3,941 research outputs found

    Block Design-Based Local Differential Privacy Mechanisms

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    In this paper, we propose a new class of local differential privacy (LDP) schemes based on combinatorial block designs for a discrete distribution estimation. This class not only recovers many known LDP schemes in a unified framework of combinatorial block design, but also suggests a novel way of finding new schemes achieving the optimal (or near-optimal) privacy-utility trade-off with lower communication costs. Indeed, we find many new LDP schemes that achieve both the optimal privacy-utility trade-off and the minimum communication cost among all the unbiased schemes for a certain set of input data size and LDP constraint. Furthermore, to partially solve the sparse existence issue of block design schemes, we consider a broader class of LDP schemes based on regular and pairwise-balanced designs, called RPBD schemes, which relax one of the symmetry requirements on block designs. By considering this broader class of RPBD schemes, we can find LDP schemes achieving near-optimal privacy-utility trade-off with reasonably low communication costs for a much larger set of input data size and LDP constraint.Comment: 18 pages, 3 figures, and 1 table. This manuscript was submitted to IEEE Transactions on Information Theory and a short version of this manuscript will be presented at 2023 IEEE International Symposium on Information Theor

    In vitro embryo rescue for the production of hypotetraploids after cross between hypotetraploid and tetraploid grape cultivars

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    Consumer demand for seedless grape with high quality and large berry has been increasing. Breeding of hypotetraploid grape was suggested as one of promising methods to satisfy it, but low frequency of hypotetraploid occurrence and low seed germination by abortive embryo were indicated as the major problem to hamper the development of hypotetraploid grape. Hence, this study was carried out to evaluate the basic efficiency of in ovulo embryo culture after the cross between hypotetraploid (‘Hanareum’) and tetraploid (‘Honey Black’ and ‘Kyoho’) grape cultivars on the establishment of hypotetraploid grapes. Embryos and plantlets were hardly obtained in ovules cultured at six after the cross pollination (WAP), but ovules inoculated at 10 WAP produced more embryos as well as plantlets regardless of cross combination. Furthermore, we found that embryo formation was not affected by the basal media in ovules cultured at six WAP, but utilization of specific medium can be more beneficial for embryo formation when ovules were cultured at 10 WAP. A total of 17 plants were obtained from ovules cultured at 10 WAP, and above 50% of plants were identified as hypotetraploid grapes. These results indicate that in vitro embryo rescue after cross pollination between hypotetraploid and tetraploid grape can enhance the efficiency for the breeding of hypotetraploid grapes

    Epidural cement leakage through pedicle violation after balloon kyphoplasty causing paraparesis in osteoporotic vertebral compression fractures - a report of two cases

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    Kyphoplasty is advantageous over vertebroplasty in terms of better kyphosis correction and diminished risk of cement extravasations. Literature described cement leakage causing neurological injury mainly after vertebroplasty procedure; only a few case reports show cement leakage with kyphoplasty without neurological injury or proper cause of leakage. We present a report two cases of osteoporotic vertebral compression fracture treated with kyphoplasty and developed cement leakage causing significant neurological injury. In both cases CT scan was the diagnostic tool to identify cause of cement leakage. CT scan exhibited violation of medial pedicle wall causing cement leakage in the spinal canal. Both patients displayed clinical improvement after decompression surgery with or without instrumentation. Retrospectively looking at stored fluoroscopic images, we found that improper position of trocar in AP and lateral view simultaneously while taking entry caused pedicle wall violation. We suggest not to cross medial pedicle wall in AP image throughout the entire procedure and keeping the trocar in the center of pedicle in lateral image would be the most important precaution to prevent such complication. Our case reports adds the neurological complications with kyphoplasty procedure and suggested that along with other precautions described in the literature, entry with trocar along the entire procedure keeping the oval shape of pedicle in mind (under C-arm) will probably help to prevent such complications

    Magnetic resonance imaging analysis of rotator cuff tear after shoulder dislocation in a patient older than 40 years

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    Background This study was designed to evaluate characters of the rotator cuff tear (RCT) recognized after primary shoulder dislocation in patients older than 40. Methods From 2008 to 2019, patients who visited two hospitals after dislocation were retrospectively reviewed. Inclusion criteria were patients over 40 who had dislocation, with magnetic resonance imaging (MRI) undergone. Exclusion criteria were patients who lost to follow-up, combined with any proximal humerus fracture, brachial plexus injury, and previous operation or dislocation history in the ipsilateral shoulder. Also patients who had only bankart or bony bakart lesion in MRI were excluded. We evaluated RCTs that were recognized by MRI after the primary shoulder dislocation with regard to tear size, degree, involved tendons, fatty degeneration, the age when the first dislocation occurred, and the duration until the MRI was evaluated after the dislocation. Results Fifty-five RCTs were included. According to age groups, the tear size was increased in coronal and sagittal direction, the number of involved tendons was increased, and the degree of fatty degeneration was advanced in infraspinatus muscle. Thirty-two cases (58.2%) conducted MRI after 3 weeks from the first shoulder dislocation event. This group showed that the retraction size of the coronal plane was increased significantly and the fatty accumulation of the supraspinatus muscle had progressed significantly. Conclusions Age is also a strong factor to affect the feature of RCT after the shoulder dislocation in patients over 40. And the delay of the MRI may deteriorate the degree of tear size and fatty degeneration

    Quantum Criticality and Global Phase Diagram of Magnetic Heavy Fermions

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    Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. It is being discussed in a number of strongly correlated electron systems. A prototype case occurs in the heavy fermion metals, in which antiferromagnetic quantum critical points have been explicitly observed. Here, I address two types of antiferromagnetic quantum critical points. In addition to the standard description based on the fluctuations of the antiferromagnetic order, a local quantum critical point is also considered. It contains inherently quantum modes that are associated with a critical breakdown of the Kondo effect. Across such a quantum critical point, there is a sudden collapse of a large Fermi surface to a small one. I also consider the proximate antiferromagnetic and paramagnetic phases, and these considerations lead to a global phase diagram. Finally, I discuss the pertinent experiments on the antiferromagnetic heavy fermions, briefly address the case of ferromagnetic heavy fermions, and outline some directions for future studies.Comment: (v2) reference added, and typos corrected; (v1) 10 pages, 2 figures, based on a plenary talk given at the International Conference on Quantum Criticality and Novel Phases (QCNP09, Dresden
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