A dinâmica foliar da cana-de-açúcar não sofre efeito da manutenção da palhada no campo.

Objetivou-se avaliar o efeito da manutenção da palhada na dinâmica foliar da cana-de-açúcar. O experimento foi conduzido na Agroindústria do Vale do São Francisco, Semiárido brasileiro. A cultivar VAT 90-212, no 3º ciclo produtivo, foi submetida a dois sistemas de cultivo, sem e com manutenção da palhada em campo. Medidas biométricas foram feitas em 12 plantas por talhão, onde se registrou: número de folhas completamente expandidas (NFVE), emergentes (NFE) e mortas (NFM), assim como comprimento e largura da folha +3. Cinco plantas por talhão foram coletadas para medição da área individual da folha, das folhas emergentes (AFoEM) e área foliar total (AFoTot). Não houve efeito da manutenção da palhada em campo no NFVE, NFE, NFM, área individual das folhas, AFoEM e AFoTot (p > 0,05). As médias do NFVE, NFE e NFM foram 7,8 unidades, 3,2 unidades e 3,1 unidades por colmo. A largura e comprimento foliar foram 39,9 mm e 165,1 mm, em média, e a área individual da folha de 553,2 cm2, 1.105,2 cm2 de folhas emergentes, que representaram 27% da AFoTot de 4.243,8 cm2. Conclui-se que, o microclima promovido pela manutenção da palhada em campo não alterou a dinâmica do número, dimensões lineares e área foliar da cana-de-açúcar no Semiárido brasileiro

Caracteristicas volumétricas do colmo da cana-de-açúcar conforme a posição dos internódios.

Objetivou-se identificar as características volumétricas dos colmos da cana-de-açúcar irrigada cultivada em sistema de cultivo sem e com a manutenção da palhada. O período experimental foi de 21 de agosto de 2015 a 28 de julho de 2016, em uma área de cana-de-açúcar com dois talhões, um sem a manutenção da palhada e o outro com 100% de cobertura, no município de Juazeiro, BA. Cinco plantas por talhão foram coletas e os colmos separados para a contabilização das seguintes variáveis: número (NI, unidades), comprimento (CI) e largura (LI) dos internódios. A partir destes dados foi calculado o volume individual de cada internódio (VI). O colmo da cana-de-açúcar variou mais em comprimento do que largura nas diferentes posições dos internódios. Várias posições dos internódios revelaram os efeitos da palhada em campo sobre o CI, LI e VI (p < 0,05). Quanto ao VI não houve efeito significativo nos sistemas de plantio. Os maiores valores de VI ocorreram entre a 3ª e a 13ª posição. De modo geral, o volume total do internódio do sistema de cultivo com palha foi 12% menor em relação ao sistema de cultivo sem palha. Conclui-se que, o efeito da manutenção da palhada em campo foi evidenciada nas características volumétricas do colmo de cana-de-açúcar a depender da posição do internódio

Integrated management of agronomic practices in the forage cactus: maximizing productivity, biological efficiency and economic profitability.

Forage cactus cropping systems that include a combination of agricultural practices (cloning, irrigation, mulching, and/or intercropping) can increase forage production and economic return in semi-arid environments. This study evaluated the effect on productivity, biological efficiency, and economic return of combining different practices with forage cactus cropping systems in the semi-arid region of Brazil. The research was conducted in four experimental areas, in a randomized block design with four replications, and included the following practices: 1) clones – irrigation - cover, 2) different irrigation depths, 3) intercropping - mulching, and 4) different levels of mulch. The treatments in experiment I consisted of three cactus clones (‘Orelha de Elefante Mexicana’—OEM; ‘Miúda’—MIU and ‘IPA-Sertânia’—IPA), two water regimes (rainfed and irrigated), and two levels of mulch (with and without mulch). Experiment II comprised four irrigation depths (0, 40, 80, and 120% of the crop evapotranspiration) and three cactus clones. In experiment III, three crop arrangements (single cactus, cactus intercropped with millet, and single millet) were evaluated under two levels of mulching (with and without mulching). In experiment IV, four levels of mulch were used (0, 5, 10, and 15 Mg ha-1). The total number of cladodes per plant, fresh matter yield (YFM), dry matter yield (YDM), and final plant density were obtained when harvesting. Economic viability was assessed using the profitability index (PI). The rainfed systems showed greater yield. The use of mulch afforded greater productivity. The OEM clone (YFM = 310.76 Mg ha-1 and YDM = 29.87 Mg ha-1) obtained a higher yield than did the IPA and MIU clones. The highest PI values were achieved under the rainfed systems. The MIU and IPA clones exhibited lower PI values. The cactus-millet intercrop achieved the best performance with the use of mulch. Cactus systems of 15.0 Mg ha-1 showed a greater PI value. It was concluded that the integrated management of such practices as intercropping, mulching, and the adoption of the OEM clone can increase the supply of forage. These practices can promote the sustainable intensification of forage input in Livestock Production Systems in semi-arid environments

How to enhance the agronomic performance of cactus-sorghum intercropped system: planting configurations, density and orientation.

Clarifying cultivation techniques and making production systems more efficient are practices that have been much sought after in agricultural systems in recent decades. In this context, the forage yield, biological efficiency, and competitive ability, of different cultivation strategies for intercropping forage cactus and sorghum were determined in biosaline production systems from 2018 to 2020 in Brazil. Four experiments were carried out, comprising: 1) cropping configurations for the forage cactus-sorghum intercropping system; 2 and 3) planting densities for the forage cactus intercropped with sorghum with an east-west and north-south row orientation, respectively; and 4) planting densities for the forage cactus and sorghum. Each experiment used a randomised block design with four replications. The intercropped forage cactus and sorghum showed higher productivity than the monocropped systems. The indices of biological efficiency (LER, ATER, LEC and SPI with mean values equal to 1.6, 1.8, 0.6 and 29.0, respectively) and competitive ability (ALGY in average 870.6) show better performance under the intercropped system compared to the single crops. The increased planting density resulted in an increase in productivity under the intercropped forage cactus-sorghum system (on average an increase of 69.4% dry matter). In turn, the orientation had no influence on the productivity of the intercropping system but offered better conditions for the forage cactus when cultivation was in an east-west direction (21.7 Mg ha&#1048576; 1 of dry matter) compared to north-south (17.5 Mg ha&#1048576; 1 of dry matter). Intercropping forage cactus and sorghum using biosaline agriculture is an excellent alternative for a production system in semi-arid environments, especially at higher planting densities (50,000 and 100,000 plants ha&#1048576; 1)

Graph Theoretical Analysis of Functional Brain Networks: Test-Retest Evaluation on Short- and Long-Term Resting-State Functional MRI Data

Graph-based computational network analysis has proven a powerful tool to quantitatively characterize functional architectures of the brain. However, the test-retest (TRT) reliability of graph metrics of functional networks has not been systematically examined. Here, we investigated TRT reliability of topological metrics of functional brain networks derived from resting-state functional magnetic resonance imaging data. Specifically, we evaluated both short-term (<1 hour apart) and long-term (>5 months apart) TRT reliability for 12 global and 6 local nodal network metrics. We found that reliability of global network metrics was overall low, threshold-sensitive and dependent on several factors of scanning time interval (TI, long-term>short-term), network membership (NM, networks excluding negative correlations>networks including negative correlations) and network type (NT, binarized networks>weighted networks). The dependence was modulated by another factor of node definition (ND) strategy. The local nodal reliability exhibited large variability across nodal metrics and a spatially heterogeneous distribution. Nodal degree was the most reliable metric and varied the least across the factors above. Hub regions in association and limbic/paralimbic cortices showed moderate TRT reliability. Importantly, nodal reliability was robust to above-mentioned four factors. Simulation analysis revealed that global network metrics were extremely sensitive (but varying degrees) to noise in functional connectivity and weighted networks generated numerically more reliable results in compared with binarized networks. For nodal network metrics, they showed high resistance to noise in functional connectivity and no NT related differences were found in the resistance. These findings provide important implications on how to choose reliable analytical schemes and network metrics of interest

Interaction between Dysfunctional Connectivity at Rest and Heroin Cues-Induced Brain Responses in Male Abstinent Heroin-Dependent Individuals

BACKGROUND: The majority of previous heroin cue-reactivity functional magnetic resonance imaging (fMRI) studies focused on local function impairments, such as inhibitory control, decision-making and stress regulation. Our previous studies have demonstrated that these brain circuits also presented dysfunctional connectivity during the resting state. Yet few studies considered the relevance of resting state dysfunctional connectivity to task-related neural activity in the same chronic heroin user (CHU). METHODOLOGY/PRINCIPAL FINDINGS: We employed the method of graph theory analysis, which detected the abnormality of brain regions and dysregulation of brain connections at rest between 16 male abstinent chronic heroin users (CHUs) and 16 non-drug users (NDUs). Using a cue-reactivity task, we assessed the relationship between drug-related cue-induced craving activity and the abnormal topological properties of the CHUs' resting networks. Comparing NDUs' brain activity to that of CHUs, the intensity of functional connectivity of the medial frontal gyrus (meFG) in patients' resting state networks was prominently greater and positively correlated with the same region's neural activity in the heroin-related task; decreased functional connectivity intensity of the anterior cingulate cortex (ACC) in CHUs at rest was associated with more drug-related cue-induced craving activities. CONCLUSIONS: These results may indicate that there exist two brain systems interacting simultaneously in the heroin-addicted brain with regards to a cue-reactivity task. The current study may shed further light on the neural architecture that supports craving responses in heroin dependence

A comprehensive curated resource for follicle stimulating hormone signaling

<p>Abstract</p> <p>Background</p> <p>Follicle stimulating hormone (FSH) is an important hormone responsible for growth, maturation and function of the human reproductive system. FSH regulates the synthesis of steroid hormones such as estrogen and progesterone, proliferation and maturation of follicles in the ovary and spermatogenesis in the testes. FSH is a glycoprotein heterodimer that binds and acts through the FSH receptor, a G-protein coupled receptor. Although online pathway repositories provide information about G-protein coupled receptor mediated signal transduction, the signaling events initiated specifically by FSH are not cataloged in any public database in a detailed fashion.</p> <p>Findings</p> <p>We performed comprehensive curation of the published literature to identify the components of FSH signaling pathway and the molecular interactions that occur upon FSH receptor activation. Our effort yielded 64 reactions comprising 35 enzyme-substrate reactions, 11 molecular association events, 11 activation events and 7 protein translocation events that occur in response to FSH receptor activation. We also cataloged 265 genes, which were differentially expressed upon FSH stimulation in normal human reproductive tissues.</p> <p>Conclusions</p> <p>We anticipate that the information provided in this resource will provide better insights into the physiological role of FSH in reproductive biology, its signaling mediators and aid in further research in this area. The curated FSH pathway data is freely available through NetPath (<url>http://www.netpath.org</url>), a pathway resource developed previously by our group.</p

Analyzing and Modeling Real-World Phenomena with Complex Networks: A Survey of Applications

The success of new scientific areas can be assessed by their potential for contributing to new theoretical approaches and in applications to real-world problems. Complex networks have fared extremely well in both of these aspects, with their sound theoretical basis developed over the years and with a variety of applications. In this survey, we analyze the applications of complex networks to real-world problems and data, with emphasis in representation, analysis and modeling, after an introduction to the main concepts and models. A diversity of phenomena are surveyed, which may be classified into no less than 22 areas, providing a clear indication of the impact of the field of complex networks.Comment: 103 pages, 3 figures and 7 tables. A working manuscript, suggestions are welcome

Functional Brain Networks Develop from a “Local to Distributed” Organization

The mature human brain is organized into a collection of specialized functional networks that flexibly interact to support various cognitive functions. Studies of development often attempt to identify the organizing principles that guide the maturation of these functional networks. In this report, we combine resting state functional connectivity MRI (rs-fcMRI), graph analysis, community detection, and spring-embedding visualization techniques to analyze four separate networks defined in earlier studies. As we have previously reported, we find, across development, a trend toward ‘segregation’ (a general decrease in correlation strength) between regions close in anatomical space and ‘integration’ (an increased correlation strength) between selected regions distant in space. The generalization of these earlier trends across multiple networks suggests that this is a general developmental principle for changes in functional connectivity that would extend to large-scale graph theoretic analyses of large-scale brain networks. Communities in children are predominantly arranged by anatomical proximity, while communities in adults predominantly reflect functional relationships, as defined from adult fMRI studies. In sum, over development, the organization of multiple functional networks shifts from a local anatomical emphasis in children to a more “distributed” architecture in young adults. We argue that this “local to distributed” developmental characterization has important implications for understanding the development of neural systems underlying cognition. Further, graph metrics (e.g., clustering coefficients and average path lengths) are similar in child and adult graphs, with both showing “small-world”-like properties, while community detection by modularity optimization reveals stable communities within the graphs that are clearly different between young children and young adults. These observations suggest that early school age children and adults both have relatively efficient systems that may solve similar information processing problems in divergent ways