First-principles study of lithium aluminosilicate glass scintillators.

Radiation sensors are an important enabling technology in several fields, such as medicine, scientific research, energy, defence, meteorology, and homeland security. Glass-based scintillators have been in use for more than 50 years and offer many benefits, including their ability to respond to different types of radiation, and to be readily formed into various shapes. There is, however, the prospect to develop new and improved glass scintillators, with low self-absorption, low refractive indices, and high radiative recombination rates. To investigate the factors limiting the improvement of glass scintillator properties, this work provides insight from atomic scale simulations of the cerium-doped lithium aluminosilicate (SiO2-Al2O3-MgO-Li2O-Ce2O3) glass scintillator system. Three glass compositions were studied using molecular dynamics and density functional theory to investigate the effect of the ratio (with RAl/M = [0.1, 0.8 and 1.2]) on the structural and electronic properties. For a ratio RAl/M > 1, it has been shown that glasses with increased polymerization allow for more effective incorporation of Ce3+ cations. The structural analysis also showed that the bond order of Al-O can be affected in the presence of a lithium-rich environment. Electronic density of states and Bader charge analysis indicate a decline in the population of localized trapping states with increasing RAl/M. This suggests a higher probability of radiative recombination which can increase the photon yield of these scintillators. These findings provide valuable guidance for optimizing Li-glasses in neutron detection systems by highlighting the intricate challenges.

Development of LIME-NZ: a generic tool for prompt estimation of economic impacts of disease for New Zealand livestock.

AIMS: To develop a simple and robust generic tool to measure the impacts of livestock diseases on New Zealand dairy, beef and sheep farms using enterprise gross margin models. METHODS: The most recent (2018-2020) livestock production benchmarking data was extracted from industry-led economic surveys. Gross margin models were built for each enterprise type, accounting for 11 dairy farm types and 16 farm types for beef and sheep. Disease parameters, including changes in mortality, reproduction performance, milk yield, price of animals and culling rate, as well as additional expenses for veterinary intervention, were applied to the infected compartment of the herd/flock using the assumed annual within-herd disease incidence. Farm-level disease impacts were estimated as the difference in annual profit between the baseline and infected farm. The baseline gross margin models were validated against the industry data. The disease impact models were validated using a recently published study on bovine viral diarrhoea (BVD). The impact assessment tool, LIME-NZ, was developed using the statistical software R and implemented in the web-based R package Shiny. The input parameters can be varied interactively to obtain a range of disease impacts for uncertain disease parameters. RESULTS: The baseline gross margin models demonstrated reasonable accuracy with a mean percentage error of <14% when compared with the industry reports. The estimated annual impacts of BVD were comparable to those reported in the BVD study, NZ$38.5-140.4 thousand and $0.9-32.6 thousand per farm per year for dairy and beef enterprises, respectively. CONCLUSIONS: LIME-NZ can be used to rapidly obtain the likely economic impacts of diseases that are endemic, recently introduced or at increased risk of introduction in the New Zealand context. This will aid communication and decision-making among government agencies and the livestock industry, including veterinarians and livestock producers, about the management of diseases, until refined information becomes available to improve decision-making.

Japanese encephalitis virus: epidemiology and risk-based surveillance approaches for New Zealand.

The introduction and subsequent rapid spread of Japanese encephalitis virus genotype IV across all Australian mainland states and the Northern Territory since late 2021 has increased the risk of an incursion of this mosquito-transmitted zoonotic virus disease into New Zealand, with serious implications for both animal and human health. The potential modes of entry are through introduction of infected mosquitoes as hitchhikers on ships or aircraft, windborne transfer of mosquitoes, or arrival of infected reservoir bird species. A competent vector mosquito, Culex quinquefasciatus, is endemic in New Zealand and other mosquito species may also become involved. If infection becomes established in New Zealand, the scale of transmission may be considerably less than has occurred in Australia because climatic and epidemiological factors are not so favourable. Early evidence of an incursion could come from detection of clinical disease in horses or pigs, or from human cases. Targeted surveillance to confirm or refute indications of an incursion could be undertaken by antibody detection in a number of species. Dogs have been shown to be a particularly valuable sentinel species due to their cohabitation with people and high seroconversion rate. Other novel methods of surveillance could include reverse transcriptase PCR (RT-PCR) on oronasal secretions of pigs. Should evidence of the disease be detected, prompt action would be required to vaccinate at-risk human populations and clarify the epidemiological situation with respect to mammalian hosts and mosquito vector species, including whether a new mosquito species had arrived in the country.Abbreviations: AHL: Animal Health Laboratory; JE: Japanese encephalitis disease; JEV: Japanese encephalitis virus; RT-PCR: Reverse transcriptase PCR.

A high-pressure flow through test vessel for neutron imaging and neutron diffraction-based strain measurement of geological materials.

Neutron scattering and neutron imaging have emerged as powerful methods for experimentally investigating material deformation and fluid flow in the interior of otherwise inaccessible or opaque structures. This paper describes the design and provides example uses of a pressure cell developed for investigating such behaviors within geological materials. The cell can accommodate cylindrical samples with diameters up to 38.1 mm and lengths up to 154 mm. Ports in the cell and a pressure isolating sleeve around the sample allow the independent application of confining pressure up to 69 MPa and axial pressure up to 34.5 MPa. Two material versions of the cell have been manufactured and used to date. An aluminum version is typically used for temperatures below 40 °C, because of its relative transparency to neutrons, while a titanium version, which is comparatively more neutron attenuating, is used for experiments requiring triaxial pressurization under conditions up to 350 °C. The pressure cells were commissioned at the VULCAN engineering diffractometer at the Oak Ridge National Laboratory (ORNL), Spallation Neutron Source, and have since been used at the ORNL high flux isotope reactor CG1-D imaging beamline, National Institute of Standard and Technology (NIST) BT-2, and NIST NG6 imaging beamlines.

First report of the use of mucosal swabs of the palatine tonsillar crypt for detection of Mycoplasma bovis in naturally infected calves.

Aims: To compare detection by real-time PCR of DNA from Mycoplasma bovis on mucosal swabs taken from the palatine tonsillar crypt and the mainstem bronchi of clinically asymptomatic calves after slaughter. Methods: We compared the sensitivity of mucosal swabs taken from two sites: the palatine tonsillar crypt and the mainstem bronchi. Paired samples were taken post-mortem at slaughter from 55 clinically well calves from an infected herd and were tested by real-time PCR for the presence of M. bovis-specific DNA. Results: Mycoplasma bovis DNA was detected in 51 palatine tonsillar crypt swabs (92.7 (95% CI = 82.4-98.0)%) and seven mainstem bronchial swabs (12.7 (95% CI = 5.3-24.5)%). All seven calves with positive mainstem bronchial swabs also had positive palatine tonsillar crypt swabs. Conclusions: When compared to mucosal swabs of the mainstem bronchi, mucosal swabs of the palatine tonsillar crypt were seven times more sensitive for the post-mortem detection of M. bovis DNA. The viability of detected M. bovis was not assessed, because any cattle carrying viable or non-viable M. bovis DNA were determined to be a potential risk to eradication. Palatine tonsillar crypt mucosa may be a useful anatomical site for real-time PCR detection of M. bovis DNA in naturally infected calves. More work is needed to define the persistence and viability of M. bovis at this anatomical site. Clinical relevance: The results of this study helped form the basis of surveillance tools used in M. bovis control and eradication efforts. Familiarity with these results may help veterinarians better communicate with their clients about the science behind the eradication efforts.

Single crystal to polycrystal neutron transmission simulation.

A collection of routines for calculation of the total cross section that determines the attenuation of neutrons by crystalline solids is presented. The total cross section is calculated semi-empirically as a function of crystal structure, neutron energy, temperature, and crystal orientation. The semi-empirical formula includes the contribution of parasitic Bragg scattering to the total cross section using both the crystal's mosaic spread value and its orientation with respect to the neutron beam direction as parameters. These routines allow users to enter a distribution of crystal orientations for calculation of total cross sections of user defined powder or pseudo powder distributions, which enables simulation of non-uniformities such as texture and strain. The spectra for neutron transmission simulations in the neutron thermal energy range (2 meV-100 meV) are presented for single crystal and polycrystal samples and compared to measurements.

Determination of Debye temperatures and Lamb-Mössbauer factors for LnFeO3 orthoferrite perovskites (Ln = La, Nd, Sm, Eu, Gd).

Lanthanide orthoferrites have wide-ranging industrial uses including solar, catalytic and electronic applications. Here a series of lanthanide orthoferrite perovskites, LnFeO3 (Ln = La; Nd; Sm; Eu; Gd), prepared through a standard stoichiometric wet ball milling route using oxide precursors, has been studied. Characterisation through x-ray diffraction and x-ray fluorescence confirmed the synthesis of phase-pure or near-pure LnFeO3 compounds. 57Fe Mössbauer spectroscopy was performed over a temperature range of 10 K-293 K to observe hyperfine structure and to enable calculation of the recoil-free fraction and Debye temperature (θ D) of each orthoferrite. Debye temperatures (Ln = La 474 K; Nd 459 K; Sm 457 K; Eu 452 K; Gd 473 K) and recoil-free fractions (Ln = La 0.827; Nd 0.817; Sm 0.816; Eu 0.812; Gd 0.826) were approximated through minimising the difference in the temperature dependent experimental centre shift and theoretical isomer shift, by allowing the Debye temperature and isomer shift values to vary. This method of minimising the difference between theoretical and actual values yields Debye temperatures consistent with results from other studies determined through thermal analysis methods. This displays the ability of variable-temperature Mössbauer spectroscopy to approximate Debye temperatures and recoil-free fractions, whilst observing temperature induced transitions over the temperature range observed. X-ray diffraction and Rietveld refinement show an inverse relationship between FeO6 octahedral volume and approximated Debye temperatures. Raman spectroscopy show an increase in the band positions attributed to soft modes of Ag symmetry, Ag(3) and Ag(5) from La to GdFeO3 corresponding to octahedral rotations and tilts in the [0 1 0] and [1 0 1] planes respectively.

Prevalence studies for Theileria orientalis conducted during the early stages of the 2012 New Zealand epidemic of Theileria associated bovine anaemia.

Since 1982 there have been two epidemics of bovine anaemia associated with Theileria orientalis infection (TABA) in New Zealand. The latest and more serious epidemic started in 2012 and is associated with the T. orientalis (Ikeda) type. In 2013 the Ministry for Primary Industries (MPI) carried out several epidemiological investigations on the TABA epidemic, which included a series of on-farm herd prevalence studies. The aims of this paper are to present and summarise the results of these herd prevalence studies. The data were collected from March 2013 to September 2013 and comprised 26 farms. For 21/26 of these farms, a T. orientalis (Ikeda) positive index case of TABA precipitated the follow-up herd prevalence study. Each herd prevalence study involved a random sample of 10 cows for haematocrit, for piroplasm counts (number of Theileria infected RBCs per 1000 RBCs) and for PCR molecular diagnosis. Animals were diagnosed anaemic if the haematocrit ≤0.24. The results showed that for the index cases, the average haematocrit = 0.10 L/L and the average piroplasm count = 10.9 Theileria infected RBCs per 1000 RBCs, and for the herd prevalence studies the average haematocrit = 0.26 and the average piroplasm count = 6.9. The average herd prevalence of T. orientalis (Ikeda) PCR positive cattle and of anaemic cattle was 87% and 26% respectively. For dairy herds (n = 7 herds) it took, on average, 80 days for the within herd prevalence of anaemia to return to zero after the initial diagnosis. In conclusion the prevalence studies showed that infection rates and anaemia rates were already high in herds when the index case of TABA was observed. At the time, these prevalence studies significantly added to our understanding of the epidemiology of the evolving T. orientalis (Ikeda) epidemic and furthermore met the New Zealand MPI objective of being rapid and applied, fit for purpose and completed at a relatively low cost.

Monitoring an epidemic of Theileria-associated bovine anaemia (Ikeda) in cattle herds in New Zealand.

Monitoring an epidemic of an emerging vector-borne disease can be problematic; particularly in a country where vector-borne disease has previously had minimal impact on livestock. This paper describes methods of past and current surveillance of the Theileria-associated bovine anaemia (Ikeda; TABA) epidemic in New Zealand, and the resulting inferences made. Over the three year period of the TABA epidemic a portfolio of surveillance methods has been used: case reporting (with subsidised PCR testing), syndromic surveillance, sentinel surveillance, testing convenience samples for herd infection, as well as specific active surveillance initiatives to understand the tick vector distribution. Surveillance data have shown that the number of affected cattle herds has continued to increase over time with seasonal peaks in spring and autumn coinciding with peak activity of nymph and adult ticks respectively. In spring 2014, the epidemic extended south into areas that were previously considered to be unsuitable for the tick vector. As a result a survey was initiated that showed that ticks were present in areas outside of the known distribution. Testing pooled blood samples from cattle herds across New Zealand showed there still remained a significant percentage of herds where only non-Ikeda type infections were present, indicating that these herds were at risk of future TABA (Ikeda) outbreaks. For some regions there had been a noticeable increase in the percentage of herds infected, yet with only a small increase in the number of outbreaks compared with the previous year. Thus, outbreaks had either gone unobserved or had not been confirmed by testing. In these regions extensive low-input beef farming could explain the non-detection observed. There was a close relationship between the number of syndromic reports of anaemia and the number of confirmed cases of TABA (Ikeda), (P<0.01, adjusted R-squared=0.74). Active monitoring of the epidemic for a three year period has provided valuable insight into seasonal nature of the disease and its continuing impact. Information from multiple surveillance sources can help build up an understanding of the epidemiology, even when data from each individual surveillance stream are limited. The TABA (Ikeda) epidemic in New Zealand represents a useful case study of long term monitoring where disease is caused by an emerging pathogen.

An assessment of the herd-level impact of the Theileria orientalis (Ikeda) epidemic of cattle in New Zealand, 2012-2013: a mixed methods approach.

AIM: To estimate incidence risk, cumulative mortality and case fatality rate within herds affected by bovine anaemia associated with Theileria orientalis infection (TABA), in New Zealand during the early phase of the epidemic (August 2012-September 2013). METHODS: A mixed methods approach was utilised to integrate data from various sources, including a detailed questionnaire carried out on 18 dairy farms which had experienced cases of TABA; a brief telephone survey of an additional 139 case farms; and data extracted from a Ministry for Primary Industries database for a further 42 case farms. The subsequent analysis determined incidence risk, cumulative mortality and case fatality rates for beef and dairy herds. RESULTS: Data were analysed from 196/263 (74%) known case farms at the date of closing the questionnaires. These farms contained 99,505 cattle; 2,847 animals were reported with clinical disease, and a further 590 animals were recorded as having died from TABA. The within-herd incidence risk, cumulative mortality and case fatality rate were consistent between the three data sources, did not differ between beef and dairy herds, and were estimated to be 0.97 (inter-quartile range (IQR) 0.36-2.07)%, 0.23 (IQR 0.00-0.66)% and 16.67 (IQR 0.00-33.33)%, respectively. There was substantial variability in the level of impact, with 22 farms severely affected (incidence risk >5% and cumulative mortality >5%). CONCLUSIONS: The mixed methods approach was effective in dealing with the disparate data sources. The inclusion of the majority of farms known to be affected at the time the questionnaires were performed implies that the information is likely to be representative. The collective outputs of the analyses represent the best estimate available of within-herd measures of disease frequency in the early phase of the epidemic in New Zealand. The limitations of the data imply that their primary application may be to inform the design of subsequent structured observational field studies. CLINICAL RELEVANCE: The results of this study provide information on the impact of TABA on cattle farms during the emergence and early spread of the disease, as well as for generating hypotheses on causal mechanisms and risk factors that may influence the course of disease.

Structure of iron phosphate glasses modified by alkali and alkaline earth additions: neutron and x-ray diffraction studies.

The structure of iron phosphate glasses modified by additions of K(2)O and BaO, with nominal molar compositions [(1 - x)(0.6P(2)O(5)-0.4Fe(2)O(3))]xMe(y)O, where x = 0-0.4 in increments of 0.1; Me=K or Ba; and y = 1 or 2, has been investigated using neutron diffraction and x-ray diffraction techniques. Fitted coordination numbers for P-O and Fe-O showed a notable change in the P-O(NBO) and P-O(BO) contributions at greater than 20 mol% modifier addition, with barium producing a markedly larger increase in P-O(NBO) contribution than potassium. Fitting of T(N)(r) and T(X)(r) provided average n(BaO) = 9 and n(KO) = 6. Iron occurs in a range of coordination sites in these glasses: ([6])Fe(2+), ([4])Fe(3+), ([5])Fe(3+) and ([6])Fe(3+). The partitioning between these sites gives average n(FeO) = 5.2-5.8, with barium-doped glasses exhibiting higher average n(FeO) than potassium-doped glasses. The stronger depolymerizing effect of Ba(2+) than K(+) on the phosphate network, coupled with its greater ionic charge and higher Me-O, Fe-O and O···O coordination numbers, explain previously observed divergences in physical properties between the barium-doped and the potassium-doped glasses.

Diagnostic specificity of an equine influenza blocking ELISA estimated from New South Wales field data from the Australian epidemic in 2007.

This observational study was undertaken in order to evaluate the diagnostic specificity of the blocking enzyme-linked immunosorbent assay (bELISA) for serum antibodies to influenza A virus nucleoprotein during the equine influenza (EI) outbreak response in New South Wales, Australia, in 2007. Using data collected during the outbreak response, bELISA testing data were collated for assumed uninfected horses from areas where EI infection was never recorded. Diagnostic specificity of the bELISA used during the EI response was high, but varied significantly between some regions, although the reason(s) for this variation could not be determined.

Investigation of a pig herd with animals seropositive for classical swine fever and where porcine circovirus-associated disease had been diagnosed.

AIM: To investigate the cause of classical swine fever (CSF) virus-seropositive animals in a nucleus pig-breeding herd in New Zealand, where porcine circovirus-associated disease had been diagnosed. CASE HISTORY AND CLINICAL FINDINGS: An exotic disease investigation was undertaken to exclude CSF and porcine reproductive and respiratory syndrome (PRRS) on a nucleus pig-breeding herd comprising approximately 300 breeding sows, 1,000 weaners, and 650 grower pigs. The herd was experiencing poor reproductive performance in sows, and breeding records showed a declining farrowing rate attributable to a single manager. The growing pigs (10-15 weeks old) were experiencing respiratory disease and wasting, and the mortality rate by pen varied between 9 and 20%. Post-mortem changes in affected grower pigs were consistent with circovirus-associated diseases. DIAGNOSTIC TESTING: Serological screening using an IDEXX-ELISA gave negative results for PRRS virus antibodies, but two grower pigs and one sow tested positive for CSF virus antibodies. These three seropositive animals remained positive to CSF virus, using three commercial ELISA test kits, over 27 weeks. A newly developed virus neutralisation test (VNT), using a New Zealand isolate of border disease (BD) virus, demonstrated that the seropositive pig sera had higher antibody titres to BD virus than to bovine viral diarrhoea (BVD) virus and CSF virus. PCR performed on tonsil, kidney, ileum and spleen gave negative results for CSF virus, and histopathology on lymph nodes, intestine, lung, kidney, liver and brain showed no evidence of the disease. Virus isolation performed on a number of samples was negative. CLINICAL RELEVANCE: The seropositive samples for CSF virus found in this investigation were likely to be a cross reaction to a pestivirus other than CSF virus. The finding of a possible endemic pestivirus capable of being transmitted between sheep and pigs on this farm may explain findings from previous serological survey work in New Zealand, and supports experience elsewhere, where BD virus was found to be the predominant ruminant pestivirus infecting pigs. The results show that pestivirus cross reactivity can result in unexpectedly high titres, and that testing with a full set of (local) pestiviruses is necessary to reach the correct conclusion. The investigation has direct relevance where pig herds with a low seroprevalence are encountered during surveillance for CSF.

Vitrified metal finishing wastes II. Thermal and structural characterisation.

Waste filter cakes from two metal finishing operations were heat treated and vitrified. Substantial weight loss during heating was due to emission of water, volatile sulphur-rich and chlorine-rich compounds, and the combustion of carbonaceous components. Estimations of CO(x), SO(x) and HCl emissions were based on chemical analyses. Upon cooling from molten, one sample remained amorphous but all others partially crystallised. Crystalline nature was dependent upon waste composition and the level of P(2)O(5) addition. Thermal stabilities of the waste forms were good, but less so than MW, a borosilicate glass developed for its high temperature stability. Mossbauer and FTIR analyses showed that iron environments in the different vitrified waste forms were very similar. Iron was present predominantly as Fe(3+), although the exact redox ratio varied slightly between waste forms. Iron in both redox states occupied distorted octahedral coordination polyhedra with similar levels of site distortion. Phosphate networks in the vitreous materials were highly de-polymerised, consisting largely of (PO(4))(3-) monomer and (P(2)O(7))(2-) dimer units. This explained the high chemical durability of these waste forms and their structural insensitivity to compositional change, underlining their suitability as hosts for the immobilisation of toxic and nuclear wastes.

Vitrified metal finishing wastes I. Composition, density and chemical durability.

Durable phosphate glasses were formed by vitrifying waste filter cakes from two metal finishing operations. Some melts formed crystalline components during cooling. Compositional analysis of dried, heat treated and vitrified samples was made using energy-dispersive X-ray spectroscopy, X-ray fluorescence spectroscopy, inductively-coupled plasma spectroscopy and Leco induction furnace combustion analysis. Hydrolytic dissolution, measured by an adapted product consistency test, was reduced by up to 3 orders of magnitude upon heat treatment or vitrification, surpassing the performance of borosilicate glass in some cases. This was attributed to the high levels of iron and zinc in the wastes, which greatly improve the durability of phosphate glasses. One of the wastes arose from a metal phosphating process and was particularly suitable for vitrification due to its high P2O5 content and favourable melting behaviour. The other waste, which arose from a number of processes, was less suitable as it had a low P2O5 content and during heating it emitted harmful corrosive gases and underwent violent reactions. Substantial volume reductions were obtained by heat treatment and vitrification of both wastes. Compositions and performances of some vitrified wastes were comparable with those of glasses which are under consideration for the immobilisation of toxic and nuclear wastes.

John Snow, William Farr and the 1849 outbreak of cholera that affected London: a reworking of the data highlights the importance of the water supply.

OBJECTIVES: This paper examines why Snow's contention that cholera was principally spread by water was not accepted in the 1850s by the medical elite. The consequence of rejection was that hundreds in the UK continued to die. METHODS: Logistic regression was used to re-analyse data, first published in 1852 by William Farr, consisting of the 1849 mortality rate from cholera and eight potential explanatory variables for the 38 registration districts of London. RESULTS: Logistic regression does not support Farr's original conclusion that a district's elevation above high water was the most important explanatory variable. Elevation above high water, water supply and poor rate each have an independent significant effect on district cholera mortality rate, but in terms of size of effect, it can be argued that water supply most strongly 'invited' further consideration. CONCLUSIONS: The science of epidemiology, that Farr helped to found, has continued to advance. Had logistic regression been available to Farr, its application to his 1852 data set would have changed his conclusion.

Ataxia-telangiectasia: the pattern of cerebellar atrophy on MRI.

We describe MRI of the brain in 19 patients with ataxia-telangiectasia (AT) and correlate the appearances with the degree of neurologic deficit. We examined 10 male and nine female patients; 17 were aged between 2 and 12 years (mean 8 years) but a woman and her brother were 35 and 38 years old, and had a variant of AT. Ataxia was the first recognized sign of the disease in every patient. We detected the following patterns of cerebellar atrophy: in the youngest patient, aged 2 years, the study was normal; in the five next youngest patients 3-7 years of age, the lateral cerebellum and superior vermis showed the earliest changes of atrophy; and all but one of the other patients had moderate to marked diffuse atrophy of vermis and cerebellar hemispheres. There were 12 patients aged 9 years and above; one, who was normal, was 9 years old. The five patients who at the time of examination were unable to walk all had diffuse atrophy involving both vermis and cerebellar hemispheres.

Complex regional pain syndrome in pediatric patients with severe factor VIII deficiency.

Two boys with severe factor VIII deficiency that initially presented with acute onset of joint pain and swelling consistent with an uncomplicated hemarthrosis are reported. When appropriate management failed to provide resolution of symptoms, alternate diagnoses were considered. Both boys ultimately had complex regional pain syndrome (CRPS) diagnosed. The delay in diagnosis contributed to prolonged patient discomfort and lack of appropriate therapy. Complex regional pain syndrome encompasses a group of disorders that are characterized by pain severity or duration disproportionate to that expected. It is uncommon in the pediatric population. Because early diagnosis and appropriate treatment may improve outcome, it is important for practitioners to consider CRPS in the differential diagnosis of persistent pain in children with hemophilia.

The methodology and operation of a pilot randomized control trial of the effectiveness of the Bug Busting method against a single application insecticide product for head louse treatment.

A Department of Health leaflet suggests two treatment methods for head lice: mechanical removal by wet combing; and insecticide lotion/rinses. However, there are no reports in the literature comparing the effectiveness of these two treatment methods and well controlled clinical trials of insecticide treatments are sparse. A pilot randomized control trial of the effectiveness of a specific method of wet combing, 'Bug Busting', against a single application of a proprietary insecticide product is reported. The difficulties of designing a trial are discussed and modifications that would allow a definitive trial to take place are suggested. The pilot study included enzyme analysis of lice for insecticide resistance status assessment.