1,124 research outputs found
An evaluation of possible relationships between solar activity and tree-ring growth in western North America
Relationship between tree ring growth variations and solar activity since 1700 in western North Americ
About low field memory and negative magnetization in semiconductors and polymers
Ginzburg-Landau bulk magnetization of itinerant electrons can provide a
negative effective field in the Weiss model by coupling to localized magnetic
moments. The coupling enforces remnant magnetization, which can be negative or
positive depending on the sample magnetic history. Stable magnetic
susceptibility of coupled nonequilibrium subsystems with magnetization reversal
is always positive. Gauss-scale fields could be expected for switching between
negative and positive remnant moments in semiconductors with coupling at
ambient temperatures. Negative magnetization in ultra-high conducting polymers
is also discussed within the developed framework.Comment: 8 pages, no figure
A comparison of electrophysiological changes during the sleep onset period of psychophysiological insomniacs, psychiatric insomniacs and normal sleepers
The EEG of the sleep onset period of
psychophysiological insomniacs, psychiatric insomniacs and
controls was compared using power spectral analysis (FFT).
Eighteen drug-free subjects were equally divided into three
groups according to their responses in the Brock Sleep and
Insomnia Questionnaire, the Minnesota Multiphasic
Personality Inventory and the Sleep Disorders Questionnaire.
Group 1 consisted of psychophysiological insomniacs, group 2
included insomniacs with an indication of psychiatric
disturbances, and group 3 was a control group. EEG, EOG and
EMG were recorded for two consecutive nights. Power
spectral analysis (FFT) of EEG at C4 from the sleep onset
period (defined as lights out to the first five minutes of
stage 2) was performed on all standard frequency bands,
delta: .5-4 Hz; theta: 4-8 Hz; alpha: 8-12 Hz; sigma: 12-15
Hz beta: 15-25 Hz. Psychophysiological insomniacs had less
alpha during wakefulness than the other two groups and did
not show the dramatic drop in alpha across the sleep onset
period, which characterizes normal sleep. They also had
less delta, especially during stage 2 on night 2. They also
showed less delta in the last quartile of the chronological
analysis of the sleep onset period. Psychiatric insomniacs
showed lower relative beta power values overall while
psychophysiological insomniacs showed higher relative beta
power values during wakefulness. This microanalysis
11
confirms that the sleep onset period is generally similar
for psychiatric insomniacs and normal sleepers. This may be
due to the sample of psychiatric insomniacs being
heterogeneous or may reflect a sleep onset system that is
essentially intact. Psychophysiological insomniacs have
higher cortical arousal during the sleep onset period than
do the psychiatric insomniacs and the controls. Clear
differences in the sleep onset period of psychophysiological
insomniacs exist. The dramatic changes in power values in
these two groups are not seen in the psychophysiological
insomniacs, which may make the discrimination between
wakefulness and sleep more difficult
CO-Dark Star Formation and Black Hole Activity in 3C 368 at z = 1.131: Coeval Growth of Stellar and Supermassive Black Hole Masses
We present the detection of four far-infrared fine-structure oxygen lines, as
well as strong upper limits for the CO(2-1) and [N II] 205 um lines, in 3C 368,
a well-studied radio-loud galaxy at z = 1.131. These new oxygen lines, taken in
conjunction with previously observed neon and carbon fine-structure lines,
suggest a powerful active galactic nucleus (AGN), accompanied by vigorous and
extended star formation. A starburst dominated by O8 stars, with an age of ~6.5
Myr, provides a good fit to the fine-structure line data. This estimated age of
the starburst makes it nearly concurrent with the latest episode of AGN
activity, suggesting a link between the growth of the supermassive black hole
and stellar population in this source. We do not detect the CO(2-1) line, down
to a level twelve times lower than the expected value for star forming
galaxies. This lack of CO line emission is consistent with recent star
formation activity if the star-forming molecular gas has low metallicity, is
highly fractionated (such that CO is photodissociated through much of the
clouds), or is chemically very young (such that CO has not yet had time to
form). It is also possible, though we argue unlikely, that the ensemble of fine
structure lines are emitted from the region heated by the AGN.Comment: 10 pages, 4 figures, 2 tables, accepted for publication in the
Astrophysical Journa
Effect of an isoenergetic traditional Mediterranean diet on apolipoprotein A-I kinetic in men with metabolic syndrome
BACKGROUND: The impact of the Mediterranean diet (MedDiet) on high-density lipoprotein (HDL) kinetics has not been studied to date. The objective of this study was therefore to investigate the effect of the MedDiet in the absence of changes in body weight on apolipoprotein (apo) A-I kinetic in men with metabolic syndrome (MetS). METHODS: Twenty-six men with MetS (NCEP-ATP III) were recruited from the general community. In this fixed sequence study, participants’ diet was first standardized to a control diet reflecting current averages in macronutrient intake in North American men, with all foods and beverages provided under isoenergetic conditions for 5 weeks. Participants were then fed an isoenergetic MedDiet over a subsequent period of 5 weeks to maintain their weight constant. During the last week of each diet, participants received a single bolus dose of [5,5,5-(2)H(3)] (L)-leucine and fasting blood samples were collected at predetermined time points. ApoA-I kinetic was determined by multicompartmental modeling using isotopic enrichment data over time. Data were analyses using MIXED models. RESULTS: The response of HDL-cholesterol (C) to MedDiet was heterogeneous, such that there was no mean change compared with the control diet. Plasma apoA-I concentration (−3.9%) and pool size (−5.3%, both P < 0.05) were significantly lower after MedDiet and apoA-I production rate tended to be reduced (−5.7%, P = 0.07) with no change in apoA-I fractional catabolic rate (FCR, -1.6%, P = 0.64). Participants among whom HDL-C concentrations were increased with MedDiet (responders: mean ∆HDL-C: +9.9 ± 3.2%, N = 11) showed significantly greater reductions in apoA-I FCR and in apoB and very-low-density lipoprotein-triglycerides (VLDL-TG) concentrations (all P < 0.04) than those among whom HDL-C levels were reduced after the MedDiet (non-responders: mean ∆HDL-C: -12.0 ± 3.9%, N = 8). Correlation analysis revealed that only variations in apoA-I FCR (r = -0.48, P = 0.01) and in plasma VLDL-TG (r = −0.45, P = 0.03) concentrations were correlated with the individual HDL-C response to the MedDiet. CONCLUSIONS: Data from this controlled feeding study suggest that the heterogeneous response of HDL-C to MedDiet, in the absence of important weight loss, is primarily related to individual variations in apoA-I FCR and in plasma VLDL-TG concentrations. TRIAL REGISTRATION: ClinicalTrial.gov registration number: NCT0098865
Estimation of the Potential Detection of Diatom Assemblages Based on Ocean Color Radiance Anomalies in the North Sea
Over the past years, a large number of new approaches in the domain of ocean-color have been developed, leading to a variety of innovative descriptors for phytoplankton communities. One of these methods, named PHYSAT, currently allows for the qualitative detection of five main phytoplankton groups from ocean-color measurements. Even though PHYSAT products are widely used in various applications and projects, the approach is limited by the fact it identifies only dominant phytoplankton groups. This current limitation is due to the use of biomarker pigment ratios for establishing empirical relationships between in-situ information and specific ocean-color radiance anomalies in open ocean waters. However, theoretical explanations of PHYSAT suggests that it could be possible to detect more than dominance cases but move more toward phytoplanktonic assemblage detection. Thus, to evaluate the potential of PHYSAT for the detection of phytoplankton assemblages, we took advantage of the Continuous Plankton Recorder (CPR) survey, collected in both the English Channel and the North Sea. The available CPR dataset contains information on diatom abundance in two large areas of the North Sea for the period 1998-2010. Using this unique dataset, recurrent diatom assemblages were retrieved based on classification of CPR samples. Six diatom assemblages were identified in-situ, each having indicators taxa or species. Once this first step was completed, the in-situ analysis was used to empirically associate the diatom assemblages with specific PHYSAT spectral anomalies. This step was facilitated by the use of previous classifications of regional radiance anomalies in terms of shape and amplitude, coupled with phenological tools. Through a matchup exercise, three CPR assemblages were associated with specific radiance anomalies. The maps of detection of these specific radiances anomalies are in close agreement with current in-situ ecological knowledge
Vancouver simplified grading system with computed tomographic angiography for blunt aortic injury
ObjectiveDelineation of blunt aortic injury by computed tomographic angiography guides management of this potentially fatal injury. Two existing grading systems are problematic to apply and not linked to outcomes. A simplified computed tomographic angiography–based grading system, linked to clinical outcomes, was developed, and feasibility and reliability were evaluated.MethodsRetrospective review was performed of all blunt aortic injury cases presenting to a single provincial quaternary referral center designated for blunt aortic injury management between 2001 and 2009. Management, associated injuries, hospital survival, and cause of death were determined. Initial computed tomographic angiography was reviewed, and injuries were graded according to the new Vancouver simplified grading system by 2 study authors. Three additional trauma radiologists then graded the aortic injuries with the 2 existing systems and the simplified system. Interrater reliability was determined.ResultsForty-eight patients were identified. Two had minimal aortic injury (grade I), 7 had an intimal flap larger than 1 cm (grade II), 32 had traumatic pseudoaneurysm (grade III), 6 had active contrast extravasation (grade IV), and 1 could not be rated. Survivals were 100%, 90%, and 33% for grades I and II, III, and IV, respectively. Of grade III injuries, 14% were medically managed, 68% repaired endovascularly, and 18% repaired with open surgery. Interrater correlation was best with the simplified score, with only 0.5% of cases unable to be classified.ConclusionsThe Vancouver simplified blunt aortic injury grading system is easy to use and correlates with clinical outcomes. Prospective external validation is required
Impact of a non-restrictive satiating diet on anthropometrics, satiety responsiveness and eating behaviour traits in obese men displaying a high or a low satiety phenotype
The aim of this study was to evaluate the impact of a non-restrictive satiating diet in men displaying various degrees of satiety efficiency. In all, sixty-nine obese men aged 41·5 (sd 5·7) years were randomly assigned to a control (10–15, 55–60 and 30 % energy as protein, carbohydrate and lipid, respectively; n 34) or satiating (20–25, 45–50 and 30–35 % energy as protein, carbohydrate and lipid, respectively; n 35) diet for 16 weeks, and were classified as having a low (LSP) or high (HSP) satiety phenotype. Both diets were consumed ad libitum. Changes in body weight, BMI, percent fat mass, waist circumference, satiety responsiveness and eating behaviour traits were assessed following the intervention. Dropout rates were higher in the control diet (44·1 %) compared with the satiating diet (8·6 %). Decreases in body weight, BMI and waist circumference were significant in both groups, yet HSP individuals lost more body weight than LSP individuals (P=0·048). Decreases in % fat mass were greater in the satiating diet (LSP: −2·1 (sd 2·1) %; P<0·01 and HSP: −3·0 (sd 2·5) %; P<0·001) compared with the control diet (LSP: −1·1 (sd 2·5) % and HSP: −1·3 (sd 2·6) %) (P=0·034). Satiety responsiveness was markedly improved in the satiating diet, whereas no significant changes were observed in the control group. Changes in dietary restraint (+3·3 (sd 2·9) to +7·2 (sd 5·5)), flexible control (+0·9 (sd 1·4) to +2·3 (sd 2·7)), rigid control (+2·2 (sd 1·5) to +2·5 (sd 2·8)), disinhibition (−2·8 (sd 3·7) to −3·2 (sd 2·6)) and susceptibility to hunger (−2·7 (sd 4·1) to −4·6 (sd 3·9)) were similar between the diets. Compared with the control diet, the satiating diet favoured adherence, decreased % fat mass and improved satiety responsiveness in both HSP and LSP individuals
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