Search Results

You are looking at 1 - 10 of 98 items for :

  • Biology and Life Sciences x
  • Refine by Access: All Content x
Clear All

Applegate, Jr. R. W., Squier, J., Vestad, T., David, J. O., Marr, W. M., Bado, P., Dugand, M. A., Saidd, A. A. (2006) Microfluidic sorting system based on optical waveguide integration and diode laser bar

Restricted access
Community Ecology
Authors:
J. Alahuhta
,
J. Rääpysjärvi
,
S. Hellsten
,
M. Kuoppala
, and
J. Aroviita

. Alahuhta , J. , L.B. Johnson , J. Olker and J. Heino . 2014 b. Species sorting determines variation in the community composition of common and rare macrophytes at various spatial extents . Ecol. Complex. 20 : 61 – 68

Restricted access

In this paper, logarithmic functions are described based on which the total diversity of a collection can be partitioned into components specific to factorial effects. The standard statistical modus operandi of testing hypotheses in a factorial design is applied, only the test criteria changed. The factor identities are chosen according to stated hypothesis, observations are made and sorted, the associated entropy and information quantities are calculated, and probabilistic tests of significance are performed regarding main effects and interaction terms. The basics are presented in the main text. The partition functions, their Venn diagram mappings, and a complete printout from the application program DIVPART.EXE are collected in a separate Appendix accessible with this article on the publisher’s website.

Restricted access

This study evaluated the effectiveness of an image sorter to select for kernel color within early generations of segregating hard winter wheat populations. The wheat crosses originated from different combinations of white and red parents. Three generations (F3, F4 and F5) of sorting were applied to six segregating populations. At each generation, samples of whitesorted, red-sorted, and unsorted populations, along with the parents of the populations, were planted in replicated trials at multiple locations. The sorter processed 1kg sized samples in ~30 min and samples were sorted for 108 plots per season. ~10% of the F3 populations were sorted and planted as white-sort population. This resulted in minimal changes in the % of white kernels. ~3% of the F4 and F5 populations were sorted and planted as white-sorted populations and significant advancement occurred. The F6 populations of white-sorted samples from Dakota Lake ranged from 80% to 92% white kernels. The F6 populations from Brookings ranged from 53% to 83% white kernels. Sorting for red seed decreased the frequency of white seed as compared to the unsorted reference populations; however reductions, of white seeds in the red populations, were modest and required three cycles of selection for significant effect. The effectiveness of the image-sorter varied with population and environment and sorting methods.

Restricted access

The fatty acid (FA) composition, especially total trans-fatty acids (TFA) content in 12 assortments of biscuits offered for children, produced by four different companies, were determined by gas chromatography. Total fat content of the biscuit samples ranged from 2.2 to 22.8 g/100 g of product. The major FAs were palmitic C16:0, oleic C18:1, and linoleic C18:2 acids. Depending on the biscuit type, the total saturated fatty acids (SFA) content was between 14.8% and 60%, total monoenoic FA (MUFA) 32.4% and 57.5%, and polyenoic FA (PUFA) 5.8% and 26.8%. The results of the examination of total FA composition of samples have shown a very large variation in the content of TFA in the biscuits produced by different plants. The total FA content ranged from 0.5 to 8.8%. The levels of TFA in studied biscuits offered for children were relatively low by comparison with products from other countries. According to the regulatory approach Danish Veterinary and Food Administration (2003), the levels of TFA in examined samples did not exceed the limited value of 2 g/100 g of product. Furthermore, these contents of TFA are conforming to the requirements under European Union Food Law.

Restricted access

’ 31” N and Longitude 4° 31’ 28” E. The collected sample was sorted into the non-sporophytic gametophytes and the sporophytic gametophytes, carefully washed in different bowls of distilled water without damaging the fragile parts and then air dried at

Restricted access

The paper responds to the question: How should one go about designing the statistical analysis of biodiversity if it had to be done across scales in time and space? The conceptual basis of the design is the definition of biodiversity as a convolution of two community components. One of the components is richness, the product of species evolution, and the other structure, the consequence of environmental sorting (biotic, physical). The method of choice takes information in the manner of frequency distributions, and decomposes the associated total diversity into additive components specific to the deemed sorting factors. Diversity quantities are supplied by the analysis by which the relative importance of sorting factors can be measured and the dynamic oscillations which they generate in diversity can be traced. Examples support the a priori idea that the velocity of compositional change in the community during the late quaternary period has co-varied closely with the specific components of Kolmogorov-type complexity, Anand's structural complexity and Rényi's entropy of order one. The paper explains what is involved and why is it important.

Restricted access

In view of the ongoing rarity of Ecbolium ligustrinum there is an urgent need for conservation of the species. For this, a detailed work was carried out regarding the untold story of its reproductive ecology. The work was done for three consecutive years (2015–2017) at Midnapore, West Bengal over three different populations collected from three different areas of West Bengal. Field data were also recorded from these three wild populations. The species produces gullet flowers with bi-labiate corolla having long slender tubes. The flowers exhibit one day of longevity. The flowers are visited by 10 species of insects. Among those, four species viz. Eristalis tenax, a Dipteran member and three ant species of Hymenoptera such as Camponotus sp., Formica sp. and Monomorium sp. are the effective pollinators. As per pollination efficiency, Eristalis tenax (PE i = 0.76) is the most successful one. The flowers are shortly protandrous (dichogamous) and passed by three distinct reproductive (male, bisexual and female) phases. The breeding system clearly depicts that the species is facultatively xenogamous supported by myophilous mode of pollination. However, geitonogamous type of pollination is also observed through myrmecophily, an atypical instance found in plants. Lastly, the plant retained some sort of autogamy through ‘fail-safe’ mechanism of pollination, an adaptation which might be developed in absence of pollinators. Therefore, undoubtedly it can be concluded that E. ligustrinum is a partially self-incompatible (ISI = 0.27) species having a mixed mating system, adapted for xenogamy through specialised mode of plant-pollinator interactions.

Restricted access

An ecological survey of the benthic communities was carried out, at both spatial and temporal scales, in Papapouli Lagoon, the first ecotouristic park in Greece by applying for the first time, ecological network analysis. The application of ecological network analysis provided novel information on the quality of interactions among species, undetected by the most frequently used methods. The sorting of substrate samples enabled the identification and density determination of 40,036 individuals belonging to 31 different taxa, although, strong dominance of only a few species was observed. “Deposit feeders” were the dominant trophic group in all sampling sites and seasons while “suspension feeders” exhibited relatively the lowest abundance. The periodic opening of the sea inlet seems to be of crucial importance. In coastal lagoons, where there is constant communication with the sea, benthic fauna patterns seem to change according to the sea-land gradient. However, in intermittently closed lagoons, such as Papapouli Lagoon, a more homogenous pattern is evident. The obtained networks showed that when communication with the sea is interrupted all the benthic fauna patterns tend to be destabilized and centralized around one species, which in most cases is a “deposit feeder”. When the inlet opens and communication with the sea is restored, the benthic composition seems to be more cohesive, especially in the most distant regions. Knowledge generated by network analysis should provide a valuable tool in order to assess potential environmental changes and assist management decisions.

Restricted access

Past inability to come to a consensus about the degree of functional redundancy in ecosystems may be due, in part, to different definitions of ecosystem function and different investigative methodologies. Here I define ecosystem function, using the largely plant-based functions of aboveground productivity and decomposition of 10 common early successional trees found in Puerto Rico, and then use two different multivariate techniques to define functional groups. I found that: (1) multivariate statistical methods worked well to sort out the test species on axes defined primarily by productivity, which may have more redundancy than decomposition, and initial leaf nutrient content, (2) there were three plant functional groups defined by species (i) Psychotria berteriana, (ii) Cecropia schreberiana and Inga vera, and (iii) a group containing the other seven species, and (3) the plant traits of nitrogen-fixing capacity and mycorrhizal strategy mapped better onto these groups then those of seed size, wood density, shade tolerance or successional status. Finally, implications for key plant structures and for conservation of Neotropical areas are discussed.

Restricted access