Activated-sludge process dynamics with continuous total organic carbon and oxygen uptake measurements

The dynamic responses of a bench-scale activated-sludge process to step changes and square-wave inputs in the feed flow and concentration were measured. Instrumentation permitted the continuous measurement of the oxygen uptake rate and dissolved organic carbon responses. Notable were the sensitivity of the oxygen uptake rate to process changes and the reliability of the dynamic oxygen electrode method. The responses were found to be greatly influenced by the organic loading, FS₀/XV, which was incorporated into a load-dependent kinetics model. Simulations showd good agreement with experiment in the case of the square-wave disturbances. Because of the changing and complex nature of the activated sludge it was necessary to reestimate the parameter set for each run.     

Observations on parasitic gastroenteritis and bronchitis in grazing calves: effect of low level feed incorporation of morantel in early season.

Pott J. M., Jones R. M. and Cornwell R. I. 1979. Observations on parasitic gastroenteritis and bronchitis in grazing calves: effect of low level feed incorporation of morantel in early season. International Journal for Parasitology9: 153–157. Twenty-four castrated Friesian calves were divided into two equal groups on a body weight basis and grazed separate halves of an infected pasture. One group was given 1.5 mg/kg per day morantel tartrate in the feed over a period extending from 2 weeks before turning out in early May to early July. The other group of calves received an equivalent amount of unmedicated food as controls. Pasture larval counts showed a similar pattern and level of infection from February to July on both pastures. This consisted of a fall from moderate winter levels to very low levels in April/July. The control pasture then showed a typical sharp rise in August to high levels extending through September and falling to moderate levels in October. The pasture being grazed by treated calves showed only a small rise in larval counts in August. The total pasture contamination was reduced by 85% compared with controls during August/October. Faecal egg and larval counts showed similar differences between treated and control calves. Mild clinical signs of parasitic gastroenteritis and bronchitis were seen in controls but not in the treated group. The latter had a weight gain advantage of 20.5 kg the difference becoming marked in the last month of the trial.     

The ultrastructure of normal and glycerol treated muscle in the ghost crab,Ocypode cursor

The ultrastructure of normal and glycerol treated fibers of the closer muscle of the ghost crab, Ocypode cursor, was studiedmthe muscle is composed of presumably phasic (short sarcomeres) and tonic (long sarcomeres) fibers, the latter greatly predominating. Horseradish peroxidase (HRP) was used as an extracellular tracer to delineate the tubular system (TS), and to determine to what extent this system becomes detached from the extracellular space as a result of glycerol treatment. Sarcolemmal clefts invade deeply into the muscle at Z-lines and I-bands; tubules invaginate into the muscle from the clefts and from the surface sarcolemma at the Z-lines, A-I overlaps and A-bands. A tubules are in frequent diadic or tetradic contact with the sarcoplasmic reticulum (SR), whereas Z tubules appear to be randomly associated with SR, terminal cisterns (TC) and Z-line fibrils. When HRP was administered to normal muscle, black reaction product was found adjacent to the outer surface of the sarcolemma, within the clefts and within profiles of the TS throughout the tissue. In glycerol treated muscle peripheral vacuolation frequently occurred; black reaction product penetrated only as far as the vacuoles and into dilated Z-line tubules, but was virtually absent from the rest of the TS. This lack of continuity between the extracellular space and the A tubules indicated disruption or constriction of the A tubules as a result of glycerol treatment, although Z tubule contact with the extracellular space appeared unimpaired. These findings provide ultrastructural correlates of the electrophysiological changes produced by glycerol treatment of the closer muscle of the ghost crab (Papir, 1973), namely, interference with excitation-contraction (e-c) coupling. The random association of the Z tubules with SR and TC, and their resistance to disruption by glycerol treatment, tend to endorse the claims that the Z tubules in crustacean muscle are not directly involved in e-c coupling (Brandt et al., 1965; Peachey, 1967; Selverston, 1967).     

Fungal functional ecology: bringing a trait‐based approach to plant‐associated fungi

Fungi play many essential roles in ecosystems. They facilitate plant access to nutrients and water, serve as decay agents that cycle carbon and nutrients through the soil, water and atmosphere, and are major regulators of macro‐organismal populations. Although technological advances are improving the detection and identification of fungi, there still exist key gaps in our ecological knowledge of this kingdom, especially related to function . Trait‐based approaches have been instrumental in strengthening our understanding of plant functional ecology and, as such, provide excellent models for deepening our understanding of fungal functional ecology in ways that complement insights gained from traditional and ‐omics‐based techniques. In this review, we synthesize current knowledge of fungal functional ecology, taxonomy and systematics and introduce a novel database of fungal functional traits (Fun^Fun). Fun^Fun is built to interface with other databases to explore and predict how fungal functional diversity varies by taxonomy, guild, and other evolutionary or ecological grouping variables. To highlight how a quantitative trait‐based approach can provide new insights, we describe multiple targeted examples and end by suggesting next steps in the rapidly growing field of fungal functional ecology.     

Developmental aspects of the tympanic membrane: Shedding light on function and disease

The ear drum, or tympanic membrane (TM), is a key component in the intricate relay that transmits air‐borne sound to our fluid‐filled inner ear. Despite early belief that the mammalian ear drum evolved as a transformation of a reptilian drum, newer fossil data suggests a parallel and independent evolution of this structure in mammals. The term “drum” belies what is in fact a complex three‐dimensional structure formed from multiple embryonic cell lineages. Intriguingly, disease affects the ear drum differently in its different parts, with the superior and posterior parts being much more frequently affected. This suggests a key role for the developmental details of TM formation in its final form and function, both in homeostasis and regeneration. Here we review recent studies in rodent models and humans that are beginning to address large knowledge gaps in TM cell dynamics from a developmental biologist's point of view. We outline the biological and clinical uncertainties that remain, with a view to guiding the indispensable contribution that developmental biology will be able to make to better understanding the TM.     

Rewiring coral: Anthropogenic nutrients shift diverse coral–symbiont nutrient and carbon interactions toward symbiotic algal dominance

Improving coral reef conservation requires heightened understanding of the mechanisms by which coral cope with changing environmental conditions to maintain optimal health. We used a long‐term (10 month) in situ experiment with two phylogenetically diverse scleractinians (Acropora palmata and Porites porites) to test how coral–symbiotic algal interactions changed under real‐world conditions that were a priori expected to be beneficial (fish‐mediated nutrients) and to be harmful, but non‐lethal, for coral (fish + anthropogenic nutrients). Analyzing nine response variables of nutrient stoichiometry and stable isotopes per coral fragment, we found that nutrients from fish positively affected coral growth, and moderate doses of anthropogenic nutrients had no additional effects. While growing, coral maintained homeostasis in their nutrient pools, showing tolerance to the different nutrient regimes. Nonetheless, structural equation models revealed more nuanced relationships, showing that anthropogenic nutrients reduced the diversity of coral–symbiotic algal interactions and caused nutrient and carbon flow to be dominated by the symbiont. Our findings show that nutrient and carbon pathways are fundamentally “rewired” under anthropogenic nutrient regimes in ways that could increase corals’ susceptibility to further stressors. We hypothesize that our experiment captured coral in a previously unrecognized transition state between mutualism and antagonism. These findings highlight a notable parallel between how anthropogenic nutrients promote symbiont dominance with the holobiont, and how they promote macroalgal dominance at the coral reef scale. Our findings suggest more realistic experimental conditions, including studies across gradients of anthropogenic nutrient enrichment as well as the incorporation of varied nutrient and energy pathways, may facilitate conservation efforts to mitigate coral loss.     

Incorporation of the Tat cell‐penetrating peptide into nanofibers improves the respective antitumor immune response

A major challenge for the development of anticancer vaccines is the induction of a safe and effective immune response, particularly mediated by CD8+ T lymphocytes, in an adjuvant‐free manner. In this respect, we present a simple strategy to improve the specific CD8+ T cell responses using KFE8 nanofibers bearing a Class I (Kb)‐restricted peptide epitope (called E. nanofibers) without the use of adjuvant. We demonstrate that incorporation of Tat, a cell‐penetrating peptide (CPP) of the HIV transactivator protein, into E. nanofibers remarkably enhanced tumor‐specific CD8+ T cell responses. E. nanofibers containing 12.5% Tat peptide (E.Tat_12.5 nanofiber) increased antigen cross‐presentation by bone marrow‐derived dendritic cells as compared with E. nanofibers, or E. nanofibers containing 25 or 50% the Tat peptide. Uptake of KFE8.Tat_12.5 nanofibers by dendritic cells (DCs) was significantly increased compared with KFE8 nanofiber lacking Tat. Peritoneal and lymph node DCs of mice immunized with E.Tat_12.5 nanofibers exhibited increased presentation of the H2kb‐epitope (reminiscent for cross‐presentation) compared with DCs obtained from E. nanofiber vaccinated mice. Tetrameric and intracellular cytokine staining revealed that vaccination with E.Tat_12.5 triggered a robust and specific CD8+ T lymphocyte response, which was more pronounced than in mice vaccinated with E. nanofibers alone. Furthermore, E.Tat_12.5 nanofibers were more potent than E. nanofiber to induce antitumor immune response and tumor‐infiltrating IFN‐γ CD8 T lymphocyte. In terms of cancer vaccine development, we propose that harnessing the nanofiber‐based vaccine platform with incorporated Tat peptide could present a simple and promising strategy to induce highly effective antitumor immune response.     

Effectiveness of naturally occurring Aphis gossypii on tomato plants as a bio-indicator for heavy metals in Riyadh and Hafar Al-Batin,Saudi Arabia

Although certain pollutants can be biologically degraded by microorganisms, rendering their impact short-term, others can not be impaired, such that their effect persists. The present study evaluates the effectiveness of using a field-collected aphid, Aphis gossypii, as a bio-indicator for heavy metals in tomato farms in Riyadh and Hafar Al-Batin, Saudi Arabia. Heavy metals were selected (Cd, Cu, Zn, and Pb) and measured for comparative screening in field-collected plants, soil, and aphids using inductively coupled plasma-mass spectrometry (ICP-MS). Field-collected aphids from both studied regions were identified as Aphis gossypii. In Riyadh, there was no significant difference observed for Cd, Cu, and Zn for all experimental samples, while, Pb was showed differences among samples especially tomato leaves None of the studied samples in Hafar Al-Batin were showed statistically significant differences in Cd, in reverse to significant differences in the other heavy metals. Comparing concentrations of selected heavy metals between the two studied regions was showed that neither region showed a significant difference in heavy metals except for Cu. This study demonstrates that tomato leaf samples showed the highest concentrations of most studied heavy metals, followed by soil, then aphids. Aphids were utilized as a bio-indicator of heavy metals in the studied regions.