17 research outputs found

    Five feet high and rising : cities and flooding in the 21st century

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    Urban flooding is an increasingly important issue. Disaster statistics appear to show flood events are becoming more frequent, with medium-scale events increasing fastest. The impact of flooding is driven by a combination of natural and human-induced factors. As recent flood events in Pakistan, Brazil, Sri Lanka and Australia show, floods can occur in widespread locations and can sometimes overwhelm even the best prepared countries and cities. There are known and tested measures for urban flood risk management, typically classified as structural or engineered measures, and non-structural, management techniques. A combination of measures to form an integrated management approach is most likely to be successful in reducing flood risk. In the short term and for developing countries in particular, the factors affecting exposure and vulnerability are increasing at the fastest rate as urbanization puts more people and more assets at risk. In the longer term, however, climate scenarios are likely to be one of the most important drivers of future changes in flood risk. Due to the large uncertainties in projections of climate change, adaptation to the changing risk needs to be flexible to a wide range of future scenarios and to be able to cope with potentially large changes in sea level, rainfall intensity and snowmelt. Climate uncertainty and budgetary, institutional and practical constraints are likely to lead to a combining of structural and non-structural measures for urban flood risk management, and arguably, to a move away from what is sometimes an over-reliance on hard-engineered defenses and toward more adaptable and incremental non-structural solutions.Hazard Risk Management,Wetlands,Natural Disasters,Adaptation to Climate Change,Climate Change Impacts

    Five feet high and rising: Cities and flooding in the 21st Century

    Get PDF
    Urban flooding is an increasingly important issue.Disaster statistics appear to show flood events arebecoming more frequent, with medium-scale eventsincreasing fastest. The impact of flooding is driven bya combination of natural and human-induced factors.As recent flood events in Pakistan, Brazil, Sri Lanka andAustralia show, floods can occur in widespread locationsand can sometimes overwhelm even the best preparedcountries and cities. There are known and tested measuresfor urban flood risk management, typically classified asstructural or engineered measures, and non-structural,management techniques. A combination of measures toform an integrated management approach is most likelyto be successful in reducing flood risk. In the short termand for developing countries in particular, the factorsaffecting exposure and vulnerability are increasing atthe fastest rate as urbanization puts more people andmore assets at risk. In the longer term, however, climatescenarios are likely to be one of the most importantdrivers of future changes in flood risk. Due to the largeuncertainties in projections of climate change, adaptationto the changing risk needs to be flexible to a wide rangeof future scenarios and to be able to cope with potentiallylarge changes in sea level, rainfall intensity and snowmelt.Climate uncertainty and budgetary, institutional andpractical constraints are likely to lead to a combining ofstructural and non-structural measures for urban floodrisk management, and arguably, to a move away fromwhat is sometimes an over-reliance on hard-engineereddefenses and toward more adaptable and incrementalnon-structural solutions

    Design of a city infrastructure quality index

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    Nigeria recently became the largest economy in Africa. The country’s economic output is outpacing population growth. GDP increased from 31billionin1990to31 billion in 1990 to 522 billion in 2013 (averaging an annual growth rate of 5.9 percent), whilst the population increased from 96 million to 170 million during the same period (averaging an annual growth rate of 2.6 percent). Urban areas in particular appear to have generated disproportionately higher rates of economic growth than rural areas. The Nigerian urban business environment, however, discourages investment and frustrates competitiveness, acting as a constraint on economic growth. Inadequate infrastructure is identified as the major constraint to growth and competitiveness. This research project designed a City Infrastructure Quality Index (CIQI) aimed at providing a relative measure of performance in urban infrastructure in Nigeria, focusing specifically on factors of production and resources for inclusive economic growth and development

    Circulating lymphangiogenic growth factors in gastrointestinal solid tumors, could they be of any clinical significance?

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    Metastasis is the principal cause of cancer mortality, with the lymphatic system being the first route of tumor dissemination. The glycoproteins VEGF-C and VEGF-D are members of the vascular endothelial growth factor (VEGF) family, whose role has been recently recognized as lymphatic system regulators during embryogenesis and in pathological processes such as inflammation, lymphatic system disorders and malignant tumor metastasis. They are ligands for the VEGFR-3 receptor on the membrane of the lymphatic endothelial cell, resulting in dilatation of existing lymphatic vessels as well as in vegetation of new ones (lymphangiogenesis). Their determination is feasible in the circulating blood by immunoabsorption and in the tissue specimen by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Experimental and clinicopathological studies have linked the VEGF-C, VEGF-D/VEGFR3 axis to lymphatic spread as well as to the clinical outcome in several human solid tumors. The majority of these data are derived from surgical specimens and malignant cell series, rendering their clinical application questionable, due to subjectivity factors and post-treatment quantification. In an effort to overcome these drawbacks, an alternative method of immunodetection of the circulating levels of these molecules has been used in studies on gastric, esophageal and colorectal cancer. Their results denote that quantification of VEGF-C and VEGF-D in blood samples could serve as lymph node metastasis predictive biomarkers and contribute to preoperative staging of gastrointestinal malignancies

    Conjugation of Penicillin-G with Silver(I) Ions Expands Its Antimicrobial Activity against Gram Negative Bacteria

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    Conjugation of penicillin G (PenH) with silver(I) ions forms a new CoMeD (conjugate of metal with a drug) with formula [Ag(pen)(CH3OH)]2 (PenAg). PenAg was characterized by a plethora of physical and spectroscopic techniques, which include in the solid state m.p.; elemental analysis; X-ray fluorescence (XRF) spectroscopy; scanning electron microscopy (SEM); energy-dispersive X-ray spectroscopy (EDX); FT-IR; and in solution: attenuated total reflection spectroscopy (FT-IR-ATR), UV–Vis, 1H NMR, and atomic absorption (AA). The structure of PenAg was determined by NMR spectroscopy. Silver(I) ions coordinate to the carboxylic group of PenH, while secondary intra-molecular interactions are developed through (i) the nitrogen atom of the amide group in MeOD-d4 or (ii) the sulfur atom in the thietane ring in deuterated dimethyl sulfoxide DMSO-d6. The antibacterial activities of PenAg and the sodium salt of penicillin (PenNa) (the formulation which is clinically used) against Gram positive (Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus)) and Gram negative (Pseudomonas aeruginosa (P. aeuroginosa PAO1)) bacteria were evaluated by the means of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and inhibition zone (IZ). PenAg inhibits the growth of the Gram negative bacterial strain P. aeuroginosa with a MIC value of 23.00 ± 2.29 μM, in contrast to PenNa, which shows no such activity (>2 mM). The corresponding antimicrobial activities of PenAg against the Gram positive bacteria S. epidermidis and S. aureus are even better than those of PenNa. Moreover, PenAg exhibits no in vivo toxicity against Artemia salina at concentration up to 300 μΜ. The wide therapeutic window and the low toxicity, make PenAg a possible candidate for the development of a new antibiotic

    Urbanisation in Nigeria: a scoping review

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    The review is the first activity during the inception period of the Urbanisation Research Nigeria programme. The existing sources on urbanisation – as situated within the themes of urban change, economic growth, well-being and planning – were collated from government, academia, development partners, other international agencies, community organisations and the private sector. The review is thus based on extensive review of secondary sources, supported by expert views and data gathered from key informants. This is complemented with an assessment of existing data sources for urbanisation research, and a discussion of their suitability for tackling questions in each of the four themes

    Silver Nanoparticles from Oregano Leaves’ Extracts as Antimicrobial Components for Non-Infected Hydrogel Contact Lenses

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    The oregano leaves’ extract (ORLE) was used for the formation of silver nanoparticles (AgNPs(ORLE)). ORLE and AgNPs(ORLE) (2 mg/mL) were dispersed in polymer hydrogels to give the pHEMA@ORLE_2 and pHEMA@AgNPs(ORLE)_2 using hydroxyethyl–methacrylate (HEMA). The materials were characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), derivative thermogravimetry/differential scanning calorimetry (DTG/DSC), ultraviolet (UV-Vis), and attenuated total reflection mode (ATR-FTIR) spectroscopies in solid state and UV–Vis in solution. The crystallite size value, analyzed with XRPD, was determined at 20 nm. The antimicrobial activity of the materials was investigated against Gram-negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). The Gram-positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) are known to be involved in microbial keratitis by the means of inhibitory zone (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The IZs, which developed upon incubation of P. aeruginosa, E. coli, S. epidermidis, and S. aureus with paper discs soaked in 2 mg/mL of AgNPs(ORLE), were 11.7 ± 0.7, 13.5 ± 1.9, 12.7 ± 1.7, and 14.3 ± 1.7 mm. When the same dose of ORLE was administrated, the IZs were 10.2 ± 0.7, 9.2 ± 0.5, 9.0 ± 0.0, and 9.0 ± 0.0 mm. The percent of bacterial viability when they were incubated over the polymeric hydrogel discs of pHEMA@AgNPs(ORLE)_2 was interestingly low (66.5, 88.3, 77.7, and 59.6%, respectively, against of P. aeruginosa, E. coli, S. epidermidis, and S. aureus) and those of pHEMA@ORLE_2 were 89.3, 88.1, 92.8, and 84.6%, respectively. Consequently, pHEMA@AgNPs(ORLE)_2 could be an efficient candidate toward the development of non-infectious contact lenses
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