Containment Facilities Research Articles

Cyclic plate testing of geosynthetic-reinforced airfield pavements

Numerous cyclic plate load tests have been performed over the past several years to investigate the potential performance benefits of including geosynthetics in paved and unpaved applications. A majority of these studies have focused on relatively thin pavement structures subjected to highway loads. Airfield pavements can be substantially thicker and include multiple aggregate layers, and data are needed to quantify geosynthetic contributions under high contact pressures (CPs). Eleven representative airfield pavement structures (four unreinforced sections, four containing geosynthetics at the subbase−subgrade interface and three containing geosynthetics at the base−subbase interface) were constructed in a laboratory containment facility and subjected to cyclic loading under 1750 kPa simulated aircraft CP. Permanent surface deformation and vertical pressure response data were collected to determine relative improvement when compared with an unreinforced pavement structure and to evaluate the influence of geosynthetics. Some geosynthetics increased the number of cycles to failure, and it was found that some level of permanent deformation (e.g. 25 mm) may be required to engage reinforcing benefits when placement occurs at the subgrade−subbase interface. Changing subbase material from a California bearing ratio of 15–18 to 55 resulted in 1·5 orders of magnitude more cycles to 25 mm of permanent deformation than any of the geosynthetic-reinforced sections evaluated.

Application of immunofluorescence assay and nested polymerase chain reaction for query fever diagnosis in animal handlers of Puducherry, South India, and phylogenetic analysis based on IS1111 repetitive gene element.

Background and Aim:Diagnosis of query fever (QF) is mostly done on the basis of serological/molecular tests, due to the stringent requirement of biosafety level-3 containment facilities for isolating Coxiella burnetii in culture. QF is an important zoonosis and is considered to be an occupational hazard to livestock handlers. This report describes our study on the serological as well as molecular evidence of QF in animal handlers from Puducherry and surrounding Tamil Nadu, from where, to the best of our knowledge, no such reports are available so far.Materials and Methods:Seventy-five animal handlers were recruited, comprising veterinarians, slaughterhouse workers, butchers, and animal attendants of various government veterinary clinics from Puducherry and surrounding areas of Tamil Nadu state. QF serology was performed to identify Phase I and Phase II immunoglobulin G antibodies to C. burnetii. Nested polymerase chain reaction (N-PCR) was carried out to detect C. burnetii DNA in buffy coat samples by targeting IS1111 gene element. N-PCR-positive samples were sequenced and phylogenetic analysis was performed using MEGA software version 10.0.Results:A total of 21 animal handlers (28.1%) were positive for either serology or PCR. PCR alone was positive in 10 (13.4%), only serology was positive in 8 (10.7%), and both serology and PCR were positive in three samples (4.0%). GenBank accession numbers were obtained for 13 N-PCR-positive samples (MG548608-MG548620). Six of our study sequences showed close similarity with the reference isolates from Bengaluru, Colombia, Brazil, France, and Iran.Conclusion:A significant percentage of QF positivity in animal handlers of this part of South India, Puducherry, warrants a prospective study with follow-up of a large number of this occupational group.

Vulnerable Interface Diagram for Translational Stability Analysis of Multilayered Cover System

AbstractTranslational failure of the multilayered cover system (MLCS) is a key issue encountered in waste containment facilities. This study extends the existing force-equilibrium method for analyz...

Desiccation-Induced Volumetric Shrinkage Characteristics of Highly Expansive Tropical Black Clay Treated with Groundnut Shell Ash for Barrier Consideration

Contamination of underground water as a result of excessive crack on clay liner material is a prevalent phenomenon in an engineered landfill. Volumetric shrinkage strain (VSS) is one of the veritable properties considered for selection of materials suitable for liners and cover in waste containment systems. Material devoid of excessive shrinkage and cracking during climate change could possibly make a better barrier material that will eventually limit or control infiltration of leachate in an engineered landfill. Hence, to obtain a clay liner and covers system that are safe and robust, stabilization of such soil (expansive clay soils) becomes imperative. In order to stabilize or reduce excessive cracking and shrinkage of this soil, earlier researchers have employed cement, chemicals, and fibers. However, in recent times, the ill effects of these stabilizers on the environment have been realized, and hence their replacement with sustainable materials that are mostly agro and or industry by-products is becoming necessary. Tropical dark grey clay treated with up to 8 % Groundnut shell ash (GSA), was carried out. Specimen were compacted using British standard light (BSL) and British standard heavy (BSH) compactive efforts; at water contents between 2% dry and 4% wet of optimum. The compacted specimens were extruded and subjected to drying under laboratory conditions to evaluate its desiccation induced shrinkage and hence its suitability as a cover material in waste containment facilities. Results of this study show that changes in mass and volumetric shrinkage strain were large within the first five days of drying. Volumetric shrinkage strain increased with higher moulding water contents (MWC) and water contents relative to optimum (WRO). The effect of GSA treatment on VSS was not consistent from -2 to +2 % of optimum moisture content. For specimen prepared at +4 % of optimum moisture content, VSS decreased up to a threshold of 28% at 6 % GSA and 30% at 4% GSA for BSH and BSL compactive effort, respectively. Generally, lower compactive effort (BSL) with higher moulding water content and lower dry density produced higher VSS. A regression function was developed from the data to estimate VSS given the compaction water content relative to optimum (WRO), groundnut shell ash content (GSA), plasticity index (PI), percentage fine content (PF) and compactive effort (CE). Compaction water content relative to optimum significantly correlated with VSS, thus should be strictly regulated during field compaction to realize a durable hydraulic barrier. Keywords: Atterberg limit, compaction, desiccation, expansive soil, groundnut shell ash, statistical analysis DOI : 10.7176/CER/11-8-06 Publication date :September 30 th 2019

The Role of Reference Materials in the Research and Development of Diagnostic Tools and Treatments for Haemorrhagic Fever Viruses.

Following the Ebola outbreak in Western Africa in 2013–16, a global effort has taken place for preparedness for future outbreaks. As part of this response, the development of vaccines, treatments and diagnostic tools has been accelerated, especially towards pathogens listed as likely to cause an epidemic and for which there are no current treatments. Several of the priority pathogens identified by the World Health Organisation are haemorrhagic fever viruses. This review provides information on the role of reference materials as an enabling tool for the development and evaluation of assays, and ultimately vaccines and treatments. The types of standards available are described, along with how they can be applied for assay harmonisation through calibration as a relative potency to a common arbitrary unitage system (WHO International Unit). This assures that assay metrology is accurate and robust. We describe reference materials that have been or are being developed for haemorrhagic fever viruses and consider the issues surrounding their production, particularly that of biosafety where the viruses require specialised containment facilities. Finally, we advocate the use of reference materials at early stages, including research and development, as this helps produce reliable assays and can smooth the path to regulatory approval.

Evaluation of the rust fungus Puccinia rapipes for biological control of Lycium ferocissimum (African boxthorn) in Australia: Life cycle, taxonomy and pathogenicity

Fungal plant pathogens are increasingly recognised as being among the most effective and safe agents in classical weed biological control programs worldwide. Suitability of the rust fungus P. rapipes as a classical biological control agent for Lycium ferocissimum (African boxthorn) in Australia was assessed using a streamlined agent selection framework. Studies with P. rapipes were undertaken to elucidate its life cycle, confirm its taxonomic placement and determine its pathogenicity to L. ferocissimum and seven closely-related Solanaceae species that occur in Australia. Field surveys in the native range of South Africa, experiments in a containment facility in Australia and DNA sequencing confirmed that P. rapipes is macrocyclic and autoecious, producing all five spore stages on L. ferocissimum. The stages not previously encountered, spermogonia and aecia, are described. Sequencing also confirmed that P. rapipes is sister to Puccinia afra, in the ‘Old World Lineage’ of Puccinia species on Lycieae. Two purified isolates of the fungus, representing the Eastern and Western Cape distributions of P. rapipes in South Africa, were cultured in the containment facility for use in pathogenicity testing. L. ferocissimum and all of the Lycium species of Eurasian origin tested ‒ Lycium barbarum (goji berry), Lycium chinense (goji berry ‘chinense’) and Lycium ruthenicum (black goji berry) – were susceptible to both isolates of P. rapipes. The Australian native L. australe and three more distantly related species in different genera tested were resistant to both isolates. The isolate from the Western Cape was significantly more pathogenic on L. ferocissimum from Australia, than the Eastern Cape isolate. Our results indicate that P. rapipes may be sufficiently host specific to pursue as a biological control agent in an Australian context, should regulators be willing to accept damage to the Eurasian goji berries being grown, albeit to a limited extent, in Australia.

94 Dietary soy isoflavone ingestion alters the acute and recovery immune responses in growing pigs infected with porcine reproductive and respiratory syndrome virus

Abstract Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically-important disease and ingestion of soy isoflavones (ISF) may benefit PRRSV-infected pigs due to demonstrated anti-inflammatory and anti-viral properties. The objective of this study was to determine long-term effects of feeding ISF on growth performance and both acute and recovery immune responses following PRRSV infection. In total, 96 weaned barrows were group-housed in a BSL-2 containment facility and allotted to 1 of 3 experimental treatments that were maintained throughout the study: non-infected pigs received an ISF-devoid control diet (NC, n = 24), and infected pigs received either the control diet (PC, n = 36) or that supplemented with total ISF in excess of 1,600 mg/kg (ISF, n = 36). Following a 7-day adaptation, weanling pigs were inoculated intranasally with either a sham-control (PBS) or live PRRSV (1×105 TCID50/mL, strain NADC20). After inoculation, individual blood samples (n = 8–12/treatment) were routinely collected to monitor viral clearance, hematological parameters, and anti-PRRSV antibody production, and pen-based oral fluids were used to monitor PRRSV clearance at later growth stages. A 2-way ANOVA (including time effect) was performed to compare NC and PC groups (infection status) and PC and ISF groups (ISF effect within infected pigs). In general, PRRSV infection decreased performance during early growth phases, resulting in 5.4% lower final BW for PC vs. NC pigs (P < 0.05). Dietary ISF elicited inconsistent effects on growth performance, reduced (P < 0.05) longitudinal serum viral loads, and increased (P < 0.05) the rate of PRRSV clearance from oral fluids. Dietary ISF also elicited earlier, more robust anti-PRRSV neutralizing antibody production as compared with PC pigs. Additionally, PC pigs experienced ~50% greater infection-related mortality vs. ISF pigs (P < 0.05), which could have significant economic implications for producers. Overall, dietary ISF ingestion supported immune responses and reduced mortality in PRRSV-infected pigs when fed to growing pigs.

The safety and immunogenicity of two novel live attenuated monovalent (serotype 2) oral poliovirus vaccines in healthy adults: a double-blind, single-centre phase 1 study

SummaryBackgroundUse of oral live-attenuated polio vaccines (OPV), and injected inactivated polio vaccines (IPV) has almost achieved global eradication of wild polio viruses. To address the goals of achieving and maintaining global eradication and minimising the risk of outbreaks of vaccine-derived polioviruses, we tested novel monovalent oral type-2 poliovirus (OPV2) vaccine candidates that are genetically more stable than existing OPVs, with a lower risk of reversion to neurovirulence. Our study represents the first in-human testing of these two novel OPV2 candidates. We aimed to evaluate the safety and immunogenicity of these vaccines, the presence and extent of faecal shedding, and the neurovirulence of shed virus.MethodsIn this double-blind, single-centre phase 1 trial, we isolated participants in a purpose-built containment facility at the University of Antwerp Hospital (Antwerp, Belgium), to minimise the risk of environmental release of the novel OPV2 candidates. Participants, who were recruited by local advertising, were adults (aged 18–50 years) in good health who had previously been vaccinated with IPV, and who would not have any contact with immunosuppressed or unvaccinated people for the duration of faecal shedding at the end of the study. The first participant randomly chose an envelope containing the name of a vaccine candidate, and this determined their allocation; the next 14 participants to be enrolled in the study were sequentially allocated to this group and received the same vaccine. The subsequent 15 participants enrolled after this group were allocated to receive the other vaccine. Participants and the study staff were masked to vaccine groups until the end of the study period. Participants each received a single dose of one vaccine candidate (candidate 1, S2/cre5/S15domV/rec1/hifi3; or candidate 2, S2/S15domV/CpG40), and they were monitored for adverse events, immune responses, and faecal shedding of the vaccine virus for 28 days. Shed virus isolates were tested for the genetic stability of attenuation. The primary outcomes were the incidence and type of serious and severe adverse events, the proportion of participants showing viral shedding in their stools, the time to cessation of viral shedding, the cell culture infective dose of shed virus in virus-positive stools, and a combined index of the prevalence, duration, and quantity of viral shedding in all participants. This study is registered with EudraCT, number 2017-000908-21 and ClinicalTrials.gov, number NCT03430349.FindingsBetween May 22 and Aug 22, 2017, 48 volunteers were screened, of whom 15 (31%) volunteers were excluded for reasons relating to the inclusion or exclusion criteria, three (6%) volunteers were not treated because of restrictions to the number of participants in each group, and 30 (63%) volunteers were sequentially allocated to groups (15 participants per group). Both novel OPV2 candidates were immunogenic and increased the median blood titre of serum neutralising antibodies; all participants were seroprotected after vaccination. Both candidates had acceptable tolerability, and no serious adverse events occurred during the study. However, severe events were reported in six (40%) participants receiving candidate 1 (eight events) and nine (60%) participants receiving candidate 2 (12 events); most of these events were increased blood creatinine phosphokinase but were not accompanied by clinical signs or symptoms. Vaccine virus was detected in the stools of 15 (100%) participants receiving vaccine candidate 1 and 13 (87%) participants receiving vaccine candidate 2. Vaccine poliovirus shedding stopped at a median of 23 days (IQR 15–36) after candidate 1 administration and 12 days (1–23) after candidate 2 administration. Total shedding, described by the estimated median shedding index (50% cell culture infective dose/g), was observed to be greater with candidate 1 than candidate 2 across all participants (2·8 [95% CI 1·8–3·5] vs 1·0 [0·7–1·6]). Reversion to neurovirulence, assessed as paralysis of transgenic mice, was low in isolates from those vaccinated with both candidates, and sequencing of shed virus indicated that there was no loss of attenuation in domain V of the 5ʹ-untranslated region, the primary site of reversion in Sabin OPV.InterpretationWe found that the novel OPV2 candidates were safe and immunogenic in IPV-immunised adults, and our data support the further development of these vaccines to potentially be used for maintaining global eradication of neurovirulent type-2 polioviruses.FundingBill & Melinda Gates Foundation.

Construction of the safe neutralizing assay system using pseudotyped Nipah virus and G protein-specific monoclonal antibody

Nipah virus (NiV) is a recently emerged paramyxovirus that causes acute respiratory illness and fatal encephalitis in a broad spectrum of vertebrates, including humans. Due to its high pathogenicity and mortality rates, NiV requires handling in biosafety level-4 (BSL-4) containment facilities and no effective vaccines or therapeutic agents are currently available. Since current diagnostic tests for detecting serum neutralizing antibodies against NiV mainly employ live viruses, establishment of more safe and robust alternative diagnostic methods is an essential medical requirement. Here, we have developed a pseudotyped NiV and closely related Hendra virus (HeV) expressing envelope attachment (G) and fusion (F) glycoproteins using the Moloney murine leukemia virus (MuLV) packaging system. We additionally generated polyclonal antibodies (pAbs) against NiV-G and HeV-G and assessed their neutralizing activities for potential utilization in the pseudovirus-based neutralization assay and further application in the serum diagnostic test. To enhance the specificity of neutralizing antibody and sensitivity of the serological diagnostic test, monoclonal antibodies (mAbs) against NiV-G were generated, and among which four out of six mAb clones showed significant reactivity. Specifically, the 7G9 clone displayed the highest sensitivity. The selected mAb clones showed no cross-reactivity with HeV-G and efficient neutralizing activities against pseudotyped NiV. These results validate the safety and specificity of neutralization assays against NiV and HeV and present a useful tool to design effective vaccines and serological diagnosis.

Characterising the insect-borne transmission of the cattle poxvirus lumpy skin disease virus

Lumpy skin disease (LSD) is an emerging poxviral disease of cattle caused by the Capripoxvirus lumpy skin disease virus (LSDV) which generates widespread cutaneous lesions in affected animals. LSD is recognised as a transboundary high consequence disease in Africa where it contributes to rural poverty and food insecurity. In 2015 LSDV spread to southeastern Europe and currently poses a threat to cattle in neighbouring regions. Previous research indicates that LSDV is most likely transmitted by insect vectors however details of transmission pathways are unclear. This study was designed to identify the risk of transmission of LSDV posed by different insect vectors. A bovine experimental model of LSD was established in the high containment facilities at The Pirbright Institute. Potential insect vectors (Aedes aegypti, Culex quinquefasciatus, Stomoxys calcitrans and Culicoides nubeculosus) were fed on LSDV-infected cattle then incubated for up to eight days. Cattle and insects were regularly sampled to quantify LSDV present in different tissues and vector species. This data was then used to model the dynamics of LSDV infection and transmission. All four species of vector successfully acquired LSDV from infected cattle and maintained the virus up to eight days post feeding. The outputs of this research will now be used to design more effective LSD control programmes.

Research and development of airtight biosafety containment facility for stainless steel structures

ObjectiveAirtightness of containment structures of a high-level biosafety laboratory is a critical parameter for preventing leakage of harmful bioaerosols. The aim of this study is to investigate the sealing technology of stainless steel structural airtight biosafety containment facilities. MethodsAn experimental study was conducted on a domestic high-level pathogenic microorganism model laboratory, considering the sealing process of the containment structure, including airtight doors, pass boxes, dunk tanks, through-wall pipeline sealing devices, and sealed floor drains. ResultsThe results indicate that the airtightness of the model laboratory containment structure meets the tightness requirements of a biosafety level-4 (BSL-4) laboratory. They also indicate that the construction technology of stainless steel enclosure structures used by the laboratory and the tightness performance and installation process of the developed airtight protective equipment meet the technical requirements of a BSL-4 laboratory. ConclusionsThis successful model laboratory indicates that China has the research and development capacity for stainless steel airtight containment structure manufacturing processes, airtight protective equipment, and technical capacity for independent construction of the highest-level pathogenic microorganism laboratories.

Use of Pseudotyped viruses for the production of reference materials as part of emerging viral outbreak preparedness

Purpose: The recent public health emergencies of international concern (PHEIC), caused by Ebola and Zika virus, have highlighted the lack of prophylactic treatments and need for effective diagnostics for emerging viruses. In response to this, we established International Reference Reagents for antibody detection, which enables the comparison of results from laboratories worldwide undertaking treatment/vaccine efficacy clinical trials. The requirement for high containment facilities to handle viruses with outbreak potential, such as BSL4 for Ebola virus, is a constraining challenge. We have developed serological assays using replication defective pseudotyped viruses (PV) for the evaluation of reference material to avert high containment requirements. Methods & Materials: The preferred candidate material is a pool of plasma or sera from convalescent patients as this provides a commutable standard. For the reference material for Ebola antibody, several donations were received at NIBSC and solvent-detergent treated to ensure inactivation of virus. Characterisation is performed in-house using both PV neutralisation assays and ELISA platforms. PV is produced via plasmid transfection of 293T cells, with plasmids encoding a lentiviral core component, a reporter gene which is packaged within the core and the sequence of the envelope protein for the virus of interest. The ability of candidate material to block PV entry into target cells is measured via reporter signal reduction. Results: Following a WHO-sponsored International Collaborative study, the 1st WHO International Standard for Ebola virus antibodies was established in 2017. Participants in the collaborative study evaluated the candidate materials using assays available in their laboratories. Data from neutralisation assays employing PV with either a lentiviral or vesiculoviral core component was correlated with the wildtype assay and showed a better correlation coefficient when the vesiculovirus PV system was used. Conclusion: To support preparedness activities, antibody reference materials are now being established for other WHO priority pathogens such as Lassa and Nipah virus. To characterise the serological material at a low containment level, we have established assays using PV generated with both the lentiviral and vesiculovirus platforms. The two systems are currently being investigated to determine the most appropriate for each high containment virus.

Poliovirus-binding inhibition ELISA based on specific chicken egg yolk antibodies as an alternative to the neutralization test

The first application results of enzyme immunoassay system (ELISA) – binding inhibition ELISA (BI ELISA) for the detection of antibodies to polioviruses of three types based on the use of specific antibodies from chicken yolk (IgY) are presented. This variant of ELISA is a “surrogate” neutralization test (NT). When comparing the results of the detection of antibodies in 90 sera of children who were vaccinated with oral and inactivated poliovirus vaccines, good correlation (r = 0.67, 0.61, 0.76 for types 1, 2, 3 respectively) between the BI ELISA and the NT results was shown. The presented variant of ELISA is the further stage of the development of “IgY-technology” for laboratory diagnostics of viral infections, namely poliovirus infection, which can be used for seroepidemiological studies as an analogue of the NT which requires the use of life poliovirus with the required standard of biosafety containment facilities.

Feasibility of Saline Gradient Solar Ponds as Thermal Energy Sources in Saskatchewan, Canada

Advancement of renewable energy is critical for sustainable development. This paper evaluates the feasibility of saline gradient solar ponds (SGSP) as an alternative energy source for Saskatchewan, Canada. The main achievements include global appraisal of SGSP from theoretical and practical perspectives, assessment of salinity and climatic criteria for SGSP potential, understanding of heat transfer mechanisms affected by thermophysical properties, and numerical modeling to simulate transient heat diffusion in SGSP. Results indicated that Saskatchewan is ideal for thermal energy harvesting from saline water bodies because of high solar insolation (1100 to 1400 kWh/m2). The solar radiation in such systems is captured under a salt concentration gradient. Locally, ten potash tailings sites (360 g/L or 36% salt) and two saline water lakes (250 g/L or 25% salt) are potentially suitable for SGSP deployment. It was found that thermal conductivity increases with temperature but decreases with water salinity increase (0.55 to 0.675 W/mK) and the opposite is true for density (1000 to 1200 kg/m3). Similarly, specific heat capacity slightly increases with temperature and inversely correlates with salinity (3000 to 4200 J/kg K). Furthermore, the heat diffusion model adequately simulated the temperature distribution for a typical SGSP in a potash tailings containment facility. For the investigated month of July (highest solar insolation), the temperatures increased from an initial value of at 20 to 52 oC at top to 37 oC at bottom. A comprehensive risk assessment of this method is required to protect air, water, soil, and biota at specific sites.

SUITABILITY OF RICE HUSK ASH TREATED BLACK COTTON SOIL FOR WASTE CONTAINMENT APPLICATION

This paper presents an experimental study aimed at assessing the suitability of rice husk ash (RHA) treated black cotton soil as a barrier in Municipal Solid Waste (MSW) containment facility. Laboratory tests were conducted on black cotton soil treated with 5, 10 and 15% RHA at moulding water contents of 2 and 4% on both wet and dry sides of optimum moisture content (OMC) using British Standard Heavy (BSH) compactive effort. Index properties, hydraulic conductivity (k), volumetric shrinkage strain (VSS), and unconfined compressive strength (UCS) tests were conducted on all the samples. The results obtained indicated that the soil was classified as A-7-5(18) according to the American Association of States Highway and Transport Officials (AASHTO) classification system and Silt of high plasticity (MH) in accordance with the Unified Soil Classification System (USCS). It was observed that addition of RHA was accompanied with decrease in the plasticity index from 24 to as low as 3%. An improvement in the moisture-density relationship of the soils showed an increase in Maximum Dry Density (MDD) from 1.46 to 1.52 Mg/m3 as well as a decrease from 24.5 to 21.2% in OMC. The increase in RHA contents up to 10% brought about an improvement in the strength of the soil specimens by almost 332.4kN/m2 at 2% on the dry side of OMC. The VSS decreases with increase in RHA content to achieve the minimum shrinkage strain of 4.1% at 5% RHA treatment.

SUITABILITY OF RICE HUSK ASH TREATED BLACK COTTON SOIL FOR WASTE CONTAINMENT APPLICATION

This paper presents an experimental study aimed at assessing the suitability of rice husk ash (RHA) treated black cotton soil as a barrier in Municipal Solid Waste (MSW) containment facility. Laboratory tests were conducted on black cotton soil treated with 5, 10 and 15% RHA at moulding water contents of 2 and 4% on both wet and dry sides of optimum moisture content (OMC) using British Standard Heavy (BSH) compactive effort. Index properties, hydraulic conductivity (k), volumetric shrinkage strain (VSS), and unconfined compressive strength (UCS) tests were conducted on all the samples. The results obtained indicated that the soil was classified as A-7-5(18) according to the American Association of States Highway and Transport Officials (AASHTO) classification system and Silt of high plasticity (MH) in accordance with the Unified Soil Classification System (USCS). It was observed that addition of RHA was accompanied with decrease in the plasticity index from 24 to as low as 3%. An improvement in the moisture-density relationship of the soils showed an increase in Maximum Dry Density (MDD) from 1.46 to 1.52 Mg/m3 as well as a decrease from 24.5 to 21.2% in OMC. The increase in RHA contents up to 10% brought about an improvement in the strength of the soil specimens by almost 332.4kN/m2 at 2% on the dry side of OMC. The VSS decreases with increase in RHA content to achieve the minimum shrinkage strain of 4.1% at 5% RHA treatment.

Diagnostic and Vaccination Approaches for Newcastle Disease Virus in Poultry: The Current and Emerging Perspectives.

Newcastle disease (ND) is one of the most devastating diseases that considerably cripple the global poultry industry. Because of its enormous socioeconomic importance and potential to rapidly spread to naïve birds in the vicinity, ND is included among the list of avian diseases that must be notified to the OIE immediately upon recognition. Currently, virus isolation followed by its serological or molecular identification is regarded as the gold standard method of ND diagnosis. However, this method is generally slow and requires specialised laboratory with biosafety containment facilities, making it of little relevance under epidemic situations where rapid diagnosis is seriously needed. Thus, molecular based diagnostics have evolved to overcome some of these difficulties, but the extensive genetic diversity of the virus ensures that isolates with mutations at the primer/probe binding sites escape detection using these assays. This diagnostic dilemma leads to the emergence of cutting-edge technologies such as next-generation sequencing (NGS) which have so far proven to be promising in terms of rapid, sensitive, and accurate recognition of virulent Newcastle disease virus (NDV) isolates even in mixed infections. As regards disease control strategies, conventional ND vaccines have stood the test of time by demonstrating track record of protective efficacy in the last 60 years. However, these vaccines are unable to block the replication and shedding of most of the currently circulating phylogenetically divergent virulent NDV isolates. Hence, rationally designed vaccines targeting the prevailing genotypes, the so-called genotype-matched vaccines, are highly needed to overcome these vaccination related challenges. Among the recently evolving technologies for the development of genotype-matched vaccines, reverse genetics-based live attenuated vaccines obviously appeared to be the most promising candidates. In this review, a comprehensive description of the current and emerging trends in the detection, identification, and control of ND in poultry are provided. The strengths and weaknesses of each of those techniques are also emphasised.

Modelling deformation and strains induced by waste settlement in a centrifuge test

A numerical model to estimate the tensile strains (loads) of the geomembrane liner in the waste containment facility due to waste settlement is presented. A centrifuge test of the geomembrane-lined landfill is used to validate the numerical model. The calculated surface settlement at the centre of the landfill and the geomembrane tensile strains on intermediate benches are generally in good agreement with the measured data. Parametric analyses associated with foundation shear strength as well as interface shear strength and stiffness are performed. The influence of geometric nonlinearity on the geomembrane tensile strains is also examined. The numerical analyses indicate that the maximum geomembrane tensile strain occurs at the crest of the side slope near the intermediate bench for the cases and conditions examined. The lessons learned are likely to be useful to landfill design engineers using numerical models to aid in the design of the geosynthetic liner system for the waste containment facilities.

Characterization and treatment alternatives of industrial container and drum cleaning wastewater: Comparison of Fenton-like process and combined coagulation/oxidation processes

Industrial container and drum cleaning (ICDC) facilities generated complex wastewater which have organic/inorganic compounds, acids, alkalis, metals, dyes, asbestos, PCBs, chemical cleaning solutions or textile auxiliary chemicals. Treatment of such these wastewaters containing all these pollutants is also very difficult. It is required that the wastewater chemical oxygen demand (COD) is below 1500 mg/L to treat in a centralized wastewater treatment facility in Thrace Region, Turkey. In this study the characterization of ICDC industrial wastewater and treatment alternatives of this wastewater using Fenton-like (FL) process, acidic coagulation-flocculation + H2O2/UV-C (CF + H2O2/UV-C) and acidic coagulation-flocculation + S2O82− (CF + S2O82−) processes have been studied. The existing treatment system already has a biological treatment system after coagulation-flocculation system and couldn't be operated effectively in spite of all the efforts. We have studied processes that can be integrated into the coagulation-flocculation (CF) process used in the existing wastewater treatment plant. According to characterization study, COD values were in the range of 4584–18125 mg/L. The COD of the wastewater used in treatment experiments were 11,853 mg/L. According to the results FL and CF + S2O82− systems were suitable for the COD discharge standards specified for the centralized wastewater treatment plant. The optimum conditions of FL process were 0.8 g/L for FeCl3 and 45 g/L for H2O2 and COD was measured as about 1500 mg/L at these doses. The optimum conditions of CF + S2O82− system were determined as 0.64 g/L FeCl3 for CF and 15 g/L H2O2 doses. At these dosages the highest COD removal efficiency was achieved to 68% after 5 h. All methods used were suitable for the removal of COD, biochemical oxygen demand (BOD), total organic carbon (TOC), total phosphorus (TP) and of some metals. Considering the integration into the existing treatment system and applicability, it is concluded that the FL process is most favorable.

Biosafety and Biosecurity Programme: Its Implementation, Requirements and Continuous Development at the Nanyang Technological University in Singapore

In Singapore, biosafety and biosecurity measures are controlled by the Biological Agents and Toxins Act (BATA) and other requirements by regulatory agencies. The law prohibits and otherwise regulates the possession, use, import, transhipment, transfer, and transportation of biological agents, inactivated biological agents, and toxins that are of public health concern. The law also defines the facility requirements for high risk biological agents and toxins. The containment facility (BSL 3) is a minimum requirement to handle biological agents that falls under Schedule 1 (Risk Group 3). The Nanyang Technological University School of Biological Sciences Biosafety Level 3 Facility (NTU-SBS BSL 3) was designed specifically for research involving potential hazardous biological materials. The facility requires yearly re-certification by an approved facility certifier to meet the local requirements and international biosafety standards for a containment facility in many instances. On the other hand, most NTU researchers conduct biological projects involving biological agents with low or moderate risk groups (Risk Groups 1 and 2 or biological agents described in schedule 3 and 4 of BATA) and GMOs, which need only a BSL 2 laboratory. BSL 2 laboratories are yet to be legally certified or registered in Singapore. Institutional Biosafety Committee (IBC) identifies the requirements; defines a minimum standard in the safe control of biological risks and registers all BSL 2 laboratories in the NTU. Therefore, under the guidance of the IBC, the University Biosafety and Biosecurity Programme includes the audit and certification program as a unique and an internal exercise to bring NTU biosafety to a higher level.