Phytoplankton in the aqueous ecological theater: Changing conditions, biodiversity, and evolving ecological concepts

Phytoplankton communities, from lakes to oceans, are changing with anthropogenic nutrient loading and climate change. So, too, are the tools by which phytoplankton are quantified and characterized, yielding a torrent of new data and new types of data that can be related to ecosystem function. New insights have been gained about the physiology of resource acquisition by phytoplankton, allowing new relationships between phytoplankton biodiversity and function to be developed. Despite years of emphasis on the use of inorganic substrates in support of phytoplankton nutrition, it is now well understood that phytoplankton rely on a broad suite of substrates, both dissolved and particulate. Simple characterizations of limiting nutrients are not sufficient to understand how phytoplankton biodiversity is changing, or may change, in future conditions. Ecological theory is also advancing. Ecological stoichiometry brings the seemingly divergent concepts of nutrient limitation and trophic interactions together by recognizing that different organisms both within and between trophic groups have fundamentally different elemental requirements, that food web structure is a function of not only food quantity but also food quality, and that these interactions result in a complex suite of feedbacks that shape community composition. Trait-based (functional response) approaches are increasingly applied in characterizing ecosystem function and response, and new models are also emerging allowing new genomic data to be incorporated in models of ecosystem function. Climate change and altered nutrient loads should continue to motivate both new dynamic balance model architectures and new experimental investigations that support them. This article uses the metaphor of ecological theater to convey contemporary trends and themes against the backdrop of a changing world. There is potential for the outcome of the aqueous play to be characterized as tragedy with more harmful taxa emerging, but with continued science advancements—and if efforts to reduce nutrient pollution and control climate change become global priorities—there can be optimism in the face of tragedy

Contribution à la connaissance de <i>Nassarius semistriatus</i> (Brocchi, 1814) (Mollusca: Gastropoda)

In this paper fossil species from the Neogene of Southern Europe or the Vienna Basin, and Recent ones from the Lusitanian and Westafrican regions, which have been incorrectly assigned to Nassa semistriata Brocchi, 1814 (= Nassa semistriatus) are described, figured and discussed. It appears that: 1- mostly commonly specimens designated as Nassarius semistriatus belong to N. elatus (Gould, 1845). This is a relatively common species, practically ignored by both zoologists and paleontologists. We have been able to trace it from the Upper Middle Miocene to Recent. 2- Some recent specimens designated as « Nassa semistriata » belong, in fact, to Nassarius cabriensis (Fischer et Tournouër, 1873) subspecies ovoideus (Locard, 1886 sub Nassa ovoidea). This subspecies has also been confused with N. trifasciatus (A. Adams, 1853; non Gmelin) = N. vinctus (Marrat, 1877). 3- less frequently fossil specimens determined as N; semistriatus do, in fact, belong to the Mio-Pliocene species: N. hoernesi (Mayer, 1864), N. gigantulus (Bonelli inMichelotti, 1840), N. badensis (Partsch in Hörnes, 1852). 4-rarely the Pleistocene and Recent specimens assigned to N. semistriatus belong to N. edwardsi (Fischer, 1882). This species is much less common than N. elatus and is mostly Mediterranean. 5- we consider Nassarius recidivus (V. Martens, 1876) to be a recent sub-species of the mio-pliocene species N. macrodon (Bronn, 1831) (= N; reconditus (Mayer, 1873), N. auingeri (Hoernes et Auinger, 1882) et N. crypsigonus (Fontannes, 1882)). 6- we have not seen any recent shell which belongs undoutably to N. semistriatus (Brocchi, 1814). 7- we have observed viviparity in two species: N. elatus (Gould, 1845) and N. cabriensis ovoideus (Locard, 1886). An appendix contains some additions and emendations to a list of fossil species of Nassarius mentioned in Glibert, M., 1963.-Les Muricacea et Buccinacea fossiles du Cénozoique étranger des collections de l'Institut royal des Sciences naturelles de Belgique. (Mémoirs I.R.Sc.N.B., 2me série, fasc. 74, 30 septembre 1963, pp. 111-114)

Observations sur le « groupe » de <i>Nassarius clathratus</i> (Born, 1778) (Mollusca prosobranchia)

In this paper 20 taxa of the genus Nassarius s. l., often classified by the authors under the sub-genus Uzita H. et A. Adams, 1853, are described and discussed. The specimens are preserved in the zoological and paleontological collections of the « Institut Royal des Sciences Naturelles » in Brussels. They are either fossils from European and North-African Neogene strata, or recent species from the Mediterranean, Lusitanian and West-African regions. However from the British Museam of Natural History and from the « Museo Civico di Storia naturale di Milano » we have obtained photographs of the original matrial of N. denticulatis (A. Adams, 1852) and of N. prismaticus (Brocchi, 1814) and so have been able to designate lectotypes for both these species. For practical reasons only, this species-group could be named the N. clathratus (Born, 1778)-« group », after its first described member. Several of these taxa are still frequently misinterpreted, especially N. denticulatis, N. limatus (Deshayes in Lamarck, 1844) and N. prismaticus. So we have restricted the synonymy to the quotations whose correctness we could verify. We arranged the taxa according to their morphological affinities, as far as it was possible to do so uniserially. This seems to correspond, at least partly, with their actual relationship. For each taxon we mentioned the geograhical and stratigraphical distribution of the studied specimens, and also some of the chief numerical data. We describe three new species: N. sperlingensis n.sp., from the Pleistocene of Sicily; N. pseudoserratus n.sp., from the Mediterranean Pliocene; N. scaldisianus n.sp., from the Atlantic Pliocene. During the Miocene the « group » is poorly represented. We only mention N. contortus (Dujardin, 1837) in the Helvetian. N. brugnonis (Bellardi, 1882), in direct lineage with N. denticulatus, in the Tortonian. N. spectabilis (Nyst, 1843 = N. elegans (Dujardin non Sowerby) in the Helvetian-Tortonian-Redonian. This last species has often been mistaken for N. limatus and extends to the Scaldisian with its form vandewouweri (Glibert, 1959). During the Pliocene this species group expanded widely and rapidely, mainly in the Mediterranean province, but also in the Atlantic province: in Belgium, France, Great Britain and the Netherlands. Most of the species studied here belong to this geological period. During the Pleistocene the « group » decreased rapidely and today, in the same regions, only N. denticulatus, with no known fossil record, N. limatus, restricted to the Mediterranean and dating from the Upper Pliocene, and N. prismaticus mentioned already by G. Brocchi, in 1814, from the Adriatic Sea, but apparently very rare, can be mentioned.We have got further evidence of two opinions expressed in a previous work about the « group » of N. semistriatus (Brocchi, 1814) (Adam, W. et Glibert, M., 1974): the size and shape of the protoconch are essential characteristics, too often neglected, for the specific identification of those shells. Also in the present case the structure of the columellar callus and the sculpture of the siphonal canal should be taken into account; the subgeneric division commonly used for the classification of the species of Nassarius are mostly missing factual basis.Of general interest are: supplementary evidence of viviparity in some fossil and recent species of Nassarius: in N. ficaratiensis (Monterosato, 1891), from the Sicilian and in N. Limatus; changes in the shell, due to preservation, can bring very great changes in sculpture and may thus lead to inaccurate descriptions. A typical example is N. anomalus (Harmer, 1914). We wish to express our appreciation and sincere gratitude to the persons who have kindly assisted us in the course of our work: Mrs. K.M. Way (British Museum Natural History, London), Dr. Giovanni Pinna (Museo Civico di Storia Naturale, Milano) and Dr. O. Priolo (Catania)

Neutrophil elastase is the 'histone H2A-specific protease'

Fundamental changes in the epigenetic status of histones from hematopoietic stem cells might be one of the driving forces behind many malignant transformations and subsequent leukemia development. The amino-terminal tail of histones and the carboxy-tail of histone H2A protrude from the nucleosome and can be modified by many different posttranslational modifications (PTM) on at least 60 different residues, thereby mediating chromatin dynamics. During an iTRAQ proteome analysis on Chronic Lymphocytic Leukemia (CLL) B-cells we came across a specific kind of histone modification that has received only little attention in epigenetics until now: histone clipping. The clipping of the histone H2A C-tail at V114 was more abundant in the CLL B-cell clones compared to healthy B-cells. This specific proteolytic product was already described in the context of leukemia in the late 70’s and is still being referenced today. To specifically quantify this clipping product, we developed and optimized a sensitive and high throughput AQUA approach, based on two isotopically labeled synthetic peptides. We screened 36 patients to investigate any discriminative power of clipped H2A as a potential prognostic marker. In doing so, we found that clipping mainly occurs in the myeloid lineage and has no clear link to the CLL B-cell clone. Here we show that the responsible enzyme, until now known as the “H2A specific protease”, but previously not identified, actually is Neutrophil Elastase. With the growing interest in the epigenetic potential of histone clipping we emphasize its potential role in hematopoietic differentiation

PiTRAQ, a strategy to simultaneously correlate protein expression and phosphorylation stoichiometry between different samples: evaluation on different mass spectrometers

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