Rotating curved spacetime signatures from a giant quantum vortex

\ua9 The Author(s) 2024.Gravity simulators1 are laboratory systems in which small excitations such as sound2 or surface waves3,4 behave as fields propagating on a curved spacetime geometry. The analogy between gravity and fluids requires vanishing viscosity2–4, a feature naturally realized in superfluids such as liquid helium or cold atomic clouds5–8. Such systems have been successful in verifying key predictions of quantum field theory in curved spacetime7–11. In particular, quantum simulations of rotating curved spacetimes indicative of astrophysical black holes require the realization of an extensive vortex flow12 in superfluid systems. Here we demonstrate that, despite the inherent instability of multiply quantized vortices13,14, a stationary giant quantum vortex can be stabilized in superfluid 4He. Its compact core carries thousands of circulation quanta, prevailing over current limitations in other physical systems such as magnons5, atomic clouds6,7 and polaritons15,16. We introduce a minimally invasive way to characterize the vortex flow17,18 by exploiting the interaction of micrometre-scale waves on the superfluid interface with the background velocity field. Intricate wave–vortex interactions, including the detection of bound states and distinctive analogue black hole ringdown signatures, have been observed. These results open new avenues to explore quantum-to-classical vortex transitions and use superfluid helium as a finite-temperature quantum field theory simulator for rotating curved spacetimes19

Biochronostratigraphy (conodonts and palynology) from a selected strata of the Itaituba Formation (Pennsylvanian of the Amazonas Basin) at Itaituba, Pará State, Brazil

This study constitutes a new biostratigraphic approach from an outcrop of the Itaituba Formation, in the Itaituba City, southern Amazonas Basin, Pará State, Brazil, integrating conodont and palynological data. Conodont associations includes Idiognathodus incurvus, Idiognathoides sinuatus, Adetognathus lautus, Hindeodus minutus, Diplognathodus coloradoensis, D. orphanus and D. ellesmeremsis. Among the palynomorphs, Costatascyclus  crenatus, Protohaploxypinus amplus, Spelaeotriletes arenaceus, S. triangulus, Meristocorpus explicatus, Striomonosaccites incrassatus and Meristocorpus sp. B constitute important biostratigraphic species, suggesting a middle Atokan age for the study section, in agreement with conodont biostratigraphy.This study constitutes a new biostratigraphic approach from an outcrop of the Itaituba Formation, in the Itaituba City, southern Amazonas Basin, Pará State, Brazil, integrating conodont and palynological data. Conodont associations includes Idiognathodus incurvus, Idiognathoides sinuatus, Adetognathus lautus, Hindeodus minutus, Diplognathodus coloradoensis, D. orphanus and D. ellesmeremsis. Among the palynomorphs, Costatascyclus crenatus, Protohaploxypinus amplus, Spelaeotriletes arenaceus, S. triangulus, Meristocorpus explicatus, Striomonosaccites incrassatus and Meristocorpus sp. B constitute important biostratigraphic species, suggesting a middle Atokan age for the study section, in agreement with conodont biostratigraphy

Registro de predação de espécies de répteis por Guira guira (Aves: Cuculidae)

Although we have a good understanding of how predation can influence community structure, we still have little information about how predation by visually oriented birds can be a significant source of mortality for reptiles. We observed adults of Guira guira feeding their offspring with four different species of reptiles, namely Amphisbaena vermicularis, Copeoglossum nigropunctatum, Iguana iguana and Tropidurus torquatus. It is the first report of G. guira predation on A. vermicularis and C. nigropunctatum. Although G. guira has been recognized as insectivorous, we believe that predation of small cryptozoic reptiles is a common event during bird breeding season.Keywords: Amphisbaena vermicularis, Copeoglossum nigropunctatum, cryptozoic reptiles, predation strategy, Pantanal.Embora tenhamos um bom entendimento de como a predação pode influenciar a estrutura de uma comunidade, ainda há carência de informações sobre como a predação por aves pode ser uma causa significativa de mortalidade de répteis. Observamos adultos da espécie Guira guira alimentando seus filhotes com quatro espécies de répteis (Amphisbaena vermicularis, Copeoglossum nigropunctatum, Iguana iguana e Tropidurus torquatus). Este é o primeiro registro de G. guira predando A. vermicularis e C. nigropunctatum. Apesar de G. guira ser reconhecido como insetívoro, acreditamos que a predação de pequenos répteis criptozóicos seja um evento frequente durante a época de reprodução da espécie.Palavras-chave: Amphisbaena vermicularis, Copeoglossum nigropunctatum, répteis criptozoicos, estratégia de predação, Pantanal

Manejo integrado dos percevejos barriga-verde, Dichelops spp. em trigo.

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Seletividade de atrazine e [paraquat + diuron] em Crotalaria spp. e controle de soja voluntária.

Resumo: Na sucessão soja-milho+crotalária, há dificuldade no controle da soja voluntária no consórcio. Por isso, objetivou-se neste estudo, identificar doses, épocas e modalidades de aplicação de atrazine e de [paraquat+diuron] em pré-emergência para o controle da soja voluntária seletivos para Crotalaria ochroleuca e Crotalaria spectabilis. Foi conduzido um ensaio para cada cultura com 12 tratamentos {testemunha sem aplicação, combinações de doses (250 g i.a ha-1 e 500 g i.a ha-1) e modalidades/épocas de aplicação de atrazine [pré-emergência (PRÉ), PRÉ e pós-emergência (PÓS) aos 14 dias ou 21 dias após a semeadura (DAS) e sequencial em PÓS aos 14 DAS e 28 DAS), além dos tratamentos de [paraquat+diuron] [500+250 g i.a ha-1] em PRÉ, associado ou não às duas doses de atrazine em PÓS aos 28 DAS]}. Apenas as aplicações sequenciais de atrazine em PÓS e as de 500 g i.a ha-1 de atrazine em PÓS aos 14 DAS e 21 DAS controlaram a soja voluntária. Entre esses tratamentos, C. spectabilis foi altamente suscetível a eles e apenas atrazine (500) PRÉ/atrazine (500) PÓS aos 21 DAS apresentou menor intoxicação de C. ochroleuca. Concluiu-se que apenas a aplicação atrazine (500) PRÉ/atrazine (500) PÓS aos 21 DAS pode ser aplicada em C. ochroleuca para o controle de soja voluntária. | Abstract: In the soybean-corn+crotalaria succession, there is difficulty in controlling volunteer soybeans in the intercropping. Therefore, the aim of this study was to identify doses, times and modalities of application of atrazine and [paraquat+diuron] in pre-emergence for the control of volunteer soybeans selective for Crotalaria ochroleuca and Crotalaria spectabilis. A trial was conducted for each crop with 12 treatments {control without application, dose combinations (250 g ai ha-1 and 500 g ai ha-1) and atrazine application modalities/times [pre-emergence (PRE), PRE and post-emergence (POST) at 14 days or 21 days after sowing (DAS) and sequentially in POST at 14 DAS and 28 DAS), in addition to treatments of [paraquat+diuron] [500+250 g ai ha-1] in PRE, associated or not with two doses of atrazine POST at 28 DAS]}. Only sequential applications of atrazine POST and 500 g ai ha-1 of atrazine POST at 14 DAS and 21 DAS controlled volunteer soybeans. Among these treatments, C. spectabilis was highly susceptible to them and only atrazine (500) PRE/atrazine (500) POST at 21 DAS showed less intoxication of C. ochroleuca. It was concluded that only the application of atrazine (500) PRE/atrazine (500) POST at 21 DAS can be applied for volunteer soybeans control in C. ochroleuca