Search

This chapter examines the causes of the flow of Caribbean people to United Kingdom, Canada and the USA and the return flow to Jamaica. It also examines adjustment issues in the receiving country and the re-adaptation process when the migrants return to the home country. The chapter assesses the impact of remittances on the Jamaican economy and society and attempt to consider how migration policies constitute an essential part of the dynamics of migration and emigration and the role of returnees in these processes. The phenomenon of return migration to the Caribbean can best be understood through an examination of the interlocking nature of outward migration and return to the home country, together with an analysis of the variables arising from the dynamics of the process. The Caribbean population used a number of adaptive mechanisms to cope with the difficulties that they encountered in Britain. International labour migration may even be realistically necessary for system maintenance of the global economy.

Objectives Commercially available binder devices are commonly used in the acute treatment of pelvic fractures, while many advocate simply placing a circumferential sheet for initial stabilization of such injuries. We sought to determine whether or not the T-POD would provide more stability to an unstable pelvic injury as compared to circumferential pelvic sheeting. Methods Unstable pelvic injuries (OTA type 61-C-1) were surgically created in five fresh, lightly embalmed whole human cadavers. Electromagnetic sensors were placed on each hemi-pelvis. The amount of angular motion during testing was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT). Either a T-POD or circumferential sheet was applied in random order for testing. The measurements recorded in this investigation included maximum displacements for sagittal, coronal, and axial rotation during application of the device, bed transfer, log-rolling, and head of bed elevation. Results There were no differences in motion of the injured hemi-pelvis during application of either the T-POD or circumferential sheet. During the bed transfer, log-rolling, and head of bed elevation, there were no significant differences in displacements observed when the pelvis was immobilized with either a sheet or pelvic binder (T-POD). Conclusions A circumferential pelvic sheet is more readily available, costs less, is more versatile, and is equally as efficacious at immobilizing the unstable pelvis as compared to the T-POD. We advocate the use of circumferential sheeting for temporary stabilization of unstable pelvic injuries.

Study design A gross anatomic and motion analysis study in cadavers. Objective Assess spinal motion in a cadaveric spinal fracture model and investigate the ability of external orthoses to control this motion. Summary of background data External orthoses are frequently prescribed for patients who have experienced burst fracture of the thoracolumbar spine. Despite the substantial expense involved, there is little data confirming their value. Methods A T12 burst fracture model was created in 5 lightly embalmed cadavers by resecting the anterior and middle columns of the T12 vertebra through a thoracolumbar anterior approach to the spine. An electromagnetic motion tracking and analysis system was used to track angular and linear displacement at the fracture during routine patient maneuvers. Several commonly used orthoses, including an extension brace and both an "off-the-shelf" and custom-molded thoracic-lumbar-sacral orthosis (TLSO), were applied to the cadavers and the affect on fracture site motion was assessed. Results Application of all 3 styles of brace resulted in angular motion of 8° to 12° in flexion-extension, 11° to 20° in axial rotation, and 8° to 10° of lateral bending. Brace application resulted in linear displacement of 29 to 46 mm in the medial-lateral plane, 21 to 23 mm in the axial plane, and 21 to 37 mm in the anterior-posterior plane. During logrolling maneuvers, TLSO style braces diminished angular motion, although residual motion in the range of 5° remained. TLSO style braces had little effect on linear translation. When placed in a seated position in bed, TLSO style braces diminished flexion and extension modestly, but did not influence lateral bending or linear translation. Extension style braces had no effect on fracture motion during any activity tested. Conclusion In a cadaver model of a burst fracture, there is surprising angular and linear motion at the fracture during common hospital activities. TLSO orthoses can decrease angular motion but do not effect translation at the fracture. An extension orthosis had no effect on motion at the spinal fracture site.

Study Design. A case report and clinical discussion. Objective. To discuss the diagnosis and treatment of Blastomyces dermatitidis in the spine. Summary of Background Data. Blastomycosis, like other fungal organisms, has a nonspecific appearance on radiographs, and is often mistaken for TB or a neoplasm. Nonsurgical treatment of this infection is possible, however, as seen in this case. The difficulty in diagnosing fungal infections often leads to a delay in treatment. Methods. We report on a 37-year-old Arabian woman who presented initially with progressive low back and anterior thigh pain without precipitating trauma. She was found to have 2 draining fistulas. Computed tomography-guided percutaneous drainage of the paravertebral phlegmon yielded purulent material that was pan cultured. The KOH preparation was consistent with a fungal pathogen, which was later identified as Blastomyces dermatitidis by polymerase chain reaction. Results. Radiologic studies of the lumbar spine and sacrum performed revealed extensive involvements with osseous destruction of L2–S1. The destruction was most severe at L3 with mild boney retropulsion at that level. Throughout the patient's treatment course, she complained of mild-to-moderate lower back pain and had no neurologic symptoms. Therefore, surgery was deferred. Conclusion. There are no pathognomonic findings of blastomycosis on magnetic resonance imaging. Fungal osteomyelitis is rarely identified in this country, and blastomycosis is even less often diagnosed. This case illustrates that fungal osteomyelitis should be considered in the radiographic differential diagnosis until a definitive diagnosis is made through biopsy.

Regulators across many different jurisdictions and industries have recently adopted the practice of setting access prices based on the current costs of providing the relevant facilities. Though widely regarded as being efficient, the efficiency implications of using current costs instead of historical costs have not been formally analyzed. Our analysis shows that given stochastic costs, forward-looking access prices retard investment and are generally dominated by access prices determined by historical cost whenever investment is desired.

The aim of this work was to develop and validate a simple and sensitive analytical method for determining enrofloxacin (EFX) and ciprofloxacin (CFX) in equine plasma and endometrial tissue samples, as a precursor to conducting pharmacokinetic/pharmacodynamic studies on equine endometritis This was achieved in the form of a liquid chromatographic procedure, with fluorometric detection, which also gave good separation of other fluoroquinolones including marbofloxacin (MFX), danofloxacin (DFX) and ofloxacin (OFX). Analytes were separated on a C18 reversed phase column using an acidified mobile phase. The exact composition of the mobile phase differed for plasma (16% acetonitrile:methanol [13:1,v/v] 84% water containing 0.4% triethylamine and 0.4% phosphoric acid [35%]) and endometrial tissue (14% acetonitrile, 86% water, without methanol) samples. EFX and CFX were both detected at excitation and emission wavelengths of 294 and 500 nm, respectively. Prior to chromatography, EFX and CFX were purified by solid phase extraction from plasma, and a combination of solvent/solid phase extraction from endometrial tissue. Mean absolute recoveries for EFX and CFX from plasma were 94.1 and 78.0%, respectively, and from endometrial tissue, 78.0 and 57.8%, respectively, with a percentage residual standard deviation (%R.S.D.)

This study compared pharmacokinetic (PK) profiles in sheep dosed intravenously with three different concentrations of oxfendazole (OFZ). An in vitro plasma OFZ dissolution study provided additional information on plasma saturation. For the PK study, 18 adult, parasite-free, female Suffolk cross sheep, allocated into three groups (n=6), were treated intravenously, at a dose rate of 5mg/kg bodyweight, with aqueous solutions containing at 4, 8 or 16% OFZ. Plasma drug concentrations were measured, for up to 72 hours post-treatment, by a validated high performance liquid chromatography (HPLC) method with UV detection. OFZ and fenbendazole sulphone (FBZSO2) were the main metabolites detected in all three experimental groups. In animals given the 4% solution, OFZ depleted according to a biexponential concentration vs. time curve. In contrast, those given 8 or 16% preparations produced atypical curves fitted by monoexponential equations. No statistically significant differences in area under concentration-time curves (AUC) were observed, but concentration-dependent differences in distribution and mean residence time (MRT) were evident. Compared with 4% OFZ, animals treated with 8 and 16% formulations had slower half-lives of metabolite formation,and lower AUC’s, suggesting that OFZ sulphonation may have been modified. In vitro there was evidence of plasma saturation and precipitation associated with 8 and 16% OFZ preparations. It is concluded that differences in PK profiles, in vivo, may have been related to inadequate dissolution and/or tissue drug precipitation. Fil: Sanchez Bruni, Sergio Fabian. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatología. Laboratorio de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Jones, Douglas G.. Moredun Research Institute. Pentlands Science Park; Reino Unido Fil: Small, John. Moredun Research Institute. Pentlands Science Park; Reino Unido Fil: McKellar, Quintin A.. Moredun Research Institute. Pentlands Science Park; Reino Unido

Co-administration of piperonyl butoxide (PB) potentiates fenbendazole (FBZ) in small ruminants. The resultant increase in bioavailability of FBZ and its metabolite oxfendazole (OFZ) has important implications for the efficacy of these drugs against benzimidazole (BZD)-resistant strains of Teladorsagia circumcincta. This study evaluated the racemic (achiral) and enantiomeric (chiral) plasma disposition kinetics of OFZ and its metabolites after the co-administration of PB and OFZ in sheep. Six 6-8-month-old, parasite-free, female Dorset sheep (30-40 kg) were used in a two-phase crossover experiment. In phase I, three sheep received 30 mg/kg PB orally, followed by a single intravenous (i.v.) injection of OFZ at 5 mg/kg. The other three animals were treated similarly except that 5 mL of water replaced PB. In phase 2, treatments for the two groups were reversed and were given 14 days after the initiation of phase I. Three analytes OFZ, FBZ and fenbendazole sulphone (FBZSO(2)) were recovered in plasma up to 48 h post-treatment in both experimental groups. Achiral and chiral pharmacokinetic (PK) profiles for OFZ, after the co-administration of PB, were characterized by a significantly greater area under the concentration--time curve (AUC) and a longer mean residence time (MRT). Chiral OFZ distribution ratios were comparable in both treatment groups. Piperonyl butoxide treatment markedly influenced the plasma PK profiles for FBZ and FBZSO(2) following OFZ administration. Production of FBZ was enhanced as reflected by increased (> 60%) AUC, delayed T(max) and a significantly delayed (> 45%) elimination (t(1/2)(el)). Although AUC values for FBZSO(2) were not significantly different between groups, this metabolite was depleted more slowly from plasma (t(1/2)(el) > 60% and MRT > 42%) following PB treatment. This study demonstrated that PB co-administration is associated with an inhibition of OFZ biotransformation, as evidenced by the significantly higher plasma concentrations of OFZ and FBZ, and this could have important implications in terms of anti-parasite therapy against BZD-resistant parasite strains.

This article is based on an interview with John Small by Guest Editor Beverley Prevatt Goldstein during the Fourth International Conference of Caribbean and International Social Work Educators, which took place in Jamaica in July 1999. Small played a key role in the recruitment of black carers, which, with its focus on the importance of identity, contributed to the radical shift in the ideological base of British social work practice from the early 1980s. After a brief introduction by the Editor, he reflects on these issues, both in the light of the pioneering work carried out by black activists at that time and the challenges for those engaged in family placement work today. In conclusion, Prevatt Goldstein comments on the interview and the relevance of Small's position in the 21st Century.

Eight normal cadaveric knee specimens were used to evaluate the effects of femoral and tibial tunnel positions on length excursions of a single wire and bone-patellar tendon-bone graft as measured by an isometer. Femoral attachment sites were varied by using a commercially available femoral pin guide with either a 5.5- or 7.0-mm offset and by aiming with the guide oriented vertically (12:00 notch position) or rotating 45 degrees toward the lateral condyle (1:30 or 10:30 notch position depending on right or left knee). Tibial isometry was altered by testing the wire against the posterior tunnel wall or 5-mm anterior using a custom centering device. Isometry was measured from 0 degrees to 120 degrees for each position tested. A 7-mm offset guide rotated to the 12:00 position yielded the best single fiber and graft excursion patterns (P < .05). A 5.5-mm offset guide yielded inferior single fiber and graft excursion patterns. Single fiber and graft isometry were found to be similar, but not identical in endoscopic anterior cruciate ligament reconstruction. Centering the single fiber in the tibial tunnel had little effect on excursion patterns, showing that the more posterior tibial positions needed for endoscopic reconstruction are acceptable from an isometry standpoint.

Copyright issues and how they apply to the Internet are under scrutiny. Downloading, ownership, and liability questions are becoming focal points for Internet users. The authors discuss the legal issues of copyright and the Internet, how those issues affect the general user, and cautions that users should consider.

Objective Most trauma centers place pelvic binders on unstable pelvic fractures for acute management and control of hemorrhage. It has been proposed that the binders be placed at the level of the greater trochanters of the femur. Our hypothesis was that application of the T-POD at this site would provide better immobilization of an unstable pelvic injury than a more cephalad location. Methods Unstable pelvic injuries (OTA type 61-C1) were surgically created in 9 fresh whole human cadavers. Electromagnetic sensors were affixed to the intact and injured sides of the pelvis. A Fastrak, three-dimensional electromagnetic motion analysis device was used to determine the angular motion occurring at the fractured sites. Maximum displacements for sagittal, coronal, and axial rotation were recorded during application of the binder, while performing bed transfers, while logrolling, and elevating the head of the bed. The T-POD device was placed either over the greater trochanters or at the level of the anterior superior iliac spine as per manufacturer's recommendations. Results There were no significant differences in the amount of motion produced during application of the T-POD at either location. There was less motion observed in all planes of motion during all maneuvers when the T-POD was placed at the level of the greater trochanters versus anterior superior iliac spine. During bed transfers, this was statistically significant in all planes. This was statistically significant while logrolling in the axial plane and the coronal plane during head of bed elevation. Conclusions We advocate the placement of pelvic binder devices at the level of the greater trochanters for improved control of the fracture in an unstable pelvic injury. This may result in improved control of hemorrhage, better access to the abdomen, and greater patient comfort.

BACKGROUND Most institutions treating pelvic fractures use some method of acute mechanical stabilization. This typically involves use of pelvic binders or circumferential sheeting, and/or external fixation. The comparative value of these different modalities is controversial. We hypothesized that an external fixator would provide more stability to an unstable pelvic injury than a commercially available binder device (trauma pelvic orthotic device [T-POD]). METHODS Unstable pelvic injuries (Tile C) were surgically created in five fresh whole human cadavers. Electromagnetic sensors were placed on the same position of each hemipelvis. The amount of angular motion during testing was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device. Maximum displacements were recorded during application of the stabilizing devices, bed transfer, logrolling, and head-of-bed elevation. External fixation frames were constructed by placing two 5.0-mm half pins into the iliac crest and then connected them with a 10-mm curved bar. The T-POD device was placed at the level of the greater trochanters as per manufacturer's recommendations. RESULTS While logrolling the patient and performing bed transfers, the T-POD conferred more stability in all planes of motion, although this did not reach statistical significance. During elevation of the head of the bed, the T-POD allowed less motion in the sagittal and coronal planes but permitted equivalent motion in axial rotation. These differences were not statistically significant. CONCLUSION There were no significant differences in stability conferred by an external fixator or a T-POD for unstable pelvic injuries. We advocate acute, temporary stabilization of pelvic injuries with a binder device and early conversion to internal fixation when the patient's medical condition allows.

Biomechanical cadaveric study.We sought to analyze the amount of motion generated in the unstable cervical spine during various maneuvers and transfers that a trauma patient would typically be subjected to prior to definitive fixation, using 2 different protocols.From the time of injury until the spine is adequately stabilized in the operating room, every step in management of the spine-injured patient can result in secondary injury to the spinal cord.The amount of angular motion between C5 and C6, after a surgically created unstable injury, was measured using an electromagnetic motion analysis device (Polhemus Inc., Colchester, VT). A total sequence of maneuvers and transfers was then performed that a patient would be expected to go through from the time of injury until surgical fixation. This included spine board placement and removal, bed transfers, lateral therapy, and turning the patient prone onto the operating table. During each of these, we performed what has been shown to be the best and commonly used (log-roll) techniques.During bed transfers and the turn prone for surgery, there was statistically more angular motion in each plane for traditional transfer with the spine board and manually turning the patient prone as commonly done (P0.01). During spine board placement, there was more motion in all 3 planes with log-rolling, and this reached statistical significance for axial rotation (P = 0.015) and lateral bending (P = 0.004). There was more motion during board removal with log-rolling in all 3 planes. This was statistically significant for lateral bending (P = 0.009) and approached significance in flexion-extension (P = 0.058) and axial rotation (P = 0.058). During lateral therapy, there was statistically more motion in flexion-extension and lateral bending with the manual log-roll technique (P0.001). The total motion was decreased by more than 50% in each plane when using an alternative to log-roll techniques during the total sequence (P0.006).We have demonstrated the total angular motion incurred to the unstable cervical spine as experienced by the typical trauma patient from the field to stabilization in the operating room using the best compared with the most commonly used techniques. As previously reported, using log-roll techniques consistently results in unwanted motion at the injured spinal segment.

General equilibrium moels are usually represented as a system of levels equations (e.g., in North America) or a system of linearized equations (e.g., in Australia). Either representation can be used to obtain accurate solutions. General-purpose software is available in both cases-GAMS or MPS/GE is typically used by levels modellers and GEMPACK by linearizers. Some equations (notably accounting identities) are naturally expressed in the levels while others (especially behavioural equations) are naturally expressed in a linearized form. This paper describes the new GEMPACK facility for solving models represented as a mixture of levels and linearized equations and discusses the advantages to modellers of using such a representation.

The ability to reliably detect anthelmintic resistance is a crucial part of resistance management. If data between countries are to be compared, the same test should give the same results in each laboratory. As the egg hatch test for benzimidazole resistance is used for both research and surveys, the ability of different laboratories to obtain similar results was studied through testing of known isolates of cyathostomins, Haemonchus contortus, Ostertagia ostertagi, and Cooperia oncophora in programs supported by the EU (Cost B16 and FP6-PARASOL). Initial results showed difficulties in obtaining reproducible and similar data within and between laboratories. A series of ring tests, i.e., simultaneous and coordinated rounds of testing of nematode isolates in different laboratories was subsequently performed. By adopting identical protocols, especially the use of deionized water and making dilutions of thiabendazole in dimethyl sulfoxide in the final ring test, laboratories correctly identified both susceptible and resistant isolates. The protocols for the test and preparation of solutions of thiabendazole are described. European Commission (FOOD-CT-2005-022851)

Simple self‐referential algorithms can model the essential logic of quantum systems and the quantum formalism is sufficiently rich to be able to model the output states of self‐referential alogrithms. We identify a key feature of self‐referentiality and show that both quantum mechanics and general relativity exhibit this feature in distinct yet complementary ways. This implies that self‐referentiality must be a foundational principle, but causality protection prohibits it being directly observed. Examining two facets of causality protection we find that quantum mechanics implements one and general relativity the other. The implication is that there can be no mathematically consistent theory for quantum gravity. However we can gain understanding of the constraints imposed on physical law when viewing a noncausal reality as if it were a causal sequence. We derive the 3+1 dimensionality of spacetime and quantum non‐locality and also possible rationale for the U(1) × SU(2) × SU(3) symmetry of the Standard Mod...

Object In this study the authors retrospectively review outcomes in patients treated for metastases to the spine. Surgery for metastatic tumors to the spine remains an important part of the treatment armamentarium. Maximum tumor resection with a minimum number of complications is one of the goals of surgery. Current surgical procedures include tumor resection and spinal stabilization for optimal results. Methods The records of 96 patients who underwent surgery for a metastatic spine tumor at the authors' institution were reviewed. Spinal instrumentation was used in the majority of patients. Ambulatory status was maintained in 91% and pain improved in 94% of patients. Complications included infection (5.2%), cerebrospinal fluid leak (2%), and delayed hardware failure (3.1%). The mortality rate was 4.1%; the main cause was due to tumor progression. Conclusions Surgery is indicated in a select group of patients with metastatic tumors to the spine. A multidisciplinary approach is recommended for patient selection and complication avoidance. Surgical options, including approach, type of reconstruction and extent of resection (including en bloc spondylectomy) need to be addressed for optimal outcomes.

1. The effect of co-administration of either short- or long-acting formulations of DXM on hepatic function and the plasma pharmacokinetic behaviour of prochiral fenbendazole (FBZ) and its metabolites was evaluated in sheep. 2. Neither DXM treatment markedly affected any of the biochemical markers of hepatic function tested. In contrast, both formulations significantly modified the plasma pharmacokinetic behaviour of FBZ and its metabolites. 3. Plasma FBZ concentrations and the associated area under the time-concentration curves were significantly lower, although the plasma detection period was longer (72 versus 48 h) in the DXM pretreated animals compared with those given FBZ alone. 4. DXM also appeared to alter the pattern of FBZ absorption, possibly through effects on abomasal pH. The shape of the plasma concentration-time curves for oxfendazole (OFZ) and fenbendazole sulphone (FBZSO(2)) were similar to FBZ, raising the possibility that DXM treatment may have altered the liver biotransformation of the parent drug. 5. The concentrations of the (+) chiral metabolite of OFZ were significantly lower in DXM pretreated animals compared with those given FBZ alone. The trend was similar for the (-) antipode, although the differences between DXM pretreated and non-pretreated animals were not statistically significant.

The effect of femoral guide rotation in endoscopic anterior cruciate ligament (ACL) reconstruction is reviewed based on a previous report. The effect of varied offsets of the femoral guide (5.5 and 7.0 mm) are described. This is one of the few isometry studies to evaluate the knee through a practically full range of motion (0 degree-120 degrees). A 7-mm offset guide rotated to the 12:00 position yields the best single fiber and graft excursion patterns (P0.05). A 5.5-mm offset guide yields inferior single fiber and graft excursion patterns. Single fiber and graft isometry are similar but not identical in endoscopic ACL reconstruction. Centering the single fiber in the tibial tunnel has little effect on isometry patterns, demonstrating that the more posterior tibial positions needed for endoscopic reconstruction are acceptable from an isometry standpoint.

Study design The effect of sitting versus standing posture on lumbar lordosis was studied retrospectively by radiographic analysis of 109 patients with low back pain. Objective To document changes in segmental and total lumbar lordosis between sitting and standing radiographs. Summary of background data Preservation of physiologic lumbar lordosis is an important consideration when performing fusion of the lumbar spine. The appropriate degree of lumbar lordosis has not been defined. Methods Total and segmental lumbar lordosis from L1 to S1 was assessed by an independent observer using the Cobb angle measurements of the lateral radiographs of the lumbar spine obtained with the patient in the sitting and standing positions. Results Lumbar lordosis averaged 49 degrees standing and 34 degrees sitting from L1 to S1, 47 degrees standing and 33 degrees sitting from L2 to S1, 31 degrees standing and 22 degrees sitting from L4 to S1, and 18 degrees standing and 15 degrees sitting from L5 to S1. Conclusion Lumbar lordosis while standing was nearly 50% greater on average than sitting lumbar lordosis. The clinical significance of this data may pertain to: 1) the known correlation of increased intradiscal pressure with sitting, which may be caused by this decrease in lordosis; 2) the benefit of a sitting lumbar support that increases lordosis; and 3) the consideration of an appropriate degree of lordosis in fusion of the lumbar spine.