Potential of Exopolysaccharide from Porphyridium marinum to Contend with Bacterial Proliferation,Biofilm Formation,and Breast Cancer

Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by Porphyridium marinum and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.e., antibacterial, anti-fungal and antibiofilm activities on Candida albicans, as well as for their effects on the viability of murine breast cancer cells. Results have shown that all EPS samples present some biological activity. For antibacterial and antibiofilm activities, the native EPS exhibited a better efficiency with Minimum Inhibitory Concentration (MIC) from 62.5 µg/mL to 1000 µg/mL depending on the bacterial strain. For Candida albicans, the biofilm formation was reduced by about 90% by using only a 31.3 µg/mL concentration. Concerning breast cancer cells, lower molar masses fractions appeared to be more efficient, with a reduction of viability of up to 55%. Finally, analyses of polymers composition and viscosity measurements were conducted on all samples, in order to propose hypotheses involving the activities caused by the intrinsic properties of polymers.     

Effect of Calcium Foliar Application on the Characteristics of Blueberry Fruit during Storage

ABSTRACT

Effect of calcium (Ca) foliar application on blueberry fruit characteristics during storage was investigated. Calcium applications began 28 d after flowering, two levels (3.9 g Ca^{2 +} and 39 g Ca^{2 +}) and a control without calcium were used (0.0; 3.0, and 30 mL L^?1). The fruits were harvested on day 103 and were stored for 56 d at 2 ± 1°C. At harvest time the fruits had a significant statistical different concentration, which were maintained until the last day of storage. The fruit from the 30 mL L^?1 treatment was the highest. The lowest texture levels are found with the treatment without calcium, which shows a statistically significant change from storage day 29. The LMP percentage did not varied in the fruit from the treatment with 30 mL L^?1, but did in the fruit without calcium. Hunter L, b, and the index chromes were influenced by the applied calcium levels, significantly greater at 30 mL L^?1; and by the time of storage in the fruits with treatment of 30 mL L^?1.     

Effect of Foliar Application of Calcium on the Quality of Blueberry Fruits

Effect of foliar application of calcium (0.78 g, 4.68 g, and 7.8 g Ca^{2 +}) in pre-harvest, at three different growing conditions (tunnel, mesh, and ambient), on texture and pectin in blueberries (Vaccinium corymbosum) was studied. Calcium contents in leaves as well in fruits were different (P ≤ 0.05), affected by growing conditions and time. Differences (P ≤ 0.05) in calcium content were found in tunnel cultivar fruit, during the period to cell expansion toward harvest, at calcium foliar level of 5 mL per L (7.8 g). Fruit texture was significantly higher at the beginning of the cell expansion period in the tunnel cultivar fruit, and a linear correlation between calcium concentration and texture was established. Increment in low methoxyl pectin (LMP) was influenced by growing conditions, and was different (P ≤ 0.05) for tunnel cultivar fruit. A good correlation between LMP and calcium content was obtained with the high dose of calcium (5 mL per L).     

陕北黄土丘陵区牧草枯落物对针叶纯林土壤极化的修复效应

针对陕北半湿润黄土丘陵区的侧柏、油松和落叶松等针叶纯林,在前期关于土壤极化研究的基础上,通过采集林地腐殖质层土壤与7种不同牧草枯落物进行混合分解培养,研究不同牧草枯落物对针叶纯林土壤的修复效应,以此作为选择适宜修复牧草种的依据。结果表明：（1）针对侧柏纯林土壤,苜蓿等7种牧草对于速效钾含量,苜蓿、胡枝子、沙打旺、小冠花和草木樨对于蛋白酶活性的负向极化具有显著缓减作用。（2）针对油松纯林土壤,7种牧草对于碱解氮含量,毛苕子、苜蓿和草木樨对于有效磷含量,苜蓿对于蔗糖酶活性的负向极化均有显著缓减作用。（3）针对落叶松纯林土壤,胡枝子和红豆草对于碱解氮含量,苜蓿、红豆草、小冠花和毛苕子对于有效磷含量,除苜蓿和毛苕子外的其他牧草对于有机质含量,苜蓿以外其他牧草对于磷酸酶活性的负向极化均具有显著缓减作用。（4）综合主成分分析表明,对侧柏纯林土壤综合修复效果较好的依次是沙打旺、小冠花、胡枝子和毛苕子;对于油松纯林土壤综合修复效果较好的依次是苜蓿、小冠花和草木樨;对于落叶松纯林土壤综合修复效果较好的依次是苜蓿、草木樨和红豆草。     

The Panama Tall and the Maypan hybrid coconut in Jamaica: did genetic contamination cause a loss of resistance to Lethal Yellowing?

We applied Bayesian population assignment methods to assess the trueness to type of four populations of the coconut cultivar Panama Tall (PNT) located in Jamaica and found that two of them presented a high percentage of off-types, while genetic contamination was low in the two others. The PNT is the pollen parent of the MAYPAN hybrid, which used to be planted in Jamaica to control an epidemic disease: Lethal Yellowing. The main source of contamination was the susceptible Jamaica Tall, thus increasing the susceptibility in the resulting MAYPAN progeny. The incidence of genetic contamination seems however to be insufficient to be the only cause of the latest outbreak of the disease. Neither the MAYPAN nor its parents can be said resistant in the present context of Jamaica.     

Integrating landscape connectivity in broad-scale forest planning through a new graph-based habitat availability methodology: application to capercaillie (Tetrao urogallus) in Catalonia (NE Spain)

The loss of connectivity of forest landscapes is seriously hindering dispersal of many forest-dwelling species, which may be critical for their viability and conservation. In this context, explicitly incorporating connectivity considerations is an important challenge in current forest planning and management, but as yet there is a lack of operative methods for appropriate decision making in this respect. We describe a new methodology based on graph structures and a habitat availability index (integral index of connectivity) that integrates forest attributes (like habitat quality) and network connectivity in a single measure. We apply this methodology to examine the connectivity of the highly fragmented habitat of capercaillie (Tetrao urogallus) in Catalonia (NE Spain), where the threatened status of this forest bird species calls for landscape-level forest planning solutions. We analyse data on the distribution of capercaillie forest habitat at 1 km spatial resolution obtained from the recent Catalan Breeding Bird Atlas. We determine the functionally connected regions existing within its habitat distribution and identify the forest habitat areas that are more important for the maintenance of overall landscape connectivity for this species. Based on these results, we provide recommendations on certain critical public forests where management oriented to the conservation of capercaillie habitat is more necessary. These results highlight the potential and practical interest of the proposed methodology for successfully integrating landscape connectivity in broad scale forest planning.