氧肥后移对超高产小麦产量及生理特性的影响

在小麦超高产栽培条件下,研究了氮肥不同追施时期追施量对籽粒产量及植株生理特性的影响。结果表明,超高产小麦施氮量以２４０ｋｇ／ｈｍ＾２,基追比例５：５为宜,追氮量过少或过多均不利于进一步提高小麦产量。氮肥不同追施时期对小麦产量也有不同的影响,小花雌雄蕊分化期和药隔形成期追肥可明显改善植株后期光合性能,降低叶片气孔阻力,并使植株体内保持高水平的保护酶活性,降低后期细胞膜脂过氧化水平,延缓植株衰老,从而     

Chemical composition and flavor of ecuadorian cocoa liquor

The contribution of the chemical composition to the flavor of cocoa liquor from an Ecuadorian selfed population of clone EET 95 was investigated. Polyphenols, purine alkaloids, organic acids, and sugars were quantified, and the key sensory characteristics of cocoa were scored by a trained panel. Despite the short bean fermentation (2 days) commonly used for Arriba cocoa, acetic acid content was closely correlated to liquor pH, demonstrating its essential role in cocoa liquor acidification. Polyphenols were positively correlated to astringency, bitterness, and the green note and negatively correlated to the fruity character. Alkaloid and polyphenol levels fluctuated significantly within the selfed progeny and tended to be lower than those of the heterozygous clone EET 95 (inbreeding effect). These results support the idea that polyphenols might be essential to the overall perception of cocoa liquor characteristics and indicate that the composition and the sensory quality of cocoa liquor are the result of both a genotypic contribution and the conditions of fermentation and roasting.     

Computerized Methodology for Evaluating Drinking Water Treatment Technologies: Part II

The previously described computer based system, Best Available Technology Evaluator (BATE), is used for least cost comparison of AST and AST with GPGAC and LPGAC processes. The underlying LPGAC cost and process dynamics simulation models are complex and need to be modified and coupled in an efficient manner in order to yield useful preliminary design data. This paper discusses a technique for such model combination and a method for finding the LPGAC least cost. Sensitivity analysis of LPGAC cost and performance with respect to common operating parameters such as empty bed contact time (EBCT), hydraulic loading rate (HL), and process configuration is discussed in light of this efficient model combination and least cost finding technique. This study shows that there is an optimal combination of EBCT and LPGAC process configuration for which its cost is comparable to that of AST alone and AST with GPGAC. Such optimal combinations are discussed for some VOC scenarios.     

Oral administration of Trapa taiwanensis Nakai fruit skin extracts conferring hepatoprotection from CCl4-caused injury

As a folk medicine, the hot-water infusion of water caltrop fruits has been used to protect the liver. In this study, the outer skins of mature water caltrop fruits ( Trapa taiwanensis Nakai) were removed, forced-air-dried, pulverized, and subjected to extraction with hot water, and the infusion was lyophilized and pulverized to prepare a hot water extract of T. taiwanensis (HWETT). HWETT was subjected to assays of α,α-diphenyl-β-picrylhydrazyl scavenging activity, reducing power, Trolox equivalent antioxidant capacity, and antioxidative potency, and all determinations showed HWETT to be a potent antioxidant. As further analyzed with LC-MS, two major HPLC-detected components were elucidated as gallic acid and ellagic acid. Hepatoprotective activity of HWETT was assessed with Sprague-Dawley male rats by oral administration. Six groups of rats (n = 8 for each) were respectively treated, namely, control, CCl(4) (20% CCl(4)/olive oil by 2.0 mL/kg bw), CCl(4) and Silymarin (200 mg/kg bw), CCl(4) and low HWETT dose (12.5 mg/kg bw), CCl(4) and medium HWETT dose (25 mg/kg bw), and CCl(4) and high HWETT dose (125 mg/kg bw). After 8 weeks, all animals were fasted for an additional day and sacrificed to collect blood, liver, and kidney for analyses. Histopathological examinations showed that oral administrations with Silymarin and HWETT were effective in protecting the liver from CCl(4)-caused fatty change. Oral administration of HWETT at 125 mg/kg bw was more effective than was Silymarin at 200 mg/kg bw. On biochemical analyses, oral administrations with HWETT at medium and high doses were effective (p < 0.05) in lowering CCl(4)-caused increases of alanine aminotransferase and aspartate aminotransferase activities. It is of merit to demonstrate HWETT as a potent source of antioxidants and hepatoprotective agents.     

铅胁迫对黄瓜幼苗叶片蛋白质的影响

黄瓜幼苗经不同质量浓度铅处理后,叶片中可溶性蛋白质含量均发生了明显的变化.100 mg/L铅处理时,黄瓜幼苗叶片中可溶性蛋白质含量高于对照值,且随处理时间的延长,与对照比增加的值逐渐减少;500 mg/L和900 mg/L铅处理的叶片中可溶性蛋白质含量随着处理时间的延长表现为下降趋势,并且铅质量浓度越高,随着处理时间的延长,蛋白质含量下降量增加.不同质量浓度铅处理不同时期黄瓜幼苗叶片可溶性蛋白质组分的变化在谱带数和表达量上有明显的差异.     

Estimating reproductive success of brooders and heritability of growth traits in Asian sea bass (Lates calcarifer) using microsatellites

Asian sea bass (Lates calcarifer) is one of the most important marine food fish species in Asia and Australia. To estimate the reproductive success of broodstock and heritabilities of growth‐related traits, two independent full‐factorial crosses (PI and PII) were created by crossing 10 males and 10 females. At 90 days post hatch (dph), the body weight (BW) and total length (TL) of 804 individuals from PI and 900 individuals from PII were measured and tissues samples of each fish were collected. Parents and offspring were genotyped with nine polymorphic microsatellites. Out of 1704 offspring from the two crosses, 98.7% were assigned to their parents. In PI, 19 of 20 parents produced offspring, while in PII, only five parents contributed to offspring. Low contribution of parents to offspring could lead to reduced genetic variation in the next generation. Heritabilities for growth‐related traits were estimated using the pedigrees reconstructed using microsatellite genotypes. The estimates of heritability were 0.22±0.16 and 0.25±0.18 for BW, 0.31±0.14 and 0.24±0.21 for TL and 0.22±0.22 and 0.15±0.09 for Fulton's condition factor in the two crosses respectively. Body weights at 90 dph and at harvest (289 dph) were significantly correlated (r=0.601, P<0.01). Therefore, growth‐related traits could be improved by exploiting additive genetic effects through selective breeding, and broodstock candidates could be selected early in the production cycle.     

Relationships between climate and tree radial growth in interior British Columbia,Canada

Climate is a main driving factor of the formation of annual tree-rings, but which climatic variables are the most influential on radial growth may vary among species and sites. To explore these interactions, tree-ring chronologies along a major elevation gradient were examined for three tree species in southern interior British Columbia (Canada): Pseudotsuga menziesii, Pinus contorta, and Picea glauca × engelmannii. We used correlations and linear and multiple regressions to explore the relationships between tree-ring radial growth and climate variables in the area from 1922 to 1997. All correlation coefficients between ring chronologies and monthly climatic variables were medium to low (from −0.3 to 0.4); nevertheless, moderate but significant trends could be identified. Multivariate models explained up to 53%, 43% and 32% of radial growth variability for P. contorta, P. menziesii and P. glauca × engelmannii, respectively. All three species showed similar radial growth–climate patterns across the elevational gradient, but they had different details that made ring width–climate relationships species-specific. Precipitation-related variables were more related to radial growth at low-elevations, changing into temperature-related variables at high-elevations. Tree-ring width for all three species was primarily and significantly affected by climate variables from the year previous to the growing season and only secondly by current year conditions, but the critical months varied for different species and altitudes. Winter precipitation also affected radial growth, either as a source of water or as a possible agent of physical damage. Although our work showed significant climate influences on breast height tree radial growth, our results also indicated that other site factors such as microclimate or stand dynamics can be as or more important than climate variability.     

Laparoscopic Splenectomy for Treatment of Splenic Hemangiosarcoma in a Dog

Objective: To report laparoscopic splenectomy in a dog. Study Design: Clinical report. Animals: Mixed breed dog (n=1). Methods: Hemangiosarcoma was diagnosed by ultrasound‐guided fine‐needle aspiration of a splenic mass in an 11‐year‐old, 30 kg, mixed breed dog. No metastatic disease was identified during complete staging (chest radiographs, echocardiogram, and abdominal ultrasonography); however, cystic calculi were identified. Laparoscopic splenectomy using Ligasure V was performed through 3 portals and the calculi were removed by laparoscopic‐assisted cystoscopy. Results: Total surgical time was 2 hours and for laparoscopic splenectomy, 65 minutes. The celiotomy incision for splenic removal was 7 cm. The dog recovered uneventfully and was ambulatory 2 hours postoperatively. Conclusion: Laparoscopy with Ligasure V facilitated successful removal of a spleen with a 3 cm mass. Clinical Relevance: Laparoscopic splenectomy in dogs is feasible for removal of a normal‐sized spleen with a moderate‐sized mass.     

Internal friction measurement of tropical species by various acoustic methods

A batch of 54 tropical species was analyzed using free-vibration and forced-released vibration tests. The free-vibration tests were conducted by bending and compression using nylon thread or elastic thread as supports. The wood species used cover a broad spectrum of density values and were obtained from the CIRAD wood collection. Samples were stabilized at a mean moisture content of 11.1%. The goals of the study were (a) to observe the effects of nylon or elastic supports on the measurement of vibration damping, (b) to compare the damping measurements obtained through free vibration in bending and in compression, (c) to understand the relationship between temporal damping and internal friction based on free-vibration and forced-vibration bending tests, and (d) to observe the effect of frequency on bending free-vibration damping on a rosewood specimen (Dalbergia sp., Madagascar). In this study we were able to demonstrate that (a) the type of support has a significant influence on the measurement of the temporal damping, (b) the temporal damping measurements obtained during bending free vibration are linearly linked to those obtained during compression vibration, (c) the expression of internal friction η _V according to temporal damping α was identical during compression and bending free vibration: η _V = α/(πf), and (d) changes in temporal damping α according to frequency f can be modeled in the form α = β ₁ f ² - β ₂ f ⁴. This form is theoretically justified as the first-order form obtained from the generalized differential equation of linear viscoelasticity.     

The effect of physiological and environmental conditions on smolt migration in Atlantic salmon Salmo salar

Hydropower development has negatively influenced Atlantic salmon (Salmo salar) populations. Compensatory hatchery‐rearing programmes exist, but released fish suffer from high mortality that may be related to the lack of experience from natural environments in hatchery‐reared smolts and their large body size and high energetic state. Here, we used acoustic telemetry to test how body size, energetic state, and the environmental conditions of the river affect migration in hatchery‐reared smolts. The study was conducted in three consecutive years between 2011 and 2013 in the lower part of the River Umeälven, Sweden. For individual fish, there was no effect of body size but the energetic state of the fish had a negative effect on sea entry. The most important factor affecting sea entry rate was the water discharge in the old river bed that differed among years. Smolts were more likely to enter the sea in years when the discharge was high or when the discharge increased substantially shortly after release. Hatchery‐reared fish had higher migration speed at a slower flowing section compared with a faster flowing section, which was likely a result of large hesitation to enter the rapid section. The increase in water discharge led to an increase in fish migration speed disproportional to the increase in water velocity. Our results highlight the importance of water discharge for the smolts during smolt migration, and we argue that concern should be given to migrating fish when managing regulated rivers.