Hypoxia and Sturgeons: report to the Chesapeake Bay Program Dissolved Oxygen Criteria Team

In this essay, three lines of evidence are developed that sturgeons in the Chesapeake Bay and elsewhere are unusually sensitive to hypoxic conditions: 1. In comparison to other fishes, sturgeons have a limited behavioral and physiological capacity to respond to hypoxia. Basal metabolism, growth, and consumption are quite sensitive to changes in oxygen level, which may indicate a relatively poor ability by sturgeons to oxyregulate. 2. During summertime, temperatures >20 C amplify the effect of hypoxia on sturgeons and other fishes due to a temperature*oxygen "squeeze" (Coutant 1987)- In bottom waters, this interaction results in substantial reduction of habitat; in dry years, nursery habitats in the Chesapeake Bay may be particularly reduced or even eliminated. 3. While evidence for population level effects by hypoxia are circumstantial, there are corresponding trends between the absence of Atlantic sturgeon reproduction in estuaries like the Chesapeake Bay where summertime hypoxia predominates on a system-wide scale. Also, the recent and dramatic recovery of shortnose sturgeon in the Hudson River (4-fold increase in abundance from 1980 to 1995) may have been stimulated by improvement of a large portion of the nursery habitat that was restored from hypoxia to normoxia during the period 1973-1978. (PDF contains 26 pages

Sceloporus occidentalis

Number of Pages: 17Integrative BiologyGeological Science

Embodied carbon and construction cost differences between Hong Kong and Melbourne buildings

Limiting the amount of embodied carbon in buildings can help minimize the damaging impacts of global warming through lower upstream emission of CO2. This study empirically investigates the embodied carbon footprint of new-build and refurbished buildings in both Hong Kong and Melbourne to determine the embodied carbon profile and its relationship to both embodied energy and construction cost. The Hong Kong findings suggest that mean embodied carbon for refurbished buildings is 33-39% lower than new-build projects, and the cost for refurbished buildings is 22-50% lower than new-build projects (per square metre of floor area). The Melbourne findings, however, suggest that mean embodied carbon for refurbished buildings is 4% lower than new-build projects, and the cost for refurbished buildings is 24% higher than new-build projects (per square metre of floor area). Embodied carbon ranges from 645-1,059 kgCO2e/m2 for new-build and 294-655 kgCO2e/m2 for refurbished projects in Hong Kong, and 1,138-1,705 kgCO2e/m2 for new-build and 900-1,681 kgCO2e/m2 for refurbished projects in Melbourne. The reasons behind these locational discrepancies are explored and critiqued. Overall, a very strong linear relationship between embodied energy and construction cost in both cities was found and can be used to predict the former, given the latter

Advocating mixed-methods approaches in health research

This methods paper provides researchers in Nepal with a broad overview of the practical and philosophical aspects of mixed-methods research. The three authors have a wide-ranging expertise in planning and conducting mixed-methods studies. The paper outlines the different paradigms or philosophies underlying quantitative and qualitative methods and some of the on-going debates about mixed-methods. The paper further highlights a number of practical issues, such as (a) the particular mix and order of quantitative and qualitative methods; (b) the way of integrating methods from different philosophical stance; and (c) how to synthesise mixed-methods findings

Distance-regular graphs

This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN' [Brouwer, A.E., Cohen, A.M., Neumaier, A., Distance-Regular Graphs, Springer-Verlag, Berlin, 1989] was written.Comment: 156 page

Alat Pemantau Pengendali dan Penyampaian Informasi Status Operasi Mesin secara Otomatis

Perkembangan industri di Indonesia semakin meningkat seiring dengan bertambahnya kebutuhan konsumen akan barang-barang produksi. Hal tersebut mengakibatkan terjadinya persaingan dalam pemenuhan hasil produksi dengan harga yang menarik. Tindakan yang dilakukan produsen dalam USAha untuk pemenuhan kebutuhan pasar pun beragam, salah satunya adalah dengan cara penambahan waktu kerja dari mesin. Namun cara tersebut memiliki kelemahan yang berakibat pada keausan atau bahkan kerusakan mesin. Hal ini tentu sangat merugikan pihak produsen, sehingga dibutuhkan perancangan suatu sistem pemantauan dan pengendali yang dapat mencegah terjadinya kerusakan mesin. Alat ini akan memantau dan mengendalikan suhu dan tegangan kontrol sesuai dengan batasan yang ditentukan. Apabila kondisi yang dinilai dapat merusak mesin, maka alat ini akan segera mematikan mesin dan bersamaan dengan tindakan tersebut juga dikirimkan pesan error ke nomor handphone yang telah ditentukan

Graphs with many valencies and few eigenvalues

Dom de Caen posed the question whether connected graphs with three distinct eigenvalues have at most three distinct valencies. We do not answer this question, but instead construct connected graphs with four and five distinct eigenvalues and arbitrarily many distinct valencies. The graphs with four distinct eigenvalues come from regular two-graphs. As a side result, we characterize the disconnected graphs and the graphs with three distinct eigenvalues in the switching class of a regular two-graph