High resolution chronology of late Cretaceous-early Tertiary events determined from 21,000 yr orbital-climatic cycles in marine sediments

A number of South Atlantic sites cored by the Deep Sea Drilling Project (DSDP) recovered late Cretaceous and early Tertiary sediments with alternating light-dark, high-low carbonate content. The sedimentary oscillations were turned into time series by digitizing color photographs of core segments at a resolution of about 5 points/cm. Spectral analysis of these records indicates prominent periodicity at 25 to 35 cm in the Cretaceous intervals, and about 15 cm in the early Tertiary sediments. The absolute period of the cycles that is determined from paleomagnetic calibration at two sites is 20,000 to 25,000 yr, and almost certainly corresponds to the period of the earth's precessional cycle. These sequences therefore contain an internal chronometer to measure events across the K/T extinction boundary at this scale of resolution. The orbital metronome was used to address several related questions: the position of the K/T boundary within magnetic chron 29R, the fluxes of biogenic and detrital material to the deep sea immediately before and after the K/T event, the duration of the Sr anomaly, and the level of background climatic variability in the latest Cretaceous time. The carbonate/color cycles that were analyzed contain primary records of ocean carbonate productivity and chemistry, as evidenced by bioturbational mixing of adjacent beds and the weak lithification of the rhythmic sequences. It was concluded that sedimentary sequences that contain orbital cyclicity are capable of providing resolution of dramatic events in earth history with much greater precision than obtainable through radiometric methods. The data show no evidence for a gradual climatic deterioration prior to the K/T extinction event, and argue for a geologically rapid revolution at this horizon

Very high Middle Miocene surface productivity on the U.S. mid-Atlantic shelf amid glacioeustatic sea level variability

The Miocene Climatic Optimum (MCO) provides important insights into how the climate system operates under elevated temperatures and atmospheric CO2 levels. Few western North Atlantic paleotemperature or paleoecological records exist from the MCO, despite their importance for understanding both regional and global climate dynamics. Here we present quantitative MCO paleoecological data from the western North Atlantic, specifically from the Baltimore Gas & Electric (BG&E) marine sediment core from southern Maryland, USA. We examine alkenones and planktic foraminifera and document the first sea surface temperature (SST) and productivity estimates for the MCO and the Middle Miocene Climate Transition (MMCT) from the continental shelf. Increased levels of planktic foraminifer species diversity and surface productivity accompany high sea level intervals of the MCO, indicating coastal upwelling. Cooling episodes correlate to unconformities in the BG&E core that reflect sea level lowstands; these and sedimentary cycles tie the record to eccentricity-paced Antarctic ice sheet growth and decay. This dynamic record not only captures the variability in SST, sea level and coastal productivity during the warm MCO and the transition to cooler global temperatures during the MMCT, but it also demonstrates the variability in local conditions within and between intervals of high sea level

Interaction potentials, spectroscopy and transport properties of C+(2PJ) and C+(4PJ) with helium

We calculate accurate interatomic potentials for the interaction of a singly-charged carbon cation with a helium atom. We employ the RCCSD(T) method, and basis sets of quadruple-zeta and quintuple-zeta quality; each point is counterpoise corrected and extrapolated to the basis set limit. We consider the two lowest C+(2P) and C+(4P) electronic states of the carbon cation, and calculate the interatomic potentials for the terms that arise from these: 2-PI and 2-SIG+, and 4-PI and 4-SIG- , respectively. We additionally calculate the interatomic potentials for the respective spin-orbit levels, and examine the effect on the spectroscopic parameters. Finally, we employ each set of potentials to calculate transport coefficients, and compare these to available data. Critical comments are made in the cases where there are discrepancies between the calculated values and measured data

Toward an understanding of tourists’ authentic heritage experiences: Evidence from Hong Kong

Authenticity in tourism has been a topic of discussion since the 1960s, but the concept is still to be fully developed. This study focuses on tourists’ perceptions of authenticity, and in particular how they evaluate authentic heritage experiences. The appearance and physical settings of attractions were found to be the initial and most important indicators of authentic or inauthentic experiences. Other criteria for assessing the authenticity of heritage experiences include the presence of local culture and customs, constructed elements, commodification, and atmosphere

Exploring Views from University Faculty and Cooperating Teachers on General Music Teacher Preparation

The purpose of this exploratory study was to examine perspectives of experienced university faculty and cooperating teachers in general music education. The co-authors’ four guiding research questions were: (a) What are the ideal components of preservice general music teacher preparation; (b) What do cooperating teachers and university supervisors expect of preservice music teachers; (c) How may preservice general music teacher preparation be improved; and (d) What are the possible roadblocks and solutions for improving preservice music teacher preparation? For this case study, 11 university faculty and 19 cooperating teachers completed a researcher-designed, open-ended survey (N = 30). Using a downward coding process to identify diversity within the data, followed by upward coding to determine synthesis within the data, three themes emerged: enabling conditions, inhibiting conditions, and curriculum reorganization. Research questions (a) and (b) matched with enabling conditions, when present, and inhibiting conditions, when absent. Curricular reorganization responses matched with question (c), while inhibiting conditions and elements of curricular reorganization matched with question (d). The co-authors discuss implications of their findings for music teacher education and make recommendations for further research to extend this exploratory study

Travelers' Diarrhea in West Africa and Mexico: Fecal Transport Systems and Liquid Bismuth Subsalicylate for Self-Therapy

The goals of this study were threefold: to compare the etiology of travelers' diarrhea in West Africa and Mexico, to evaluate two fecal transport systems for the recovery of enteropathogens, and to verify the efficacy of liquid bismuth subsalicylate (BSS) in different locations and under different entrance criteria for disease severity. The study populations consisted of 133 European tourists in West Africa and 112 American students in Mexico who had suffered from travelers' diarrhea. In 60% and 38% of the stool samples at the two study sites, similar proportions of enteropathogens were detected. A two-vial system consisting of Enteric Plus medium and polyvinyl alcohol fixative was slightly superior for identifying enteric pathogens than was a three-vial system with buffered glycerol saline, Cary-Blair medium with campylobacter antibodies, and polyvinyl alcohol fixative. In a parallel, double-blind, randomized trial, BSS significantly shortened disease duration at both study site

Dyadic Coping in Patients Undergoing Radiotherapy for Head and Neck Cancer and Their Spouses

Background: Head and neck cancer (HNC) adversely affects the psychological (i.e., depression, anxiety) and marital adjustment of patients and their spouses. Dyadic coping refers to how couples cope with stress. It includes positive actions like sharing practical or emotional concerns (i.e., problem- and emotion-focused stress communication; PFSC, EFSC), and engaging in problem- or emotion-focused actions to support each other (problem- and emotion-focused dyadic coping; PFDC, EFDC). It also includes negative actions like avoidance (negative dyadic coping; NEGDC). In this secondary analysis of a randomized pilot trial of a couple-based intervention called SHARE (Spouses coping with the Head And neck Radiation Experience), we first examined associations between patients’ and spouses’ dyadic coping (and satisfaction with dyadic coping; SATDC) and their own/each other’s psychological and marital adjustment. Next, we examined the effects of SHARE relative to usual medical care (UMC) on patients’ and spouses’ dyadic coping. Finally, we examined whether changes in dyadic coping were associated with changes in patients’ and spouses’ psychological and marital adjustment.Methods and Measures: Thirty HNC patients (80% men) and their spouses (N = 60) completed baseline surveys prior to initiating radiotherapy (RT) and were randomized to SHARE or UMC. One month after RT, they completed follow-up surveys.Results: Baseline multilevel Actor-Partner Interdependence Models revealed significant actor effects of PFSC (effect size r = −0.32) and PFDC (r = −0.29) on depression. For marital adjustment, significant actor effects were found for PFSC, PFDC, EFDC, and SATDC (p < 0.05, r = 0.23 to 0.38). Actor (r = −0.35) and partner effects (r = −0.27) for NEGDC were also significant. Moderate to large effect sizes were found in favor of SHARE on PFSC (Cohen’s d = 1.14), PFDC (d = 0.64), NEGDC (d = −0.68), and SATDC (d = 1.03). Improvements in PFDC were associated with reductions in depression and anxiety (p < 0.05); and, improvements in SATDC were associated with improvements in anxiety and marital adjustment (p < 0.05).Conclusion: The SHARE intervention improved positive and decreased negative dyadic coping for patients and spouses. Increases in positive dyadic coping were also associated with improvements in psychological and marital adjustment. Although findings are preliminary, more research on ways to integrate dyadic coping into oncology supportive care interventions appears warranted

Role of land-ocean interactions in stepwise Northern Hemisphere Glaciation

The investigation of triggers causing the onset and intensification of Northern Hemisphere Glaciation (NHG) during the late Pliocene is essential for understanding the global climate system, with important implications for projecting future climate changes. Despite their critical roles in the global climate system, influences of land-ocean interactions on high-latitude ice sheets remain largely unexplored. Here, we present a high-resolution Asian dust record from Ocean Drilling Program Site 1208 in the North Pacific, which lies along the main route of the westerlies. Our data indicate that atmosphere-land-ocean interactions affected aeolian dust emissions through modulating moisture and vegetation in dust source regions, highlighting a critical role of terrestrial systems in initiating the NHG as early as 3.6 Myr ago. Combined with additional multi-proxy and model results, we further show that westerly wind strength was enhanced, mainly at low-to-middle tropospheric levels, during major glacial events at about 3.3 and 2.7 Myr ago. We suggest that coupled responses of Earth’s surface dynamics and atmospheric circulation in the Plio-Pleistocene likely involved feedbacks related to changes in paleogeography, ocean circulation, and global climate

Group 2i Isochrysidales produce characteristic alkenones reflecting sea ice distribution

Alkenones are biomarkers produced solely by algae in the order Isochrysidales that have been used to reconstruct sea surface temperature (SST) since the 1980s. However, alkenone based SST reconstructions in the northern high latitude oceans show significant bias towards warmer temperatures in core-tops, diverge from other SST proxies in down core records, and are often accompanied by anomalously high relative abundance of the C37 tetra-unsaturated methyl alkenone (%C37:4). Elevated %C37:4 is widely interpreted as an indicator of low sea surface salinity from polar water masses, but its biological source has thus far remained elusive. Here we identify a lineage of Isochrysidales that is responsible for elevated C37:4 methyl alkenone in the northern high latitude oceans through next-generation sequencing and lab-culture experiments. This Isochrysidales lineage co-occurs widely with sea ice in marine environments and is distinct from other known marine alkenone-producers, namely Emiliania huxleyi and Gephyrocapsa oceanica. More importantly, the %C37:4 in seawater filtered particulate organic matter and surface sediments is significantly correlated with annual mean sea ice concentrations. In sediment cores from the Svalbard region, the %C37:4 concentration aligns with the Greenland temperature record and other qualitative regional sea ice records spanning the past 14 kyrs, reflecting sea ice concentrations quantitatively. Our findings imply that %C37:4 is a powerful proxy for reconstructing sea ice conditions in the high latitude oceans on thousand- and, potentially, on million-year timescales.publishedVersio