Commentary on the adoption of a test-based versus syndromic-based approach to outbreak declaration and management in hospital and institutional settings.

At present, Ontario, like most other jurisdictions in Canada, uses a syndromic-based surveillance definition for acute respiratory infection (ARI) outbreaks in institutions and public hospitals. Confirmed outbreaks are defined as either two or more ARIs in 48 hours with any common epidemiological link and at least one that is laboratory-confirmed; or three cases of ARIs occurring within 48 hours with any common epidemiological link, and not necessarily with lab confirmation. However, with the adoption of broader test-based approaches for sick patients/residents throughout the pandemic, new challenges have surfaced regarding the declaration and management of ARI outbreaks with a variety of scenarios in respiratory testing results. Decisions, including the determination of epidemiological linkage when there are discordant/negative test results, have become more complicated with the addition of virus-specific test results for every sick individual. The ARI outbreak case definition and management guidance was updated in 2018. The purpose of this commentary is to highlight epidemiological trends in ARI outbreaks in Ontario over the 2022-2023 season compared to the 2018-2019 and 2019-2020 pre-pandemic seasons. This is followed by a discussion around some of the benefits and challenges of implementing a test-based versus syndromic-based approach to ARI outbreaks.

Nursing home crowding and its association with outbreak-associated respiratory infection in Ontario, Canada before the COVID-19 pandemic (2014-19): a retrospective cohort study.

BACKGROUND: Studies conducted during the COVID-19 pandemic have shown that crowding in nursing homes is associated with high incidence of SARS-CoV-2 infections, but this effect has not been shown for other respiratory pathogens. We aimed to measure the association between crowding in nursing homes and outbreak-associated respiratory infection incidence and related mortality before the COVID-19 pandemic. METHODS: We conducted a retrospective cohort study of nursing homes in Ontario, Canada. We identified, characterised, and selected nursing homes through the Ontario Ministry of Long-Term Care datasets. Nursing homes that were not funded by the Ontario Ministry of Long-Term Care and homes that closed before January, 2020 were excluded. Outcomes consisting of respiratory infection outbreaks were obtained from the Integrated Public Health Information System of Ontario. The crowding index equalled the mean number of residents per bedroom and bathroom. The primary outcomes were the incidence of outbreak-associated infections and mortality per 100 nursing home residents per year. We examined the incidence of infections and deaths as a function of the crowding index by use of negative binomial regression with adjustment for three home characteristics (ie, ownership, number of beds, and region) and nine mean resident characteristics (ie, age, female sex, dementia, diabetes, chronic heart failure, renal failure, cancer, chronic obstructive pulmonary disease, and activities of daily living score). FINDINGS: Between Sept 1, 2014, and Aug 31, 2019, 5107 respiratory infection outbreaks in 588 nursing homes were recorded, of which 4921 (96·4%), involving 64 829 cases of respiratory infection and 1969 deaths, were included in this analysis. Nursing homes with a high crowding index had higher incidences of respiratory infection (26·4% vs 13·8%; adjusted rate ratio per one resident per room increase in crowding 1·89 [95% CI 1·64-2·17]) and mortality (0·8% vs 0·4%; 2·34 [1·88-2·92]) than did homes with a low crowding index. INTERPRETATION: Respiratory infection and mortality rates were higher in nursing homes with high crowding index than in homes with low crowding index, and the association was consistent across various respiratory pathogens. Decreasing crowding is an important safety target beyond the COVID-19 pandemic to help to promote resident wellbeing and decrease the transmission of prevalent respiratory pathogens. FUNDING: None.

Determining Domains of Practice for Youth Support Co-Coordinator Work in Teenage/Young Adult Cancer Care in United Kingdom.

Purpose: Youth support coordinators (YSCs) provide youth-focused psychosocial support to teenagers and young adults (TYA) with cancer, within multidisciplinary teams (MDTs) in National Health Service (NHS) specialist cancer environments. This action research project aimed to provide insight into the work of YSCs with TYA with cancer, within MDTs in clinical settings, and to develop a knowledge and skill framework for YSCs. Methods: An action research approach was taken involving two focus groups, with Health Care Professionals (n = 7) and TYA with cancer (n = 7), and a questionnaire with YSCs (n = 23). Data were analyzed using a thematic analysis approach. A research steering group ensured consistency with the participatory methodology. Results: The positive value of YSC contribution to patients and MDT was echoed across the data sets. Four domains of practice were identified for inclusion in a YSC knowledge and skill framework: (1) adolescent development; (2) the TYA with cancer; (3) working with TYA with cancer; and (4) professional practice of YSC work. Conclusion: Findings highlight the interdependence of YSC domains of practice. For example, the impact of cancer and its treatment must be considered alongside biopsychosocial knowledge relating to adolescent development. Similarly, skills for running youth-focused activities need adapting to the professional cultures, rules, and practices of working in health care systems. Further questions and challenges are raised, such as the value and challenge of therapeutic conversations; practice supervision; and the complexities of the "insider/outsider" perspectives YSCs bring. These insights potentially have important transferability to other areas of adolescent health care.

Soil erosion response to land use change in a mountainous rural area of Son La Province of Vietnam.

This study investigated the changes in soil erosion associated with land use change from 2000 to 2020 in a mountainous rural area. Land use change was detected using Landsat images and soil erosion was estimated using the revised universal soil loss equation (RUSLE). The results show that deforestation and fallow cultivation caused substantial soil loss, whereas conversion from uncultivated land to cropland reduced soil erosion. A conversion from 711 ha cropland and 234 ha forestland to uncultivated land increased the average soil loss from 17 ton·ha-1·year-1 to 42 ton·ha-1·year-1 and the area of eroded soil at the very high level from 276 to 1058 ha between 2000 and 2010. In contrast, a wide expansion of cropland from 637 ha uncultivated land decreased the average soil loss from 42 ton·ha-1·year-1 to 32 ton·ha-1·year-1 and the area of eroded soil at the very high level from 1058 to 690 ha between 2010 and 2020. We suggest management measures such as forest protection, afforestation, reforestation, fruit tree development, and soil erosion control practices in coffee and maize cultivation to reduce soil erosion.

Effect of Pre-Slaughter Practises and Early Post-Mortem Interventions on Sheep Meat Tenderness and Its Impact on Microbial Status.

Tenderness, together with flavour, is the main quality trait that defines consumer acceptance of sheep meat. The factors affecting tenderness can be grouped as those influenced before slaughter, in the early post-mortem intervention and, finally, during the aging period. These factors have been extensively studied with respect to tenderness, but the impact of early post-mortem interventions and subsequent aging on the microbial quality of the final products has not been broadly reviewed to date. In this review, the authors summarize the most recent knowledge on lamb meat tenderness management and how such practices may impact the final meat quality, especially its microbial status. The impacts of pre-slaughter factors (age, sex, diet, genotype and transport) and post-mortem interventions (chilling regime, electrical stimulation, or hanging method), are described and comprehensively discussed.

Increased Household Secondary Attacks Rates With Variant of Concern Severe Acute Respiratory Syndrome Coronavirus 2 Index Cases.

We compared secondary attack rates in households with B.1.1.7 variant of concern (VOC) versus non-VOC index cases in a matched cohort in Ontario, Canada. The secondary attack rate for VOC index cases was 1.31 times higher than non-VOC index cases. This increase was particularly accentuated for asymptomatic or presymptomatic index cases.

Application of multimedia models for understanding the environmental behavior of volatile methylsiloxanes: Fate, transport, and bioaccumulation.

Multimedia fate and transport models (MFTMs) describe how chemicals behave in the environment based on their inherent properties and the characteristics of receiving systems. We critically review the use of MFTMs for understanding the behavior of volatile methylsiloxanes (VMS). MFTMs have been used to predict the fate of VMS in wastewater treatment, rivers, lakes, marine systems, and the atmosphere, and to assess bioaccumulation and trophic transfers. More widely, they have been used to assess the overall persistence, long-range transport potential (LRTP), and the propensity for atmosphere-surface exchange. The application of MFTMs for VMS requires particularly careful selection of model inputs because the properties of VMS differ from those of most organic compounds. For example, although n-octanol/water partition coefficient (KOW ) values are high, air:water partition coefficient (KAW ) values are also high and n-octanol/air partition coefficient (KOA ) values are relatively low. In addition, organic carbon/water partition coefficient (KOC ) values are substantially lower than expectations based on KOW . This means that most empirical relationships between KOC and KOW are not appropriate. Good agreement between modeled and measured concentrations in air, sediment, and biota indicates that our understanding of environmental fate is reasonable. VMS compounds are "fliers" that principally partition to the atmosphere, implying high LRTP, although they have low redeposition potential. They are degraded in air (half-lives 3-10 days) and, thus, have low overall persistence. In water, exposure can be limited by hydrolysis, volatilization, and partitioning to sediments (where degradation half-lives are likely to be high). In food webs, they are influenced by metabolism in biota, which tends to drive trophic dilution (i.e., trophic magnification factors are often but not always <1). Key remaining uncertainties include the following: (i) the strength and direction of the temperature dependence for KOC ; (ii) the fate of atmospheric reaction products; and (iii) the magnitude of emissions to wastewater. Integr Environ Assess Manag 2022;18:599-621. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Association of Age and Pediatric Household Transmission of SARS-CoV-2 Infection.

Importance: As a result of low numbers of pediatric cases early in the COVID-19 pandemic, pediatric household transmission of SARS-CoV-2 remains an understudied topic. Objective: To determine whether there are differences in the odds of household transmission by younger children compared with older children. Design, Setting, and Participants: This population-based cohort study took place between June 1 and December 31, 2020, in Ontario, Canada. Private households in which the index case individual of laboratory-confirmed SARS-CoV-2 infection was younger than 18 years were included. Individuals were excluded if they resided in apartments missing suite information, in households with multiple index cases, or in households where the age of the index case individual was missing. Exposures: Age group of pediatric index cases categorized as 0 to 3, 4 to 8, 9 to 13, and 14 to 17 years. Main Outcomes and Measures: Household transmission, defined as households where at least 1 secondary case occurred 1 to 14 days after the pediatric index case. Results: A total of 6280 households had pediatric index cases, and 1717 households (27.3%) experienced secondary transmission. The mean (SD) age of pediatric index case individuals was 10.7 (5.1) years and 2863 (45.6%) were female individuals. Children aged 0 to 3 years had the highest odds of transmitting SARS-CoV-2 to household contacts compared with children aged 14 to 17 years (odds ratio, 1.43; 95% CI, 1.17-1.75). This association was similarly observed in sensitivity analyses defining secondary cases as 2 to 14 days or 4 to 14 days after the index case and stratified analyses by presence of symptoms, association with a school/childcare outbreak, or school/childcare reopening. Children aged 4 to 8 years and 9 to 13 years also had increased odds of transmission (aged 4-8 years: odds ratio, 1.40; 95% CI, 1.18-1.67; aged 9-13 years: odds ratio, 1.13; 95% CI, 0.97-1.32). Conclusions and Relevance: This study suggests that younger children may be more likely to transmit SARS-CoV-2 infection compared with older children, and the highest odds of transmission was observed for children aged 0 to 3 years. Differential infectivity of pediatric age groups has implications for infection prevention within households, as well as schools/childcare, to minimize risk of household secondary transmission. Additional population-based studies are required to establish the risk of transmission by younger pediatric index cases.

Beyond flu: Trends in respiratory infection outbreaks in Ontario healthcare settings from 2007 to 2017, and implications for non-influenza outbreak management.

BACKGROUND: Outbreaks cause significant morbidity and mortality in healthcare settings. Current testing methods can identify specific viral respiratory pathogens, yet the approach to outbreak management remains general. OBJECTIVES: Our aim was to examine pathogen-specific trends in respiratory outbreaks, including how attack rates, case fatality rates and outbreak duration differ by pathogen between hospitals and long-term care (LTC) and retirement homes (RH) in Ontario. METHODS: Confirmed respiratory outbreaks in Ontario hospitals and LTC/RH reported between September 1, 2007, and August 31, 2017, were extracted from the integrated Public Health Information System (iPHIS). Median attack rates and outbreak duration and overall case fatality rates of pathogen-specific outbreaks were compared in both settings. RESULTS: Over the 10-year surveillance period, 9,870 confirmed respiratory outbreaks were reported in Ontario hospitals and LTC/RH. Influenza was responsible for most outbreaks (32% in LTC/RH, 51% in hospitals), but these outbreaks were shorter and had lower attack rates than most non-influenza outbreaks in either setting. Human metapneumovirus, while uncommon (<4% of outbreaks) had high case fatality rates in both settings. CONCLUSION: Attack rates and case fatality rates varied by pathogen, as did outbreak duration. Development of specific outbreak management guidance that takes into account pathogen and healthcare setting may be useful to limit the burden of respiratory outbreaks.

Exploring Young People's Experience of Ending Active Cancer Treatment: When the "Little Cancer Treatment Bubble" Pops.

BACKGROUND: The end of active cancer treatment is described as a stressful period for adolescents and young adults (AYAs). However, research evidence describing the experience of AYAs as they transition from active treatment into follow-up care is scarce. OBJECTIVE: We aimed to understand AYAs' experiences within the first 12 months of ending active treatment. METHODS: Data were collected using semistructured interviews, which were digitally recorded and transcribed verbatim. Qualitative analysis of transcripts was used to identify key themes/subthemes. RESULTS: Eleven AYAs (8 female participants), diagnosed with cancer aged 17 to 25 years and 19 to 26 years at point of interview, participated. At time of interview, 7 were within 6 months of treatment completion, and in 4 participants, treatment ended 6 to 12 months prior. Three main themes were identified: (1) challenges of social reintegration and self-identity, (2) expectations versus the lived experience of ending treatment, and (3) sudden loss of the safe "bubble" of treatment. CONCLUSIONS: Adolescents and young adults were underprepared for and challenged by the unexpected emotional and physical consequences of ending active cancer treatment. IMPLICATIONS FOR PRACTICE: Young people require information and support to prepare for ending active treatment and reintegration to everyday life. Preparation for the short- and long-term physical, social, and psychological impact of a cancer diagnosis even when treatment ends will assist young people in managing this transition. Further research is required to develop and test interventions to provide timely, structured, and equitable information and support at the end of treatment to better prepare AYAs for the challenges they may face as treatment ends.

Epidemiology, clinical characteristics, household transmission, and lethality of severe acute respiratory syndrome coronavirus-2 infection among healthcare workers in Ontario, Canada.

INTRODUCTION: Protecting healthcare workers (HCWs) from Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a priority to maintain a safe and functioning healthcare system. Our objective was to describe and compare the epidemiology, clinical characteristics, and lethality of SARS-CoV-2 infections among HCWs compared to non-HCWs. METHODS: Using reportable disease data at Public Health Ontario, we conducted a population-based cross-sectional study comparing demographic, exposure, and clinical variables between HCWs and non-HCWs with SARS-CoV-2 infections as of 30 September 2020. We calculated rates of infections over time and determined the frequency of within household transmissions using natural language processing based on residential address. We evaluated the risk of death using a multivariable logistic regression model adjusting for age, sex, comorbidities, symptoms, and long-term care home exposure. RESULTS: There were 7,050 (12.5%) HCW SARS-CoV-2 infections in Ontario, Canada, of whom 24.9% were nurses, 2.3% were physicians, and the remaining 72.8% other specialties, including personal support workers. Overall HCWs had an infection rate of 1,276 per 100,000 compared to non-HCWs of 346 per 100,000 (3.7 times higher). This difference decreased from a 7 times higher rate in April to no difference in September 2020. Twenty-six percent of HCWs had a household member with SARS-CoV-2 infection; 6.8% were probable acquisitions, 12.3% secondary transmissions, and 6.9% unknown direction of transmission. Death among HCWs was 0.2% compared to 6.1% of non-HCWs. The risk of death in HCWs remained significantly lower than non-HCWs after adjustment (adjusted odds ratio 0.09; 95%CI 0.05-0.17). CONCLUSION: HCWs represent a disproportionate number of diagnosed SARS-CoV-2 infections in Ontario, however this discrepancy is at least partially explained by limitations in testing earlier in the pandemic for non-HCWs. We observed a low risk of death in HCWs which could not be completely explained by other factors.

The support and information needs of adolescents and young adults with cancer when active treatment ends.

BACKGROUND: The end of active treatment is a period of high stress for young people with cancer, but limited literature exists about their information and support needs during this phase. This study aimed to understand the needs of young people with cancer, how these needs are currently being met, and how best to provide information and support at the end of active treatment. METHODS: This was a multi-stage, mixed methods study exploring the end of treatment experience from the perspectives of young people, and the healthcare professionals caring for them. Semi-structured interviews were undertaken with healthcare professionals, which informed a survey administered nationally. Subsequently, semi-structured interviews were conducted with young people. These combined results informed a co-design workshop to develop recommendations. RESULTS: Telephone interviews were conducted with 12 healthcare professionals and 49 completed the online survey. A total of 11 young people aged 19-26 years (female = 8; 73%) were interviewed. The stakeholder workshop was attended by both healthcare professionals (n = 8) and young people (n = 3). At the end of treatment young people experience numerous ongoing physical issues including pain, fatigue and insomnia; in addition to a range of psychosocial and emotional issues including anxiety, fear of recurrence and isolation. The top three priorities for end of treatment care were: earlier provision and preparation around on-going impact of cancer and cancer treatment; standardised and continued follow-up of young people's emotional well-being; and development of more information and resources specific to young people. CONCLUSION: The access and availability of appropriate information and sources of support at the end of treatment is variable and inequitable. Young people's needs would be more effectively met by timely, structured and accessible information, and support provision at the end of treatment to both prepare and enable adaptation across their transition to living with and beyond cancer. This will require both organisational and practical adjustments in care delivery, in addition to a renewed and updated understanding of what the 'end of treatment' transition process means.

Surveillance of persons-who tested negative for COVID-19 in Ontario, January 22-February 22, 2020.

As of January 22, 2020, "disease caused by a novel coronavirus" became a reportable disease of public health significance in Ontario. Public health units were provided with guidance on the entry of patients tested for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the virus causing 2019 coronavirus disease (COVID-19), into the provincial public health information system. Between January 22 and February 22, 2020, there were 359 individuals who had a negative test result recorded and three confirmed cases of COVID-19. Of those who tested negative, 51% were female and 71% were under 50 years of age. The most common symptoms reported were cough (55%), fever (37%) and sore throat (35%). The majority were tested within three days of symptom onset, but over one-quarter tested more than seven days after symptom onset. Over the first month of reportability, reported travel history shifted from China to an increasing proportion with travel outside of China.

All together now: aggregating multiple records to develop a person-based dataset to integrate and enhance infectious disease surveillance in Ontario, Canada.

SETTING: Syndemics occur when two or more health conditions interact to increase morbidity and mortality and are exacerbated by social, economic, environmental, and political factors. Routine provincial surveillance in Ontario assesses and reports on the epidemiology of single infectious diseases separately. Therefore, we aimed to develop a method that allows disease overlaps to be examined routinely as a path to better understanding and addressing syndemics in Ontario. INTERVENTION: We extracted data for individuals with a record of chlamydia, gonorrhea, infectious syphilis, hepatitis B and C, HIV/AIDS, invasive group A streptococcal disease (iGAS), or tuberculosis in Ontario's reportable disease database from 1990 to 2018. We transformed the data into a person-based integrated surveillance dataset retaining individuals (clients) with at least one record between 2006 and 2018. OUTCOMES: The resulting dataset had 659,136 unique disease records among 470,673 unique clients. Of those clients, 23.1% had multiple disease records with 50 being the most for one client. We described the frequency of disease overlaps; for example, 34.7% of clients with a syphilis record had a gonorrhea record. We quantified known overlaps, finding 1274 clients had gonorrhea, infectious syphilis, and HIV/AIDS records, and potentially emerging overlaps, finding 59 clients had HIV/AIDS, hepatitis C, and iGAS records. IMPLICATIONS: Our novel person-based integrated surveillance dataset represents a platform for ongoing in-depth assessment of disease overlaps such as the relative timing of disease records. It enables a more client-focused approach, is a step towards improved characterization of syndemics in Ontario, and could inform other jurisdictions interested in adopting similar approaches.

Increasing plant availability of legacy phosphorus in calcareous soils using some phosphorus activators.

Legacy phosphorus (P) in soil, accumulated over several years of fertilizer application in excess of crop demand, represents a huge and largely untapped resource. P activators can increase the availability of this P to plants by accelerating its transformation into soluble P fractions. In this study, we evaluated the potentials of four "P activators" (oxalic acid, lignin, phytase and ascorbic acid) to increase plant available P in a laboratory incubation experiment with two P-deficient calcareous soils used for wheat production. Samples were analysed for Olsen P, phosphomonoesterase and with Hedley sequential P fractionation. All four treatments had significant effects on different soil P fractions. Oxalic acid mainly enhanced inorganic P (Pi) solubility from the HCl-extractable P pool. Lignin enhanced P lability from the NaOH-, HCl- and residual-P pools. Phytase and ascorbic acid principally affected the organic P fractions (Po). Oxalic acid and lignin showed most potential to improve P (H2O-P, NaHCO3-Pi and NaHCO3-Po) availability, which increased by 110-419% and 4.1-122%, respectively. These findings illustrated the potential mechanisms responsible for P release associated with different P activators and reinforced the case for their use in increasing legacy P availability for agriculture in calcareous soils.

Getting a grippe on severity: a retrospective comparison of influenza-related hospitalizations and deaths captured in reportable disease and administrative data sources in Ontario, Canada.

BACKGROUND: Since 2009, in Ontario, reportable disease surveillance data has been used for timely in-season estimates of influenza severity (i.e., hospitalizations and deaths). Due to changes in reporting requirements influenza reporting no longer captures these indicators of severity, necessitating exploration of other potential sources of data. The purpose of this study was to complete a retrospective analysis to assess the comparability of influenza-related hospitalizations and deaths captured in the Ontario reportable disease information system to those captured in Ontario's hospital-based discharge database. METHODS: Hospitalizations and deaths of laboratory-confirmed influenza cases reported during the 2010-11 to 2013-14 influenza seasons were analyzed. Information on hospitalizations and deaths for laboratory-confirmed influenza cases were obtained from two databases; the integrated Public Health Information System, which is the provincial reportable disease database, and the Discharge Abstract Database, which contains information on all in-patient hospital visits using the International Classification of Diseases, 10th Revision, Canada (ICD-10-CA) coding standards. Analyses were completed using the ICD-10 J09 and J10 diagnosis codes as an indicator for laboratory-confirmed influenza, and a secondary analysis included the physician-diagnosed influenza J11 diagnosis code. RESULTS: For each season, reported hospitalizations for laboratory-confirmed influenza cases in the reportable disease data were higher compared to hospitalizations with J09 and J10 diagnoses codes, but lower when J11 codes were included. The number of deaths was higher in the reportable disease data, whether or not J11 codes were included. For all four seasons, the weekly trends in the number of hospitalizations and deaths were similar for the reportable disease and hospital data (with and without J11), with seasonal peaks occurring during the same week or within 1 week of each other. CONCLUSION: In our retrospective analyses we found that hospital data provided a reliable estimate of the trends of influenza-related hospitalizations and deaths compared to the reportable disease data for the 2010-11 to 2013-14 influenza seasons in Ontario, but may under-estimate the total seasonal number of deaths. Hospital data could be used for retrospective end-of-season assessments of severity, but due to delays in data availability are unlikely to be timely estimates of severity during in-season surveillance.

Issues experienced and support provided to adolescents and young adults at the end of active treatment for cancer: A rapid review of the literature.

INTRODUCTION: The end of active treatment is a stressful period for adolescents and young adults (AYA), but little is known about AYA experiences at this time point. The aim was to describe the issues young people experienced and identify interventions to support AYA at the end of treatment. METHODS: We conducted a rapid review of published primary research to identify what is currently known about AYA experiences of the end of treatment, the issues which arise and existing interventions to support AYA at this time. RESULTS: Searches identified 540 papers of which 16 met the inclusion criteria. Five main themes were identified: physical/medical issues; psychological, social and emotional issues; information and support needs; sources of information and support; and difficulties accessing information and support. Within these broader themes, several subthemes were identified and explored further. CONCLUSION: Adolescents and young adults are under prepared for the unpredictable and ongoing nature of the physical, psychological and social issues they face at the end of cancer treatment. Enabling young people's inclusion within their relevant social and educational peer networks should be a priority. Timely, structured and equitable information/support is needed to prepare AYA for treatment ending and subsequent reintegration to "everyday" life.

Microbial community composition and activity controls phosphorus transformation in rhizosphere soils of the Yeyahu Wetland in Beijing, China.

Microorganisms in the rhizosphere of wetland plants can have a significant impact on phosphorus (P) interception. We investigated the seasonal pattern of microbial community structure and its relationship with different P forms in the rhizosphere of three plants Scirpus planiculmis, Zizania latifolia, and Phragmites australis from the Yeyahu Wetland, China. Chloroform fumigation-extraction was used to determine the soil microbial biomass P (SMBP) and phospholipid fatty acids (PLFA) were used to characterize microbial community composition. P fractions in rhizosphere soil samples were also observed using sequential chemical fractionation. Results showed that the average total PLFA (TPLFA) contents of rhizosphere soils ranged from 34.9 to 40.7nmol·g-1 and were highest in summer. Bacteria were predominant in the rhizospheres of all three plants, accounting for >63% of TPLFA. Aerobic bacteria, represented by 16:0 PLFA, were most abundant. Both organic P (OP) and inorganic P (IP) accumulated in the rhizosphere during the winter die-back phase. Furthermore, both TPLFA and bacterial PLFA decreased with increases in highly resistant OP (HR-OP), occluded P (Oc-P) and Calcium-bound P (Ca-P). This suggests that bacteria play an important role in P transformation and can make use of various P forms. We also found that SMBP was significantly negatively correlated with labile OP (L-OP), moderately labile OP (ML-OP) and HR-OP, reflecting a high degree of cross correlation between SMBP and the PLFA indices.

A virus-like particle vaccine candidate for influenza A virus based on multiple conserved antigens presented on hepatitis B tandem core particles.

Existing Influenza A virus (IAV) vaccines target variable parts of the virus that may change between seasons. Vaccine design relies on predicting the predominant circulating influenza strains but when there is a mismatch between vaccine and circulating strains, efficacy is sub-optimal. Furthermore, current approaches provide limited protection against emerging influenza strains that may cause pandemics. One solution is to design vaccines that target conserved protein domains of influenza, which remain largely unchanged over time and are likely to be found in emergent variants. We present a virus-like particle (VLP), built using the hepatitis B virus tandem core platform, as an IAV vaccine candidate containing multiple conserved antigens. Hepatitis B core protein spontaneously assembles into a VLP that is immunogenic and confers immunogenicity to proteins incorporated into the major insertion region (MIR) of core monomers. However, insertion of antigen sequences may disrupt particle assembly preventing VLP formation or result in unstable particles. We have overcome these problems by genetically manipulating the hepatitis B core to express core monomers in tandem, ligated with a flexible linker, incorporating different antigens at each of the MIRs. Immunisation with this VLP, named Tandiflu1, containing 4 conserved antigens from matrix protein 2 ectodomain and hemagglutinin stalk, leads to production of cross-reactive and protective antibodies. The polyclonal antibodies induced by Tandiflu1 can bind IAV Group 1 hemagglutinin types H1, H5, H11, H9, H16 and a conserved epitope on matrix protein 2 expressed by most strains of IAV. Vaccination with Tandiflu1 results in 100% protection from a lethal influenza challenge with H1N1 IAV. Serum transfer from vaccinated animals is sufficient to confer protection from influenza-associated illness in naïve mice. These data suggest that a Tandem Core based IAV vaccine might provide broad protection against common and emergent H1 IAV strains responsible for seasonal and pandemic influenza in man.

Predicted persistence and response times of linear and cyclic volatile methylsiloxanes in global and local environments.

We investigated the response times of eight volatile methylsiloxanes (VMSs) in environmental systems at different scales from local to global, with a particular focus on overall loss rates after cessation of emissions. In part, this is driven by proposals to restrict the use of some of these compounds in certain products in Europe. The GloboPOP model estimated low absolute Arctic Contamination Potentials for all VMSs and rapid response times in all media except sediment. VMSs are predicted to be distributed predominantly in air where they react with OH radicals, leading to short response times. After cessation of emissions VMSs concentrations in the environment are expected to decrease rapidly from current levels. Response times in specific water and sediment systems were evaluated using a dynamic QWASI model. Response times were sensitive to both physico-chemical properties and environmental characteristics. Degradation was predicted to play the most important role in determining response times in water and sediment. In the case of the lowest molecular weight VMSs such as L2 and D3, response times were essentially independent of environmental characteristics due to fast hydrolysis in water and sediment. However, response times for the other VMSs are system-specific. They are relatively short in shallow water bodies but increase with depth due to the diminishing role of volatilization on concentration change as volume to surface area ratio increases. In sediment, degradation and resuspension rates also contribute most to the response times. The estimated response times for local environments are useful for planning future monitoring programs.