 5 figures in 9 ps/eps files. Accepted for publication in A&A
Main Journa
Exploring Network Security Educator Knowledge
It is critical for nations to have trained professionals in network security who can safeguard hardware, information systems, and electronic data. Network security education is a key knowledge unit of the National Centers of Academic Excellence in Cybersecurity and various information systems security curricula at the master\u27s and bachelor\u27s levels in higher education. Network security units are components of computer science curricula in high school contexts as well. Educators who teach these concepts play a significant role in developing a skilled workforce of network security experts for both governmental and non-governmental organizations. Understanding the necessary knowledge and skills of network security educators serve to better inform institutes of higher education, educator preparation programs, and others who support educators in the field. This study describes knowledge constructs of a higher education faculty member who teaches networking and network security and was developing, and piloting innovative network security curriculum embedded in both undergraduate and graduate courses. Data were transcripts of recorded monthly meetings with the educator, fieldnotes taken during the meetings, and course artifacts. Existing teacher knowledge frameworks that have been applied in both K-12 and higher education contexts were used to deductively code the data. Examples of curricular knowledge and pedagogical content knowledge specific to the teaching of network security are provided. The affordances of using engagement within curriculum development to understand educator knowledge constructs and the existing teacher knowledge frameworks as tools for analyses are highlighted
On the Use of Electrooculogram for Efficient Human Computer Interfaces
The aim of this study is to present electrooculogram signals that can be used for human computer interface efficiently. Establishing an efficient alternative channel for communication without overt speech and hand movements is important to increase the quality of life for patients suffering from Amyotrophic Lateral Sclerosis or other illnesses that prevent correct limb and facial muscular responses. We have made several experiments to compare the P300-based BCI speller and EOG-based new system. A five-letter word can be written on average in 25 seconds and in 105 seconds with the EEG-based device. Giving message such as âclean-upâ could be performed in 3 seconds with the new system. The new system is more efficient than P300-based BCI system in terms of accuracy, speed, applicability, and cost efficiency. Using EOG signals, it is possible to improve the communication abilities of those patients who can move their eyes
AMPK Is the Crucial Target for the CDK4/6 Inhibitors Mediated Therapeutic Responses in PANC-1 and MIA PaCa-2 Pancreatic Cancer Cell Lines
The survival rate of pancreatic ductal adenocarcinoma (PDAC) patients is short, and PDAC is a cancer type that ranks fourth in the statistics regarding death due to cancer. Mutation in the KRAS gene, which plays a role in pancreatic cancer development, activates the PI3K/AKT/mTOR signaling pathway. The activity of the AMPK as a cellular energy sensor is one of the fundamental mechanisms that can induce effective therapeutic responses against CDK4/6 inhibitors via adjusting the cellular and tumor microenvironment stress management. The phosphorylation of AMPKα at the different phosphorylation residues such as Thr172 and Ser 377 causes metabolic differentiation in the cells following CDK4/6 inhibitor treatment in accordance with an increased cell cycle arrest and senescence under the control of different cellular players. In this study, we examined the competencies of the CDK4/6 inhibitors LY2835219 and PD-0332991 on the mechanism of cell survival and death based on AMPK signaling. Both CDK4/6 inhibitors LY2835219 and PD-0332991 modulated different molecular players on the PI3K/AKT/mTOR and AMPK signaling axis in different ways to reduce cell survival in a cell type dependent manner. These drugs are potential inducers of apoptosis and senescence that can alter the therapeutic efficacy cells
A temporal approach for morphological indices of the common sole (Solea solea Linnaeus 1758) from the coast of the Aegean Sea, Turkey
810-818Temporal changes of the morphological indices (Relative Gut Length (RGL), Fullness Index (FI), Hepatosomatic Index
(HSI), Visceral Index (VSI), Gonadosomatic Index (GSI) and Fulton condition)) in 122 (â: 94, â: 19, immature: 9)
common sole were evaluated. Total length-weight relationships were calculated as W = 0.085TL3.01 and W = 0.0547TL2.40
in females and males, respectively, whereby isometric growth was observed in females and negative allometric growth was
observed in males. While there was no statistically significant difference was observed between the FI, HSI, Viscerosomatic
Index (VSI), RGL and GSI values of both sexes, however, there was a statistically significant difference in terms of
Fulton K values (P < 0.05). In addition, there are statistical differences between the sexes total lengths and the values of
RGL, FI, HSI, VSI, and Fulton-K (P < 0.05), as it is discernible in their HSI and VSI index values according to the month
the specimens were obtained (P < 0.05). According to the results of the analysis, it has been determined that the female
common sole along the Aegean coast adjust their energy temporally and store the energy they obtain from vegetative and
carnivorous feeding. Contrary to the situation seen in females, the male individuals invest in energy through omnivorous
feeding, according to the diet in the active process. Based on the results, it can be stated that the VSI and HSI are both
important indicators of fish condition status. The results found here may be useful in both fishery research and fishery
management
The Vela Pulsar and its Synchrotron Nebula
(Abridged) We present high-resolution Chandra X-ray observations of PSR
B0833-45, the 89 ms pulsar associated with the Vela supernova remnant. We have
acquired two observations separated by one month to search for changes in the
pulsar and its environment following an extreme glitch in its rotation
frequency. We find a well-resolved nebula with a toroidal morphology remarkably
similar to that observed in the Crab Nebula, along with an axial Crab-like jet.
Between the two observations the flux from the pulsar is found to be steady to
within 0.75%; the 3 sigma limit on the fractional increase in the pulsar's
X-ray flux is < ~10^-5 of the inferred glitch energy. We use this limit to
constrain parameters of glitch models and neutron star structure. We do find a
significant increase in the flux of the nebula's outer arc; if associated with
the glitch, the inferred propagation velocity is > 0.7c, similar to that seen
in the brightening of the Crab Nebula wisps. We propose an explanation for the
X-ray structure of the Vela synchrotron nebula based on a model originally
developed for the Crab Nebula. In a departure from the Crab model, the
magnetization parameter "sigma" of the Vela pulsar wind is allowed to be of
order unity; this is consistent with the simplest MHD transport of magnetic
field from the pulsar to the nebula, where B < 4 X 10^-4 G. We review effects
that may enhance the probability of alignment between the spin axis and space
velocity of a pulsar, and speculate that short-period, slowly moving pulsars
are just the ones best-suited to producing synchrotron nebulae with such
aligned structures.Comment: 16 pages with 8 figures, uses LaTex, emulateapj.sty. Refereed
version. To appear in The Astrophysical Journa
Inflammatory Pathway Analytes Predicting Rapid Cognitive Decline in MCI stage of Alzheimerâs disease
Objective: To determine the inflammatory analytes that predict clinical progression and evaluate their performance against biomarkers of neurodegeneration. Methods: A longitudinal study of MCI-AD patients in a Discovery cohort over 15 months, with replication in the Alzheimerâs Disease Neuroimaging Initiative (ADNI) MCI cohort over 36 months. Fifty-three inflammatory analytes were measured in the CSF and plasma with a RBM multiplex analyte platform. Inflammatory analytes that predict clinical progression on Clinical Dementia Rating Scale-Sum of Boxes (CDR-SB) and Mini Mental State Exam scores were assessed in multivariate regression models. To provide context, key analyte results in ADNI were compared against biomarkers of neurodegeneration, hippocampal volume, and CSF neurofilament light (NfL), in receiver operating characteristic (ROC) analyses evaluating highest quartile of CDR-SB change over two years (â„3 points). Results: Cerebrospinal fluid inflammatory analytes in relation to cognitive decline were best described by gene ontology terms, natural killer cell chemotaxis, and endothelial cell apoptotic process and in plasma, extracellular matrix organization, blood coagulation, and fibrin clot formation described the analytes. CSF CCL2 was most robust in predicting rate of cognitive change and analytes that correlated to CCL2 suggest IL-10 pathway dysregulation. The ROC curves for â„3 points change in CDR-SB over 2 years when comparing baseline hippocampal volume, CSF NfL, and CCL2 were not significantly different. Interpretation: Baseline levels of immune cell chemotactic cytokine CCL2 in the CSF and IL-10 pathway dysregulation impact longitudinal cognitive and functional decline in MCI-AD. CCL2âs utility appears comparable to biomarkers of neurodegeneration in predicting rapid decline
Longitudinal metabolomics analysis reveals the acute effect of cysteine and NAC included in the combined metabolic activators
Growing evidence suggests that the depletion of plasma NAD+ and glutathione (GSH) may play an important role in the development of metabolic disorders. The administration of Combined Metabolic Activators (CMA), consisting of GSH and NAD+ precursors, has been explored as a promising therapeutic strategy to target multiple altered pathways associated with the pathogenesis of the diseases. Although studies have examined the therapeutic effect of CMA that contains N-acetyl-L-cysteine (NAC) as a metabolic activator, a system-wide comparison of the metabolic response to the administration of CMA with NAC and cysteine remains lacking. In this placebo-controlled study, we studied the acute effect of the CMA administration with different metabolic activators, including NAC or cysteine with/without nicotinamide or flush free niacin, and performed longitudinal untargeted-metabolomics profiling of plasma obtained from 70 well-characterized healthy volunteers. The time-series metabolomics data revealed the metabolic pathways affected after the administration of CMAs showed high similarity between CMA containing nicotinamide and NAC or cysteine as metabolic activators. Our analysis also showed that CMA with cysteine is well-tolerated and safe in healthy individuals throughout the study. Last, our study systematically provided insights into a complex and dynamics landscape involved in amino acid, lipid and nicotinamide metabolism, reflecting the metabolic responses to CMA administration containing different metabolic activators
Safety of Intraperitoneal Injection of Adipose Tissue-Derived Autologous Mesenchymal Stem Cells in Cats
BACKGROUND: Chronic inflammatory diseases are common in cats and mesenchymal stem cells (MSC) are a promising therapeutic approach for management of these disorders. The purpose of this study was to evaluate the safety of intraperitoneal injection of MSC in cats. HYPOTHESIS: Intrapertioneal injection of autologous MSC in cats is safe. ANIMALS: Ten healthy adult purposeâbred cats. METHODS: Mesenchymal stem cells were isolated from subcutaneous adipose tissue collected during ovariohysterectomy and characterized for expression of CD90, CD105 and CD44 and trilineage differentiation. Three weeks postoperatively a complete blood count, serum chemistry profile, urinalysis, and abdominal ultrasound were performed. Five cats then received 1 Ă 10(6) of autologous MSC/kg of body weight intraperitoneally with ultrasound guidance; 5 additional cats were sham injected. Cats were monitored for 6 weeks with daily physical examinations and weekly clinicopathological evaluations. Abdominal ultrasonography was repeated at weeks 1 and 5 after injection. RESULTS: Serious adverse effects were not observed in any MSCâinjected cat. Two animals developed transient lethargy and decreased activity. Jejunal lymph node size was increased in MSCâinjected cats compared to controls at weeks 1 (1.38 ± 0.25 versus 0.88 ± 0.25 cm(2); P = .036) and 5 (1.75 ± 0.82 versus 0.79 ± 0.12 cm(2); P = .047). A hyperechoic renal segmental cortical lesion was observed in 1 MSCâinjected cat. CONCLUSIONS AND CLINICAL RELEVANCE: Intraperitoneal MSC injection was well tolerated with only mild, selfâlimiting adverse effects being observed in 2 cats. This route provides a safe means of administration for cellâbased treatment in cats
LOFAR/H-ATLAS: The low-frequency radio luminosity - star-formation rate relation
Radio emission is a key indicator of star-formation activity in galaxies, but
the radio luminosity-star formation relation has to date been studied almost
exclusively at frequencies of 1.4 GHz or above. At lower radio frequencies the
effects of thermal radio emission are greatly reduced, and so we would expect
the radio emission observed to be completely dominated by synchrotron radiation
from supernova-generated cosmic rays. As part of the LOFAR Surveys Key Science
project, the Herschel-ATLAS NGP field has been surveyed with LOFAR at an
effective frequency of 150 MHz. We select a sample from the MPA-JHU catalogue
of SDSS galaxies in this area: the combination of Herschel, optical and
mid-infrared data enable us to derive star-formation rates (SFRs) for our
sources using spectral energy distribution fitting, allowing a detailed study
of the low-frequency radio luminosity--star-formation relation in the nearby
Universe. For those objects selected as star-forming galaxies (SFGs) using
optical emission line diagnostics, we find a tight relationship between the 150
MHz radio luminosity () and SFR. Interestingly, we find that a single
power-law relationship between and SFR is not a good description of
all SFGs: a broken power law model provides a better fit. This may indicate an
additional mechanism for the generation of radio-emitting cosmic rays. Also, at
given SFR, the radio luminosity depends on the stellar mass of the galaxy.
Objects which were not classified as SFGs have higher 150-MHz radio luminosity
than would be expected given their SFR, implying an important role for
low-level active galactic nucleus activity.Comment: 21 pages, 12 figures, accepted for publication in MNRA
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