Within-tree spatial variation in the leaf monoterpenes of Sequoia sempervirens

Location within a tree was analyzed as a source of variation in Sequoia sempervirens leaf monoterpenes. No differences were found for quantitative composition or total yield/dry wt among lower, middle and upper canopy positions. The awlshaped, spirally arranged leaves of vigorous upper shoots showed small quantitative compositional differences, but not differences in total yield. The intermediate leaf form of young sprouts had the most different monoterpene quantitative composition and about three times the total yield of the above two leaf forms. Analysis of a clonal ring of 17 adult trees resulted in coefficients of variation similar to those for samples collected from different canopy levels of the same shoot. Results revealed the sources and magnitudes of experimental error in comparative studies of this species' leaf monoterpenes, and did not support the concept that somatic mutation provides an important source of variation in a large, long-lived organism such as coast redwood.     

Quantification of polyacrylamide gel bands by digital image processing

A method of quantifying bands on polyacrylamide gels based on image processing of digitized photographic negatives is presented.     

Six-year field test results of micropropagated black cherry (Prunus serotina)

Summary A field test was established in 1987 to evaluate the growth of micropropagated black cherry plantlets and control seedlings. The study also evaluated effects of two container types on initial survival and growth and of pruning on stem form and growth. At the time of field establishment, plantlets had more extensive root systems than the control seedlings. Survival and height growth were not influenced by container size. Through the first three growing seasons, seedlings were larger than micropropagated plants, but growth differences diminished in the fourth through sixth seasons. Pruning increased the length of clear stem by nearly five-fold but adversely affected diameter growth. Although all clones were from ortet trees more than 50 yr old, none showed plagiotropic growth. Six-year results showed that in a well-prepared and maintained plantation, black cherry trees derived from tissue culture can have at least 80% survival, and growth rates in excess of 1 m per year.     

Coding and decoding with dendrites

Since the discovery of complex, voltage dependent mechanisms in the dendrites of multiple neuron types, great effort has been devoted in search of a direct link between dendritic properties and specific neuronal functions. Over the last few years, new experimental techniques have allowed the visualization and probing of dendritic anatomy, plasticity and integrative schemes with unprecedented detail. This vast amount of information has caused a paradigm shift in the study of memory, one of the most important pursuits in Neuroscience, and calls for the development of novel theories and models that will unify the available data according to some basic principles. Traditional models of memory considered neural cells as the fundamental processing units in the brain. Recent studies however are proposing new theories in which memory is not only formed by modifying the synaptic connections between neurons, but also by modifications of intrinsic and anatomical dendritic properties as well as fine tuning of the wiring diagram. In this review paper we present previous studies along with recent findings from our group that support a key role of dendrites in information processing, including the encoding and decoding of new memories, both at the single cell and the network level.     

Intercompany Energy Integration

Reusing heat through process integration in heat exchanger networks has long been a key measure for increasing energy efficiency in energy‐intensive industries. Thermal pinch analysis is commonly used for a systematic matching of process streams and thus planning of optimal process integration in large chemical plants. The possible savings increase with the amount of heat and the number of integrated process streams. Therefore co‐ siting of several companies in a symbiotic network opens new opportunities for process integration even in small and medium‐size enterprises (SMEs), but also introduces new challenges. Thermal pinch analysis is extended here to account for piping distances and fluctuations and limited availability of energy flows by adding additional costs for the piping system and a backup utility system in the optimization function. Cooperative game theory is proposed to derive a sharing of savings between the partners of the industrial symbiosis that is optimal for each partner and should prevent partners from leaving the network because of higher benefits in a subgroup or alone. It is argued that knowledge about the optimality of a network for each partner creates trust between the partners that is a necessary base for the long‐term commitment needed in industrial symbioses. An exemplary symbiotic network combining the production of pulp and woody biomass energy carriers is used to illustrate the proposed approaches.     

Character compatibility of molecular markers to distinguish asexual and sexual reproduction

Particularly in polyploids, the potential of the high variability of dominant markers such as random amplified polymorphic DNA fragments (RAPDs) and amplified fragment length polymorphisms (AFLPs) in population genetic studies and analysis of breeding systems is reduced due to their dominant nature. In contrast, the criterion of character compatibility is hindered neither by dominance nor by polyploidy as allelic interpretation is not necessary. Character compatibility, which can be used to detect events of genetic exchange (or recombination), is particularly informative if these events are expected to be rare such as in taxa with extensive vegetative reproduction or apomixis. Binary unordered characters such as presence and absence of anonymous DNA markers are incompatible if all four pairwise combinations of character states are present among the individuals studied. Because incompatible character state distributions defy any progenitor–derivative relationship among individuals, they provide strong evidence for genetic exchange. Both the absolute number of incompatible character combinations and the probability of compatibility can be used as a measure of incompatibility. Although these measures may not directly relate to the frequency of genetic exchange, they provide a useful tool to heuristically explore data sets. The most commonly used input for multivariate analyses and analysis of molecular variance in population genetic studies of (dis)similarity of marker distributions are amalgamates of mutation and recombination. Character compatibility can be used to complement these traditional methods of analysis. Advantages and disadvantages of character incompatibility relative to multilocus analysis of modes of reproduction and population genetics are demonstrated with data from RAPDs, isozymes, and restriction fragment length polymorphisms (RFLPs) of the nuclear ribosomal and chloroplast genome.     

Cold-induced anesthesia impairs path integration memory in dung beetles

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