A large West Antarctic Ice Sheet explains early Neogene sea-level amplitude.

Early to Middle Miocene sea-level oscillations of approximately 40-60 m estimated from far-field records1-3 are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth2. This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene4,5. Data and model outputs can be reconciled if a large West Antarctic Ice Sheet (WAIS) existed and expanded across most of the outer continental shelf during the Early Miocene, accounting for maximum ice-sheet volumes. Here we provide the earliest geological evidence proving large WAIS expansions occurred during the Early Miocene (~17.72-17.40 Ma). Geochemical and petrographic data show glacimarine sediments recovered at International Ocean Discovery Program (IODP) Site U1521 in the central Ross Sea derive from West Antarctica, requiring the presence of a WAIS covering most of the Ross Sea continental shelf. Seismic, lithological and palynological data reveal the intermittent proximity of grounded ice to Site U1521. The erosion rate calculated from this sediment package greatly exceeds the long-term mean, implying rapid erosion of West Antarctica. This interval therefore captures a key step in the genesis of a marine-based WAIS and a tipping point in Antarctic ice-sheet evolution.

Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation.

Our understanding of the deglacial evolution of the Antarctic Ice Sheet (AIS) following the Last Glacial Maximum (26,000-19,000 years ago) is based largely on a few well-dated but temporally and geographically restricted terrestrial and shallow-marine sequences. This sparseness limits our understanding of the dominant feedbacks between the AIS, Southern Hemisphere climate and global sea level. Marine records of iceberg-rafted debris (IBRD) provide a nearly continuous signal of ice-sheet dynamics and variability. IBRD records from the North Atlantic Ocean have been widely used to reconstruct variability in Northern Hemisphere ice sheets, but comparable records from the Southern Ocean of the AIS are lacking because of the low resolution and large dating uncertainties in existing sediment cores. Here we present two well-dated, high-resolution IBRD records that capture a spatially integrated signal of AIS variability during the last deglaciation. We document eight events of increased iceberg flux from various parts of the AIS between 20,000 and 9,000 years ago, in marked contrast to previous scenarios which identified the main AIS retreat as occurring after meltwater pulse 1A and continuing into the late Holocene epoch. The highest IBRD flux occurred 14,600 years ago, providing the first direct evidence for an Antarctic contribution to meltwater pulse 1A. Climate model simulations with AIS freshwater forcing identify a positive feedback between poleward transport of Circumpolar Deep Water, subsurface warming and AIS melt, suggesting that small perturbations to the ice sheet can be substantially enhanced, providing a possible mechanism for rapid sea-level rise.

Obliquity-paced Pliocene West Antarctic ice sheet oscillations.

Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch ( approximately 5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming. Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, approximately 40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to approximately 3 degrees C warmer than today and atmospheric CO(2) concentration was as high as approximately 400 p.p.m.v. (refs 5, 6). The evidence is consistent with a new ice-sheet/ice-shelf model that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and air temperatures above freezing, suggesting an additional influence of surface melt under conditions of elevated CO(2).

First evidence of natural reproduction of the Allis shad Alosa alosa in the River Rhine following re-introduction measures.

After stocking with larvae from the Gironde-Garonne-Dordogne population, in 2013, three young-of-the-year Allis shad Alosa alosa, probably originating from natural reproduction, were documented for the first time in a period of nearly 100 years in the River Rhine. In 2014, a further increase was observed when 57 juveniles and eight adults were caught; seven of these eight adults were derived from stocking, indicating the success of stocking measures within the framework of the EU-LIFE project.

Ice sheet-free West Antarctica during peak early Oligocene glaciation.

One of Earth's most fundamental climate shifts, the greenhouse-icehouse transition 34 million years ago, initiated Antarctic ice sheet buildup, influencing global climate until today. However, the extent of the ice sheet during the Early Oligocene Glacial Maximum (~33.7 to 33.2 million years ago) that immediately followed this transition-a critical knowledge gap for assessing feedbacks between permanently glaciated areas and early Cenozoic global climate reorganization-is uncertain. In this work, we present shallow-marine drilling data constraining earliest Oligocene environmental conditions on West Antarctica's Pacific margin-a key region for understanding Antarctic ice sheet evolution. These data indicate a cool-temperate environment with mild ocean and air temperatures that prevented West Antarctic Ice Sheet formation. Climate-ice sheet modeling corroborates a highly asymmetric Antarctic ice sheet, thereby revealing its differential regional response to past and future climatic change.

The matrilin-3 VWA1 domain modulates interleukin-6 release from primary human chondrocytes.

OBJECTIVE: We previously demonstrated the ability of matrilin-3 to modulate the gene expression profile of primary human chondrocytes (PHCs) toward a state favoring cartilage catabolism. The structure within matrilin-3 responsible for the induction of these catabolic genes is unknown. Here, we investigated the potential of matrilin-3 (MATN3) and truncated matrilin-3 proteins, in both monomeric and oligomeric form, to stimulate interleukin (IL)-6 release in PHCs. METHODS: We expressed full-length matrilin-3 oligomers, matrilin-3 von Willebrand factor A (VWA) domain oligomers, matrilin-3 four epidermal growth factor (EGF) domain oligomers, matrilin-3 monomers without oligomerization domains, matrilin-3 VWA domain monomers, and matrilin-3 4EGF monomers. We then incubated PHCs in the absence or presence of full-length matrilin-3 or one of the truncated matrilin-3 proteins and finally determined the release of IL-6 in cell-culture supernatants. RESULTS: The addition of full-length matrilin-3 oligomers, matrilin-3 VWA domain oligomers, and, less pronounced, matrilin-3 monomers without oligomerization domains, and matrilin-3 4EGF-oligomers to the cell-culture medium led to a significant induction of IL-6 in PHCs. DISCUSSION: Based on recombinant expression of different matrilin-3 domains in both monomeric and oligomeric form, this work demonstrated that the VWA1 domain of matrilin-3 is primarily responsible for the induction of IL-6 release and that the oligomerization of the VWA1 domain markedly promotes its activity.

Characterization and genomic organization of PERI, a repetitive DNA in the Drosophila buzzatii cluster related to DINE-1 transposable elements and highly abundant in the sex chromosomes.

BACKGROUND/AIMS: Transposable elements (TEs) are dynamic components of eukaryotic genomes. We aimed to characterize TEs to help elucidate their impact on the genomic architecture, diversity and evolution of chromosomes in the D. buzzatii cluster of species (repleta group). METHODS: A full TE element of D. buzzatii, named PERI, was identified in a BAC clone available in GenBank. PERI was further analysed using bioinformatics tools, PCR and in-situ hybridization to metaphase chromosomes and DNA fibers. RESULTS: PERI shares several structures in common with DINE-1, an abundant TE found widespread along the Drosophila genus. The central region of PERI is very dynamic but revealed a disrupted pattern of nucleotide variability among its internal tandem repeats. The minimal sequence variation in D. serido suggests recent amplification. PERI accumulates near or at heterochromatic regions of all 6 pairs of chromosomes, especially on the sex chromosomes, with some clustering. CONCLUSIONS: PERI is an abundant type of DINE-1 transposon but with characteristic sequence signatures and probably restricted to the buzzatii complex. The conservation of different central domains and association with genes suggests selective constraints. Although at or near heterochromatin, the distribution of PERI does not overlap with satDNAs, probably a consequence of functional or molecular constraints.

Analysis of sintered polymer scaffolds using concomitant synchrotron computed tomography and in situ mechanical testing.

The mechanical behaviour of polymer scaffolds plays a vital role in their successful use in bone tissue engineering. The present study utilised novel sintered polymer scaffolds prepared using temperature-sensitive poly(DL-lactic acid-co-glycolic acid)/poly(ethylene glycol) particles. The microstructure of these scaffolds was monitored under compressive strain by image-guided failure assessment (IGFA), which combined synchrotron radiation computed tomography (SR CT) and in situ micro-compression. Three-dimensional CT data sets of scaffolds subjected to a strain rate of 0.01%/s illustrated particle movement within the scaffolds with no deformation or cracking. When compressed using a higher strain rate of 0.02%/s particle movement was more pronounced and cracks between sintered particles were observed. The results from this study demonstrate that IGFA based on simultaneous SR CT imaging and micro-compression testing is a useful tool for assessing structural and mechanical scaffold properties, leading to further insight into structure-function relationships in scaffolds for bone tissue engineering applications.

Test deformation and chemistry of foraminifera as response to anthropogenic heavy metal input.

Benthic foraminifera are sensitive to environmental changes and widely used as tools to monitor pollution. Rising numbers of deformed tests are often used as indicator for elevated levels of heavy metals, but little is known about the relation between heavy metal incorporation into foraminiferal tests and the formation of test deformities. Here, two sediment cores from the south-eastern North Sea are compared, regarding the occurrence of deformed foraminiferal tests, foraminiferal test chemistry (ICP-MS) and bulk sediment Pb content (XRF). The total abundance of deformed foraminiferal tests seems not to align temporarily with historical heavy metal pollution. Therefore, we suggest that foraminifera react with test deformation to other environmental stressors than the studied heavy metals. Test chemistry reflects historical increased bulk sediment heavy metal content, despite a slight temporal offset. We propose that Pb (and Cd) are only incorporated into foraminiferal tests above a yet to be defined threshold of pollution.

Evolutionary dynamics and sites of illegitimate recombination revealed in the interspersion and sequence junctions of two nonhomologous satellite DNAs in cactophilic Drosophila species.

Satellite DNA (satDNA) is a major component of genomes but relatively little is known about the fine-scale organization of unrelated satDNAs residing at the same chromosome location, and the sequence structure and dynamics of satDNA junctions. We studied the organization and sequence junctions of two nonhomologous satDNAs, pBuM and DBC-150, in three species from the neotropical Drosophila buzzatii cluster (repleta group). In situ hybridization to microchromosomes, interphase nuclei and extended DNA fibers showed frequent interspersion of the two satellites in D. gouveai, D. antonietae and, to a lesser extent, D. seriema. We isolated by PCR six pBuM x DBC-150 junctions: four are exclusive to D. gouveai and two are exclusive to D. antonietae. The six junction breakpoints occur at different positions within monomers, suggesting independent origin. Four junctions showed abrupt transitions between the two satellites, whereas two junctions showed a distinct 10 bp tandem duplication before the junction. Unlike pBuM, DBC-150 junction repeats are more variable than randomly cloned monomers and showed diagnostic features in common to a 3-monomer higher-order repeat seen in the sister species D. serido. The high levels of interspersion between pBuM and DBC-150 repeats suggest extensive rearrangements between the two satellites, maybe favored by specific features of the microchromosomes. Our interpretation is that the junctions evolved by multiples events of illegitimate recombination between nonhomologous satDNA repeats, with subsequent rounds of unequal crossing-over expanding the copy number of some of the junctions.

Dietary resveratrol impairs body weight gain due to reduction of feed intake without affecting fatty acid composition in Atlantic salmon.

Recent studies suggest that the use of vegetable oils at expense of fish oil in aquaculture feeds might have potential negative effects on fish redox homeostasis and adiposity. Resveratrol (RESV) is a lipid-soluble phytoalexin present in fruits and vegetables with proven in vivo antioxidant function in animals. The present study aims to assess the potential use of RESV in Atlantic salmon feeds. To this end, post-smolt salmons with an initial BW of 148±3 g were fed four experimental diets for 15 weeks. A diet low in fish oil served as a control and was supplemented with 0, 0.5, 1.5 and 2.5 g/kg of RESV, respectively. The effect of the experimental diets on animal performance, tissue fatty acid composition, and the expression of genes encoding proteins involved in antioxidant signalling, lipid peroxidation, and metabolism were studied. Resveratrol significantly reduced feed intake and final BW of the salmon. Feeding RESV did not affect the sum of saturated and monounsaturated fatty acids or total lipids in the fillet. While the content of total polyunsaturated fatty acids was not affected, the percentages of some fatty acids in the liver and fillet were changed by RESV. Furthermore, in liver, the relative expression of glutathione peroxidase 4b, nuclear factor-like 2, and arachidonate 5-lipoxygenase remained unchanged across treatment groups. In conclusion, the negative impact of dietary RESV on FI and hence reduction of the BW discourages its inclusion in low fish oil diets for Atlantic salmon.

Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode.

The Antarctic Peninsula Ice Sheet is currently experiencing sustained and accelerating loss of ice. Determining when these changes were initiated and identifying the main drivers is hampered by the short instrumental record (1992 to present). Here we present a 6,250 year record of glacial discharge based on the oxygen isotope composition of diatoms (δ18Odiatom) from a marine core located at the north-eastern tip of the Antarctic Peninsula. We find that glacial discharge - sourced primarily from ice shelf and iceberg melting along the eastern Antarctic Peninsula - remained largely stable between ~6,250 to 1,620 cal. yr BP, with a slight increase in variability until ~720 cal. yr. BP. An increasing trend in glacial discharge occurs after 550 cal. yr BP (A.D. 1400), reaching levels unprecedented during the past 6,250 years after 244 cal. yr BP (A.D. 1706). A marked acceleration in the rate of glacial discharge is also observed in the early part of twentieth century (after A.D. 1912). Enhanced glacial discharge, particularly after the 1700s is linked to a positive Southern Annular Mode (SAM). We argue that a positive SAM drove stronger westerly winds, atmospheric warming and surface ablation on the eastern Antarctic Peninsula whilst simultaneously entraining more warm water into the Weddell Gyre, potentially increasing melting on the undersides of ice shelves. A possible implication of our data is that ice shelves in this region have been thinning for at least ~300 years, potentially predisposing them to collapse under intensified anthropogenic warming.

Application and evaluation of double digest selective label (DDSL) typing technique for Pseudomonas aeruginosa hospital isolates.

This study describes the application and evaluation of a recently developed fast bacterial typing technique (double digest selective label - DDSL) for hospital isolates of Pseudomonas aeruginosa. The protocol was based on a simultaneous double digestion/labelling reaction which was performed in a single reaction tube. After agarose gel separation selectively tagged restriction fragments were transferred using deonised water to a nylon membrane and visualized by a colour reaction. Starting from overnight culture, turn around time using this technique was only 8 h. The DDSL typing technique was applied for 77 hospital isolates. Among them 63 isolates were also typed by PFGE and the typing results were compared with those of DDSL. In conclusion, both techniques discriminated bacterial isolates into the same major clusters. DDSL proved to be as discriminatory as PFGE but much faster and easier to set up in a standard microbiological laboratory.

Technical note: standardized and semiautomated Harris lines detection.

Arrest in long bone growth and the subsequent resumption of growth may be visible as radiopaque transverse lines in radiographs (Harris lines, HL; Harris, HA. 1933. Bone growth in health and disease. London: Oxford University Press). The assessment of individual age at occurrence of such lines, as part of paleopathological skeletal studies, is time-consuming and shows large intra- and interobserver variability. Thus, a standardized, automated detection algorithm would help to increase the validity of such paleopathological research. We present an image analysis application facilitating automatic detection of HL. On the basis of established age calculation methods, the individual age-at-formation can be automatically assessed with the tool presented. Additional user input to confirm the automatic result is possible via an intuitive graphical user interface. Automated detection of HL from digital radiographs of a sample of late Medieval Swiss tibiae was compared to the consensus of manual assessment by two blinded expert observers. The intra- and interobserver variability was high. The quality of the observer result improved when standardized detection criteria were defined and applied. The newly developed algorithm detected two-thirds of the HL that were identified as consensus lines between the observers. It was, however, necessary to validate the last one-third by manual editing. The lack of a large test series must be noted. The application is freely available for further testing by any interested researcher.

A second look at the influence of birth weight on carcass and meat quality in pigs.

To re-examine the relationship of birth weight with carcass and meat quality of pigs at market weight, offspring (n=378) of 63 sows were assigned to three birth weight groups; 25% low weight (LW), 50% middle weight (MW), and 25% heavy weight (HW), with runts (<800g) being excluded. LW pigs exhibited the lowest postnatal growth performance, the lowest lean mass and the greatest degree of fatness in terms of perirenal fat compared with MW and HW pigs. Only in females, but not in male castrates, the lean percentage was highest in HW pigs. Characteristics of longissimus muscle technological quality declined either in LW (pH, drip loss) or HW (conductivity, lightness) compared with MW pigs. In contrast, intramuscular fat percentage (IMF) was highest in LW pigs. The results suggest that the most desirable carcass composition is obtained with HW pigs, whereas optimum technological pork quality, except for IMF, is achieved with MW pigs.

[Implementation of cross-compliance in the area of animal welfare]. / Umsetzung von Cross Compliance im Bereich Tierschutz.

From 1 January 2007, requirements concerning animal welfare were introduced with effect to cross-compliance. Farmers receiving single payment as well as agri-environmental payments (payments of second pillar) shall respect the statutory management requirements of the following 3 directives in the area of animal welfare: Council Directive 91/629/EEC laying down minimum standards for the protection of calves; Council Directive 91/630/EEC laying down minimum standards for the protection of pigs; Council Directive 98/58/EC concerning the protection of animals kept for farming purposes. The competent authority shall carry out annual systematic inspections on at least 1% of all farmers submitting payments on the basis of a risk analysis and partly at random. In case of non-compliance with the conditions due to specific rules, there will be a reduction or cancellation of the payments to be granted in the calendar year in which non-compliance occurs. Cross-compliance controls should take place on the basis of documented procedures so as to ensure that these controls are carried out uniformly and are of a consistently high quality. For this purpose, a working group composed of representatives from the Federal Ministry of Food, Agriculture and Consumer Protection and from the Lander developed uniform control reports in order to monitor compliance and a guidance booklet for control execution of animal welfare requirements. In the control report (Level 1), the outcomes of inspections of all systematic testable animal welfare requirements are summarized in 6 items. Furthermore, the non-systematically testable requirements are integrated in the control report as a independent item. The guidance booklet (Level 2) with a matrix of validation serves as a specification for on-the-spot checks. Where appropriate, on-the-spot checks provided for cross-compliance and any other checks in animal welfare rules as well as requirements to animal identification and registration shall be carried out at the same time in Baden-Württemberg (integrated control system). Farmers subjected to on-the-spot checks shall be selected on the basis of a centralized common risk analysis and partly at random. This is the best way of safeguarding that the control rate will not be much higher than the established 1% with a minimum administrative burden and costs for farmers and competent control authorities. Integrated check lists for on-the-spot checks were established which take into account systematic cross compliance inspections to improve compliance with 3 existing standards in the area of animal welfare and official controls as proved in Council Directives concerning animal welfare and Regulation (EC) No 882/2004. All staff of the competent authorities performing controls received, for their area of competence, appropriate training enabling them to make their duties competently and to carry out controls in a consistent manner. Integrated systematic controls are very time-consuming and a burden for farmers and the competent authorities. For the beginning of this year, we will expect a discharge by Decision (EC) 2006/778. A controlling system was installed to ensure that cross compliance rules are applied consistently, for example by making subsequent controls by controlling institutions.

Effects of dietary daidzein supplementation of pregnant sows on carcass and meat quality and skeletal muscle cellularity of the progeny.

The effects of dietary daidzein during late gestation on maternal performance, neonatal body composition, carcass and meat quality at market weight, and skeletal muscle cellularity were studied. Multiparous sows received a soybean-free diet (n=8, control) or the same diet supplemented with 1mg daidzein/kg body weight (n=7) daily from d 85 of gestation to parturition. Litter size, litter weight, and birth weight remained unaffected by daidzein feeding. In newborn piglets from litters >15, the proportions of muscle tissue and skin tended to be decreased (P=0.09) or increased (P=0.03), respectively, after gestational daidzein feeding. The body fat percentage was higher in response to maternal daidzein (P=0.04). Postnatal growth and carcass composition at 180d of age were not affected, however, maternal daidzein supplementation led to increases in longissimus muscle pH(45) (P=0.02) and pH(end) (P=0.11) in pigs from large litters. The proportion of fast-twitch glycolytic fibres in semitendinosus muscle was increased (P=0.06) by maternal daidzein feeding. The results suggest that supplemental daidzein in the maternal diet during late gestation marginally affects meat quality and skeletal muscle cellularity of the progeny.

Diagnostic value of micro-CT in comparison with histology in the qualitative assessment of historical human postcranial bone pathologies.

Micro-computed tomography (muCT) is of great interest for palaeopathological examination because it is less invasive than histology. This study evaluates the diagnostic value of muCT for postcranial macerated bones. We investigated five specimens (osteomyelitis, tuberculosis, trauma, osteosarcoma and hypertrophic osteoarthropathy) of a pathology reference series by muCT and polarised light microscopy. The 3D muCT images allow an easy orientation within the specimen. Surface structures, thickness, continuity of the cortex and number, thickness and orientation of the trabeculae can be evaluated. The high number of muCT slices helps to choose the most interesting areas for further investigations. Grey value images display the degree of mineralisation. Yet, the differentiation between woven and lamellar bone is only possible using polarised light microscopy. muCT is a tool of high value for the examination of postcranial bone disorders. It cannot replace histological examinations completely because it cannot assess the bone quality (woven or lamellar). For the choice of the optimal location where slices for the microscopic investigation are later cut in heterogeneous samples, muCT is very useful. Therefore, we suggest performing the muCT examination first, followed by histology if necessary.

Exogenous somatotropin alters IGF axis in porcine endometrium and placenta.

The aim of this study was to examine whether exogenous somatotropin (ST) can alter the insulin-like growth factor (IGF) axis in the porcine epitheliochorial placenta. Crossbred gilts were injected either 6 mg of recombinant porcine ST or vehicle from days 10 to 27 after artificial insemination (term day 116). Control and ST-treated gilts were euthanized on day 28 (8 control/5 treated), day 37 (4 control/6 treated), and day 62 (4 control/6 treated) of gestation. Endometrium and placental tissue samples were collected and subjected to mRNA analyses. In control gilts, somatotropin receptor (STR) and IGF-I mRNA abundance in the endometrium decreased with gestation. Conversely, the amounts of IGF-II mRNA and of IGF binding protein (BP)-2 and -3 mRNA, which were analyzed in endometrium and placental chorion, increased with gestation. The endometrium contained less IGF-II mRNA but more IGFBP-2 and-3 mRNA than the placental chorion. In response to pST treatment, the amounts of endometrial STR and IGF-I mRNA were lower at days 28 and 37, but higher at day 62 of gestation. The content of IGF-II mRNA was higher in the endometrium of pST-treated than control gilts on day 37. The amount of IGFBP-2 mRNA was increased on day 37 in endometrium and placenta of pST-treated gilts, whereas no changes in IGFBP-3 mRNA were observed. The IGF-II/IGFBP-2 ratio was higher in the placenta in response to pST on day 28 of gestation. Results show that pST treatment of pregnant gilts during early gestation alters IGF axis in maternal and fetal placental tissues and suggest pST may exert an effect on fetal growth by altering the relative amount of IGFBPs and IGFs at the fetal-maternal interface.