Sound Recording Devices Used as Evidence

Recordings have been offered in evidence in a wide variety of cases, including an attempted bribery of a draft board official, treasonous radio broadcasts, conspiracy to obstruct justice in a federal narcotics case, illegal short-wave radio transmissions aiding the illegal entry of Mexican nationals, disturbance to a motel by barking dogs in an adjoining pet hospital, and noises made by trains, planes, and a cement factory. Use by attorneys is virtually limitless, including the recording of discussions with clients, of library research, of depositions, and of wills

Sound Recording Devices Used as Evidence

Recordings have been offered in evidence in a wide variety of cases, including an attempted bribery of a draft board official, treasonous radio broadcasts, conspiracy to obstruct justice in a federal narcotics case, illegal short-wave radio transmissions aiding the illegal entry of Mexican nationals, disturbance to a motel by barking dogs in an adjoining pet hospital, and noises made by trains, planes, and a cement factory. Use by attorneys is virtually limitless, including the recording of discussions with clients, of library research, of depositions, and of wills

Natural age dispersion arising from the analysis of broken crystals, part I. Theoretical basis and implications for the apatite (U-Th)/He thermochronometer

Over the last decade major progress has been made in developing both the theoretical and practical aspects of apatite (U-Th)/He thermochronometry and it is now standard practice, and generally seen as best practice, to analyse single grain aliquots. These individual prismatic crystals are often broken and are fragments of larger crystals that have broken during mineral separation along the weak basal cleavage in apatite. This is clearly indicated by the common occurrence of only 1 or no clear crystal terminations present on separated apatite grains, and evidence of freshly broken ends when grains are viewed using a scanning electron microscope. This matters because if the 4He distribution within the whole grain is not homogeneous, because of partial loss due to thermal diffusion for example, then the fragments will all yield ages different from each other and from the whole grain age. Here we use a numerical model with a finite cylinder geometry to approximate 4He ingrowth and thermal diffusion within hexagonal prismatic apatite crystals. This is used to quantify the amount and patterns of inherent, natural age dispersion that arises from analysing broken crystals. A series of systematic numerical experiments were conducted to explore and quantify the pattern and behaviour of this source of dispersion using a set of 5 simple thermal histories that represent a range of plausible geological scenarios. In addition some more complex numerical experiments were run to investigate the pattern and behaviour of grain dispersion seen in several real data sets. The results indicate that natural dispersion of a set of single fragment ages (defined as the range divided by the mean) arising from fragmentation alone varies from c. 7% even for rapid (c. 10 ∘C/Ma), monotonic cooling to over 50% for protracted, complex histories that cause significant diffusional loss of 4He. The magnitude of dispersion arising from fragmentation scales with the grain cylindrical radius, and is of a similar magnitude to dispersion expected from differences in absolute grain size alone (spherical equivalent radii of 40 to 150 μm). This source of dispersion is significant compared with typical analytical uncertainties on individual grain analyses (c. 6%) and standard deviations on multiple grain analyses from a single sample (c. 10-20%). Where there is a significant difference in the U and Th concentration of individual grains (eU), the effect of radiation damage accumulation on 4He diffusivity (assessed using the RDAAM model of Flowers et al. (2009)) is the primary cause of dispersion for samples that have experienced a protracted thermal history, and can cause dispersion in excess of 100% for realistic ranges of eU conentration (i.e. 5-100 ppm). Expected natural dispersion arising from the combined effects of reasonable variations in grain size (radii 40-125 μm), eU concentration (5-150 ppm) and fragmentation would typically exceed 100% for complex thermal histories. In addition to adding a significant component of natural dispersion to analyses, the effect of fragmentation also acts to decouple and corrupt expected correlations between grain ages and absolute grain size and to a lesser extent between grain age and effective uranium concentration (eU). Considering fragmentation explicitly as a source of dispersion and analysing how the different sources of natural dispersion all interact with each other provides a quantitative framework for understanding patterns of dispersion that otherwise appear chaotic. An important outcome of these numerical experiments is that they demonstrate that the pattern of age dispersion arising from fragmentation mimics the pattern of 4He distribution within the whole grains, thus providing an important source of information about the thermal history of the sample. We suggest that if the primary focus of a study is to extract the thermal history information from (U-Th)/He analyses then sampling and analytical strategies should aim to maximise the natural dispersion of grain ages, not minimise it, and should aim to analyse circa 20-30 grains from each sample. The key observations and conclusions drawn here are directly applicable to other thermochronometers, such as the apatite, rutile and titanite U-Pb systems, where the diffusion domain is approximated by the physical grain size

Foray search: An effective systematic dispersal strategy in fragmented landscapes

In the absence of evidence to the contrary, population models generally assume that the dispersal trajectories of animals are random, but systematic dispersal could be more efficient at detecting new habitat and may therefore constitute a more realistic assumption. Here, we investigate, by means of simulations, the properties of a potentially widespread systematic dispersal strategy termed "foray search." Foray search was more efficient in detecting suitable habitat than was random dispersal in most landscapes and was less subject to energetic constraints. However, it also resulted in considerably shorter net dispersed distances and higher mortality per net dispersed distance than did random dispersal, and it would therefore be likely to lead to lower dispersal rates toward the margins of population networks. Consequently, the use of foray search by dispersers could crucially affect the extinction-colonization balance of metapopulations and the evolution of dispersal rates. We conclude that population models need to take the dispersal trajectories of individuals into account in order to make reliable predictions

PATENTS, R&D AND LAG EFFECTS: EVIDENCE FROM FLEXIBLE METHODS FOR COUNT PANEL DATA ON MANUFACTURING FIRMS

Hausman, Hall and Griliches (1984) and Hall, Griliches and Hausman (1986) investigated whether there was a lag in the patent-R&D relationship for the U.S. manufacturing sector using 1970¿s data. They found that there was little evidence of anything but contemporaneous movement of patents and R&D. We reexamine this important issue employing new longitudinal patent data at the firm level for the U.S. manufacturing sector from 1982 to 1992. To address unique features of the data, we estimate various distributed lag and dynamic multiplicative panel count data models. The paper also develops a new class of count panel data models based on series expansion of the distribution of individual effects. The empirical analyses show that, although results are somewhat sensitive to different estimation methods, the contemporaneous relationship between patenting and R&D expenditures continues to be rather strong, accounting for over 60% of the total R&D elasticity. Regarding the lag structure of the patents-R&D relationship, we do find a significant lag in all empirical specifications. Moreover, the estimated lag effects are higher than have previously been found, suggesting that the contribution of R&D history to current patenting has increased from the 1970¿s to the 1980¿s.Innovative activity, Patents and R&D, Individual effects, count panel data methods.

Non-random dispersal in the butterfly Maniola jurtina: implications for metapopulation models

The dispersal patterns of animals are important in metapopulation ecology because they affect the dynamics and survival of populations. Theoretical models assume random dispersal but little is known in practice about the dispersal behaviour of individual animals or the strategy by which dispersers locate distant habitat patches. In the present study, we released individual meadow brown butterflies (Maniola jurtina) in a non-habitat and investigated their ability to return to a suitable habitat. The results provided three reasons for supposing that meadow brown butterflies do not seek habitat by means of random flight. First, when released within the range of their normal dispersal distances, the butterflies orientated towards suitable habitat at a higher rate than expected at random. Second, when released at larger distances from their habitat, they used a non-random, systematic, search strategy in which they flew in loops around the release point and returned periodically to it. Third, butterflies returned to a familiar habitat patch rather than a non-familiar one when given a choice. If dispersers actively orientate towards or search systematically for distant habitat, this may be problematic for existing metapopulation models, including models of the evolution of dispersal rates in metapopulations

Pulled apart, pushed together: diversity and unity within the Congress of South African Trade Unions

This is a study of horizontal and vertical solidarity within a national labour movement, based on a nationwide survey of members of affiliated unions of the Congress of South African Trade Unions. On the one hand, the survey reveals relatively high levels of vertical and horizontal solidarity, despite the persistence of some cleavages on gender and racial lines. On the other hand, the maintenance and deepening of existing horizontal and vertical linkages in a rapidly changing socio-economic context, represents one of many challenges facing organized labour in an industrializing economy. COSATU’s strength is contingent not only on an effective organizational capacity, and a supportive network linking key actors and interest groupings, but also on the ability to meet the concerns of existing constituencies and those assigned to highly marginalized categories of labour

MOLECULAR AND CELLULAR MECHANISMS LEADING TO SIMILAR PHENOTYPES IN DOWN AND FETAL ALCOHOL SYNDROMES

poster abstractDown syndrome (DS) and Fetal Alcohol Syndrome (FAS) are two leading causes of birth defects with phenotypes ranging from cognitive impairment to craniofacial abnormalities. These syndromes have an estimated occurrence of 1/750 and 1/1000 live births, respectively. While DS originates from the trisomy of human chromosome 21 and FAS from excess alcohol consumption, many of the defining characteristics for these two disorders are stunningly similar. Our research of the published literature has identified more than 20 similarities in DS and FAS phenotypes including precise craniofacial and neurological abnormalities. We hypothesize that the similar phenotypes in these two syndromes are caused by disruptions in common molecular and cellular pathways. To test our hypothesis we are examining morphometric, genetic, and cellular phenotypes during development of DS and FAS mouse models. Our preliminary evidence indicates that during early development, expression of Dyrk1a and Rcan1 (two genes found in three copies in individuals with DS) is dysregulated in the craniofacial and neurological precursors of both DS and FAS as compared to normal control embryos. Using immuocytochemistry, we are analyzing cellular properties of neurological development in DS embryos and comparing deficiencies found between trisomic and normal mice to those found in FAS embryos at similar stages. These results will further define molecular and cellular alterations leading to DS and FAS phenotypes and provide mechanisms to target for potential pharmacotherapy