Studies on the fish ponds at Pitipana, Negombo 1: seasonal and diurnal variation of some hydrobiological factors

The present paper is a part of a detailed investigation on the biology of grey mullet, Mugli cephalus L., and the feasibility of its culture in the brackish waters of Sri Lanka. The authors present the results of investigation on the water quality of five experimental ponds at the Pitipana Brackishwater Fisheries Station, Negombo, carried out over a period of one year, December 1976 to November 1977, together with studies on the primary productivity are presented

Fish fauna of a coastal lagoon in Sri Lanka: distribution and seasonal variation

In this paper results of investigations carried out over the period of September 1977 to August 1978 are presented. These data were collected in the course of a detailed investigation into the biology and the eco-physiology of the young grey mullet and the grey mullet fishery of the Negombo Lagoon. In this paper the distribution and seasonal variation of fin fish species within the Negombo Lagoon are presented

Hydrobiology of Colombo (Beira) Lake, 1. Diurnal variations in temperature, hydrochemical factors and zooplankton

An extensive study of the hydrobiology of the Colombo Lake was initiated by the authors in May 1969 as a contribution to the International Biological Program (Productivity of freshwater communities) by the Department of Zoology, Vidyalankara University of Ceylon, Kelaniya. The Colombo Lake often referred to as the Beira Lake covers an area of approximately 160 acres. The water is usually very turbid with a greenish blue appearance due to the presence of large quantities of blue green algae

Nonlinear analysis of beams, plane frames and arch using a dierent co-rotating beam element

En este trabajo se describe la formulación corrotacional de un elemento de viga que utiliza distintas teorías, Euler-Bernoulli, Timoshenko y Euler-Bernoulli incluyendo el acoplamiento entre los efectos de los esfuerzos de flexión y axil lo que genera coeficientes no lineales en la matriz de rigidez elástica de dicho elemento. La cinemática corrotacional se basa en la separación del movimiento de un sólido en una parte deformacional y otra en movimiento de cuerpo rígido. La parte deformacional del movimiento es representada por tres grados de libertad: una traslación debido al esfuerzo axil y por las rotaciones nodales debidas a la flexión del elemento. A nivel local se obtienen los esfuerzos internos mediante el princípio de los trabajos virtuales una vez definidas las funciones de interporlación que describen el movimiento deformacional para cada teoría de viga utilizada. Se describe de forma detallada la obtención de las matrices de rigideces elástica para los tres tipos de elementos de viga. A través de algunos ejemplos numéricos se muestra la habilidad del elemento para obtener el comportamiento no lineal de vigas, pórticos y arcos.The present work uses a co-rotating approach for obtain the internal forces and tangent stiffness matrices for three plane beam elements. All of them are based on the same co-rotational approach, and differ by the strain definition used in the local co-rotational coordinate system. Based on the Bernoulli assumption, the first two elements use a linear and a shallow arch strain definition, respectively. The third element is based on the Timoshenko assumption with linear interpolations for the displacements. Some examples are presented and the numerical results demonstrate that the beam elements here presented are able to perform the nonlinear analysis of plane frames and 2D arches and to handle large rotations too.Peer Reviewe

CGIAR aquatic research priorities revisited: a case for a higher priority for reservoir-lake system research

The case presented in this article clearly indicates that reservoir and lake resource systems, reservoirs in the Asian context lakes plus reservoirs in the African context, have been given a lower priority than deserved

Tackling tourism-driven development in World Heritage cities: A comparison between Macao, China and Evora, Portugal

World Heritage cities, all over the world, are a centre of tourist attraction. In many of these cities, tourism is one of the main driving forces of local economies. As a result, these cities come under intense pressure to accommodate tourism-driven developments; summed up with the pressure to fulfil the needs of local communities. How development in World Heritage cities can be tackled is, thus, an important issue for both heritage management and urban development. This paper presents two World Heritage cities – Macao, a former Portuguese colony in China and Évora, the capital of Alentejo region in Portugal - as case studies and discusses and compares the way tourism-driven development is being tackled in these cities. Macao’s economy depends almost entirely on tourism-driven activities. While the World Heritage status has added additional attractiveness to Macao, the main attraction there is gambling. On the other hand, Évora is much less dependent on tourism. Similar to Macao, the World Heritage status has raised the attractiveness of Évora as a tourist destination; however, the university plays also a fundamental role. Consequently, despite the efforts of the local authorities, the city is losing its local community. Even if for different reasons, in both case studies, heritage is often sidelined in the urban development agenda. The case studies identify the raise of cultural-driven tourism and the consequent urban developments and illustrate the role of legislations and regulations and the impact of their variation per heritage protection zones. Moreover, it identifies the resultant urban development scenario that enhance or diminish the heritage values of the cities and, therefore, help retain or cause destruction to the very cultural capital that has brought and can bring many more benefits to these cities of outstanding universal value

Tackling tourism-driven development in World Heritage cities: A comparison between Macao, China and Evora, Portugal

World Heritage cities, all over the world, are a centre of tourist attraction. In many of these cities, tourism is one of the main driving forces of local economies. As a result, these cities come under intense pressure to accommodate tourism-driven developments; summed up with the pressure to fulfil the needs of local communities. How development in World Heritage cities can be tackled is, thus, an important issue for both heritage management and urban development. This paper presents two World Heritage cities – Macao, a former Portuguese colony in China and Évora, the capital of Alentejo region in Portugal - as case studies and discusses and compares the way tourism-driven development is being tackled in these cities. Macao’s economy depends almost entirely on tourism-driven activities. While the World Heritage status has added additional attractiveness to Macao, the main attraction there is gambling. On the other hand, Évora is much less dependent on tourism. Similar to Macao, the World Heritage status has raised the attractiveness of Évora as a tourist destination; however, the university plays also a fundamental role. Consequently, despite the efforts of the local authorities, the city is losing its local community. Even if for different reasons, in both case studies, heritage is often sidelined in the urban development agenda. The case studies identify the raise of cultural-driven tourism and the consequent urban developments and illustrate the role of legislations and regulations and the impact of their variation per heritage protection zones. Moreover, it identifies the resultant urban development scenario that enhance or diminish the heritage values of the cities and, therefore, help retain or cause destruction to the very cultural capital that has brought and can bring many more benefits to these cities of outstanding universal value

Genetic analysis of members of the species Oropouche virus and identification of a novel M segment sequence

Oropouche virus (OROV) is a public health threat in South America, and in particular Northern Brazil, causing frequent outbreaks of febrile illness. Using a combination of deep sequencing and Sanger sequencing approaches we have determined complete genome sequences of eight clinical isolates that were obtained from patient sera during an Oropouche fever outbreak in Amapa state, northern Brazil in 2009. We also report complete genome sequences of two OROV reassortants isolated from two marmosets in Minas Gerais state, southeast Brazil in 2012 that contain a novel M genome segment. Interestingly, all ten isolates posses a 947 nucleotide long S segment that lacks 11 residues in the S segment 3' UTR compared to the recently redetermined Brazilian prototype OROV strain BeAn19991. OROV maybe circulating more widely in Brazil and in the non-human primate population than previously appreciated and the identification of yet another reassortant highlights the importance of bunyavirus surveillance in South America

Sustainable utilization of inland water resources: an integrated program for research and management

In both developed and developing countries, there is increased competition for water resources, resulting in deficiencies in supply and in various forms of pollution. In developing countries, the nutritional potential of aquatic resources is very important. To realize this potential, integrated research and management for sustainable water resource use are needed. This requires a sound understanding of the structure and function of aquatic ecosystems. A programme is presented which stresses the interrelationships of the physical, chemical and biological components of aquatic systems and their catchments. The programme consists of 16 stages in 5 phases, which are as follows: System description; System functioning and modelling; Resource assessment/dynamics; Resource potential; and, Resource utilization for sustainability. This programme enables workers within different disciplines to identify how their expertise contributes to the overall research requirements to support resource development