A flexible proton beam imaging energy spectrometer (PROBIES) for high repetition rate or single-shot high energy density (HED) experiments (invited).

The PROBIES diagnostic is a new, highly flexible, imaging and energy spectrometer designed for laser-accelerated protons. The diagnostic can detect low-mode spatial variations in the proton beam profile while resolving multiple energies on a single detector or more. When a radiochromic film stack is employed for "single-shot mode," the energy resolution of the stack can be greatly increased while reducing the need for large numbers of films; for example, a recently deployed version allowed for 180 unique energy measurements spanning ∼3 to 75 MeV with <0.4 MeV resolution using just 20 films vs 180 for a comparable traditional film and filter stack. When utilized with a scintillator, the diagnostic can be run in high-rep-rate (>Hz rate) mode to recover nine proton energy bins. We also demonstrate a deep learning-based method to analyze data from synthetic PROBIES images with greater than 95% accuracy on sub-millisecond timescales and retrained with experimental data to analyze real-world images on sub-millisecond time-scales with comparable accuracy.

Additively manufactured electrodes for plasma and power-flow studies in high-power transmission lines on the 1-MA MAIZE facility.

Power-flow studies on the 30-MA, 100-ns Z facility at Sandia National Laboratories have shown that plasmas in the facility's magnetically insulated transmission lines (MITLs) and double post-hole convolute can result in a loss of current delivered to the load. To study power-flow physics on the 1-MA, 100-ns MAIZE facility at the University of Michigan, planar MITL loads and planar post-hole convolute loads have been developed that extend into the lines of sight for various imaging diagnostics on MAIZE. These loads use 3D-printed dielectric support structures lined with thin foils of either aluminum or stainless steel. The metal foils serve as the current-carrying power-flow surfaces, which generate plasma during the current pulse. The foil thickness (50 µm) and widths (11.5-16 mm) are selected to ensure a sufficient linear current density (0.5-0.7 MA/cm) for plasma formation. Laser backlighting (532 nm) and visible-light self-emission imaging capture the overall plasma evolution in the anode-cathode gaps, including the gap closure velocities (1-4 cm/µs).

A pulsed-power implementation of "Laser Gate" for increasing laser energy coupling and fusion yield in magnetized liner inertial fusion (MagLIF).

Magnetized Liner Inertial Fusion (MagLIF) at Sandia National Laboratories involves a laser preheating stage where a few-ns laser pulse passes through a few-micron-thick plastic window to preheat gaseous fusion fuel contained within the MagLIF target. Interactions with this window reduce heating efficiency and mix window and target materials into the fuel. A recently proposed idea called "Laser Gate" involves removing the window well before the preheating laser is applied. In this article, we present experimental proof-of-principle results for a pulsed-power implementation of Laser Gate, where a thin current-carrying wire weakens the perimeter of the window, allowing the fuel pressure to push the window open and away from the preheating laser path. For this effort, transparent targets were fabricated and a test facility capable of studying this version of Laser Gate was developed. A 12-frame bright-field laser schlieren/shadowgraphy imaging system captured the window opening dynamics on microsecond timescales. The images reveal that the window remains largely intact as it opens and detaches from the target. A column of escaping pressurized gas appears to prevent the detached window from inadvertently moving into the preheating laser path.

Optimization of switch diagnostics on the MAIZE linear transformer driver.

The MAIZE Linear Transformer Driver consists of 40 capacitor-switch-capacitor "bricks" connected in parallel. When these 40 bricks are charged to ±100-kV and then discharged synchronously, the MAIZE facility generates a 1-MA current pulse with a 100-ns rise time into a matched load impedance. Discharging each of the capacitors in a brick is carried out by the breakdown of a spark-gap switch, a process that results in the emission of light. Monitoring this output light with a fiber optic coupled to a photomultiplier tube (PMT) and an oscilloscope channel provides information on switch performance and timing jitter-whether a switch fired early, late, or in phase with the other switches. However, monitoring each switch with a dedicated detector-oscilloscope channel can be problematic for facilities where the number of switches to be monitored (e.g., 40 on MAIZE) greatly exceeds the number of detector-oscilloscope channels available. The technique of using fibers to monitor light emission from switches can be optimized by treating a PMT as a binary digit or bit and using a combinatorial encoding scheme, where each switch is monitored by a unique combination of fiber-PMT-oscilloscope channels simultaneously. By observing the unique combination of fiber-PMT-oscilloscope channels that are turned on, the prefiring or late-firing of a single switch on MAIZE can be identified by as few as six PMT-oscilloscope channels. The number of PMT-oscilloscope channels, N, required to monitor X switches can be calculated by 2N = X + 1, where the number "2" is selected because the PMT-oscilloscope acts as a bit. In this paper, we demonstrate the use of this diagnostic technique on MAIZE. We also present an analysis of how this technique could be scaled to monitor the tens of thousands of switches proposed for various next generation pulsed power facilities.

Hemopoietic-specific Sf3b1-K700E knock-in mice display the splicing defect seen in human MDS but develop anemia without ring sideroblasts.

Heterozygous somatic mutations affecting the spliceosome gene SF3B1 drive age-related clonal hematopoiesis, myelodysplastic syndromes (MDS) and other neoplasms. To study their role in such disorders, we generated knock-in mice with hematopoietic-specific expression of Sf3b1-K700E, the commonest type of SF3B1 mutation in MDS. Sf3b1K700E/+ animals had impaired erythropoiesis and progressive anemia without ringed sideroblasts, as well as reduced hematopoietic stem cell numbers and host-repopulating fitness. To understand the molecular basis of these observations, we analyzed global RNA splicing in Sf3b1K700E/+ hematopoietic cells. Aberrant splicing was associated with the usage of cryptic 3' splice and branchpoint sites, as described for human SF3B1 mutants. However, we found a little overlap between aberrantly spliced mRNAs in mouse versus human, suggesting that anemia may be a consequence of globally disrupted splicing. Furthermore, the murine orthologues of genes associated with ring sideroblasts in human MDS, including Abcb7 and Tmem14c, were not aberrantly spliced in Sf3b1K700E/+ mice. Our findings demonstrate that, despite significant differences in affected transcripts, there is overlap in the phenotypes associated with SF3B1-K700E between human and mouse. Future studies should focus on understanding the basis of these similarities and differences as a means of deciphering the consequences of spliceosome gene mutations in MDS.

Evaluation of a health resources management course for Nigerian doctors.

AIMS AND OBJECTIVES: This study aimed to evaluate the March 2010 edition of the regular biannual two-week course on health resources management organised by the National Postgraduate Medical College of Nigeria. The main objectives were to assess participants' perception of the course and to measure change in their knowledge brought about by the course. SUBJECTS AND METHODS: This is a primarily cross-sectional study but with a before and after component. The study population comprised all participants who attended the course. Data were collected using pre-tested structured self- administered questionnaires. Data analysis was done with Epi Info 3.5.1. Student's T-test was used to compare mean scores at pre-test and post-test and the p-value of <0.05 was considered statistically significant. RESULTS: Majority (95.8%) of the participants were senior registrars from teaching hospitals and most of them (70.5%) claimed the course met their needs a great deal/to a large extent. The participants were satisfied to a varying degree with different aspects of the course but overall 50.9% claimed they got value for their money. There was a statistically significant difference in the knowledge score at pre- and post-test (t = 3.19, p = 0.002). CONCLUSION: The course met the needs of the participants largely and was able to improve their knowledge of health resources management as intended. A behaviour evaluation is recommended in order to assess the usefulness of the course to participants' practice.

The effect of surgical approach on the histologyof the femoral head following resurfacing of the hip: Analysis of retrieval specimens.

OBJECTIVES: We aimed to determine the effect of surgical approach on the histology of the femoral head following resurfacing of the hip. METHODS: We performed a histological assessment of the bone under the femoral component taken from retrieval specimens of patients having revision surgery following resurfacing of the hip. We compared the number of empty lacunae in specimens from patients who had originally had a posterior surgical approach with the number in patients having alternative surgical approaches. RESULTS: We found a statistically significant increase in the percentage of empty lacunae in retrieval specimens from patients who had the posterior approach compared with other surgical approaches (p < 0.001). CONCLUSIONS: This indicates that the vascular compromise that occurs during the posterior surgical approach does have long-term effects on the bone of the femoral head, even if it does not cause overt avascular necrosis. Cite this article: Bone Joint Res 2013;2:200-5.

Job satisfaction: rural versus urban primary health care workers' perception in Ogun State of Nigeria.

BACKGROUND: Job satisfaction implies doing a job one enjoys, doing it well, and being suitably rewarded for one' efforts. Several factors affect job satisfaction. OBJECTIVE: To compare factors influencing job satisfaction amongst rural and urban primary health care workers in southwestern Nigeria. METHODS: A cross sectional comparative study recruited qualified health workers selected by multi stage sampling technique from rural and urban health facilities in four local government areas (LGAs) of Ogun State in Southwestern Nigeria. Data were collected and analysed using Epi info V 3.5.1 RESULTS: The response rates were 88(88%) and 91(91%) respectively in the rural and urban areas. While urban workers derived satisfaction from availability of career development opportunities, materials and equipment, in their current job, rural workers derived satisfaction from community recognition of their work and improved staff relationship. Major de-motivating factors common to both groups were lack of supportive supervision, client-provider relationship and lack of in-service training. However more rural 74(84.1%) than urban 62(68.1%) health workers would prefer to continue working in their present health facilities (p=0.04). There was a statistically significant difference between the two groups in job satisfaction with respect to tools availability and career development opportunities (p<0.05). CONCLUSION: There is dissimilarity in factors influencing job satisfaction between rural and urban healthcare workers. There is need for human resource policy to be responsive to the diverse needs of health workers particularly at the primary level.

An assessment of client satisfaction with services at a model primary health care centre in Ogun State, Nigeria.

BACKGROUND: Assessing patient satisfaction with health care is increasingly becoming an integral component of quality monitoring in health care systems. However, studies that have been conducted in this environment often show that clients' perceptions of quality of care from public sector providers are generally low. Timeliness, which refers to obtaining needed care and minimizing unnecessary delays in getting that care, may impact considerably on patients' satisfaction. This study w as designed toexamine how the consumers of services at a model primary health centre in Ogun State, Nigeria, viewed their health-seeking experience, relating this to the level of organization.and timeliness of health services provision. OBJECTIVES: This study sought to assess the satisfaction of clients with services at a model PHC centre at Pakoto, Ogun State, Nigeria. METHODS: The Pakoto model primary health care centre is an outstation of the Lagos University Teaching Hospital (LUTH) Idi-Araba, Lagos State. The study was carried out on weekday mornings at the model PHC clinic during the month of June, 2006. Methods of data collection employed were a general observation of clinic activities, and the administration of a modified client flow analysis chart to clients as they exited the health facility. RESULTS: The peak time of arrival of clients was between 9.00 and 11.00 a.m. when the majority (58.5%) of clients arrived; the majority of clients (84%) exited the facility oetween 11:00 a.m. and 1:00 p.m. The highest proportion of clients (33.1%) spent 3-4 hours accessing services at the model PHC facility. Good staff attitude topped the list of aspects of service liked most by clients (36%), while the aspect of service liked least by respondents was lack of timeliness of services (43%). Suggestions for improvement of services included increase in the number of staff and staff training (30%) and early arrival of staff to work (13%). CONCLUSION: The study concludes that timeliness of services at the primary health care level impacts positively upon the perception of quality of services rendered to clients.

An Assessment of Client Satisfaction with Services at a Model Primary Health Care Centre in Ogun State; Nigeria

BACKGROUND: Assessing patient satisfaction with health care is increasingly becoming an integral component of quality monitoring in health care systems. However; studies that have been conducted in this environment often show that clients' perceptions of quality of care from public sector providers are generally low. Timeliness; which refers to obtaining needed care and minimizing unnecessary delays in getting that care; may impact considerably on patients' satisfaction. This study w as designed toexamine how the consumers of services at a model primary health centre in Ogun State; Nigeria; viewed their health-seeking experience; relating this to the level of organization.and timeliness of health services provision. OBJECTIVES: This study sought to assess the satisfaction of clients with services at a model PHC centre at Pakoto; Ogun State; Nigeria. METHODS: The Pakoto model primary health care centre is an outstation of the Lagos University Teaching Hospital (LUTH) Idi-Araba; Lagos State. The study was carried out on weekday mornings at the model PHC clinic during the month of June; 2006. Methods of data collection employed were a general observation of clinic activities; and the administration of a modified client flow analysis chart to clients as they exited the health facility. RESULTS: The peak time of arrival of clients was between 9.00 and 11.00 a.m. when the majority (58.5) of clients arrived; the majority of clients (84) exited the facility oetween 11:00 a.m. and 1:00 p.m. The highest proportion of clients (33.1) spent 3-4 hours accessing services at the model PHC facility. Good staff attitude topped the list of aspects of service liked most by clients (36); while the aspect of service liked least by respondents was lack of timeliness of services (43). Suggestions for improvement of services included increase in the number of staff and staff training (30) and early arrival of staff to work (13). CONCLUSION: The study concludes that timeliness of services at the primary health care level impacts positively upon the perception of quality of services rendered to clients

Maternal and perinatal mortality in ward A, Ikosi-Isheri LCDA in Lagos State, Nigeria: from "guestimates" to near actuals.

BACKGROUND: The problem of authentic statistics on maternal and peri-natal mortality has persisted in Nigeria probably because of inadequate involvement of community members in data management. OBJECTIVE: The objective of this study was to improve the accuracy of information on pregnancy outcome in a ward in Lagos state. METHODS: Residents of Ward A of Ikosi-Isheri Local Council Development Area (LCDA) of Lagos State were educated on the importance of accurate health data. Youths selected based on criteria and community-based health care providers, following refresher training on research methods, assisted with the collection, analysis and presentation of data. RESULTS: The records of churches, mosques, Traditional Birth Attendants, the government owned Primary Health Care (PHC) centre and 7 private health facilities in the ward reported no (0) maternal mortality, but 14 out of 633 live births in the latter died, giving a peri-natal mortality of 22.1 per thousand in one year. However, neither the CDAs, nor LCDA nor the state received regular reports on pregnancy outcome. CONCLUSION: Under-reporting or over-estimation of pregnancy outcome can be reduced by involvement of the leaders of Residents Associations and other relevant community members in data management. Data should be collected by smaller units into which a ward is divided and collated at the ward level for transmission to the LGA/LCDA. Feedback to community members will improve awareness about the importance of appropriate antenatal, natal and peri-natal care. Health care providers are also more likely to take prompt action to prevent maternal and peri-natal mortality.

Perceptions and practices of private medical practitioners to adolescent reproductive health in Lagos State, Nigeria.

INTRODUCTION AND OBJECTIVES: Adolescent sexual and reproductive ill health is a major global public health issue, contributing to high levels of morbidity and mortality in adolescents. Although adolescents are known to have low levels of doctor consultations, private medical practitioners remain the preferred health care providers. This study was carried out to document the attitudes and experiences of private medical practitioners to adolescent reproductive health issues and to assess the factors that may influence their attitudes. METHODS: Information was obtained from a random sample of 187 out of 352 (53% ) registered private medical practitioners in 5 of the 20 Local Government Areas in Lagos State using a self-administered structured questionnaire. RESULTS: Sixty-two per cent of the doctors claimed they saw adolescents regularly, mainly for the treatment of sexually transmitted infections (STIs). Many (86% ) believed that adolescents should use contraception and suggested that parents, teachers and health workers provide sexuality information to adolescents. Sixty one percent of the practitioners believed that abortion should be legalised, though with restrictions. Many of them admitted to providing post abortion care to adolescents. The religious affiliation of the private medical practitioners influenced their perception and practices. CONCLUSION AND RECOMMENDATIONS: Improving the reproductive health care of adolescents is key to improving the world's future economic and social well being. It is recommended that appropriate sexuality education be made widely available to adolescents. In addition, private medical practitioners should strengthen their skills and be more actively involved in the care of adolescents by making their facilities more adolescent friendly.

Liver tumours and muscle relaxants. Electromyographic studies in children.

Electromyographic studies of the onset of action of tubocurarine or alcuronium were performed on eight occasions in five patients who had liver masses. There was a slow onset of action and an increased dose requirement in those with malignant disease. Normal responses were found in a patient with benign nodular hyperplasia and in another where the malignant tumour was successfully treated with chemotherapy.

The structure of a cDNA clone corresponding to mouse cardiac muscle actin mRNA.

A cDNA library was constructed from mouse cardiac muscle mRNA, and a clone corresponding to part of the mRNA for the cardiac muscle isoform of actin was isolated from this library. The nucleotide sequence of the cloned insert was determined and was found to contain almost the complete amino acid coding region for actin (only codons for the first two amino acids, absent from the mature protein, were lacking) and a substantial portion derived from the 3' untranslated region of the mRNA. Comparison of the latter with the corresponding region in cardiac actin mRNA from man and rat showed that this 3' untranslated region has been subject to conservational pressure during evolution. However a comparison with the corresponding region in skeletal muscle actin mRNAs indicated that the pattern of conservation is quite different in the two striated muscle actin isoforms.

Organization of a multifunctional protein in pyrimidine biosynthesis. A domain hypersensitive to proteolysis.

When the multifunctional protein that catalyses the first three steps of pyrimidine biosynthesis in hamster cells is treated with staphylococcal V8 proteinase, a single cleavage takes place. The activities of carbamoyl-phosphate synthetase (EC 6.3.5.5), aspartate carbamoyltransferase (EC 2.1.3.2) and dihydro-orotase (EC 3.5.2.3) and the allosteric inhibition by UTP are unaffected. One fragment, of Mr 182000, has the first and third enzyme activities, whereas the other fragment, of Mr 42000, has aspartate carbamoyltransferase activity and an aggregation site. A similar small fragment is observed in protein digested with low concentrations of trypsin. A similar large fragment is seen after digestion with trypsin and as the predominating form of this protein in certain mutants defective in pyrimidine biosynthesis. These results indicate that a region located adjacent to the aspartate carbamoyltransferase domain is hypersensitive to proteinase action in vitro and may also be sensitive to proteolysis in vivo.