GEOMETRIC MORPHOMETRICS OF THE SKULL ROOF OF STEREOSPONDYLS (AMPHIBIA: TEMNOSPONDYLI)

Abstract:  Geometric morphometric analysis using relative warps is applied to the skull roof of 62 species of stereospondyls and their closest outgroups (i.e. basal archegosauriforms) from among temnospondyl amphibians. Twenty-one landmarks and five taxonomic groups are used for comparisons. Their skull evolution is quantified in a morphospace defined by two relative warps axes. The majority of groups show poor concordance between morphological and phylogenetic distances. The only exception is represented by Yates and Warren's study of stereospondyl relationships, in which concordance is high. Only basal archegosauriforms and rhinesuchids show significant overlap in morphospace, although this might be due to low sample sizes. Regression of estimated mean disparity against taxon sample size shows that species within both the trematosauroid and the rhytidostean groups are more widely dispersed in morphospace than species belonging to any of the remaining stereospondyl groups. Stereospondyl skull evolution was characterized by divergence between major clades and convergence within those clades. Changes in patterns of morphospace occupation through time agree with the hypothesis of an 'explosive' radiation in the early Early Triassic, after the extinction of basal archegosauriforms at the end of the Permian.     

Further Evidence for a Growth-Promoting and Flower-Inhibiting Hormone in Strawberry

Further experiments with runner plants of the cultivated strawberryjoined in pairs as donor/receptor units are reported. Stolonproduction was promoted in receptor plants in short days bylong-day treatment of donor plants. This was a photoperiodiceffect induced by low intensity light. Again, as previously,petiole length was increased and flower induction inhibitedby these, or similar treatments. An attempt to demonstrate thetranslocation and activity of a vegetative-growth-inhibiting,flower-promoting hormone gave negative results. It is argued that the photoperiodic control of the growth habitis mediated mainly by a transmissible vegetative-growth-promotingand flower-inhibiting hormone, which is produced in leaves andacts at the growing regions.     

CONSUMER PERCEPTION OF WHEY AND SOY PROTEIN IN MEAL REPLACEMENT PRODUCTS

ABSTRACT

Meal replacement products including protein bars, shakes and powdered drinks have increased in demand and sales. The objective of this study was to assess the consumer perception of protein content and type and product claims for meal replacement beverages and bars. The impact of exercise frequency on product perception was also investigated. Focus groups were conducted with exercisers and nonexercisers. An adaptive conjoint analysis survey was subsequently developed and conducted (n = 138 consumers, ages 18–35 years). Relative importance of product attributes was determined through a realistic trade‐off scenario. Utility scores were extracted and rescaled by the zero‐centered differences method, and two‐way analysis of variance was conducted to identify the differences between exercise frequency and product attributes. Both groups preferred bars to beverages, and no clear preferences were observed for protein type, which was consistent with focus group results of low knowledge/understanding of specific proteins. All respondents valued the products with low‐fat/fat‐free, calcium, all‐natural, protein, vitamin/mineral, heart health and muscle‐building claims. Exercisers viewed muscle‐building claims as more important than nonexercisers. Nonexercisers viewed heart health, calcium and vitamin/mineral claims as more important than exercisers. Three distinct consumer clusters were identified, and both exercise groups were found in all three clusters, although exercise frequency influenced membership in two of the three clusters (P < 0.05). These findings can be used to develop and market meal replacement products to specific consumer groups while leveraging their specific and unique needs.

PRACTICAL APPLICATIONS

Conjoint analysis provides a useful model of how consumers think during the purchase process and an understanding of the motivation for purchase through the testing of possible claims or product attributes. By applying this method to the purchase process of meal replacement bars and beverages, those in the field of development of these products can benefit from this information by being able to understand the motivation for purchase by the targeted consumer.     

Evidence for a Flower Inhibitor and Vegetative Growth Promoter in the Strawberry

Experiments with pairs of strawberry runner plants joined bythe stolon and acting as donor/receptor units are reported.Long photoperiods or a light-break treatment on donor plantsbrought about increased petiole length, increased leaf size,and delayed flower initiation in receptor plants themselvesin short photo-periods. The response of receptor plants wasincreased by exposing donor plants to illumination by full daylight3 hours earlier each morning than receptor plants. It is thoughtthat this earlier illumination increased translocation fromthe earlier to the later illuminated plants. In translocationexperiments, radioactive P32 moved more freely from the olderto the younger plant of each pair, except when the older plantswere partially defoliated or when the younger plants were exposedto full light for a longer period of time each day than theolder attached plants. The results are discussed and it is concluded that they aregood evidence for the existence of a growth-regulating substance(s)which promotes vegetative growth and inhibits flower initiation.It seems possible that the regulation of vegetative growth andthe control of flower induction is principally achieved in thestrawberry by a flower inhibiting, vegetative growth-promotingsystem.     

Conservation genetics of Hebe speciosa (Plantaginaceae) an endangered New Zealand shrub

All extant populations of Hebe speciosa (Plantaginaceae), a threatened endemic New Zealand shrub, were investigated using the amplified fragment length polymorphism technique (AFLP). Genetic diversity indices varied significantly among geographical regions and were positively correlated with population size. Among-population genetic differentiation was high (mean pairwise Φ_ST = 0.47), implying complex historical relationships between disjunct populations and negligible contemporary gene flow. Southern populations exhibited extremely low genetic diversity relative to those found in Northland, suggesting that these populations may be more recent in origin. Patterns of genetic relationship among some populations indicate pre-European Māori dispersal and cultivation. The three northernmost populations were found to contain the majority of the species' remaining genetic diversity and thus, should be a focus for future conservation management. Some southern sites may also be culturally significant as evidence of Māori trade and cultivation of Hebe speciosa .  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 229–239.     

The Dependence of Calcium Transport and Leaf Tipburn in Strawberry on Relative Humidity and Nutrient Solution Concentration

Strawberry plants were grown in controlled-environment cabinetswith different day-and-night relative humidities, in nutrientsolutions of different osmotic potential and different calciumconcentrations. Leaf calcium (% d. wt.) depended strongly on leaf age and waslowest and very sensitive to environment when the leaf was emergingfrom the bud. Calcium in the emergent leaf was greatest andtipburn least when plants were grown in humid nights (VPD usually< 100 Pa) and weak nutrient solutions (osmotic potentialabout –25 kPa). Such plants guttated freely. In contrastplants grown in dry nights (VPD, c. 600 Pa) never guttated,had small concentrations of calcium in emergent leaves and sufferedtipburn. The behaviour of plants transferred between humiditytreatments rapidly reflected the new conditions. Increasingthe osmotic potential of the nutrient increased tipburn anddecreased calcium in emergent leaves even though the nutrientcontained more calcium. When the calcium concentration in the emergent leaf exceeded0.07 per cent of d. wt, tipburn was never seen; below 0.05 percent tipburn was usually severe. These results suggest that pre-emerged, and therefore non-transpiring,leaves depend for their calcium on water flow arising from rootpressure at night. After leaf emergence, calcium intake intoleaves was promoted by dry days, indicating that calcium wasthen supplied by transpirational water flow. Humid nights, drydays and weak nutrient solutions minimize the risk of leaf tipburnin strawberry. Fragaria ananassa Duch., strawberry, tipburn, calcium transport, relative humidity, nutrient supply, guttation     

Overfishing of top predators eroded the resilience of the Black Sea system regardless of the climate and anthropogenic conditions

It is well known that human activities, such as harvesting, have had major direct effects on marine ecosystems. However, it is far less acknowledged that human activities in the surroundings might have important effects on marine systems. There is growing evidence suggesting that major reorganization (i.e., a regime shift) is a common feature in the temporal evolution of a marine system. Here we show, and quantify, the interaction of human activities (nutrient upload) with a favourable climate (run‐off) and its contribution to the eutrophication of the Black Sea in the 1980s. Based on virtual analysis of the bottom‐up (eutrophication) vs. top‐down (trophic cascades) effects, we found that an earlier onset of eutrophication could have counteracted the restructuring of the trophic regulation at the base of the food web that resulted from the depletion of top predators in the 1970s. These enhanced bottom‐up effects would, however, not propagate upwards in the food web beyond the zooplankton level. Our simulations identified the removal of apex predators as a key element in terms of loss of resilience that inevitably leads to a reorganization. Once the food web has been truncated, the type and magnitude of interventions on the group replacing the apex predator as the new upper trophic level have no effect in preventing the trophic cascade. By characterizing the tipping point at which increased bottom‐up forcing exactly counteracts the top‐down cascading effects, our results emphasize the importance of a comprehensive analysis that take into account all structuring forces at play (including those beyond the marine system) at a given time.