Primary familial congenital erythrocytosis: two novel EPOR mutations found in Spain

Two-carbon ring expansions of vinyl β-lactones, were carried out by Lewis acids (BF3-Et2O or Et2AlCl) via an ionization/cation rearrangement. β,γ-unsaturated δ-lactones were produced as efficient protocols for the synthesis of bioactive substances. Vinyl β-lactones were prepared via ring closure of corresponding unsaturated β-hydroxy acids. Differently structured substrates were examined to study the influence of the substituents on the rearrangement. Other factors, such as temperature, solvent and catalyst were also studied in search of suitable reaction conditions. This method is moderately successful in providing fused-ring δ-lactones, but higher yields (so far total yield of 24.8%) and a better method for the separation of β- and δ-lactones are required for useful synthetic applications. The successful implementation of this conceptually novel strategy will provide a versatile and expedient route for the synthesis of δ-lactones bearing a wide range of substitution patterns

Charge delocalization and hyperpolarizability in ionic liquids

In this work the role that charge delocalization plays in the non-linear optical response of ionic liquids is evaluated. The first hyperpolarizability for the non-linear process of second harmonic generation (SHG) and second hyperpolarizability for the non-linear process of electro-optical Kerr-Effect (EOKE) of a large number of ionic liquid forming ions were estimated by means of density functional theory calculations. The results point to that both charge delocalization and molecular geometry are the key features that govern their hyperpolarizabilities. Our findings show that some of the most commonly used anions in ionic liquids are expected to present strong non-linear responses while common cations present a much more limited performance. However, this limitation can be overcome by a proper tailoring of cations to present charge delocalization over large molecular regions. The hypothesis of additivity of hyperpolarizabilities in ionic liquids is tested and exploited to obtain a map of second and third order non-linear susceptibilities of 1496 ion combinations. This map is intended to be a guide for future works on the hyperpolarizability of ILsComment: 12 pages, 6 figures, 4 tables, supplementary data associated with this article can be found, in the online version, at https://doi.org/10.1016/j.molliq.2021.11815

Immunological identity of brucella native hapten, polysaccharide B, and yersinia enterocolitica serotype 9 native hapten

Yersinia enterocolitica serotype 9 contained an antigenic component giving a reaction of total identity with Brucella native hapten and polysaccharide B. This component was present in a phenol-water extract (fraction 5; M. Redfearn, Ph.D. Thesis, University of Wisconsin, Madison, 1960) along with the smooth lipopolysaccharide. The native hapten could be purified free of lipopolysaccharide and proteins by gel filtration

Efficient Behavior of Small-World Networks

We introduce the concept of efficiency of a network, measuring how efficiently it exchanges information. By using this simple measure small-world networks are seen as systems that are both globally and locally efficient. This allows to give a clear physical meaning to the concept of small-world, and also to perform a precise quantitative a nalysis of both weighted and unweighted networks. We study neural networks and man-made communication and transportation systems and we show that the underlying general principle of their construction is in fact a small-world principle of high efficiency.Comment: 1 figure, 2 tables. Revised version. Accepted for publication in Phys. Rev. Let

Scale-free brain functional networks

Functional magnetic resonance imaging (fMRI) is used to extract {\em functional networks} connecting correlated human brain sites. Analysis of the resulting networks in different tasks shows that: (a) the distribution of functional connections, and the probability of finding a link vs. distance are both scale-free, (b) the characteristic path length is small and comparable with those of equivalent random networks, and (c) the clustering coefficient is orders of magnitude larger than those of equivalent random networks. All these properties, typical of scale-free small world networks, reflect important functional information about brain states.Comment: 4 pages, 5 figures, 2 table

Incidence of Dengue Virus Infection in Adults and Children in a Prospective Longitudinal Cohort in the Philippines

BACKGROUND: The mean age of dengue has been increasing in some but not all countries. We sought to determine the incidence of dengue virus (DENV) infection in adults and children in a prospective cohort study in the Philippines where dengue is hyperendemic. METHODOLOGY/PRINCIPAL FINDINGS: A prospective cohort of subjects \u3e /=6 months old in Cebu City, Philippines, underwent active community-based surveillance for acute febrile illnesses by weekly contact. Fever history within the prior seven days was evaluated with an acute illness visit followed by 2, 5, and 8-day, and 3-week convalescent visits. Blood was collected at the acute and 3-week visits. Scheduled visits took place at enrolment and 12 months that included blood collections. Acute samples were tested by DENV PCR and acute/convalescent samples by DENV IgM/IgG ELISA to identify symptomatic infections. Enrolment and 12-month samples were tested by DENV hemagglutination inhibition (HAI) assay to identify subclinical infections. Of 1,008 enrolled subjects, 854 completed all study activities at 12 months per-protocol undergoing 868 person-years of surveillance. The incidence of symptomatic and subclinical infections was 1.62 and 7.03 per 100 person-years, respectively. However, in subjects \u3e 15 years old, only one symptomatic infection occurred whereas 27 subclinical infections were identified. DENV HAI seroprevalence increased sharply with age with baseline multitypic HAIs associated with fewer symptomatic infections. Using a catalytic model, the historical infection rate among dengue naive individuals was estimated to be high at 11-22%/year. CONCLUSIONS/SIGNIFICANCE: In this hyperendemic area with high seroprevalence of multitypic DENV HAIs in adults, symptomatic dengue rarely occurred in individuals older than 15 years. Our findings demonstrate that dengue is primarily a pediatric disease in areas with high force of infection. However, the average age of dengue could increase if force of infection decreases over time, as is occurring in some hyperendemic countries such as Thailand

Shortest paths on systems with power-law distributed long-range connections

We discuss shortest-path lengths $\ell(r)$ on periodic rings of size L supplemented with an average of pL randomly located long-range links whose lengths are distributed according to P_l \sim l^{-\xpn}. Using rescaling arguments and numerical simulation on systems of up to $10^7$ sites, we show that a characteristic length $\xi$ exists such that $\ell(r) \sim r$ for $r>\xi$. For small p we find that the shortest-path length satisfies the scaling relation \ell(r,\xpn,p)/\xi = f(\xpn,r/\xi). Three regions with different asymptotic behaviors are found, respectively: a) \xpn>2 where $\theta_s=1$, b) 1<\xpn<2 where 0<\theta_s(\xpn)<1/2 and, c) \xpn<1 where $\ell(r)$ behaves logarithmically, i.e. $\theta_s=0$. The characteristic length $\xi$ is of the form $\xi \sim p^{-\nu}$ with \nu=1/(2-\xpn) in region b), but depends on L as well in region c). A directed model of shortest-paths is solved and compared with numerical results.Comment: 10 pages, 10 figures, revtex4. Submitted to PR

Network 'small-world-ness': a quantitative method for determining canonical network equivalence

Background: Many technological, biological, social, and information networks fall into the broad class of 'small-world' networks: they have tightly interconnected clusters of nodes, and a shortest mean path length that is similar to a matched random graph (same number of nodes and edges). This semi-quantitative definition leads to a categorical distinction ('small/not-small') rather than a quantitative, continuous grading of networks, and can lead to uncertainty about a network's small-world status. Moreover, systems described by small-world networks are often studied using an equivalent canonical network model-the Watts-Strogatz (WS) model. However, the process of establishing an equivalent WS model is imprecise and there is a pressing need to discover ways in which this equivalence may be quantified. Methodology/Principal Findings: We defined a precise measure of 'small-world-ness' S based on the trade off between high local clustering and short path length. A network is now deemed a 'small-world' if S. 1-an assertion which may be tested statistically. We then examined the behavior of S on a large data-set of real-world systems. We found that all these systems were linked by a linear relationship between their S values and the network size n. Moreover, we show a method for assigning a unique Watts-Strogatz (WS) model to any real-world network, and show analytically that the WS models associated with our sample of networks also show linearity between S and n. Linearity between S and n is not, however, inevitable, and neither is S maximal for an arbitrary network of given size. Linearity may, however, be explained by a common limiting growth process. Conclusions/Significance: We have shown how the notion of a small-world network may be quantified. Several key properties of the metric are described and the use of WS canonical models is placed on a more secure footing

Disturbed functional brain networks and neurocognitive function in low-grade glioma patients: a graph theoretical analysis of resting-state MEG

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