Thermal properties of charge noise sources

Measurements of the temperature and bias dependence of Single Electron Transistors (SETs) in a dilution refrigerator show that charge noise increases linearly with refrigerator temperature above a voltage-dependent threshold temperature, and that its low temperature saturation is due to SET self-heating. We show further that the two-level fluctuators responsible for charge noise are in strong thermal contact with the electrons in the SET, which can be at a much higher temperature than the substrate. We suggest that the noise is caused by electrons tunneling between the SET metal and nearby potential wells

Die Rolle von Religionen in Gewaltkonflikten und Friedensprozessen. 2. Interdisziplinärer Workshop von DSF, EAD und FEST zur Einrichtung eines multidisziplinären Forschungsverbundes "Religion und Konflikt" am 12. und 13. Mai 2006 in Loccum

Minor child physical abuse has decreased in Sweden since 1979, when a law banning corporal punishment of children was passed, but more serious forms have not decreased. The aim of this study was to examine risk and background factors in cases of severe child abuse reported to the police. Files from different agencies (e.g., Social services, Adult and Child psychiatry and Pediatric clinic) for 20 children and 34 caretakers were studied. An accumulation of risk factors was found. It is concluded that when the following four factors are present, there is a risk for severe child abuse: 1) a person with a tendency to use violence in conflict situations; 2) a strong level of stress on the perpetrator and the family; 3) an insufficient social network that does not manage to protect the child; 4) a child that does not manage to protect him or herself. Thus, multiple sources of information must be used when investigating child abuse.The original publication is available at www.springerlink.com:Eva-Maria Annerbäck, Carl Göran Svedin and Per Gustafsson, Characteristic Features of Severe Child Physical Abuse-A Multi-informant Approach, 2010, JOURNAL OF FAMILY VIOLENCE, (25), 2, 165-172.http://dx.doi.org/10.1007/s10896-009-9280-1Copyright: Springer Science Business Mediahttp://www.springerlink.com

Propagating phonons coupled to an artificial atom

Quantum information can be stored in micromechanical resonators, encoded as quanta of vibration known as phonons. The vibrational motion is then restricted to the stationary eigenmodes of the resonator, which thus serves as local storage for phonons. In contrast, we couple propagating phonons to an artificial atom in the quantum regime, and reproduce findings from quantum optics with sound taking over the role of light. Our results highlight the similarities between phonons and photons, but also point to new opportunities arising from the unique features of quantum mechanical sound. The low propagation speed of phonons should enable new dynamic schemes for processing quantum information, and the short wavelength allows regimes of atomic physics to be explored which cannot be reached in photonic systems.Comment: 30 pages, 6 figures, 1 tabl

Comparing Auditory Noise Treatment with Stimulant Medication on Cognitive Task Performance in Children with Attention Deficit Hyperactivity Disorder: Results from a Pilot Study

Background: Recent research has shown that acoustic white noise (80 dB) can improve task performance in people with attention deficits and/or Attention Deficit Hyperactivity Disorder (ADHD). This is attributed to the phenomenon of stochastic resonance in which a certain amount of noise can improve performance in a brain that is not working at its optimum. We compare here the effect of noise exposure with the effect of stimulant medication on cognitive task performance in ADHD. The aim of the present study was to compare the effects of auditory noise exposure with stimulant medication for ADHD children on a cognitive test battery. A group of typically developed children (TDC) took the same tests as a comparison. Methods: Twenty children with ADHD of combined or inattentive subtypes and twenty TDC matched for age and gender performed three different tests (word recall, spanboard and n-back task) during exposure to white noise (80 dB) and in a silent condition. The ADHD children were tested with and without central stimulant medication. Results: In the spanboard- and the word recall tasks, but not in the 2-back task, white noise exposure led to significant improvements for both non-medicated and medicated ADHD children. No significant effects of medication were found on any of the three tasks. Conclusion: This pilot study shows that exposure to white noise resulted in a task improvement that was larger than the one with stimulant medication thus opening up the possibility of using auditory noise as an alternative, non-pharmacological treatment of cognitive ADHD symptoms

Polytraumatization and psychological symptoms in children and adolescents

Previous research on the impact of traumatic experiences in children and adolescents has focused almost entirely on the effect of single trauma. Research on cumulative traumas has been lacking, but Finkelhor (Child Abuse Negl 31:7–26, 2007) has recently directed the attention to the concept of polyvictimization. As an extension of this concept, this study examined the impact of polytraumatization, operationalized as the number of different potentially traumatic events. The study population comprised two cross-sectional samples of school-aged children (n = 270) and adolescents (n = 400). Information of life-time incidence of traumatic events was collected by the life incidence of traumatic events (LITE), and psychological symptoms by the parent version of the strengths and difficulties questionnaire (SDQ) for the school children and the self-report trauma symptom checklist for children (TSCC) for the adolescents. We found that exposure to at least one traumatic event was common in both the samples (63% of the children and 89.5% of the adolescents). The number of different traumatic events, polytraumatization, was highly predictive of symptoms in both samples, and with a few exceptions surpassed the impact of specific events in exploratory analyses. We furthermore replicated previous findings of the important impact of interpersonal over non-interpersonal events on symptoms in both samples, and found an indication that this effect differed by gender in different manners in the two samples. This study emphasizes the significance of both the quantity of traumatic events, polytraumatization, as well as the quality, interpersonal events