Notes on the melittofauna from La Tatacoa Desert, Huila, Colombia

We present a checklist of the melittofauna from La Tatacoa Desert, Department of Huila, a remnant of highly disturbed tropical dry forest located in the upper valley of the Magdalena River. The list consists of 33 species in 20 genera of three families. The most abundant species was the emphorine bee Melitomella schwarzi (Michener, 1954), which accounted for 43% of the specimens collected. Exomalopsis (Phanomalopsis) trifasciata Brèthes, 1910 and Paratetrapedia connexa (Vachal, 1909) are newly recorded for Colombia.Facultad de Ciencias Naturales y Muse

A gynandromorph of Xylocopa augusti and an unusual record of X. iris from Brazil (Hymenoptera: Apidae: Xylocopini)

We describe and illustrate for the first time a mixed gynandromorph of Xylocopa(Neoxylocopa) augusti Lepeletier de Saint Fargeau from Buenos Aires, Argentina. Also, we document and discuss a historical specimen of the Old World carpenter bee X. (Copoxyla) iris (Christ) possibly collected in Brazil.Facultad de Ciencias Naturales y Muse

A gynandromorph of Xylocopa augusti and an unusual record of X. iris from Brazil (Hymenoptera: Apidae: Xylocopini)

We describe and illustrate for the first time a mixed gynandromorph of Xylocopa(Neoxylocopa) augusti Lepeletier de Saint Fargeau from Buenos Aires, Argentina. Also, we document and discuss a historical specimen of the Old World carpenter bee X. (Copoxyla) iris (Christ) possibly collected in Brazil.Facultad de Ciencias Naturales y Muse

Proyecto para la creación de una empresa de confección de camisetas a base de algodón orgánico en la ciudad de Guayaquil

Este documento presenta un análisis de viabilidad y factibilidad de implantar una fábrica que confeccione camisetas en la ciudad de Guayaquil y muestra el plan de negocios para esta empresa. Para esto se realizó un análisis del sector textil e investigación de mercados para identificar estrategias y acciones a seguir. La investigación incluyó a compradores en centros comerciales y competencia en el mercado. En base a la investigación sectorial y a resultados del análisis de la investigación se llegó a la conclusión que el proyecto es totalmente viable; debido a que hay una gran disposición ecologista de la gente y que estarían dispuestos a comprar, y es también factible; porque a través de la aplicación de estrategia de nicho de mercado y diferentes tácticas, la fábrica logrará participación de mercado y sobre todo alta rentabilidad.FEN-ESPO

Global biasing using a Hardware-based artificial Zeeman term in Spinwave Ising Machines

A spinwave Ising machine (SWIM) is a newly proposed type of time-multiplexed hardware solver for combinatorial optimization that employs feedback coupling and phase sensitive amplification to map an Ising Hamiltonian into phase-binarized propagating spin-wave RF pulses in an Yttrium-Iron-Garnet (YIG) film. In this work, we increase the mathematical complexity of the SWIM by adding a global Zeeman term to a 4-spin MAX-CUT Hamiltonian using a continuous external electrical signal with the same frequency as the spin pulses and phase locked with with one of the two possible states. We are able to induce ferromagnetic ordering in both directions of the spin states despite antiferromagnetic pairwise coupling. Embedding a planar antiferromagnetic spin system in a magnetic field has been proven to increase the complexity of the graph associated to its Hamiltonian and thus this straightforward implementation helps explore higher degrees of complexity in this evolving solver.Comment: Index Terms: combinatorial optimization problems, Ising machines, spinwaves, unconventional computing, physical computing, spinwave

New andean bee species of chilicola spinola (hymenoptera: colletidae, xeromelissinae) with notes on their biology

We describe and illustrate three new bee species of the genus Chilicola Spinola that occur at high altitudes in the Eastern Andes of Colombia: C. (Anoediscelis) paramoides Gonzalez sp. nov., C. (Hylaeosoma) bochica Gonzalez sp. nov., and C.(Oroediscelis) deborahae Gonzalez sp. nov. We also provide biological notes and discuss the phylogenetic relationships of C. deborahae; nests of this species were found inside dry fl ower stems of Espeletia argentea Humb. and amp; Bonpl. (Asteraceae) and a palynological analysis showed that 80 % of the pollen grains found in brood cells belonged to Arcytophyllum aff. nitidum and A. muticum (Rubiaceae). The ichneumonid wasp Grotea sp. is also recorded parasitizing brood cells of C. deborahae

Voltage control of frequency, effective damping and threshold current in nano-constriction-based spin Hall nano-oscillators

Using micromagnetic simulations, we study the interplay between strongly voltage-controlled magnetic anisotropy (VCMA), $\Delta K = \pm$200 kJ/m$^3$, and gate width, $w=$ 10--400 nm, in voltage-gated W/CoFeB/MgO based nano-constriction spin Hall nano-oscillators. The VCMA modifies the local magnetic properties such that the magnetodynamics transitions between regimes of \emph{i}) confinement, \emph{ii}) tuning, and \emph{iii}) separation, with qualitatively different behavior. We find that the strongest tuning is achieved for gate widths of the same size as the the constriction width, for which the effective damping can be increased an order of magnitude compared to its intrinsic value. As a consequence, voltage control remains efficient over a very large frequency range, and subsequent manufacturing advances could allow SHNOs to be easily integrated into next-generation electronics for further fundamental studies and industrial applications

Maniobrabilidad de buques: pruebas a escala real del Buque Patrullero de Apoyo Fluvial de la Armada de Colombia

Methodology and results of full scale maneuvering trials for Riverine Support Patrol Vessel “RSPV”, built by COTECMAR for the Colombian Navy are presented. This ship is equipped with a “Pump – Jet” propulsion system and the hull corresponds to a wide-hull with a high Beam – Draft ratio (B/T=9.5). Tests were based on the results of simulation of turning diameters obtained from TRIBON M3˝ design software, applying techniques of Design of Experiments “DOE”, to rationalize the number of runs in different conditions of water depth, ship speed, and rudder angle. Results validate the excellent performance of this class of ship and show that turning diameter and other maneuvering characteristics improve with decreasing water depth.En el presente trabajo se presenta la metodología y los resultados de las pruebas de maniobrabilidad a escala real del Buque Patrullero de Apoyo Fluvial Pesado “PAF-P”, construido por COTECMAR para la Armada Nacional de Colombia. El buque está equipado con un sistema de propulsión de bomba de agua tipo “Pump – Jet” y su casco corresponde a un casco con una relación Manga – Calado muy alta (B/T = 9.5). Las pruebas se basaron en los resultados de simulación de círculos evolutivos obtenidos en el software de Diseño TRIBON M3©, aplicando técnicas de Diseño de Experimentos “DOE”, para racionalizar el número de corridas en diferentes condiciones de profundidad, velocidad y ángulo de timón. Los resultados validan el excelente desempeño de esta clase de buques y muestran que el diámetro de giro y otras características de maniobrabilidad mejoran con la disminución de la profundidad

Especies nuevas y filogenia de las abejas de fuego, oxytrigona (hymenoptera: apidae, meliponini)

We describe and illustrate three new species from Central America and northern South America, present descriptions for previously unknown males and queens, and explore the internal phylogeny of Oxytrigona. Oxytrigona chocoana sp. nov., the sister species of O. daemoniaca, is from the Chocó biogeographic region; O. huaoranii sp. nov., and O. isthmina sp. nov., from the Eastern Andes of Ecuador and Darién (Panamá), are much smaller than their sister species, O. mellicolor. Oxytrigona huaoranii exhibits unusual characters including a short fore femur with carinate inferior margin, and  striated basal propodeum. The male of O. isthmina primarily differs from O. mellicolor in having genitalia with an apically enlarged and strongly bent gonostylus. We also described the males of O. daemoniaca and O. mediorufa, and the male and queen of O. mellicolor. The taxonomic status O. mediorufa is revised; as here understood, this species is distributed only from Mexico to El Salvador. We obtained a single tree for Oxytrigona in a cladistic analysis of 18 morphological and five body coloration characters, which did not support the monophyly of the mulfordi and tataira groups. We also found variation in the gradular and distal margin shapes of the worker sixth sternum, which were useful in the taxonomic analysis. Such characters have not yet been used in the systematics of Meliponini, and we hope to draw more attention to and encourage future phylogenetic studies using these characters. We also present an identification key for the species.Describimos e ilustramos tres especies nuevas de Oxytrigona de Centroamérica y norte de Suramérica, presentamos descripciones de machos y reinas previamente desconocidos, y exploramos la filogenia interna del género. Oxytrigona chocoana sp. nov., del Chocó biogeográfico, es la especie hermana de O. daemoniaca; O. huaoranii sp. nov. y O. isthmina sp. nov., del oriente de los Andes ecuatorianos y del Darién panameño, son mucho más pequeñas que su especie hermana, O. mellicolor. Oxytrigona huaoranii presenta caracteres inusuales tales como el fémur anterior corto, con el margen inferior fuertemente carenado, y el área basal del propódeo estriada. El macho de O. isthmina se diferencia principalmente de O. mellicolor por el gonostilo de la genitalia mucho más curvo y ensanchado apicalmente. También describimos los machos de O. daemoniaca y O. medioru f a, y el macho y la reina de O. mellicolor. El estatus taxonómico de O. medioru f a es revisado; según como la entendemos en este trabajo, esta especie se encuentra únicamente desde México hasta El Salvador. Un solo árbol fue obtenido para las especies de Oxytrigona, a partir del análisis cladístico de 18 caracteres morfológicos y cinco de coloración del cuerpo, el cual no apoya la monofilia de los grupos m u l f o rdi y tataira. Las variaciones encontradas en la forma del grádulo y del m a rgen distal del sexto esterno de la obrera, fueron útiles en el análisis taxonómico. Estos caracteres no han sido usados en la sistemática de Meliponini, y esperamos llamar la atención y promover su uso en futuros análisis filogenéticos. También presentamos una clave para la identificación de las especies

SIDM on FIRE: Hydrodynamical Self-Interacting Dark Matter simulations of low-mass dwarf galaxies

We compare a suite of four simulated dwarf galaxies formed in 10$^{10} M_{\odot}$ haloes of collisionless Cold Dark Matter (CDM) with galaxies simulated in the same haloes with an identical galaxy formation model but a non-zero cross-section for dark matter self-interactions. These cosmological zoom-in simulations are part of the Feedback In Realistic Environments (FIRE) project and utilize the FIRE-2 model for hydrodynamics and galaxy formation physics. We find the stellar masses of the galaxies formed in Self-Interacting Dark Matter (SIDM) with $\sigma/m= 1\, cm^2/g$ are very similar to those in CDM (spanning $M_{\star} \approx 10^{5.7 - 7.0} M_{\odot}$) and all runs lie on a similar stellar mass -- size relation. The logarithmic dark matter density slope ($\alpha=d\log \rho / d\log r$) in the central $250-500$ pc remains steeper than $\alpha= -0.8$ for the CDM-Hydro simulations with stellar mass $M_{\star} \sim 10^{6.6} M_{\odot}$ and core-like in the most massive galaxy. In contrast, every SIDM hydrodynamic simulation yields a flatter profile, with $\alpha >-0.4$. Moreover, the central density profiles predicted in SIDM runs without baryons are similar to the SIDM runs that include FIRE-2 baryonic physics. Thus, SIDM appears to be much more robust to the inclusion of (potentially uncertain) baryonic physics than CDM on this mass scale, suggesting SIDM will be easier to falsify than CDM using low-mass galaxies. Our FIRE simulations predict that galaxies less massive than $M_{\star} < 3 \times 10^6 M_{\odot}$ provide potentially ideal targets for discriminating models, with SIDM producing substantial cores in such tiny galaxies and CDM producing cusps.Comment: 10 Pages, 7 figures, submitted to MNRA