Computing the Cech cohomology of decomposition spaces

A line pattern in a free group $F$ is defined by a malnormal collection of cyclic subgroups. Otal defined a decomposition space $\mathcal{D}$ associated to a line pattern. We provide an algorithm that computes a presentation for the \v{C}ech cohomology of $\mathcal{D}$, thought of as a $F$-module. This answers a relative version of a question of Epstein about boundaries of hyperbolic groups.Comment: 10 pages, 2 figure

An Account of the Smallpox and Its Modifications, as They Existed in Northampton, from July 1827, to January 1828

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Thick embeddings of graphs into symmetric spaces via coarse geometry

We prove estimates for the optimal volume of thick embeddings of finite graphs into symmetric spaces, generalising results of Kolmagorov-Barzdin and Gromov-Guth for embeddings into Euclidean spaces. We distinguish two very different behaviours depending on the rank of the non-compact factor. For rank at least 2, we construct thick wirings of $N$-vertex graphs with volume $CN\ln(N)$ and prove that this is optimal. For rank at most $1$ we prove lower bounds of the form $cN^a$ for some (explicit) $a>1$ which depends on the dimension of the Euclidean factor and the conformal dimension of the boundary of the non-compact factor. The key ingredient is a coarse geometric analogue of a thick embedding called a coarse wiring, with the key property that the minimal volume of a thick embedding is comparable to the minimal volume of a coarse wiring for symmetric spaces of dimension at least $3$.Comment: 27 page

Towards the modeling of mucus draining from human lung: role of airways deformation on air-mucus interaction

Chest physiotherapy is an empirical technique used to help secretions to get out of the lung whenever stagnation occurs. Although commonly used, little is known about the inner mechanisms of chest physiotherapy and controversies about its use are coming out regularly. Thus, a scientific validation of chest physiotherapy is needed to evaluate its effects on secretions. We setup a quasi-static numerical model of chest physiotherapy based on thorax and lung physiology and on their respective biophysics. We modeled the lung with an idealized deformable symmetric bifurcating tree. Bronchi and their inner fluids mechanics are assumed axisymmetric. Static data from the literature is used to build a model for the lung's mechanics. Secretions motion is the consequence of the shear constraints apply by the air flow. The input of the model is the pressure on the chest wall at each time, and the output is the bronchi geometry and air and secretions properties. In the limit of our model, we mimicked manual and mechanical chest physiotherapy techniques. We show that for secretions to move, air flow has to be high enough to overcome secretion resistance to motion. Moreover, the higher the pressure or the quicker it is applied, the higher is the air flow and thus the mobilization of secretions. However, pressures too high are efficient up to a point where airways compressions prevents air flow to increases any further. Generally, the first effects of manipulations is a decrease of the airway tree hydrodynamic resistance, thus improving ventilation even if secretions do not get out of the lungs. Also, some secretions might be pushed deeper into the lungs; this effect is stronger for high pressures and for mechanical chest physiotherapy. Finally, we propose and tested two adimensional numbers that depend on lung properties and that allow to measure the efficiency and comfort of a manipulation

Fully fault tolerant quantum computation with non-deterministic gates

In certain approaches to quantum computing the operations between qubits are non-deterministic and likely to fail. For example, a distributed quantum processor would achieve scalability by networking together many small components; operations between components should assumed to be failure prone. In the logical limit of this architecture each component contains only one qubit. Here we derive thresholds for fault tolerant quantum computation under such extreme paradigms. We find that computation is supported for remarkably high failure rates (exceeding 90%) providing that failures are heralded, meanwhile the rate of unknown errors should not exceed 2 in 10^4 operations.Comment: 5 pages, 3 fig

Participatory research emergent recommendations for researchers and academic institutions: a rapid scoping review

In recent years, a range of academic disciplines have emphasized the potential benefits of prioritizing meaningful engagement with individuals and communities who have lived and have living experience with the topics, phenomena and problems researchers seek to study. In March 2022, we were asked to produce a paper to inform a university workshop and training materials to help students and faculty engage with participatory methods. In turn, we conducted a rapid scoping review of reviews to document key recommendations relating to methodology, logistics and ethics within the various modes of participatory research. Searches were conducted in Web of Science, SCOPUS, ProQuest, Pub Med, OVID (including Medline, PschyInfo/EMBASE, APAPsych) to identify published academic reviews (e.g., systematic, scoping, literature reviews and evidence gap maps), for best practices relating to participatory research. This approach drew out aggregated best practices and lessons learned across many primary studies and increased the speed of the review. From 276 studies imported for screening, 43 full-text studies were assessed for eligibility and 28 were deemed relevant for full inclusion. Results are presented as: 1) participatory research recommendations for researchers; and 2) participatory research recommendations for academic institutions. Three sub-themes emerged within the context of suggestions for researchers engaging with participatory methods: 1) early-stage considerations for study design and planning; 2) conducting the research; and 3) dissemination and knowledge exchange. This rapid scoping review highlights key recommendations for researchers interested in using participatory approaches in their own research, and for academic and institutional stakeholders who aim to support these practices

The Intersection of the Criminal Justice, Education, and Mental Healthcare Systems and Its Influence on Boys and Young Men of Color

The authors provide a scan of the academic and gray literature on the intersection of the criminal justice, mental health, and education systems, and how it influences the lives of at-risk racial/ethnic minority youth (boys and young men of color). As well, the authors identify interventions that aim to improve outcomes for racial/ethnic minority at-risk youth at the intersection of these three structural systems

The relationship between subnormal peak-stimulated growth hormone levels and auxological characteristics in obese children

Context: The hypothesis that obese children are overdiagnosed with growth hormone deficiency (GHD) has not been adequately investigated in the context of adiposity-related differences in auxology. Aim: To investigate the differences in auxological parameters between short, prepubertal, obese children, and normal-weight peers who underwent growth hormone stimulation testing (GHST). Hypothesis: Over-weight/obese children with GHD [peak growth hormone (GH) \u3c 10 μg/L] will have higher values for growth velocity (GV) standard deviation score (SDS), bone age minus chronological age (BA − CA), and child height SDS minus mid-parental height (MPTH) SDS when compared to normal-weight GHD peers. Subjects and Methods: A retrospective review of anthropometric and provocative GHST data of 67 prepubertal, GH-naïve children of age 10.21 ± 2.56 years (male n = 45, age 10.8 ± 2.60 years; female n = 22, age 8.94 ± 2.10). Inclusion criteria: GHST using arginine and clonidine. Exclusion criteria: hypopituitarism, abnormal pituitary magnetic resonance imaging scan, syndromic obesity, or syndromic short stature. Data were expressed as mean ± SD. Results: The over-weight/obese children with peak GH of \u3c10 μg/L had significantly lower value for natural log (ln) peak GH (1.45 ± 0.09 vs. 1.83 ± 0.35, p = 0.022), but similar values for GV SDS, insulin-like growth factor-I, insulin-like growth factor binding protein-3, bone age, BA − CA, MPTH, and child height SDS minus MPTH SDS compared to normal-weight peers with GHD. After adjusting for covariates, the over-weight/obese children (BMI ≥ 85th percentile) were \u3e7 times more likely than normal-weight subjects (BMI \u3c 85th percentile) to have a peak GH of \u3c10 μg/L, and 23 times more likely to have a peak GH of \u3c7 μg/L (OR = 23.3, p = 0.021). There was a significant inverse relationships between BMI SDS and the ln of peak GH (β = −0.40, r2 = 0.26, p = 0.001), but not for BMI SDS vs. GV SDS, ln peak GH vs. BA, or ln peak GH vs. GV SDS. Conclusion: Subnormal peak GH levels in obese prepubertal children are not associated with unique pre-GHST auxological characteristics