Small-sample improved seasonal unit root tests for trending and breaking series

In this article three unit root tests that allow for a break in both the seasonal mean and linear trend of the data are proposed. The tests, which can be seen as small-sample corrected versions of already known asymptotic tests, are shown to perform very well in simulations, and much better than their asymptotic counterparts.

Too hot to move? Objectively assessed seasonal changes in Australian children's physical activity

BACKGROUND: Seasonal variations may influence children's physical activity patterns. The aim of this study was to examine how children's objectively-measured physical activity differed across seasons, and whether different seasonal patterns were observed for boys and girls. METHODS: Three hundred and twenty-six children aged 8-11 years from nine primary schools in Melbourne, Australia, participated in the study. Physical activity was measured every 15-s using hip-mounted GT3X+ ActiGraph accelerometers for seven consecutive days in the Winter (n = 249), Spring (n = 221), Summer (n = 174) and Autumn (n = 152) school terms. Time spent in moderate (MPA), vigorous (VPA) and moderate- to vigorous-intensity physical activity (MVPA) at each time point was derived using age-specific cut-points. Meteorological data (maximum temperature, precipitation, daylight hours) were obtained daily during each season. Longitudinal data were analysed using multilevel analyses, adjusted for age, sex, accelerometer wear time, number of valid days, and meteorological variables. RESULTS: Compared to Winter, children engaged in significantly less MPA (-5.0 min) and MVPA (-7.8 min) in Summer. Girls engaged in less MVPA in Spring (-18 min) and Summer (-9.2 min) and more MVPA in Autumn (9.9 min) compared to Winter. Significant changes in MPA and VPA bout frequency and duration were also observed. Significant decreases in VPA bout frequency (3.4 bouts) and duration (2.6 min) were observed for girls in Spring compared to Winter. No significant seasonal changes were observed for boys for all intensities and physical activity accumulation. CONCLUSIONS: Physical activity decreased in Summer compared to Winter, contrasting previous research that typically reports that children are most active in summer. Greater fluctuations were observed for girls' activity levels. In addition, girls' activity duration and bouts appeared to be more susceptible to seasonal changes compared to boys. The results suggest that strategies to promote physical activity may be needed in Australia during the hot summer months, particularly for girls.

Marketing ethics in context: the promotion of unhealthy foods and beverages to children

Marketing ethics has been described as an inherently relative conceptwhereby ethical problems and consequences result from interactionsbetween individuals, but are also shaped by the context in which theyoccur (Chonko and Hunt 1985; Singhapakdi et al. 1996). In makingethical decisions, marketers are influenced by a complex interplay offactors in the broader cultural, economic and organizational environments(Singhapakdi et al. 1996). Within this field, issues arise from organizations’ marketing activities and their consequences (Chonko and Hunt 1985), and the way marketing decisions are shaped by moral standards (Murphy et al. 2005).

Seasonal timing of the spring departure of waders from the Banc D'Arguin, Mauritania

The northward departure of 13 wader species was studied in the Baie d' Aouatif, Bane d'Arguin, Mauritania, in the springs of 1985, 1986 and 1988. Waders left the area in the late afternoon. Wind speed and direction were registered near ground level (all years) and at altitudes up to 5 km (in 1988). A total of 31 000 waders were observed heading northwards, with those species wintering locally in largest numbers being most common. The majority of wader species showed fairly short periods of departure and unimodal departure peaks. Redshank and Dunlin departed over extended periods. Average departure dates of species correlated positively with the estimated midpoints of ranges in breeding latitude (ca. 2 d per 0 latitude).  Since winds at ground level did not correlate with winds at higher altitudes, and since it is likely that the departing waders traveled at great heights, it was not surprising that there is no correlation between the average afternoon tail wind vector at ground level and the daily departure intensity. We suggest that the timing ofdeparture from the Bane d'Arguin is largely under internal, instead of under direct environmental, control.

Digital marketing of unhealthy foods to Australian children and adolescents

The emergence of new media—including branded websites, social media and mobile applications—has created additional touch points for unhealthy food and beverage companies to target children and adolescents. The aim of this study was to perform an audit of new media for three top selling food and beverage brands in Australia. The top selling brand in three of the most advertised food and beverage categories was identified. Facebook, websites and mobile phone applications from these three brands were assessed using a combination of descriptive analyses and structured data collection during June and July 2013. Information on target audience, main focus of the activity, marketing strategies employed and connectivity were collected. Promotional activities were assessed against industry self-regulatory codes. McDonald's, Coca-Cola and Cadbury Dairy Milk were audited, with 21 promotional activities identified. These promotional activities appeared to use a number of marketing strategies, with frequent use of indirect product association, engagement techniques and branding. We identified strategic targeting of both children and adolescents. We found that while all promotional activities technically met self-regulatory codes (usually due to media-specific age restrictions) a number appeared to employ unhealthy food or beverage marketing directed to children. Brands are using engaging content via new media aimed at children and adolescents to promote unhealthy food and beverages. Given the limitations of self-regulatory codes in the context of new media, strategies need to be developed to reduce exposure of children and adolescents to marketing of unhealthy food and beverage products via these avenues.

Chronic contamination assessment integrating biomarkers' responses in transplanted mussels-A seasonal monitoring

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seasonal variations in chemical composition and stable isotopes of farmed and wild Brazilian freshwater fish

This study examined variations in the Fulton condition factor, chemical composition, and stable isotopes of carbon and nitrogen in the Brazilian freshwater fish cachara (Pseudoplatystoma fasciatum), comparing farmed and wild fish in different seasons. Values for energy, protein, moisture, and Fulton's condition factor were higher for farmed than for wild fish in the rainy season, indicating better nutritional quality; however, these differences were not observed in the dry season. Likewise, we found significant enhancement of delta(15)N in farmed fish in the rainy season but not in the dry season, whereas enhancement of delta(13)C was observed in both seasons. The combined measurement of delta(13)C and delta(15)N provided traceability under all conditions. Our findings show that stable isotope analysis of C and N can be used to trace cachara origin, and that seasonal variations need to be considered when applying chemical and isotopic authentication of fish and fish products. (C) 2010 Elsevier Ltd. All rights reserved.

Africanized honey bee (Apis mellifera) venom profiling: Seasonal variation of melittin and phospholipase A(2) levels

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seasonal changes in fecal testosterone concentrations and their relationship to the reproductive behavior, antler cycle and grouping patterns in free-ranging male Pampas deer (Ozotoceros bezoarticus bezoarticus)

The purpose of this study was to validate noninvasive endocrine monitoring techniques for Pampas deer and to evaluate seasonal changes in testicular steroidogenic activity and their correlation to reproductive behavior, antler cycle and group size. Thus, fecal samples, behavioral data and observations of antler status were collected at monthly intervals during 1 year from free-ranging Pampas deer stags (three radio-collared individuals and 15 random individuals) living in Emas National Park, Brazil (18 degrees S latitude). Fecal steroids were extracted using 80% methanol and steroid concentrations were quantified by a commercial enzyme immunoassay (EIA). Fecal testosterone concentrations peaked in December-January (summer), March (early autumn) and in August-September (winter-spring), with minimal values from April-July. Reproductive behavior had two peaks, the first in December-January, characterized by predominately anogenital sniffing, flehmen, urine sniffing, chasing and mounting behavior, and the second peak in July-September (behavior primarily related to gland marking). There were significant correlations between fecal testosterone and reproductive behavior (r = 0.490), and between fecal testosterone and antler phases (r = 0.239). Antler casting and regrowth occurred under low testosterone concentrations, whereas velvet shedding was associated with high concentrations of testosterone. We inferred that Pampas deer stags exhibited a seasonal cycle that modulated sexual behavior and the antler cycle, and we concluded that fecal steroid analysis was a practical and reliable non-invasive method for the evaluation of the endocrine status of free-ranging Pampas deer. (c) 2004 Elsevier B.V. All rights reserved.