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1.
The methods used to quantify total alginate in brown algal tissue are time-consuming and may also be misleading, so faster
and simpler methods for measuring alginate content would be beneficial in a variety of applications. This study reports on
the use of near infra-red (NIR) analysis to monitor the alginate content of Laminaria hyperborea stipe during biodegradation.
NIR reflectance spectra were recorded for 78 different freeze-dried samples of its stipe. The samples were collected during
several biological degradation experiments and the total alginate content varied from 2.2 to 40.8% Na-alginate (w/w), determined
by established methods based on ion exchange. Data analysis was performed using multivariate calibration methods in order
to relate the spectral data to the alginate content. PLS2 analysis revealed some dependence on material type, probably reflecting
differences in polyphenol content. In the end, a PLS1 model with 9 components was selected. The calculated model was validated
both with internal data and with an external test set. Internal full cross validation explained 96.6% of the variance in alginate
content. The external validation showed that the PLS1 model was able to predict the alginate concentration with a root mean
square prediction accuracy of 2.1%.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
2.
探讨了傅立叶变换近红外光谱技术(FT-NIRS)检测豌豆蛋白质、淀粉、脂肪和总多酚含量的可行性。用化学方法测定190份豌豆种质的蛋白质、淀粉、脂肪以及总多酚含量,采集其子粒与粉末的近红外光谱,采用偏最小二乘法(PLS)分别建立两种光谱与成份含量预测模型。豌豆粉末模型结果优于子粒模型,其中蛋白质和淀粉的粉末模型的预测残差(RPD)为5.88、5.82,相关系数r2达到0.99、0.99,具有很好的预测性能。对其中产地信息详细明确的150份豌豆种质的品质性状与产地进行两步聚类分析,明确得到3种类型,其特点分别为:类群1低蛋白质含量,类群2高总多酚含量,类群3高蛋白质、高淀粉和高脂肪含量。进一步分析了豌豆品质性状随播种期、经度、纬度、海拔高度的变化情况。结果表明,近红外光谱技术可对豌豆种质资源的部分品质性状进行快速筛选鉴定,聚类分析结论、地理坐标与播期对豌豆种质主要品质性状的影响规律,都可为收集高品质性状豌豆种质资源提供可靠依据。 相似文献
3.
4.
应用付立叶变换红外光谱(FT-IR)测定胆石中胆红素钙的含量,使用KBr压片法,吸收度是由积分法表示。胆红素钙在1622.3cm~(-1),1253.1cm~(-1)等处有特征吸收峰,在FT-IR减谱分析的基础上,选定1253.1cm~(-1)为定量吸收峰,它符合Beer-Lambert’s定律(r=0.998)而且共存物干扰小。标准工作曲线是使用胆红素为标准。胆石样品中胆红素钙含量用此法测定,其结果与化学法结果相似。应用FT-IR对混合物定量分析简单、迅速、准确。 相似文献
5.
Alime Ozlem Kirdar Guoxiang Chen James Weidner Anurag S. Rathore 《Biotechnology progress》2010,26(2):527-531
Control of raw materials based on an understanding of their impact on product attributes has been identified as a key aspect of developing a control strategy in the Quality by Design (QbD) paradigm. This article presents a case study involving use of a combined approach of Near‐infrared (NIR) spectroscopy and Multivariate Data Analysis (MVDA) for screening of lots of basal medium powders based on their impact on process performance and product attributes. These lots had identical composition as per the supplier and were manufactured at different scales using an identical process. The NIR/MVDA analysis, combined with further investigation at the supplier site, concluded that grouping of medium components during the milling and blending process varied with the scale of production and media type. As a result, uniformity of blending, impurity levels, chemical compatibility, and/or heat sensitivity during the milling process for batches of large‐scale media powder were deemed to be the source of variation as detected by NIR spectra. This variability in the raw materials was enough to cause unacceptably large variability in the performance of the cell culture step and impact the attributes of the resulting product. A combined NIR/MVDA approach made it possible to finger print the raw materials and distinguish between good and poor performing media lots. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 相似文献
6.
讨论蜘蛛的主要种群拟水狼蛛、食虫瘤胸蛛、粽管巢蛛对稻纵卷叶螟、白背飞虱的选择捕食特性。由结果可见:猎物被捕食量与参试种群编码值(密度)的数量关系可由二次多项式模型技术。当取每科水稻上有稻纵卷叶螟5头,白背飞虱10头,拟水狼蛛2头,粽管巢蛛2头,食虫瘤胸蛛2头时,蜘蛛种群对白背飞虱有较大的选择捕食比率。 相似文献
7.
Quantitative characters of the flowering head of a garden population ofMicroseris laciniata were scored during the second, third, and fourth season of growth. Number of achenes per head, number of phyllaries per head and the average number of pappus parts per achene in single heads show significant plant to plant variation. Achenes per head and pappus parts per achene were scored in identical plants in two subsequent seasons. The number of pappus parts per achene varies freely between five and ten. This contrasts with annual species ofMicroseris in which either five or ten pappus parts are found, depending on the species. In spite of a clear plant-specific average of pappus parts, both high and low pappus part determination can be demonstrated in all specimens. The number of pappus parts depends on the position of an achene on the receptacle, marginal achenes usually having fewer pappus parts than central ones. This gradient is not closely correlated with the position of an achene on the genetic spiral. 相似文献
8.
Hassett AL Radvanski DC Vaschillo EG Vaschillo B Sigal LH Karavidas MK Buyske S Lehrer PM 《Applied psychophysiology and biofeedback》2007,32(1):1-10
Fibromyalgia (FM) is a non-inflammatory rheumatologic disorder characterized by musculoskeletal pain, fatigue, depression,
cognitive dysfunction and sleep disturbance. Research suggests that autonomic dysfunction may account for some of the symptomatology
of FM. An open label trial of biofeedback training was conducted to manipulate suboptimal heart rate variability (HRV), a
key marker of autonomic dysfunction. Methods: Twelve women ages 18–60 with FM completed 10 weekly sessions of HRV biofeedback. They were taught to breathe at their resonant
frequency (RF) and asked to practice twice daily. At sessions 1, 10 and 3-month follow-up, physiological and questionnaire
data were collected. Results: There were clinically significant decreases in depression and pain and improvement in functioning from Session 1 to a 3-month
follow-up. For depression, the improvement occurred by Session 10. HRV and blood pressure variability (BPV) increased during
biofeedback tasks. HRV increased from Sessions 1–10, while BPV decreased from Session 1 to the 3 month follow-up. Conclusions: These data suggest that HRV biofeedback may be a useful treatment for FM, perhaps mediated by autonomic changes. While HRV
effects were immediate, blood pressure, baroreflex, and therapeutic effects were delayed. This is consistent with data on
the relationship among stress, HPA axis activity, and brain function. 相似文献
9.
Larry C. Peterson Gerald H. Haug 《Palaeogeography, Palaeoclimatology, Palaeoecology》2006,234(1):97-113
Changes in the strength and position of the Intertropical Convergence Zone (ITCZ) are an important component of climate variability in the tropical Atlantic. The Cariaco Basin, located on the northern margin of Venezuela, is sensitive to tropical Atlantic climate change and its sediments provide a record of past ITCZ behavior. Today, the Cariaco Basin experiences two distinct seasons that reflect the annual migration of the Atlantic ITCZ. Between January and March, when the ITCZ lies south of the equator, northeasterly trade winds sit directly over Cariaco Basin and strong coastal upwelling and dry conditions dominate. Beginning in June-July, as the ITCZ moves north, local rainfall reaches a maximum and the upwelling diminishes or disappears. Here we summarize new and previously published data on the river-derived terrigenous fraction of Cariaco Basin sediments, as well as comparisons to other paleoclimate records, which together suggest a coherent climatologic response in the tropical Atlantic triggered by a pattern of ITCZ migration that mimics the seasonal cycle. During periods of cooler North Atlantic SSTs, on time-scales ranging from the Little Ice Age to the Younger Dryas to the cold stadials of the last glacial, decreased detrital delivery to Cariaco Basin from local rivers suggests a southward shift in the mean latitudinal position of the ITCZ. During warm interstadials and periods of Holocene and deglacial warmth, northward shifts in ITCZ position and its belt of convective rainfall are inferred from increased detrital delivery to the basin. Whether the rapid shifts in ITCZ position and precipitation recorded by Cariaco Basin sediments and other regional records reflect a response to forcing originating in the high latitude Atlantic or to forcing potentially sourced in the tropics is a key question yet to be fully answered. 相似文献
10.
Abstract. 1. Variability in life-history traits of the common pond skater Gerris lacustris (L.) (Heteroptera: Gerridae) was investigated on a small geographical scale in Bavaria, Germany (≈ 49 °N). In an area of approximately 3.5 × 3.0 km, voltinism and wing length data of G. lacustris were recorded from 65 ponds located either in an open field or surrounded by forest.
2. Life history differed significantly between populations in the two habitat types. Gerris lacustris showed a bivoltine life-cycle in most of the field ponds with a high proportion of long-winged individuals in the diapause generation and a large increase of the short-winged morph in the midsummer generation. In contrast, almost all populations inhabiting forest ponds were univoltine. Only a few forest populations produced any second generation larvae. The long-winged morph dominated during the whole season in forest ponds.
3. The appearance of first-instar larvae was delayed by 3–4 weeks in forest ponds compared with field ponds. Presumably, low temperatures led to this reduction in the developmental rate of eggs and larvae. Consequently, 'field larvae' of the first generation developed under increasing daylight conditions (triggering direct reproduction and brachyptery) but 'forest larvae' developed under a shortening photoperiod (triggering diapause and macroptery).
4. Offspring raised from 'forest parents' in the laboratory showed the same variability in life history when reared in a cool (16.9 ± 2.4 °C) or warm (23.1 ± 1.8 °C) temperature regime.
5. Given the small spatial scale of the study, it is concluded that the variability in the life history of G. lacustris has a strong phenotypic component. 相似文献
2. Life history differed significantly between populations in the two habitat types. Gerris lacustris showed a bivoltine life-cycle in most of the field ponds with a high proportion of long-winged individuals in the diapause generation and a large increase of the short-winged morph in the midsummer generation. In contrast, almost all populations inhabiting forest ponds were univoltine. Only a few forest populations produced any second generation larvae. The long-winged morph dominated during the whole season in forest ponds.
3. The appearance of first-instar larvae was delayed by 3–4 weeks in forest ponds compared with field ponds. Presumably, low temperatures led to this reduction in the developmental rate of eggs and larvae. Consequently, 'field larvae' of the first generation developed under increasing daylight conditions (triggering direct reproduction and brachyptery) but 'forest larvae' developed under a shortening photoperiod (triggering diapause and macroptery).
4. Offspring raised from 'forest parents' in the laboratory showed the same variability in life history when reared in a cool (16.9 ± 2.4 °C) or warm (23.1 ± 1.8 °C) temperature regime.
5. Given the small spatial scale of the study, it is concluded that the variability in the life history of G. lacustris has a strong phenotypic component. 相似文献
11.
Yolanda del Rocio Moreno‐Ramírez Aurelio Hernndez‐Bautista Pedro A. Lpez Venancio Vanoye‐Eligio María Lorena Torres‐Rodríguez Jorge Ariel Torres‐Castillo 《化学与生物多样性》2019,16(10)
The variability in the phytochemical concentrations of Capsicum annuum var. glabriusculum has not been extensively analyzed among wild populations and ecologic niches in its phylogeographic area. This study aimed to determine the variations in the phytochemical and antioxidant contents of the wild Piquin chili. The total flavonoid content of hydroalcoholic extracts (0.06 to 0.70 mg equivalent of quercetin per gram of dry weight (mg QE/g DW)), free radical‐scavenging capacity for 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH.) radicals (0.55 to 8.55 mm TE/g DW), amount of 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS+) in aqueous extracts (18.13 to 107.6 mm TE/g DW) and pungency (21,760 to 88,476 Scoville heat units) were highly variable. By analyzing the spatial distribution using the first three principal components, correlations between the phytochemical content and the free radical‐scavenging capacity (in both extracts) and flavonoid and phenolic contents (in the hydroalcoholic extract) were observed. Consistent with the statistical analysis, the spatial analysis showed intraregional differences in composition patterns, with an emphasis on central and coastal areas. Flavonoid contents, polyphenol contents and free radical‐scavenging activity were the phytochemical components that mainly contributed to the diversity of the population. 相似文献
12.
The purpose of this research was to investigate the influence of changes in the amorphous state on the crystallization of
trehalose. Amorphous trehalose is known to stabilize biomaterials; hence, an understanding of crystallization is vital. Amorphous
trehalose, prepared by spray-drying, was exposed to either a single step (0–75%) in relative humidity (RH) or to modulated
0–75–0% RH to cause crystallization. For the single-step experiment, two samples crystallized in a predictable manner to form
the dihydrate. One sample, while notionally identical, did not crystallize in the same way and showed a mass loss throughout
the time at 75% RH, with a final mass less than that expected for the dihydrate. The idiosyncratic sample was seen to have
a starting near infrared (NIR) spectra similar to that exhibited by anhydrous crystalline trehalose, implying that short-range
order in the amorphous material (or a small amount of crystalline seed, not detectable using powder X-ray diffraction) caused
the sample to fail to form the dihydrate fully when exposed to high RH. The modulated RH study showed that the amorphous material
interacted strongly with water; the intensity of the NIR traces was not proportional to mass of water but rather the extent
of hydrogen bonding. Subsequent crystallization of this sample clearly was a partial formation of the dihydrate, but with
the bulk of the sample then shielded such that it was unable to show significant sorption when exposed to elevated RH. It
has been shown that the nature of the amorphous form will alter the way in which samples crystallize. With oscillation in
RH, it was possible to further understand the interactions between water and amorphous trehalose. 相似文献
13.
C. A. Lopes † E. Benedito-Cecilio ‡ L. A. Martinelli § 《Journal of fish biology》2007,70(6):1649-1659
The spatial and seasonal variability of stable carbon isotopes in detritivorous Prochilodus lineatus , primary producers and particulate organic carbon (POC) were examined to promote a better understanding of the trophic dynamics of food webs in Neotropical ecosystems. Spatial variability in carbon isotope composition in the species showed a decreasing gradient in the Upper Paraná River system, from the Paraná River and Itaipu Reservoir subsystems to the Baía and Ivinheima subsystems. Fish δ13 C followed the isotopic trend of POC along the Paraná River and Baía subsystem. Seasonal differences were not observed in fish. The analysis of percentile contribution of C3 and C4 sources in the species diet revealed the predominance of C3 plants (phytoplanktonic and periphytic algae and riparian vegetation) in most of the analysed subsystems and seasons. Nevertheless, the considerable participation of riparian vegetation was verified, especially in the Ivinheima subsystem in the dry season. C4 macrophytes presented a maximum contribution along the Upper Paraná River. These results demonstrate the existence of specific variability for the consumer and their food sources in different environments of the same ecosystem. 相似文献
14.
C. Souty-Grosset A. Chentoufi J. P. Mocquard P. Juchault 《Invertebrate reproduction & development.》2013,57(2-3):131-151
Summary Armadillidium vulgare females of ten geographical origins were reared under various photoperiodic regimes. Long days stimulated reproduction in all the strains, but, whatever the conditions, females originating from high latitudes began to breed later than ones from low latitudes and, under natural photoperiod of Poitiers, the lag time was increased, more or less linearly, by 2 days per degree of latitude. The ability to remain in reproduction, after a first brood, was also related to the latitudinal origin of the strain. The onset of reproduction in the Sucre strain (Bolivia) was very late in respect to the latitude of the original site; the high altitude of Sucre may explain the divergence from the common rule. Reproduction characteristics of each strain persist in the females born and reared in the laboratory for several generations. This stability makes it possible to study the genetic determination of the photoperiodic responses. One genie system probably controls induction and maintenance of reproduction. This system involves maternal sex linked gene(s) (carried by W heterochromosome) and also autosomal genes with additive effects. 相似文献
15.
In common bean (Phaseolus vulgaris L.), Fusarium root rot (caused by Fusarium solani f. sp. phaseoli) disease severity is increased by environmental factors that stress the plant. The current study used reciprocal grafting
techniques with the resistant cultivar FR266 and the susceptible cultivar Montcalm to determine if the genetic control of
resistance is conferred by the rootstock (root genotype) or the scion (shoot genotype) and if root vigor played a role in
resistance. The influence of a compacted layer on root and shoot genotype response and root rot resistance was studied. Root
rot resistance was found to be controlled by the root genotype, such that on a scale of 1 to 7 (severe disease) the FR266
root had an average score of 2.3 and the Montcalm root had an average score of 4.4. However, when grafted plants were grown
in the presence of a compacted layer, the FR266 root and/or shoot genotype in any graft combination with the susceptible Montcalm
had reduced root rot (score = 2.4 average) than the Montcalm self graft (score = 4.5). Root mass was shown to be controlled
by the root genotype in the absence of compaction such that the FR266 root was 26% larger that the Montcalm root when grafted
onto a FR266 shoot or a Montcalm shoot. When a compacted layer was present the root and shoot genotype both contributed to
root mass. Average root diameter was controlled by the shoot genotype, as the FR266 shoot grafted to Montcalm or FR266 roots
had thicker roots (average diameter 0.455 mm) than the Montcalm shoot (average diameter 0.418 mm). This study shows evidence
that root vigor in the presence of Fusarium disease pressure should be evaluated to effectively develop common bean lines
resistant to Fusarium root rot across a range of environments. 相似文献
16.
Koji Takechi Hideyuki Tamura Kiyoshi Yamaoka Hiromu Sakurat 《Free radical research》1997,26(6):483-496
In pharmacokinetic studies, a variety of analytical method including radioisotopic detection and HPLC (high performance liquid chromatography) has been used. In the present investigation, we developed in vivo BCM (Blood Circulation Monitoring)-ESR method, which is a new technique with a conventional X-band ESR spectrometer for observing stable free radicals in the circulating blood of living rats under anaesthesia. Both 5-(PROXYL derivatives) and 6-(TEMPO derivatives) membered nitroxide spin probes with various types of substituent functional group were used. After physicochemical properties of the spin probes such as hyperfine coupling constant (A-value), g-value and partition coefficient as well as chemical stability of the compounds in the fresh blood were obtained, the in vivo BCM-ESR method was performed in normal rats. Several pharmacokinetic parameters such as half-life of the probes, distribution volume, total body clearance and mean residence time were obtained and discussed in terms of their chemical structures. In addition, clearance of a spin probe was related to the urine concentration. The BCM-ESR method was found to be very useful to observe free radicals at the real time. By time-dependent ESR signal decay of spin probes, pharmacokinetic parameters were obtained. 相似文献
17.
《Free radical research》2013,47(6):483-496
In pharmacokinetic studies, a variety of analytical method including radioisotopic detection and HPLC (high performance liquid chromatography) has been used. In the present investigation, we developed in vivo BCM (Blood Circulation Monitoring)-ESR method, which is a new technique with a conventional X-band ESR spectrometer for observing stable free radicals in the circulating blood of living rats under anaesthesia. Both 5–(PROXYL derivatives) and 6–(TEMPO derivatives) membered nitroxide spin probes with various types of substituent functional group were used. After physicochemical properties of the spin probes such as hyperfine coupling constant (A-value), g-value and partition coefficient as well as chemical stability of the compounds in the fresh blood were obtained, the in vivo BCM-ESR method was performed in normal rats. Several pharmacokinetic parameters such as half-life of the probes, distribution volume, total body clearance and mean residence time were obtained and discussed in terms of their chemical structures. In addition, clearance of a spin probe was related to the urine concentration. The BCM-ESR method was found to be very useful to observe free radicals at the real time. By time-dependent ESR signal decay of spin probes, pharmacokinetic parameters were obtained. 相似文献
18.
B. O. Saidman J. C. Vilardi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,75(1):109-116
Summary
Prosopis (mesquite) is a commercially promising plant genus that has received increased attention lately. Allelic frequencies at 25 enzyme loci in seven species from the section Algarobia were transformed in matrices of genetic distance using three methods. The indices give highly correlated results; only in the cluster Prosopis alba -P. hassleri were minor discrepancies evident. The phenetic relationships observed agree with other biochemical evidence (chromatography of phenol compounds, electrophoresis of seed proteins, etc) but not with morphological groupings. The present data support the hypothesis that the species belonging to the section Algarobia would be equivalent to sub- or semispecies; the community of such sympatric subspecies constitutes a syngameon. 相似文献
19.
20.
Cruz P Ibarra AM Mejia-Ruiz H Gaffney PM Pérez-Enríquez R 《Marine biotechnology (New York, N.Y.)》2004,6(2):157-164
Genetic diversity in a shrimp-breeding program was monitored for 2 generations by microsatellite DNA markers (Pvan1578 and Pvan1815) to establish levels of variation and proceed with a selection program. An increase in the number and frequencies of some alleles in both microsatellite loci from G0 to G2 was induced by foreign sire contributions. Most common alleles and high heterozygosities (around 70% in both loci) were maintained through the generations, indicating that there had not been a significant loss of genetic variability in the breeding program. However, when compared with variability in other wild and cultured stocks, the presence of 4 main alleles at both loci may be an indication that a certain reduction in variability already was present in the line used as founder stock (G0). Therefore, it is recommended that additional genetic variability be introduced to the breeding stock by crossing it with a different line. 相似文献