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Blackberries are an emerging third-generation fruit that are popular in Europe, and specific nitrogen (N) supply is an important factor affecting their growth and development. To study the optimal N fertilizer for blackberry seedlings, no N (CK), nitrate (NO3−)–N, ammonium (NH4+)–N and urea were applied to one-year-old 'Ningzhi 4' blackberry plants at a key growth period (from May to August) to explore the effects of different N forms on the physiological characteristics. Correlation and principal component analysis were used to determine the relationships between various indexes. Ammonium (NH4+) or urea-fed plants had a better growth state, showed a greater plant height, biomass, SPAD values and enhanced antioxidant enzyme activities and photosynthesis. In addition, NH4+ was beneficial to the accumulation of sugars and amino acids in leaves and roots, and promoted the transport of auxin and cytokinin to leaves. NO3− significantly inhibited root growth and increased the contents of active oxygen, malondialdehyde and antioxidants in roots. Correlation and principal component analysis showed that growth and dry matter accumulation were closely related to the antioxidant system, photosynthetic characteristics, amino acids and hormone content. Our study provides a new idea for N regulation mechanism of blackberry and proposes a scientific fertilization strategy. [ABSTRACT FROM AUTHOR]

Prior research on sex differences in relationship jealousy and on reactions to third-party rivals has been conducted primarily within the U.S., Central Europe, and Asia. As these effects vary in magnitude across cultures, it is important to investigate both how these patterns differ across a wider range of cultures and the key mediating cultural variables. One hundred and fourteen English and 202 Romanian participants provided their reactions to hypothetical relationship infidelity situations and to various traits that a mate rival could possess. In both samples, males were more upset than females by sexual infidelity, as compared with emotional infidelity, but this effect was much smaller for the Romanian sample. In line with evolutionary predictions, men were more upset by a rival who had better financial prospects, greater status and prestige, and was physically stronger, whereas women were more upset by a rival with a more attractive body and face. Additional, unpredicted, sex differences in the evaluation of rival traits were also found. Finally, different correlations were found (both across cultures and across sexes) between reported reactions to infidelities and to specific mate rival traits. [ABSTRACT FROM AUTHOR]