4,382 research outputs found
Varroakvalstrets effekt pÄ virus i angripna honungsbisamhÀllen
Vilken effekt har varroakvalster pÄ de virus som infekterar bisamhÀllen? Forskare vid INRA (Frankrikes nationella institution för jordbruksforskning) i Avignon, Frankrike, University of Otago i Nya Zeeland och Sveriges lantbruksuniversitet (SLU), nyttjade en unik situation i Nya Zeeland dÀr landet, liksom Sverige, har varroaangripna respektive icke angripna regioner. Varroa Àr relativt nyetablerad i Nya Zeeland. Den pÄvisades först pÄ Nordön Är 2000, och har stadigt spridits söderut under de 14 Ären som gÄtt sedan introduktionen. Forskarna har undersökt virusprofilen hos bisamhÀllena sedan etablering av kvalstret i de olika regionerna. Studien, som publicerades 2014, visar en drastisk Àndring av det virala landskapet i bisamhÀllena som sammanfaller med etablering av varroa, vilket ökar risken för synergier mellan olika virus som Àr skadliga för bina
E-ÎČ-Ocimene, a Volatile Brood Pheromone Involved in Social Regulation in the Honey Bee Colony (Apis mellifera)
Background: In honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae) was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-ÎČ-ocimene, which partially inhibits ovary development in workers. [br/]
Methodology and Principal Finding: Our analysis of E-ÎČ-ocimene production revealed that young brood (newly hatched to 3 days old) produce the highest quantity of E-b-ocimene relative to their body weight. By testing the potential action of this molecule as a non-specific larval signal, due to its high volatility in the colony, we demonstrated that in the presence of E-ÎČ-ocimene nest workers start to forage earlier in life, as seen in the presence of real brood. [br/]
Conclusions/Significance: In this way, young larvae are able to assign precedence to the task of foraging by workers in order to increase food stores for their own development. Thus, in the complexity of honey bee chemical communication, E-ÎČ- ocimene, a pheromone of young larvae, provides the brood with the means to express their nutritional needs to the workers
Intrabeam scattering analysis of measurements at KEK's ATF damping ring
We derive a simple relation for estimating the relative emittance growth in x
and y due to intrabeam scattering (IBS) in electron storage rings. We show that
IBS calculations for the ATF damping ring, when using the formalism of
Bjorken-Mtingwa, a modified formalism of Piwinski (where eta squared divided by
beta has been replaced by the dispersion invariant), or a simple high-energy
approximate formula all give results that agree well. Comparing theory,
including the effect of potential well bunch lengthening, with a complete set
of ATF steady-state beam size vs. current measurements we find reasonably good
agreement for energy spread and horizontal emittance. The measured vertical
emittance, however, is larger than theory in both offset (zero current
emittance) and slope (emittance change with current). The slope error indicates
measurement error and/or additional current-dependent physics at the ATF; the
offset error, that the assumed Coulomb log is correct to within a factor of
1.75.Comment: 17 pages, 6 figures, .bbl fil
A SNP assay for assessing diversity in immune genes in the honey bee (Apis mellifera L.)
With a growing number of parasites and pathogens experiencing large-scale range expansions, monitoring diversity in immune genes of host populations has never been so important because it can inform on the adaptive potential to resist the invaders. Population surveys of immune genes are becoming common in many organisms, yet they are missing in the honey bee (Apis mellifera L.), a key managed pollinator species that has been severely affected by biological invasions. To fill the gap, here we identified single nucleotide polymorphisms (SNPs) in a wide range of honey bee immune genes and developed a medium-density assay targeting a subset of these genes. Using a discovery panel of 123 whole-genomes, representing seven A. mellifera subspecies and three evolutionary lineages, 180 immune genes were scanned for SNPs in exons, introns (< 4 bp from exons), 3â and 5ÂŽUTR, and < 1 kb upstream of the transcription start site. After application of multiple filtering criteria and validation, the final medium-density assay combines 91 quality-proved functional SNPs marking 89 innate immune genes and these can be readily typed using the high-sample-throughput iPLEX MassARRAY system. This medium-density-SNP assay was applied to 156 samples from four countries and the admixture analysis clustered the samples according to their lineage and subspecies, suggesting that honey bee ancestry can be delineated from functional variation. In addition to allowing analysis of immunogenetic variation, this newly-developed SNP assay can be used for inferring genetic structure and admixture in the honey bee.We are deeply indebted to Frank Aguiar, LuĂs Silva, Edgardo Melo, JoĂŁo Martins, JoĂŁo Melo, Manuel Moura,
Manuel Viveiros, and Ricardo Sousa from "Direção Regional da Agricultura e Desenvolvimento Rural dos Açores"
(Portugal), and to Laura Garreau, Laurent Maugis, Pascale Sauvage and Jacques Kermagoret, from âAssociation
Conservatoire de lâAbeille Noir Bretonneâ (France), for sampling the apiaries in SĂŁo Miguel, Santa Maria, and
Ouessant islands. Genotyping was outsourced to the Epigenetics and Genotyping laboratory, Central Unit for
Research in Medicine (UCIM), University of Valencia, Spain. Data analyses were performed using computational
resources at the Research Centre in Digitalization and Intelligent Robotics (CeDRI), Instituto Politécnico de
Bragança. Ana Rita Lopes is supported by a PhD scholarship (SFRH/BD/143627/2019) from the Foundation
for Science and Technology (FCT), Portugal. FCT provided financial support by national funds (FCT/MCTES)
to CIMO (UIDB/00690/2020).This research was funded through the projects BEEHAPPY (POCI-01-0145-
FEDER-029871, FCT and COMPETE/QREN/EU) and BEEHEAL. BEEHEAL was funded by the ARIMNet2 2016
Call by the following agencies: INIA (Spain), MOARD (Israel), ANR (France) and FCT (Portugal). ARIMNet2 (ERA-NET) received funding from the European Unionâs Seventh Framework Programme for research, technological
development and demonstration under grant agreement no. 618127.info:eu-repo/semantics/publishedVersio
AMPK is a mechano-metabolic sensor linking cell adhesion and mitochondrial dynamics to Myosin-dependent cell migration
Cell migration is crucial for cancer dissemination. We find that AMP-activated protein kinase (AMPK) controls cell migration by acting as an adhesion sensing molecular hub. In 3-dimensional matrices, fast-migrating amoeboid cancer cells exert low adhesion/low traction linked to low ATP/AMP, leading to AMPK activation. In turn, AMPK plays a dual role controlling mitochondrial dynamics and cytoskeletal remodelling. High AMPK activity in low adhering migratory cells, induces mitochondrial fission, resulting in lower oxidative phosphorylation and lower mitochondrial ATP. Concurrently, AMPK inactivates Myosin Phosphatase, increasing Myosin II-dependent amoeboid migration. Reducing adhesion or mitochondrial fusion or activating AMPK induces efficient rounded-amoeboid migration. AMPK inhibition suppresses metastatic potential of amoeboid cancer cells in vivo, while a mitochondrial/AMPK-driven switch is observed in regions of human tumours where amoeboid cells are disseminating. We unveil how mitochondrial dynamics control cell migration and suggest that AMPK is a mechano-metabolic sensor linking energetics and the cytoskeleton. Cell metabolism must adapt to the energy needs of migrating cells. This study finds that fast amoeboid migrating cells harbor high AMPK activity, which controls both mitochondrial dynamics and cytoskeletal remodeling, enabling reduced energy needs
AMPK is a mechano-metabolic sensor linking cell adhesion and mitochondrial dynamics to Myosin-dependent cell migration
Cell migration is crucial for cancer dissemination. We find that AMP-activated protein kinase (AMPK) controls cell migration by acting as an adhesion sensing molecular hub. In 3-dimensional matrices, fast-migrating amoeboid cancer cells exert low adhesion/low traction linked to low ATP/AMP, leading to AMPK activation. In turn, AMPK plays a dual role controlling mitochondrial dynamics and cytoskeletal remodelling. High AMPK activity in low adhering migratory cells, induces mitochondrial fission, resulting in lower oxidative phosphorylation and lower mitochondrial ATP. Concurrently, AMPK inactivates Myosin Phosphatase, increasing Myosin II-dependent amoeboid migration. Reducing adhesion or mitochondrial fusion or activating AMPK induces efficient rounded-amoeboid migration. AMPK inhibition suppresses metastatic potential of amoeboid cancer cells in vivo, while a mitochondrial/AMPK-driven switch is observed in regions of human tumours where amoeboid cells are disseminating. We unveil how mitochondrial dynamics control cell migration and suggest that AMPK is a mechano-metabolic sensor linking energetics and the cytoskeleton
Projeto BEEHEAL: promover a saĂșde da abelha para uma agricultura sustentĂĄvel
O BEEHEAL, com o tĂtulo original âPromoting bee
health for sustainable agricultureâ, Ă© um projeto internacional
colaborativo aprovado no ùmbito da Ação ERA-Net
ARIMNet2 (Coordination of Agricultural Research in the
Mediterranean). O projeto Ă© coordenado por Raquel MartĂn-
HernĂĄndez, investigadora do âCentro de InvestigaciĂłn ApĂcola
y Agroambiental de Marchamaloâ (CAR), Espanha. Para
além deste centro de investigação, representado por Raquel
MartĂn-HernĂĄndez e Mariano Higes, o consĂłrcio inclui mais
trĂȘs instituiçÔes, nomeadamente: o Centro de Investigação
de Montanha (CIMO) do Instituto Politécnico de Bragança,
representado por M. Alice Pinto e Ana Rita Lopes, o âCentre
de Recherche Provence-Alpes-CĂŽte dâAzur UnitĂ©: Abeilles
et Environnement do âInstitut National de la Recherche
Agronomiqueâ (INRA), França, representado por Yves Le
conte, Anne Dalmon e Maritza Maritza Reyes-Carreno, e o
âVolcani Centerâ da âAgricultural Research Organizationâ
(ARO), Israel, representado por Nor Chevjanovsky e Victoria
Soroker.
As populaçÔes de abelha melĂfera (Apis mellifera L.) tĂȘm
vindo a sofrer perdas acentuadas em todo o mundo. Estas
perdas estĂŁo relacionado com vĂĄrios factores, que podem atuar
sozinhos ou em combinação, incluindo (i) propagação de
parasitas e agentes patogénicos exóticos , como por exemplo
o ĂĄcaro ectoparasita Varroa destructor, o qual serve de vetor de
transmissĂŁo de vĂĄrios vĂrus, e o fungo microsporĂdeo Nosema
ceranae, (ii) exposição das colĂłnias a agro-quĂmicos, (iii) mĂĄ nutrição, (iv) alteraçÔes climĂĄticas, entre outros (vanEngelsdorp
& Meixner, 2010; Potts et al., 2010).Ao Paulo Ventura pelo acompanhamento técnico feito ao
apĂĄrio no primeiro ano do projeto. O BEEHEAL Ă© financiado
por ARIMNet2 (2016) com os financiadores nacionais
Instituto Nacional de InvestigaciĂłn y Teccnologia Agraria y alimentaria (INIA â Espanha), Agence Nationale de la recherche (ARN â France), Ministry off Agriculture & Rural Development, (MOARD â Israel) e Fundação para a CiĂȘncia e a Tecnologia (FCT â Portugal)info:eu-repo/semantics/publishedVersio
Swift follow-up observations of candidate gravitational-wave transient events
We present the first multi-wavelength follow-up observations of two candidate
gravitational-wave (GW) transient events recorded by LIGO and Virgo in their
2009-2010 science run. The events were selected with low latency by the network
of GW detectors and their candidate sky locations were observed by the Swift
observatory. Image transient detection was used to analyze the collected
electromagnetic data, which were found to be consistent with background.
Off-line analysis of the GW data alone has also established that the selected
GW events show no evidence of an astrophysical origin; one of them is
consistent with background and the other one was a test, part of a "blind
injection challenge". With this work we demonstrate the feasibility of rapid
follow-ups of GW transients and establish the sensitivity improvement joint
electromagnetic and GW observations could bring. This is a first step toward an
electromagnetic follow-up program in the regime of routine detections with the
advanced GW instruments expected within this decade. In that regime
multi-wavelength observations will play a significant role in completing the
astrophysical identification of GW sources. We present the methods and results
from this first combined analysis and discuss its implications in terms of
sensitivity for the present and future instruments.Comment: Submitted for publication 2012 May 25, accepted 2012 October 25,
published 2012 November 21, in ApJS, 203, 28 (
http://stacks.iop.org/0067-0049/203/28 ); 14 pages, 3 figures, 6 tables;
LIGO-P1100038; Science summary at
http://www.ligo.org/science/Publication-S6LVSwift/index.php ; Public access
area to figures, tables at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p110003
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