Amount of substance and the Mole

The International System of Units, the SI, is built upon seven base quantities and seven base units, as summarized in the table below. Although most of these are familiar to all scientists, the quantity “amount of substance” and its unit “mole” are less familiar and are mainly used by chemists.1 In the chemistry community, the unit “mole” is familiar, but the name of the corresponding quantity “amount of substance” is not so familiar, and the concept is still a source of difficulty for many students. This article reviews and clarifies these two concepts2 and discusses the definition of the unit “mole” and its possible revision.

Amount of substance and the proposed redefinition of the mole

There has been considerable discussion about the merits of redefining four of the base units of the SI, including the mole. In this paper, the options for implementing a new definition for the mole based on a fixed value for the Avogadro constant are discussed. They are placed in the context of the macroscopic nature of the quantity amount of substance and the opportunity to introduce a system for molar and atomic masses with unchanged values and consistent relative uncertainties.

Establishment of a Cross-European Field Site Network in the ALARM Project for Assessing Large-Scale Changes in Biodiversity

The field site network (FSN) plays a central role in conducting joint research within all Assessing Large-scale Risks for biodiversity with tested Methods (ALARM) modules and provides a mechanism for integrating research on different topics in ALARM on the same site for measuring multiple impacts on biodiversity. The network covers most European climates and biogeographic regions, from Mediterranean through central European and boreal to subarctic. The project links databases with the European-wide field site network FSN, including geographic information system (GIS)-based information to characterise the test location for ALARM researchers for joint on-site research. Maps are provided in a standardised way and merged with other site-specific information. The application of GIS for these field sites and the information management promotes the use of the FSN for research and to disseminate the results. We conclude that ALARM FSN sites together with other research sites in Europe jointly could be used as a future backbone for research proposals

ALARM: Assessing large-scale environment risks for biodiversity with tested methods

The EU-funded research project ALARM will develop and test methods and protocols for the assessment of large-scale environmental risks in order to minimise negative human impacts. Research focuses on the assessment and forecast of changes in biodiversity and in the structure, function, and dynamics of ecosystems. This includes the relationships between society, the economy and biodiversity.

Amount of substance and the mole

The unit mole is very familiar amongst both chemists and physicists, but the name of the corresponding quantity 'amount of substance' is not so familiar and the concept is still a source of difficulty for many students. This paper reviews and clarifies these concepts and also discusses the definition of the unit mole, and its possible revision.

Integrated motivational interviewing and cognitive behavioural therapy for people with psychosis and comorbid substance misuse: randomised controlled trial

Objectives To evaluate the effectiveness of integrated motivational interviewing and cognitive behaviour therapy in addition to standard care for patients with psychosis and a co-morbid substance use problem. Design Two-centre, open, rater-blind randomised controlled trial Setting UK Secondary Care Participants 327 patients with clinical diagnoses of schizophrenia, schizophreniform or schizoaffective disorder and DSM-IV diagnoses of drug and/or alcohol dependence or abuse Interventions Participants were randomly allocated to integrated motivational interviewing and cognitive behaviour therapy or standard care. Therapy has two phases. Phase one – “motivation building” – concerns engaging the patient, then exploring and resolving ambivalence for change in substance use. Phase two –“Action” – supports and facilitates change using cognitive behavioural approaches. Up to 26 therapy sessions were delivered over one year. Main outcomes The primary outcome was death from any cause or admission to hospital in the 12 months after therapy. Secondary outcomes were frequency and amount of substance use (Timeline Followback), readiness to change, perceived negative consequences of use, psychotic symptom ratings, number and duration of relapses, global assessment of functioning and deliberate self harm, at 12 and 24 months, with additional Timeline Followback assessments at 6 and 18 months. Analysis was by intention-to-treat with robust treatment effect estimates. Results 327 participants were randomised. 326 (99.7%) were assessed on the primary outcome, 246 (75.2%) on main secondary outcomes at 24 months. Regarding the primary outcome, there was no beneficial treatment effect on hospital admissions/ death during follow-up, with 20.2% (33/163) of controls and 23.3% (38/163) of the therapy group deceased or admitted (adjusted odds-ratio 1.16; P= 0.579; 95% confidence interval 0.68 to 1.99). For secondary outcomes there was no treatment effect on frequency of substance use or perceived negative consequences, but a statistically significant effect of therapy on amount used per substance-using day (adjusted odds-ratios: (a) for main substance 1.50; P=0.016; 1.08 to 2.09, (b) all substances 1.48; P=0.017; 1.07 to 2.05). There was a statistically significant treatment effect on readiness to change use at 12 months (adjusted odds-ratio 2.05; P=0.004; 1.26 to 3.31), not maintained at 24 months. There were no treatment effects on assessed clinical outcomes. Conclusions Integrated motivational interviewing and cognitive behaviour therapy for people with psychosis and substance misuse does not improve outcome in terms of hospitalisation, symptom outcomes or functioning. It does result in a reduction in amount of substance use which is maintained over the year’s follow up. Trial registration Current Controlled Trials: ISRCTN14404480

Neural networks for power systems alarm handling

A multi-layered architecture of self-organizing neural networks is being developed as part of an intelligent alarm processor to analyse a stream of power grid fault messages and provide a suggested diagnosis of the fault location. Feedback concerning the accuracy of the diagnosis is provided by an object-oriented grid simulator which acts as an external supervisor to the learning system. The utilization of artificial neural networks within this environment should result in a powerful generic alarm processor which will not require extensive training by a human expert to produce accurate results.

Adaptive alarm processor for fault diagnosis on power transmission networks

The authors describe a learning classifier system (LCS) which employs genetic algorithms (GA) for adaptive online diagnosis of power transmission network faults. The system monitors switchgear indications produced by a transmission network, reporting fault diagnoses on any patterns indicative of faulted components. The system evaluates the accuracy of diagnoses via a fault simulator developed by National Grid Co. and adapts to reflect the current network topology by use of genetic algorithms.

Auditory hallucinations and Posttraumatic Stress Disorder within schizophrenia and substance abuse

There is a high prevalence of traumatic events within individuals diagnosed with schizophrenia, and of auditory hallucinations within individuals diagnosed with posttraumatic stress disorder (PTSD). However, the relationship between the symptoms associated with these disorders remains poorly understood. We conducted a multidimensional assessment of auditory hallucinations within a sample diagnosed with schizophrenia and substance abuse, both with and without co-morbid PTSD. Results suggest a rate of co-morbid PTSD similar to those reported within other studies. Patients who suffered co-morbid PTSD reported more distressing auditory hallucinations. However, the hallucinations were not more frequent or of longer duration. The need for a multidimensional assessment is supported. Results are discussed within current theoretical accounts of traumatic psychosis.

Turning on the alarm: the neural mechanisms of the transition from innocuous to painful sensation

The experience of pain occurs when the level of a stimulus is sufficient to elicit a marked affective response, putatively to warn the organism of potential danger and motivate appropriate behavioral responses. Understanding the biological mechanisms of the transition from innocuous to painful levels of sensation is essential to understanding pain perception as well as clinical conditions characterized by abnormal relationships between stimulation and pain response. Thus, the primary objective of this study was to characterize the neural response associated with this transition and the correspondence between that response and subjective reports of pain. Towards this goal, this study examined BOLD response profiles across a range of temperatures spanning the pain threshold. 14 healthy adults underwent functional magnetic resonance imaging (fMRI) while a range of thermal stimuli (44-49oC) were applied. BOLD responses showed a sigmoidal profile along the range of temperatures in a network of brain regions including insula and mid- cingulate, as well as a number of regions associated with motor responses including ventral lateral nuclei of the thalamus, globus pallidus and premotor cortex. A sigmoid function fit to the BOLD responses in these regions explained up to 85% of the variance in individual pain ratings, and yielded an estimate of the temperature of steepest transition from non-painful to painful heat that was nearly identical to that generated by subjective ratings. These results demonstrate a precise characterization of the relationship between objective levels of stimulation, resulting neural activation, and subjective experience of pain and provide direct evidence for a neural mechanism supporting the nonlinear transition from innocuous to painful levels along the sensory continuum.