Sediment Transfer From Gravel-Bed Rivers to Beaches

A morphological approach was used to quantify the transfer of gravel-sized (> 2mm) sediment from one river to the coast and its subsequent redistribution within the coastal zone. The study investigates sediment transport in wandering gravel-bed rivers, river mouth processes and sediment transport on gravel beaches. The research was largely field based and used results from repeat morphologic surveys of the lower, wandering gravel-bed reach of the River Spey, the Speymouth delta and gravel beaches of Spey Bay, north-east Scotland. The supply of gravel to the river mouth was episodic, with transport rates varying from 41 000 +/- 6 000 m3a-1 (1993-1994) to 6 000 +/- 4 000 m3a-1 (1997-1999). Transport rates were not directly related to flow conditions because the availability of sediment for transport was critical. Sediment was mobilised according to the recent local history of erosion, deposition and channel adjustment and not only the magnitude of the flood. Delivery to the coast of this episodic sediment supply was made more variable depending on the operation of the delta. A gravel spit complex extended westwards across the river mouth at a mean rate of 150 ma' between 1997 and 1999. This resulted in temporary storage of sediment in the extending spit which had implications for the downdrift coast. Cycles of accretion and erosion were created in the lee of the spit which were most significant at the river mouth before being propagated downdrift. Volumetric information obtained from successive beach profile surveys indicated that zones of accretion and erosion were spatially and temporally variable along the 16km coastline of Spey Bay. This variability was caused by the passage of pulses (or slugs) of sediment which moved alongshore in response to variations in sediment supply (e.g. episodic delivery of fluvial sediment, river mouth processes, beach feeding and storms). It is argued that gravel sediment moves alongshore as slugs by a given distance depending on the magnitude of storm events. Travel distances of ca. 2-3km were recorded following a major storm event in March 1998. This has important implications for the management of gravel beaches, as erosional zones (or "problems") are not static and vary in space and time. . Fluvial, deltaic and coastal volume changes were combined to estimate a short-term (3 year) sediment budget for the system. A medium-term budget (100 year) was also compiled from map analysis and river-modelling studies. Both budgets showed a net loss of sediment from the system, indicating a system that has been erosional for at least the last century

Mast cells in human periodontal disease

Recently, mast cells have been shown to produce cytokines which can direct the development of T-cell subsets. The aim of the present study was to determine the relationship between mast cells and the Th1/Th2 response in human periodontal disease. Tryptase+ mast cell numbers were decreased in chronic periodontitis tissues compared with healthy/gingivitis lesions. Lower numbers of c-kit+ cells, which remained constant regardless of clinical status, indicate that there may be no increased migration of mast cells into periodontal disease lesions. While there were no differences in IgG2+ or IgG4+ cell numbers in healthy/gingivitis samples, there was an increase in IgG4+ cells compared with IgG2+ cells in periodontitis lesions, numbers increasing with disease severity. This suggests a predominance of Th2 cells in periodontitis, although mast cells may not be the source of Th2-inducing cytokines

Phosphorylation of the androgen receptor is associated with reduced survival in hormonerefractory prostate cancer patients

Cell line studies demonstrate that the PI3K/Akt pathway is upregulated in hormone-refractory prostate cancer (HRPC) and can result in phosphorylation of the androgen receptor (AR). The current study therefore aims to establish if this has relevance to the development of clinical HRPC. Immunohistochemistry was employed to investigate the expression and phosphorylation status of Akt and AR in matched hormone-sensitive and -refractory prostate cancer tumours from 68 patients. In the hormone-refractory tissue, only phosphorylated AR (pAR) was associated with shorter time to death from relapse (<i>P</i>=0.003). However, when an increase in expression in the transition from hormone-sensitive to -refractory prostate cancer was investigated, an increase in expression of PI3K was associated with decreased time to biochemical relapse (<i>P</i>=0.014), and an increase in expression of pAkt<sup>473</sup> and pAR<sup>210</sup> were associated with decreased disease-specific survival (<i>P</i>=0.0019 and 0.0015, respectively). Protein expression of pAkt<sup>473</sup> and pAR<sup>210</sup> also strongly correlated (<i>P</i><0.001, c.c.=0.711) in the hormone-refractory prostate tumours. These results provide evidence using clinical specimens, that upregulation of the PI3K/Akt pathway is associated with phosphorylation of the AR during development of HRPC, suggesting that this pathway could be a potential therapeutic target

Novel Campylobacter concisus lipooligosaccharide is a determinant of inflammatory potential and virulence

This work was supported in part by Department of Veterans Affairs Merit Review award BX000727 (to G.A.J.). The authors also acknowledge National Institutes of Health National Center for Research Resources Shared Instrumentation Grant S10 RR029446 (to H. E. Witkowska) for acquisition of the Synapt G2 high definition mass spectrometer, which is located at the University of California, San Francisco Sandler-Moore Mass Spectrometry Core Facility and supported by the Sandler Family Foundation, the Gordon and Betty Moore Foundation, National Institutes of Health/National Cancer Institute Cancer Center Support Grant P30 CA082103, and the Canary Foundation. G.A.J. is a recipient of the Senior Research Career Scientist award from the Department of Veterans Affairs. R.H. is funded by a Career Researcher Fellowship from NHS Research Scotland. The BISCUIT study was funded by a Clinical Academic Training Fellowship from the Chief Scientist Office (CAF/08/01). This is paper number 116 from the Center for Immunochemistry. The contents of this article do not represent the views of the Department of Veterans Affairs or the United States Government. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. K.B. acknowledges funding from the Child Health Research Charitable Incorporated Organisation and the Bogue Fellowship for travel. The authors declare that they have no conflicts of interest with the contents of this article.Peer reviewe

Inflammation, heat shock proteins and periodontal pathogens in atherosclerosis: an immunohistologic study

Background: Inflammation is a significant component of atherosclerosis lesions. Bacteria, including periodontopathogens, have been demonstrated in atherosclerotic plaques and cross-reactivity of the immune response to bacterial GroEL with human heat shock protein 60 has been suggested as a link between infections and atherosclerosis

Easy on that trigger dad: a study of long term family photo retrieval

We examine the effects of new technologies for digital photography on people's longer term storage and access to collections of personal photos. We report an empirical study of parents' ability to retrieve photos related to salient family events from more than a year ago. Performance was relatively poor with people failing to find almost 40% of pictures. We analyze participants' organizational and access strategies to identify reasons for this poor performance. Possible reasons for retrieval failure include: storing too many pictures, rudimentary organization, use of multiple storage systems, failure to maintain collections and participants' false beliefs about their ability to access photos. We conclude by exploring the technical and theoretical implications of these findings

Inflammation, heat shock proteins and periodontal pathogens in atherosclerosis: an immunohistologic study

Background: Inflammation is a significant component of atherosclerosis lesions. Bacteria, including periodontopathogens, have been demonstrated in atherosclerotic plaques and cross-reactivity of the immune response to bacterial GroEL with human heat shock protein 60 has been suggested as a link between infections and atherosclerosis

Nonlinear interaction of charged particles with a free electron gas beyond the random-phase approximation

A nonlinear description of the interaction of charged particles penetrating a solid has become of basic importance in the interpretation of a variety of physical phenomena. Here we develop a many-body theoretical approach to the quadratic decay rate, energy loss, and wake potential of charged particles moving in an interacting free electron gas. Explicit expressions for these quantities are obtained either within the random-phase approximation (RPA) or with full inclusion of short-range exchange and correlation effects. The Z^3 correction to the energy loss of ions is evaluated beyond RPA, in the limit of low velocities.Comment: 5 pages, 2 figures To appear in Phys. Rev.

Is facilitation a true species interaction?

Current ecological literature considers facilitation to be a positive interaction alongside symbiosis or mutualism. But unlike these interactions, the fitness of one of the species involved in facilitation remains unaffected which precludes coevolution. Therefore, we believe that facilitation is not a true species interaction and should be kept within the framework of succession.Pablo Munguia, Alfredo F. Ojanguren, Andrew N. Evans, Laura Ryckman, Brad Gemmell, Colt Cook, Geoff Hensge

Evidence of two deeply divergent co-existing mitochondrial genomes in the Tuatara reveals an extremely complex genomic organization

Animal mitochondrial genomic polymorphism occurs as low-level mitochondrial heteroplasmy and deeply divergent co-existing molecules. The latter is rare, known only in bivalvian mollusks. Here we show two deeply divergent co-existing mt-genomes in a vertebrate through genomic sequencing of the Tuatara (Sphenodon punctatus), the sole-representative of an ancient reptilian Order. The two molecules, revealed using a combination of short-read and long-read sequencing technologies, differ by 10.4% nucleotide divergence. A single long-read covers an entire mt-molecule for both strands. Phylogenetic analyses suggest a 7–8 million-year divergence between genomes. Contrary to earlier reports, all 37 genes typical of animal mitochondria, with drastic gene rearrangements, are confirmed for both mt-genomes. Also unique to vertebrates, concerted evolution drives three near-identical putative Control Region non-coding blocks. Evidence of positive selection at sites linked to metabolically important transmembrane regions of encoded proteins suggests these two mt-genomes may confer an adaptive advantage for an unusually cold-tolerant reptile