30 research outputs found
Self-Averaging, Distribution of Pseudo-Critical Temperatures and Finite Size Scaling in Critical Disordered Systems
The distributions of singular thermodynamic quantities in an ensemble
of quenched random samples of linear size at the critical point are
studied by Monte Carlo in two models. Our results confirm predictions of
Aharony and Harris based on Renormalization group considerations. For an
Ashkin-Teller model with strong but irrelevant bond randomness we find that the
relative squared width, , of is weakly self averaging. , where is the specific heat exponent and is the
correlation length exponent of the pure model fixed point governing the
transition. For the site dilute Ising model on a cubic lattice, known to be
governed by a random fixed point, we find that tends to a universal
constant independent of the amount of dilution (no self averaging). However
this constant is different for canonical and grand canonical disorder. We study
the distribution of the pseudo-critical temperatures of the ensemble
defined as the temperatures of the maximum susceptibility of each sample. We
find that its variance scales as and NOT as
R_\chi\sim 70R_\chi (T_c)\chiT_c(i,l)m_i(T_c,l)T_c(i,l)(T-T_c(i,l))/T_c$. This function is found to be universal and to behave
similarly to pure systems.Comment: 31 pages, 17 figures, submitted to Phys. Rev.
Transmission of SARS-CoV-2 on mink farms between humans and mink and back to humans
Animal experiments have shown that nonhuman primates, cats, ferrets, hamsters, rabbits, and bats can be infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition, SARS-CoV-2 RNA has been detected in felids, mink, and dogs in the field. Here, we describe an in-depth investigation using whole-genome sequencing of outbreaks on 16 mink farms and the humans living or working on these farms. We conclude that the virus was initially introduced by humans and has since evolved, most likely reflecting widespread circulation among mink in the beginning of the infection period, several weeks before detection. Despite enhanced biosecurity, early warning surveillance, and immediate culling of animals in affected farms, transmission occurred between mink farms in three large transmission clusters with unknown modes of transmission. Of the tested mink farm residents, employees, and/or individuals with whom they had been in contact, 68% had evidence of SARS-CoV-2 infection. Individuals for which whole genomes were available were shown to have been infected with strains with an animal sequence signature, providing evidence of animal-to-human transmission of SARS-CoV-2 within mink farms
X-linked markers in the Duchenne muscular dystrophy gene associated with oral clefts
10.1111/eos.12025European Journal of Oral Sciences121263-6
Transplante de membrana amniótica canina criopreservada para cicatrização de córnea com deficiência de células límbicas em coelhos Transplantation of cryopreserved canine amniotic membrane for cicatrisation in cornea with limbal stem cells deficiency in rabbits
Avaliaram-se as alterações relacionadas à deficiência das células límbicas precursoras do epitélio corneano de coelhos e o efeito da membrana amniótica sobre sua cicatrização. A lesão, induzida com n-heptanol associado à peritomia conjuntival em 360°, foi recoberta com membrana amniótica canina, suturada à episclera perilímbica, criopreservada em meio para congelação de embrião ou em meio próprio, ambos com glicerol a 50% e mantida a -80°C. O grupo-controle não foi tratado com a membrana. As avaliações histológicas foram realizadas ao sétimo, 15º e 30º dias. Todos desenvolveram deficiência de células germinativas do limbo, denominada conjuntivalização, com presença de neovascularização, inflamação e defeitos epiteliais recorrentes, caracterizada na histopatologia pela presença de neovasos, edema, leucócitos e células caliciformes. O transplante de membrana amniótica não foi eficiente para o tratamento desta deficiência, entretanto auxiliou o processo de cicatrização da córnea.<br>Changes related to limbal stem cells deficiency in corneal epithelium in rabbits, as well as the results of amniotic membrane transplant on the cicatrisation were evaluated. The ulcer was induced with n-heptanol associated to 360° conjunctival peritomy; the corneal surface was covered with canine amniotic membrane, sutured to perilimbal episclera, cryopreserved in embryo solution or own medium, both with 50% glycerol and stored at -80°C. The control group was not treated with membrane. Histological evaluations were performed at seven, 15, and 30 days. All of them developed limbal stem cells deficiency, named conjunctivalization, with neovascularization, inflammation and recurrent epithelial defects, observed in histopathology by the occurrence of neovascularization, edema, leukocytes and goblet cells. Thus amniotic membrane transplantation was not efficient in the treatment of limbal stem cells deficiency, however it helped in the process of cicatrisation
Evidence for gene-environment interaction in a genome wide study of nonsyndromic cleft palate
10.1002/gepi.20595Genetic Epidemiology356469-478GENY