Transcriptome profiling of ontogeny in the acridid grasshopper Chorthippus biguttulus

Acridid grasshoppers (Orthoptera:Acrididae) are widely used model organisms for developmental, evolutionary, and neurobiological research. Although there has been recent influx of orthopteran transcriptomic resources, many use pooled ontogenetic stages obscuring information about changes in gene expression during development. Here we developed a de novo transcriptome spanning 7 stages in the life cycle of the acridid grasshopper Chorthippus biguttulus. Samples from different stages encompassing embryonic development through adults were used for transcriptomic profiling, revealing patterns of differential gene expression that highlight processes in the different life stages. These patterns were validated with semi-quantitative RT-PCR. Embryonic development showed a strongly differentiated expression pattern compared to all of the other stages and genes upregulated in this stage were involved in signaling, cellular differentiation, and organ development. Our study is one of the first to examine gene expression during post-embryonic development in a hemimetabolous insect and we found that only the fourth and fifth instars had clusters of genes upregulated during these stages. These genes are involved in various processes ranging from synthesis of biogenic amines to chitin binding. These observations indicate that post-embryonic ontogeny is not a continuous process and that some instars are differentiated. Finally, genes upregulated in the imago were generally involved in aging and immunity. Our study highlights the importance of looking at ontogeny as a whole and indicates promising directions for future research in orthopteran development

I. Encuentro de la Red de Asentamientos Populares : aportes teórico-metodológicos para la reflexión sobre políticas públicas de acceso al hábitat

Contenidos Introducción / M. Cecilia Marengo, Ana Laura Elorza, Virginia Monayar ; Eje 1. Acceso al hábitat y urbanizaciones informales; Asentamientos (in)formales en pequeñas metrópolis del Cono Sur. Estado de situación y debate actual / Ricardo Apaolaza, Elizabeth Zenteno Torres, Marco Sumiza; Un análisis comparativo sobre la expansión de asentamientos populares en las ciudades patagónicas / Santiago Bachiller, Mariana Giaretto, Pablo Marigo, Natalia Usach ; Acceso al Hábitat para los ¨sin techo¨: la lucha por la tierra en la Ciudad de Posadas-Misiones / Myriam Elena Barone, Jonas Dumas, Mariela Dachary, Celia Draganchuk; El mercado informal de suelo y vivienda en resistencia. El caso del asentamiento en "La Rubita" Resistencia, Argentina / María Andrea Benitez, María Victoria Cazorla; Brazos Unidos un realojo en construcción colectiva / Borelli, Lily, Halich, Verónica; Transformaciones en el hábitat de asentamientos informales y políticas públicas sociales. El caso de barrio nuestro hogar III / Renzo Cáceres; Discursividad mediática sobre el acceso y producción del hábitat popular en el barrio Costanera / Debora Leticia Decima; Trayectorias residenciales y usos de la ciudad como clave de lectura de la lucha por el acceso a la ciudad / María Mercedes Di Virgilio, Natalia Cosacov, Denise Brikman, Mercedes Najman; Asentamientos en el borde metropolitano. Avances de investigación, reflexiones y preguntas / Lucas Jordán Dombroski; Repensando el acceso al hábitat en ciudades medias. La problemática habitacional de Tandil / Agustina Girado; Narrativas de un asentamiento de comienzos de siglo: más allá de la épica y la mafia / María Maneiro; Informalidad y periferia urbana. Derivas de la política habitacional / M. Cecilia Marengo, Virginia Monayar, Florencia Sosa; Sobre las ¿nuevas? ocupaciones de tierras. Notas para una periodización de las tomas en San Francisco Solano, 1981-2002 / Santiago Nardin Memorias villeras en disputa sobre las intervenciones estatales de erradicación en Villa 20 (1976-1983) / Julieta Oxman; El Centro para Erradicación de Villas de Emergencia. Planificación, censo y viviendas, Rosario (1964-1983) / Anahí G. Pagnoni; Ensayo de una cartografía de asentamientos informales en la Ciudad de Córdoba / German Gustavo Rebord, Andrea Karina Stiefkens; Urbanización y prácticas estatales en asentamientos populares en Comodoro Rivadavia. El caso del “Barrio las Américas” / Letizia Vázquez; Eje 2: Derecho a la ciudad: conflictos y disputas por el territorio urbano; La ciudad contra el barrio. El caso de los Barrios del Sur en San José de Costa Rica / Pablo Acuña Quiel; Procesos autogestionarios de hábitat popular y políticas urbanas en la ciudad de Ushuaia. Tierra del Fuego. Argentina / Alicia Delia Alcaráz; Conflictos y tensiones en la ocupación del suelo en Posadas. Misiones, Argentina: procesos de diferenciación / Lucia Mariana Andrujovich, Laura Josefa Krujoski,Myriam Elena Barone; Políticas públicas, exclusión y conformación de identidades colectivas / Sandra Raquel Ávalos; La reurbanización del Playón de Chacarita como problema público. Arenas, actores y políticas públicas / Joaquín Benítez; Relocalización, organización y derecho a la ciudad. El caso de Barrio Nuevo (La Plata) / María Sofía Bernat; Resistencias y disputas político-judiciales en casos de desalojos de asentamientos en Buenos Aires / María Cristina Cravino; Análisis de las herramientas territoriales de la organización ArqCom (LP) en el periodo 2012-2018 / Andrea Di Croce Garay, Nahir Meline Cantar, Ángeles Belén Carrizo Romero, Tamara Dileo; Planificación y urbanización del Barrio 31 y 31 bis / Rosana Karina Espejo; Mercado de suelo: tensiones y ambigüedades. El caso de la zona Norte de Resistencia, Chaco, Argentina / Sebastián Galvaliz, María del Rosario Olmedo; Marta Graciela Giró; Experiencias de urbanización y ciudadanización en La Carbonilla. Una propuesta de análisis en escalas / María Belén Garibotti, Luciana Boroccioni, María Florencia Girola ¿Integración? A la trama formal. De complejidades a desafíos / Carolain Izaguirre, Marion Tejera y Carolina Leiva; ¿Urbanizar o aniquilar? Disyuntivas ontológicas en los procesos de urbanización de las sierras de Córdoba / Denise Mattioli; Conflicto y construcción de resistencias en el asentamiento Barrio Flores / Emilia Elisa Molina; Conflictos territoriales y recualificación de la ribera. Los pescadores artesanales y los espacios públicos / Diego Roldán; El Bajo Belgrano: del Barrio de las Latas a la Villa 30 / Valeria Laura Snitcofsky; Líneas de fuga en un barrio de resistencia. Visualización de una lucha / Rafael Ramón Franco Spatuzza; Nuevas legalidades para la reurbanización de villas en CABA. Un desafío para los derechos / Agustín Territoriale, María Julia López; Los Vacíos Urbanos. Dinámicas Urbanas y Respuestas Innovadoras frente al Derecho a la Ciudad / Ezequiel Zeitune, Silvia A Politi, Natalia Czytajlo; Eje 3: Políticas públicas para atender la informalidad y de gestión en el hábitat popular; Tolerancia y precariedad. Advertencias de la política de regularización del Gran Resistencia al RENABAP / Miguel Ángel Barreto, Evelyn Roxana Abildgaard, María Laura Puntel; Adicciones y narcomenudeo, barreras (in) franqueables para los asentamientos informales en Tucumán, Argentina / Paula Boldrini; Políticas de relocalización de villas: ¿qué pasa después? La organización consorcial como práctica comunitaria / María Florencia Bruno, Belén Demoy, Natalia Fainburg, Romina Olejarczyk; La disputa por la participación y la noción de participación en disputa: una reflexión desde el proceso de urbanización de la Villa 31 (2015-2019) / Tomás Capalbo; Economía popular en asentamientos informales del Gran San Miguel de Tucumán / Corina María Cattáneo; La producción de territorialidades en el habitar un asentamiento: procesos de intervención estatal y disociaciones socio espaciales / Magali Chanampa; Estrategias de gestión territorial desde las políticas públicas: replicando el “modelo Medellín” con acento Cordobés / Ana Laura Elorza, Mónica Alvarado Rodríguez, Fani Balcazar, Ernesto Morillo, Mariana Gamboa; Discusiones sobre la conceptualización e identificación de asentamientos informales. Análisis de la realidad en Chubut / María Paula Ferrari, Sergio Andrés Kaminker, Roxana Yanina Velásquez; Barrios autoproducidos en ciudades intermedias. El caso de Río Grande, Tierra del Fuego AIAS / Nadia B. Finck; Luces y sombras del Programa Compra de Vivienda Usada / Elena Inés Gabriel Hernández; Programas de Inclusión Socio-Urbana: ¿Producto de última generación de la Nueva Agenda Urbana? / Fernando Murillo, Gabriel Artese, Andrés Mage; Los dispositivos de espera en las políticas habitacionales / Romina Olejarczyk; Tres debates recurrentes acerca de la vivienda para la población urbana de menores ingresos / Juan Santiago Palero; Nuevos asentamientos precarios: un desafío a la Política Habitacional y Urbana Chilena / Rubén Sepúlveda Ocampo, Felipe Núñez Orrego; Irrumpir con las recetas. Reflexiones en torno a desarrollo, políticas públicas y hábitat popular / Carla Eleonora Pedrazzani, María Inés Sesma.Esta publicación presenta los trabajos del I. Encuentro de la Red de Asentamientos Populares: aportes teórico -metodológicos para la reflexión sobre políticas públicas de acceso al hábitat, desarrollado los días 23 y 24 de mayo de 2019 en la Facultad de Arquitectura, Urbanismo y Diseño de la Universidad Nacional de Córdoba. En las últimas dos décadas, el INVIHAB (Instituto de Investigación de Vivienda y Hábitat) se ha conformado como un espacio de referencia en la investigación, transferencia y formación en temáticas relativas a las políticas de vivienda, territorio, informalidad urbana, ambiente y ciudadanía. Experiencia que ha llevado a la articulación con otros espacios académicos, organizaciones socio-territoriales, gobiernos locales, en el sentido de confluir en la comprensión, reflexión y formulación de propuestas para mitigar las desigualdades socioterritoriales. En este escenario, se viene construyendo una red de investigadores que estudian la informalidad urbana desde diversos enfoques -territoriales, físico-espaciales, sociales, urbanos, laborales, entre otros- tendientes a superar las miradas parciales y locales desde los abordajes teórico metodológicos y propiciar la comprensión del fenómeno desde una perspectiva que abarque la multiplicidad de campos y su complejidad.FIL: Marengo, María Cecilia. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; Argentina.FIL: Elorza, Ana Laura. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; Argentina.FIL: Monayar, Virginia. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; Argentina

Reproductive isolation and chemical communication in grasshoppers

In dieser Arbeit identifizierte und quantifizierte ich zunächst mehrere Isolationsbarrieren zwischen den nah verwandten Feldheuschreckenarten Chorthippus biguttulus und C. mollis (Kapitel 2). Meine Ergebnisse deuten auf eine wichtige Rolle von chemischen Signalen bei der reproduktiven Isolation zwischen diesen Arten hin. Durch die Kombination von verschiedenen Ansätzen untersuchte ich die ultimaten und proximaten Ursachen von chemischen Signalen auf das Fortpflanzungsverhalten. Im dritten Kapitel zeigte ich, dass die kutikulären Kohlenwasserstoff Profile (CHC) von C. biguttulus und C. mollis art- und geschlechtsspezifisch sind. Mit Hilfe eines RNA-seq Ansatzes untersuchte ich transkriptionelle Unterschiede in Kandidatengenen, die für die Divergenz in den CHC Profilen zwischen den Arten und den Geschlechtern verantwortlich sein könnten. Ein solches Gen zeigte artspezifische Expression und trägt möglicherweise zur reproduktiven Isolation zwischen den Arten bei. Darüber hinaus fand ich Expressionsunterschiede zwischen den Geschlechtern in vier Kandidatengenen. Zwei von diesen Genen zeigten eine erhöhte Expression in Männchen, was eventuell in Verbindung mit dem höheren Anteil von dimethyl-verzweigten Kohlenwasserstoffen in Männchen steht. Ich fand keine Hinweise für positive Selektion in den Kandidatengenen, was vermuten lässt, dass die Unterschiede in CHC Profilen durch transkriptionelle Unterschiede entstehen. In Kapitel 4 erforschte ich mit Hilfe eines Bioassays, wie sich verschiedene CHC Signale auf das Balzverhalten von Männchen auswirkten. Zusammenfassend zeigt diese Arbeit, dass der Genfluss zwischen C. biguttulus und C. mollis durch verschiedene Barrieren unterbrochen ist und dass diese Feldheuschrecken multimodale Kanäle im Paarungsverhalten verwenden. Zusätzlich lassen meine Ergebnisse eine zentrale Rolle von kutikulären Kohlenwasserstoffen in der reproduktiven Isolation beider Arten und in der Artbildung vermuten.In this thesis, I first conducted several experiments to identify and quantify reproductive isolation at multiple stages in the life history of the closely related species Chorthippus biguttulus and C. mollis (chapter 2). My results indicated a crucial role of chemical cues in the maintenance of species isolation. I combined multiple approaches to examine the ultimate and proximate causes of chemical cues on reproductive behavior in these species. In chapter 3, I demonstrated that the cuticular hydrocarbon (CHC) profiles of C. biguttulus and C. mollis provide species- and sex-specific cues. I used a RNA-seq approach to examine transcriptional differences of candidate genes, which might cause the divergence in CHC profiles between species and sex. One candidate gene showed species-specific transcriptional differences and may contribute to reproductive isolation. In addition, four candidate genes were differentially expressed between the sexes. Two of them exhibited a strong male-biased expression, which may be linked to higher proportions of dimethyl-branched CHCs in males. I found no evidence for positive selection acting on these genes, suggesting that differences in CHC profiles are presumably mediated at transcriptional level. In chapter 4, I developed a bioassay to determine if female CHCs act as chemical cues that induce courtship behavior in males. In summary, this thesis demonstrated that various reproductive isolating mechanisms reduce the gene flow between C. biguttulus and C. mollis and that in these species the courtship display consists of multimodal signals. In addition, my results suggest a key role of chemical cues in reproductive isolation and speciation

Investigation and optimisation of mobile Nal(Tl) and He-3-based neutron detectors for finding point sources

Neutron radiation produces high-energy gamma radiation through (n,gamma) reactions in matter. This can be used to detect neutron sources indirectly using gamma spectrometers. The sensitivity of a gamma spectrometer to neutrons can be amplified by surrounding it with polyvinyl chloride (PVC). The hydrogen in the PVC acts as a moderator and the chlorine emits prompt gammas when a neutron is captured. A 4.7-l He-3-based mobile neutron detector was compared to a 4-1 NOM-detector covered with PVC using this principle. Methods were also developed to optimise the measurement parameters of the systems. The detector systems were compared with regard to their ability to find (AmBe)-Am-241, (CI)-C-252 and Pu-238-C-13 neutron sources. Results from stationary measurements were used to calculate optimal integration times as well as minimum detectable neutron emission rates. It was found that the 3He-based detector was more sensitive to Cf-252 sources whereas the Nal(TI) detector was more sensitive to (AmBe)-Am-241 and Pu-238-C-13 sources. The results also indicated that the sensitivity of the detectors to sources at known distances could theoretically be improved by 60% by changing from fixed integration times to list mode in mobile surveys. (C) 2015 Elsevier B.V. All rights reserved

A deviation display method for visualising data in mobile gamma-ray spectrometry.

A real time visualisation method, to be used in mobile gamma-spectrometric search operations using standard detector systems is presented. The new method, called deviation display, uses a modified waterfall display to present relative changes in spectral data over energy and time. Using unshielded (137)Cs and (241)Am point sources and different natural background environments, the behaviour of the deviation displays is demonstrated and analysed for two standard detector types (NaI(Tl) and HPGe). The deviation display enhances positive significant changes while suppressing the natural background fluctuations. After an initialisation time of about 10min this technique leads to a homogeneous display dominated by the background colour, where even small changes in spectral data are easy to discover. As this paper shows, the deviation display method works well for all tested gamma energies and natural background radiation levels and with both tested detector systems

Data from: Exploring the hidden landscape of female preferences for complex signals

A major challenge in evolutionary biology is explaining the origins of complex phenotypic diversity. In animal communication, complex signals may evolve from simpler signals because novel signal elements exploit preexisting biases in receivers’ sensory systems. Investigating the shape of female preference functions for novel signal characteristics is a powerful, but underutilized, method to describe the adaptive landscape potentially guiding complex signal evolution. We measured female preference functions for characteristics of acoustic appendages added to male calling songs in the grasshopper Chorthippus biguttulus, which naturally produces only simple songs. We discovered both hidden preferences for and biases against novel complex songs, and identified rules governing song attractiveness based on multiple characteristics of both the base song and appendage. The appendage's temporal position and duration were especially important: long appendages preceding the song often made songs less attractive, while following appendages were neutral or weakly attractive. Appendages had stronger effects on songs of shorter duration, but did not restore the attractiveness of very unattractive songs. We conclude that sensory biases favor, within predictable limits, the evolution of complex songs in grasshoppers. The function-valued approach is an important tool in determining the generality of these limits in other taxa and signaling modalities

Bayesian algorithm to estimate position and activity of an orphan gamma source utilizing multiple detectors in a mobile gamma spectrometry system.

To avoid harm to the public and the environment, lost ionizing radiation sources must be found and brought back under the regulatory control as soon as possible. Usually, mobile gamma spectrometry systems are used in such search missions. It is possible to estimate the position and activity of point gamma sources by performing Bayesian inference on the measurement data. The aim of this study was to theoretically investigate the improvements in the Bayesian estimations of the position and activity of a point gamma source due to introduction of data from multiple detectors with angular variations of efficiency. Three detector combinations were tested-a single 123% HPGe detector, single 4l NaI (Tl) detector and a 123% HPGe with 2x4l NaI (Tl) detector combination-with and without angular efficiency variations for each combination resulting in six different variants of the Bayesian algorithm. It was found that introduction of angular efficiency variations of the detectors did improve the accuracy of activity estimation slightly, while introduction of data from additional detectors lowered the signal-to-noise ratio threshold of the system significantly, increasing the stability and accuracy of the estimated source position and activity, for a given signal-to-noise ratio

Accuracy of a Bayesian technique to estimate position and activity of orphan gamma-ray sources by mobile gamma spectrometry : Influence of imprecisions in positioning systems and computational approximations

The purpose of this study was to investigate the effects of experimental data on performance of a developed Bayesian algorithm tailored for orphan source search, estimating which parameters affect the accuracy of the algorithm. The algorithm can estimate the position and activity of a gamma-ray point source from experimental mobile gamma spectrometry data. Bayesian estimates were made for source position and activity using mobile gamma spectrometry data obtained from one 123% HPGe detector and two 4-l NaI(Tl) detectors, considering angular variations in counting efficiency for each detector. The data were obtained while driving at 50 km/h speed past the sources using 1 s acquisition interval in the detectors. It was found that deviations in the recorded coordinates of the measurements can potentially increase the uncertainty in the position of the source 2 to 3 times and slightly decrease the activity estimations by about 7%. Due to the various sources of uncertainty affecting the experimental data, the maximum predicted relative deviations of the activity and position of the source remained about 30% regardless of the signal-to-noise ratio of the data. It was also found for the used vehicle speed of 50 km/h and 1 s acquisition time, that if the distance to the source is greater than the distance travelled by the detector during the acquisition time, it is possible to use point approximations of the count-rate function in the Bayesian likelihood with minimal deviations from the integrated estimates of the count-rate function. This approximation reduces the computational demands of the algorithm increasing the potential for applying this method in real-time orphan source search missions

A rotating-slit-collimator-based gamma radiation mapper

For situations with radioactive material out of control where it may be physically difficult or prohibited to access areas close to the source, measurements from distance may be the only way to assess the radiation environment. Using collimated detectors will provide means to locate the direction of the radiation from the source. To investigate the possibilities of mapping gamma emitting radioactive material in a closed non-enterable area, a tentative system for mapping radioactive materials from a distance was built. The system used a computer controlled cylindrical rotating slit collimator with a high purity germanium detector placed in the cylinder. The system could be placed on a car-towed trailer, with the centre of the detector about 1.4 m above ground. Mapping was accomplished by the use of a specially developed image reconstruction algorithm that requires measurements from two or more locations around the area to be investigated. The imaging capability of the system was tested by mapping an area, 25 by 25 m2, containing three 330 MBq 137Cs point sources. Using four locations outside the area with about 20 min measuring time in each location and applying the image reconstruction algorithm on the deconvoluted data, the system indicated the three source locations with an uncertainty of 1–3 m. The results demonstrated the potential of using collimated mobile gamma radiometry combined with image reconstruction to localize gamma sources inside non-accessible areas

Divergence of cuticular hydrocarbons in two sympatric grasshopper species and the evolution of fatty acid synthases and elongases across insects

Cuticular hydrocarbons (CHCs) play a major role in the evolution of reproductive isolation between insect species. The CHC profiles of two closely related sympatric grasshopper species, Chorthippus biguttulus and C. mollis, differ mainly in the position of the first methyl group in major methyl- branched CHCs. The position of methyl branches is determined either by a fatty acid synthase (FAS) or by elongases. Both protein families showed an expansion in insects. Interestingly, the FAS family showed several lineage-specific expansions, especially in insect orders with highly diverse methyl-branched CHC profiles. We found five putative FASs and 12 putative elongases in the reference transcriptomes for both species. A dN/dS test showed no evidence for positive selection acting on FASs and elongases in these grasshoppers. However, one candidate FAS showed species-specific transcriptional differences and may contribute to the shift of the methyl-branch position between the species. In addition, transcript levels of four elongases were expressed differentially between the sexes. Our study indicates that complex methyl- branched CHC profiles are linked to an expansion of FASs genes, but that species differences can also mediated at the transcriptional level