Hiding from the Moonlight: Luminosity and Temperature Affect Activity of Asian Nocturnal Primates in a Highly Seasonal Forest

The effect of moonlight and temperature on activity of slow lorises was previously little known and this knowledge might be useful for understanding many aspects of their behavioural ecology, and developing strategies to monitor and protect populations. In this study we aimed to determine if the activity of the pygmy loris (Nycticebus pygmaeus) is affected by ambient temperature and/or moonlight in a mixed deciduous forest. We radio-collared five females and five males in the Seima Protection Forest, Cambodia, in February to May, 2008 and January to March, 2009 and recorded their behaviour at 5 minutes intervals, totalling 2736 observations. We classified each observation as either inactive (sleeping or alert) or active behaviour (travel, feeding, grooming, or others). Moon luminosity (bright/dark) and ambient temperature were recorded for each observation. The response variable, activity, was binary (active or inactive), and a logit link function was used. Ambient temperature alone did not significantly affect mean activity. Although mean activity was significantly affected by moonlight, the interaction between moonlight and temperature was also significant: on bright nights, studied animals were increasingly more active with higher temperature; and on dark nights they were consistently active regardless of temperature. The most plausible explanation is that on bright cold nights the combined risk of being seen and attacked by predators and heat loss outweigh the benefit of active behaviours

Oxidative discolouration in whole-head and cut lettuce: biochemical and environmental influences on a complex phenotype and potential breeding strategies to improve shelf-life

Lettuce discolouration is a key post-harvest trait. The major enzyme controlling oxidative discolouration has long been considered to be polyphenol oxidase (PPO) however, levels of PPO and subsequent development of discolouration symptoms have not always correlated. The predominance of a latent state of the enzyme in plant tissues combined with substrate activation and contemporaneous suicide inactivation mechanisms are considered as potential explanations for this phenomenon. Leaf tissue physical properties have been associated with subsequent discolouration and these may be influenced by variation in nutrient availability, especially excess nitrogen and head maturity at harvest. Mild calcium and irrigation stress has also been associated with a reduction in subsequent discolouration, although excess irrigation has been linked to increased discolouration potentially through leaf physical properties. These environmental factors, including high temperature and UV light intensities, often have impacts on levels of phenolic compounds linking the environmental responses to the biochemistry of the PPO pathway. Breeding strategies targeting the PALand PPOpathway biochemistry and environmental response genes are discussed as a more cost-effective method of mitigating oxidative discolouration then either modified atmosphere packaging or post-harvest treatments, although current understanding of the biochemistry means that such programs are likely to be limited in nature and it is likely that they will need to be deployed alongside other methods for the foreseeable future

Armazenamento de frutos de quiabo embalados com filme de PVC em condição ambiente Shelf life of four cultivars of okra covered with PVC film at room temperature

O presente trabalho objetivou avaliar a influência do filme de PVC durante o armazenamento, em condição ambiente, de frutos de quatro cultivares de quiabo para consumo in natura. O experimento foi organizado segundo delineamento experimental em blocos casualizados, em esquema de parcelas subdivididas, tendo nas parcelas um fatorial 2x4, ou seja, embalagens sem e com PVC e quatro cultivares (Amarelinho, Red Velvet, Star of David, Mammoth Spinless), e nas subparcelas os seis períodos de amostragem com quatro blocos. As características avaliadas foram: massa fresca, teor relativo de água, teor de vitamina C, teor de clorofila total e análise visual do escurecimento. O uso do PVC proporcionou menor perda de massa fresca e maior teor relativo de água ao longo do armazenamento para todas as cultivares estudadas em relação às não embaladas com o filme. As menores perdas de massa fresca foram verificadas nas cvs. Amarelinho e Star of David sem e com PVC, respectivamente. Os frutos das cvs. Red Velvet e Star of David, embalados com PVC, apresentaram menores perdas no teor de vitamina C. Foi observado que a cv. Mammoth Spinless manteve maior teor de clorofila. Observou-se, de maneira geral, maior incidência de escurecimento nos frutos armazenados sem PVC. Verificou-se que de toda as cultivares estudadas o que manifestou melhor conservação com relação ao escurecimento foi o Red Velvet.<br>The present work evaluated the influence of PVC film on the postharvest shelf life of four cultivars of okra stored at room temperature. The experiment was arranged in random blocks, in sub split parcels, where the parcels were a factorial 2x4, with and without PVC film and the cvs. Amarelinho, Red Velvet, Star of David and Mammoth Spinless, and the subparcels the six sample time with four blocks. The characteristics evaluated were: percentage of weight loss, relative water content, total chlorophyll and chlorophyll a and b, content of vitamin C, visual browning. The PVC was efficient in controlling the weight loss and retained the water content through storage. The lowest losses were observed for the cvs. Amarelinho and Star of David, without and with PVC, respectively. There was higher retention of vitamin C in the fruits wrapped with PVC and the cvs. Red Velvet and Star of David kept higher content of it. In general, the cv. Mammoth Spinless kept higher content of chlorophyll. The higher incidence of browning was in fruits stored without PVC. The Red Velvet had better shelf life due to lower browning