Nutrient Supply and Primary Production in Clear Lake, Eastern Ontario

1970 ◽  
Vol 27 (11) ◽  
pp. 2009-2036 ◽  
Author(s):  
D. W. Schindler ◽  
J. E. Nighswander
Keyword(s):  
Standing Crop ◽  
Nutrient Supply ◽  
Canadian Shield ◽  
Clear Lake ◽  
Nitrogen And Phosphorus ◽  
Sodium Potassium ◽  
Production Values ◽  
Filtration Error ◽  
High Production ◽  
Calcium And Magnesium

Clear Lake, a small Canadian Shield lake that has been influenced little by human activity, was found to be more productive than expected from chemical and optical properties and geological surroundings. Production during the ice-free season ranged from 0.10 to 2.57 g C/m2 per day and averaged 250 g C/m2 per year for the lake as a whole. Other limnological factors studied (phytoplankton standing crop, oxygen, temperature, and nutrient regimes) were typical for an oligotrophic lake.The high production values are partially explained by the high correction for filtration error, which averaged 3.2 times for all occasions tested.Atmospheric precipitation is undoubtedly the major source of supply of the nutrients nitrogen and phosphorus to Clear Lake. Calcium and magnesium also appear to be largely carried in by precipitation, although most of the sodium, potassium, and silica entering the lake is weathered from the terrestrial watershed.

Influence of increased nutrient supply on Microcystis aeruginosa at cellular and proteomic levels

2020 ◽  
Vol 85 ◽  
pp. 47-58
Author(s):  
Y Jiang ◽  
Y Liu
Keyword(s):  
Microcystis Aeruginosa ◽  
Regulatory Protein ◽  
Acid Synthesis ◽  
Nutrient Supply ◽  
Nitrogen Supply ◽  
Nitrogen And Phosphorus ◽  
Comprehensive Description ◽  
Amino Acid Synthesis ◽  
High Nutrient ◽  
Proteomic Responses

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

scholarly journals Nutritional factors in milk from Brazilian mothers delivering small for gestational age neonates

1993 ◽  
Vol 27 (6) ◽  
pp. 455-462 ◽  
Author(s):  
Anete S. Grumach ◽  
Solange E.I. Jerônimo ◽  
Marcia Hage ◽  
Magda M.S. Carneiro-Sampaio
Keyword(s):  
Breast Milk ◽  
Low Birthweight ◽  
Total Proteins ◽  
Sodium Potassium ◽  
Nutritional Factors ◽  
High Sodium ◽  
Milk Samples ◽  
Calcium Magnesium ◽  
Preterm Babies ◽  
Calcium And Magnesium

The composition of breast milk from brazilian mothers delivering low birthweight infants and its adequacy as a source of nutrients for this group has not yet been fully elucidated. A total of 209 milk samples from 66 women were analysed. The mothers were divided into three groups: G1, mothers delivering term babies of low birthweight (TSGA, n=16); G2, mothers delivering preterm babies of appropriate birthweight (PTAGA, n=20); G3, mothers delivering term babies of appropriate birthweight (TAGA, n=30). The following factors were analysed: osmolarity, total proteins and protein fractions, creamatocrit, sodium, potassium, calcium and magnesium. Milk samples were collected 48 h and 7, 15, 30 and 60 days after delivery. The groups did not differ significantly in terms of osmolarity, total proteins and fractions, creamatocrit, calcium, magnesium or potassium throughout the study period. Sodium levels were higher in all samples from mothers of TSGA infants and in samples from mothers of PTAGA infants on the 7th, 15th and 30th days than in milk from the TAGA group. The authors consider the needs of the low birthweight and TAGA infants and that these high sodium levels may be necessary for growth of low birthweight infants.

scholarly journals Engines of alternative objectivity: Re-articulating the nature and value of participatory mental health organisations with the Hearing Voices Movement and Stepping Out Theatre Company

2015 ◽  
Vol 22 (3) ◽  
pp. 205-222 ◽  
Author(s):  
Claire Blencowe ◽  
Julian Brigstocke ◽  
Tehseen Noorani
Keyword(s):  
Mental Health ◽  
Material Culture ◽  
Science Studies ◽  
Drama Therapy ◽  
Biomedical Science ◽  
Sociology Of Culture ◽  
Hearing Voices ◽  
Production Values ◽  
Theatre Company ◽  
High Production

Through two case studies, the Hearing Voices Movement and Stepping Out Theatre Company, we demonstrate how successful participatory organisations can be seen as ‘engines of alternative objectivity’ rather than as the subjective other to objective, biomedical science. With the term ‘alternative objectivity’, we point to collectivisations of experience that are different to biomedical science but are nonetheless forms of objectivity. Taking inspiration from feminist theory, science studies and sociology of culture, we argue that participatory mental health organisations generate their own forms of objectivity through novel modes of collectivising experience. The Hearing Voices Movement cultivates an ‘activist science’ that generates an alternative objective knowledge through a commitment to experimentation, controlling, testing, recording and sharing experience. Stepping Out distinguishes itself from drama therapy by cultivating an alternative objective culture through its embrace of high production values, material culture, aesthetic standards. A crucial aspect of participatory practice is overcoming alienation, enabling people to get outside of themselves, encounter material worlds and join forces with others.

Nutrients Within Integrated Bleached Kraft Mills: Sources and Behaviour in Aerated Stabilisation Basins

1999 ◽  
Vol 40 (11-12) ◽  
pp. 77-84 ◽  
Author(s):  
A. H. Slade ◽  
C. M. Nicol ◽  
J. Grigsby
Keyword(s):  
Nitrogen Fixation ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Nutrient Supply ◽  
Point Sources ◽  
Nutrient Requirements ◽  
Nitrogen And Phosphorus ◽  
Nutrient Supplementation ◽  
Nutrient Sources ◽  
Kraft Mill

As constraints on the discharge of nitrogen and phosphorus from the pulp and paper industry become tighter, a thorough knowledge of nutrient sources, and their behaviour through treatment systems, is required. Once nutrient behaviour has been characterised, strategies to minimise discharge can be formulated. A survey of nutrient sources around a modern ECF integrated bleached kraft mill showed that point sources of nitrogen and phosphorus could be identified. Approximately 40% of the nitrogen was contained in the foul condensate stream and 40% of the phosphorus contained in the acid stage of bleaching. Three Aerated Stabilisation Basin treatment systems were studied, two of which were nutrient limited in terms of theoretical nutrient requirements. All three systems achieved approximately 90% BOD removal without nutrient supplementation. For the wastewater with a high BOD:N ratio (100:0.8), nitrogen fixation was shown to be important. Benthic recycling was a more important mechanism when the BOD:N ratio was lower (100:2.1). For a severely phosphorus limited wastewater (BOD:P 100:0.04), treated in a system with a long retention time (85 d), benthic recycling was the predominant mechanism for nutrient supply. The relative roles of nitrogen fixation and benthic feed back to the nitrogen cycle in aerated stabilisation basins are discussed.

Rapid atomic spectrometric determination of sodium, potassium, calcium and magnesium in powdered milk by direct dispersion

The Analyst ◽  
1986 ◽  
Vol 111 (12) ◽  
pp. 1375 ◽  
Author(s):  
Miguel de la Guardia ◽  
Amparo Salvador ◽  
Pilar Bayarri ◽  
Rosaura Farre
Keyword(s):  
Powdered Milk ◽  
Sodium Potassium ◽  
Calcium And Magnesium

Water, nitrogen and phosphorus use efficiencies of four tree species in response to variable water and nutrient supply

2016 ◽  
Vol 406 (1-2) ◽  
pp. 187-199 ◽  
Author(s):  
Feike A. Dijkstra ◽  
Yolima Carrillo ◽  
Michael J. Aspinwall ◽  
Chelsea Maier ◽  
Alberto Canarini ◽  
...  
Keyword(s):  
Tree Species ◽  
Nutrient Supply ◽  
Nitrogen And Phosphorus ◽  
Variable Water
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