A study of the association between timing of solid food introduction in infants and overweight and obesity in pre-school aged children in NHANES 2003-2008

Background. Previous studies suggest an association between timing of introduction of solid food and increased risk of obesity in pre-school aged children, but no study included a representative sample of US children. We sought to examine whether there was any association between the timing of solid food introduction and overweight/obesity in pre-school aged children. Design/methods. Cross-sectional study of a nationally representative sample (N=2050) of US children aged 2 to 5 years with information on infant feeding practices and measured weight and height from the National Health and Nutrition Examination Survey 2003–2008. The main outcome measure was BMI for age and sex ≥ 85th percentile. The main exposure was timing of solid food introduction at < 4, 4–5, or ≥ 6 months of age. Binomial logistic regression was used in the analysis controlling for child's sex, birth weight and breastfeeding status as well as maternal age at birth, smoking status and socio-demographic variables. Results. Two thousand and fifty children were included in the sample; 51% male and 49% female; 57.1% Non-Hispanic White, 21.9% Hispanic, 14.0% Non-Hispanic Black, and 7% other race/ethnicity. Twenty-two percent of the children were overweight or obese. Sixty-nine percent were breastfed or fed breast milk at birth and 36% continued breastfeeding for ≥ six months. Solid foods were introduced before 4 months of age for 11.2% of the children; 30.3% received solid foods between 4 to 5 months; with 58.6% receiving solid foods at 6 months or later. Timing of solid food introduction was not associated with weight status (OR= 1.36, 95% CI [0.83–2.24]). Formula-fed infants and infants breastfed for < 4 months had increased odds of overweight and obesity (OR=1.54, 95% CI [1.05–2.27] and OR= 1.60, 95% CI [1.05–2.44], respectively) when compared to infants breastfed for ≥ 6 months. Conclusion. Timing of solid food introduction was not associated with weight status in a national sample of US children ages 2 to 5 years. More focus should be placed on promoting breastfeeding and healthy infant feeding practices as strategies to prevent obesity in children. ^

Messinian and pre-Messinian sediments of ODP Holes 107-652A and 107-654A

Sedimentology, mineralogy, and petrology of the pre-Pliocene sediments drilled at ODP Sites 652 and 654 in the Tyrrhenian Sea (Leg 107) have been studied with emphasis on the lower Messinian to pre-Messinian intervals. Messinian at Site 652 is essentially turbiditic and basinal in character; it was deposited during the syn-rift phase in a strongly subsiding half-graben and is correlatable with emerged coeval sequences; in part with the Laga Formation of the foredeep of Apennines, and in part with the filling of grabens dissecting that chain in the Tyrrhenian portion of Tuscany. The sequence found in Site 654 indicates an upper Tortonian to Messinian transgression accompanying crustal stretching in the western Tyrrhenian Sea and is perfectly correlatable with the so-called "Sahelian cycle" and with "postorogenic" cycles recognized in peninsular Italy and in Sicily.

Geochemical analysis of minerals from sediment core CRP-2 in the Ross Sea, Antarctica

Distribution patterns, petrography, whole-rock and mineral chemistry, and shape and fabric data are described for the most representative basement lithologies occurring as clasts (granule to bolder grain-size class) from the 625 m deep CRP-2/2A drillcore. A major change in the distribution pattern of the clast types occurs at c. 310 mbsf., with granitoid-dominated clasts above and mainly dolerite clasts below; moreover, compositional and modal data suggest a further division into seven main detrital assemblages or petrofacies. In spite of this variability, most granitoid pebbles consist of either pink or grey biotite±hornblende monzogranites. Other less common and ubiquitous lithologies include biotite syenogranite, biotite-hornblende granodiorite, tonalite, monzogranitic porphyries (very common below 310 mbsf), microgranite, and subordinately, monzogabbro, Ca-silicate rocks, biotite-clinozoisite schist and biotite orthogneiss (restricted to the pre-Pliocene strata). The ubiquitous occurrence of biotite±hornblende monzogranite pebbles in both the Quaternary-Pliocene and Miocene-Oligocene sections, apparently reflects the dominance of these lithologies in the onshore basement, and particularly in the Cambro-Ordovician Granite Harbour Igneous Complex which forms the most extensive outcrop in southern Victoria Land. The petrographical features of the other CRP-2/2A pebble lithologies are consistent with a supply dominantly from areas of the Transantarctic Mountains facing the CRP-2/2A site, and they thus provide further evidence of a local provenance for the supply of basement clasts to the CRP-2/2A sedimentary strata.

Geochemistry of boninite and harzburgite of ODP Leg 125 basement samples

Holes drilled into the volcanic and ultrabasic basement of the Izu-Ogasawara and Mariana forearc terranes during Leg 125 provide data on some of the earliest lithosphere created after the start of Eocene subduction in the Western Pacific. The volcanic basement contains three boninite series and one tholeiite series. (1) Eocene low-Ca boninite and low-Ca bronzite andesite pillow lavas and dikes dominate the lowermost part of the deep crustal section through the outer-arc high at Site 786. (2) Eocene intermediate-Ca boninite and its fractionation products (bronzite andesite, andesite, dacite, and rhyolite) make up the main part of the boninitic edifice at Site 786. (3) Early Oligocene intermediate-Ca to high-Ca boninite sills or dikes intrude the edifice and perhaps feed an uppermost breccia unit at Site 786. (4) Eocene or Early Oligocene tholeiitic andesite, dacite, and rhyolite form the uppermost part of the outer-arc high at Site 782. All four groups can be explained by remelting above a subduction zone of oceanic mantle lithosphere that has been depleted by its previous episode of partial melting at an ocean ridge. We estimate that the average boninite source had lost 10-15 wt% of melt at the ridge before undergoing further melting (5-10%) shortly after subduction started. The composition of the harzburgite (<2% clinopyroxene, Fo content of about 92%) indicates that it underwent a total of about 25% melting with respect to a fertile MORB mantle. The low concentration of Nb in the boninite indicates that the oceanic lithosphere prior to subduction was not enriched by any asthenospheric (OIB) component. The subduction component is characterized by (1) high Zr and Hf contents relative to Sm, Ti, Y, and middle-heavy REE, (2) light REE-enrichment, (3) low contents of Nb and Ta relative to Th, Rb, or La, (4) high contents of Na and Al, and (5) Pb isotopes on the Northern Hemisphere Reference Line. This component is unlike any subduction component from active arc volcanoes in the Izu-Mariana region or elsewhere. Modeling suggests that these characteristics fit a trondhjemitic melt from slab fusion in amphibolite facies. The resulting metasomatized mantle may have contained about 0.15 wt% water. The overall melting regime is constrained by experimental data to shallow depths and high temperatures (1250? C and 1.5 kb for an average boninite) of boninite segregation. We thus envisage that boninites were generated by decompression melting of a diapir of metasomatized residual MORB mantle leaving the harzburgites as the uppermost, most depleted residue from this second stage of melting. Thermal constraints require that both subducted lithosphere and overlying oceanic lithosphere of the mantle wedge be very young at the time of boninite genesis. This conclusion is consistent with models in which an active transform fault offsetting two ridge axes is placed under compression or transpression following the Eocene plate reorganization in the Pacific. Comparison between Leg 125 boninites and boninites and related rocks elsewhere in the Western Pacific highlights large regional differences in petrogenesis in terms of mantle mineralogy, degree of partial melting, composition of subduction components, and the nature of pre-subduction lithosphere. It is likely that, on a regional scale, the initiation of subduction involved subducted crust and lithospheric mantle wedge of a range of ages and compositions, as might be expected in this type of tectonic setting.

Two pollen profiles of the middle Pleistocene at Samerberg/Upper Bavaria, Germany

Previous pollen analytical studies on sediments from the pleistocene lake basin at Samerberg, situated on the northern edge of the Bavarian Alps (47°45' N, 12°12' E, 607 m a.s.l.) had been performed on samples taken from cores and exposures close to the southern shore of the former lake. After geoelectric and refraction-seismic measurements had shown that the lake basin had been much deeper in its northern part, another core was taken where maximum depth could be expected. The corer penetrated three moraines, two of them lying above pollen-bearing sediments, and one below them, and reached the hard rock (Kössener Kalk) at a depth of 93 m. Two forest phases could be identified by pollen analysis. The pollen record begins abruptly in a forest phase at the end of a spruce-dominated period when fir started to spread (DA 1, DA = pollen zone). Following this, Abies (fir) was the main tree species at Samerberg, Picea being second, and deciduous trees were almost non-existent. First box (Buxus) was of major importance in the fir forests (DA 2), but later on beech (Fagus) and wing-nut (Pterocarya) spread (DA 3). Finally this forest gave way to a spruce forest with pine (DA 4). The beginning and the end of this interglacial cycle are not recorded. Its vegetational development is different from the eemian one known from earlier studies at Samerberg. It is characterized by the occurrence of Abies together with Buxus, Pterocarya and Fagus. A similar association of woody species is known only from the Holsteinian age deposits in an area ranging from England to Poland, though at no other place these species were such important constituents of the vegetation as at Samerberg. Therefore zone 1 to 4 are attributed to the Holsteinian interglacial period. The younger forest phase, separated from the interglacial by a stadial with open vegetation (DA 5), seems to be completely represented, though its sediments are disturbed, apparently by sliding which caused repetition of same-age-sediments in the core (DA 7a, b, c) The vegetational development is simple. A juniper phase (DA 6) was followed by reforestation with spruce, accompanied by some fir (DA 7, 9). Finally pine became the dominant species (DA 9). The simple vegetational development of this younger forest phase does not allow a safe correlation with one of the known pre-eemian interstadials, but for stratigraphical reasons it can be related best to the Dömnitz-interglacial, which among others is also known as Wacken- or Holstein-II-interglacial. Possibly another phase of reforestation is indicated at the end of the following stadial (DA 10). But due to an erosional unconformity nothing than the rise of the juniper curve can be stated. It was only after this sequence of forest phases and periods with open vegetation that glaciers reached the Samerberg area again.

Sedimentology, biogeochemistry stable isotopes, pollen, plant macrofossils, and diatoms from two sediments cores from the northern Yukon permafrost peatlands (Canada)

Ice-wedge polygon (IWP) mires in the Arctic and Subarctic are extremely vulnerable to climatic and environmental change. We present the results of a multidisciplinary paleoenvironmental study on IWPs in the northern Yukon, Canada. High-resolution laboratory analyses were carried out on a permafrost core and the overlying seasonally thawed (active) layer, from a low-centered IWP located in a drained lake basin on Herschel Island. In relation to 14 Accelerator Mass Spectrometry (AMS) radiocarbon dates spanning the last 5000 years, we report sedimentary data including grain size distribution and biogeochemical parameters (organic carbon, nitrogen, C/N ratio, d13C), stable water isotopes (d18O, dD), as well as fossil pollen, plant macrofossil and diatom assemblages. Three sediment units (SUs) correspond to the main stages of deposition (1) in a thermokarst lake (SU1: 4950 to 3950 cal yrs BP), (2) during transition from lacustrine to palustrine conditions after lake drainage (SU2: 3950 to 3120 cal yrs BP), and (3) in palustrine conditions in the IWP field that developed after drainage (SU3: 3120 cal yrs BP to AD 2012). The lacustrine phase (pre 3950 cal yrs BP) is characterized by planktonic-benthic and pioneer diatoms species indicating circumneutral waters, and very few plant macrofossils. The pollen record has captured a regional signal of relatively stable vegetation composition and climate for the lacustrine stage of the record until 3950 cal yrs BP. Palustrine conditions with benthic and acidophilic species characterize the peaty shallow-water environments of the low-centered IWP. The transition from lacustrine to palustrine conditions was accompanied by acidification and rapid revegetation of the lake bottom within about 100 years. Since the palustrine phase we consider the pollen record as a local vegetation proxy dominated by the plant communities growing in the IWP. Ice-wedge cracking in water-saturated sediments started immediately after lake drainage at about 3950 cal yrs BP and led to the formation of an IWP mire. Permafrost aggradation through downward closed-system freezing of the lake talik is indicated by the stable water isotope record. The originally submerged IWP center underwent gradual drying during the past 2000 years. This study highlights the sensitivity of permafrost landscapes to climate and environmental change throughout the Holocene.

Barium intensities and tie points between holes of Leg 208

The Paleocene - Eocene thermal maximum (PETM) is one of the best known examples of a transient climate perturbation, associated with a brief, but intense, interval of global warming and a massive perturbation of the global carbon cycle from injection of isotopically light carbon into the ocean-atmosphere system. One key to quantifying the mass of carbon released, identifying the source(s), and understanding the ultimate fate of this carbon is to develop high-resolution age models. Two independent strategies have been employed, cycle stratigraphy and analysis of extraterrestrial Helium (HeET), both of which were first tested on Ocean Drilling Program (ODP) Site 690. Both methods are in agreement for the onset of the PETM and initial recovery, or the clay layer ("main body"), but seem to differ in the final recovery phase of the event above the clay layer, where the carbonate contents rise and carbon isotope values return toward background values. Here we present a state-of-the-art age model for the PETM derived from a new orbital chronology developed with cycle stratigraphic records from sites drilled during ODP Leg 208 (Walvis Ridge, Southeastern Atlantic) integrated with published records from Site 690 (Weddell Sea, Southern Ocean, ODP Leg 113). During Leg 208, five Paleocene - Eocene (P-E) boundary sections (Sites 1262 to 1267) were recovered in multiple holes over a depth transect of more than 2200 m at the Walvis Ridge yielding the first stratigraphically complete P-E deep-sea sequence with moderate to relatively high sedimentation rates (1 to 3 cm/kyr). A detailed chronology was developed with non-destructive X-ray fluorescence (XRF) core scanning records on the scale of precession cycles, with a total duration of the PETM now estimated to be ~ 170 kyr. The revised cycle stratigraphic record confirms original estimates for the duration of the onset and initial recovery, but suggests a new duration for the final recovery that is intermediate to the previous estimates by cycle stratigraphy and HeET.