KNOWLEDGE UPGRADE ON EUROCODE AND THE EFFECTS OF USING OLD BRITISH STANDARD AS DESIGN GUIDANCE IN NIGERIA

Being a technical paper on the need for knowledge enhancement for Nigerian engineers

 

 

Publication:            National Development Initiative

Release date:          25th June 2012

 

By

Olugbenro Falola

MSc.(Structural Engineering, UK), B.Eng.(Ogbomoso)

Correspondence e-mail: olugbenro@structuralsolution.co.uk

Editing/Proof: Olatunji Ariyomo & Olugbenro Falola

Published by NDi

www.nd-i.org

publications@nd-i.org

25TH JUNE 2012


 

1.0      INTRODUCTION

It is over two years now that the use of British Standard has been replaced with the 58 parts of Eurocodes (March 31, 2010 – BSI, 2009). The British standard committee has made it clear since that time that all public works should be designed in accordance with the new Eurocode (BSI, 2009). They also made it known to the public that there would be no amendment or revision of the British standards (BSI, 2009) which suggests that the design code would be obsolete in the nearest future. The advantages of the Eurocode cannot be over emphasized. Numerous literatures and experience have shown that the Eurocode provides economical design than British Standard (Mostley et al., 2007, Narayanan 2010, Concrete centre, 2010). Aside this, the code is less restrictive and allows choice of safety parameters to be used by each country knowing that design and construction practices, standard and quality of materials, climatic conditions, human behaviour to structures among other factors differ from country to country.

Recent short survey has shown more than 85% of Nigerian engineers, lecturers, students and graduates with no exception of companies are not aware of this replacement and dangers associated with it (Falola, 2011). The aim of this article is to alert users of the British Standard to the effects of using the code, identify areas that need public attention in the old British Standard, enumerate the advantages of adopting the new Eurocode and suggest how we can develop the Nigeria’s indigenous code.

2.0      BENEFITS OF ADOPTING THE NEW EUROCODE

2.1 General Benefits

  • Provide a common basis for research and development.
  • Allow the preparation of common design aids and software.
  • Eurocode 2 should result in more economic structures for clients.
  • Eurocode 2 is less restrictive than British Standards.
  • Eurocode 2 is extensive and comprehensive.
  • The new Eurocodes are reputed as the most technically advanced codes in the world (Concrete Centre, 2010). 

2.2 Benefits to Companies:

  • Eligibility to design and work freely in all European countries

    Lagos: Partial Collapse Of 21-Storey Skyscraper
    Lagos: Partial Collapse Of 21-Storey Skyscraper
  • Enhance career opportunity for the company and staff.
  • Improve design competency.
  • Abreast with latest design standard.
  • Enable companies to bid for international projects especially in all EU.
  • Improve companies’ standard and quality.
  • Economical design – reduced construction cost. (Concrete Centre, 2010)

2.3       Benefits to Students & Graduates:

  • Eligibility to design and work freely in all European countries.
  • Enhance international career opportunity.
  • Improve design competency.
  • Allow academic research in higher institutions to meet current global challenges.

3.0      WHY IS IT NECESSARY TO ADOPT THE NEW EUROCODE?

It is obvious that many Nigerians will feel reluctant to adopt the new eurocode. Answers to the following questions will help to form the right judgment:

  1. Do we know the consequences of using the old British standards on the standard and quality of our academic research, design and quality of our projects?
    Do we know the flaws in BS8110?
    Do we think that our academic research in the nation’s universities will still be acceptable in the global knowledge using the old code as references?
  2. What would be the fate of our students and graduates even if engineers are reluctant to adopt new knowledge knowing that the British Standard is now obsolete?
  3. Are we working towards the development of our own code, If yes, How?
  4. Are we developing our own code from the previous code without resolving the flaws in the code?
  5. Are we developing our own codes based on non-empirical factors of the ideas of some practising engineers knowing that a code should be developed along with experimental research?
  6. Are we involving academic scholars or researchers to channel their research towards the development of our own code?
  7. Do we even have funds available for this?
    Are we developing just an aspect of the code such as design of concrete buildings?
  8. What of other areas such as highway, geotechnical, steel design, etc?
    Do we even welcome contributions from scholars towards the development of our own code knowing that nobody is an embodiment of knowledge?
  9. However the adoption of eurocode will not only answer the aforementioned questions but also provide the benefits as stated earlier.

I am not of the opinion that we should suddenly drop the old British standard but it is high time we got acquainted with new ideas. There are several systematic ways we can adopt the new eurocode rather than continue using the obsolete British Standards.

We should also have in mind that there are sections that need further clarification in the British Standards especially the BS8110. Further articles and research papers by the same author will reveal some of these in due course. In the mean time, it is of great necessity to point the art of column classification in the BS8110 to the public. Several arguments have been raised to know the specific parameters that influence column classification. The enclosed short term paper at the back of this article will further shed light upon this.

3.1      NATIONAL ANNEX AS A WAY TO DEVELOP OUR OWN CODE

Having known that the eurocode is flexible and allow each country to choose their safety parameters through what is called Country National Annex to Eurocode, the National Annex is concise and easy to develop than a whole code. It gives us the opportunity to select our own safety parameters such  as load factors, material factors, etc which are mainly dependent on our construction practices, materials standard and quality, human behaviour to structures, etc in the country – although this still requires some practical works and experimental findings. It is obvious that this huge advantage is not available in the old British Standards wherein the safety factors were mainly developed based on the design and construction practices in the United Kingdom.

Do we even know that this system was also adopted by the owner of old British Standard? The United Kingdom now uses “UK National Annex to Eurocode”. Similar procedure is in place in South Africa where they already have their own design code (SABS). The country still intends to adopt the Eurocode alongside the SABS knowing the benefits and the importance of global knowledge. This means that developing an effective “Stand Alone” design code in Nigeria might take years.

The “Nigeria National Annex to Eurocode” will not only provide us the integration to global knowledge and design practices but can also be used as a foundation for the development of our own code after extensive design practices and qualitative researches.

4.0      SAMPLE PROBLEM AND COMPUTATION

4.1 COLUMN CLASSIFICATION IN ACCORDANCE WITH BS8110 & EUROCODE 2 COMPARED

Columns are structural elements which are primarily used to provide either temporary or permanent support to compressive loads, and sometimes used to resist bending. It may be referred to as “spinal cord” of structures due to the fact that their failure may trigger the collapse of the whole structure if not properly designed. However, this poor design may be due to inappropriate guidance procedures given in the adopted design code rather incompetency of the designer alone.

The design of columns perhaps in any design code in the world is primarily based on column classification (either as short or slender). Inappropriate classification may lead to failure of the column especially when local buckling and second moment is expected to be considered in the design which will affect the anticipated design load capacity of the column. This error may be due to the adopted design code as aforementioned. It is obvious that the main essence of column classification is to know the failure types of the column. Therefore it is necessary to understand those parameters that govern such failure which in turn affects column classification.

 4.2 Research Objectives

  • To investigate column classification in accordance with BS8110 in comparison with Eurocode.

4.3 Research Significance

The results of this study will validate further applicability of the present column classification approach described in BS8110. It will also give general notice to the insisted present users of BS8110 to make adequate revision of the code where necessary or get acquainted with the latest Eurocode.

4.4 Research methods

In order to achieve the objective of this research, a critical analysis of column classification in accordance with BS8110 and Eurocode 2 were thoroughly examined. A questionnaire was also developed to examine the art of column classification in accordance with BS8110.

4.5 Terms definitions:

Short column– one in which the ultimate load capacity is dictated by the material strength and cross-section. This type of column fails by crushing of the material.

Slender column– one in which the ultimate load is influenced by material strength, cross-section as well as slenderness. This type of column can fail either by material crushing or instability (buckling) of the column.

(a)               BS 8110 approach (BSI, 1997):

According to the above design code, a column is regarded as short when both the ratios lex/h and ley/b are less than 15 and 10 for braced and unbraced respectively, otherwise is slender. Where lex and ley are the effective length in major and minor axes respectively; ‘h’ and ‘ b’ are the larger and smaller dimension of the column section respectively (BS8110, 1997). The effective length is given as:

le = β l                                                                                 (4.1)

Where lo is the clear length between end restraints and not exceeding 60 times the minimum thickness of a column according to section 3.8.1.7 of BS8110, 1997. For a cantilever column, this should not exceed:

                                                                                 (4.2)

 

The value of β depends on end conditions and lateral restraint against sideway (braced or unbraced) as shown below.

Table 2.1 Values of β for (a) Braced column and (b) Unbraced column.

  End condition at top End condition at bottom
1 2 3
1 0.75 0.80 0.90
2 0.80 0.85 0.95
3 0.90 0.95 1.00

(a)

 

 

  End condition at top End condition at bottom
1 2 3
1 1.2 1.3 1.6
2 1.3 1.5 1.8
3 1.6 1.8
4 2.2

 

 

(b)

 

 

Source: Table 3.19 and 3.20 of BS8110, Part 1(1997).  For conditions 1 to 4 see section 3.8.1.6

(b)               Eurocode approach (EN, 1992; Mosley, et al., 2007)

 

In contrast to BS8110 slenderness approach for column classification, EC2 takes into account the contribution of design ultimate axial load on the column, concrete strength, longitudinal reinforcement as well as creep effect along with aforementioned parameters when classifying a column.  In this approach, columns are classified as either short or slender by placing a limit on slenderness ratio. Columns having slenderness ratio λ not exceeding slenderness ratio limit lim) are regarded as short, otherwise as slender and second order effects must be taken into account in design (EN, 1992; Mosley, et al., 2007). The slenderness ratio of a column bent about an axis is given as:

λ =                                                               (4.3)

Where lo is the effective length, ‘i’ is the radius of gyration (uncracked section) and ‘I’ is the second moment of area of section about the axis in consideration, and ‘A’ is the cross-sectional area of the column.

For braced columns;

lo =                                                (4.4)

For unbraced columns, the larger of:

lo =                          or                                                              (4.5a)

lo =                                                                                    (4.5b)

where k1 and k2 are the relative flexibilities of the rotational restraints at ends ‘1’ and ‘2’ of the column respectively. See EC2 (EN 1992) and Mosley, et al. (2007) for further reading.

Relative flexibilities k [EC 2: 5.8.3.2 (3) – (5)]

( =   If top & bottom columns does not contribute to column rotational restraint. But if top & bottom columns contribute to column restraint, k is given as:

+ (. Refer to EC 2: 5.8.3.2 (3) for their definitions.

As previously mentioned, EC 2 places a limit on slenderness ratio and this is given as:

λlim =                                                                              (4.6)

A =  and A can be taken as 0.7 if  is not known.                (4.6.1)

B =   and B can be taken as 1.1 if ω is not known.         (4.6.2)

C = 1.7 – rm and C can be taken as 0.7 if rm is unknown.                              (4.6.3)

n =                                                                                                   (4.6.4)

ω =                                                                              (4.6.5)

Where:

   = effective creep ratio

= design yield strength of the concrete

= design compressive strength of the concrete

= total longitudinal reinforcement area

NEd = design ultimate axial load in the column and rm is the ratio of first order moments at the end of the column. Refer to EN (1992) and Mosley, et al. (2007) for proper definitions.

Therefore, for a short column, λ < λlim otherwise as slender; whereas the code does not states any specific guidance if λ lim.

4.6 Comparison between the two design codes

As aforementioned that short column fails by material crushing and this failure depends on the column geometry, properties (concrete strength), creep, reinforcement area and strength, design ultimate axial load on the column and so on. It is not understood how these factors were accounted for when classifying column as short or slender in BS8110 apart from the effective height of the column, column size, and degree of fixity at ends as well as limiting values given for slenderness ratio.

It is clearly shown from equation 4.6 on how these factors were considered in EC 2 by placing an upper limit on the slenderness ratio.

4.7 Summary of on-going results from questionnaire:

About 44.44% were civil/structural engineers, 11.11% were professors/lecturers, 11.11 % were graduates and 33.33% were students.  Approximately 80% of them have used BS8110 for column design. About 90% of the respondents agreed that short column fails by material crushing and slender column fails by either material crushing or instability (buckling). The same number agreed that the term failure will be dictated by column geometry, concrete strength, reinforcement grade and design applied load on the column. However about 77% of them did not know how these aforementioned parameters were considered in the classification of column with BS8110.

Based on the findings from several literatures, thorough comparison of the two design codes and the results from current questionnaire, this principal conclusion was drawn.

  • Column classification should also be based on design axial load, concrete strength, reinforcement grade and area, aside from slenderness ratio (which is calculated from column geometry, fixity, end conditions and side restraints). These parameters were clearly considered in Eurocode 2 & ACI 318 (American code). However it is not yet understood how BS8110 incorporated these parameters.

Conclusion

Nigerian engineers have to start from somewhere. In this age of convergence, they must adopt a technology philosophy that promotes catching up. This can be accomplished if they understand the details of research and development carried out by others before them and adapt this to suite local needs especially in the area of standard.

References & Bibliography:

a)      British Standards Institution, 1997. BS8110: 1997 Code of practice for design and construction. London: BSI.

b)      British Standards Institution, 1990. BS EN 1990: Basis of structural design. London: BSI.

c)      British Standards Institution, 1991. BS EN 1991: Actions on structures-Densities, selfweight, imposed loads for buildings. London: BSI.

d)      British Standards Institution, 1992. BS EN 1992: Design of concrete structures-General rules and rules for building. London: BSI.

e)      British Standards Institution Shop, 2009. Available at : http://shop.bsigroup.com/en/Browse-By-Subject/Eurocodes/

f)       Concrete Centre, 2010.  Available at: http://www.concretecentre.com/codes__standards/eurocodes/eurocode_2/background_to_ec2/benefits_of_eurocode_2.aspx

g)      Falola, O. O., 2011. Investigation of Column Classification Parameters Survey. kwiksurveys.com

h)      Falola, O. O., 2010. Comparison between Reinforced Solid Column and the Equivalent Hollow Column. London: University of East London.

i)        Mosley, B.  Bungey, J. & Hulse, R., 2007. Reinforced concrete design. 6th ed. China: BookPower.

j)        Narayanan, R. S, et al. eds., 2010. How to Design Concrete Structures using Eurocode 2. London: Concrete Centre.

 

The author Olugbenro Falola is a PhD student at the Eastern Mediterranean University, Cyprus
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An assessment of the Nigeria’s power sector reform

…an engineer’s review of Nigeria’s power sector reform with suggestions

By Olatunji Ariyomo

June 15 2012 | Sheffield, England

1.0       INTRODUCTION

A distressing fact about Nigeria’s repeated attempts to get electricity production and distribution right is that such attempts have failed repeatedly. This is despite the infusion of several billion dollars thus implying that government or the overall leadership will to fund and get result may not be the problem but the capacity of sector leadership to know the right thing to do. Put differently, it appears that what is lacking is the capacity of sector leadership to know the right strategy and path that will most efficiently produce the required results as the usual paths have significantly failed to generate envisaged results. Between 1999 and 2012, it is estimated that the country expended over $25billion (USD) on her electricity subsector of the energy industry yet production alone hovered between 2,500MW and 4,400MW at any time during this period with citizens even willing to commend government if they noticed stable electricity supply beyond 3 hours in a single day. Some have described this as an unprecedented and extraordinary expenditure to procure darkness.

Sector leadership in the context of this paper refers to the authority of the Minister of Power of the federation and any such sub-authority that derives its power directly or indirectly from the federal minister. Can current sector leadership end age-long epileptic electricity supply? Yes. Put differently however, can current sector leadership end age-long epileptic electricity supply if it continues on Nigeria’s present path to reform? No. It would take a pyrrhic victory to record an instance of yes if the current course of its reform is not altered.

2.0       THE FAULT LINE
A major fault line in the ongoing reform lies in the decision to make the unbundling of the Power Holding Company of Nigeria (PHCN) the core of the policy thrust of government when it should ordinarily have been the reform’s obiter dictum ­– important, but not critical enough to derail or define a negative outcome for the entire agenda. Current strategy appears to put privatisation before sector liberalization, a situation akin to putting the cart before the horse. If the cart were ahead of the horse, what would drive the cart? Also, the reform’s current direction is the equivalent of making NITEL privatization the core of the policy thrust of government during the reform of the telecommunication sector. That singular error has succeeded in fortifying the position of PHCN workers and enhancing their capacity to slow down, make or even mar the entire process. This was a tactical blunder that was avoidable from a strategy point of view.

Simplified electricity distribution grid diagram
Simplified electricity distribution grid diagram

This strategic error draws strength from another technical and tactical misconception which appears to punctuate some of the responses from government’s team – that the electricity reform matrix does not perfectly mirror the telecommunication sector scenario because of the pervasive nature and present ownership structure of the national power distribution and transmission backbone required by the former. This is erroneous and only gains currency when the crucial nexus that connects both and the parallels that define the core elements that qualify as critical success factors are overlooked even when it is easy to recollect that the participating private investors at the time of telecom sector liberalization initially relied on an equally pervasive national telecommunication backbone exclusively owned by NITEL for the bulk of their call terminations which gave NITEL some business edge and cost termination advantage in those early days.

Essentially therefore, current electricity sustainability strategy suggests a flagrant disregard of the knowledge curve gained from the successful liberalization of the telecommunication sector. Again put differently, Nigeria is today experiencing energy growth penalties from lack of inherent capacity to see a nexus between her telecommunication industry and the electricity sub-sector of the energy industry which is chiefly the result of not being able to view her entire electricity sub-sector as a value system, that is, see the mobility and dynamics of the value chain inherent in the totality of electricity generation, transmission, distribution and management stream. Present resistance by sector unions and workers as well as the strategic delays purportedly engineered by entrenched ‘interests’ and the herculean tasks and politics of aggregating, positioning and empanelling new leadership for various companies so created from the unbundled PHCN are self-imposed burdens that should never have been the primary duty or concern of the government’s core reform team. One can only imagine with pity the quantum of effort, resources and energy being devoted to the management of these avoidable distractions!

The huge expenses sunk into schemes aimed at fattening and conferring the status of ‘juicy investments’ upon the 18 successor companies of PHCN to make them appealing so that they could qualify as most sought after brides on the international market could have served a better purpose if deployed as counterpart funds with reputable Greenfield investors to address the same layers of national challenge portfolio. By the time the actual dollar value pushed into the sector is factored into consideration (estimated at $16billion as at May 2007 and presently approximately put at close to $25billion), it is doubtful that returns (based on actual sales) from bids by winners of the 17 successor companies would fetch the Nigerian people a quarter of what t has been expended so far. Hence, as it is today, the myriads of explanations being lobbed at the public in explaining the rationale for increase in salaries and tariffs when the target companies are candidates for privatization would have been unnecessary even as an informed public would easily identify them as executive spins and a way to ensure that the new high tariffs make takeover more profitable for the new owners at the expense of the Nigerian people.

3.0       THREE GOOD STEPS LADEN WITH LANDMINES
Three good steps have however been taken by the present sector leadership. These are listed below:

  1. Creation of a bulk electricity trading company (BETraC)
  2. Reported decision to outsource management of national power transmission backbone to a reputable Canadian firm (Nigeria will pay agreed fees to this firm for this role).
  3. Reported empowerment of states and local governments (LGAs) to invest in production and distribution.

These could be described as the three best things that have happened since the commencement of the reform. It is however pertinent to observe that these three have again been laden with the usual in-built ‘landmines’ and ‘reform viruses’ that have come to define reform processes in Africa.

3.1 HIGHLIGHTS OF THE LANDMINES
Available reports on the bulk electricity trading company (BETraC), the contract for the management of the national power transmission backbone and the involvement of the second and third tiers of government in the sector point to the following as facts:

  1. BETraC is a government bureaucracy rather than a system driven or institution propelled initiative empowered with robust legislation to utilize transparent accounting system, settlement capabilities, and self governance structures using bilateral cooperation involving limited government but sizable private sector involvement. Unending bureaucracy with its attendant road-blocks is a crucial problem identified by this writer as an impediment to sustainable energy growth in Africa and a direct inhibitor of real private sector involvement. Maintaining this structure as part of the current reform path makes it sure booby-trap.
  2. It appears strongly that the responsibility for the management of the entire national power transmission backbone covering the 910,768 sq km of the nation’s land space is being outsourced to one single monopoly. This has corresponding impact on the reform’s capacity to act as stimulant for massive job creation, widespread private sector growth and knowledge transfer along the transmission corridor as well the potential to impede the promotion of fair consumer price. Paul K. Ogden described this as “creating a government sanctioned monopoly for a private company” (Ogden, 2009). It also does appear that rather than receiving payments from the manager, government of Nigeria would be paying the manager. This is awkward. It directly negates the entire narrative behind a private sector led electricity sub-sector while potentially leaving room for collusion and ultimately corruption.
  3. Reported empowerment of states and LGAs is superficial as it is solely within the limitation imposed by Section 14(b), Part II of the Second Schedule (Concurrent Legislative List) of the Nigerian Constitution which restricts state’s investment to “areas not covered by a national grid system within that State”.  Any strategic manoeuvring beyond this constitutional intendment without actually amending the constitution to remove restrictions imposed upon states and local governments would limit the capacity of states to be real owners of their investments, promote conflicts and open up future avenues for possible abuse which could result from socio-political differences in a nation as diverse as Nigeria. An improvement would be a model that would guarantee stronger legislative protection, fairness and sustainability for states and local governments as well as private investors. This can be accomplished by way of amendment of the extant regulation.

4.0       SUGGESTIONS
What is the guiding philosophy of the reform? Shouldn’t sector liberalization precede privatization? If yes, do we have evidence of nations that have followed similar direction to success? Can Nigeria learn any lesson from Ghana’s success despite retaining state-owned public electric utilities such as the Volta River Authority (VRA), Ghana Grid Company (GRIDCo) and the Electricity Company of Ghana (ECG)?

What the reform intends achieving must be clear – for instance, would adding more government money qualify as privatization? If it is ultimately necessary for the reform to receive the injection of public funds in order to jump start the process, would that not be better infused as joint venture funds into enterprises sponsored wholly and primarily by internationally acclaimed Greenfield investors thereby bypassing the politics of PHCN altogether? Ordinarily the reform should be aiming at ultimately eliminating government fund while bringing in private fund, eliminating government control while promoting system driven control mechanisms, eliminating secrecy while bringing in transparency, eliminating established interest and pre-determination in order to bring in equity, fairness and spontaneity.

This writer empirically estimated Nigeria’s urgent electricity requirement to be a minimum of 55,694.50MW in order to merely get by. The nation needs more for optimum power stability. Putting the arrays of complex options required to properly govern the sector in context requires thinking outside the box as well as looking back to take advantage of what we did right in the past.

Among other considerations, the focus of government’s reform should include:

  1. Strategy for jumpstarting attainment of reform objectives. It is baloney to advance that because Nigeria has suffered electricity deprivation for 50 years, it must ultimately take another 50 years to get it right. No. A good sector reform strategy will lead to sustainable electricity that the people can begin to tangibly experience in the cities within 2 years.
  2. Strategy for technology transfer and knowledge enhancement
  3. Strategy for massive job creation (taking advantage of item number 2)
  4. Strategy for sustainability and ensuring reform cannot be truncated (robust legislation, sector leadership and masses’ support)
  5. Strategy for massive revenue generation for the people of Nigeria (government should earn payments – taxes, levies, rents etc – and not the other way round)
  6. Strategies for correcting the identified ‘landmines’ enumerated in 3.1.
  7. Strategy that would lead to the reform benefiting from contributions of professional bodies and other sector stakeholders. Sector leadership cannot be an island of knowledge. As part of wide consultation (before decisions are taken) the reform would benefit more if subject matter experts from the various professional organizations are allowed to make input. This is the tradition in the United Kingdom and the United States.

Getting Nigeria’s quest for steady electricity right requires the appropriate strategy, thorough industry expertise and objectivity. There is no such place where Nigeria’s current model of financially fattening up a moribund and non-performing government agency in order to sell it to private sector handlers does have a successful precedent as a cost effective model. It could only further promote corruption as well as serve as an opportunity for local elites to apportion national utilities among themselves under the guise of privatization.

In conclusion, Nigeria can get it right with sustainable electricity, put the years of epileptic electricity supply behind her and join the rest of the world in the pursuit of renewable energy alternative. This is however only possible if the nation is doing the right things.

Paper authored by,
Engr. Olatunji Ariyomo

Mosquitoes Bred to Be Incapable of Transmitting Malaria

ScienceDaily (June 12, 2012) — Mosquitoes bred to be unable to infect people with the malaria parasite are an attractive approach to helping curb one of the world’s most pressing public health issues, according to UC Irvine scientists.

Anthony James and colleagues from UCI and the Pasteur Institute in Paris have produced a model of theAnopheles stephensi mosquito — a major source of malaria in India and the Middle East — that impairs the development of the malaria parasite. These mosquitoes, in turn, cannot transmit the disease through their bites.

Mosquito
The Anopheles stephensi mosquito is a major vector of malaria in India and the Middle East. (Credit: Jim Gathany / Centers for Disease Control & Prevention)

“Our group has made significant advances with the creation of transgenic mosquitoes,” said James, a UCI Distinguished Professor of microbiology & molecular genetics and molecular biology & biochemistry. “But this is the first model of a malaria vector with a genetic modification that can potentially exist in wild populations and be transferred through generations without affecting their fitness.”

More than 40 percent of the world’s population lives in areas where there is a risk of contracting malaria. According to the Centers for Disease Control & Prevention, 300 million to 500 million cases of malaria occur each year, and nearly 1 million people die of the disease annually — largely infants, young children and pregnant women, most of them in Africa.

James said one advantage of his group’s method is that it can be applied to the dozens of different mosquito types that harbor and transmit the Plasmodium falciparum parasite, including those in Africa. Study results appear this week in the early online version of the Proceedings of the National Academy of Sciences.

The researchers conceived their approach through mouse studies. Mice infected with the human form of malaria create antibodies that kill the parasite. James’ team exploited the molecular components of this mouse immune-system response and engineered genes that could produce the same response in mosquitoes. In their model, antibodies are released in genetically modified mosquitoes that render the parasite harmless to others.

“We see a complete deletion of the infectious version of the malaria parasite,” said James, a member of the National Academy of Sciences. “This blocking process within the insect that carries malaria can help significantly reduce human sickness and death.”

He and his colleagues have pioneered the creation of genetically altered mosquitoes that limit the transmission of dengue fever, malaria and other vector-borne illnesses.

Alison Isaacs, Nijole Jasinskiene and Mikhail Tretiakov of UCI and Isabelle Thiery, Agnes Zettor and Catherine Bourgouin of the Pasteur Institute contributed to the study, which received support from the National Institute of Allergy & Infectious Diseases — a National Institutes of Health entity — through grant number R37 AI029746.

Story Source:

The above story is reproduced by NDi based upon a reprint by Science Daily from materials provided byUniversity of California – Irvine.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. A. T. Isaacs, N. Jasinskiene, M. Tretiakov, I. Thiery, A. Zettor, C. Bourgouin, A. A. James. PNAS Plus: Transgenic Anopheles stephensi coexpressing single-chain antibodies resist Plasmodium falciparum developmentProceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1207738109
Need to cite this story in your essay, paper, or report? Use one of the following formats:
 APA: University of California – Irvine (2012, June 12). Mosquitoes bred to be incapable of transmitting malaria. ScienceDaily. Retrieved June 14, 2012, from http://www.sciencedaily.com­/releases/2012/06/120612115949.htm  MLA: University of California – Irvine. “Mosquitoes bred to be incapable of transmitting malaria.”ScienceDaily, 12 Jun. 2012. Web. 14 Jun. 2012.

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff

Physical planning approach to reducing fatalities and managing aircraft disasters in Nigeria

By Olapeju Olasunkanmi

Social networking sites and their paraphernalia of smart phones have once again proven to be most effective in the delivery and sharing of facts; real time data; half truths; falsehoods; political mudslings,and cyber spatial assaults ,in the unfortunate Dana Plane mishap that happened last Sunday. From the eerie pictures, real time video files, tweets and re-tweets of the names on the manifest of the crashed plane to the very revealing details of John I. Nnorom-a former Executive Director for finance at Air Nigeria who warned Nigerians to stop flying Air Nigeria until they were sure its planes are properly maintained, the information appetite of a highly dynamic blogosphere population that will no longer wait to get its news from the dailies of the following day was satisfactorily met.

A rescue worker walks past the wreckage of a plane in Lagos, Nigeria on Monday, June 4, 2012. (AP Photo/Sunday Alamba)
A rescue worker walks past the wreckage of a plane in Lagos, Nigeria on Monday, June 4, 2012. (AP Photo/Sunday Alamba)

But shallow and mischievous minds will not rest. They will take advantage of the insufferable and curious mind state of the public to reducing the significance of the national introspection that should attend such national disasters to mere politics. This morning, the tweets I woke up seeing dominating the cyber space centered on the alleged closure of the nations’ airspace for Madam Goodluck Patience on that fateful Sunday. They are obviously the handiwork of such elements that do not know beyond politics. Unfortunately, the toxic tweets will spread more virally and linger more on walls, despite the fact that disclaimers have been logically written to refute them. My grouse with such misinformation is that they add to the toxic content in the minds of the ignorant and devilishly potent in hypnotizing professionals and technocrats who should rather be thinking of how to dispassionately but creatively fashion out solutions to our present challenges beyond regurgitating the old stories we are used to.

Now, let me state clearly that this piece is not about holding brief for the Government of Goodluck Jonathan,whose general performances in office have been short of expectations, for obvious reasons that mostly border on sabotage and the everlasting corruption endemic in our development delivery procedures across all tiers of government. It is rather about x-raying the problems of the aviation sector-especially aircrafts accidents beyond the platitudes of human errors,technical faults and systemic corruption that have been mainly established as the causative factors of air plane crashes in Nigeria,and presenting a wider professional perspective in fundamentally ameliorating the aviation challenges that appear to now abide with us forever.
In a recent study by commercial aircraft maker Boeing,of the 364 plane accidents that globally occurred between 1998 and 2007,87 were caused by technical or human error while landing,and 11% of the total 5147 fatalities were due to accidents borne out of problems in landing. According to the report titled ‘’statistical summary of commercial jet air plane accidents’’,1959 -2008,about 12% of plane accidents take place during takeoff,while 8% during the plane’s initial climb and 12% between the period of climb and cruises, accounting for 45% of total fatalities. While descending ,there were only 5% of mishaps whereas 10% of accidents occurred during the flights initial approach, and 9% during the final approach before landing,resulting in about 27% of total fatalities during the observed years.

The foregoing is to make the point that plane accidents are not only restricted to technical deficiencies that result in crashes during cruising, but that accidents due to taking off and landing of aircrafts are also statistically significant. This is of course is a major consideration in the locational criteria for airports in saner climes. It is definitely the strategic rationale behind the siting of 45 of the 50 busiest airports in the USA in locations that are contiguous to water bodies. Here in Nigeria,airports are sited without recourse to considerations about environmental impacts that relates to noise,resonance effects,and collateral damages and destructions that attend plane crashes. They locate in the heart of the cities,while coastal areas are left to either erode,and sometimes reclaimed by the rich to erecting posh buildings that dot littoral skyline,and command incredible market values.

What am I saying? There is a provable chance that we would have had survivors in the last Sunday’s Dana air mishap had Agbado –Iju,where the crash occurred, which is just seconds away from MMA, been within the radius of a coastal catchment for MMA. Global airplane water crashes statistics corroborate my reasoning. The story of the 155 passengers and crew of Airbus A320,a US airways flight that remained intact after crashing into the Hudson river,in Newyork on 9th January 2009 still remains a legendary testimony that owes more to rational planning and pilot’s ingenuity(let me be generous). We also have fair survival rates of 20 of 39 on board and 59 of 50 on board for Tuninter 1153(an ATR 72,which ditched off the silicon coast after running out of fuel in 2005) and Garuda Indonesia flights(a Boeing 737 which ditched into a river in Java island) ,respectively. As a matter of fact,a recent study done in the US puts ditching(intentional and controlled water landing of an aircraft) survival rate at 88%,though factors like the size of aircraft,type of waterbody for landing,and the speed at which the pilot eases the craft into water also account for survival rates.

Like in many cases that we wound around the person of the President whose face we don’t like anymore,despite our knowledge of the fact that they have existed long before he came on board, the problems in the aviation sector are beyond superficial political dressings . The absence of a viable framework for national physical planning over the years, and the unseriousness of state governments in proactively preparing and implementing regional,urban,local,and subject plans in times past(since the supreme court judgment In the case between Lagos state and the FG now makes the monopoly state governments have in respect to land management and control lucid)is what is responsible for proliferations of major incompatible land uses and indiscriminate construction of buildings in special areas in our cities.

While we wait for the outcome of the black box investigations, and ruminate on how to improve aviation regulation and quality control, and reduce corruption in that sensitive sector, we should also consider the re-ordering of airport locations in ensuring better disaster prevention and management. It is not enough for planning authorities to merely restrict planning standards within a particular radius from airports to building heights regulation and telecommunication mast control. Rather, approval order for airports should emphasize strictly on littoral locations and several miles radius away from built up area. The coastal habitats and mangroves that will be left if such an approval order is sustainably implemented could also represent a gain in environmental management, eco-system and biodiversity protection, and afford the banking of vegetation-carbon sinks to help mitigate global warming. Planning authorities must be empowered to ensuring that their development control powers are not compromised. While government should seize this opportunity in facing the issues squarely, and achieving spatial re-engineering of our cities, the public should also be more sensitized that urban management is not just about scoring political points and making huge tax gains, but chiefly about the greater good of public safety, health, and environmental sustainability.