Eigencentrality based on dissimilarity measures reveals central nodes in complex networks.

One of the most important problems in complex network's theory is the location of the entities that are essential or have a main role within the network. For this purpose, the use of dissimilarity measures (specific to theory of classification and data mining) to enrich the centrality measures in complex networks is proposed. The centrality method used is the eigencentrality which is based on the heuristic that the centrality of a node depends on how central are the nodes in the immediate neighbourhood (like rich get richer phenomenon). This can be described by an eigenvalues problem, however the information of the neighbourhood and the connections between neighbours is not taken in account, neglecting their relevance when is one evaluates the centrality/importance/influence of a node. The contribution calculated by the dissimilarity measure is parameter independent, making the proposed method is also parameter independent. Finally, we perform a comparative study of our method versus other methods reported in the literature, obtaining more accurate and less expensive computational results in most cases.

New hosts for the mite Ornithonyssus bursa in Argentina.

The mite Ornithonyssus bursa (Berlese) (Mesostigmata: Macronyssidae) is considered a poultry pest causing important infestations in chickens and it is considered a potential vector of arbovirus. Despite being considered a common parasite in wild birds, there is scarce published information about its potential hosts and effects on them. Here we present new bird hosts for O. bursa, assess the presence of Alphavirus, Flavivirus and Bunyavirus in mites from three host species, and discuss its potential impact on wild bird populations. We found O. bursa infecting five raptor and six passerine wild bird species. For nine of these species, this is the first record of infection by O. bursa. Although all analysed mites were negative for the examined arboviruses, the small sample size of mites does not allow further conclusions at the present moment. Because of the general nature of this ectoparasite, its presence in migratory long dispersal and endangered bird species, and the seropositivity for arboviruses in some of the species studied here, we consider it critical to assess the role of O. bursa and other ectoparasites as vectors and reservoirs of pathogens and as potential deleterious agents in wild bird populations.

Comment on "Similarity between quantum mechanics and thermodynamics: Entropy, temperature, and Carnot cycle".

In the paper by Abe and Okuyama [Phys. Rev. E 83, 021121 (2011)], the quantum Carnot cycle of a simple two-state model of a particle confined in a one-dimensional infinite potential well is discussed. It is claimed that the state at the beginning of the quantum Carnot cycle is pure. After that, it is apparently transmuted to a mixed state if Clausius equality is imposed. We prove that this statement is incorrect. In particular, we prove that the state at the beginning of the cycle is mixed due to the process of measuring energy.

Detection of Orthobunyavirus in mosquitoes collected in Argentina.

Bunyamwera virus (BUNV) (Bunyaviridae, genus Orthobunyavirus, serogroup Bunyamwera) is considered an emerging pathogen for humans and animals in American countries. The CbaAr-426 strain of BUNV was recovered from mosquitoes Ochlerotatus albifasciatus (Diptera: Culicidae) collected in Córdoba province (Argentina), where serological studies detected high seroprevalences in humans and animals. Molecular detection of Orthobunyavirus was performed in mosquitoes collected in Córdoba province. Seventeen mosquito pools of Oc. albifasciatus, Ochlerotatus scapularis and Culex quinquefasciatus (Diptera: Culicidae) showed positive results; four of these positive pools, all of Oc. scapularis, were sequenced. All amplicons grouped with BUNV in the Bunyamwera serogroup. The findings highlight the circulation of BUNV in Córdoba province and represent the first report of BUNV-infected Oc. scapularis mosquitoes in Argentina.

Winnerless competition in coupled Lotka-Volterra maps.

Winnerless competition is analyzed in coupled maps with discrete temporal evolution of the Lotka-Volterra type of arbitrary dimension. Necessary and sufficient conditions for the appearance of structurally stable heteroclinic cycles as a function of the model parameters are deduced. It is shown that under such conditions winnerless competition dynamics is fully exhibited. Based on these conditions different cases characterizing low, intermediate, and high dimensions are therefore computationally recreated. An analytical expression for the residence times valid in the N-dimensional case is deduced and successfully compared with the simulations.

Cocirculation of Rio Negro Virus (RNV) and Pixuna Virus (PIXV) in Tucumán province, Argentina.

Venezuelan equine encephalitis complex includes viruses considered emerging pathogens for humans and animals in the Americas. Two members of this complex have been detected previously in Argentina: Rio Negro Virus (RNV), detected in mosquitoes from Chaco province and rodents from Formosa province, and Pixuna Virus (PIXV), detected in mosquitoes from Chaco province. To carry out surveillance studies in other parts of the country, detection of a 195-bp fragment of alphaviruses by RT-nested PCR was performed in mosquito samples from San Miguel de Tucumán city. Four pools resulted positive and three were sequenced. Two amplicons grouped with RNV and one with PIXV. This is the first report of viral activity of members of the Venezuelan equine encephalitis complex in north-eastern Argentina.

Visual attention in children with migraine: a controlled comparative study.

The aim of this study was to evaluate the visual attention of children with migraine and compare it with a control group. Thirty migrainous children and 30 controls without headache were subjected to a visual attention assessment with Trail Making Tests (TMT) A/B, Letter Cancellation Test, and the Brazilian computerized test Visual Attention Test, third edition. The migraine group was evaluated after 2 days without headache. The migraine group had an inferior performance compared with the control group on TMT A (P = 0.03) and B (P = 0.001), and more errors on tasks 1 (P = 0.032) and 2 (P = 0.015) of the Visual Attention Test, presenting difficulty with selective and alternate attention. Attention is a neurological function that depends on structures such as the brainstem, cerebral cortex and the limbic system and on neurotransmitters such as dopamine and noradrenaline. The neurochemical aspects involved in the physiopathology of migraine and attention mechanisms probably predispose these children to visual attention deficits.

Clinical and serological follow-up studies of endemic pemphigus foliaceus (fogo selvagem) in Western Parana, Brazil (2001-2002).

BACKGROUND: Fogo selvagem (FS) has been described in several regions of Brazil, including the Western regions of the state of Parana. In 1990, Empinotti et al. reported case studies of 213 patients with FS that were collected from 1976 to 1988. The same author (J.C.E.) has observed that the frequency of cases in these regions of Parana has decreased. OBJECTIVES: The purpose of this study was to clinically and serologically evaluate a small group of the patients originally reported in 1990 and compare data with a group of control individuals. These patients were treated at the onset of the disease with systemic steroids. PATIENTS AND METHODS: Patients with FS, their unaffected relatives (n = 80) and genetically unrelated controls (n = 15) were identified during a field study from 1 May 2001 to 30 June 2002. Sera from nine patients with FS and six normal controls that were collected in the 1976-1988 evaluation were available for this study. The sera were tested by indirect immunofluorescence, enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation using recombinant human desmoglein 1 (Dsg1). RESULTS: Only 16 of the originally identified 213 patients with FS were found during the field studies. Thirteen of the 16 patients were in clinical and serological remission; 20% of normal controls (19 of 95) were positive in the Dsg1 ELISA. The majority of these subjects (17 of 19) were genetically related to FS patients. Six normal controls that were positive in the Dsg1 ELISA in the original survey were found to be negative or weakly positive in this evaluation. CONCLUSION: The reduced frequency of positive serological markers of disease in patients and normal controls from Western Parana, as well as the absence of recurrent disease in previously identified patients, suggest that environmental antigenic stimulation of the population at risk may have decreased in recent years.

Transplacental passage of maternal pemphigus foliaceus autoantibodies induces neonatal pemphigus.

The association of maternal pemphigus foliaceus (PF) with neonatal PF is rare and may be secondary to transplacental passage of PF autoantibodies. We describe a 25-year-old patient with PF who was delivered of two consecutive babies, one with classic skin lesions of PF and another that was normal. The neonate with PF was born when the mother had widespread skin disease; the normal newborn was born when the mother was in partial remission. The titers of PF autoantibodies were higher in the mother's serum and the cord serum of the baby with PF than in the mother during partial remission and the unaffected baby. The mother and affected baby had autoantibodies to desmoglein 1. Furthermore, cord blood from the baby with PF induced skin disease when injected into mice. In this case, maternal PF was associated with neonatal PF when the titers of maternal anti-desmoglein 1 autoantibodies were elevated. The cutaneous disease in neonatal PF is due to anti-desmoglein 1 autoantibodies.

The prevalence of antibodies against desmoglein 1 in endemic pemphigus foliaceus in Brazil. Cooperative Group on Fogo Selvagem Research.

BACKGROUND: Pemphigus foliaceus is an autoimmune skin disease mediated by autoantibodies against desmoglein 1. The endemic form is thought to have an environmental cause. The Terena reservation of Limão Verde in Mato Grosso do Sul, Brazil, is a recently identified focus of the disease, with a prevalence of 3.4 percent in the population. We tested the hypothesis that normal subjects living in an endemic area have antibodies against desmoglein 1. METHODS: We used an enzyme-linked immunosorbent assay to detect antibodies against desmoglein 1 in serum samples from 60 patients with endemic pemphigus foliaceus (fogo selvagem) who lived in Limão Verde or elsewhere in Brazil, 372 normal subjects (without pemphigus foliaceus) from Limão Verde and surrounding locations, and 126 normal subjects from the United States and Japan. RESULTS: Antibodies against desmoglein 1 were detected in 59 of the 60 patients with fogo selvagem (98 percent) but in only 3 of the 126 normal subjects from the United States and Japan (2 percent). Antibodies were also detected in 51 of the 93 normal subjects from Limão Verde (55 percent) and in 54 of the 279 normal subjects from surrounding areas (19 percent). Serum samples obtained one to four years before the onset of disease were available for five patients; all five had antibodies in the initial serum samples, and the onset of disease was associated with a marked increase in antibody values. CONCLUSIONS: The prevalence of antibodies against desmoglein 1 is high among normal subjects living in an area among where fogo selvagem is endemic, and the onset of the disease is preceded by a sustained antibody response. These findings support the concept that the production of antibodies against desmoglein 1 is initiated by exposure to an unknown environmental agent.

Comparison of black fly species (Diptera: Simuliidae) on an Amerindian reservation with a high prevalence of fogo selvagem to neighboring disease-free sites in the State of Mato Grosso do Sul, Brazil. The Cooperative Group on Fogo Selvagem Research.

Fogo selvagem is an autoimmune blistering skin disease that principally occurs among rural Brazilians living in geographically clumped disease foci. Exposure to hematophagous black flies possibly is related to the cause of the disease. We compared the occurrence, proportions, and richness of simuliid species immatures and the biting activity of adult females within a recently discovered, high prevalence focus of fogo selvagem, the Limão Verde Terena Reservation, to that of neighboring regions with no reported cases of fogo selvagem. Nine black fly species were collected from 12 stream sites during 5 trips to the fogo selvagem focus. The species showed longitudinal (upstream-downstream) trends in occurrence, proportions, and richness, and the abundance of simuliid immatures was greater at downstream sites. The most prevalent species at the focus, Simulium nigrimanum (Macquart), dominated the stream sites with highly abundant simuliid assemblages, and was the most common black fly in human bait collections. This species was absent or in very low numbers in neighboring valleys and villages that did not have cases of fogo selvagem.

Epidemic Venezuelan equine encephalitis in La Guajira, Colombia, 1995.

In 1995, the first Venezuelan equine encephalitis (VEE) outbreak in Colombia in 22 years caused an estimated 75,000 human cases, 3000 with neurologic complications and 300 fatal, in La Guajira State. Of the state's estimated 50,000 equines, 8% may have died. An epizootic IC virus, probably introduced from Venezuela, was rapidly amplified among unvaccinated equines. Record high rainfall, producing high densities of vector Aedes taeniorhynchus, led to extensive epidemic transmission (30% attack rate) in the four affected municipalities. Native Wayuu Indians, constituting 24% of the state's population, were at increased risk of infection (risk ratio, 3.3; 95% confidence interval, 2.2-5.3). Epidemiologic studies found no evidence of human-to-human transmission. A higher-than-expected number of abortions during the outbreak confirmed a previously suspected abortifacient role of VEE infection. Pesticide applications and a mass equine vaccination program contributed to preventing the outbreak's spread south of La Guajira.

An epitope in the third hypervariable region of the DRB1 gene is involved in the susceptibility to endemic pemphigus foliaceus (fogo selvagem) in three different Brazilian populations.

Endemic pemphigus foliaceus or fogo selvagem (FS) in an organ-specific autoimmune skin disease characterized by epidermal vesicles and mediated by autoantibodies. Family cases are frequent and not everyone living in endemic region develops FS suggesting that host factors play a role in determining whether exposed individuals will be affected. Because our previous works with Brazilian Mestizos and with Xavante Indians have shown that particular HLA alleles confer increased risk for the disease, we decided to extend these studies to another homogeneous population, the Terena Indians. 19 out of 20 Terena patients were either positive for DRB1*0404, 1402 or 1406 (p < 0.005, RR = 14). These findings were in agreement with the data obtained from the Xavante study. In Mestizos the association was with DRB1*01. All these alleles involved in predisposition to the disease in different populations shared the same amino acid sequence at position 67-74 on the third hypervariable region of the DRB1 gene: LLEQRRAA, suggesting that inheritance of this sequence is involved in the susceptibility to FS. When patients and controls data from different studies were pooled and analyzed disregarding the ethnic background and the HLA alleles involved, the results obtained clearly supported the hypothesis that matching for this epitope is highly significant and predictive of FS predisposition (p < 0.00001, RR = 6.4).

An active focus of high prevalence of fogo selvagem on an Amerindian reservation in Brazil. Cooperative Group on Fogo Selvagem Research.

Fogo Selvagem (FS) is an autoimmune disease characterized by subcorneal vesicles and antidesmoglein-1 autoantibodies. Previous epidemiologic data have linked the onset of FS to exposure to an environmental antigen(s). This investigation describes a unique human settlement with an extraordinarily high prevalence of FS. This community is made up of Amerindians belonging to the Terena tribe, which has settled on the Limao Verde reservation in the state of Mato Grosso do Sul in Brazil. Twenty-six well-characterized FS cases have been identified within a total population of 998, yielding a prevalence of 2.6%. Seventeen of the patients (65 %) were males, and over 50% were older than 30 y of age. The incidence of the disease shows temporal periodicity, i.e., years with several cases of FS alternating with years with no cases. Over one-half of the cases occurred in genetically related family members. Another Terena reservation, the Ipegue/Taunay, located 90 km west of the Limao Verde reservation, was also evaluated as a control group. This reservation, with a population of 2203, had no recorded cases of FS. Thus, the Limao Verde reservation represents a new focus of FS in which the disease exhibits temporal, geographic, and familial clustering. These results suggest that the environmental antigen or antigens precipitating FS are endemic to the Limao Verde reservation. This reservation appears to be an ideal population for carrying out sero-epidemiologic, genetic, and environmental studies aimed at disclosing the etiology of FS.

Hay Bilharzia!, by Klock, Ildefonso, and Mateo-Serrano: medical images of poverty and development in Puerto Rico in the 1950s.

From 1940 to 1970 Puerto Rico underwent a dramatic change in its economic, social, political, and medical characteristics. Schistosomiasis (known locally as bilharzia) persisted throughout this period as a nearly intractable problem. In 1954, staff from the Puerto Rico Department of Health, and the Puerto Rico Field Station of the U.S. Communicable Disease Center (now San Juan Laboratories, Centers for Disease Control and Prevention) created a set of black and white 35 mm slides as a tool for community education. The presentation, titled "Hay Bilharzia!" ("There is schistosomiasis here!") is organized in four major sections (Introduction, Disease Cycle, Disease Prevention, Treatment). Each section consists of two to four sub-themes, with three to eight slides each. The slides were used extensively in public schools and community lectures. This set of slides is worthy of preservation as evidence of the bilharzia control efforts and the dismal living conditions widely prevalent in Puerto Rico in the 1950s. It is also an example of the educational programs that were produced at the time to stimulate community development and health.

Pemphigus foliaceus autoantibodies bind both epidermis and squamous mucosal epithelium, but tissue injury is detected only in the epidermis. The Cooperative Group on Fogo Selvagem Research.

BACKGROUND: Fogo selvagem (FS) is an autoimmune intraepidermal blistering disease mediated by antidesmosomal autoantibodies. Patients with FS do not have mucosal lesions despite extensive skin involvement. OBJECTIVE: Our purpose was to evaluate the epidermis and the oral epithelium of patients with FS as targets of antidesmosomal autoantibodies. METHODS: Fifteen patients were studied clinically, histologically, and immunologically. Biopsy specimens from the skin and the oral mucosa were studied by light microscopy and direct immunofluorescence. The serum of each of these patients was also titrated by indirect immunofluorescence. RESULTS: All patients showed skin lesions and subcorneal acantholyis, but none exhibited oral blisters or erosions. Direct immunofluorescence analysis demonstrated the presence of tissue-bound autoantibodies in both the epidermis and the oral epithelium of all patients with FS. Antiepidermal autoantibodies were also found in the sera of the patients. CONCLUSION: Relevant epitopes on desmoglein 1 molecules of oral epithelium may not be available to react with pathogenic FS autoantibodies.

Brazilian pemphigus foliaceus, endemic pemphigus foliaceus, or fogo selvagem (wild fire).

Brazilian pemphigus foliaceus, also known as fogo selvagem, is the endemic form of pemphigus foliaceus occurring in certain regions of Brazil. Epidemiologic data strongly support the notion that this disease is caused by exposure to an environmental agent or agents. This form of pemphigus foliaceus is a true human autoimmune disease mediated by autoantibodies of the IgG class, IgG4 subclass. These autoantibodies are pathogenic and highly specific for the disease. The environment agent may sensitize the patient to produce autoantibodies. These autoantibodies may cross-react with the epidermis and induce disease in the patient.