1,233 research outputs found
Localization transition on complex networks via spectral statistics
The spectral statistics of complex networks are numerically studied.
The features of the Anderson metal-insulator transition are found to be
similar for a wide range of different networks. A metal-insulator transition as
a function of the disorder can be observed for different classes of complex
networks for which the average connectivity is small. The critical index of the
transition corresponds to the mean field expectation. When the connectivity is
higher, the amount of disorder needed to reach a certain degree of localization
is proportional to the average connectivity, though a precise transition cannot
be identified. The absence of a clear transition at high connectivity is
probably due to the very compact structure of the highly connected networks,
resulting in a small diameter even for a large number of sites.Comment: 6 pages, expanded introduction and referencess (to appear in PRE
Two pup vocalization types are genetically and functionally separable in deer mice
Vocalization is a widespread vertebrate social behavior that is essential for fitness in the wild. While many vocal behaviors are highly conserved, heritable features of specific vocalization types can vary both within and between species, raising the questions of why and how some vocal behaviors evolve. Here, using new computational tools to automatically detect and cluster vocalizations into distinct acoustic categories, we compare pup isolation calls across neonatal development in eight taxa of deer mice (genusPeromyscus) and compare them to laboratory mice (C57Bl6/j strain) and free-living, wild house mice (Mus musculus musculus). Whereas bothPeromyscusandMuspups produce ultrasonic vocalizations (USVs),Peromyscuspups also produce a second call type with acoustic features, temporal rhythms, and developmental trajectories that are distinct from those of USVs. In deer mice, these tonal and low frequency “cries” are predominantly emitted in postnatal days one through nine, while USVs are primarily made after day nine. Using playback assays, we show that cries result in a more rapid approach byPeromyscusmothers than USVs, suggesting a role for cries in eliciting parental care early in neonatal development. Using genetic crosses between two sister species of deer mice exhibiting large, innate differences in the acoustic structure of cries and USVs, we find that variation in vocalization rate, duration, and pitch display different degrees of genetic dominance and that cry and USV features can be uncoupled in second-generation hybrids. Taken together, this work shows that vocal behavior can evolve quickly between closely related rodent species in which vocalization types, likely serving distinct functions in communication, are controlled by distinct genetic loci
Morphological and molecular evidence for the recognition of hypoglossum sabahense sp. Nov. (delesseriaceae, rhodophyta) from sabah, malaysia
Funding Information: This work was supported by the UK Natural Environment Research Council (NERC, Programme Oceans 2025, WP 4.5 and grant NE/D521522/1). This work also received support from the Marine Alliance for Science and Technology for Scotland pooling initiative. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. FCK is grateful to faculty, staff and students at the Institute of Ocean and Earth Sciences of the University of Malaya for hosting his visits in November-December 2007 and November-December 2008. Dr. Akira F. Peters (Bezhin Rosko, 29250 Santec, Brittany, France) is acknowledged for his laboratory assistance. The University of Melbourne, School of Biosciences and the facilities provided by Prof. Geoffrey McFadden for 25 years have been invaluable for JAW’s culture programs and publications since 1994.Peer reviewedPublisher PD
use of bone health agents bhas in patients pts with metastatic castration resistant prostate cancer mcrpc treated with radium 223 ra 223 after abiraterone abi an interim review of reassure
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Canal wall reconstruction and mastoid obliteration with composite multi-fractured osteoperiosteal flap
We used inferior pedicled composite multi-fractured osteoperiosteal flap (CMOF), our original and new surgical approach, to obliterate the mastoid cavity and reconstruct the external auditory canal (EAC) to prevent the open cavity problems. CMOF was used to obliterate the mastoid cavity and reconstruct the EAC in 24 patients (13 women, 11 men; age span 12–51 years) who underwent radical mastoidectomy to treat the chronic otitis media between 1998 and 2004. Small meatoplasty was done in all 24 patients to relive their aesthetical concerns. Temporal bone CT scanning was done to observe the neo-osteogenesis in the mastoidectomy cavity and the CMOF, and the EAC volume was measured postoperatively. All our patients were followed-up for 2 years. The epithelization of the new EAC in our patients was complete at the end of the second month. Cholesteatoma, granulation, and recurrence of osteitis did not occur in any of the patients. We saw the new bone formation filling the mastoid cavity in the postoperative temporal bone CT scanning images. The mean volume of the new EAC on the 24th month was 1.83 ± 0.56 cm(3). We had an almost natural EAC, which owed its existence to the neo-osteogenesis that grows behind the CMOF, which we use to obliterate the mastoid cavity and to reconstruct the EAC
Quinolinic Acid Amyloid-like Fibrillar Assemblies Seed α-Synuclein Aggregation
Quinolinic acid (QA), a downstream neurometabolite in the kynurenine pathway, the biosynthetic pathway of tryptophan, is associated with neurodegenerative diseases pathology. Mutations in genes encoding kynurenine pathway enzymes, which control the level of QA production, are linked with elevated risk of developing Parkinson\u27s disease. Recent findings have revealed the accumulation and deposition of QA in post-mortem samples, as well as in cellular models of Alzheimer\u27s disease and related disorders. Furthermore, intrastriatal inoculation of mice with QA results in increased levels of phosphorylated α-synuclein and neurodegenerative pathological and behavioral characteristics. However, the cellular and molecular mechanisms underlying the involvement of QA accumulation in protein aggregation and neurodegeneration remain elusive. We recently established that self-assembled ordered structures are formed by various metabolites and hypothesized that these “metabolite amyloids” may seed amyloidogenic proteins. Here we demonstrate the formation of QA amyloid-like fibrillar assemblies and seeding of α-synuclein aggregation by these nanostructures both in vitro and in cell culture. Notably, α-synuclein aggregation kinetics was accelerated by an order of magnitude. Additional amyloid-like properties of QA assemblies were demonstrated using thioflavin T assay, powder X-ray diffraction and cell apoptosis analysis. Moreover, fluorescently labeled QA assemblies were internalized by neuronal cells and co-localized with α-synuclein aggregates. In addition, we observed cell-to-cell propagation of fluorescently labeled QA assemblies in a co-culture of treated and untreated cells. Our findings suggest that excess QA levels, due to mutations in the kynurenine pathway, for example, may lead to the formation of metabolite assemblies that seed α-synuclein aggregation, resulting in neuronal toxicity and induction of Parkinson\u27s disease
Single cell RNA-sequence analyses reveal uniquely expressed genes and heterogeneous immune cell involvement in the rat model of intervertebral disc degeneration
Intervertebral disc (IVD) degeneration is characterized by a loss of cellularity, and changes in cell-mediated activity that drives anatomic changes to IVD structure. In this study, we used single-cell RNA-sequencing analysis of degenerating tissues of the rat IVD following lumbar disc puncture. Two control, uninjured IVDs (L2–3, L3–4) and two degenerated, injured IVDs (L4–5, L5–6) from each animal were examined either at the two- or eight-week post-operative time points. The cells from these IVDs were extracted and transcriptionally profiled at the single-cell resolution. Unsupervised cluster analysis revealed the presence of four known cell types in both non-degenerative and degenerated IVDs based on previously established gene markers: IVD cells, endothelial cells, myeloid cells, and lymphoid cells. As a majority of cells were associated with the IVD cell cluster, sub-clustering was used to further identify the cell populations of the nucleus pulposus, inner and outer annulus fibrosus. The most notable difference between control and degenerated IVDs was the increase of myeloid and lymphoid cells in degenerated samples at two- and eight-weeks post-surgery. Differential gene expression analysis revealed multiple distinct cell types from the myeloid and lymphoid lineages, most notably macrophages and B lymphocytes, and demonstrated a high degree of immune specificity during degeneration. In addition to the heterogenous infiltrating immune cell populations in the degenerating IVD, the increased number of cells in the AF sub-cluster expressing Ngf and Ngfr, encoding for p75NTR, suggest that NGF signaling may be one of the key mediators of the IVD crosstalk between immune and neuronal cell populations. These findings provide the basis for future work to understand the involvement of select subsets of non-resident cells in IVD degeneration
Sons of low-ranking female rhesus macaques can attain high dominance rank in their natal groups
Five adult and subadult sons of middle- and low-ranking female rhesus macaques ( Macaca mulatta ) were observed to hold high dominance rank in their natal groups during a 12-month study at Cayo Santiago, Puerto Rico. Three of these males also experienced high mating success during at least one mating season. These findings contrast with all previously published accounts of rank acquisition by natal male rhesus macaques in provisioned colonies, and they present a challenge to the hypothesis that natal transfer functions to increase male access to fertile females.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41609/1/10329_2006_Article_BF02382622.pd
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