Critical Cooperation Range to Improve Spatial Network Robustness

A robust worldwide air-transportation network (WAN) is one that minimizes the number of stranded passengers under a sequence of airport closures. Building on top of this realistic example, here we address how spatial network robustness can profit from cooperation between local actors. We swap a series of links within a certain distance, a cooperation range, while following typical constraints of spatially embedded networks. We find that the network robustness is only improved above a critical cooperation range. Such improvement can be described in the framework of a continuum transition, where the critical exponents depend on the spatial correlation of connected nodes. For the WAN we show that, except for Australia, all continental networks fall into the same universality class. Practical implications of this result are also discussed

Optogenetic modeling of human neuromuscular circuits in Duchenne muscular dystrophy with CRISPR and pharmacological corrections

Duchenne muscular dystrophy (DMD) is caused by dystrophin gene mutations leading to skeletal muscle weakness and wasting. Dystrophin is enriched at the neuromuscular junction (NMJ), but how NMJ abnormalities contribute to DMD pathogenesis remains unclear. Here, we combine transcriptome analysis and modeling of DMD patient-derived neuromuscular circuits with CRISPR-corrected isogenic controls in compartmentalized microdevices. We show that NMJ volumes and optogenetic motor neuron-stimulated myofiber contraction are compromised in DMD neuromuscular circuits, which can be rescued by pharmacological inhibition of TGFβ signaling, an observation validated in a 96-well human neuromuscular circuit coculture assay. These beneficial effects are associated with normalization of dysregulated gene expression in DMD myogenic transcriptomes affecting NMJ assembly (e.g., MUSK) and axon guidance (e.g., SLIT2 and SLIT3). Our study provides a new human microphysiological model for investigating NMJ defects in DMD and assessing candidate drugs and suggests that enhancing neuromuscular connectivity may be an effective therapeutic strategy

Índice de sustentabilidade ambiental do uso da água: Estudo de caso do Projeto Sertão de Pernambuco ISA-PSP.

A pesquisa divulga com este trabalho a construção do Índice de Sustentabilidade Ambiental do Uso da Água para o Gerenciamento do Projeto do Sertão de Pernambuco (ISA PSP), com a finalidade de preencher a lacuna de conhecimento básico existente, em âmbito regional. O ISA_PSP é o método que permite integrar três dimensões da análise ambiental ecológico, econômico e social a partir de dados coletados a campo e de estatísticas de fontes secundárias. Participaram do processo 830 famílias, representando 181 localidades existentes em 19 municípios avaliados: Afrânio, Araripina, Bodocó, Cedro, Dormentes, Exú, Granito, Ipubi, Lagoa Grande, Moreilândia, Ouricuri, Parnamirim, Petrolina, Salgueiro, Santa Cruz, Santa Filomena, Serrita e Trindade, no Estado de Pernambuco e o município de Casa Nova, no Estado da Bahia. Não há restrição quanto aos recursos edafoambientais, uma vez que foi estimada a existência de um potencial para áreas irrigáveis ao redor de 876,2 mil hectares, dos quais 300 mil hectares podem ser efetivamente irrigados

Copy number variation arising from gene conversion on the human Y chromosome

We describe the variation in copy number of a ~ 10 kb region overlapping the long intergenic noncoding RNA (lincRNA) gene, TTTY22, within the IR3 inverted repeat on the short arm of the human Y chromosome, leading to individuals with 0–3 copies of this region in the general population. Variation of this CNV is common, with 266 individuals having 0 copies, 943 (including the reference sequence) having 1, 23 having 2 copies, and two having 3 copies, and was validated by breakpoint PCR, fbre-FISH, and 10× Genomics Chromium linked-read sequencing in subsets of 1234 individuals from the 1000 Genomes Project. Mapping the changes in copy number to the phylogeny of these Y chromosomes previously established by the Project identifed at least 20 mutational events, and investigation of fanking paralogous sequence variants showed that the mutations involved fanking sequences in 18 of these, and could extend over > 30 kb of DNA. While either gene conversion or double crossover between misaligned sister chromatids could formally explain the 0–2 copy events, gene conversion is the more likely mechanism, and these events include the longest non-allelic gene conversion reported thus far. Chromosomes with three copies of this CNV have arisen just once in our data set via another mechanism: duplication of 420 kb that places the third copy 230 kb proximal to the existing proximal copy. Our results establish gene conversion as a previously under-appreciated mechanism of generating copy number changes in humans and reveal the exceptionally large size of the conversion events that can occur

A new patient-derived iPSC model for dystroglycanopathies validates a compound that increases glycosylation of alpha-dystroglycan

Dystroglycan, an extracellular matrix receptor, has essential functions in various tissues. Loss of α‐dystroglycan‐laminin interaction due to defective glycosylation of α‐dystroglycan underlies a group of congenital muscular dystrophies often associated with brain malformations, referred to as dystroglycanopathies. The lack of isogenic human dystroglycanopathy cell models has limited our ability to test potential drugs in a human‐ and neural‐specific context. Here, we generated induced pluripotent stem cells (iPSCs) from a severe dystroglycanopathy patient with homozygous FKRP (fukutin‐related protein gene) mutation. We showed that CRISPR/Cas9‐mediated gene correction of FKRP restored glycosylation of α‐dystroglycan in iPSC‐derived cortical neurons, whereas targeted gene mutation of FKRP in wild‐type cells disrupted this glycosylation. In parallel, we screened 31,954 small molecule compounds using a mouse myoblast line for increased glycosylation of α‐dystroglycan. Using human FKRP‐iPSC‐derived neural cells for hit validation, we demonstrated that compound 4‐(4‐bromophenyl)‐6‐ethylsulfanyl‐2‐oxo‐3,4‐dihydro‐1H‐pyridine‐5‐carbonitrile (4BPPNit) significantly augmented glycosylation of α‐dystroglycan, in part through upregulation of LARGE1 glycosyltransferase gene expression. Together, isogenic human iPSC‐derived cells represent a valuable platform for facilitating dystroglycanopathy drug discovery and therapeutic development