8,402 research outputs found
The mapping class group and the Meyer function for plane curves
For each d>=2, the mapping class group for plane curves of degree d will be
defined and it is proved that there exists uniquely the Meyer function on this
group. In the case of d=4, using our Meyer function, we can define the local
signature for 4-dimensional fiber spaces whose general fibers are
non-hyperelliptic compact Riemann surfaces of genus 3. Some computations of our
local signature will be given.Comment: 24 pages, typo adde
Chromosome assignment of two cloned DNA probes hybridizing predominantly to human sex chromosomes
In situ hybridization experiments were carried out with two clones, YACG 35 and 2.8, which had been selected from two genomic libraries strongly enriched for the human Y chromosome. Besides the human Y chromosome, both sequences strongly hybridized to the human X chromosome, with few minor binding sites on autosomes. In particular, on the X chromosome DNA from clone YACG 35 hybridized to the centromeric region and the distal part of the short arm (Xp2.2). On the Y chromosome, the sequence was assigned to one site situated in the border region between Yq1.1 and Yq1.2. DNA from clone 2.8 also hybridized to the centromeric region of the X and the distal part of the short arm (Xq2.2). On the Y, however, two binding sites were observed (Yp1.1 and Yq1.2). The findings indicate that sex chromosomal sequences may be localized in homologous regions (as suggested from meiotic pairing) but also at ectopic sites
Dialectica Categories for the Lambek Calculus
We revisit the old work of de Paiva on the models of the Lambek Calculus in
dialectica models making sure that the syntactic details that were sketchy on
the first version got completed and verified. We extend the Lambek Calculus
with a \kappa modality, inspired by Yetter's work, which makes the calculus
commutative. Then we add the of-course modality !, as Girard did, to
re-introduce weakening and contraction for all formulas and get back the full
power of intuitionistic and classical logic. We also present the categorical
semantics, proved sound and complete. Finally we show the traditional
properties of type systems, like subject reduction, the Church-Rosser theorem
and normalization for the calculi of extended modalities, which we did not have
before
E-QED: Electrical Bug Localization During Post-Silicon Validation Enabled by Quick Error Detection and Formal Methods
During post-silicon validation, manufactured integrated circuits are
extensively tested in actual system environments to detect design bugs. Bug
localization involves identification of a bug trace (a sequence of inputs that
activates and detects the bug) and a hardware design block where the bug is
located. Existing bug localization practices during post-silicon validation are
mostly manual and ad hoc, and, hence, extremely expensive and time consuming.
This is particularly true for subtle electrical bugs caused by unexpected
interactions between a design and its electrical state. We present E-QED, a new
approach that automatically localizes electrical bugs during post-silicon
validation. Our results on the OpenSPARC T2, an open-source
500-million-transistor multicore chip design, demonstrate the effectiveness and
practicality of E-QED: starting with a failed post-silicon test, in a few hours
(9 hours on average) we can automatically narrow the location of the bug to
(the fan-in logic cone of) a handful of candidate flip-flops (18 flip-flops on
average for a design with ~ 1 Million flip-flops) and also obtain the
corresponding bug trace. The area impact of E-QED is ~2.5%. In contrast,
deter-mining this same information might take weeks (or even months) of mostly
manual work using traditional approaches
Internal representations, external representations and ergonomics: towards a theoretical integration
Compositional nonblocking verification with always enabled events and selfloop-only events
This paper proposes to improve compositional nonblocking verification through the use of always enabled and selfloop-only events. Compositional verification involves abstraction to simplify parts of a system during verification. Normally, this abstraction is based on the set of events not used in the remainder of the system, i.e., in the part of the system not being simplified. Here, it is proposed to exploit more knowledge about the system and abstract events even though they are used in the remainder of the system. Abstraction rules from previous work are generalised, and experimental results demonstrate the applicability of the resulting algorithm to verify several industrial-scale discrete event system models, while achieving better state-space reduction than before
The Minimal Solution to the mu/B_mu Problem in Gauge Mediation
We provide a minimal solution to the mu/B_mu problem in the gauge mediated
supersymmetry breaking by introducing a Standard Model singlet filed S with a
mass around the messenger scale which couples to the Higgs and messenger
fields. This singlet is nearly supersymmetric and acquires a relatively small
Vacuum Expectation Value (VEV) from its radiatively generated tadpole term.
Consequently, both mu and B_mu parameters receive the tree-level and one-loop
contributions, which are comparable due to the small S VEV. Because there
exists a proper cancellation in such two kinds of contributions to B_mu, we can
have a viable Higgs sector for electroweak symmetry breaking.Comment: 15 pages, 2 figures, version published on JHE
Bipolar disorder and dopamine dysfunction: an indirect approach focusing on tardive movement syndromes in a naturalistic setting
The impact of epilepsy surgery on the structural connectome and its relation to outcome
BACKGROUND:
Temporal lobe surgical resection brings seizure remission in up to 80% of patients, with long-term complete seizure freedom in 41%. However, it is unclear how surgery impacts on the structural white matter network, and how the network changes relate to seizure outcome.
METHODS:
We used white matter fibre tractography on preoperative diffusion MRI to generate a structural white matter network, and postoperative T1-weighted MRI to retrospectively infer the impact of surgical resection on this network. We then applied graph theory and machine learning to investigate the properties of change between the preoperative and predicted postoperative networks.
RESULTS:
Temporal lobe surgery had a modest impact on global network efficiency, despite the disruption caused. This was due to alternative shortest paths in the network leading to widespread increases in betweenness centrality post-surgery. Measurements of network change could retrospectively predict seizure outcomes with 79% accuracy and 65% specificity, which is twice as high as the empirical distribution. Fifteen connections which changed due to surgery were identified as useful for prediction of outcome, eight of which connected to the ipsilateral temporal pole.
CONCLUSIONS:
Our results suggest that the use of network change metrics may have clinical value for predicting seizure outcome. This approach could be used to prospectively predict outcomes given a suggested resection mask using preoperative data only
- ā¦