Incised palaeo-channels of the Late Middle Pleistocene Thames: age, origins and implications for fluvial palaeogeography and sea-level reconstruction in the southern North Sea Basin.

Multidisciplinary investigations of the infills of steeply-incised buried channels on the coast of Essex, England, provide important insights into late Middle Pleistocene climate and sea-level change and have a direct bearing on the differentiation of MIS 11 and MIS 9 in terrestrial records. New data are presented from Rochford and Burnham-on-Crouch where remnants of two substantial palaeo-channels filled with interglacial sediment can be directly related to the terrace stratigraphy of the Thames. The sediments in both channels accumulated in an estuarine environment early in an interglacial when mixed oak forest was becoming established. Lithological evidence suggests that the interglacial beds post-date the brackish-water infill of an older palaeo-channel ascribed to the Hoxnian and correlated with part of MIS 11, and pre-date terrace gravels (Barling Gravel) ascribed to MIS 8. An MIS 9 attribution is supported by molluscan biostratigraphy, palaeo-salinity and amino-acid racemization data. The relative sea-level record in this area thus includes evidence for two major marine transgressions during MIS 11 and MIS 9, with local maxima of >10 m O.D. Both are associated with sediments that show ‘Hoxnian’ palynological affinities. The wider significance of these findings, and of an intermediate phase of pronounced fluvial incision during MIS 10, is discussed.

Examining the uncertainties in a 'tuned and stacked' peatland water table reconstruction

Tuning and stacking approaches have been used to compile non-annually resolved peatland palaeo-water table records in several studies. This approach has been proposed as a potential way forward to overcome the chronological problems that beset the correlation of records and may help in the upscaling of palaeoclimate records for climate model-data comparisons. This paper investigates the uncertainties in this approach using a published water table compilation from Northern Ireland. Firstly, three plausible combinations of chronological match points are used to assess the variability of the reconstructions. It is apparent that even with markedly different match point combinations, the compilations are highly similar, especially when a 100-year running mean line is used for interpretation. Secondly, sample-specific reconstruction errors are scaled in relation to the standardised water table units and illustrated on the compiled reconstruction. Thirdly, the total chronological errors for each reconstruction are calculated using Bayesian age-modelling software. Although tuning and stacking approaches may be suitable for compiling peat-based palaeoclimate records, it is important that the reconstruction and chronological errors are acknowledged and clearly illustrated in future studies. The tuning of peat-based proxy climate records is based on a potentially flawed assumption that events are synchronous between sites. © 2011 Elsevier Ltd and INQUA.

North Atlantic marine radiocarbon reservoir ages through Heinrich event H4: A new method for marine age model construction

Cooling and sinking of dense saline water in the Norwegian–Greenland Sea is essential for the formation of North Atlantic Deep Water. The convection in the Norwegian–Greenland Sea allows for a northward flow of warm surface water and southward transport of cold saline water. This circulation system is highly sensitive to climate change and has been shown to operate in different modes. In ice cores the last glacial period is characterized by millennial-scale Dansgaard–Oeschger (D–O) events of warm interstadials and cold stadials. Similar millennial-scale variability (linked to D–O events) is evident from oceanic cores, suggesting a strong coupling of the atmospheric and oceanic circulations system. Particularly long-lasting cold stadials correlate with North Atlantic Heinrich events, where icebergs released from the continents caused a spread of meltwater over the northern North Atlantic and Nordic seas. The meltwater layer is believed to have caused a stop or near-stop in the deep convection, leading to cold climate. The spreading of meltwater and changes in oceanic circulation have a large influence on the carbon exchange between atmosphere and the deep ocean and lead to profound changes in the 14C activity of the surface ocean. Here we demonstrate marine 14C reservoir ages (R) of up to c. 2000 years for Heinrich event H4. Our R estimates are based on a new method for age model construction using identified tephra layers and tie-points based on abrupt interstadial warmings.

Culture Age, temperature, and pH affect the polyol and trehalose contents of fungal propagules

The growth and conidial physiology of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Paecilomyces farinosus were studied under different conditions. The effects of culture age (up to 120 days), temperature (5 to 35°C), and pH (2.9 to 11.1) were determined. Growth was optimal at pH 5 to 8 for each isolate and between 20 and 35°C, depending on the isolate. The predominant polyol in conidia was mannitol, with up to 39, 134, and 61 mg g of conidia-1 for B. bassiana, M. anisopliae, and P. farinosus, respectively. Conidia of M. anisopliae contained relatively small amounts of lower-molecular-weight polyols and trehalose (less than 25 mg g-1 in total) in all treatments. Conidia of B. bassiana and P. farinosus contained up to 30, 32, and 25 mg of glycerol, erythritol, and trehalose, respectively, g-1, depending on the treatment. Conidia of P. farinosus contained unusually high amounts of glycerol and erythritol at pH 2.9. The apparent effect of pH on gene expression is discussed in relation to the induction of a water stress response. To our knowledge, this is the first report of polyols and trehalose in fungal propagules produced over a range of temperature or pH. Some conditions and harvesting times were associated with an apparent inhibition of synthesis or accumulation of polyols and trehalose. This shows that culture age and environmental conditions affect the physiological quality of inoculum and can thereby determine its potential for biocontrol.

Interaction between water and nutrient deficiencies in helianthus annuus

The physiological response of plants to water deficits are known to vary according to the conditions of application of drought stress and the rate of development of leaf water deficits. At the whole plant level the effect of the water shess is usually perceived as a decrease in photosynthesis and growth, and is associated with alterations in C and N metabolism (McDonald and Davies, 1996). The decrease in water potential affects transpiration and hence xylem transport of nitrate or reduced N into growing regions. The response of the photo-synthetic apparatus either to water stress or rehydration seems to be dependent "on leaf age (O'Neill, 1983; Wolfe et al., 1988). Degradation of both thylakoid and stromal N-containing compounds can occur in response to water stress, recovery from which may pequire more than a week (Chaves, 1991).

Chronic versus acute ingestion of sodium citrate: a randomized placebo controlled cross-over trial for swimming 200 metres in well-trained swimmers age 13-17

A double-blinded, placebo controlled, cross-over design was used to investigate sodium citrate dihydrate (Na-CIT) supplementation improve 200m swimming performance. Ten well-trained, male swimmers (14.9 ± 0.4y; 63.5 ± 4kg) performed four 200m time trials: acute (ACU) supplementation (0.5g/kg), acute placebo (PLC-A), chronic (CHR) (0.1g/kg for 3 days and 0.3g/kg on the 4th day pre-trial), and chronic placebo (PLC-C). Na-CIT was administered 120min pre-trial in solution with 500mL of flavored water; placebo was flavored water. Blood lactate, base excess (BE), bicarbonate, pH, and PCO2 were analyzed at basal, 100min post-ingestion, and 3min post-trial via finger prick. Time, lactate, and rate of perceived exertion were not different between trials. BE and bicarbonate were significantly higher for the ACU and CHR trials compared to placebo. “Responders” improved by 1.03% (P=0.043) and attained significantly higher post-trial lactate concentrations in the ACU versus PLC-A trials and compared to non-responders in the ACU and CHR trials.

Effects of Different Feeding Regimes on the Digestibility and Faecal Excretion of Nitrogen, Soluble Carbohydrates and Fibre Fractions in Water Buffaloes kept under Subtropical Conditions

In the course of the ‘Livestock Revolution’, extension and intensification of, among others, ruminant livestock production systems are current phenomena, with all their positive and negative side effects. Manure, one of the inevitable secondary products of livestock rearing, is a valuable source of plant nutrients and its skillful recycling to the soil-plant interface is essential for soil fertility, nutrient - and especially phosphorus - uses efficiency and the preservation or re-establishment of environmentally sustainable farming systems, for which organic farming systems are exemplarily. Against this background, the PhD research project presented here, which was embedded in the DFG-funded Research Training Group 1397 ‘Regulation of soil organic matter and nutrient turnover in organic agriculture ’ investigated possibilities to manipulate the diets of water buffalo (Bubalus bubalis L.) so as to produce manure of desired quality for organic vegetable production, without affecting the productivity of the animals used. Consisting of two major parts, the first study (chapter 2) tested the effects of diets differing in their ratios of carbon (C) to nitrogen (N) and of structural to non-structural carbohydrates on the quality of buffalo manure under subtropical conditions in Sohar, Sultanate of Oman. To this end, two trials were conducted with twelve water buffalo heifers each, using a full Latin Square design. One control and four tests diets were examined during three subsequent 7 day experimental periods preceded each by 21 days adaptation. Diets consisted of varying proportions of Rhodes grass hay, soybean meal, wheat bran, maize, dates, and a commercial concentrate to achieve a (1) high C/N and high NDF (neutral detergent fibre)/SC (soluble carbohydrate) ratio (HH), (2) low C/N and low NDF/SC ratio (LL); (3) high C/N and low NDF/SC ratio (HL) and (4) low C/N and high NDF/SC (LH) ratio. Effects of these diets, which were offered at 1.45 times maintenance requirements of metabolizable energy, and of individual diet characteristics, respectively, on the amount and quality of faeces excreted were determined and statistically analysed. The faeces produced from diets HH and LL were further tested in a companion PhD study (Mr. K. Siegfried) concerning their nutrient release in field experiments with radish and cabbage. The second study (chapter 3) focused on the effects of the above-described experimental diets on the rate of passage of feed particles through the gastrointestinal tract of four randomly chosen animals per treatment. To this end, an oral pulse dose of 683 mg fibre particles per kg live weight marked with Ytterbium (Yb; 14.5 mg Yb g-1 organic matter) was dosed at the start of the 7 day experimental period which followed 21 days of adaptation. During the first two days a sample for Yb determination was kept from each faecal excretion, during days 3 – 7 faecal samples were kept from the first morning and the first evening defecation only. Particle passage was modelled using a one-compartment age-dependent Gamma-2 model. In both studies individual feed intake and faecal excretion were quantified throughout the experimental periods and representative samples of feeds and faeces were subjected to proximate analysis following standard protocols. In the first study the organic matter (OM) intake and excretion of LL and LH buffaloes were significantly lower than of HH and HL animals, respectively. Digestibility of N was highest in LH (88%) and lowest in HH (74%). While NDF digestibility was also highest in LH (85%) it was lowest in LL (78%). Faecal N concentration was positively correlated (P≤0.001) with N intake, and was significantly higher in faeces excreted by LL than by HH animals. Concentrations of fibre and starch in faecal OM were positively affected by the respective dietary concentrations, with NDF being highest in HH (77%) and lowest in LL (63%). The faecal C/N ratio was positively related (P≤0.001) to NDF intake; C/N ratios were 12 and 7 for HH and LL (P≤0.001), while values for HL and LH were 11.5 and 10.6 (P>0.05). The results from the second study showed that dietary N concentration was positively affecting faecal N concentration (P≤0.001), while there was a negative correlation with the faecal concentration of NDF (P≤0.05) and the faecal ratios of NDF/N and C/N (P≤0.001). Particle passage through the mixing compartment was lower (P≤0.05) for HL (0.033 h-1) than for LL (0.043 h-1) animals, while values of 0.034 h-1 and 0.038 h-1 were obtained for groups LH and HH. At 55.4 h, total tract mean retention time was significantly (P≤0.05) lower in group LL that in all other groups where these values varied between 71 h (HH) and 79 h (HL); this was probably due to the high dietary N concentration of diet LL which was negatively correlated with time of first marker appearance in faeces (r= 0.84, P≤0.001), while the dietary C concentration was negatively correlated with particle passage through the mixing compartment (r= 0.57, P≤0.05). The results suggest that manure quality of river buffalo heifers can be considerably influenced by diet composition. Despite the reportedly high fibre digestion capacity of buffalo, digestive processes did not suppress the expression of diet characteristics in the faeces. This is important when aiming at producing a specific manure quality for fertilization purposes in (organic) crop cultivation. Although there was a strong correlation between the ingestion and the faecal excretion of nitrogen, the correlation between diet and faecal C/N ratio was weak. To impact on manure mineralization, the dietary NDF and N concentrations seem to be the key control points, but modulating effects are achieved by the inclusion of starch into the diet. Within the boundaries defined by the animals’ metabolic and (re)productive requirements for energy and nutrients, diet formulation may thus take into account the abiotically and biotically determined manure turnover processes in the soil and the nutrient requirements of the crops to which the manure is applied, so as to increase nutrient use efficiency along the continuum of the feed, the animal, the soil and the crop in (organic) farming systems.

The high-water mark. The siting of megalithic tombs on the Swedish island of Tjorn

In 1977 Grahame Clark suggested that the siting of megalithic tombs along the west coast of Scandinavia reflected the distribution of productive fishing grounds. Unlike the situation in other parts of Europe, these monuments were not associated with agriculture. Opinions have varied over the last quarter century, but enough is now known about changes of sea-level for his interpretation to be investigated on the ground. There seems to have been considerable diversity. On the large island of Örust some of the tombs located near to the sea appear to be associated with small natural enclosures defined by rock outcrops and may have been associated with grazing land. On the neighbouring island of Tjörn, however, the tombs were associated with small islands and important sea channels. During the Bronze Age the same areas included carvings of ships. Recent fieldwork in western Norway suggests that such locations were especially important in a maritime economy.

Effect of fecal water on an in vitro model of colonic mucosal barrier function

Fecal water (FW) has been shown to exert, in cultured cells, cytotoxic and genotoxic effects that have implications for colorectal cancer (CRC) risk. We have investigated a further biological activity of FW, namely, the ability to affect gap junctions in CACO2 cell monolayers as an index of mucosal barrier function, which is known to be disrupted in cancer. FW samples fi-om healthy, free-living, European subjects that were divided into two broad age groups, adult (40 +/- 9.7 yr; n = 53) and elderly (76 +/- 7.5 yr; n = 55) were tested for effects on gap junction using the transepithelial resistance (TER) assay. Overall, treatment of CACO2 cells with FW samples fi-om adults increased TER (+ 4 %), whereas FW from elderly subjects decreased TER (-5%); the difference between the two groups was significant (P < 0.05). We also measured several components of FW potentially associated with modulation of TER, namely, short-chain fatty acid (SCFA) and ammonia. SCFAs (propionic, acetic, and n-butyric) were significantly lower in the elderly population (-30%, -35%, and -21%, respectively, all P pound 0.01). We consider that FW modulation of in vitro epithelial barrier function is a potentially useful noninvasive biomarker, but it requires further validation to establish its relationship to CRC risk.

Oxygen isotope composition of bivalve seasonal growth increments and ambient water in the rivers Rhine and Meuse

The application of oxygen isotope ratios ({delta}18O) from freshwater bivalves as a proxy for river discharge conditions in the Rhine and Meuse rivers is investigated. We compared a dataset of water temperature and water {delta}18O values with a selection of recent shell {delta}18O records for two species of the genus Unio in order to establish: (1) whether differences between the rivers in water {delta}18O values, reflecting river discharge conditions, are recorded in unionid shells; and (2) to what extent ecological parameters influence the accuracy of bivalve shell {delta}18O values as proxies of seasonal, water oxygen isotope conditions in these rivers. The results show that shells from the two rivers differ significantly in {delta}18O values, reflecting different source waters for these two rivers. The seasonal shell {delta}18O records show truncated sinusoidal patterns with narrow peaks and wide troughs, caused by temperature fractionation and winter growth cessation. Interannual growth rate reconstructions show an ontogenetic growth rate decrease. Growth lines in the shell often, but not always, coincide with winter growth cessations in the {delta}18O record, suggesting that growth cessations in the shell {delta}18O records are a better age estimator than counting internal growth lines. Seasonal predicted and measured {delta}18O values correspond well, supporting the hypothesis that these unionids precipitate their shells in oxygen isotopic equilibrium. This means that (sub-) fossil unionids can be used to reconstruct spring-summer river discharge conditions, such as Meuse low-discharge events caused by droughts and Rhine meltwater-influx events caused by melting of snow in the Alps.

A randomised crossover study investigating the effects of galacto-oligosaccharides on the faecal microbiota in men and women over 50 years of age

Faecal microbial changes associated with ageing include reduced bifidobacteria numbers. These changes coincide with an increased risk of disease development. Prebiotics have been observed to increase bifidobacteria numbers within humans. The present study aimed to determine if prebiotic galacto-oligosaccharides (GOS) could benefit a population of men and women of 50 years and above, through modulation of faecal microbiota, fermentation characteristics and faecal water genotoxicity. A total of thirty-seven volunteers completed this randomised, double-blind, placebo-controlled crossover trial. The treatments – juice containing 4 g GOS and placebo – were consumed twice daily for 3 weeks, preceded by 3-week washout periods. To study the effect of GOS on different large bowel regions, three-stage continuous culture systems were conducted in parallel using faecal inocula from three volunteers. Faecal samples were microbially enumerated by quantitative PCR. In vivo, following GOS intervention, bifidobacteria were significantly more compared to post-placebo (P = 0·02). Accordingly, GOS supplementation had a bifidogenic effect in all in vitro system vessels. Furthermore, in vessel 1 (similar to the proximal colon), GOS fermentation led to more lactobacilli and increased butyrate. No changes in faecal water genotoxicity were observed. To conclude, GOS supplementation significantly increased bifidobacteria numbers in vivo and in vitro. Increased butyrate production and elevated bifidobacteria numbers may constitute beneficial modulation of the gut microbiota in a maturing population.

The domestication of water: water management in the ancient world and its prehistoric origins in the Jordan Valley

The ancient civilizations were dependent upon sophisticated systems of water management. The hydraulic engineering works found in ancient Angkor (ninth to thirteenth century AD), the Aztec city of Tenochtitlan (thirteenth to fifteenth century AD), Byzantine Constantinople (fourth to sixth century AD) and Nabatean Petra (sixth century BC to AD 106) are particularly striking because each of these is in localities of the world that are once again facing a water crisis. Without water management, such ancient cities would never have emerged, nor would the urban communities and towns from which they developed. Indeed, the ‘domestication’ of water marked a key turning point in the cultural trajectory of each region of the world where state societies developed. This is illustrated by examining the prehistory of water management in the Jordan Valley, identifying the later Neolithic (approx. 8300–6500 years ago) as a key period when significant investment in water management occurred, laying the foundation for the development of the first urban communities of the Early Bronze Age.

Variability in fecal water genotoxicity, determined using the Comet assay, is independent of endogenous N-nitroso compound formation attributed to red meat consumption

Red meat consumption causes a dose-dependent increase in fecal apparent total N-nitroso compounds (ATNC). The genotoxic effects of these ATNCs were investigated using two different Comet assay protocols to determine the genotoxicity of fecal water samples. Fecal water samples were obtained from two studies of a total of 21 individuals fed diets containing different amounts of red meat, protein, heme, and iron. The first protocol incubated the samples with HT-29 cells for 5 min at 4 degrees C, whereas the second protocol used a longer exposure time of 30 min and a higher incubation temperature of 37 degrees C. DNA strand breaks were quantified by the tail moment (DNA in the comet tail multiplied by the comet tail length). The results of the two Comet assay protocols were significantly correlated (r = 0.35, P = 0.003), however, only the second protocol resulted in detectable levels of DNA damage. Inter-individual effects were variable and there was no effect on fecal water genotoxicity by diet (P > 0.20), mean transit time (P = 0.588), or weight (P = 0.705). However, there was a highly significant effect of age (P = 0.019). There was no significant correlation between concentrations of ATNCs in fecal homogenates and fecal water genotoxicity (r = 0.04, P = 0.74). ATNC levels were lower in fecal water samples (272 microg/kg) compared to that of fecal homogenate samples (895 microg/kg) (P < 0.0001). Failure to find dietary effects on fecal water genotoxicity may therefore be attributed to individual variability and low levels of ATNCs in fecal water samples.

The earth, the sky and the water's edge: changing beliefs in the earlier prehistory of Northern Europe

There have been two kinds of study of ancient beliefs in the earlier prehistory of Scandinavia. One considers the impact of ideas which originated further to the south and east. It considers a cosmology based on the movements of the sun. A second tradition develops out of the ethnography of the circumpolar region and combines archaeological evidence with the beliefs of hunter-gatherers. It postulates the existence of a three-tier cosmology in which people could communicate between different worlds. This paper argues that certain elements that are thought to epitomize the ‘Southern’ system might have been suggested by existing ideas within Scandinavia itself. Both sets of beliefs came to influence one another, but they became increasingly distinct towards the end of the Bronze Age. This paper reconsiders the rock carvings, metalwork and mortuary cairns of that period and the Iron Age in relation to the process of religious change.

A later Bronze Age well complex at Swalecliffe, Kent

This paper examines the significance of seventeen later Bronze Age wells found during construction at Swalecliffe, in north-east Kent. The unusual depth of the features made for exceptional preservation of wooden structural elements, including steps and revetments, demonstrating rare evidence for woodworking and woodmanship. Extensive biological remains facilitated environmental reconstruction, and a lengthy dendrochronological sequence corroborates the internationally important Flag Fen chronology. Dendrochronological and radiocarbon dates demonstrate around 500 years of seemingly continuous use and replacement of wells. Votive deposits and apparatus used for water collection provide glimpses of small-scale ritual and domestic activities. The highly unusual concentration of wells is compared to contemporary sites regionally and elsewhere.