The Dimerization Interface in VraR is Essential to Induction of the Cell Wall Stress Response in Staphylococcus aureus: A potential Druggable Target

Background Staphylococcus aureus remains a medical challenge in the treatment of bacterial infections. It has acquired resistance to commonly used antibiotics, and to those considered to be the last weapons in treating staphylococcal infections, such as vancomycin. Studies have revealed that S. aureus is capable of mounting a rapid response to antibiotics that target cell wall peptidoglycan biosynthesis, such as β-lactams and vancomycin. The two-component system VraSR has been linked to the coordination of this response. VraS is a histidine kinase that undergoes autophosphorylation in the presence of signals elicited upon cell wall damage and it then transfers its phosphoryl group to VraR. VraR is a response regulator protein that functions as a transcription factor. Phosphorylation of VraR leads to its dimerization, which is required for optimum binding to its target promoters. Two-component systems have been targeted for the development of antibacterial agents. Deletion of the vraS or vraR gene has been shown to re-sensitize S. aureus to β-lactams and vancomycin. Results In this study, we explored perturbation of the VraR phosphorylation-induced activation as a means to inhibit the VraSR-mediated signal transduction pathway. We show that dimerization of VraR is essential for the phosphorylation-induced activation of VraR. A single point mutation in the dimerization interface of VraR, in which Met13 was replaced by Ala, led to the inability of VraR to dimerize and to bind optimally to the target promoter. The consequences of these in vitro molecular deficiencies are equally dramatic in vivo. Complementation of a vraR deletion S. aureus strain with the vraRM13Ala mutant gene failed to induce the cell wall stress response. Conclusions This study highlights the potential of targeting the phosphorylation-induced dimerization of VraR to disrupt the S. aureus cell wall stress response and in turn to re-sensitize S. aureus to β-lactams and vancomycin.York University Librarie

Spunbonding studies with polypropylene polymers

Spunbonding is a continuous process to produce polymer laid nonwovens for various applications. Polypropylene is the major polymer used in this process. Metallocene polypropylene (mPP) manufactured using the single site catalyst technology has been of interest for this industry and some research has been done for the past few years. This polymer seems to be different compared to the conventional Ziegler-Natta catalyzed polypropylene (znPP). This research was conducted to investigate the structure and properties of the filaments and fabrics produced with a metallocene catalyzed propylene polymer and to determine the optimum process conditions to produce good quality fabrics. A comparison is also made between the filaments and the fabrics produced from both types of polymers i.e., mPP and znPP. An investigation of the processing behavior of mPP polymer was conducted using the Reicofil spunbonding pilot line at the University of Tennessee, Knoxville. The filaments at three different throughput rates were studied for tensile properties and other structural features such as birefringence, x-ray diffraction and thermal responses. The fabrics bonded at different process conditions were tested for various mechanical properties. The structure and properties of the two types of spunbond filaments and fabrics were compared. The failure mechanism of the fabrics at different bonding temperatures was studied using scanning electron microscope. The results showed that mPP filaments have lower melting temperature than znPP filaments. They also have higher strengths and lower elongation than znPP filaments. The mPP fabrics also have shown higher strength and elongation properties than the comparable znPP fabrics. The rupture mechanism of the mPP fabrics was found to be different than that of the znPP fabrics. Also higher strength and elongation were observed in mPP fabrics that were bonded at relatively lower temperatures. For spunbonding process mPP was found to be much better than the znPP polymer

Organic and inorganic geochemistry of samples returned from Mars

Although a tremendous amount of knowledge can be obtained by in situ experiments on Mars, greater benefits will be realized with the sample return mission from the perspective of exobiology. Sampling techniques are briefly discussed

Impact of cyclone PAM on rainwater harvesting prospects in the Pacific region

Aims: To assess the impact of cyclone PAM on the rainwater harvesting prospects in the Pacific region. Study Design: The study was conducted based on the field observations, data from various government organizations and NGOs. Place and Duration of Study: The study was based in Port Vila, Vanuatu along with nearby Island countries like New Caledonia, Solomon Islands, Fiji and Tuvalu were part of the study. The study was conducted from mid-March to the end of June, 2015. Methodology: The study was based on the field observations; estimates from authenticated sources with the evidence of the pictorial data of remote areas; community feedback; government department’s data and NGO’s reports. The views of individuals, community heads, government bodies and relief workers of various national and international agencies were integral part of this assessment. Results: The impact of category 5 cyclone PAM on the prospects of rainwater harvest in the Pacific region

National Chemical Profile of Vanuatu 2021

This consultancy report is part of the development of “Vanuatu’s National Chemicals Profile” which is one of the different components of the project “Strengthening the national institutional capacity for chemicals and waste management in Vanuatu”. The objective of the project is to support country-driven institutional strengthening at the national level, in the context of an integrated approach to address the financing of the efficient management of chemicals and wastes, taking into account the national development strategies, plans and priorities of Vanuatu, to increase sustainable public institutional capacity for the sound management of chemical and wastes throughout their life cycle. Institutional strengthening under the Special Programme will facilitate and enable the implementation of the Basel, Rotterdam, Stockholm and Minamata conventions and the Strategic Approach of International Chemicals Management (SAICM). Dr Krishna Kumar Kotra working at The University of the South Pacific had carried out this consultancy work for Department of Environmental Protection and Conservation (DEPC). In developing the National Chemical Profile of Vanuatu, stakeholder meetings, data collection, site visits etc. were done during August 2020 and March 2021. As expected, the data collection part was difficult due to lack of proper records and non-supply of data from some stakeholder’s in-spite of several requests. Thus, the current documentation was limited to all available data that is being supplied by various stakeholders and from Customs and Inland Revenue. The collected data shows that Vanuatu is an importer of chemicals but not a supplier. An average of 2,031 Million Vatu imports were done for chemicals and allied products for the years 2018-2020 with over 2,000 Million Vatu for each year. The mineral imports for the same period are 11,030, 9,987 and 6,475 Million Vatu. Most of the chemical imports are for general usage in various sectors of industries and for household purposes. Even though, Vanuatu being part of many conventions over the years, there seems lack of some components of these frameworks being not implemented to a full spirit. There are multiple reasons being brought forward which include political, administrative, human resources, expertise and financial constraints. The implementation of the safe management and disposal of chemicals in the country was found as a non-monitored programme. It was not noted that many storage sites do lack any emergency response equipment nor trained staff. There is very limited knowledge in regard to chemical storage, usage and discharge. These underlines an urgent need to frame proper legislation with administrative support for the monitoring program to track the life cycle of all chemical imports. The program should also include the protocols needed to follow for transport, storage and safe disposal. It is recommended that there is a need also for promotional activities for safe usage and storage of chemicals/chemical related products. To achieve this, the consultant recommends strengthening DEPC’s capacity by establishing “Chemicals Monitoring Officer”. In-spite of Customs and Inland Revenue Department do track the chemical imports as raw material or in bulk quantities, there are multiple anomalies being observed in the data entry. There is no other proper track of chemicals there onwards either in their usage/storage/disposal by various end users in the country. This clearly calls for an urgent need to develop appropriate legislations that enable proper record maintenance by stakeholders. Added, a National Chemical Management Database to track the flow of these in the country should also be established. Furthermore, proper legislation for transport, storage, usage and discharge should be established for the sound management of chemicals in the country. Alongside, trainings and workshops for staff of DEPC and stakeholders are also strongly recommended, as there are currently none being implemented in the country. The consultant believes that here is an urgent need to establish a National Chemical Testing Laboratory to regularly test various water/soil/air samples for chemical constituents for maintaining a sustainable environment in Vanuatu. These regular analyses would align to enable to further strengthen SDG 3, Good Health and Wellbeing and also SDG 6, Clean Water and Sanitation. It is hoped that by considering the recommendations and plan to implement the recommendations would strengthen and track in achieving Sustainable Development agenda for 2030 of Sound Management of Chemicals and Waste under SDG 12, Sustainable Consumption and Production

Analysis and Classification of Dermoscopic Images Using Spectral Graph Wavelet Transform

The abnormal growth of skin cells leads to skin cancer which occurs due to the unrepaired DNA impairment to the skin cells. Worldwide every year more than 1.23 lakhs of skin cancers are diagnosed, out of which Melanoma is the deadliest one. The aim of this research work is Recognition of Melanoma and skin lesion classification from the Dermoscopic images. Feature extraction of Dermoscopic images can be done by Shape, Color and Texture features. Texture features comprises of Gray Level Co-occurrence Matrix (GLCM) and statistical texture features calculated from the coefficients of the Multiresolution transforms such as Discrete Wavelet Transform (DWT), Curvelet, Tetrolet, and Spectral Graph Wavelet Transform (SGWT). The novelty in this work is using SGWT for extraction of texture features. The superiority of SGWT over conventional wavelet transform is its ability to work on irregular shaped images. Weighted graphs are the base for the SGWT which can be obtained in the form of meshes for irregular shapes. In the present work, skin lesions are obtained from the International Skin Imaging Collaboration (ISIC) 2016 archive. The features obtained from the Dermoscopic images are classified using Naïve Baye's, K-Nearest Neighbor (KNN) and Support Vector Machine (SVM) classifiers. The proposed method using Shape, Color and Texture based features for Melanoma Recognition with SGWT results in an Area Under the Curve (AUC) of 0.951 with Accuracy of 96.79 %, Sensitivity of 88 % and Specificity of 98.26 %. Further, the AUC of skin lesion classification such as Melanoma vs Nevus, Seborrheic Keratosis vs Squamous Cell Carcinoma, Melanoma vs Seborrheic Keratosis, Melanoma vs Basal Cell Carcinoma and Nevus vs Basal Cell Carcinoma using SGWT is 0.895, 0.945, 0.9645, 0.945 and 0.98 respectively

WASH in short agri-food supply chains and marketplaces in Pacific Islands countries: a framework for assessing wash-related vulnerabilities to heath

The COVID-19 global pandemic has informed us about the resilience of family-based food production in many Pacific Island Countries (PICs) as well as exposing some of the vulnerabilities inherent in social, economic, political and biophysical systems. The pandemic has further raised global and regional awareness of the importance of good water, sanitation and hygiene (WASH) to providing some protection against not only COVID-19 but the many other infectious diseases that have long impacted human health and well-being across the region. Identifying where WASH-related vulnerabilities to infectious disease, ill-health and reduced well-being exist in the agri-food supply chain is essential to supporting resilience, protecting local food systems and livelihoods, and 'building-back better' into the future. This assessment Framework is designed to assist organisations and people involved in supporting and governing WASH, food supply chains or women’s livelihoods to identify where WASH-related vulnerabilities to infectious disease and ill-health are located in agri-food supply chains characteristic of many PICs

WASH in the market house - a situation analysis of water, sanitation and hygiene services in market places in Vanuatu

This report presents the results of research undertaken in thirteen fresh produce markets in the Republic of Vanuatu, located in Lakatoro (Malekula island), Luganville (Santo) and Port Vila (Efate) (Figure 1). The overarching research objective was to better understand the water, sanitation and hygiene (WASH) situation in a variety market places, from central market houses through to smaller satellite markets, in order to identify WASH-related COVID-19 vulnerabilities, the types and effectiveness of preparation and protection measures undertaken in market places thus far, and to explore their impacts on market vendors. Since the beginning of the pandemic there has been, as of June, 2021, just three active COVID-19 cases in Vanuatu - all of which have been detected in quarantine. Despite there being no community transmission of COVID-19 in Vanuatu to date, the pandemic has had a substantial impact on the country. The State of Emergency border lockdown and cessation of tourism has led to an economic recession, resulting in major job losses in the two main tourist centres of Port Vila and Luganville. Additionally, local and international remittances have greatly decreased. Whilst the government have implemented some economic support measures for small business this does not include market vendors. In response to the threat of COVID-19 the government have instigated a variety of public health measures that have directly impacted markets. These include an increased focus on hygiene (e.g. the installation of handwashing stations), social distancing guidelines, restricted selling hours and, in many but not all locales, a one-day-market rule whereby vendors are no longer permitted to sleep at markets. Combined with a general drop in demand for fresh produce due to the economic down turn, these measures are disproportionally impacting women, who make -up over 90% of market vendors. Results from this study affirm that vendors' income has decreased by half or more, with the greatest decrease experienced in Port Vila. Elsewhere in the world, the COVID-19 pandemic has disrupted the availability of affordable and nutritional food services, and there has been some concern that this may occur in Pacific Island Countries and Territories (e.g. United Nations, 2020a). Recent research from Solomon Islands has identified increased food insecurity in both rural and urban areas (Wairiu et al, 2020). Markets are one of the top three sources of food for Port Vila residents (World Vision Vanuatu, 2018) and there is a fear that if markets closed, prices increase and/or food supplies where disrupted, this would detrimentally impact urban residents - many of whom are already amongst the most socio-economically vulnerable in the country (VNSO, 2013). Whilst this study did not gather household level data (and hence cannot ascertain if household food insecurity has risen ) the data suggests that from a food systems perspective the impact of the COVID-19 pandemic has thus far been on the demand, rather than the production and supply, side

Application of phytoremediation for heavy metal contaminated sites in the South Pacific: strategies, current challenges and future prospects

Effectively dealing with hazardous and recalcitrant pollutants such as heavy metals (HMs) has become a global challenge with limited options available for reprieve. This is true for Pacific Island Countries and Territories (PICTs) which have witnessed significant economic transitions and substantial increases hazardous waste depositions. Although several physico-chemical remediation techniques exist, the economic and geographic limitations of PICTs render them impractical for the region. Phytoremediation, a plant–based remediation technology which exploits hyperaccumulator plants to extract, accumulate and/or stabilize HMs, has received significant interest as a sustainable and non–intrusive remediation option. Nonetheless, improving the application and efficiency of phytoremediation programs not only requires a better understanding of the fundamental mechanisms governing HM accumulation and tolerance in plants, but also demands fast and reliable spectroscopic techniques for in–situ analysis. This review critically examines the current practices in phytoremediation and its prospects for the treatment of HM–contaminated sites in PICTs. We also review the limitations of traditional spectroscopic techniques such as inductively coupled plasma mass spectroscopy/atomic emission spectroscopy (ICP–MS/AES) and the promise of novel techniques such as field portable X–ray fluorescence spectrometry (FP–XRF), atmospheric pressure discharge plasma (APDP) and lab on chip (LOC) in phytoremediation studies