Usage of temporary anchorage devices: A cross-cultural and cross-sectional survey of orthodontists in Australia and the UK.

INTRODUCTION: Detailed insight regarding the use of temporary anchorage devices (TAD) in Australia and the United Kingdom (UK) is lacking. The primary aim of the present cross-sectional survey was to investigate TAD usage among UK-based and Australian-based orthodontists. The secondary objectives were to compare TAD-related preferences and protocols between orthodontists in the two countries. METHODS: A pilot-tested electronic questionnaire was distributed to members of the British Orthodontic Society and the Australian Society of Orthodontists. Questions pertained to their demographic details, and current use of TADs including protocols, treatment objectives and factors influencing their use. RESULTS: A total of 192 responses were recorded (Australia: 122; UK: 70). One hundred and forty-two respondents (74.0%) reported using TADs as part of their orthodontic treatment, 77.0% in Australia (n=94) and 68.6% in the UK (n=48). Molar protraction was the most common procedure for which TADs were reportedly used (Australia: n=118; 87.2%, UK: n=36; 75.0%). "Loosening" was the most prevalent reported complication overall (n=124; 90.1%). "Confidence", "insufficient postgraduate education" and "availability of equipment" were the factors that most influenced the decision not to provide TADs. CONCLUSIONS: Most orthodontists in both countries provided TADs. TAD protocols of orthodontists in both countries were reported. Similarities and differences regarding TAD-related clinical practices and procedures, complications and factors influencing the use of TADs and reasons for not using TADs were explored. Information from the present study can provide baseline data for future related studies in each country and for comparison of TAD usage in other countries.

Optimization of convection-enhanced evaporation (CEE) using generalized cost ratios.

Brine is a byproduct of desalination plants and several industrial processes which can have an adverse impact on the environment if not managed properly. Conventional brine management technologies are energy intensive and costly which limit their adoption. This study presents the first cost optimization of convection-enhanced evaporation (CEE) system to achieve a modular, cost-effective brine management and on-site treatment option for decentralized desalination plants and small-volume industries. CEE involves evaporating water from saline liquid films, released on evaporation surfaces, by the difference in vapor pressure created by forced air convection. The optimization identifies the optimal operating settings (brine flow rates, brine temperatures, and air speeds) and enables comprehensive investigation of the effect of various operational decisions on operating (energy) cost, capital cost, and footprint area. The objective functions are formulated using two cost ratios that relate material, thermal, and electrical energy costs, effectively generalizing the optimization results to be independent of location-specific cost parameters. The optimization reveals two distinct operation modes, "all-electric mode" and "heating mode". The "all-electric mode" corresponds to a lower total specific cost, ranging from $1.4 to $5 per m3, and higher footprint area, ranging from 0.5 to 1.8 m2 per m3 of evaporated volume. The "heating mode" corresponds to a higher total specific cost, up to $6.5 per m3; at low energy cost ratios, a compact footprint area ranging from 0.072 to 0.5 m2 per m3 of evaporated volume is achieved. Proposed designs were found to have lower costs than technologies available in the literature.

Encapsulation technology for decentralized brewery wastewater treatment: A small pilot experiment.

The feasibility of implementing encapsulation technology for the biological anaerobic treatment of high-strength wastewater was investigated. The small pilot-scale wastewater treatment process, deployed at a local brewery, consisted of a 4-L fermenting first-stage reactor containing alginate-encapsulated fermenting microorganisms and a 30-L methanogenic second-stage reactor containing alginate-encapsulated anaerobic digester sludge (CH4E reactor). A parallel second-stage 30-L anaerobic membrane bioreactor (AnMBR) was operated for comparison. The first-stage reactor produced 40.4 ± 47.3% more volatile fatty acids than present in the influent wastewater. The CH4E reactor stared rapidly, with an off-gas methane content >60% after 14 days. It took >1 month for the AnMBR to achieve this performance. Nevertheless, the CH4E reactor performance declined relative to the AnMBR over time. This was thought to be a result of encapsulant leakage and the encapsulation of a non-ideal initial community. Further optimization is needed, but encapsulation shows promise for small-footprint anaerobic biological treatment applications.

Embedding Usage Sensors in Point-of-Use Water Treatment Devices: Sensor Design and Application in Limpopo, South Africa.

Health benefits from point-of-use (POU) water treatment devices come only with consistent use. Embedded sensors can measure the consistency of POU-device use and can provide insights about improving it. We demonstrate both potentials with data from SmartSpouts: accelerometer-based sensors embedded in spigot handles that record the duration and timing of use. In the laboratory, most sensor readings correlated well (>0.98) with manually timed water withdrawals. In the field, SmartSpouts measured >60,000 water withdrawals across 232 households in Limpopo, South Africa. Sensors proved critical to understanding consistent use; surveys overestimated it by 53 percentage points. Sensor data showed when households use POU devices (evening peaks and delayed weekend routines) and user preferences (safe storage over filters). We demonstrate analytically and with data that (i) consistent use (e.g., 7 continuous days) is extremely sensitive to single-day use prevalence and (ii) use prevalence affects the performance of contact-time-based POU devices, exemplified with silver tablets. Deployed SmartSpouts had limitations, including memory overflows and confounding device relocation with water withdrawal. Nevertheless, SmartSpouts provided useful and objective data on the prevalence of single-day and consistent use. Considerably less expensive than alternatives, SmartSpouts enable an order of magnitude increase in how many POU-device sensors can be deployed.

Impact of Low-Cost Point-of-Use Water Treatment Technologies on Enteric Infections and Growth among Children in Limpopo, South Africa.

Enteric infections early in life have been associated with poor linear growth among children in low-resource settings. Point-of-use water treatment technologies provide effective and low-cost solutions to reduce exposure to enteropathogens from drinking water, but it is unknown whether the use of these technologies translates to improvements in child growth. We conducted a community-based randomized controlled trial of two water treatment technologies to estimate their effects on child growth in Limpopo, South Africa. We randomized 404 households with a child younger than 3 years to receive a silver-impregnated ceramic water filter, a silver-impregnated ceramic tablet, a safe-storage water container alone, or no intervention, and these households were followed up quarterly for 2 years. We estimated the effects of the interventions on linear and ponderal growth, enteric infections assessed by quantitative molecular diagnostics, and diarrhea prevalence. The silver-impregnated ceramic water filters and tablets consistently achieved approximately 1.2 and 3 log reductions, respectively, in total coliform bacteria in drinking water samples. However, the filters and tablets were not associated with differences in height (height-for-age z-score differences compared with no intervention: 0.06, 95% CI: -0.29, 0.40, and 0.00, 95% CI: -0.35, 0.35, respectively). There were also no effects of the interventions on weight, diarrhea prevalence, or enteric infections. Despite their effectiveness in treating drinking water, the use of the silver-impregnated ceramic water filters and tablets did not reduce enteric infections or improve child growth. More transformative water, sanitation, and hygiene interventions that better prevent enteric infections are likely needed to improve long-term child growth outcomes.

How is quality of cardiopulmonary resuscitation being assessed? A national survey of Canadian emergency medicine physicians.

BACKGROUND: High-quality cardiopulmonary resuscitation (CPR) is a fundamental intervention for cardiac arrest, yet health care providers rarely adhere to recommended guidelines. Real-time feedback improves CPR performance. It is currently unknown how Canadian emergency physicians assess CPR quality during cardiac arrest and if they use feedback devices. Our aim was to describe how emergency physicians assess CPR quality and to describe eventual barriers to implementation of feedback technology. METHODS: This was a cross-sectional survey that was distributed to attending and resident emergency physicians through the Canadian Association of Emergency Physicians. Responses were summarized and analyzed using descriptive statistics. RESULTS: The response rate was 19% (323/1735). Visual observation was the most common method of assessing CPR quality (41.2%), with leaders standing at the foot of the bed (67.4%). This was followed by real-time pulse check (29.7%) and end-tidal CO2 values (21.7%). Only 12% of physicians utilized CPR feedback technology. The most common perceived barrier to utilization was unavailability, inexperience with devices and lack of guidelines/evidence for their use. CONCLUSION: Most Canadian emergency physicians that responded to our survey, assess quality of CPR by standing at the foot of the bed and utilize visual observation and palpation methods which are known to be inaccurate. A minority utilize objective measurements such as ETCO2 or feedback devices, with the greatest barrier being lack of availability.

CONTEXTE: Il est crucial d'effectuer des manœuvres de réanimation cardiopulmonaire (RCP) de qualité dans le traitement des arrêts cardiaques; pourtant, rares sont les fournisseurs de soins qui respectent les lignes directrices recommandées. Les rétroactions en temps réel améliorent l'efficacité des manœuvres de RCP. Toutefois, on ne sait pas comment les urgentologues au Canada évaluent la qualité des RCP durant les arrêts cardiaques et s'ils utilisent des dispositifs de rétroaction. L'étude visait donc à établir la manière dont les urgentologues évaluent la qualité des RCP et à faire ressortir de possibles obstacles à l'utilisation de la rétroaction technologique. MÉTHODE: Il s'agit d'une enquête transversale menée par l'Association canadienne des médecins d'urgence, parmi les urgentologues traitants et les résidents dans le domaine. Les chercheurs ont d'abord résumé les réponses, puis analysé les données à l'aide de statistiques descriptives. RÉSULTATS: Le taux de réponse a atteint 19 % (323/1735). La méthode d'évaluation la plus courante de la qualité des manœuvres de RCP reposait sur l'observation visuelle (41,2 %) faite au pied du lit par les chefs d'équipe (67,4 %). Suivaient la vérification du pouls en temps réel (29,7 %) et les valeurs de CO2 en fin d'expiration (21,7 %). Enfin, seuls 12 % des médecins avaient recours à la rétroaction technologique sur la RCP. Les obstacles évoqués le plus souvent étaient le manque de dispositifs, le manque d'expérience d'utilisation de ces appareils et le manque de lignes directrices sur leur emploi ou de données probantes à l'appui. CONCLUSION: La plupart des urgentologues au Canada qui ont participé à l'enquête évaluent la qualité des manœuvres de RCP en se tenant au pied du lit et en se fondant sur l'observation visuelle et la palpation, deux méthodes connues pour leur inexactitude. Les autres, soit la minorité, ont recours à des mesures objectives comme la pression de CO2 en fin d'expiration ou à des dispositifs de rétroaction, et le plus grand obstacle perçu est le manque d'appareils.

Marijuana Use Is Associated with Behavioral Approach and Depressive Symptoms in Adolescents and Emerging Adults.

BACKGROUND: Repeated CB1 binding due to THC results in downregulation of the endocannabinoid system in cortex and limbic regions, perhaps disrupting frontolimbic functioning. This is particularly a concern in young adults who are still undergoing neurodevelopment in frontal and limbic regions. Such disruptions may be linked to increased depressive symptoms, anxiety symptoms, and executive dysfunction, and decreased behavioral approach. OBJECTIVES: Here we examine the influence of young adult marijuana use on anxiety, depressive symptoms, behavioral approach, and executive dysfunction. The influence of alcohol and gender were also assessed. METHODS: 84 participants (42 MJ, 42 controls) aged 18-25 were balanced for gender (39 F). Exclusion criteria included: MRI contraindications, left handed, comorbid Axis-I disorders, major medical or neurologic disorders, prenatal issues, or prenatal alcohol/illicit drug exposure, or excessive other drug use. Participants completed the FrsBE, BIS/BAS, State-Trait Anxiety Inventory (State), and BDI-II. Multiple regressions were run to predict anxiety, depressive symptoms, behavioral approach, and executive dysfunction from MJ group status, past year alcohol use, gender, and MJ*gender interactions, controlling for cotinine and ecstasy. RESULTS: MJ group predicted increased depressive symptoms (p =.049). Decreased fun-seeking (p =.04), reward response (p =.01), and BAS total (p =.01) were predicted by MJ group. Gender predicted decreased reward responsiveness in females (p =.049) and decreased BIS in females (p =.03). Female marijuana users had increased anxiety symptoms (p =.04) and increased disinhibition (p =.04). Increased cotinine predicted increased drive (p =.046), reward responsiveness (p =.008) and BAS Total (p =.02). Apathy and Executive Dysfunction were not predicted by any measures. All results had small effect sizes. CONCLUSIONS/IMPORTANCE: Depressive symptoms were greater in MJ users, while behavioral approach was decreased. Cotinine levels predicted increased behavioral approach. Female MJ users also had greater anxiety and disinhibition. In sum, these findings suggest sub-clinical threshold deficits related to regular marijuana use that are indicative of a need to prevent marijuana use in adolescents and young adults.

Outcome of combined orthodontic-surgical treatment in a United Kingdom university dental institute.

INTRODUCTION: This retrospective observational cohort study evaluated effectiveness of combined orthodontic-orthognathic surgical treatment in a UK University Dental Institute. METHODS: Patients were identified from a database maintained prospectively throughout a 5-year period of observation. Demographic and clinical data included age, malocclusion, Index of Treatment Need, Index of Orthognathic Functional Treatment Need, orthodontist, surgeon, surgical procedure and treatment-time. Peer Assessment Rating (PAR) scores were generated from pre- and post-treatment dental study casts by a single calibrated examiner. RESULTS: One hundred and sixty two subjects began treatment during the period of observation, 92 completed, 14 elected to discontinue before surgery and 56 remained in treatment. Outcome data were available for 73, 16 males and 57 females (mean age 23.28 [SD, 7.92] years). Within this sample, 33 (45.2%) presented with class II division 1, 6 (8.2%) with class II division 2 and 34 (46.6%) with class III malocclusion. Isolated maxillary and mandibular surgery was carried out in 3 (4.1%) and 24 cases (32.8%), respectively; bimaxillary surgery was performed in 46 (63.1%). Mean total treatment time in fixed appliances was 920.28 days (30.7 months). Mean pre-treatment PAR score was 39.09 [SD, 9.42] and post-treatment 5.86 [SD, 4.25] with a mean 83.7% PAR score reduction, representing a greatly improved occlusal result. Kruskal-Wallis testing found no evidence of any relationship between independent variables and percentage PAR reduction; however, surgeon identity did significantly influence treatment length (P = 0.007). CONCLUSIONS: This investigation demonstrates that in terms of static occlusion combined orthodontic-orthognathic surgery is effective in correcting severe malocclusion.

5-HTTLPR Genotype Moderates the Effects of Past Ecstasy Use on Verbal Memory Performance in Adolescent and Emerging Adults: A Pilot Study.

OBJECTIVE: Ecstasy use is associated with memory deficits. Serotonin transporter gene (5-HTTLPR) polymorphisms have been linked with memory function in healthy samples. The present pilot study investigated the influence of 5-HTTLPR polymorphisms on memory performance in ecstasy users, marijuana-using controls, and non-drug-using controls, after a minimum of 7 days of abstinence. METHOD: Data were collected from 116 young adults (18-25 years-old), including 45 controls, 42 marijuana users, and 29 ecstasy users, and were balanced for 5-HTTLPR genotype. Participants were abstinent seven days prior to completing memory testing. Three MANCOVAs and one ANCOVA were run to examine whether drug group, 5-HTTLPR genotype, and their interactions predicted verbal and visual memory after controlling for gender, past year alcohol use, other drug use, and nicotine cotinine levels. RESULTS: MANCOVA and ANCOVA analysis revealed a significant interaction between drug group and genotype (p = .03) such that ecstasy users with the L/L genotype performed significantly worse on CVLT-2 total recall (p = .05), short (p = .008) and long delay free recall (p = .01), and recognition (p = .006), with the reverse pattern found in controls. Ecstasy did not significantly predict visual memory. 5-HTTLPR genotype significantly predicted memory for faces (p = .02); short allele carriers performed better than those with L/L genotype. CONCLUSIONS: 5-HTTLPR genotype moderated the effects of ecstasy on verbal memory, with L/L carriers performing worse compared to controls. Future research should continue to examine individual differences in ecstasy's impact on neurocognitive performance as well as relationships with neuronal structure. Additional screening and prevention efforts focused on adolescents and emerging adults are necessary to prevent ecstasy consumption.

Considering Cannabis: The Effects of Regular Cannabis Use on Neurocognition in Adolescents and Young Adults.

Thirty-six percent of high school seniors have used cannabis in the past year, and an alarming 6.5% smoked cannabis daily, up from 2.4% in 1993 (Johnston et al., 2013). Adolescents and emerging adults are undergoing significant neurodevelopment and animal studies suggest they may be particularly vulnerable to negative drug effects. In this review, we will provide a detailed overview of studies outlining the effects of regular (at least weekly) cannabis use on neurocognition, including studies outlining cognitive, structural and functional findings. We will also explore the public health impact of this research.

Dare to delay? The impacts of adolescent alcohol and marijuana use onset on cognition, brain structure, and function.

Throughout the world, drug and alcohol use has a clear adolescent onset (Degenhardt et al., 2008). Alcohol continues to be the most popular drug among teens and emerging adults, with almost a third of 12th graders and 40% of college students reporting recent binge drinking (Johnston et al., 2009, 2010), and marijuana (MJ) is the second most popular drug in teens (Johnston et al., 2010). The initiation of drug use is consistent with an overall increase in risk-taking behaviors during adolescence that coincides with significant neurodevelopmental changes in both gray and white matter (Giedd et al., 1996a; Paus et al., 1999; Sowell et al., 1999, 2002, 2004; Gogtay et al., 2004; Barnea-Goraly et al., 2005; Lenroot and Giedd, 2006). Animal studies have suggested that compared to adults, adolescents may be particularly vulnerable to the neurotoxic effects of drugs, especially alcohol and MJ (see Schneider and Koch, 2003; Barron et al., 2005; Monti et al., 2005; Cha et al., 2006; Rubino et al., 2009; Spear, 2010). In this review, we will provide a detailed overview of studies that examined the impact of early adolescent onset of alcohol and MJ use on neurocognition (e.g., Ehrenreich et al., 1999; Wilson et al., 2000; Tapert et al., 2002a; Hartley et al., 2004; Fried et al., 2005; Townshend and Duka, 2005; Medina et al., 2007a; McQueeny et al., 2009; Gruber et al., 2011, 2012; Hanson et al., 2011; Lisdahl and Price, 2012), with a special emphasis on recent prospective longitudinal studies (e.g., White et al., 2011; Hicks et al., 2012; Meier et al., 2012). Finally, we will explore potential clinical and public health implications of these findings.

Reporting quality of abstracts of randomized controlled trials published in dental specialty journals.

OBJECTIVES: A widespread assessment of the reporting of RCT abstracts published in dental journals is lacking. Our aim was to investigate the quality of reporting of abstracts published in leading dental specialty journals using, as a guide, the CONSORT for abstracts checklist. METHODS: Electronic and supplementary hand searching were undertaken to identify RCTs published in seven dental specialty journals. The quality of abstract reporting was evaluated using a modified checklist based on the CONSORT for abstracts checklist. Descriptive statistics followed by univariate and multivariate analyses were conducted. RESULTS: 228 RCT abstracts were identified. Reporting of interventions, objectives and conclusions within abstracts were adequate. Inadequately reported items included: title, participants, outcomes, random number generation, numbers randomized and effect size estimate. Randomization restrictions, allocation concealment, blinding, numbers analyzed, confidence intervals, intention-to-treat analysis, harms, registration and funding were rarely described. CONCLUSIONS: The mean overall reporting quality score was suboptimal at 62.5% (95% CI: 61.9, 63.0). Significantly better abstract reporting was noted in certain specialty journals and in multicenter trials.

Phospholipase A2: the key to reversing long-term memory impairment in a gastropod model of aging.

Memory failure associated with changes in neuronal circuit functions rather than cell death is a common feature of normal aging in diverse animal species. The (neuro)biological foundations of this phenomenon are not well understood although oxidative stress, particularly in the guise of lipid peroxidation, is suspected to play a key role. Using an invertebrate model system of age-associated memory impairment that supports direct correlation between behavioral deficits and changes in the underlying neural substrate, we show that inhibition of phospholipase A(2) (PLA(2)) abolishes both long-term memory (LTM) and neural defects observed in senescent subjects and subjects exposed to experimental oxidative stress. Using a combination of behavioral assessments and electrophysiological techniques, we provide evidence for a close link between lipid peroxidation, provocation of phospholipase A(2)-dependent free fatty acid release, decline of neuronal excitability, and age-related long-term memory impairments. This supports the view that these processes suspend rather than irreversibly extinguish the aging nervous system's intrinsic capacity for plasticity.

Do you do Damon®? What is the current evidence base underlying the philosophy of this appliance system?

Self-ligating bracket systems are increasing in popularity amongst orthodontists. This reflects their high quality engineering, improved reliability and relative ease of use. However, it might also be related to claims of superior function made by the manufacturers of these appliances. In particular, the Damon(®) appliance system claims to offer significant advantages to both orthodontist and patient over conventional-ligation and other forms of self-ligated appliances. We have reviewed current literature relating to use of the Damon(®) appliance system. There is some evidence to suggest this appliance may lead to reductions in chairside time for the orthodontist, particularly those experienced with this system, in comparison to conventional-ligation. However, evidence that pain experience is reduced for the patient when using Damon(®) brackets is not conclusive. In the presence of identical archwire sequences, there is no evidence that Damon(®) brackets can align teeth faster or in a qualitatively differently manner, when compared with conventional-ligation. There is no high quality evidence that treatment with the Damon(®) appliance takes place more rapidly or leads to a superior occlusal or aesthetic result. Indeed, the best available evidence would suggest there is no difference in treatment outcome or time, at least in extraction cases. There is no evidence that treatment with the Damon(®) appliance is more stable. Claims relating to improved clinical performance of the Damon(®) appliance system are currently being made to orthodontists and patients that are not substantiated in the scientific literature.

Influence of supplemental written information on adolescent anxiety, motivation and compliance in early orthodontic treatment.

OBJECTIVES: To test the null hypotheses that supplementation of verbal information with written information when obtaining consent to orthodontic treatment has no effect on (1) anxiety, motivation and apprehension related to treatment and (2) compliance in the early stages of fixed appliance therapy. MATERIALS AND METHODS: Seventy-six adolescents who were due to start fixed appliance therapy were randomly allocated to receive verbal information only or verbal and written information before orthodontic treatment. Participants' anxiety, motivation, and apprehension were assessed using a questionnaire that was completed prior to meeting the orthodontic clinician (T1), following consent to treatment (T2), and after 12 weeks of treatment (T3). Appointment attendance, appliance breakages, and periodontal scores were used as measures of patient compliance. RESULTS: Sixty participants completed the study. At T2 there was no change in anxiety scores for either group (P = .412); however, increased motivation was detected in the group that had been given both written and verbal information (P = .049). At T3 both groups demonstrated similar reductions in anxiety (P = .311) and apprehension (P = .790) and similar levels of motivation (P = .756). A reduction in periodontal scores (P = .065), better appointment attendance (P = .732), and fewer breakages (P = .525) were reported in the group that was given additional information, although these changes were not statistically significant. CONCLUSIONS: Supplementation of verbal information with written information resulted in improved motivation for orthodontic treatment but had no statistically significant effect on anxiety, apprehension, or patient compliance.

Enrichment of a bipotent hepatic progenitor cell from naïve adult liver tissue.

BACKGROUND/AIM: Recent interest in the liver stem cell field has led to the identification and characterization of several hepatic progenitor cell populations from fetal and adult tissues. We isolated a hepatic progenitor cell from naïve adult liver and the current studies focus on differentiation and growth. RESULTS: A Sca-1(+) hepatic progenitor cell was identified within the liver parenchyma. This cell expresses numerous liver related genes and transcription found in the developing and/or adult liver. It is located in the peri-portal region and expresses markers associated with undifferentiated hepatic cell populations, mature hepatocytes and biliary cells which distinguish it from the Sca-1(-) fraction. CONCLUSION: This hepatic progenitor cell from uninjured liver has features of both hepatocytic and biliary populations and demonstrates proliferative potential. Further studies will focus on sca-HPC subsets and conditions that regulate differentiation towards hepatic or biliary lineages.

Modeling early Epstein-Barr virus infection in Drosophila melanogaster: the BZLF1 protein.

Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis and is associated with several forms of cancer, including lymphomas and nasopharyngeal carcinoma. The EBV immediate-early protein BZLF1 functions as a transcriptional activator of EBV early gene expression and is essential for the viral transition between latent and lytic replication. In addition to its role in the EBV life cycle, BZLF1 (Z) also has profound effects upon the host cellular environment, including disruption of cell cycle regulation, signal transduction pathways, and transcription. In an effort to understand the nature of Z interactions with the host cellular environment, we have developed a Drosophila model of early EBV infection, where we have expressed Z in the Drosophila eye. Using this system, we have identified a highly conserved interaction between the Epstein-Barr virus Z protein and shaven, a Drosophila homolog of the human Pax2/5/8 family of genes. Pax5 is a well-characterized human gene involved with B-cell development. The B-cell-specific Pax5 also promotes the transcription of EBV latent genes from the EBV Wp promoter. Our work clearly demonstrates that the Drosophila system is an appropriate and powerful tool for identifying the underlying genetic networks involved in human infectious disease.

Structure and microstructure of hexagonal Ba3Ti2RuO9 by electron diffraction and microscopy.

We have used electron microscopy and diffraction to refine the structure and investigate the microstructure of Ba(3)Ti(2)RuO(9). The parent compound is hexagonal BaTiO(3) with the space group P6(3)/mmc. Using convergent-beam electron diffraction (CBED) combined with electron-sensitive image plates we have found that the space group of Ba(3)Ti(2)RuO(9) is the non-centrosymmetric group P6(3)mc at room temperature and at approximately 110 K. This is consistent with the Ru and Ti atoms occupying alternate face-sharing octahedral sites in the 0001 direction. This maintains the c-glide, but breaks the mirror normal to the c axis and consequently removes the centre of symmetry. Using powder X-ray diffraction, we have measured the lattice parameters from polycrystalline samples to be a = 5.7056 +/- 0.0005, c = 14.0093 +/- 0.0015 A at room temperature. Using high-resolution electron microscopy (HREM) we observed highly coherent, low-strain {10\bar 10} grain boundaries intersecting at 60 and 120 degrees . From CBED we deduce that adjacent grains are identical but for the relative phase of the Ti and Ru atom ordering along the c axis. HREM also revealed occasional stacking faults, normal to the c-axis.