This study examined the effect of a commercial mix of Bacillus sp. on survival, growth and digestive enzyme activities of Florida pompano, red drum and common snook. Larvae were fed either live feed ...enriched with Algamac 3050 (Control), Algamac 3050 and probiotics (PB), or the previous diet combined with a daily addition of probiotics to the tank water (PB+). Survival was not affected by the treatments for any of the species. At the end of the pompano and snook trial, standard lengths of larvae from the PB and PB+ treatments were significantly greater than for the control larvae. Microbiological analyses were performed at the end of the pompano trial, and numbers of presumptive Vibrio were not a concern in the system. For both pompano and snook, trypsin‐specific activity was higher in PB and PB+ larvae compared with the control larvae. Similarly, alkaline phosphatase activity was higher for the pompano larvae fed the PB and PB+ treatments and for the snook larvae fed the PB+ treatment compared with the control larvae. This experiment suggests that a mix of Bacillus sp. can promote growth through an early maturation of the digestive system during the early larval stages of pompano and snook.
Aerobic biological filtration systems employing nitrifying bacteria to remediate excess ammonia and nitrite concentrations are common components of recirculating aquaculture systems (RAS). However, ...significant water exchange may still be necessary to reduce nitrate concentrations to acceptable levels unless denitrification systems are included in the RAS design. This study evaluated the design of a full scale denitrification reactor in a commercial culture RAS application. Four carbon sources were evaluated including methanol, acetic acid, molasses and Cerelose™, a hydrolyzed starch, to determine their applicability under commercial culture conditions and to determine if any of these carbon sources encouraged the production of two common “off-flavor” compounds, 2-methyisoborneol (MIB) or geosmin. The denitrification design consisted of a 1.89
m
3 covered conical bottom polyethylene tank containing 1.0
m
3 media through which water up-flowed at a rate of 10
lpm. A commercial aquaculture system housing 6 metric tonnes of Siberian sturgeon was used to generate nitrate through nitrification in a moving bed biological filter. All four carbon sources were able to effectively reduce nitrate to near zero concentrations from influent concentrations ranging from 11 to 57
mg/l NO
3–N, and the maximum daily denitrification rate was 670–680
g
nitrogen
removed/m
3
media/day, regardless of the carbon source. Although nitrite production was not a problem once the reactors achieved a constant effluent nitrate, ammonia production was a significant problem for units fed molasses and to a less extent Cerelose™. Maximum measured ammonia concentrations in the reactor effluents for methanol, vinegar, Cerelose™ and molasses were 1.62
±
0.10, 2.83
±
0.17, 4.55
±
0.45 and 5.25
±
1.26
mg/l NH
3–N, respectively. Turbidity production was significantly increased in reactors fed molasses and to a less extent Cerelose™. Concentrations of geosmin and MIB were not significantly increased in any of the denitrification reactors, regardless of carbon source. Because of its very low cost compared to the other sources tested, molasses may be an attractive carbon source for denitrification if issues of ammonia production, turbidity and foaming can be resolved.
Hearing loss remains a neglected public health issue in the rural and agricultural communities in the United States and therefore, promotion of a low-cost hearing screening may be important for these ...underserved populations. The major objectives of our study were to assess feasibility of a low-cost telephone-administered hearing test in rural Indiana and to identify the challenges, barriers and viable implementation strategies associated with this test. Also, we evaluated whether a focus group session could change the hearing health attitude of rural residents.
We recruited 126 adults from six rural Indiana counties who participated in study activities in the following order: 1) a pre-focus group demographic, knowledge and attitude survey, 2) a focus group for discussing the feasibility of a telephone-administered hearing screening, 3) a post focus group attitude survey and 4) hearing was screened using an audiometer and self-assessment scale. These activities generated both qualitative and quantitative data, which were subsequently analyzed.
Hearing impairment was perceived as an important public health issue. Many participants expressed interests to try the low-cost National Hearing Test (NHT). However, participants recommended NHT to be facilitated by community organizations to provide access to landline phones. The focus group turned out to be an excellent awareness building activity producing significant improvement in hearing health attitudes. Comparison of self and audiometric evaluations indicated underestimation of hearing handicap in our rural study population.
The study results underscore the urgent need for an effective strategy to promote low-cost hearing screening in rural US communities.
We describe oocyte development in Common Snook Centropomus undecimalis and, secondarily, present results from a comparison of the wet mount technique with histological preparations of ovarian ...biopsies. Potential differences in ovarian development between wild and captive broodstock were investigated. Results showed that mean oocyte diameter (μm) was not statistically different between the two groups or within each defined stage and step of reproductive condition. Histological preparations were used to validate the wet mount technique as a rapid, yet accurate, low-cost alternative for assessing reproductive condition in Common Snook. When compared with histology, the wet mount provided a precise method for determining whether female broodstock were candidates for hormone induction in aquaculture applications. However, due to the loss of fine resolution, it was not possible to identify cortical alveoli, oocyte atresia, and postovulatory follicle complexes by using the wet mount technique. Despite these limitations, findings from this study indicate that the wet mount technique may have applications in fishery biology as a noninvasive method for assessing reproductive condition in wild fish stocks. Received November 7, 2012; accepted March 18, 2013
Background
Parabens may be added to cosmetic and personal care products for preservation purposes. Low‐molecular weight (LMW) phthalate diesters function as plasticizers, fixatives or solvents in ...such products, but may also be found in small quantities as contaminants from plastic containers.
Objective
To evaluate the association between emollient use, atopic dermatitis and FLG mutations, respectively, with urinary concentrations of phthalate metabolites and parabens in Danish children.
Methods
Eight hundred and forty‐five Danish children 4‐9 years of age were studied. Urinary concentrations of phthalate metabolites and parabens were determined, and children were genotyped for common FLG loss‐of‐function mutations. Information about atopic dermatitis and use of emollients was obtained from questionnaires completed by parents.
Results
The prevalence of atopic dermatitis was 16.1%. Phthalate metabolite and paraben levels were generally higher in children with frequent use of emollients compared to uncommon users, reaching statistical significance for some LMW phthalates and parabens. While there was no association with common FLG mutations, children with atopic dermatitis had significantly higher urinary levels of one LMW phthalate and two parabens, respectively, when compared to children without atopic dermatitis.
Conclusion
Emollient use and atopic dermatitis were associated with modestly increased internal LMW phthalate and paraben exposure in 4‐9 year old children. It is unknown whether the difference is explained by increased use of the specific emollients that are used to treat pruritic and inflamed skin, and/or whether the impaired skin barrier allows chemicals to penetrate more easily. Moreover, the putative toxicological burden is unknown.
The Anaerobic Digestion Model No. 1 (ADM1) can be used to describe treatment of dairy manure once manure characteristics have been incorporated in the model. In this paper a parameter set is ...presented that can be used with ADM1 for simulation of dairy manure digester performance. Model results have been verified with bench-scale experiments and reported data from full-scale systems. Model predictions fit experimental data best for biogas composition and digester effluent COD. Simulated biogas productions were inconsistent with measurements from three different digesters. The model overpredicted acetogenesis, resulting in higher simulated than observed acetate concentrations. However, total volatile acid concentrations were simulated reasonably well. The model consistently predicted higher inorganic nitrogen than measured or reported results, indicating a need for further research in that area. The presented model and associated parameter set can be used to simulate and optimize the performance of full-scale dairy manure digesters.
Common snook (
Centropomus undecimalis) is a new candidate species for aquaculture. Its reproductive cycle has not been completed in farmed fish since knowledge of their behaviour in the wild and its ...reproductive physiology remains incomplete, and the only source of seeds comes from wild broodstock. This study was undertaken to examine the fatty acid profile of common snook eggs throughout the spawning season (May to September) in relation to egg quality and larval survival. The fatty acid (FA) composition of eggs collected from wild broodstock stripped on the field (2002–2005), was determined over the spawning season. In general the FA profile observed was consistent with that observed in marine fish apart from a high level of arachidonic acid (ARA) (3.68% of Total FA). The profile of polyunsaturated fatty acids (PUFA) changed over the spawning season (37.5%–29.4% Total FA) and egg quality was best in May, June and July. Eggs with higher concentration (13% of Total FA) of docosahexaenoic acid (DHA) were found to have higher fertilization, hatching and larval survival rate.
Behavioral responses to predators may influence distribution and abundance patterns of prey. Earlier predator—preference experiments and analyses of natural diets revealed that the caridean shrimp ...Tozeuma carolinense is underrepresented in the diet of pinfish, Lagodon rhomboides, the dominant predatory fish in marine seagrass meadows in the southeastern USA. I examined the influence of prey behavioral responses, microhabitat shifts, and cryptic coloration on prey accessibility to Lagodon with a combination of field observations and laboratory experiments. Tozeuma's behavior and microhabitat choice were extremely similar in the field and the laboratory and were tightly coupled to the seagrasses Tozeuma inhabits. In the presence of predatory fishes, Tozeuma increased the time spent in some otherwise rare behaviors. In particular, laboratory experiments revealed that the behavioral response of moving around the grass blade, to which a shrimp was clinging, resulted in a significant increase in shrimp survival, and thus is strongly adaptive. In addition, Tozeuma shifted microhabitats in response to predators; individuals that did not respond were often consumed. For the shrimp, predator—avoidance behaviors were far more important than cryptic coloration in eluding predatory fish. The presence of a physical structure alone did not necessarily provide protection for shrimp from these visual predators; the combination of active predator—avoidance behaviors and the presence of a structurally complex, opaque substrates resulted in a visual barrier between predator and prey. Such prey behavior—microhabitat links can be more important than physical interference of the habitat as factors affecting foraging success of visual predators.
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