Accrediting outputs of noisy intermediate-scale quantum computing devices

We present an accreditation protocol for the outputs of noisy intermediate-scale quantum devices. By testing entire circuits rather than individual gates, our accreditation protocol can provide an upper-bound on the variation distance between noisy and noiseless probability distribution of the outputs of the target circuit of interest. Our accreditation protocol requires implementation of quantum circuits no larger than the target circuit, therefore it is practical in the near term and scalable in the long term. Inspired by trap-based protocols for the verification of quantum computations, our accreditation protocol assumes that noise in single-qubit gates is bounded (but potentially gate-dependent) in diamond norm. We allow for arbitrary spatial and temporal correlations in the noise affecting state preparation, measurements and two-qubit gates. We describe how to implement our protocol on real-world devices, and we also present a novel cryptographic protocol (which we call `mesothetic' protocol) inspired by our accreditation protocol.Comment: Accepted versio

A test of the Geographic Mosaic Theory of Coevolution: investigating widespread species of Amazonian Protium (Burseraceae) trees, their chemical defenses, and their associated herbivore faunas

IntroductionPlants and their insect herbivores represent a large fraction of the species in Amazonian forests and are often directly implicated in the origin and maintenance of biodiversity at local and regional scales. How these interactions may change over geographic distance is unknown because very few studies have investigated the herbivore fauna and defense chemicals of any host plant species at multiple sites in tropical forests. One hypothesis, the Geographic Mosaic Theory of Coevolution, predicts that if herbivore assemblages turn over in different parts of a plant’s range, then plant defense chemicals should also change, reflecting local selection pressures.MethodsWe tested this theory by studying 12 species of Protium (Burseraceae) trees that occur in both Iquitos, Peru, and Manaus, Brazil, in rainforests separated by 1500 km. We surveyed all insects observed directly feeding on the plants in both locations for 48 weeks in Manaus and 64 weeks in Iquitos. We analyzed the secondary metabolites in the leaves of all species in both locations using GC/MS and HPLC.Results and DiscussionAlthough in both locations we found that Protium herbivores were dominated by insects from the orders Hemiptera, Coleoptera and Lepidoptera, we found almost complete turnover in the herbivore species composition in the two sites, and each host plant species had a different assemblage of herbivores in each location. Comparing the phylogenetic beta-diversity, we found low similarity in herbivore phylogenetic relatedness between host plant species in the two locations. However, the secondary metabolites found within a Protium species were similar across the two locations. We found no strong evidence that individuals from a host plant species in Iquitos or Manaus expressed locally-adapted defense chemicals, as individuals from geographic locations did not form clusters when looking at patterns of chemical similarity. These results are not consistent with the Geographic Mosaic Theory of Coevolution. The most intriguing pattern we found was a strong correlation between the diversity of herbivores per host plant species in both locations. We also found that plants with high chemical richness had lower numbers of herbivore species and numbers of total herbivores in both locations. We conclude that high chemical diversity is the most effective strategy for Protium trees to reduce insect herbivore attacks. We speculate that each secondary metabolite is effective at repelling only a few insect herbivores, and that different chemicals are likely effective in different parts of a plants’ geographic range. Future studies should investigate additional locations and additional natural enemies (i.e., fungal pathogens) to test the hypothesis that chemical diversity reduces attack from natural enemies and may explain the ecological and evolutionary success of rainforest trees over time and space

Influência do efeito de borda sobre a abundância e composição de formigas infectadas por fungos Ophiocordyceps

Recentemente o papel de parasitas na estrutura e funcionamento de comunidades tem recebido destaque. Esse interesse se justifica pelo fato dos parasitas representarem boa parte da biodiversidade e interagir com organismos em todos os níveis tróficos. No entanto, o conhecimento está em grande parte enviesado para os hospedeiros, e a importância de inúmeros aspectos da biologia e ecologia dos parasitas continuam virtualmente desconhecidos. Por exemplo, alguns parasitas podem manipular o comportamento de seus hospedeiros, aumentando suas chances de transmissão (fenótipo estendido), mas seu efeito na dinâmica e no processo de infecção ainda são desconhecidos. Esse é o caso das formigas zumbis, que na realidade são formigas parasitadas por um fungo entomopatogênico pertencente ao gênero Ophiocordyceps. As formigas infectadas por Ophiocordyceps morrem em locais específicos fora do formigueiro onde, o microambiente é ideal para esporulação e dispersão do fungo. No entanto, além de necessitar da formiga, esses fungos parasitas altamente especializados, provavelmente sofrem influência direta de fatores ambientais, como umidade e temperatura. Neste trabalho, investigarei como as alterações ambientais causadas pela fragmentação ambiental modifica a dinâmica populacional desses parasitas.CNP

Learning everyday entrepreneurial practices through coworking

This article aims to understand learning in coworking. Coworking is an emergent global phenomenon that involves independent workers, often from various occupational backgrounds, working collectively in shared workspaces. I situate coworking in broader debates on entrepreneurialism and socioeconomic change to conceptualise it as a twofold process: of learning everyday coworking practices and learning through coworking practices. While coworking, individuals learn to make sense of their place in the entrepreneurial milieu by developing practices that contest established entrepreneurial norms. Drawing on an ethnographic study, I show how coworkers learn to become collaborative, intentional and to perform contestation through co-created situated learning. That learning enables them to co-construct a sense of community necessary to become entrepreneurially proficient in an increasingly uncertain world of work. By critically understanding why and how learning occurs in coworking, this research contributes to our knowledge of what learning is, and why and where it can occur

Coworking spaces in urban settings: Prospective roles?

Coworking spaces (CWS) are workplaces created to provide infrastructure and interaction opportunities for independent professionals and freelancers. They are a result of a trend toward flexible and project-based assignments, shared use of durable assets and exchange of services. Despite controversy, they are argued to compose the hardscape of innovative urban ecosystems and public policies have stimulated their creation. In São Paulo, since 2016, both city and state administrations conducted initiatives to start public CWS. Despite efforts, results have been mixed, and the problem is related, in part to lack of clarity regarding the roles CWS can play to users and in their cities. To address this issue, five CWS roles are proposed: infrastructure provider, community host, knowledge disseminator, local coupling point and global pipeline connector, and the more roles a CWS plays, the greater its impact on the city