2,595 research outputs found
Black Holes in Modified Gravity (MOG)
The field equations for Scalar-Tensor-Vector-Gravity (STVG) or modified
gravity (MOG) have a static, spherically symmetric black hole solution
determined by the mass with two horizons. The strength of the gravitational
constant is where is a parameter. A regular
singularity-free MOG solution is derived using a nonlinear field dynamics for
the repulsive gravitational field component and a reasonable physical
energy-momentum tensor. The Kruskal-Szekeres completion of the MOG black hole
solution is obtained. The Kerr-MOG black hole solution is determined by the
mass , the parameter and the spin angular momentum . The
equations of motion and the stability condition of a test particle orbiting the
MOG black hole are derived, and the radius of the black hole photosphere and
the shadows cast by the Schwarzschild-MOG and Kerr-MOG black holes are
calculated. A traversable wormhole solution is constructed with a throat
stabilized by the repulsive component of the gravitational field.Comment: 14 pages, 3 figures. Upgraded version of paper to match published
version in European Physics Journal
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Comparison of governance approaches for the control of antimicrobial resistance: Analysis of three European countries
Policy makers and governments are calling for coordination to address the crisis emerging from the ineffectiveness of current antibiotics and stagnated pipe-line of new ones – antimicrobial resistance (AMR). Wider contextual drivers and mechanisms are contributing to shifts in governance strategies in health care, but are national health system approaches aligned with strategies required to tackle antimicrobial resistance? This article provides an analysis of governance approaches within healthcare systems including: priority setting, performance monitoring and accountability for AMR prevention in three European countries: England, France and Germany. Advantages and unresolved issues from these different experiences are reported, concluding that mechanisms are needed to support partnerships between healthcare professionals and patients with democratized decision-making and accountability via collaboration. But along with this multi-stakeholder approach to governance, a balance between regulation and persuasion is needed
The rise of China in the international trade network: a community core detection approach
Theory of complex networks proved successful in the description of a variety of static networks ranging from biology to computer and social sciences and to economics and
finance. Here we use network models to describe the evolution of a particular economic system, namely the International Trade Network (ITN). Previous studies often assume that globalization and regionalization in international trade are contradictory to each other. We re-examine the relationship between globalization and regionalization by viewing the international trade system as an interdependent complex network. We use the modularity optimization method to detect communities and community cores in the ITN during the years 1995-2011. We find rich dynamics over time both inter- and intra-communities. Most importantly, we have a multilevel description of the
evolution where the global dynamics (i.e., communities disappear or reemerge) tend to be correlated with the regional dynamics (i.e., community core changes between
community members). In particular, the Asia-Oceania community disappeared and reemerged over time along with a switch in leadership from Japan to China. Moreover,
simulation results show that the global dynamics can be generated by a preferential attachment mechanism both inter- and intra- communities
Automatic Network Fingerprinting through Single-Node Motifs
Complex networks have been characterised by their specific connectivity
patterns (network motifs), but their building blocks can also be identified and
described by node-motifs---a combination of local network features. One
technique to identify single node-motifs has been presented by Costa et al. (L.
D. F. Costa, F. A. Rodrigues, C. C. Hilgetag, and M. Kaiser, Europhys. Lett.,
87, 1, 2009). Here, we first suggest improvements to the method including how
its parameters can be determined automatically. Such automatic routines make
high-throughput studies of many networks feasible. Second, the new routines are
validated in different network-series. Third, we provide an example of how the
method can be used to analyse network time-series. In conclusion, we provide a
robust method for systematically discovering and classifying characteristic
nodes of a network. In contrast to classical motif analysis, our approach can
identify individual components (here: nodes) that are specific to a network.
Such special nodes, as hubs before, might be found to play critical roles in
real-world networks.Comment: 16 pages (4 figures) plus supporting information 8 pages (5 figures
Generation of Antibodies against Foot-and-Mouth-Disease Virus Capsid Protein VP4 Using Hepatitis B Core VLPs as a Scaffold
The picornavirus foot-and-mouth disease virus (FMDV) is the causative agent of the economically important disease of livestock, foot-and-mouth disease (FMD). VP4 is a highly conserved capsid protein, which is important during virus entry. Previous published work has shown that antibodies targeting the N-terminus of VP4 of the picornavirus human rhinovirus are broadly neutralising. In addition, previous studies showed that immunisation with the N-terminal 20 amino acids of enterovirus A71 VP4 displayed on the hepatitis B core (HBc) virus-like particles (VLP) can induce cross-genotype neutralisation. To investigate if a similar neutralising response against FMDV VP4 could be generated, HBc VLPs displaying the N-terminus of FMDV VP4 were designed. The N-terminal 15 amino acids of FMDV VP4 was inserted into the major immunodominant region. HBc VLPs were also decorated with peptides of the N-terminus of FMDV VP4 attached using a HBc-spike binding tag. Both types of VLPs were used to immunise mice and the resulting serum was investigated for VP4-specific antibodies. The VLP with VP4 inserted into the spike, induced VP4-specific antibodies, however the VLPs with peptides attached to the spikes did not. The VP4-specific antibodies could recognise native FMDV, but virus neutralisation was not demonstrated. This work shows that the HBc VLP presents a useful tool for the presentation of FMDV capsid epitopes
Surgical management of a diabetic calcaneal ulceration and osteomyelitis with a partial calcanectomy and a sural neurofasciocutaneous flap
The treatment of calcaneal osteomyelitis in diabetic patients poses a great challenge to the treating physician and surgeon. The use of a distally based sural neurofasciocutaneous flap after an aggressive debridement of non-viable and poorly vascularized tissue and bone that is combined with a thorough antibiotic regimen provides a great technique for adequate soft tissue coverage of the heel. In this case report, the authors describe the aforementioned flap as a versatile alternative to the use of local or distant muscle flaps for diabetic patients with calcaneal osteomyelitis and concomitant large wounds
Individualization as driving force of clustering phenomena in humans
One of the most intriguing dynamics in biological systems is the emergence of
clustering, the self-organization into separated agglomerations of individuals.
Several theories have been developed to explain clustering in, for instance,
multi-cellular organisms, ant colonies, bee hives, flocks of birds, schools of
fish, and animal herds. A persistent puzzle, however, is clustering of opinions
in human populations. The puzzle is particularly pressing if opinions vary
continuously, such as the degree to which citizens are in favor of or against a
vaccination program. Existing opinion formation models suggest that
"monoculture" is unavoidable in the long run, unless subsets of the population
are perfectly separated from each other. Yet, social diversity is a robust
empirical phenomenon, although perfect separation is hardly possible in an
increasingly connected world. Considering randomness did not overcome the
theoretical shortcomings so far. Small perturbations of individual opinions
trigger social influence cascades that inevitably lead to monoculture, while
larger noise disrupts opinion clusters and results in rampant individualism
without any social structure. Our solution of the puzzle builds on recent
empirical research, combining the integrative tendencies of social influence
with the disintegrative effects of individualization. A key element of the new
computational model is an adaptive kind of noise. We conduct simulation
experiments to demonstrate that with this kind of noise, a third phase besides
individualism and monoculture becomes possible, characterized by the formation
of metastable clusters with diversity between and consensus within clusters.
When clusters are small, individualization tendencies are too weak to prohibit
a fusion of clusters. When clusters grow too large, however, individualization
increases in strength, which promotes their splitting.Comment: 12 pages, 4 figure
Cirripedia of Madeira
We give a list of Cirripedia from Madeira Island and nearby deep water, based on specimens in the collection of the Museu Municipal do Funchal (Historia Natural) (MMF), records mentioned in the literature, and recent collections. Tesseropora atlantica Newman and Ross, 1976 is recorded from Madeira for the first time. The Megabalanus of Madeira is M. azoricus. There are 20 genera containing 27 species, of which 22 occur in depths less than 200 m. Of these shallow water species, eight are wide-ranging oceanic forms that attach to other organisms or to floating objects, leaving just 13 truly benthic shallow water barnacles. This low diversity is probably a consequence of the distance from the continental coasts and the small area of the available habitat. No endemic species have been found
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ALMaQUEST. IV. The ALMA-MaNGA QUEnching and STar Formation (ALMaQUEST) Survey
The ALMaQUEST (ALMA-MaNGA QUEnching and STar formation) survey is a program
with spatially-resolved CO(1-0) measurements obtained with the Atacama
Large Millimeter Array (ALMA) for 46 galaxies selected from the Mapping Nearby
Galaxies at Apache Point Observatory (MaNGA) DR15 optical integral-field
spectroscopic survey. The aim of the ALMaQUEST survey is to investigate the
dependence of star formation activity on the cold molecular gas content at kpc
scales in nearby galaxies. The sample consists of galaxies spanning a wide
range in specific star formation rate (sSFR), including starburst (SB),
main-sequence (MS), and green valley (GV) galaxies. In this paper, we present
the sample selection and characteristics of the ALMA observations, and showcase
some of the key results enabled by the combination of spatially-matched stellar
populations and gas measurements. Considering the global (aperture-matched)
stellar mass, molecular gas mass, and star formation rate of the sample, we
find that the sSFR depends on both the star formation efficiency (SFE) and the
molecular gas fraction (), although the correlation with the
latter is slightly weaker. Furthermore, the dependence of sSFR on the molecular
gas content (SFE or ) is stronger than that on either the atomic
gas fraction or the molecular-to-atomic gas fraction, albeit with the small HI
sample size. On kpc scales, the variations in both SFE and
within individual galaxies can be as large as 1-2 dex thereby demonstrating
that the availability of spatially-resolved observations is essential to
understand the details of both star formation and quenching processes.STFC
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FISH as an effective diagnostic tool for the management of challenging melanocytic lesions
<p>Abstract</p> <p>Background</p> <p>The accuracy of melanoma diagnosis continues to challenge the pathology community, even today with sophisticated histopathologic techniques. Melanocytic lesions exhibit significant morphological heterogeneity. While the majority of biopsies can be classified as benign (nevus) or malignant (melanoma) using well-established histopathologic criteria, there exists a cohort for which the prediction of clinical behaviour and invasive or metastatic potential is difficult if not impossible to ascertain on the basis of morphological features alone. Multiple studies have shown that there is significant disagreement between pathologists and even expert dermatopathologists in the diagnosis of this subgroup of difficult melanocytic lesions.</p> <p>Methods</p> <p>A four probe FISH assay was utilized to analyse a cohort of 500 samples including 157 nevus, 176 dysplastic nevus and 167 melanoma specimens.</p> <p>Results</p> <p>Review of the lesions determined the assay identified genetic abnormalities in a total of 83.8% of melanomas, and 1.9% of nevus without atypia, while genetic abnormalities were identified in 6.3%, 6.7%, and 10.3% of nevus identified with mild, moderate and severe atypia, respectively.</p> <p>Conclusions</p> <p>Based on this study, inheritable genetic damage/instability identified by FISH testing is a hallmark of a progressive malignant process, and a valuable diagnostic tool for the identification of high risk lesions.</p
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