SENSORY SHELF-LIFE ESTIMATION OF ALFAJOR BY SURVIVAL ANALYSIS

Survival analysis methodology was used to estimate the shelf life of alfajor (a chocolate‐coated individually wrapped cake) at 20 and 35C by using results obtained from consumers when asked if they would accept or reject samples with different storage times. Sensory acceptability (measured by consumers), off‐flavor (measured by a trained panel) and moisture content were linearly related to time. These correlations were used to estimate values at the shelf‐life times calculated for 25 and 50% rejection probability. Survival analysis provided the following shelf‐life estimation: 74 days at 20C and 33 days at 35C for a 25% of rejection, 87 days at 20C and 39 days at 35C for a 50% of rejection. An alfajor stored at 20C having an acceptability value below 4.9 (1–9 hedonic scale) and off‐flavor intensity above 5.3 (0–10 scale) would be rejected by 25% of the consumers. Chemical data were not good shelf‐life predictors.     

SHELF-LIFE ESTIMATION OF APPLE-BABY FOOD

The aim of the present work was to study the evolution of the color of an apple‐baby food and to estimate its sensory shelf life. Samples of apple‐baby food stored at 25C were analyzed using trained assessors and a consumer panel. A zero‐order reaction kinetics was found for the evolution of sensory color with storage time. Color was highly correlated with consumers' rejection percentage and overall acceptability, which indicates that consumers consider this attribute when deciding to accept or reject this product and in assigning their acceptability scores. Using this correlation, the sensory cutoff point for color, corresponding to a 25% consumer rejection, was calculated. Sensory shelf life was estimated using consumer data. Sensory shelf life estimated by survival analysis was in agreement with that calculated considering an acceptability limit of 6.0 in a 9‐point hedonic scale.     

EFFECTIVENESS OF CATEGORY AND LINE SCALES TO CHARACTERIZE CONSUMER PERCEPTION OF FRUITY FERMENTED FLAVOR IN PEANUTS

Fruity fermented (FF) flavor is a common off‐flavor in peanuts resulting from high‐temperature curing. The 9‐point hedonic scale is the most widely used scale to determine consumer acceptance; however, research has indicated that line scales may provide equal reliability and greater sensitivity. The objectives of this study were to characterize consumer perception of FF flavor in peanuts and to compare the effectiveness of the two scale types. Consumers (n = 208) evaluated control (no FF), low‐intensity (1.0) FF and high‐intensity (3.0) FF peanut pastes for the strength/intensity of roasted peanut flavor (RPF), sweet taste (ST), fresh peanut flavor (FPF) and overall liking (OV) using randomly assigned ballots. Sensitivity in defining consumer perception of off‐flavor in peanuts was greater with use of line scales than with the hedonic scale. The line scale indicated that FF flavor in peanuts, even at low intensity, negatively impacted OV and further identified significantly lower RPF and FPF perception by consumers. The hedonic scale identified only a difference in FPF and was not sensitive enough to show a difference in OV.     

EFFECT OF TAXON SAMPLING,CHARACTER WEIGHTING,AND COMBINED DATA ON THE INTERPRETATION OF RELATIONSHIPS AMONG THE HETEROKONT ALGAE1

Nuclear ribosomal small subunit and chloroplast rbcL sequence data for heterokont algae and potential outgroup taxa were analyzed separately and together using maximum parsimony. A series of taxon sampling and character weighting experiments was performed. Traditional classes (e.g. diatoms, Phaeophyceae, etc.) were monophyletic in most analyses of either data set and in analyses of combined data. Relationships among classes and of heterokont algae to outgroup taxa were sensitive to taxon sampling. Bootstrap (BS) values were not always predictive of stability of nodes in taxon sampling experiments or between analyses of different data sets. Reweighting sites by the rescaled consistency index artificially inflates BS values in the analysis of rbcL data. Inclusion of the third codon position from rbcL enhanced signal despite the superficial appearance of mutational saturation. Incongruence between data sets was largely due to placement of a few problematic taxa, and so data were combined. BS values for the combined analysis were much higher than for analyses of each data set alone, although combining data did not improve support for heterokont monophyly.     

PHYLOGENY OF THE BASAL LINEAGES OF STREPTOPHYTA BASED ON RBCL AND ATPB GENE SEQUENCE DATA

The streptophytes comprise the Charophyceae sensu Mattox and Stewart (a morphologically diverse group of fresh‐water green algae) and the embryophytes (land plants). Several charophycean groups are currently recognized. These include the Charales, Coleochaetales, Chlorokybales, Klebsormidiales and Zygnemophyceae (Desmidiales and Zygnematales). Recently, SSU rRNA gene sequence data allied Mesostigma viride (Prasinophyceae) with the Streptophyta. Complete chloroplast sequence data, however, placed Mesostigma sister to all green algae, not with the streptophytes. Several morphological, ultrastructural and biochemical features unite these lineages into a monophyletic group including embryophytes, but evolutionary relationships among the basal streptophytes remain ambiguous. To date, numerous studies using SSU rRNA gene sequences have yielded differing phylogenies with varying degrees of support dependent upon taxon sampling and choice of phylogenetic method. Like SSU data, chloroplast DNA sequence data have been used to examine relationships within the Charales, Coleochaetales, Zygnemophyceae and embryophytes. Representatives of all basal streptophyte lineages have not been examined using chloroplast data in a single analysis. Phylogenetic analyses were performed using DNA sequences of rbcL (the genes encoding the large subunit of rubisco) and atpB (the beta‐subunit of ATPase) to examine relationships of basal streptophyte lineages. Preliminary analyses placed the branch leading to Mesostigma as the basal lineage in the Streptophyta with Chlorokybus, the sole representative of the Chlorokybales, branching next. Klebsormidiales and the enigmatic genus Entransia were sister taxa. Sister to these, the Charales, Coleochaetales, embryophytes and Zygnemophyceae formed a monophyletic group with Charales and Coleochaetales sister to each other and this clade sister to the embryophytes.     

ANALYSIS OF A PLASTID MULTIGENE DATA SET AND THE PHYLOGENETIC POSITION OF THE MARINE MACROALGA CAULERPA FILIFORMIS (CHLOROPHYTA)1

Molecular phylogenetic relationships within the Chlorophyta have relied heavily on rRNA data. These data have revolutionized our insight in green algal evolution, yet some class relationships have never been well resolved. A commonly used class within the Chlorophyta is the Ulvophyceae, although there is not much support for its monophyly. The relationships among the Ulvophyceae, Trebouxiophyceae, and Chlorophyceae are also contentious. In recent years, chloroplast genome data have shown their utility in resolving relationships between the main green algal clades, but such studies have never included marine macroalgae. We provide partial chloroplast genome data (～30,000 bp, 23 genes) of the ulvophycean macroalga Caulerpa filiformis (Suhr) K. Herig. We show gene order conservation for some gene combinations and rearrangements in other regions compared to closely related taxa. Our data also revealed a pseudogene (ycf62) in Caulerpa species. Our phylogenetic results, based on analyses of a 23‐gene alignment, suggest that neither Ulvophyceae nor Trebouxiophyceae are monophyletic, with Caulerpa being more closely related to the trebouxiophyte Chlorella than to Oltmannsiellopsis and Pseudendoclonium.     

THE PLEURASTROPHYCEAE AND MICROMONADOPHYCEAE: A CLADISTIC ANALYSIS OF NUCLEAR rRNA SEQUENCE DATA1

Partial sequences from the nuclear-encoded 18S and 26S ribosomal RNA molecules from representatives of the five classes of Chlorophyta sensu Mattox and Stewart (1984) were analyzed cladistically in a study of the phylogenetic relationships among the Micromonadophyceae, Pleurastrophyceae, and other green algae. The sequence data indicate that the Micromonadophyceae (= Prasinophyceae) is not monophyletic but comprises at least three lineages occupying a basal position among the green algae. Though the Pleurastrophyceae and the Ulvophyceae both possess counter-clockwise basal body orientations, the sequence data indicate that the Pleurastrophyceae is the sister group to the Chlorophyceae. The molecular data alone do not resolve the monophyly of the Pleurastrophyceae or the Ulvophyceae; however, a combined data set of molecular and non-molecular characters support a monophyletic Pleurastrophyceae. Analyses with user-defined tree topologies and the bootstrap method of character resampling indicate that the relationships shown in the most parasimonious cladograms are well supported by the character data.     

DATA AND DATA INTERPRETATION IN THE STUDY OF LIMB EVOLUTION: A REPLY TO GALIS ET AL. ON THE REEVOLUTION OF DIGITS IN THE LIZARD GENUS BACHIA

Galis and collaborators (2010) claim that our recent paper ( Kohlsdorf and Wagner 2006 ), presenting statistical evidence for the reevolution of digits in the genus Bachia, may be flawed. Their reanalysis of the data does not support the possibility of a reevolution of digits and the authors also argue that such a reevolution would be implausible on functional and developmental grounds. In response, we reanalyzed our data with additional outgroup species. Our results differ from the one published in 2006, but this incongruence is not statistically significant. In contrast, the hypothesis presented by Galis et al. is significantly worse. An analysis of digit number evolution, using novel techniques to test for irreversibility of character loss ( Goldberg and Igic 2008 ), confirmed our original conclusion that there is strong evidence for reevolution of digits in Bachia. We also point out that this result is not in conflict with the hypothesis by Galis and Metz (2001) that mutations affecting the initial digit patterning are associated with strong negative pleiotropic effects and thus unlikely to be fixed in evolution. An important avenue of future research will be to directly test whether reevolved digits develop from conserved digit condensations retained after digit loss.     

PHYLOGENY OF THE ULVOPHYCEAE (CHLOROPHYTA): CLADISTIC ANALYSIS OF NUCLEAR-ENCODED rRNA SEQUENCE DATA1

Cladistic analysis of nuclear-encoded rRNA sequence data provided us with the basis for some new hypotheses of relationships within the green algal class Ulvophyceae. The orders Ulotrichales and Ulvales are separated from the clade formed by the remaining orders of siphonous and siphonocladous Ulvophyceae (Caulerpales, Siphonocladales /Cladophorales [S/C] complex, and the Dasycladales), by the Chlorophyceae and Pleurastrophyceae. Our results suggest that the Ulvophyceae is not a monophyletic group. Examination of inter- and intra-ordinal relationships within the siphonous and siphonocladous ulvophycean algae revealed that Cladophora, Chaetomorpha, Anadyomene, Microdictyon, Cladophoropsis and Dictyosphaeria form a clade. Thus the hypothesis, based on ultrastructural features, that the Siphonocladales and Cladophorales are closely related is supported. Also, the Caulerpales is a monophyletic group with two lineages; Caulerpa, Halimeda, and Udotea comprise one, and Bryopsis and Codium comprise the other. The Dasycladales (Cymopolia and Batophora) also forms a clade, but this clade is not inferred to be the sister group to the S/C complex as has been proposed. Instead, it is either the sister taxon to the Caulerpales or basal to the Caulerpales and S/C clade The Trentepohliales is also included at the base of the siphonous and siphonocladous ulvophycean clade. The Pleurastrophyceae, which, like the Ulvophyceae, posses a counter-clockwise arrangement of flagellar basal bodies, are more closely related to the Chlorophyceae than to the Ulvophyceae based on rRNA sequences. Thus, the arrangement of basal bodies does not diagnose a monophyletic group. Previously reported hypotheses of phylogenetic relationships of ulvophycean algae were tested. In each case, additional evolutionary steps were required to obtain the proposed relationships. Relationships of ulvophycean algae to other classes of green algae are discussed.     

PHYLOGENY OF THE HYDRODICTYACEAE (CHLOROPHYCEAE): INFERENCES FROM rDNA DATA1

The hydrodictyacean green algal lineage has been the focus of much research due to the fossil record of at least some members, their ornamented cell walls, and their distinctive reproductive strategies. The phylogeny of the family was, until recently, exclusively morphology based. This investigation examines hydrodictyacean isolates from several culture collections, focusing on sequences from ribosomal data: 18S rDNA, 26S rDNA (partial), and internal transcribed spacer (ITS)‐2 data. Results from phylogenetic analyses of independent and combined data matrices support the Hydrodictyaceae as a monophyletic lineage that includes isolates of Chlorotetraedron, Hydrodictyon, Pediastrum, Sorastrum, and Tetraedron. Phylogenetic analyses of rDNA data indicate that the three‐dimensional coenobium of Hydrodictyon is evolutionarily distinct from the three‐dimensional coenobium of Sorastrum. The more robust aspects of the ITS‐2 data corroborate the 18S+26S rDNA topology and provide a structural autapomorphy for the Hydrodictyaceae and Neochloridaceae, that is, an abridgment of helix IV in the secondary structure. The rDNA data do not support monophyly of Pediastrum but rather suggest the existence of four additional hydrodictyacean genera: Monactinus, Parapediastrum, Pseudopediastrum, and Stauridium.     

CLONING AND QUANTITATIVE ANALYSIS OF THE CARBONIC ANHYDRASE GENE FROM PORPHYRA YEZOENSIS1

Carbonic anhydrase (CA), an enzyme that catalyzes the interconversion of CO₂ and HCO₃^?, has a critical role in inorganic carbon acquisition in many kingdoms, including animals, plants, and bacteria. In this study, the full‐length cDNA of the CA gene from Porphyra yezoensis Ueda (denoted as PyCA) was cloned by using an expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE). The nucleotide sequence of PyCA consists of 1,153 bp, including a 5′ untranslated region (UTR) of 177 bp, a 3′ UTR of 151 bp, and an open reading frame (ORF) of 825 bp that can be translated into a 274‐amino‐acid putative peptide with a molecular mass (M) of 29.8 kDa and putative isoelectric point (pI) of 8.51. The predicted polypeptide has significant homology to the β‐CA from bacteria and unicellular algae, such as Porphyridium purpureum. The mRNA in filamentous thalli, leafy thalli, and conchospores was examined, respectively, by real‐time fluorescent quantitative PCR (qPCR), and the levels of PyCA are different at different stages of the life cycle. The lowest level of mRNA was observed in leafy thalli, and the level in filamentous thalli and in the conchospores was 4‐fold higher and 10‐fold higher, respectively.     

PHYLOGENY OF THE CONJUGATING GREEN ALGAE BASED ON CHLOROPLAST AND MITOCHONDRIAL NUCLEOTIDE SEQUENCE DATA1

The conjugating green algae represent a lineage of charophyte green algae known for their structural diversity and unusual mode of sexual reproduction, conjugation. These algae are ubiquitous in freshwater environments, where they are often important primary producers, but few studies have investigated evolutionary relationships in a molecular systematic context. A 109‐taxon data set consisting of three gene fragments (two from the chloroplast and one from the mitochondrial genome) was used to estimate the phylogeny of the genera of the conjugating green algae. Maximum likelihood (ML), maximum parsimony (MP), and Bayesian inference (BI) were used to estimate relationships from the 4,047 alignable nucleotides. This study confirmed the polyphyly of the Zygnemataceae and Mesotaeniaceae with respect to one another. The Peniaceae were determined to be paraphyletic, and two genera traditionally classified among the Zygnematales appear to belong to the lineage that gave rise to the Desmidiales. Six genera, Euastrum, Cosmarium, Cylindrocystis, Mesotaenium, Spondylosium, and Staurodesmus, were polyphyletic in this analysis. These findings have important implications for the evolution of structural characteristics in the group and will require some taxonomic changes. More work will be required to delineate lineages of Zygnematales in particular and to identify structural synapomorphies for some of the newly identified clades.     

CONCORDANCE OF MOLECULAR AND ULTRASTRUCTURAL DATA IN THE STUDY OF ZOOSPORIC CHLOROCOCCALEAN GREEN ALGAE1

Alternative evolutionary hypotheses generated from features of vegetative cell morphology and motile cell ultra-structure were investigated using a molecular data set. Complete nuclear-encoded small subunit (18S) ribosomal RNA (rRNA) gene sequences were determined for six species (three each) of the chlorococcalean green algae “Neo chloris” and Characium. Based on motile cell ultra-structure, it was previously shown that both genera could be separated into three distinct groups possibly representing three separate orders and two classes of green algae. 18S rRNA gene sequences were also obtained for three additional taxa, Dunaliella parva Lerche, Pediastrum duplex Meyen, and Friedmannia israelensis Chantanachat and Bold. These organisms were selected because each, in turn, is a representative of one of the three ultrastructural groups into which the Neochloris and Characium species are separable. Phylogenetic analyses utilizing the molecular data fully support the ultrastructural findings, suggesting that the similar vegetative cell morphologies observed in these organisms have resulted from convergence.     

多维球面模型应用于草原监测数据分析的探讨

 提出分析归纳草原监测多元数据的新数学方法,多维球面模型。M个物种所组成的草原的状态可以用M元向量来表示,向量的长度用来表示草原的量值,向量的方向表示草原组成。从草原监测的角度,草原的相对组成是更重要的,成份变化的比率更能说明问题。在处理草原监测数据中使用向量等比系列和向量等差系列是可行的。等比系列比较能反映生物几何增长的本质。为了纠正中间过程被忽略的弱点,要坚持逐年监测,逐步分析,或使用滑动平均。二阶趋势值可尝试用于解决时间滞后问题,卡门滤波用于降低预报误差。因为草原监测需要使用分种数据,必须以人工监测记录为主,再辅以其它高科技手段,如遥感。     

SYSTEMATIC ANALYSIS OF SPHAEROPLEA (CHLOROPHYCEAE)1

A systematic investigation of the genus Sphaeroplea was conducted using cladistic analyses of both structural and isozyme characters for the same set of taxa. The structural data were not able to fully resolve some of the taxa while the isozyme data did produce a tree in which all nodes were supported by data. The structural characters were relatively consistent with one another, whereas the isozyme characters were much less internally consistent. Results from independent, cladistic analyses of both data sets support the concept that among those Sphaeroplea species investigated, S. fragilis Buchheim et Hoffman had an early divergence. The two data sets differed primarily in that the structural data support monophyly of the genus Sphaeroplea and the isozyme data do not. The greater relative consistency of the structural data suggests better support for trees inferred from its analysis. Furthermore, searches for character congruence between the two data sets revealed isozyme data which support monophyly of the genus Sphaeroplea, but had been overwhelmed by conflicting isozyme characters.     

DIFFERENTIAL PROTEOME ANALYSIS OF THE MALE AND FEMALE ANTENNAE FROM Holotrichia parallela

To understand the olfactory mechanisms of Holotrichia parallela antennae in detecting volatile compounds in the environment, protein profiles of H. parallela antennae were analyzed using two‐dimensional electrophoresis followed by mass spectrometry and bioinformatics analyses. Approximately 1,100 protein spots in silver staining gel were detected. Quantitative image analysis revealed that in total 47 protein spots showed significant changes in different genders of adult antennae. Thirty‐five differentially expressed proteins were identified by Matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF/TOF) tandem mass spectrometer, among which 65.7% are involved in carbohydrate and energy metabolism, antioxidant system, transport, and amino acid/nucleotide metabolism. Some proteins identified here have not been reported previously in insect antennae. Identified male‐biased proteins included odorant‐binding protein 4, pheromone‐binding protein‐related protein 2, odorant‐binding protein 14, prophenoloxidase‐I, acyl‐CoA dehydrogenase, aldo‐keto reductase‐like, carbamoyl phosphate synthetase, etc. whereas some proteins are female biased, such as antennae‐rich cytochrome P450, aldehyde dehydrogenase, and putative glutamine synthetase. Alterations in the levels of some proteins were further confirmed by real time polymerase chain reaction (RT‐PCR). The proteomic resources displayed here are valuable for the discovery of proteins from H. parallela antennae.     

农业科研试验数据分析系统－LNT

分析了农业科研试验统计的基本方法,简述了统计软件包－ＬＮＴ的程序总控流程及主要功能,阐述了软件包的主要特点,提出了将农业统计分为方差分析、相关通径、回归分析、遗传分析和数据管理五大类２４小类的思想,编写了１２１种统计方法,运行于各种机型的集成软件包－ＬＮＴ。