Spawning substrata are important for breeding habitat selection but do not determine premating reproductive isolation in three sympatric Hexagrammos species

Habitat use and spawning substrata were surveyed to characterize the contribution of habitat divergence to reproductive isolation in greenling Hexagrammos species. The spawning substrata and microhabitat in breeding territories differed amongst the three Hexagrammos species studied: H. octogrammus, H. agrammus and H. otakii used small red algae, surfgrass and bryozoans, respectively, as spawning substrata, and breeding territories were established in areas where those substrata were abundant. In contrast, non-territorial individuals were observed in a comparatively wider range of habitats than conspecific territories. Consequently, the distributions of non-territorial individuals of the three species partially overlapped. Since hybrids have been frequently collected, the difference in spawning substrata and the subsequent microhabitat divergence in breeding territories do not prevent females from encountering males of other species. Thus, in addition to habitat divergence, other factors such as behavioural differentiation may be needed to complete premating reproductive isolation amongst these three Hexagrammos species.     

Byssus attachment strength of two mytilids in mono-specific and mixed-species mussel beds

The mussel Xenostrobus securis is endemic to the brackish waters of New Zealand and Australia, but has successfully invaded the inner Galician Rías of NW Spain, where it coexists with the indigenous mussel Mytilus galloprovincialis. In this laboratory study, the plasticity of the byssus attachment strength of two mytilids was compared by manipulating substratum, salinity, and bed assembly. M. galloprovincialis showed stronger byssus detachment strength than X. securis, despite lower byssus coverage. Both species responded similarly to the substratum, with substantially lower byssus strength on methacrylate, which offered the lowest surface free energy. Byssus detachment values for M. galloprovincialis were lower at lower salinity. In mixed beds, a number of mussels moved upwards, eventually colonising the upper layers of the assemblage. This behaviour increased byssus strength but only for X. securis. X. securis is adapted to a wide spectrum of abiotic conditions, a trait that may promote its dissemination within estuarine environments.     

Examining the bank of microscopic stages in kelps using culturing and barcoding

This paper describes a method to study the diversity of young kelp sporophytes that are recruited from the bank of microscopic stages. Small samples of rocky substratum (0.5 cm²) were collected from the low intertidal zone, which was dominated by the kelp Laminaria digitata. Samples were cultivated in the laboratory under conditions permitting gametogenesis. Sporophyte recruits in the cultures were isolated and identified at the species level using the barcoding mitochondrial marker rpl31–rns. Sixty per cent of the collected samples had at least one to a maximum of 30 kelp recruits, belonging to five different species (L. digitata, L. hyperborea, L. ochroleuca, Saccharina latissima and Sacchorhiza polyschides). As the examination of freshly collected rocky samples under a stereo microscope did not reveal any kelp sporophytes, the recruitment in these samples after culture probably occurred from the bank of microscopic forms present on the substratum. Despite the dominance of L. digitata in the field, the young sporophytes obtained after culturing were mainly S. polyschides. This study illustrates the suitability of culturing in combination with molecular identification of young sporophytes to address several key aspects of kelp ecology related to the existence of a bank of microscopic stages in the field.     

Timing matters: species‐specific interactions between spawning time,substrate quality,and recruitment success in three salmonid species

Substratum quality and oxygen supply to the interstitial zone are crucial for the reproductive success of salmonid fishes. At present, degradation of spawning grounds due to fine sediment deposition and colmation are recognized as main factors for reproductive failure. In addition, changes in water temperatures due to climate change, damming, and cooling water inlets are predicted to reduce hatching success. We tested the hypothesis that the biological effects of habitat degradation depend strongly on the species‐specific spawning seasons and life‐history strategies (e.g., fall‐ vs. spring‐spawners, migratory vs. resident species) and assessed temperature as an important species‐specific factor for hatching success within river substratum. We studied the species‐specific differences in their responses to such disturbances using egg‐to‐fry survival of Danube Salmon (Hucho hucho), resident brown trout (Salmo trutta fario), and migratory brown trout (Salmo trutta lacustris) as biological endpoint. The egg incubation and hatching success of the salmonids and their dependence on temperature and stream substratum quality were compared. Hatching rates of Danube salmon were lower than of brown trout, probably due to higher oxygen demands and increased interstitial respiration in spring. Increases in maximum water temperature reduced hatching rates of resident and migratory brown trout (both fall‐spawners) but were positively correlated with hatching rates of Danube salmon (a spring‐spawner). Significantly longer incubation periods of resident and migratory brown trout coincided with relatively low stream substratum quality at the end of the egg incubation. Danube salmon seem to avoid low oxygen concentrations in the hyporheic zone by faster egg development favored by higher water temperatures. Consequently, the prediction of effects of temperature changes and altered stream substratum properties on gravel‐spawning fishes and biological communities should consider the observed species‐specific variances in life‐history strategies to increase conservation success.     

Effectiveness of Rice Agricultural Waste,Microbes and Wetland Plants in the Removal of Reactive Black-5 Azo Dye in Microcosm Constructed Wetlands

Azo dyes are commonly generated as effluent pollutants by dye using industries, causing contamination of surface and ground water. Various strategies are employed to treat such wastewater; however, a multi-faceted treatment strategy could be more effective for complete removal of azo dyes from industrial effluent than any single treatment. In the present study, rice husk material was used as a substratum in two constructed wetlands (CWs) and augmented with microorganisms in the presence of wetland plants to effectively treat dye-polluted water. To evaluate the efficiency of each process the study was divided into three levels, i.e., adsorption of dye onto the substratum, phytoremediation within the CW and then bioremediation along with the previous two processes in the augmented CW. The adsorption process was helpful in removing 50% dye in presence of rice husk while 80% in presence of rice husk biocahr. Augmentation of microorganisms in CW systems has improved dye removal efficiency to 90%. Similarly presence of microorganisms enhanced removal of total nitrogen (68% 0 and Total phosphorus (75%). A significant improvement in plant growth was also observed by measuring plant height, number of leaves and leave area. These findings suggest the use of agricultural waste as part of a CW substratum can provide enhanced removal of textile dyes.     

Effects of seat surface inclination on respiration and speech production in children with spastic cerebral palsy

Background

Respiratory and speech problems are commonly observed in children with cerebral palsy (CP). The purpose of this study was to identify if inclination of seat surface could influence respiratory ability and speech production in children with spastic diplegic CP.

Methods

Sixteen children with spastic diplegic CP, ages 6 to 12 years old, participated in this study. The subjects’ respiratory ability (forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), peak expiratory flow (PEF), and maximum phonation time (MPT)) were measured in three sitting conditions: a seat surface inclined 0°, anterior 15°, and posterior 15°.

Results

FVC was significantly different across three inclinations of seat surface, F(2, 45) = 3.81, P = 0.03. In particular, the subjects’ FVC at a seat surface inclined anterior 15° was significantly greater than at a seat surface inclined posterior 15° (P < 0.05). However, FEV1, PEF, and MPT were not significantly affected by seat surface inclination (P > 0.05).

Conclusions

The results suggest that anterior inclination of seat surface may provide a positive effect on respiratory function in children with spastic diplegic CP.     

The response of a tropical estuarine gastropod,Cerithidea cingulata (Gmelin), to different types of substrata

The behavioural reaction of a tropical estuarine gastropod, Cerithidea cingulata (Gmelin), to different types of substrata was investigated by subjecting the snails to different mixtures of natural sediment. In addition the organic matter in the sediments was estimated, and an attempt has also been made to relate these results to the distribution of snails in the field.     

Anatomical changes in the structure of the temporomandibular joint caused by complete edentulousness

doi: 10.1111/j.1741‐2358.2011.00498.x
Anatomical changes in the structure of the temporomandibular joint caused by complete edentulousness Background: The posterior slope of the articular eminence of completely edentulous patients compared to patients with maintained occlusion shows significant flattening. Objective: The aim of this present study was to reveal a possible correlation between edentulousness and the flattening of the eminence and to find out whether this deformation is connected to age. Material and methods: Thirty patients were examined in three groups, each consisting of 10 persons (group I: 18‐ to 25‐year‐old patients with maintained occlusion, group II: patients over 60 with maintained occlusion, group III: edentulous patients over 60). The three groups were compared according to dental status, age, sex and side. Measurements were carried out on orthopantomographic images taken with Kodak 8000 Digital Panoramic System. The angle of the posterior slope of the articular eminence relative to the Frankfort plane was measured on both sides. Data were analysed statistically with the one‐way anova test (α = 0.05). Results: The highest values were measured in group I (right side: 39.8 ± 5.4°, left side: 43.0 ± 5.9°), values were somewhat lower in group II (right side: 38.9 ± 4.7°, left side: 39.5 ± 7.4°) and were the lowest in group III, which was significantly lower on both sides than the results of group I and group II (right side: 29.8 ± 6.0°, left side: 31.9 ± 5.2°, p < 0.01). The correlation coefficient between age and the flattening of the eminence in group I, II and III was 0.23, 0.35 and 0.92, respectively. Conclusion: The flattening of the articular eminence could be correlated with age; however, the rate of deformation is significantly higher in completely edentulous patients than in patients with maintained occlusion.     

Structure–Activity Studies of Brassinosteroids and the Search for Novel Analogues and Mimetics with Improved Bioactivity

A number of novel brassinosteroid analogues were synthesized and subjected to the rice leaf lamina inclination bioassay. Modified B-ring analogues included lactam, thiolactone, cyclic ether, ketone, hydroxyl, and exocyclic methylene derivatives of brassinolide. Those derivatives containing polar functional groups retained considerable bioactivity, whereas the exocyclic methylene compounds were devoid of activity. Analogues containing normal alkyl and cycloalkyl substituents at C-24 (in place of the isopropyl group of brassinolide) showed an inverse relationship between activity and chain length or ring size, respectively. The corresponding cyclopropyl and cyclobutyl derivatives were significantly more active than brassinolide and appear to be the most potent brassinosteroids reported to date. When synergized with the auxin indole-3-acetic acid (IAA), their bioactivity can be further enhanced by 1–2 orders of magnitude. The cyclopropyl derivative, when coapplied with the auxin naphthaleneacetic acid, gave a significant increase in yield of wheat in a field trial. Certain 25- and 26-hydroxy derivatives are known metabolites of brassinosteroids. All of the C-25 stereoisomers of 25-hydroxy, 26-hydroxy, and 25,26-dihydroxy derivatives of brassinolide were prepared and shown to be much less active than brassinolide. This indicates that they are likely metabolic deactivation products of the parent phytohormone. A series of methyl ethers of brassinolide was synthesized to block deactivation by glucosylation of the free hydroxyl groups. The most significant finding was that the compound where three of the four hydroxyl groups (at C-3, C-22, and C-23) had been converted to methyl ethers retained substantial bioactivity. This type of modification could, in theory, allow brassinolide or 24-epibrassinolide to resist deactivation and thus offer greater persistence in field applications. A series of nonsteroidal mimetics of brassinolide was designed and synthesized. Two of the mimetics showed significant bioactivity and one had bioactivity comparable to brassinolide, but only when formulated and coapplied with IAA. They thus represent the first nonsteroidal analogues possessing brassinosteroid activity.     

Ecophysiological consequences of non-random leaf orientation in the prairie compass plant,Silphium laciniatum

Summary The prairie compass plant (Silphium laciniatum L.) has vertical leaves that are characteristically oriented in a north-south plane (i.e., the flat surfaces of the lamina face east and west). We explored the consequences of this orientation by determining basic photosynthetic and water use characteristics in response to environmental factors and by determining total daily photosynthesis and water use of leaves held in different orientations. Average maximum CO₂ exchange rate (CER) of leaves near Ames, IA was constant at 22 micromol m^–2 s^–1 from May through August and then declined. CER did not exhibit a distinct lightsaturation point. CER at photon flux densities near full sunlight was constant from 22 to 35°C leaf temperature but declined at higher temperatures. However, leaf temperatures rarely exceed 35°C during the growing season. There was no change in the pattern of response of CER to temperature over the growing season. We constrained leaves to face east-west (EW,=natural), to face north-south (NS), or to be horizontal (HOR) on eight days in 1986–1988. EW leaves had the highest light interception, leaf temperatures, CER, and transpiration early and late in the day, whereas HOR leaves had the highest values in the middle of the day. Integrations of CER and transpiration over the eight daytime periods showed EW and HOR leaves to have equivalent carbon gain, higher than that of NS leaves. HOR leaves had the highest daily transpiration. Daily water use efficiency (WUE, carbon gained/water lost) was always highest in EW leaves, with the HOR leaves having 16% lower WUE and NS leaves having 33% lower WUE. The natural orientation of compass plant leaves results in equivalent or higher carbon gain and in increased WUE when compared to leaves with other possible orientations; this is likely to have a selective advantage in a prairie environment.