Courtship herding in the fiddler crab <Emphasis Type="Italic">Uca elegans</Emphasis>

Male and female animals are not always complicit during reproduction, giving rise to coercion. One example of a system that is assumed to involve sexual coercion is the mate herding behaviour of fiddler crabs: males push females towards the home burrow with the goal of forcing copulation at the burrow entrance. We recorded and analysed in detail the courtship behaviour of a North Australian species of fiddler crab Uca elegans. Courtship was composed of four main phases: broadcast waving, outward run, herding and at burrow display. During interactions males produced claw-waving displays which were directed posteriorly towards the female and which varied in timing and structure depending on the courtship phase. We suggest that courtship herding in U. elegans is driven primarily by mate choice for the following reasons, (1) females can evade herding, (2) no other reproductive strategies were observed, (3) males broadcast their presence and accompany courtship with conspicuous claw waves, and (4) the behaviour ends with the female leading the male into the home burrow. As an alternative function for herding in U. elegans we suggest that the behaviour represents a form of courtship guiding, in which males direct complicit females to the correct home burrow.     

Scale-dependent effects of windthrow disturbance on forest arthropod communities

The effect of disturbance on local communities may operate within the context of the spatial landscape. We examined the scale-dependent effects of windthrow disturbance caused by a large typhoon on three arthropod communities in a temperate forest of Japan. Canopy arthropods were collected by beating foliage, forest-floor arthropods were collected by sweeping the vegetation, and flying arthropods were collected in Malaise traps. To assess the “functional spatial scale” at which arthropods responded to tree-fall disturbance, the gap rate was quantified at different spatial scales by sequentially enlarging the radius of a circular landscape sector in 10-m increments from 10 to 500 m. We then analyzed the responses of order richness and abundance to the gap rate for each arthropod community. The spatial scale of the significant best-fitting model, which was selected from the models fitted to the gap rate at stepwise spatial scales, was regarded as the arthropod-specific functional spatial scale. Arthropod order richness was not dependent on the gap rate. In contrast, arthropod order abundance depended significantly on the gap rate in many orders, but varied in the response direction and functional spatial scale. These order-specific, scale-dependent responses to tree-fall gaps could complicate interactions among organisms, leading to complex community organization. An understanding of the spatial processes that link the use of space by organisms with the spatial scale at which ecological processes are experienced is required to elucidate the responses of populations, communities, and biotic interactions to disturbances in a spatial landscape context.     

<Emphasis Type="Italic">In vitro</Emphasis> selection and regeneration of chrysanthemum (<Emphasis Type="Italic">Dendranthema grandiflorum</Emphasis> Tzelev) plants resistant to culture filtrate of <Emphasis Type="Italic">Septoria obesa</Emphasis> Syd

Callus cultures derived from leaf segments of chrysanthemum cultivar ‘Snow Ball’ which was susceptible to Septoria obesa were successfully used for in vitro selection for resistance to this pathogenic fungus. Resistant cell lines were selected by culturing callus on growth medium containing various concentrations of S. obesa filtrate. Resistant calluses obtained after two cycles (30 d each cycle) of selection were used for plant regeneration. About 30% of the plants regenerated from the resistant calluses and 70–80% of the plants raised from cuttings had acquired considerable resistance against the pathogen in the field. No phenotypic variation was observed in the selected regenerates.     

Electronic properties of neuroleptics: ionization energies of benzodiazepines

Vertical ionization energies (VIEs) of medazepam, nordazepam and their molecular subunits have been calculated using the electron propagator method in the P3/CEP-31G* approximation. Vertical electron affinities (VEAs) have been obtained with a ∆SCF procedure at the DFT-B3LYP/6-31+G* level of theory. Excellent correlations have been achieved between IE_calc and IE_exp, allowing reliable assignment of the ionization processes. Our proposed assignment differs in many instances from that previously reported in the literature. The electronic structure of the frontier Dyson orbitals shows that the IE and EA values of the benzodiazepines can be modulated by substitution at the benzene rings. Hardness values, evaluated as (IE − EA)/2, follow the trend of the experimental singlet transition energies. Medazepam is a less hard (i.e., less stable) compound than nordazepam.     

Cloning and characterization of a 9-lipoxygenase gene induced by pathogen attack from <Emphasis Type="Italic">Nicotiana benthamiana</Emphasis>for biotechnological application

Background  

Plant lipoxygenases (LOXs) have been proposed to form biologically active compounds both during normal developmental stages such as germination or growth as well as during responses to environmental stress such as wounding or pathogen attack. In our previous study, we found that enzyme activity of endogenous 9-LOX in Nicotiana benthamiana was highly induced by agroinfiltration using a tobacco mosaic virus (TMV) based vector system.     

A wavelet-based ECG delineation algorithm for 32-bit integer online processing

Background  

Since the first well-known electrocardiogram (ECG) delineator based on Wavelet Transform (WT) presented by Li et al. in 1995, a significant research effort has been devoted to the exploitation of this promising method. Its ability to reliably delineate the major waveform components (mono- or bi-phasic P wave, QRS, and mono- or bi-phasic T wave) would make it a suitable candidate for efficient online processing of ambulatory ECG signals. Unfortunately, previous implementations of this method adopt non-linear operators such as root mean square (RMS) or floating point algebra, which are computationally demanding.     

Recovery of photosynthetic capacity in <Emphasis Type="Italic">Vaccinium vitis</Emphasis>-<Emphasis Type="Italic">idaea</Emphasis> during mild spells in winter

Recent studies suggest that evergreen plants may maintain their photosynthetic capacity through the winter. Since mild winters are predicted to be more frequent in the future, the metabolic activity of plants is also likely to increase. The aim of the present study was to assess how various environmental factors, such as temperature, photoperiod and preceding frost, affect the recovery of photosynthesis during a mild spell in winter. The recovery of photosynthesis was studied in a series of growth chamber experiments where the overwintering of lingonberry (Vaccinium vitis-idaea) was interrupted by an intermittent warm spell of 1 week during different phases of winter. Rapid activation was observed in all the experiments during the first 3–4 days. No obvious effects of the phase of winter or photoperiod on the recovery of photosynthesis were observed, but a severe freezing treatment prior to the warm spell retarded the recovery significantly. Once recovered, however, lingonberry was able to maintain high rates of photosynthesis even at near-freezing temperatures, which prevail in their natural sub-nivean environment. The apparent quantum yield of photosynthesis remained high through the winter for lingonberry. This may prove advantageous for evergreen dwarf shrubs which overwinter in dim environments under snow.     

Previously Undescribed Fibrinolysis Inhibitor in Human Blood

HUMAN serum contains several protease inhibitors, one of which is identified as α₁-globulin (α₁-antitrypsin) and another as α₂-macroglobulin. Serum also contains inhibitors against the activation of plasminogen, which may differ from the protease inhibitors. Thus, inhibition of plasminogen activation by urokinase is selectively increased during the last trimester of pregnancy^1,2. Likewise, increased inhibition of streptokinase-activated human euglobulin or of a tissue plasminogen activator was noticed in some groups of patients with thrombotic disease^3,4. This observation is of particular interest because the tissue activator, which is present in venous endothelium⁵, is believed to assist in the removal of fibrinous deposits caused by tissue injury⁶.     

An fMRI Study Exploring the Overlap and Differences between Neural Representations of Physical and Recalled Pain

Implementing a recall paradigm without hypnosis, we use functional MRI (fMRI) to explore and compare nociceptive and centrally-driven pain experiences. We posit that a trace of a recent nociceptive event can be used to create sensory-re-experiencing of pain that can be qualified in terms of intensity and vividness. Fifteen healthy volunteers received three levels of thermal stimuli (warm, low pain and high pain) and subsequently were asked to recall and then rate this experience. Neuroimaging results reveal that recalling a previous sensory experience activates an extensive network of classical pain processing structures except the contralateral posterior insular cortex. Nociceptive-specific activation of this structure and the rated intensity difference between physical and recalled pain events allow us to investigate the link between the quality of the original nociceptive stimulus and the mental trace, as well as the differences between the accompanying neural responses. Additionally, by incorporating the behavioural ratings, we explored which brain regions were separately responsible for generating either an accurate or vivid recall of the physical experience. Together, these observations further our understanding of centrally-mediated pain experiences and pain memory as well as the potential relevance of these factors in the maintenance of chronic pain.