103 research outputs found
Implications of the Optical Observations of Neutron Stars
We show that observations of pulsars with pulsed optical emission indicate
that the peak flux scales according to the magnetic field strength at the light
cylinder. The derived relationships indicate that the emission mechanism is
common across all of the observed pulsars with periods ranging from 33ms to 385
ms and ages of 1000-300,000 years. It is noted that similar trends exist for
ray pulsars. Furthermore the model proposed by Pacini (1971) and
developed by Pacini and Salvati (1983,1987) still has validity and gives an
adequate explanation of the optical phenomena.Comment: 23 pages, 6 figures, accepted for publication in the Astrophysical
Journa
emb-1 Encodes the APC16 Subunit of the Caenorhabditis elegans Anaphase-Promoting Complex
In the nematode Caenorhabditis elegans, temperature-sensitive mutants of emb-1 arrest as one-cell embryos in metaphase of meiosis I in a manner that is indistinguishable from embryos that have been depleted of known subunits of the anaphase-promoting complex or cyclosome (APC/C). Here we show that the emb-1 phenotype is enhanced in double mutant combinations with known APC/C subunits and suppressed in double mutant combinations with known APC/C suppressors. In addition to its meiotic function, emb-1 is required for mitotic proliferation of the germline. These studies reveal that emb-1 encodes K10D2.4, a homolog of the small, recently discovered APC/C subunit, APC16
The direct drivers of recent global anthropogenic biodiversity loss
Effective policies to halt biodiversity loss require knowing which anthropogenic drivers are the most important direct causes. Whereas previous knowledge has been limited in scope and rigor, here we statistically synthesize empirical comparisons of recent driver impacts found through a wide-ranging review. We show that land/sea use change has been the dominant direct driver of recent biodiversity loss worldwide. Direct exploitation of natural resources ranks second and pollution third; climate change and invasive alien species have been significantly less important than the top two drivers. The oceans, where direct exploitation and climate change dominate, have a different driver hierarchy from land and fresh water. It also varies among types of biodiversity indicators. For example, climate change is a more important driver of community composition change than of changes in species populations. Stopping global biodiversity loss requires policies and actions to tackle all the major drivers and their interactions, not some of them in isolation.Fil: Jaureguiberry, Pedro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂa Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto Multidisciplinario de BiologĂa Vegetal; ArgentinaFil: Titeux, Nicolas. German Centre For Integrative Biodiversity Research (idiv) Halle-Jena-Leipzig; Alemania. Luxembourg Institute Of Science And Technology; Luxemburgo. Helmholtz Zentrum FĂĽr Umweltforschung; AlemaniaFil: Wiemers, Martin. Helmholtz Zentrum FĂĽr Umweltforschung; Alemania. Senckenberg Gesellschaft FĂĽr Naturforschung; AlemaniaFil: Bowler, Diana E.. German Centre For Integrative Biodiversity Research (idiv) Halle-Jena-Leipzig; Alemania. Universitat Jena; Alemania. Helmholtz Zentrum FĂĽr Umweltforschung; AlemaniaFil: Coscieme, Luca. Hot Or Cool Institute; AlemaniaFil: Golden, Abigail S.. University of Washington; Estados Unidos. German Centre For Integrative Biodiversity Research (idiv) Halle-Jena-Leipzig; Alemania. Department Of Marine And Coastal Sciences; Estados UnidosFil: Guerra, Carlos A.. German Centre For Integrative Biodiversity Research (idiv) Halle-Jena-Leipzig; Alemania. Martin Luther University Halle Wittenberg; AlemaniaFil: Jacob, Ute. Universität Oldenburg; Alemania. Alfred-Wegener-Institut Helmholtz-Zentrum FĂĽr Polar- Und Meeresforschung; AlemaniaFil: Takahashi, Yasuo. Institute For Global Environmental Strategies; JapĂłnFil: Settele, Josef. German Centre For Integrative Biodiversity Research (idiv) Halle-Jena-Leipzig; Alemania. University Of The Philippines, Los Baños; Filipinas. Helmholtz Zentrum FĂĽr Umweltforschung; AlemaniaFil: DĂaz, Sandra Myrna. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂa Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto Multidisciplinario de BiologĂa Vegetal; ArgentinaFil: Molnár, Zsolt. Institute Of Ecology And Botany; HungrĂaFil: Purvis, Andy. Imperial College London; Reino Unido. Natural History Museum; Reino Unid
Caenorhabditis elegans PIEZO Channel Coordinates Multiple Reproductive Tissues to Govern Ovulation
PIEZO1 and PIEZO2 are newly identified mechanosensitive ion channels that exhibit a preference for calcium in response to mechanical stimuli. In this study, we discovered the vital roles of pezo-1, the sole PIEZO ortholog in Caenorhabditiselegans, in regulating reproduction. A number of deletion alleles, as well as a putative gain-of-function mutant, of PEZO-1 caused a severe reduction in brood size. In vivo observations showed that oocytes undergo a variety of transit defects as they enter and exit the spermatheca during ovulation. Post-ovulation oocytes were frequently damaged during spermathecal contraction. However, the calcium signaling was not dramatically changed in the pezo-1 mutants during ovulation. Loss of PEZO-1 also led to an inability of self-sperm to navigate back to the spermatheca properly after being pushed out of the spermatheca during ovulation. These findings suggest that PEZO-1 acts in different reproductive tissues to promote proper ovulation and fertilization in C. elegans
Can remote sensing enable a Biomass Climate Adaptation Index for agricultural systems?
IFPRI Project: Digital Innovation Initiative/204025.000.400Systematic tools and approaches for measuring climate change adaptation at multiple scales of spatial resolution are lacking, limiting measurement of progress toward the adaptation goals of the Paris Agreement. In particular, there is a lack of adaptation measurement or tracking systems that are coherent (measuring adaptation itself), comparable (allowing comparisons across geographies and systems), and comprehensive (are supported by the necessary data). In addition, most adaptation measurement efforts lack an appropriate counterfactual baseline to assess the effectiveness of adaptation-related interventions. To address this, we are developing a “Biomass Climate Adaptation Index” (Biomass CAI) for agricultural systems, where climate adaptation progress across multiple scales can be measured by satellite remote sensing. The Biomass CAI can be used at global, national, landscape and farm-level to remotely monitor agri-biomass productivity associated with adaptation interventions, and to facilitate more tailored “precision adaptation”. The Biomass CAI places focus on decision-support for end-users to ensure that the most effective climate change adaptation investments and interventions can be made in agricultural and food systems
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