Learning recurrent representations for hierarchical behavior modeling

We propose a framework for detecting action patterns from motion sequences and modeling the sensory-motor relationship of animals, using a generative recurrent neural network. The network has a discriminative part (classifying actions) and a generative part (predicting motion), whose recurrent cells are laterally connected, allowing higher levels of the network to represent high level phenomena. We test our framework on two types of data, fruit fly behavior and online handwriting. Our results show that 1) taking advantage of unlabeled sequences, by predicting future motion, significantly improves action detection performance when training labels are scarce, 2) the network learns to represent high level phenomena such as writer identity and fly gender, without supervision, and 3) simulated motion trajectories, generated by treating motion prediction as input to the network, look realistic and may be used to qualitatively evaluate whether the model has learnt generative control rules

A New Chamber for Studying the Behavior of Drosophila

Methods available for quickly and objectively quantifying the behavioral phenotypes of the fruit fly, Drosophila melanogaster, lag behind in sophistication the tools developed for manipulating their genotypes. We have developed a simple, easy-to-replicate, general-purpose experimental chamber for studying the ground-based behaviors of fruit flies. The major innovative feature of our design is that it restricts flies to a shallow volume of space, forcing all behavioral interactions to take place within a monolayer of individuals. The design lessens the frequency that flies occlude or obscure each other, limits the variability in their appearance, and promotes a greater number of flies to move throughout the center of the chamber, thereby increasing the frequency of their interactions. The new chamber design improves the quality of data collected by digital video and was conceived and designed to complement automated machine vision methodologies for studying behavior. Novel and improved methodologies for better quantifying the complex behavioral phenotypes of Drosophila will facilitate studies related to human disease and fundamental questions of behavioral neuroscience

Student News

Calyptrates are a megadiverse, actively radiating, group of dipterans, which are widely spread and abundant in nearly all terrestrial environments. Despite huge diversity and economic importance, their phylogeny is far from resolved. Recent attempts employing few taxa seem converging in retrieving monophyly for most of the families and subfamilies, but deep relationships among these, especially for those of the oestroid clade (blow flies and relatives), are labile when not changing. The goal of the present project is to shed some light on the deep phylogenetic relationships among Calyptratae by using an anchored hybridization approach with a careful taxon sampling. Furthermore, we aim at resolving the generic phylogeny of two key families of parasitoid flies: Rhinophoridae and Polleniidae. Rhinophorids are interesting because of their peculiar parasitoid habit: they are the only insects having exploited crustaceans (Crustacea, Isopoda, Oniscidea) as hosts. Moreover, adult rhinophorids are difficult to recognize from other oestroids due to the lack of autapomorphies. Differently, however, the preimaginal instars present sound autapomorphies. Notwithstanding the several phylogenetic investigations conducted so far, the phylogenetic position of the rhinophorids is ambiguous and there is an impelling need of improving both taxon sampling and sequence data in order to gain a better resolution. In turn, the phylogenetic position of the polleniids as sister group of the Tachinidae is becoming consensus recently, but the phylogenetic relationships within the family are still unknown. In conclusion we aim to reconstruct a solid phylogeny of these groups in order to build up a stable and predictive classification of the Oestroidea

Leishmania tarentolae: taxonomic classification and its application as a promising biotechnological expression host

In this review, we summarize the current knowledge concerning the eukaryotic protozoan parasite Leishmania tarentolae, with a main focus on its potential for biotechnological applications. We will also discuss the genus, subgenus, and species-level classification of this parasite, its life cycle and geographical distribution, and similarities and differences to human-pathogenic species, as these aspects are relevant for the evaluation of biosafety aspects of L. tarentolae as host for recombinant DNA/protein applications. Studies indicate that strain LEM-125 but not strain TARII/UC of L. tarentolae might also be capable of infecting mammals, at least transiently. This could raise the question of whether the current biosafety level of this strain should be reevaluated. In addition, we will summarize the current state of biotechnological research involving L. tarentolae and explain why this eukaryotic parasite is an advantageous and promising human recombinant protein expression host. This summary includes overall biotechnological applications, insights into its protein expression machinery (especially on glycoprotein and antibody fragment expression), available expression vectors, cell culture conditions, and its potential as an immunotherapy agent for human leishmaniasis treatment. Furthermore, we will highlight useful online tools and, finally, discuss possible future applications such as the humanization of the glycosylation profile of L. tarentolae or the expression of mammalian recombinant proteins in amastigotelike cells of this species or in amastigotes of avirulent human-pathogenic Leishmania species

The Deer Flies of Indiana (Diptera: Tabanidae: \u3ci\u3eChrysops\u3c/i\u3e)

(excerpt) The great majority of specimens, over 12,000 out of 13,185, which form the basis of this study, were collected by the writer during the flight season of the summer of 1963. These are on deposit in the Museum of the Department of Entomology, Purdue University, West Lafayette, Indiana. Other specimens in the collections of the Indiana Department of Natural Resources, Indianapolis, Indiana, of Purdue, and of Earlham College, Richmond, Indiana are incorporated herein. Most specimens in the latter museum were collected, some by the writer, during an earlier general insect survey of the Whitewater River watershed

Host resistance does not explain variation in incidence of male-killing bacteria in Drosophila bifasciata

Background Selfish genetic elements that distort the sex ratio are found widely. Notwithstanding the number of records of sex ratio distorters, their incidence is poorly understood. Two factors can prevent a sex ratio distorter from invading: inability of the sex ratio distorter to function (failure of mechanism or transmission), and lack of drive if they do function (inappropriate ecology for invasion). There has been no test to date on factors causing variation in the incidence of sex ratio distorting cytoplasmic bacteria. We therefore examined whether absence of the male-killing Wolbachia infection in D. bifasciata in Hokkaido island of Japan, in contrast to the presence of infection on the proximal island of Honshu, was associated with failure of the infection to function properly on the Hokkaido genetic background. Results The male-killer both transmitted and functioned well following introgression to each of 24 independent isofemale inbred lines carrying Hokkaido genetic backgrounds. This was maintained even under stringent conditions of temperature. We therefore reject the hypothesis that absence of infection is due to its inability to kill males and transmit on the Hokkaido genetic background. Further trap data indicates that D. bifasciata may occur at different densities in Hokkaido and Honshu populations, giving some credence to the idea that ecological differentiation could be important. Conclusions The absence of the infection from the Hokkaido population is not caused by failure of the male-killer to function on the Hokkaido genetic background

Hawaiian Picture‐Winged Drosophila Exhibit Adaptive Population Divergence along a Narrow Climatic Gradient on Hawaii Island

1. Anthropogenic influences on global processes and climatic conditions are increasingly affecting ecosystems throughout the world. 2. Hawaii Island’s native ecosystems are well studied and local long‐term climatic trends well documented, making these ecosystems ideal for evaluating how native taxa may respond to a warming environment. 3.This study documents adaptive divergence of populations of a Hawaiian picture‐winged Drosophila, D. sproati, that are separated by only 7 km and 365 m in elevation. 4.Representative laboratory populations show divergent behavioral and physiological responses to an experimental low‐intensity increase in ambient temperature during maturation. The significant interaction of source population by temperature treatment for behavioral and physiological measurements indicates differential adaptation to temperature for the two populations. 5.Significant differences in gene expression among males were mostly explained by the source population, with eleven genes in males also showing a significant interaction of source population by temperature treatment. 6.The combined behavior, physiology, and gene expression differences between populations illustrate the potential for local adaptation to occur over a fine spatial scale and exemplify nuanced response to climate change