Saturday, February 27, 2010

Ikaite, a mineral named after the Ika Fjord in southwest Greenland

The mineral ikaite is named after the Ika Fjord, now spelled Ikka Fjord, in southwest Greenland. This fjord is about 12 km long and forms the southern border of Ivigtut Peninsula, which is bordered on the north by Arsuk Fjord [1].
Ikaite is a metastable hexahydrate of calcium carbonate with formula CaCO3·6H2O [2]. It forms in lake and sea water in glaciomarine environments at temperatures near 0°C and converts to calcite at higher temperatures. The metastability of this mineral has been illustrated with the description of the treatment of the first samples, secured by a diver in 1962 near skerries (tiny islands) in the Ikka Fjord [1]:
Samples taken fresh from skerries appear as white porous material that is rather friable but forms coherent masses, which disintegrate within a few hours into a wet powder. These and other observations showed that samples had to be stored and shipped with special care. The excellent samples obtained in August from the bottom of small pillars were shipped to Copenhagen in the refrigator aboard the M. S. Nanok S of the Royal Greenland Trading Company.
Ikaite has also been found in ocean floor sediments off the coast of Antartica (in 1982) and in minor amounts in Mono Lake, Mono County in eastern California [3]. Present understanding of the geochemistry of ikaite explains the existence of today's tufa columns at lakes in the Great Basin area, including Pyramid Lake (Nevada) and Mono Lake, as a result of climate warming that pseudomorphed ikaite into tufa since the end of the ice age, when ancient Lake Lahontan and other lakes began their gradual desiccation.

Keywords: mineralogy, geography, Greenland, Mono Lake, history

References and suggested reading
[1] Hans Pauly: “Ikaite”, a new mineral from Greenland. Artic 1963, 16, pp. 264-264.
pubs.aina.ucalgary.ca/artic/Arctic16-4-263.pdf.
[2] The mineral and locality database: Ikaite. www.mindat.org/min-2007.html.
[3] Timothy Tierney: Geology of the Mono Basin. Kutsavi Press, Lee Vining, California, 2000
; pp. 59-60.
[4] J. L. Bischoff, J. A. Fitzpatrick and R. J. Rosenbauer: The Solubility and Stabilization of ikaite (CaCO3·6H2O) from 0°C to 25°C: Environmental and Paleoclimatic Implications for Thinolite Tufa. J. Geol. January 1993, 101 (1), pp. 21-33.
Abstract: www.jstor.org/pss/30066092.
[5] B. Buchardt, C. Israelson, P. Seaman and G. Stockmann: Ikaite Tufa Towers in Ikka Fjord, Southwest Greenland: Their Formation by Mixing of Seawater and Alkaline Spring Water. J. Sediment. Res. January 2001, 71 (1), pp. 176-189.
DOI
: 10.1306/042800710176.

Friday, February 26, 2010

Hazenite, a mineral named after earth scientist Robert M. Hazen

Hazenite is a hydrous alkali magnesium phosphate with the formula KNaMg2(PO4)2·14H2O [1,2]. This mineral was discovered and described by Hexiong Yang of the University of Arizona and named after Robert M. Hazen, a senior staff scientist at the Carnegie Institution's Geophysical Laboratory and Clarence Robinson Professor of Earth Science at George Mason University [3].

Hazenite is a white, vitreous, and transparent mineral (see picture on page 64 in [3]). It is precipitated by microbes in the highly alkaline Mono Lake in Mono County, California. Hazenite, like many minerals on Earth, owes its existence to life. Current knowledge of the formation process of hazenite supports the hypothesis/fact of co-dependence and co-evolution of organisms and minerals. The subtitle of a recent article by Robert Hazen summarizes this view [3]:
Looking at the mineral kingdom through the lens of deep time leads to a startling conclusion: most mineral species owe their existence to life.
The lifeless matter is, from the viewpoint of a large time-scale, becoming alive. Geology is going to recognize terms like species and kingdom that are commonly associated with biological nomenclature and taxonomy.

Synonym/code for hazenite: IMA2007-061 [2].

Keywords: earth science, mineralogy, geochemistry, biology, history

References
[1] Carnegie Institution for Science: Hazenite officialy approved as a new mineral. hazen.gl.ciw.edu/node/270.
[2] The mineral and locality database: Hazenite. www.mindat.org/min-38992.html.
[3] Robert M. Hazen: Evolution of Minerals. Scientific American March 2010, 302 (3), pp. 58-65.

Thursday, February 25, 2010

Don't (mis)match Deutsch and Dutch!

Drop the two letters e and s from the German word Deutsch and you get Dutch. This is what a Danish student of German did—according to his teacher—while he tried to short-cut his homework assignment (see Däne verwechselte Deutsch und Dutch). The Danish German teacher Frank Lacay at the private Ådalen school of Ishøj near Copenhagen, Danemark, proved that his pupil, who thought he had translated some Danish text into German (as he was supposed to do by means of his acquired German language skills), in fact translated the given text into Dutch language by using an on-line translation tool on the Internet. By checking on-line translation services himself, the teacher found it obvious that the schoolboy used such a service and clicked Dutch instead of Deutsch: the text of the delivered “homework” translation and the Dutch-triggered machine output were identical.

The best machine is counterproductive when you press the wrong button. But even if you stay button-accurate, I doubt that there is a reliable “best translation” machine—at least not for text embedded in context. Anyway, it is always fun to try, as long as you press the relevant keys and think ahead of the machine …

And this is for the schoolboys:
Deutsch is the German word for the English word German,
Holländisch is the German word for the English word Dutch,
Niederländisch is a German-language synonym for Holländisch,
Dänisch is the German word for the English word Danish.

Monday, February 22, 2010

Short notations for α-amino acids and peptides based on one-letter code (1LC)

A three-letter code (3LC) is typically applied to encode molecular structures that contain sequences of the proteinogenic amino acids. The notations for such structures can further be shortened by about 75% (also omitting hyphens in the sequence notation) when one-letter codes (1LCs) are used. Both, 3LCs and 1LCs for the proteinogenic amino acids can be looked up by their names in different languages (English, French, German, Italian, Portuguese and Spanish) and in context of thermodynamic property links.
The synthetic pentapeptide pentigetide, for which the 3LC-based encoding has previously been demonstrated (see Short notations for α-amino acids and peptides based on three-letter code (3LC) ) being Asp-Ser-Asp-Pro-Arg, shrinks to DSDPR by using the 1LC system.
1LC-based notations are very efficient for sequence search and similarity-based modeling of peptides and derivatives in large libraries.

Note: The design of an encoding system for derivatives of amino acid sequences needs a syntax that distiguishes between amino acid 1LCs and one-letter chemical element symbols. Ambiguities arise for the following letters:
  • C: cysteine (carbon)
  • F: phenylalanine (fluorine)
  • H: histidine (hydrogen)
  • I: isoleucine (iodine)
  • K: lysine (potassium)
  • N: asparagine (nitrogen)
  • O: pyrrolysine (oxygen)
  • P: proline (phosphorus)
  • S: serine (sulfur)
  • U: selenocysteine (uranium)
  • V: valine (vanadium)
  • Y: tyrosine (yttrium)
Finally, the 1LC for aspartic acid (D) may conflict with the symbol for the hydrogen isotope deuterium.

Sunday, February 21, 2010

Short notations for α-amino acids and peptides based on three-letter code (3LC)

α-Amino acids are the building blocks of biomolecules such as peptides and proteins as well as supramolecular structures that are of interest in materials science and nanotechnology. Abbreviations and short notations are frequently used for the “standard” and other amino acids. For the 22 proteinogenic amino acids, which include the 20 standard amino acids plus pyrrolysine and selenocysteine, three-letter codes (3LCs) are in common use. These 3LCs are applied to encode peptides as linear notations. For example, the notation for the synthetic pentapeptide pentigetide [1],
Asp-Ser-Asp-Pro-Arg,
indicates that the molecule consists of a sequence of the L-enantiomers of the α-amino acids aspartic acid (Asp), serine (Ser), aspartic acid (Asp), proline (Pro) and arginine (Arg). The four hyphens in the notation “symbolize” peptide bonds that each connect the carboxylic group of the left-side amino acid residue to the amino group at the Cα-atom of the right-side amino acid residue. The Chemical Abstract name for pentigetide is [1]:
N2-[1-[N-(N-L-α-aspartyl-L-seryl)-L-α-aspartyl]-L-prolyl]-L-arginine.
Pentigetide is an oligopeptide. Many biomolecules, polypeptides and other biopolymers contain more than five amino acid units and the efficiency of the 3LC is immediately appreciated when encoding their molecular structure.

References
[1] Entry 7086 on page 1130 in The Merck Index, Eleventh Edition, Merck & Co. Inc., Rahway, NJ, U.S.A., 1989.
[2] Bibliography and links: Notations for amino acids.

Amino acids in English, French, German, Italian, Portuguese and Spanish

The twenty standard amino acids have one-word names in the languages English, French, German, Italian, Portuguese and Spanish. The only exceptions are the names aspartic acid (Asp) and glutamic acid (Gln), whose molecules contain an additional -COOH group in the side chain. For comparison, the names of standard amino acids are presented in an overview table along with their short notations, the three-letter codes (3LCs) and one-letter codes (1LCs):
Names of α-amino acids in different languages.
With the exception of Asp and Gln, the one-word names are composed from a stem and an ending. The stem spelling is very similar, sometimes undistinguishable, while comparing names of a given amino acid across the considered languages. The endings show language-specific patterns. German names have the ending in (or an in Tryptophan), not having the terminal e of their English and French counterparts that end in ine; with the exception of tryptophan ending in an in German and English and in ane in French. The Italian, Portuguese and Spanish names have the ending na. Here, again, the names of tryptophan make for an exception: the ending is no in these three languages.

The English term amino acid in other languages:
French: acide aminé
German: Aminosäure
Italian: amminoacido
Portuguese: aminoácido
Spanish: aminoácido

Wednesday, February 17, 2010

Click chemistry, a term now recognized in many branches of chemistry

The term click chemistry refers to a synthetic strategy that focuses on “ easy-to-make” chemical compounds and materials from modular “blocks.” In 2001, Sharpless, Kolb, and Finn introduced this term to label a chemical synthesis approach conceptualized to advance fast, modular, process-driven design and application-oriented molecular discovery [1/de,1/en]. They defined a set of criteria that a useful process (reaction scheme) must meet in the context of click chemistry:
The reaction must be modular, wide in scope, give very high yields, generate only inoffensive byproducts that can be removed by nonchromatographic methods, and be stereospecific (but not necessarily enantio-selective). The required process characteristics include simple reaction conditions (ideally, the process should be insensitive to oxygen and water), readily available starting materials and reagents, the use of no solvent or a solvent that is benign (such as water) or easily removed, and simple product isolation. Purification—if required—must be by nonchromatographic methods, such as crystallization or distillation, and the product must be stable under physiological conditions.
In various aspects, the goals of click chemistry overlap with those of sustainable chemistry (green chemistry). Although originally demonstrated and discussed within applications in biochemistry and medicine, click chemistry today is recognized in many other areas including materials science, biotechnology, nanotechnology and photovoltaics. References to selected articles, communicating and reviewing research in and applications of click chemistry in such fields, are given below.

Keywords: chemical synthesis, library synthesis, thermodynamics, kinetics, pharmaceutical chemistry, drug design, material design, chemical reaction types, cycloaddition, nucleophile addition

References
[1/de] H. C. Kolb, M. G. Finn and K. B. Sharpless:
Click Chemie: diverse chemische Funktionalität mit einer Handvoll guter Reaktionen. Angew. Chem. 2001, 113 (11), pp. 2056-2075.
DOI: 10.1002/1521-3757(20010601)113:11<2056::aid-ange2056>3.0.CO;2-W.
[1/en] H. C. Kolb, M. G. Finn and K. B. Sharpless:
Click Chemistry: Diverse Chemical Function from a Few Good Reactions. Angew. Chem. Int. Ed. 2001, 40, pp. 2004-2021.
DOI: 10.1002/1521-3773(20010601)40:11<2004::aid-anie2004>3.0.CO;2-5.
[2] A. J. Dirks, J. J. L. M. Cornelissen, F. L. van Delft, J. C. M. van Hest, R. J. M. Nolte, A. E. Rowan and F. P. J. T. Rutjes:
From (bio)Molecules to Biohybrid Materials with the Click Chemistry Approach. QSAR & Combinatorial Science 2007, 26 (11-12), pp. 1200-1210.
DOI
: 10.1002/qsar.200740085.
[3] W. Zhan, W. Wu, J. Hua, Y. Jing, F. Meng and He Tian:
Photovoltaic properties of new cyanine-naphthalimide dyads synthesized by ‘Click’ chemistry. Tetrahedron Lett. 2007, 48 (14), pp. 2461-2465.
DOI
: 10.1016/j.tetlet.2007.02.034.
[4] J. Lutz and H. G. Bömer:
Modern trends in polymer bioconjugates design. Prog. Polym. Sci. 2008, 33 (1), pp. 1-39.
DOI: 10.1016/j.progpolymsci.2007.07.005.
[5]
Special Issue: Click Chemistry in Polymer Science. Macromol. Rapid Commun. 2008. Table of Contents.
[6] D. Kunz:
Klick-Chemie. Synthesen, die gelingen. Chemie in unserer Zeit (ChiuZ) 2009, 43 (4), pp. 224-230.
DOI: 10.1002/ciuz.200900475.

Saturday, February 13, 2010

The chemical term selenious acid, synonymously used for selenous acid

The chemical compound selenous acid (H2SeO3, or more detailed: SeO(OH)2) is the selenium analogue of sulfurous acid (SO(OH)2), containing one selenium atom in its molecule instead of the sulfur atom in the latter. The term selenous acid is the common name for this compound, but the spelling selenious acid has also been used in the literature.
The name based on the systematic additive nomenclature is dihydroxidooxidoselenium [1].
Selenous acid is used, for example, in its isotopically labeled form (H2[75Se]O3) as a reagent in the preparation of 75Se-labeled cells for studies on selenium metabolism in human T-cells [2].

Note: Selenous acid should not be confused with selenonic acid, which has the same brutto formula as selenous acid, but a different structural formula, SeHO2(OH), with the systematic additive name hydridohydroxidodioxidoselenium [1].

Keywords: inorganic chemistry, biochemistry, nomenclature, synonyms, different spellings of chemical compound names

IUPAC reference
[1] N. G. Connelly, T. Damhus, R. M. Hartshorn and A. T. Hutton (preparators): Nomenclature of Inorganic ChemistryIUPAC Recommendations 2005. RSC Publishing, Cambridge, UK, 2005; Table IR-8.1, page 130.

Selected references using the name selenious acid
[2] V. N. Gladyshev, K.-T. Jeang and T. C. Stadtman:
Selenocysteine, identified as the penultimate C-terminal residue in human T-cell thioredoxin reductase, corresponds to TGA in the human placental gene. Proc. Natl. Acad. Sci. USA June 1996, 93, pp. 6146-6151. Abstract.
[3] H. E. Ganther: Selenotrisulfides.
Formation by the reaction of thiols with selenious acid. Biochemistry 1968, 7 (8), pp. 2898-2905. DOI: 10.1021/bi00848a029.

Selected references using the name selenous acid
[4] F. S. Grimaldi and M. M. Schnepfe:
Semimicrodetermination of Tantalum with Selenous Acid. Anal. Chem. 1958, 30 (12), pp. 2046-2049. DOI: 10.1021/ac60144a056.
[5] J. Milne: Chemical shift references for 77Se NMR spectroscopy. Selenous acid. Magn. Reson. Chem. April 2005, 31 (7), pp. 652-655.
DOI: 10.1002/mrc.1260310709.

Wednesday, February 10, 2010

The term romance in musical compositions and arts

The Orchestra and Community Choral Artists of the Tahoe Area (TOCCATA) performed works of Bach, Bruch and Dvorák this February. The Dvorák piece was Romance in F minor for violin and piano, Op. 11, with Elizabeth Pitcairn as the violin virtuoso. Listening to the guest violinist and orchestra clearly is the best way to get the feeling of what romance means, but I also like the brief introduction given in the program notes [1]:
The term romance has a centuries-long history. As applied to narrative ballads in Spain, by the 18th century, it came to be used for simple lyrical pieces for voice as well as for instruments alone. During the 18th and 19th centuries, Russian composers developed the French variety of the romance as a sentimental category of Russian art song. (“Ochi Chornie” - “Dark Eyes” - is a well-known example.) The Oxford Dictionary of Music states that “generally it implies a specially personal or tender quality.” As for instrumental romances, Mozart subtitled the second movement of his piano concerto no. 20 in D minor (K.466) “Roamanze” and his Horn Concerto has a romanze and Rondo. Robert Schumann was particularly fond of the title for lyrical piano pieces.
Romances became an international affair in the 19th century. Carl Dahlhaus wrote [2]:
[…] the French romance has a history more complicated than would seem to be the case if we simply accept the general verdict, issued from the standpoint of the German lied, that it was nothing but salon music for voice. At the time of Rosseau's Dictionnaire du musique (1767) the romance may well have been a “folklike” narrative song in a “simple, touching” style with a “certain antique aura,” but in the hands of Méhul and Boieldieu in the early nineteenth century it drew either on the cantabile of Italian canzonettas and cavatinas or on the declamatory melodic style of the German lied. True, before Berlioz there were no significant examples of the genre known as romance dialoguée, where the vocal part was held in balance by an illustrative piano accompaniment.
True, now we know what a romance is (if we didn't already before).

References
[1] TOCCATA, The Tahoe Symphony Orchestra, Bach & Bruch with James Rawie (Artistic Director & Conductor):
Program NotesAntonín Dvorák, February 5-9, 2010.
[2] Carl Dahlhaus: Nineteenth-Century Music (translated from German into English by J. Bradford Robinson). University of California Press, Berkeley and Los Angeles, 1989; p. 104.

Sunday, February 7, 2010

Acronym in architecture: BIPV for building integrated photovoltaics

The term building integrated photovoltaics (BIPV) refers to “the architectural, structural and aesthetic integration of photovoltaics into buildings, allowing the incorporation of energy generation into everyday structures such as homes, schools, offices, hospitals and all sort of buildings”[1]. Photovoltaic device and module integration, as a renewable energy technology, produces on-site energy from sunlight. BIPV installations can stand alone (off-grid BIPV systems) or be interfaced with the available utility grid (grid-tied BIPV systems) [2]. BIPV advances as a sustainable practice avoiding adverse environmental impacts associated with the production of electricity from non-renewable resources such as fossil and nuclear fuel. Affordability and growth of BIPV construction depends on the future cost of solar cells and modules as well as the life cycle design of the integrated photovoltaic and building materials. A project to study these aspects of “industrial ecology” has been undertaken [3].
The BIPV concept and technology is multifunctional [1,7]: beyond electricity generation, BIPV-based design includes purposes such as weather protection, thermal insulation, noise protection and modulation of daylight.

The English term building integrated photovoltaics in other languages:
French: renforcement des systèmes photovoltaïques intégrés
German: gebäudeintegrierte Photovoltaik
Italian: costruzione di impianto fotovoltaico integrato
Spanish: construccion de la energía fotovoltaica integrada


Keywords: architecture, photovoltaics, sustainable engineering, translation

References
[1] Mario Pagliaro, Rosaria Ciriminna and Giovanni Palmisano: BIPV: merging photovoltaic with the construction industry. Prog. Photovolt: Res. Appl. January 2010, 18 (1), pp. 61-72. DOI: 10.1002/pip.920.
[2] Steven Strong: Building Integrated Photovoltaics (BIPV) at www.wbdg.org/resources/bipv.php.
[3] Gregory Keoleian and team members: Life Cycle Design of Building Integrated Photovoltaic Systems at www.umich.edu/~nppcpub/research/bipv.htm.
[4] Mario Pagliaro: BIPV - Il fotovoltaico integrato nell'edilizia at www.qualitas 1998.net.bipv.
[5] Stillwell Avenue Station at www.opengreenmap.org/greenmap/nycs-green-apple-map/stillwell-avenue-station-2485.
[6] Integrierte Photovoltaik Demonstrationsanlage Dimbach at www.ipdad.de.
[7] F. Crassard and J. Rode: The evolution of building integrated photovoltaics (BIPV) in the German and French technological innovation systems for solar cells. Master of Science Thesis in Management and Economics of Innovation, Chalmers University of Technology, Göteborg, 2007. Essay at www.essays.se/essay/3e36c09e32.

Saturday, February 6, 2010

Mathematical term in circle packing: Apollonian gasket

Apollonian packings of circles are named after the Greek geometer Apollonius of Perga (ca. 262-190 B.C.) [1]. In such packings, groups of circles are mutually tangent. A key generation step in the construction of Apollonian packings is the placement of a new circle into an interstice, which is formed by mutually tangent circles, in such a way that the new circle is tangent with those interstice-defining circles [2-5]. The successive repetition of this generation step with the newly forming interstices is building up an Apollonian gasket. Apollonian gaskets and similar constructions based on polygons instead of circles are of interest in physics for investigating the “architecture” of foams and powders by computer simulations. Also, fascinating relations between Apollonian gaskets and number theory have recently been studied. Finally, Apollonian gaskets are always good in the design of geometrically inspiring screensavers and op-art images.

Keywords: mathematics, geometry, fractals

References
[1] Biography: Apollonius of Perga.
[2] Kenneth Stephenson: Introduction to Circle PackingThe Theory of Discrete Analytic Functions. Cambridge University Press, Cambridge and New York, 2005; pp. 213-214.
[3] Edward Kasner and Fred Supnick: The Apollonian Packing of Circles. Proc. Natl. Acad. Sci USA December 1943, 29 (11), pp.378-384. Access.
[4] Dana Mackenzie: A Tisket, a Tasket, an Apollonian GasketFractals made of circles do funny things to mathematicians. American Scientist January-February 2010, Volume 98, Number 1, pp. 10-14.
[5] Wolfram MathWorld: Apollonian Gasket.

Friday, February 5, 2010

German: Bonifatiuspfennige; English: St. Cuthbert's beads

The word Bonifatiuspfennige (Saint Boniface's pennies) stands for the German version of Saint Cuthbert's beads (or Cuddy's beads). St. Cuthbert's beads are separated segments of fossil crinoid (sea lily) stalks, found, for example, in northeastern England or in parts of Germany such as the Elm mountain range near Braunschweig (Brunswick), Lower Saxony. They are disk-shaped and have a central hole, making them look like coins or beads. In Germany these disk-shaped fossils are named after Bischof (bishop) Bonifatius (683-755): Bonifatiuspfennige or Bischofspfennige [2] (Pfennig means penny). Anna Marie Roos describes the natural history and discovery of these ancient objects in her fascinating article on crinoid fossils [2], including the following section on mythology and naming:
In other parts of England, the coinlike beads were known as fairy money, and intact cylindrical stems, ringed with ridges, as screw stone. Beads with pentagonal shapes were called star stones, and legend had it that they were created in the clouds and dropped to the Earth during thunderstorms. The sixteenth-century German author Georgius Agricola, in his work De Re Metallica (“Of Metallic Things,” a work also devoted to other minerals and to fossils), described the same sort of stones. But the Germans called them Bonifatiuspfennige, or Saint Boniface's pennies, displaying pride in their own local religious luminary [all bold face mark-up mine].
Yet other German names for Boniface's pennies, such as Hexengeld, Hünentränen, Wichtelsteinchen, Zwergensteinchen, Mühlensteinchen, Sonnensteine, Rädersteine or Sonnenrädchen point back in time to superstition and mystical beliefs in the “dark” Middle Ages [3]. Scientists in Germany simply call them Trochiten after the Greek word trochos for wheel [4].

Keywords: Echinodermata, Crinozoa, Crinoidea, crinoid stalks, paleontology, history, German-English translation

References
[1] wissenschaft-online: www.wissenschaft-online.de/abo/lexikon/bio/10017.
[2] Anna Marie Roos: Lilies of the Sea. Natural History December 2009 / January 2010, Volume 118, Number 10, pp. 26-30.
[3]
Chapter with title “Trochiten in Volksglauben und Brauchtum” at elm-asse-kultur.de/html/geologie.html.
[4] Wikipedia: Trochiten.

Thursday, February 4, 2010

Ancient sea lily remains: St. Cuthbert's beads

Sea lilies, also known as crinoids, are marine animals: echinoderms related to starfish and sea urchins. Stem and branches of a sea lily are built as a stack of disk-shaped, calcareous plates. Each plate features a central hole in such a way that a fluid-filled canal can run through the inside of the stack (or stalk), allowing the passage of a nerve cord. The separated plates of fossil sea lily stalks are called St. Cuthbert's beads, named in the 17th century by English naturalist John Ray and Thomas Willisel of the Royal Society after Saint Cuthbert (ca. 634-687), bishop of Lindisfarne in northeastern England [1]:
The two men “gathered on the sea-shore under the town [on Lindisfarne island], those stones which they call St. Cuthbert's beads. ” The “beads,” which ranged in size from the diameter of a pea to that of a half dollar, were the ridged and perforated fossil disks of stalked crinoids, or sea lilies.
According to today's knowledge, the “beads” found by Ray and Willisel originate from sea lilies that were living in a warm, shallow sea bed between 363 and 325 million years ago, when northern England was near the earth's equator.

Keywords: Echinodermata, Crinozoa, Crinoidea, crinoid stalks, paleontology, history

References
[1] Anna Marie Roos: Lilies of the Sea. Natural History December 2009 / January 2010, Volume 118, Number 10, pp. 26-30.
[2] N. Gary Lane and William I. Ausich: The Legend of St Cuthbert's Beads: A Palaeontological and Geological Perspective. April 2001. BNET-Article.
[3] Natural History Museum: Fossil Folklore, Crinoids: St Cuthbert's Beads.

Tuesday, February 2, 2010

The tip of the gallberg

Everybody knows the idiomatic expression “the tip of the iceberg.” Recently, I came across a metamorphosis of this expression: “the tip of the gall-berg.” It was used by Ron Russo in a fascinating article about galls [1]. Galls are swellings on plant leaves—shaped like nipples, blisters, bulbs, veins, baskets, or stars. They nurse insect larvae. About 13,000 insect species have evolved the ability to induce galls in specific host plants.
Many questions about plant-insect relations remain unanswered. Curiosity and appreciation for beautiful shapes and biodiversity is needed to shine, by long-term exploration, some light onto “the bottom of the gallberg”—possible only if respective guest-host species and their ecosystems will be preserved.

Keywords: idioms, entomology, plant science

Reference:
[1] Ron Russo: Confessions of a Gall Hunter. Natural History December 2009 / January 2010, Volume 118, Number 10, pp. 20-25. Article.