Directional Tuning of Phase Precession Properties in the Hippocampus

Running direction in the hippocampus is encoded by rate modulations of place field activity but also by spike timing correlations known as theta sequences. Whether directional rate codes and the directionality of place field correlations are related, however, has so far not been explored and therefore the nature of how directional information is encoded in the cornu ammonis remains unresolved. Here, using a previously published dataset that contains the spike activity of rat hippocampal place cells in the CA1, CA2 and CA3 subregions during free foraging of male Long-Evans rats in a 2D environment, we found that rate and spike timing codes are related. Opposite to a place field's preferred firing rate direction spikes are more likely to undergo theta phase precession and, hence, more strongly impact paired correlations. Furthermore, we identified a subset of field pairs whose theta correlations are intrinsic in that they maintain the same firing order when the running direction is reversed. Both effects are associated with differences in theta phase distributions, and are more prominent in CA3 than CA1. We thus hypothesize that intrinsic spiking is most prominent when the directionally modulated sensory-motor drive of hippocampal firing rates is minimal, suggesting that extrinsic and intrinsic sequences contribute to phase precession as two distinct mechanisms.

O TRABALHO DE CAMPO COMO PRODUÇÃO DE CONHECIMENTO:

Os trabalhos de campo são importantes na trajetória dos estudos geográficos. Propiciam à produção de conhecimentos, contribuindo para uma interação particular entre teoria e prática. Além disso, por meio do campo garante-se autenticidade às observações e experiências, possibilitam-se descobertas e o desenvolvimento de novas teorias, inclusive, colocando-as à prova. Entre o(a)s geógrafo(a)s parece haver consenso e até certa obviedade com relação à importância do campo. Contudo, compreende-se que, para atingir a potencialidade na construção de conhecimentos, o campo não pode ser concebido como uma atividade meramente lúdica. Então, impõe-se a necessidade de refletir sobre a práxis e justificar sua necessidade no ensino, na pesquisa e extensão. Nessa perspectiva, busca-se responder: qual é a importância do trabalho de campo para a produção de conhecimentos geográficos no ensino, pesquisa e extensão? O que considerar ao propor um trabalho de campo? Apresentam-se, amparados na literatura sobre o tema, os elementos fundamentais que constituem as experiências de trabalho de campo no âmbito da ciência geográfica. As reflexões produzidas a partir dos princípios orientadores levam a considerar que tais práticas são produtos e produtoras do conhecimento, envolvendo uma atitude investigativa com reflexão e intervenção da/na realidade estudada. Assim, defende-se o trabalho de campo como práxis geográfica. Palavras-chave Metodologia, Geografia, Práticas espaciais. FIELDWORK AS KNOWLEDGE PRODUCTION: methodological contributions to geographical practice Abstract Fieldwork is important in the trajectory of geographic studies that provide a unique form of knowledge production, contributing to a particular interaction between theory and practice. In addition, the field guarantees authenticity to observations and experiences, enables discoveries and the development of new theories, including, putting them to the test. Between the geographer there seems to be consensus and even a certain obviousness regarding the importance of field activity. However, it is understood that in order to achieve potential in the construction of knowledge, the field cannot be conceived as an ludic activity. So, the need to reflect on praxis and justify its need in teaching, research and extension is increasingly imposed. The authors will seek to answer the following questions: what is the importance of fieldwork for the production of geographic knowledge in teaching, research and extension? What to consider when proposing fieldwork? In this article, supported by the literature on the subject, the fundamental elements that constitute the fieldwork experiences in the scope of geographic science are presented. The reflections produced from the guiding principles led us to consider that such practices are products and producers of knowledge, involving an investigative attitude with reflection and intervention of / in the studied reality. Thus, we defend fieldwork as geographic praxis. Keywords Methodology, Geography, Space practices.

Integration management – adaptive life cycle approach in solar plant construction project – experience report

The objective of this experience report was to present the solutions used in the Management Process of the Construction and Assembly project of a Solar Photovoltaic Plant in utilitarian scale, in complex, uncertain and conflicting contexts. As a leading issue, it is intended to demonstrate that new approaches adopted in the project reported here – distinct from the traditional model and practices – allowed the mitigation of the main problems common to construction projects, including divergences between executive project and field activity, delays in delivery and deadlines initially contracted, and consequent additional expenses to the base budget. As a methodology, its theoretical foundation was based on bibliographic survey, addressing aspects such as: project management and life cycle ofthem,integration between the various processes and stakeholders, and Solar Energy on a utilitarian scale, in the scope of construction. This experience report aimed to discuss and demonstrate the approach used in the Guañizuil II A project, located in Argentina, in which agility, flexibility and innovation resulted in the mitigation of delays and additional costs, the achievement of notable records and the development of practical alternatives that can be applied to other construction projects. It is concluded that engineering projects, in their executive phase, need to be aligned with reality in the field, where an adaptive approach can bring positive gains and impacts throughout the life cycle.

Duration of Downy Mildew Control Achieved with Fungicides on Cucumber under Florida Field Conditions

Cucurbit production in Florida is impacted by downy mildew on a yearly basis. Cucurbit downy mildew (CDM), caused by Pseudoperonospora cubensis, is one of the most devastating cucurbit diseases and can lead to complete yield loss. Nearly continuous production of cucurbits occurs temporally throughout Florida, which puts extensive pressure on the pathogen population to select for individuals that are resistant to current fungicides labeled for CDM. Loss of efficacy due to fungicide resistance developing is becoming a major concern for Florida cucurbit growers who rely on these products to manage CDM. This study was established to evaluate the field activity of eleven currently utilized fungicides by determining their duration of activity when applied at various intervals for the management of CDM in cucumber under Florida field conditions. By comparing levels of percent CDM control and area under the disease progress curve (AUDPC) values, the fungicide’s duration of field activity was established. Field activities were less than one week for dimethomorph and fluopicolide; one week for cymoxanil; one to two weeks for chlorothalonil and mancozeb; two weeks for ethaboxam; two to three weeks for propamocarb , cyazofamid, and ametoctradin + dimethomorph; and two to four weeks for oxathiapiprolin and fluazinam. Knowledge of duration of field activity can potentially improve the development of CDM management programs and slow resistance selection.

UM OLHAR SOBRE AS UNIDADES DE PAISAGEM DA REGIÃO CENTRAL E OESTE DO RIO GRANDE DO NORTE: aspectos importantes da prática de campo na Geografia Física

A LOOK AT LANDSCAPE UNITS IN THE CENTRAL AND WEST REGION OF RIO GRANDE DO NORTE: important aspects of field practice in Physical GeographyUNA MIRADA A LAS UNIDADES DE PAISAJE EN LA REGIÓN CENTRAL Y OESTE DE RIO GRANDE DO NORTE: aspectos importantes de la práctica de campo en Geografía FísicaRESUMOO presente trabalho relata as experiências vivenciadas na região Central e Oeste do estado do Rio Grande do Norte. As atividades em campo ocorreram no âmbito da disciplina Geografia do Rio Grande do Norte, coordenada pelo Prof. Dr. Marco Túlio Mendonça Diniz, na Universidade Federal do Rio Grande do Norte, tendo como objetivo analisar os aspectos geomorfológicos e litológicos das paisagens do estado. Diante do que fora abordado, foi possível obter uma maior compreensão acerca dos aspectos históricos, geológicos, econômicos, físicos, geográficos, geomorfológicos e climatológicos em alguns municípios visitados no Rio Grande do Norte. As áreas visitadas se caracterizaram por serem da depressão sertaneja, planaltos e chapadas, no interior seridoense e oeste, e do litoral setentrional, como as planícies e a Chapada de Serra do Mel. Ademais, cabe salientar que todo o percurso ocorreu seguindo pelos dois principais rios do Estado. No mais, foi relatada a experiência e importância da atividade.Palavras-chave: Atividade de Campo; Geocomplexo; Paisagem.ABSTRACTThe present report describes the experiences lived in the Central and West regions of the state of Rio Grande do Norte. The field activities took place within the scope of the discipline Geography of Rio Grande do Norte, coordinated by Prof. Dr. Marco Túlio Mendonça Diniz, at the Federal University of Rio Grande do Norte, aiming to analyze the geomorphological and lithological aspects of the state's landscapes. Given what was discussed, it was possible to obtain a greater understanding of the historical, geological, economic, physical, geographic, geomorphological and climatological aspects in some municipalities visited in Rio Grande do Norte. The areas visited were characterized by being from the hinterland depression, plateaus and plateaus, in the interior of the seridense and west, and from the northern coast, such as the plains and the Chapada de Serra do Mel. It is also worth noting that the entire route took place following the two main rivers of the State. In addition, the experience and importance of the activity are reported.Keywords: Field Activity; Geocomplex; Landscape.RESUMENEl presente informe describe las experiencias vividas en las regiones Centro y Oeste del estado de Rio Grande do Norte. Las actividades de campo se llevaron a cabo en el ámbito de la disciplina Geografía de Rio Grande do Norte, coordinada por el Prof. Dr. Marco Túlio Mendonça Diniz, de la Universidad Federal de Rio Grande do Norte, con el objetivo de analizar los aspectos geomorfológicos y litológicos de los paisajes del estado. Dado lo discutido, fue posible obtener un mayor conocimiento de los aspectos históricos, geológicos, económicos, físicos, geográficos, geomorfológicos y climatológicos en algunos municipios visitados en Rio Grande do Norte. Las áreas visitadas se caracterizaron por ser de la depresión del interior, mesetas y mesetas, en el interior de la seridense y oeste, y de la costa norte, como los llanos y la Chapada de Serra do Mel. Cabe señalar también que todo el recorrido se realizó siguiendo los dos ríos principales del Estado. Además, se reporta la experiencia e importancia de la actividad.Palabras clave: Actividad de Campo; Geocomplejo; Paisaje.

Comparison of Antinociceptive Effect of Octreotide With Morphine in a Rat Model of Acute Inflammatory Pain

Background: Opioids such as morphine are used for treating moderate to severe pain. However, they also produce adverse effects such as nausea, constipation, addiction, and respiratory depression. Thus, other suitable analgesics need to be identified. Somatostatin is an inhibitory neuropeptide that modulates the transmission of pain. However, the half-life of somatostatin is short. In the present study, the antinociceptive effect of octreotide (a stable long-acting analog of somatostatin) was evaluated in rats with acute inflammatory pain. Methods: Sprague Dawley rats ( n = 42) were divided into control ( n = 6) and carrageenan injected groups ( n = 36). The carrageena group was divided into three equal subgroups and treated with saline, morphine (10 mg/kg), and octreotide (3 µg). Rats belonging to each subgroup ( n = 12) were again randomly divided into two equal sets. They were subjected to (a) behavioral evaluation of pain (allodynia) and estimation of paw edema, followed by immunohistochemical analysis of the expression of somatostatin type 2 receptor (sst2r) in the spinal cord and (b) estimation of open-field activity. Allodynia and paw edema were measured by von Frey filaments and plethysmometer, respectively, at 3 and 4 h after carrageenan injection. Expression of sst2r was examined after 24 hours, whereas open-field activity was evaluated after 3 hours. Results: In comparison to the saline-treated group, allodynia was partially attenuated by octreotide, though this was almost completely reversed by morphine. Paw edema was unaffected by octreotide, though it was marginally increased by morphine. This was not related to increased activity of rats, following relief from pain. Immunohistochemistry revealed a significant increase in the expression of sst2r in saline-treated rats, but a decrease in other groups. Conclusion: Octreotide has an antinociceptive effect, which was less than morphine. Increased edema following morphine could result from venodilation. Variations in the sst2r expression suggest its involvement in pain modulation at the spinal level. This information may have clinical relevance.

GABAA Alpha 2,3 Modulation Improves Select Phenotypes in a Mouse Model of Fragile X Syndrome

Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability. FXS is caused by functional loss of the Fragile X Protein (FXP), also known as Fragile X Mental Retardation Protein (FMRP). In humans and animal models, loss of FXP leads to sensory hypersensitivity, increased susceptibility to seizures and cortical hyperactivity. Several components of the GABAergic system, the major inhibitory system in the brain, are dysregulated in FXS, and thus modulation of GABAergic transmission was suggested and tested as a treatment strategy. However, so far, clinical trials using broad spectrum GABAA or GABAB receptor-specific agonists have not yielded broad improvement of FXS phenotypes in humans. Here, we tested a more selective strategy in Fmr1 knockout (KO) mice using the experimental drug BAER-101, which is a selective GABAA α2/α3 agonist. Our results suggest that BAER-101 reduces hyperexcitability of cortical circuits, partially corrects increased frequency-specific baseline cortical EEG power, reduces susceptibility to audiogenic seizures and improves novel object memory. Other Fmr1 KO-specific phenotypes were not improved by the drug, such as increased hippocampal dendritic spine density, open field activity and marble burying. Overall, this work shows that BAER-101 improves select phenotypes in Fmr1 KO mice and encourages further studies into the efficacy of GABAA-receptor subunit-selective agonists for the treatment of FXS.