Zhang F.,Stellenbosch University |
Zhang F.,Gansu Agricultural University |
Hui C.,Stellenbosch University
Animal Behaviour | Year: 2014
Owing to the trade-off between time for searching for and exploiting resources, choosing a profitable food resource is key for an animal's survival and reproductive success. Although the optimal diet model (ODM) from optimal foraging theory (OFT) has demonstrated this point successfully by modelling the global maximization of energy intake rate for foraging, the behavioural mechanisms by which animals achieve optimization, especially when facing a novel environment, have yet to be understood. Here we propose a recent experience-driven (RED) decision-making rule of foraging that relies only on short-term memory of recent feeding experience and hunger aversion. This contrasts with the ODM, which assumes both global information access to the forager and its apparent ability to reach optimal choices. Despite relying only on limited past experience and hunger aversion, this behavioural rule not only accounts for nearly the same energy intake rate as predicted by the ODM but also can flexibly respond to changing environments by rapidly reaching new optimization. The RED behaviour also predicts a more realistic partial preference for diet choice, contrasting with the zero-one rule of OFT which allows for no partial preference within the forager's diet. The partial preference simply emerges from the RED strategy, as opposed to decision-making errors imposed from behavioural and physiological constraints. The RED rule further elucidates three potential traits that natural selection can act upon for optimizing foraging: (1) short-term memory of recent feeding experience, (2) ability to recognize encountered resources, and (3) basic neural set-up for alternative responses to environmental cues. This simple and flexible RED rule thus provides a behavioural mechanism for optimal foraging, and can be further applied to decision-making theory in psychology and economics. © 2013 The Association for the Study of Animal Behaviour.
Gan Y.,Gansu Agricultural University |
Gan Y.,Agriculture and Agri Food Canada |
Liang C.,Environment Canada |
Chai Q.,Gansu Agricultural University |
And 3 more authors.
Nature Communications | Year: 2014
Wheat is one of the world's most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging -256 kg CO2 eq ha-1 per year. For each kg of wheat grain produced, a net 0.027-0.377 kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production. © 2014 Macmillan Publishers Limited. All rights reserved.
Zhu Z.,Chinese Academy of Agricultural Sciences |
Zhang X.,Chinese Academy of Agricultural Sciences |
Wang G.,Gansu Agricultural University |
Zheng H.,Chinese Academy of Agricultural Sciences
Hepatitis Monthly | Year: 2014
MicroRNAs (miRNAs) are small, noncoding RNAs that play an important role in posttranscriptional gene regulation and function as negative gene regulators. They are an abundant class of RNA, each of which can control hundreds of gene targets and regulate diverse biological processes such as hematopoiesis, organogenesis, apoptosis and cell proliferation. Aberrant miRNA expression contributes to tumorigenesis and cancer progression. Evidence Acquisition: In this study we provided a summarized review of the most important new data available on hepatocellular carcinoma (HCC)-associated miRNAs. The data were collected through searching the related keywords and were categorized and summarized in different sections. Results: Researchers have reported that miRNAs can repress the expression of important cancer-related genes and might be helpful in the diagnosis and treatment of cancer. During the past two decades, numerous studies have shown that miRNAs play an essential role in inhibiting HCC via several different pathways. Deregulated miRNAs may contribute to carcinogenesis, indicating that miRNAs can act as tumor suppressors and oncogenes. Conclusions: In this mini review, we highlight current findings and discuss recent work to determine the contribution of miRNA expression to the maintenance and growth of HCC, thereby providing a significant source of hope that miRNAs could serve as therapeutic targets. © 2014, Kowsar Corp.
Wei Y.J.,Gansu Agricultural University
New Zealand Journal of Zoology | Year: 2011
Individuals of Nysius huttoni White, a ground-dwelling hemipteran, develop one of three wing forms. Field studies were carried out from 1995 to 1998 to investigate the proportion of each wing form; adult populations consisted of 94.1% macropters, 5.5% sub-brachypters and 0.4% brachypters. Paired mating adults were collected for two years in 1995-1996 and 1996-1997 to investigate which wing forms were mating with which, and the proportions of the wing form combinations among the mating pairs. Theoretically, there are nine possible mating combinations among three wing forms. However, only six mating combinations were found in the field. Four mating combinations, M × M, ♀M × ♂Sb, ♂M × ♀Sb and Sb × Sb occurred in both years; and two mating combinations, ♂M × ♀B and ♂Sb × ♀B were found only in 1996-1997. The other three mating combinations, ♀M × ♂B, ♀Sb × ♂B and B×B were not found in either year. M×M was the predominant mating combination with an average percentage of 81.2%. The effects of temperature and photoperiod on wing development of this species were investigated at five constant temperatures (15, 20, 25, 30 and 35±0.5°C), one ambient (laboratory room conditions) temperature and three photoperiods (16-h, 12-h, and 8-h of light) in the laboratory. The results indicate that both low and high temperatures, and short day-length at lower temperature, tend to accelerate the production of sub-brachypters and brachypters, while high temperature under long photoperiod appears to favour the production of macropters. This ability to produce macropters possibly benefits this bug by enabling rapid dispersal of adults during occasional very dry summers (which may kill preferred weedy hosts) to temporary alternative crop hosts in Canterbury and Central Otago. © 2011 The Royal Society of New Zealand.
Wei Y.J.,Gansu Agricultural University
New Zealand Entomologist | Year: 2012
The tolerance of adult Nysius huttoni to starvation, and the effect of water and glucose on the longevity of adults, were studied. When no food or water was provided, adults lived for an average of 2-4 days. Mean longevity of first-generation adults (4.2 days) was significantly greater than that of second- and third-generation adults (2.2 and 2.5 days respectively; P < 0.05) suggesting that differences in resistance to starvation of adults between generations are influenced by the nutrient status during their nymphal development. There was no significant difference between longevity of male and female adults. When water alone was provided, mean adult longevity was 8.4 days. The effect of glucose on adult longevity was examined with the use of eight different glucose concentrations (2, 5, 10, 15, 20, 25, 30 and 40%) at 20 ± 0.5°C and 65-75% relative humidity (RH). Mean maximum longevity (49.0-51.6 days) was obtained at glucose concentrations of 10-20%, but decreased at higher (25-40%, 27.0-31.7 days) and lower (2- 5%, 32.1-41.4 days) glucose concentrations. The relationship between longevity and the absorption and metabolism of glucose by N. huttoni adults is discussed. © 2012 The Entomological Society of New Zealand.
She Y.,Gansu Agricultural University
Acta biochimica et biophysica Sinica | Year: 2013
In this study, we assessed the toxic effects of formaldehyde (FA) on mouse bone marrow mesenchymal stem cells (BM-MSCs). Cytotoxicity was measured by using MTT assay. DNA strand breakage was detected by standard alkaline comet assay and comet assay modified with proteinase K (PK). DNA-protein crosslinks (DPCs) were detected by KCl-SDS precipitation assay. We found that FA at a concentration from 75 to 200 μM inhibited cell survival and induced DPCs over 125 μM. The PK-modified comet assay showed that FA-induced DNA strand breakage was increased in a dose-dependent manner from 75 to 200 μM. On the other hand, standard alkaline comet assay showed that DNA strand breakage was decreased with FA concentration over 125 μM. We confirmed by using Pearson correlation that there was a negative linear correlation between DPCs and survival rate (r = -0.987, P < 0.01) and positive linear relationships between DPCs and (i) sister chromatid exchange and (ii) micronucleus (r = 0.995, P < 0.01; r = 0.968, P < 0.01). DNA damage RT(2) profiler polymerase chain reaction array was used to investigate the changes in the expression of damage response genes. Xpa and Xpc of the nucleotide excision repair pathway and Brca2, Rad51, and Xrcc2 of the homologous recombination pathway were all up-regulated in both 75 and 125 μM FA. However, the same genes were down-regulated with 175 μM FA. The expressions of Chek1 and Hus1, which are involved in cell cycle regulation, were altered in the same manner with 75, 125, and 175 μM FA. These results indicated that Xpa, Xpc, Brca2, Rad51, Xrcc2, Chek1, and Hus1 were essential for the BM-MSCs to counteract the effects of FA.
Li H.J.,Gansu Agricultural University
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2012
The epidermal growth factor receptor (EGFR), a transmembrane protein receptor, is a member of ErbB family with signal-transducing tyrosine kinase activity. After combined with the ligand, EGFR homologous or heterologous dimers are formed to induce intracellular signal transduction, activate downstream signal transduction pathways, and then produce a series of biological effects. RAF/MEK/RAS/ERK pathway is relevant to cell proliferation, differentiation and apoptosis; while PDK1/AKT /PI3K pathway is involved in cell migration and adhesion. EGFR can promote the maturity of pulmonary type II epithelial cells and the synthesis and secretion of pulmonary surfactant. EGFR shows the effect on mammal lungs in a time-space and dose-dependent manner. The down-regulated expression of it will lead to immature lung development, while the over-expression can promote the cell proliferation, invasion and metastasis of the lung cancer cells. This paper reviewed advances in the study for EGFR and its signal pathway, as well as the relationship among EGFR, atelectasis and lung cancer.
Liu B.,Gansu Agricultural University
Molecular biology reports | Year: 2012
Potato (Solanum tuberosum L.) tuber dormancy and sprouting is very important to potato cultivation and processing. In the present experiment, suppression subtractive hybridization was employed to identify differentially expressed genes in potato associated with tuber dormancy release. 576 random clones were selected from subtractive library and successfully sequenced. A total of 304 effective expressed sequence tags (ESTs) were obtained ultimately. The ESTs have been deposited in the EMBL\GenBank\DDBJ nucleotide sequence data libraries under accession numbers from JK483901 to JK484204. GO annotation showed that 45, 34 and 3 % ESTs were associated with binding, catalytic activity and signaling respectively, some of which were confirmed to be involved in plant dormancy breaking, however, 14 % of the ESTs did not show significant homology to any database proteins. A real-time quantitative PCR (RT-qPCR) analysis of the expression patterns of 14 selectable transcripts showed that 13 selected candidate genes were significantly up-regulated in the development process of tuber from dormancy to sprouting. A full length cDNA of ADP-ribosylation factor (ARF) gene was cloned and found it belonged to potato ARF1 gene. Tissue specific expression analysis showed ARF1 expression level was the highest in tuber. RT-qPCR analysis of the expression profile of ARF1 gene from potato tuber dormancy to sprouting revealed that the ARF1 gene expression was significantly increased after tuber dormancy breaking, which suggested that it probably associated with tuber dormancy and sprouting.
Yan D.,Gansu Agricultural University |
Yun J.,Gansu Agricultural University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013
In recent years, researchers have paid more and more attention to bioflocculants in waste disposal study. Because the bioflocculants were usually biodegradable and their degradation products were harmless to environment, so the bioflocculants have a good application prospects. However, it was not widely used to practical application till now, because of its low flocculation ability of producing strain and high cost. One measure to decrease the cost associated with the production on industrial scale was to employ low-cost substrates. To develop a novel bioflocculant, a novel technology of producing bioflocculant was studied through screening biofloccuant-producing microorganism which could utilize potato starch wastewater as substrate, then its nutritional conditions was optimized. Moreover, the study would provide a new way for potato starch wastewater reutilization. In the study, 100 strains were isolated from activated sludge. Each strain was cultured separately in either nutrient agar or potato dextrose agar as primarily screening flocculant-producing strain medium. The flocculation rate of fermentation broth against Kaolin clay suspension was used as the evaluation index, 13 bioflocculant-producing strains were screened. According to the ability of strains fermenting potato starch wastewater and producing flocculants, one high yield strain was obtained, named as F5, which was identified as Candida anglica by 26SrDNA analysis. The nutritional contditons that C. anglica fermented potato starch wastewater to produce bioflocculant were optimized through single factor test and the orthogonal test. The results showed that under the conditions of pH value 5.6, inoculum size 10%( volume fraction), 150 r/min and 28°C for 48 h, the best nutritional compositions were: 1 mL/100 mL glycerin as adding carbon sources, 0.05 g/100 mL (NH4)2SO4 as nitrogen source, 0.1 g/100 mL MgCl2 and 0.1 g/100 mL KH2PO4. The test showed that C. anglica could grow well in non-sterilization potato starch wastewater as basic substrate, and could accumulate flocculation active substance effectively. At that time, the flocculation rate of fermentation broth against Kaolin clay suspension was 94.6%, the CODCr removal rate of potato starch wastewater was 93.7%, and the yield of bioflocculant was 1.36 g/L. It indicated that C. anglica would be a new strain for producing bioflocculants. The results could provide a reference for potato starch wastewater treatment and biological reuse.
Zhang L.P.,Gansu Agricultural University
Genetics and molecular research : GMR | Year: 2012
Thyroid transcription factor-1 (TTF-1), a member of the Nkx2 family of homeodomain-containing proteins, is involved in binding to and in activating the promoters of several important genes in the thyroid, lungs, and brain, and in regulating expression of these tissue-specific genes. We investigated potential roles of sheep (Ovis aries) TTF-1 in regulating cell fate and organ morphogenesis and in controlling puberty and reproductive capability of females. We amplified and cloned the sheep TTF-1 full-length DNA for the first time, analyzed its functional domains and regions, predicted molecular structure of its homeodomain and DNA-binding sites, and examined its expression in pituitary, brain, thyroid gland, ovary, and hypothalamus. We found that sheep TTF-1 has a high degree of homologous identity with that of other mammals, and it has several important domains including domain N, DNA-binding domain, domain C, TN-domain, domain I, and NK2-SD. The DNA-binding domain of sheep TTF-1 has 10 potential DNA-binding sites and is a novel mammalian homeodomain that shows considerable sequence homology with the corresponding rat homeodomain. Several functional regions in sheep TTF-1 share high sequence identity with rat TTF-1, indicating that these regions may have the same activity as in the rat. Expression of TTF-1 in several specific tissues implies that sheep TTF-1 in involved in sheep sexual development and reproductive capability. These results suggest a role of sheep TTF-1 in enhancing sheep reproduction performance and we propose it as a candidate gene for selection.