Steep Positive Slope Research Articles

Evidence of association between higher cardiorespiratory fitness and higher cerebral myelination in aging

Emerging evidence suggests that altered myelination is an important pathophysiologic correlate of several neurodegenerative diseases, including Alzheimer and Parkinson's diseases. Thus, improving myelin integrity may be an effective intervention to prevent and treat age-associated neurodegenerative pathologies. It has been suggested that cardiorespiratory fitness (CRF) may preserve and enhance cerebral myelination throughout the adult lifespan, but this hypothesis has not been fully tested. Among cognitively normal participants from two well-characterized studies spanning a wide age range, we assessed CRF operationalized as the maximum rate of oxygen consumption (VO2max) and myelin content defined by myelin water fraction (MWF) estimated through our advanced multicomponent relaxometry MRI method. We found significant positive correlations between VO2max and MWF across several white matter regions. Interestingly, the effect size of this association was higher in brain regions susceptible to early degeneration, including the frontal lobes and major white matter fiber tracts. Further, the interaction between age and VO2max exhibited i) a steeper positive slope in the older age group, suggesting that the association of VO2max with MWF is stronger at middle and older ages and ii) a steeper negative slope in the lower VO2max group, indicating that lower VO2max levels are associated with lower myelination with increasing age. Finally, the nonlinear pattern of myelin maturation and decline is VO2max-dependent with the higher VO2max group reaching the MWF peak at later ages. This study provides evidence of an interconnection between CRF and cerebral myelination and suggests therapeutic strategies for promoting brain health and attenuating white matter degeneration.

Anomalous to normal dispersion nonlinear optical dephasing switch in electromagnetically induced transparency using a Kerr effect

The atomic decoherence effect (DE) on a Kerr nonlinear (KNL) electromagnetically induced transparency (EIT)is studied in a Δ system. The DE between the ground state hyperfine levels is caused by the dephasing rate γ d which dramatically modifies the medium response. It controls the normal dispersive region which shows steep positive slopes for linear response at the line center while the nonlinear response experiences steep negative slopes for low γ d . The microwave field strength and γ d modify the nonlinear response from the anomalous dispersion to normal dispersion. The calculations show that room-temperature atoms are used to quantify the quantum interference (QI) on linear and nonlinear absorption with γ d . The EIT spectrum explores the understanding of the subluminal and superluminal wave propagation of probe signal and this study opens a new pathway for the understanding of the QI devices and their nonlinearities based on EIT.

Race- and Sex-Specific Factors Associated With Age-Related Slopes in Systolic Blood Pressure: Findings From the CARDIA Study.

Although blood pressure (BP) increases throughout young adulthood for most individuals, the age-related slope is not uniform. This study aimed to assess associations of demographic, clinical, behavioral, psychosocial, and neighborhood characteristics with age-related BP slope among 4 race-sex groups who participated in the Coronary Artery Risk Development in Young Adults study. Individuals (n=3554) aged 18 to 30 years were included in this analysis if they had normal BP at baseline and ≥2 BP measurements during the years 1985/1986 to 2015/2016. Associations of exposure variables with systolic BP slope were assessed using multivariate linear models. Over a mean follow-up of ~30 years, greater decade increases in systolic BP were estimated among Black than White participants (mean difference between Black females and White females: 3.0 mm Hg/decade; between Black males and White males: 4.7 mm Hg/decade). The exposure risk factors associated with greater increases in systolic BP throughout adulthood varied by race and sex. None of these factors were associated with increases in systolic BP in all race-sex groups. Parent history of high BP was associated with a steeper positive slope among Black females (effect size per decade: 1.1 [95% CI, 0.6-1.6]; P<0.01), Black males (0.6 [95% CI, 0.02-1.2]; P<0.05), and White females (0.6 [95% CI, 0.2-1.0]; P<0.01). Other risk factors were associated with greater age-related yearly increases in systolic BP among 1 or 2 of the 4 race-sex groups or were not statistically significant. Culturally tailored BP reduction approach should be considered in conjunction with primordial prevention, to moderate increases in BP throughout adulthood.

Normal and anomalous dispersion study on probe light propagation in the presence of structured coupling light using electromagnetically induced transparency protocol

Here, we present a study on the dispersion features obtained in an electromagnetically induced transparency (EIT) experiment using a three-level cascade configuration in an 87Rb atomic vapor medium in the presence of Laguerre–Gaussian (LG) light as a coupling. A doublet transmission structure was obtained experimentally, and dispersion spectra were extracted using transmission spectra to study the probe light behavior. Dispersive regions that exhibit normal and anomalous nature were studied considering the polarization of various orientations as a coupling light. We established that normal dispersive region shows steep positive slopes, and anomalous dispersive region shows negative slopes, which can be controlled by polarization orientations. Owing to the change in the slopes of dispersion, normal and anomalous dispersive region is observed, and spectrum shows the effects of subluminal and superluminal propagation of probe light. This work, to the best of our knowledge, is novel in the study of dispersive region arising out of double-resonance EIT transmission spectra in the presence of LG light with the l=10 and p=0 mode as a coupling light with various polarization orientations. In the discussion, we establish that single parameter θ is sufficient for identifying the orientation and ellipticity of the polarization ellipse and also determine that the polarization of coupling light acts as a tuning parameter for changing the behavior of normal and anomalous dispersive region. Slow and fast light or superluminal propagation of probe light arise as a consequence of positive or negative group index, and fast light does not violate the principle of causality. Slow and fast light have future applications in high-speed quantum information and quantum communication using EIT-based protocol.

Transtemporal brain contrast-enhanced ultrasound in children: preliminary experience in patients without neurological disorders.

To evaluate the use of transtemporal brain contrast-enhanced ultrasound (CEUS) to assess cerebral blood perfusion in a cohort of children without neurological disorders. We included pediatric patients who were undergoing a clinically-indicated CEUS study. Brain scans were performed with a Siemens Sequoia scanner and a 4V1 transducer, that was placed on the left transtemporal bone. Brain scans were performed simultaneously with the images of the clinically-indicated organ of interest. Qualitative and quantitative analysis was performed to evaluate the hemispherical blood flow at the level of the midbrain during the wash-in and wash-out phases of the time-intensity curve. Clinical charts were reviewed to evaluate post-CEUS adverse events. Five patients were evaluated (mean age 5.8 ± 5.1years). Qualitatively, more avid enhancement in the midbrain than the cortex was observed. Structures depicted ranged between the centrum semiovale at the level of the lateral ventricles and the midbrain. A quantitative analysis conducted on four patients demonstrated less avid perfusion on the contralateral (i.e. right) side, with a mean left/right ratio ranging between 1.51 and 4.07. In general, there was a steep positive wash-in slope starting at approximately 10s after contrast injection, reaching a peak intensity around 15-26s on the left side, and 17-29s on the right side. No adverse events were reported. Transtemporal brain CEUS is feasible and safe in the pediatric population and allows qualitative and quantitative assessment of cerebral perfusion.

Summer precipitation characteristics on the southern Tibetan plateau

AbstractPrecipitation is an important source of streamflow and a critical parameter in hydrological studies. However, spatiotemporal variation of precipitation in the Tibetan Plateau (TP) has been poorly characterized due to the limited distribution of meteorological stations mostly in the lowlands. In this study, we set‐up rain gauges to study summer precipitation on mountain slopes in three catchments of the southern TP from 2013 to 2016. We studied the precipitation gradients (PGs) averaged during the Indian monsoon season (PGms), as well as daily PGs (PGd) and unit PGs (PGu) under various precipitation intensity grades (PIGs) and subdiurnal precipitation distributions. We also analysed the correlations between the PGs and precipitation amounts under various PIGs. Results showed that the mean PGms, PGd and PGu in the study catchments were 0.0071–0.0082% for monsoon season, 0.11–0.13 mm·100 m−1 d−1 and 2.2–3.1%·100 m−1 for the total (nonintensity‐graded) precipitation, but varied widely under different PIGs. PGms, PGd and PGu were all strongly correlated to precipitation amounts, which were relatively consistent between years but varied between different catchments. In addition, the correlations showed a steep positive slope under fine precipitation but became flat or even negative with increasing PIG. Generally, two distinct precipitation peaks were noted in each of the three catchments: a dispersed peak in the morning, and a stronger but sharper peak at around 18:00 LST; overall, this subdiurnal pattern was temporally stable. The mean precipitation durations of the three catchments were approximately 1.0–1.4 hr (nonintensity‐graded) and increased from &lt;0.5 hr, to &lt;1 hr, 2–5 hr and 6–11 hr for trace, light, moderate and heavy precipitation intensities, respectively. Among the various PG units, both PGd and PGu better represented precipitation at different altitudes than that of PGms. Summer precipitation in the study catchments was influenced more by valley‐scale convection than by large‐scale monsoon circulation.

Analysis of Streamflow Variability and Trends in the Meta River, Colombia

The aim of this research is the detection and analysis of existing trends in the Meta River, Colombia, based on the streamflow records from seven gauging stations in its main course, for the period between June 1983 to July 2019. The Meta River is one of the principal branches of the Orinoco River, and it has a high environmental and economic value for this South American country. The methods employed for the trend detection and quantification were the Mann–Kendall (MK) test, the modified MK (MMK) test, and the Sen’s slope (SS) estimator. Statistically significant trends (at a 95% level of confidence) were detected in more than 30% of the 105 evaluated datasets. The results from the MK test indicate the presence of statistically significant downward trends in the upstream stations and upward trends in the downstream stations, with the latter presenting steep positive slopes. The findings of this study are valuable assets for water resources management and sustainable planning in the Meta River Basin.

Girls' brain structural connectivity in late adolescence relates to history of depression symptoms.

Girls' depressive symptoms typically increase in adolescence, with individual differences in course and severity being key risk factors for impaired emotional functioning in young adulthood. Given the continued brain white matter (WM) maturation that occurs in adolescence, the present study tested whether structural connectivity patterns in late adolescence are associated with variation in the course of depression symptom severity throughout adolescence. Participants were girls (N=115) enrolled in a multiyear prospective cohort study of risk for depression. Initial depression severity (intercept) at age 10 and change in severity (linear slope) across ages 10-19 were examined in relation to WM tractography collected at age 19. Network-based statistic analyses were used to identify clusters showing variation in structural connectivity in association with depressive symptomintercept, slope, and their interaction. Higher initial depressive severity and steeper positive slope (separately) were associated with greater structural connectivity between temporal, subcortical socioaffective, and occipital regions. Intercept showed more connectivity associations than slope. The interaction effect indicated that higher initial symptom severity and a steeper negative slope (i.e., alleviating symptoms) were related to greater connectivity between cognitive control regions. Moderately severe symptoms that worsened over time were followed by greater connectivity between self-referential and cognitive regions (e.g., posterior cingulate and frontal gyrus). Higher depressive symptomseverity in early adolescence and increasing symptom severity over time may forecast structural connectivity differences in late adolescence, particularly in pathways involving cognitive and emotion-processing regions. Understanding how clinical course relates to neurobiological correlates may inform new treatment approaches to adolescent depression.

Allometry of male sound‐producing structures indicates sexual selection on wing size and stridulatory teeth density in a bushcricket

AbstractThe majority of bushcricket species (Insecta: Orthoptera: Tettigoniidae) use acoustic signals for mate attraction. Song production and the sound‐producing structures, therefore, can be argued to be under sexual selection. The sound‐producing structures might determine differences in the acoustic parameters of male songs, like the fundamental frequency. We investigated the morphology and scaling relationships of the sound production organs in males of the bushcricket Poecilimon ampliatus. Selection acting on morphological traits can be inferred from allometric relationships. Our results show that heavier and larger males have bigger sound‐producing organs: wing area scales positively with body mass as well as with body size. The length of the stridulatory file and the stridulatory teeth length both increase with wing area. In contrast, the number and density of teeth on the stridulatory file decrease in heavier males. As a result, males with larger wings and longer stridulatory files have a reduced teeth density. Positive isometric scaling was detected for the length of stridulatory teeth, as well as negative isometry for teeth number and teeth density. Wing area in turn seems to be under positive sexual selection, as the relationship of wing size on male body size show a steep positive slope (β = 2.4). The morphological results indicate positive selection on sound‐producing structures and are in line with the female preference for heavier males in mate choice experiments.

The paradox of inverted biomass pyramids in kelp forest fish communities.

Theory predicts that bottom-heavy biomass pyramids or 'stacks' should predominate in real-world communities if trophic-level increases with body size (mean predator-to-prey mass ratio (PPMR) more than 1). However, recent research suggests that inverted biomass pyramids (IBPs) characterize relatively pristine reef fish communities. Here, we estimated the slope of a kelp forest fish community biomass spectrum from underwater visual surveys. The observed biomass spectrum slope is strongly positive, reflecting an IBP. This is incongruous with theory because this steep positive slope would only be expected if trophic position decreased with increasing body size (consumer-to-resource mass ratio, less than 1). We then used δ(15)N signatures of fish muscle tissue to quantify the relationship between trophic position and body size and instead detected strong evidence for the opposite, with PPMR ≈ 1650 (50% credible interval 280-12 000). The natural history of kelp forest reef fishes suggests that this paradox could arise from energetic subsidies in the form of movement of mobile consumers across habitats, and from seasonally pulsed production inputs at small body sizes. There were four to five times more biomass at large body sizes (1-2 kg) than would be expected in a closed steady-state community providing a measure of the magnitude of subsidies.

Influence of positive slopes on ultrafast heating in an atmospheric nanosecond-pulsed plasma synthetic jet

The influence of positive slopes on the energy coupling and hydrodynamic responses in an atmospheric nanosecond-pulsed plasma synthetic jet (PSJ) was investigated using a validated dry air plasma kinetics model. Based on a 1D simulation of the energy transfer mechanism in ultrafast gas heating, and with reasonable simplification, a 2D model of a PSJ was developed to investigate the discharge characteristics and hydrodynamic responses under different rise times. In the 1D simulation, a shorter voltage rise time results in a higher electric field in less time, reduces the time of ionization front propagation and produces stronger ionization. The energy transfer efficiency of ultrafast heating is approximately 60% but a steeper positive slope could raise local heating power density and make input energy 77% higher at the cost of 2.4% lower energy transfer efficiency under the same voltage amplitude and pulse width. The quench heating power density is always 27–30 times higher than that of ion collision in most discharge regions, while ion collision heating power density is 10–103 times higher in the sheath region. In 2D PSJ simulation, spatial-temporal distribution of electron density, reduced electric field and deposited energy were calculated for the first time. Heating energy increases sharply with voltage rise time decrease in the time scale of 20–50 ns. Jet velocity increases by 100 m s−1 when the rise time is reduced by 20 ns. A shorter voltage rise time also leads to higher orifice pressure and temperature, but their peak values are limited by the structure of the orifice and the discharge cavity.

Mechano optical behavior of polyethylene terephthalate films during simultaneous biaxial stretching: Real time measurements with an instrumented system

We present an experimental study of real time true stress–strain–birefringence measurements to elucidate the sequence of structural mechanisms that occur during simultaneous biaxial stretching of PET films from amorphous precursors in rubbery state. Stress–birefringence relationship, wide angle X-ray diffraction, Raman spectroscopy and DSC thermal analysis were used to identify the stages of the mechano-optical behavior of the films during stretching, and to identify their structural origins. The measurements revealed four regimes for the relationship between the stress and birefringence. In the first regime the stress has a linear relationship with birefringence where the linear stress optical rule holds and the stress optical constant for PET is 5.8 GPa−1 (5800 Brewster). In the second regime, the relationship is also nearly linear with a steeper positive slope, and in the third regime the relationship is nonlinear. At very high stretching rates, a fourth stage could be seen, where the stress increases while the birefringence reaches a plateau. This stage is reached when the polymer chains attain their finite extensibilities. This stage was not observed if low rates of stretching employed, where high relaxation movements dominate the orientation effects. The deviation from the initial linear stress optical rule coincides with the onset of the stress-induced crystallization as revealed by the off line measurements. This transition was found to be rate dependent and increased rate delays this transition to higher stresses.

Roles of Long-range Electrostatic Domain Interactions and K+ in Phosphoenzyme Transition of Ca2+-ATPase

Sarcoplasmic reticulum Ca(2+)-ATPase couples the motions and rearrangements of three cytoplasmic domains (A, P, and N) with Ca(2+) transport. We explored the role of electrostatic force in the domain dynamics in a rate-limiting phosphoenzyme (EP) transition by a systematic approach combining electrostatic screening with salts, computer analysis of electric fields in crystal structures, and mutations. Low KCl concentration activated and increasing salt above 0.1 m inhibited the EP transition. A plot of the logarithm of the transition rate versus the square of the mean activity coefficient of the protein gave a linear relationship allowing division of the activation energy into an electrostatic component and a non-electrostatic component in which the screenable electrostatic forces are shielded by salt. Results show that the structural change in the transition is sterically restricted, but that strong electrostatic forces, when K(+) is specifically bound at the P domain, come into play to accelerate the reaction. Electric field analysis revealed long-range electrostatic interactions between the N and P domains around their hinge. Mutations of the residues directly involved and other charged residues at the hinge disrupted in parallel the electric field and the structural transition. Favorable electrostatics evidently provides a low energy path for the critical N domain motion toward the P domain, overcoming steric restriction. The systematic approach employed here is, in general, a powerful tool for understanding the structural mechanisms of enzymes.

Eculizumab (ECU) in Atypical Hemolytic Uremic Syndrome (aHUS) Patients with Progressing Thrombotic Microangiopathy (TMA): 2-Year Data.

AbstractAbstract 2084 Introduction:aHUS is a rare, life-threatening genetic disease marked by chronic, uncontrolled complement activation leading to TMA and subsequent kidney and vital organ damage. 33%–40% patients (pts) die or progress to end-stage renal disease after the first clinical manifestation. In a phase 2 extension trial (64-week [wk] median ECU duration), pts receiving the terminal complement inhibitor ECU had a highly significant increase in platelet count (98×109/L; P=0.0001)—a measure of TMA improvement—and 4 pts (80%) discontinued prior dialysis by data cutoff. Here we report 2-year (y) results. Methods:Pts ≥12 y with aHUS and progressing TMA enrolled in an open-label, phase 2 trial with long-term extension. Pts had ≥4 plasma exchange/infusion (PE/PI) sessions in the wk before screening. ECU was administered at 900 mg/wk × 4 wk, 1200 mg at wk 5 and 1200 mg q2 wk thereafter. Results:The 26-wk study enrolled 17 pts, and 13 entered the extension phase. Data analysis was on the intention-to-treat population (n=17). Median time from diagnosis to screening was 10 months (range 0.3–236). Four pts (24%) had no identified complement regulatory factor mutation. Seven pts (41%) had prior renal transplant. All pts had estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 prior to ECU. Median ECU duration was 100 wk (range 2–145).Suppression of terminal complement activity was sustained at data cutoff. Significant platelet count improvement from baseline was seen at the 2-y data cutoff (P<0.0001; Table), with 15 pts (88%) achieving and maintaining a platelet count ≥150×109/L. Hematologic normalizationa was achieved by 88% of pts for an average duration of 629 days (d). Fifteen pts (88%) achieved TMA event-free status,b and TMA intervention ratec decreased from a median 0.88 (range 0.04–1.59) prior to ECU to 0 (range 0–0.31) during ECU treatment. Significant improvements in eGFR were observed throughout the study period (P=0.0008; Table). Earlier intervention with ECU was associated with greater eGFR improvement (P<0.01). Results of a 3-piece linear model demonstrated a flat slope for eGFR change from d −42 to 0, followed by a steep positive slope from d 0 to 28 (P<0.0001), then a continuous increase from d 28 to 860 (P=0.03). Improvements in other renal endpoints, including serum creatinine, proteinuria, and chronic kidney disease (CKD) stage, were observed with ongoing ECU. Significant improvements in quality of life (QOL) were observed. Pts received benefit regardless of the presence or absence of an identified complement mutation. Treatment with ECU was generally well tolerated, with 1 report of a serious adverse event (SAE; hypertension) deemed possibly drug related, which resolved with no change in ECU dosing. Two pts discontinued treatment due to worsening renal function unrelated to ECU. Conclusions:Long-term ECU therapy inhibited complement-mediated TMA and resulted in significant and continuous time-dependent improvements in renal function. At a median duration of almost 2 y, all pts entering the extension phase remain alive and report better QOL. The low rate of SAEs is consistent with the known safety profile of ECU. These results highlight the ongoing benefit of earlier intervention and long-term treatment with ECU in aHUS.TableChange from baseline in key outcomes from 26 wk and 100 wk of ECU treatment (N=17)Key OutcomesWk 26Median 100 WkMean platelet count change (primary), ×109/L (95% CI)73 (40–105)88 (63–112)P=0.0001P<0.0001 (wk 96)Hematologic normalization (primary),a n (%)13 (76)15 (88)TMA event-free status,b n (%)15 (88)15 (88)eGFR increase of ≥15 mL/min/1.73 m2, n (%)8 (47)10 (59)CKD improvement ≥1 stage, n (%)10 (59)12 (71)Serum creatinine decrease ≥25%, n (%)11 (65)13 (76)Mean eGFR change, mL/min/1.73 m2 (95% CI)31 (17, 45)32 (15, 49)dP=0.0001P<0.0008 (wk 96)Proteinuria decrease ≥1 grade,e n/N12/157/9 (wk 96)Mean health-related QOL change,f0.32 (0.27, 0.38)0.33 (0.30, 0.36)EuroQOL 5D score (95% CI)P<0.0001P=0.0001 (wk 96)CI=confidence interval.cPE/PI or new dialysis events/pt/d.aNormal platelet and lactate dehydrogenase levels, ≥2 consecutive measurements, ≥4 wk apart.b≥12 wk of stable platelet count, no PE/PI and no new dialysis.dECU eliminated need for dialysis in 4/5 pts receiving dialysis at baseline. An additional pt initiated dialysis at wk 64 (eGFR, 19 mL/min/1.73 m2 at screening).eEvaluable pts.fClinically meaningful threshold ≥0.6. Disclosures:Greenbaum:Alexion Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau. Legendre:Alexion Pharmaceuticals: Speakers Bureau. Babu:Alexion Pharmaceuticals: Honoraria, Research Funding. Cohen:Alexion Pharmaceuticals Inc.: Research Funding. Bedrosian:Alexion Pharmaceuticals: Employment. Loirat:Alexion Pharmaceuticals: Coordinator of Alexion trials of eculizumab in atypical HUS for France. Honoraria for conferences. Other.

The Volch’etundrovsky Massif of the autonomous anorthosite complex of the Main Range, the Kola Peninsula: Geological, petrogeochemical, and isotope-geochronological studies

The Volch’etundrovsky Massif occupies the middle part of the autonomous anorthosite complex of the Main Range, has a sheet morphology and marks the tectonic suture between the Kola block and the Belomorian mobile belt. The massif is characterized by homogenous structure and consists of the volumetrically dominant Main Zone including leucogabbro, leucogabbronorites, and anorthosites, and Marginal Zone made up of leuconorites and gabbronorites with subordinate plagioclasites and orthopyroxenites. Chemically, the rocks of the Volch’etundrovsky Massif are ascribed to the normal (tholeiitic and calc-alkaline) petrochemical series with typomorphic high Al2O3 contents (11.71–29.32 wt %). With Al2O3 increase in the leuconorite-anorthosite series, the SiO2 and TiO2 contents show weak variations, CaO and alkalis insignificantly increase, whereas the MgO and FeO contents sharply decrease. The rocks of the Volch’etundrovsky Massif reveal significant REE fractionation and increase in total REE content in the leuconorite-anorthosite series, most approximating the Paleoproterozoic (Sumian) anorthosites of the Kola region. The anorthosites and leucogabbro are characterized by flat HREE, while the leuconorites is strongly depleted in HREE due to garnet fractionation. All rocks of the massif have significant positive Eu anomalies caused by the plagioclase accumulation. Zircons are characterized by LREE depletion and enrichment in HREE. This defines the steep positive slope of the plots complicated by the negative Eu and positive Ce (in zircons from leucogabbro) anomalies, which is typical of the REE distribution patterns in the unaltered zircons from igneous rocks. In zircons from anorthosites, the Ce anomaly is weak to absent. The trace-element distribution in the rocks of the Volch’etundrovsky Massif show positive Ba, Ta, Pb, Sr, Sc, and V anomalies, being controlled by the mineral specifics of the massif and the presence of definite accessory minerals. New U-Pb zircon data on the rocks of the Volch’etundrovsky Massif indicate that the leuconorites from the Marginal Zone were formed 2473 ± 7 Ma and 2463 ± 2.4 Ma ago, and the leucogabbro from the Main Zone, 2467 ± 8 Ma. These rocks have negative ɛNd(T) from -1.54 up to -3.10, which indicates their derivation from enriched mantle reservoir variably contaminated by crustal material. The anorthosites of the Main Zone define an U-Pb age of 2407 ± 3 Ma and ɛNd(T) = −3.78, which presumably reflect the timing of hydrothermal-metasomatic alterations in the upper part of the magmatic chamber accompanied by significant crustal contamination.

Seasonal variation, sources, and gas/particle concentrations of PCBs and OCPs at high altitude suburban site in Western Black Sea Region of Turkey

Daily gas and particle phase samples were collected during winter and summer seasons in Bolu, which is located in the high altitude Western Black Sea Region of Turkey. Samples were analyzed to determine the concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Concentrations of endosulfan sulfate and methoxychlor were found to be highest in the summer and winter periods, respectively. The measured average concentration of endrin was considerably higher (10-50 fold) than the values reported in the literature for similar sites. The agricultural areas located to the south, south-east and south-west of the sampling point were identified as source regions. PCBs were found predominantly in the gas phase in both seasons and 3-chlorinated biphenyls were found to be abundant in the winter period, due to pollutants transported from the city centre and a waste incineration plant by southerly and easterly winds. The concentrations of PCB-180 and PCB-194 were found to be higher than values reported in the literature. The correlation between atmospheric concentrations and temperature was obtained by using Clausius-Clapeyron (CC) plots. The CC plots for most of the OCPs showed shallow negative slopes with low r(2) values, which might be due to the presence of local sources, i.e., agricultural areas around the sampling site and the dominance of evaporation. The CC plots showed steep positive slopes for most of the PCB compounds. Most of the PCB compounds were carried from the ongoing local sources.

Evaluating Field Measurements of Impact Sound

Analyzing data from an earlier investigation revealed uncertainties concerning data evaluation. Therefore, data points comprising 1/3-octave impact sound data and interview data from the earlier investigation are partly replaced by new data points. The data removed pertain to horizontal measurements. The investigation is then completed with data for 10 new housing units pertaining to vertical impact sound measurements. Including the new floor structures, a total number of 22 vertical data points are included. It was found that the current international standard method is unsatisfactory, and that the single-number value proposed in the earlier investigation suffers from shortcomings: when analyzing the new data sample, the correlation coefficient fell from 87% to 83%. The best choice proved to be a reference curve with a steep positive slope of 5.5 dB/octave between 50–100 Hz and the curve becomes a straight line. This reference curve resulted in a correlation coefficient again equal to 87%.

Distinguishing magmatic zircon from hydrothermal zircon: A case study from the Gidginbung high-sulphidation Au–Ag–(Cu) deposit, SE Australia

Zircons within the mineralized, silica-pyrite zone of the Gidginbung (Temora) high-sulphidation Au–Ag–(Cu) deposit in the Lachlan Orogen, Australia have been analyzed by both ion microprobe and laser ablation inductively coupled plasma mass spectrometry for titanium and rare earth element (REE) concentrations, as well as their oxygen and hafnium isotopic compositions. These zircons were previously interpreted to be hydrothermal in origin, but the new data are indicative of a magmatic origin. The zircons exhibit chondrite-normalized REE patterns that are characterized by a steep positive slope from La to Lu with a large positive Ce-anomaly and a relatively small negative Eu-anomaly, similar to igneous zircons from the nearby Middledale Gabbroic Diorite and the Boggy Plain Zoned Pluton in the Lachlan Orogen and some hydrothermal zircons from the Mole Granite in the New England Orogen. Apparent temperatures calculated using the Ti-in-zircon thermometer for the Gidginbung zircons are 692° to 782 °C, significantly higher than the inferred ore-forming temperature (≤ 350 °C) but consistent with magmatic crystallization. The Gidginbung zircons have mantle-like δ 18O values averaging 5.4 ± 0.9‰ VSMOW (2 standard deviations, n = 17), lower than those from the Barmedman granite (7.6 ± 2.0‰, n = 17) in the same area. The Gidginbung zircons also have ε Hf( t = 435 Ma) values between 6.4 ± 0.9 and 7.8 ± 0.9 (2 standard errors), while the ε Hf( t = 370 Ma) for zircons from the Barmedman granite is more variable, ranging from 5.1 ± 1.1 to 8.4 ± 0.8. Consideration of the data from this and previous studies indicates that the zircons in the Gidginbung deposit are indistinguishable from magmatic zircons with regards to their morphology, cathodoluminescence patterns, and chemical and isotopic signatures. The large measured oxygen isotopic fractionation between quartz and zircon (average: ∼ 10‰) indicates that the minerals did not form by the same process and/or from the same reservoir at T ≥ 350 °C. While most inclusions in zircon are interpreted to have been trapped after zircon formation or resorption, it is possible that, like quartz, rutile, and anatase, a few pyrite inclusions occurring wholly within zircons have formed at relatively high temperatures during zircon crystallization in magma. Thus, the U–Pb age of these zircons (436 Ma) represents the igneous crystallization age and the Gidginbung zircons investigated by us are best interpreted as magmatic relicts of the earliest Silurian igneous rocks, which survived the processes of hydrothermal alteration and mineralization.

Effects of parental presence and child characteristics on children's neuropsychological test performance: Third party observer effect confirmed

An observer's presence during neuropsychological testing can impair task performance in adults, but this phenomenon has yet to be examined as it pertains to neuropsychological testing of children. The current study focused on parental presence effects on nonverbal intelligence and verbal learning performance of children aged 6 to 8 years. Each of 53 children completed one form of the Test of Nonverbal Intelligence–3rd Edition (TONI-3) and the Selective Reminding Test (SRT) with his/her parent in the room and an alternate form of each with only the experimenter with the child in the testing room. Of several possible covariates, only the child's age was significant and included in final analyses. Using a doubly multivariate MANCOVA it was discovered that parent's observation status significantly interacted with the order of observation to impact task performance. This significant effect can mainly be attributed to a steeper positive slope (i.e., children's greater improvement over time) for TONI-3 T scores in children whose parent observed first; children whose parents were absent for the first half of testing improved to a lesser extent over time. No significant relationship was found between observation and SRT scores. These results lend some support to the assertion of previous studies that the presence of third party observers may affect the validity of neuropsychological test results.

Self-sustained phantom wormholes in semi-classical gravity

A possible candidate for the late time accelerated expanding universe is phantom energy, which possesses rather bizarre properties, such as the prediction of a Big Rip singularity and the violation of the null energy condition. The latter is a fundamental ingredient of traversable wormholes, and it has been shown that phantom energy may indeed sustain these exotic geometries. Inspired by the evolving dark energy parameter crossing the phantom divide, we consider in this work a varying equation of state parameter dependent on the radial coordinate, i.e., ω(r) = p(r)/ρ(r). We shall impose that phantom energy is concentrated in the neighbourhood of the throat, to ensure the flaring out condition, and several models are analysed. We shall also consider the possibility that these phantom wormholes be sustained by their own quantum fluctuations. The energy density of the graviton one-loop contribution to a classical energy in a phantom wormhole background and the finite one-loop energy density are considered as a self-consistent source for these wormhole geometries. The latter semi-classical approach prohibits solutions with a constant equation of state parameter, which further motivates the imposition of a radial dependent parameter, ω(r), and only permits solutions with a steep positive slope proportional to the radial derivative of the equation of state parameter, evaluated at the throat. The size of the wormhole throat as a function of the relevant parameters is also explored.