Burrowing in Marine Muds by Crack Propagation: Kinematics and Forces

The polychaete Nereis virens burrows through muddy sediments by exerting dorsoventral forces against the walls of its tongue-depressor- shaped burrow to extend an oblate hemispheroidal crack. Stress is concentrated at the crack tip, which extends when the stress intensity factor (K-I) exceeds the critical stress intensity factor (K-Ic). Relevant forces were measured in gelatin, an analog for elastic muds, by photoelastic stress analysis, and were 0.015 +/- 0.001 N (mean +/- s.d.;N= 5). Measured elastic moduli (E) for gelatin and sediment were used in finite element models to convert the forces in gelatin to those required in muds to maintain the same body shapes observed in gelatin. The force increases directly with increasing sediment stiffness, and is 0.16 N for measured sediment stiffness of E=2.7x10(4) Pa. This measurement of forces exerted by burrowers is the first that explicitly considers the mechanical behavior of the sediment. Calculated stress intensity factors fall within the range of critical values for gelatin and exceed those for sediment, showing that crack propagation is a mechanically feasible mechanism of burrowing. The pharynx extends anteriorly as it everts, extending the crack tip only as far as the anterior of the worm, consistent with wedge-driven fracture and drawing obvious parallels between soft-bodied burrowers and more rigid, wedge-shaped burrowers(i.e. clams). Our results raise questions about the reputed high energetic cost of burrowing and emphasize the need for better understanding of sediment mechanics to quantify external energy expenditure during burrowing.

Effects of Externally Applied, Cyclical, Low Magnitude Forces on Orthodontic Tooth Movement in Rats

Orthodontic tooth movement requires external orthodontic forces to be converted to cellular signals that result in the coordinated removal of bone on one side of the tooth (compression side) by osteoclasts, and the formation of new bone by osteoblasts on the other side (tension side). The length of orthodontic treatment can take several years, leading to problems of caries, periodontal disease, root resorption, and patient dissatisfaction. It appears that the velocity of tooth movement is largely dependent on the rate of alveolar bone remodeling. Pharmacological approaches to increase the rate of tooth movement are limited due to patient discomfort, severe root resorption, and drug-induced side effects. Recently, externally applied, cyclical, low magnitude forces (CLMF) have been shown to cause an increase in the bone mineral density of long bones, and in the growth of craniofacial structures in a variety of animal models. In addition, CLMF is well tolerated by the patient and produces no known adverse effects. However, its application in orthodontic tooth movement has not been specifically determined. Since factors that increase alveolar bone remodeling enhance the rate of orthodontic tooth movement, we hypothesized that externally applied, cyclical, low magnitude forces (CLMF) will increase the rate of orthodontic tooth movement. In order to test this hypothesis we used an in vivo rat orthodontic tooth movement model. Our specific aims were: Specific Aim 1: To develop an in vivo rat model for tooth movement. We developed a tooth movement model based upon two established rodent models (Ren and Yoshimatsu et al, See Figure 1.). The amount of variation of tooth movement in rats exposed to 25-60 g of mesial force activated viii from the first molar to the incisor for 4 weeks was calculated. Specific Aim 2: To determine the frequency dose response of externally applied, cyclical, low magnitude forces (CLMF) for maximal tooth movement and osteoclast numbers. Our working hypothesis for this aim was that the amount of tooth movement would be dose dependent on the frequency of application of the CLMF. In order to test this working hypothesis, we varied the frequency of the CLMF from 30, 60, 100, and 200 Hz, 0.4N, two times per week, for 10 minutes for 4 weeks, and measured the amount of tooth movement. We also looked at the number of osteoclasts for the different frequencies; we hypothesized an increase in osteoclasts for the dose respnse of different frequencies. Specific Aim 3: To determine the effects of externally applied, cyclical, low magnitude forces (CLMF) on PDL proliferation. Our working hypothesis for this aim was that PDL proliferation would increase with CLMF. In order to test this hypothesis we compared CLMF (30 Hz, 0.4N, two times per week, for 10 minutes for 4 weeks) performed on the left side (experimental side), to the non-CLMF side, on the right (control side). This was an experimental study with 24 rats in total. The experimental group contained fifteen (15) rats in total, and they all received a spring plus a different frequency of CLMF. Three (3) received a spring and CLMF at 30 Hz, 0.4N for 10 minutes. Six (6) received a spring and CLMF at 60 Hz, 0.4N for 10 minutes. Three (3) received a spring and CLMF at 100 Hz, 0.4N for 10 minutes. Three (3) received a spring and CLMF at 200 Hz, 0.4N for 10 minutes. The control group contained six (6) rats, and received only a spring. An additional ix three (3) rats received CLMF (30 Hz, 0.4N, two times per week, for 10 minutes for 4 weeks) only, with no spring, and were used only for histological purposes. Rats were subjected to the application of orthodontic force from their maxillary left first molar to their left central incisor. In addition some of the rats received externally applied, cyclical, low magnitude force (CLMF) on their maxillary left first molar. micro-CT was used to measure the amount of orthodontic tooth movement. The distance between the maxillary first and second molars, at the most mesial point of the second molar and the most distal point of the first molar (1M-2M distance) were used to evaluate the distance of tooth movement. Immunohistochemistry was performed with TRAP staining and BrdU quantification. Externally applied, cyclical, low magnitude forces (CLMF) do appear to have an effect on the rate, while not significant, of orthodontic tooth movement in rats. It appears that lower CLMF decreases the rate of tooth movement, while higher CLMF increases the rate of tooth movement. Future studies with larger sample sizes are needed to clarify this issue. CLMF does not appear to affect the proliferation in PDL cells, and has no effect on the number of osteoclasts.

Evaluation of Police Patrol Patterns

This paper describes an ArcView extension that allows police planners to design patrol districts and to evaluate them by displaying various performance measures. It uses a spatially distributed queuing system (the Larson Hypercube) to calculate expected travel times, workloads, preventive patrol frequencies, and other variables; and it allows planners to see the unavoidable tradeoffs among their objectives. Using this tool, planners can experiment with various patrol patterns to find those that best meet their Department.s goals. For example, those patrol patterns which are best in terms of average response time don.t do as well as others in terms of workload balance, or those that are best in terms of achieving a uniform response time across different parts of the city don't do as well as others in terms of minimizing inter-district dispatches. There is, of course, no perfect solution for this problem: the facts of the situation force us to balance competing goals. Described here is a way of explicitly weighting the alternative objectives.

Search, Seizure and (False?) Arrest: An Analysis of Fourth Amendment Remedies when Police can Plant Evidence

The Fourth Amendment prohibits unreasonable searches and seizures in criminal investigations. The Supreme Court has interpreted this to require that police obtain a warrant prior to search and that illegally seized evidence be excluded from trial. A consensus has developed in the law and economics literature that tort liability for police officers is a superior means of deterring unreasonable searches. We argue that this conclusion depends on the assumption of truth-seeking police, and develop a game-theoretic model to compare the two remedies when some police officers (the bad type) are willing to plant evidence in order to obtain convictions, even though other police (the good type) are not (where this type is private information). We characterize the perfect Bayesian equilibria of the asymmetric-information game between the police and a court that seeks to minimize error costs in deciding whether to convict or acquit suspects. In this framework, we show that the exclusionary rule with a warrant requirement leads to superior outcomes (relative to tort liability) in terms of truth-finding function of courts, because the warrant requirement can reduce the scope for bad types of police to plant evidence

Na 1 Nachlass Max Horkheimer, 687 - "Experimental Movie Project", "The Police and Minority Groups" u.a. (p. IX 150.1-17 - IX 152.1-2)

"Experimental Movie Project" (1945-46):; 1. "Below the Surface", Drehbuch des Testfilms, a) als Typoskript vervielfältigt, 46 Blatt, b) als Typoskript vervielfältigt, 26 Blatt, c) als Typoskript vervielfältigt, 26 Blatt, d) als Typoskript vervielfältigt, 26 Blatt "Experimental Movie Project" (1945-46): Memoranden zum Test; 2. 'Notes' 25.4.1946, Typoskript, 1 Blatt; 3. "Memorandum on Experimental Movie Project", 19.4.1946. Typoskript, 3 Blatt; 4. "Memorandum re: 'Below the Surface" (Juli 1945). Typoskript, 2 Blatt; 5. Dore Schary und Allen Rivkin: 'Memorandum, Subject: New Suggested Treatment for 'Below the Surface'", 13.7.1945. Typoskript, 2 Blatt; 6. Hans Richter: "Report about the film script 'Below the surface'", 7. u. 8.7.1945, a) Typoskript, 1 Blatt, b) Typoskript, 1 Blatt; 7. Hans Richter: Bestätigung der Vereinbarung mit dem American Jewish Committee, 3.7.1945. Typoskript, 1 Blatt; 8. "Notes and Suggestions re Experimental Motion Picture", Juni 1945. Typoskript, 2 Blatt; 9. Siegfried Kracauer; "Suggestions for the Dialogue" (4.4.1945). Typoskript, 3 Blatt; 10. "Motion Picture", März 1945. Typoskript, 5 Blatt; 11. "Project on a Test film", a) Typoskript, 4 Blatt, b) Typoskript, 5 Blatt; 12. "Memorandum re: 'Below the Surface'", a) Typoskript, 3 Blatt, b) Typoskript mit eigenhändigen Korrekturen von Theodor W. Adorno, 3 Blatt; "Experimental Movie Project" (1945-46): Korrespondenz zum Test-Film-Projekt:; 13. Friedrich Pollock: 1 Brief an Max Horkheimer, Santa Monica, California, 12.10.1945; 14. Theodor W. Adorno: 2 Briefe an Max Horkheimer, Los Angeles und Santa Monica, California, 1945; 15. Joseph M. Proskauer: 1 Brief von Max Horkheimer, o.O., 29.6.1945, 1 Brief mit Unterschrift an Max Horkheimer, o.O., o.D., 3 Blatt; 16. Alexander Hackenschmied, 1 Brief mit Unterschrift an Max Horkheimer, New York, 19.6.1945, 1 Blatt; 17. Gilbert Gabriel: 1 Brief von John Slawson, o.O., 22.3.1945, 2 Blatt; "The Police and Minority Groups" (1946):; 1. "The Police and Minority Groups". Typoskript, 2 Blatt; 2. Robert W. Kenny: "Police and Minority Groups - an Experiment". Als Typoskript vervielfältigt, 17 Blatt; 3. Davis McEntire, Robert B. Powers: "Police Training Bulletin. A Guide to Race Relations for Police Officers", State of California, 1946, 38 Seiten; Max Horkheimer: "Memorandum on a Study of Race Hatred in Post-War Germany" (1946):; 1. Memorandum, a) Typoskript, 8 Blatt, b) Typoskript mit eigenhändigen und handschriftlichen Korrekturen, 6 Blatt, c) Typoskript, 5 Blatt, d) Teilstück, Typoskript mit eigenhändigen Korrekturen, 1 Blatt e) Typoskript mit eigenhändigen Korrekturen, 5 Blatt, f) Teilstück, Typoskript mit handschriftlichen Korrekturen, 2 Blatt, g) Typoskript mit eigenhändigen Korrekturen, 7 Blatt, h) Teilstück, Typoskript mit eigenhändigen Korrekturen und Ergänzungen, 1 Blatt, i) Typoskript, 2 Blatt; 2. Theodor W. Adorno: "Ad Memorandum Neumann", Manuskript, 3 Blatt;

Houston police officer attitudes towards the mentally ill: CIT trained and non-CIT trained

The purpose of this study was to develop a better understanding of police officer attitudes towards the mentally ill and what impact that might have on their behavior. Focused on the effects of Crisis Intervention Team (CIT) training on Houston police officers, this research wanted to determine if CIT training decreases attitudes of authoritarianism and increases attitudes of self-efficacy in dealing with the mentally ill—other factors assessed were age, years of service, ethnicity, and gender. Results confirmed that CIT training had an effect on an officer's attitudes with CIT officers being less authoritarian and having more self-efficacy with respect to dealing with the mentally ill as compared to non-CIT officers. Because of these results, this study could offer support in tailoring training programs to have successful officer-mentally ill person interactions. ^

The public health applications of law enforcement medical direction: A practical experience with the Dallas Police Department

In 2008, 132 law enforcement officers were killed in the line of duty in The United States. Additionally, some have explored both the public health implications of interactions with law enforcement as well as the potential benefits of the use of law enforcement officers as public health and emergency healthcare providers. By virtue of these novel analyses and techniques, professional medical direction of the emerging specialty of law enforcement medicine is needed. This paper, an analysis of law enforcement medical direction through a look at the Dallas Police Medical Direction Program, seeks to examine origins of law enforcement medicine through a comprehensive literature review, as well as begin to define to core competencies of law enforcement medical direction. ^ The unique intersection of public health, medicine and law enforcement, and the subsequent specialty that is developing to manage this interface, is in its relative infancy. An analysis of this nature is in order to begin to lay down the foundations necessary for future study and improvements in the field. ^

El lado B de la historia, un caso de violencia política en el corregimiento de Arauca, Caldas, Colombia, el 29 y 30 de octubre de 1949

Investigar 'el lado B' de la Historia proporciona otras respuestas y perspectivas para comprender un hecho traumático ocurrido el 29 de octubre de 1949 en Arauca, Caldas; cuando 49 personas perdieron su vida en el contexto histórico de lo que la Violentología denomina en Colombia 'La violencia'. Las indagaciones se circunscriben en el orden de ¿Qué pasó?, ¿Cómo pasó? y ¿Qué se ha narrado? Ya que las respuestas difieren, esencialmente, dependiendo de si las versiones provienen del diario manizalita 'La Patria' y la historia oficial, donde la autoría de los asesinatos fue atribuida a los liberales gaitanistas; o de fuentes tales como: el diario 'El Tiempo', los archivos judiciales, los testimonios orales de las víctimas sobrevivientes, los álbumes fotográficos y la asistencia de los estudios de memoria, donde se evidencia que la masacre fue ejecutada por la Policía, las fuerzas paramilitares de la época, conocidos como "los pájaros", y civiles conservadores que a su vez fueron la pieza procesal para iniciar la investigación judicial tendiente a "esclarecer" los hechos

Formas de violencia policial en la provincia de Buenos Aires a comienzos de la década de 1960

Este artículo estudia la violencia policial en su desempeño cotidiano alrededor de 1960. Se procuran reconocer los aspectos fundamentales de la misma, que pasaron a formar parte del accionar operativo de la policía y que incorporaron, a escala institucional, las coacciones ilegales como metodología para la 'resolución' de casos. Los mandatos políticos orientados a una determinada idea de 'orden social' y las demandas sociales por 'seguridad y orden' no estuvieron ajenos a la convalidación de las formas de violencia policial. Las fuentes consultadas también arrojan luz sobre los 'debates' al interior de la fuerza policial acerca de su rol como auxiliar de un poder militar represivo y totalitario frente a una sociedad cuyos crecientes reclamos políticos y sociales la convertirían en el 'enemigo interno'. El trabajo concluye en el año 1962, que puede ser visto como un punto de maduración en el cual la policía bonaerense aplicó su experiencia operativa acumulada en el orden cotidiano, a la represión y eliminación de la protesta social y la disidencia política

Naishtat, F. Action et Langage: Desniveaux linguistiques de l'action aux forces illocutionnaires de la protestation. París: L'Hartmattan. 2010. 260 páginas

Fil: Parra, Fabiana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

El lado B de la historia, un caso de violencia política en el corregimiento de Arauca, Caldas, Colombia, el 29 y 30 de octubre de 1949

Investigar 'el lado B' de la Historia proporciona otras respuestas y perspectivas para comprender un hecho traumático ocurrido el 29 de octubre de 1949 en Arauca, Caldas; cuando 49 personas perdieron su vida en el contexto histórico de lo que la Violentología denomina en Colombia 'La violencia'. Las indagaciones se circunscriben en el orden de ¿Qué pasó?, ¿Cómo pasó? y ¿Qué se ha narrado? Ya que las respuestas difieren, esencialmente, dependiendo de si las versiones provienen del diario manizalita 'La Patria' y la historia oficial, donde la autoría de los asesinatos fue atribuida a los liberales gaitanistas; o de fuentes tales como: el diario 'El Tiempo', los archivos judiciales, los testimonios orales de las víctimas sobrevivientes, los álbumes fotográficos y la asistencia de los estudios de memoria, donde se evidencia que la masacre fue ejecutada por la Policía, las fuerzas paramilitares de la época, conocidos como "los pájaros", y civiles conservadores que a su vez fueron la pieza procesal para iniciar la investigación judicial tendiente a "esclarecer" los hechos

Formas de violencia policial en la provincia de Buenos Aires a comienzos de la década de 1960

Este artículo estudia la violencia policial en su desempeño cotidiano alrededor de 1960. Se procuran reconocer los aspectos fundamentales de la misma, que pasaron a formar parte del accionar operativo de la policía y que incorporaron, a escala institucional, las coacciones ilegales como metodología para la 'resolución' de casos. Los mandatos políticos orientados a una determinada idea de 'orden social' y las demandas sociales por 'seguridad y orden' no estuvieron ajenos a la convalidación de las formas de violencia policial. Las fuentes consultadas también arrojan luz sobre los 'debates' al interior de la fuerza policial acerca de su rol como auxiliar de un poder militar represivo y totalitario frente a una sociedad cuyos crecientes reclamos políticos y sociales la convertirían en el 'enemigo interno'. El trabajo concluye en el año 1962, que puede ser visto como un punto de maduración en el cual la policía bonaerense aplicó su experiencia operativa acumulada en el orden cotidiano, a la represión y eliminación de la protesta social y la disidencia política