341 research outputs found
Absolute sets of rigid local systems
The absolute sets of local systems on a smooth complex algebraic variety are
the subject of a conjecture of N. Budur and B. Wang based on an analogy with
special subvarieties of Shimura varieties. An absolute set should be the
higher-dimensional generalization of a local system of geometric origin. We
show that the conjecture for absolute sets of simple cohomologically rigid
local systems reduces to the zero-dimensional case, that is, to Simpson's
conjecture that every such local system with quasi-unipotent monodromy at
infinity and determinant is of geometric origin. In particular, the conjecture
holds for this type of absolute sets if the variety is a curve or if the rank
is two.Comment: 33 pages, v2: references adde
Application of bioabsorbable screw fixation for anterior cervical decompression and bone grafting
OBJECTIVES: To examine the application of bioabsorbable screws for anterior cervical decompression and bone grafting fixation and to study their clinical effects in the treatment of cervical spondylosis. METHODS: From March 2007 to September 2012, 56 patients, 36 males and 20 females (38-79 years old, average 58.3±9.47 years), underwent a novel operation. Grafts were fixed by bioabsorbable screws (PLLA, 2.7 mm in diameter) after anterior decompression. The bioabsorbable screws were inserted from the midline of the graft bone to the bone surface of the upper and lower vertebrae at 45 degree angles. Patients were evaluated post-operatively to observe the improvement of symptoms and evaluate the fusion of the bone. The Japanese Orthopaedic Association (JOA) score was used to evaluate the recovery of neurological functions. RESULTS: All screws were successfully inserted, with no broken screws. The rate of symptom improvement was 87.5%. All of the grafts fused well with no extrusion. The average time for graft fusion was 3.8±0.55 months (range 3-5 months). Three-dimensional reconstruction of CT scans demonstrated that the grafts fused with adjacent vertebrae well and that the screws were absorbed as predicted. The MRI findings showed that the cerebrospinal fluid was unobstructed. No obvious complications appeared in any of the follow-up evaluations. CONCLUSIONS: Cervical spondylosis with one- or two-level involvement can be effectively treated by anterior decompression and bone grafting with bioabsorbable screw fixation. This operative method is safe and can avoid the complications induced by metal implants
Unsupervised Multi-document Summarization with Holistic Inference
Multi-document summarization aims to obtain core information from a
collection of documents written on the same topic. This paper proposes a new
holistic framework for unsupervised multi-document extractive summarization.
Our method incorporates the holistic beam search inference method associated
with the holistic measurements, named Subset Representative Index (SRI). SRI
balances the importance and diversity of a subset of sentences from the source
documents and can be calculated in unsupervised and adaptive manners. To
demonstrate the effectiveness of our method, we conduct extensive experiments
on both small and large-scale multi-document summarization datasets under both
unsupervised and adaptive settings. The proposed method outperforms strong
baselines by a significant margin, as indicated by the resulting ROUGE scores
and diversity measures. Our findings also suggest that diversity is essential
for improving multi-document summary performance.Comment: Findings of IJCNLP-AACL 202
A CRISPR-Based Toolbox for Studying T Cell Signal Transduction
CRISPR/Cas9 system is a powerful technology to perform genome editing in a variety of cell types. To facilitate the application of Cas9 in mapping T cell signaling pathways, we generated a toolbox for large-scale genetic screens in human Jurkat T cells. The toolbox has three different Jurkat cell lines expressing distinct Cas9 variants, including wild-type Cas9, dCas9-KRAB, and sunCas9. We demonstrated that the toolbox allows us to rapidly disrupt endogenous gene expression at the DNA level and to efficiently repress or activate gene expression at the transcriptional level. The toolbox, in combination with multiple currently existing genome-wide sgRNA libraries, will be useful to systematically investigate T cell signal transduction using both loss-of-function and gain-of-function genetic screens
Worcester Chamber of Commerce: Recruiting Minority Business Owners
Our capstone project was to help the Worcester Regional Chamber of Commerce identify how to re-frame their marketing so it would be appealing to immigrant and minority owned businesses. Based on interviews and external research, our group was able to create a tangible and resourceful data set that provided justified recommendations and ideas on how the Chamber could make adjustments to their marketing plan to attract more businesses of this particular demographic in the city of Worcester. By implementing these recommendations, we believe the Chamber has the opportunity to create a more diverse group of Chamber members, add value to a previously underserved community, and support minority and immigrant owned small businesses through Worcesterâs growth in the coming years
Discussion of âValidation of a Novel Sensing Approach for Continuous Pavement Monitoring Using Full-Scale APT Testingâ
202407 bcchAccepted ManuscriptSelf-fundedPublishedGreen (AAM
Note on absolute sets of rigid local systems
In this note we give a description up to a quasi-finite morphism of the absolute sets of simple cohomologically rigid local systems on a smooth complex quasi-projective algebraic variety. In dimension one or rank two, this proves a conjecture of BudurâWang on the structure of these sets
Boron-Made N2: Realization of a BâĄB Triple Bond in the B2Al3â Cluster
Until now, all BâĄB triple bonds have been achieved by adopting two ligands in the LâBâĄBâL manner. Herein, we report an alternative route of designing the BâĄB bonds based on the assumption that by acquiring two extra electrons, an element with the atomic number Z can have properties similar to those of the element with the atomic number Z+2. Specifically, we show that due to the electron donation from Al to B, the negatively charged BâĄB kernel in the B2Al3â cluster mimics a triple NâĄN bond. Comprehensive computational searches reveal that the global minimum structure of B2Al3â exhibits a direct BâB distance of 1.553â
Ă
, and its calculated electron vertical detachment energies are in excellent agreement with the corresponding values of the experimental photoelectron spectrum. Chemical bonding analysis revealed one Ï and two Ï bonds between the two B atoms, thus confirming a classical textbook BâĄB triple bond, similar to that of N2
Note on absolute sets of rigid local systems
In this note we give a description up to a quasi-finite morphism of the absolute sets of simple cohomologically rigid local systems on a smooth complex quasi-projective algebraic variety. In dimension one or rank two, this proves a conjecture of BudurâWang on the structure of these sets
Cache attack on MISTY1
Side-channel attacks exploit information from physical implementations of cryptographic systems. Cache attacks have improved at recovering information by combining observations of the victim\u27s cache access and knowledge of the cipherâs structure. Cache attacks have been implemented for most Feistel- and SPN-structured block cipher algorithms, but the security of algorithms for special structures has seen little attention.
We perform a Flush+Reload attack on MISTY1, a class of block cipher with a recursive structure. The function is performed before the plaintext input S-box and after the ciphertext output S-box, making it difficult to attack the first and last rounds. However, the key scheduling part of MISTY1 leaks many bits of the key, which, together with the leakage of partial bits of the round key during encryption, is sufficient to recover it.
We design an algorithm that can recover the MISTY1 128-bit key after observing encryption one time, and then use leakage during encryption to reduce its complexity. We experiment on 32- and 64-byte cache line environments. An adversary need observe as little as 5 encryptions to recover the 128-bit key in 0.035 second in the first case, and 10 encryptions to recover the key in 2.1 hours in the second case
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