Changes in Predictive Ability with Mixed Frequency Data

This paper proposes a new regression model - a smooth transition mixed data sampling (STMIDAS) approach - that captures recurrent changes in the ability of a high frequency variable in predicting a low frequency variable. The STMIDAS regression is employed for testing changes in the ability of financial variables in forecasting US output growth. The estimation of the optimal weights for aggregating weekly data inside the quarter improves the measurement of the predictive ability of the yield curve slope for output growth. Allowing for changes in the impact of the short-rate and the stock returns in future growth is decisive for finding in-sample and out-of-sample evidence of their predictive ability at horizons longer than one year.Smooth transition, MIDAS, Predictive ability, Asset prices, Output growth

Structural Breaks and Non-Linearities for Predicting the Probability of US Recessions using the Spread

This paper proposes a structural break threshold model (SBT) to the dynamic relationship between US output growth and the spread between long- and short-term interest rates. This model is able to account for non-linearities, parameter changes and the reduction of the variability of output growth. The SBT model gives better in-sample predictions of the probability of US recessions during 1955-1999 than models with only non-linearity or structural breaks. The presence of a structural break affects the timing and the size of predictions of the probability of recession for 2001.

Macroeconomic Forecasting with Mixed Frequency Data: Forecasting US Output Growth

Many macroeconomic series such as US real output growth are sampled quarterly, although potentially useful predictors are often observed at a higher frequency. We look at whether a mixed data-frequency sampling (MIDAS) approach can improve forecasts of output growth. The MIDAS approach is compared to other ways of making use of monthly data to predict quarterly output growth. The MIDAS specification used in the comparison employs a novel way of including an autoregressive term. We find that the use of monthly data on the current quarter leads to significant improvement in forecasting current and next quarter output growth, and that MIDAS is an effective way of exploiting monthly data compared to alternative methods. We also exploit the best method to use the monthly vintages of the indicators for real-time forecasting.Mixed data frequency, Coincident indicators, Real-time forecasting, US output growth

An?lise comparativa dos recursos de assist?ncia estudantil destinados aos discentes do IFPB - campus Itaporanga

No ano de 2016, a regi?o polarizada de Itaporanga foi contemplada com um campus do Instituto Federal de Educa??o, Ci?ncias e Tecnologia da Para?ba (IFPB), como parte do plano de expans?o III da Rede Federal de Educa??o, beneficiando uma regi?o que antes era desassistida de ensino profissional e tecnol?gico. O Campus Itaporanga tem como prop?sito atender aos alunos egressos das escolas estaduais e municipais da cidade e regi?es circunvizinhas cumprindo seu papel de inclus?o social, uma vez que possibilita a capacita??o t?cnica destes jovens. Para isso conta com um Programa de Assist?ncia Estudantil para atender estudantes que vivem em situa??es decorrentes da pobreza, perda ou fragilidade de v?nculos de afetividade, pertencimento e sociabilidade. Nesse trabalho enfocaremos a import?ncia do programa de assist?ncia estudantil no ?mbito do IFPB Campus Itaporanga, para os alunos da regi?o do Vale do Pianc?, no alto sert?o paraibano, assegurando o seu ingresso e a sua perman?ncia na institui??o de ensino. Os resultados mostram que o programa de assist?ncia estudantil cumpre o seu papel no IFPB, ajudando estudantes com importantes vulnerabilidades socioecon?micas a terem condi??es de competir com igualdade frente ?queles que s?o mais favorecidos. No que diz respeito ao comparativo entre os campi, cada um atende conforme suas especificidades

Transmissivity of aquifer by capture zone method : an application in the Sete Lagoas Karst aquifer, MG, Brazil.

Transmissivity is an important hydraulic parameter to determine the amount of water passed horizontally across a given saturated thickness of an aquifer. The techniques to quantify this parameter, such as grain size analyses or pumping tests, can have limitations of time/spatial scale, viability, or economically. One technique that can be used, but little adopted, is the capture zone analysis. In this paper, capture zone analytical equations were used to estimate transmissivity values in order to verify the effectiveness of this methodology as alternative in situations where other traditional methods present implementation difficulties. The results were compared with field data estimated by aquifer tests conducted in the same region. A sensitivity analysis was also performed to identify possible discrepancies between the analytical and field data results. The aquifer studied was the Sete Lagoas Karst Aquifer in the urban region of the municipality of Sete Lagoas, Brazil. The method proved to be a viable and economical tool, where the analytical values compared to the aquifer tests showed similarities, being confirmed by a sensitivity analysis. However, a reliable potentiometric surface map, which enables the identification of the parameters for analytical capture zone equations, is needed

Geometry and water quality of the unconfined aquifer near the Piracicaba river, Ipatinga/MG, Brazil.

Groundwater is the main source of drinking water for the city of Ipatinga/MG, Brazil. However, there is a lack of study about hydrogeology in the region, as well as indications of quality alterations of water resources. The goal is to understand the hydrogeology surrounding the COPASA's Water Treatment Plant and the Piracicaba river areas, where the main water supply wells are located. Maps of potentiometric surface, isobaths and isopachs, hydrogeological cross-section, aquifer pumping tests, and physicochemical analysis interpretations were performed. Results indicate the aquifer is unconfined, with high transmissivity and hydraulic conductivity values, which explain the high values of discharge in the wells. The Piracicaba river can be considered as influent, with its water flow converging to the aquifer. Groundwater shows chemical parameters at low levels, according to Brazilian drinking-water quality guidelines, with local presence of aluminum, iron, and manganese, requiring only conventional treatment processes before distributio

Spatial and temporal evolution of nitrate contamination in the urban aquifer of Ur?nia (SP).

Localizada sobre os dom?nios do Aqu?fero Adamantina (Sistema Aqu?fero Bauru), a cidade de Ur?nia/SP est? significativamente contaminada por nitrato (NO3-) via processo de urbaniza??o, inicialmente sem instala??o da rede de esgoto ainda na d?cada de 1960. Este estudo objetiva avaliar a evolu??o dessa contamina??o no tempo e espa?o, a partir de an?lises qu?micas de 13 campanhas de amostragem nos ?ltimos 20 anos. Foi efetuada a compila??o de dados qu?micos e sele??o de grupos de po?os, bem como novas amostragens de ?gua, para buscar padr?es de concentra??o de nitrato em regi?es distintas da cidade. Concluiu-se que o maior grau de contamina??o est? historicamente na por??o rasa do aqu?fero, nas proximidades do c?rrego Comprido e na regi?o noroeste da cidade (>150 e 100 mg/L NO3-, respectivamente). Isso se deve ? alta densidade de fossas negras previamente existentes (48 fossas/km? e 23 fossas/km?, respectivamente) e, no caso da ?rea noroeste, devido ? ocupa??o urbana mais antiga e por vazamentos de uma rede de esgoto instalada ainda em 1977 e sem manuten??o. Essas duas ?reas tamb?m apresentaram elevadas concentra??es (50 a 100 mg/L NO3-) na por??o intermedi?ria do aqu?fero, indicando que a contamina??o atinge profundidades maiores. A por??o sul da cidade ? historicamente a de menor contamina??o, devido a urbaniza??o tardia, em parte concomitante com a chegada da rede de esgoto (em 1985), al?m da menor densidade de fossas negras (17 fossas/km?), apresentando, na maioria das an?lises, valores de at? 50 mg/L NO3-.Located over the Adamantina Aquifer domains (Bauru Aquifer System), the city of Ur?nia/SP is significantly contaminated with nitrate (NO3-) via urbanization process, initially without sewage system installation in the 1960s. This study aims to evaluate the evolution of this contamination in time and space, based on chemical analysis of 13 sampling campaigns in the last 20 years. Chemical data were compiled and well groups were selected, as well as new water samplings, to search for nitrate concentration patterns in distinct regions of the city. It was concluded that the highest degree of contamination is historically in the shallow portion of the aquifer, near the Comprido stream and in the northwest region of the city (>150 and 100 mg/L NO3-, respectively). This is due to the high density of previously existing cesspits (48 cesspit/km? and 23 cesspit/km?, respectively) and, in the case of the northwest area, due to the older urban occupation and leaks of a sewage network installed in 1977 and without maintenance. These two areas also showed high concentrations of nitrate (50 to 100 mg/L NO3-) in the intermediate portion of the aquifer, indicating contamination reaching greater depths. The southern portion of the city is historically the least contaminated due to late urbanization, in part concomitant with the arrival of the sewage system (in 1985), as well as the lower density of cesspits (17 cesspit/km?), presenting in most analyzes values of nitrate up to 50 mg/L NO3-

The groundwater exploitation condition in Minas Gerais in the light of the criteria in the normative deliberation COPAM-CERH 05/2017.

A superexplota??o da ?gua subterr?nea traz uma s?rie de consequ?ncias nas mais diversas escalas espacial e temporal devido ? complexidade do funcionamento dos sistemas aqu?feros e sua intera??o com o meio f?sico. No Brasil, a falta de uma legisla??o espec?fica e consolidada, que discipline o uso das ?guas subterr?neas, tem contribu?do para este problema. Visando aprimorar a gest?o dos recursos h?dricos e enfrentar os desafios frente ao controle e manuten??o das ?guas subterr?neas no estado de Minas Gerais, a Delibera??o Normativa Conjunta COPAM-CERH N? 05, de 14/09/2017 (DN 05/2017), estabelece diretrizes e procedimentos para definir ?reas de restri??o e controle do uso das ?guas subterr?neas. O artigo tem como objetivo o levantamento preliminar das ??reas de Restri??o e Controle em Avalia??o?, devido ? superexplota??o no estado de Minas Gerais, de acordo com as diretrizes estabelecidas pela DN 05/2017. A partir da an?lise da distribui??o espacial das outorgas de ?gua subterr?nea vigentes e cadastros de uso insignificantes nas ottobacias de n?vel 6 e 8 do estado, foram definidas 215 ??reas de Restri??o e Controle em Avalia??o? dentre as 15.352 ottobacias analisadas. Identificadas estas ?reas, cabe ao ?rg?o gestor estabelecer a ordem de prioridade para execu??o dos estudos que venham ou n?o confirmar a superexplota??o, conforme previsto nos artigos 11 e 12 da DN 05/2017 e, se necess?rio, adotar as medidas de controle necess?rias.Groundwater overexploitation brings a series of consequences in the most diverse spatial and temporal scales due to the complex functioning of aquifer systems and their interaction with the physical environment. The lack of specific and consolidated legislation governing the use of groundwater has contributed to this issue in Brazil. To improve the water resource managements and face the challenges related to groundwater control and maintenance in the state of Minas Gerais, the COPAM-CERH Normative Deliberation No. 05, dated 09/14/2017 (DN 05/2017), establishes guidelines and procedures for defining groundwater use restriction and control areas. The goal of this paper is the preliminary survey of ?Restriction and Control in Evaluation Areas? due to overexploitation in the state of Minas Gerais, according to the guidelines established by DN 05/2017. Based on analysis of spatial distribution of existing well grants and groundwater use insignificant registries in the ottobasins of level 6 and 8 of the state, 215 ?Restriction and Control in Evaluation Areas? were defined, among the 15,352 ottobasins analyzed. Once these areas have been identified, it is up to the managing agency to establish the order of priority for carrying out studies that may or may not confirm overexploitation, indicated in Articles 11 and 12 of the Deliberation and, adopt the necessary control measures, if necessary

Corn hybrids height in different eucalyptus trees distances in systems agroforestry

Todos os textos, informa??es e resultados apresentados s?o de inteira responsabilidade dos autores.Objetivou-se avaliar as alturas de plantas de milho a diferentes dist?ncias das ?rvores de eucalipto em cons?rcio com capim-marandu, cultivado em diferentes arranjos de eucalipto em sistemas agrossilvipastoris, estabelecido h? cinco anos. Utilizou-se o delineamento experimental em blocos completos casualizados, com tr?s repeti??es e os tratamentos consistiram do arranjo fatorial (2x2)+2, sendo dois h?bridos de milho (duplo ? BM207, com folhas planiformes e triplo ? BM502, com folhas eretas) em cons?rcio com a Brachiaria brizantha cv. Marandu (capim-marandu), dois espa?amentos entre ?rvores de eucalipto (12x2 e 12x4 m), e os dois h?bridos de milho em monocultivo. Aos 110 dias ap?s a semeadura, ?poca de gr?os pastoso farin?ceo, foram determinadas as alturas de plantas de milho em tr?s diferentes distancias das ?rvores (2, 4 e 6 m) e determinada a m?dia entre as tr?s diferentes distancias, em cada unidade experimental. A altura dos h?bridos de milho foi influenciada pelas dist?ncias das ?rvores, pelos diferentes espa?amentos das ?rvores e entre os h?bridos utilizados nos sistemas em agrossilvipastoris j? estabelecidos h? cinco anos.ABSTRACT It was aimed to evaluate the height of corn plants at different distances from eucalyptus trees in consortium with marandugrass, grown in different eucalyptus arrangements in agroforestry systems, from five years ago. We used the experimental randomized complete block design, with three replications and the treatments consisted of a factorial arrangement (2x2) +2, two corn hybrids (double - BM207 with planiformes leaves and triple - BM502, with erect leaves) in consortium with Brachiariabrizantha cv. Marandu (marandugrass), two spacing between eucalyptus trees (12x2 and 12x4 meters), and the two corn hybrids in monoculture. At 110 days after sowing, period of pasty chalky grains, it was determined the height of corn plants in three different distances from the trees (2, 4 and 6 meters) and it was determined the average of the three different distances in each experimental unit. The height of the corn hybrids was influenced by the distances of the trees, by different spacing from the trees and among the hybrids used in the systems agroforestry from five years ago