Simulating the dynamics of dispersal and dispersal ability in fragmented populations with mate-finding Allee effects

We consider the spatial propagation and genetic evolution of model populations comprising multiple subpopulations, each distinguished by its own characteristic dispersal rate. Mate finding is modeled in accord with the assumption that reproduction is based on random encounters between pairs of individuals, so that the frequency of interbreeding between two subpopulations is proportional to the product of local population densities of each. The resulting nonlinear growth term produces an Allee effect, whereby reproduction rates are lower in sparsely populated areas; the distribution of dispersal rates that evolves is then highly dependent upon the population's initial spatial distribution. In a series of numerical test cases, we consider how these dynamics affect lattice-like arrangements of population fragments, and investigate how a population's initial fragmentation determines the dispersal rates that evolve as a habitat is colonized. First, we consider a case where initial population fragments coincide with habitat islands, within which death rates differ from those that apply outside; the presence of inhospitable exterior regions exaggerates Allee effect-driven reductions in dispersal ability. We then examine how greater distances separating adjacent population fragments lead to more severe reductions in dispersal ability. For populations of a fixed initial magnitude, fragmentation into smaller, denser patches leads not only to greater losses of dispersal ability, but also helps ensure the population's long-term persistence, emphasizing the trade-offs between the benefits and risks of rapid dispersal under Allee effects. Next, simulations of well-established populations disrupted by localized depopulation events illustrate how mate-finding Allee effects and spatial heterogeneity can drive a population's dispersal ability to evolve either downward or upward depending on conditions, highlighting a qualitative distinction between population fragmentation and habitat heterogeneity. A final test case compares populations that are fragmented across multiple scales, demonstrating how differences in the relative scales of micro- and macro-level fragmentation can lead to qualitatively different evolutionary outcomes

Complex of primary and secondary parasitoids (Hymenoptera: Encyrtidae and Signiphoridae) of Hypogeococcus spp. Mealybugs (Hemiptera: Pseudococcidae) in the New World

Se informan los resultados de los relevamientos de los parasitoides primarios y secundarios (hiperparasitoides) de Hypogeococcus spp. (Hemiptera: Pseudococcidae) realizados en el Nuevo Mundo durante el período 2009 para 2017 para obtener enemigos naturales de la cochinilla harinosa de los cactus (Harrisia cactus mealybug) Hypogeococcus sp., que está devastando cactus nativos en Puerto Rico y amenaza a los cactus presentes en Islas del Caribe adyacentes. Se registraron cinco especies de Encyrtidae (Hymenoptera: Chalcidoidea) como parasitoides primarios de Hypogeococcus spp., incluyendo el recientemente descrito Leptomastidea hypogeococci Triapitsyn sp. n., que es la única especie del género Leptomastidea García Mercet en el Nuevo Mundo cuya clava de la antena de la hembra es contrastantemente blanca. El análisis genético de los individuos de L. hypogeococci de Argentina, Brasil y Puerto Rico (EE. UU.) corrobora los datos morfológicos de que la misma especie se encuentra en América del Sur, las islas del Caribe y Florida (EE. UU.). Se proporciona una clave para las especies del Nuevo Mundo de Leptomastidea. Leptomastidea antillicola Dozier, syn. n. de Puerto Rico es sinonimizado bajo L. abnormis (Girault). Basado en los datos moleculares presentados, Anagyrus ciomperliki Triapitsyn syn. n. (Encyrtidae), originalmente descrito de Puerto Rico, es sinonimizado bajo A. quilmes Triapitsyn, Logarzo & Aguirre, cuyo rango de distribución conocido también se amplía para incluir a Brasil. Anagyrus cachamai Triapitsyn, Logarzo y Aguirre, A. lapachosus Triapitsyn, Aguirre y Logarzo y A. quilmes se registraron recientemente en Paraguay. Se describe el macho previamente desconocido de Prochiloneurus argentinensis (De Santis) (Encyrtidae) de la provincia de Misiones de Argentina, y el de P. narendrani Noyes & Triapitsyn de la Isla de Mona, Puerto Rico. Hasta aquí, Anagyrus cachamai y A. lapachosus se consideran como las principales especies para la introducción desde Argentina y Paraguay a Puerto Rico para el control biológico de la cochinilla harinosa de los cactus. El holotipo de Anagyrus tanystis De Santis de Buenos Aires, Argentina, cuyos hospederos asociados son desconocidos, se ilustra para facilitar su reconocimiento de otras especies congenéricas.Parasitoids, both primary and secondary (hyperparasitoids), of Hypogeococcus spp. mealybugs (Hemiptera: Pseudococcidae) are reviewed to report results of the surveys in the New World conducted during 2009 to 2017 for prospective natural enemies of the Harrisia cactus mealybug, Hypogeococcus sp., which is devastating native cacti in Puerto Rico and threatening cacti in the adjacent Caribbean islands. Five species of Encyrtidae (Hymenoptera: Chalcidoidea) are recorded as primary parasitoids of Hypogeococcus spp., including the newly described Leptomastidea hypogeococci Triapitsyn sp. n., which is the only species of the genus Leptomastidea García Mercet in the New World where the clava of the female antenna is contrastingly white. Genetic analysis of the individuals of L. hypogeococci from Argentina, Brazil, and Puerto Rico (USA) corroborates the morphological data that the same species occurs in South America, the Caribbean islands, and Florida (USA). A key to the New World species of Leptomastidea is given and taxonomic notes are provided on its other known species in the Neotropical region. Leptomastidea antillicola Dozier, syn. n. from Puerto Rico is synonymized under L. abnormis (Girault). Based on the presented molecular data, Anagyrus ciomperliki Triapitsyn syn. n. (Encyrtidae), originally described from Puerto Rico, is synonymized under A. quilmes Triapitsyn, Logarzo & Aguirre, where the known distributional range is expanded to also include Brazil. Anagyrus cachamai Triapitsyn, Logarzo & Aguirre, A. lapachosus Triapitsyn, Aguirre & Logarzo, and A. quilmes are newly recorded from Paraguay. The previously unknown male of Prochiloneurus argentinensis (De Santis) (Encyrtidae) is described from Misiones Province of Argentina, and that of P. narendrani Noyes & Triapitsyn is described from Mona Island, Puerto Rico. So far, Anagyrus cachamai and A. lapachosus are considered to be the primary target species for introduction from Argentina and Paraguay into Puerto Rico for the biological control of Harrisia cactus mealybug. The holotype of Anagyrus tanystis De Santis from Buenos Aires, Argentina, host associations are unknown, and is illustrated to facilitate its recognition from other congeneric species.Fil: Triapitsyn, Serguei V.. University of California; Estados UnidosFil: Aguirre, María Belén. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Logarzo, Guillermo Alejandro. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Hight, Stephen D.. United States Department of Agriculture. Agriculture Research Service; Estados UnidosFil: Ciomperlik, Matthew A.. United States Department of Agriculture. Agriculture Research Service; Estados UnidosFil: Rugman Jones, Paul F.. University of California; Estados UnidosFil: Rodrigues, Jose C. Verle. Universidad de Puerto Rico; Puerto Ric

Mind-Body Skills Groups for Adolescents with Depression in Primary Care: A Pilot Study

Objective: To determine acceptability and preliminary effectiveness of Mind-Body Skills Groups (MBSGs) as a treatment for depressed adolescents in primary care. Methods: A single arm clinical trial was conducted. A 10-week MBSG program was implemented in primary care. Participants completed self-report measures at baseline, post-intervention, and 3-months following the MBSGs. Measures included the Children’s Depression Inventory-2, Suicidal Ideation Questionnaire, Mindful Attention Awareness Scale, Self-Efficacy for Depressed Adolescents, rumination subscale of the Children’s Response Style Questionnaire, and a short acceptability questionnaire. Results: Participants included 43 adolescents. The total depression scores significantly improved following the MBSG intervention and continued to improve significantly from post-treatment to follow-up. Mindfulness, self-efficacy, rumination, and suicidal ideation all had significant improvement following the intervention. Acceptability of the program was strong, and attendance was excellent. Discussion: Preliminary evidence suggests that MBSGs are an acceptable treatment for primary care settings and lead to improved depression symptoms in adolescents.Sandra Eskenazi Mental Health Center and the Herbert Simon Family Foundation (070241-00002B

Photochemical “in-air” combinatorial discovery of antimicrobial co-polymers

There is an urgent need to identify new, non‐traditional antimicrobials. The discovery of new polymeric antimicrobials is limited by current low‐throughput synthetic tools, which means that limited chemical space has been explored. Herein, we employ photochemical “in‐air” reversible addition–fragmentation chain‐transfer (RAFT) polymerization with microwell plates, using liquid‐handling robots to assemble large libraries of cationic polymers, without the need for degassing or purification steps, facilitating transfer to screening. Several lead polymers were identified including a co‐polymer with propylene glycol side chains with significantly enhanced antimicrobial activity and increased therapeutic window. Mechanistic studies showed that this polymer was bacteriostatic, and surprisingly did not lyse the cell membranes, implying an alternative mode of action. This versatile method using simple robotics will help to develop new biomaterials with emergent properties

Projective Ribbon Permutation Statistics: a Remnant of non-Abelian Braiding in Higher Dimensions

In a recent paper, Teo and Kane proposed a 3D model in which the defects support Majorana fermion zero modes. They argued that exchanging and twisting these defects would implement a set R of unitary transformations on the zero mode Hilbert space which is a 'ghostly' recollection of the action of the braid group on Ising anyons in 2D. In this paper, we find the group T_{2n} which governs the statistics of these defects by analyzing the topology of the space K_{2n} of configurations of 2n defects in a slowly spatially-varying gapped free fermion Hamiltonian: T_{2n}\equiv {\pi_1}(K_{2n})$. We find that the group T_{2n}= Z \times T^r_{2n}, where the 'ribbon permutation group' T^r_{2n} is a mild enhancement of the permutation group S_{2n}: T^r_{2n} \equiv \Z_2 \times E((Z_2)^{2n}\rtimes S_{2n}). Here, E((Z_2)^{2n}\rtimes S_{2n}) is the 'even part' of (Z_2)^{2n} \rtimes S_{2n}, namely those elements for which the total parity of the element in (Z_2)^{2n} added to the parity of the permutation is even. Surprisingly, R is only a projective representation of T_{2n}, a possibility proposed by Wilczek. Thus, Teo and Kane's defects realize `Projective Ribbon Permutation Statistics', which we show to be consistent with locality. We extend this phenomenon to other dimensions, co-dimensions, and symmetry classes. Since it is an essential input for our calculation, we review the topological classification of gapped free fermion systems and its relation to Bott periodicity.Comment: Missing figures added. Fixed some typos. Added a paragraph to the conclusio