bluuebunny/crossref_metadata_2025 huggingface dataset:
Interleukin‐2‐Induced Nitric Oxide Synthase and Nuclear Factor‐κB Activity in Activated Natural Killer Cells and the Production of Interferon‐γ
Authors: Jyothi  , Khar
Published: March 2003

We have previously shown that inducible nitric oxide synthase (iNOS) was up‐regulated in natural killer (NK) cells when AK‐5 tumour cells were transplanted subcutaneously into syngeneic Wistar rats. This study was designed to investigate the role of interleukin (IL)‐2 during the induction of iNOS and to understand the subsequent events involved in NK cell activation. There was up‐regulation of iNOS expression when naïve NK cells were cultured in the presence of recombinant IL‐2. These NK cells produced a higher nitrite content and possessed cytotoxic activity against YAC‐1 and AK‐5 tumour cells. Induction of iNOS enhanced nuclear factor (NF)‐κB binding activity in IL‐2 activated NK cells, which was confirmed using l‐NAME, an NO synthesis inhibitor. Addition of L‐NAME along with rIL‐2 significantly blocked NF‐κB activity and also down‐regulated the production of NO and the cytotoxic activity of NK cells. Furthermore, injection of anti‐IL‐2 antibody in subcutaneous tumour transplanted animals abrogated significantly the expression of iNOS and NF‐κB activity, leading to reduced NO production and cytotoxic activity of NK cells against YAC‐1 and AK‐5 cells. In addition, the expression of interferon (IFN)‐γ by NK cells was also inhibited in anti‐IL‐2 antibody injected animals compared with the control animals. Finally, there was enhanced tumour growth and delayed regression in anti‐IL‐2 injected animals compared with control animals.
Modulation of Transforming Growth Factor β‐1 Gene Expression by Interleukin‐12
Authors: Wilkinson  , Aung  , Wu  , Toossi
Published: March 2003

The interaction of cytokines and their net balance with regard to macrophage activation (or deactivation) and immune stimulation (or suppression), ultimately determines the success of host‐immune response at sites of active infection. A regulatory role for interleukin (IL)‐12 in production of transforming growth factor (TGF)‐β1 has been suggested, however, remains controversial. In this study, we analyzed the effect of IL‐12 on TGF‐β1 expression in the human lines, K562 and A549, and in primary human monocytes and macrophages. We found that IL‐12 down‐regulates TGF‐β1 mRNA expression in K562, monocytes and bone marrow cells, and to a lesser extent in the A549 cells. Using constructs containing different regions of the first promoter of the TGF‐β1 gene and a reporter gene, we also demonstrate that this effect is mediated through the TGF‐β1 gene promoter in the K562 and monocytic cell types. In conclusion, the critical role of IL‐12 in the early activation of the immune response to pathogens may include down‐modulation of TGF‐β1 gene activity.
Cord Blood Leucocyte Expression of Functionally Significant Molecules Involved in the Regulation of Cellular Immunity
Authors: Hodge S. , Hodge G. , Flower R. , Han P.
Published: March 2003

The cellular immune system of the newborn infant is immature and hypo‐responsive when compared with adults. The extent to which immaturity of the leucocyte function underlies hyporesponsiveness in the newborn is incompletely understood. In this study flow cytometric techniques were applied to investigate the concurrent expression of a range of surface and intracellular leucocyte functional molecules and cytokines in resting and stimulated cord and adult blood. Production of interleukin (IL)‐2 and expression of the components of its receptor, IL‐2Rα/β/γ, were investigated. No differences in the proportion of leucocytes producing IL‐2Rα and IL‐2Rγ were observed for newborns and adults. A lower proportion of T cells and natural killer (NK) cells from newborns expressed IL‐2Rβ and upregulation of expression was slower. We hypothesize that reduced IL‐2Rβ may curtail early autocrine IL‐2 activation of immune responses in the newborn. This hypothesis was supported by the observation that an increased proportion of stimulated T cells from newborns produced IL‐2 at 4 h poststimulation, but at 24 h the proportion was lower than for adult T cells. The very low levels of interferon (IFN)‐γ produced by neonatal T cells and NK cells may also be partly explained by a curtailment of early autocrine activation of T cells. Expression and kinetics of upregulation for other functional molecules were studied. CD71, HLA‐DR, tissue factor and CD152 levels were not significantly different for adults and newborns, suggesting that cord blood leucocytes, in some respects, may demonstrate functional maturity. IL‐6 secretion by stimulated monocytes was also comparable in cord and adult blood. However, IL‐1α and IL‐1β were produced by a lower proportion of monocytes from newborns than adults. Similarly, tumour necrosis factor (TNF)‐α production for monocytes and T cells was lower in cord blood. The mean fluorescence intensity for IL‐1α, IL‐1β and TNF‐α was also lower for leucocytes from cord blood. These findings are significant in relation to the inability of newborn infants to mount a febrile response to infection. The findings of lower expression of IL‐2Rβ and lower production of inflammatory cytokines IL‐1α, IL‐1β and TNF‐α is a basis for improved understanding of the immunological immaturity of leucocytes in the newborn.
Immunity in the Female Lower Genital Tract and the Impact of HIV Infection
Authors: Ahmed S. M. , Al‐Doujaily H. , Johnson M. A. , Kitchen V. , Reid W. M. N. , Poulter L. W.
Published: March 2003

This study investigates the distribution of immunocompetent cells in the ectocervix, and cytokine and immunoglobulin (Ig) levels in cervicovaginal secretions to determine whether they are altered in asymptomatic human immunodeficiency virus (HIV) infection. Ectocervical biopsies from 10 HIV+ and 10 presumed HIV‐ve women were studied by immunocytochemistry. Levels of Igs in cervicovaginal secretions were quantified by radial immunodiffusion (RID) and cytokine levels by ELISA. HIV+ women had significantly increased numbers of CD8+ lymphocytes resulting in reversal of the CD4:CD8 ratio. There was a significant increase in the proportion of activated CD8+ HLA‐DR+ and CD4+ HLA‐DR + lymphocytes, but not in CD8+ TIA‐1+ cells. The epithelium of the cervix from HIV+ subjects showed a significant increase in both numbers of macrophages (CD68+) and proportions of activated macrophages (CD68+ HLA‐DR+) compared to normal. The stroma contained increased proportions of inductive (D1+) and suppressive (D1+ D7+) macrophages but a decrease in effector phagocyte (D7+) proportions and Langerhans' cells. Significantly lower tumour necrosis factor (TNF)‐α levels were observed in cervicovaginal secretions from HIV+ subjects. IgG levels were 4 times higher and IgM levels twice higher in cervicovaginal secretions from HIV+ women, compared to results from normal subjects. These results suggest a response within the CD8+ cells in HIV+ women, yet these cells may have a low cytolytic capacity. The raised proportions of HLA‐DR+ and D1+ CD4+ macrophages could act as antigen‐presenting cells (APC) for CD4+ CD45RO+ lymphocytes, and represent a local acquired response. However, the close juxtaposition of these cells offers the potential for them to act as a local reservoir of virus and promote its proliferation. The increase of IgG over sIgA in secretions of HIV+ subjects provides evidence suggesting a dysregulation of local humoral immunity.
Morphologic and Functional Changes in Bovine Monocytes Infected In vitro with the Bovine Leukaemia Virus
Authors: Altreuther G. , Llames L. , Neuenschwander S. , Langhans W. , Werling D.
Published: March 2003

Experiments on the host cell spectrum of bovine leukaemia virus (BLV), a retrovirus closely related to the human T‐cell leukaemia virus (HTLV), have yielded conflicting data. Currently, BLV is known to infect B cells, whereas its ability to infect other cell types, e.g. monocytes/macrophages, is doubtful. As monocytes/macrophages may have profound effects on the diversity of the T‐cell response, we studied the possibility of in vitro infection, using bovine monocytes and SV40‐transformed bovine macrophages. Proviral DNA was detected by nested polymerase chain reaction (PCR) from day 1 until the end of the experiments at either day 5 or day 80, depending on the quantity of virus used for infection. In addition, the infection was associated with morphological changes in infected cells as revealed by electron microscopy. The in vitro infection did not significantly change either the expression of surface antigens (CD11b, CD32, and major histocompatibility complex (MHC) class II) or the amounts of cytokine transcripts (interleukin (IL)‐1β, tumour necrosis factor (TNF)‐α, IL‐6 and IL‐12p40) with or without lipopolysaccharide (LPS) stimulation. The data suggest that BLV can infect monocytes, but the infection does not seem to influence the function or the phenotype of these cells. Infected monocytes may, however, play a role as a viral reservoir in vivo.
Age‐Related Changes in CCR9+ Circulating Lymphocytes: Are CCR9+ Naive T Cells Recent Thymic Emigrants?
Authors: Olaussen R. W. , Farstad I. N. , Brandtzaeg P. , Rugtveit J.
Published: March 2003

The chemokine receptor CCR9 is reported to be predominantly expressed by thymocytes as well as by circulating gut‐homing and resident T cells in the small intestinal mucosa. Its ligand thymus‐expressed chemokine (TECK) is produced by thymic and small intestinal epithelium. Here we report that the proportion of circulating CCR9+ naive T cells (mostly CD4+) declines with age, from approximately 15% of all T cells at birth to around 1% in adults. The proportion of CCR9+ T cells lacking the classical gut‐homing receptor α4β7, was much higher in children than in adults. Therefore, circulating CD3+CCR9+CD45RA+ cells have most likely left the thymus quite recently. This notion was supported by the small number of CCR9+ naive T cells which was present shortly after thymectomy. Establishing a phenotypic marker for recent thymic emigrants might provide a powerful tool in the clinical assessment and follow‐up after cancer chemotherapy, hematopoietic stem cell transplantation, and during antiretroviral treatment of human immunodeficiency virus (HIV)‐infected patients.
Responses of the Rat Immune System to Arthritogenic Adjuvant Oil
Authors: Svelander L. , Holm B. C. , Bucht A. , Lorentzen J. C.
Published: March 2003

T‐cell mediated inflammatory joint diseases with similarities to rheumatoid arthritis (RA) can be triggered in arthritis‐prone rat strains by intradermal injection of adjuvant oils. The pathogenesis of oil‐induced arthritis (OIA) remains elusive, and a largely unresolved question is how the rat immune system responds to arthritogenic oils such as incomplete Freund's adjuvant (IFA). Here we report that IFA already induces increased plasma levels of the acute‐phase reactants (APR) fibrinogen and α1‐acid glycoprotein at day 4 postinjection (p.i). In contrast, no early responses were detected in the joints before infiltration of the T cells, which coincided with arthritis onset at 11–14 days post injection (d.p.i.) The infiltrating cells were possibly derived from draining lymph nodes (LN), which were hyperplastic and contained increased cell numbers from 4 days p.i. and onwards. The magnitude of the early increase in cell numbers and APR was regulated by non‐major histocompatibility complex (MHC) genes, as determined by comparison between arthritis‐susceptible DA rats and arthritis‐resistant but MHC‐identical LEW.1AV1 and PVG.1AV1 rats. Arthritis‐prone DA rats developed a weak acute‐phase response, suggesting that this systemic response may be counteracting disease. The DA rats also had the largest early increase in LN‐cell numbers, suggesting that the LN hyperplasia is part of a disease pathway. The analysis of hyperplastic LN after in vivo labelling with bromodeoxyuridine (BrdU) revealed increased numbers and proportions of proliferating lymphocytes, including T cells. Furthermore, polymerase chain reaction (PCR)‐analysis of LN cytokine mRNA revealed upregulation of interleukin (IL)‐1β at 4 d.p.i. We conclude that adjuvant oil exposure triggers both systemic acute phase reactions and local activation of the peripheral lymphoid system. These responses are genetically regulated and may determine arthritis development and susceptibility.
The Role of an Exposed Loop in the α2 Domain in the Mouse MHC Class I H‐2Dd Molecule for Recognition by the Monoclonal Antibody 34‐5‐8S and the NK‐Cell Receptor Ly49A
Authors: Waldenström M. , Achour A. , Michaelsson J. , Rölle A. , Kärre K.
Published: March 2003

Natural killer (NK) cells express major histocompatibility complex (MHC) class I‐specific inhibitory receptors. The region mediating the protective effect of the MHC class I molecule H‐2Dd (Dd), recognized by the inhibitory receptor Ly49A, has been mapped to the α1/α2 domains. Here we have focused on an exposed loop in the N‐terminal part of the α2 domain, which constitutes a major structural motif that differs between Dd (strong binding to Ly49A) and Db (weak binding to Ly49A at best). We mutated the residues 103, 104 and 107 in Dd to the corresponding amino acids in Db. The Dd mutant molecule retained the ability to be stabilized by a Dd‐binding peptide. However, the mutation totally abolished the recognition by the conformational dependent monoclonal antibody (MoAb) 34‐5‐8S, known to inhibit the interaction between Dd and Ly49A. In addition, there was a marked impairment of the binding to Ly49A as evaluated by the ability of tetramers of the Dd mutant molecule to bind to Ly49A‐transfected reporter cells and spleen cells. These results demonstrate that the introduced changes at positions 103, 104 and 107 directly or indirectly affect the epitopes for the MoAb 34‐5‐8S and the Ly49A receptor.
Differences between the Large and Small Intestine in the Immunodominant Amoebic Proteins Recognized by IgG and IgA Antibodies in BALB/c Mice
Authors: Moreno‐Fierros L. , López‐Revilla R. , Reséndiz‐Albor A. A.
Published: March 2003

We have previously reported that there are differences in the number of predominant amoebic antigens recognized by serum and small intestinal antibodies induced after local and systemic immunization with glutarldehyde‐fixed Entamoeba histolytica trophozoites (GFT) in BALB/c mice, by an immunoblot analysis. Moreover, by enzyme‐linked immunosorbent assay (ELISA) analysis, we found differences in the antiamoebic antibody isotype patterns elicited at the large and small intestines. To further characterize the antiamoebic immune response induced in BALB/c mice, after local (oral and rectal) and systemic (intraperitoneal and intramuscular) immunization with GFT, we performed an immunoblot analysis of the amoebic proteins predominantly recognized by immunoglobulins (Ig)G, IgA and IgM in the serum and in the small and large intestines. The present work shows differences between the large and small intestine in the IgG‐ and IgA‐antibody recognition pattern of amoebic proteins, thus confirming and extending our previous findings supporting the compartmentalization of the intestinal immune response. Furthermore, our reported observation that there are differences in the amoebic proteins predominantly recognized by antibodies of different isotypes was extended to the intestines, as some proteins with relative molecular weights of 24–25, 66, 140 kDa are strongly recognized by IgG but not by other antibody isotypes.
Cyclosporin‐A Differentially Affects Apoptosis During In Vivo Rat Thymocyte Maturation
Authors: DAMOISEAUX J. G. M. C. , DEFRESNE M.‐P. , REUTELINGSPERGER C. P. M. , VAN BREDA VRIESMAN P. J. C.
Published: March 2003

Maturation arrest and interference with selection are two well‐documented effects of cyclosporin‐A (CsA) on the thymus. We recently hypothesized that these effects are related and owing to the reduced T‐cell receptor (TCR)–CD3 complex‐mediated signal transduction in thymocytes upon CsA treatment. In this hypothesis, the maturation arrest is the result of the additional depletion of thymocytes that normally survive by positive selection, whereas the impaired self‐tolerance induction is caused by an increased survival of thymocytes that normally undergo negative selection. In this view, it is anticipated that CsA differentially affects thymocyte apoptosis during in vivo thymocyte maturation. Indeed, we report in this study a strong increase in apoptotic cells in the thymic cortex on in situ analysis. Simultaneously, the number of apoptotic cells had decreased at the cortico‐medullary zone which is held to be the site for negative selection. Rapamycin (Rapa) also interferes with thymocyte maturation by inhibiting cytokine‐driven proliferation. Hence, Rapa preferentially affects the early maturational stages of thymocyte development and is considered not to alter thymocyte selection and subsequent apoptotic events. Indeed, the number of apoptotic events appears not to be altered. However, possibly owing to the decrease in cortical macrophages, the apoptotic cells revealed an atypical enumeration around blood vessels. Taken together, our results favour the hypothesis that the dominant effect of CsA on the thymus is the reduction of the TCR–CD3 complex‐mediated signal transduction in thymocytes upon interaction with stromal cells. Furthermore, the preferential localization of apoptotic cells next to blood vessels upon Rapa administration may indicate that endothelial cells are a back‐up system for the removal of apoptotic cells.
Current State of Pneumococcal Vaccines
Authors: Wuorimaa T. , Käyhty H.
Published: March 2003

Streptococcus pneumoniae is a leading cause of bacterial pneumonia, meningitis, and acute otitis media in children and adults worldwide. According to World Health Organization estimates, at least 1 million children under 5 years of age die each year from pneumococcal pneumonia. The emergence of resistant strains necessitates the development of an effective vaccine with a large serotype coverage. The 11 most common serotypes cause 72–83% of all serious pneumococcal diseases worldwide. Currently marketed 23‐valent pneumococcal polysaccharide vaccine provides large serotype coverage and offers a less expensive option. However, it is efficacious only in adults but not in infants. Conjugate vaccines offer a solution by generating immunological memory already at early age. A recently licensed 7‐valent conjugate vaccine is immunogenic and efficacious in infants. Its serotype coverage might be sufficient in Europe and North America, but not in Africa, Asia and Oceania. A need exists to develop pneumococcal vaccines with lower cost and larger serotype coverage. Several 11‐valent pneumococcal conjugate vaccines are being evaluated in phase I–III trials. This study reviews the current state of pneumococcal problem and pneumococcal vaccines in clinical use.
Downregulation of mafB Expression in T‐Helper Cells During Early Differentiation In Vitro
Authors: Hashizume H. , Hamalainen H. , Sun Q. , Sucharczuk A. , Lahesmaa R.
Published: March 2003

We have studied the expression of a human homologue of mafB (maf‐1), a member of the family of large maf transcription factors. In support of the suggested key role that mafB expression plays in differentiating macrophages, we found mafB to be expressed at a very high level in monocytic U937 and THP‐1 cell lines. However, we show here that mafB transcription is not restricted to myeloid cells but can also be detected in lymphoid cells, indicating transcriptional plasticity during haematopoiesis. In conclusion, strong proliferative signals mediated by T‐cell activation and interleukins (IL‐4 and IL‐12) downregulate the mafB messenger RNA transcript level when resting naïve CD4+ T‐helper cells enter the differentiation pathway in vitro.
A highstand oolitic sequence and associated facies from a Late Triassic lake basin, south‐west England
Authors: Milroy Paul G. , Wright V. Paul
Published: March 2003

High energy, lake‐shoreline carbonate sequences are rarely documented in the geological record. However, one example occurs in the Upper Triassic Mercia Mudstone Group (MMG) of southern Britain. The MMG is one of a number of thick, non‐fossiliferous mudstone deposits associated with North Atlantic Mesozoic rift basins. The origin of the MMG mudstones is the subject of current debate, with marine, playa‐lacustrine and alluvial–aeolian models having been proposed. Shoreline features have been documented from the northern margin of the basin, but the rarity of such features elsewhere in the MMG has led many workers to doubt a lacustrine origin for the mudstones. Wave‐dominated, lake‐shoreline deposits have been recognized in several sections from the southern basin margin in the Clevedon area of the Bristol Channel in south‐west England. These deposits provide evidence for the development of a sizeable perennial to semi‐perennial hypersaline lake in which the MMG mudstones accumulated. Shoreline sediments overlie alluvial stream and sheet‐flood deposits, and pass from transgressive gravel–conglomerate beach units with bioclasts, influenced by shore‐normal waves (deposited under semi‐humid conditions), to lower gradient, highstand oolitic sands affected by more varied wave approach (deposited under progressively more arid conditions), which culminated in lowstand, oolitic strand‐plain deposits overlain by a playa‐mudflat unit. Shoreline deposits record a simple shallowing‐upward transgressive–highstand–lowstand sequence. However, a change from a reflective (transgressive) to dissipative (highstand) shoreline is believed to represent a climatically induced change in prevailing wind direction. Shoreline features recognized in the MMG are similar to those of recent playa‐lacustrine basins of the western United States. Ooids display a variety of size, fracture and dissolution features in addition to beachrock fabrics, suggesting that they were originally composed of radial aragonite, similar to modern ooids from the Great Salt Lake, Utah.
An origin for laminated glacimarine sediments through sea‐ice build‐up and suppressed iceberg rafting
Authors: Dowdeswell  , Whittington  , Jennings  , Andrews  , Mackensen  , Marienfeld
Published: March 2003

Laminated glacimarine sediments are observed in visual core logs and x‐radiographs from Scoresby Sund and Nansen Fjord, east Greenland. They are mostly underlain and overlain by massive or stratified glacimarine diamicton (Dmm or Dms), which is a product of iceberg delivery of heterogeneous debris and, in Scoresby Sund, reworking by deep‐drafted iceberg keels. The laminated sediments are AMS radiocarbon dated to two cold periods since the last, Late Weichselian deglaciation: the Younger Dryas stadial (Milne Land Stadial in east Greenland) and the Little Ice Age. During cold climatic events, multiyear shorefast sea ice (‘sikussak’) formed in these fjords and trapped the icebergs. Fine‐grained, laminated muds (Fl) were deposited in Scoresby Sund when the flux of icebergs was suppressed, but turbid meltwater continued to provide some sediment flux to the fjord systems, varying through time to produce laminations. In Nansen Fjord, thinner and often massive mud layers (Fm) resulted from shorter intervals of sea‐ice cover with no ice rafting. Stratified diamicton layers (Dms), which alternate with mud deposition to produce a laminated unit, probably represent intervening times of more open conditions with iceberg rafting. In Scoresby Sund, foraminifera are either absent from the laminated unit or begin to appear towards the end of its deposition. The absence of both benthic and planktonic foraminifera also suggests that multiyear sea ice was covering the core sites. There is no evidence of macrofaunal activity, and bioturbation is absent from the laminated sediments. Satellite data show that multiyear shorefast sea ice is present in several areas of the high Arctic today, and this traps icebergs calved from interior ice‐cap drainage basins. Thus, the process of laminated glacimarine sediment formation is likely to be applicable to a number of areas of the modern and Quaternary Arctic.
Disseminated ‘jigsaw piece’ dolomite in Upper Jurassic shelf sandstones, Central North Sea: an example of cement growth during bioturbation?
Authors: Hendry James P. , Wilkinson Mark , Fallick Anthony E. , Trewin Nigel H.
Published: March 2003

Unusual textural and chemical characteristics of disseminated dolomite in Upper Jurassic shelf sediments of the North Sea have provided the basis for a proposed new interpretation of early diagenetic dolomite authigenesis in highly bioturbated marine sandstones. The dolomite is present throughout the Franklin Sandstone Formation of the Franklin and Elgin Fields as discrete, non‐ferroan, generally unzoned, subhedral to highly anhedral ‘jigsaw piece’ crystals. These are of a similar size to the detrital silicate grains and typically account for ≈5% of the rock volume. The dolomite crystals are never seen to form polycrystalline aggregates or concretions, or ever to envelop the adjacent silicate grains. They are uniformly dispersed throughout the sandstones, irrespective of detrital grain size or clay content. Dolomite authigenesis predated all the other significant diagenetic events visible in thin section. The dolomite is overgrown by late diagenetic ankerite, and bulk samples display stable isotope compositions that lie on a mixing trend between these components. Extrapolation of this trend suggests that the dolomite has near‐marine δ18O values and low, positive δ13C values. The unusual textural and chemical characteristics of this dolomite can all be reconciled if it formed in the near‐surface zone of active bioturbation. Sea water provided a plentiful reservoir of Mg and a pore fluid of regionally consistent δ18O. Labile bioclastic debris (e.g. aragonite, Mg‐calcite) supplied isotopically positive carbon to the pore fluids during shallow‐burial dissolution. Such dissolution took place in response to the ambient ‘calcite sea’ conditions, but may have been catalysed by organic matter oxidation reactions. Bioturbation not only ensured that the dissolving carbonate was dispersed throughout the sandstones, but also prohibited coalescence of the dolomite crystals and consequent cementation of the grain framework. Continued exchange of Mg2+ and Ca2+ with the sea‐water reservoir maintained a sufficient Mg/Ca ratio for dolomite (rather than calcite) to form. Irregular crystal shapes resulted from dissolution, of both the dolomite and the enclosed fine calcitic shell debris, before ankerite precipitation during deep‐burial diagenesis.
High‐resolution (2–7 kHz) acoustic and geometric characters of submarine creep deposits in the South Korea Plateau, East Sea
Authors: Lee S. H. , Chough S. K.
Published: March 2003

A synthesis of high‐resolution (Chirp, 2–7 kHz) seismic profiles in the South Korea Plateau reveals that large masses of wavy stratified sediment (≈60–90 m thick) cover broad, gently sloping (<0·5°) ridges in water depths of 1000–2000 m. The wavy stratified sediment (WSS) is characterized by wavy (0·2–5 km in wavelength and <15 m in relief), continuous reflective layers with a basal deformed zone that overlies undeformed, strong reflectors. The WSS exhibits systematic variation in wave dimensions and thickness of internal reflective layers with changes in slope gradient. The troughs of the waves are commonly associated with internal growth faults, and wave amplitude generally increases with subbottom depth. On steep slopes around the ridges, the WSS masses are bounded downslope by slide and slump deposits including slightly translated or rotated WSS blocks. The acoustic and geometric characters, and association with downslope slides and slumps on the steeper slopes, suggest that the WSS masses were most probably formed by slow creep movement before slope failure. In the absence of significant sediment input to the South Korea Plateau, the deep (1000–2000 m in water depth) mass movements were probably triggered by earthquakes that have occurred frequently in this region. Some slightly displaced, intact WSS blocks in the associated slides and slumps downslope reflect a progressive evolution from submarine creep into slide and slump.
Ice‐marginal environment and ecosystem prior to initial advance of the late Palaeozoic ice sheet in the Mount Butters area of the central Transantarctic Mountains, Antarctica
Authors: Isbell John L. , Miller Molly F. , Babcock Loren E. , Hasiotis Stephen T.
Published: March 2003

Basal rocks of the Upper Carboniferous to Lower Permian Pagoda Formation at Mount Butters provide an unusual view of periglacial conditions in the central Transantarctic Mountains region prior to the initial advance of the Gondwanide ice sheet. These rocks were deposited on a high relief unconformity that developed on granite. Deposition within relief on the unconformity, possibly in the lee of a granite buttress, protected the rocks from erosion during subsequent overriding by the ice sheet. The succession reflects deposition in a glacial‐fed to ice‐contact lake that contained a freshwater crustacean fauna. Centimetre‐ to decimetre‐scale basal layers include breccia and coarse‐grained sandstone. The occurrence of breccia resting on weathered granite suggests sedimentation as scree and as mass flow deposits. Overlying decimetre‐to metre‐scale stratified diamictites interbedded with metre‐scale, coarsening‐upward successions of siltstone to cross‐laminated sandstone suggest lacustrine deposition by suspension settling, rain out of ice‐rafted debris, and deltaic progradation. Thin zones with abundant conchostracans and/or with prolific trace fossils, in addition to less common remains of other crustaceans, attest to the presence of a low diversity benthic fauna. Conchostracans are concentrated in a series of thin beds that reflect moderately lengthy, perhaps seasonal, periods of free‐flowing water. Patchy vertical and lateral distribution of intense bioturbation and profuse trace fossils probably reflect repeated colonization events during times of favourable environmental conditions. Massive diamictite overlies the basal rocks and indicates that the ice‐marginal lake was subsequently overridden by the late Palaeozoic ice sheet. Occurrences of lodgement till, glacitectonite and deformation till suggest deposition from temperate or warm‐based ice, whereas underlying lacustrine and deltaic deposits, along with a crustacean and trace fossil fauna, suggest temperate periglacial conditions. Previous studies have stressed that upper Palaeozoic glacigenic deposits in Antarctica, and in Gondwanaland, record deglaciation events. In contrast, rocks at Mt. Butters provide an unusual glimpse into an ice‐margin lake and its fauna just prior to ice sheet advance.
On the frequency distribution of turbidite thickness
Authors: Talling Peter J.
Published: March 2003

The frequency distribution of turbidite thickness records information on flow hydrodynamics, initial sediment volumes and source migration and is an important component of petroleum reservoir models. However, the nature of this thickness distribution is currently uncertain, with log‐normal or negative‐exponential frequency distributions and power‐law cumulative frequency distributions having been proposed by different authors. A detailed analysis of the Miocene Marnoso Arenacea Formation of the Italian Apennines shows that turbidite bed thickness and sand‐interval thickness within each bed have a frequency distribution comprising the sum of a series of log‐normal frequency distributions. These strata were deposited predominantly in a basin‐plain setting, and bed amalgamation is relatively rare. Beds or sand intervals truncated by erosion were excluded from this analysis. Each log‐normal frequency distribution characterizes bed or sand‐interval thickness for a given basal grain‐size or basal Bouma division. Measurements from the Silurian Aberystwyth Grits in Wales, the Cretaceous Great Valley Sequence in California and the Permian Karoo Basin in South Africa show that this conclusion holds for sequences of disparate age and variable location. The median thickness of these log‐normal distributions is positively correlated with basal grain‐size. The power‐law exponent relating the basal grain‐size and median thickness is different for turbidites with a basal A or B division and those with only C, D and E divisions. These two types of turbidite have been termed ‘thin bedded’ and ‘thick bedded’ by previous workers. A change in the power‐law exponent is proposed to be related to: (i) a transition from viscous to inertial settling of sediment grains; and (ii) hindered settling at high sediment concentrations. The bimodal thickness distribution of ‘thin‐bedded’ and ‘thick‐bedded’ turbidites noted by previous workers is explained as the result of a change in the power‐law exponent. This analysis supports the view that A and B divisions were deposited from high‐concentration flow components and that distinct grain‐size modes undergo different depositional processes. Summation of log‐normal frequency distributions for thin‐ and thick‐bedded turbidites produces a cumulative frequency distribution of thickness with a segmented power‐law trend. Thus, the occurrence of both log‐normal and segmented power‐law frequency distributions can be explained in a holistic fashion. Power‐law frequency distributions of turbidite thickness have previously been linked to power‐law distributions of earthquake magnitude or volumes of submarine slope failure. The log‐normal distribution for a given grain‐size class observed in this study suggests an alternative view, that turbidite thickness is determined by the multiplicative addition of several randomly distributed parameters, in addition to the settling velocity of the grain‐sizes present.
A new species of Omicrus Sharp (Coleoptera: Hydrophilidae) from Puerto Rico and its larva, the first known larva of Omicrini
Authors: HANSEN MICHAEL , RICHARDSON BARBARA A.
Published: March 2003

A remarkable new species of bromeliadicolous Hydrophilidae, Omicrus ingens sp.n., is described from Puerto Rico. Notes on the habitat and occurrence of the species are given. Larvae found in association with adult beetles are assigned to the same species and described as such. It is the first known larva of the sphaeridiine tribe Omicrini. Comparative notes are given to other hydrophilid larvae, particularly Sphaeridiinae, and preliminary keys to larvae are presented for known subfamilies of Hydrophilidae and known tribes of Sphaeridiinae.
Phylogeny of Hydrophiloidea (Coleoptera: Staphyliniformia) using characters from adult and preimaginal stages
Authors: ARCHANGELSKY MIGUEL
Published: March 2003

A phylogenetic analysis using characters from egg cases, larvae, pupae and adults was conducted; the outgroups included the beetle families Silphidae, Hydraenidae and Histeridae. Characters from the immature stages were obtained mostly from material reared in the laboratory, those from the adults were obtained from Hansen's generic revision for the superfamily. The results support the position of Hydraenidae within the Staphylinoidea, and not as part of Hydrophiloidea; Histeroidea is proposed as the sister group of Hydrophiloidea. At family level two clades are distinguished; the relationships within the first clade are ((Georissidae Epimetopidae) Helophoridae), those within the second are ((Hydrophilidae Spercheidae) Hydrochidae). Larval characters were most informative at the base of the tree, especially those associated with the spiracular atrium; adult characters were most informative at the apex of the tree.
Cladistic analysis, phylogeny and biogeography of the Hawaiian Platynini (Coleoptera: Carabidae)
Authors: LIEBHERR JAMES K. , ZIMMERMAN ELWOOD C.
Published: March 2003

The 128 known native Hawaiian species of the tribe Platynini are analysed cladistically. Cladistic analysis is based on 206 unit‐coded morphological characters, and also includes forty‐one outgroup taxa from around the Pacific Rim. Strict consensus of the multiple equally parsimonious cladograms supports the monophyly of the entire species swarm. The closest outgroup appears to be the south‐east Asian‐Pacific genus Lorostema Motschulsky, whose species are distributed from India and Sri Lanka to Tahiti, supporting derivation of the Hawaiian platynines from a source in the western or south‐western Pacific. The biogeographic relationships of the Hawaiian taxa are analysed using tree mapping, wherein items of error are minimized. The area cladogram found to be most congruent with the phylogenetic relationships, and most defensible based on underlying character data is {Kauai[Oahu(Hawaii{Lanai[East Maui(West Maui + Molokai)]})]}. This progressive vicariant pattern incorporates progressive colonization from Kauai, and vicariance of the former Maui Nui into the present islands of Molokai, Lanai, West Maui and East Maui. The evolution of flightlessness, tarsal structure, pronotal setation and bursal asymmetry are evaluated in the context of the cladogram. Brachyptery is a derived condition for which reversal is not mandated by the cladogram, although repeated evolution of reduced flight wings is required. Tarsal structure supports Sharp's (1903) recognition of Division 1 as a monophyletic assemblage, but exposes his Division 2 as a paraphyletic group requiring removal of the genus Colpocaccus Sharp. Pronotal setation is exceedingly homoplastic, and is not useful for delimiting natural groups. Left‐right asymmetry of the bursa copulatrix reversed twice independently, resulting in mirror‐image bursal configurations in B. rupicola and Prodisenochus terebratus of East Maui. The amount of character divergence is greater among species comprising Division 1 than among species of its sister group, the redefined Division 2. Based on superior fit of Division 1 relationships to the general biogeographic pattern, a greater speciation rate coupled with more extensive extinction is rejected as the cause for this greater divergence. Intrinsic differentiation in the processes underlying cuticular evolution appears to be more consistent with the observed biogeographic and morphological patterns.
The micropylar plate of the eggs of Phasmida, with a survey of the range of plate form within the order
Authors: SELLICK J. T.
Published: March 2003

Eggs of Phasmida are characterized by the presence of a micropylar plate system. The nature of this plate is discussed and the relevance of differences in plate structure to the taxonomy of the order is considered. A survey is made of the range of plate structure throughout the order, covering the external plate structure of 384 species and the internal plate structure of 179 species in forty of the forty‐four subgroups of the order.
End‐products of behaviour versus behavioural characters: a phylogenetic investigation of pupal cocoon construction and form in some North American black flies (Diptera: Simuliidae)
Authors: STUART ALISON E. , HUNTER FIONA F.
Published: March 2003

Cocoon spinning was analysed, using video recording and playback, in eighteen Nearctic black fly species, comparing nine Simulium species, six Eusimulium species, Stegopterna mutata, Cnephia dacotensis and Prosimulium mixtum. Fourteen behavioural characters were revealed that produced twenty‐two equally parsimonious trees (CI = 0.93, RI = 0.96). Another tree was constructed on the basis of five characters relating to the cocoon structure (end‐product characters). The goal of the study was to determine whether characters relating to behavioural components of black fly cocoon spinning or those based on end‐products of the behaviour are superior for revealing phylogenetic relationships. This was accomplished by comparing both data sets to a phylogeny constructed with the use of cytological and morphological characters. If taxa are grouped according to end‐products (the cocoons) there are some spurious groupings. The behavioural analysis only required one extra step to duplicate the morphological and cytological tree. In the case of black flies, it is more informative to use characters resulting from the analysis of the cocoon spinning behaviour than cocoon morphology.
DNA identification of museum specimens of the Anopheles gambiae complex: an evaluation of PCR as a tool for resolving the formal taxonomy of sibling species complexes
Authors: Townson Harold , Harbach Ralph E. , Callan Tara A.
Published: March 2003

Species‐specific rDNA primers were tested for their ability to identify museum specimens of the Anopheles gambiae complex ranging in age from 15 to 93 years. Twenty pinned females of known or inferred identity were selected for study from the collection of The Natural History Museum in London, primarily on grounds of their provenance and/or presumed identity. The abdomens were removed and provided ‘blind’ to the first author for identification. Most of the specimens (17/20) yielded amplifiable DNA and sixteen were identified to species, fifteen unambiguously. The PCR identifications of twelve specimens matched identifications on museum labels, including seven of unambiguous identity. One of the specimens identified correctly was a 93‐year‐old syntype of An. gambiae. This study demonstrates that PCR‐based methods, by establishing the genetic identity of name‐bearing type specimens in museum collections, may help in the application of available names to members of sibling species complexes.
A fossil nymphomyiid (Diptera) from the Baltic and Bitterfeld amber
Authors: Wagner R. , Hoffeins C. , Hoffeins H. W.
Published: March 2003

Nymphomyia succina sp.n., the first fossil nymphomyiid fly (Diptera) from the Eocene Baltic and Bitterfeld amber is described and figured, based on four males. A probably conspecific female from the Baltic amber is also described and figured. With the discovery of this species, a gap in the distribution pattern of extant Nymphomyiidae is closed. It is probable that nymphomyiids colonized the eastern Nearctic Region via the Thule landbridge approximately 25–30 million years before present.
Phylogeny of Oestridae (Insecta: Diptera)
Authors: Pape Thomas
Published: March 2003

The phylogeny of Oestridae was analysed at the generic level using 118 characters from all developmental stages and including morphology, ontogeny, physiology and behaviour. Four major clades were given subfamilial rank with the phylogenetic relationship (Cuterebrinae (Gasterophilinae (Hypodermatinae + Oestrinae))). The subdermal parasites of the African elephant, Neocuterebra squamosa Grünberg and Ruttenia loxodontis Rodhain, had their most probable affiliation subordinate to the clade of stomach parasites, although their exact position needs further investigation. Genus Ochotonia Grunin, which is known from a single third‐instar larva only, was the probable sister group of all other Hypodermatinae. Twenty‐five oestrid genera were recognised as valid and those containing more than one species were defined through lists of autapomorphies. Cuterebra Clark was proposed as a senior synonym of Alouattamyia Townsend, Andinocuterebra Guimarães, Pseudogametes Bischof and Rogenhofera Brauer. The clade of hypodermatine ungulate parasites (Hypoderma Latreille +Pallasiomyia Rubtzov +Pavlovskiata Grunin +Przhevalskiana Grunin +Strobiloestrus Brauer) remained largely unresolved, and genus Przhevalskiana emerged without defining characters.
Identity and phylogenetic status of two sibling gall midge species (Diptera: Cecidomyiidae: Contarinia) on the perennial herb Vincetoxicum hirundinaria
Authors: Widenfalk Olof , Gyllenstrand Niclas , Sylvén Edvard , Solbreck Christer
Published: March 2003

Abstract Contarinia comprises one of the largest genera among gall forming midges of Cecidomyiidae, where identification and species relationships are uncertain. Using data on phenological development, morphometric relationships and mitochondrial DNA, the status of two isomorphic species, C. vincetoxici and C. asclepiadis, which attack the perennial herb Vincetoxicum hirundinaria, were investigated. Data show that they are two distinct species. In rearing experiments, the two gall midges were shown to have different times of adult emergence. Small differences in wing morphology were revealed that separate the two species from each other, as well as from C. loti, the type species of Contarinia. Sequence differences in the mitochondrial cytochrome b gene corroborate the specific status of C. vincetoxici and C. asclepiadis. Furthermore, a phylogenetic analysis, also including three other Contarinia species, showed that the two gall midges on V. hirundinaria are not even the most closely related species, suggesting two separate evolutionary colonizations of the host plant.
Phylogeny of Habronattus jumping spiders (Araneae: Salticidae), with consideration of genital and courtship evolution
Authors: Maddison Wayne , Hedin Marshal
Published: March 2003

Abstract. DNA sequences from the mitochondrial (including ND1, 16S) and nuclear (EF‐1α) genomes of about ninety‐four species were obtained to reconstruct phylogenetic relationships of Habronattus jumping spiders. Maximum parsimony trees were sought with both separate (mitochondrial, nuclear) and combined analyses; maximum likelihood trees were sought with both separate (ND1, 16S, EF‐1α introns, EF‐1α exons) and combined (mitochondrial, nuclear) analyses. All analyses agreed on some fundamental aspects of the tree, including the monophyly of the previously recognized agilis, amicus, dorotheae and americanus species groups. The deep phylogenetic structure is well resolved, placing the agilis, amicus, tranquillus and dorotheae groups basally. Several other previously unrecognized clades were well supported, including a newly formulated decorus group. The large group of species with modified male first and third legs was supported as monophyletic except for the surprising placement elsewhere of three species of the group. The phenotypic similarities between these three and the others are so detailed and precise that convergence in ornamentation can probably be ruled out. There are hints of phylogenetically distant genetic introgression involving the coecatus group. The combination Habronattus paratus is restored based on the species falling within Habronattus. Regarding patterns of character evolution, there was consistent support for the basal placement of several species groups with a long embolus, suggesting that there were more evolutionary reductions in embolus length than postulated in a previous morphological phylogeny. This is in accord with the expectation that there is a bias to an overly conservative interpretation of a character's evolution if it is interpreted on a phylogeny based in part on that same character. In contrast, the molecular phylogeny did not suggest any instances of the evolutionary transformation of one complex style of courtship into another, a possibility that could have been difficult to detect using the morphological phylogeny because of the same bias to conservativism.
Cooling history of granulite samples from the ocean–continent transition of the Galicia margin: implications for rifting
Authors: Fuegenschuh  , Froitzheim  , Boillot
Published: March 2003

Zircon and apatite fission track ages were obtained on two granulite samples that were recovered from the sea floor in the ocean–continent transition area of the Galicia margin (North Atlantic) using the French submersible Nautile. Zircon ages indicate that the rocks cooled through about 250°C in Carboniferous to Early Permian time (307 ± 42 Ma and 287±35 Ma). Hence, the granulites do not represent the prerift lower crust but were in an upper crustal position long before rifting started. Apatites yielded Early Cretaceous ages (126 ± 6.7 Myr and 129 ± 13.4 Myr), indicating cooling through 90 ± 30°C coeval with the main rifting phase that preceded continental breakup. We assume that the granulite samples originate from a tectonic breccia cropping out near one of the sample locations. This breccia formed along a synrift detachment accommodating continental breakup and final exhumation of the Galicia margin’s peridotite ridge.