Using Markov-Switching models in Italian, British, U.S. and Mexican equity portfolios: a performance test

In this paper we test the use of Markov Switching models in equity trading strategies, following Brooks and Persand (2001), Kritzman et al. (2012) and Hauptmann et al. (2014), who suggest their use as warning systems of bad performing periods. We extend their reviews by testing again (with the impact of trading fees) the U.S. and U.K. markets and by extending our tests to the Italian and Mexican case. The rationale behind our Markov-Switching strategy is to invest in equity index tracking ETFs in low volatility or ”good performing” periods and in the local risk-free asset in high-volatility or ”bad performing” ones. Our results show that in a weekly simulation from January 4, 2001 to July 30, 2017 with a 0.35% trading fee plus taxes, our system is useful to create alpha in all the simulated markets even if the Italian case showed several deep distress moments due to a financial or political crisis

New frontiers of cognitive rehabilitation in geriatric age: the Mozart effect (ME)

The ME was described for the first time in 1993. Subsequently other studies with similar designs were performed. The present study, therefore, proposes: (i) to verify the existence of the benefits of exposure to music in elderly subjects with mild cognitive impairment (MCI), (ii) to explore whether it is possible to find any lasting improvement after training, conducted for a long period of time, with such musical pieces, in the measurable cognitive performances. The study we conducted showed that the ME is present in geriatric patients with MCI; the influence on spatial–temporal abilities remains constant in time if the stimulation is maintained. The continuation of our study will consist of increasing the number of individuals examined and in having them listen to music during the study of ECG rhythms and during the acquisition of cerebral functional magnetic resonance imaging (fMRI), and, at the same time, testing them by neuropsychometric methods

Chemical Composition of Woody Species at Browsed Caatinga under Different Forage Allowance

Native rangelands are essential for Brazilian livestock production in the northeast Caatinga because they are abundant and inexpensive. Greater knowledge of nutritive values of these native plants is a needed because they fit well in prevailing edapho-climatic conditions. The chemical composition of plants, however, may differ according to ontogeny, elevation, soil, climate, plant community and human actions. Caatinga plants usually have high crude protein (CP) although some of this is fiber-bound (Santos et al., 2009). Browse can therefore become a key livestock diet component. Condensed tannins (CT) in browse can provide benefits, including anthelmintic activity greater amino acid absorption, synthesis of microbiological protein and reduction in methane emission when consumed at 20 to 50 g kg-1 dry matter (DM) (Littlefield et al., 2011; Muir, 2011). Above those levels, animals may suffer negative consequences because of the strong linkage with enzymes, metal ions and carbohydrates although browsers can neutralize CT via salivary proline (Naumann et al., 2013). The objective of this study was to estimate the chemical composition of commonly browsed Caatinga woody species in four forage allowances

Using Markov-Switching models in US stocks optimal portfolio selection in a Black–Litterman context (Part 1)

In this study, we tested the benefit of using Markov-Switching (M-S) models to forecast the views of the 26 most traded stocks in the US in a Black–Litterman (B–L) optimal selection context. With weekly historical data of these stocks from 1 January 1980, we estimated and simulated (from 7 January 2000, to 7 February 2022) three portfolios that used M-S views in each stock and blended them with the market equilibrium views in a B–L context. Our position was that the B–L optimal portfolios could generate alpha (extra return) against a buy-and-hold and an actively managed portfolio with sample portfolio parameters (à la Markowitz, SampP). Our results suggest that the outperformance of the B–L managed portfolios holds only in the short term. In the long-term, the performance of the B–L portfolios, the SampP, and the market portfolio are statistically equal in terms of returns or their mean–variance efficiency in an ex-ante or ex-post analysis.Junta de Extremadur

­Genotypic value in hybrid progenies of Panicum maximum Jacq.

Genetic breeding of forage plants has increasingly contributed to the release of more productive plants. In this regard, evaluating the genotypic value is essential when aiming to rank genotypes based on the mean free of environmental factors. Therefore, this study aimed to predict the genotypic value of agronomic and nutritive value characters of three progenies of Panicum maximum. Hybrids were evaluated in a clonal test in an incomplete-randomized design with three treatments (progenies 1, 2, and 3) and two replications (clones). Six harvests were performed at 25cm from the ground level throughout one year. Progeny 2 provided better results for total and leaf dry mass yield, regrowth, and height, and lower incidence of leaf spot. Progenies 1 and 3 had a better response for qualitative characters such as higher crude protein and digestibility and lower lignin and fiber content. Hybrid progenies of P. maximum have forage characters of interest for breeding, and when using ?Mombaça? grass as parents, the progeny stands out for leaf production and resistance to leaf spot and for ?Tanzania? grass as parent has resulted in better forage quality

Obesity and diabetes mellitus association in rural community of Katana, South Kivu, in Eastern Democratic Republic of Congo : Bukavu Observ Cohort study results

Background: Factual data exploring the relationship between obesity and diabetes mellitus prevalence from rural areas of sub-Saharan Africa remain scattered and are unreliable. To address this scarceness, this work reports population study data describing the relationship between the obesity and the diabetes mellitus in the general population of the rural area of Katana (South Kivu in the Democratic Republic of the Congo). Methods: A cohort of three thousand, nine hundred, and sixty-two (3962) adults (>15 years old) were followed between 2012 and 2015 (or 4105 person-years during the observation period), and data were collected using the locally adjusted World Health Organization's (WHO) STEPwise approach to Surveillance (STEPS) methodology. The hazard ratio for progression of obesity was calculated. The association between diabetes mellitus and obesity was analyzed with logistic regression. Results: The diabetes mellitus prevalence was 2.8 % versus 3.5 % for obese participants and 7.2 % for those with metabolic syndrome, respectively. Within the diabetes group, 26.9 % had above-normal waist circumference and only 9.8 % were obese. During the median follow-up period of 2 years, the incidence of obesity was 535/100,000 person-years. During the follow-up, the prevalence of abdominal obesity significantly increased by 23 % (p < 0.0001), whereas the increased prevalence of general obesity (7.8 %) was not significant (p = 0.53). Finally, diabetes mellitus was independently associated with age, waist circumference, and blood pressure but not body mass index. Conclusion: This study confirms an association between diabetes mellitus and abdominal obesity but not with general obesity. On the other hand, the rapid increase in abdominal obesity prevalence in this rural area population within the follow-up period calls for the urgent promoting of preventive lifestyle measures

Fiabilidad y validez de la escala de actitudes hacia el medio ambiente natural para adolescentes (Aman-a)

Resumen: El objetivo de este trabajo fue construir y validar una escala de actitudes hacia el medio ambiente natural en adolescentes españoles. Se generaron 72 ítems a partir de los escritos de 264 adolescentes sobre actitudes hacia el medio ambiente. A través del juicio de expertos y de un estudio piloto se efectuó́ una depuración reduciendo la escala a 9 ítems que se administraron a una muestra de 833 adolescentes de ambos sexos. Mediante un análisis factorial exploratorio, se identificaron dos dimensiones, actitud proximal y actitud distal, que fueron replicadas a través de un análisis confirmatorio cuyos resultados mostraron un buen ajuste a los datos. Los índices de fiabilidad fueron adecuados y respecto de la validez se obtuvieron relaciones significativas con la empatía con el medio ambiente natural en sus dos dimensiones, cognitiva y emocional, y el ajuste escolar. También se obtuvieron diferencias significativas en función del género en la actitud distal, pero no en la actitud proximal. Se analizan los resultados obtenidos y se subraya la importancia de esta escala en la investigación ambiental en la adolescencia. Abstract: The aim of this study was to design and validate a scale of attitudes towards the natural environment among Spanish teenagers. 72 items were generated from the writings of 264 adolescents on attitudes towards the environment. Through expert judgement and a pilot study, a depuration was carried out, reducing the scale to 9 items that were administered to a sample of 833 adolescents of both sexes. By means of an exploratory Factor analysis, two dimensions were identified, proximal attitude and distal attitude, which were replicated through a confirmatory analysis whose results showed a good fit to the data. Reliability indices were adequate and with respect to validity significant relationships were obtained with empathy with the natural environment in its two dimensions, cognitive and emotional, and school adjustment. Significant gender differences were also found in distal, but not proximal, attitudes. Results obtained are analysed and the importance of this scale in environmental research in adolescence is also highlighted

Produtividade de cultivares de soja em três ambientes do Tocantins.

A produção de soja no Tocantins tem ocupado papel de destaque no Brasil. Fazendo parte do MATOPIBA (interface Maranhão, Tocantins, Piauí e Bahia), o Estado apresenta boa disponibilidade de água nos períodos de chuva, elevada radiação, boa logística de escoamento da produção, relevo favorável à mecanização, entre outros. Um dos principais fatores para o desenvolvimento de um sistema sustentável de produção de soja está relacionado à escolha correta das cultivares para a região, que pode proporcionar ganhos de produtividade sem grandes impactos no custo e consumo de recursos naturais. Este trabalho apresenta informações sobre o comportamento de cultivares em três regiões do Estado do Tocantins, com diferentes características de solo (com e sem cascalho) e altitude. Estas informações podem orientar os produtores e técnicos na escolha de cultivares mais adaptadas para a sua área de cultivo.bitstream/item/201402/1/Boletim-PD-21-2.pd