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The split-operator technique for wave packet propagation in quantum systems is expanded here to the case of propagatingwave functions describing Schrödinger particles, namely, charge carriers in semiconductor nanostructures within the effective mass approximation, in the presence of Zeeman effect, as well as of Rashba and Dresselhaus spin-orbit interactions. We also demonstrate that simple modifications to the expanded technique allow us to calculate the time evolution of wave packets describing Dirac particles, which are relevant for the study of transport properties in graphene.
Pattern analysis has emerged as a tool to depict the role of multiple nutrients/foods in relation to health outcomes. The present study aimed at extracting nutrient patterns with respect to breast cancer (BC) aetiology.
Nutrient patterns were derived with treelet transform (TT) and related to BC risk. TT was applied to twenty-three log-transformed nutrient densities from dietary questionnaires. Hazard ratios (HR) and 95 % confidence intervals computed using Cox proportional hazards models quantified the association between quintiles of nutrient pattern scores and risk of overall BC, and by hormonal receptor and menopausal status. Principal component analysis was applied for comparison.
The European Prospective Investigation into Cancer and Nutrition (EPIC).
Women (n 334 850) from the EPIC study.
The first TT component (TC1) highlighted a pattern rich in nutrients found in animal foods loading on cholesterol, protein, retinol, vitamins B12 and D, while the second TT component (TC2) reflected a diet rich in β-carotene, riboflavin, thiamin, vitamins C and B6, fibre, Fe, Ca, K, Mg, P and folate. While TC1 was not associated with BC risk, TC2 was inversely associated with BC risk overall (HRQ5 v. Q1=0·89, 95 % CI 0·83, 0·95, Ptrend<0·01) and showed a significantly lower risk in oestrogen receptor-positive (HRQ5 v. Q1=0·89, 95 % CI 0·81, 0·98, Ptrend=0·02) and progesterone receptor-positive tumours (HRQ5 v. Q1=0·87, 95 % CI 0·77, 0·98, Ptrend<0·01).
TT produces readily interpretable sparse components explaining similar amounts of variation as principal component analysis. Our results suggest that participants with a nutrient pattern high in micronutrients found in vegetables, fruits and cereals had a lower risk of BC.
Although both cognitive therapy (CT) and interpersonal psychotherapy (IPT) have been shown to be effective treatments for major depressive disorder (MDD), it is not clear yet whether one therapy outperforms the other with regard to severity and course of the disorder. This study examined the clinical effectiveness of CT v. IPT in a large sample of depressed patients seeking treatment in a Dutch outpatient mental health clinic. We tested whether one of the treatments was superior to the other at post-treatment and at 5 months follow-up. Furthermore, we tested whether active treatment was superior to no treatment. We also assessed whether initial depression severity moderated the effect of time and condition and tested for therapist differences.
Depressed adults (n = 182) were randomized to either CT (n = 76), IPT (n = 75) or a 2-month waiting list control (WLC) condition (n = 31). Main outcome was depression severity, measured with the Beck Depression Inventory – II (BDI-II), assessed at baseline, 2, 3, and 7 months (treatment phase) and monthly up to 5 months follow-up (8–12 months).
No differential effects between CT and IPT were found. Both treatments exceeded response in the WLC condition, and led to considerable improvement in depression severity that was sustained up to 1 year. Baseline depression severity did not moderate the effect of time and condition.
Within our power and time ranges, CT and IPT appeared not to differ in the treatment of depression in the acute phase and beyond.
It is unclear whether there is a direct link between economic crises and changes in suicide rates.
The Lopez-Ibor Foundation launched an initiative to study the possible impact of the economic crisis on European suicide rates.
Data was gathered and analysed from 29 European countries and included the number of deaths by suicide in men and women, the unemployment rate, the gross domestic product (GDP) per capita, the annual economic growth rate and inflation.
There was a strong correlation between suicide rates and all economic indices except GPD per capita in men but only a correlation with unemployment in women. However, the increase in suicide rates occurred several months before the economic crisis emerged.
Overall, this study confirms a general relationship between the economic environment and suicide rates; however, it does not support there being a clear causal relationship between the current economic crisis and an increase in the suicide rate.
The ORGANIC experiment on EXPOSE-R spent 682 days outside the International Space Station, providing continuous exposure to the cosmic-, solar- and trapped-particle radiation background for fourteen samples: 11 polycyclic aromatic hydrocarbons (PAHs) and three fullerenes. The thin films of the ORGANIC experiment received, during space exposure, an irradiation dose of the order of 14 000 MJ m−2 over 2900 h of unshadowed solar illumination. Extensive analyses were performed on the returned samples and the results compared to ground control measurements. Analytical studies of the returned samples included spectral measurements from the vacuum ultraviolet to the infrared range and time-of-flight secondary ion mass spectrometry. Limited spectral changes were observed in most cases pointing to the stability of PAHs and fullerenes under space exposure conditions. Furthermore, the results of these experiments confirm the known trend in the stability of PAH species according to molecular structure: compact PAHs are more stable than non-compact PAHs, which are themselves more stable than PAHs containing heteroatoms, the last category being the most prone to degradation in the space environment. We estimate a depletion rate of the order of 85 ± 5% over the 17 equivalent weeks of continuous unshadowed solar exposure in the most extreme case tetracene (smallest, non-compact PAH sample). The insignificant spectral changes (below 10%) measured for solid films of large or compact PAHs and fullerenes indicate a high stability under the range of space exposure conditions investigated on EXPOSE-R.
Subthreshold psychotic and bipolar experiences are common in major depressive disorder (MDD). However, it is unknown if effectiveness of psychotherapy is altered in depressed patients who display such features compared with those without. The current paper aimed to investigate the impact of the co-presence of subclinical psychotic experiences and subclinical bipolar symptoms on the effectiveness of psychological treatment, alone or in combination with pharmacotherapy.
In a naturalistic study, patients with MDD (n = 116) received psychological treatment (cognitive behavioural therapy or interpersonal psychotherapy) alone or in combination with pharmacotherapy. Depression and functioning were assessed six times over 2 years. Lifetime psychotic experiences and bipolar symptoms were assessed at the second time point.
Subclinical psychotic experiences predicted more depression over time (β = 0.20, p < 0.002), non-remission [odds ratio (OR) 7.51, p < 0.016] and relapse (OR 3.85, p < 0.034). Subthreshold bipolar symptoms predicted relapse (OR 1.16, p < 0.037).
In general, subclinical psychotic experiences have a negative impact on the course and outcome of psychotherapy in MDD. Effects of subclinical bipolar experiences were less prominent.
Polycyclic Aromatic Hydrocarbons (PAHs) are widespread across the Universe and influence
many stages of the Galactic lifecycle. The presence of PAHs has been well established and
the rich mid-IR PAH spectrum is now commonly used as a probe into (inter)stellar
environments. The NASA Ames PAH IR Spectroscopic Database has been key to test and refine
the “PAH hypothesis”. This database is a large coherent set (>600 spectra) of
laboratory measured and DFT computed infrared spectra of PAHs from
C10H8 to C130H28 and has been made available
on the web at (http://www.astrochem.org/pahdb). With a new spectral window opening up; the
far-IR, the study of PAH far-IR spectra and the quest for identifying a
unique member of the interstellar PAH family has begun. To guide this research, the far-IR
(>20 μm) spectra of different sets of PAHs are investigated
using the NASA Ames PAH IR Spectroscopic Database. These sets explore the influence of
size, shape, charge and composition on the far-IR PAH spectrum. The far-IR is also the
domain of the so-called “drumhead” modes and other molecular vibrations involving low
order bending vibrations of the carbon skeleton as a whole. As with drums, these are
molecule and shape specific and promise to be a key diagnostic for specific PAHs. Here,
the sensitivity of these “drumhead” modes to size and shape is assessed by comparing the
frequencies of the lowest drumhead modes of a family of circular shaped (the coronene
“family”) and rhombus shaped (the pyrene “family”) PAH molecules. From this study, some
consequences for an observing strategy are drawn.
The damage induced in the low-k material upon exposure to dry etch and ash
plasmas is a point of major concern in terms of preservation of the
dielectric properties. There is urgent need to assess, classify and quantify
the extent of such damage to allow the optimization of patterning processes
and conditions. Meander-fork structures with spacings between 250nm and 70nm
are used in this study as vehicle to compare trends in electrical
performance for different dielectrics: SiO2 and two SiOC:H low-k
materials with pristine k values of 3.0 and 2.6. Here we demonstrate that
the ‘electrical equivalent damage’ model is a valid and precise methodology
for assessing dielectric damage upon processing from interline capacitance
evaluation. This analysis allows to distinguish between bulk and sidewall
modification and to quantify the extent of damage. Moreover, it provides an
interpretation for the degradation of leakage current and breakdown field of
the interline dielectric, revealing different trends whether due to only
sidewall or total damage.
The field of “non-silicon MEMS” is today rapidly expanding. The reasons are numerous: silicon has a limited functionality in many MEMS applications; the toolbox for micromaching of non-silicon materials is steadily growing in size and versatility; the price level of a variety of other advanced materials for MEMS has become more competitive etc. This development is here illustrated by a number of examples from a wide variety of materials classes, methods for synthesis and microprocessing, and fields of application. Among these examples are high-aspect ratio processing of different materials by ion track technology (MITE) and deep ion projection lithography (DIPL); laser microprocessing and free-space 3D laser writing; high-precision 3D diamond replicas from microstructured silicon masters; and microreplication in polymeric materials for microoptics and microsystems technology.
Many applications of MEM sensors require hermetic or high vacuum packaging of sensor clusters. For example, multiple gyroscopes or accelerometers are fabricated on a single chip to improve alignment and stability of input axes or increase the dynamic range of instruments. Chemical sensors are fabricated as large arrays to both improve selectivity and increase the number of species that can be detected. Still larger arrays of sensors must be packaged for hydrophone and bolometer imaging devices. All of these applications place a demanding combination of requirements on the sensor package. The electrical outputs of the sensor array must be well isolated from each other as well as power and excitation signals, while parasitic capacitance is minimized. The package must also be capable of being evacuated and sealed to achieve a pressure of 5 millitorr with a leakage rate below 10−11 [Std cc sec−l]. Finally, the package must be compact and low cost to realize these same attributes of the MEM sensor. This paper describes a packaging approach that is based on low temperature cofired ceramic materials. This technology meets the packaging requirements of sensor arrays and is well suited to the research environment in which the sensor design is continually evolving.
Life on Earth is one of the outcomes of the formation and evolution of our solar system and has adapted to every explored environment on planet Earth. Recent discoveries have shown that life can exist in extreme environments, such as hydrothermal vents, in deserts and in ice lakes in Antarctica. These findings challenge the definition of the ‘planetary habitable zone’. The objective of future international planetary exploration programmes is to implement a long-term plan for the robotic and human exploration of solar system bodies. Mars has been a central object of interest in the context of extraterrestrial life. The search for extinct or extant life on Mars is one of the main goals of space missions to the Red Planet during the next decade. In this paper we describe the investigation of the physical and chemical properties of Mars soil analogues collected in arid deserts. We measure the pH, redox potential and ion concentrations, as well as carbon and amino acid abundances of soils collected from the Atacama desert (Chile and Peru) and the Salten Skov sediment from Denmark. The samples show large differences in their measured properties, even when taken only several meters apart. A desert sample and the Salten Skov sediment were exposed to a simulated Mars environment to test the stability of amino acids in the soils. The presented laboratory and field studies provide limits to exobiological models, evidence on the effects of subsurface mineral matrices, support current and planned space missions and address planetary protection issues.
Although clinical findings suggest that in the aftermath of depression a process of ‘scarring’ may ensue, research examining the issue of ‘scars’ (including biological, psychological and cognitive changes) has remained largely inconclusive. This paper proposes a new approach to the concept of ‘scars’ that is (i) based on a dimensional view of depression, (ii) uses methods that take into account the dynamic interplay between the person and his context, (iii) differentiates between scars following depression and scars following the factor that actually caused the depression such as stress and (iv) introduces a dynamic view of the concept of ‘scars’ in that it hypothesizes that scars can wax and wane. This approach may stimulate the discovery of new entries in the puzzle underlying the ontogenesis of vulnerability and resilience. Furthermore, it may provide insights that help to develop new therapies for depression.
The development of steel refining operations at ArcelorMittal
FCWE for the production of ULS steels is reported. Several plants with different equipments produce grades with S <30 ppm, thus permitting to identify the most efficient process, from hot metal desulfurization to secondary metallurgy. For sites producing steels with S <30 ppm, four secondary metallurgy routes coexist in ArcelorMittal FCWE. The Vacuum Tank Degasser makes it possible to reach very low S and N contents simultaneously. To face the increase of the share of Ultra Low Sulfur products, it is necessary to further enhance the kinetics of desulfurization by steel - slag stirring at the atmospheric pressure.
Previous work suggests that daily life stress-sensitivity may be an intermediary phenotype associated with both genetic risk for depression and developmental stress exposures. In the current analysis we hypothesized that genetic risk for depression and three environmental exposures over the course of development [prenatal stress, childhood adversity and adult negative life events (NLEs)] combine synergistically to produce the phenotype of stress-sensitivity.
Twin pairs (n=279) participated in a momentary assessment study using the Experience Sampling Method (ESM), collecting appraisals of stress and negative affect (NA) in the flow of daily life. Prospective data on birthweight and gestational age, questionnaire data on childhood adversity and recent NLEs, and interview data on depression were used in the analyses. Daily life stress-sensitivity was modelled as the effect of ESM daily life stress appraisals on ESM NA.
All three developmental stress exposures were moderated by genetic vulnerability, modelled as dizygotic (DZ) or monozygotic (MZ) co-twin depression status, in their effect on daily life stress-sensitivity. Effects were much stronger in participants with MZ co-twin depression and a little stronger in participants with DZ co-twin depression status, compared to those without co-twin depression. NLE main effects and NLE genetic moderation were reducible to birthweight and childhood adversity.
The findings are consistent with the hypothesis that adult daily life stress-sensitivity is the result of sensitization processes initiated by developmental stress exposures. Genes associated with depression may act by accelerating the process of stress-induced sensitization.
Alongitudinal study of growth and physical fitness of twins and their parents was designed in 1985. The major aims of this Leuven Longitudinal Twin Study were to quantify the genetic and environmental determination of (1) somatic characteristics, biological maturation and physical performance characteristics during the growth process, (2) the growth and developmental patterns, and (3) the covariation in somatic and performance characteristics.
We review mid-infrared N-band spectra (8–13 μm) for a sample of 28 targets, obtained with the TIMMI2 camera at La Silla Observatory. The sample contains 5 FU Orionis stars, 6 Herbig Ae/Be objects, 7 T Tauri stars and 10 Vega-type main sequence objects. All targets show infrared excess, but for several the proof of circumstellar matter was lacking up to our observations. We model the N-band emission features with a mixture of silicates consisting of different grain sizes and composition, and determine the status of dust processing in these disks. While for some targets the emission spectrum resembles those of known pre-main sequence stars of evolved dust, other objects show strong isolated PAH bands but no silicate emission. For the first time we find evidence of PAH processing occurring in a T Tauri star. The Vega-type object HD 113766 exhibits highly-processed secondary generation dust, likely released by the collision of planetesimal-sized bodies. The findings of our dust analysis are set in context to previous dust studies of young stellar objects.
The reliability of visual interpretation of electroencephalograms (EEG) is of great importance in assessing the value of this diagnostic tool. We prospectively obtained 50 standard EEGs and 61 EEGs after partial sleep deprivation from 93 children (56 males, 37 females) with a mean age of 6 years 10 months (SE 5mo; range 4mo–15y 7mo) with one or more newly diagnosed, unprovoked seizures. Two clinical neurophysiologists independently classified the background pattern and the presence of epileptiform discharges or focal non-epileptiform abnormalities of each EEG. The agreement was substantial for the interpretation of the EEG as normal or abnormal (kappa 0.66), almost perfect for the presence of epileptiform discharges (kappa 0.83), substantial for the occurrence of an abnormal background pattern (kappa 0.73), and moderate for the presence of focal non-epileptiform discharges (kappa 0.54). In conclusion, the reliability of the visual interpretation of EEGs in children is almost perfect as regards the presence of epileptiform abnormalities, and moderate to substantial for the presence of other abnormalities.
Clogging of Continuous Casting nozzle has a detrimental effect
on productivity and product quality; it also increases production
costs and goes against security. Many factors contribute to the
clogging phenomenon, including the detailed process parameters
of continuous casting and secondary metallurgy. Clogging can be effectively limited by Argon injection that is
usually performed through the stopper rod. The nature and
quality of the refractory equipment is another factor that must be
considered carefully. The clogging mechanism has been clearly
ascribed to the level and nature of non metallic inclusions, thus to
the secondary metallurgy process. Effective counter measures that have been successfully
implemented in Arcelor to achieve long sequence casting are