The biopsychosocial context of ADHD.

attention-deficit/hyperactivity disorder (adhd) represents adaptation to defective neurotransmission – an adaptation seldom with benefit. the resulting behavioural style not only increases vulnerability to adverse experiences, but also creates a context in which encountering adversity is more likely. furthermore, the fact that adhd is a highly heritable condition increases the probability of a child with a compromised neurobiological disposition being raised by caregivers with suboptimal resources

On wavenumber spectra for sound within subsonic jets

This paper clarifies the nature of sound spectra within subsonic jets. Three problems, of increasing complexity, are presented. Firstly, a point source is placed in a two-dimensional plug flow and the sound field is obtained analytically. Secondly, a point source is embedded in a diverging axisymmetric jet and the sound field is obtained by solving the linearised Euler equations. Finally, an analysis of the acoustic waves propagating through a turbulent jet obtained by direct numerical simulation is presented. In each problem, the pressure or density field are analysed in the frequency-wavenumber domain. It is found that acoustic waves can be classified into three main frequency-dependent groups. A physical justification is provided for this classification. The main conclusion is that, at low Strouhal numbers, acoustic waves satisfy the d'Alembertian dispersion relation.Comment: 20 pages, 9 figure

A Cultural Criminology of ‘New’ Jihad: Insights from Propaganda Magazines

The backgrounds and modus operandi of more recent jihadi terrorists tend to share factors and characteristics more typically associated with non-political violence such as mass- killings and gang violence. Their attacks, moreover, seem to have been precipitated not by the direct instructions of a formal hierarchy but by the encouragement of propaganda produced and disseminated by networked, media-savvy terrorist groups. It is necessary to explain how these ‘recruitment’ efforts work. Cultural criminology with its understanding of the relationship between mediated meaning and individual experience, can provide such an analysis. The paper presents a qualitative document analysis of 32 propaganda magazines produced by the Islamic State and Al-Qaeda. It demonstrates that they contain significantly more than religious rhetoric and military strategy. Rather, they are part of a process that crystalizes a jihadi subculture that appeals to disaffected and/or marginalized, excitement- seeking youths. The magazines cultivate violence by constructing a militarized style that celebrates outlaw status, where violence is eroticized and aestheticized. They idealize the notion of a jihadi terrorist that is tough and willing to commit brutal violence. The lifestyle portrayed offers the possibility of heroism, excitement, belonging and imminent fame, themes often espoused by conventional, Western consumer culture. The magazines occasionally draw on street jargon, urban music, fashion, films and video games. The subcultural model of jihadi propaganda we explicate provides a novel way of understanding terrorist recruiting tactics and motivations that are not necessarily in opposition to contemporary conventional criminal and ‘mainstream’ cultures, but in resonance with them

The changes in chemical composition during development of the bovine nuchal ligament

Whole bovine nuchal ligaments, or portions thereof (in the case of commercially valuable animals), were obtained from 45 animals (28 fetal and 17 postnatal) ranging in age from 110 days of gestation to 10 yr. Insoluble elastin was quantitatively prepared from the fresh ligaments by extraction with hot alkali and by a combination of multiple extractions with alkaline buffer and then repeated autoclaving. When adult samples were examined, the yields of insoluble residue by these two methods were very similar, but with young fetal samples the second method gave significantly higher values, because of incomplete purification of the elastin residue. The changes in the concentration of collagen, alkali-insoluble elastin, and DNA have been examined. DNA concentration, and, thus, cell population density, fell progressively during the fetal period of development, to reach a steady value soon after birth. Collagen appeared in appreciable quantities before elastin, but its concentration was rapidly halved at about the time of birth. Insoluble elastin concentration was low until the end of the 7th fetal month, at which time it began to rise rapidly. The rate of increase in elastin concentration remained high throughout the next 10–12 wk, by which time the adult value had been reached. Quantitative studies, on the basis of the whole ligament, showed that the total cell content rises to a maximum at birth, but falls soon after to a level about half that at birth. Total collagen production and elastin deposition continue at a steady, maximal rate over the interval from 235 days of gestation to the end of the 1st postnatal month. It is concluded that the immediate postnatal period would be the most favorable phase in which to attempt the isolation of the soluble precursor elastin

Shoreline recession: past, present, and future, Lake Sakakawea, North Dakota

Shoreline erosion is a major problem at Lake Sakakawea, North Dakota. Instrumentation along the eastern shore was initiated in 1983 to measure shoreline recession and determine the processes responsible, with the ultimate goal being the development of a relatively simple equation to predict the rate of recession which is better than the model currently used by the U.S. Army Corps of Engineers. For the twenty stations, the present rate of recession ranges from 0.2 to 4.3 m/y. Approximately 78 percent of the yearly recession occurs during the warm months (May-October) due to wave erosion. Erosion over the cold months occurs as a result of thaw failure. The most important variables associated with shoreline recession include: bank height, effective fetch, offshore slope angle, beach width, mean grain size, percentage of coarse beach clasts, angle between the shoreline and dominant wind, and bank orientation with respect to the sun. These variables, along with the average monthly rate of recession, were submitted to regression analysis. Because the rates of recession are seasonally dependent a separate equation was developed for warm and cold season recession. The warm season recession equation, in cm/mo, is: 1a) Rs = 141.53 – [17.2√A + 8.44√B + 25.08√C + 10.4√D] where A= angle between the dominant wind and the shoreline, B= bank height, C= offshore slope angle, and D= beach width. This equation exceeds the 95 percent confidence level with an r² of 59.3 percent. This equation is preferred to equation 1b: 1b) Rs=154.9-[18.8√A + 25.12√B + 10.06√C + 6.91√D + 5.03√E + 1.1√F] which includes effective fetch (E) and percentage of coarse clasts (F). This equation exceeds the 75 percent confidence level only. Both equations, however, produce similar results. The cold season rate is: 2) Rw = Rs [(2.05 (bank height) + 0.043 (bank orientation) - 2)/100, where bank orientation is with respect to the sun. This analysis exceeds the 99 percent confidence level and produces an r² of 46 percent. The yearly rate of recession (cm/yr) is the sum of the warm and cold season recession multiplied by their active months. 3) Rt= 6(Rs) + 6(Rw) For future bank recession it was assumed that the rate of recession will decrease with time. Thus, an equation was developed that incorporated the present yearly recession rate and the formula for a parabola. Recession calculated from the equations predicts cumulative recession up to 495m over the 500-year life of the reservoir. Although these equations are a significant improvement over the template method in use by the U.S. Army Corps of Engineers, further testing is necessary to determine their applicability to other inland bodies of water

Effects of high school engineering course availability and participation on engineering school recruitment, discipline selection, persistence attitudes, and self-efficacy

The need for engineers in the workforce continues to grow. Filling this need requires recruiting future engineers to colleges and universities and retaining them through to degree completion. However, this is easier said than done. Universities are tasked with attempting to keep up with the demand for new engineers and companies are searching for new engineers to recruit. One avenue that has been established in the attempt to reach students for engineering is offering engineering or STEM classes in K-12 schools. This dissertation looked at engineering classes offered at the high school level. These courses were analyzed for relationships with the steps in producing new engineers – recruitment and persistence. Historical data was used to study the effect of high school engineering courses on engineering recruitment. The availability of engineering courses in Mississippi high schools was analyzed against the percentage of graduates from those high schools entering the largest engineering school in the state. The influence of high school engineering participation on engineering discipline selection was also studied using a nationwide sample of current undergraduate engineering students. This same survey sample was used to study two factors related to engineering persistence – persistence attitudes and engineering self-efficacy. Analysis found significant relationships between high school engineering courses and engineering recruitment. Engineering availability correlated to a higher percentage of students entering engineering. Participation in these engineering courses was also significantly associated with choice in certain engineering disciplines. However, once students have chosen their path in engineering and entered their undergraduate journey, the high school courses do not impact persistence factors. No relationships were found between high school engineering participation and persistence attitudes or overall engineering self-efficacy

Finitely generated ideal languages and synchronizing automata

We study representations of ideal languages by means of strongly connected synchronizing automata. For every finitely generated ideal language L we construct such an automaton with at most 2^n states, where n is the maximal length of words in L. Our constructions are based on the De Bruijn graph.Comment: Submitted to WORDS 201