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Prenatal adversity shapes child neurodevelopment and risk for later mental health problems. The quality of the early care environment can buffer some of the negative effects of prenatal adversity on child development. Retrospective studies, in adult samples, highlight epigenetic modifications as sentinel markers of the quality of the early care environment; however, comparable data from pediatric cohorts are lacking. Participants were drawn from the Maternal Adversity Vulnerability and Neurodevelopment (MAVAN) study, a longitudinal cohort with measures of infant attachment, infant development, and child mental health. Children provided buccal epithelial samples (mean age = 6.99, SD = 1.33 years, n = 226), which were used for analyses of genome-wide DNA methylation and genetic variation. We used a series of linear models to describe the association between infant attachment and (a) measures of child outcome and (b) DNA methylation across the genome. Paired genetic data was used to determine the genetic contribution to DNA methylation at attachment-associated sites. Infant attachment style was associated with infant cognitive development (Mental Development Index) and behavior (Behavior Rating Scale) assessed with the Bayley Scales of Infant Development at 36 months. Infant attachment style moderated the effects of prenatal adversity on Behavior Rating Scale scores at 36 months. Infant attachment was also significantly associated with a principal component that accounted for 11.9% of the variation in genome-wide DNA methylation. These effects were most apparent when comparing children with a secure versus a disorganized attachment style and most pronounced in females. The availability of paired genetic data revealed that DNA methylation at approximately half of all infant attachment-associated sites was best explained by considering both infant attachment and child genetic variation. This study provides further evidence that infant attachment can buffer some of the negative effects of early adversity on measures of infant behavior. We also highlight the interplay between infant attachment and child genotype in shaping variation in DNA methylation. Such findings provide preliminary evidence for a molecular signature of infant attachment and may help inform attachment-focused early intervention programs.
Dysfunctional attitudes are a feature of depression that has been correlated with receptor binding abnormalities in limbic and cortical regions. We sought to investigate the functional neuroanatomy of dysfunctional attitudes in major depressive disorder (MDD) and the effects of treatment with cognitive–behavioural therapy (CBT).
Participants were 16 patients with unipolar depression in an acute depressive episode (mean age 40.0 years) and 16 matched healthy controls (mean age 39.9 years). Patients were medication free and received a course of treatment with CBT. All participants underwent functional magnetic resonance imaging (fMRI) scans at baseline and at week 16, prior to the initiation of therapy and following the course of CBT for patients. During each fMRI scan, participants indicated their attributions to statements from a modified Dysfunctional Attitudes Scale (mDAS-48).
MDD patients in an acute depressive episode endorsed a greater number of extreme responses to DAS statements, which normalized following CBT treatment. Extreme attributions were associated with greater activation in the left hippocampal region, inferior parietal lobe and precuneus in MDD patients as compared with healthy controls as a main effect of group. An interaction effect was found in the left parahippocampal region, which showed less attenuation in MDD patients at the follow-up scan relative to healthy controls.
Attenuation of activity in the parahippocampal region may be indicative of an improvement in dysfunctional thinking following CBT treatment in depression, while persistent engagement of regions involved in attentional processing and memory retrieval with extreme attributions reflects a trait feature of depression.
Narghile (water pipe, hookah, shisha, goza, hubble bubble, argeela) is a traditional method of tobacco use. In recent years, its use has increased worldwide, especially among young people. Narghile smoking, compared to cigarette smoking, can result in more smoke exposure and greater levels of carbon monoxide (CO). We present an acutely confused adolescent patient who had CO poisoning after narghile tobacco smoking. She presented with syncope and a carboxyhemoglobin level of 24% and was treated with hyperbaric oxygen. Five additional cases of CO poisoning after narghile smoking were identified during a literature search, with carboxyhemoglobin levels of 20 to 30%. Each patient was treated with oxygen supplementation and did well clinically. In light of the increasing popularity of narghile smoking, young patients presenting with unexplained confusion or nonspecific neurologic symptoms should be asked specifically about this exposure, followed by carboxyhemoglobin measurement.
Biotechnological techniques comprise useful tools for the conservation of endangered plant genetic resources. In the present work, polymorphism and usefulness of amplified fragment length polymorphism (AFLP) markers in assessing the genetic diversity in populations of Billbergia zebrina were investigated in nodular cultures and adult plants of the species. AFLP markers revealed moderate-to-high genetic diversity based on the estimations of Nei's gene diversity (mean He = 0.28), Shannon index of diversity (mean HS = 0.48) and the number of polymorphic fragments (mean of 56.17 polymorphic fragments over six primer pairs). In comparison to published studies of population genetics performed in other bromeliad species, the present study suggests that natural populations of B. zebrina likely maintain high levels of genetic diversity, an important feature towards conservation of plant genetic resources. The results obtained reveal that AFLP markers comprise a powerful tool in order to assess the levels of genetic diversity in natural populations of this endangered species. Integrating AFLP markers with in vitro propagation techniques is understood as an adequate strategy for conservation programmes of this species.
This chapter discusses the role of structural imaging using CT and MRI, conventional angiography and CT angiography, and physiological imaging using CT perfusion, 131Xenon CT, MRI and magnetic resonance spectroscopy (MRS), single-photon emission computed tomography (SPECT) and positron emission tomography (PET) in the assessment, management and prediction of outcome neurological injury. Acute CT is useful in identifying those individuals in whom deterioration is as a result of a mass lesion and can demonstrate extradural, subdural or intracranial haemorrhage and midline shift, or subarachnoid haemorrhage and ventricular abnormality. Contrast-enhanced CT imaging is also used to produce CT angiography and perfusion imaging. MRI data are produced using powerful static magnetic fields and intermittent oscillating radiofrequency electromagnetic fields that elicit signals from the nuclei of certain atoms. Single-photon emission CT uses conventional gamma-emitting nuclear medicine isotopes with multiple detectors to generate tomographic images.
An instrument equipped with total electron yield detectors was designed and constructed for in situ X-ray absorption spectroscopy (XAS) investigations in the soft X-ray range (100 eV ≤ hν ≤ 1000 eV) at elevated pressures (mbar range) and sample temperatures (T ≤ 1000 K) . This allows, for the first time, XAS studies in a surface-sensitive mode of the light elements (Z = 3-15). Furthermore, the gas phase XAS and the surface-related XAS of the solid state phase can be collected simultaneously in order to correlate the gas/solid reaction rate with the surface electronic structure under working conditions in a flow-through mode.
The novel experimental tool represents a contribution to the experimental overcoming of the “pressure gap” in material science. In this work examples are presented belonging to the field of heterogeneous catalysis [2-4] and to the reactivity of diamond surfaces . Additionally, prospects for in situ studies in material science will be given.
The thermal conductivity of porous silicon is measured as prepared and after oxidation. The measurement method uses thermal wave propagation in the porous film. We investigate three types of porous silicon: Nanoporous p-type silicon, nanoporous n-type silicon and mesoporous p+-type silicon. The nanoporous material shows a thermal conductivity in the region of 1.2 W/mK to 1.8 W/mK as prepared and after oxidation. This value is close to silicon oxide. The mesoporous material shows a high thermal conductivity of 80 W/mK as prepared which drops to 2.7 W/mK after oxidation.
We investigate the crystalline and electrical quality of thin layers epitaxially grown on polycrystalline substrates from metallic solution by the method of electron beam induced current, transmission electron microscopy and etching experiments. We observe a reduced recombination strength of dislocations and small angle grain boundaries, i.e. an improved electrical quality of the epitaxial layer compared to the substrate. The improved quality can be attributed (i) to an altered structure of grain boundaries and dislocations and (ii) to a reduced defect density in the epitaxial layer.
We have oxidized porous (n-)silicon samples in solutions of H202 and have found that PL can be stabilized at a high level. The PL intensity of as prepared samples (PL quantum efficiencies in the range of 5 %) degrades to about 1/3 of the initial value in some ten minutes (the exact value depends on the experimental conditions). After having treated the samples for about 30 - 45 minutes in hydrogen peroxide it can be observed that bright PL remains stable for hours. These results confirm similar experiments performed with porous silicon made from p-substrates1. While red electroluminescing samples have shown long time stability for about 100 hours2, samples with blue-green electroluminescence have a lifetime of about 20 - 40 minutes. Oxidizing electroluminescent samples as described above results in a stabilization of electroluminescence for more than 7 hours.
In addition to photoluminescence and electroluminescence porous silicon is capable of emitting an ultraviolet line spectrum. This emission can be observed already at ambient conditions. We could identify this line emission as the spectrum of nitrogen. At a pressure of about 10 mbar the UV-intensity exceeds the intensity at ambient pressure about two orders of magnitude. Angular dependent spectroscopy and the light emission behaviour at lowered pressure led us to the conclusion that the silicon structures in the samples behave as sub-micrometer-sized electron guns. Dye covered glass substrates can be excited by the intense UV-light at about 5-20 mbar so that the red and green light of the dyes can easily be recognized under usual laboratory illumination. A luminous density of 240 Cd/m2 and 40 Cd/m2 could be achieved for the green luminescing ZnS:Cu,Al and the red luminescing YVO4:Eu respectively. Continuous UV-light emission could be observed for more than 1.5 hours at 2 mbar.