不同时间尺度环境因子对黑河下游胡杨(Populus euphratica)径向生长的影响

本研究以黑河下游额济纳旗成熟的河岸胡杨林为对象,分析不同年龄胡杨(Populus euphratica)的年轮宽度序列与不同时间尺度环境因子的关系。结果表明:①在年尺度上,气温是影响胡杨径向生长的主要因子,但不同年龄胡杨对气温的响应有所不同。②在季节尺度上,休眠季气温越高越有利于壮龄胡杨的径向生长,而生长季气温越高越不利于老龄胡杨的径向生长。③在月尺度上,前一年3月和当年9月的平均气温越高,对壮龄胡杨的径向生长越有利,而当年10月平均气温越高,对老龄胡杨的径向生长越不利;前一年7月径流量的增加对老龄胡杨的径向生长有利,而当年2月径流量的增加对壮龄胡杨径向生长有利。综上所述,在季节和年等相对较长的时间尺度上,气温是影响胡杨径向生长量的主要因素,随着时间尺度的缩小,胡杨对环境因子的响应更为细化,并且表现出一定的滞后效应。径流量作为重要的环境因子在月尺度上才突显出来,前一年7月和当年2月的径流补给对胡杨径向生长有极大的促进作用。因此,在黑河统一调度管理过程中,可通过适度调增2月和7月洪水的下泄量来满足胡杨径向生长对水分的需求。     

Plasma fluctuation in estradiol-17β and bone resorption markers around parturition in dairy cows

Blood samples were obtained sequentially from 10 dairy cows around the time of parturition to assess plasma fluctuations in estradiol-17β (E₂) levels in association with those of several bone resorption markers. Plasma E₂ concentration increased sharply a few days prepartum and decreased quickly after parturition. In terms of bone resorption markers, the plasma level of tartrate-resistant acid phosphatase isoform 5b (TRAP5b) rose significantly, commencing 1 week prepartum, and was maintained at this level to a few days postpartum. The plasma concentration of carboxyterminal collagen cross-links of type-I collagen (CTx) increased significantly after parturition. These observations suggest that osteoclast-mediated bone resorption was activated after parturition when plasma E₂ concentrations decreased.     

The therapeutic effects of SET/I2PP2A inhibitors on canine melanoma

Canine melanoma is one of the most important diseases in small animal medicine. Protein phosphatase 2A (PP2A), a well conserved serine/threonine phosphatase, plays a critical role as a tumor suppressor. SET/I2PP2A is an endogenous inhibitor for PP2A, which directly binds to PP2A and suppresses its phosphatase activity. Elevated SET protein levels have been reported to exacerbate human tumor progression. The role of SET in canine melanoma, however, has not been understood. Here, we investigated the potential therapeutic role for SET inhibitors in canine melanoma. The expression of SET protein was observed in 6 canine melanoma cell lines. We used CMeC-1 cells (primary origin) and CMeC-2 cells (metastatic origin) to generate cell lines stably expressing SET-targeting shRNAs. Knockdown of SET expression in CMeC-2, but not in CMeC-1, leads to decreased cell proliferation, invasion and colony formation. Phosphorylation level of p70 S6 kinase was decreased by SET knockdown in CMeC-2, suggesting the involvement of mTOR (mammalian target of rapamycin)/p70 S6 kinase signaling. The SET inhibitors, OP449 and FTY720, more effectively killed CMeC-2 than CMeC-1. We observed PP2A activation in CMeC-2 treated with OP449 and FTY720. These results demonstrated the potential therapeutic application of SET inhibitors for canine melanoma.     

Evidence of LAT1 expression in canine caput epididymis

L-type amino acid transporter 1 (LAT1), the first isotype of amino acid transport system L, transports aromatic and branched amino acids pivotal for fundamental cellular activities such cellular growth and proliferation. LAT1 expression was high only in the brain in contrast to its limited distribution and low level of expression in normal tissues. We found potent LAT1 expression in canine caput epididymis by quantitative RT-PCR and Western blotting analysis. Immnuno-histochemical examination revealed observable LAT1 in microvillous epithelial cells.     

Nutrient starvation affects expression of LC3 family at the feto-maternal interface during murine placentation

LC3 − the mammalian homolog of Atg8 − was found as autophagosome membrane binding protein in mammals and widely used as an autophagosomal marker. LC3A, B and C show different expression patterns in each tissue. The aim of this study was to reveal the differences of expression patterns among LC3 families in mouse placenta under normal condition and nutrient starving condition. LC3A and B were highly expressed in decidual cells. LC3A and B were increased in D14 compared with D12 and D16 in mouse placenta, while LC3C was decreased. Starvation induced increase in LC3B expression specifically. Immunohistochemistry showed different expression patterns among LC3A, B and C. LC3A expression in syncytiotrophoblast was vanished by starvation. The results of real time RT-PCR suggested differences between D12 and D16 in autophagic cascade induced by starvation. Taken together, this study suggests that autophagy could play a role in placental invasion system and that nutrient starvation affects LC3B expression.     

Differentiation of canine bone marrow stromal cells into voltage- and glutamate-responsive neuron-like cells by basic fibroblast growth factor

We investigated the in vitro differentiation of canine bone marrow stromal cells (BMSCs) into voltage- and glutamate-responsive neuron-like cells. BMSCs were obtained from the bone marrow of healthy beagle dogs. Canine BMSCs were incubated with the basal medium for neurons containing recombinant human basic fibroblast growth factor (bFGF; 100 ng/ml). The viability of the bFGF-treated cells was assessed by a trypan blue exclusion assay, and the morphology was monitored. Real-time RT-PCR was performed to evaluate mRNA expression of neuronal, neural stem cell and glial markers. Western blotting and immunocytochemical analysis for the neuronal markers were performed to evaluate the protein expression and localization. The Ca²⁺ mobilization of the cells was evaluated using the Ca²⁺ indicator Fluo3 to monitor Ca²⁺ influx. To investigate the mechanism of bFGF-induced neuronal differentiation, the fibroblast growth factor receptor inhibitor, the phosphoinositide 3-kinase inhibitor or the Akt inhibitor was tested. The bFGF treatment resulted in the maintenance of the viability of canine BMSCs for 10 days, in the expression of neuronal marker mRNAs and proteins and in the manifestation of neuron-like morphology. Furthermore, in the bFGF-treated BMSCs, a high concentration of KCl and L-glutamate induced an increase in intracellular Ca²⁺ levels. Each inhibitor significantly attenuated the bFGF-induced increase in neuronal marker mRNA expression. These results suggest that bFGF contributes to the differentiation of canine BMSCs into voltage- and glutamate-responsive neuron-like cells and may lead to the development of new cell-based treatments for neuronal diseases.     

Detecting endotoxin activity in bovine serum using an automated testing system

The aim of the present study was to compare the ability of the commercially available portable test system (PTS^TM) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS^TM was not significantly different from that of the traditional LAL-based assays. The results using PTS^TM correlated with those using KT (r²=0.963, P<0.001) or KC assays (r²=0.982, P<0.001). Based on these findings, the PTS^TM could be applied as a simplified system to assess endotoxin activity in bovine serum.     

Variation in cooking and eating quality traits in Japanese rice germplasm accessions

The eating quality of cooked rice is important and determines its market price and consumer acceptance. To comprehensively describe the variation of eating quality in 183 rice germplasm accessions, we evaluated 33 eating-quality traits including amylose and protein contents, pasting properties of rice flour, and texture of cooked rice grains. All eating-quality traits varied widely in the germplasm accessions. Principal-components analysis (PCA) revealed that allelic differences in the Wx gene explained the largest proportion of phenotypic variation of the eating-quality traits. In 146 accessions of non-glutinous temperate japonica rice, PCA revealed that protein content and surface texture of the cooked rice grains significantly explained phenotypic variations of the eating-quality traits. An allelic difference based on simple sequence repeats, which was located near a quantitative trait locus (QTL) on the short arm of chromosome 3, was associated with differences in the eating quality of non-glutinous temperate japonica rice. These results suggest that eating quality is controlled by genetic factors, including the Wx gene and the QTL on chromosome 3, in Japanese rice accessions. These genetic factors have been consciously selected for eating quality during rice breeding programs in Japan.     

Efficiency of fisheries is increasing at the ecosystem level

Managing fisheries presents trade‐offs between objectives, for example yields, profits, minimizing ecosystem impact, that have to be weighed against one another. These trade‐offs are compounded by interacting species and fisheries at the ecosystem level. Weighing objectives becomes increasingly challenging when managers have to consider opposing objectives from different stakeholders. An alternative to weighing incomparable and conflicting objectives is to focus on win–wins until Pareto efficiency is achieved: a state from which it is impossible to improve with respect to any objective without regressing at least one other. We investigate the ecosystem‐level efficiency of fisheries in five large marine ecosystems (LMEs) with respect to yield and an aggregate measure of ecosystem impact using a novel calibration of size‐based ecosystem models. We estimate that fishing patterns in three LMEs (North Sea, Barents Sea and Benguela Current) are nearly efficient with respect to long‐term yield and ecosystem impact and that efficiency has improved over the last 30 years. In two LMEs (Baltic Sea and North East US Continental Shelf), fishing is inefficient and win–wins remain available. We additionally examine the efficiency of North Sea and Baltic Sea fisheries with respect to economic rent and ecosystem impact, finding both to be inefficient but steadily improving. Our results suggest the following: (i) a broad and encouraging trend towards ecosystem‐level efficiency of fisheries; (ii) that ecosystem‐scale win–wins, especially with respect to conservation and profits, may still be common; and (iii) single‐species assessment approaches may overestimate the availability of win–wins by failing to account for trade‐offs across interacting species.