GROWTH AND SURVIVAL OF BACTERIA IN PEAT: II. PEAT PELLETS

1947 ◽  
Vol 25c (1) ◽  
pp. 14-21 ◽  
Author(s):  
A. G. Lochhead ◽  
R. H. Thexton
Keyword(s):  
Absorptive Capacity ◽  
Buffering Capacity ◽  
Growth And Survival ◽  
Test Organisms ◽  
Humified Peat

Pellets prepared from spongy, unhumified peat, were found to be well suited to the growth of the test organisms and were superior to pellets made from compressed, well humified peat. Sterilization had the effect of lowering somewhat the absorptive capacity of the spongy pellets and increased the buffering capacity. Neutralization was essential for sterilized pellets in maintaining viable organisms, though it was much less important with unsterilized peat. In contrast to powdered, humified peat, pellets of spongy peat showed to best advantage when allowed to become air-dry immediately following inoculation. In pellets subjected to immediate desiccation, the test organisms attained a much greater development, and were maintained in greater numbers than in peat kept moist or when desiccation was delayed.

Analysis, prevalence and impact of microplastics in freshwater and estuarine environments: an evidence review

2020 ◽  
Author(s):  
John Iwan Jones ◽  
John Francis Murphy ◽  
Amanda Arnold ◽  
James Laurence Pretty ◽  
Kate Spencer ◽  
...  
Keyword(s):  
Sublethal Effects ◽  
Field Studies ◽  
Threshold Concentration ◽  
Taxonomic Group ◽  
Lethal Effects ◽  
Growth And Survival ◽  
Test Organisms ◽  
Evidence Review ◽  
The Mean ◽  
Size Of Particles

<p>We used the systematic review procedure to assess the evidence available on the analysis, prevalence and impact of microplastics in freshwater and estuarine environments. As the study of microplastics in freshwaters is relatively new, measurement methods are yet to be standardized, and a wide variety of methods of variable robustness have been used. Critically, the sampling methodology used in the literature had a systematic influence on the concentration of microplastic particles returned. The volume of water sampled varied over many orders of magnitude, and there was a direct relationship between the size of the smallest particles studied and the volume of water sampled in both freshwater and estuaries: large volumes of water can only be sampled using nets of relatively coarse mesh, which in turn do not capture smaller particles. Consequently, the mean abundance of microplastic particles reported was inversely correlated with both the volume of water sampled and the size of particles studied.</p><p>The size of microplastic particles had a substantial and overriding effect on threshold concentrations above which microplastics affect freshwater and estuarine biota. For the ecotoxicological endpoints of feeding, behaviour, growth and survival there was a clear relationship between the size of the particles used in the test and the threshold concentration at which an effect was seen. Although the taxonomic coverage of test organisms was limited, there were sufficient data to test the influence of taxonomic group used on size-specific thresholds for Crustacea, fish and algae. There was no significant effect of either the endpoint measured or the taxonomic group used, suggesting that there might not be any difference in sensitivity among different taxa.</p><p>In order to establish a threshold concentration where microplastics present a hazard to a limited number of taxa, quantile regression was used to determine the size-specific concentration of microplastics that was lower than 90% of the thresholds identified for survival and, as a more conservative limit, across all endpoints tested including sublethal effects. By comparing these thresholds with the data on concentrations of microplastics reported by field studies, it was apparent that the calculated size specific threshold concentration for lethal effects was considerably higher than 99% of reported environmental concentrations. Lethal effects of microplastics on freshwater and estuarine biota are likely to be limited to exceptional circumstances. Over certain size ranges the calculated size specific threshold concentration for sublethal effects was exceeded by the highest 10% of concentrations reported from environmental samples, suggesting that there is a risk of sublethal effects in a small proportion of sites.</p><p> </p>

INNOVATION CAPABILITY, ABSORPTIVE CAPACITY AND SMES PERFORMANCE IN PAKISTAN: THE MODERATING EFFECT OF BUSINESS STRATEGY

2018 ◽  
Vol 13 (Number 2) ◽  
pp. 1-11
Author(s):  
Muhammad Zulqarnain Arshad ◽  
Darwina Arshad
Keyword(s):  
Economic Growth ◽  
Absorptive Capacity ◽  
Business Strategy ◽  
Innovation Capability ◽  
Research Directions ◽  
Conceptual Paper ◽  
And Performance ◽  
New Research ◽  
The Relationship ◽  
Crucial Part

The small and medium-sized enterprises (SMEs) play a crucial part in county’s economic growth and a key contributor in country’s GDP. In Pakistan SMEs hold about 90 percent of the total businesses. The performance of SMEs depends upon many factors. The main aim for the research is to examine the relationship between Innovation Capability, Absorptive Capacity and Performance of SMEs in Pakistan. This conceptual paper also extends to the vague revelation on Business Strategy in which act as a moderator between Innovation Capability, Absorptive Capacity and SMEs Performance. Conclusively, this study proposes a new research directions and hypotheses development to examine the relationship among the variables in Pakistan’s SMEs context.

PREFERENSI PENEMPELAN, PERTUMBUHAN, DAN SINTASAN LARVA TERIPANG PASIR, Holothuria scabra PADA SUBSTRAT LAMUN YANG BERBEDA

2017 ◽  
Vol 11 (3) ◽  
pp. 249
Author(s):  
Lisa Fajar Indriana ◽  
Yuli Afrianti ◽  
Sitti Hilyana ◽  
Muhammad Firdaus Firdaus
Keyword(s):  
Survival Rate ◽  
Economic Value ◽  
Growth And Survival ◽  
Holothuria Scabra ◽  
Enhalus Acoroides ◽  
Randomized Design ◽  
Settlement Substrate ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Cymodocea Serrulata

Teripang pasir, Holothuria scabra merupakan komoditas hasil laut yang bernilai ekonomis tinggi. Penangkapan berlebihan stok di alam mendorong berkembangnya kegiatan budidaya. Penempelan merupakan fase kritis pada larva teripang karena terjadi peralihan sifat planktonis ke bentik yang memerlukan substrat. Penelitian ini bertujuan untuk mengetahui preferensi penempelan, pertumbuhan, dan sintasan larva H. scabra fase penempelan pada substrat lamun yang berbeda. Penelitian menggunakan metode rancangan acak lengkap dengan perlakuan empat jenis daun lamun berbeda dan lima ulangan. Perlakuan terdiri atas Enhalus acoroides (L-1), Syringodium isoetifolium (L-2), Cymodocea serrulata (L-3), dan Cymodocea rotundata (L-4). Jumlah awal larva sebanyak 1.000 individu dan substrat dirangkai dengan luasan yang sama sebesar 12 cm x 17 cm untuk setiap unit penelitian. Hasil penelitian menunjukkan jenis lamun yang digunakan sebagai substrat berpengaruh secara nyata terhadap preferensi penempelan dan sintasan larva teripang pasir, namun tidak berpengaruh terhadap pertumbuhan. E. acoroides menunjukkan hasil terbaik dengan preferensi penempelan 0,26 ind. cm-2 dan sintasan 10,66%; sehingga layak digunakan sebagai substrat penempelan dalam pembenihan teripang pasir, H. scabra.Holothuria scabra larvae on different seagrass substrates. By: Lisa Fajar Indriana, Yuli Afrianti, Sitti Hilyana, and Muhammad FirdausSandfish Holothuria scabra is marine commodities with a high economic value. Overfishing of natural stocks has compelled an interest to begin aquaculture practice. Settlement is a critical phase for the planktonic larvae as they will transform to benthic form in the presence of substrate. This study aims to evaluate the settlement preferences, growth, and survival rate of H. scabra larvae settled on different seagrass leaves. The research was conducted using the Completely randomized design with four different species of seagrass leaves and five replications. The treatments consist of Enhalus acoroides (L-1), Syringodium isoetifolium (L-2), Cymodocea serrulata (L-3), and Cymodocea rotundata (L-4). Initial number of larvae was 1,000 individuals and the substrate was set with same widthof 12 cm x 17 cm for each unit. Results of the experiment indicated that settlement preference and survival rate of H. scabra larvae was significantly affected by seagrass used as substrate while no significantly differences was observed for growth of larvae. E. acoroides showed the best result with 0.26 ind. cm-2 settelement preference and 10.66% survival rate, so that suitable to be used as settlement substrate in H. scabra hatchery.

ICT SMEs, Performance, Absorptive Capacity and Transformative Capacity

2019 ◽  
Vol 118 (3) ◽  
pp. 178-188
Author(s):  
Yeon-Sung Cho ◽  
Kyung-Il Khoe
Keyword(s):  
Firm Performance ◽  
Market Orientation ◽  
Empirical Analysis ◽  
Absorptive Capacity ◽  
Latent Variables ◽  
Equation Modeling ◽  
Transformative Capacity ◽  
The Impact ◽  
The Empirical Analysis ◽  
Innovative Capacity

This study intends to integrate the relationship of market orientation, innovative capacity and firm performance to Information and Communication Technology(ICT) SMEs. The purpose of this study is to identify the role of absorptive capacity and transformative capacity that affect the performance of ICT SMEs. Hypotheses were established between five latent variables. A total of six hypotheses were established including the moderated effects of absorptive capacity and transformative capacity. Of the data collected after the survey, 112 valid surveys were selected as the final sample, except for 17 questionnaires with high non - response and insincere response. The empirical analysis of this study used smartpls3.0, Partial Least Squares (PLS), a variance-based structural equation modeling. The empirical analysis of this study revealed that the impact of market orientation on innovative capacity was significant. Moreover, the innovative capacity had a positive effect on the performance of ICT SMEs. In addition, the absorptive activity had a positive moderated effect between the market orientation and the innovative capacity. On the other hand, the transformative capacity showed a positive moderated effect in relation to innovative capacity and firm performance. Our empirical results have demonstrated the importance of knowledge based capacity in the ICT SMEs.

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