Relaxation dynamics of an isolated large-spin Fermi gas far from equilibrium

A fundamental question in many-body physics is how closed quantum systems reach equilibrium. We address this question experimentally and theoretically in an ultracold large-spin Fermi gas where we find a complex interplay between internal and motional degrees of freedom. The fermions are initially prepared far from equilibrium with only a few spin states occupied. The subsequent dynamics leading to redistribution among all spin states is observed experimentally and simulated theoretically using a kinetic Boltzmann equation with full spin coherence. The latter is derived microscopically and provides good agreement with experimental data without any free parameters. We identify several collisional processes, which occur on different time scales. By varying density and magnetic field, we control the relaxation dynamics and are able to continuously tune the character of a subset of spin states from an open to a closed system.Comment: 18 pages, 9 figure

Sustainable Recovery of the Taquari River Riparian Forest: Public Ministry in the Defense of Collective Interests

Riparian forest, an Area of Permanent Preservation, has suffered anthropic pressure for decades, which makes its recovery imperative. To preserve it, the Constitution has established the responsibility of the Public Prosecutor's Office to ensure diffuse environmental rights. Therefore, under the 1965 Forest Code, the Program for the Sustainable Development of Riparian Forest of Taquari River (PRSMCRT in the Portuguese acronym) was implemented in 14 marginal municipalities, whose areas are part of the Atlantic Forest Biome supported by methodology which was developed for it observing the regional characteristics and coordinated by the Public Ministry of the Rio Grande do Sul State (MPRS). This paper uses a qualitative approach with bibliographic research and analysis of the documents. It is exploratory in its objectives, descriptive about the methodology referred and purposeful in the end, because shows the results of the documentary analysis carried out by the Civil Inquiry that covered the Program and records the methodology developed by UNIVATES for the recovery the riparian area, which served as a basis for combining the required environmental protection, albeit in a smaller area than the legally foreseen in that time, with the constitutional right to property. Results show the recovery of riparian zones after the MPRS and counties work defending the collective rights. The other hand, researches need to be developed in the riparian zone of Taquari river to verify the efficient of the methodology which was created and applied in the PRSMCRT, especially about ecosystem services. Regardless of that, it is possible to replicate the global idea elsewhere

Licófitas Arborescentes in Situ Como Elementos Importantes na Definição de Modelos Deposicionais (Formação Rio Bonito - Bacia do Paraná - Brasil)

The study of an assemblage of in situ stumps of arborescents lycopods casts in a coaly sedimentary sequence in Permian (Artinskian – Kungurian) of south brazilian Gondwana, allowed to infer a higromesofilous habita for these plants. The absence of stigmarian-like apendages suggest a root system developed in soils subjected to occasional inundation. These data confirm the depositional model proposed for these successions, related to litoraneous basins (Lagon-barrier System)

A Method to Track 3D Knee Kinematics by Multi-Channel 3D-Tracked A-Mode Ultrasound

This paper introduces a method for measuring 3D tibiofemoral kinematics using a multi-channel A-mode ultrasound system under dynamic conditions. The proposed system consists of a multi-channel A-mode ultrasound system integrated with a conventional motion capture system (i.e., optical tracking system). This approach allows for the non-invasive and non-radiative quantification of the tibiofemoral joint’s six degrees of freedom (DOF). We demonstrated the feasibility and accuracy of this method in the cadaveric experiment. The knee joint’s motions were mimicked by manually manipulating the leg through multiple motion cycles from flexion to extension. To measure it, six custom ultrasound holders, equipped with a total of 30 A-mode ultrasound transducers and 18 optical markers, were mounted on various anatomical regions of the lower extremity of the specimen. During experiments, 3D-tracked intra-cortical bone pins were inserted into the femur and tibia to measure the ground truth of tibiofemoral kinematics. The results were compared with the tibiofemoral kinematics derived from the proposed ultrasound system. The results showed an average rotational error of 1.51 ± 1.13° and a translational error of 3.14 ± 1.72 mm for the ultrasound-derived kinematics, compared to the ground truth. In conclusion, this multi-channel A-mode ultrasound system demonstrated a great potential of effectively measuring tibiofemoral kinematics during dynamic motions. Its improved accuracy, nature of non-invasiveness, and lack of radiation exposure make this method a promising alternative to incorporate into gait analysis and prosthetic kinematic measurements later.</p

As bases institucionais das comunidades (picadas) teuto-brasileiras: os commons e o capital social

The historiography of German immigration to Brazil knows just a little about the structures that animated social life in Germany before the process of immigration. Therefore, the americanização of the German-Brazilian settlers is considered solely from the perspective of the host society, creating a gap that needs to be filled in order to understand another dimension of German immigration, the European side and influence over it. In this sense, it is possible to perceive that generally the social origins of German-Brazilian settlers is linked to a village context experience, especially those who came from Western and Southwestern Germany. Historically these villages were social organizations able to control natural and economic resources under their jurisdictions with a great political and economic autonomy. The so called commons were a feature of the German agrarian history, and its institutions of participatory, mutual, protectionist, communal management had the effect to generate social capital, one social attribute that supported the formation of the German-Brazilian communities in Southern Brazil. Thus, the German-Brazilian communities were forged under a solid institutional tradition and under a substrate of social capital, facilitating the emergence of autonomous and cooperative behaviors that resulted on the communitarian structures and on the associativism phenomenon. The method was the analytical descriptive based on research in primary sources in Brazilian and German Archives.A historiografia da imigração alemã ao Brasil pouco conhece sobre as estruturas que animavam a vida social dos teuto-brasileiros no período pré-imigratório. Por conseguinte, a americanização dos teuto-brasileiros é considerada unicamente dentro da perspectiva da sociedade receptora, gerando uma lacuna que precisa ser preenchida no sentido de se compreender a outra dimensão da imigração, a face europeia dessa moeda. Nesse sentido, percebe-se, em grande parte, que a origem social dos teuto-brasileiros está ligada à vivência de um contexto de aldeia, principalmente aqueles que vieram das regiões do Oeste e Sudoeste da Alemanha. Historicamente, essas aldeias eram organizações sociais que controlavam recursos naturais e econômicos com grande poder de autonomia político-econômica. Os denominados commons marcaram a história agrária alemã, e suas instituições de gestão participativa, mutualista, protecionista e comunal tiveram como efeito a geração de capital social, atributo que embasou o processo de germanização do Brasil meridional. Assim, as picadas teuto-brasileiras foram forjadas dentro de uma tradição institucional solidamente estabelecida e sob um substrato de capital social, facilitando o surgimento de comportamentos autônomos e cooperativos, que desembocaram nos aparelhos comunitários e embasaram o fenômeno do associativismo. O método utilizado foi o analítico descritivo, baseado em pesquisa em fontes primárias em arquivos brasileiros e alemães