The tailless Ortholog nhr-67 Regulates Patterning of Gene Expression and Morphogenesis in the C. elegans Vulva

Regulation of spatio-temporal gene expression in diverse cell and tissue types is a critical aspect of development. Progression through Caenorhabditis elegans vulval development leads to the generation of seven distinct vulval cell types (vulA, vulB1, vulB2, vulC, vulD, vulE, and vulF), each with its own unique gene expression profile. The mechanisms that establish the precise spatial patterning of these mature cell types are largely unknown. Dissection of the gene regulatory networks involved in vulval patterning and differentiation would help us understand how cells generate a spatially defined pattern of cell fates during organogenesis. We disrupted the activity of 508 transcription factors via RNAi and assayed the expression of ceh-2, a marker for vulB fate during the L4 stage. From this screen, we identified the tailless ortholog nhr-67 as a novel regulator of gene expression in multiple vulval cell types. We find that one way in which nhr-67 maintains cell identity is by restricting inappropriate cell fusion events in specific vulval cells, namely vulE and vulF. nhr-67 exhibits a dynamic expression pattern in the vulval cells and interacts with three other transcriptional regulators cog-1 (Nkx6.1/6.2), lin-11 (LIM), and egl-38 (Pax2/5/8) to generate the composite expression patterns of their downstream targets. We provide evidence that egl-38 regulates gene expression in vulB1, vulC, vulD, vulE, as well as vulF cells. We demonstrate that the pairwise interactions between these regulatory genes are complex and vary among the seven cell types. We also discovered a striking regulatory circuit that affects a subset of the vulval lineages: cog-1 and nhr-67 inhibit both one another and themselves. We postulate that the differential levels and combinatorial patterns of lin-11, cog-1, and nhr-67 expression are a part of a regulatory code for the mature vulval cell types

Classification of Southern Ocean krill and icefish echoes using random forests

Acknowledgements The authors thank the crews, fishers, and scientists who conducted the various surveys from which data were obtained. This work was supported by the Government of South Georgia and South Sandwich Islands. Additional logistical support provided by The South Atlantic Environmental Research Institute, with thanks to Paul Brickle. PF receives funding from the MASTS pooling initiative (TheMarine Alliance for Science and Technology for Scotland), and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. SF is funded by the Natural Environment Research Council, and data were provided from the British Antarctic Survey Ecosystems Long-term Monitoring and Surveys programme as part of the BAS Polar Science for Planet Earth Programme. The authors also thank the anonymous referees for their helpful suggestions on an earlier version of this manuscript.Peer reviewedPostprin

Global Atlas of Marine Fisheries: A Critical Appraisal of Catches and Ecosystem Impacts. Edited by D. Pauly & D. Zeller. 497 pp. Published by Island Press, Washington, DC, U.S.A., 2016. Price $80.00. ISBN: 9781610917698

Peer reviewedPostprin

Assessing consistency of fish survey data : uncertainties in the estimation of mackerel icefish (Champsocephalus gunnari) abundance at South Georgia

Acknowledgments The authors wish to thank the crews, fishermen and scientists who conducted the various surveys from which data were obtained, and Mark Belchier and Simeon Hill for their contributions. This work was supported by the Government of South Georgia and South Sandwich Islands. Additional logistical support provided by The South Atlantic Environmental Research Institute with thanks to Paul Brickle. Thanks to Stephen Smith of Fisheries and Oceans Canada (DFO) for help in constructing bootstrap confidence limits. Paul Fernandes receives funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland), and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. We also wish to thank two anonymous referees for their helpful suggestions on earlier versions of this manuscript.Peer reviewedPostprin

Chert procurement in Corsica during the Neolithic: Inferring social territories in the Tyrrhenian islands

From the Neolithic, foreign siliceous materials were imported into Corsica as the island lacks local chert and obsidian. Such a context constitutes a real opportunity to investigate the relationship of the island with surrounding areas, in perspective with cultural evolutions. For 20 years, chert sourcing studies were carried out. We took into account 26 sites, dating from the Ancient Neolithic to the Final Neolithic. The work is based on non-destructive petro-archaeological observations of the artefacts. and on the survey and characterization of Sardinian sources (320 samples collected and 60 different lithotypes characterized). The study aims to better understand the place of chert among the lithic assemblages throughout time and identify the provenance of most of the chert material introduced into Corsica. It reveals procurement evolution in terms of preferred facies and of stages of introduction, depending on the chronology and geographical situation of the sites. The results confirm connections with Sardinia, among which Perfugas basin constitutes a major source of raw material for Corsica. It also shows relations with the Italian Peninsula for some Middle Neolithic sites in Northern Corsica. Comparisons with data from Sardinia show the affinities and differences between the two islands and open further avenues for research

Fishers' knowledge detects ecological decay in the Mediterranean Sea

Acknowledgements We thank all the fishermen that have participated in the interviews, who have given their time and shared their knowledge. We particularly acknowledge Nevio Torresi and Tomas Parenti for acting as cultural brokers. Finally, we thank Attilio Rinaldi and Giuseppe Prioli whose interest for our research and knowledge of the local fisheries has been particularly welcomed.Peer reviewedPublisher PD

Ultrafast observation of critical nematic fluctuations and giant magnetoelastic coupling in iron pnictides

Many of the iron pnictides have strongly anisotropic normal-state characteristics, important for the exotic magnetic and superconducting behavior these materials exhibit. Yet, the origin of the observed anisotropy is unclear. Electronically driven nematicity has been suggested, but distinguishing this as an independent degree of freedom from magnetic and structural orders is difficult, as these couple together to break the same tetragonal symmetry. Here we use time-resolved polarimetry to reveal critical nematic fluctuations in unstrained Ba(Fe_(1-x)Co_x)_2As_2. The femtosecond anisotropic response, which arises from the two-fold in-plane anisotropy of the complex refractive index, displays a characteristic two-step recovery absent in the isotropic response. The fast recovery appears only in the magnetically ordered state, whereas the slow one persists in the paramagnetic phase with a critical divergence approaching the structural transition temperature. The dynamics also reveal a gigantic magnetoelastic coupling that far exceeds electron-spin and electron-phonon couplings, opposite to conventional magnetic metals.Comment: The final, published version in Nature Communications Nat. Commun. 5:3229 doi: 10.1038/ncomms4229 (2014

Comment on "Fisheries Management"

The recent article by O’Leary et al. (2011) raises an important question about the relationship between science and those who manage fisheries. They contend that fishery managers do not give due cognisance to scientific advice and consistently set Total Allowable Catches (TACs) above values advised by scientists (which they define as ‘‘political adjustment’’). The authors claim that the consequence of this is that there is a high probability of stock collapse in the next 40 years. They use a simulation model to argue that this probability may exceed 80% at the mean level of political adjustment adopted by managers, depending on the degree of environmental variability and life history strategy of the fish

Spatially optimized wireless multicast networks with guaranteed bit-rate

Multicasting is a mode of transmission in which the same information is relayed to a subset of users. Delivering the same information to multiple users of the subset via a series of one-to-one (unicast) transmissions quickly exhausts bandwidth. Delivering information in a series of one-to-all (broadcast) transmissions such that each subset receives its information in a round-robin manner causes latency, or equivalently, a reduction in bandwidth. The techniques of this disclosure estimate the angular locations of each multicast subset using channel state information received across an antenna array. The locations are clustered using machine learning models. The available transmit power is allocated amongst clusters via spatially directed beams. The power allocation is designed to optimize the aggregate multicast bit rate while guaranteeing a minimum per-user bit-rate. Relevant information is beamed in a focused manner to each multicast subset, thus increasing the throughput to a subset while reducing interference to other subsets