2,525 research outputs found
Habitat preference of two sympatric coastal cetaceans in Langkawi, Malaysia, as determined by passive acoustic monitoring
Little is known about the ecology of the Indo-Pacific finless porpoise Neophocaena phocaenoides or the Indo-Pacific humpback dolphin Sousa chinensis in Southeast Asia. The present study describes the distribution and habitat preferences of these species around the Langkawi Archipelago of Malaysia. Vessel-based passive acoustic monitoring surveys were conducted 5 times between 2012 and 2013. Both species mainly preferred relatively shallow waters, especially on the east sides of the islands at <15 m depth. However, the species differed in number of detections and spatial distribution, preferred distance from shore, chlorophyll a concentration in the water where they resided, and season in which they were detected, indicating that they have different habitat preferences. The best spatial habitat model for the prediction of finless porpoise distribution included bathymetric depth and longitude. The distribution of finless porpoises was relatively stable around the islands and especially in the eastern waters, whereas humpback dolphins may only seasonally visit specific regions of the waters around the islands. Their detection sites were too patchy to enable distribution modeling. The results of this study provide baseline information that can facilitate conservation planning for these species according to their habitat preferences and core areas
The Itinerary of Autophagosomes: From Peripheral Formation to Kiss-and-Run Fusion with Lysosomes
Macroautophagy, a constitutive process in higher eukaryotic cells, mediates degradation of many long-lived proteins and organelles. The actual events occurring during the process in the dynamic system of a living cell have never been thoroughly investigated. We aimed to develop a live-cell assay in which to follow the complete itinerary of an autophagosome. Our experiments show that autophagosomes are formed randomly in peripheral regions of the cell. They then move bidirectionally along microtubules, accumulating at the microtubule-organizing centre, in a similar way to lysosomes. Their centripetal movement is dependent on the motor protein dynein and is important for their fusion with lysosomes. Initially, autophagosomes dock on to lysosomes, independent of lysosomal acidification. Two kinds of fusion then occur: complete fusions, creating a hybrid organelle, or more often kiss-and-run fusions, i.e. transfer of some content while still maintaining two separate vesicles. Surprisingly, the autophagolysosomal compartment seems to be more long lived than expected. Our study documents many aspects of autophagosome behaviour, adding to our understanding of the mechanism and control of autophagy. Indeed, although the formation of autophagosomes is completely different from any other vesicular structures, their later itinerary appears to be very similar to those of other trafficking pathways
From counting to construction of BPS states in N=4 SYM
We describe a universal element in the group algebra of symmetric groups,
whose characters provides the counting of quarter and eighth BPS states at weak
coupling in N=4 SYM, refined according to representations of the global
symmetry group. A related projector acting on the Hilbert space of the free
theory is used to construct the matrix of two-point functions of the states
annihilated by the one-loop dilatation operator, at finite N or in the large N
limit. The matrix is given simply in terms of Clebsch-Gordan coefficients of
symmetric groups and dimensions of U(N) representations. It is expected, by
non-renormalization theorems, to contain observables at strong coupling. Using
the stringy exclusion principle, we interpret a class of its eigenvalues and
eigenvectors in terms of giant gravitons. We also give a formula for the action
of the one-loop dilatation operator on the orthogonal basis of the free theory,
which is manifestly covariant under the global symmetry.Comment: 41 pages + Appendices, 4 figures; v2 - refs and acknowledgments adde
Surprisingly Simple Spectra
The large N limit of the anomalous dimensions of operators in
super Yang-Mills theory described by restricted Schur polynomials, are studied.
We focus on operators labeled by Young diagrams that have two columns (both
long) so that the classical dimension of these operators is O(N). At large N
these two column operators mix with each other but are decoupled from operators
with columns. The planar approximation does not capture the large N
dynamics. For operators built with 2, 3 or 4 impurities the dilatation operator
is explicitly evaluated. In all three cases, in a certain limit, the dilatation
operator is a lattice version of a second derivative, with the lattice emerging
from the Young diagram itself. The one loop dilatation operator is diagonalized
numerically. All eigenvalues are an integer multiple of and there
are interesting degeneracies in the spectrum. The spectrum we obtain for the
one loop anomalous dimension operator is reproduced by a collection of harmonic
oscillators. This equivalence to harmonic oscillators generalizes giant
graviton results known for the BPS sector and further implies that the
Hamiltonian defined by the one loop large dilatation operator is
integrable. This is an example of an integrable dilatation operator, obtained
by summing both planar and non-planar diagrams.Comment: 34 page
Thermodynamics of Large N Gauge Theories with Chemical Potentials in a 1/D Expansion
In order to understand thermodynamical properties of N D-branes with chemical
potentials associated with R-symmetry charges, we study a one dimensional large
N gauge theory (bosonic BFSS type model) as a first step. This model is
obtained through a dimensional reduction of a 1+D dimensional SU(N) Yang-Mills
theory and we use a 1/D expansion to investigate the phase structure. We find
three phases in the \mu-T plane. We also show that all the adjoint scalars
condense at large D and obtain a mass dynamically. This dynamical mass protects
our model from the usual perturbative instability of massless scalars in a
non-zero chemical potential. We find that the system is at least meta-stable
for arbitrary large values of the chemical potentials in D \to \infty limit. We
also explore the existence of similar condensation in higher dimensional gauge
theories in a high temperature limit. In 2 and 3 dimensions, the condensation
always happens as in one dimensional case. On the other hand, if the dimension
is higher than 4, there is a critical chemical potential and the condensation
happens only if the chemical potentials are below it.Comment: 37 pages, 4 figures; v2: minor corrections, references added; v3:
minor corrections, to appear in JHE
Pharmacists in Pharmacovigilance: Can Increased Diagnostic Opportunity in Community Settings Translate to Better Vigilance?
The pharmacy profession has undergone substantial change over the last two to three decades. Whilst medicine supply still remains a central function, pharmacist’s roles and responsibilities have become more clinic and patient focused. In the community (primary care), pharmacists have become important providers of healthcare as Western healthcare policy advocates patient self-care. This has resulted in pharmacists taking on greater responsibility in managing minor illness and the delivery of public health interventions. These roles require pharmacists to more fully use their clinical skills, and often involve diagnosis and therapeutic management. Community pharmacists are now, more than ever before, in a position to identify, record and report medication safety incidents. However, current research suggests that diagnostic ability of community pharmacists is questionable and they infrequently report to local or national schemes. The aim of this paper is to highlight current practice and suggest ways in which community pharmacy can more fully contribute to patient safety
Analysis of resveratrol as a lung cancer chemopreventive agent in A/J mice exposed to benzo[a]pyrene
Flavour singlets in gauge theory as permutations
50 pages, v2: typos corrected, v3: to appear in JHEPJHEP is an open-access journal funded by SCOAP3 and licensed under CC BY 4.
Strings on Bubbling Geometries
We study gauge theory operators which take the form of a product of a trace
with a Schur polynomial, and their string theory duals. These states represent
strings excited on bubbling AdS geometries which are dual to the Schur
polynomials. These geometries generically take the form of multiple annuli in
the phase space plane. We study the coherent state wavefunction of the lattice,
which labels the trace part of the operator, for a general Young tableau and
their dual description on the droplet plane with a general concentric ring
pattern. In addition we identify a density matrix over the coherent states on
all the geometries within a fixed constraint. This density matrix may be used
to calculate the entropy of a given ensemble of operators. We finally recover
the BMN string spectrum along the geodesic near any circle from the ansatz of
the coherent state wavefunction.Comment: 41 pages, 12 figures, published version in JHE
Recurrent and founder mutations in the Netherlands: cardiac Troponin I (TNNI3) gene mutations as a cause of severe forms of hypertrophic and restrictive cardiomyopathy
Background About 2-7% of familial cardiomyopathy cases are caused by a mutation in the gene encoding cardiac troponin 1 (TNNI3). The related clinical phenotype is usually severe with early onset. Here we report on all currently known mutations in the Dutch population and compared these with those described in literature. Methods TheTNNI3 gene was screened for mutations in all coding exons and flanking intronic sequences in a large cohort of cardiomyopathy patients. All Dutch index cases carrying a TNNI3 mutation that are described in this study underwent extensive cardiological evaluation and were listed by their postal codes. Results In 30 families, 14 different mutations were identified. Three TNNI3 mutations were found relatively frequently in both familial and non-familial cases of hypertrophic cardiomyopathy (HCM) or restrictive cardiomyopathy (RCM). Haplotype analysis showed that p. Arg145Trp and p.Ser166Phe are founder mutations in the Netherlands, while p.Glu209Ala is not. The majority of Dutch TNNI3 mutations were associated with a HCM phenotype. Mean age at diagnosis was 36.5 years. Mutations causing RCM occurred less frequently, but were identified in very young children with a poor prognosis. Conclusion In line with previously published data, we found TNNI3 mutations to be rare and associated with early onset and severe clinical presentation
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