10,042 research outputs found

    Analysis of the communities of an urban mobile phone network

    Get PDF
    This is the final version. Available from Public Library of Science via the DOI in this record. Data Availability: Data available at: Telecom Italia Big Data Challenge 2014, https://dandelion.eu/datamine/open-big-data/.Being able to characterise the patterns of communications between individuals across different time scales is of great importance in understanding people's social interactions. Here, we present a detailed analysis of the community structure of the network of mobile phone calls in the metropolitan area of Milan revealing temporal patterns of communications between people. We show that circadian and weekly patterns can be found in the evolution of communities, presenting evidence that these cycles arise not only at the individual level but also at that of social groups. Our findings suggest that these trends are present across a range of time scales, from hours to days and weeks, and can be used to detect socially relevant events.EPSRCEuropean Commissio

    Finding network communities using modularity density

    Get PDF
    This is the author's accepted manuscript. The final published version is available from IOP Publishing via the DOI in this recordMany real-world complex networks exhibit a community structure, in which the modules correspond to actual functional units. Identifying these communities is a key challenge for scientists. A common approach is to search for the network partition that maximizes a quality function. Here, we present a detailed analysis of a recently proposed function, namely modularity density. We show that it does not incur in the drawbacks suffered by traditional modularity, and that it can identify networks without ground-truth community structure, deriving its analytical dependence on link density in generic random graphs. In addition, we show that modularity density allows an easy comparison between networks of different sizes, and we also present some limitations that methods based on modularity density may suffer from. Finally, we introduce an efficient, quadratic community detection algorithm based on modularity density maximization, validating its accuracy against theoretical predictions and on a set of benchmark networks.Engineering and Physical Sciences Research Council (EPSRC

    Expanding the Genetic Spectrum of ANOS1 Mutations in Patients with Congenital Hypogonadotropic Hypogonadism

    Get PDF
    STUDY QUESTION: What is the prevalence and functional consequence of ANOS1 (KAL1) mutations in a group of men with congenital hypogonadotropic hypogonadism (CHH)? SUMMARY ANSWER: Three of forty-two (7.1%) patients presented ANOS1 mutations, including a novel splice site mutation leading to exon skipping and a novel contiguous gene deletion associated with ichthyosis. WHAT IS KNOWN ALREADY: CHH is characterized by lack of pubertal development and infertility, due to deficient production, secretion or action of GnRH, and can be associated with anosmia/hyposmia (Kallmann syndrome, KS) or with a normal sense of smell (normosmic CHH). Mutations in the anosmin-1 (ANOS1) gene are responsible for the X-linked recessive form of KS. STUDY DESIGN, SIZE, DURATION: This cross-sectional study included 42 unrelated men with CHH (20 with KS and 22 with normosmic CHH). PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients were screened for mutations in the ANOS1 gene by DNA sequencing. Identified mutations were further investigated by RT-PCR analysis and multiplex ligation-dependent probe amplification (MLPA) analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Hemizygous mutations were identified in three (7.1%) KS cases: a novel splice acceptor site mutation (c.542-1G>C), leading to skipping of exon 5 in the ANOS1 transcript in a patient with self-reported normosmia (but hyposmic upon testing); a recurrent nonsense mutation (c.571C>T, p.Arg191*); and a novel 4.8 Mb deletion involving ANOS1 and eight other genes (VCX3B, VCX2, PNPLA4, VCX, STS, HDHD1, VCX3A and NLGN4X) in KS associated with ichthyosis. LIMITATIONS, REASONS FOR CAUTION: Objective olfactory testing was not performed in all cases of self-reported normosmia and this may have underestimated the olfactory deficits. WIDER IMPLICATIONS OF THE FINDINGS: This study further expands the spectrum of known genetic defects associated with CHH and suggests that patients with self-reported normal olfactory function should not be excluded from ANOS1 genetic testing. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Portuguese Foundation for Science and Technology. The authors have no conflicts of interest.info:eu-repo/semantics/publishedVersio

    Expanding the Genetic Spectrum of ANOS1 Mutations in Patients with Congenital Hypogonadotropic Hypogonadism

    Get PDF
    STUDY QUESTION: What is the prevalence and functional consequence of ANOS1 (KAL1) mutations in a group of men with congenital hypogonadotropic hypogonadism (CHH)? SUMMARY ANSWER: Three of forty-two (7.1%) patients presented ANOS1 mutations, including a novel splice site mutation leading to exon skipping and a novel contiguous gene deletion associated with ichthyosis. WHAT IS KNOWN ALREADY: CHH is characterized by lack of pubertal development and infertility, due to deficient production, secretion or action of GnRH, and can be associated with anosmia/hyposmia (Kallmann syndrome, KS) or with a normal sense of smell (normosmic CHH). Mutations in the anosmin-1 (ANOS1) gene are responsible for the X-linked recessive form of KS. STUDY DESIGN, SIZE, DURATION: This cross-sectional study included 42 unrelated men with CHH (20 with KS and 22 with normosmic CHH). PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients were screened for mutations in the ANOS1 gene by DNA sequencing. Identified mutations were further investigated by RT-PCR analysis and multiplex ligation-dependent probe amplification (MLPA) analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Hemizygous mutations were identified in three (7.1%) KS cases: a novel splice acceptor site mutation (c.542-1G>C), leading to skipping of exon 5 in the ANOS1 transcript in a patient with self-reported normosmia (but hyposmic upon testing); a recurrent nonsense mutation (c.571C>T, p.Arg191*); and a novel 4.8 Mb deletion involving ANOS1 and eight other genes (VCX3B, VCX2, PNPLA4, VCX, STS, HDHD1, VCX3A and NLGN4X) in KS associated with ichthyosis. LIMITATIONS, REASONS FOR CAUTION: Objective olfactory testing was not performed in all cases of self-reported normosmia and this may have underestimated the olfactory deficits. WIDER IMPLICATIONS OF THE FINDINGS: This study further expands the spectrum of known genetic defects associated with CHH and suggests that patients with self-reported normal olfactory function should not be excluded from ANOS1 genetic testing. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Portuguese Foundation for Science and Technology. The authors have no conflicts of interest.info:eu-repo/semantics/publishedVersio

    Methods and Apparatus for Determining a Path in a Communication Network

    Get PDF
    United States Patent Filing No:United States Patent Filing No:United States Patent Filing No:Typically paths are provisioned in a network with a margin which allows for component variations and failures in the network and so on. By providing more information about the requirements of the link in a path request, it is possible to more efficiently calculate a route for the path through the network. The efficiency gain allows greater network utilization which in turn saves costs for the network service provider

    Growth performance of hybrid catfish (Heterobranchus bidorsalis (♀) x Clarias gariepinus (♂)) at various stocking densities in varied culture tanks

    Get PDF
    Stocking density effect of Heterobranchus bidorsalis (Š) and Clarias gariepinus (‰) hybrid juveniles stocked at densities of 7, 14 and 21 catfishes m-2 in three varied culture tanks (concrete, metal and plastic) were studied for 20 weeks. Total length and weight of catfish juveniles were recorded every fortnight. Plastic tanks with stocking density of 7catfishes m-2 had the best weight gain (4.89 } 6.81 g) while the least weight gain (1.39 } 2.16 g) was recorded in concrete tank with stocking density of 21 catfishes m-2. There was significant difference between stocking density of 7 catfishes m-2 (4.13 } 5.38 g) and 21 catfishes m-2 (1.82 } 2.26 g) (P < 0.05). There was no significant difference inspecific growth rate, feed efficiency and condition factor of catfishes in all culture tanks and stocking densities. The best total length of 12.23 } 5.22 cm was obtained in concrete tank with stocking density of 7 catfish m-2. The least mean total length (9.44 } 4.04 cm) was recorded in plastic tank with stocking density of 21 catfishes m-2. The effect of stocking density on total length was significant between stocking densities of 7 catfishes m-2 (11.85 } 5.52 cm) and 21 catfishes m-2 (9.54 } 4.01 cm) (P < 0.05)

    A single sub-km Kuiper Belt object from a stellar Occultation in archival data

    Get PDF
    The Kuiper belt is a remnant of the primordial Solar System. Measurements of its size distribution constrain its accretion and collisional history, and the importance of material strength of Kuiper belt objects (KBOs). Small, sub-km sized, KBOs elude direct detection, but the signature of their occultations of background stars should be detectable. Observations at both optical and X-ray wavelengths claim to have detected such occultations, but their implied KBO abundances are inconsistent with each other and far exceed theoretical expectations. Here, we report an analysis of archival data that reveals an occultation by a body with a 500 m radius at a distance of 45 AU. The probability of this event to occur due to random statistical fluctuations within our data set is about 2%. Our survey yields a surface density of KBOs with radii larger than 250 m of 2.1^{+4.8}_{-1.7} x 10^7 deg^{-2}, ruling out inferred surface densities from previous claimed detections by more than 5 sigma. The fact that we detected only one event, firmly shows a deficit of sub-km sized KBOs compared to a population extrapolated from objects with r>50 km. This implies that sub-km sized KBOs are undergoing collisional erosion, just like debris disks observed around other stars.Comment: To appear in Nature on December 17, 2009. Under press embargo until 1800 hours London time on 16 December. 19 pages; 7 figure

    Update in laparoscopic approach to acute mesenteric ischemia

    Get PDF
    AMI is an uncommon but serious disease often associated with a bad prognosis, associated with occlusion of Superior Mesenteric Artery (SMA) for embolism or thrombosis (67.2%), mesenteric venous thrombosis (15.7%), and non-occlusive mesenteric ischemia (15.4%). Clinical markers are often aspecific and symptoms low suggestive. The gold standard for the diagnosis is multidetector CT Angiography (CTA) with sensibility of 93.3% and specificity of 95.9%. Abdominal exploration could be useful to confirm cases of AMI without signs of SMA occlusion at CTA. Few reports have been found on the diagnostic role of Exploratory Laparoscopy. To increase the sensibility of laparoscopy in the diagnosis of AMI in the last ten years, some studies had shown the possibility of using fluorescein to underline the bowel areas of interest by ischemia. The best of laparoscopy in AMI diagnosis remains the second look and bedside use (directly in ICU when possible) overall in patients with Aortic dissection type B (preferable chronic type). In a limited number of cases, it is possible to evaluate bowel perfusion laparoscopically and at the same time perform a laparoscopical bowel resection of residual ischemic segments. However, laparoscopic primary access overall in AoD is an important tool for leading therapeutic decision and timing. Finally, laparoscopy may be a feasible alternative to CTA in patients with kidney failure that contraindicates injection of iodate CT contrast medium
    • …
    corecore