DNA Replication

DNA replication is the process of producing identical DNA molecules and transferring genetic information to the next generation (CSU, n.d.; Spark Notes, 2014). Double helix unwinds, each strand separates to form a template for new DNA strand in the replication process (CSU, n.d.). Replication can be semiconservative and conservative. Each new strand acquires one strand from parent DNA in semi-conservative replication while an old set of strands and completes new set of strands and a complete new set of strands is formed in conservative replication (CSU, n.d.).

DNA replication involves a complex enzymatic activity. DNA polymerase, primase, ligase, helicase, single strand binding proteins, gyrase, telomerase are replication enzymes (Eric G Lambert School, 2014; Spark Notes, 2014; University of Leicester, 2010). DNA replication involves four steps: initiation, elongation, termination and proofreading and correction. At the very first stage of replication, hydrogen bonds between the nitrogenous bases break down (Eric G Lambert School, 2014). The double helix unwinds and two strands move in opposite directions in the initiation stage (Spark Notes, 2014). DNA polymerase is the enzyme placed between the two strands and produces nucleotides facilitating elongation of the strand (Eric G Lambert School, 2014). Some fragments, known as Okazaki fragments, contains newly formed DNA. The newly produced DNA molecule forms double helix structure after the completion of new strand at the termination stage (Eric G Lambert School, 2014). Proofreading and correction stage involves assessment of hydrogen bonding mismatch and accuracy of replication.

Replication process is different in prokaryotic and eukaryotic cells. More protein components are involved in eukaryotic replication however replication form moves ten times faster in prokaryotes than eukaryotes (University of Leicester, 2010). DNA replication is bi-directional. Only single origin of replication can be found in bacteria however eukaryotes have multiple origins of replication (University of Leicester, 2010).


California State University (CSU) (n.d.) DNA Replication [Online] Available at http://www.csun.edu [Accessed on 17 February 2014].

Eric G Lambert School (2014) Explain the Steps Involved in DNA Replication [Online] Available at http://www.ericlambert.ca/docs [Accessed on 21 February 2014].

Spark Notes (2014) DNA Replication and Repair [Online] Available at http://www.sparknotes.com [Accessed on 28 February 2014].

University of Leicester (2010) DNA Replication and Repair [Online] Available at www2.le.ac.uk [Accessed on 17 February 2014].


Nano Filtration

Science, Technology and Health

Nano filtration is a pressure driven filtration process where mixture water passes through a membrane by the application of a gravity or pressure. High removal of divalent ions (calcium, magnesium, arsenic, iron, sulphate) and low removal of monovalent ions (sodium, potassium, chloride) can be achieved in Nano filtration process.  Nano filtration membranes can be used in desalination, organic matter and iron removal from surface water (Bartels et. al., 2007).

A number of problems such as membrane fouling, corrosion and scaling are caused by suspended solids, organic and inorganic materials in the feed water. Membrane fouling due to high levels of organic compounds in water can change permeability of Nano filtration membrane affecting water quality and operating cost (Bartels, et. al., 2007). Membrane bio fouling, growth of micro-organisms on a membrane, is a serious challenge causing technical problems (Ivnitsky et. al., 2005). According to Ivnitsky et. al. (2005) microbes such as Flavobacterium species,

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Water Stewardship

Science, Technology and Health

Water stewardship is the accountability of individual, family, community and organization for the management of the resources of water. Water stewardship progress can be achieved by joint actions from businesses, governments and communities (AWS, 2010). EWP (2013) recognized access to water supply and sanitation as a human right and claimed ‘water democracy’ through the application of the principles of transparency, integrity, solidarity and equity. Stakeholders must be aware of their water rights and responsibilities toward water resources for a better water stewardship.

WWF (n.d.) formulated water stewardship strategy steps in the increasing order of watershed sustainability as water awareness, knowledge of impact, internal action, stakeholder engagement and influence governance.  Active involvement of the stakeholders in the decision making process assists water governance. Pinero (2012) suggested the use of water foot printing methodology to enhance knowledge about human-water interaction. Businesses are being committed to improve water efficiency, recycle water and minimize…

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Life Cycle Assessment: Introduction

Science, Technology and Health

According to ISO (1997 cited in Hendrickson, 2006) life cycle assessment “studies the environmental aspects and potential impacts throughout a product’s life from raw material acquisition through production, use, and disposal”. LCA helps to understand true and total cost associated with the manufacture of a product, its use and disposal. Environmental releases to air, water and land from each life cycle stage of a product can be quantified from life cycle assessment (ALCAS, n.d.; Environment Agency, 2011; RSC, n.d.). LCA contains three components: an inventory analysis, impact analysis, and an improvement analysis (Hendrickson, 2006; Svoboda, 1995).

Inventory is the data collection stage which assesses energy and raw material requirements and environmental pollution such as air emissions, solid waste disposal and waste water discharges throughout the life cycle of the product (ALCAS, n.d.; Svoboda, 1995). The stage involves construction of process maps or flow charts and establishing material and energy balance…

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Diabetes is one of the leading causes of death. According to WHO (2013), 347 million people have diabetes in the world and 80% of the disease is prevalent among populations of low and middle income countries. Twenty nine million people in UK are affected by diabetes and 850,000 people are undiagnosed patients (NHS, 2013).

Glucose, produced from carbohydrate, is used in human body cells as a source of energy. Insulin produced by pancreas, is needed in the glucose metabolism process. Cells absorb glucose from the blood in the metabolism process to produce energy stimulated by insulin [BBC, 2013]. When body cannot metabolise high amount of glucose, a condition develops known as diabetes [diabetes.org, 2012; NHS, 2013].

Diabetes can be divided into two, Type I and Type II diabetes, Type I diabetes is insulin-dependent condition where body stops producing insulin and Type 2 is insulin resistant condition where body do not produce enough insulin or cells do not react to insulin (diabetes.org, 2012; NHS, 2013]. Frequent urination, increased thirst, extreme tiredness and weight loss are common symptoms of Type I diabetes [JDRF, 2013; NHS, 2013]. Third type of diabetes is gestational diabetes.

Diabetes treatment includes reducing blood glucose levels by using medicines and subcutaneous injection of insulin. Medications such as Bignanide, Sulphonylureas, Alpha glucosidase inhibitor, prandial glucose regulators, thiazolidinediones, incretin, mimetics, and DPP-4 inhibitors are used to lower blood glucose levels [diabetes.org, 2012]. WHO (2013) suggested maintaining body weight, physically active healthy diet and avoiding tobacco use can reduce the risk of diabetes.


British Broadcasting Corporation (BBC) What is Diabetes? [Online] Available at www.bbc.co.uk [Accessed on 28 October 2013].

Diabetes UK (2012) Diabetes UK: Care Connect. Campaign [Online] Available at www.diabetes.org.uk [Accessed on 28 October 2013].

Juvenile Diabetes Research Foundation Ltd (JDRF) (2013) What is Type I Diabetes? [Online] Available at www.jdrf.co.uk [Accessed on 28 October 2013].

National Health Service (NHS, 2013) Diabetes [Online] Available at http://www.nhs.ac.uk [Accessed on 28 October 2013].

World Health Organization (WHO) (2013) Diabetes [Online] Available at www.who.int [Accessed on 28 October 2013].

Membrane Bioreactor

Science, Technology and Health

Pressure has been increased on authorities for efficient waste water treatment with environmental consideration due to rapid growth and urbanisation (EU, 2010). Various physical, mechanical, biological and chemical methods of water treatment have been used to remove suspended solids, organic matter and dissolved pollutants or toxins. Membrane bioreactor (MBR) has been regarded as one of the processes in the treatment of waste liquids.

Membrane bioreactor is a combination of biological treatment process and membrane filtration. Membrane is a thin material with a narrow range of pore size and high surface porosity that resist the transfer of different constituents of a fluid (Visvanathan and Aim, 2000). The membrane filters suspended solids and is an alternative for conventional filtration and sand filtration in the treatment of industrial wastewater and municipal sewage (EU, 2010).

Membrane filtration processes are classified according to the membrane pore sizes: microfiltration (0.1 to 10 microns), ultrafiltration (0.003 to…

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Climate Change Adaptation-II

Science, Technology and Health

Policies and strategies to balance climate change consequences are formulated and implemented in adaptation process. The process involves appraisal of climate impacts, preparation for adaptation, application of appropriate actions and evaluation of the acts (UNFCC, 2011). A number of methods and approaches can be found for adaptation planning.Adaptation policies should be holistic and realistic in the real-world situations in which policies are implemented (Mathys, et. al., 2010).

Approaches based on the analysis of existing socio-economic conditions are appropriate for tackling present susceptibilities and adaptive capacity. While scenario and model driven approaches are more suited for estimating climate change impacts, particularly on a large scale. Hazard based approaches assesses existing climate hazards and future climatic risks over time and space using climatic projections. Adaptive capacity approaches assesses the existing adaptive capacity and proposes to increase the strength of adaptive capacity to contest future extremes.

Economic diversification at the national level and…

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Climate Change Adaptation

Science, Technology and Health

Freshwater resource has been recognized as an economic good.  Observed and projected climatic changes are likely to increase water stress in the future. Individuals and communities need to be prepared to minimise the negative impacts and maximise the benefits from changes. Autonomous adaptation such as maintaining water supply practices and restoring default or poorly maintained water facilities is supportive to increase adaptive capacity.

Insight of climate probabilities and knowledge of environmental consequences help building long term resilience to impacts. Continuation of research and assessment helps generating scientific knowledge which facilitates decision making for adaptation options.  Development of human capital, strengthening institutional system and good management of public finances and natural resources are necessities for adaptation to future climatic changes.

Individuals and societies are already stressed by globalisation, urbanisation, environmental degradation, disease outbreaks and market uncertainties.  Projected climatic changes and resulting water stress will intensify the condition.  Increasing water supply, expansion…

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3D Technology

Three dimensional (3D), an object with length, breadth and height, technology is becoming popular across the countries and continents. 3D technology includes 3D television, 3D cinema, 3D camera and 3D printer. 3D technology has a wider range of applications including television, computer, architecture and industry (visionnw.com, 2013). 3D technology can be helpful for game industry and solar energy industry.

Cinemas started showing 3D technology in the nineteenth century. The first public 3D movie was ‘The Power of Love’ produced in 1922. Viewers can perceive depth of the objects of cinema produced using special motion picture camera and stereoscopic photography (visionnw.com, 2013). 3D television market is booming in the recent years. In Global post (2013)’s statistics, 3D television sales increased by 72 percent in 2012 with a total shipment of 41.45 million units.

3D printing is changing the future and our social life by converting digital data into physical objects (Science Museum, 2013). Handgun with firing capacity of 50 shots has been recently produced using 3D printing technology (Guardian, 2013). 3D printer has been successful in drawing customer’s attention in the past 10 years. Price (2013) estimated 56507 units of 3D printer’s shipment in 2013, 75 percent growth in 2014 to 98065 units.

Architects, engineers and consultants can take advantage of 3D architecture of buildings and structure and its commercial applications (visionnw.com, 2013). 3D technologies can lead a society in a different way by changing the work patterns, business technologies and innovation. 3D technologies can transform the theory into practice by lowering the cost to the society, environment and economy.


Gibbs, S. (2013) First Metal 3D Printed Gun is Capable of Firing 50 Shots [Online] Available at www.guardian.com [Accessed on 28 November 2013].

Global Post (2013) 3D TV Sales Growth [Online] Available at www.globalpost.com [Accessed on 24 November 2013].

Price, G. (2013) Statistics Gartner Says Worldwide Shipments of 3D Printers to Grow 49 Percent in 2013 [Online] Available at www.infodocket.com [Accessed on 29 November 2013]. <br>

Science Museum (2013) 3D Printing the Future [Online] Available at www.sciencemuseum.org.uk [Accessed on 28 November 2013].

Visionnw (2013) What is 3D Technology? [Online] Available at visionnw.com [Accessed on 28 November 2013].