Deformation monitoring between 2004 and 2011 at the rock slope instability above Randa (Switzerland) has revealed an intriguing seasonal trend. Relative dislocation rates across active fractures ...increase when near‐surface rock temperatures drop in the fall and decrease after snowmelt as temperatures rise. This temporal pattern was observed with different monitoring systems at the ground surface and at depths up to 68 m, and represents the behavior of the entire instability. In this paper, the second of two companion pieces, we interpret this seasonal deformation trend as being controlled by thermomechanical (TM) effects driven by near‐surface temperature cycles. While Part 1 of this work demonstrated in a conceptual manner how TM effects can drive deep rock slope deformation and progressive failure, we present here in Part 2 a case study where temperature‐controlled deformation trends were observed in a natural setting. A 2D discrete‐element numerical model is employed, which allows failure along discontinuities and successfully reproduces the observed kinematics of the Randa instability. By implementing simplified ground surface temperature forcing, model results were able to reproduce the observed deformation pattern, and TM‐induced displacement rates and seasonal amplitudes in the model are of the same order of magnitude as measured values. Model results, however, exhibit spatial variation in displacement onset times while field measurements show more synchronous change. Additional heat transfer mechanisms, such as fracture ventilation, likely create deviations from the purely transient‐conductive temperature field modeled. We suggest that TM effects are especially important at Randa due to the absence of significant groundwater within the unstable rock mass.
Key Points
Displacement monitoring at Randa exhibit increased rates in winter
Temporal behavior at Randa is not related to ground water
Thermomechanical effects drive progressive failure at Randa
Cells in microbial communities on surfaces live and divide in close proximity, which greatly enhances the potential for social interactions. Spatiogenetic structures are manifested through ...competitive and cooperative interactions among the same and different genotypes within a shared space, and extracellular secretions appear to function dynamically at the forefront. A previous experimental evolution study utilizing Pseudomonas fluorescens Pf0-1 colonies demonstrated that diverse mutations in the
gene were repeatedly and exclusively selected through the formation of a dominant spatial structure. RsmE's primary molecular function is translation repression, and its homologs regulate various social and virulence phenotypes. Pseudomonas spp. possess multiple paralogs of Rsm proteins, and RsmA, RsmE, and RsmI are the most prevalent. Here, we demonstrate that the production of a mucoid polymer and a biosurfactant are exclusively regulated through RsmE, contradicting the generalized notion of functional redundancy among the Rsm paralogs. Furthermore, we identified the biosurfactant as the cyclic lipopeptide gacamide A. Competition and microscopy analyses showed that the mucoid polymer is solely responsible for creating a space of low cellular density, which is shared exclusively by the same genotype. Gacamide A and other RsmE-regulated products appear to establish a physical boundary that prevents the encroachment of the competing genotype into the newly created space. Although cyclic lipopeptides and other biosurfactants are best known for their antimicrobial properties and reducing surface tension to promote the spreading of cells on various surfaces, they also appear to help define spatial structure formation within a dense community.
In densely populated colonies of the bacterium Pseudomonas fluorescens Pf0-1, diverse mutations in the
gene are naturally selected by solving the problem of overcrowding. Here, we show that RsmE-regulated secretions function together to create and protect space of low cell density. A biosurfactant generally promotes the spreading of bacterial cells on abiotic surfaces; however, it appears to function atypically within a crowded population by physically defining genotypic boundaries. Another significant finding is that these secretions are not regulated by RsmE's paralogs that share high sequence similarity. The experimental pipeline described in this study is highly tractable and should facilitate future studies to explore additional RsmE-regulated products and address why RsmE is functionally unique from its paralogs.
The 2015 Sustainable Development Goals emphasise good health to all with reduced inequalities, and surgical and anaesthesia care is essential to achieve these. https://sdgs.un.org/goals. However, it ...has been estimated that 1.7 billion children do not have access to safe anaesthesia and surgery when needed and this disproportionately affects children in low- and middle-income countries (1). It is alarming that 1 in 10 individuals in LMICs do not have access to safe surgical care. Both safe surgery and anaesthesia are essential for ensuring that individuals receive proper medical attention. Economically viable public health initiatives that can avert many disability-adjusted years are needed. (2-4) Morbidity and mortality from surgical disease and anaesthesia care remain high in low-income countries, unlike in high-income countries. The incidence of severe anaesthesia-related critical events and perioperative cardiac arrest is between three and ten times more in LMICs than in HICs (5-7) A baseline POMR that is 100 times higher in LMICs compared to HICs is reported. (8) This perioperative morbidity and mortality gap is more evident in neonates and younger age groups, especially in children with congenital abnormalities. The challenges facing providers of anaesthesia and perioperative care are multifactorial and include but are not limited to the inadequate workforce, inadequate and inappropriate infrastructure, lack of adequate and appropriately sized equipment, including monitors, and safe monitoring capacity, supply chain challenges for medicines and reusable consumables, unreliable supply of oxygen and blood products, lack of data and research for policy formulation, inadequate resource allocation from governments and lack of safety culture among other things. In paediatrics, this is further multiplied by the variability in the sizes of the patients, from neonates to older children (9).
Prenatal exposure to phthalates has been associated with neurodevelopmental outcomes, but little is known about the association with language development.
To examine the association of prenatal ...phthalate exposure with language development in children in 2 population-based pregnancy cohort studies.
Data for this study were obtained from the Swedish Environmental Longitudinal Mother and Child, Asthma and Allergy (SELMA) study conducted in prenatal clinics throughout Värmland county in Sweden and The Infant Development and the Environment Study (TIDES) conducted in 4 academic centers in the United States. Participants recruited into both studies were women in their first trimester of pregnancy who had literacy in Swedish (SELMA) or English or Spanish (TIDES). This study included mothers and their children from both the SELMA study (n = 963) and TIDES (n = 370) who had complete data on prenatal urinary phthalate metabolite levels, language delay, and modeled covariables. For SELMA, the data were collected from November 1, 2007, to June 30, 2013, and data analysis was conducted from November 1, 2016, to June 30, 2018. For TIDES, data collection began January 1, 2010, and ended March 29, 2016, and data analysis was performed from September 15, 2016, to June 30, 2018.
Mothers completed a language development questionnaire that asked the number of words their children could understand or use at a median of 30 months of age (SELMA) and 37 months of age (TIDES). The responses were categorized as fewer than 25, 25 to 50, and more than 50 words, with 50 words or fewer classified as language delay.
In the SELMA study, 963 mothers, 455 (47.2%) girls, and 508 (52.8%) boys were included. In TIDES, 370 mothers, 185 (50.0%) girls, and 185 (50.0%) boys were included in this analysis. The prevalence of language delay was 10.0% in both SELMA (96 reported) and TIDES (37 reported), with higher rates of delay in boys than girls (SELMA: 69 13.5% vs 27 6.0%; TIDES: 23 12.4% vs 14 7.6%). In crude analyses, the metabolite levels of dibutyl phthalate and butyl benzyl phthalate were statistically significantly associated with language delay in both cohorts. In adjusted analyses, a doubling of prenatal exposure of dibutyl phthalate and butyl benzyl phthalate metabolites increased the odds ratio (OR) for language delay by approximately 25% to 40%, with statistically significant results in the SELMA study (dibutyl phthalate OR, 1.29 95% CI, 1.03-1.63; P = .03; butyl benzyl phthalate OR, 1.26 95% CI, 1.07-1.49; P = .003). A doubling of prenatal monoethyl phthalate exposure was associated with an approximately 15% increase in the OR for language delay in the SELMA study (OR, 1.14; 95% CI, 1.00-1.31; P = .05), but no such association was found in TIDES (OR, 0.98; 95% CI, 0.79-1.23).
In findings from this study, prenatal exposure to dibutyl phthalate and butyl benzyl phthalate was statistically significantly associated with language delay in children in both the SELMA study and TIDES. These findings, along with the prevalence of prenatal exposure to phthalates, the importance of language development, and the inconsistent results from a 2017 Danish study, suggest that the association of phthalates with language delay may warrant further examination.
Lymphangioleiomyomatosis (LAM) is a rare fatal cystic lung disease due to bi-allelic inactivating mutations in tuberous sclerosis complex (TSC1/TSC2) genes coding for suppressors of the mechanistic ...target of rapamycin complex 1 (mTORC1). The origin of LAM cells is still unknown. Here, we profile a LAM lung compared to an age- and sex-matched healthy control lung as a hypothesis-generating approach to identify cell subtypes that are specific to LAM. Our single-cell RNA sequencing (scRNA-seq) analysis reveals novel mesenchymal and transitional alveolar epithelial states unique to LAM lung. This analysis identifies a mesenchymal cell hub coordinating the LAM disease phenotype. Mesenchymal-restricted deletion of Tsc2 in the mouse lung produces a mTORC1-driven pulmonary phenotype, with a progressive disruption of alveolar structure, a decline in pulmonary function, increase of rapamycin-sensitive expression of WNT ligands, and profound female-specific changes in mesenchymal and epithelial lung cell gene expression. Genetic inactivation of WNT signaling reverses age-dependent changes of mTORC1-driven lung phenotype, but WNT activation alone in lung mesenchyme is not sufficient for the development of mouse LAM-like phenotype. The alterations in gene expression are driven by distinctive crosstalk between mesenchymal and epithelial subsets of cells observed in mesenchymal Tsc2-deficient lungs. This study identifies sex- and age-specific gene changes in the mTORC1-activated lung mesenchyme and establishes the importance of the WNT signaling pathway in the mTORC1-driven lung phenotype.
The stress acting on fractures in a 3.5 km deep borehole in granite is examined to place constraints on fracture strength and to evaluate whether permeable fractures tended to be “critically ...stressed.” Two data sets consisting of some 500 fractures are analyzed. The first considers the permeable/impermeable fracture populations in their natural state. The second considers the populations after the hole had been subject to a prolonged, 9 MPa overpressure in two major injections which increased the number of permeable fractures from 18 to more than 95. For both data sets it is found that permeable fractures are critically stressed inasmuch as they support levels of shear stress that would be verging on failure if their strength were governed by a Coulomb friction law with a coefficient of 0.6–1.0. However, the vast majority of impermeable fractures are also critically stressed, implying that critical stressing is a necessary, but not a sufficient, condition for permeability to develop. Most permeable fractures showed evidence of shear failure after the injections and tended to occur in hydrothermally altered cataclastic shear zones, suggesting that they may have been relatively weak because of the presence of illite. To prevent failure of the impermeable fractures during the injections requires a cohesion of at least 6.5 MPa to augment a maximum allowable friction coefficient of 1.0. These are probably early mode 1 fractures that are sealed primarily with calcite. The strength of the shear zones appears to be significantly greater than the illite‐rich fractures from which they are composed. This imposes constraints on their internal architecture.
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