Main Pool Research Articles

Response of nerica and sativa rice lines to nitrogen and phosphorus rates by number of tillers and shoot biomass yield

An experiment was conducted at the Savanna Agricultural Research Institute on a Euteric Gleisol on latitude 9 - 25 - 41” N longitude O - 58’ 42”W in the Guinea Savanna Zone of West Africa, Ghana. The objective was to establish the responses of the lowland “New Rice for Africa” (NERICA) and Sativa varieties for recommendation of optimum N and P rates. Six lowland NERICAs, three Oryza sativa and one Oryza glaberima lines were used. Number of tillers/m 2 quadrant and shoot dry biomass /15cm 2 was used to evaluate the P/N response of crop performance. For the dry biomass weight, destructive sampling was done at the 50% flowering stage. The Phosphorus and Nitrogen fertilizers rates were 0, 13, 26 kg P/ha and 0, 30, 60, 120 kg N/ha respectively. Potassium was applied at a uniform rate of 30 kg K 2 O/ha to all plots before planting. The average days of 50% flowering and 80 % maturity of all varieties used, counting from seedling emergence, were 73 to 82 days and 104 to 113 days respectively. There were significant differences on the effect of P and N - levels on shoot – biomass/15 cm 2 quadrant ( p< 0.05 ) but number of tillers/ m 2 quadrant were not ( p > 0.05 ). The interaction of P/N fertilizer levels by variety was highly significant ( p < 0.001 ). Increasing N levels increased biomass and tillers more markedly than increasing P - levels. It was noted that P may have been fixed because available Bray 1 P was not appreciably higher in the 26 kg P/ ha plots than 0 kg P/ha. It could have been due to the oxidation of Iron (II) to Iron (III) resulting in insoluble Iron (III) Phosphate complexes or by formation of complex insoluble Aluminium (III) phosphates. Varieties such as V1, V2, V3, V8 and V9 were responsive to lower P and N inputs such as P0/N0 or P0/N30 and also to moderate inputs such as P13/N30, P26/N30 or P13/N60. Varieties such as, V4, V5 and V6 are not responsive to lower inputs but were very responsive to the higher inputs outlined above. Phosphorus and Nitrogen main plots pool for two years at high input rate, (P26/N60 and P26/N120 ), has no significant advantage over the lower ( P0/N0 or P0/N30, P13/N0, P13/N30 ) and moderate combinations, ( P13/N60, P13/120 ) as regards biomass yields ( p .> 0. 05 ).

Effect of wheat (Triticum aestivum L.) rhizosphere and sewage sludge application on zinc desorption with dilute citric acid

Rhizosphere processes have a major impact on Zn desorption and Zn uptake by plant. However, information about Zn desorption characteristics in the rhizosphere of wheat is limited. Therefore, a greenhouse experiment was performed to determine Zn desorption characteristics in the bulk and rhizosphere soil of wheat (Triticum aestivum L.) of 10 soils amended and un-amended with municipal sewage sludge using rhizoboxes. The kinetics of Zn desorption was determined by successive extraction with 10 mM citric acid in a period of 1–504 h at 25 ± 1°C in the bulk and rhizosphere of un-amended and amended soils. The results showed that the Zn amount extracted after 504 h in the rhizosphere soils was significantly (p < 0.01) higher than the bulk soils. The mean of Zn desorption in the bulk and rhizosphere of un-amended soils were 10.4 ± 0.34 and 11.4 ± 0.43 mg kg−1, respectively, while the mean of Zn desorption in the bulk and the rhizosphere of amended soils were 13.2 ± 0.48 and 14.8 ± 0.67 mg kg−1, respectively. Desorption kinetics of Zn conformed fairly well to the first-order, parabolic diffusion, power function, and zero-order equations. The results of Zn fractionation indicated that exchangeable Zn and Zn associated with organic matter decreased and Zn associated with iron-manganese oxides and residual Zn increased in the rhizosphere soils compared to the bulk soils. Zinc desorption after 504 h and residual Zn in the bulk and rhizosphere of un-amended and amended soils were significantly positively correlated (p < 0.05). Therefore, residual Zn was the main Zn pool that controlled Zn desorption after 504 h in the bulk and rhizosphere soils studied.

Postnatal Down-Regulation of the GABAA Receptor γ2 Subunit in Neocortical NG2 Cells Accompanies Synaptic-to-Extrasynaptic Switch in the GABAergic Transmission Mode

NG2 cells, a main pool of glial progenitors, express γ-aminobutyric acid A (GABA(A)) receptors (GABA(A)Rs), the functional and molecular properties of which are largely unknown. We recently reported that transmission between GABAergic interneurons and NG2 cells drastically changes during development of the somatosensory cortex, switching from synaptic to extrasynaptic communication. Since synaptic and extrasynaptic GABA(A)Rs of neurons differ in their subunit composition, we hypothesize that GABA(A)Rs of NG2 cells undergo molecular changes during cortical development accompanying the switch of transmission modes. Single-cell RT-PCR and the effects of zolpidem and α5IA on evoked GABAergic currents reveal the predominance of functional α1- and α5-containing GABA(A)Rs at interneuron-NG2 cell synapses in the second postnatal week, while the α5 expression declines later in development when responses are exclusively extrasynaptic. Importantly, pharmacological and molecular analyses demonstrate that γ2, a subunit contributing to the clustering of GABA(A)Rs at postsynaptic sites in neurons, is down-regulated in NG2 cells in a cell type-specific manner in concomitance with the decline of synaptic activity and the switch of transmission mode. In keeping with the synaptic nature of γ2 in neurons, the down-regulation of this subunit is an important molecular hallmark of the change of transmission modes between interneurons and NG2 cells during development.

Mathematical model for robust control of an irrigation main canal pool

This paper describes the formulation and development of a mathematical model for high-performance robust controller design techniques, based on a complete identification for control procedure, of an irrigation main canal pool (true plant), which is characterized by the exhibition of large variations in its dynamic parameters when the discharge regime changes in the operating range [Qmin, Qmax]. Real-time field data has been used. Four basic steps of the proposed procedure have been defined in which all the stages, from the design of the experiments to the model validation, are considered. This procedure not only delivers a nominal model of the true plant, but also a reliable estimate of its model uncertainty region bounded by the true plant models under minimum and maximum operating discharge regimes (limit operating models). The model uncertainty set, defined by the nominal model and its uncertainty region, is characterized by its being as tight as possible to the true irrigation main canal pool. The obtained results are very promising since this kind of models facilitates the design of robust controllers, which allow improving the operability of irrigation main canal pools and also substantially reduce water losses.

Microbes and global carbon

The amount of organic material that microbes assimilate into their biomass is critical in regulating whether soils, the planet's main pool of organic matter, will absorb or emit carbon in a warmer world.

Direct Evaluation of in Situ Biodegradation in Athabasca Oil Sands Tailings Ponds Using Natural Abundance Radiocarbon

Compound-specific stable (δ(13)C) and radiocarbon (Δ(14)C) isotopes of phospholipid fatty acids (PLFAs) were used to evaluate carbon sources utilized by the active microbial populations in surface sediments from Athabasca oil sands tailings ponds. Algal-specific PLFAs were absent at three of the four sites investigated, and δ(13)CPLFA values were generally within ~3‰ of that reported for oil sands bitumen (~-30‰), suggesting that the microbial communities growing on petroleum constituents were dominated by aerobic heterotrophs. Δ(14)CPLFA values ranged from -906 to -586‰ and pointed to significant uptake of fossil carbon, particularly in PLFAs (e.g., cy17:0 and cy19:0) often associated with petroleum hydrocarbon degrading bacteria. The comparatively heavier Δ(14)C values found in other, less specific PLFAs (e.g., 16:0) indicated the preferential uptake of younger organic matter by the general microbial population. Since the main carbon pools in tailings sediment were essentially "radiocarbon dead" (i.e., Δ(14)C ~ -1000‰), the principal source for this relatively modern carbon is considered to be the Athabasca River, which provides the bulk of the water used in the bitumen extraction process. The preferential utilization of the minor amount of younger and presumably more labile material present in systems otherwise dominated by petroleum carbon has important implications for remediation strategies, since it implies that organic contaminants may persist long after reclamation has begun. Alternatively, this young organic matter could play a vital and necessary role in supporting the microbial utilization of fossil carbon via cometabolism or priming processes.

Population genetics of Mediterranean and Saharan olives: geographic patterns of differentiation and evidence for early generations of admixture

The olive (Olea europaea subsp. europaea) was domesticated in the Mediterranean area but its wild relatives are distributed over three continents, from the Mediterranean basin to South Africa and south-western Asia. Recent studies suggested that this crop originated in the Levant while a secondary diversification occurred in most westward areas. A possible contribution of the Saharan subspecies (subsp. laperrinei) has been highlighted, but the data available were too limited to draw definite conclusions. Here, patterns of genetic differentiation in the Mediterranean and Saharan olives are analysed to test for recent admixture between these taxa. Nuclear microsatellite and plastid DNA (ptDNA) data were compiled from previous studies and completed for a sample of 470 cultivars, 390 wild Mediterranean trees and 270 Saharan olives. A network was reconstructed for the ptDNA haplotypes, while a Bayesian clustering method was applied to identify the main gene pools in the data set and then simulate and test for early generations of admixture between Mediterranean and Saharan olives. Four lineages of ptDNA haplotypes are recognized: three from the Mediterranean basin and one from the Sahara. Only one haplotype, primarily distributed in the Sahara, is shared between laperrinei and europaea. This haplotype is detected once in 'Dhokar', a cultivar from the Maghreb. Nuclear microsatellites show geographic patterns of genetic differentiation in the Mediterranean olive that reflect the primary origins of cultivars in the Levant, and indicate a high genetic differentiation between europaea and laperrinei. No first-generation hybrid between europaea and laperrinei is detected, but recent, reciprocal admixture between Mediterranean and Saharan subspecies is found in a few accessions, including 'Dhokar'. This study reports for the first time admixture between Mediterranean and Saharan olives. Although its contribution remains limited, Laperrine's olive has been involved in the diversification of cultivated olives.

Conservation genetics of Leucadendron argenteum (Silvertree) — A flag ship species of the Cape Peninsula

The Silvertree (Leucadendron argenteum (L.) R.Br.) is an iconic tree to South Africans and tourists alike. This endangered species is endemic to the Cape Peninsula, the most southwestern part of Africa. Despite its visual presence, no population genetic data of L. argenteum are currently available, but such information is crucial for effective conservation management. A historical question is whether the inland populations are natural or planted? This study aimed to reveal the genetic structure and possible differences of L. argenteum populations on the Cape Peninsula and inland at Helderberg, Paarl Mountain and Simonsberg. It was expected that inland populations would exhibit reduced genetic variation due to their isolation from each other and the main Cape Peninsula gene pool. Furthermore, genetic differences between populations were expected to be higher at inland populations because they are further apart from each other, relative to the Peninsula populations. Plant leaf material was collected and AFLP was used to assess the genetic variation. In general, low genetic variation was present within all populations (mean Nei's gene diversity 0.11±0.01) and no significant differences between Peninsula and inland populations were found. Minor differences in molecular variances were found between Peninsula and inland populations (PhiPt=0.11), being double between Peninsula populations (PhiPt=0.08) than between inland populations (PhiPt=0.04). This supports a possible anthropogenic origin of inland populations. Although the genetic variation of populations is very similar, they should not be managed as a single gene pool. Inland populations are more similar to each other compared to the Peninsula ones and therefore might be managed as one genetic entity. In contrast, Peninsula populations show a higher degree of differentiation and should be managed to maintain genetic integrity by minimizing further cross planting.

Management Insights

Management Insights

Partição de substâncias húmicas em solos brasileiros

As substâncias húmicas (SH) representam o principal reservatório de carbono orgânico total do solo (COT) e sua partição entre diferentes frações de solubilidade em meio alcalino ou ácido pode guardar relação com o tipo de solo e manejo adotado. O objetivo deste trabalho foi comparar a partição das SHs, de acordo com profundidade, tipo de solo, bioma e uso do solo no Brasil. Revisou-se a literatura, incluindo teses, dissertações, artigos e resumos em anais de eventos, em busca de dados sobre o teor de COT, sua porcentagem como ácidos húmicos (AH), ácidos fúlvicos (AF) e humina (HU) e a razão AH/AF. Os dados foram estratificados por intervalos comparáveis de profundidades (0-5, 5-10, 0-20, 20-50, 50-100 e &gt;100 cm), biomas (Mata Atlântica, Cerrado, Amazônia, Pampa e Caatinga), ordem de solo (Argissolo, Latossolo, Cambissolo, Planossolo, Neossolo, Gleissolo e Organossolo) e principais usos do solo (florestas nativas, pastagem natural, pastagem plantada, eucalipto, culturas perenes e anuais). Os dados foram analisados por estatística descritiva, correlações de Spearman e análise de componentes principais (ACP). Nos Argissolos, Latossolos e Organossolos, a fração HU contribuiu com metade do COT, tendendo a diminuir em profundidade. Para Latossolos e Organossolos, a fração AF tendeu a aumentar em profundidade. Em Neossolos, a fração AH aumentou em profundidade, embora tenha diminuído em Gleissolos e Planossolos. A razão AH/AF geralmente diminui em profundidade. Pela ACP, não foi possível identificar um padrão de agrupamento das amostras em razão do tipo de bioma e uso do solo, sugerindo que a partição das SHs tem baixo potencial como indicador de efeitos do manejo ou condições ambientais, embora seja útil para discriminar processos de humificação em algumas ordens de solo.

What Are Investors Willing to Pay to Customize Their Investment Product?

Even though buy-and-hold (B&amp;H) investment strategies can take the risk tolerance of an investor into account by specifying a suitable stock proportion, the outcome profiles of B&amp;H strategies are restricted to a specific class of return distributions. For investors with particular risk preferences, further customization should thus provide additional value. The objective of this paper is to investigate the strength of preference for such customized distributions and to draw conclusions about the demand for personalized investment products. In two experimental studies, 256 participants could adjust the return distribution of an initially chosen B&amp;H investment by using an interactive software program. Our main finding is that most investors make extensive use of the customization option and many are willing to pay a substantial fee for this additional flexibility. We further find that the willingness to pay for customization is lower if the fee is integrated into the display of the return distribution, making its impact on final returns more obvious. We also observe that investors can be clustered into distinct subgroups via their adjustment patterns, but individually elicited prospect theory parameters are barely able to explain and predict these adjustments. As a robustness check, we also survey real investors at an investors fair to compare their preferences with those of our main pool of student subjects. We find that the willingness to pay for customization is slightly lower for these real investors and the main effect of fee integration is also less pronounced. In summary, we observe a strong willingness to pay for additional flexibility even though the actual benefits of customization vary markedly according to the individual. In many cases the accepted fees are so high that standard B&amp;H strategies stochastically dominate the customized distributions after fee integration. This paper was accepted by Peter Wakker, decision analysis.

Deep pools of the Danube River: ecological function or turbulent sink?

Danube main channel deep pools are in- stream habitats of high ecological relevance. We used dual-frequency identification sonar to investigate seasonal and diel fish abundance in two hydrodynam- ically different deep pools in the main channel of the Danube River in 2008. In general, fish of different species were present in both deep pools throughout the year, irrespective of water level. High fish abundance was recorded during autumn and winter, low abun- dance during spring and summer. During low dis- charge and low temperature and particularly during low flow velocity, low kinetic energy and low shear stress, high fish abundance in densely packed aggre- gations were observed, a clear indication for the refuge capacity of deep pools. In contrast, during turbulent hydraulic conditions with high flow velocity, high turbulent kinetic energy and high shear stress, low fish abundance occurred, mainly consisting of single fish, small fish shoals and benthic fish specimens. Further- more, we could reveal that calm as well as turbulent pools fulfil the requirements as refuge and feeding habitat of eurytopic, piscivorous catfish throughout the year. The application of a multiple linear model based on the hydrological parameters discharge and water temperature as well as the hydraulic parameters flow velocity, turbulent kinetic energy and shear stress provided highly significant evidence between the observed and the expected seasonal fish abundance in the deep pools (R 2 = 0.77, P \ 0.001). For the first time these results make clear that the main channel deep pools are important refuge and resource habitats of different species of the Danube fish community. Deep pools are key habitats for the in-stream fish community of the Danube River.

Architect Sinan's Kırkçeşme water supply system outside the city of Istanbul and city network

The city of Istanbul has important water system remnants from old civilizations among which water line systems begun with Byzantine period and continued during Ottoman era, including Kırkçeşme water supply system. The original gallery structure within the Kırkçeşme system has been altered with time at some places as a result of necessary planning activities, restoration and repair works. All these activities helped to keep almost the system originality. Since its first opening in 1564, its discharge increased steadily as a result of additional drainage feeding line connections to the main gallery. However, through time only a couple of the 570 additional lines have remained in operation. Although other similar establishments have perished in time without leaving even traces, the Kırkçeşme system is its vivid and harmonious appearance in front of eyes even today. Four dams were constructed at the most convenient locations along the water supply lines from 1620 to 1818. The water from the streams was collected during the rainy season and discharged to the city at times of need with increasing capacity. In general, the Kırkçeşme system has two branches: one extends towards the east, which seemed to have more water, due to its feedback from the Kirazlı, Topuz and Paşa tributaries of the Kağıthane stream; the other branch is westwards which is fed by the Ayvad Deresi, Orta Dere and Bakraç Dere tributaries of the Kağıthane stream. All the water are brought together at Başhavuz (main pool) south of Kemerburgaz, where they collectively enter the main supply line crossing the Alibey Stream over the Mağlova Aqueduct, and then joining a branch from the Cebeciköy Stream and finally flow in towards the south. In a historical document called Tezkiret'ül Bünyan, (The Book of Structures) the author states that Sinan pledged to the Sultan about the existence of some old waterways. However, the Roman waterway still remains in the vicinity of Cebeciköy, which is located at a higher elevation than the Kırkçeşme water supply line but ran parallel to it. The water supply system should have integrated perspective for operation and maintenances. On the other hand, standing structures give to humanity the impression that the stability and design carry not only water, but also valuable cultural heritage. Moreover, they connect many civilizations with each other and also past as well as future.

Genetic and morphological characterization of chestnut (Castanea sativa Mill.) germplasm in Piedmont (north-western Italy)

Castanea sativa Mill. is an important multipurpose tree species for north-western Italy, and specially for Piedmont Region. The preservation of its germplasm from the genetic erosion due to the changes in socio-economic structure of rural areas and specific pathogen attacks is critical. The principal aims of this work were to characterize the chestnut germplasm grown in Piedmont and investigate its genetic structure. Sixty-eight grafted chestnut trees were evaluated using 10 SSRs (simple sequence repeats) loci and 20 morphological descriptors. Thirty-six different genotypes were identified; the analysis of the genetic structure of this germplasm revealed that four gene pools contributed to the formation of the population sampled. In general, cultivars tended to group into a main gene pool on the basis of their prevalent use and growing area. These results are substantially in agreement with those of the cluster analysis that was carried out to estimate the genetic relationships among the cultivars. Morphological analyses showed large variation of traits among the individuals, related with the market destination of the nuts and useful for cultivar and clonal selection. Discriminant analysis was applied to find a correlation between genetic and morphological data: nut and leaf shape, nut hairiness and male flower type resulted to be the most discriminant traits associated with the genetic structure. In the end, this work clarified the genetic structure of the cultivated germplasm in Piedmont describing the main cultivars of the region, giving useful information for conservation and breeding purposes.

An M&lt;SUP align="right"&gt;x&lt;/SUP&gt;/G/1 retrial queue with two phase service under active server breakdowns, two types of repair and multiple vacations with N-policy

This paper analyses a single server batch arrival retrial queue with active breakdowns, two types of repair, a second optional service and multiple vacations with N-policy. The server may breakdown while providing first essential service. When the server fails, it is repaired immediately. On successful completion of first essential service, the customer may opt for second optional service with probability α. At a service completion epoch, without any request for re-service and the orbit size being zero, the server does a secondary job (vacation) repeatedly until the number of customers in the orbit reaches the threshold value N. At a secondary job completion epoch, if the orbit size in at least N, then the server remains in the system to render service for customers from main pool or from retrial group. The steady state queue size distribution of number of customers in the orbit and expected number of customers in the retrial group are obtained. Some particular cases and reliability measures are discussed. Also, some performance measures are obtained. Numerical illustrations are also provided.

A Freshwater Lake Saga: Carbon Routing Within the Aquatic Food Web of Lake Schwerin

Recently, several case studies have demonstrated the presence of human radiocarbon dietary reservoir effects in inland contexts. Freshwater reservoir effects present a high degree of variability, making it difficult to define local reservoir effect reference values necessary for correcting chronologies based on 14C dating of human bone material. Here, we investigate the hypothesis that 14C ages of edible freshwater species are delimited by the 14C ages of the main water carbon pools (DIC, POC, and DOC).Water, plant, algae, bivalve, and fish samples were collected from lakes Schwerin and Ostorf (Germany). 14C and isotopic measurements were performed on the floral and faunal species and on water DIC, POC, and DOC. The results demonstrate the potential of the study area for large and variable freshwater reservoir effects. In the case of Lake Schwerin, the working hypothesis was verified as the 14C ages of faunal and floral species were delimited by the 14C ages of water DIC and POC, probably associated with 2 extreme categories of food chains (grazing and detritus). While the results obtained confirm the working hypothesis and suggest a relatively straightforward interpretation, further research is necessary to investigate possible spatial and seasonal variations.

Analysis of efforts to maintain safe donor in main donor pool after completion of temporary deferral period

Background:Voluntary blood donation is not satisfactory all over India. In India, about 55% of donation is through voluntary non-remunerated blood donors (VNRBD). However, about one third already motivated blood donors are deferred due to stringent screening criteria, either temporarily or permanently. The temporarily deferred donors could be a good source of blood donation after deferral period.Aims:The present study is carried out to know retrieval of blood donors those who are deferred temporarily.Design:The present study is carried out in the Regional Blood Transfusion Centre of Western India. All donors screened as per the guideline and deferred donors are categorized as temporary and permanently deferred donors.Materials and Methods:From temporarily deferred donors, reason for deferral is considered. As per reason of deferral, time duration for recalling the donor is defined. Based on this, donor is called back to donate again.Statistical Analysis:Chi-square test is applied.Result:A total of 33% donors were deferred either temporarily or permanently. In the repeat donors (5.32%) deferral rate was significantly higher than first time (1.32%) donors. Significant female preponderance was observed (15.05% vs 2.51%). Majority of temporarily deferred donors were less than 40 years of age (80.80%), graduate (82.90%), from low income group (62.90%) and profession was service (48.10%).Conclusion:Low hemoglobin (78.30%) was the most common reason of temporary deferral, both in first time and repeat donors (71.00%). Efforts to increase the hemoglobin in the repeat donors will improve the donor retention and overall blood safety can be increased.

A Freshwater Lake Saga: Carbon Routing Within the Aquatic Food Web of Lake Schwerin

Recently, several case studies have demonstrated the presence of human radiocarbon dietary reservoir effects in inland contexts. Freshwater reservoir effects present a high degree of variability, making it difficult to define local reservoir effect reference values necessary for correcting chronologies based on 14C dating of human bone material. Here, we investigate the hypothesis that 14C ages of edible freshwater species are delimited by the 14C ages of the main water carbon pools (DIC, POC, and DOC).Water, plant, algae, bivalve, and fish samples were collected from lakes Schwerin and Ostorf (Germany). 14C and isotopic measurements were performed on the floral and faunal species and on water DIC, POC, and DOC. The results demonstrate the potential of the study area for large and variable freshwater reservoir effects. In the case of Lake Schwerin, the working hypothesis was verified as the 14C ages of faunal and floral species were delimited by the 14C ages of water DIC and POC, probably associated with 2 extreme categories of food chains (grazing and detritus). While the results obtained confirm the working hypothesis and suggest a relatively straightforward interpretation, further research is necessary to investigate possible spatial and seasonal variations.

Dynamics and partitioning of the ionome in seeds and germinating seedlings of winter oilseed rape

Germination and seedling establishment are among the most critical phases in the development of plants, and seed vigour has become an important trait for the selection of robust crop cultivars. Little is known about the potentially limiting role of mineral nutrients in early metabolic and developmental processes during germination. Therefore, we assessed the ionome and relative distribution of mineral elements in different seed and seedling tissues of oilseed rape (Brassica napus L.) and monitored the internal allocation of nutrients during germination. In seeds, cotyledons harboured the main pool of K, P, S, Mg, Fe, Mn and Zn, whereas the seed coat contained most of the Ca, Na, B, Cu and Mo. Although the early root and hypocotyl tissue expanded first, concentrations of most elements were initially low. Re-allocation of elements to the root/hypocotyl tissue from other pools set in two days after seed imbibition and was most rapid for K. Relative to the critical deficiency levels of vegetative tissues, seed tissues were particularly low in B, K and Fe. Further analyses of the ionome of seeds and seedlings, grouped according to their germination efficiency, indicated that in particular low S, Mg and Ca coincided with germination failure. This study documents highly dynamic changes in the ionome of seed and seedling tissues and provides evidence for potentially limiting elements during early germination and seedling establishment in rapeseed.

The biomass quality of algae used for CO2 sequestration is highly species-specific and may vary over time

The utilization of microalgae to temporarily sequester CO2 is a hot topic in algal biotechnology. Its association with biomass utilization is often proposed to increase economical revenues. Although C allocation patterns may determine the success or failure of such use of algae, the impact of elevated CO2 on biomass quality has not been investigated systematically. In this study, four algae of different taxonomy and mode of inorganic carbon acquisition were subjected to a transition from low (390 μL L−1) to elevated (1,000 μL L−1) pCO2. Fourier transform infrared spectroscopy, a rapid, nonextractive, and reliable technique, was used to attain the necessary information on all main organic pools concomitantly and with no need for extractive procedures. Cell organic composition was analyzed after 24 hours and 20 days since the transition. The responses were very species-specific, and the biomass quality was modified over time, indicating that species selection and monitoring of biomass are essential for an adequate control on the quality of the product. Although these concepts may have been in the mind of the illuminated algae users, the experimental evidence is essentially nonexisting. We intended to make a first step towards filling this gap in knowledge.