Effects of long-term phosphorus fertilization and winter cover cropping on soil phosphorus transformations in less weathered soil

Information concerning sources and sinks of available P in soil is needed to improve soil P management and protect water quality. This study, conducted from 1989 to 1998 on a Sultan silt loam soil (Aquantic Xerochrept), determined the annual P removal rate by corn (Zea mays L.) and P transformation as affected by P rate and winter cover cropping. Treatments included two P rates (0 and 44 kg P ha^–1) applied to corn at planting each year. All cover crops received 19.6 kg P ha^–1 at seeding each fall. Also included was a control without any cover crop and with no P addition. Corn yield and P uptake were affected by P fertilizer additions, but not by cover crops. A fairly constant amount of P was supplied from indigenous soil P when no external P was added. When the amount of P added exceeded that removed by corn, the excess P was converted mainly to NaOH-extractable inorganic P (NaOH-P_i). When the amount of P applied was below that removed by corn, indigenous soil NaOH-P_i acted as a source of available P for the plant. With no reduction of organic P (P_o) extractable by NaOH or NaHCO₃, the contribution from P_o to the available P pool appeared limited. The role of NaOH-P_i in P availability in the soil was substantiated by its significant correlation with labile NH₄Cl-extractable P (NH₄Cl-P; r² =0.60, P <0.001) or NaHCO₃-P_i (r² =0.81, P <0.001) pools. The NaOH-P_i for the soil reflected the changes in soil P resulting from past fertilizer P input and P removal by the crops.Scientific Paper Number 0005-34     

Analysis of amino acids by gas chromatography as the N-trifluoroacetyl n-butyl esters

This presentation describes amino acid analysis with the gas chromatographic method and experimental conditions using the N-trifluoroacetyl n-butyl ester derivatives; the study we describe here was undertaken to compare gas chromatographic (GC) and ion-exchange chromatographic (IEC) analyses of amino acids in hydrolysates of 9 diverse sample types to gain insight into effects of these 2 chromatographic methods of analysis on variation in amino acid results. Our study showed that values for samples prepared by 2 separate laboratories using the same procedure were generally in good agreement when all of the hydrolysates were analyzed by a single laboratory using a single method of analysis. To compare results from gas chromatography with those from ion-exchange chromatography analyses were performed by 2 different laboratories on the same hydrolysates and on different hydrolysates prepared by the same method by both laboratories. The data demonstrate that GC and IEC can be expected to yield essentially identical results when applied to the same hydrolysate. Agreement is so close that interlaboratory differences in hydrolysate preparation of the same sample contribute as much to variation in amino acid results as does the method of analysis, a fact which should be noted in planning collaborative studies.     

Variability in the concentration of three heat stable proteinase inhibitor proteins in potato tubers

The variability of three well characterized proteinase inhibitors, Inhibitor I, molecular weight 39,000, Inhibitor II, molecular weight 21,000, and Carboxypeptidase Inhibitor, molecular weight 4,100, were determined in apical cortical tissues of individual potato tubers of the Russet Burbank variety. The three inhibitors varied within ± 20% among sixty-five tubers and cumulatively represented about 7% of the total soluble proteins. The inhibitors were highly variable among tubers of 106 clones from randomly chosen varieties. Inhibitor I varied about twelve-fold (60 to 745 μg/ml juice), and Inhibitor II varied about seven-fold (158 to 1,025 μg/ml juice). Carboxypeptidase Inhibitor varied from as low as zero (seven varieties) to over 850 μg/ml tuber juice. With 80 tubers from fourteen varieties of potatoes, a positivecorrelation was found between the concentrations of Inhibitor I and Inhibitor II and total soluble protein. Carboxypeptidase Inhibitor did not correlate well with total soluble protein. The positive correlations of Inhibitors I and II (a correlation coefficient of 0.70) with total soluble protein indicated that the proteinase inhibitors may be excellent markers for genetic studies for selecting high protein potato tuber varieties.     

施用黑炭和羊粪对库尔勒香梨园土壤理化性质与产量的影响

为了解黑炭和羊粪在库尔勒香梨生产中的应用效果,采用化肥配施黑炭和羊粪的田间调控试验,研究黑炭和羊粪对库尔勒香梨园土壤理化性质和产量的影响。结果表明:与不施黑炭和羊粪的CK处理相比,施用黑炭和羊粪能有效改变果园土壤颗粒组成,改善土壤物理性质,提高土壤有机质及速效养分含量,促进果园增产。施用黑炭、羊粪27 000 kg·hm^-2的处理效果较为显著,其中施用黑炭27 000 kg·hm^-2对提高土壤有机质含量和改善土壤物理性质效果更显著;施用羊粪27 000 kg·hm^-2对提高土壤碱解氮、有效磷和速效钾的含量以及香梨产量效果更显著。     

A comparison of anesthetic risk factors and outcomes in light and draft horses

As a result of anatomic and physiologic differences, draft breeds may be at greater risk of developing anesthetic complications. The aim of the study was to evaluate and compare anesthetic management of draft (DR) and light (LT) horses. A case‐matched retrospective study of 371 clinical case records of DR (124 cases) and LT (247 cases) horses presented for general anesthesia between 1991 and 1998 was performed. Data were tabulated and comparisons were made using Student's t‐test (significance p < 0.05). Prior to induction, there were significant differences in mean body weight, rectal temperature, PCV, RBC, and serum TP concentration between DR and LT breeds. There were differences in mean doses of pre‐operative butorphanol (LT 21 µg kg^?1; DR 17 µg kg^?1), induction guaifenesin (LT 99 mg kg^?1; DR 88 mg kg^?1), and intraoperative ketamine (LT 0.35 mg kg^?1; DR 0.56 mg kg^?1) required. There were no significant differences in the mean doses of pre‐operative xylazine, detomidine, or induction barbiturate administered. The mean, average, and maximum concentrations of inspired halothane were significantly higher for DR than for LT horses. Draft horses received 33% less intraoperative IV fluids (8.2 mL kg^?1 hour^?1) than LT horses. Mean anesthetic duration, time to extubation, and standing recovery were not significantly different. Induction complications were not reported for either group. Rates of occurrence of intraoperative bradycardia, hypercarbia, hypoxemia, and metabolic acidosis (SBE, TCO₂, and bicarbonate concentration) did not differ significantly. Average MAP was greater in DR horses, but neither the degree nor the mean duration of hypotension differed between DR and LT horses. Mean PaO₂ was significantly lower in DR (246 mm Hg, 32.8 kPa) than in LT (305 mm Hg, 40.7 kPa) breeds. Draft horses were at greater relative risk of hypoventilation than LT horses. The greater MAP and requirement for halothane and intraoperative ketamine may indicate problems in achieving and maintaining a surgical plane of anesthesia. Draft horses may be at a greater risk of ventilation–perfusion mismatching.     

Inducible nitric oxide synthase and cyclooxygenase-2 participate in anti-inflammatory activity of imperatorin from Glehnia littoralis

In this study, we have investigated the anti-inflammatory effects of imperatorin, a compound isolated from the roots of Glehnia littoralis, using a lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) in vitro and a carrageenan (Carr)-induced mouse paw edema model in vivo. When RAW264.7 macrophages were treated with imperatorin together with LPS, a significant concentration-dependent inhibition of NO production was detected. Western blotting revealed that imperatorin blocked the protein expression of iNOS and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW264.7 macrophages significantly. In the anti-inflammatory test, imperatorin decreased the paw edema at 4 and 5 h after Carr administration and increased the activities of catalase, superoxide dismutase, and glutathione peroxidase in paw edema. We also demonstrated that imperatorin significantly attenuated the malondialdehyde level in the edema paw at the fifth hour after Carr injection. Imperatorin decreased the NO and tumor necrosis factor and prostaglandin E2 levels on serum at 5 h after Carr injection. Western blotting revealed that imperatorin decreased Carr-induced iNOS and COX-2 expressions at 5 h in edema paw. An intraperitoneal injection treatment with imperatorin also diminished neutrophil infiltration into sites of inflammation as did indomethacin. The results suggested that imperatorin had anti-inflammatory effects in LPS-stimulated RAW 264.7 cells and Carr-injected mice, respectively. In addition, inhibition of elevated iNOS and COX-2 protein expression as well as neutrophil infiltration of Carr-injected paws may be involved in the beneficial effects of imperatorin.     

Physicochemical and Antioxidant Properties of Gelatin and Gelatin Hydrolysates Obtained from Extrusion-Pretreated Fish (Oreochromis sp.) Scales

Fish gelatin and its hydrolysates exhibit a variety of biological characteristics, which include antihypertensive and antioxidant properties. In this study, fish gelatins were extracted from extrusion-pretreated tilapia scales, and then subjected to analyses to determine the physicochemical properties and antioxidant activity of the extracted gelatins. Our findings indicate that TSG2 (preconditioned with 1.26% citric acid) possessed the greatest extraction yield, as well as higher antioxidant activities compared with the other extracted gelatins. Hence, TSG2 was subjected to further hydrolyzation using different proteases and ultrafiltration conditions, which yielded four gelatin hydrolysates: TSGH1, TSGH2, TSGH3, and TSGH4. The results showed that TSGH4 (Pepsin + Pancreatin and ultrafiltration < 3000 Da) had a higher yield and greater antioxidant activity in comparison with the other gelatin hydrolysates. As such, TSGH4 was subjected to further fractionation using a Superdex peptide column and two-stage reverse-phase column HPLC chromatography, yielding a subfraction TSGH4-6-2-b, which possessed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity compared with the other fractions. Further LC-ESI/MS/MS analysis of TSGH4-6-2-b suggested two novel peptides (GYDEY and EPGKSGEQGAPGEAGAP), which could have potential as naturally-occurring peptides with antioxidant properties. These promising results suggest that these antioxidant peptides could have applications in food products, nutraceuticals, and cosmetics.     

不同施肥措施对冀西北坝上萝卜生长发育的影响

在冀西北冷凉气候条件下,采用田间小区试验方法,研究了不同施肥措施对当地主栽萝卜品种生长发育的影响.结果表明:氮磷钾(NPK)配施的萝卜生物量最大.缺少氮、磷或钾任一元素或萝卜生育前期钾素供应不足,均会影响肉质根膨大期以后叶片的生长,甚至导致早衰;同时降低萝卜产量,减产幅度达18.74%～70.38%.萝卜叶片的干物质累...     

Chitosan-Based Anti-Oxidation Delivery Nano-Platform: Applications in the Encapsulation of DHA-Enriched Fish Oil

Refined cobia liver oil is a nutritional supplement (CBLO) that is rich in polyunsaturated fatty acids (PUFAs), such as DHA and EPA; however, PUFAs are prone to oxidation. In this study, the fabrication of chitosan-TPP-encapsulated CBLO nanoparticles (CS@CBLO NPs) was achieved by a two-step method, including emulsification and the ionic gelation of chitosan with sodium tripolyphosphate (TPP). The obtained nanoparticles were inspected by dynamic light scattering (DLS) and showed a positively charged surface with a z-average diameter of between 174 and 456 nm. Thermogravimetric analysis (TGA) results showed the three-stage weight loss trends contributing to the water evaporation, chitosan decomposition, and CBLO decomposition. The loading capacity (LC) and encapsulation efficiency (EE) of the CBLO loading in CS@CBLO NPs were 17.77–33.43% and 25.93–50.27%, respectively. The successful encapsulation of CBLO in CS@CBLO NPs was also confirmed by the Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The oxidative stability of CBLO and CS@CBLO NPs was monitored by FTIR. As compared to CBLO, CS@CBLO NPs showed less oxidation with a lower generation of hydroperoxides and secondary oxidation products after four weeks of storage. CS@CBLO NPs are composed of two ingredients that are beneficial for health, chitosan and fish oil in a nano powdered fish oil form, with an excellent oxidative stability that will enhance its usage in the functional food and pharmaceutical industries.     

Dynamic modeling of dry non-woven fabric roller carding and control of web density uniformity. I. Precisely industrial controller design

This series of paper discussed the dynamic modeling of non-woven fabric roller carding and the control of web density uniformity. The dynamic system of dry non-woven fabric roller carding was set up to analyze the dynamic model; then in the process of derivation, theoretical exploration and studies were carried out on one carding unit in the system, consisting of cylinder, worker roller, stripper roller. After that, we probed into the relation between rotation angle and angular velocity of carding unit, and analyzed the time-delay of carding unit. With Pade approximation, the time-delay was taken as the simplification of the system model. The above conditions were utilized to derive the transfer function of carding unit and it was extended to the dry non-woven fabric roller carding system combining four of carding units, feed roller, take-in and doffer in series to obtain the transfer function of this whole system. After confirmed by the designed controller, the system was obviously improved in its tracking property. The steady-state error was also eliminated. Meanwhile, with the participation of the controller, this system might produce the maximum overshoot during its transient response. Therefore, this research regulated the reference input according to the designed dominant poles. This combination scheme effectively control the occurrence of the maximum overshoot and make for good system objectives.