43 research outputs found
Structure and function of language networks in temporal lobe epilepsy
Individuals with temporal lobe epilepsy (TLE) may have significant language deficits. Language capabilities may further decline following temporal lobe resections. The language network, comprised of dispersed grey matter regions interconnected with white matter fibres, may be atypical in those with TLE. This review explores the structural changes to the language network and the functional reorganisation of language abilities in TLE. We discuss the importance of detailed reporting of patient's characteristics, such as, left- and right-sided focal epilepsies as well as lesional and non-lesional pathological subtypes. These factors can affect the healthy functioning of grey and/or white matter. Dysfunction of white matter and displacement of grey matter function could impact each other's ability, in turn, producing an interactive effect on typical language organisation and function. Surgical intervention can result in impairment of function if the resection includes parts of this structure-function network that are critical to language. Further, impairment may occur if language function has been reorganized and is included in a resection. Conversely, resection of an epileptogenic zone may be associated with recovery of cortical function and thus improvement in language function. We explore the abnormality of functional regions in a clinically applicable framework and highlight the differences in the underlying language network. Avoidance of language decline following surgical intervention may depend on tailored resections to avoid critical areas of grey matter and their white matter connections. Further work is required to elucidate the plasticity of the language network in TLE and to identify sub-types of language representation, both of which will be useful in planning surgery to spare language function
Magneto-Optical Trapping and Sub-Doppler Cooling of a Polyatomic Molecule
We report magneto-optical trapping (MOT) of a polyatomic molecule, calcium
monohydroxide (CaOH). The MOT contains CaOH molecules at a
peak density of cm. CaOH molecules are further
sub-Doppler laser cooled in an optical molasses, to a temperature of 110(4)
K. The temperatures and densities achieved here make CaOH a viable
candidate for a wide variety of quantum science applications, including the
creation of optical tweezer arrays of CaOH molecules. This work also suggests
that laser cooling and magneto-optical trapping of many other polyatomic
species will be both feasible and practical.Comment: 6 pages, 4 figure
Adversarial Privacy-preserving Filter
While widely adopted in practical applications, face recognition has been
critically discussed regarding the malicious use of face images and the
potential privacy problems, e.g., deceiving payment system and causing personal
sabotage. Online photo sharing services unintentionally act as the main
repository for malicious crawler and face recognition applications. This work
aims to develop a privacy-preserving solution, called Adversarial
Privacy-preserving Filter (APF), to protect the online shared face images from
being maliciously used.We propose an end-cloud collaborated adversarial attack
solution to satisfy requirements of privacy, utility and nonaccessibility.
Specifically, the solutions consist of three modules: (1) image-specific
gradient generation, to extract image-specific gradient in the user end with a
compressed probe model; (2) adversarial gradient transfer, to fine-tune the
image-specific gradient in the server cloud; and (3) universal adversarial
perturbation enhancement, to append image-independent perturbation to derive
the final adversarial noise. Extensive experiments on three datasets validate
the effectiveness and efficiency of the proposed solution. A prototype
application is also released for further evaluation.We hope the end-cloud
collaborated attack framework could shed light on addressing the issue of
online multimedia sharing privacy-preserving issues from user side.Comment: Accepted by ACM Multimedia 202
Direct Laser Cooling of a Symmetric Top Molecule
We report direct laser cooling of a symmetric top molecule, reducing the
transverse temperature of a beam of calcium monomethoxide (CaOCH) to
mK while addressing two distinct nuclear spin isomers. These
results open a path to efficient production of ultracold chiral molecules and
conclusively demonstrate that by using proper rovibronic optical transitions,
both photon cycling and laser cooling of complex molecules can be as efficient
as for much simpler linear species
Contribution of White Matter Fiber Bundle Damage to Language Change After Surgery for Temporal Lobe Epilepsy.
Background and Objectives:In medically refractory temporal lobe epilepsy (TLE), 30-50% of patients experience substantial language decline following resection in the language dominant hemisphere. Here, we investigate the contribution of white matter fiber bundle damage to language change at 3- and 12-months after surgery.Methods:We studied 127 patients who underwent TLE surgery from 2010–2019. Neuropsychological testing included picture naming, semantic, and phonemic verbal fluency, performed pre-operatively, 3- and 12-months post-operatively. Outcome was assessed using reliable change index (RCI; clinically significant decline) and change across timepoints (post- minus pre-operative scores).Functional MRI was used to determine language lateralization. The arcuate (AF), inferior fronto-occipital (IFOF), inferior longitudinal, middle longitudinal (MLF), and uncinate fasciculi were mapped using diffusion MRI probabilistic tractography. Resection masks, drawn comparing co-registered pre- and post-operative T1 MRI scans, were used as exclusion regions on pre-operative tractography to estimate the percentage of pre-operative tracts transected in surgery. Chi-squared assessments evaluated the occurrence of RCI-determined language decline. Independent samples T-tests and MM-estimator robust regressions were used to assess the impact of clinical factors and fiber transection on RCI and change outcomes, respectively.Results:Language dominant and non-dominant resections were treated separately for picture naming, as post-operative outcomes were significantly different between these groups. In language dominant hemisphere resections, greater surgical damage to the AF and IFOF was related to RCI-decline at 3 months. Damage to the inferior frontal sub-fasciculus of the IFOF was related to change at 3 months. In language non-dominant hemisphere resections, increased MLF resection was associated with RCI-decline at 3 months, and damage to the anterior sub-fasciculus was related to change at 3 months.Language dominant and non-dominant resections were treated as one cohort for semantic and phonemic fluency, as there were no significant differences in post-operative decline between these groups. Post-operative seizure freedom was associated with an absence of significant language decline 12 months after surgery for semantic fluency.Discussion:We demonstrate a relationship between fiber transection and naming decline after temporal lobe resection. Individualized surgical planning to spare white matter fiber bundles could help to preserve language function after surgery
Molecular regulation of lysine trimethylation by the <i>P. aeruginosa</i> methyltransferase EftM
Overproduction of the AlgT Sigma Factor Is Lethal to Mucoid Pseudomonas aeruginosa
Pseudomonas aeruginosa
is an opportunistic bacterial pathogen capable of causing chronic lung infections. Phenotypes important for the long-term persistence and adaption to this unique lung ecosystem are largely regulated by the AlgT sigma factor. Chronic infection isolates often contain mutations in the anti-sigma factor
mucA
, resulting in uncontrolled AlgT and continuous production of alginate in addition to the expression of ∼300 additional genes. Here, we report that in the absence of wild-type MucA, AlgT overproduction is lethal and that suppressors of toxic AlgT production have mutations in the MucA protease, MucP. Since AlgT contributes to the establishment of chronic infections, understanding how AlgT is regulated will provide vital information on how
P. aeruginosa
is capable of causing long-term infections.
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Overproduction of the AlgT sigma factor is lethal to mucoid<i>Pseudomonas aeruginosa</i>
ABSTRACTPseudomonas aeruginosaisolates from chronic lung infections often overproduce alginate, giving rise to the mucoid phenotype. Isolation of mucoid strains from chronic lung infections correlates with a poor patient outcome. The most common mutation that causes the mucoid phenotype is calledmucA22and results in a truncated form of the anti-sigma factor MucA that is continuously subjected to proteolysis. When a functional MucA is absent, the cognate sigma factor, AlgT, is no longer sequestered and continuously transcribes the alginate biosynthesis operon leading to alginate overproduction. In this work, we report that in the absence of wild-type MucA, providing exogenous AlgT is toxic. This is intriguing since mucoid strains endogenously possess high levels of AlgT. Furthermore, we show that suppressors of toxic AlgT production have mutations inmucP, a protease involved in MucA degradation, and provide the first atomistic model of MucP. Our findings support a model where mutations inmucPstabilize the truncated form of MucA22 rendering it functional and therefore able to reduce toxicity by properly sequestering AlgT.IMPORTANCEPseudomonas aeruginosais an opportunistic bacterial pathogen capable of causing chronic lung infections. Phenotypes important for the long-term persistence and adaption to this unique lung ecosystem are largely regulated by the AlgT sigma factor. Chronic infection isolates often contain mutations in the anti-sigma factormucAresulting in uncontrolled AlgT and continuous production of alginate, in addition to the expression of ~300 additional genes includingalgTitself. Here we report that in the absence of wild-type MucA, AlgT overproduction is lethal and that suppressors of toxic AlgT production have mutations in the MucA protease, MucP. Since AlgT contributes to the establishment of chronic infections, understanding how AlgT is regulated will provide vital information on howP. aeruginosais capable of causing long-term infections.</jats:sec
