Archaic mitochondrial DNA inserts in modern day nuclear genomes

Traces of interbreeding of Neanderthals and Denisovans with modern humans in the form of archaic DNA have been detected in the genomes of present-day human populations outside sub-Saharan Africa. Up to now, only nuclear archaic DNA has been detected in modern humans; we therefore attempted to identify archaic mitochondrial DNA (mtDNA) residing in modern human nuclear genomes as nuclear inserts of mitochondrial DNA (NUMTs)

Approximation of conformal mappings using conformally equivalent triangular lattices

Consider discrete conformal maps defined on the basis of two conformally equivalent triangle meshes, that is edge lengths are related by scale factors associated to the vertices. Given a smooth conformal map $f$, we show that it can be approximated by such discrete conformal maps $f^\epsilon$. In particular, let $T$ be an infinite regular triangulation of the plane with congruent triangles and only acute angles (i.e.\ $<\pi/2$). We scale this tiling by $\epsilon>0$ and approximate a compact subset of the domain of $f$ with a portion of it. For $\epsilon$ small enough we prove that there exists a conformally equivalent triangle mesh whose scale factors are given by $\log|f'|$ on the boundary. Furthermore we show that the corresponding discrete conformal maps $f^\epsilon$ converge to $f$ uniformly in $C^1$ with error of order $\epsilon$.Comment: 14 pages, 3 figures; v2 typos corrected, revised introduction, some proofs extende

Constructing solutions to the Bj\"orling problem for isothermic surfaces by structure preserving discretization

In this article, we study an analog of the Bj\"orling problem for isothermic surfaces (that are more general than minimal surfaces): given a real analytic curve $\gamma$ in ${\mathbb R}^3$, and two analytic non-vanishing orthogonal vector fields $v$ and $w$ along $\gamma$, find an isothermic surface that is tangent to $\gamma$ and that has $v$ and $w$ as principal directions of curvature. We prove that solutions to that problem can be obtained by constructing a family of discrete isothermic surfaces (in the sense of Bobenko and Pinkall) from data that is sampled along $\gamma$, and passing to the limit of vanishing mesh size. The proof relies on a rephrasing of the Gauss-Codazzi-system as analytic Cauchy problem and an in-depth-analysis of its discretization which is induced from the geometry of discrete isothermic surfaces. The discrete-to-continuous limit is carried out for the Christoffel and the Darboux transformations as well.Comment: 29 pages, some figure

Comparing Mental Health across Distinct Groups of Users of Psychedelics, MDMA, Psychostimulants, and Cannabis.

Differences in mental health (MH) of users of distinct psychoactive substances have been shown. Both substance use (SU) and MH in users are influenced by stressful life events. This study compared MH parameters in distinct groups of substance users and evaluated the impact of stress factors on these outcomes. Data stem from the longitudinal Swiss Cohort Study on Substance Use Risk Factors (C-SURF) involving 4,475 young adult men. Distinct groups were created for the past 12 months' use of psychedelics, MDMA, psychostimulants, and cannabis. MH measurements (depressive symptoms, overall MH, perceived stress, life satisfaction) were used as outcome variables, while indicators of past family functioning and stressful life events served as covariates. The MH of psychedelics users was not significantly different from the no-drug-use group, whereas poorer MH was found in the other SU groups. Observed effects were influenced by the tested stress factors. The absence of association between use of psychedelics and worsening of MH deserves further investigation in male and female samples. Stressful life experiences must be considered when assessing the MH of users of illicit substances. These findings suggest that some men practice SU as self-medication to cope with life adversity

Discrete complex analysis on planar quad-graphs

We develop a linear theory of discrete complex analysis on general quad-graphs, continuing and extending previous work of Duffin, Mercat, Kenyon, Chelkak and Smirnov on discrete complex analysis on rhombic quad-graphs. Our approach based on the medial graph yields more instructive proofs of discrete analogs of several classical theorems and even new results. We provide discrete counterparts of fundamental concepts in complex analysis such as holomorphic functions, derivatives, the Laplacian, and exterior calculus. Also, we discuss discrete versions of important basic theorems such as Green's identities and Cauchy's integral formulae. For the first time, we discretize Green's first identity and Cauchy's integral formula for the derivative of a holomorphic function. In this paper, we focus on planar quad-graphs, but we would like to mention that many notions and theorems can be adapted to discrete Riemann surfaces in a straightforward way. In the case of planar parallelogram-graphs with bounded interior angles and bounded ratio of side lengths, we construct a discrete Green's function and discrete Cauchy's kernels with asymptotics comparable to the smooth case. Further restricting to the integer lattice of a two-dimensional skew coordinate system yields appropriate discrete Cauchy's integral formulae for higher order derivatives.Comment: 49 pages, 8 figure

Approximation of conformal mappings by circle patterns

A circle pattern is a configuration of circles in the plane whose combinatorics is given by a planar graph G such that to each vertex of G corresponds a circle. If two vertices are connected by an edge in G, the corresponding circles intersect with an intersection angle in $(0,\pi)$. Two sequences of circle patterns are employed to approximate a given conformal map $g$ and its first derivative. For the domain of $g$ we use embedded circle patterns where all circles have the same radius decreasing to 0 and which have uniformly bounded intersection angles. The image circle patterns have the same combinatorics and intersection angles and are determined from boundary conditions (radii or angles) according to the values of $g'$ ($|g'|$ or $\arg g'$). For quasicrystallic circle patterns the convergence result is strengthened to $C^\infty$-convergence on compact subsets.Comment: 36 pages, 7 figure

Non-medical use of prescription drugs by young men: impact of potentially traumatic events and of social-environmental stressors.

&lt;b&gt;Background&lt;/b&gt; : Non-medical use of prescription drugs (NMUPD) is an increasing phenomenon associated with physical and psychological consequences. This study investigated the effects of distinct forms of stress on NMUPD. &lt;b&gt;Methods&lt;/b&gt; : Data from 5308 young adult men from the Swiss cohort study on substance use risk factors (C-SURF) were analysed regarding NMUPD of sleeping pills, tranquilizers, opioid analgesics, psychostimulants, and antidepressants. Various forms of stress (discrete, potentially traumatic events, recent and long-lasting social-environmental stressors) during the period preceding the NMUPD assessment were measured. Backward log-binomial regression was performed and risk ratios (RR) were calculated. &lt;b&gt;Results&lt;/b&gt; : NMUPD was significantly associated with the cumulative number of potentially traumatic events (e.g. for opioid analgesics, RR = 1.92, &lt;i&gt;p&lt;/i&gt;  &lt; .001), with problems within the family (e.g. for sleeping pills, RR = 2.45, &lt;i&gt;p&lt;/i&gt;  &lt; .001), and the peer group (e.g. for tranquilizer use, RR = 2.34, &lt;i&gt;p&lt;/i&gt;  &lt; .01). Factors describing family functioning in childhood showed very few significant associations. Sexual assault by acquaintances was associated only with use of sleeping pills (RR = 2.91, &lt;i&gt;p&lt;/i&gt;  p &lt;.01); physical assault by acquaintances was not associated with NMUPD. Physical (e.g. for psychostimulants, RR = 2.01, &lt;i&gt;p&lt;/i&gt;  &lt; .001) or sexual assaults (e.g. for antidepressants, RR = 4.64, &lt;i&gt;p&lt;/i&gt;  &lt; .001) perpetrated outside the family context did show associations with several drug categories. &lt;b&gt;Conclusion&lt;/b&gt; : NMUPD appears to be more consistently associated with discrete and potentially traumatic events and with recent social-environmental stressors than with long-lasting stressors due to family functioning during childhood and youth. Physical and sexual assaults perpetrated by strangers showed more associations with NMUPD than those perpetrated by a family member

Snus and Snuff Use in Switzerland Among Young Men: Are There Beneficial Effects on Smoking?

There are few recent longitudinal studies on smokeless tobacco (SLT) products and smoking outside the United States or European Nordic countries. The present longitudinal study tests whether Swedish-type snus and nasal snuff use decreases smoking incidence and prevalence in a central European country. The sample consisted of 5198 Swiss men (around 20 years of age). Retention rate was 91.5% over 15 months. Regression models, adjusting for a variety of psychosocial, smoking-related, and other risk factors, assessed whether no, low (less than weekly), and high (weekly or more) use baseline groups showed changes or maintenance in snus and snuff use related to smoking initiation, cessation, and reduction. Among baseline nonsmokers, snus initiators (OR = 1.90, p = .003) and low baseline maintainers (OR = 4.51, p &lt; .001) were more likely to start smoking (reference: persistent nonusers of snus). Among baseline smokers, initiators (OR = 2.79, p &lt; .001) and low baseline maintainers (OR = 2.71, p = .005) more often continued smoking, whereas snus quitters less frequently continued smoking (OR = 0.57, p = .009). High baseline maintainers were non-significantly less likely to continue smoking (OR = 0.71, p = .315). Among continuing smokers, only snus quitters significantly reduced the number of cigarettes smoked per day (b = -1.61, p = .002) compared with persistent nonusers of snus. Results were similar for snuff. SLT use did not have any significant beneficial effects on young men in Switzerland but significantly increased the likelihood of smoking initiation and continuation, independent of whether the substance is legally sold (snuff) or not (snus). This does not exclude that there may be beneficial effects at older ages. Our research provides evidence that SLT use has no benefits for cigarette smoking initiation, cessation, or reduction among young men in a central European country, where SLT is not highly promoted or receives tax incentives. This is true for both legally sold nasal snuff and Swedish-type snus that cannot be legally sold. Results indicate that without incentives for using it, among young people shifts from smoking to SLT use are questionable and confirms the need for country-specific studies before the global public health community engages in promoting SLT