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Coelacanths are well-known sarcopterygian (lobe-finned) fishes, which together with lungfishes are the closest extant relatives of land vertebrates (tetrapods). Coelacanths have both living representatives and a rich fossil record, but lack fossils older than the late Middle Devonian (385–390Myr ago), conflicting with current phylogenies implying coelacanths diverged from other sarcopterygians in the earliest Devonian (410–415Myr ago). Here, we report the discovery of a new coelacanth from the Early Devonian of Australia (407–409Myr ago), which fills in the approximately 20Myr ‘ghost range’ between previous coelacanth records and the predicted origin of the group. This taxon is based on a single lower jaw bone, the dentary, which is deep and short in form and possesses a dentary sensory pore, otherwise seen in Carboniferous and younger taxa.

The ability to measure properties of a single cross-bridge in working muscle is important because it avoids averaging the signal from a large number of molecules and because it probes cross-bridges in their native crowded environment. Because the concentration of myosin in muscle is large, observing the kinetics of a single myosin molecule requires that the signal be collected from small volumes. The introduction of small observational volumes defined by diffraction-limited laser beams and confocal detection has made it possible to limit the observational volume to a femtoliter (10 15liter). By restraining labeling to 1 fluorophore per 100 myosin molecules, we were able to follow the kinetics of approximately 400 cross-bridges. To reduce this number further, we used two-photon (2P) microscopy. The focal plane in which the laser power density was high enough to produce 2P absorption was thinner than in confocal microscopy. Using 2P microscopy, we were able to observe approximately 200 cross-bridges during contraction. The novel method of confocal total internal reflection (CTIR) provides a method to reduce the observational volume even further, to approximately 1 attoliter (10 18liter), and to measure fluorescence with a high signal-to-noise (S/N) ratio. In this method, the observational volume is made shallow by illuminating the sample with an evanescent field produced by total internal reflection (TIR) of the incident laser beam. To guarantee the small lateral dimensions of the observational volume, a confocal aperture is inserted in the conjugate-image plane of the objective. With a 3.5-μm confocal aperture, we achieved a volume of 1.5 attoliter. Association-dissociation of the myosin head was probed with rhodamine attached at cys707 of the heavy chain of myosin. Signal was contributed by one to five fluorescent myosin molecules. Fluorescence decayed in a series of discrete steps, corresponding to bleaching of individual molecules of rhodamine. The S/N ratio was sufficiently large to make statistically significant comparisons from rigor and contracting myofibrils.

Verkieselte Brachiopoden dominierte Faunen (55 Arten, d. h. ein Zuwachs von 64% gegenüber vorherigen Untersuchungen) aus dem untersten Devon (mittleres Lochkovium) des Garra Kalksteins von Manildra, östliches Zentral Neu-Süd Wales, werden dokumentiert. Die Arbeit wird vervollständigt durch die Untersuchung der begleitenden tabulaten und rugosen Korallen (12 bzw. 4 Arten) und Conodonten (14 Arten und Unterarten aus 57 Proben), die für die Bestimmung des stratigraphischen Alters der Faunen von zentraler Bedeutung sind. Über weitere, überraschend seltene Funde (vor allem Mollusken), wird nur kurz berichtet. Auch die in den liegenden Schichten des höchsten Maradan Schiefers nachgewiesenen tabulaten und rugosen Korallen (4 bzw. 2 Arten) werden dokumentiert. Sie kommen alle auch in den verkieselten Faunen des Garra Kalksteins vor, obwohl sie dort schlechter erhalten sind. Daneben finden sich Conodonten, die auch in der im Hangenden folgenden Mandagery Park Formation in Erscheinung treten. Die Conodonten Faunen zeigen Maximalalter an, die der delta-Zone für den Garra Kalkstein bei Manildra und pesavis-Zone bis unteres Pragium für die Karbonate der überlagernden Mandagery Park Formation entsprechen. Die verkieselten Brachiopoden-Gemeinschaften aus dem unteren Abschnitt des Garra Kalksteins weisen auf biogeographische Beziehungen zur Alten Welt hin mit bemerkenswerten Beziehungen zu verschiedenen Brachiopoden Faunen aus dem westlichen Nordamerika sowie arktischem Kanada. Engste Beziehungen bestehen zur unteren Quadrithyris Zone oder dem Übergang zur Gypidula pelagica-Quadrithyris Zone von Nevada. Im Gegensatz zur gegenwärtig verbreiteten Annahme, dass die provinzielle Prägung von Brachiopoden Faunen ihre stratigraphische Bedeutung erheblich einschränkt, zeigen die übereinstimmenden stratigraphischen Alter für die Conodonten im Vergleich mit jenen der Brachiopoden Faunen des unteren Devons des westlichen und arktischen Nordamerikas, dass sogar präzise, interkontinentale stratigraphische Korrelationen mit Hilfe von Brachiopoden möglich sind, vorausgesetzt, dass, wie im vorliegenden Fall, die Faunen artenreich sind und aus entsprechenden biogeographischen Räumen stammen. Für die sedimentologischen Zusammenhänge, die Paläoökologie und die biogeographischen Beziehungen der Brachiopoden, Korallen und Conodonten Faunen von Manildra werden neue Daten vorgelegt. Die Tiefwasserablagerungen des Maradana Schiefers gehen ins Hangende in die flach marinen, Brachiopoden dominierten Garra Kalksteine über. Diese werden durch eckige, schwach sortierte allochemische Komponenten, einen hohen Feinklastika Anteil sowie Krusten bildende Algenmatten von Girvanella geprägt, was auf ein niedrig energetisches Milieu und kurze postmortale Transportwege schließen lässt. Dies wird durch den relativ geringen Anteil an disartikulierten Schalen bei den verkieselten Brachiopoden gestützt. Die sedimentologischen Daten weisen auf flache (innerhalb der photischen Zone), offen marine Verhältnisse mit mäßiger bis geringer Strömungsenergie in einem geschützten Gebiet innerhalb einer Karbonatplattform oder einem Schelfrand hin. Die Ablagerungen der Garra Kalksteine werden durch die Klastika und Vulkanoklastika der Mandagery Park Formation (neu definiert) nach oben begrenzt. Die 55 Brachiopodenarten der Garra Kalksteine von Manildra werden 36 Gattungen zugewiesen, einschließlich zwei neuer Rhynchonelliden Gattungen (Protodorsisinus mit der Typusart P. similis und Discamella mit der Typusart D. troparvis). Eine neue Art einer zementierenden Strophomenide (Colletostracia) wird beschrieben, aber nicht näher benannt. Die Korallen und Conodonten Taxa sind durchgehend bereits bekannt.

Late Devonian trilobites from horizons close to the Frasnian-Famennian boundary in the Shogram Formation at Kuragh, Chitral (NW Pakistan) are described. A new species of Asteropyginae, Neocalmonia chitralensis sp. nov., and a new subpecies, Neocalmonia batillifera orientalis subsp. nov., are described; these extend the range of Asteropyginae eastwards from Iran and southern Afghanistan. The Upper Kellwasser Event is located within KUR 19 of Talent et al. (1999).

The levels of oxidatively modified proteins were examined in blood from Alzheimer's disease (AD) patients, non-AD controls, and AD relatives. Oxidative modification was measured by reacting the protein carbonyls with 2,4-dinitrophenyl hydrazine (DNPH). The total oxidized proteins were determined by HPLC, while specific protein oxidation was assessed from Western blots of electrophoretic gels using antibody to the DNPderivatives. Statistically significant elevations (P < 0.05) of total oxidized proteins were observed in both AD subjects and AD relatives when compared with non-AD controls. Moreover, a protein band (e.g., MW = 78-kDa) was uniquely oxidized in the plasma of AD subjects. Furthermore, this protein from AD subjects was more susceptible to in vitro oxidation. These data suggest that such oxidized proteins may be useful as biomarkers for the detection and evaluation of AD.

Abstract: Silicified Early Devonian (Lochkovian;eurekaensis Zone) brachiopods from the Windellama Limestone of south-eastern Australia are documented. New taxa consist of one new genus, a schizophoriid,Pelecymya, type speciesP. caperata sp. nov., 9 other new species,Morinorhynchus trypeter, Asymmetrochonetes picketti, Hadrorhynchia? attinarum, Sphaerirhynchia? mastodon, Ambothyris? inopis. Howellella placeotextilis, Howellella alatextilis, Howellella legirupa, andReticulariopsis saginatus, and 2 new subspecies,Schizophoria antiqua erugata, andGypidula pelagica lunata. Though a typical Old World fauna, it has little resemblance to previously documented Late Silurian-Early Devonian (Ludlow-Lochkovian) brachiopod faunas, including silicified faunas, from elsewhere in Australia. Also documented are the poorly preserved brachiopods from the clastic and volcaniclastic Tangerong Formation (Early Devonian; ?Pragian) overlying the Windellama Limestone.

The conformational change which results from the opening and closing of the hinged lid over the catalytic center of triosephosphate isomerase is transmitted to the subunit interface of the dimer and eventually leads to the spontaneous, specific deamidation of Asn71. This is followed by the deamidation of Asn15 approximately 5 Å away on the neighboring subunit and leads to destabilization of the protein and degradation. However, it has not been established whether this molecular wear and tear occurs via an intra-subunit or inter-subunit transmission of the conformational change. We have studied this first step in the terminal marking by reacting the active-site Glu165 with the substrate analog 3-chloroacetol phosphate (CAP) which immobilizes the hinged lid. Under mild deamidation conditions (pH 9.5, 24 h, 30°C) the native homodimer readily deamidated. In contrast, the CAP-modified homodimers were resistant to deamidation. Heterodimers composed of one native subunit and one CAP subunit showed intermediate deamidation. When the native and CAP-labeled subunits were resolved by electrophoresis in urea gels, it was found that the unlabeled subunit had preferentially deamidated. These data coupled with molecular modeling considerations show that restricting movement of the hinged lid prevents deamidation of Asn71 on that subunit, but that the other subunit with the free hinged lid functions independently and still deamidates. Thus, the conformationally induced wear and tear appears to be largely intra-subunit. These observations clearly link catalysis with terminal marking of the protein and suggest a general mechanism for how other enzymes may wear out.

Oxidative modification of proteins plays a major role in the etiology of aging and age-related diseases. For example, in Alzheimer's disease, although evidence points to oxidation of proteins as a causative factor in loss of cognitive abilities, it is not known which specific proteins of the brain are most susceptible to these modifications. Thus, it is of interest to identify the specific proteins which are susceptible to oxidationin vivo.Two-dimensional protein fingerprint methods offer the analytical potential for resolution of thousands of individual proteins from tissues, and the oxidized proteins can be visualized with immunological probes. Sensitive methods permit recovery and sufficient amino acid sequencing to identify these proteins. However, for such analyses it is essential to simultaneously analyze both protein content and level of oxidation. We have evaluated several approaches, identified the sources of artifacts and interferences, and developed a double-staining procedure that allows visualization and quantitation of total protein patterns as well as the specific oxidized proteins from two-dimensional protein fingerprints. The method has been applied to cells grown in culture and to tissue extracts from young and old animals.

In a brief career, 1911-early 1930s, Georgly Nikolaevich Frederiks swiftly became a leading authority on the paleontology and stratigraphy of the Late Paleozoic of the USSR. Tireless in field and laboratory, he contributed importantly to unraveling the structure of the Urals, and established an international reputation as a paleontologist and stratigrapher, notably for his numerous contributions on Late Paleozoic stratigraphy and paleontology, especially brachiopods. One of the most impressive Soviet paleontologist-geologists of the inter-war era, Frederiks, like so many of the intelligentsia in the USSR, was believed by many to have perished in one of Stalin's 'corrective labor camps'. He was in fact shot, like legions of others, on the charge of conspiring to kill the leaders of the USSR and for personally planning to kill Stalin. His career and fate exemplify what befell the cream of the intelligentsia in the USSR during the Stalin epoch.

Our studies focus on the mechanisms of molecular wear and tear, terminal marking, protein degradation, and how these processes are altered with age. Molecular wear and tear directly links catalysis with postsynthetic terminal marking. For example, the binding of ligands and catalysis cause conformational changes that are transmitted from the catalytic center to the site of terminal marking and enhance the rates of specific covalent modifications, such as deamidation or oxidation. These oxidations or deamidations can introduce “KFERQ motifs” into proteins, which may permit them to be recognized and transported to the site(s) of complete degradation. Terminally marked proteins accumulate in aging cells and tissues and account for many of the health problems of the elderly. Two-dimensional protein fingerprinting coupled with immunostaining permits identification and characterization of these proteins. Free-radical traps or caloric restriction, which may prevent the formation or enhance the degradation of terminally marked proteins, may be useful in the prevention or treatment of age- associated health problems, including dementia. J. Exp. Zool. 282:18–27, 1998. © 1998 Wiley-Liss, Inc.

Experimental parameters affecting photolysis of tryptophan in the lens were evaluated, including: (a) the use of previously-frozen vs. freshly excised lenses, (b) the use of lenses in aqueous buffered solutions vs. in air, (c) the species source of the lens, and (d) the effects of oxygen depletion. Lenses were subjected to monochromatic ultraviolet radiation followed by monitoring of the tryptophan fluorescence spectra while exciting at two or more wavelengths. Previously frozen lenses showed faster UV-induced degradation of tryptophan, particularly in aqueous media. A rapid leakage of fluorescent components (including amino acids and peptides) from intact lenses was observed. Evidence for the artifactual production of free radicals during photometric monitoring of samples in solution was obtained. Species dependent differences were also observed.