Yellow Species Research Articles

MOLLUSCS: THEIR USAGE AS NUTRITION, MEDICINE, APHRODISIAC, COSMETIC, JEWELRY, COWRY, PEARL, ACCESSORY AND SO ON FROM THE HISTORY TO TODAY

Present study has evaluated the usage and properties of the mollusc phylum from the history to today. Many types of molluscs are eaten worldwide, either cooked or raw due to their rich nutritional value. Furthermore, they are used as pearls, cowry and accessory materials, for tools like household dishes, cooking pots and utensils such as spoon, cutlery, scoops, spatulas, etc. Some of them are destructive and caused ecological damage, some serve as intermediate hosts for human parasites; some can cause damage to crops. Mollusc meat is known to be highly nutritious and salutary owing to its high content of essential amino acids, proteins, fatty acids, vitamins and minerals. In addition, some of the bioactive compounds including antiviral, antimicrobial, antiprotozoal, antifungal, antihelminthic and anticancer products are producing by molluscs. The largest edible snail is African land snail Achatina achatina mostly consumed by African people. Molluscs were very prominent dishes during the Roman Empire due to their aphrodisiac effect. Some mollusc species include zinc and essential amino acids which keeping up body energy and boost sex drive as aphrodisiac, arrange immune system and makes bones stronger. Pearls are highly esteemed bivalve products containing nacreous deposit composed of 82 - 86% calcium carbonate (aragonite crystals), 10-14% organic substance conchiolin and 2-4% water. Cowry is a marine snail from genus Cypraea dwelling on mostly in coastal waters of the Indian and Pacific oceans and used instead of money. Money cowry ( Cypraea moneta ), a 2.5cm yellow species, has served as currency in Africa.

Allium Discoloration: Color Compounds Formed during Greening of Processed Garlic.

Structures and formation pathways of compounds responsible for blue-green discoloration of processed garlic were studied in model systems. A procedure was developed for isolation of the color compounds and their tentative identification by high-performance liquid chromatography coupled to a diode array detector and tandem mass spectrometry. It was found that the pigment is a mixture of numerous pyrrole-based purple/blue and yellow species. Experiments with isotope-labeled precursors revealed that two molecules of an amino acid are involved in the formation of each color compound. In the purple/blue species (λmax = 565-600 nm), both amino acid molecules are incorporated into two 3,4-dimethylpyrrole-derived rings linked together by a propenylidine bridge. On the other hand, the yellow compounds (λmax = 420-450 nm) contain only one N-substituted 3,4-dimethylpyrrole ring, to which the second amino acid is bound via a propenylidine side chain.

Divergence among generalist herbivores: the Frankliniella schultzei species complex in Australia (Thysanoptera: Thripidae)

Understanding and interpreting the host plant interactions of “generalist” herbivorous insects requires that species limits are accurately defined, as such taxa frequently harbour cryptic species with restricted host use. We tested for the presence of cryptic species across different host plant species in Australian Frankliniella schultzei using a combination of gene sequencing and newly developed microsatellite markers. We detect deep divergence between three colour morphs (black, brown and yellow) but no discordance between mitochondrial and nuclear genes in areas of sympatry, indicating the presence of at least three species in Australia (and potentially six globally). Microsatellite markers were developed for the brown species but could not be amplified in the black or yellow species because the divergence between them is too great. When applied to six populations across Queensland and New South Wales the microsatellites showed high levels of gene flow across thrips collected from Gossypium hirsutum (cotton), Hibiscus rosa-sinensis and Malvaviscus arboreus, and over distances of at least 950 km, indicating considerable movement by these insects and no host-associated genetic differentiation in the brown species. Significantly, the divergence between the three species in Australia was not associated with any noticeable host specialisation. The substantial overlap in geographical distribution and host plant range raises questions about the process of speciation in generalist insects. Our results provide the basis from which detailed quantification of relative host use can be conducted for each species within the F. schultzei complex; this next step is crucial to fully understanding the host plant relationships of each and, thus, the basis of their speciation.

Camellia tuyenquangensis (Theaceae), a new species from Vietnam

Camellia tuyenquangensis (Theaceae), a new yellow species of camellia from the Chiem Hoa district of the Tuyen Quang province in Vietnam, is described and illustrated. Camellia tuyenquangensis is similar to Camellia luongii but different from the latter species in several morphological features: leaves oblong-ovate to narrow elliptic; flowers 1-2; bracteoles glabrous on both sides; sepal margins ciliate; style cleft one half of the length. The morphological data provisionally support its placement in Camellia sect. Chrysantha Chang.

Identification of Barley Yellow Dwarf Viruses in Poland

Barley yellow dwarf (BYD) is the most important and widespread viral disease of cereal crops, and is caused by a group of related spherical viruses belonging to the family Luteoviridae. In the spring of 2015, BYD symptoms were observed on several winter barley (Hordeum vulgare L.), triticale (Triticosecale Wittm. ex A. Camus), rye (Secale cereale L.), and wheat (Triticum aestivum L.) plants throughout Poland. Infections were confirmed with an enzyme-linked immunosorbent assay involving polyclonal antibodies raised against Barley yellow dwarf virus (BYDV)-MAV and BYDV-PAV. Reverse transcription polymerase chain reaction diagnostic assays were conducted on a subset of 35 samples collected from 11 provinces of Poland. The primer sets targeted the open reading frame-3 fragments of BYDV-GAV, -MAV, -PAV, -PAS, -RMV, and -SGV as well as Cereal yellow dwarf virusRPV species. The specificity of obtained products were verified by sequencing. Molecular analyses revealed the predominance of co-infections with BYDV-MAV and BYDV-PAV, and the presence of other viral species that induced BYD symptoms. A comparative analysis of coat protein gene sequences indicated that some Polish isolates were highly similar (i.e., 99% identity) to Chinese BYDV-GAV, Czech BYDV-PAS, and Jordanian and Turkish BYDV-SGV isolates, thus confirming that these isolates are BYDV-GAV, -PAS, or -SGV species. To the best of my knowledge, this is the first report describing BYDV-GAV, BYDVPAS, and BYDV-SGV infections in Poland.

Assessing the Taxonomic Identity of White and Orange Specimens ofCantharellus: Occasional Colour Variants or Independent Species?

Abstract Species of Cantharellus contain carotenoid pigments, which produce yellow, orange and red colours. As microscopic characters are of limited value to separate species, colour has always been an important taxonomic character for species delimitation in Cantharellus. Entirely white Cantharellus or specimens lacking yellow pigments are occasionally reported from Europe, but it is unclear whether these represent independent species or are simply unusual colour variants of otherwise yellow species. The main objective of this study is to assess the taxonomic identity of such white and orange specimens using molecular data. In the context of an ongoing 4-gene phylogeny of European Cantharellus, an ITS2-LSU dataset representing all the European taxa was assembled, including 9 white and 3 orange specimens. Bayesian analyses revealed that white specimens may occasionally occur in C. amethysteus, C. cibarius, C. ferruginascens, C. pallens and C. romagnesianus, whereas orange specimens are found in C. cibariu...

Taxonomy and phylogeny of yellow Clavaria species with clamped basidia—Clavaria flavostellifera sp. nov. and the typification of C. argillacea, C. flavipes and C. sphagnicola

This study explores species limits of a group of Clavaria species with taxonomic and nomenclatural problems and discusses the phylogeny and circumscription of the genus. The nuc 28S rDNA (28S) and internal transcribed spacer region phylogenies resolve species relationships, and the ITS is shown to be an adequate barcode marker for Clavaria. Yellow, clamped species of Clavaria are distributed in two clades, (i) C. flavostellifera, sister to C. incarnata and C. asterospora in ITS analyses, characterized by producing ornamented spores, and (ii) C. argillacea-C. citrinorubra-C. flavipes-C. sphagnicola, with smooth spores. Clavaria flavostellifera is described as new species based on morphological and molecular characters. Molecular evidence that supports C. sphagnicola as distinct from C. argillacea is provided. The usefulness of spore ornamentation as a taxonomic character is discussed; it is present only in some taxa and then only on spores trapped in the hymenium. Descriptions of C. argillacea, C. flavipes and C. sphagnicola are provided, along with color photographs and a key to yellow species of Clavaria with clamped basidia. Camarophyllopsis and Clavicorona are recovered within a paraphyletic Clavaria in our 28S phylogeny. Clampless contextual hyphae and narrow, slightly thick-walled mycelial hyphae are proposed as synapomorphies of Camarophyllopsis and Clavaria.

Daily rhythm of mutualistic pollinator activity and scent emission in Ficus septica: ecological differentiation between co-occurring pollinators and potential consequences for chemical communication and facilitation of host speciation.

The mutualistic interaction between Ficus and their pollinating agaonid wasps constitutes an extreme example of plant-insect co-diversification. Most Ficus species are locally associated with a single specific agaonid wasp species. Specificity is ensured by each fig species emitting a distinctive attractive scent. However, cases of widespread coexistence of two agaonid wasp species on the same Ficus species are documented. Here we document the coexistence of two agaonid wasp species in Ficus septica: one yellow-colored and one black-colored. Our results suggest that their coexistence is facilitated by divergent ecological traits. The black species is longer-lived (a few more hours) and is hence active until later in the afternoon. Some traits of the yellow species must compensate for this advantage for their coexistence to be stable. In addition, we show that the composition of the scent emitted by receptive figs changes between sunrise and noon. The two species may therefore be exposed to somewhat different ranges of receptive fig scent composition and may consequently diverge in the way they perceive and/or respond to scents. Whether such situations may lead to host plant speciation is an open question.

Speciation of Technetium in Sulfuric Acid/Hydrogen Sulfide Solutions

The speciation of technetium after the reaction of KTcO4 in 12 M H2SO4/H2S(g) has been studied. The mechanism of formation can be described as a transformation from the yellow species TcVIIO3(H2O)2(OH) to the green complex TcVO(HSO4)3(OH)– followed by polymerization, leading to precipitation of Tc2S7 and the presence of the polymeric species Tc–O–Tc coordinated to sulfate ligands in solution.

Molecular phylogenetic relationship between Trichiurus margarites Li, 1992 and Trichiurus sp.2 (sensu Nakabo, 2002) (Perciformes: Trichi-uridae) based on mitochondrial 16S rRNA sequence analysis

The taxonomic identification of the genus Trichiurus(Trichiuridae) has historically been challenging because of the morphological similarities between the species.As a result,Trichiurus lepturus Linnaeus,1758 was recognized as a monotypic cosmopolitan species of Trichiurus prior to 1990.In 1992,Li proposed the new species T.margarites Li,1992,based on morphological differences in the skull patterns and dorsal fin coloration,i.e.su-praoccipital bone with a hard knob and yellow dorsal fin respectively.Subsequently,Yamada et al.described a species of Trichiurus with a yellow dorsal fin from the Ryukyu Islands and East China Sea coast of Kyushu,Japan.This species is very similar to T.margarites,but shows some variation in the size of a pair of knobs on the su-praoccipital crest.Accordingly,the yellow dorsal fin species of Trichiurus from Japan was provisionally called Trichiurus sp.2 by Nakabo.There remains no molecular evidence that elucidates the genetic differences between T.margarites and T.sp.2(sensu Nakabo,2002).Thus,the phylogenetic relationship and taxonomic status of these two species remain unresolved. In this study we examined the mitochondrial 16S rRNA gene sequence from 11 T.margarites individuals collected from the coast of western Hainan Island(Baimajing,Yinggehai and Sanya),South China Sea,China which is the type locality of T.margarites.The 16S rRNA genes were amplified using PCR techniques.Homolo-gous sequences from T.sp.2 and closely-related species from previous studies were also included in the compara-tive analysis.Genetic information indexes,including base composition,sequence variation,and Kimura-2 pa-rameter net genetic distance were examined.Phylogenetic analysis using neighbor-joining(NJ) and maxi-mum-likelihood(ML) methods were conducted using Eupleurogrammus muticus as the outgroup. There was evidence of insertion or deletion of base pairs in the 435 bp sequence alignment,with 63 variable sites,48 parsimony informative sites,and 15 singleton sites.The net genetic distances between T.margarites(from western Hainan Island) and T.sp.2(from Japan,eastern Hainan Island,and Indian Ocean) ranged from 0.000 to 0.006.These values were much lower than those found for interspecific 16S rRNA comparisons in some species of Trichiurus(0.037–0.061),and for intraspecies comparisons between populations of T.lepturus(0.010–0.016).Moreover,the haplotypes of T.margarites and T.sp.2 did not form reciprocal monophyletic clades in the phylogenetic trees(NJ,ML),and the close relationship of the haplotypes of these two species was supported by high confidence levels(NJ 100%,ML 99%).These results indicated that the genetic distance between T.mar-garites and T.sp.2 was at the intraspecific level,and the species T.sp.2(sensu Nakabo,2002) from Japan should be classified as T.margarites Li,1992.It has been suggested that T.margarites is widely distributed from the In-dian Ocean to the western Pacific,and not merely limited to the South China Sea,Taiwan Strait,and Taiwan coastal waters.Based on coalescent estimates of divergence times among species,the origin and evolution of T.margarites are primarily discussed in this study.

Solvent optimization extraction of antioxidants from foxtail millet species’ insoluble fibers and their free radical scavenging properties

In this study, water and 80% of four organic solvents were employed to optimize the extraction of antioxidants from two species of foxtail millet’s insoluble fibers under the same temperature, time, and solid/solvent ratio. The results showed that the acetone was able to extract the maximum amount of antioxidants (2.32mg/g fiber for white specie and 3.86mg/g fiber for yellow specie) followed by methanol and propanol from both samples. The neutral and the ethanol on the other hand extracted small amount of the antioxidants from the two fiber materials. While considerable level of Total Polyphenols Content (TPC) was recorded in both the water and the organic solvents’ extracts, only traces of Total Flavonoid content (TFC) were observed in water, methanol and ethanol extracts. Propanol and acetone extracts was negative to the TFC test.The potency of both white and yellow foxtail millets’ insoluble fibers antioxidant extracts was investigated using five different in vitro tests. It was realized that there was a variation in their capacities to quench DPPH and ABTS+ radicals for the time running of 0–60min. The samples from the yellow cereal exhibited high inhibition capacity against ABTS+. No correlation was observed between TPC and radical scavenging capacities for DPPH and ABTS+. In general, the yellow species contained more antioxidants in comparison with the white one and this accounted for its high antioxidant activity.

Twin-screw Extrusion Processing of Vegetable-based Protein Feeds for Yellow Perch (Perca flavescens) Containing Distillers Dried Grains, Soy Protein Concentrate, and Fermented High Protein Soybean Meal

<span style="color: #800000; font-family: Times New Roman; font-size: small;"> </span><p class="MsoNormal" style="margin: 0in 0in 4pt; line-height: 12pt; mso-line-height-rule: exactly;">Changing to alternative protein sources supports production of more economic aquafeeds. Two isocaloric (3.06 kcal/g) and isonitrogenous (40% db) experimental feeds for juvenile yellow perch were formulated with incorporation of fermented soybean meal (FSBM) and soy protein concentrate (SPC), each of which were at two levels (0 and 20% db), along with constant amounts of high protein distillers dried grains (DDG) (~30% db), and appropriate amounts of other ingredients. Using a pilot scale twin-screw extruder, feed production was performed in two replications for each diet at conditioner steam levels of 0.11 to 0.16 kg/min, extruder water of 0.11 to 0.19 kg/min, and screw speeds of 230 to 300 rpm. The effects of SPC and FSBM<ins datetime="2012-07-09T13:59" cite="mailto:k"> </ins>inclusion on extrudate physical properties were compared with those of a control diet (which contained 20% fishmeal and ~30% DDG). Inclusion of 20% FSBM and 20%SPC resulted in a substantial decrease in unit density by 9.2 and 24%, but an increase in lightness, greenness, yellowness, and expansion ratio of the extrudates by 7, 27, 14, 7, 17, 34, 15, and 16.5%, respectively. SPC inclusion led to a considerable increase in water absorption, thermal resistivity, and thermal diffusivity by 17.5, 6.3, and 17.6%, respectively, whereas no significant change was observed for these properties with incorporation of 20% FSBM. Additionally, all extruded products had high durability. Taken together, using ~30% DDG with20% FSBM or20% SPC as alternative protein sources resulted in viable extrudates with properties appropriate for yellow perch production. A future study investigating the effect of extrusion processing conditions on the production of complete vegetable-based protein feeds for yellow perch species would be appropriate.</p><span style="color: #800000; font-family: Times New Roman; font-size: small;"> </span>

Relevance of an integrative approach for taxonomic revision in sponge taxa: case study of the shallow-water Atlanto-Mediterranean Hexadella species (Porifera:Ianthellidae:Verongida)

The identification of sponges that lack a mineral skeleton is always highly challenging, especially for Hexadella species, which are also fibreless. Recently, the yellow species Hexadella pruvoti Topsent was identified as a cryptic species complex while the pink coloured Hexadella racovitzai Topsent showed two highly divergent lineages. We performed a COI phylogenetic reconstruction using 27 new Mediterranean Hexadella samples in order to confirm the presence of divergent lineages within both shallow-water species. Specimens were described with an integrative approach combining morphological and cytological investigations, biochemical profiling and assessment of natural toxicity in order to identify diagnostic characters for each taxon. H. topsenti, sp. nov. is distinguished from H. racovitzai by its colour, its surface network shape, divergent secondary metabolite patterns and toxicity values. H. crypta, sp. nov. differs from H. pruvoti by a different encrusting growth form when alive, and by distinctively colouring the ethanol fixative solution. In addition, H. pruvoti and H. crypta show different types of cells with inclusions as well as distinct metabolic fingerprints. Natural toxicity values, however, do not permit the separation of H. pruvoti and H. crypta. Our work shows that only the use of a combination of complementary tools can provide relevant descriptions for some problematic taxa.

MORPHOLOGICAL STUDIES ON SIX HAPTORIDA CILIATES (PROTOZOA, CILIOPHORA) FROM THE DAYA BAY, SOUTH CHINA

Ciliated protozoa are an important and abundant component of aquatic ecosystems. Our knowledge on their distribution and the species inventory in South China Sea is still limited. Six free-living marine haptorid ciliates, Phialina salinarum Kahl, 1928, Lacrymaria marina Kahl, 1933, Pseudotrachelocerca trepida (Kahl, 1928) Song, 1990, Chaenea vorax Quennerstedt, 1867, Cyclotrichium cyclokaryon Meunier, 1907, and Didinium gargantua Meunier, 1910, isolated from the coastal waters (salinity 25‰—32‰) of the Daya Bay (114°34'E, 22°36'N), South China, were inves-tigated using live observation and protargol impregnation methods according to Song and Xu 1999. All of these six species were firstly reported from the South China Sea. Based on the Daya Bay populations, much more information par-ticularly with respect to their cortical granules, cell colour, infraciliature and other morphological features in vivo as well as original morphometric data were provided. Compared with related Yellow Sea and Bohai Sea species, some variable characters of these species were recorded. As a new contribution, present paper firstly disclosed another type of cortical granules of Lacrymaria marina and found the Daya Bay population of Cyclotrichium cyclokaryon having more somatic kineties than the Qingdao population. Meanwhile, this work indicates that there is a confirming support of evidence for the haptorid ciliates recognized at the coastal waters of the Daya Bay. A particularly fruitful line of investigation on the high biodiversity haptorid ciliates may be the exploration in these habitats from the South China Sea.

Proton transferversusnontransfer in compounds of the diazo-dye precursor 4-(phenyldiazenyl)aniline (aniline yellow) with strong organic acids: the 5-sulfosalicylate and the dichroic benzenesulfonate salts, and the 1:2 adduct with 3,5-dinitrobenzoic acid

The structures of two 1:1 proton-transfer red-black dye compounds formed by reaction of aniline yellow [4-(phenyldiazenyl)aniline] with 5-sulfosalicylic acid and benzenesulfonic acid, and a 1:2 nontransfer adduct compound with 3,5-dinitrobenzoic acid have been determined at either 130 or 200 K. The compounds are 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 3-carboxy-4-hydroxybenzenesulfonate methanol solvate, C12H12N3+.C7H5O6S-.CH3OH, (I), 2-(4-aminophenyl)-1-phenylhydrazin-1-ium 4-(phenyldiazenyl)anilinium bis(benzenesulfonate), 2C12H12N3+.2C6H5O3S-, (II), and 4-(phenyldiazenyl)aniline-3,5-dinitrobenzoic acid (1/2), C12H11N3.2C7H4N2O6, (III). In compound (I), the diazenyl rather than the aniline group of aniline yellow is protonated, and this group subsequently takes part in a primary hydrogen-bonding interaction with a sulfonate O-atom acceptor, producing overall a three-dimensional framework structure. A feature of the hydrogen bonding in (I) is a peripheral edge-on cation-anion association also involving aromatic C-H...O hydrogen bonds, giving a conjoint R(1)(2)(6)R(1)(2)(7)R(2)(1)(4) motif. In the dichroic crystals of (II), one of the two aniline yellow species in the asymmetric unit is diazenyl-group protonated, while in the other the aniline group is protonated. Both of these groups form hydrogen bonds with sulfonate O-atom acceptors and these, together with other associations, give a one-dimensional chain structure. In compound (III), rather than proton transfer, there is preferential formation of a classic R(2)(2)(8) cyclic head-to-head hydrogen-bonded carboxylic acid homodimer between the two 3,5-dinitrobenzoic acid molecules, which, in association with the aniline yellow molecule that is disordered across a crystallographic inversion centre, results in an overall two-dimensional ribbon structure. This work has shown the correlation between structure and observed colour in crystalline aniline yellow compounds, illustrated graphically in the dichroic benzenesulfonate compound.

Molecular switching of nickel(ΙΙ) complexes using a hemilabile N,N′-bis(β-carbamoylethyl)1,2-diaminocyclohexane ligand

Abstract The reaction of NiCl2·6H2O with one equivalent hemilabile diaminodiamide ligand N,N′-bis(β-carbamoylethyl)1,2-diaminocyclohexane (1) gave a pale blue compound [Ni(C12H24N4O2)(H2O)2]2·3H2O·4Cl (2). With more than one equivalent ligands, 2 was transformed to a yellow species [Ni(C12H22N4O2)]·3H2O (3) by the Ni–O to Ni–N bond rearrangement at two amide sites of the complex. The color change could be described as a pH dependent isomerization of the ligand. The results presented could be useful in the design of new Ni(II)-based switching materials.

Reversible switching of coordination modes of nickel(ΙΙ) complexes using a hemilabile 4,7-diazadecanediamide ligand

The reaction of NiCl 2·6H 2O with a hemilabile diaminodiamide ligand 4,7-diazadecanediamide gave a pale blue compound [Ni(C 8H 18N 4O 2)(H 2O) 2]·2Cl ( 1). In basic solution, 1 was transformed to a yellow species [Ni(C 8H 16N 4O 2)]·3H 2O ( 2) by the Ni–O to Ni–N bond rearrangement at two amide sites of the complex. Structures of 1 and 2 were characterized by single-crystal X-ray diffraction analysis. Structural data for 1 indicated that the nickel atom adopts a six-coordinated N 2O 4 environment and gives an octahedral geometry. The structure of 2 showed that the nickel atom adopts a four-coordinated N 4 environment, giving a square-planar geometry. Compounds 1 and 2 are structurally switchable in response to pH in an aqueous solution. The results presented could be useful in the design of new Ni(II)-based switching materials.

Exploring Pattern Analysis with Sycamore Aphids

Many students enjoy biology as a qualitative science but struggle with its quantitative aspects. Yet the detection of patterns and testing hypotheses about their causes is a central aim of biological inquiry. That is the goal of the laboratory analysis described in this article. This exercise involves the students right away in collecting data from living organisms, calculation of some basic statistics, and the formal test of a hypothesis. This fall will be the 10th year I've used this exercise at the college freshman level, but I believe this lab could be used on almost any campus and adapted to any class size. The equipment requirements are minimal and the protocol is simple to follow. The real value lies in empowering students to work with their own data and to see that patterns in biology can be approached quantitatively (requiring only algebra), all critical tools for inquiry-based learning. The aphid of study, likely to be found on practically any sycamore tree in North America, is Drepanosiphum platanoides (Schrank), a relatively large pale or dark green or reddish yellow species with the wing veins slightly dusky (Essig, 1958, p.234). A few other aphids may be found on sycamore leaves (Drepanaphis spp., Periphyllus spp.) and may be used instead. The point is to illustrate how individuals in a population may be distributed and to test a null hypothesis of randomness that, if rejected, suggests a host of possible biotic or abiotic causes. To activate student interest in the project, solicit their own ideas for causes, after a brief discussion of aphid biology. What follows is the handout I give to the students on the first day; they have a week to complete the lab. After the handout discussion is a section for the instructor on implementation of the techniques used and some possible extensions. Purpose In this lab you will practice important aspects of biological inquiry: observation, data collection, data analysis, and scientific writing. You will work in pairs and do the lab on your own time. The objectives of this laboratory are: 1. to become familiar with how to calculate a sample mean and variance 2. to become familiar with population sampling and data analysis 3. to collect your own data from live organisms and puzzle over a real biological pattern. Ecology has been defined as the study of the distribution and abundance of organisms (Andrewartha & Burch, 1954). This is because patterns we see may reflect and reveal unseen ecological relationships. Thus the analysis of spatial pattern can lead to a better understanding of the biotic and abiotic forces that affect organisms. Our null hypothesis may be that individuals of a species are distributed at random, implying no particular interactions with each other or the environment. For example, when cottonwood seeds drift down onto a newly-formed Platte River sandbar, they may land randomly (that is, any chosen square meter of sandbar has an equal probability of receiving a seed). Later, the emerging seedlings may not show a random pattern. Pattern analysis might reveal a population of organisms to be aggregated (clumped) or evenly-distributed (regular). Both terms refer to a deviation from randomness that can be quantified. One must use care in selecting a technique for sampling organisms that will not bias one's results. Also, different techniques and scales will have different powers of detection. For example, consider that a newspaper photo represents an image at a distance but only dots of various sizes on very close inspection. What we choose to measure, count, etc. has a great influence on the pattern we detect. In some cases, sampling units (SUs) present themselves naturally (i.e., leaves on a plant). In other cases we may choose the size, shape, and location of the SUs. Over a century ago, two University of Nebraska graduate students (Roscoe Pound & Frederick Clements, 1898) championed the use of the quadrat in plant community analysis. …

2-(1H-Pyrrolyl)carboxylic Acids as Pigment Precursors in Garlic Greening

Six model compounds having a 2-(1 H-pyrrolyl)carboxylic acid moiety and a hydrophobic R group were synthesized to study their effects on garlic greening, the structures of which are similar to that of 2-(3,4-dimethyl-1 H-pyrrolyl)-3-methylbutanoic acid (PP-Val) (a possible pigment precursor for garlic greening). The puree of freshly harvested garlic bulbs turned green after being soaked in solutions of all these compounds, and with both increasing concentrations and incubation time the green color of the puree became deeper. In contrast, neither pyrrole alone nor pyrrole combined with free amino acids had the ability to discolor the puree. The compounds exhibited a good relationship between structure and activity of garlic greening, namely, the smaller the size of the R group, the larger the contribution. Also, it was found that the unidentified yellow species can be produced by reacting the model compounds with pyruvic acid at room temperature (23-25 degrees C). Moreover, blue species were formed by incubation of the model compounds with di(2-propenyl) thiosulfinate at room temperature. On the basis of these observations, a pathway for garlic greening was proposed.

Acarospora stictica, a new yellow species containing stictic acid, from Mexico.

Acarospora stictica, a new yellow species containing stictic acid, from Mexico.