Analyzing the Reduced Required BS Density due to CoMP in Cellular Networks

In this paper we investigate the benefit of base station (BS) cooperation in the uplink of coordinated multi-point (CoMP) networks. Our figure of merit is the required BS density required to meet a chosen rate coverage. Our model assumes a 2-D network of BSs on a regular hexagonal lattice in which path loss, lognormal shadowing and Rayleigh fading affect the signal received from users. Accurate closed-form expressions are first presented for the sum-rate coverage probability and ergodic sum-rate at each point of the cooperation region. Then, for a chosen quality of user rate, the required density of BS is derived based on the minimum value of rate coverage probability in the cooperation region. The approach guarantees that the achievable rate in the entire coverage region is above a target rate with chosen probability. The formulation allows comparison between different orders of BS cooperation, quantifying the reduced required BS density from higher orders of cooperation.Comment: Accepted for presentation in IEEE Globecom Conf., to be held in Atlanta, USA, Dec. 2013. arXiv admin note: text overlap with arXiv:1302.159

Analyzing the Impact of Access Point Density on the Performance of Finite-Area Networks

Assuming a network of infinite extent, several researchers have analyzed small-cell networks using a Poisson point process (PPP) location model, leading to simple analytic expressions. The general assumption has been that these results apply to finite-area networks as well. However, do the results of infinite-area networks apply to finite-area networks? In this paper, we answer this question by obtaining an accurate approximation for the achievable signal-to-interference-plus-noise ratio (SINR) and user capacity in the downlink of a \textit{finite-area} network with \textit{a fixed number of} access points (APs). The APs are uniformly distributed within the area of interest. Our analysis shows that, crucially, the results of infinite-area networks are very different from those for finite-area networks of low-to-medium AP density. Comprehensive simulations are used to illustrate the accuracy of our analysis. For practical values of signal transmit powers and AP densities, the analytic expressions capture the behavior of the system well. As an added benefit, the formulations developed here can be used in parametric studies for network design. Here, the analysis is used to obtain the required number of APs to guarantee a desired target capacity in a finite-area network.Comment: This article has been accepted for publication in a future issue of the journal of IEEE Transactions on Communications, but has not been fully edited. Content may change prior to final publicatio

The inner centromere is a biomolecular condensate scaffolded by the chromosomal passenger complex.

The inner centromere is a region on every mitotic chromosome that enables specific biochemical reactions that underlie properties, such as the maintenance of cohesion, the regulation of kinetochores and the assembly of specialized chromatin, that can resist microtubule pulling forces. The chromosomal passenger complex (CPC) is abundantly localized to the inner centromeres and it is unclear whether it is involved in non-kinase activities that contribute to the generation of these unique chromatin properties. We find that the borealin subunit of the CPC drives phase separation of the CPC in vitro at concentrations that are below those found on the inner centromere. We also provide strong evidence that the CPC exists in a phase-separated state at the inner centromere. CPC phase separation is required for its inner-centromere localization and function during mitosis. We suggest that the CPC combines phase separation, kinase and histone code-reading activities to enable the formation of a chromatin body with unique biochemical activities at the inner centromere

Dermatomyositis revealing breast cancer: report of a case

Dermatomyositis (DM) is a rare connective corresponding to an inflammatory disease of skeletal muscles. Paraneoplastic origin must always be sought, primarily gynecological tumor in women, but the investigations are often made difficult by the fact that a primary tumor is often not detectable at the time of the cutaneous manifestations. This approach includes in addition to the monitoring report at regular intervals of 6 to 12 months for two years after diagnosis. We report a case of Dermatomyositis revealing breast cancer

Tumeurs rares de l’ovaire: à propos d’une série de 11 cas de tumeurs non épithéliales malignes de l’ovaire

Les tumeurs non épithéliales malignes de l'ovaire représentent environ 20% des cancers de l'ovaire. L'objectif de notre travail est de dresser lesparticularités diagnostiques cliniques et d'imagerie de ces tumeurs. Nous avons procédé à une étude rétrospective portant sur 11 cas de tumeursnon épithéliales de l'ovaire. Ces tumeurs ont été colligées au service de gynécologie et obstétrique I du CHU Hassan II de Fès sur une période de 4 ans, entre janvier 2009 et décembre 2012. Les tumeurs germinales représentant 54% (6 patientes) des cas alors que les tumeurs du cordonsexuel ont été représentées par 4 cas de tumeurs de granulosa de type adulte et nous avons colligés un cas de lymphome ovarien primitif. Lasymptomatologie clinique était dominée par la distension abdominale associée souvent à des douleurs abdominopelviennes chroniques. La tailletumorale moyenne était de 175 mm avec un aspect solido-kystique dans 54% des cas. Le dosage des marqueurs tumoraux (hormone chorioniquegonadotrope, lactate déshydrogénase, CA 125, alpha-foetoprotéine) a été réalisé chez toutes les patientes. La découverte d'une masse annexiellesuspecte chez une jeune femme doit, outre une tumeur frontière ou un cancer épithélial de l'ovaire, évoquer une tumeur non épithéliale, a fortiorisi cette masse est volumineuse, si elle est associée à des signes d'hyperestrogénie ou d'androgénie

Sheehan's Syndrome A Case Report and Literature Review

Post-partum pituitary necrosis (Sheehan's syndrome) is a rare complication of post-partum hemorrhage. The diagnosis can be erratic and often delayed. In this case report of Sheehan's syndrome in the post-partum period, the signs were characterized by agalactia, severe hypoglycemia, and low serum levels of thyroid hormones, cortico-adrenal hormones, and gonadotrophin (FSH, LH). The hypophyseal magnetic resonance imaging confirmed the diagnosis of hypopituitarism secondary to pituitary necrosis

Carcinome métaplasique du sein avec différenciation osseuse extensive: À propos d’un cas

Le carcinome métaplasique du sein est une entité rare et bien individualisé par l'OMS. Il représente moins de 1 % des cancers invasifs du sein et constitue un groupe tumoral hétérogène soit purement épithélial soit à doublecontingent épithélial et mésenchymateuse. Le carcinome métaplasique avec différenciation osseuse extensive est très rare. Il représente 0.2% des carcinomes du sein. Nous rapportant un cas exceptionnel d'un carcinome métaplasique du sein avec différenciation osseuse extensive chez une patiente de 53 ans. A travers ce cas et une revue de la littérature, les caractéristiques anatomo-cliniques, radiologique, thérapeutiques et évolutives seront discutées

Role of condensates in modulating DNA repair pathways and its implication for chemoresistance

For cells, it is important to repair DNA damage, such as double-strand and single-strand DNA breaks, because unrepaired DNA can compromise genetic integrity, potentially leading to cell death or cancer. Cells have multiple DNA damage repair pathways that have been the subject of detailed genetic, biochemical, and structural studies. Recently, the scientific community has started to gain evidence that the repair of DNA double-strand breaks may occur within biomolecular condensates and that condensates may also contribute to DNA damage through concentrating genotoxic agents used to treat various cancers. Here, we summarize key features of biomolecular condensates and note where they have been implicated in the repair of DNA double-strand breaks. We also describe evidence suggesting that condensates may be involved in the repair of other types of DNA damage, including single-strand DNA breaks, nucleotide modifications (e.g., mismatch and oxidized bases), and bulky lesions, among others. Finally, we discuss old and new mysteries that could now be addressed considering the properties of condensates, including chemoresistance mechanisms