12,109 research outputs found
Recommended from our members
Real-Time Selective Monitoring of Exposure Controlled Projection Lithography
Exposure Controlled Projection Lithography (ECPL) is a stereolithographic process in
which incident radiation, patterned by a dynamic mask, passes through a transparent substrate to
cure photopolymer which grows progressively from the substrate surface. We present here a
novel method of capturing useful information about the curing process from a simple,
inexpensive, real-time monitoring system based on interferometry. This approach can be used to
provide feedback control to the ECPL process, thus making the process more robust and
increasing system accuracy. The results obtained from this monitoring system provide a means to
better visualize and understand the various phenomena occurring during the photopolymerization of transparent photopolymers. In order to lessen the measurement error, caused
by internal diffraction within the substrate, the interferometry system has been designed such that
the laser light used can be selectively targeted. This selective monitoring approach is
experimentally validated to measure the height and profile of the cured part in real-time.Mechanical Engineerin
A simple model for the vibrational modes in honeycomb lattices
The classical lattice dynamics of honeycomb lattices is studied in the
harmonic approximation. Interactions between nearest neighbors are represented
by springs connecting them. A short and necessary introduction of the lattice
structure is presented. The dynamical matrix of the vibrational modes is then
derived, and its eigenvalue problem is solved analytically. The solution may
provide deeper insight into the nature of the vibrational modes. Numerical
results for the vibrational frequencies are presented. To show that how
effective our method used for the case of honeycomb lattice is, we also apply
it to triangular and square lattice structures. A few suggested problems are
listed in the concluding section.Comment: 9 pages, 12 figures, submitted to American Journal of Physic
Parameter dependence of magnetized CMB observables
Pre-decoupling magnetic fields affect the scalar modes of the geometry and
produce observable effects which can be constrained also through the use of
current (as opposed to forthcoming) data stemming from the Cosmic Microwave
Background observations. The dependence of the temperature and polarization
angular power spectra upon the parameters of an ambient magnetic field is
encoded in the scaling properties of a set of basic integrals whose derivation
is simplified in the limit of small angular scales. The magnetically-induced
distortions patterns of the relevant observables can be computed analytically
by employing scaling considerations which are corroborated by numerical
results.Comment: 48 pages, 11 figures; corrected minor typos; discussions added; to
appear in Physical Revie
A connectivity portfolio effect stabilizes marine reserve performance
Well-managed and enforced no-take marine reserves generate important larval subsidies to neighboring habitats and thereby con-tribute to the long-term sustainability of fisheries. However, larval dispersal patterns are variable, which leads to temporal fluctua-tions in the contribution of a single reserve to the replenishment of local populations. Identifying management strategies that mit-igate the uncertainty in larval supply will help ensure the stability of recruitment dynamics and minimize the volatility in fishery catches. Here, we use genetic parentage analysis to show extreme variability in both the dispersal patterns and recruitment contribu-tion of four individual marine reserves across six discrete recruit-ment cohorts for coral grouper (Plectropomus maculatus) on the Great Barrier Reef. Together, however, the asynchronous contri-butions from multiple reserves create temporal stability in recruit-ment via a connectivity portfolio effect. This dampening effect reduces the variability in larval supply from individual reserves by a factor of 1.8, which effectively halves the uncertainty in the recruitment contribution of individual reserves. Thus, not only does the network of four marine reserves generate valuable larval subsidies to neighboring habitats, the aggregate effect of individual reserves mitigates temporal fluctuations in dispersal patterns and the replenishment of local populations. Our results indicate that small networks of marine reserves yield previously unrecog-nized stabilizing benefits that ensure a consistent larval supply to replenish exploited fish stocks
Autistic Traits Mediate Reductions in Social Attention in Adults with Anorexia Nervosa
Anorexia nervosa (AN) is associated with difficulties in social and emotional functioning. A significant proportion of individuals with AN show autistic traits, which may influence social attention. This study examined attention to faces and facial features in AN, recovered AN (REC), and healthy controls, as well as relationships with comorbid psychopathology. One hundred and forty-eight participants’ eye movements were tracked while watching a naturalistic social scene. Anxiety, depression, alexithymia, and autistic traits were assessed via self-report questionnaires. Participants with AN spent significantly less time looking at faces compared to REC and controls; patterns of attention to individual facial features did not differ across groups. Autistic traits mediated the relationship between group and time spent looking at faces
Autistic traits mediate reductions in social attention in adults with anorexia nervosa
Anorexia nervosa (AN) is associated with difficulties in social and emotional functioning. A significant proportion of individuals with AN show autistic traits, which may influence social attention. This study examined attention to faces and facial features in AN, recovered AN (REC), and healthy controls, as well as relationships with comorbid psychopathology. One hundred and forty-eight participants’ eye movements were tracked while watching a naturalistic social scene. Anxiety, depression, alexithymia, and autistic traits were assessed via self-report questionnaires. Participants with AN spent significantly less time looking at faces compared to REC and controls; patterns of attention to individual facial features did not differ across groups. Autistic traits mediated the relationship between group and time spent looking at faces
Single cell analysis identifies <em>CRLF2</em> rearrangements as both early and late events in Down syndrome and non-Down syndrome acute lymphoblastic leukaemia
Deregulated expression of the type I cytokine receptor, CRLF2, is observed in 5-15% of precursor B-cell acute lymphoblastic leukaemia (B-ALL). We have previously reported the genomic landscape of patients with CRLF2 rearrangements (CRLF2-r) using both whole genome and exome sequencing, which identified a number of potential clonal and sub-clonal genomic alterations. In this study, we aimed to assess when the CRLF2-r; IGH-CRLF2 or P2RY8-CRLF2, arose during the evolution of both Down syndrome-ALL (DS-ALL) and non-DS-ALL. Using fluorescence in situ hybridisation, we were able to track up to four structural variants in single cells from 47 CRLF2-r B-ALL patients, which in association with our multiplex single cell analysis of a further four patients, permitted simultaneous tracking of copy number alterations, structural and single nucleotide variants within individual cells. We observed CRLF2-r arising as both early and late events in DS and non-DS-ALL patients. Parallel evolution of discrete clones was observed in the development of CRLF2-r B-ALL, either involving the CRLF2-r or one of the other tracked abnormalities. In depth single cell analysis identified both linear and branching evolution with early clones harbouring a multitude of abnormalities, including the CRLF2-r in DS-ALL patients
Dynamic clonal progression in xenografts of acute lymphoblastic leukemia with intrachromosomal amplification of chromosome 21
Intrachromosomal amplification of chromosome 21 is a heterogeneous chromosomal rearrangement occurring in 2% of childhood precursor B-cell acute lymphoblastic leukemia. There are no cell lines with iAMP21 and these abnormalities are too complex to faithfully engineer in animal models. As a resource for future functional and pre-clinical studies, we have created xenografts from intrachromosomal amplification of chromosome 21 leukemia patient blasts and characterised them by in-vivo and ex-vivo luminescent imaging, FLOW immunophenotyping, and histological and ultrastructural analysis of bone marrow and the central nervous system. Investigation of up to three generations of xenografts revealed phenotypic evolution, branching genomic architecture and, compared with other B-cell acute lymphoblastic leukemia genetic subtypes, greater clonal diversity of leukemia initiating cells. In support of intrachromosomal amplification of chromosome 21 as a primary genetic abnormality, it was always retained through generations of xenografts, although we also observed the first example of structural evolution of this rearrangement. Clonal segregation in xenografts revealed convergent evolution of different secondary genomic abnormalities implicating several known tumour suppressor genes and a region, containing the B-cell adaptor, PIK3AP1, and nuclear receptor co-repressor, LCOR, in the progression of B-ALL. Tracking of mutations in patients and derived xenografts provided evidence for co-operation between abnormalities activating the RAS pathway in B-ALL and for their aggressive clonal expansion in the xeno-environment. Bi-allelic loss of the CDKN2A/B locus was recurrently maintained or emergent in xenografts and also strongly selected as RNA sequencing demonstrated a complete absence of reads for genes associated with the deletions
- …