RESUMO
The collisionless ion-Weibel instability is a leading candidate mechanism for the formation of collisionless shocks in many astrophysical systems, where the typical distance between particle collisions is much larger than the system size. Multiple laboratory experiments aimed at studying this process utilize laser-driven (Iâ³10^{15} W/cm^{2}), counterstreaming plasma flows (Vâ²2000 km/s) to create conditions unstable to Weibel-filamentation and growth. This technique intrinsically produces temporally varying plasma conditions at the midplane of the interaction where Weibel-driven B fields are generated and studied. Experiments discussed herein demonstrate robust formation of Weibel-driven B fields under multiple plasma conditions using CH, Al, and Cu plasmas. Linear theory based on benchmarked radiation-hydrodynamic FLASH calculations is compared with Fourier analyses of proton images taken â¼5-6 linear growth times into the evolution. The new analyses presented here indicate that the low-density, high-velocity plasma-conditions present during the first linear-growth time (â¼300-500 ps) sets the spectral characteristics of Weibel filaments during the entire evolution. It is shown that the dominant wavelength (â¼300µm) at saturation persists well into the nonlinear phase, consistent with theory under these experimental conditions. However, estimates of B-field strength, while difficult to determine accurately due to the path-integrated nature of proton imaging, are shown to be in the â¼10-30 T range, an order of magnitude above the expected saturation limit in homogenous plamas but consistent with enhanced B fields in the midplane due to temporally varying plasma conditions in experiments.
RESUMO
OBJECTIVE: The first world witnessed a laparoscopic revolution in the 1990s. At the start, laparoscopic surgery was heavily criticized and ridiculed. Despite this, the specialty has blossomed where almost any procedure can be done laparoscopically with the now obvious tremendous benefit to the patients. The objective of this paper is to examine where the Caribbean is placed relative to the rest of the world in terms of laparoscopic surgery and to understand why we are here. DESIGN AND METHODS: The literature written on laparoscopy in the region was reviewed and contributions were taken from key surgeons in three main islands, Trinidad and Tobago, Barbados and Jamaica. RESULTS: Though the first laparoscopic cholecystectomy in the Caribbean, in most islands, took place in the early 1990s like the rest of the world, there was relative dormancy for at least a decade in Trinidad and Tobago and even longer in other islands with regards to implementing advanced procedures or increasing case volumes. Reasons for this included lack of funding, lack of operating time in public facilities, lack of information of the public and the medical fraternity but most importantly lack of trained laparoscopic surgeons. This last factor was proven to be the key one in Trinidad and Tobago in 2003, Jamaica 2005 and Barbados 2011/12, when the return of trained personel engineered the transition from basic to advanced laparoscopy CONCLUSION: Despite the delay of approximately 10 years in Trinidad and Tobago and 15 years in other islands, the return of trained surgeons has seen a rapid increase in case variety and volumes in laparoscopy. The wheels of motion of the laparoscopic revolution in the Caribbean have finally begun.
Assuntos
Cirurgia Geral/educação , Laparoscopia/história , Colecistectomia Laparoscópica/história , História do Século XX , Humanos , Laparoscopia/educação , Índias OcidentaisRESUMO
OBJECTIVE: The first world witnessed a laparoscopic revolution in the 1990s. At the start, laparoscopic surgery was heavily criticized and ridiculed. Despite this, the specialty has blossomed where almost any procedure can be done laparoscopically with the now obvious tremendous benefit to the patients. The objective of this paper is to examine where the Caribbean is placed relative to the rest of the world in terms of laparoscopic surgery and to understand why we are here. DESIGN AND METHODS: The literature written on laparoscopy in the region was reviewed and contributions were taken from key surgeons in three main islands, Trinidad and Tobago, Barbados and Jamaica. RESULTS: Though the first laparoscopic cholecystectomy in the Caribbean, in most islands, took place in the early 1990s like the rest of the world, there was relative dormancy for at least a decade in Trinidad and Tobago and even longer in other islands with regards to implementing advanced procedures or increasing case volumes. Reasons for this included lack of funding, lack of operating time in public facilities, lack of information of the public and the medical fraternity but most importantly lack of trained laparoscopic surgeons. This last factor was proven to be the key one in Trinidad and Tobago in 2003, Jamaica 2005 and Barbados 2011/12, when the return of trained personel engineered the transition from basic to advanced laparoscopy. CONCLUSION: Despite the delay of approximately 10 years in Trinidad and Tobago and 15 years in other islands, the return of trained surgeons has seen a rapid increase in case variety and volumes in laparoscopy. The wheels of motion of the laparoscopic revolution in the Caribbean have finally begun.
OBJETIVO: El primer mundo fue testigo de una revolución laparoscópica en los años 1990. Al comienzo, la cirugía laparoscópica fue muy criticada y ridiculizada. A pesar de ello, la especialidad ha florecido, siendo el caso que ahora casi cualquier procedimiento puede hacerse laparoscópicamente, con evidentes grandes beneficios para los pacientes. El objetivo de este trabajo es examinar donde se encuentra el Caribe en relación con el resto del mundo en lo que se refiere a la cirugía laparoscópica, y asimismo el por qué nos hallamos en ese lugar. DISEÑO Y MÉTODOS: Se examinó la literatura sobre laparoscopia escrita en la región, y se tomaron contribuciones de cirujanos claves de tres islas principales, a saber, Trinidad y Tobago, Barbados y Jamaica. RESULTADOS: Aunque las primeras colecistectomías laparoscópicas en la mayoría de las islas del Caribe, tuvieron lugar a principio de los años 1990 como en el resto del mundo, hubo un período de relativa inactividad por espacio de casi una década en Trinidad y Tobago, y aun por más largo tiempo en otras islas, en relación con la implementación de procedimientos avanzados o el aumento del volumen de casos. Las razones para esta relativa inactividad incluyeron la falta de fondos, la falta de tiempo de operación de los centros públicos, la falta de información del público y la fraternidad médica, pero sobre todo la falta de cirujanos entrenados en laparoscopia. Esto ultimo resultó ser el factor clave en Trinidad y Tobago en 2003, Jamaica en 2005 y Barbados en 2011/12, cuando el regreso del personal entrenado hizo técnicamente posible la transición de una laparoscopia básica a una avanzada. CONCLUSIÓN: A pesar de la demora de aproximadamente 10 años en Trinidad and Tobago, y de 15 años en las otras islas, el regreso de los cirujanos entrenados ha visto un rápido aumento en la variedad casos y los volúmenes de laparoscopia. El motor de la revolución laparoscópica en el Caribe ha por fin echado a andar.
Assuntos
História do Século XX , Humanos , Cirurgia Geral/educação , Laparoscopia/história , Colecistectomia Laparoscópica/história , Laparoscopia/educação , Índias OcidentaisRESUMO
OBJECTIVE: We present an exploratory analysis of data collected on perforated diverticular disease (PDD) in Barbados and suggest possible areas for further study. SUBJECTS AND METHODS: All cases of perforated diverticular disease treated at the Queen Elizabeth Hospital (QEH) Barbados, between January 1, 2005 and December 31, 2006 were reviewed. The patient's age, gender, location of disease, Hinchey stage, operative procedure, rate of colostomy reversal, length of hospitalization, incidence of peri-operative morbidity and postoperative mortality were analysed using principal components analysis (PCA). RESULTS: Fourteen cases of PDD were treated at the QEH during this period. Six (43%) of the patients had perforated right-sided diverticulitis (PRSD). In the PCA, Dimensions 1 and 2 were the two dimensions examined, as they both had Eigenvalues over 1. Dimension 1 can be taken as an indicator of the intensity of the disease. On dimension 2, length of hospitalization had the highest component loading (0.875). The mean hospital stay was 10.6 days in PRSD, 9.5 in left-sided perforations with primary anastomosis, and 16.2 days for those with a Hartmann's procedure. The overall peri-operative morbidity was 28% and there was no mortality in the series. CONCLUSION: This preliminary study seems to show a relatively high incidence of PRSD in a predominantly Afro-Caribbean population. More research is needed to determine the exact aetiology of this disease. In our experience, primary anastomosis in carefully selected patients with either PRSD or perforated left-sided diverticulitis (PLSD) may result in shorter hospitalization.
OBJETIVO: Presentamos un análisis exploratorio de la enfermedad diverticular perforada (EDP) en Barbados, y sugerimos posibles áreas de análisis ulterior. SUJETOS Y MÉTODOS: Se revisaron todos los casos de enfermedad diverticular perforada tratados en el Hospital Queen Elizabeth (QEH) de Barbados, entre enero 1 de 2005 y diciembre 31 de 2006. Mediante el análisis de componentes principales (ACP), se analizaron los siguientes: edad del paciente, género, localización de la enfermedad, estadio de Hinchey, procedimiento operatorio, tasa de colostomía inversa, tiempo de hospitalización, incidencia de morbilidad perioperatoria, y mortalidad postoperatoria. RESULTADOS: Catorce casos de EDP fueron tratados en el HQE durante este período. Seis (43%) de los pacientes presentaban diverticulitis del lado derecho perforada (DLDP). En el ACP, las dimensiones 1 y 2 fueron las dos dimensiones examinadas, ya que ambas tenían valores propios por encima de 1. La dimensión 1 puede tomarse como indicador de la intensidad de la enfermedad. En la dimensión 2, el tiempo de hospitalización tuvo la carga de componente más alta (0.875). La estadía promedio en el hospital fue de 10.6 días en los casos de DLDP, 9.5 en las perforaciones del lado izquierdo con anastomosis primaria, y 16.2 días para aquellos con procedimiento de Hartmann. La morbilidad perioperatoria fue 28% y no hubo mortalidad en la serie. CONCLUSIÓN: Este estudio preliminar parece mostrar una incidencia relativamente alta de DLDP en una población predominantemente afro-caribeña. Se necesita más investigación a fin de determinar la etiología exacta de esta enfermedad. En nuestra experiencia, la anastomosis primaria en pacientes cuidadosamente seleccionados, que sufren de DLDP o padecen diverticulitis del lado izquierdo perforada (DLIP), puede tener por resultado una hospitalización más corta.
Assuntos
Humanos , Diverticulose Cólica/epidemiologia , Perfuração Intestinal/epidemiologia , População Negra , Região do Caribe/epidemiologia , Colectomia/estatística & dados numéricos , Colostomia/estatística & dados numéricos , Diverticulose Cólica/etnologia , Diverticulose Cólica/cirurgia , Ileostomia/estatística & dados numéricos , Incidência , Perfuração Intestinal/etnologia , Perfuração Intestinal/cirurgia , Análise de Componente Principal , Encaminhamento e Consulta/estatística & dados numéricos , Estudos RetrospectivosRESUMO
OBJECTIVE: We present an exploratory analysis of data collected on perforated diverticular disease (PDD) in Barbados and suggest possible areas for further study. SUBJECTS AND METHODS: All cases of perforated diverticular disease treated at the Queen Elizabeth Hospital (QEH) Barbados, between January 1, 2005 and December 31, 2006 were reviewed. The patient's age, gender location of disease, Hinchey stage, operative procedure, rate of colostomy reversal, length of hospitalization, incidence of peri-operative morbidity and postoperative mortality were analysed using principal components analysis (PCA). RESULTS: Fourteen cases of PDD were treated at the QEH during this period. Six (43%) of the patients had perforated right-sided diverticulitis (PRSD). In the PCA, Dimensions 1 and 2 were the two dimensions examined, as they both had Eigenvalues over 1. Dimension 1 can be taken as an indicator of the intensity of the disease. On dimension 2, length of hospitalization had the highest component loading (0.875). The mean hospital stay was 10.6 days in PRSD, 9.5 in left-sided perforations with primary anastomosis, and 16.2 days for those with a Hartmann's procedure. The overall peri-operative morbidity was 28% and there was no mortality in the series. CONCLUSION: This preliminary study seems to show a relatively high incidence of PRSD in a predominantly Afro-Caribbean population. More research is needed to determine the exact aetiology of this disease. In our experience, primary anastomosis in carefully selected patients with either PRSD or perforated left-sided diverticulitis (PLSD) may result in shorter hospitalization.
Assuntos
Diverticulose Cólica/epidemiologia , Perfuração Intestinal/epidemiologia , População Negra , Região do Caribe/epidemiologia , Colectomia/estatística & dados numéricos , Colostomia/estatística & dados numéricos , Diverticulose Cólica/etnologia , Diverticulose Cólica/cirurgia , Humanos , Ileostomia/estatística & dados numéricos , Incidência , Perfuração Intestinal/etnologia , Perfuração Intestinal/cirurgia , Análise de Componente Principal , Encaminhamento e Consulta/estatística & dados numéricos , Estudos RetrospectivosRESUMO
OBJECTIVES: The purpose of this study is to assess the knowledge, attitudes and practices among medical students in relation to medical ethics and law. The results of the study will be a useful guide to tutors of medical students and curricula designers. METHODS: A thirty-item self-administered questionnaire about knowledge of law and ethics, and the role of an ethics committee in the healthcare system was devised, tested and distributed to all levels of students and staff at the Queen Elizabeth Hospital in Barbados (a tertiary care teaching hospital) in 2003. The data from the completed questionnaires were entered into an SPSS database and analyzed using frequency and multiple cross-tabulation tables. RESULTS: Completed responses were obtained from 55 (96%) of the medical students. Medical students generally attested to the importance of ethical knowledge but felt that they knew little of the law. Students varied widely as regards the frequency with which they saw ethical or legal problems, with a quarter seeing them infrequently, but another quarter seeing them every day. They received their knowledge from multiple sources and particularly from lectures/seminars, and found case conferences the most helpful. Only a few students felt that text books had been helpful. Students were generally knowledgeable about most ethical issues, but many had uncertainties on how to deal with religious differences in treating patients, on the information to be given to relatives, and how violent patients should be treated. CONCLUSIONS: The results of the study highlight that medical students felt an inadequacy of knowledge of law as it pertains to their chosen career Since most of their knowledge of law was obtained from lectures, these should be reviewed and other avenues of tuition explored. The study also highlights the need to identify the minority of students who have problems with their ethical knowledge and to devise means whereby any deficiencies can be discussed and modified.
Assuntos
Educação de Graduação em Medicina , Ética Médica/educação , Conhecimentos, Atitudes e Prática em Saúde , Legislação Médica , Estudantes de Medicina/psicologia , Adulto , Barbados , Coleta de Dados , Comitês de Ética Clínica , Feminino , Hospitais de Ensino/ética , Humanos , Masculino , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: The purpose of this study is to assess the knowledge, attitudes and practices among medical students in relation to medical ethics and law. The results of the study will be a useful guide to tutors of medical students and curricula designers. METHODS: A thirty-item self-administered questionnaire about knowledge of law and ethics, and the role of an ethics committee in the healthcare system was devised, tested and distributed to all levels of students and staff at the Queen Elizabeth Hospital in Barbados (a tertiary care teaching hospital) in 2003. The data from the completed questionnaires were entered into an SPSS database and analyzed using frequency and multiple cross-tabulation tables. RESULTS: Completed responses were obtained from 55 (96) of the medical students. Medical students generally attested to the importance of ethical knowledge but felt that they knew little of the law. Students varied widely as regards the frequency with which they saw ethical or legal problems, with a quarter seeing them infrequently, but another quarter seeing them every day. They received their knowledge from multiple sources and particularly from lectures/seminars, and found case conferences the most helpful. Only a few students felt that text books had been helpful. Students were generally knowledgeable about most ethical issues, but many had uncertainties on how to deal with religious differences in treating patients, on the information to be given to relatives, and how violent patients should be treated. CONCLUSIONS: The results of the study highlight that medical students felt an inadequacy of knowledge of law as it pertains to their chosen career Since most of their knowledge of law was obtained from lectures, these should be reviewed and other avenues of tuition explored. The study also highlights the need to identify the minority of students who have problems with their ethical knowledge and to devise means whereby any deficiencies can be discussed and...
OBJETIVOS: El propósito de este estudio es evaluar los conocimientos, las actitudes y la práctica entre los estudiantes de medicina en relación con la ética y las leyes en el campo de la medicina. Los resultados del estudio serán una guía útil para los tutores de los estudiantes de medicina y los diseñadores de currículos de estudios. MÉTODOS: Una encuesta auto-administrada de treinta puntos sobre los conocimientos de leyes y ética, y el papel de un comité de ética en el sistema de atención a la salud, fue diseñada, probada y distribuida a todos los niveles entre los estudiantes y el personal del Hospital Queen Elizabeth en Barbados (un hospital docente de atención terciaria) en 2003. Los datos de las encuestas completadas fueron introducidos en una base de datos de SPSS, y analizados usando tablas de frecuencia y tablas múltiples de tabulación cruzada. RESULTADOS: Se obtuvieron cuestionarios respondidos por parte de 55 (96%) de los estudiantes de medicina. Los estudiantes de medicina por lo general atestiguaron la importancia de los conocimientos éticos, pero sentían que sabían poco de las leyes. Hubo grandes diferencias entre los estudiantes con respecto a la frecuencia con que veían problemas éticos o legales una cuarta parte de ellos señalando que no los veía frecuentemente, y otra cuarta parte indicando que los veía todos los días. Ellos recibieron sus conocimiento de múltiples fuentes especialmente de conferencias y seminarios y encontraron que las conferencias sobres casos, fueron las más útiles en tal sentido. Sólo unos pocos estudiantes fueron del parecer de que los libros de texto habían sido útiles. Por lo general, los estudiantes se mostraron conocedores de la mayoría de los problemas éticos, pero muchos manifestaron incertidumbre en cuanto a cómo abordar las diferencias religiosas al tratar con los pacientes, qué información dar a los familiares, y cómo debían ser tratados los pacientes violentos...
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Humanos , Masculino , Feminino , Adulto , Conhecimentos, Atitudes e Prática em Saúde , Educação de Graduação em Medicina , Estudantes de Medicina/psicologia , Legislação Médica , Ética Médica/educação , Barbados , Coleta de Dados , Comitês de Ética Clínica , Hospitais de Ensino , Inquéritos e QuestionáriosRESUMO
Data on all patients scheduled to have elective and emergency surgeries during the period of 6 weeks from September 1999 to October 1999 were prospectively collected to determine scheduled starting times, actual starting times, completion times, causes for delays and cancellations. Of 840 procedures scheduled during the study period, 594 (71%) were available for analysis. Eighty-nine per cent of cancellations occurred in patients undergoing elective surgery. The common causes of cancellations were non-availability of beds in recovery room (RR) (15%), patients not showing up (9%), improper pre-operative patient preparation (13%), unavailability of nurses (11%) and anaesthetists (8%). Twenty-three per cent of the cancellations were day cases. Public patients were cancelled more frequently than private patients. Surgical procedures started on time in only 7% of patients. The most common cause of delay was due to delayed transport of patients to the operating theatre (17%). Optimal utilisation of operating theatres in our situation may be effected by increasing the bed-strength of ICUs to free the RR, proper pre-operative work up, adequate counselling of day-care surgery patients and efficient floor management of the operating theatre.
Assuntos
Agendamento de Consultas , Países em Desenvolvimento , Hospitais Universitários/organização & administração , Centro Cirúrgico Hospitalar/organização & administração , Barbados , Atenção à Saúde/organização & administração , Humanos , Estudos Prospectivos , Procedimentos Cirúrgicos OperatóriosRESUMO
Data on all patients scheduled to have elective and emergency surgeries during the period of 6 weeks from September 1999 to October 1999 were prospectively collected to determine scheduled starting times, actual starting times, completion times, causes for delays and cancellations. Of 840 procedures scheduled during the study period, 594 (71 per cent) were available for analysis. Eighty-nine per cent of cancellations occurred in patients undergoing elective surgery. The common causes of cancellations were non-availability of beds in recovery room (RR) (15 per cent), patients not showing up (9 per cent), improper pre-operative patient preparation (13 per cent), unavailability of nurses (11 per cent) and anaesthetists (8 per cent). Twenty-three per cent of the cancellations were day cases. Public patients were cancelled more frequently than private patients. Surgical procedures started on time in only 7 per cent of patients. The most common cause of delay was due to delayed transport of patients to the operating theatre (17 per cent). Optimal utilisation of operating theatres in our situation may be effected by increasing the bed-strength of ICUs to free the RR, proper pre-operative work up, adequate counselling of day-care surgery patients and efficient floor management of the operating theatre.
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Humanos , Cirurgia Geral/normas , Cirurgia Geral/tendências , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Procedimentos Cirúrgicos Operatórios/normas , Procedimentos Cirúrgicos Operatórios/tendênciasRESUMO
Global environmental regulations are changing the leather-processing industry. Pre-tanning and tanning processes contribute 80-90% of the total pollution in the industry and generate noxious gases, such as hydrogen sulfide, as well as solid wastes, such as lime and chrome sludge. The use of enzyme-based products is currently being explored for many areas of leather making. Furthermore, enzymes are gaining increasing importance in the de-hairing process, eliminating the need for sodium sulfide. This review discusses emerging novel biotechnological methods used in leather processing. One significant achievement is the development of a bioprocess-based de-hairing and fiber-opening methodology to reduce toxic waste.