If speed is of the essence: rapid analysis of ambergris by APCI compact mass spectrometry.

The use of atmospheric pressure chemical ionisation (APCI) compact mass spectrometry (CMS) was investigated for the analysis of jetsam and museum-archived ambergris and of ambergris components in perfumes. The data were compared with those from existing methods. Authentic samples of some individual ambergris constituents (ambrein, coprostanol, epicoprostanol and coprostanone), were also examined. Rapid APCI CMS was achieved using either a solids probe or a probe with solutions held in capillary melting point tubes. Interpretation is made of the spectra of the principal natural product components, the relative ion responses were measured and the elemental composition of key ions in the spectra confirmed using high resolution accurate mass APCI MS. Rapid analysis of ambergris by APCI CMS may prove to be a further convenient method of identifying ambrein, of measuring the relative ratios of ambrein and steroids in ambergris and even of quantifying the latter, with minimal sample preparation.

The vanishing ozone weekday/weekend effect.

UNLABELLED: A national analysis of weekday/weekend ozone (O3) differences conducted using 1997-1999 data found that many urban areas experienced at least 5% higher 8-hr maximum O3 concentrations on weekends than on weekdays even though emissions of precursors were significantly lower on weekends. This phenomenon was observed mostly in urban areas in the Northeast, Midwest, and coastal California. A similar analysis using 2008-2010 O3 data shows that this phenomenon has mostly vanished. From 1997-1999 to 2008-2010, the percentage of U.S. monitoring sites that experienced 95th percentile daily 8-hr maximum average O3 concentration on weekends that were 5% or more higher than on weekdays declined from about 35% to less than 5%. At the same time the percentage of sites that experienced higher weekday concentrations increased from 3% to about 27%. The majority (68%) of the sites, however exhibited little sensitivity to the weekday/weekend emission changes as they had similar (+/- 5%) O3 on weekdays and weekends. Similar trends were observed for the three other O3 metrics examined: the 95th percentile of the 1-hr maximum and the April-September means of the 1-hr and 8-hr daily maxima. Over this time period, U.S. emissions of O3 precursors declined significantly. However, a greater decline in nitrogen oxides (NOx) emissions has caused an increase in the volatile organic compounds (VOC)/NOx emission ratios and it appears that this is the reason for the shift away from higher weekend O3 concentrations. IMPLICATIONS: In areas where weekend emissions of ozone precursors are lower than on weekdays because of mainly lower motor vehicle emissions, an inadvertent test of ozone control strategies occurs. Such a test provides information on how control strategies that produce emission changes similar to those that occur on weekends affect ozone concentrations. In the late 1990s, lower NOx emissions on weekends resulted in higher levels of ozone in many urban areas. Emission controls that have been enacted since then appear to have eliminated that phenomenon in most urban areas. However, most areas now indicate that weekend emission reductions now have little effect on ozone concentrations at most sites.

Scoping intergenerational effects of nanoplastic on the lipid reserves of Antarctic krill embryos.

Antarctic krill (Euphausia superba) plays a central role in the Antarctic marine food web and biogeochemical cycles and has been identified as a species that is potentially vulnerable to plastic pollution. While plastic pollution has been acknowledged as a potential threat to Southern Ocean marine ecosystems, the effect of nanoplastics (<1000 nm) is poorly understood. Deleterious impacts of nanoplastic are predicted to be higher than that of larger plastics, due to their small size which enables their permeation of cell membranes and potentially provokes toxicity. Here, we investigated the intergenerational impact of exposing Antarctic krill to nanoplastics. We focused on whether embryonic energy resources were affected when gravid female krill were exposed to nanoplastic by determining lipid and fatty acid compositions of embryos produced in incubation. Embryos were collected from females who had spawned under three different exposure treatments (control, nanoplastic, nanoplastic + algae). Embryos collected from each maternal treatment were incubated for a further 6 days under three nanoplastic exposure treatments (control, low concentration nanoplastic, and high concentration nanoplastic). Nanoplastic additions to seawater did not impact lipid metabolism (total lipid or fatty acid composition) across the maternal or direct embryo treatments, and no interactive effects were observed. The provision of a food source during maternal exposure to nanoplastic had a positive effect on key fatty acids identified as important during embryogenesis, including higher total polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) when compared to the control and nanoplastic treatments. Whilst the short exposure time was ample for lipids from maternally digested algae to be incorporated into embryos, we discuss why the nanoplastic-fatty acid relationship may be more complex. Our study is the first to scope intergeneration effects of nanoplastic on Antarctic krill lipid and fatty acid reserves. From this, we suggest directions for future research including long term exposures, multi-stressor scenarios and exploring other critical energy reserves such as proteins.

Biosynthesis of ambrein in ambergris: evidence from isotopic data and identification of possible intermediates.

Ambrein is found in ambergris, a coprolith occurring in the rectum of the sperm whale. In vitro, ambrein is produced by enzymatic cyclisation of squalene, via a monocyclic intermediate. However, little is known of the in vivo process. In order to find evidence for the reaction in vivo, a comparison was made of the δ13C relative isotopic ratios of ambrein in ambergris with those of co-occurring sterols. A statistically significant difference was noted. This suggests that ambrein originates via a different biosynthetic mechanism from that of the sterols. Examination of the minor constituents of a hydrogenolysed extract of ambergris revealed compounds with a bicyclic polypodane nucleus, rather than those with monocyclic structures. It is hypothesised that in vivo biosynthesis of ambrein proceeds, at least in some cases, via bacterial production of bicyclic polypodenols. The latter are known products of non-concerted squalene (or squalene oxide) cyclisations in other organisms.

New Zealand Ginger mouse: novel model that associates the tyrp1b pigmentation gene locus with regulation of lean body mass.

The study of spontaneous mutations in mice over the last century has been fundamental to our understanding of normal physiology and mechanisms of disease. Here we studied the phenotype and genotype of a novel mouse model we have called the New Zealand Ginger (NZG/Kgm) mouse. NZG/Kgm mice are very large, rapidly growing, ginger-colored mice with pink eyes. Breeding NZG/Kgm mice with CAST/Ei or C57BL/6J mice showed that the ginger coat colour is a recessive trait, while the excessive body weight and large body size exhibit a semidominant pattern of inheritance. Backcrossing F1 (NZG/Kgm x CAST/Ei) to NZG/Kgm mice to produce the N2 generation determined that the NZG/Kgm mouse has two recessive pigmentation variant genes (oca2(p) and tyrp-1(b)) and that the tyrp-1(b) gene locus associates with large body size. Three coat colors appeared in the N2 generation; ginger, brown, and dark. Strikingly, N2 male coat colour associated with body weight; the brown-colored mice weighed the most followed by ginger and then dark. The male brown coat-colored offspring reached adult body weights indistinguishable from NZG/Kgm males. The large NZG/Kgm mouse body size is a result of excessive lean body mass since these mice are not obese or diabetic. NZG/Kgm mice exhibit an unusual pattern of fat distribution; compared with other mouse strains they have disproportionately higher amounts of subcutaneous and gonadal fat. These mice are susceptible to high-fat diet-induced obesity but are resistant to high-fat diet-induced diabetes. We propose NZG/Kgm mice as a novel model to delineate gene(s) that regulate 1) growth and metabolism, 2) resistance to Type 2 diabetes, and 3) preferential fat deposition in the subcutaneous and gonadal areas.

Mineralized soft-tissue structure and chemistry in a mummified hadrosaur from the Hell Creek Formation, North Dakota (USA).

An extremely well-preserved dinosaur (Cf. Edmontosaurus sp.) found in the Hell Creek Formation (Upper Cretaceous, North Dakota) retains soft-tissue replacement structures and associated organic compounds. Mineral cements precipitated in the skin apparently follow original cell boundaries, partially preserving epidermis microstructure. Infrared and electron microprobe images of ossified tendon clearly show preserved mineral zonation, with silica and trapped carbon dioxide forming thin linings on Haversian canals within apatite. Furthermore, Fourier transform infrared spectroscopy (FTIR) of materials recovered from the skin and terminal ungual phalanx suggests the presence of compounds containing amide groups. Amino acid composition analyses of the mineralized skin envelope clearly differ from the surrounding matrix; however, intact proteins could not be obtained using protein mass spectrometry. The presence of endogenously derived organics from the skin was further demonstrated by pyrolysis gas chromatography mass spectrometry (Py-GCMS), indicating survival and presence of macromolecules that were in part aliphatic (see the electronic supplementary material).

Agouti signaling protein stimulates cell division in "viable yellow" (A(vy)/a) mouse liver.

Enhanced linear growth, hyperplasia, and tumorigenesis are well-known characteristics of "viable yellow" agouti A(vy)/- mice (Wolff GL, Roberts DW, Mountjoy KG. Physiol Genomics 1:151-163, 1999); however, the functional basis for this aspect of the phenotype is unknown. In the present study, we ascertained whether agouti signaling protein (ASIP) levels in A(vy)/a or a/a livers are associated with hepatocyte proliferation as a possible factor in promotion of hepatocellular tumor formation. Proliferating cell nuclear antigen (PCNA) assays and quantitative real-time reverse transcriptase polymerase chain reaction assays were performed on liver samples from mottled yellow A(vy)/a, pseudoagouti A(vy)/a, and black a/a VY mice to determine mitotic indices and expression levels of A(vy )and a in relation to the expression level of the housekeeping gene hprt. We found that ASIP levels were approximately 100-fold higher in yellow than in pseudoagouti or black mice and that the proportion of PCNA-positive hepatocytes was greater (P < 0.001) in yellow than in pseudoagouti or black mice.

Linear and non-linear responses of vegetation and soils to glacial-interglacial climate change in a Mediterranean refuge.

The impact of past global climate change on local terrestrial ecosystems and their vegetation and soil organic matter (OM) pools is often non-linear and poorly constrained. To address this, we investigated the response of a temperate habitat influenced by global climate change in a key glacial refuge, Lake Ohrid (Albania, Macedonia). We applied independent geochemical and palynological proxies to a sedimentary archive from the lake over the penultimate glacial-interglacial transition (MIS 6-5) and the following interglacial (MIS 5e-c), targeting lake surface temperature as an indicator of regional climatic development and the supply of pollen and biomarkers from the vegetation and soil OM pools to determine local habitat response. Climate fluctuations strongly influenced the ecosystem, however, lake level controls the extent of terrace surfaces between the shoreline and mountain slopes and hence local vegetation, soil development and OM export to the lake sediments. There were two phases of transgressional soil erosion from terrace surfaces during lake-level rise in the MIS 6-5 transition that led to habitat loss for the locally dominant pine vegetation as the terraces drowned. Our observations confirm that catchment morphology plays a key role in providing refuges with low groundwater depth and stable soils during variable climate.

Landscape-scale spatial heterogeneity in phytodetrital cover and megafauna biomass in the abyss links to modest topographic variation.

Sinking particulate organic matter (POM, phytodetritus) is the principal limiting resource for deep-sea life. However, little is known about spatial variation in POM supply to the abyssal seafloor, which is frequently assumed to be homogenous. In reality, the abyss has a highly complex landscape with millions of hills and mountains. Here, we show a significant increase in seabed POM % cover (by ~1.05 times), and a large significant increase in megafauna biomass (by ~2.5 times), on abyssal hill terrain in comparison to the surrounding plain. These differences are substantially greater than predicted by current models linking water depth to POM supply or benthic biomass. Our observed variations in POM % cover (phytodetritus), megafauna biomass, sediment total organic carbon and total nitrogen, sedimentology, and benthic boundary layer turbidity, all appear to be consistent with topographically enhanced current speeds driving these enhancements. The effects are detectable with bathymetric elevations of only 10 s of metres above the surrounding plain. These results imply considerable unquantified heterogeneity in global ecology.

Dose-response effects of ectopic agouti protein on iron overload and age-associated aspects of the Avy/a obese mouse phenome.

Isogenic and congenic offspring from matings of inbred black a/a dams by sibling (or non-sibling from another inbred strain) yellow agouti Avy/a sires provide an animal model of obese yellow agouti Avy/a and isogenic lean pseudoagouti Avy/a mice exhibiting two different in vivo concentrations (high, very low) of ectopic agouti protein (ASP) with congenic lean black a/a mice as null controls. This makes it possible to differentiate between the high and very low dose levels of ectopic ASP with respect to interactions with diverse physiological and molecular pathways. Assay of differential responses to 12 or 24 months of carbonyl iron overload assessed the possible suitability of this animal model for the study of hemochromatosis. Agouti A/a B6C3F1 mice were used as non-congenic null controls. The age-related waxing and waning of body weight, food consumption, and caloric efficiency, as well as associated changes in pancreatic islets and islet cells, and formation of liver tumors were assayed. While the hypothesis that these mice might serve as a tool for investigating hemochromatosis was not confirmed, the data did provide evidence that even the very low levels of ASP in pseudoagouti Avy/a mice affect the network of molecular/metabolic/physiological response pathways that comprises the yellow agouti obese phenome. We suggest that the combination of yellow agouti Avy/a, pseudoagouti Avy/a, and black a/a congenic mice provides a practical tool for applying a dose-response systems biology approach to understanding the dysregulatory influence of ectopic ASP on the molecular-physiological matrix of the organism.

Evaluation of metals and hydrocarbons in sediments from a tropical tidal flat estuary of Southern Brazil.

Although the Passagem Channel estuary, Espírito Santo State, Brazil, is located in an urbanized and industrialized region, it has a large mangrove system. Here we examined natural and anthropogenic inputs that may influence trace metal (Cd, Cr, Cu, Ni, Sc, Pb and Zn) and hydrocarbon (n-alkane and terpane) deposition in three sediment cores collected in the tidal flat zone of the estuary. The cores were also analyzed for carbonate, grain size and stable isotopic composition (δ(13)Corg. and δ(15)Ntotal). Metal enrichment and its association to petroleum hydrocarbons in the surficial sediments of one of the cores, indicate crude oil and derivative inputs, possibly from small vessels and road run-off from local heavy automobile traffic. At the landward sites, the major contributions for metals and hydrocarbons are from natural sources, but in one case, Cu may have been enriched by domestic effluent inputs.

Identification of genes contributing to the obese yellow Avy phenotype: caloric restriction, genotype, diet x genotype interactions.

The incidence and severity of obesity and type 2 diabetes are increasing in Western societies. The progression of obesity to type 2 diabetes is gradual with overlapping symptoms of insulin resistance, hyperinsulinemia, hyperglycemia, dyslipidemias, ion imbalance, and inflammation; this complex syndrome has been called diabesity. We describe here comparisons of gene expression in livers of A/a (agouti) vs. A(vy)/A (obese yellow) segregants (i.e., littermates) from BALB/cStCrlfC3H/Nctr x VYWffC3Hf/Nctr-A(vy)/a matings in response to 70% and 100% of ad libitum caloric intakes of a reproducible diet. Twenty-eight (28) genes regulated by diet, genotype, or diet x genotype interactions mapped to diabesity quantitative trait loci. A subset of the identified genes is linked to abnormal physiological signs observed in obesity and diabetes.

Weekday/weekend ozone differences: what can we learn from them?

A national analysis of weekday/weekend ozone (O3) differences demonstrates significant variation across the country. Weekend 1-hr or 8-hr maximum O3 varies from 15% lower than weekday levels to 30% higher. The weekend O3 increases are primarily found in and around large coastal cities in California and large cities in the Midwest and Northeast Corridor. Both the average and the 95th percentile of the daily 1-hr and 8-hr maxima exhibit the same general pattern. Many sites that have elevated O3 also have higher O3 on weekends even though traffic and O3 precursor levels are substantially reduced on weekends. Detailed studies of this phenomenon indicate that the primary cause of the higher O3 on weekends is the reduction in oxides of nitrogen (NOx) emissions on weekends in a volatile organic compound (VOC)-limited chemical regime. In contrast, the lower O3 on weekends in other locations is probably a result of NOx reductions in a NOx-limited regime. The NOx reduction explanation is supported by a wide range of ambient analyses and several photochemical modeling studies. Changes in the timing and location of emissions and meteorological factors play smaller roles in weekend O3 behavior. Weekday/weekend temperature differences do not explain the weekend effect but may modify it.

A picture on the wall: innovative mapping reveals cold-water coral refuge in submarine canyon.

Cold-water corals are azooxanthellate species found throughout the ocean at water depths down to 5000 m. They occur in patches, reefs or large mound structures up to 380 m high, and as ecosystem engineers create important habitats for a diverse fauna. However, the majority of these habitats are now within reach of deep-sea bottom trawling. Many have been severely damaged or are under threat, despite recent protection initiatives. Here we present a cold-water coral habitat type that so far has been overlooked--quite literally--and that has received minimal impact from human activities. Vertical and overhanging cliffs in deep-sea canyons, revealed using an innovative approach to marine habitat mapping, are shown to provide the perfect substratum for extensive cold-water coral-based communities. Typical canyon-related processes, including locally enhanced internal tides and focussed downslope organic carbon transport, provide favourable environmental conditions (current regime, food input) to sustain the communities, even outside the optimal depth and density envelopes reported elsewhere in the NE Atlantic. Our findings show that deep-sea canyons can form natural refuges for faunal communities sensitive to anthropogenic disturbance, and have the potential to fulfil the crucial role of larval sources for the recolonisation of damaged sites elsewhere on the margin.

The effects of natural iron fertilisation on deep-sea ecology: the Crozet Plateau, Southern Indian Ocean.

The addition of iron to high-nutrient low-chlorophyll (HNLC) oceanic waters stimulates phytoplankton, leading to greater primary production. Large-scale artificial ocean iron fertilization (OIF) has been proposed as a means of mitigating anthropogenic atmospheric CO(2), but its impacts on ocean ecosystems below the photic zone are unknown. Natural OIF, through the addition of iron leached from volcanic islands, has been shown to enhance primary productivity and carbon export and so can be used to study the effects of OIF on life in the ocean. We compared two closely-located deep-sea sites (∼400 km apart and both at ∼4200 m water depth) to the East (naturally iron fertilized; +Fe) and South (HNLC) of the Crozet Islands in the southern Indian Ocean. Our results suggest that long-term geo-engineering of surface oceanic waters via artificial OIF would lead to significant changes in deep-sea ecosystems. We found that the +Fe area had greater supplies of organic matter inputs to the seafloor, including polyunsaturated fatty acid and carotenoid nutrients. The +Fe site also had greater densities and biomasses of large deep-sea animals with lower levels of evenness in community structuring. The species composition was also very different, with the +Fe site showing similarities to eutrophic sites in other ocean basins. Moreover, major differences occurred in the taxa at the +Fe and HNLC sites revealing the crucial role that surface oceanic conditions play in changing and structuring deep-sea benthic communities.

Hydroxamate siderophores: occurrence and importance in the Atlantic Ocean.

Siderophores are chelates produced by bacteria as part of a highly specific iron uptake mechanism. They are thought to be important in the bacterial acquisition of iron in seawater and to influence iron biogeochemistry in the ocean. We have identified and quantified two types of siderophores in seawater samples collected from the Atlantic Ocean. These siderophores were identified as hydroxamate siderophores, both ferrioxamine species representative of the more soluble marine siderophores characterized to date. Ferrioxamine G was widely distributed in surface waters throughout the Atlantic Ocean, while ferrioxamine E had a more varied distribution. Total concentrations of the two siderophores were between 3 and 20 pM in the euphotic zone. If these compounds are fully complexed in seawater, they represent approximately 0.2-4.6% of the <0.2 microm iron pool. Our data confirm that siderophore-mediated iron acquisition is important for marine heterotrophic bacteria and indicate that siderophores play an important role in the oceanic biogeochemical cycling of iron.

Determination of steryl sulphates in invertebrate tissue by liquid chromatography-tandem mass spectrometry.

A method for the identification and quantification of underivatised steryl sulphates in invertebrates by liquid chromatography (LC) coupled with tandem mass spectrometry (MS) involving a single cleanup step has been developed. Negative electrospray ionisation and positive and negative atmospheric-pressure chemical ionisation (APCI) spectra of steryl sulphate showed pseudomolecular ions ([M+H-H2SO4]+ or [M-H]-). Collision-induced dissociation (CID) was efficient only in positive APCI. LC-MS in negative APCI was least susceptible to interference and possible differences in response factors. The detection limits (signal-to-noise ratio of 3) based on cholest-5-enyl-3-sulphate in positive and negative APCI modes are 3.66 and 0.73 pmol microL(-1), respectively. Calibration plots and response factors for cholest-5-enyl-3-sulphate relative to the internal standard, cholecalciferyl-3-sulphate, in both positive and negative polarities, were linear in the concentration range from 1.22 to 16.4 pmol microL(-1) with good coefficients of determination (R2 > 0.98). It is suggested that the structure elucidation of steryl sulphates is best achieved in CID positive APCI mode, whereas their quantification should be carried out using negative APCI.

Regulation of yellow pigment formation in mice: a historical perspective.

Pigment synthesis by hair follicle melanocytes is modulated by a large number of environmental and genetic factors, many of which are discussed in this review. Eumelanic (non-yellow) pigment is produced by hair follicle melanocytes following the binding of alpha-melanocyte stimulating hormone to melanocortin receptor 1. Binding of this hormone to the melanocyte membrane is blocked by agouti signaling protein (ASP) which is encoded by the agouti locus and results in the synthesis of yellow pigment, instead of non-yellow (black/brown) pigment. The cyclical release of ASP by hair follicle cells results in a black/brown hair with a subapical yellow band. This is the wild-type coat color pattern of many mammals and is called agouti. Several dominant mutations at the agouti locus in mice, induced by retrotransposon-like intracisternal A particles, result in ectopic over-expression of ASP and animals with much higher proportions of all-yellow hairs. This abnormal presence of ASP in essentially all body cells results in the 'yellow agouti obese mouse syndrome.' The obesity has been associated with binding of ASP to melanocortin receptor 4 inactivating the latter. The syndrome also includes hyperinsulinemia, increased somatic growth, and increased susceptibility to hyperplasia and carcinogenesis. The physiologic and molecular bases for these syndrome components have not yet been elucidated. This historically orientated review is subdivided, where applicable, into pre- and post-1992 subsections to emphasize the impact of the cloning of the agouti and extension loci and their protein products on the identification of the molecular and physiological pathways modulating the manifold aspects of pheomelanogenesis.