Growth change of young Picea sitchensis in response to deer browsing

Taking advantage of the introduction of the black-tailed deer to the Queen Charlotte Islands (British Columbia, Canada), we used dendrochronological analyses to understand the consequences of deer browsing on Sitka spruce growth. We compared shape, radial growth, height growth and age of young spruce in three sites. We identified two types of trees growing side by side: (1) stunted and heavily browsed spruce, smaller than the browsing limit and (2) escaped spruce that were taller than the browsing limit but still browsed in their lower part. The compact and heavily ramified shape in stunted spruce was the result of repeated and intense browsing. In escaped spruce this was also the case below the browsing limit (1.16 m±0.07 m), in sharp contrast with the normal shape that escaped spruce resumed above the browsing limit. We show that the release of browsing pressure, once the tree reaches the browsing limit, is characterised by an abrupt increase in radial growth. Before release, trees show a growth stagnation characterized by narrow rings (0.5 mm per year) and small annual height increments (<5 cm per year). After release, trees show a growth stabilisation characterised by wider rings (3 mm per year) and larger annual height increments (20 cm per year). We use this pattern to estimate frequency and age at release and their possible variation over time. Age differences between stunted and escaped spruce are highly significant and indicate that, despite of browsing, most if not all trees will ultimately reach the browsing limit and escape. Heavy deer pressure (30 deer per km²) delays spruce sapling recruitment by about 8 years. This delay varies in relation to site quality and seems to have increased over time, suggesting an increase in browsing pressure.     

Gas chromatographic and mass spectrometric (GC-MS) analysis of lignin-derived products from <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> treated in supercritical water

Sugi (Cryptomeria japonica D. Don) wood was treated with supercritical water (374°C, 22.1MPa), and fractionated into the water-soluble portion, the methanol-soluble portion, and the methanol-insoluble residue. The methanol-soluble portion mainly consisted of the lignin-derived products. To characterize the compounds in the methanol-soluble portion, gel permeation chromatographic (GPC) and gas chromatographic-mass spectrometric (GC-MS) analyses were performed. The GPC analysis indicated that the methanol-soluble portion contained lignin-derived monomeric and dimeric products. GC-MS analysis detected 31 products which were expected to be monomeric compounds, and 18 of these were identified to be guaiacol, methylguaiacol, ethylguaiacol, vinylguaiacol, eugenol, propylguaiacol, vanillin, cis-isoeugenol, homovanillin, trans-isoeugenol, acetoguaiacone, propioguaiacone, guaiacylacetone, 2-methoxy-4-(1-hydroxypropyl)phenol, homovanillic acid, 2-methoxy-4-(prop-1-en-3-one)phenol, coniferyl aldehyde, and ferulic acid. In addition, 22 dimeric products were detected, and 4 of these were believed to be compounds with biphenyl type (5-5), diphenylethane type (-1), stilbene type (-1), and phenylcoumaran type (-5) structures. These results clearly indicated that the methanol-soluble portion included various monomeric and dimeric compounds produced as a result of the cleavage of ether linkages and propyl chains of lignin.     

The impact of weight loss on circulating cytokines in Beagle dogs

Chronic low-grade inflammation in obesity is characterized by an increased production of pro-inflammatory and chemotactic cytokines that are contributing to insulin resistance and related co-morbidities. Cytokines act in networks and exhibit pleiotropic effects so we investigated the circulating levels of a wide array of cytokines (pro and anti-inflammatory, chemotactic and growth factors) in a canine model of weight loss. The dogs served as their own control in order to study the impact of weight loss independent of potential confounding factors, such as history of excess weight or gender. While low-grade inflammation had been previously investigated in obese dogs by measuring changes in adipokines, acute phase proteins and key pro-inflammatory cytokines, to the best of our knowledge this is the first study to evaluate how weight loss impacts a wide array of circulating cytokines.Eighteen overweight Beagle dogs were recruited (six spayed females and 12 neutered males), and none of them were grossly obese according to the body condition score (BCS). All the dogs reached an ideal weight by the end of the program. Parameters were assessed before (baseline), at mid-point (month 3) and at end-point (month 6). Plasma GM-CSF, IL-2, Il-4, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, IFNγ, IP-10, TNFα, monocyte chemotactic protein 1 (MCP-1), keratinocyte chemokine (KC) were measured with canine multiplex immunoassays. Fat mass was assessed by dual energy X-ray absorption (DEXA).Several cytokines decreased throughout the weight loss program (p < 0.01) and were correlated with the percentage of fat measured by DEXA (p < 0.05): chemotactic (MCP-1), growth factors (GM-CSF, IL-7 and IL-2), and pro-inflammatory (KC and IL-18). We could not show trends for several cytokines, possibly because their level may be lower than the assay sensitivity: anti-inflammatory (IL-4 and IL-10), and pro-inflammatory (IL-6 and TNFα).In conclusion, while our findings for several pro-inflammatory and chemotactic cytokines are in accordance with human and rodent studies, we may have identified additional cytokines, such as growth factors, related to obesity-induced low-grade inflammation. Considering the weight loss was enabled by an adjusted diet, the role of this association of cytokines in insulin resistance and related co-morbidities needs to be clarified. Our results could help better understand the cytokine biology in dogs, and as such are relevant for further elucidating the relationship between immune function and metabolism/nutrition.     

植物生长调节剂GGR8在寒富苹果栽培上的应用

通过对绿色植物生长调节剂GGR8号在寒富苹果栽培上的应用进行的试验研究,结果表明:GGR8能够提高寒富苹果的品质,20、40、60 mg·kg-1等3种施用浓度在新梢生长量、含糖量、硬度方面均比对照有所提高,尤以60 mg·kg-1的施用浓度应用效果最好,其新梢生长量达到了36.7 cm,比对照增加9.3 cm;单果质量达到了240 g,比对照增加了95 g;含糖量达到了15%,比对照提高3个百分点;硬度达到了9.5 kg·cm-2,比对照增加了1.1 kg·cm-2。     

池塘培育草鱼种关键技术

1999年6月9月，使用池塘3口（面积1．21hm^2)培育草鱼种。经87d，总产10571kg,其中草鱼种6249kg，出塘率92．5％，饵料系数1．57；鲢、鳙鱼种4322kg，出塘率71．3％。总产值7．35万元，利润4．15万元。同时对草鱼夏花至秋片不同生长阶段蛋白质需求量，以及颗粒饲料粒径与鱼口裂大小关系等进行了试验。     

Relationship between rate of infection and markers of inflammation/immunity in Holy Birman cats with feline coronavirus

The aim of this study was to assess whether Holy Birman cats (HB) have a peculiar immune profile and a higher rate of infection by feline coronaviruses (FCoV). Leucocyte and lymphocyte subsets, antibody titers, α₁-acid glycoprotein (AGP), globulin fractions, IL-4, IL-12 and IFN-γ in blood and fecal FCoV excretion were determined in HB (n = 75) and in cats from other breeds (n = 94). Significantly higher CD4/CD8 ratio, IFN-γ concentration and IL12/IL4 ratio and significantly lower IL-4 concentration and proportion of shedders were found in HB than in other breeds. No other differences were found. In conclusion, this study did not provide evidence of peculiar immune profiles in HB, except for a prevalent Th1 profile, that may explain why in our caseload the rate of shedders was lower in HB than in other breeds.     

Functional characteristics of porcine peripheral T cells stimulated with IL-2 or IL-2 and PMA

In human or mouse, mature T cells express either CD4 or CD8, resulting in different functions in the periphery. Interestingly, porcine CD4 and CD8 double positive (DP) T cells are present in the blood, and their proportions change from youth to adulthood. However, the features of these cells in swine are poorly understood. We investigated the fate of porcine peripheral T cells based on their functional characteristics, including proliferation and the expression of CD4 and CD8 co-receptors. The results showed that all the populations changed their CD8 expression in a time-dependent manner and porcine T cells had different proliferative pattern from human T cells. The results further revealed that Th2 cytokines were increased later in porcine T cells compared to human T cells upon stimulation with IL-2 + PMA. Collectively, we found that the fate of porcine peripheral T cells is different from that of human T cells, and the changes occur in a time- and stimulation-dependent manner.     

PRRSV特异性肽对CSF、PRRS免疫猪IFN-Y、IL-10分泌的影晌

应用PRRSV-GP5特异性肽刺激CSF、PRRS免疫猪外周血淋巴细胞,采用EI。IsA方法测定不同时间点淋巴细胞分泌IFN-7及IL-10的水平,分析PRRSv_GP5特异性肽刺激后,淋巴细胞培养上清中细胞因子的变化规律。结果显示,CSFV高抗PRRSV低抗体组于PRRSV免疫14d,肽刺激组中IFN-7水平显著高于对照组（P〈0．05）;其他组均差异不显著（P〉0．05）。PRRSV免疫14d,细胞培养24,72h后加PRRSV—GP5肽刺激,各组中试验组与对照组相比IL-10水平明显降低（P〈0．01）;PRRSV免疫28d,各组中肽刺激组与空白组相比,IL-10水平均无显著性差异（P〉0．05）。结果表明,PRRSV-GP5肽在PRRSV免疫早期可以促进IFN-7的分泌,并抑制IL-10的产生,但在免疫后期对淋巴细胞分泌的调节作用还需进-步研究。     

种植密度对洛薯8号生物学性状及产量的影响

以洛薯8号为材料,采取随机区组设计,进行相同施肥管理水平下的密度试验,探索洛薯8号获得最好经济效益的栽培密度.结果表明:群体随密度增加而增大,但个体转弱,导致营养生长与生殖生长不协调,植株的抗病性、抗逆性变差;随着密度加大(45 000～90 000株/hm2),单株结薯个数由4.8个减少到3.6个,单株结薯质量由684.71 g减小到410.41 g,平均薯块质量由142.64 g减小到114.00 g,大薯率由75.26％减小到38.92％,商品率逐渐变差,由90.64％下降到63.54％;产量随着栽培密度的增加呈现先增加后减少趋势,栽植密度为45 000株/hm2时产量最低,为30 811.80 kg/hm2,密度为67 500株/hm2时产量达到峰值,为38 426.10 kg/hm2,随后产量逐渐降低.密度67 500株/hm2与密度为60 000、75 000、82 500株/hm2之间产量差异不显著,而与其他密度(45 000、52 500、90 000株/hm2)处理间存在显著差异.从而得出洛薯8号在河南两季作区的适宜栽植密度为60 000～82 500株/hm2,最适宜密度为67 500株/hm2.