595 research outputs found
Efficient Joint Network-Source Coding for Multiple Terminals with Side Information
Consider the problem of source coding in networks with multiple receiving
terminals, each having access to some kind of side information. In this case,
standard coding techniques are either prohibitively complex to decode, or
require network-source coding separation, resulting in sub-optimal transmission
rates. To alleviate this problem, we offer a joint network-source coding scheme
based on matrix sparsification at the code design phase, which allows the
terminals to use an efficient decoding procedure (syndrome decoding using
LDPC), despite the network coding throughout the network. Via a novel relation
between matrix sparsification and rate-distortion theory, we give lower and
upper bounds on the best achievable sparsification performance. These bounds
allow us to analyze our scheme, and, in particular, show that in the limit
where all receivers have comparable side information (in terms of conditional
entropy), or, equivalently, have weak side information, a vanishing density can
be achieved. As a result, efficient decoding is possible at all terminals
simultaneously. Simulation results motivate the use of this scheme at
non-limiting rates as well
New perspectives on glaucoma treatment
Introduction. Glaucoma disease, the silent thief of sight, is a neurodegenerative disease, characterized by
a progressive optic disc cupping, a loss of retinal ganglion cells and a visual field damage, representing as
the second leading causes of irreversible blindness worldwide. Treatment and regular checkups can help
slow or prevent vision loss, especially if catching the disease in early stages. Glaucoma is treated by
lowering eye pressure (intraocular pressure) and regulating balance between aqueous formation and
drainage system.
Aim of study. Investigation perspective points of views on glaucoma disease of standard surgical treatment
vs XEN Gel stent.
Methods and materials. Data collection from published 51 abstracts and articles found on Pubmed for a
period of 5 years (2017-2022) and the medical book Minimally Invasive Glaucoma Surgery – "Practical
Guide", helped us to compare the changes in the anterior structure of the eye and IOP after trabeculectomy
versus XEN Gel Stent implantation.
Results. Recently, the approach of glaucoma treatment became the gold standard focus on MIGS
(minimally invasive glaucoma surgery). The XEN Gel Micro stent is a subconjunctival micro-invasive
glaucoma surgical device developed to improve the predictability and safety profile of glaucoma surgical
procedures. The stent is a hydrophilic tube composed of a porcine gel cross-linked with glutaraldehyde with
good stability and biocompatibility with minimal tissue reaction that reduces the complications and the time
of healing in the postoperative period. The baseline mean corneal endothelial cell density in the
trabeculectomy group was representing a cell loss of 2.1% compared with XEN Gel Stent group [Ali Olgun,
2020]. Usually, the surgery is undergone combined XEN + cataract extraction (phacoemulsification) which
has a better influence on IOP (intraocular pressure). The median IOP reduction was 17.7% [Cosme LavinDapena, 2021] after XEN Gel Stent and a significant reduction in the number of ocular hypotensive drugs.
Also, Xen reduces IOP and the number of medications in eyes with failed trabeculectomy [Ayesha Karimi,
2018]. The top priority of glaucoma treatment is to decrease the IOP and prevent obstruction drainage.
Nowadays, MIGS surgical procedures manage the balance between aqueous formation and drainage, reduce
IOP that shows promise for better safety and excellent results in glaucoma treatment. Trabeculectomy
caused more endothelial cell damage than XEN Gel Stent implantation in the follow-up period. The device
significantly reduced both IOP and the amount of ocular hypotensive medications while maintaining a good
safety profile.
Conclusion. Xen Gel stent seems to be a viable, effective, and safe option for glaucoma surgery even in
comparison with trabeculectomy. Anyway, it should be considered the type of glaucoma, patient profile
and safety
Динамика цен на драгоценные металлы
Приводится динамика цен на драгоценные металлы в долгосрочных и среднесрочных периодах. Показана низкая эластичность цен на золото, серебро, платину и палладий в среднесрочных и долгосрочных периодах. При сравнении стоимости драгоценных металлов в различных национальных валютах выявлено отсутствие относительного роста их цен (в долларах США) в среднесрочном периоде после 2001 г. Выявлена отрицательная зависимость цен на золото с объемами перетоков международных инвестиций
Exposure to continuous political violence: rational and experiential thinking styles, coping styles and post traumatic stress symptoms
Cognitive style is considered an important determinant of individual behavior. The aim of the present study was to examine the relations between rational and experiential thinking styles, coping styles and Post Traumatic Stress (PTS) symptoms among civilians exposed to continuous and ongoing exposure to political violence. Three-hundred and thirty-two Israeli adult citizens living in the south region of Israel reported on their experiences of exposure to political violence as well as level of PTS, coping styles, and preference toward rational and experiential processing style. Results showed that low rational thinking was related with elevated PTS, both directly and indirectly through the mediation of high emotion-focused coping. The findings suggest that rational thinking may serve as a protective factor against stress related to chronic exposure to political violence; conversely, a preference for low rationality may be a risk factor
Hybrid Fabrics as Cement Matrix Reinforcement
Hybrid systems with two or more fiber materials were used to combine the benefits of each fiber into a single composite product. Strength and toughness optimization of hybrid thin sheet composites has been studied extensively using combination of different fiber types with low and high modulus of elasticity. Hybrid reinforcement is more significant when the reinforcing structure is in fabric geometry. Fabric structure provides full control on the exact location of each yarn and its orientation in the composite during production, thus maximizes the reinforcing efficiency. A high-strength, high-modulus fiber primarily tends to increase the composite strength with nominal improvements in toughness. A low-modulus fiber expected to mainly improve toughness and ductility. Combination of two or more types of fiber can produce a composite that is both strong and tough as compared to a mono fiber composite. The purpose of the current work was to study hybrid warp knitted fabrics as reinforcement for cementbased composite, having AR (Alkali Resistance) glass and Polypropylene (PP) as the reinforcing yarns. The examined ratios between the two different yarns were 0:100, 25:75, 50:50, 75:25, 100:0 (glass: PP, by percentage). It was found that in the hybrid system, the fracture mechanism is a superposition of the mono systems, and the tensile behavior is a combination between the two materials
Effect of hydrogen peroxide production and the Fenton reaction on membrane composition of Streptococcus pneumoniae
AbstractAs part of its aerobic metabolism, Streptococcus pneumoniae generates high levels of H2O2 by pyruvate oxidase (SpxB), which can be further reduced to yield the damaging hydroxyl radicals via the Fenton reaction. A universal conserved adaptation response observed among bacteria is the adjustment of the membrane fatty acids to various growth conditions. The aim of the present study was to reveal the effect of endogenous reactive oxygen species (ROS) formation on membrane composition of S. pneumoniae. Blocking carbon aerobic metabolism, by growing the bacteria at anaerobic conditions or by the truncation of the spxB gene, resulted in a significant enhancement in fatty acid unsaturation, mainly cis-vaccenic acid. Moreover, reducing the level of OH· by growing the bacteria at acidic pH, or in the presence of an OH· scavenger (salicylate), resulted in increased fatty acid unsaturation, similar to that obtained under anaerobic conditions. RT-PCR results demonstrated that this change does not originate from a change in mRNA expression level of the fatty acid synthase II genes. We suggest that endogenous ROS play an important regulatory role in membrane adaptation, allowing the survival of this anaerobic organism at aerobic environments of the host
Commiphora gileadensis sap extract induces cell cycle-dependent death in immortalized keratinocytes and human dermoid carcinoma
We would like to dedicate this article to the memory of Professor Yoram Milner, who has passed away before this study was achieved. We are immeasurably indebted to him, professionally and personally. The study was supported by grants from the ICA Foundation and the Ministry of Science, Technology and Space.Peer reviewedPublisher PD
Preferential Attachment as a Unique Equilibrium
International audienceThis paper demonstrates that the Preferential Attachment rule naturally emerges in the context of evolutionary network formation, as the unique Nash equilibrium of a simple social network game. In this game, each node aims at maximizing its degree in the future, representing its social capital in the "society" formed by the nodes and their connections. This result provides additional formal support to the commonly used Preferential Attachment model, initially designed to capture the "rich get richer" aphorism. In the process of establishing our result, we expose new connections between Preferential Attachment, random walks, and Young's Lattice
Spag17 Deficiency Results in Skeletal Malformations and Bone Abnormalities
Height is the result of many growth and development processes. Most of the genes associated with height are known to play a role in skeletal development. Single-nucleotide polymorphisms in the SPAG17 gene have been associated with human height. However, it is not clear how this gene influences linear growth. Here we show that a targeted mutation in Spag17 leads to skeletal malformations. Hind limb length in mutants was significantly shorter than in wild-type mice. Studies revealed differences in maturation of femur and tibia suggesting alterations in limb patterning. Morphometric studies showed increased bone formation evidenced by increased trabecular bone area and the ratio of bone area to total area, leading to reductions in the ratio of marrow area/total area in the femur. Micro-CTs and von Kossa staining demonstrated increased mineral in the femur. Moreover, osteocalcin and osterix were more highly expressed in mutant mice than in wild-type mice femurs. These data suggest that femur bone shortening may be due to premature ossification. On the other hand, tibias appear to be shorter due to a delay in cartilage and bone development. Morphometric studies showed reduction in growth plate and bone formation. These defects did not affect bone mineralization, although the volume of primary bone and levels of osteocalcin and osterix were higher. Other skeletal malformations were observed including fused sternebrae, reduced mineralization in the skull, medial and metacarpal phalanges. Primary cilia from chondrocytes, osteoblasts, and embryonic fibroblasts (MEFs) isolated from knockout mice were shorter and fewer cells had primary cilia in comparison to cells from wild-type mice. In addition, Spag17 knockdown in wild-type MEFs by Spag17 siRNA duplex reproduced the shorter primary cilia phenotype. Our findings disclosed unexpected functions for Spag17 in the regulation of skeletal growth and mineralization, perhaps because of its role in primary cilia of chondrocytes and osteoblasts
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