28 research outputs found
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The effect of cold temperatures on the length of diapause of the spruce budworm (Choristoneura fumiferana (Clem.)
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Biology and feeding habits of pleocoma larvae (Coleptera : Scarabaeidae) in western Oregon coniferous forest
Food habits and biology of five species of Pleocoma larvae were
studied at a dozen forested sites in western Oregon between May 1960
and December 1961.
First instar Pleocoma hatch in late summer and moult to second
instars in early fall. Second and subsequent instars moult annually
between mid-summer and early fall. Larvae appear to go through
more than nine instars pupating after the seventh, in the upper 20
inches of soil, in mid-summer. Male larvae outnumber females by
about 30 percent.
Larvae move through the soil primarily by use of the mandibles.
This movement can exceed a rate of four inches a day.
Larval populations varied from none to 4.4 larvae per square
foot and were distributed between two and 44 inches in depth. Soil
temperatures and soil moisture influenced most larvae at some sites
to leave the upper 16 inches of soil during the summer. At other
sites, however, a shallow silicate clay hardpan influenced larvae to
remain at shallow depths throughout the year. A fungus disease
killed from five to more than 20 percent of the larvae in some areas.
Dipterous predators killed some larvae.
Coniferous roots comprise the major part of the larval diet
throughout most of the year, being found exclusively in 86 percent
of the larvae. Thirty percent of the roots in the guts were definitely
identified as Douglas-fir, the predominant conifer at the sites of
the collections. Larvae preferred smaller roots, mostly smaller
than 2mm, many of them mycorrhizal rootlets. A few larvae merely
girdled the roots, stripping the bark leaving the xylem in the soil.
Most larvae, however, severed and consumed the entire root.
Larvae either severed and ingested intact root segments or gnawed
on root ends masticating them into very fine pieces before ingestion.
Except for last instar larvae, usually at shallower depths, and
first stage larvae, neither of which appeared to feed on roots, all
other larval stages at all depths were feeding on roots throughout
the year, except during the moulting period. The cessation of root
feeding extended over about a four-month moulting period from
June to September, inclusive. The moulting period varied somewhat
between species. Most larvae consumed the exuvia. Some soil,
probably less than five percent by volume, was ingested.
Other material tentatively identified in larval guts was: remains
of fungal hyphae, cast ventricular epithelium, gregarine parasites, and bacteria.
Pleocoma larvae do not appear to be serious forest pests in old-growth and advanced second-growth coniferous forests because of the
generally low and scattered larval populations. In newly-established
forests, however, Pleocoma larvae are a potential pest as one or
two feeding larvae can kill a small tree. Only further studies in regenerated
areas will determine their role in these cut-over and reestablished
forests
Enhanced Astrocytic Ca\u3csup\u3e2+\u3c/sup\u3e Signals Contribute to Neuronal Excitotoxicity after Status Epilepticus
Status epilepticus (SE), an unremitting seizure, is known to cause a variety of traumatic responses including delayed neuronal death and later cognitive decline. Although excitotoxicity has been implicated in this delayed process, the cellular mechanisms are unclear. Because our previous brain slice studies have shown that chemically induced epileptiform activity can lead to elevated astrocytic Ca2+ signaling and because these signals are able to induce the release of the excitotoxic transmitter glutamate from these glia, we asked whether astrocytes are activated during status epilepticus and whether they contribute to delayed neuronal death in vivo. Using two-photon microscopy in vivo, we show that status epilepticus enhances astrocytic Ca2+ signals for 3 d and that the period of elevated glial Ca2+ signaling is correlated with the period of delayed neuronal death. To ask whether astrocytes contribute to delayed neuronal death, we first administered antagonists which inhibit gliotransmission: MPEP [2-methyl-6-(phenylethynyl)pyridine], a metabotropic glutamate receptor 5 antagonist that blocks astrocytic Ca2+ signals in vivo, and ifenprodil, an NMDA receptor antagonist that reduces the actions of glial-derived glutamate. Administration of these antagonists after SE provided significant neuronal protection raising the potential for a glial contribution to neuronal death. To test this glial hypothesis directly, we loaded Ca2+ chelators selectively into astrocytes after status epilepticus.We demonstrate that the selective attenuation of glial Ca2+ signals leads to neuronal protection. These observations support neurotoxic roles for astrocytic gliotransmission in pathological conditions and identify this process as a novel therapeutic target
NT2 Derived Neuronal and Astrocytic Network Signalling
A major focus of stem cell research is the generation of neurons that may then be implanted to treat neurodegenerative diseases. However, a picture is emerging where astrocytes are partners to neurons in sustaining and modulating brain function. We therefore investigated the functional properties of NT2 derived astrocytes and neurons using electrophysiological and calcium imaging approaches. NT2 neurons (NT2Ns) expressed sodium dependent action potentials, as well as responses to depolarisation and the neurotransmitter glutamate. NT2Ns exhibited spontaneous and coordinated calcium elevations in clusters and in extended processes, indicating local and long distance signalling. Tetrodotoxin sensitive network activity could also be evoked by electrical stimulation. Similarly, NT2 astrocytes (NT2As) exhibited morphology and functional properties consistent with this glial cell type. NT2As responded to neuronal activity and to exogenously applied neurotransmitters with calcium elevations, and in contrast to neurons, also exhibited spontaneous rhythmic calcium oscillations. NT2As also generated propagating calcium waves that were gap junction and purinergic signalling dependent. Our results show that NT2 derived astrocytes exhibit appropriate functionality and that NT2N networks interact with NT2A networks in co-culture. These findings underline the utility of such cultures to investigate human brain cell type signalling under controlled conditions. Furthermore, since stem cell derived neuron function and survival is of great importance therapeutically, our findings suggest that the presence of complementary astrocytes may be valuable in supporting stem cell derived neuronal networks. Indeed, this also supports the intriguing possibility of selective therapeutic replacement of astrocytes in diseases where these cells are either lost or lose functionality
Mimicking human neuronal pathways in silico: an emergent model on the effective connectivity
International audienceWe present a novel computational model that detects temporal configurations of a given human neuronal pathway and constructs its artificial replication. This poses a great challenge since direct recordings from individual neurons are impossible in the human central nervous system and therefore the underlying neuronal pathway has to be considered as a black box. For tackling this challenge, we used a branch of complex systems modeling called artificial self-organization in which large sets of software entities interacting locally give rise to bottom-up collective behaviors. The result is an emergent model where each software entity represents an integrate-and-fire neuron. We then applied the model to the reflex responses of single motor units obtained from conscious human subjects. Experimental results show that the model recovers functionality of real human neuronal pathways by comparing it to appropriate surrogate data. What makes the model promising is the fact that, to the best of our knowledge, it is the first realistic model to self-wire an artificial neuronal network by efficiently combining neuroscience with artificial self-organization. Although there is no evidence yet of the model's connectivity mapping onto the human connectivity, we anticipate this model will help neuroscientists to learn much more about human neuronal networks, and could also be used for predicting hypotheses to lead future experiments
Fungal Planet description sheets: 1284-1382
Novel species of fungi described in this study include those from various countries as follows: Antartica, Cladosporium austrolitorale from coastal sea sand. Australia, Austroboletus yourkae on soil, Crepidotus innuopurpureus on dead wood, Curvularia stenotaphri from roots and leaves of Stenotaphrum secundatum and Thecaphora stajsicii from capsules of Oxalis radicosa. Belgium, Paraxerochrysium coryli (incl. Paraxerochrysium gen. nov.) from Corylus avellana. Brazil, Calvatia nordestina on soil, Didymella tabebuiicola from leaf spots on Tabebuia aurea, Fusarium subflagellisporum from hypertrophied floral and vegetative branches of Mangifera indica and Microdochium maculosum from living leaves of Digitaria insularis. Canada, Cuphophyllus bondii fromagrassland. Croatia, Mollisia inferiseptata from a rotten Laurus nobilis trunk. Cyprus, Amanita exilis oncalcareoussoil. Czech Republic, Cytospora hippophaicola from wood of symptomatic Vaccinium corymbosum. Denmark, Lasiosphaeria deviata on pieces of wood and herbaceousdebris. Dominican Republic, Calocybella goethei among grass on a lawn. France (Corsica) , Inocybe corsica onwetground. France (French Guiana) , Trechispora patawaensis on decayed branch of unknown angiosperm tree and Trechispora subregularis on decayed log of unknown angiosperm tree. [...]P.R. Johnston thanks J. Sullivan (Lincoln University)
for the habitat image of Kowai Bush, Duckchul Park (Manaaki Whenua –
Landcare Research) for the DNA sequencing, and the New Zealand Department
of Conservation for permission to collect the specimens; this research
was supported through the Manaaki Whenua – Landcare Research Biota
Portfolio with funding from the Science and Innovation Group of the New
Zealand Ministry of Business, Innovation and Employment. V. Hubka was
supported by the Czech Ministry of Health (grant number NU21-05-00681),
and is grateful for the support from the Japan Society for the Promotion of
Science – grant-in-aid for JSPS research fellow (grant no. 20F20772).
K. Glässnerová was supported by the Charles University Grant Agency (grant
No. GAUK 140520). J. Trovão and colleagues were financed by FEDERFundo
Europeu de Desenvolvimento Regional funds through the COMPETE
2020 – Operational Programme for Competitiveness and Internationalisation
(POCI), and by Portuguese funds through FCT – Fundação para a Ciência
e a Tecnologia in the framework of the project POCI-01-0145-FEDER-PTDC/
EPH-PAT/3345/2014. This work was carried out at the R&D Unit Centre for
Functional Ecology – Science for People and the Planet (CFE), with reference
UIDB/04004/2020, financed by FCT/MCTES through national funds
(PIDDAC). J. Trovão was also supported by POCH – Programa Operacional
Capital Humano (co-funding by the European Social Fund and national
funding by MCTES), through a ‘FCT – Fundação para a Ciência e
Tecnologia’ PhD research grant (SFRH/BD/132523/2017). D. Haelewaters
acknowledges support from the Research Foundation – Flanders (Junior
Postdoctoral Fellowship 1206620N). M. Loizides and colleagues are grateful
to Y. Cherniavsky for contributing collections AB A12-058-1 and AB A12-
058-2, and Á. Kovács and B. Kiss for their help with molecular studies of
these specimens. C. Zmuda is thanked for assisting with the collection of
ladybird specimens infected with Hesperomyces parexochomi. A.V. Kachalkin
and colleagues were supported by the Russian Science Foundation
(grant No. 19-74-10002). The study of A.M. Glushakova was carried out as
part of the Scientific Project of the State Order of the Government of Russian
Federation to Lomonosov Moscow State University No. 121040800174-6.
S. Nanu acknowledges the Kerala State Council for Science, Technology
and Environment (KSCSTE) for granting a research fellowship and is grateful
to the Chief Conservator of Forests and Wildlife for giving permission to
collect fungal samples. A. Bañares and colleagues thank L. Monje and
A. Pueblas of the Department of Drawing and Scientific Photography at the
University of Alcalá for their help in the digital preparation of the photographs,
and J. Rejos, curator of the AH herbarium for his assistance with the specimens
examined in the present study. The research of V. Antonín received
institutional support for long-term conceptual development of research institutions
provided by the Ministry of Culture (Moravian Museum, ref.
MK000094862). The studies of E.F. Malysheva, V.F. Malysheva, O.V. Morozova,
and S.V. Volobuev were carried out within the framework of a research
project of the Komarov Botanical Institute RAS, St Petersburg, Russia
(АААА-А18-118022090078-2) using equipment of its Core Facility Centre
‘Cell and Molecular Technologies in Plant Science’.The study of A.V. Alexandrova
was carried out as part of the Scientific Project of the State Order
of the Government of Russian Federation to Lomonosov Moscow State
University No. 121032300081-7. The Kits van Waveren Foundation (Rijksherbariumfonds
Dr E. Kits van Waveren, Leiden, Netherlands) contributed
substantially to the costs of sequencing and travelling expenses for
M.E. Noordeloos. The work of B. Dima was partly supported by the ÚNKP-
20-4 New National Excellence Program of the Ministry for Innovation and
Technology from the source of the National Research, Development and
Innovation Fund. The work of L. Nagy was supported by the ‘Momentum’
program of the Hungarian Academy of Sciences (contract No. LP2019-
13/2019 to L.G.N.). G.A. Kochkina and colleagues acknowledge N. Demidov
for the background photograph, and N. Suzina for the SEM photomicrograph.
The research of C.M. Visagie and W.J. Nel was supported by the National
Research Foundation grant no 118924 and SFH170610239162. C. Gil-Durán
acknowledges Agencia Nacional de Investigación y Desarrollo, Ministerio
de Ciencia, Tecnología, Conocimiento e Innovación, Gobierno de Chile, for
grant ANID – Fondecyt de Postdoctorado 2021 – N° 3210135. R. Chávez
and G. Levicán thank DICYT-USACH and acknowledges the grants INACH
RG_03-14 and INACH RT_31-16 from the Chilean Antarctic Institute, respectively.
S. Tiwari and A. Baghela would like to acknowledge R. Avchar
and K. Balasubramanian from the Agharkar Research Institute, Pune, Maharashtra
for helping with the termite collection. S. Tiwari is also thankful to
the University Grants Commission, Delhi (India) for a junior research fellowship
(827/(CSIR-UGC NET DEC.2017)). R. Lebeuf and I. Saar thank D. and
H. Spencer for collecting
and photographing the holotype of C. bondii, and
R. Smith for photographing the habitat. A. Voitk is thanked for helping with
the colour plate and review of the manuscript, and the Foray Newfoundland
and Labrador for providing the paratype material. I. Saar was supported by
the Estonian Research Council (grant PRG1170) and the European Regional
Development Fund (Centre of Excellence EcolChange). M.P.S. Câmara
acknowledges the ‘Conselho Nacional de Desenvolvimento Científico
e Tecnológico – CNPq’ for the research productivity fellowship, and financial
support (Universal number 408724/2018-8). W.A.S. Vieira acknowledges
the ‘Coordenação de Aperfeiçoamento Pessoal de Ensino Superior – CAPES’
and the ‘Programa Nacional de Pós-Doutorado/CAPES – PNPD/CAPES’ for
the postdoctoral fellowship. A.G.G. Amaral acknowledges CNPq, and
A.F. Lima and I.G. Duarte acknowledge CAPES for the doctorate fellowships.
F. Esteve-Raventós and colleagues were financially supported by FEDER/
Ministerio de Ciencia, Innovación y Universidades – Agencia Estatal de Investigación
(Spain)/ Project CGL2017-86540-P. The authors would like to
thank L. Hugot and N. Suberbielle (Conservatoire Botanique National de
Corse, Office de l’Environnement de la Corse, Corti) for their help. The research
of E. Larsson is supported by The Swedish Taxonomy Initiative, SLU
Artdatabanken, Uppsala. Financial support was provided to R.J. Ferreira by
the National Council for Scientific and Technological Development (CNPq),
and to I.G. Baseia, P.S.M. Lúcio and M.P. Martín by the National Council for
Scientific and Technological Development (CNPq) under CNPq-Universal
2016 (409960/2016-0) and CNPq-visiting researcher (407474/2013-7).
J. Cabero and colleagues wish to acknowledge A. Rodríguez for his help to
describe Genea zamorana, as well as H. Hernández for sharing information
about the vegetation of the type locality. S. McMullan-Fisher and colleagues
acknowledge K. Syme (assistance with illustrations), J. Kellermann (translations),
M. Barrett (collection, images and sequences), T. Lohmeyer (collection
and images) and N. Karunajeewa (for prompt accessioning). This research
was supported through funding from Australian Biological Resources Study
grant (TTC217-06) to the Royal Botanic Gardens Victoria. The research of
M. Spetik and co-authors was supported by project No. CZ.02.1.01/0.0/0.0
/16_017/0002334. N. Wangsawat and colleagues were partially supported
by NRCT and the Royal Golden Jubilee Ph.D. programme, grant number
PHD/0218/2559. They are thankful to M. Kamsook for the photograph of the
Phu Khiao Wildlife Sanctuary and P. Thamvithayakorn for phylogenetic illustrations.
The study by N.T. Tran and colleagues was funded by Hort Innovation
(Grant TU19000). They also thank the turf growers who supported
their surveys and specimen collection. N. Matočec, I. Kušan, A. Pošta,
Z. Tkalčec and A. Mešić thank the Croatian Science Foundation for their
financial support under the project grant HRZZ-IP-2018-01-1736 (ForFungiDNA).
A. Pošta thanks the Croatian Science Foundation for their support
under the grant HRZZ-2018-09-7081. A. Morte is grateful to Fundación
Séneca – Agencia de Ciencia y Tecnología de la Región de Murcia (20866/
PI/18) for financial support. The research of G. Akhmetova, G.M. Kovács,
B. Dima and D.G. Knapp was supported by the National Research, Development
and Innovation Office, Hungary (NKFIH KH-130401 and K-139026),
the ELTE Thematic Excellence Program 2020 supported by the National
Research, Development and Innovation Office (TKP2020-IKA-05) and the
Stipendium Hungaricum Programme. The support of the János Bolyai Research
Scholarship of the Hungarian Academy of Sciences and the Bolyai+
New National Excellence Program of the Ministry for Innovation and Technology
to D.G. Knapp is highly appreciated. F.E. Guard and colleagues are
grateful to the traditional owners, the Jirrbal and Warungu people, as well
as L. and P. Hales, Reserve Managers, of the Yourka Bush Heritage Reserve.
Their generosity, guidance, and the opportunity to explore the Bush Heritage
Reserve on the Einasleigh Uplands in far north Queensland is greatly appreciated.
The National Science Foundation (USA) provided funds
(DBI#1828479) to the New York Botanical Garden for a scanning electron
microscope used for imaging the spores. V. Papp was supported by the
ÚNKP-21-5 New National Excellence Program of the Ministry for Innovation
and Technology from the National Research, Development and Innovation
Fund of Hungary. A.N. Miller thanks the WM Keck Center at the University
of Illinois Urbana – Champaign for sequencing Lasiosphaeria deviata.
J. Pawłowska acknowledges support form National Science Centre, Poland
(grant Opus 13 no 2017/25/B/NZ8/00473). The research of T.S. Bulgakov
was carried out as part of the State Research Task of the Subtropical Scientific
Centre of the Russian Academy of Sciences (Theme No. 0492-2021-
0007). K. Bensch (Westerdijk Fungal Biodiversity Institute, Utrecht) is thanked
for correcting the spelling of various Latin epithets.Peer reviewe
Modelling human choices: MADeM and decision‑making
Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)
Abundance of arthropods inhabiting duff and soil after prescribed burning on forest clearcuts in northern Idaho /
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