The component sizes of a critical random graph with given degree sequence

Consider a critical random multigraph $\mathcal{G}_n$ with $n$ vertices constructed by the configuration model such that its vertex degrees are independent random variables with the same distribution $\nu$ (criticality means that the second moment of $\nu$ is finite and equals twice its first moment). We specify the scaling limits of the ordered sequence of component sizes of $\mathcal{G}_n$ as $n$ tends to infinity in different cases. When $\nu$ has finite third moment, the components sizes rescaled by $n^{-2/3}$ converge to the excursion lengths of a Brownian motion with parabolic drift above past minima, whereas when $\nu$ is a power law distribution with exponent $\gamma\in(3,4)$, the components sizes rescaled by $n^{-(\gamma -2)/(\gamma-1)}$ converge to the excursion lengths of a certain nontrivial drifted process with independent increments above past minima. We deduce the asymptotic behavior of the component sizes of a critical random simple graph when $\nu$ has finite third moment.Comment: Published in at http://dx.doi.org/10.1214/13-AAP985 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Partial Match Queries in Two-Dimensional Quadtrees : a Probabilistic Approach

We analyze the mean cost of the partial match queries in random two-dimensional quadtrees. The method is based on fragmentation theory. The convergence is guaranteed by a coupling argument of Markov chains, whereas the value of the limit is computed as the fixed point of an integral equation

Covalent organic frameworks

The first members of covalent organic frameworks (COF) have been designed and successfully synthesized by condensation reactions of phenyl diboronic acid C6H4[B(OH)2]2 and hexahydroxytriphenylene C18H6(OH)6. The high crystallinity of the products (C3H2BO)6 (C9H12)1 (COF-1) and C9H4BO2 (COF-5) has allowed definitive resolution of their structure by powder X-ray diffraction methods which reveal expanded porous graphitic layers that are either staggered (COF-1, P63/mmc) or eclipsed (COF-5, P6/mmm). They exhibit high thermal stability (to temperatures up to 500- to 600-C), permanent porosity, and high surface areas (711 and 1590 m2/g, respectively) surpassing those of related inorganic frameworks. A similar approach has been used for the design of other extended structures

A phase transition for the heights of a fragmentation tree

We provide information about the asymptotic regimes for a homogeneous fragmentation of a finite set. We establish a phase transition for the asymptotic behaviours of the shattering times, defined as the first instants when all the blocks of the partition process have cardinality less than a fixed integer. Our results may be applied to the study of certain random split trees

Retracing the molecular basis and evolutionary history of the loss of benzaldehyde emission in the genus Capsella

The transition from pollinator‐mediated outbreeding to selfing has occurred many times in angiosperms. This is generally accompanied by a reduction in traits attracting pollinators, including reduced emission of floral scent. In Capsella, emission of benzaldehyde as a main component of floral scent has been lost in selfing C. rubella by mutation of cinnamate‐CoA ligase CNL1. However, the biochemical basis and evolutionary history of this loss remain unknown, as does the reason for the absence of benzaldehyde emission in the independently derived selfer Capsella orientalis. We used plant transformation, in vitro enzyme assays, population genetics and quantitative genetics to address these questions. CNL1 has been inactivated twice independently by point mutations in C. rubella, causing a loss of enzymatic activity. Both inactive haplotypes are found within and outside of Greece, the centre of origin of C. rubella, indicating that they arose before its geographical spread. By contrast, the loss of benzaldehyde emission in C. orientalis is not due to an inactivating mutation in CNL1. CNL1 represents a hotspot for mutations that eliminate benzaldehyde emission, potentially reflecting the limited pleiotropy and large effect of its inactivation. Nevertheless, even closely related species have followed different evolutionary routes in reducing floral scent

Metal-organic and covalent organic frameworks (MOFs and COFs) as adsorbents for environmentally significant gases (H2, CO2, and CH4)

A series of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) possessing various functionalities, pore structures, and surface areas were evaluated for sorption and storage properties of environmentally significant gases (H_2, CO_2, and CH_4). It was concluded that the gas sorption behavior follows a general trend that materials with high surface area show enhanced gas uptake performance. For example, MOF-177 (SA = 5200 m^2/g) captures 7.2 wt% of H_2 at 77 K and 19 wt% of CH_4 at 298 K. In addition, MOF-177 exhibits exceptionally high gravimetric CO_2 uptake up to 120 wt% at 298 K. Similarly, the gas storage capacity for COFs seems to follow the same trend and it is determined by the apparent surface area. The architectural stability of both COFs and MOFs upon high pressure H_2 and CH_4 gas sorption measurements were manifested by isotherms which reach saturation without significant hysteresis

Does aging affect the immune status? A comparative analysis in 300 healthy volunteers from France, Austria and Spain

Background: As the European population is getting older, there is growing need in scientific data on how to achieve healthy and successful aging. A decline in immune function with age is unanimously supported by many epidemiological and clinical observations, with a decrease in T-cell mediated function encompassing a large part of this alteration. In the EU-funded VITAGE project, the effects of aging on biomarkers of immune status are being studied in three European countries. According to strict inclusion/exclusion criteria, a cohort of 300 healthy male non-smoking 20-75 years old volunteers were enrolled in France (n = 99), Spain (n = 100) and Austria (n = 101). In each country, the volunteers were classified as a function of age (one age group per decade). Biomarkers of immune status were determined including delayed-type hypersensitivity tests, measurement of lymphocyte surface markers, and serum determinations of interleukin-2, complement fractions and immunoglobulins. [br/] Results: There were moderate differences in the biomarkers of immune status of the VITAGE study volunteers among the three European centres. The percentage of Natural Killer (NK) cells was 156% and 142% higher in Spain as compared to France and Austria, respectively (p < 0.0001), and this increase was observed at any age group above 30 years. Comparison between age-groups showed that in Spain, but not in France or Austria, older individuals had significantly a lower B lymphocyte distribution and conversely, a higher NK cell distribution. Moreover, the CD4/CD8 ratio was positively correlated with age in Austrian subjects (p < 0.0001). [br/] Conclusion: Our results provide evidence of an increased NK cell distribution in the elderly, especially in the Spanish population. NK cell status may predict morbidity and mortality in the elderly, emphasizing the importance of innate as well as adaptive immunity in ensuring healthy longevity and cancer resistance, possibly in link with the Mediterranean diet

Laser-generated ultrasound with optical fibres using functionalised carbon nanotube composite coatings

Optical ultrasound transducers were created by coating optical fibres with a composite of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS). Dissolution of CNTs in PDMS to create the composite was facilitated by functionalisation with oleylamine. Composite surfaces were applied to optical fibres using dip coating. Under pulsed laser excitation, ultrasound pressures of 3.6 MPa and 4.5 MPa at the coated end faces were achieved with optical fibre core diameters of 105 and 200 μm, respectively. The results indicate that CNT-PDMS composite coatings on optical fibres could be viable alternatives to electrical ultrasound transducers in miniature ultrasound imaging probes

Reduced epithelial suppressor of cytokine signalling 1 in severe eosinophilic asthma

Severe asthma represents a major unmet clinical need. Eosinophilic inflammation persists in the airways of many patients with uncontrolled asthma, despite high-dose inhaled corticosteroid therapy. Suppressors of cytokine signalling (SOCS) are a family of molecules involved in the regulation of cytokine signalling via inhibition of the Janus kinase–signal transducers and activators of transcription pathway. We examined SOCS expression in the airways of asthma patients and investigated whether this is associated with persistent eosinophilia.Healthy controls, mild/moderate asthmatics and severe asthmatics were studied. Whole genome expression profiling, quantitative PCR and immunohistochemical analysis were used to examine expression of SOCS1, SOCS2 and SOCS3 in bronchial biopsies. Bronchial epithelial cells were utilised to examine the role of SOCS1 in regulating interleukin (IL)-13 signalling in vitro.SOCS1 gene expression was significantly lower in the airways of severe asthmatics compared with mild/moderate asthmatics, and was inversely associated with airway eosinophilia and other measures of T-helper type 2 (Th2) inflammation. Immunohistochemistry demonstrated SOCS1 was predominantly localised to the bronchial epithelium. SOCS1 overexpression inhibited IL-13-mediated chemokine ligand (CCL) 26 (eotaxin-3) mRNA expression in bronchial epithelial cells.Severe asthma patients with persistent airway eosinophilia and Th2 inflammation have reduced airway epithelial SOCS1 expression. SOCS1 inhibits epithelial IL-13 signalling, supporting its key role in regulating Th2-driven eosinophilia in severe asthma.</jats:p