Metazoan Detritivores and Underwater Decomposition Processes of Detached Sublittoral Macrophytes

A great deal of attention has been paid to the importance of marine angiosperm litter to coastal marine ecosystems, its decomposition and the role played by associated metazoans in this process. In the Clyde Sea area, autumn storms result in large quantities of kelp being detached. This kelp forms large accumulations on the sea bed in certain;areas. This project sought to examine the involvement of metazoans in the decomposition of this algal material. The fauna associated with sea-bed accumulations of decomposing Laminaria saccharina has been studied by year-round SCUBA diving at two sites in the Clyde Sea Area. Seasonal changes in the densities of 6k species were recorded. The Laminaria carries with it to the sea-bed a large part of its normal fauna. Additional species settle onto the weed from the plankton whilst others migrate onto it from the surrounding sea-bed. Peak densities of associated species were recorded in autumn. Three species were selected for detailed investigation in the laboratory concerning their importance in the decomposition process. These were the polychaete Platynereis dumerilii, the echinoid Psammechinus miliaris and the amphipod Gammarus locusta. The roles of both Platynereis and Psammechinus were examined by comparing their responses (behavioural choice, growth rates, absorption efficiencies of both carbon and protein, gut retention times and faecal output) to fresh and rotting kelp. Platynereis builds its parchment tubes preferentially on the fresh weed and feeds at the mouth of this tube. It grows faster on this diet. Platynereis is a detritivore which exploits the substratum directly. Psammechinus, although showing a behavioural preference for the rotting weed, grows equally well on either diet once it has reached a particular size. Substratum digestion is of paramount importance for Psammechinus when feeding on either diet. Gammarus locusta's responses to the two diets (examined by comparing survival and growth rates in juveniles, fecundity, fertility and breeding behaviour in adults) illustrated the importance of the rotting weed (with its associated micro-organisms) to this organism. The relative importance of interactive cropping by these three detritivores was studied by in situ containment of different species combinations. The presence of Gammarus with Psammechinus resulted in less weed being lost than when Psammechinus was isolated. This is because Gammarus selectively crops rotting weed, retarding frond disintegration by microbes. Platynereis retards microbial colonization of frond tissues ruptured during its feeding by repeated cropping of the same region. These results reflect the situation found in the field with the complete detached weed fauna present. Litter bag experiments in situ showed that , except during the summer, weed is lost from sea-bed accumulations at a faster rate when macrofaunal animals are excluded. Macrofaunal cropping prevents the weed from decomposing very rapidly. Macroalgal decay thus differs profoundly from that of vascular plants. The ecological consequences of this difference are discussed

Lost in knowledge translation:Our shifting research landscape

In 2018 there is a new research modality. Research is increasingly produced by individuals and organizations not formally affiliated with academic institutions; based on funding that does not come from the public sphere; aligned with and intended to support advocacy perspectives and is designed for use by particular communities and agents. The new research modality presents challenges and opportunities. While all of these new agents in the research landscape are well educated and qualified to conduct research, in many cases they are operating outside of the traditional research environment and perhaps with a different set of “research cultural norms”. This new research modality in fact begs for a solution similar to that promoted within the health sciences field – a model of knowledge translation. A panel of researchers drawn from across the new research landscape will engage with information professionals to discuss six key questions.</p

The influence of the ligand chelate effect on iron-amine-catalysed Kumada cross-coupling

The performance of Fe-amine pre-catalysts in a representative Kumada reaction is inversely proportional to the lability of the chelate ligand.</p

Embedding external referencing of standards in higher education: collaborative relationships are the key

External referencing of assessment and students’ achievement standards is a growing priority area within higher education, which is being pressured by government requirements to evidence outcome attainment. External referencing benefits stakeholders connected to higher education by helping to assure that assessments and standards within courses are appropriate and comparable among institutions. External referencing takes many forms, which have different resourcing requirements, outcomes, and operational strengths and challenges. This paper describes the External Referencing of Standards (ERoS) approach developed, tested and adopted by a university consortium. ERoS draws on the strengths of existing methodologies to produce an evolved model that is effective, efficient, transparent and open, capability building and sustainable. The model enables participants to communicate directly and construct peer relationships, and findings suggest this is a significant design strength. The process facilitates capability building, such that participants garnered insights valuable to enact quality assurance and enhancement of existing courses, and fosters connections that facilitate collaboration and peer-learning. ERoS successfully used open source collaborative tools to review work samples, which can be used to benchmark costed systems

Is surgical intervention avoidable in cases of emphysematous gastritis? A case presentation and literature review

AbstractINTRODUCTIONGas located within the gastric wall is a rare finding that is associated with a mortality rate of 50%. It confers two main diagnoses: gastric emphysema and emphysematous gastritis. Due to its high mortality rate, emphysematous gastritis must be differentiated from gastric emphysema early to avoid adverse outcomes and plan the management of these patients.PRESENTATION OF CASEWe introduce a 55 year-old male who presents with diffuse abdominal pain associated with fever, nausea, vomiting, and diarrhea. Patient has positive peritoneal signs with fever and leukocytosis. Air in the gastric wall and portal venous system was visualized on Computed Tomography (CT). The patient underwent emergent laparotomy which showed normal bowel with few adhesions.DISCUSSIONVarious etiologies can cause gas within the gastric wall but concomitant air in the hepatic venous system is highly suspicious for emphysematous gastritis. CT imaging is the most sensitive and specific way to differentiate emphysematous gastritis versus gastric emphysema. Although rare, there are many cases of emphysematous gastritis that undergo prompt surgical exploration. Recently, however, medical treatment has become more common and surgical management reserved for complications.CONCLUSIONWe conclude by stating that this case of emphysematous gastritis, due to gastric ulcers, would have no difference in outcome if treated medically instead of surgically. Historically, patients with emphysematous gastritis warranted surgical intervention. More recently, case reports of emphysematous gastritis are favoring conservative management. The consensus still remains that there is no standard approach for these patients and most patients in extremis are undergoing surgical intervention

The similarity of the effect of carbohydrase or prebiotic supplementation in broilers aged 21 days, fed mixed cereal diets and challenged with coccidiosis infection

The aim of this study was to investigate the effect on growth performance and nutrient utilisation when supplementing diets deficient in energy and protein with carbohydrase enzymes or xylo-oligosaccharide in broilers challenged with coccidia. 960 Ross 308 broilers were used in this 21-day study. The treatments were arranged into a 2×4 factorial with 2 challenge states (challenged and non-challenged) and 4 different additive types (control, xylanase alone, xylanase and β-glucanase mixture and xylo-oligosaccharide). On day 14, the challenged group received 12× the recommended dose of coccidiosis vaccine while the non-challenged group received a sham treatment of water only. The birds and feed were weighed on days 0, 14 and 21. On day 21, two birds per pen were euthanized, the caeca were removed and the contents collected for short chain fatty acid analysis. Six more birds per pen were euthanized and ileal digesta were collected and pooled per pen for nutrient digestibility analysis. Feed intake was greater (P &lt; 0.05) on days 14 and 21 when xylo-oligosaccharide was included in the diet compared to the xylanase and β-glucanase mixture in birds challenged with coccidiosis. Including xylo-oligosaccharide in the diet improved (P &lt; 0.05) the digestibility of nitrogen and supplementing diets with the xylanase and β-glucanase mixture improved (P &lt; 0.05) the digestibility of several amino acids. The concentration of arabinose and xylose was (P &lt; 0.001) greater when broiler diets were supplemented with carbohydrase enzymes or xylo-oligosaccharide compared to the control. Although there was an increase in short chain fatty acid production due to the addition of carbohydrase enzymes or xylo-oligosaccharide, there was no additive effect on the %G+C profile of caecal bacteria however there was a negative effect of coccidiosis. In conclusion, the similarity in the response to carbohydrase enzymes or xylo-oligosaccharide supplementation illustrates that the hydrolysis products from carbohydrase activity may have prebiotic like effects

The effect of carbohydrases or prebiotic oligosaccharides on growth performance, nutrient utilisation and the development of the small intestine and immune organs in broilers fed nutrient-adequate diets based on either wheat or barley

BACKGROUND: Non‐starch polysaccharides are large complex molecules and are found in cereal grains. This study was conducted to investigate the effect of carbohydrase enzymes or prebiotic oligosaccharides on growth performance, nutrient utilisation and weight of organs associated with the immune system in broilers fed wheat‐ or barley‐based diets. RESULTS: In wheat‐based diets, feed intake was lower (P &lt; 0.05) following xylo‐oligosaccharide supplementation, whereas in barley‐based diets feed intake was greater (P &lt; 0.05) following β‐glucanase supplementation. Gross energy digestibility was improved (P &lt; 0.01) when either level of xylanase was added to wheat diets. Ileal digestible energy was greater (P &lt; 0.01) in wheat diets including an additive compared with the control diet. In wheat diets, bursa weight was lower (P &lt; 0.05) following xylo‐oligosaccharide supplementation compared with the control treatment. CONCLUSIONS: The current study showed that supplemented carbohydrases or prebiotic oligosaccharides could alter the development of immune organs or small intestine without any significant effect on growth performance in broilers receiving nutrient‐adequate diets