Pilot study of an arts- and theatre-based HIV prevention intervention for men who have sex with men and transgender women migrants in South Africa: acceptability, feasibility and preliminary efficacy

Innovative approaches addressing the elevated human immunodeficiency virus (HIV) risk among men who have sex with men (MSM) or transgender women (TGW) migrants in South Africa are urgently needed. We sought to present the acceptability, feasibility and preliminary efficacy of 'Externalize and Mobilize!', a multi-session arts- and theatre-based HIV prevention group intervention for MSM and TGW migrants in South Africa. Fourteen participants-MSM (n = 7; 50%), genderqueer/nonbinary persons (n = 4; 29%) and TGW (n = 3; 21%)-in Cape Town were recruited and enrolled in the intervention and administered pre- and post-intervention assessments of HIV knowledge, HIV risk-reduction self-efficacy, stigma and resilience. The intervention, delivered over 4 days, was completed by all 14 participants. Scores on HIV knowledge and HIV risk-reduction self-efficacy were statistically significantly higher at post-intervention compared with pre-intervention. Additionally, participants responded affirmatively (i.e. 'Agree' or 'Strongly agree') on all items assessing intervention acceptability. Findings demonstrate the high acceptability, feasibility and preliminary efficacy of an arts- and theatre-based intervention for increasing HIV knowledge and HIV risk-reduction self-efficacy among MSM and TGW migrants in South Africa. This study provides further support for the use of creative and innovative interventions to address entrenched HIV disparities in South Africa.

Identifying the core genome of the nucleus-forming bacteriophage family and characterization of Erwinia phage RAY

We recently discovered that some bacteriophages establish a nucleus-like replication compartment (phage nucleus), but the core genes that define nucleus-based phage replication and their phylogenetic distribution were still to be determined. Here, we show that phages encoding the major phage nucleus protein chimallin share 72 conserved genes encoded within seven gene blocks. Of these, 21 core genes are unique to nucleus-forming phage, and all but one of these genes encode proteins of unknown function. We propose that these phages comprise a novel viral family we term Chimalliviridae. Fluorescence microscopy and cryoelectron tomography studies of Erwinia phage vB_EamM_RAY confirm that many of the key steps of nucleus-based replication are conserved among diverse chimalliviruses and reveal variations on this replication mechanism. This work expands our understanding of phage nucleus and PhuZ spindle diversity and function, providing a roadmap for identifying key mechanisms underlying nucleus-based phage replication.

Identifying the core genome of the nucleus-forming bacteriophage family and characterization of Erwinia phage RAY

We recently discovered that some bacteriophages establish a nucleus-like replication compartment (phage nucleus), but the core genes that define nucleus-based phage replication and their phylogenetic distribution were unknown. By studying phages that encode the major phage nucleus protein chimallin, including previously sequenced yet uncharacterized phages, we discovered that chimallin-encoding phages share a set of 72 highly conserved genes encoded within seven distinct gene blocks. Of these, 21 core genes are unique to this group, and all but one of these unique genes encode proteins of unknown function. We propose that phages with this core genome comprise a novel viral family we term Chimalliviridae. Fluorescence microscopy and cryo-electron tomography studies of Erwinia phage vB_EamM_RAY confirm that many of the key steps of nucleus-based replication encoded in the core genome are conserved among diverse chimalliviruses, and reveal that non-core components can confer intriguing variations on this replication mechanism. For instance, unlike previously studied nucleus-forming phages, RAY doesn't degrade the host genome, and its PhuZ homolog appears to form a five-stranded filament with a lumen. This work expands our understanding of phage nucleus and PhuZ spindle diversity and function, providing a roadmap for identifying key mechanisms underlying nucleus-based phage replication.

Pediatric maxillary expansion has a positive impact on hearing? A systematic review and meta-analysis

OBJECTIVE

Hearing loss is a highly prevalent condition in the pediatric population. Pediatric maxillary expansion is a widespread treatment to address transverse maxillary deficiency. First reports describing an association between improvements for patients with HL and PME initiated in the 1960s. In this systematic review and meta-analysis we aim to review the role of maxillary expansion in reducing conductive hearing loss in pediatric population.

REVIEW METHODS

Pubmed (Medline), the Cochrane Library, EMBASE and Trip Database were checked. Main outcome was expressed as the difference between air-bone gap, compliance, ear volume and conductive hearing thresholds before and after treatment and the 95% confidence interval.

RESULTS

A total of 10 studies (218 patients) met inclusion criteria. The pooled data in the meta-analysis under a random effects model shows a statistically significant difference of 10.57dB mean reduction after palatal expansion. The air-bone gap was significantly reduced by 5.39dB (CI 95% 3.68, 7.10). Compliance and volume were assessed in three studies, with a non-significant positive difference in the compliance (0.14) and a statistically significant difference for volume (0.80) after palatal expansion.

CONCLUSION

This systematic review and meta-analysis found a positive effect of pediatric maxillary expansion in conductive hearing loss in well-select children. However, results cannot be extrapolated for children with conductive hearing loss without an accompanying orthodontic indication (maxillary constriction). It showed that the existing prospective studies exhibited qualitative pitfalls, limiting the ability to obtain conclusive evidence about the role of pediatric maxillary expansion on conductive hearing loss in children.

Hydroxocobalamin Administration After Inhalation Injury Is Not Associated With Mesenteric Ischemia

Hydroxocobalamin has been administered in the United States since 2006 by first responders and burn centers as a safe antidote for cyanide toxicity, a serious complication of smoke inhalation. There are no current contraindications to the use of this rescue measure. A recent retrospective French publication reported a potential correlation between hydroxcobalamin administration and acute mesenteric ischemia (AMI) in critically ill burn and inhalation injury patients. The purpose of this study is to characterize the risk of AMI related to hydroxocobalamin. A retrospective review of hydroxocobalamin administration among adult burn patients was conducted at a regional burn center over a 2-year period. Injury characteristics, demographics, and outcomes including presence of mesenteric ischemia (defined as presence of pneumatosis or perforation on CT scan or necrotic bowel on laparotomy) were recorded. Of 17 confirmed inhalation injuries, patients had a median (interquartile range) age, total body surface area (TBSA), and abbreviated burn severity (ABSI) index as follows: 60 (45, 65 IQR), 8.5 (1.8, 39 IQR), and 6 (5,7 IQR). Inhalation injury was diagnosed with bronchoscopy, carboxyhemoglobin, or clinical suspicion. Eighty-two percent of those with bronchoscopy had an inhalation grade of 2 or greater. None (0%) of the patients showed signs of mesenteric ischemia, tube feeding intolerance, pneumatosis/perforation on CT, or necrotic bowel on laparotomy. Aware of the study limitations, we conclude that hydroxocobalamin does not increase risk for AMI.

Animal welfare in the context of World Trade Organization dispute settlement

This paper was written to give veterinarians and decision-makers an overview of World Trade Organization (WTO) findings relevant to animal welfare. The article has a practical focus and does not attempt to provide a legal analysis of WTO dispute settlement. The author has simplified very technical legal language so that the paper will be useful to a broader audience. The global trade rules comprise a series of legal agreements that came into effect in 1995, when the WTO was established. The overarching objective of the WTO is to promote international trade by avoiding unjustified discrimination between trading partners. The harmonisation of national measures with relevant international standards is encouraged by the WTO to facilitate safe trade. The broad objective of the World Organisation for Animal Health (OIE) is to promote global improvements in animal health and welfare, and veterinary public health. To this end, the OIE sets intergovernmental standards and works to strengthen the capacities of Members to implement them. The OIE standards are recognised as WTO references with respect to animal health and zoonotic diseases and a significant number of WTO disputes have addressed the relevance of these OIE standards to international trade measures. In addition to animal health standards, the OIE also sets standards for animal welfare, and has implemented regional and global strategies to encourage their adoption by Members. In comparison with measures to protect animal health or food safety, few WTO disputes have considered animal welfare related measures. A lack of WTO case law has contributed to uncertainty about the consistency of WTO animal welfare measures. This paper considers some WTO disputes and findings relevant to animal welfare. The outcomes of these disputes suggest that WTO Panels and the Appellate Body are prepared to accept the right of Members to regulate for animal welfare purposes, providing that they respect the established WTO disciplines. This article draws two main conclusions. Firstly, regardless of whether measures are adopted to protect animal welfare or animal health, for WTO consistency, they must not result in unjustifiable, arbitrary or unnecessary discrimination. Secondly, regardless of how the WTO deals with animal welfare, governments must respond to the growing interest of consumers in farm animal welfare. The OIE standards, as recognised references for trading countries and the WTO, will continue to be influential in relation to global trade in animal products. It is important that the OIE update its animal welfare standards regularly, to ensure that they are consistent with latest scientific understanding and appropriate to consumer expectations for ethical food production.

Abstract P5-09-06: Underdiagnosis of HBOC in breast cancer patients: Are genetic testing guidelines a tool or an obstacle?

Background: Pathogenic genetic variants are estimated to occur in 10-15% of all breast cancer patients, with BRCA 1/2 accounting for 40-50% of pathogenic/likely pathogenic (P/LP) variants. However, it is estimated that <30% of breast cancer patients harboring a BRCA 1/2 variant have been identified, with the percentage being much less for ˜20 other breast cancer associated genes. Reasons for this are multifactorial and include complicated and restrictive testing guidelines developed at a time when the cost of testing was high and guidelines for management were limited. Today, cost has plummeted and there are definitive management guidelines for a broader range of genes. We created a community based Registry to determine the incidence of P/LP variants in breast cancer patients who meet and who do not meet the NCCN 2017 genetic testing criteria.

Methods: An IRB-approved multicenter prospective registry was initiated with 20 community and academic sites experienced incancer genetic testing and counseling.

Eligibility criteria included patients with a breast cancer diagnosis who had not been previously tested. Consecutive patients aged 18-90 were consented and underwent an 80 gene panel test (Invitae –Multi-Cancer Panel). The non-inferiority study was powered to detect a difference in P/LP variant rate of 4 percentage points with statistical significance (p<0.05, Fisher's exact test).

HIPAA compliant electronic case report forms collected information on patient diagnosis, test results, and physician recommendations made after test results were received.

Results: Over 1000 patients were enrolled and data from 910 subjects analyzed to date. 50.4% met NCCN criteria and 49.5% did not. Median age for the enrolled patients is 60.5 and ranged from 22-93. 56.0% of patients were recently diagnosed with breast cancer. 10.9% of patients had a history of a prior non breast cancer. Overall, 8.9% of patients had a pathogenicvariant. 9.6% of patients who met NCCN criteria with test results had a P/LP variant. 8.2% of patients who did not meet criteria had a P/LP variant. The difference of positive cases among the two groups is not statistically significant (P = 0.49)

4.9% of patients had pathogenic variants if only an 11 gene standard breast cancer panel was considered.

The spectrum of mutated genes varied between the two groups, with some overlap.

Conclusions:

There was no statistically significant difference in the number of pathogenic/likely pathogenic variants between those patients who met and those who did not meet NCCN guidelines. Expanded panel testing yields more medically actionable P/LP variants than testing BRCA 1/2 alone or breast cancer panels with 11 genes. This study demonstrates that there will be a significant number of patients with P/LP variants are missed if NCCN guidelines are required for genetic testing. Current NCCN guidelines for the genetic testing of breast cancer patients are an obstacle to identifying patients with P/LP variants and should be removed.

Universal BC Genetic Testing RegistryNCCN Criteria (910 patients analyzed)#/% who have P/LP variants#/% who do not have P/LP variantsPatients who meet guidelines44/459 (9.6%)415/459 (90.4%)Patients who do not meet guidelines37/451 (8.2%)414/451 (91.8%)

Citation Format: Beitsch P, Whitworth P, Baron P, Rosen B, Compagnoni G, Simmons R, Smith LA, Holmes D, Brown E, Gold L, Clark P, Coomer C, Grady I, Barbosa K, Riley L, Kinney M, Lyons S, MacDonald H, Kahn S, Ruiz A, Patel R, Curcio L, Esplin E, Yang S. Underdiagnosis of HBOC in breast cancer patients: Are genetic testing guidelines a tool or an obstacle? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-06.

Abstract P5-09-03: Expanded panel testing superior to BRCA1/2 and breast cancer panel in patients with breast cancer

Background: The testing of hereditary breast and ovarian cancer (HBOC) patients for BRCA1/2 only was established years ago to identify patients with clinically actionable variants and limit the economic burden. However, the cost of genetic testing has plummeted, and the number of breast cancer-risk genes with management guidelines has expanded. We created a community-based registry to test all breast cancer patients. A primary objective of this registry included accruing and comparing patients who did and did not meet NCCN guidelines and determining if providing all breast cancer patients with comprehensive multi-gene panel testing yields additional clinical value than testing BRCA1/2 alone.

Methods: An IRB-approved multicenter prospective registry was initiated with 20 community-based and academic breast sites, selected to insure geographic and ethnic diversity. Consecutive patients ages 18-90 with current or prior breast cancer were offered testing with an 80-gene panel (Invitae, San Francisco, CA). HIPAA-compliant case report forms collected patient diagnosis, test results, and physician recommendations made after test results.

Results: Over 1,000 patients were enrolled and data on 911 have been analyzed to date. Median age of patients is 60.5 (range 22 to 93). 56.0% were recently diagnosed with breast cancer. Of these patients, 50.54% met NCCN criteria, and 49.5% did not. 10.9% had history of a prior non-breast cancer. The pathogenic/likely pathogenic (P/LP) variant rate for patients on a comprehensive 80-gene panel was 8.9%. When restricted to a guidelines-based 11-gene breast cancer panel (BRCA1/2, ATM, CDH1, CHEK2, NBN, NF1, PTEN, STK11, TP53, PALB2), 4.9% had P/LP variants; when limited to BRCA1/2, 1.6% had P/LP variants. Of all patients with P/LP findings, 93% had variants in cancer-risk genes with established management recommendations (Table 1) and 80% had germline variants conferring eligibility for precision medicine-based cancer treatments, such as PARP inhibitors, through actively enrolling clinical trials.

Conclusions: This study demonstrates that comprehensive panel testing of breast cancer patients provides a higher yield of clinically actionable P/LP variants than BRCA1/2 testing alone. Limited panels may miss clinically relevant P/LP variants, leaving risk for preventable cancers undiscovered and unnecessarily restricting patients' treatment options. These results also suggest that variants in tumor suppressor genes, not previously thought related to breast cancer, may contribute to its etiology. A comprehensive panel strategy reveals untapped clinical utility and can impact breast cancer patient care by informing implementation of precision medicine treatment interventions and guiding long-term medical management and surveillance for patients and their family members.

 PatientsVariantsWith breast cancer management guidelines (including variants ATM*, BRCA1*, BRCA2*, CHEK2*, NBN*, NF1, PALB2*, TP53*)45 (56%)46 (55%)With cancer guidelines and clinical management implications (including variants BARD1*, FH, MITF, MSH6*, MUTYH*, PTCH1, RAD50*, RAD51C*, RAD51D*, RB1, RET, VHL)31 (38%)33 (39%)Evidence of actionability accruing (including variants BLM, DIS3L2, RECQL4)5 (6%)5 (6%)Totals8184*P/LP variants in these genes confer potential clinical trial eligibility, e.g. NCT02401347.

Citation Format: Beitsch P, Whitworth P, Baron P, Rosen B, Compagnoni G, Simmons R, Smith LA, Holmes D, Brown E, Gold L, Clark P, Coomer C, Grady I, Barbosa K, Riley L, Kinney M, Lyons S, MacDonald H, Kahn S, Ruiz A, Patel R, Curcio L, Esplin E, Yang S, Michalski S. Expanded panel testing superior to BRCA1/2 and breast cancer panel in patients with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-03.

Abstract P1-10-07: Prospective longitudinal study of epidermal thickening in breast cancer patients treated with conventional versus hypofractionated radiotherapy

Purpose: We conducted two prospective longitudinal studies of epidermal thickening in breast cancer (BRCA) patients treated with either conventional (CRT) or hypofractionated radiotherapy (HRT) using ultrasound images to objectively measure radiotherapy (XRT)-induced skin changes. Methods: Following breast conserving surgery, 105 consenting Stage 0-IIIA BRCA patients were enrolled on two studies of whole breast XRT without regional nodal irradiation. In the first, 66 subjects were treated with conventional fractionation (50 Gy plus a sequential 10 Gy boost at 2 Gy per fraction). In the second, subsequent study, 39 patients with characteristics under-represented in trials of HRT were treated to 39.9 Gy at 2.66 Gy per fraction with a simultaneous integrated boost of 8.1 Gy at 0.54 Gy per fraction. Inclusion criteria for this trial included breast separation >25cm, age <50 years, chemotherapy treatment, or non-Caucasian race. Prior to XRT, the last week of XRT, and 12 weeks and 1 year post XRT, subjects underwent objective ultrasound measurements of epidermal thickness over all four quadrants of the treated breast. A skin thickness ratio (STRA) was generated normalizing for corresponding measurements taken of the untreated breast. Pertinent patient, tumor, and treatment characteristics were collected at all time points, as well as peripheral blood for gene expression assays and assessment of inflammatory markers. Results: HRT patients were significantly younger than CRT patients [mean age 52 (38-73) versus (vs.) 56 years (26-75), p=0.03]. There were no other significant differences in patient, tumor, or treatment characteristics. Baseline measurements indicated 68% of CRT (mean increase 27%, SD 0.30) vs. 71% of HRT patients (mean increase 23%, SD 0.29) had skin thickening in the treated versus untreated breast prior to XRT (p=0.50). At all subsequent time points, CRT patients had significantly higher mean STRA than HRT patients [1.53, SD 0.48 vs. 1.33, SD 0.34 during RT (p=0.03); 1.62, SD 0.48 vs. 1.31, SD 0.45 at 12 weeks post RT (p=0.002); and 1.45, SD 0.39 vs. 1.27, SD 0.40 at 1 year post RT (p=0.03), respectively]. At 1 year, 31% of CRT and 38% of HRT patients had an STRA which was either less than or equal to baseline, indicating full recovery. In multivariable analysis, baseline STRA (p<0.001), BMI (p=0.002), chemotherapy (p=0.004) and CRT treatment (p=0.02) predicted for higher STRA 1 year post XRT. Dmax and breast volume receiving 107% of the dose did not predict for STRA. Gene ontology analysis revealed an over-representation of genes, differentially regulated among patients with high and low STRA, involved in the immune and defense responses. Tumor necrosis factor 2 receptor levels were also significantly higher in CRT than HRT treated patients at 1 year (p=0.03). Conclusions: Our findings indicate that CRT is associated with higher and more severe changes in STRA up 1 year after XRT than HRT, even among patients perceived to be at high risk for XRT-induced skin toxicity and who were not well-represented in the original HRT trials. An increase in peripheral markers of inflammation may be one mechanism by which CRT, BMI, and chemotherapy are associated with higher STRA 1 year post XRT.

Citation Format: Torres MA, Yang X, Mister D, Ali A, Kahn S, Liu T. Prospective longitudinal study of epidermal thickening in breast cancer patients treated with conventional versus hypofractionated radiotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-10-07.

Decomposition Pathways of the Mono- and Bis(Pivaloyloxymethyl) Esters of Azidothymidine 5′-Monophosphate in Cell Extract and in Tissue Culture Medium: An Application of the ‘on-line ISRP-Cleaning’ HPLC Technique

Bis(pivaloyloxymethyl) azidothymidine 5′-monophosphate (piv2-AZTMP) was designed as a cell membrane-permeable precursor of AZTMP. We have reported previously that when incubated with CEM cells deficient in thymidine kinase, piv2-AZTMP gives rise to intracellular AZTMP and the corresponding diphosphate (AZTDP) and triphosphate (AZTTP). Under similar conditions, no intracellular nucleotides were formed with AZT. However, the mechanism by which piv2-AZTMP is converted to AZTMP has not been established. To address this question, we have used the recently developed ‘on-line ISRP-cleaning’ HPLC technique to investigate the stability and metabolic fate of piv2-AZTMP (1) in RPMI 1640 medium, (2) in RPMI containing 10% heat-inactivated fetal calf serum, and (3) in CEM cell extracts. Similar studies were conducted starting with mono(pivaloyloxymethyl) azidothymidine 5′-monophosphate (piv2 AZTMP).

From the kinetics of these reactions, it appears that piv2-AZTMP is slowly hydrolyzed to piv1-AZTMP in RPMI and that the metabolic sequence in cell extract and in tissue culture medium is clearly: piv2-AZTMP→ piv1AZTMP→ AZTMP→ AZT. The rate constants are quite different in these three media. Although it is evident that the first step in the metabolism of piv2-AZTMP is catalysed by carboxylate esterase, the enzyme(s) responsible for the second step, piv1-AZTMP→ AZTMP, is less apparent, as carboxylate esterases and/or phosphodiesterases can be taken in account. However, analysis of the kinetic data strongly suggests that carboxylate esterase does not play a significant role and that this second step is mediated by phosphodiesterases. Collectively, these studies demonstrate that piv2-AZTMP is an effective prodrug of AZTMP. They also establish that prv1-AZTMP is an intermediate in this process, and define the sequence of the overall metabolic reaction. With this increased understanding of the metabolism of piv2-AZTMP, it should be possible rationally to design analogues with optimal structural and pharmacological properties for use in vivo.

Awareness and implementation of the regional animal welfare strategy for the Americas: a questionnaire

The World Organisation for Animal Health (OIE) is the global standard-setting organisation for animal health and these standards are references for the World Trade Organization legal framework. In 2002, noting the relationship between animal health and welfare, the OIE accepted the mandate to develop animal welfare standards. These standards were subsequently adopted by Member Countries and have been included in the TerrestrialAnimal Health Code and the Aquatic Animal Health Code. The implementation of the OIE standards by Member Countries is continually promoted. National OIE Delegates are encouraged to nominate National Focal Points for key topics, including animal welfare. In 2012, the OIE Regional Commission of the Americas adopted a Regional Animal Welfare Strategy (Regional Strategy) to promote a coordinated approach to the implementation of the OIE animal welfare standards by the 29 Member Countries in the region. In February 2015, the OIE Regional Representation for the Americas distributed a questionnaire to determine the level of awareness and implementation of the Regional Strategy. This paper presents the results of the questionnaire. With a few exceptions, veterinary officials and stakeholders are only just becoming aware of the strategy and implementation is at an early stage. To promote the implementation of the Regional Strategy, it will be.necessary to continue building the capacity of the national Veterinary Services, strengthening public-private partnerships, modernising legislation and promoting veterinary involvement in animal welfare. Through the implementation of the Regional Strategy, the OIE will provide support to countries in establishing animal welfare standards, in line with government priorities and consumer concerns.

The scientific rationale for the World Organisation for Animal Health standards and recommendations on avian influenza

The World Organisation for Animal Health (OIE) prescribes standards for the diagnosis and control of avian influenza, as well as health measures for safe trade in birds and avian products, which are based on up-to-date scientific information and risk management principles, consistent with the role of the OIE as a reference standard-setting body for the World Trade Organization (WTO). These standards and recommendations continue to evolve, reflecting advances in technology and scientific understanding of this important zoonotic disease. The avian influenza viruses form part of the natural ecosystem by virtue of their ubiquitous presence in wild aquatic birds, a fact that human intervention cannot change. For the purposes of the Terrestrial Animal Health Code (Terrestrial Code), avian influenza is defined as an infection of poultry. However, the scope of the OIE standards and recommendations is not restricted to poultry, covering the diagnosis, early detection and management of avian influenza, including sanitary measures for trade in birds and avian products. The best way to manage avian influenza-associated risks to human and animal health is for countries to conduct surveillance using recommended methods, to report results in a consistent and transparent manner, and to applythe sanitary measures described in the Terrestrial Code. Surveillance for and timely reporting of avian influenza in accordance with OIE standards enable the distribution of relevant, up-to-date information to the global community.

Photoinduced doping in heterostructures of graphene and boron nitride

The design of stacks of layered materials in which adjacent layers interact by van der Waals forces has enabled the combination of various two-dimensional crystals with different electrical, optical and mechanical properties as well as the emergence of novel physical phenomena and device functionality. Here, we report photoinduced doping in van der Waals heterostructures consisting of graphene and boron nitride layers. It enables flexible and repeatable writing and erasing of charge doping in graphene with visible light. We demonstrate that this photoinduced doping maintains the high carrier mobility of the graphene/boron nitride heterostructure, thus resembling the modulation doping technique used in semiconductor heterojunctions, and can be used to generate spatially varying doping profiles such as p-n junctions. We show that this photoinduced doping arises from microscopically coupled optical and electrical responses of graphene/boron nitride heterostructures, including optical excitation of defect transitions in boron nitride, electrical transport in graphene, and charge transfer between boron nitride and graphene.

The challenges of good governance in the aquatic animal health sector

Animal health is fundamental to efficient animal production and, therefore, to food security and human health. This holds true for both terrestrial and aquatic animals. Although partnership between producers and governmental services is vital for effective animal health programmes, many key activities are directly carried out by governmental services. Noting the need to improve the governance of such services in many developing countries, the World Organisation for Animal Health (OIE), using the OIE Tool for the Evaluation of Performance of Veterinary Services, conducts assessments of Veterinary Services and Aquatic Animal Health Services (AAHS) to help strengthen governance and support more effective delivery of animal health programmes. While good governance and the tools to improve governance in the aquatic animal sector are largely based on the same principles as those that apply in the terrestrial animal sector, there are some specific challenges in the aquatic sector that have a bearing on the governance of services in this area. For example, the aquaculture industry has experienced rapid growth and the use of novel species is increasing; there are important gaps in scientific knowledge on diseases of aquatic animals; there is a need for more information on sustainable production; the level of participation of the veterinary profession in aquatic animal health is low; and there is a lack of standardisation in the training of aquatic animal health professionals. Aquaculture development can be a means of alleviating poverty and hunger in developing countries. However, animal diseases, adverse environmental impacts and food safety risks threaten to limit this development. Strengthening AAHS governance and, in consequence, aquatic animal health programmes, is the best way to ensure a dynamic and sustainable aquaculture sector in future. This paper discusses the specific challenges to AAHS governance and some OIE initiatives to help Member Countries to address them.

Animal production food safety: priority pathogens for standard setting by the World Organisation for Animal Health

In this short study, expert opinion and a literature review were used to identify the pathogens that should be prioritised by the World Organisation for Animal Health (OIE) for the development of future standards for animal production food safety. Prioritisation was based on a pathogen's impact on human health and amenability to control using on-farm measures. As the OIE mandate includes alleviation of global poverty, the study focused on developing countries and those with 'in-transition' economies. The regions considered were Eastern Europe, Asia, the Middle East, Africa and South America. Salmonella (from species other than poultry) and pathogenic Escherichia coli were considered to be top priorities. Brucella spp., Echinococcus granulosus and Staphylococcus aureus were also mentioned by experts. As Salmonella, and to a lesser extent pathogenic E. coli, can be controlled by on-farm measures, these pathogens should be considered for prioritisation in future standard setting. On-farm control measures for Brucella spp. will be addressed in 2010-2011 in a review of the OLE Terrestrial Animal/Health Code chapter on brucellosis. In Africa, E. granulosus, the causative agent of hydatidosis, was estimated to have the greatest impact of all pathogens that could potentially be transmitted by food (i.e. via contamination). It was also listed for the Middle East and thought to be of importance by both South American experts consulted. Taenia saginata was thought to be of importance in South America and Africa and by one expert in the Middle East.

The role of the World Trade Organization and the 'three sisters' (the World Organisation for Animal Health, the International Plant Protection Convention and the Codex Alimentarius Commission) in the control of invasive alien species and the preservation of biodiversity

The missions of the World Organisation for Animal Health (OIE) include the design of surveillance and control methods for infectious transboundary animal diseases (including zoonoses), the provision of guarantees concerning animal health and animal production food safety, and the setting of standards for, and promotion of, animal welfare. The OIE role in setting standards for the sanitary safety of international trade in animals and animal products is formally recognised in the World Trade Organization (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement). While the primary focus of the OIE is on animal diseases and zoonoses, the OIE has also been working within the WTO framework to examine possible contributions the organisation can make to achieving the goals of the Convention on Biological Diversity, particularly to preventing the global spread of invasive alien species (IAS). However, at the present time, setting standards for invasive species (other than those connected to the cause and distribution of diseases listed by the OIE) is outside the OIE mandate. Any future expansion of the OIE mandate would need to be decided by its Members and resources (expertise and financial contributions) for an extended standard-setting work programme secured. The other international standard-setting organisations referenced by the SPS Agreement are the International Plant Protection Convention (IPPC) and the Codex Alimentarius Commission (CAC). The IPPC mandate and work programme address IAS and the protection of biodiversity. The CAC is not involved in this field.

Free-roaming dog control among OIE-member countries

A questionnaire was distributed to the state veterinary services of all 172 OIE countries to collect data on the different national approaches to dog population control. We used all 81 completed questionnaires with ≥80% of the question answered to identify the different national approaches to the issue. The intensity of the free-roaming dog (FRD) problem was negatively correlated with the value of the UN's human development index recognized for each country. Dog bites/attacks and rabies were the main problems associated with FRDs, and these problems were reported disproportionately by less-developed countries. Dog-control programs (DCP) were more widely used among the more-developed countries. In less-developed countries, DCPs (when they existed at all) tended to employ killing methods (including poisoned baits), that are not recommended on animal-welfare grounds.

Circadian characteristics of serum calcium, magnesium and eight trace elements and of their metallo-moieties in urine of healthy middle-aged men

OBJECTIVE

To monitor the around-the-clock distribution of serum and urine concentrations of calcium, magnesium and eight trace elements and of those same elements in urine after their dialysis, and to statistically describe their circadian characteristics by chronobiological procedures.

MATERIALS AND METHODS

Serum and urine samples were collected every 3h over a single 24h period from eleven clinically-healthy male subjects, 41-60 years of age, and were analyzed for calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), cobalt (Co), chromium (Cr), and nickel (Ni). Urines were also sequentially dialyzed against ammonium-barbituric acid buffer at pH 7.35+/-0.02 using a 12.000-14.000 molecular weight exclusion sieve and then reanalyzed for the same elements. Urine concentrations were adjusted by urine volume to reflect a 3h excretion rate. Time-series were analyzed for circadian time-effect by ANOVA and for rhythm characteristics by the single cosinor fitting procedure.

RESULTS

The dialysis effectively removed 90% of total solids, 97% of urea, 92% creatinine, 72% uric acid, and essentially all of glucose. It also removed 99% of potassium (K), 96% of sodium (Na), 65% of Ca and P, 55% of Mg, 41% of Zn and 88% of Ni. A significant or borderline-significant 24h rhythm in serum was detected for Ca, Mg, Fe, Cu, Zn, Cd and Cr; in untreated urine for Ca, Fe, Cu, Zn, Ni, creatinine and volume; and in dialyzed urine for Ca, Fe, Cu, Zn, Pb, Cr, Cd and Ni. A 12h component was significant or borderline-significant in serum for Mg, Fe, Zn, and Cd; in untreated urine for volume, creatinine, Ca, Mg, Cu, and Ni; and in dialyzed urine for Ca, Mg, Fe, Cu, Zn, and Cr. In general, values in serum were lowest near the onset of sleep and highest in the first half of the day (between 02:28 and 13:56 h), while highest values in untreated or dialyzed urine were found several hours later in the day and at night.

CONCLUSIONS

Significant circadian variations were found in levels of nearly every element that was measured in blood and urine of 11 healthy men, but with highest and lowest levels occurring at different times. This suggests not only that urine concentrations need to be adjusted for collection time interval and urine volume, but that different biological limits at different times of the 24h day should be applied for serum and urinary monitoring of trace elements. We also found that the non-dialyzable segments of these elements in urine represent metallo-moieties composed of proteinacious matter greater than 12,000-14,000 Daltons. Further studies would be of interest to reveal time specificity for metabolic functions associated with any of these trace elements.

Search for flavor-changing-neutral-current d meson decays

We study the flavor-changing-neutral-current process c-->u micro(+) micro(-) using 1.3 fb(-1) of pp[over ] collisions at square root s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the charged-current mediated D(s)(+) and D(+)-->phipi(+) --> micro(+)micro(-)pi(+) final states with significance greater than 4 standard deviations above background for the D(+) state. We search for the continuum neutral-current decay of D(+)-->pi(+) micro(+) micro(-) in the dimuon invariant mass spectrum away from the phi resonance. We see no evidence of signal above background and set a limit of B(D(+) --> pi(+) micro(+) micro(-))<3.9 x 10(-6) at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c--> u micro(+) micro(-) transition.

OIE guidelines on dog population control

At the 73rd General Session the OIE decided to develop guidance for Members on humane methods for the control of stray animal populations. In 2006, an ad hoc Group was convened under the leadership of the OIE Permanent Animal Welfare Working Group. With valuable assistance from the OIE Collaborating Centre on Animal Welfare, a Questionnaire was developed and sent to OIE Members, of which 81 countries submitted responses. In light of this information, the ad hoc Group prepared a first draft report, which notes the importance of controlling stray dog populations to help prevent zoonotic diseases and non-disease related nuisances to society and the environment. In choosing the preferred method of control, the risks to operators must be taken into account, as well as religious, cultural and economic contexts of the country concerned. Depending on the situation, methods requiring individual animal restraint or methods for use at a distance may be recommended. While activities that aim to physically reduce the numbers of stray dogs are important, achievement of the long term goals of dog population control and avoidance of risks to human health depends on the education of dog owners and the general public as to their responsibilities. The draft report notes that sub-national jurisdictions are often those responsible for the control of stray dog populations. The key role played by non-governmental organisations in stray dog management in many countries is acknowledged. The draft report emphasises that the close involvement of veterinarians and of official Veterinary Services, working in collaboration with public health authorities, is necessary to realise long term goals.

Study of the decay Bs(0)-->Ds(*)Ds(*)

We report a study of the decay Bs(0)-->Ds(*)Ds(*) using a data sample corresponding to 1.3 fb(-1) of integrated luminosity collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. One Ds(*) meson was partially reconstructed in the decay Ds-->phi mu nu, and the other Ds(*) meson was identified using the decay Ds-->phi pi where no attempt was made to distinguish Ds and Ds(*) states. For the branching fraction Br(Bs(0)-->Ds(*)Ds(*)) we obtain a 90% C.L. range [0.002,0.080] and central value 0.039(-0.017)(+0.019)(stat)(-0.015)(+0.016)(syst). This was subsequently used to make the most precise estimate of the width difference DeltaGamma(s)CP in the Bs(0)-Bs(0) system: DeltaGamma(s)CP/Gamma(s)=0.079(-0.035)(+0.038)(stat)(-0.030)(+0.031)(syst).

Search for production of single top quarks via tcg and tug flavor-changing-neutral-current couplings

We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb{-1} of lepton+jets data from pp[over] collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters kappa{g}{c}/Lambda and kappa{g}{u}/Lambda, where kappa{g} define the strength of tcg and tug couplings, and Lambda defines the scale of new physics. The limits at 95% C.L. are kappa{g}{c}/Lambda<0.15 TeV-1 and kappa{g}{u}/Lambda<0.037 TeV-1.

Measurement of the Lambdab0 lifetime using semileptonic decays

We report a measurement of the Lambda(b)(0) lifetime using a sample corresponding to 1.3 fb(-1) of data collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. The Lambda(b)(0) baryon is reconstructed via the decay Lambda(b)(0)-->micronuLambda(c)(+)X. Using 4437+/-329 signal candidates, we measure the Lambda(b)(0) lifetime to be tau(Lambda(b)(0))=1.290(-0.110)(+0.119)(stat)(-0.091)(+0.087)(syst) ps, which is among the most precise measurements in semileptonic Lambda(b)(0) decays. This result is in good agreement with the world average value.

Properties of L=1 B(1) and B(2)* mesons

This Letter presents the first strong evidence for the resolution of the excited B mesons B(1) and B(2)* as two separate states in fully reconstructed decays to B(+)(*)pi(-). The mass of B(1) is measured to be 5720.6+/-2.4+/-1.4 MeV/c(2) and the mass difference DeltaM between B(2)* and B(1) is 26.2+/-3.1+/-0.9 MeV/c;{2}, giving the mass of the B(2)* as 5746.8+/-2.4+/-1.7 MeV/c(2). The production rate for B(1) and B(2)* mesons is determined to be a fraction (13.9+/-1.9+/-3.2)% of the production rate of the B+ meson.

Measurement of the Lambda b lifetime in the exclusive decay Lambda b --> J/psi Lambda

We have measured the Lambda b lifetime using the exclusive decay Lambda b --> J/psi Lambda, based on 1.2 fb(-1) of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda b decays, where the J/psi and Lambda are identified via the decays J/psi --> mu+ mu- and Lambda --> ppi, we measured the Lambda b lifetime to be tau(Lambda b)=1.218 (+0.130)/(-0.115) (stat) +/- 0.042(syst) ps. We also measured the B0 lifetime in the decay B0 --> J/psi(mu+ mu-)K(0)/(S)(pi+ pi-) to be tau(B0)=1.501 (+0.078)/(-0.074) (stat) +/- 0.050(syst) ps, yielding a lifetime ratio of tau(Lambda b)/tau(B0)=0.811 (+0.096)/(-0.087) (stat) +/- 0.034(syst).

Search for stopped gluinos from pp collisions at square root s = 1.96 TeV

Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb(-1) of pp collisions at square root(s) = 1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such "stopped gluinos" decaying into a gluon and a neutralino (chi(1)(0)). Limits are placed on the (gluino cross section) x (probability to stop) x [BR(g --> g chi(1)(0))] as a function of the gluino and chi(1)(0) masses, for gluino lifetimes from 30 micros-100 h.

Search for third-generation scalar leptoquarks in pp at square root s=1.96 TeV

We report on a search for charge-1/3 third-generation leptoquarks (LQ) produced in pp collisions at square root s =1.96 TeV using the D0 detector at Fermilab. Third-generation leptoquarks are assumed to be produced in pairs and to decay to a tau neutrino and a b quark with branching fraction B. We place upper limits on sigma(pp --> LQLQ)B2 as a function of the leptoquark mass M(LQ). Assuming B=1, we exclude at the 95% confidence level third-generation scalar leptoquarks with M(LQ)<229 GeV.

Direct observation of the strange b baryon Xib-

We report the first direct observation of the strange b baryon Xi(b)- (Xi(b)+). We reconstruct the decay Xi(b)- -->J/psiXi-, with J/psi-->mu+mu-, and Xi--->Lambdapi--->ppi-pi- in pp collisions at square root of s =1.96 TeV. Using 1.3 fb(-1) of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat)(-0.4)(+1.9)(syst) Xi(b)- candidates at a mass of 5.774 +/- 0.011(stat) +/- 0.015(syst) GeV. The significance of the observed signal is 5.5 sigma, equivalent to a probability of 3.3 x 10(-8) of it arising from a background fluctuation. Normalizing to the decay Lambda(b)-->J/psiLambda, we measure the relative rate sigma(Xi(b-) x B(Xi)b})- -->J/psiXi-)/sigma(Lambda(b)) x B(Lambda(b)-->J/psiLambda) = 0.28+/-0.09(stat)(-0.08)(+0.09)(syst).

Search for techniparticles in e+jets events at D0

We search for the technicolor process pp-->rhoT/omegaT-->WpiT in events containing one electron and two jets, in data corresponding to an integrated luminosity of 390 pb(-1), recorded by the D0 experiment at the Fermilab Tevatron. Technicolor predicts that technipions pi(T) decay dominantly into bb, bc, or bc, depending on their charge. In these events b and c quarks are identified by their secondary decay vertices within jets. Two analysis methods based on topological variables are presented. Since no excess above the standard model prediction was found, the result is presented as an exclusion in the pi(T) vs rho(T) mass plane for a given set of model parameters.

Evidence for production of single top quarks and first direct measurement of |Vtb|

The D0 Collaboration presents first evidence for the production of single top quarks at the Fermilab Tevatron pp[over ] collider. Using a 0.9 fb(-1) dataset, we apply a multivariate analysis to separate signal from background and measure sigma(pp[over ]-->tb+X,tqb+X)=4.9+/-1.4 pb. The probability to measure a cross section at this value or higher in the absence of a signal is 0.035%, corresponding to a 3.4 standard deviation significance. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa matrix element that describes the Wtb coupling and find 0.68<|V(tb)|</=1 at 95% C.L. within the standard model.

Measurement of the charge asymmetry in semileptonic Bs0 decays

We have performed the first direct measurement of the time-integrated flavor untagged charge asymmetry in semileptonic Bs0 decays ASLs,unt by comparing the decay rate of Bs0-->micro+Ds-nuX, where Ds- -->phipi- and phi-->K+K-, with the charge-conjugate Bs0 decay rate. This sample was selected from 1.3 fb-1 of data collected by the D0 experiment in run II of the Fermilab Tevatron collider. We obtain ASLs,unt=[1.23+/-0.97(stat)+/-0.17(syst)]x10(-2). Assuming that Deltam(s)/Gamma(s)>>1, this result can be translated into a measurement of the CP-violating phase in Bs0 mixing: DeltaGamma(s)/Deltam(s)tanphi(s)=[2.45+/-1.93(stat)+/-0.35(syst)]x10(-2).

Lifetime difference and CP-violating phase in the Bs0 system

From an analysis of the decay Bs0-->J/psi phi, we obtain the width difference between the light and heavy mass eigenstates DeltaGamma identical with (GammaL-GammaH)=0.17+/-0.09(stat)+/-0.02(syst) ps-1 and the CP-violating phase phis=-0.79+/-0.56(stat)(-0.01)(+0.14)(syst). Under the hypothesis of no CP violation (phis identical with 0), we obtain 1/Gamma=tau(Bs0)=1.52+/-0.08(stat)(-0.03)(+0.01)(syst) ps and DeltaGamma=0.12(-0.10)(+0.08)(stat)+/-0.02(syst) ps-1. The data sample corresponds to an integrated luminosity of about 1.1 fb-1 accumulated with the D0 detector at the Fermilab Tevatron collider. This is the first direct measurement of the CP-violating mixing phase in the Bs0 system.

Experimental discrimination between charge 2e/3 top quark and charge 4e/3 exotic quark production scenarios

We present the first experimental discrimination between the 2e/3 and 4e/3 top quark electric charge scenarios, using top quark pairs (tt) produced in pp collisions at (square root) s = 1.96 TeV by the Fermilab Tevatron Collider. We use 370 pb;{-1} of data collected by the D0 experiment and select events with at least one high transverse momentum electron or muon, high transverse energy imbalance, and four or more jets. We discriminate between b- and b-quark jets by using the charge and momenta of tracks within the jet cones. The data are consistent with the expected electric charge, |q|=2e/3. We exclude, at the 92% C.L., that the sample is solely due to the production of exotic quark pairs QQ with |q|=4e/3. We place an upper limit on the fraction of QQ pairs rho<0.80 at the 90% C.L.

Measurement of the Bs(0) lifetime using semileptonic decays

We report a measurement of the Bs(0) lifetime in the semileptonic decay channel Bs(0) --> Ds- mu+ nuX (and its charge conjugate), using approximately 0.4 fb(-1) of data collected with the D0 detector during 2002-2004. Using 5176 reconstructed Ds- mu+ signal events, we have measured the Bs(0) lifetime to be tau(Bs(0))=1.398+/-0.044(stat)(-0.025)(+0.028)(syst) ps. This is the most precise measurement of the Bs(0) lifetime to date.

Search for pair production of scalar bottom quarks in pp collisions at square root of s = 1.96 TeV

A search for direct production of scalar bottom quarks (b) is performed with 310 pb(-1) of data collected by the D0 experiment in pp collisions at square root s = 1.96 TeV at the Fermilab Tevatron Collider. The topology analyzed consists of two b jets and an imbalance in transverse momentum due to undetected neutralinos (chi(1)0), with chi(1)0 assumed to be the lightest supersymmetric particle. We find the data consistent with standard model expectations, and set a 95% C.L. exclusion domain in the (m(b), m(chi(1)0)) mass plane, improving significantly upon the results from run I of the Tevatron.

Search for neutral, long-lived particles decaying into two muons in pp[over] collisions at sqrt[s]=1.96 TeV

We present a search for a neutral particle, pair produced in pp[over] collisions at sqrt[s]=1.96 TeV, which decays into two muons and lives long enough to travel at least 5 cm before decaying. The analysis uses approximately 380 pb(-1) of data recorded with the D0 detector. The background is estimated to be about one event. No candidates are observed, and limits are set on the pair-production cross section times branching fraction into dimuons + X for such particles. For a mass of 10 GeV and lifetime of 4x10(-11) s, we exclude values greater than 0.14 pb (95% C.L.). These results are used to limit the interpretation of NuTeV's excess of dimuon events.

Search for the standard model Higgs Boson in the pp[over]-->ZH-->nunu[over]bb[over] channel

We report a search for the standard model (SM) Higgs boson based on data collected by the D0 experiment at the Fermilab Tevatron Collider, corresponding to an integrated luminosity of 260 pb(-1). We study events with missing transverse energy and two acoplanar b jets, which provide sensitivity to the ZH production cross section in the nunu[over]bb[over] channel, and to WH production when the lepton from the W-->lnu decay is undetected. The data are consistent with the SM background expectation, and we set 95% C.L. upper limits on sigma(pp[over]-->ZH/WH)xB(H-->bb[over]) from 3.4/8.3 to 2.5/6.3 pb, for Higgs-boson masses between 105 and 135 GeV.

Search for associated higgs boson production WH-->WWW*-->l+/-nul'+/-nu'+X in pp collisions at square root s=1.96 Te V

We present a search for associated Higgs boson production in the process pp-->WH-->WWW*-->l;+/-nul'+/-nu'+X in final states containing two like-sign isolated electrons or muons (e+/-e;+/-, e+/-micro+/-, or micro+/-micro+/-). The search is based on D0 run II data samples corresponding to integrated luminosities of 360-380 pb-1. No excess is observed over the predicted standard model background. We set 95% C.L. upper limits on sigma(pp-->WH)xBr(H-->WW*) between 3.2 and 2.8 pb for Higgs boson masses from 115 to 175 GeV.