Magnetostratigraphy of ODP Leg 178 holes

We present revised magnetostratigraphic interpretations for Ocean Drilling Program Sites 1095, 1096, and 1101, cored in sediment drifts located off the Pacific margin of the Antarctic Peninsula. The revised interpretations incorporate a variety of observations and results obtained since the end of Leg 178, of which the most significant are new paleomagnetic measurements from U-channel samples, composite depth scales that allow stratigraphic correlation between multiple holes cored at a site, and revised biostratigraphic interpretations. The U-channel data, which include more than 102,000 paleomagnetic observations from more than 13,400 intervals along U-channel samples, are included as electronic files. The magnetostratigraphic records at all three sites are consistent with sedimentation being continuous over the intervals cored, although the data resolution does not preclude short hiatuses less than a few hundred thousand years in duration. The magnetostratigraphic records start at the termination of Subchron C4Ar.2n (9.580 Ma) at ~515 meters composite depth (mcd) for Site 1095, at the onset of Subchron C3n.2n (4.620 Ma) at ~489.68 mcd for Site 1096, and at the onset of Subchron C2An.1n (3.040 Ma) at 209.38 meters below seafloor for Site 1101. All three sites provide paleomagnetic records that extend upward through the Brunhes Chron.

(Table T2) Biogenic opal in Palmer Deep sediments at ODP Site 178-1098

High-resolution records of sedimentary proxies provide insights into fine-scale geochemical responses to climatic forcing. Gamma-ray attenuation (GRA) bulk-density data and magnetic stratigraphy records from Palmer Deep, Site 1098, show variability close to the same scale as ice cores, making this site ideal for high-resolution geochemical investigations. In conjunction with shipboard geophysical measurements, silica records allow high-resolution evaluation of the frequencies and amplitudes of biogenic variability. This provides investigators additional data sets to evaluate the global extent of climatic events that are presently defined by regional oceanic data sets (e.g., Younger Dryas in the North Atlantic) and to evaluate the potential mechanisms that link biological productivity and climate in the Southern Ocean. In addition, because of the observed links between diatom blooms and export productivity (Michaels and Silver, 1988, doi:10.1016/0198-0149(88)90126-4), biogenic silica may be an indicator of the efficiency of the biological pump (removal of organic carbon from the euphotic zone and burial within the sediments). Because the net removal of CO2 (on short time scales up to millennial, the balance between upwelled CO2, carbon fixation, and the removal of organic carbon from the surface ocean) can determine the atmospheric concentration; proxies that allow us to quantify export production yield insights into carbon cycle responses. In today's ocean, diatoms are integrally linked with new production (production based on the use of nitrate and molecular nitrogen rather than ammonium, which is generated by the microbial degradation of organic carbon) (Dugdale and Goering, 1967). Thus, as with nutrient utilization proxies, biogenic silica may be a good indicator of export production. The difficulties lie in translating the biogenic opal burial records to export production. Numerous factors control the preservation of sedimentary biogenic silica, including depth of the water column, water temperature, trace element chemistry, grazing pressure, bloom structure, and species composition of the diatom assemblage (Nelson et al., 1995, doi:10.1029/95GB01070). In addition, several recent investigations have noted additional complications. Iron limitation increases the uptake of Si relative to carbon (Hutchins et al., 1998, ; Takeda, 1998, doi:10.1038/31674). In the Southern Ocean, iron limitation could produce more robust, and thus better preserved, diatoms; thus, the burial record may be a record of iron limitation rather than of the export of organic carbon (Boyle, 1998). In addition, laboratory experiments show that bacteria accelerate the dissolution of biogenic silica (Bidle and Azam, 1999, doi:10.1038/17351). Both the species composition and temperature seem to influence the amount of dissolution. Evidence of recycling of silicic acid within the photic zone (Brzezinski et al., 1997) suggests that the silica pump (removal from the euphotic zone of silica relative to nitrogen and phosphorus) may work with variable efficiency. This becomes an issue when trying to reconstruct the removal of organic carbon from sedimentary biogenic silica records. In fact, there is a wide range in the Si:Corganic molar ratio in the Southern Ocean (0.18-0.81) (Nelson et al., 1995; Ragueneau et al., 2000, doi:10.1016/S0921-8181(00)00052-7). Thus, the presence (or absence) of biogenic silica alone may tell us little about the export productivity, complicating the interpretation of age-related trends. One recent assessment has added some hope to links between productivity and opal burial in the Southern Ocean (Pondaven et al., 2000). Quantitative comparison of different productivity proxies will greatly aid in this evaluation.

El humor gráfico español ante el referéndum escocés del 18 de septiembre de 2014 ¿Dibujando la independencia de Cataluña?

El presente artículo analiza el discurso que los principales diarios españoles dieron al referéndum por la independencia de Escocia, celebrado el 18 de septiembre de 2014, a través del humor gráfico. Mediante el Análisis Textual, el objetivo primordial de este estudio es examinar el tratamiento informativo que realizaron El País, El Mundo, ABC, La Razón, La Vanguardia y El Periódico por medio de sus viñetas de opinión. Esta investigación presenta un campo novedoso de análisis tanto en el tema, abriendo nuevas áreas de trabajo sobre el nacionalismo y el papel de los medios, como en la metodología, pues el examen del humor gráfico continúa siendo una asignatura pendiente en los estudios de comunicación.

Moving from Awareness to Knowing, Understanding, Speaking and Doing: Indigenous Women Academics in Higher Education. National Tertiary Education Women's Conference, 18-19 July 2009, South Melbourne, Victoria.

Bronwyn Fredericks was asked to outline some of the issues faced by Indigenous women academics.

Heavy truck suspension optimization based on modified skyhook damping control

This paper presents a multi-objective optimization strategy for heavy truck suspension systems based on modified skyhook damping (MSD) control, which improves ride comfort and road-friendliness simultaneously. A four-axle heavy truck-road coupling system model was established using functional virtual prototype technology; the model was then validated through a ride comfort test. As the mechanical properties and time lag of dampers were taken into account, MSD control of active and semi-active dampers was implemented using Matlab/Simulink. Through co-simulations with Adams and Matlab, the effects of passive, semi-active MSD control, and active MSD control were analyzed and compared; thus, control parameters which afforded the best integrated performance were chosen. Simulation results indicated that MSD control improves a truck’s ride comfort and roadfriendliness, while the semi-active MSD control damper obtains road-friendliness comparable to the active MSD control damper.

Prevalence of upper-body symptoms following breast cancer and its relationship with upper-body function and lymphoedema

This investigation describes the prevalence of upper-body symptoms in a population-based sample of women with breast cancer (BC) and examines their relationships with upper-body function (UBF) and lymphoedema, as two clinically important sequelae. Australian women (n=287) with unilateral BC were assessed at three-monthly intervals, from six to 18 months post-surgery (PS). Participants reported the presence and intensity of upper-body symptoms on the treated side. Objective and self-reported UBF and lymphoedema (bioimpedance spectroscopy) were also assessed. Approximately 50% of women reported at least one moderate-to-extreme symptom at 6- and at 18-months PS. There was a significant relationship between symptoms and function (p<0.01), whereby perceived and objective function declined with increasing number of symptoms present. Those with lymphoedema were more likely to report multiple symptoms and presence of symptoms at baseline increased risk of lymphoedema (ORs>1.3, p=0.02). Although, presence of symptoms explained only 5.5% of the variation in the odds of lymphoedema. Upper-body symptoms are common and persistent following breast cancer and are associated with clinical ramifications, including reduced UBF and increased risk of developing lymphoedema. However, using the presence of symptoms as a diagnostic indicator of lymphoedema is limited.

Anna Clark (2008) History’s Children: History Wars in the Classroom. UNSW Press, Sydney, 178 pages

“History’s Children” stems from Anna Clark’s 2004 postdoctoral research into the ways in which Australian students connect with the past, and aims at bringing some classroom perspectives into the public debates about Australian history education. Although the title makes reference to the “History Wars”, there is little evidence of contestation, engagement, passion or intellectual excitement in Clark’s conclusions about what happens in history classrooms. Rather, Clark’s small focus groups with 182 high school students in 34 high schools around Australia indicate that “it got a bit dismal hearing student after student being so dismissive of Australian history” (p. 143). Apart from some enthusiasm for the study of Australians at war, a sort of resigned boredom seems to characterise what students have to say about learning Australian history, despite their acknowledgement that it is important to “know about” it.

The effect of exercise intensity on fat oxidation and non-exercise activity thermogenesis in overweight/obese men

It is frequently reported that the actual weight loss achieved through exercise interventions is less than theoretically expected. Amongst other compensatory adjustments that accompany exercise training (e.g., increases in resting metabolic rate and energy intake), a possible cause of the less than expected weight loss is a failure to produce a marked increase in total daily energy expenditure due to a compensatory reduction in non-exercise activity thermogenesis (NEAT). Therefore, there is a need to understand how behaviour is modified in response to exercise interventions. The proposed benefits of exercise training are numerous, including changes to fat oxidation. Given that a diminished capacity to oxidise fat could be a factor in the aetiology of obesity, an exercise training intensity that optimises fat oxidation in overweight/obese individuals would improve impaired fat oxidation, and potentially reduce health risks that are associated with obesity. To improve our understanding of the effectiveness of exercise for weight management, it is important to ensure exercise intensity is appropriately prescribed, and to identify and monitor potential compensatory behavioural changes consequent to exercise training. In line with the gaps in the literature, three studies were performed. The aim of Study 1 was to determine the effect of acute bouts of moderate- and high-intensity walking exercise on NEAT in overweight and obese men. Sixteen participants performed a single bout of either moderate-intensity walking exercise (MIE) or high-intensity walking exercise (HIE) on two separate occasions. The MIE consisted of walking for 60-min on a motorised treadmill at 6 km.h-1. The 60-min HIE session consisted of walking in 5-min intervals at 6 km.h-1 and 10% grade followed by 5-min at 0% grade. NEAT was assessed by accelerometer three days before, on the day of, and three days after the exercise sessions. There was no significant difference in NEAT vector magnitude (counts.min-1) between the pre-exercise period (days 1-3) and the exercise day (day 4) for either protocol. In addition, there was no change in NEAT during the three days following the MIE session, however NEAT increased by 16% on day 7 (post-exercise) compared with the exercise day (P = 0.32). During the post-exercise period following the HIE session, NEAT was increased by 25% on day 7 compared with the exercise day (P = 0.08), and by 30-33% compared with the pre-exercise period (day 1, day 2 and day 3); P = 0.03, 0.03, 0.02, respectively. To conclude, a single bout of either MIE or HIE did not alter NEAT on the exercise day or on the first two days following the exercise session. However, extending the monitoring of NEAT allowed the detection of a 48 hour delay in increased NEAT after performing HIE. A longer-term intervention is needed to determine the effect of accumulated exercise sessions over a week on NEAT. In Study 2, there were two primary aims. The first aim was to test the reliability of a discontinuous incremental exercise protocol (DISCON-FATmax) to identify the workload at which fat oxidation is maximised (FATmax). Ten overweight and obese sedentary male men (mean BMI of 29.5 ¡Ó 4.5 kg/m2 and mean age of 28.0 ¡Ó 5.3 y) participated in this study and performed two identical DISCON-FATmax tests one week apart. Each test consisted of alternate 4-min exercise and 2-min rest intervals on a cycle ergometer. The starting work load of 28 W was increased every 4-min using 14 W increments followed by 2-min rest intervals. When the respiratory exchange ratio was consistently >1.0, the workload was increased by 14 W every 2-min until volitional exhaustion. Fat oxidation was measured by indirect calorimetry. The mean FATmax, ƒtV O2peak, %ƒtV O2peak and %Wmax at which FATmax occurred during the two tests were 0.23 ¡Ó 0.09 and 0.18 ¡Ó 0.08 (g.min-1); 29.7 ¡Ó 7.8 and 28.3 ¡Ó 7.5 (ml.kg-1.min-1); 42.3 ¡Ó 7.2 and 42.6 ¡Ó 10.2 (%ƒtV O2max) and 36.4 ¡Ó 8.5 and 35.4 ¡Ó 10.9 (%), respectively. A paired-samples T-test revealed a significant difference in FATmax (g.min-1) between the tests (t = 2.65, P = 0.03). The mean difference in FATmax was 0.05 (g.min-1) with the 95% confidence interval ranging from 0.01 to 0.18. Paired-samples T-test, however, revealed no significant difference in the workloads (i.e. W) between the tests, t (9) = 0.70, P = 0.4. The intra-class correlation coefficient for FATmax (g.min-1) between the tests was 0.84 (95% confidence interval: 0.36-0.96, P < 0.01). However, Bland-Altman analysis revealed a large disagreement in FATmax (g.min-1) related to W between the two tests; 11 ¡Ó 14 (W) (4.1 ¡Ó 5.3 ƒtV O2peak (%)).These data demonstrate two important phenomena associated with exercise-induced substrate oxidation; firstly, that maximal fat oxidation derived from a discontinuous FATmax protocol differed statistically between repeated tests, and secondly, there was large variability in the workload corresponding with FATmax. The second aim of Study 2 was to test the validity of a DISCON-FATmax protocol by comparing maximal fat oxidation (g.min-1) determined by DISCON-FATmax with fat oxidation (g.min-1) during a continuous exercise protocol using a constant load (CONEX). Ten overweight and obese sedentary males (BMI = 29.5 ¡Ó 4.5 kg/m2; age = 28.0 ¡Ó 4.5 y) with a ƒtV O2max of 29.1 ¡Ó 7.5 ml.kg-1.min-1 performed a DISCON-FATmax test consisting of alternate 4-min exercise and 2-min rest intervals on a cycle ergometer. The 1-h CONEX protocol used the workload from the DISCON-FATmax to determine FATmax. The mean FATmax, ƒtV O2max, %ƒtV O2max and workload at which FATmax occurred during the DISCON-FATmax were 0.23 ¡Ó 0.09 (g.min-1); 29.1 ¡Ó 7.5 (ml.kg-1.min-1); 43.8 ¡Ó 7.3 (%ƒtV O2max) and 58.8 ¡Ó 19.6 (W), respectively. The mean fat oxidation during the 1-h CONEX protocol was 0.19 ¡Ó 0.07 (g.min-1). A paired-samples T-test revealed no significant difference in fat oxidation (g.min-1) between DISCON-FATmax and CONEX, t (9) = 1.85, P = 0.097 (two-tailed). There was also no significant correlation in fat oxidation between the DISCON-FATmax and CONEX (R=0.51, P = 0.14). Bland- Altman analysis revealed a large disagreement in fat oxidation between the DISCONFATmax and CONEX; the upper limit of agreement was 0.13 (g.min-1) and the lower limit of agreement was ¡V0.03 (g.min-1). These data suggest that the CONEX and DISCONFATmax protocols did not elicit different rates of fat oxidation (g.min-1). However, the individual variability in fat oxidation was large, particularly in the DISCON-FATmax test. Further research is needed to ascertain the validity of graded exercise tests for predicting fat oxidation during constant load exercise sessions. The aim of Study 3 was to compare the impact of two different intensities of four weeks of exercise training on fat oxidation, NEAT, and appetite in overweight and obese men. Using a cross-over design 11 participants (BMI = 29 ¡Ó 4 kg/m2; age = 27 ¡Ó 4 y) participated in a training study and were randomly assigned initially to: [1] a lowintensity (45%ƒtV O2max) exercise (LIT) or [2] a high-intensity interval (alternate 30 s at 90%ƒtV O2max followed by 30 s rest) exercise (HIIT) 40-min duration, three times a week. Participants completed four weeks of supervised training and between cross-over had a two week washout period. At baseline and the end of each exercise intervention,ƒtV O2max, fat oxidation, and NEAT were measured. Fat oxidation was determined during a standard 30-min continuous exercise bout at 45%ƒtV O2max. During the steady state exercise expired gases were measured intermittently for 5-min periods and HR was monitored continuously. In each training period, NEAT was measured for seven consecutive days using an accelerometer (RT3) the week before, at week 3 and the week after training. Subjective appetite sensations and food preferences were measured immediately before and after the first exercise session every week for four weeks during both LIT and HIIT. The mean fat oxidation rate during the standard continuous exercise bout at baseline for both LIT and HIIT was 0.14 ¡Ó 0.08 (g.min-1). After four weeks of exercise training, the mean fat oxidation was 0.178 ¡Ó 0.04 and 0.183 ¡Ó 0.04 g.min-1 for LIT and HIIT, respectively. The mean NEAT (counts.min-1) was 45 ¡Ó 18 at baseline, 55 ¡Ó 22 and 44 ¡Ó 16 during training, and 51 ¡Ó 14 and 50 ¡Ó 21 after training for LIT and HIIT, respectively. There was no significant difference in fat oxidation between LIT and HIIT. Moreover, although not statistically significant, there was some evidence to suggest that LIT and HIIT tend to increase fat oxidation during exercise at 45% ƒtV O2max (P = 0.14 and 0.08, respectively). The order of training treatment did not significantly influence changes in fat oxidation, NEAT, and appetite. NEAT (counts.min-1) was not significantly different in the week following training for either LIT or HIIT. Although not statistically significant (P = 0.08), NEAT was 20% lower during week 3 of exercise training in HIIT compared with LIT. Examination of appetite sensations revealed differences in the intensity of hunger, with higher ratings after LIT compared with HIIT. No differences were found in preferences for high-fat sweet foods between LIT and HIIT. In conclusion, the results of this thesis suggest that while fat oxidation during steady state exercise was not affected by the level of exercise intensity, there is strong evidence to suggest that intense exercise could have a debilitative effect on NEAT.