An Introduction to Quantum Networks

A network (or graph) is a set of nodes with connections between them. A quantum network describes the behavior of waves in a network of wires. One may study the spectrum of a quantum network, which is akin to determining the set of frequencies of waves on a network of guitar strings joined together. The usefulness of these quantum networks has been enhanced by the ability to study the spectrum by relying on closed paths of the network. In the last few decades, quantum networks have been a model of increasing interest in mathematical physics, chemistry, and engineering; some examples of application include nanotechnology, wave guides, and quantum chaos. The talk will serve as an introduction to the topic of quantum graphs and their spectral properties. A family of graphs which are particularly amenable to demonstrate these network spectral connections are binary quantum graphs, the topic of my current research

Orbits, pseudo orbits, and the characteristic polynomial of q-nary quantum graphs.

Quantum graphs provide a simple model of quantum mechanics in systems with complex geometry and can be used to study quantum chaos. We evaluate the variance of the coefficients of a quantum binary graph’s associated characteristic polynomial, which is related to the quantum graph’s spectrum. This variance can be written as a finite sum over pairs of short pseudo orbits on the graph with the same topological and metric lengths.To account for all pairs of this type, we first count the numbers of primitive periodic orbits and primitive pseudo orbits on general q-nary graphs by exploiting properties of Lyndon words. We then classify the primitive pseudo orbits on binary graphs by their numbers of self-intersections, the number of repetitions of each self-intersection, and the lengths of self-intersections, in order to determine the contributions of primitive pseudo orbit pairs to the variance. By arranging the sum in a way that considers the contribution of each primitive pseudo orbit paired with all possible partners, we can evaluate the sum over all pairs of primitive pseudo orbits and then use the graph’s ergodicity to asymptotically determine the variance in the limit of large binary graphs. The Bohigas-Giannoni-Schmit conjecture suggests spectral statistics of generic quantum graphs are typically modeled by those of random matrices, in the limit of large graphs. However, we show that, for families of binary graphs, there is a uniform family-specific deviation from random matrix behavior in the variance of coefficients of the characteristic polynomial. Related results for the variance of the coefficients of the characteristic polynomial for general q-nary quantum graphs are also investigated

Biological invasions are a population‐level rather than a species‐level phenomenon

Biological invasions pose a rapidly expanding threat to the persistence, functioning and service provisioning of ecosystems globally, and to socio-economic interests. The stages of successful invasions are driven by the same mechanism that underlies adaptive changes across species in general—via natural selection on intraspecific variation in traits that influence survival and reproductive performance (i.e., fitness). Surprisingly, however, the rapid progress in the field of invasion science has resulted in a predominance of species-level approaches (such as deny lists), often irrespective of natural selection theory, local adaptation and other population-level processes that govern successful invasions. To address these issues, we analyse non-native species dynamics at the population level by employing a database of European freshwater macroinvertebrate time series, to investigate spreading speed, abundance dynamics and impact assessments among populations. Our findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that levels of invasiveness and impact differ markedly. Discrepancies and inconsistencies among species-level risk screenings and real population-level data were also identified, highlighting the inherent challenges in accurately assessing population-level effects through species-level assessments. In recognition of the importance of population-level assessments, we urge a shift in invasive species management frameworks, which should account for the dynamics of different populations and their environmental context. Adopting an adaptive, region-specific and population-focused approach is imperative, considering the diverse ecological contexts and varying degrees of susceptibility. Such an approach could improve and refine risk assessments while promoting mechanistic understandings of risks and impacts, thereby enabling the development of more effective conservation and management strategies

Biological invasions are a population-level rather than a species-level phenomenon

International audienceBiological invasions pose a rapidly expanding threat to the persistence, functioning and service provisioning of ecosystems globally, and to socio‐economic interests. The stages of successful invasions are driven by the same mechanism that underlies adaptive changes across species in general—via natural selection on intraspecific variation in traits that influence survival and reproductive performance (i.e., fitness). Surprisingly, however, the rapid progress in the field of invasion science has resulted in a predominance of species‐level approaches (such as deny lists), often irrespective of natural selection theory, local adaptation and other population‐level processes that govern successful invasions. To address these issues, we analyse non‐native species dynamics at the population level by employing a database of European freshwater macroinvertebrate time series, to investigate spreading speed, abundance dynamics and impact assessments among populations. Our findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that levels of invasiveness and impact differ markedly. Discrepancies and inconsistencies among species‐level risk screenings and real population‐level data were also identified, highlighting the inherent challenges in accurately assessing population‐level effects through species‐level assessments. In recognition of the importance of population‐level assessments, we urge a shift in invasive species management frameworks, which should account for the dynamics of different populations and their environmental context. Adopting an adaptive, region‐specific and population‐focused approach is imperative, considering the diverse ecological contexts and varying degrees of susceptibility. Such an approach could improve and refine risk assessments while promoting mechanistic understandings of risks and impacts, thereby enabling the development of more effective conservation and management strategies

Biological invasions are a population‐level rather than a species‐level phenomenon

Biological invasions pose a rapidly expanding threat to the persistence, functioning and service provisioning of ecosystems globally, and to socio-economic interests. The stages of successful invasions are driven by the same mechanism that underlies adaptive changes across species in general-via natural selection on intraspecific variation in traits that influence survival and reproductive performance (i.e., fitness). Surprisingly, however, the rapid progress in the field of invasion science has resulted in a predominance of species-level approaches (such as deny lists), often irrespective of natural selection theory, local adaptation and other population-level processes that govern successful invasions. To address these issues, we analyse non-native species dynamics at the population level by employing a database of European freshwater macroinvertebrate time series, to investigate spreading speed, abundance dynamics and impact assessments among populations. Our findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that levels of invasiveness and impact differ markedly. Discrepancies and inconsistencies among species-level risk screenings and real population-level data were also identified, highlighting the inherent challenges in accurately assessing population-level effects through species-level assessments. In recognition of the importance of population-level assessments, we urge a shift in invasive species management frameworks, which should account for the dynamics of different populations and their environmental context. Adopting an adaptive, region-specific and population-focused approach is imperative, considering the diverse ecological contexts and varying degrees of susceptibility. Such an approach could improve and refine risk assessments while promoting mechanistic understandings of risks and impacts, thereby enabling the development of more effective conservation and management strategies. Biological invasions increasingly threaten global ecosystems and socio-economic interests, advancing through mechanisms like natural selection that enhance survival and reproductive traits. Our study focuses on population-level analyses of non-native European freshwater macroinvertebrates to better understand their spread and impact. We found significant variability in invasion dynamics across populations and regions, suggesting that current species-level risk assessments may overlook crucial population-specific factors.imag

Biological invasions are a population-level rather than a species-level phenomenon

Biological invasions pose a rapidly expanding threat to the persistence, functioning and service provisioning of ecosystems globally, and to socio-economic interests. The stages of successful invasions are driven by the same mechanism that underlies adaptive changes across species in general-via natural selection on intraspecific variation in traits that influence survival and reproductive performance (i.e., fitness). Surprisingly, however, the rapid progress in the field of invasion science has resulted in a predominance of species-level approaches (such as deny lists), often irrespective of natural selection theory, local adaptation and other population-level processes that govern successful invasions. To address these issues, we analyse non-native species dynamics at the population level by employing a database of European freshwater macroinvertebrate time series, to investigate spreading speed, abundance dynamics and impact assessments among populations. Our findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that levels of invasiveness and impact differ markedly. Discrepancies and inconsistencies among species-level risk screenings and real population-level data were also identified, highlighting the inherent challenges in accurately assessing population-level effects through species-level assessments. In recognition of the importance of population-level assessments, we urge a shift in invasive species management frameworks, which should account for the dynamics of different populations and their environmental context. Adopting an adaptive, region-specific and population-focused approach is imperative, considering the diverse ecological contexts and varying degrees of susceptibility. Such an approach could improve and refine risk assessments while promoting mechanistic understandings of risks and impacts, thereby enabling the development of more effective conservation and management strategies. Biological invasions increasingly threaten global ecosystems and socio-economic interests, advancing through mechanisms like natural selection that enhance survival and reproductive traits. Our study focuses on population-level analyses of non-native European freshwater macroinvertebrates to better understand their spread and impact. We found significant variability in invasion dynamics across populations and regions, suggesting that current species-level risk assessments may overlook crucial population-specific factors.imag

KAT6A Syndrome:genotype-phenotype correlation in 76 patients with pathogenic KAT6A variants

Purpose Pathogenic variants in KAT6A have recently been identified as a cause of syndromic developmental delay. Within 2 years, the number of patients identified with pathogenic KAT6A variants has rapidly expanded and the full extent and variability of the clinical phenotype has not been reported. Methods We obtained data for patients with KAT6A pathogenic variants through three sources: treating clinicians, an online family survey distributed through social media, and a literature review. Results We identified 52 unreported cases, bringing the total number of published cases to 76. Our results expand the genotypic spectrum of pathogenic variants to include missense and splicing mutations. We functionally validated a pathogenic splice-site variant and identified a likely hotspot location for de novo missense variants. The majority of clinical features in KAT6A syndrome have highly variable penetrance. For core features such as intellectual disability, speech delay, microcephaly, cardiac anomalies, and gastrointestinal complications, genotype– phenotype correlations show that late-truncating pathogenic variants (exons 16–17) are significantly more prevalent. We highlight novel associations, including an increased risk of gastrointestinal obstruction. Conclusion Our data expand the genotypic and phenotypic spectrum for individuals with genetic pathogenic variants in KAT6A and we outline appropriate clinical management