The application of palaeolimnology to evidence‐based lake management and conservation: examples from UK lakes

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Astaxanthin profiles and corresponding colour properties in Australian farmed black tiger prawn (Penaeus monodon) during frozen storage

The colour of commercial cooked black tiger prawns (Penaeus monodon) is a key quality requirement to ensure product is not rejected in wholesale markets. The colour, due to the carotenoid astaxanthin, can be impacted by frozen storage, but changes in colour or astaxanthin profile, during frozen storage, have not been studied in detail. Subsequently in this study, the aims were to define the astaxanthin (as cis, trans, mono‐ester and di‐ester forms) content, together with the colour properties, in both pleopods (legs) and abdominal segments. Changes in astaxanthin content and colour properties were further determined during frozen storage (?20°C). Total astaxanthin content was seen to decrease in all samples over time, with the rate of degradation being significantly greater (P < 0.05) in pleopods than abdomen. In both pleopods and abdomen, rate of degradation of esterified forms was significantly greater (P < 0.05) than non‐esterified forms. Hue angle (increase), a* value (decrease) and L value (increase) were all seen to significantly change (P < 0.05) during storage, with changes being more prevalent in the pleopods. The pleopods are the key indicator of astaxanthin and colour loss in cooked black tiger prawns and preservation strategies are required to preserve astaxanthin and colour during frozen storage.     

Limited open reduction and stabilization of sacroiliac fracture-luxations using fluoroscopically assisted placement of a trans-iliosacral rod in five dogs

Objective— To describe percutaneous fluoroscopically assisted placement of a trans-iliosacral rod to stabilize sacroiliac fracture-luxations after limited open reduction.
Study Design— Retrospective clinical case series.
Animals— Dogs (n=5) with sacroiliac fracture-luxations.
Methods— Medical records and radiographs were reviewed to evaluate implant placement, fracture reduction, pelvic canal diameter ratio, maintenance of reduction, implant stability, assessment of union, and to identify any complications. Owners were contacted to obtain long-term assessment of limb function.
Results— Dogs weighed between 6 and 31 kg. Trans-iliosacral rods were placed correctly traversing the sacral body. Mean (±SD) percent reduction of the sacroiliac joint was 92.9±6.6%. Pelvic canal diameter ratio did not differ significantly between time periods. With the exception of 1 dog, which died in the early postoperative period, all sacroiliac fracture-luxations healed without appreciable complications. Three dogs were sound and 1 dog had a subtle lameness at final physical and radiographic examination (mean±SD: 217±205 days). Owners assessed their dog's limb function (mean±SD: 355±205 days) as good or excellent.
Conclusions— Trans-iliosacral rods can be accurately placed using intraoperative fluoroscopy after limited open reduction of sacroiliac fracture-luxations. Trans-iliosacral rods provided bilateral secure fixation, allowed early weight-bearing and dogs consistently had good long-term clinical results.
Clinical Relevance— Trans-iliosacral rods are suitable implants for the stabilization of sacroiliac fracture-luxations, particularly in dogs with bilateral fracture-luxations and/or concurrent musculoskeletal injuries.     

Sample collection factors affect the sensitivity of the diagnostic test for Tritrichomonas foetus in bulls

The current diagnostic test for Tritrichomonas foetus involves the culture of collected preputial or vaginal samples. In an earlier study, which evaluated sampling tools for use with bulls, it was observed that the sensitivity of the diagnostic test was higher for 2nd samples collected from the right side of the prepuce than it was for samples collected 1st from the left side. The study described in this paper was conducted to evaluate which of these factors was responsible for the effect on diagnostic sensitivity. Twenty-nine bulls infected with T. foetus were repeatedly sampled in a 2-factor cross-over design. Samples taken from the right side of the prepuce were 4 times as likely to be positive as samples taken from the left side (P = 0.03). Other factors did not have a significant effect on the outcome of the diagnostic test. Unexpected factors may affect the sensitivity of the diagnostic test for T. foetus.     

Review of induced molting by feed removal and contamination of eggs with Salmonella enterica serovar Enteritidis

As laying hens age, egg production and quality decreases. Egg producers can impose an induced molt on older hens that results in increased egg productivity and decreased hen mortality compared with non-molted hens of the same age. This review discusses the effect of induced molting by feed removal on immune parameters, Salmonella enterica serovar Enteritidis (SE) invasion and subsequent production of SE-contaminated eggs. Experimental oral infections with SE show molted hens are more susceptible to SE infection and produce more SE-contaminated eggs in the first few weeks post-molt compared with pre-molt egg production. In addition, it appears that molted hens are more likely to disseminate SE into their environment. Molted hens are more susceptible to SE infection by contact exposure to experimentally infected hens; thus, transmission of SE among molted hens could be more rapid than non-molted birds. Histological examination of the gastrointestinal tracts of molted SE-infected hens revealed more frequent and severe intestinal mucosal lesions compared with non-molted SE-infected hens. These data suggest that induced molting by feed deprivation alters the normal asymptomatic host-pathogen relationship. Published data suggest the highest proportion of SE-positive eggs is produced within 1-5 weeks post-molt and decreases sharply by 6-10 weeks and dissipates to the background level for non-molted hens by 11-20 weeks. Appropriate treatment measures of eggs produced in the fist 5 weeks post-molting may decrease the risk of foodborne infections to humans.     

Once and future farming: Some meditations on the historical and cultural roots of sustainable agriculture in the United States

American agricultural history, literature, and thought reveal historical circumstances that have often been unfavorable to the development of a sustainable agriculture in the United States. Further critical examination of these historical and cultural roots reveals that sustainable agriculture is an evolving concept that can be traced to the tradition of agrarian idealism, scientific and organic agriculture, and the recent history of ecological ideas, beginning with the Dust Bowl and extending to the present.Carl D. Esbjornson received his Ph. D. in English, with an emphasis in American literature and culture, from the University of Iowa. He taught at the University of Iowa, Oklahoma State University, the University of South Dakota, and, for the last four years, as an assistant professor in the Department of American Thought and Language at Michigan State University. He has published articles on Wendell Berry and on recent American poetry. He is now engaged in a more extended interdisciplinary study of sustainable agriculture. He now lives in Minnesota, working as an independent scholar, free-lance writer, and an advocate for sustainable agriculture.     

COMPUTED TOMOGRAPHY OF RAMBOUILLET SHEEP AFFECTED WITH NEURONAL CEROID LIPOFUSCINOSIS

Computed tomography (CT) was performed on 3 normal Rambouillet sheep and 6 Rambouillet sheep affected with neuronal ceroid lipofuscinosis. Characteristic lesions seen in the brain of affected sheep included dramatically enlarged lateral ventricles and reduced cerebral thickness. The lesions were seen in sheep as young as 4 months of age. Antemortem CT observations correlated well with postmortem findings in this model of Neuronal Ceroid Lipofuscinosis.     

The remarkable reproductive diversity of teleost fishes

Teleosts display the most striking reproductive diversity of all vertebrates. However, no convincing hypothesis has yet been proposed to explain why they have evolved this remarkable variability in their modes of reproduction. Some of the features of the reproductive biology of teleosts are briefly reviewed, and unique characteristics of the group that may have made possible the evolution of their remarkable reproductive diversity are considered. These include whole‐genome duplication, the mode of differentiation of the gonads and the organization of the brain–pituitary relationship.     

Results of the international aqueous mercury speciation intercomparison exercise

Twenty-seven laboratories from around the world agreed to participate in an intercomparison exercise for total Hg (Hg_t) and methyl Hg (MMHg) in pristine lake water. Unfiltered samples from a remote brown water lake in northern Wisconsin (USA) were collected into acid cleaned Teflon^® bottles using ultra-clean sample handling techniques. The samples were acidified in the field with 0.4% by volume of pre-analyzed HCl (12N; <5 pg Hg/mL), and sent to the primary reference laboratory (PRL) by overnight mail. Within one week of receipt, the samples were randomized, and 10% analyzed for Hgt and MMHg at the PRL to verify the homogeneity of the set. Each participating laboratory was then sent 3 randomly selected 1 L bottles, while the PRL retained 30, and the secondary reference laboratory (SRL) retained 12 samples. The participating laboratories were asked to analyze each bottle in triplicate for both Hgt and MMHg, reporting all QA data including blanks, spike recoveries, and detection limits. The PRL analyzed samples in triplicate at both the beginning and the end of the analytical window, to provide a controlled estimate of any changes in concentration or speciation over that time. Of the 23 laboratories that returned results, 18 utilized BrCl oxidation, gold trapping, and cold vapor atomic fluorescence (CVAFS) detection for Hg_t. Four laboratories reported similar techniques, varying either in detector (cold vapor atomic absorption), or wet chemistry. Only 16 laboratories reported MMHg results, with 15 using a variation of the aqueous phase ethylation, GC separation, and CVAFS detection technique. The results show good convergence between the participating labs for both Hg_t and MMHg. For Hgt 18 of 23 labs reported means within 20% of the consensus value and PRL results (1.27±0.18 ng/L and 1.27±0.14 ng/L respectively). For MMHg, 13 of the 16 labs reported results within 20% of either the consensus value (0.420±0.055 ng/L) or the PRL value (0.446±0.041 ng/L).