Density-Temperature-Softness Scaling of the Dynamics of Glass-forming Soft-sphere Liquids

The principle of dynamic equivalence between soft-sphere and hard-sphere fluids [Phys. Rev. E \textbf{68}, 011405 (2003)] is employed to describe the interplay of the effects of varying the density n, the temperature T, and the softness (characterized by a softness parameter {\nu}^{-1}) on the dynamics of glass-forming soft-sphere liquids in terms of simple scaling rules. The main prediction is that the dynamic parameters of these systems, such as the {\alpha}-relaxation time and the long-time self-diffusion coefficient, depend on n, T, and {\nu} only through the reduced density n^\ast \equiv n{\sigma}^{3}_{HS}(T, {\nu}),where the effective hard-sphere diameter {\sigma}_{HS}(T, {\nu}) is determined, for example, by the Andersen-Weeks-Chandler condition for soft-sphere-hard-sphere structural equivalence. A number of scaling properties observed in recent simulations involving glass-forming fluids with repulsive short range interactions are found to be a direct manifestation of this general dynamic equivalence principle. The self-consistent generalized Langevin equation (SCGLE) theory of colloid dynamics is shown to accurately capture these scaling rule

Effective Lagrangian description of Higgs mediated flavor violating electromagnetic transitions: implications on lepton flavor violation

Higgs mediated flavor violating electromagnetic interactions, induced at the one--loop level by a nondiagonal $Hf_if_j$ vertex, with $f_i$ and $f_j$ charged leptons or quarks, are studied within the context of a completely general effective Yukawa sector that comprises $SU_L(2)\times U_Y(1)$--invariant operators of up to dimension--six. Exact formulae for the one--loop $\gamma f_if_j$ and $\gamma \gamma f_if_j$ couplings are presented and their related processes used to study the phenomena of Higgs mediated lepton flavor violation. The experimental limit on the $\mu \to e\gamma$ decay is used to derive a bound on the branching ratio of the $\mu \to e\gamma \gamma$ transition, which is 6 orders of magnitude stronger than the current experimental limit. Previous results on the $\tau \to \mu \gamma$ and $\tau \to \mu \gamma \gamma$ decays are reproduced. The possibility of detecting signals of lepton flavor violation at $\gamma \gamma$ colliders is explored through the $\gamma \gamma \to l_il_j$ reaction, putting special emphasis on the $\tau \mu$ final state. Using the bound imposed on the $H\tau \mu$ vertex by the current experimental data on the muon anomalous magnetic moment, it is found that about half a hundred events may be produced in the International Linear Collider.Comment: 18 pages, 12 figure

Alelopatía diferencial entre los géneros de un árbol invasor dioico sobre plantas de desierto

"The Peruvian peppertree (Schinus molle) is a dioecious species from South America that was introduced into central Mexico five centuries ago. This tree has invaded abandoned agricultural fields from semiarid regions, where it can be found with several native succulent plants that have recolonized these areas. Although peppertrees have negative allelopathic effects on crops, their effects on these native plants remain unknown. Indeed, the allelopathy of peppertrees has only been tested for female individuals, while the allelopathic potential of male peppertrees has not been assessed yet. This study focused on these issues and assessed whether peppertrees affect germination of succulent plants from the Chihuahuan Desert and whether these effects differ between male and female trees. For this we conducted a series of germination bioassays where seeds of native species were watered with aqueous extracts of staminate flowers and leaves produced by male peppertrees, and with aqueous extracts of fruits and leaves produced by female peppertrees. Additionally, we conducted experiments where seeds of native species were sowed on soils collected beneath the canopy of both tree genders. The results of all these experiments indicated that both peppertree genders can reduce germination of native species, but also suggested that male peppertrees would have stronger allelopathic effects than female peppertrees. To our best knowledge, this is the first study reporting allelopathic effects of peppertrees on native plants from Mexico, but this is also the first study indicating differential gender effects for invasive dioecious species with allelopathic potential.""El pirul (Schinus molle) es una especie dioica de Sudamérica que fue introducida en México hace cinco siglos atrás. Este árbol ha invadido campos agrícolas abandonados de regiones semiáridas, donde puede ser encontrado con varias especies de plantas suculentas nativas que han recolonizado estas áreas. Aunque los pirules tienen efectos alelopáticos negativos sobre los cultivos, sus efectos sobre estas plantas nativas siguen siendo desconocidos. De hecho, la alelopatía de los pirules sólo se ha probado para individuos femeninos, mientras que el potencial alelopático de los pirules masculinos aún no se ha evaluado. Este estudio se enfocó en estos temas y evaluó si los pirules inhiben la germinación de plantas suculentas del desierto Chihuahuense y si estos efectos diferen entre árboles masculinos y femeninos. Para ello se realizó una serie de bioensayos de germinación donde semillas de las especies nativas fueron regadas con extractos acuosos obtenidos de fores estaminadas y hojas producidas por pirules masculinos, y con extractos acuosos de frutos y hojas producidas por pirules femeninos. Adicionalmente, realizamos experimentos donde semillas de las especies nativas fueron sembraron en suelos recogidos bajo el dosel de ambos géneros de pirul. Los resultados de todos estos experimentos indicaron que ambos géneros del pirul pueden reducir la germinación de especies nativas, pero también sugirieron que los pirules masculinos tendrpian efectos alelopáticos más fuertes sobre las especies nativas que los pirules femeninos. Hasta donde estamos enterados, este es el primer estudio que reporta efectos alelopáticos de los pirules sobre plantas nativas de México, pero esto también es el primer estudio que indica los efectos de diferenciales del género para especies invasoras dioicas con potencial alelopático.

CRYPTOMEIGENIA SP. (DIPTERA: TACHINIDAE) COMO PARASITOIDE DE ADULTOS DE PHYLLOPHAGA (PHYTALUS) RUFOTESTACEA (MOSER, 1918) (COLEOPTERA: MELOLONTHIDAE) EN CHIAPAS, MÉXICO

A description is made of the biology and activity of Cryptomeigenia sp. (Diptera: Tachinidae), an endoparasitoid of Phyllophaga rufotestacea (Moser, 1918) (Coleoptera: Melolonthidae) adults. Phyllophaga rufotestacea specimens were collected from May to October in 2002 and from June to September in 2003 in agricultural and forested plots in southern San Cristobal de Las Casas, Chiapas, Mexico. The collections were performed three nights a week, between 1900 and 2130 h. Of the 1385 adult specimens collected in 2002, 564 were female and 821 male; 26.9% of the males were parasitized. Of the 1023 specimens collected in 2003, 25.17% of males and 15.58% of females were parasitized. In 2003, parasitism by Cryptomeigenia sp. was shown to occur throughout the flying period of P. rufotestacea (June 9 to September 8), although the percentage of infected individuals varied during this period (from cero to 38.7%). Laboratory study showed that Cryptomeigenia sp. has four development stages: egg, larva, pupa and adult. Under laboratory conditions the first stages occur in P. rufotestacea beetles over a period of 29-32 days. Cryptomeigenia sp. oviposits anywhere between one and 45 eggs in a male or female beetle’s abdominal cavity, where the eggs develop and eclose. A number of larvae hatch though only one survives. This larva becomes the sole survivor by eating the other, smaller larvae and the host’s organs, which causes host death. This parasite is specific to P. rufotestacea adults. Over 12 Melolonthidae species are found at the same site and do not parasitize this potential host.Se describe la biología de Cryptomeigenia sp. (Diptera: Tachinidae) y su actividad como endoparasitoide de adultos de Phyllophaga rufotestacea (Moser, 1918) (Coleoptera: Melolonthidae). Los escarabajos se recolectaron durante los meses de mayo a octubre de 2002, y de junio a septiembre de 2003, en parcelas agrícolas y arbolado en el sur de San Cristóbal de Las Casas, Chiapas, tres noches de cada semana, de 7 a 9:30 p.m. De 1385 escarabajos adultos recolectados en 2002, 564 fueron hembras y 821 machos, de estos últimos el 26.9% estuvo parasitado. En la recolecta de 2003 se encontró el 25.17% de machos parasitados y el 15.58% de las hembras. En 2003 se comprobó que el parasitismo está presente en todo el periodo de vuelo de P. rufotestacea (del 9-junio al 8-septiembre), variando en ese tiempo el porcentaje de organismos afectados (de cero a 38.7%). Las tres primeras fases del ciclo biológico de Cryptomeigenia sp. tienen una duración de entre 29-32 días, bajo condiciones de laboratorio. El díptero oviposita de 1-45 huevos en la cavidad abdominal de los escarabajos, machos y hembras. Sin embargo, solo una larva sobrevive, alimentándose de las demás, que generalmente son más pequeñas, y de las vísceras del escarabajo, provocándole la muerte. Es un endoparasitoide específico de P. rufotestacea en estado adulto, ya que en el mismo sitio se encuentran 15 especies de Melolonthidae sin que las parasite

PRIMER REGISTRO DE PHYLLOPHAGA (PHYTALUS) RUFOTESTACEA (MOSER, 1918) (COLEOPTERA: SCARABAEOIDEA) PARA MÉXICO Y CHIAPAS

The presence of Phyllophaga (Phytalus) rufotestacea (Moser, 1918) including some data on biology, behavior and hosts, is documented for the first time in Mexico based on material collected from an agricultural plot in San Cristobal de Las Casas, Chiapas

Descripción de los estados inmaduros de Ligyrus nasutus (Burmeister, 1847) (Coleoptera: Melolonthidae: Dynastinae) con información sobre su biología.

The third instar larva of Ligyrus nasutus Burmeister is described based on five specimens collected from agricultural fields, where cattle fed with stubble from the previous cycle, and pastures with cattle in Villa Flores, Chiapas, Mexico. The pupa of L. nasutus is also described using specimens obtained from rearing in captivity. Drawings of the diagnostic structures, biological data and a key to the known larvae of the species of Ligyrus are included.Se describe la larva de tercer estadio de Ligyrus nasutus (Burmeister) con base en cinco ejemplares procedentes de parcelas agrícolas en Villa Flores, Chiapas, México. También se describe la pupa de L. nasutus con base en ejemplares obtenidos durante el desarrollo de las larvas en cautiverio. Se incluyen ilustraciones de los caracteres diagnósticos, datos sobre su biología y una clave para separar las larvas conocidas del género

Descripción de los estados inmaduros de Ligyrus nasutus (Burmeister, 1847) (Coleoptera: Melolonthidae: Dynastinae) con información sobre su biología.

The third instar larva of Ligyrus nasutus Burmeister is described based on five specimens collected from agricultural fields, where cattle fed with stubble from the previous cycle, and pastures with cattle in Villa Flores, Chiapas, Mexico. The pupa of L. nasutus is also described using specimens obtained from rearing in captivity. Drawings of the diagnostic structures, biological data and a key to the known larvae of the species of Ligyrus are included.Se describe la larva de tercer estadio de Ligyrus nasutus (Burmeister) con base en cinco ejemplares procedentes de parcelas agrícolas en Villa Flores, Chiapas, México. También se describe la pupa de L. nasutus con base en ejemplares obtenidos durante el desarrollo de las larvas en cautiverio. Se incluyen ilustraciones de los caracteres diagnósticos, datos sobre su biología y una clave para separar las larvas conocidas del género