D-lactate-induced neurotoxicity in calves

D-lactic acidosis occurs as a complication of short-bowel syndrome in humans and in a variety of other gastrointestinal disorders in monogastrics and ruminants. It is associated with signs of impaired central nervous system (CNS) function including ataxia and coma. The objective of this experiment was to determine if either acidification of nervous tissue or D-lactic acid is responsible for decreased neurological function. Eight Holstein calves (32 ± 11 d) were surgically catheterized with indwelling intravenous jugular and atlanto-occipital space cerebrospinal fluid (CSF) catheters and infused for 6 h in random order with iso-molar DL-lactic acid (DL-LA), L-lactic acid (L-LA), hydrochloric acid (HCl) or saline. DL-LA induced ataxia after 4 h of infusion and produced the greatest obtunding of CNS function (at 7 h, score 8.0 ± 0.4), whereas, the other infusions caused neither ataxia nor scores over 1.5 (p < 0.01 from DL-LA). After 6 h, DL-LA induced significantly less acidemia than HCl (pH 7.13 ± 0.06 and 7.00 ± 0.04, base excess −16 ± 1 and −23 ± 3 mmol/l, bicarbonate 11 ± 1 and 8 ± 1 mmol/L respectively, all p < 0.01), but greater than L-LA and saline (p < 0.01). CSF changes followed a similar but less pronounced pattern. Although HCl infusion produced a severe acidemia and CSF acidosis, only minor effects on neurological function were evident suggesting that D-lactate has a direct neurotoxic effect that is independent of acidosis. Conversely, L-LA produced only minor neurological changes.     

基于高光谱特征和偏最小二乘法的春小麦叶绿素含量估算

叶绿素含量是影响作物生长及产量的主要因素。该研究以2017年6月小型试验田获取的抽穗期春小麦叶绿素含量及其对应的光谱反射率为数据源,对红边(627~780 nm)、黄边(566~589 nm)、蓝边(436~495 nm)、绿边(495~566 nm)、吸收谷和反射峰的最大反射率及反射率总和等16个高光谱特征参数与叶绿素含量之间的相关性进行了分析,并结合偏最小二乘回归法(partial least-squares regression,PLSR)对叶绿素含量进行高光谱建模及验证。结果表明:1)对特定的16个光谱特征参数而言,光谱特征参数绿边最大反射率与春小麦叶绿素质量分数之间的决定系数最低(R~20.5);决定系数较高(R~2≥0.5)的光谱特征参数包括蓝边最大反射率、蓝边反射率总和、黄边最大反射率、黄边反射率总和、红边最大反射率、红边反射率总和、绿边反射率总和、820~940 nm反射率总和及最大反射率、500~670 nm归一化吸收深度和560~760 nm归一化吸收深度,其中820~940 nm反射率总和决定系数达到最高(R~2为0.8);2)利用16个特征参量进行PLSR建模后,发现波段范围在820~940 nm的最大反射率及反射率总和所建立的PLSR估算模型为最优模型,其精度参数R~2p=0.8、RMSEp=2.0 mg/g、RPD=3.2。因此,该模型具有极好的预测能力。该研究为相关研究及当地精准农业提供科学支持和应用参考。     

Principal component analysis applied to Fourier transform infrared spectroscopy for the design of calibration sets for glycerol prediction models in wine and for the detection and classification of outlier samples

Principal component analysis (PCA) was used to identify the main sources of variation in the Fourier transform infrared (FT-IR) spectra of 329 wines of various styles. The FT-IR spectra were gathered using a specialized WineScan instrument. The main sources of variation included the reducing sugar and alcohol content of the samples, as well as the stage of fermentation and the maturation period of the wines. The implications of the variation between the different wine styles for the design of calibration models with accurate predictive abilities were investigated using glycerol calibration in wine as a model system. PCA enabled the identification and interpretation of samples that were poorly predicted by the calibration models, as well as the detection of individual samples in the sample set that had atypical spectra (i.e., outlier samples). The Soft Independent Modeling of Class Analogy (SIMCA) approach was used to establish a model for the classification of the outlier samples. A glycerol calibration for wine was developed (reducing sugar content < 30 g/L, alcohol > 8% v/v) with satisfactory predictive ability (SEP = 0.40 g/L). The RPD value (ratio of the standard deviation of the data to the standard error of prediction) was 5.6, indicating that the calibration is suitable for quantification purposes. A calibration for glycerol in special late harvest and noble late harvest wines (RS 31-147 g/L, alcohol > 11.6% v/v) with a prediction error SECV = 0.65 g/L, was also established. This study yielded an analytical strategy that combined the careful design of calibration sets with measures that facilitated the early detection and interpretation of poorly predicted samples and outlier samples in a sample set. The strategy provided a powerful means of quality control, which is necessary for the generation of accurate prediction data and therefore for the successful implementation of FT-IR in the routine analytical laboratory.     

利用蔷薇科植物基因5'UTR快速扩增狗蔷薇RcPIN1和RcPLT的5’末端

狗蔷薇不定根可被噻苯隆(TDZ)高效诱导形成类原球茎,深入探讨其诱导阶段的分子生物学机制,有利于指导切花月季建立类似高效再生和遗传转化体系.快速、准确克隆和筛选狗蔷薇类原球茎发生的关键基因是进行分子生物学水平研究的一个重要前提.利用苹果(Malus×domestica)、桃(Prunus persica)和草莓(Fragaria vesca)高同源性基因5'UTR(非翻译区)的相对保守性,在其内保守区域设计上游简并引物,以M-MLV逆转录酶反转录合成cDNA为模板,直接扩增蔷薇科植物狗蔷薇(Rosa canina)RcPIN1(pin-formed)和RcPLT(plethora)基因5’末端,大大减少了获取众多目的基因全长的时间及成本.结果显示,在狗蔷薇RcPIN1和RcPLT基因与其对应苹果、桃和草莓高同源性基因的5'UTR内,很多区域表现出较高保守性,表明在5'UTR相对保守区域设计上游简并引物扩增目的基因5’末端的合理性.与常规5'CDNA末端快速扩增技术(5’RACE)相比,本方法无需对cDNA模板5’末端加尾同聚物和引入锚定引物,即不必使用昂贵的5’RACE试剂盒,具有快捷、节约等优点,是一种获取蔷薇科植物基因5'末端的可行途径.     

Coinoculated fermentations using saccharomyces yeasts affect the volatile composition and sensory properties of Vitis vinifera L. cv. sauvignon blanc wines

Alcoholic fermentation using Saccharomyces wine yeast is an effective means of modulating wine aroma. This study investigated the impact of coinoculating commercial yeast strains (Vin7, QA23, Vin13) on the volatile composition and sensory profile of Sauvignon Blanc wines. Small-scale replicated fermentations were conducted using single-strain and coinoculations of Vin7 with QA23 and with Vin13. The results showed that the chemical and sensory profiles of the coinoculated wines were different from both the single-strain wines and equal blends of the single-strain wines. Volatile thiol analysis indicated that the Vin7/QA23 coinoculated wines were highest in 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA), although this pattern was not observed for the Vin7/Vin13 yeast combination. The negative white vinegar aroma and high volatile acidity measured in the Vin7 single-strain wines were not present in the coinoculated wines. This study demonstrates that coinoculations can modify the aroma profile of wines, when complementary yeasts are used.     

Enhancing volatile phenol concentrations in wine by expressing various phenolic acid decarboxylase genes in Saccharomyces cerevisiae

Phenolic acids, which are generally esterified with tartaric acid, are natural constituents of grape must and wine and can be released as free acids (principally p-coumaric, caffeic, and ferulic acids) by certain cinnamoyl esterase activities during the wine-making process. Some of the microorganisms present in grape can metabolize the free phenolic acids into 4-vinyl and 4-ethyl derivatives. These volatile phenols contribute to the aroma of wine. The Saccharomyces cerevisiae phenyl acrylic acid decarboxylase gene (PAD1) is steadily transcribed, but its encoded product, Pad1p, shows low activity. In contrast, the phenolic acid decarboxylase (PADC) from Bacillus subtilis and the p-coumaric acid decarboxylase (PDC) from Lactobacillus plantarum display substrate-inducible decarboxylating activity in the presence of phenolic acids. In an attempt to develop wine yeasts with optimized decarboxylation activity on phenolic acids, the padc, pdc, and PAD1 genes were cloned under the control of S. cerevisiae's constitutive phosphoglyceratekinase I gene promoter (PGK1(P)()) and terminator (PGK1(T)()) sequences. These gene constructs were integrated into the URA3 locus of a laboratory strain of S. cerevisiae, Sigma1278b. The overexpression of the two bacterial genes, padc and pdc, in S. cerevisiae showed high enzyme activity. However, this was not the case for PAD1. The padc and pdc genes were also integrated into an industrial wine yeast strain, S. cerevisiae VIN13. As an additional control, both alleles of PAD1 were disrupted in the VIN13 strain. In microvinification trials, all of the laboratory and industrial yeast transformants carrying the padc and pdc gene constructs showed an increase in volatile phenol formation as compared to the untransformed host strains (Sigma1278b and VIN13). This study offers prospects for the development of wine yeast starter strains with optimized decarboxylation activity on phenolic acids and the improvement of wine aroma in the future.     

Dietary supplementation for Santa Inês hair ewes on pasture at pre- and postpartum periods: dry matter intake,digestibility, milk production,and mineral metabolism

The aim of this study was to evaluate the impact of different levels of dietary supplementation and reproductive stages on dry matter intake, digestibility, milk production, and mineral metabolism in Santa Inês hair ewes. Two dietary supplement levels of 0.5 and 1.5%, based on body weight, were used. A total of 12 hair ewes (six subjected to 0.5 and six subjected to 1.5% of concentrate supplementation based on body weight—BW) of the Santa Inês breed were evaluated in a completely randomized design with fixed effects of supplementation level, period, and its interactions. Dry matter intake, digestibility, milk production, and mineral metabolism (calcium (Ca), phosphorus (P), magnesium (Mg), alkaline phosphatase (ALP), type I insulin-like growth factor (IGF-I), parathyroid hormone (PTH), and osteocalcin (OC)) were assessed. Dry matter digestibility was affected by the supplementation level (during both pregnancy and lactation), with higher values in ewes fed at a level of 1.5% of BW. A significant interaction between treatment × reproductive stages was found for the Mg concentration. A period effect (P?<?0.05) on serum concentrations of P, Ca/P, Mg, and IGF-I was observed. Serum P concentrations were influenced (P?<?0.05) by treatments and reproductive stages. There were significant differences in the Ca/P ratio among the reproductive stages. The enzymatic activity of ALP and serum IGFI differed among reproductive stages. Ewes supplemented at a level of 1.5% of BW produced 18.5% more milk than ewes supplemented at a level of 0.5% of BW. The use of 0.5% of body weight in concentrate supplementation is recommended for the reduction of production costs, without having an effect on the mineral metabolism of Santa Inês hair ewes.

     

Evaluation of Four Commercial Grower Diets for Production of Largemouth Bass

We compared performance (growth, survival, condition, and health indices) of largemouth bass, Micropterus salmoides, fingerlings (10.3 g [SE ± 0.5 g] and 92 mm [SE ± 1 mm] total length) fed one of four commercial grower feeds: Purina Aquamax Grower 400 (PAG; PMI Nutrition International LLC), Bio-Oregon BioDiet Grower (BDG; Bio-Oregon), Silver Cup Steelhead (SCS; Silver Cup), and Richloam Bass Fry Diet 12 (RBF; Silver Cup). Sixteen 833-L circular tanks, connected in parallel to a recirculation system, were initially stocked with 2.25 kg of fish (219 fish each, 0.32 fish/L) with four replicates per feed treatment. Water temperature was 25°C, and photoperiod was 15 h light:9 h dark. Feed sizes (2.4–3.0 mm) were comparable, and protein compositions ranged from 49% to 61%. Fish were fed to satiation multiple times per day (trial duration = 100 days). Overall, performance was best for fish fed RBF, followed by PAG and BDG, and then SCS. The SCS feed resulted in significantly lower growth and survival (P ≤ 0.05). The PAG and BDG feeds resulted in significantly lower growth than the RBF feed (P ≤ 0.05); however, survival did not differ (P > 0.05). Performance measures were positively correlated with protein, and protein to energy ratio and negatively correlated with fat and carbohydrate compositions. The four commercial grower feeds resulted in highly varied growth, survival, and health indices, and this research should facilitate feed choice for various largemouth bass production strategies as well as increase contribution of stocked fish.     

Practical Comparison of Commercial Starter Diets for Feed Training Largemouth Bass Fingerlings

We compared performance (growth, survival, and condition) of northern largemouth bass Micropterus salmoides salmoides fingerlings fed one of three commercial starter feeds: Otohime Marine Weaning (OMW; Marubeni Nisshin Feed), Bio-Oregon BiVita Fry (BVF; Bio-Oregon), and Purina Aquamax Starter (PAS; PMI Nutrition International LLC). Nine 833-L circular tanks, connected in parallel to a recirculation system, were stocked with 465 fish (1.4 kg), each to provide a rearing density of 1.1 fish/L. Water temperature was maintained at 27°C, and photoperiod was 15:9 h light:dark. Feed sizes (1.5–1.6 mm) were comparable and had similar protein composition (48%–50%). Feed was dispensed by vibratory feeders at a rate of 5% BWPD from 0730 h to 2130 h every 0.5 h for a total of 29 feedings per day (trial duration = 22 days). Overall performance was best for fish fed OMW, followed by BVF, then PAS. The PAS feed resulted in significantly lower growth, survival, and condition factor (P ≤ 0.05). Though not statistically significant, the BVF feed resulted in lower growth, condition factor, and survival than OMW (P > 0.05). Performance measures were positively correlated with crude fat and negatively correlated with protein to energy ratio of feeds. The OMW or BVF diets may be more appropriate for intensive culture when the artificial feed is the sole food supply, while the PAS diet may be more suitable for extensive culture as a supplemental food source.     

Analyses of BioVOCs variation related to vegetation predominance in the natural park of ampezzo dolomites, UNESCO world heritage area of dolomites

The determination of emitted Biogenic Volatile Compounds (BioVOCs) profile via Field Air Analysis (FAA) — Solid Phase Micro Extraction (75 μm Carboxen/PDMS portable field sampler) was performed using GC-MS. The six sampling sites located in the Natural Park of Ampezzo Dolomites, part of the UNESCO’s World Heritage List, are characterized by different predominating vegetation. The ubiquitous compound hexanal was chosen as internal standard, in order to compare the amounts of the different compound in the different sites. The main terpenes identified were α-pinene, β-pinene, δ-3-carene and d-limonene, while 1,8 cineole was the highest abundant oxygenated terpene. In the site next the national road a higher amount of benzene derivatives (benzene, toluene, o-xylene, p-xylene and ethylbenzene) were observed. In the site relatively close to the road a marked decrease of benzene derivatives was observed. In the sites close to conifers (i.e. Fir, Pine and Larch) the terpenic content observed was higher than in the site close to the mixed forest (mainly large-leaf and some conifers). Some terpenes were observed also in the high-quote meadow site, although of lower abundance than in the other sites. The highest abundance of terpenes was observed in the Pinus cembra (Swiss Pine) site.