Role of input self-sufficiency in the economic and environmental sustainability of specialised dairy farms

Increasing input self-sufficiency is often viewed as a target to improve sustainability of dairy farms. However, few studies have specifically analysed input self-sufficiency, by including several technical inputs and without only focussing on animal feeding, in order to explore its impact on farm sustainability. To address this gap, our work has three objectives as follows: (1) identifying the structural characteristics required by specialised dairy farms located in the grassland area to be self-sufficient; (2) analysing the relationships between input self-sufficiency, environmental and economic sustainability; and (3) studying how the farms react to a decrease in milk price according to their self-sufficiency degree. Based on farm accounting databases, we categorised 335 Walloon specialised conventional dairy farms into four classes according to their level of input self-sufficiency. To this end, we used as proxy the indicator of economic autonomy – that is, the ratio between costs of inputs related to animal production, crop production and energy use and the total gross product. Classes were then compared using multiple comparison tests and canonical discriminant analysis. A total of 30 organic farms – among which 63% had a high level of economic autonomy – were considered separately and compared with the most autonomous class. We showed that a high degree of economic autonomy is associated, in conventional farms, with a high proportion of permanent grassland in the agricultural area. The most autonomous farms used less input – especially animal feeding – for a same output level, and therefore combined good environmental and economic performances. Our results also underlined that, in a situation of decrease in milk price, the least autonomous farms had more latitude to decrease their input-related costs without decreasing milk production. Their incomes per work unit were, therefore, less impacted by falling prices, but remained lower than those of more autonomous farms. In such a situation, organic farms kept stable incomes, because of a slighter decrease in organic milk price. Our results pave the way to study the role of increasing input self-sufficiency in the transition of dairy farming systems towards sustainability. Further research is required to study a wide range of systems and agro-ecological contexts, as well as to consider the evolution of farm sustainability in the long term.     

Field Hypothesis on the Self-regulation of Gene Expression

The mechanism of the self-regulation of gene expression in living cells is generally explained by considering complicated networks of key-lock relationships, and in fact there is a large body of evidence on a hugenumber of key-lock relationships. However, in the present article we stress that with the network hypothesis alone it is impossible to fully explain the mechanism of self-regulation in life. Recently, it has been established that individual giant DNA molecules, larger than several tens of kilo base pairs, undergo a large discrete transition in their higher-order structure. It has become clear that nonspecific weak interactions with various chemicals, suchas polyamines, small salts, ATP and RNA, cause on/off switching in the higher-order structure of DNA. Thus, the field parameters of the cellular environment should play important roles in the mechanism of self-regulation, in addition to networks of key and locks. This conformational transition induced by field parameters may be related to rigid on/off regulation, whereas key-lock relationships may be involved in a more flexible control of gene expression.     

Effects of water from Nakhodka Bay (Peter the Great Bay, Sea of Japan) on the early development of the Sea UrchinStrongylocentrotus intermedius

Our studies show that seawater from different sites in Nakhodka Bay has a deleterious effect on the development of the sea urchinStrongylocentrotus intermedius. As development proceeded to the pluteus I stage, the percentage of abnormal larvae maintained in water from Nakhodka, Novitskogo, and Vrangelya Bights increased markedly (66.7±2.2, 67.1±2.6, and 54.6±1.8%, respectively). These larvae developed more slowly, were smaller, and differed from those in the control in the intensity of color of their echinochrome granules. In water from Nakhodka and Novitskogo bights, larval survival rates were lower than in the control. This suggests that the water of Nakhodka Bay is heavily polluted, especially in its harbor areas.     

BioEssays 10/2020

Frequent independent origins of environmental sex determination (ESD) are assumed within amniotes. However, the phylogenetic distribution of sex-determining modes suggests that ESD is likely very ancient and may be homologous across ESD groups. Sex chromosomes are demonstrated to be old and stable in endothermic (mammals and birds) and many ectothermic (non-avian reptiles) lineages, but they are mostly non-homologous between individual amniote lineages. The phylogenetic pattern may be explained by ancestral ESD with multiple transitions to later evolutionary stable genotypic sex determination. It is pointed out here that amniote ESD shares several key aspects with sequential hermaphroditism of fishes such as a lack of sex differences in genomes, biased population sex ratios, and potentially also molecular mechanism related to general stress responses. Here, it is speculated that ESD evolves via a heterochronic shift of the sensitive period of sex change from the adult to the embryonic stage in a hermaphroditic amniote ancestor. Also see the video abstract here https://youtu.be/q2mjtlCefu4 .     

Analysis and assessment of heavy metals pollution in soils around a Pb and Zn smelter in Baoji City,Northwest China

Soil heavy metal pollution from mining activities is potentially harmful to human health through the food chain. In this study, a total of 43 soil samples were collected from a depth of 0–20 cm from fields close to a Pb and Zn smelter. The samples were used to: 1) analyze the pollution level of heavy metals (Pb, Zn, Cr, and Cu) and spatial distribution pattern; 2) evaluate the degree of accumulation and enrichment, potential ecological risk, and human health risk; and 3) perform source apportionment in Fengxiang County, Shaanxi Province of China. The results showed that the concentration ranged from 43.67 to 189.55, 131.43 to 239.53, 74.77 to 112.25, and 24.69 to 37.71 mg·kg^?1 for Pb, Zn, Cr, and Cu, respectively, and the mean concentration for Pb, Zn, Cr, and Cu was 129.46, 192.85, 91.98 and 31.67 mg·kg^?1, respectively. The concentrations were greater than the Shaanxi Province background values, while they were lower than the second-level limits of Environmental Quality Standard for Soils of China (EQSS). The spatial distribution of heavy metal contents showed a banded in soil except Cu. The spatial distribution pattern and pollution assessment indexes (I_geo, EF) indicated that the investigated metals had been accumulated in the study areas, and implied significant influences from anthropogenic activities, local meteorological situation, and soil properties. The ecological risk assessment showed that the risks were relatively low (RI<150). Compared with the exposure risk for adults, that for children was significantly greater. The ingestion of heavy metals in the soils by humans was the main exposure pathway compared with the dermal exposure. There may be a risk of noncarcinogenic adverse health effects (HQ < 1, 0.377 ≤ HI≤1.553) on children, but the adults were unlikely to experience obvious adverse health effects (HQ < 1, HI < 1). The carcinogenic risk of Cr for adults and children was at an unacceptable level. The carcinogenic and noncarcinogenic risks were in the order of children > adults. The correlation analysis showed that Pb, Cr, and Cu have identical anthropogenic and natural sources, while Zn has another identical source. This study could provide a basis for the sustainable management of this region by reducing metal inputs and to protect soils from long-term heavy metal accumulation.