Conjunctival habronemiasis in a square‐lipped rhinoceros (Ceratotherium simum)

A captive female square‐lipped rhinoceros born in 1993 had been showing intermittent signs of bilateral conjunctivitis and conjunctival proliferation since 1998. Periodic improvement was noted, especially in winter, but overall the condition had deteriorated over the years. Treatment with various topical, intralesional, and systemic antibiotics and glucocorticosteroids was largely ineffective, as were repeated dewormings. No primary cause for these lesions was found in biopsies taken in 2000 and 2006, although a severe infiltrate of numerous eosinophils was observed in the latter. As the condition worsened, secondary corneal changes were noted, and eventually vision was lost due to proliferative conjunctival tissue. Aggressive resection of the proliferating tissue in 2013 restored vision and submitted biopsies yielded a diagnosis of severe allergic conjunctivitis, eosinophilic granuloma, and habronematid (Habronema or Draschia) larval infection. As no other rhinoceros in the herd was affected, including two calves born to the patient who were in close contact with their mother, it was concluded the presentation was most likely due to a hypersensitivity reaction to the dead or dying larvae. Fly repellent is now regularly applied around the eye of this rhinoceros, and a protective face mask has been fitted. Ongoing periodic relapses are treated with oral ivermectin, topical antibiotics, and steroids.     

Femtosecond dynamics of electron localization at interfaces

The dynamics of two-dimensional small-polaron formation at ultrathin alkane layers on a silver(111) surface have been studied with femtosecond time- and angle-resolved two-photon photoemission spectroscopy. Optical excitation creates interfacial electrons in quasi-free states for motion parallel to the interface. These initially delocalized electrons self-trap as small polarons in a localized state within a few hundred femtoseconds. The localized electrons then decay back to the metal within picoseconds by tunneling through the adlayer potential barrier. The energy dependence of the self-trapping rate has been measured and modeled with a theory analogous to electron transfer theory. This analysis determines the inter- and intramolecular vibrational modes of the overlayer responsible for self-trapping as well as the relaxation energy of the overlayer molecular lattice. These results for a model interface contribute to the fundamental picture of electron behavior in weakly bonded solids and can lead to better understanding of carrier dynamics in many different systems, including organic light-emitting diodes.     

Cuticular uptake of xenobiotics into living plants. Part 2: influence of the xenobiotic dose on the uptake of bentazone, epoxiconazole and pyraclostrobin, applied in the presence of various surfactants, into Chenopodium album, Sinapis alba and Triticum aestivum leaves

This study has determined the uptake of three pesticides, applied as commercial or model formulations in the presence of a wide range of surfactants, into the leaves of three plant species (bentazone into Chenopodium album L. and Sinapis alba L., epoxiconazole and pyraclostrobin into Triticum aestivum L.). The results have confirmed previous findings that the initial dose (nmol mm(-2)) of xenobiotic applied to plant foliage is a strong, positive determinant of uptake. This held true for all the pesticide formulations studied, although surfactant concentration was found to have an effect. The lower surfactant concentrations studied showed an inferior relationship between the amount of xenobiotic applied and uptake. High molecular mass surfactants also produced much lower uptake than expected from the dose uptake equations in specific situations.     

‘Candidatus Phytoplasma australiense’ is the phytoplasma associated with Australian grapevine yellows, papaya dieback and Phormium yellow leaf diseases

Sequence comparisons and phylogenetic analysis of the 16S rRNA genes and the 16S/23S spacer regions of the phytoplasmas associated with Australian grapevine yellows, papaya dieback and Phormium yellow leaf diseases revealed minimal nucleotide differences between them resulting in the formation of a monophyletic group. Therefore, along with Australian grapevine yellows, the phytoplasmas associated with Phormium yellow leaf and papaya dieback should also be considered as Candidatus Phytoplasma australiense.     

Mechanisms of cuticular uptake of xenobiotics into living plants: 1. Influence of xenobiotic dose on the uptake of three model compounds applied in the absence and presence of surfactants into Chenopodium album, Hedera helix and Stephanotis floribunda leaves

This study determined the uptake of three model compounds, applied in the presence and absence of surfactants, into the leaves of three plant species (Chenopodium album L, Hedera helix L and Stephanotis floribunda Brongn). The results with 2-deoxy-D-glucose, 2,4-dichlorophenoxyacetic acid and epoxiconazole in the presence ofsurfactants (the polyethylene glycol monododecyl ethers C12EO3, C12EO6, C12EO10 and a trisiloxane ethoxylate with mean EO of 7.5, all used at one equimolar concentration and therefore different percentage concentrations) illustrate that the initial dose (nmol mm(-2)) of xenobiotic applied to plant foliage is a strong positive determinant of uptake. This held true for all the xenobiotics studied over a wide concentration range in the presence of these surfactants. Uptake on a unit area basis (nmol mm(-2)) could be related to the initial dose of xenobiotic applied per unit area (ID) by an equation of the form: Uptake = a [ID]b at time t = 24h. ID is given by the mass of xenobiotic applied, M divided by the droplet spread area, A. Total mass uptake is then calculated from an equation of the form: Total Uptake = a [ID]b x A.     

Untersuchungen zur Assimilatverteilung in Ackerbohnen (Vicia faba L.) während der Blühphase

Investigations about the distribution of assimilates during flowering in broad beans ( Vicia faba L.)
The distribution of assimilates during flowering was studied on single plants exposed to ¹⁴CO₂ in the field. The plants were harvested 1, 3, 15 days after exposition and at ripening. Results:
1. At the begin of flowering the nodes with flowers assimilated much ¹⁴C with a tendency of higher contents in the more above situated nodes. The concentration of ¹⁴C was similar in blades, stalks and flowers.
2. The assimilates incorporated after 24 hours were only to a small amount translocated afterwards. Only 3 % went to the apical region. An intensive restorement out of the blades took place at the time of ripening.
3. In the midst of flowering the concentration of ¹⁴C was lower in the nodes with open flowers than in those with shut or with pods. At that time pods are already strong sinks that withdraw assimilates from blades and stalks.
4. At the time when large and small pods are growing on the lower and middle nodes, the nodes in the apical region will be deprived of assimilates (effects of dominance).
5. Roots and nodules had low but stable contents and concentrations of ¹⁴C during flowering. These descended distinctly at ripening.     

Identification of cultivars and accessions of Lolium, Festuca and Festulolium hybrids through the detection of simple sequence repeat polymorphism

Molecular diversity and genetic affinity in the Lolium/Festuca grass complex have been assessed using simple sequence repeat (SSR) marker technology. The genotypic set was derived from three accessions of perennial ryegrass, two cultivars of Italian ryegrass, two cultivars of meadow fescue, two cultivars of tall fescue and 10 accessions from different intergeneric hybrid (Festulolium) combinations. The majority of the genomic DNA‐derived SSR primer pairs from perennial ryegrass (LPSSR) and Italian ryegrass (LMSSR) produced clear, simple and distinctive amplification products from the majority of the genotypes. The efficiency of cross‐specific amplification for LPSSR markers varied from 38% in meadow fescue to 93% in two cultivars of Festulolium and from 57% in meadow fescue to 87% in Italian ryegrass for LMSSR markers. Of 40 amplified markers, 14 (35%) produced species‐difference alleles in the relation to cultivars used in the present study. Thirty‐five LPSSR locus‐derived alleles were found to be specific to Lolium species, four to meadow fescue and six to tall fescue. For LMSSR alleles, eight were specific to Lolium species and five were only associated with Italian ryegrass, and null alleles were detected for meadow fescue in all instances. These species‐difference markers could clearly identify different accessions of Festulolium. Cluster analysis separated the individual taxa and showed grouping of intergeneric hybrids based on genomic composition. The data distinguished between the species and reflected the known pedigree of the cultivars and the differences between the species. The dendrogram also distinguished between the Festulolium accessions and clearly demonstrated the relations between Festulolium hybrids and their parent species.     

Effect of N-enriched co-compost on transpiration efficiency and water-use efficiency of maize (Zea mays L.) under controlled irrigation

Population growth, urban expansion and economic development are increasing competition for water use between agriculture and other users. In addition, the high rate of soil degradation and declining soil moisture in the Sub-Saharan African Region have called for several crop production management and irrigation options to improve soil fertility, reduce water use by crops and produce ‘more crops per drop of water’. Notwithstanding this, considerable variations exist in the literature on water-use efficiency, WUE_cwu (economic yield per water used) for maize (Zea mays L.) across climates and soil management practices. Different views have been expressed on the effect of different rates of nitrogen (N) application on transpiration efficiency, TE (biomass produced per unit of water transpired). The objectives of the study were to assess the effect of different rates of N-enriched municipal waste co-compost and its derivatives on TE, WUE_cwu and yield of maize (Z. mays L.) in comparison to inorganic fertiliser. The greenhouse pot experiment was conducted in Accra, Ghana on a sandy loam soil (Ferric Lixisol) using a split plot design. The main plot treatments were soil (S), dewatered faecal sludge (DFS), municipal solid waste compost (C), co-compost from municipal solid waste and dewatered faecal sludge (Co), compost enriched with (NH₄)₂SO₄ (EC), co-compost enriched with (NH₄)₂SO₄ (ECO), (NH₄)₂SO₄ and NPK15-15-15 + (NH₄)₂SO₄. The sub-plot treatments were different rates of application of nitrogen fertiliser applied at the rate of 91, 150 and 210 kg N ha⁻¹ respectively. Maize cv. Abelehii was grown in a poly bag filled with 15 kg soil. Eight plants per treatment were selected randomly and used for the collection of data on growth parameters forth-nightly. At physiological maturity two plants per treatment were also selected randomly from each treatment plot for yield data. The results showed that TE of maize (Z. mays) varied for the different treatments and these are 6.9 Pa in soil (S) alone to 8.6 Pa in ECO. Increase in N application rate increased TE at the vegetative phase for fast nutrient releasing fertilisers (DFS, ECO, EC, NPK + (NH₄)₂SO₄, (NH₄)₂SO₄) and at the reproductive phase for slow nutrient releasing fertilisers (C and CO). Water-use efficiency increased significantly as rate of N application increased. Treatment ECO improved crop WUE_cwu and was 11% and 4 times higher than that for NPK + (NH₄)₂SO₄ or soil alone; and 18-36% higher than those for DFS and CO. Treatment ECO used less amount of water to produce dry matter yield (DMY) and grain yield (GY) that was 5.2% and 12.6%, respectively, higher than NPK + (NH₄)₂SO₄. Similarly, the DMY and GY for ECO was 8.9-18.5% and 23.4-34.7%, respectively, higher than DFS and CO. High nutrient (N and K) uptake, TE, and low leaf senescence accounts for 83% of the variations in DMY whereas WUE_cwu accounts for 99% of the variations in GY. Thus, the study concluded that different sources of fertiliser increased TE and WUE_cwu of maize differently as N application rate increases.