bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissolution kinetics, transit times through subglacial hydrological pathways and diurnal variations of solute content of meltwaters draining from an alpine glacier
Authors: Collins David N.
Published: February 2007

Experimental results are reported for dissolved solids concentration increase when clear meltwaters from the surface of an Alpine glacier were reacted with suspended sediment derived from the subsole. The experiments, at Findelengletscher, Switzerland, were conducted at temperatures of about 1°C. Rates of reaction, which decrease through time as solute content rises, were slower in meltwaters which had not been allowed to equilibrate with the atmosphere before sediment was added. Diurnal variations in transit times of meltwater from the surface to the glacier portal were derived from injections of rhodamine dye into large moulin‐conduit systems. Experimentally‐determined rates of increase of electrical conductivity were used together with observed transit times in a Lagrangian formulation. This model was used to assess the contributions of rate of reaction and flow‐through velocity to production of observed variations of solute concentration with portal meltwater discharge. The observed diurnal concentrations varied inversely but in phase with portal discharge. Diurnal variations in discharge through such moulin‐conduit systems lead to substantial changes in flow‐through velocity, altering the periods of time available for parcels of meltwater to react with basally‐entrained suspended sediment en route to the portal. Hence, there is considerable variability in the amount of solute acquired by meltwaters in transit. A diurnal pattern of solute concentration variation with discharge is generated by the model, although absolute levels of solute concentration are underestimated. Parcels of meltwaters flowing more slowly, having entered the glacier down small cracks, crevasses and tiny moulins, acquire larger concentrations of solute during longer transit times. These waters, which cumulatively account for a significant proportion of total discharge, mix with those traversing moulin‐conduit systems and presumably raise the overall solute content of the total discharge from Findelengletscher to the measured levels.
Snow‐induced thermal variations around a single conifer tree
Authors: Hardy Janet P. , Albert Mary R.
Published: February 2007

The influence of trees on the ground thermal regime is important to the overall winter energy exchange in a snow‐covered, forested watershed. In this work, spatial zones around a single conifer tree were defined and examined for their controls on the snow cover, snow‐ground interface temperatures and frozen ground extent. A large white spruce (Picea glauca), approximately 18 m tall with a crown diameter of 7.5 m and located in northern Vermont, was the subject of this study. The tree was instrumented with thermistors to measure the snow‐ground interface temperature between the tree trunk and 6 m from the tree into undisturbed snow. Four distinct zones around the conifer are defined that affect the snow distribution characteristics: adjacent to the trunk; the tree well; the tree crown perimeter; and the unaffected area away from the tree. At the time of peak snow accumulation and during the ablation season, snow depth and density profiles were measured. The area beneath the canopy accumulated 34% of the snow accumulated in the undisturbed zone. By the end of the ablation season, the depth of snow under the canopy had decreased to 18% of the undisturbed snow depth. The tree and branch characteristics of spruce in this temperate climate resulted in a different snow depth profile compared with previous empirical relationships around a single conifer. A new relationship is presented for snow distribution around conifer trees that has the ability to better fit data from a variety of conifer types than previously published relationships. Less snow beneath the canopy led to colder snow‐ground interface temperatures than measured in undisturbed snow. The depth of frozen ground in the different zones was modelled using a simple analytical solution that showed deeper frost penetration in the tree well than beneath the undisturbed snow.
Winter methane dynamics beneath ice and in snow in a temperate poor fen
Authors: Melloh Rae A. , Crill Patrick M.
Published: February 2007

The influence of winter on methane (CH4) stored in pore water and emitted through snow was investigated in a temperate poor fen in New Hampshire over two winters. Methane accumulated beneath ice layers (1 cm) deposited by freezing rain, resulting in snow‐pore air mixing ratios as high as 140 ppmv during the first winter and 600 ppmv during the second. An early winter snow crust of 300 kg m−3 caused no discontinuity in a linear mixing ratio profile and therefore was not observed to retard snowpack emissions. Methane concentration‐depth profiles in pore water steepened and concentrations increased by as much as 400 μM at the 10 and 20 cm depths as the ice cover formed. This suggests that the peat‐ice cover plays an important part in CH4 build‐up in pore water by limiting the transport of gases between the peat and the atmosphere. Pore water concentrations gradually declined through late winter. The seasonality of dissolved CH4 in pore water over two winters and one summer showed an average annual amplitude of 1.3 gCH4m−2 (25–75cm depth range), with a winter maximum of 4.7gCH4m−2. Emissions during the winter with average snowfall accounted for a larger percentage (9.2% in 1993–1994) of total annual emission than the winter with below‐average snowfall and warmer air temperature (2% in 1994–1995). Emissions averaged 56 and 26mg m−2 day−1 during the first and second winter (December, January and February), respectively.
A wide difference in cancer survival between middle aged and elderly patients in Europe
Authors: Quaglia Alberto , Capocaccia Riccardo , Micheli Andrea , Carrani Eugenio , Vercelli Marina ,   the EUROCARE‐3 Working Group
Published: February 2007

Nowadays the burden of cancer in elderly people has reached an alarming extent. The purpose of this study is comparing cumulative and conditional relative survival in elderly patients between 65 and 84 years and younger adults aged from 55 to 64. Fifty‐three cancer registries of 22 European countries, participating in the EUROCARE‐3 programme, collected information on the cases diagnosed over the period 1990–1994. We computed cumulative and conditional relative survival for 16 cancer sites. Middle aged patients experienced a better prognosis than the elderly for all cancer sites, in both sexes and the differences were more marked at 1 than 5 years since diagnosis. The very large differences noted in the first period after cancer detection declined in the subsequent years and, when 5‐years conditional survival was considered, for several cancers the elderly and younger adults had the same probabilities of surviving. The death relative excess risks (RERs) in the elderly with respect younger individuals were really very high and markedly larger at 1 than 5 years, and in women than men. Genitourinary and gynaecological cancers showed the highest RERs, around 2.0 and between 1.5 and 2.5 respectively. This very high early mortality could be due not only to clinical aspects: the barriers to health care access and a consequent late diagnosis might represent for elderly patients the main determinant of this very large prognostic disadvantage. In conclusion, clinical management of cancer in the elderly remains a major issue to be faced with complex social and health care policies. © 2007 Wiley‐Liss, Inc.
Identification of genomic aberrations associated with shorter overall survival in patients with oligodendroglial tumors
Authors: Trost Detlef , Ehrler Marion , Fimmers Rolf , Felsberg Jörg , Sabel Michael C. , Kirsch Lutz , Schramm Johannes , Wiestler Otmar D. , Reifenberger Guido , Weber Ruthild G.
Published: February 2007

Deletions on chromosomes 1p and 19q are associated with favorable prognosis in patients with oligodendroglial tumors. The aim of our study was to identify additional genomic aberrations linked to patient survival. We performed a genome‐wide screen for genomic imbalances by comparative genomic hybridization on tumors from 70 patients, including 40 oligodendrogliomas, 30 oligoastrocytomas (21 WHO grade II tumors, 49 WHO grade III tumors). Data were correlated with overall patient survival (OS, median follow‐up: 5.8 years). The most frequent aberrations were losses on chromosome 19q (64%), 1p (59%), 9p (26%), 4q (21%), 10q (19%), 18q (17%); gains on 7q (24%), 19p (19%), 7p (17%). In univariate analyses, combined 1p/19q and 19q loss were significantly associated with longer OS, and gains on 7, 8q, 19q, 20, losses on 9p, 10, 18q, Xp with shorter OS. Multivariate analyses showed the most significant prognostic factors for OS of patients with any oligodendroglial tumor to be WHO grade [odds ratio (OR) 8], 7p gain (OR 6), 9p loss (OR 3); for OS of patients with anaplastic tumors to be 7p gain (OR 10), 8q gain (OR 5), 18q loss (OR 3). Patients with anaplastic oligodendroglial tumors containing one or more prognostically unfavorable genomic aberration had a poor outcome independent of the 1p/19q status. In summary, we identified several independent genomic markers of shorter survival in patients with oligodendroglial tumors. Thus, molecular diagnostic testing, which is usually restricted to 1p/19q deletion analysis, may need to be refined by additionally assessing the prognostically unfavorable genomic aberrations identified. © 2007 Wiley‐Liss, Inc.
Aberrant promoter methylation in pleural fluid DNA for diagnosis of malignant pleural effusion
Authors: Katayama Hideki , Hiraki Akio , Aoe Keisuke , Fujiwara Keiichi , Matsuo Keitaro , Maeda Tadashi , Murakami Tomoyuki , Toyooka Shinichi , Sugi Kazuro , Ueoka Hiroshi , Tanimoto Mitsune
Published: February 2007

Accumulating evidence implicates epigenetic changes such as hypermethylation in carcinogenesis. We investigated whether DNA methylation of 5 tumor suppressor genes in pleural fluid samples could aid in diagnosis of malignant effusion. In samples from 47 patients with malignant pleural effusions and 34 with nonmalignant effusions, we used a methylation‐specific polymerase chain reaction to detect aberrant hypermethylation of the promoters of the DNA repair gene O6‐methylguanine‐DNA methyltransferase (MGMT), p16INK4a, ras association domain family 1A (RASSF1A), apoptosis‐related genes, death‐associated protein kinase (DAPK), and retinoic acid receptor β (RARβ). Promoter hypermethylation was associated with malignant effusion for MGMT (Odds ratio (OR) = ∞), p16INK4a (OR = ∞), RASSF1A (OR = 13.8; CI, 1.71–112), and RARβ (OR = 3.17; CI, 1.10–9.11), but not for DAPK. Instead, DAPK methylation was associated with the length of smoking (p < 0.05). Patients with hypermethylation of MGMT, p16INK4a, RASSF1A or RARβ were 5.68 times more likely to have malignant effusions than patients without methylation (p = 0.008). Methylations per patient were more numerous for lung cancer than nonmalignant pulmonary disease (0.915 vs. 0.206, p < 0.001). Sensitivity, specificity, and positive predictive value of methylation in one or more genes for diagnosis of malignant effusion were 59.6%, 79.4%, and 80.0% respectively. In conclusion, aberrant promoter methylation of tumor suppressor genes in pleural fluid DNA could be a valuable diagnostic marker for malignant pleural effusion. © 2007 Wiley‐Liss, Inc.
Cardiovascular changes after pulmonary embolism from injecting calcium phosphate cement
Authors: Krebs Jörg , Aebli Nikolaus , Goss Ben G. , Sugiyama Sadahiro , Bardyn Thibaut , Boecken Ilka , Leamy Patrick J. , Ferguson Stephen J.
Published: February 2007

Concerns have been raised that the use of calcium phosphate (CaP) cements for the augmentation of fractured, osteoporotic bones may aggravate cardiovascular deterioration in the event of pulmonary cement embolism by stimulating coagulation. The aim of the present study was therefore to investigate the cardiovascular changes after pulmonary embolism of CaP cement using an animal model. In 14 sheep, 2.0 mL CaP or polymethylmethacrylate cement were injected intravenously. Cardiovascular parameters and antithrombin levels were monitored until 60 min postinjection. Postmortem, lungs were subjected to CT scanning, and 3D reconstruction of the cement was performed. Intravenous injection of CaP cement resulted in a more severe increase in pulmonary arterial pressure and decrease in arterial blood pressure. Disintegration of the CaP cement seemed to be the reason for the more severe reaction. There was no evidence of thromboembolism. Disintegration of CaP cement in circulating blood does not only compromise the mechanical properties, but also represents a risk of cardiovascular complications. Reliable cohesion of CaP cements in an aqueous environment is essential for clinical applications such as osteoporotic bone augmentation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Carvable calcium phosphate bone substitute material
Authors: Hofmann M. P. , Gbureck U. , Duncan C. O. , Dover M. S. , Barralet J. E.
Published: February 2007

This study investigated the use of partially set hydroxyapatite forming calcium phosphate cement as a carvable and mechanically stable bone substitute material. Hydroxyapatite‐forming cements were made of either mechanically activated α‐tricalcium phosphate or a mixture of tetracalcium phosphate and dicalcium phosphate anhydrous and setting was arrested up to 4 h post setting. The study showed that these partially set rigid samples of defined geometry could be carved into a desired shape when the degree of reaction was 30–40% and the relative porosity between 40 and 50%; samples are then expected to set completely after implantation in the presence of water or serum, having the same compressive strength as a continuously set calcium phosphate cement (up to 36 MPa). The development of compressive strength, phase composition, and crystallinity when varying production parameters of these partially “preset” bone substitute materials are presented for both cement systems. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Cytokine secretion from monocytes persists differentially after activator removal—One mechanism of long‐term biological response to implants
Authors: Messer R. L. W. , Lewis J. B. , Wataha J. C. , Adams Y. , Tseng W. Y.
Published: February 2007

Biomedical implants significantly improve the quality of life in an ever‐increasing number of patients. However, inflammation of tissues around implants remains a long‐term, post‐placement sequelae that may contribute to implant failure. Infection‐mediated failure is partly a consequence of inappropriate host response and chronic inflammation, and is mediated primarily by the secretory products of monocytes and macrophages. Although the secretion of inflammatory mediators from activated monocytes is well characterized, the resolution of mediator levels post‐activation is relatively unstudied. The current study defines the time course of cytokine secretion by activated human monocytes after the activator has been removed. THP1 human monocytes were activated by LPS, and cytokine secretion was monitored over time after LPS removal using enzyme‐linked immunosorbent assays (TNFα or IL8) or a cytokine array. The release of cytokines was compared with conditions without LPS removal. As expected, secretion of nearly all cytokines was reduced when LPS was removed, but the amount of the reduction was highly cytokine‐dependent. Furthermore, levels of cytokines were stable in medium alone but not in cell‐culture, suggesting an active process to either degrade or internalize secreted cytokines. Our results are consistent with clinical experience that inflammation resolves rapidly after treatment to remove bacteria or inflamed tissue. However, the differential cytokine regulation indicates a sophisticated coordination of cytokine levels probably associated with management of the wound healing response after removal of the bacterial insult. This wound healing response is one critical component of the long‐term success of biomedical implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Biomedical applications of diamond‐like carbon coatings: A review
Authors: Roy Ritwik Kumar , Lee Kwang‐Ryeol
Published: February 2007

Owing to its superior tribological and mechanical properties with corrosion resistance, biocompatibility, and hemocompatibility, diamond‐like carbon (DLC) has emerged as a promising material for biomedical applications. DLC films with various atomic bond structures and compositions are finding places in orthopedic, cardiovascular, and dental applications. Cells grew on to DLC coating without any cytotoxity and inflammation. DLC coatings in orthopedic applications reduced wear, corrosion, and debris formation. DLC coating also reduced thrombogenicity by minimizing the platelet adhesion and activation. However, some contradictory results (Airoldi et al., Am J Cardiol 2004;93:474–477, Taeger et al., Mat‐wiss u Werkstofftech 2003;34:1094–1100) were also reported that no significant improvement was observed in the performance of DLC‐coated stainless stent or DLC‐coated femoral head. This controversy should be discussed based on the detailed information of the coating such as atomic bond structure, composition, and/or electronic structure. In addition, instability of the DLC coating caused by its high level of residual stress and poor adhesion in aqueous environment should be carefully considered. Further in vitro and in vivo studies are thus required to confirm its use for medical devices. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Successful repeat therapy with rituximab for relapsed thrombotic thrombocytopenic purpura
Authors: Patino Wilmar , Sarode Ravindra
Published: February 2007

Thrombotic thrombocytopenic purpura (TTP) is a life‐threatening disease that is treated successfully with therapeutic plasma exchange (TPE) and often with corticosteroids; however, almost one third of TTP patients have treatment failures that require either long‐term TPEs or other adjunct therapies. Recent insights into the autoimmune‐pathophysiology of this disease provide the rationale for immune‐based therapies. Cumulative evidence suggests that rituximab, an anti‐CD20 antibody that depletes B‐cells temporarily, is an effective therapy in patients with refractory or relapsing TTP. We report here two patients with chronic relapsing TTP who were treated successfully with rituximab. However, both experienced TTP relapse following sustained and prolonged remissions for 21 and 37 months, respectively. They responded favorably with repeat therapy with rituximab. The benefits of rituximab treatment for refractory or relapsing TTP as well as in the prevention of recurrences are discussed. J. Clin. Apheresis. 22:, 2007 © 2007 Wiley‐Liss, Inc.
Drug‐resistant bullous pemphigoid and inflammatory bowel disease in a pediatric case successfully treated by plasma exchange and extracorporeal photochemotherapy
Authors: Tripodi Gino , Risso Marco , Tenerini Loredana , Gandullia Paolo , Castellano Emanuela , Rivabella Lucia
Published: February 2007

Bullous pemphigoid (BP) is an autoimmune skin disease that occurs mainly in elderly patients; onset of BP is rare in childhood. Inflammatory bowel diseases (IBD), by contrast, have a pediatric onset in 25% of presenting cases, requiring expert multidisciplinary management. Here we report a pediatric case of IBD (involving stomach, duodenum, ileum, and colon‐rectum) associated with a disseminated form of drug‐resistant BP successfully treated by plasma exchange (PEX), extracorporeal photochemotherapy (ECP), and corticosteroid therapy. The addition of PEX and ECP to standard treatment induced no severe side effects, prompted a rapidly achieved complete and long‐term remission, and allowed dose tapering of the immunosuppressive drugs over an 18‐month follow‐up. J. Clin. Apheresis. 22:, 2007 © 2007 Wiley‐Liss, Inc.
Therapeutic plasmapheresis as a bridge to liver transplantation in fulminant Wilson disease
Authors: Jhang Jeffrey S. , Schilsky Michael L. , Lefkowitch Jay H. , Schwartz Joseph
Published: February 2007

Wilson disease is an autosomal recessive disorder of copper metabolism that leads to the accumulation of copper mainly in the liver, cornea, brain, and kidney. Rarely, Wilson disease can present as fulminant hepatic failure with direct antiglobulin test–negative hemolytic anemia and renal failure. In the absence of liver transplantation, this disease is uniformly fatal because medical therapy is ineffective. This report describes the successful use of plasmapheresis for a patient with fulminant Wilson disease as a bridge to transplantation. Five daily therapeutic plasmapheresis procedures using fresh frozen plasma as a replacement fluid were performed over 6 days. Serum copper, urinary copper excretion, and hemolysis were significantly reduced and renal function improved. The patient's clinical status improved and she remained clinically stable until a liver transplant was possible. Plasmapheresis can be a successful medical treatment in fulminant Wilson disease and should be considered as a therapeutic measure to stabilize a patient by decreasing serum copper, reducing hemolysis, and helping to prevent renal tubular injury from copper and copper complexes until liver transplantation is possible. J. Clin. Apheresis. 22:, 2007 © 2007 Wiley‐Liss, Inc.
Bargaining power and efficiency—rural households in Ethiopia
Authors: Seebens Holger , Sauer Johannes
Published: February 2007

It appears to be clear from literature that bargaining power associated with greater control over household resources affects the share of an individual's consumption, that is, higher bargaining power leads to higher levels of consumption. However, it has remained unexplored, if and in which way bargaining power has an impact on household production. By applying different stochastic efficiency models, we try to fill this gap by investigating the role of the distribution of productive resources among 558 couples of rural Ethiopian households in determining the outcome of household production. The results clearly confirm that the more equal the allocation of resources, the higher the household's productivity which could be predominantly due to the incentives to participate efficiently in the production process. Copyright © 2007 John Wiley & Sons, Ltd.
In situ diagnostics of the decomposition of silacyclobutane on a hot filament by vacuum ultraviolet laser ionization mass spectrometry
Authors: Shi Y. J. , Lo B. , Tong L. , Li X. , Eustergerling B. D. , Sorensen T. S.
Published: February 2007

The gas‐phase reaction products of silacyclobutane (SCB) and 1, 1‐dideuterio‐silacyclobutane (SCB‐d2) from a hot‐wire chemical vapor deposition (HWCVD) chamber were diagnosed in situ using vacuum ultraviolet (VUV) laser single‐photon ionization (SPI) coupled with time‐of‐flight (TOF) mass spectrometry. The SCB molecule was found to decompose at a filament temperature as low as 900 °C. Both Si‐ (silylene, methylsilylene, and silene) and C‐containing (ethene and propene) species were produced from the SCB decomposition on the filament. Ethene and propene were detected by the mass spectrometer. It is demonstrated that the formation of ethene is favored over that of propene. The experimental study of hot‐wire decomposition of SCB‐d2 shows that propene is most likely produced by a process that is initiated by a 1,2‐H(D) migration to form n‐propylsilylene, followed by an equilibration with silacyclopropane, which then decomposes to propene. The detection of ethene in our experiment indicates that a competitive route of fragmentation exists for SCB decomposition on the filament. It has been shown that this competitive route occurs without H/D scrambling. The highly reactive silylene, silene, and methylsilylene species produced from SCB decomposition underwent either insertion reactions into the SiH bonds of the parent molecule or π‐type addition reaction across the double and triple CC bonds. The dimerization product of silene, 1,3‐disilacyclobutane, at m/z = 88 was also observed. Copyright © 2007 John Wiley & Sons, Ltd.
Activity of oxidative enzymes in fungal mycelia from grassland and forest soils
Authors: Gramss G.
Published: February 2007

In the vegetation periods of 1994 and 1995, fungus‐colonized soil samples from around the base of fruit bodies of basidiomycete fungi were excised. They were collected from fairy rings on grass‐ and woodlands and from stands of ectomycorrhizal fungi. Control samples devoid of conspicuous mycelia originated from adjacent plots with a comparable vegetation and soil structure. Water extraction and spectrophotometric analysis of fungus‐colonized samples indicated the presence of several cellfree polyphenol oxidases, peroxidases, manganese peroxidases, hydroxylases, aromatic‐ring cleavage dioxygenases, and esterases as well as active oxygen species. Tests for ligninolytic activity were in part positive. The activities of enzymes involved in the catalysis of H2O2, the essential co‐substrate of ligninolytic peroxidases, were also detected. Unvegetated control soils contained occasional traces of free polyphenol oxidases and peroxidases. Vegetated control samples were dominated by the activity of guaiacol peroxidase, which is known to be linked with plant tissue. It is concluded that basidiomycetous mycelia grown in the field are associated with the activities of enzymes which directly catalyze the degradation of lignin, some humic material in soil, and aromatic xenobiotics by hydroxylation, oxidation, and cleavage of aromatic ring structures. Further enzymes detected by their activities may be indirectly involved in these degradation processes by forming highly reactive substrate radicals, active oxygen species, and higher‐valency metal ions with considerable oxidative capacity.
A regional high‐frequency reconstruction of May–June precipitation in the north Aegean from oak tree rings, A.D. 1089–1989
Authors: Griggs Carol , DeGaetano Arthur , Kuniholm Peter , Newton Maryanne
Published: February 2007

May–June precipitation is the primary limiting factor in annual tree‐ring growth of the oaks of northeastern Greece and northwestern Turkey (39–42°N, 22–37°E). In a regional tree‐ring chronology of historic building and modern forest samples, the May–June precipitation explains at least 40% of the variance for 1900–1985, and is reconstructed here from A.D. 1089–1989. The reconstruction is compared to three other precipitation reconstructions for Turkey. The mean temperature of May and June is also a growth‐limiting factor owing to its effect on the availability of precipitation to the trees, but is more difficult to calibrate and reconstruct accurately owing to the trees' indirect response and the low number of long‐temperature records available for the interior of northwestern Turkey.

An analysis of the various methods of manipulating oak tree‐ring data for regional climate reconstruction shows that removing all but the high‐frequency variability plus normalizing the oak data sets before combining them into a master chronology are optimal techniques for a reasonable precipitation reconstruction of the entire area over the instrumental period. However, these methods do remove the low‐frequency signal and dampen some of the evidence of local extremes in May–June precipitation; these issues are discussed here and will be addressed in future research. Copyright © 2007 Royal Meteorological Society
Freshwater organic deposits and stratified sediments between Early and Late Midlandian (Devensian) till sheets, at Aghnadarragh, County Antrim, Northern Ireland
Authors: McCabe A. Marshall , Coope G. Russell , Gennard Dorothy E. , Doughty Philip
Published: February 2007

The following events have been identified from a complex sequence of Midlandian (Devensian) sediments recently exposed at Aghnadarragh, County Antrim: (1) A lower till interpreted as Early Midlandian was deposited by a major lowland ice sheet which moved south‐eastwards from central Ulster across the Lough Neagh depression. (2) Deglacial conditions were followed by a periglacial phase characterised by ice‐wedge growth and sedimentation by gravelly debris flows. The latter contain the oldest known remains of Mammuthus primigenius in Ireland. (3) An Early Midlandian interstadial is represented by a woody detritus peat, with evidence of Betula, Pinuos and Picea woodlands and a rich beetle fauna. Wood from this horizon has been shown to be beyond the range of radiocarbon dating (>48 180 BP). (4) Interstadial conditions were succeeded by a cold, non‐glacial phase dominated by in‐channel gravelly flows and deposition of organic muds which contain plant and insect fossils. These horizons are older than 46 850 BP. (5) An upper, non‐drumlinised till was deposited during the Late‐Midlandian by a major lowland ice sheet which moved generally eastwards across the Lough Neagh Lowlands from central Ulster. This glaciation probably reached its maximum at ca 20–24 ka. (6) Drumlin formation occurred in the Lough Neagh Lowlands towards the end of the Late‐Midlandian. The limiting moraines are dated to 17 ka. The lower till at Aghnadarragh is the first positive record of a major lowland ice sheet in Ireland during the early part of the last cold stage. The Early Midlandian interstadial peats have not been documented elsewhere in Ireland and correlate broadly with the Chelford Interstadial complex of the English Midlands. Related exposures elsewhere in Ulster confirm that the middle part of the last cold stage was free of major lowland ice masses but deposits of this period are absent from Aghnadarragh.
Arctic‐alpine brown soils as a source of palaeoenvironmental information: Further 14C dating and palynological evidence from Vestre Memurubreen, Jotunheimen, Norway
Authors: Matthews John A. , Caseldine Christopher J.
Published: February 2007

14C dating and pollen analytical evidence is presented relating to the usefulness of arctic‐alpine Brown Soils for palaeoenvironmental reconstruction. A present‐day soil has been examined together with its continuation beneath the outermost ‚Little Ice Age’︁ end moraine of the glacier Vestre Memurubreen at a location well above the tree‐line in the mid‐alpine belt of southern Norway. Fourteen 14C dates from chemically‐fractionated soil samples, which range in age from 495 ± 55 14C yr in the uppermost 1 cm to > 4000 14C yr within 13 cm of the buried soil surface, demonstrate near‐linear age/depth gradients in the palaeosol. Continuous development of the palaeosol over at least 5000 calendar yr prior to burial confirms that Vestre Memurubreen attained its Neoglacial maximum extent in the ‚Little Ice Age’︁. Pollen stratification in buried and unburied profiles indicates a single vegetation change from a low‐alpine dwarf‐shrub heath to a mid‐alpine ‚grass’︁ heath, reflecting an altitudinal lowering of vegetation belts and a possible climatic cooling of 2‐4°C. Surface additions of allochthonous (aeolian) mineral particles appear to have contributed to soil development, whilst mixing processes have been relatively unimportant at this site. The immobilisation of resistant organic residues and the ineffectiveness of biological and chemical activity are major reasons for the preservation of a palaeoenvironmental record in these high altitude soils.
The use of mineral magnetic analyses in the study of glacial diamicts: A pilot study
Authors: Walden John , Smith John P. , Dackombe Roger V.
Published: February 2007

Mineral magnetic methods of characterising glacial diamicts and their associated sediments are applied to deposits within the Manx Quaternary sequence. The possible advantages of these techniques over more traditional methods of sediment characterisation are outlined, and the results obtained in a pilot study are examined. Results show that both distinctions and similarities exist within the magnetic mineral assemblages of the four diamict units studied. The possible implications of these results for interpreting the Late Quaternary history of the Isle of Man and the future potential of the techniques are briefly discussed.
Lower Pleistocene deltaic and marine sediments in boreholes from the central North Sea
Authors: Stoker Martyn S. , Bent Alistair J. A.
Published: February 2007

Lower Pleistocene sediments recovered in boreholes from the Aberdeen Ground Formation in the central North Sea indicate that the unit was deposited in a delta front to prodelta/shallow, open shelf marine setting. Possible estuarine and clastic nearshore marine deposits have been identified on the western margin of the basin. The delta front sediments consist of interbedded, structureless to laminated sands and muds with organic debris, ferruginous nodules and common soft sediment deformation structures. Sporadic rippled and graded beds, basal scours to beds and starved ripples suggest periodic wave–current reworking. Prodelta/shelf marine sediments are predominantly argillaceous with only occasional thin sand beds and rare phosphatic bands. One exceptionally thick sand body or submarine channel‐fill although this remains uncertain. The estuarine/clastic nearshore marine sediments include coarse channel‐lag deposits and rippled and laminated subtidal sands. A rich microfossil assemblage recovered from the prodelta/shelf marine sequence indicates that deposition occurred under fluctuating climatic conditions.
The ‚loess’︁ section at Borden, Kent, SE England
Authors: Catt John A. , Bateman Richard M. , Wintle Ann G. , Murphy Christopher P.
Published: February 2007

A 5.3m profile originally described as loess with a buried interglacial soil is reinterpreted from petrographic evidence and thermoluminescence dating as a Holocene colluvial accretionary soil. Mineralogical analyses of coarse silt (16–63 μm) fractions suggest that most of the silty colluvium was derived from weathered Thanet Beds upslope, though some loess was incorporated during the final depositional phase. Thin sections show that clay illuviation occurred penecontem‐poraneously with deposition of colluvium. Thermoluminescence properties suggest partial optical bleaching of the grains during rapid deposition, which is consistent with a Holocene colluvial origin.
Introduction
Authors: French Hugh M. , Koster Eduard A.
Published: February 2007

Environmental reconstructions utilising the evidence of relic or fossil periglacial features are necessarily based on the nature and present distribution of comparable active features. The most critical features are those indicative of permafrost, because of the negative mean annual temperatures required for permafrost, whereas many other cold climate features are much less informative as to temperature implications. (Washburn, Geocryology, 1980, 279).
The permafrost regime in the Mackenzie Delta, Beaufort Sea region, N.W.T. and its significance to the reconstruction of the palaeoclimatic history
Authors: Allen Diana M. , Michel Frederick A. , Judge Alan S.
Published: February 2007

Observed depths to the base of the ice‐bearing permafrost (!BPF) as determined from geophysical well‐log and survey information in the Mackenzie Delta and offshore Beaufort Sea continental shelf show significant variation. Depths range from over 700m beneath the northeastern portion of Richards Island and the adjacent offshore region to the north, to less than 100m in the modern Mackenzie Delta and offshore Mackenzie Bay regions. Along the Tuktoyaktuk Peninsula, permafrost thicknesses exceed 600m but tend to thin to less than 100m in a southeasterly direction.

The wide variation in the thickness and distribution of permafrost is due in part to differences in the subsurface deltaic lithologies and to the complexity of the past surface temperature history, exhibited, for example, by fluctuations of the mean annual ground temperature. Geological cross‐sections showing variation in the Tertiary and Upper Cretaceous deltaic sequences indicate a good correlation with the permafrost distribution. In particular, where the sand and gravel units of the Iperk and Kugmallit Sequences predominate, permafrost is thick owing to the high thermal conductivities of the ice‐rich sediments. Conversely, where the low thermal conductivity shales and mudstones of the Richards Sequence are present, permafrost is accordingly thinner.

Numerical models of permafrost aggradation in the Mackenzie Delta region suggest that Early and Late Wisconsinan surface temperatures were of the order −18°C. A mid‐Wisconsinan rise in temperature to approximately −8°C, similar to mean surface temperature today, is also indicated. This proposed palaeoclimate is sufficient to account for the observed maximum permafrost thicknesses in the region.
A constraint to the Wisconsinan glacial history, Canadian Arctic Archipelago
Authors: Taylor Alan
Published: February 2007

Thick ice‐bearing permafrost is not observed today beneath the deeper channels of the central Queen Elizabeth Islands, Canadian Arctic Archipelago. Analysis of a precision temperature log recently obtained at an offshore well near Ellef Ringnes Island indicates that the thermal regime beneath the seabed is in equilibrium with today's marine environment. If thick permafrost similar to that observed on land today had existed in the Pleistocene in areas that are presently offshore, then such permafrost must have started melting no later than 25000 years ago in order to allow the present thermal regime to evolve. This suggests that the inter‐island channels must have been water‐filled at least by that date.
The development of near‐surface ground ice during the Holocene at sites near Mayo, Yukon Territory, Canada
Authors: Burn C. R.
Published: February 2007

An examination of soil thermal and hydrologic regimes at several sites near Mayo, Yukon Territory, and the ground‐ice stratigraphy of a thaw‐slump headwall close to these sites supports the hypothesis that an ice‐rich zone, frequently observed at the base of the active layer, may be due to the annual water balance of permafrost. Observations demonstrate that ice lenses have grown at the top of permafrost in soil tubes installed in 1983. In addition, 90 cm of segregated ice are exposed in the thaw‐slump headwall above a thaw unconformity, dated at 8870 ± 200 years BP, but below the base of the present active layer. These data suggest that the rate of water incorporation into permafrost over the last 8000 years in the Mayo area has been at least 0.1 mm yr−1.
Ancient and modern cold‐climate aeolian sand deposition: A review
Authors: Koster Eduard A.
Published: February 2007

Although partly active aeolian sand sheets and dunes cover large areas in the zones of (dis)continuous permafrost, little precise information is available about the influence of cold‐climate conditions on modern aeolian processes. This means that palaeoenvironmental reconstructions in the stabilised, mainly Late Pleistocene dune fields and cover sand regions in the ‘sand belts’ of the European Lowlands and the Northern Great Plains of the USA and Canada, are necessarily still based on ancient evidence. Cold‐climate wind deposits are typically derived from areas of abundant sediment supply like unvegetated flood plains, glacial outwash plains, till plains and lake shores. The common parabolic and transverse dune forms resemble those observed in temperate regions. Although a variety of periglacial features has been identified in Late Pleistocene dune and cover sands none of them indicate that permafrost is crucial to aeolian activity. Specific structures in aeolian strata permit tentative interpretation of the moisture content of depositional sand surfaces, the nature of annual sedimentation cycles and the processes by which strata were deposited and/or contorted. But surprisingly little is known about the role of vegetation in the process of sand accumulation. Dunes are most informative with respect to reconstructions of past wind regimes, which offer important data for verification of palaeoclimatic simulations.
A reinterpretation of the Lateglacial environmental history of the Isle of Skye, Inner Hebrides, Scotland
Authors: Walker Michael J. C. , Ballantyne Colin K. , Lowe J. John , Sutherland Donald G.
Published: February 2007

This paper presents a major revision of the Late Devensian Lateglacial environmental history of the Isle of Skye, Scotland, based upon a combination of geomorphological, biostratigraphical and radiocarbon evidence. The distribution of glacial and periglacial landforms, and of raised shorelines, suggests that there was only one extensive readvance of local glaciers in southern Skye following the wastage of the Late Devensian ice sheet. Pollen‐stratigraphic evidence from 10 sites inside and 4 sites outside the mapped ice limits indicates that this readvance occurred during the Loch Lomond Stadial. At that time over 180km2of the uplands of south‐central Skye were covered by glacier ice, a much more extensive glaciation than previously envisaged. Palynological evidence from four Lateglacial profiles implies that degree of exposure to strong westerly winds was the principal factor determing vegetational contrasts on the island, and that regional differences in vegetational type were less pronounced than has hitherto been suggested. The glacial and palaeobotanical reconstructions reported here are more compatible with Lateglacial data from the Scottish mainland and Hebridean islands than were the previously‐published accounts for the Isle of Skye.
Late Quaternary sea‐level changes: Measurement, correlation, and future applications ‐ the international significance of IGCP Project 200
Authors: Shennan Ian
Published: February 2007

International Geological Correlation Project 200 ran from 1983 to 1987 and was a major stimulus to sea‐level research. The results arising from the project were very varied, with much new data collected and analysed, but there remain some problems for international research.
Late Holocene sea levels in Ireland
Authors: Carter Richard W. G. , Devoy Robert J. N. , Shaw John
Published: February 2007

The course of Irish sea levels during the late‐Holocene is not well‐known, yet it is an understanding of this period that will prove crucial in the definition and management of future sea‐level changes. The coastline of Ireland embraces wide environmental and glacio‐isostatic contrasts, which serve and, to some extent, control sea‐level events at both local and regional scales, making definitive resolution of relative sea‐level changes difficult. In the southwest, the picture is of inexorable relative sea‐level rise. Studies in Co. Kerry show a gradual submergence of terrestrial facies, by estuarine and, in places, marine materials. Pollen and diatom studies, together with 14C dates, suggest a decreasing rate of relative sea‐level rise in the last 2500 years, often associated with geomorphological changes. Sites on the south coast of Ireland confirm the evidence from the southwest. In Cork Harbour, recent relative sea‐level rise since 2100 BP was responsible for marginal land submergence, while elsewhere rising water levels appear to have caused rapid barrier migrations and coast erosion. Palaeoenvironmental evidence from this region suggests a distinctive pattern of sea‐level change, associated with sedimentary and/or crustal dynamics, which is not encountered elsewhere in northwest Europe. The overall rate of relative sea‐level change on the south and southwest coasts falls between 0.6 and 1.1 mm/year over the last 5000 years. In the north, there is a clear east to west variation in relative sea‐level trends, following an isostatically‐controlled peak (+3 to −1 m OD) between 6500 BP (east) and 3500 BP (west). Falling sea levels from 3500 to 1500 BP have been followed by a general slow rise, although there are still local anomalies to this pattern, most noticeably at Malin Head, where sea level is currently falling at 2.4mm/year. Relative sea‐level signatures in Ireland differ markedly between the north and south coasts. Furthermore geomorphological and ecological contexts of this rise vary from east to west, providing a complex all‐Ireland framework for future investigations.
Holocene sedimentation on the North Norfolk barrier coast in relation to relative sea‐level change
Authors: Funnell Brian M. , Pearson Ian
Published: February 2007

Fourteen distinct sedimentary environments have been recognised in the surface sediments of the intertidal zone of the North Norfolk coast. Nine of these can be distinguished in borehole samples on the basis of sedimentological and micro‐palaeontological characteristics. They comprise: gravel; channel sand; intertidal sand; intertidal silty sand; intertidal mud and marsh creek; lower salt marsh; upper salt marsh; dune sand; and peat.

Sediment accumulations have been penetrated to a depth of −8 m OD and basal peats dated by 14C back to 8410 ± 50 years BP. An overall rate of sediment accumulation (and subsidence) of about 1 m per thousand years is indicated. There is considerable persistence of sedimentary environments in the same areas during up‐building, but some erosion and roll‐over of the coastal barrier system has occurred. Evidence of positive and negative sea‐level tendencies are present in the record, but the main development of the tract is determined by sediment supply to the beach and marshes; positive sea‐level tendencies occur at c. 6610, 5970, 4630 and 2790 BP, negative sea‐level tendencies occur at 4520 to 4450 and (possibly) 3470 BP.
Loch Lomond Stadial and Flandrian shorelines in the inner Moray Firth area, Scotland
Authors: Firth Callum R. , Haggart B. Andrew
Published: February 2007

Morphological mapping and stratigraphical investigations have identified surface and buried relict marine features in the inner Moray Firth area. The features consist of a buried gravel layer formed during the Loch Lomond Stadial, a buried beach of early Flandrian age, and surface beaches and estuarine flats of mid‐late Flandrian age. Analysis of the altitudes of morphological features has identified two buried and five (possibly six) surface glacio‐isostatically tilted raised shorelines. The steepest shoreline is associated with the buried gravel layer and slopes down towards N20°E at a gradient of 0.20m/km. Younger shorelines have lower gradients between 0.16–0.03m/km. The shoreline sequence combined with published data defines relative sea‐level movements in the area during the last 11000 years. The inner Moray Firth shorelines are correlated with similar features in other areas of Scotland which include the Main Lateglacial, Main Buried and Main Postglacial Shorelines.
Evidence of early Flandrian tidal surges in Lower Strathearn, Scotland
Authors: Cullingford Robin A. , Caseldine Christopher J. , Gotts Paul E.
Published: February 2007

Detailed stratigraphic, palaeobotanical (diatom and pollen) and radiometric evidence from a sequence of buried estuarine deposits, buried peat and overlying estuarine ‘carse’ deposits at Wester Rhynd, in Lower Strathearn, suggests the occurrence of two brief marine incursions between the abandonment by the sea of a buried estuarine flat, probably the Low Buried Beach, at about 8765 ± 75 BP, and c. 8500 BP. The first incursion, shortly after 8565 ± 85 BP, caused bottom‐living marine diatoms to be thrown without clastic material onto the rapidly accumulating terrestrial peat. The second, bracketed by dates of 8485 ± 80 and 8510 ± 85 BP, deposited an extremely thin (1 mm) layer of fine sand that interrupts an otherwise unbroken buried peat succession covering the period 8765 ± 75 to 7710 ± 70 BP. The marine diatom, lithostratigraphic and 14C evidence together are consistent with a storm, storm‐surge or tsunami origin for these events, which are recognised principally from the diatom evidence, having left no mark in the pollen record.