Host plant growth response to inoculation withFrankia

Optimum growth conditions and inoculation regimes were determined for severalFrankia strains isolated from both Alnus and Casuarina host plants. Growth conditions were estabilished that allowed a reduction in generation time to less than 15 hours for certain Alnus derivedFrankia. Differences in plant growth response were observed with differing inoculum levels and soil mixtures. Elite strains of Alnus derivedFrankia were isolated that elicited similar growth reponses in allAlnus species tested; however, differences were observed betweenFrankia strains and plant growth response of variousCasuarina species tested.     

Low root zone temperature favours shoot B partitioning into young leaves of oilseed rape (Brassica napus)

In previous studies with tropical plant species, low root zone temperature (RZT) induced boron (B) deficiency, but it is not known if the same response to RZT will be expressed in temperate species, like oilseed rape, that are more tolerant of low temperature. The present experiments investigated the effect of RZT (10 and 20°C) on oilseed rape ( Brassica napus L. cv. Hyola 42) response to B in solution culture, in summer and winter. Regardless of canopy growth conditions, low RZT (10°C) promoted the partitioning of shoot B to the actively growing leaves, especially when B supply was low. However, low RZT did not significantly alter net B uptake rates or plant biomass. Low RZT decreased the shoot-to-root ratio, countering the effects of low B which increased it, leading to a decreased demand for B in the shoot at low RZT. At low B supply, B-deficiency symptoms appeared later at 10 than at 20°C, corresponding with higher B concentrations in the youngest fully opened leaves (YOLs) at 10°C RZT. Thus 10°C RZT increased the tolerance to low B supply. As a result, it is concluded that the effect of decreasing RZT on the responses of the temperate species, oilseed rape, to low B supply depends on whether the low RZT is above or below the optimal root temperature for growth.     

Joint Segregation of Biochemical Loci in Salmonidae. II. Linkage Associations from a Hybridized Salvelinus Genome (S. NAMAYCUSHxS. FONTINALIS)

The results of more than 300 pairwise examinations of biochemical loci for joint segregation in brook trout (Salvelinus fontinalis) and in the hybridized genome of lake trout (S. namaycush) x brook trout are summarized. Nineteen loci have been assigned to the following eight linkage groupings on the basis of nonrandom assortment, including cases of both classical linkage and pseudolinkage: ODH with PMI with PGI-3, PGI-2 with SDH, ADA-1 with AGP-2, AAT-(1,2) with AGP-1 with MDH-1, MDH-3 with MDH-4, LDH-3 with LDH-4, IDH-3 with ME-2 and GUS with CPK-1. Pseudolinkage (an excess of nonparental progeny types) was observed only for male testcross parents. The results suggest that this phenomenon involves homeologous chromosome arms as evidenced by the de novo association of presumed duplicate loci in each case. Classical linkage has not been found for the five pairs of duplicate loci examined in Salvelinus, suggesting that not all of the eight metacentrics in the haploid complement involve fusions of homeologous chromosomes. Females consistently showed a greater degree of recombination.     

Genetic diversity and reproductive mode in two non-native hydromedusae, Maeotias marginata and Moerisia sp., in the upper San Francisco Estuary, California

Reproductive strategy can play a significant role in invasion success and spread. Asexual and sexual reproduction may confer different advantages and disadvantages to a founding population, resulting in varying impacts on genetic diversity and the ability to invade. We investigate the role of reproductive mode in two species of non-native hydromedusae (Maeotias marginata and Moerisia sp.) in the San Francisco Estuary (SFE). Both species can reproduce asexually and sexually. We employed 7?C8 microsatellite markers to determine overall genetic diversity and to investigate contributions of asexual and sexual reproduction to the populations. We found both species had high levels of genetic diversity (Average H_E?=?0.63 and 0.58, Number individuals sampled?=?111 and 277, for M. marginata and Moerisia sp. respectively) but also detected multiple individuals in clonal lineages. We identified the same clones across sampling locations and time, and the index of asexual reproduction (R) was 0.89 for M. marginata and 0.91 for Moerisia sp. Our results suggest both species maintain high population genetic diversity through sexual reproduction, in combination with asexual reproduction, which allows rapid propagation. In addition, we conducted genetic sequence analyses at the ribosomal ITS1 marker, using samples of Moerisia sp. from the SFE and M. lyonsi from Chesapeake Bay. We found 100?% sequence similarity showing that Moerisia sp. in the SFE and Chesapeake Bay are the same species. The two hydromedusae studied here possess the means to propagate rapidly and have high genetic diversity, both of which may allow them to successfully adapt to changing environments and expand their invasions.     

Mutualism Disruption Threatens Global Plant Biodiversity: A Systematic Review

Background

As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create “widow” species, which may face reduced ecological fitness. Hypothetically, such mutualism disruptions could have cascading effects on biodiversity by causing additional species coextinctions. However, the scope of this problem – the magnitude of biodiversity that may lose mutualist partners and the consequences of these losses – remains unknown.

Methodology/Principal Findings

We conducted a systematic review and synthesis of data from a broad range of sources to estimate the threat posed by vertebrate extinctions to the global biodiversity of vertebrate-dispersed and -pollinated plants. Though enormous research gaps persist, our analysis identified Africa, Asia, the Caribbean, and global oceanic islands as geographic regions at particular risk of disruption of these mutualisms; within these regions, percentages of plant species likely affected range from 2.1–4.5%. Widowed plants are likely to experience reproductive declines of 40–58%, potentially threatening their persistence in the context of other global change stresses.

Conclusions

Our systematic approach demonstrates that thousands of species may be impacted by disruption in one class of mutualisms, but extinctions will likely disrupt other mutualisms, as well. Although uncertainty is high, there is evidence that mutualism disruption directly threatens significant biodiversity in some geographic regions. Conservation measures with explicit focus on mutualistic functions could be necessary to bolster populations of widowed species and maintain ecosystem functions.     

Overcoming the constraints of long range radio telemetry from animals: getting more useful data from smaller packages

Many species carry out their most interesting activities wherethey cannot readily be observed or monitored. Marine mammalsare extreme among this group, accomplishing their most astoundingactivities both distant from land and deep in the sea. Collection,storage and transmission of data about these activities areconstrained by the energy requirements and size of the recordingloggers and transmitters. The more bits of information collected,stored and transmitted, the more battery is required and thelarger the tag must be. We therefore need to be selective aboutthe information we collect, while maintaining detail and fidelity.To accomplish this in the study of marine mammals, we have designed"intelligent" data logger/transmitters that provide context-drivendata compression, data relay, and automated data base storage.We later combine these data with remotely sensed environmentalinformation and other oceanographic data sets to recreate theenvironmental context for the animal's activity, and we displaythe combined data using computer animation techniques. In thisway, the system can provide near real time "observation" ofanimal behavior and physiology from the remotest parts of theglobe.     

Children's participation in healthcare in the UK--gesture,rhetoric, or real involvement?

In the United Kingdom (England, Wales, Scotland, and Northern Ireland) children and their best interests are protected through a range of best practice initiatives, and legislation and guidance at country, national, European, and global levels. Some of the recent commitment by the government may be the result of enlightened thinking, but some of it has resulted from the aftermath of at least two major healthcare incidents. This article reviews the UK's recent national and international efforts to protect its thirteen million children and ensure that their voices are heard.     

Comparison of stress induced by manual restraint and immobilisation in the estuarine crocodile,Crocodylus porosus

This study compared the stress induced in captive estuarine crocodiles, Crocodylus porosus, by two different handling methods: manual restraint (noosing with ropes) and immobilization by electro-stunning. To stun, a short charge (approx. 6 s) at 110 V was delivered to the back of the necks of C. porosus using a custom-built device, which immobilized the animals for 5-10 min. Immobilized and restrained animals were measured and sexed, and the condition of the skin assessed. Blood samples were taken from some animals immediately after restraint or immobilization. Other animals were returned to their pens to recover for periods of 30 min, 1, 4, 12, 24 or 48 hours after which they were stunned and blood samples taken. Individual animals (mean body length 1.96 m, N=99) were bled only once. Haematocrit and haemoglobin concentrations were measured and plasma samples were analysed for corticosterone, glucose and lactate levels. Following restraint, there were significant increases in haematocrit, haemoglobin, glucose, lactate and corticosterone concentrations in C. porosus. For restrained animals, recovery to baseline levels occurred after approximately 8 hours. The stress response of stunned animals was significantly reduced compared to manually captured and restrained crocodiles. Both groups showed a significant increase in haematocrit, haemoglobin concentration and lactate levels, however the magnitude of change was significantly reduced, and recovery was faster in stunned animals. No increase in either glucose or corticosterone levels occurred with immobilisation. The results imply that immobilization by electro-stunning is much less stressful.