Análise de componentes principais de atributos químicos e físicos do solo limitantes à produtividade de grãos.

O objetivo deste trabalho foi avaliar, por meio da análise dos componentes principais, a redução na dimensionalidade de atributos químicos e físicos do solo para a compreensão da variabilidade espacial e temporal da produtividade de culturas de grãos. A área experimental, de 54 ha, é manejada em agricultura de precisão há oito anos. Com base em seis mapas de colheita (soja - safra 2000/2001; milho - 2001/2002; soja - 2002/2003; trigo - 2003; soja - 2003/2004; e milho - 2004/2005), a área foi dividida em três zonas de produtividade de grãos (alta, média e baixa). Foram definidos 15 pontos georreferenciados representativos, para determinação de atributos químicos e físicos do solo, o que totalizou 63 variáveis analisadas. Entre os atributos químicos, o elevado teor de K no solo é o que melhor explica a variabilidade espacial da produtividade das culturas de grãos, provavelmente em razão do desbalanço das relações Ca:K e Mg:K. A zona de baixa produtividade apresentou baixa qualidade física do solo. Neste caso, a infiltração de água no solo, isoladamente, é a variável que melhor explica o desempenho das culturas de grãos. A análise dos componentes principais dos atributos químicos e físicos do solo é estratégia eficiente para explicar a variabilidade espacial e temporal da produtividade de culturas de grãos

Once-monthly paliperidone palmitate in recently diagnosed and chronic non-acute patients with schizophrenia

OBJECTIVE: To explore the treatment response, tolerability and safety of once-monthly paliperidone palmitate (PP1M) in non-acute patients switched to oral antipsychotics stratified by time since diagnosis as recently diagnosed (3 years). RESEARCH DESIGN AND METHODS: Post-hoc analysis of a prospective, interventional, single-arm, multicentre, open-label, 6-month study performed in 233 recently diagnosed and 360 chronic patients. MAIN OUTCOME MEASURES: The proportion achieving treatment response (defined as >/=20% improvement in Positive and Negative Syndrome Scale [PANSS] total score from baseline to endpoint) and maintained efficacy (defined as non-inferiority in the change in PANSS total score at endpoint [Schuirmann's test]). RESULTS: 71.4% of recently diagnosed and 59.2% of chronic patients showed a >/=20% decrease in PANSS total score (p=0.0028 between groups). Changes in PANSS Marder factors, PANSS subscales, and the proportion of patients with a Personal and Social Performance scale (PSP) total score of 71-100 were significantly greater in recently diagnosed compared with chronic patients. PP1M was well tolerated, presenting no new safety signals. CONCLUSION: These data show that recently diagnosed patients treated with PP1M had a significantly higher treatment response and improved functioning, as assessed by the PSP total score, than chronic patients

Incident adverse drug reactions in geriatric inpatients : a multicentred observational study

Background: Adverse drug reactions (ADRs) are common in older adults and frequently have serious clinical and economic consequences. This study was conducted as a feasibility study for a randomized control trial (RCT) that will investigate the efficacy of a software engine to optimize medications and reduce incident (in-hospital) ADRs. This study's objectives were to (i) establish current incident ADR rates across the six sites participating in the forthcoming RCT and (ii) assess whether incident ADRs are predictable. Methods: This was a multicentre, prospective observational study involving six European hospitals. Adults aged 65 years, hospitalized with an acute illness and on pharmacological treatment for three or more conditions were eligible for inclusion. Adverse events (AEs) were captured using a trigger list of 12 common ADRs. An AE was deemed an ADR when its association with an administered drug was adjudicated as being probable/certain, according to the World Health Organization Uppsala Monitoring Centre causality assessment. The proportion of patients experiencing at least one, probable/certain, incident ADR within 14 days of enrolment/discharge was recorded. Results: A total of 644 patients were recruited, evenly split by sex and overwhelmingly of White ethnicity. Over 80% of admissions were medical. The median number of chronic conditions was five (interquartile range 4-6), with eight or more conditions present in approximately 10%. The mean number of prescribed medications was 9.9 (standard deviation 3.8), which correlated strongly with the number of conditions (r = 0.54, p < 0.0001). A total of 732 AEs were recorded in 382 patients, of which 363 were incident. The majority of events were classified as probably or possibly drug related, with heterogeneity across sites (chi(2) = 88.567, df = 20, p value < 0.001). Out of 644 patients, 139 (21.6%; 95% confidence interval 18.5-25.0%) experienced an ADR. Serum electrolyte abnormalities were the most common ADR. The ADRROP (ADR Risk in Older People) and GerontoNet ADR risk scales correctly predicted ADR occurrence in 61% and 60% of patients, respectively. Conclusion: This feasibility study established the rates of incident ADRs across the six study sites. The ADR predictive power of ADRROP and GerontoNet ADR risk scales were limited in this population

Shapley-Value based Inductive Conformal Prediction

Shapley values of individual instances were recently proposed for the problem of data valuation. They were defined as the average marginal instance contributions to the performance of a given predictor. In this paper we propose to use Shapley values of individual instances as conformity scores. To compute these values efficiently and exactly we employ a standard algorithm based on nearest neighbor classification and propose a variant of this algorithm for clustered data. Both variants are used for computing Shapley conformity scores for inductive conformal predictors. The experiments show that the Shapley-value conformity scores result in smaller prediction sets for significance level epsilon &lt;= 0:1 compared with those produced by standard conformity scores (i.e. similarity between true and predicted output values)

Shapley-Value based Inductive Conformal Prediction

Shapley values of individual instances were recently proposed for the problem of data valuation. They were defined as the average marginal instance contributions to the performance of a given predictor. In this paper we propose to use Shapley values of individual instances as conformity scores. To compute these values efficiently and exactly we employ a standard algorithm based on nearest neighbor classification and propose a variant of this algorithm for clustered data. Both variants are used for computing Shapley conformity scores for inductive conformal predictors. The experiments show that the Shapley-value conformity scores result in smaller prediction sets for significance level epsilon &lt;= 0:1 compared with those produced by standard conformity scores (i.e. similarity between true and predicted output values)

Revealing soil legacy phosphorus to promote sustainable agriculture in Brazil

Exploiting native soil phosphorus (P) and the large reservoirs of residual P accumulated over decades of cultivation, namely "legacy P", has great potential to overcome the high demand of P fertilisers in Brazilian cropping systems. Long-term field experiments have shown that a large proportion (> 70%) of the surplus P added via fertilisers remains in the soil, mainly in forms not readily available to crops. An important issue is if the amount of legacy P mobilized from soil is sufficient for the crop nutritional demand and over how long this stored soil P can be effectively 'mined' by crops in a profitable way. Here we mapped the spatial-temporal distribution of legacy P over the past 50 years, and discussed possible agricultural practices that could increase soil legacy P usage by plants in Brazil. Mineral fertiliser and manure applications have resulted in ~ 33.4 Tg of legacy P accumulated in the agricultural soils from 1967 to 2016, with a current annual surplus rate of 1.6 Tg. Following this same rate, soil legacy P may reach up to 106.5 Tg by 2050. Agricultural management practices to enhance soil legacy P usage by crops includes increasing soil pH by liming, crop rotation, double-cropping, inter-season cover crops, no-tillage system and use of modern fertilisers, in addition to more efficient crop varieties and inoculation with P solubilising microorganisms. The adoption of these practices could increase the use efficiency of P, substantially reducing the new input of fertilisers and thus save up to 31.8 Tg of P fertiliser use (US$ 20.8 billion) in the coming decades. Therefore, exploring soil legacy P is imperative to reduce the demand for mineral fertilisers while promoting long-term P sustainability in Brazil

Map of total phosphorus content in native soils of Brazil

Knowledge of the distribution of total phosphorus (P) content in native soils provides information on the management of ecosystem, land capability for agriculture, environmental quality, and biodiversity conservation. We mapped the spatial distribution of total P concentrations in topsoils (0-30 cm) of uncultivated (native) areas in Brazil. We obtained data on native total P of the southern, south-eastern, and north-eastern regions from reports of exploratory projects developed between 1960s and 1970s by EMBRAPA and by the RADAM Brazil Project. We estimated data from the central-western and northern regions from the relationship between total P and soil properties (Fe, Al, C and clay content), based on the RADAM Brazil Project. Soil total P varied widely (&lt; 25 to &gt; 500 mg kg–1) in all regions in Brazil. Higher concentrations (&gt; 500 mg kg–1) were observed in southern region compared to most of the rest of the country (&lt; 200 mg kg–1), while the Cerrado (Central), Amazon (North) and Caatinga (Northeast) biomes are very poor in total P. This first national native soil total P map provides a valuable baseline for understanding the historical patterns of agriculture expansion in Brazil. It allows quantifying the effect of agriculture expansion and future cropping systems on soil available P content and legacy P, targeting regional soil-crop specific strategies for optimization of ecosystem services, and mitigating potential environmental risk due to P transference to water bodies

Tree component influences soil carbon storage and litter decomposition in agrosilvopastoral system.

Integrated farming systems are recognized as agricultural production models that enhance soil carbon storage. This study aimed to evaluate the influence of the tree component on the litter dynamics and soil C and N stocks in an agrosilvopastoral system in the Brazilian Cerrado. We compared nine-years-old agrosilvopastoral system (ASP) with an arrangement of 3x2+14m, with a 24-years-old nominal pasture (NP) and a native vegetation (NV). Five treatments including three sampling points in ASP [between the eucalyptus trees (P1), in the canopy projection area (P2) and in the middle of the alley (P3)], and two areas (PN and VN) were evaluated. Litterfall production from eucalyptus were evaluated in suspended collectors while the decomposition rate was evaluated in litterbags. The assessments were carried out monthly over one year, as well as CO2 fluxes. Soil samples were taken at six soil layers until 0.5m depth to evaluate bulk density, soil fertility and soil C and N stocks. The litterfall production higher in P1, with decrease during the dry season. P1 and P3 showed higher decomposition rates, with final remaining mass of 28.71 and 32.33%. CO2 efflux was higher in the rainy season and showed similar pattern between P1 e NV. Regarding the soil fertility, NV showed higher values of macronutrients and base saturation, and these results can be associated to the nutrient exportation and the deficit of fertilization management in ASP and NP. Soil C and N stocks at 0-50 cm depth were higher in NV (115.4 and 11.3 Mg ha-1), followed by NP (92.4 and 8 .8 Mg ha-1) and ASP (89.9 and 9.0 Mg ha-1). In the sampled points within ASP, soil C and N stocks were higher in P1, showing the influence of tree component. Our results showed that the arrangement as well as the management of eucalyptus trees in the integrated farming system influenced the dynamics of litter decomposition and soil C and N storage over time

Light dependent redox catalysis by Photosystem I complexes encapsulated in organic nanoparticles

Photosystem I (PSI) is a pigment binding multi-subunit protein complexes involved in photosynthesis. PSI is localized in the thylakoid membranes and catalyze the electron transfer reaction from plastocyanin to ferredoxin, as one of the main steps involved in conversion of light energy into chemical energy. PSI is highly efficiency with a photochemical efficiency close to one. Several attempts have doing in the past in order to exploit the high efficiency and high stability of PSI in an extra-cellular context in order to catalyze electron transfer reactions: in this work we present an innovative solution for exploiting the photochemical properties of PSI, by encapsulation of PSI complexes in organic nanoparticles. Nanoparticles offer a protected environment to the encapsulated molecule, giving it the possibility of preserving its functional properties and studying how they change over time. In this work the complete characterization, both morphological and functional, of nanostructures obtained by encapsulation of PSI complexes purified from higher plants with PLGA (poly lactic-co-glycolic acid) polymer is presented. The results obtained by transient absorption and time-resolved fluorescence demonstrate that encapsulated PSI were characterized by an higher photochemcial activity compared to PSI complexes in detergent solution. Moreover, encapsulated PSI maintained the high efficiency observed for several weeks even if exposed to very strong light, being more stable compared to PSI in detergent solution. Finally, the nanostructures obtained by encapsulated PSI were able to catalyze light dependent redox reactions with electron acceptors and donors outside the nanostructures Potential application of these PLGA encapsulated PSI in different fields are thus presented and discussed