An economic analysis of trading on private information by external administrators: international comparisons

This paper examines the regulation of trades in listed securities by external administrators (EAs), such as trustees in bankruptcy, liquidators, receivers, and administrators on the basis of private information. We consider the economic policy issues associated with such trades. The principal considerations counsel in favour of taking a permissive approach. These are: the difficulties of associating trades with insider information, given the EA's necessarily short expected holding period, the asymmetric application of the insider trading prohibition to sales (rather than decisions not to sell), the market incentives not to misuse private information that apply to EAs, and the unlikelihood that the EA has monopolistic access to the information in question. We consider these considerations by reference to a number of hypothetical scenarios. The paper argues that the law should regulate the subject by coupling a broad exemption for EAs with a "goiod faith" proviso, a continuous disclosure obligation, and a requirement to sell "all or nothing" of a holding of listed securities

Influence of land use and landscape setting on the ecological status of rivers

The development of bioassessment methods for lotic ecosystems, combined with advances in geographic information systems and spatial analysis, has resulted in a rapidly expanding literature linking land use to river condition. Such studies provide evidence that declines in forested land and increases in agricultural and urban land frequently are predictors of a degraded state of the habitat and biota. However, further research should address a number of challenges to our current knowledge. Both linear and non-linear relationships have been described, and it will be useful to know when to expect non-linear or threshold responses. Legacy effects, where historical impacts may be stronger than present-day impacts, may be common but can be difficult to recognize. There is ample evidence that landscape factors influence lotic ecosystems across a wide range of spatial scales, but the roles of near-stream vs. larger spatial scales can be difficult to separate. This is part of the larger issue that multiple, interacting factors link landscape change to stream response, and the pathways or mechanisms are rarely identified. Natural and anthropogenic gradients often co-vary, because human activities are most intense in certain landscape settings, making it difficult to determine how much of the variation in stream condition should be attributed to human actions. Finally, because bioassessment methods are intended to detect impairment rather than diagnose cause, it is important to establish mechanisms that more precisely link land-use activities to stream condition, in order to prescribe appropriate restoration action. Future research that combines landscape-stream condition analyses with a basic understanding of the pathways whereby human alteration of landscapes influences river condition can serve the dual function of advancing both the management and the understanding of lotic ecosystems.El desarrollo de métodos de evaluación biológica para ecosistemas lóticos, combinados con los avances en los sistemas de información geográfica y de análisis espacial, han originado un rápido incremento en las publicaciones sobre la relación de los usos del suelo con el estado de los ríos. Tales estudios aportan evidencias de que una disminución en la superficie forestal y un incremento en el suelo agrícola y urbano, frecuentemente suponen una degradación del hábitat y la biota. No obstante, las futuras investigaciones deberían conducir hacia nuevos retos para nuestro actual conocimiento. Se han descrito relaciones tanto lineares como no lineares, por lo que será útil conocer cuando prever respuestas límites o no lineares. Los efectos heredados, donde los impactos históricos pueden ser más fuertes que los actuales, pueden ser comunes pero difíciles de reconocer. Hay una amplia evidencia de que los factores del paisaje influyen en los ecosistemas lóticos en un amplio rango a escala espacial, aunque puede resultar difícil separar los papeles de las escalas espaciales locales vs. grandes escalas. Esto es parte de una cuestión mayor en la que múltiples factores que interaccionan relacionan cambios en el paisaje con las respuestas de los ríos, y donde las vías o mecanismos son raramente identificados. Los gradientes naturales y antropogénicos a menudo covarían, debido a que las actividades humanas son más intensas en determinadas formaciones del paisaje, haciendo difícil determinar que grado de la alteración en las condiciones del río serían debidas a las acciones humanas. Finalmente, ya que los métodos de evaluación biológica están dirigidos a detectar impactos más que a diagnosticar las causas, es importante establecer mecanismos que relacionen de forma más precisa las actividades en los usos del suelo con el estado de los ríos, con el fin de prescribir las actuaciones adecuadas de restauración. La investigación futura que sea capaz de combinar los análisis de las condiciones del paisaje y del río con una interpretación básica de los caminos por los que la alteración humana del paisaje influye en el estado del río, puede servir para la doble función de avanzar tanto en la gestión como en el entendimiento de los ecosistemas lóticos

Abdominal functional electrical stimulation to enhance mechanical insufflation-exsufflation

Context: Respiratory complications, attributed to the build-up of secretions in the airway, are a leading cause of rehospitalisation for the tetraplegic population. Previously, we observed that the application of Abdominal Functional Electrical Stimulation (AFES) improved cough function and increased demand for secretion removal, suggesting AFES may aid secretion clearance. Clinically, secretion clearance is commonly achieved by using Mechanical insufflation-exsufflation (MI-E) to simulate a cough. In this study the feasibility of combining AFES with MI-E is evaluated. Findings: AFES was successfully combined with MI-E at eight fortnightly assessment sessions conducted with one sub-acute participant with tetraplegia. By using the signal from a pressure sensor, integrated with the MI-E device, AFES was correctly applied in synchrony with MI-E with an accuracy of 96.7%. Acute increases in exhaled volume and peak flow were observed during AFES assisted MI-E, compared to MI-E alone, at six of eight assessment sessions. Conclusion: The successful integration of AFES with MI-E at eight assessment sessions demonstrates the feasibility of this technique. The acute increases in respiratory function observed at the majority of assessment sessions generate the hypothesis that AFES assisted MI-E may be more effective for secretion clearance than MI-E alone

Abdominal functional electrical stimulation to assist ventilator weaning in acute tetraplegia: a cohort study

Background Severe impairment of the major respiratory muscles resulting from tetraplegia reduces respiratory function, causing many people with tetraplegia to require mechanical ventilation during the acute stage of injury. Abdominal Functional Electrical Stimulation (AFES) can improve respiratory function in non-ventilated patients with sub-acute and chronic tetraplegia. The aim of this study was to investigate the clinical feasibility of using an AFES training program to improve respiratory function and assist ventilator weaning in acute tetraplegia.<p></p> Methods AFES was applied for between 20 and 40 minutes per day, five times per week on four alternate weeks, with 10 acute ventilator dependent tetraplegic participants. Each participant was matched retrospectively with a ventilator dependent tetraplegic control, based on injury level, age and sex. Tidal Volume (VT) and Vital Capacity (VC) were measured weekly, with weaning progress compared to the controls.<p></p> Results Compliance to training sessions was 96.7%. Stimulated VT was significantly greater than unstimulated VT. VT and VC increased throughout the study, with mean VC increasing significantly (VT: 6.2 mL/kg to 7.8 mL/kg VC: 12.6 mL/kg to 18.7 mL/kg). Intervention participants weaned from mechanical ventilation on average 11 (sd: ± 23) days faster than their matched controls.<p></p> Conclusion The results of this study indicate that AFES is a clinically feasible technique for acute ventilator dependent tetraplegic patients and that this intervention may improve respiratory function and enable faster weaning from mechanical ventilation.<p></p&gt

Ethics, Welfare, and Laboratory Animal Management

Animals have been used in medical research from as far back as 129-199 A.D. when Galen, a Greek medical scientist, used a pig for his experiments. In the sixteenth and seventeenth centuries, anatomical dissections were carried out on animals; Galvani used frogs in 1791 for his experiments and the Russian physiologist, Pavlov, carried out his famous dog experiments in the early 1900s. Since this time, large numbers of animals have been used in biomedical and other research. In 1963 the first edition of The Guide for the Care and Use of Laboratory Animals was published, and the United States Public Health Service began to require all recipients of grants in which animals were used to adhere to these guidelines. There is now worldwide interest in welfare issues, and the ethics of using animals for research has been raised in many countries. The study of ethics is the treating of moral questions and is concerned with right and wrong. There will always be differing opinions on the ethics of animal use which may raise dilemmas for workers. In a practical sense this has often been dealt with by drafting codes for the care and use of experimental animals. Adherence to a code, however, does not exclude the experimenter from actively considering ethical and welfare issues. Three important issues in laboratory animal management are the ethics of using the animals for experimentation, the welfare of the animals being used, and the scientific validity of the selected species and number to be used

Stream Restoration in the Upper Midwest, U.S.A.

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72831/1/j.1526-100X.2006.00171.x.pd

The Morphologic Categorization of Cell Death Induced by Mild Hyperthermia and Comparison with Death Induced by Ionizing Radiation and Cytotoxic Drugs

This paper presents 1. a summary of the morphological categorization of cell death, 2. results of two in vivo studies on the cell death induced by mild hyperthermia in rat small intestine and mouse mastocytoma, and 3. a comparison of the cell death induced by hyperthermia, radiation and cytotoxic drugs. Two distinct forms of cell death, apoptosis and necrosis, can be recognized on morphologic grounds. Apoptosis appears to be a process of active cellular self-destruction to which a biologically meaningful role can usually be attributed, whereas necrosis is a passive degenerative phenomenon that results from irreversible cellular injury. Light and transmission electron microscopic studies showed that lower body hyperthermia (43°C for 30 min) induced only apoptosis of intestinal epithelial cells, and of lymphocytes, plasma cells, and eosinophils. In the mastocytoma, hyperthermia (43°C for 15 min) produced widespread tumor necrosis and also enhanced apoptosis of tumor cells. Ionizing radiation and cytotoxic drugs are also known to induce apoptosis in a variety of tissues. It is attractive to speculate that DNA damage by each agent is the common event which triggers the same process of active cellular self-destruction that characteristically effects selective cell deletion in normal tissue homeostasis

Acoustic calibration apparatus for calibrating plethysmographic acoustic pressure sensors

An apparatus for calibrating an acoustic sensor is described. The apparatus includes a transmission material having an acoustic impedance approximately matching the acoustic impedance of the actual acoustic medium existing when the acoustic sensor is applied in actual in-service conditions. An elastic container holds the transmission material. A first sensor is coupled to the container at a first location on the container and a second sensor coupled to the container at a second location on the container, the second location being different from the first location. A sound producing device is coupled to the container and transmits acoustic signals inside the container

X-Ray-Induced Cell Death by Apoptosis in the Immature Rat Cerebellum

The cells of the external granular layer (EGL) of the developing cerebellum are known to be particularly sensitive to radiation. In the past, changes induced in this layer by irradiation have been referred to by non-specific terms such as pyknotic cells and the mode of cell death has been assumed to be necrosis. However, in published light micrographs of these dying cells, the appearance is suggestive of apoptosis, a distinctive mode of cell death which occurs spontaneously in normal adult and embryonic tissues and can also be triggered by certain pathological stimuli. This light and transmission electron microscopic study of control and irradiated (7 h post-irradiation) rat cerebellum from 18 day fetuses and 5 day-old neonates showed that the cell death was effected by apoptosis. The apoptosis was markedly enhanced by x-irradiation and quantification of the cell death in the EGL of 5 day-old rats exposed to 4, 8, 25, 100, and 400 cGy x-irradiation demonstrated that there was a positive dose response relationship. The extent of cell death by apoptosis which was 0.2% in control, ranged from 0.8% after 4 cGy to 62.3% after 400cGy x-irradiation. The recognition that cell death by apoptosis can be a major component of x-irradiation damage has important implications for radiobiological studies

External stress-corrosion cracking of a 1.22-m-diameter type 316 stainless steel air valve

An investigation was conducted to determine the cause of the failure of a massive AISI Type 316 stainless steel valve which controlled combustion air to a jet engine test facility. Several through-the-wall cracks were present near welded joints in the valve skirt. The valve had been in outdoor service for 18 years. Samples were taken in the cracked regions for metallographic and chemical analyses. Insulating material and sources of water mist in the vicinity of the failed valve were analyzed for chlorides. A scanning electron microscope was used to determine whether foreign elements were present in a crack. On the basis of the information generated, the failure was characterized as external stress-corrosion cracking. The cracking resulted from a combination of residual tensile stress from welding and the presence of aqueous chlorides. Recommended countermeasures are included