Characterization of Agfa Structurix series D4 and D3sc x-ray films in the 0.7-4.6 keV energy range.

X-ray films remain a key asset for high-resolution x-ray spectral imaging in high-energy-density experiments conducted at the National Ignition Facility (NIF). The soft x-ray Opacity Spectrometer (OpSpec) fielded at the NIF has an elliptically shaped crystal design that measures x rays in the 900-2100 eV range and currently uses an image plate as the detecting medium. However, Agfa D4 and D3sc x-ray films' higher spatial resolution provides increased spectral resolution to the data over the IP-TR image plates, driving the desire for regular use of x-ray film as a detecting medium. The calibration of Agfa D4 x-ray film for use in the OpSpec is communicated here. These calibration efforts are vital to the accuracy of the NIF opacity measurements and are conducted in a previously un-studied x-ray energy range under a new film development protocol required by NIF. The absolute response of Agfa D4 x-ray film from 705 to 4620 eV has been measured using the Nevada National Security Site Manson x-ray source. A broader range of energies was selected to compare results with previously published data. The measurements were taken using selected anodes, filters, and applied voltages to produce well-defined energy lines.

Upgrades and redesign of the National Ignition Facility's soft x-ray opacity spectrometer (OpSpec).

The soft x-ray Opacity Spectrometer (OpSpec) used on the National Ignition Facility (NIF) has recently incorporated an elliptically shaped crystal. The original OpSpec used two convex cylindrical crystals for time-integrated measurements of point-projection spectra from 540 to 2100 eV. However, with the convex geometry, the low-energy portion of the spectrum suffered from high backgrounds due to scattered x-rays as well as reflections from alternate crystal planes. An elliptically shaped crystal allows an acceptance aperture at the crossover focus between the crystal and the detector, which reduces background and eliminates nearly all reflections from alternate crystal planes. The current elliptical design is an improvement from the convex cylindrical design but has a usable energy range from 900 to 2100 eV. In addition, OpSpec is currently used on 18 NIF shots/year, in which both crystals are typically damaged beyond reuse, so efficient production of 36 crystals/year is required. Design efforts to improve the existing system focus on mounting reliability, reducing crystal strain to increase survivability between mounting and shot time, and extending the energy range of the instrument down to 520 eV. The elliptical design, results, and future options are presented.

Research ethics committees in the Pacific Islands: gaps and opportunities for health sector strengthening.

There has been a range of developments in recent years to stimulate increasing public health research activity throughout the Pacific. Development of local capacity for ethics committee review and oversight is, however, frequently underdeveloped. This is reflected in the number of Pacific Island nations where ethics committees have not been established or where only informal processes exist for ethics review and oversight. This is problematic for the optimal development of relevant and culturally appropriate research, and building up local ethics committees should be part of continued research development in the Pacific. Three areas in which local ethics committees may add value are 1) offering better capacity to reflect local priorities, 2) providing broader benefits for research capacity building, and 3) assisting to strengthen systems beyond research ethics. This article considers benefits and challenges for ethics committees in the Pacific, and suggests directions for regional development to further strengthen public health research activity.

Il y a eu toute une gamme de développements au cours des dernières années visant à stimuler un accroissement des activités de recherche en santé publique à travers la région Pacifique. Cependant, le renforcement des capacités locales de révision et de surveillance par les comités d'éthique est fréquemment sous-développé. Ceci est reflété par le nombre de nations insulaires du Pacifique où aucun comité d'éthique n'a été mis en place ou seules des procédures informelles de revue et de surveillance existent. Ceci pose un problème pour le bon développement d'une recherche pertinente et culturellement appropriée ; la mise en place de comités d'éthique locaux devrait faire partie du développement continu de la recherche dans le Pacifique. Trois domaines dans lesquels les comités d'éthique locaux pourraient avoir une valeur ajoutée sont 1) offrir une meilleure capacité de refléter les priorités locales, 2) apporter des bénéfices plus grands pour le renforcement des capacités de recherche, et 3) contribuer à renforcer les systèmes au-delà de l'éthique de la recherche. Cet article envisage les bénéfices et les défis des comités d'éthique dans le Pacifique et suggère des orientations pour le développement régional afin de développer davantage les activités de recherche en santé publique.

En los últimos años se ha observado una diversidad de progresos que estimulan las actividades de investigación en salud pública en toda la región del Pacífico. Sin embargo, la creación de competencias locales en materia de comités de ética y supervisión suele ser deficiente. Esta situación se refleja en el número de estados insulares del Pacífico que aun no cuentan con comités de ética o donde se practica solo un proceso informal de examen de los aspectos éticos y de supervisión de los estudios clínicos. Estas circunstancias representan un obstáculo al desarrollo óptimo de una investigación pertinente y culturalmente apropiada; la creación de comités de ética debe formar parte del desarrollo continuo de la investigación en el Pacífico. Estos comités aportarían ventajas en tres esferas principales, a saber: 1) una mayor capacidad de responder a las prioridades locales; 2) la ampliación de las ventajas que ofrece el fortalecimiento de la capacidad de realizar investigaciones; y 3) el mejoramiento de los sistemas de salud, más allá del terreno de la ética de la investigación. En el presente artículo se examinan las ventajas y las dificultades que presentan los comités de ética en la región del Pacífico y se proponen orientaciones para el desarrollo regional que promuevan la actividad de investigación en salud pública.

Structure and magnetism in LaCoO3.

The temperature dependence of the hexagonal lattice parameter c of single crystal LaCoO3(LCO) with H = 0 and 800 Oe, as well as LCO bulk powders with H = 0, was measured using high-resolution x-ray scattering near the transition temperature To ≈35 K. The change of c(T) is well characterized by a power law in T − To for T>To and by a temperature independent constant for T

Mapping HPV Vaccination and Cervical Cancer Screening Practice in the Pacific Region-Strengthening National and Regional Cervical Cancer Prevention.

OBJECTIVE: To provide background information for strengthening cervical cancer prevention in the Pacific by mapping current human papillomavirus (HPV) vaccination and cervical cancer screening practices, as well as intent and barriers to the introduction and maintenance of national HPV vaccination programmes in the region. MATERIALS AND METHODS: A cross-sectional questionnaire-based survey among ministry of health officials from 21 Pacific Island countries and territories (n=21). RESULTS: Cervical cancer prevention was rated as highly important, but implementation of prevention programs were insufficient, with only two of 21 countries and territories having achieved coverage of cervical cancer screening above 40%. Ten of 21 countries and territories had included HPV vaccination in their immunization schedule, but only two countries reported coverage of HPV vaccination above 60% among the targeted population. Key barriers to the introduction and continuation of HPV vaccination were reported to be: (i) Lack of sustainable financing for HPV vaccine programs; (ii) Lack of visible government endorsement; (iii) Critical public perception of the value and safety of the HPV vaccine; and (iv) Lack of clear guidelines and policies for HPV vaccination. CONCLUSION: Current practices to prevent cervical cancer in the Pacific Region do not match the high burden of disease from cervical cancer. A regional approach, including reducing vaccine prices by bulk purchase of vaccine, technical support for implementation of prevention programs, operational research and advocacy could strengthen political momentum for cervical cancer prevention and avoid risking the lives of many women in the Pacific.

The unusual magnetism of nanoparticle LaCoO3.

Bulk and nanoparticle powders of LaCoO3 (LCO) were synthesized and their magnetic and structural properties were studied using SQUID magnetometry and neutron diffraction. The bulk and large nanoparticles exhibit weak ferromagnetism (FM) below T ≈ 85 K and a crossover from strong to weak antiferromagnetic (AFM) correlations near a transition expressed in the lattice parameters, To≈40 K. This crossover does not occur in the smallest nanoparticles; instead, the magnetic behavior is predominantly ferromagnetic. The amount of FM in the nanoparticles depends on the amount of Co3O4 impurity phase, which induces tensile strain on the LCO lattice. A core-interface model is introduced, with the core region exhibiting the AFM crossover and with FM in the interface region near surfaces and impurity phases.

The effects of Co3O4 on the structure and unusual magnetism of LaCoO3.

Bulk La(w)CoO(3) particles with w = 1.1, 1.0, 0.9, 0.8, and 0.7 were synthesized using starting materials with varying molar ratios of La(2)O(3) and Co(3)O(4). The resulting particles are characterized as LaCoO(3) crystals interfaced with a crystalline Co(3)O(4) phase. X-ray and neutron scattering data show little effect on the average structure and lattice parameters of the LaCoO(3) phase resulting from the Co(3)O(4) content, but magnetization data indicate that the amount of Co(3)O(4) strongly affects the ferromagnetic ordering at the interfaces below TC ≈ 89 K. In addition to ferromagnetic long-range order, LaCoO(3) exhibits antiferromagnetic behavior with an unusual temperature dependence. The magnetization for fields 20 Oe ⩽ H ⩽ 5 kOe is fit to a combination of a power law ((T - TC)/TC)(ß) behavior representing the ferromagnetic long-range order and sigmoid-convoluted Curie-Weiss-like behavior representing the antiferromagnetic behavior. The critical exponent ß = 0.63 ± 0.02 is consistent with 2D (surface) ordering. Increased Co(3)O(4) correlates well to increased ferromagnetism. The weakening of the antiferromagnetism below T ≈ 40 K is a consequence of the lattice reaching a critical rhombahedral distortion as T is decreased for core regions far from the Co(3)O(4) interfaces. We introduce a model that describes the ferromagnetic behavior of the interface regions and the unusual antiferromagnetism of the core regions.

Magnetism and phase transitions in LaCoO3.

Neutron scattering and magnetometry measurements have been used to study phase transitions in LaCoO3 (LCO). For H ≤ 100 Oe, evidence for a ferromagnetic (FM) transition is observed at Tc ≈ 87 K. For 1 kOe ≤ H ≤ 60 kOe, no transition is apparent. For all H, Curie-Weiss analysis shows predominantly antiferromagnetic (AFM) interactions for T > Tc, but the lack of long-range AFM order indicates magnetic frustration. We argue that the weak ferromagnetism in bulk LCO is induced by lattice strain, as is the case with thin films and nanoparticles. The lattice strain is present at the bulk surfaces and at the interfaces between the LCO and a trace cobalt oxide phase. The ferromagnetic ordering in the LCO bulk is strongly affected by the Co-O-Co angle (γ), in agreement with recent band calculations which predict that ferromagnetic long-range order can only take place above a critical value, γC. Consistent with recent thin film estimations, we find γC = 162.8°. For γ > Î³C, we observe power-law behavior in the structural parameters. γ decreases with T until the critical temperature, To ≈ 37 K; below To the rate of change becomes very small. For T < To, FM order appears to be confined to regions close to the surfaces, likely due to the lattice strain keeping the local Co-O-Co angle above γC.

The use of appropriateness criteria for the selection of clinical preventive services for a Pacific island health service.

Clinical preventive services are measures performed in the clinic setting for the prevention of disease and the promotion of health. The general practice/public health physician residency class of the Palau Area Health Education Center reviewed existing clinical preventive services protocols for the Ministry of Health of the Republic of Palau and revised them, taking four criteria into consideration for each candidate intervention (local patterns of disease and risk factors, evidence for effectiveness of the intervention, local system capability for delivery of the intervention and its consequences, and competing priorities). The resulting package of interventions is much more focused and appropriate to local conditions than was the one that it replaced. It has the potential to improve the health status of the population by making better use of available resources.

Acaricide efficiency of amitraz/cypermethrin and abamectin pour-on preparations in game.

The efficacy of an amitraz/cypermethrin pour-on preparation (1% w/v each) was tested against natural tick infestations of buffaloes, eland and blesbok in three separate trials. The eland were also treated with a 0.02% abamectin (w/v) acaricidal pour-on preparation. The amitraz/cypermethrin pour-on was effective against Amblyomma hebraeum, Rhipicephalus evertsi evertsi, Rhipicephalus appendiculatus and Hyalomma marginatum rufipes on the buffaloes. Both acaricides were effective against R. appendiculatus and Rhipicephalus (Boophilus) decoloratus in the eland. The amitraz/cypermethrin acaricide was effective against R. (Boophilus) decoloratus in the blesbok. Ticks can cause damage to the skins, secondary infections, abscesses, anaemia, loss of condition, tick toxicosis and act as vectors of infectious diseases. Introduction of hosts and/or ticks from endemic to non-endemic areas because of translocation of game, may lead to severe losses. The pouron acaricides tested were effective against natural tick infestations and should always be used according to the manufacturer's instructions and efficacy claims.

Childhood vitamin A status and the risk of otitis media.

BACKGROUND: It has been suggested that vitamin A deficiency may predispose to otitis media. METHODS: We conducted a prospective, observational study of 200 children, ages 3 to 5 years, on the island of Saipan in the Commonwealth of the Northern Mariana Islands. Baseline measurements of serum retinol concentrations were obtained from the children, and incidence of otitis media was determined during the following year by review of medical records. The sera were also tested for concentration of other carotenoids (beta-carotene, alpha-carotene, lutein and zeaxanthin, beta-cryptoxanthin, lycopene), and alpha-tocopherol and baseline concentrations of these compounds were also examined for relationship to incidence of otitis media. RESULTS: Serum retinol concentrations of the children ranged from 13 to 58 microg/dl. Episodes of otitis media occurred in 22% of children during the follow-up period. Children with low serum retinol concentrations did not have an excess of episodes of otitis media (chi square for trend, 0.438; P = 0.508 for children grouped by serum retinol concentration; mean serum retinol concentrations were 29.1 and 28.6 microg/dl, respectively, for children who had and did not have a subsequent episode of otitis media). Controlling for potential confounding variables (duration of breast feeding, smoking in the household, illness or live virus vaccination in the 2 weeks before serum collection, day-care attendance) did not substantially alter this finding. Baseline serum concentrations of the other carotenoids and alpha-tocopherol also demonstrated no relation to incidence of otitis media. CONCLUSION: In the range of serum vitamin concentrations found in this population, the status of vitamin A and related compounds in children appeared to have no effect on the incidence of otitis media.

Diabetes in the indigenous population of the Commonwealth of the Northern Mariana Islands.

Diabetes prevalence and complications rates were examined for the indigenous population of the Commonwealth of the Northern Mariana Islands in the western Pacific. Diabetes is common, with 4% of the population and 11% of adults having diagnosed diabetes. Diabetes is more common among females and islanders of Carolinian descent. End stage renal disease, hospitalizations for pneumonia, non-traumatic lower extremity amputations and retinopathy are more common than expected (with relative risks of 3.9, 3.0, 1.5 and 1.3, respectively, compared with diabetics in US), while diabetes-related mortality and hospitalizations for ischemic heart disease/cerebrovascular disease are less (with relative risks of 0.9 and 0.8). Implications for primary and secondary prevention of diabetes and its complications are discussed.

Alcohol abuse and alcoholism in primary health care settings.

Alcohol problems are common in primary care patients, yet they are often not detected and treated. Methods for improving the detection and diagnosis of alcohol problems in the primary care setting are reviewed in terms of pertinent history, physical examination, and laboratory findings. Screening instruments such as the CAGE questionnaire and the Michigan Alcoholism Screening Test are recommended for routine use by primary care physicians. Such instruments have been shown to have higher sensitivity than laboratory tests alone. Although less is known about intervention and management, earlier intervention with innovative (less costly) management techniques may be both efficacious and acceptable to the patient.

[Various approaches to virologic diagnosis and the corresponding sampling]. / Les différentes approches du diagnostic virologique et les prélèvements correspondants.

Owing to the diversity of viral infections and to the high cost of laboratory techniques the diagnostic approach must be chosen according to clinical data. The two ways of approaching the viral diagnosis are of unequal value: detection of the virus or its constituents is preferable to detection of specific immune response. The virus or its constituents is either detected directly in the specimen collected (rapid diagnosis) or isolated after inoculation of a cellular system. Several methods can be used for rapid diagnosis: the virus may be visualized at electron microscopy; immunological techniques detect viral antigens bound to specific antibodies, the binding being revealed by immunofluorescence, enzyme-linked immunoassay or passive agglutination; detection of viral nucleic acids is particularly useful when the virus is difficult to isolate or the antigenic expression difficult to detect, or when immune response is deficient. Virus isolation from a cellular system is usually performed by cell cultivation. Typing of the isolated virus is effected by the same immunological methods os those used for rapid diagnosis, but also by seroneutralization of agglutination inhibition. Genic amplification, of CPR, is a special technique which detects the virus in the specimen studied after its genome has been amplified in an acellular system. Owing to technical problems and difficulties of interpretation, for the time being PCR is reserved to research. Success in diagnosis depends on the quality of the specimens and on their transfer to the laboratory under adequate conditions. Practitioners therefore play a major role in the diagnosis of viral diseases by prescribing the appropriate examinations, providing clinical information and making sure that the specimens are correctly collected.

Salmonella isolated from feeds and feed ingredients during the period 1982-1988: animal and public health implications.

The prevalence of Salmonella in southern Africa in farm feeds and by-products of animal origin during 1982-1988 was determined. Salmonella occurred in 5.18% of the farm feed samples and in 9.54% of the by-product samples. Different serovars were isolated, some only once. The findings underestimate the true prevalence of Salmonella in farm feeds and by-products, and is representative of only the most severely contaminated products. The epidemiology of salmonellosis is discussed with special reference to the importance of multiple resistance to antibiotics, the increase in the number of cases of salmonellosis worldwide and "Salmonella free" feeds and foods. More detailed research on the role of farm feeds in the epidemiology of salmonellosis is required. Efforts should be made to increase awareness of the problem, to improve quality management at farm feed production plants and to develop efficient systems to monitor the hygienic safety of feeds and foods.

Resistance to various antibiotics of Salmonella and Escherichia coli isolated from registrable farm feeds.

Resistance to 20 antibiotics of 128 Salmonella and 97 Escherichia coli isolates from various registrable farm feeds was determined. A high frequency of comparatively low levels of resistance was found in both the Salmonella and E. coli isolates. This, together with an elevated frequency of multiple resistance, indicates that problems related to an effective transfer in bacterial populations of resistance to certain antibiotics are a distinct possibility. The addition of antibiotics, such as penicillin and tetracyclines, to animal feeds can create conditions for rapid selection amongst bacteria resistant to antibiotics. The numbers of resistant bacteria in the animal environment may be increased and may lead to the development of veterinary and human health problems from the possible transfer of antimicrobial resistance from animal pathogens to human pathogens or spreading in the human population of animal pathogens resistant to antibiotics. There is a need for caution in the use of antibiotics, particularly in animal feeds. Extended survey of, and epidemiological research on, farm feeds, manufacturing mills and animal production units are emphasized.

Electron microscopic observations on the luminal surface of teat cup liners of milking machines used under South African conditions.

An investigation undertaken with the aid of scanning electron microscopy (SEM) on new and used teat cup liners revealed the generally poor quality of luminal surfaces. Even those of the brand-new distributor controls showed significant faults in the evenness and continuity of the liner surface. A hundred and 500 milkings apparently tend to aggravate faults like cracks, pores, grooves and pits, because of the general brittleness of some of the teat cup liners. The poor quality of the liners investigated raises various questions about the method of distribution of teat cup liners and serious concern about the role they play in predisposing bovine udders to mastitogenic infections, spreading mastitis, affecting the production and quality of milk, increasing the cost of milk production and reducing profits of dairy farming.