A 212-nt long RNA structure in the Tobacco necrosis virus-D RNA genome is resistant to Xrn degradation

Plus-strand RNA viruses can accumulate viral RNA degradation products during infections. Some of these decay intermediates are generated by the cytosolic 5′-to-3′ exoribonuclease Xrn1 (mammals and yeast) or Xrn4 (plants) and are formed when the enzyme stalls on substrate RNAs upon encountering inhibitory RNA structures. Many Xrn-generated RNAs correspond to 3′-terminal segments within the 3′-UTR of viral genomes and perform important functions during infections. Here we have investigated a 3′-terminal small viral RNA (svRNA) generated by Xrn during infections with Tobacco necrosis virus-D (family Tombusviridae). Our results indicate that (i) unlike known stalling RNA structures that are compact and modular, the TNV-D structure encompasses the entire 212 nt of the svRNA and is not functionally transposable, (ii) at least two tertiary interactions within the RNA structure are required for effective Xrn blocking and (iii) most of the svRNA generated in infections is derived from viral polymerase-generated subgenomic mRNA1. In vitro and in vivo analyses allowed for inferences on roles for the svRNA. Our findings provide a new and distinct addition to the growing list of Xrn-resistant viral RNAs and stalling structures found associated with different plant and animal RNA viruses.York University Librarie

A static model of a Sendzimir mill for use in shape control.

The design of shape control systems is an area of current interest in the steel industry. Shape is defined as the internal stress distribution resulting from a transverse variation in the reduction of the strip thickness. The object of shape control is to adjust the mill so that the rolled strip is free from internal stresses. Both static and dynamic models of the mill are required for the control system design.The subject of this thesis is the static model of the Sendzimir cold rolling mill, which is a 1-2-3-4 type cluster mill. The static model derived enables shape profiles to be calculated for a given set of actuator positions, and is used to generate the steady state mill gains. The method of calculation of these shape profiles is discussed. The shape profiles obtained for different mill schedules are plotted against the distance across the strip. The corresponding mill gains are calculated and these relate the shape changes to the actuator changes. These mill gains are presented in the form of a square matrix, obtained by measuring shape at eight points across the strip

ESTIMATION OF LOCAL RECREATIONAL VALUE OF HAKGALA BOTANIC GARDEN

The Botanical garden at Hakgala is one of the oldest ex-situ conservation areas in SriLanka. It is a unique environmental asset, nationally as well as globally, due to itsconservation, recreation, historical, cultural, educational and other values.A study was carried out in the Hakgala botanic garden to estimate its local recreationalvalue. The economic approach used to estimate the recreational value was the travel costmethod. The travel cost approach is a way to value unpriced goods. The surroundingareas were divided into concentric zones of increasing distance, which representedincreasing levels of travel cost. A survey of users was conducted at the Hakgala garden todetermine zone of origin, visitation rates, travel costs, and various socio economiccharacteristics. The data generated were used to regress visitation rates, the total travelcost and urban population fraction of each zone. With respect to multiple trips, the costcomponent was differentiated based on distances to particular destinations traveled.Demand curve based on visitation rates, was constructed using these data to estimate theconsumer surplus, or benefits, from the site.Estimated minimum total cost experienced by the visitors at the current entrance fee (Rs.20.00) was Rs.6,943,520. When this amount is subtracted from the total consumersurplus (total welfare) of Rs.228,493,714 the estimated consumer surplus is Rs.221,550,194. This figure can be used to demonstrate the contribution of a botanicalgarden to the economy and to attract more funds to develop infrastructural facilitiesinside the garden from the government allocations.

Assessment of Chemical and Microbiological Quality of Bottled Drinking Water and Evaluation of Accelerated Shelf Life

Bottled drinking water was a concept introduced to Sri Lanka in 1980’s and new brands are often introduced to the market as it has become a highly moving product so that the health ministry stepped in to the regulation of bottled water and it has become mandatory for the manufacturing companies to register the products under the food act No 26. The specification given in SLSI standards regarding bottled drinking water (SLS 894) can be applied to determine the microbial quality of bottled drinking water just after filling. The SLS specification 894 cannot be applied to determine microbial quality of bottles available in market months after manufacturing. Even though it is very important to consider the consumer’s point of view, at the time of consumption, no microbial specification is provided in the standard 894.There is a possibility of chemical and microbial changes occurring within the content of water during its shelf period .One of the main objectives, of the project was to establish a permissible limit for the Total Plate Count (TPC as CFU per ml) at any time of storage. Determination of shelf life by accelerating and incubating samples at an elevated temperature was another objective of the project. Along with the above mentioned objectives a quality evaluation of selected fifteen brands were carried out with relevance to the chemical and microbial parameters. The focused parameters were TPC, fecal Coliforms, Escherichia coli, Algae count, pH, total nitrate, total nitrite, conductivity, Chemical Oxygen Demand (COD), and Free ammonia. Out of the fifteen brands, randomly selected four brands were evaluated according to the Q10 principle to determine the accelerated shelf life. After the incubation period at 420 C, all four brands showed a decrease in the CFU compared to the initial counts and 84% of analyzed chemical parameters were approximate with the initial values. Algae were detected in one of the brands and the same brand exceeded the COD limit (max 10 mg/l) after the incubation period. The CFU obtained for the fifteen brands ranged from 36 to 3200 and the permissible CFU range was decided as 87.362 to 1184.170. Around 94% of the selected brands were within the permissible chemical limits while one of the brands exceeded the COD limit (10 mg/l). Since most of the chemical parameters were not deviated from the limits stated in SLS 894, it is concluded that microbial parameters are crucial compared to the chemical parameters in the bottled water industry.Keywords: Bottled water, Accelerated shelf life, Permissible limits, Chemical and microbia

EVALUATION OF POLLUTION DAMAGE COST IN BELLANWILA A.TTIDIYA WETLAND

Management of waste, both liquid and solid has become a critical environmental concernparticularly in the more urbanized areas ill 'Sri Lanka and this problem is most severe inthe densely populated areas of Western province. Bellanwila Attidiya wetland is also one ofthe places, which is used as open dumpsites. It has bad effects on the health, air quality, biodiversity water, and land.The main objective of the present study was to evaluate the pollution damage cost of thewetland. In addition peoples views were also obtained on possibility of recreation in thewetland.In the present study the Contingent Valuation Method was used to evaluate the pollutiondamage cost of the wetland. Data was derived from a Contingent Valuation survey carriedout among the residents of the area and commuters who travel along the road which passesthrough the wetland. The results were consistent with theory and an aggregate cost ofwetland pollution was estimated to be 2870 00 million rupees per year. People expressedtheir willingness for proposals of developing the wet land as a recreation site.The valuation may be useful in cost benefit analysis of wetland management and otherrelated policy and planning programmes related to wetlands. This could be used as aninstrument to get the local and international attention and draw funds for the wetlandconservation.

Evidence for a critical leopard conservation stronghold from a large protected landscape on the island of Sri Lanka

The decline and extirpation of large carnivore populations can lead to cascading effects in natural ecosystems. An understanding of large carnivore population densities, distribution and dynamics is therefore critical for developing effective conservation strategies across landscapes. This is particularly important in island environments where species face increased extinction risk due to genetic isolation coupled with local losses of finite habitat. The Sri Lankan leopard Panthera pardus kotiya is one of two remaining island-living leopards on Earth and the only apex predator in Sri Lanka. Despite its iconic status in Sri Lanka, robust research on the species has been limited to only a handful of scientific studies, limiting meaningful scientific recommendations for the species’ conservation and management. In this study, we conducted a single season camera trap survey in Sri Lanka’s largest protected area, Wilpattu National Park (1317 km2), located in the country’s northwest. Our objective was to estimate key ecological state variables of interest (density, abundance, sex-specific movement and spatial distribution) of this leopard subspecies. Our results indicate that Wilpattu National Park supports a density of 18 individuals/100 km2 (posterior SD=1.5; 95% HPD interval=16–21) with a mean abundance of 144 (posterior SD=15) individual leopards and a healthy sex ratio (f:m=2.03:1). The estimated activity range for male leopards > 2 years old was 49.53 km2 (Posterior SD=3.43; HPD interval=43.09–56.41) and for female leopards > 2 years old was 22.04 km2 (Posterior SD=1.82; HPD interval=18.34–25.65). This density falls at the higher end of published estimates for the species anywhere in its global range, based on similar methods. Given Sri Lanka’s limited size, this national park system should be considered as a critical stronghold that maintains a source population of leopards, contributing to the long-term population viability of leopards in the larger landscape.Full Tex

Long-term outcomes of the pentaspline pulsed field ablation catheter for the treatment of paroxysmal atrial fibrillation: Results of the prospective, multicenter FARA-Freedom Study.

INTRODUCTION/OBJECTIVES Pulmonary vein isolation (PVI) is well-established strategy for the treatment of paroxysmal atrial fibrillation (PAF). Despite randomized controlled trials and real-world data showing the promise of pulsed-field ablation (PFA) for this treatment, long term efficacy and safety data demonstrating single procedure outcomes off antiarrhythmic drugs remain limited. The aim of the FARA-Freedom Study was to evaluate long-term efficacy and safety of PFA using the pentaspline catheter for PAF. METHODS FARA-Freedom, a prospective, non-randomized, multicenter study, enrolled patients with PAF undergoing de novo PVI with PFA, which were followed for 12 months with weekly transtelephonic monitoring (TTMs) and 72-hr Holter ECG at 6 and 12 months. The primary safety endpoint was a composite of device- or procedure-related serious adverse events out to 7 days post-ablation and PV stenosis or atrioesophageal (AE) fistula out to 12 months. Treatment success is a composite of acute PVI and chronic success; which includes freedom from any documented atrial tachyarrhythmia longer than 30 s, use of antiarrhythmic drugs or cardioversion after a 3-month blanking period, or use of amiodarone or repeat ablation at any time. RESULTS The study enrolled 179 PAF patients (62 ± 10 yr, 39% female) at 13 centers. At index procedure, all PVs were successfully isolated with the pentaspline PFA catheter. Procedure and left atrial dwell times, with a 20 min waiting period, were 71.9 ± 17.6 and 41.0 ± 13.3 min, respectively. Fluoroscopy time was 11.5 ± 7.4 min. Notably, monitoring compliance was high with 88.4% and 90.3% with weekly event and 72-hour Holter monitors, respectively. Freedom from composite primary effectiveness endpoint was 66.6%, 41 patients had atrial tachyarrhythmia recurrence: mostly recurrent atrial fibrillation (31 patients). The composite safety endpoint occurred in 2 patients (1.1%), 1 tamponade and 1 TIA. There was no coronary spasm, PV stenosis, or AE fistula. There were 4 cases of transient phrenic nerve palsy, but all resolved during index procedure. CONCLUSIONS In this prospective, non-randomized, multicenter study, PVI using a pentaspline PFA catheter was effective in treating PAF patients despite rigorous endpoint definitions and high monitoring compliance and demonstrated favorable safety

Safety and Effectiveness of Pulsed Field Ablation for Atrial Fibrillation in Patients With Heart Failure

Background: Atrial fibrillation (AF) and heart failure (HF) coexist, increasing morbidity and mortality. Studies have demonstrated improved outcomes following AF ablation in HF patients with reduced ejection fraction (EF).Objectives: This study sought to assess the outcomes of pulsed field ablation (PFA) in HF.Methods: MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-Approval Clinical Use of Pulsed Field Ablation) is a multicenter, patient-level registry of consecutive patients undergoing PFA for paroxysmal AF or persistent AF (PerAF). In this substudy, patients were stratified as no history of HF (no-HF), HF with preserved EF (HFpEF) (left ventricular EF of ≥50%) or HF with reduced/mildly reduced EF (HFmr/rEF) (left ventricular EF of &lt;50%). The primary effectiveness and safety endpoints were freedom from documented atrial arrhythmias lasting ≥30 seconds and major adverse events, respectively.Results: Of the 1,381 patients, 85% (n = 1,174) were no-HF, 6.2% (n = 87) were HFpEF, and 8.6% (n = 120) were HFmr/rEF. No-HF patients had less PerAF than patients with HF (P &lt; 0.001), with no difference between HF subtypes (P &gt; 0.99). The 1-year freedom from atrial arrhythmia was significantly higher in no-HF patients than in those with HFpEF or HFmr/rEF (79.9%, 71.3%, and 67.5%, respectively; P &lt; 0.001) but similar between patients with HFmr/rEF and HFpEF (P = 0.26). However, there was no significant difference in freedom from atrial arrhythmia among patients with no-HF vs HFpEF vs HFmr/rEF for those with paroxysmal AF (82.8%, 82.4%, and 71.7%, respectively; P = 0.09) and PerAF (73.3%, 64.2%, and 64.9%, respectively; P = 0.14). Major adverse event rates were similar between the no-HF, HFpEF, and HFmr/rEF groups (1.9%, 0%, and 2.5%, respectively).Conclusions: PFA appears to be potentially safe and effective in AF patients with HF. Freedom from atrial arrhythmia post-PFA was higher in patients without a history of HF, with no significant difference between HF subtypes.</p

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

© 2016 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity