Search

ϵ Eridani is the closest star to our Sun known to host a debris disc. Prior observations in the (sub-)millimetre regime have potentially detected clumpy structure in the disc and attributed this to interactions with an (as yet) undetected planet. However, the prior observations were unable to distinguish between structure in the disc and background confusion. Here, we present the first ALMA image of the entire disc, which has a resolution of 1.6 × 1.2 arcsec2. We clearly detect the star, the main belt, and two-point sources. The resolution and sensitivity of this data allow us to clearly distinguish background galaxies (that show up as point sources) from the disc emission. We show that the two-point sources are consistent with background galaxies. After taking account of these, we find that resolved residuals are still present in the main belt, including two clumps with a >3σ significance – one to the east of the star and the other to the north-west. We perform N -body simulations to demonstrate that a migrating planet can form structures similar to those observed by trapping planetesimals in resonances. We find that the observed features can be reproduced by a migrating planet trapping planetesimals in the 2:1 mean motion resonance and the symmetry of the most prominent clumps means that the planet should have a position angle of either ∼10° or ∼190°. Observations over multiple epochs are necessary to test whether the observed features rotate around the star. [ABSTRACT FROM AUTHOR]

HD 38206 is an A0V star in the Columba association, hosting a debris disc first discovered by IRAS. Further observations by Spitzer and Herschel showed that the disc has two components, likely analogous to the asteroid and Kuiper belts of the Solar system. The young age of this star makes it a prime target for direct imaging planet searches. Possible planets in the system can be constrained using the debris disc. Here, we present the first ALMA observations of the system's Kuiper belt and fit them using a forward modelling MCMC approach. We detect an extended disc of dust peaking at around 180 au with a width of 140 au. The disc is close to edge on and shows tentative signs of an asymmetry best fit by an eccentricity of |$0.25^{+0.10}_{-0.09}$|⁠. We use the fitted parameters to determine limits on the masses of planets interior to the cold belt. We determine that a minimum of four planets are required, each with a minimum mass of 0.64 M J , in order to clear the gap between the asteroid and Kuiper belts of the system. If we make the assumption that the outermost planet is responsible for the stirring of the disc, the location of its inner edge and the eccentricity of the disc, then we can more tightly predict its eccentricity, mass, and semimajor axis to be |$e_{\rm {p}}=0.34^{+0.20}_{-0.13}$|⁠ , |$m_{\rm {p}}=0.7^{+0.5}_{-0.3}\, \rm {\it M}_{\rm {J}}$|⁠ , and |$a_{\rm {p}}=76^{+12}_{-13}\, \rm {au}$|⁠. [ABSTRACT FROM AUTHOR]

Gut microbiota plays a crucial role in nutrient digestibility and fish health. This study aimed to investigate the effects of alternative feed raw materials on the bacterial communities in the distal intestine and its relationship with nutrient digestibility in yellowtail kingfish (YTK), Seriola lalandi. Two 4-week digestibility trials were conducted to evaluate fish meal (FM), two sources of poultry by-product meal (PBM-1 & PBM-2), blood meal (BLM), faba bean meal (FBM), corn gluten meal (CGM), soy protein concentrate (SPC) and wheat flour (WH). The nutrient digestibility value was determined using the stripping fecal collection method. Bacterial communities were characterized by high-throughput sequencing based on V3-V4 region of the 16S rRNA gene. The most abundant phylum identified in the present study was Proteobacteria. A significant change in the distal intestine was observed in fish fed diets containing CGM and BLM, characterized by a reduction of species richness and diversity. Additionally, significant correlation between nutrient digestibility and intestinal microbiota was observed. Allivibrio, Vibrio, Curvibacter, Ruminococcaceae, and Clostridium were positively correlated, whereas Ralstonia genus was negatively correlated with nutrient digestibility. This study demonstrated that intestinal microbiota could be a useful tool for evaluating the digestibility of feed raw materials; however, further culture-based study is needed to confirm this observation. [ABSTRACT FROM AUTHOR]

Two-photon photoemission is a useful technique for examining interface, surface, and image-potential states in various materials. We report the temperature and wavelength dependences of the two-photon photoemission yield for several multialkali semiconductors used as photocathode materials in commercially available photomultiplier tubes. We also report the dependence on temperature and wavelength of one-photon photoemission associated with the Fermi tail of the electron-occupancy probability distribution, which can mask two-photon photoemission. The results are expected to be of use in entangled-photon photoemission experiments, for which a large value of the two-photon photoemission yield is required. [ABSTRACT FROM AUTHOR]

One of the defining properties of debris discs compared to protoplanetary discs used to be their lack of gas, yet small amounts of gas have been found around an increasing number of debris discs in recent years. These debris discs found to have gas tend to be both young and bright. In this paper, we conduct a deep search for CO gas in the system HD 95086 – a 17 Myr old, known planet host that also has a debris disc with a high fractional luminosity of 1.5 × 10−3. Using the Atacama Large Millimeter/submillimeter Array (ALMA), we search for CO emission lines in bands 3, 6, and 7. By implementing a spectro-spatial filtering technique, we find tentative evidence for CO J = 2–1 emission in the disc located at a velocity, 8.5 ± 0.2 km s−1, consistent with the radial velocity of the star. The tentative detection suggests that the gas on the east side of the disc is moving towards us. In the same region where continuum emission is detected, we find an integrated line flux of 9.5 ± 3.6 mJy km s−1, corresponding to a CO mass of (1.4–13) × 10−6 M⊕. Our analysis confirms that the level of gas present in the disc is inconsistent with the presence of primordial gas in the system and is consistent with second generation production through the collisional cascade. [ABSTRACT FROM AUTHOR]

When a protoplanetary disc loses gas, it leaves behind planets and one or more planetesimal belts. The belts get dynamically excited, either by planets ('planet stirring') or by embedded big planetesimals ('self-stirring'). Collisions between planetesimals become destructive and start to produce dust, creating an observable debris disc. Following Kenyon & Bromley, it is often assumed that self-stirring starts to operate as soon as the first $${\sim } 1000\,\hbox{km}$$ sized embedded 'Plutos' have formed. However, state-of-the-art pebble concentration models robustly predict planetesimals between a few $$\,\hbox{km}$$ and $${\sim } 200\,\hbox{km}$$ in size to form in protoplanetary discs rapidly, before then slowly growing into Pluto-sized bodies. We show that the time-scale, on which these planetesimals excite the disc sufficiently for fragmentation, is shorter than the formation time-scale of Plutos. Using an analytic model based on the Ida & Makino theory, we find the excitation time-scale to be $$T_{\rm excite} \approx 100 \, x_{\rm m}^{-1} \, M_\star ^{-3/2} \, a^3\,\hbox{Myr}$$, where x m is the total mass of a protoplanetary disc progenitor in the units of the Minimum-Mass Solar Nebula, a is its radius in the units of $$100\,\hbox{au}$$, and M ⋆ is the stellar mass in solar masses. These results are applied to a set of 23 debris discs that have been well resolved with ALMA or SMA. We find that the majority of these discs are consistent with being self-stirred. However, three large discs around young early-type stars do require planets as stirrers. These are 49 Cet, HD 95086, and HR 8799, of which the latter two are already known to have planets. [ABSTRACT FROM AUTHOR]

Monica Ory, who passed away in June 2023, was the Deputy County Archivist at the Warwickshire County Record Office from 1968 to 1996. She was known for her gentle and reassuring presence among staff and researchers. Monica had an impressive career as a cataloguer, creating detailed and extensive catalogs for major collections, including the Feildings of Newnham Paddox and the Warwickshire County Lunatic Asylum. She also worked on exhibitions, wrote talks for local history groups, and trained and oversaw other staff and volunteers. Monica's contributions to the archival world and her kindness and support will be remembered by all who worked with her. [Extracted from the article]

The world is experiencing environmental and social change at an unprecedented rate, with the effects being felt at local, regional, and international scales. This phenomenon may disrupt interventions against neglected tropical diseases (NTDs) that operate on the basis of linear scaling and ‘one-size-fits-all’. Here we argue that investment in field-based data collection and building modelling capacity is required; that it is important to consider unintended consequences of interventions; that inferences can be drawn from wildlife ecology; and that interventions should become more location-specific. Collectively, these ideas underpin the development of adaptive decision-support tools that are sufficiently flexible to address emerging issues within the Anthropocene. [ABSTRACT FROM AUTHOR]

Climate change is expected to impact across every domain of society, including health. The majority of the world's population is susceptible to pathological, infectious disease whose life cycles are sensitive to environmental factors across different physical phases including air, water and soil. Nearly all so-called neglected tropical diseases (NTDs) fall into this category, meaning that future geographic patterns of transmission of dozens of infections are likely to be affected by climate change over the short (seasonal), medium (annual) and long (decadal) term. This review offers an introduction into the terms and processes deployed in modelling climate change and reviews the state of the art in terms of research into how climate change may affect future transmission of NTDs. The 34 infections included in this chapter are drawn from the WHO NTD list and the WHO blueprint list of priority diseases. For the majority of infections, some evidence is available of which environmental factors contribute to the population biology of parasites, vectors and zoonotic hosts. There is a general paucity of published research on the potential effects of decadal climate change, with some exceptions, mainly in vector-borne diseases. [ABSTRACT FROM AUTHOR]

When conducting digestibility experiments with fish many researchers encounter problems that result in erroneous digestibility coefficients. Erroneous digestibility coefficients result from variability in the raw data which is amplified by the formulae used to calculate them. Variation can stem from natural differences in the digestibility of the same diet between individuals or groups of fish. It can also creep insidiously into studies due to poor preparation and mixing of ingredients or problems with the collection of faecal material or the veracity of analytical results. Therefore, it is fairly common to expect variability in data collected from digestibility trials with fish. But what can be done about it? In this paper, we present an experiment with yellowtail kingfish ( Seriola lalandi ) that was done to determine whether the digestibility of extruded wheat (EW) was affected by its inclusion rate (10, 20, 30 or 40% diet − 1 ). The experiment, based on the indicator–ratio method, was conducted without incident, but the raw data on the nutrient and marker concentration of faecal samples was variable. We dealt with this problem by using linear regression to estimate more reliable analytical values for faecal samples. These values were used to recalculate logical digestibility coefficients for EW. Using this approach, we show that dry matter (≈ 57%–40%), carbohydrate (≈ 48%–27%) and gross energy (57–42%) digestibility of EW decline as its inclusion rate rises, whereas the digestibility of protein (≈ 84%) and the digestibility of fat (≈ 94%), remain reasonably constant. We validated the regression approach applied to yellowtail kingfish by examining published data from a similar digestibility experiment on Australian snapper Pagrus auratus . A regression approach was useful in reducing the variability in our raw data because the design of our experiment approximated a dose-response relationship. Designing digestibility experiments using a dose-response approach may prove useful in overcoming the inherent variability often encountered in these types of experiments. [ABSTRACT FROM AUTHOR]

This study aimed to 1) investigate the incidence and characteristics of injuries in emerging rugby league players; and 2) explore the differences in injury incidence and characteristics between the various sub-elite competitions. An NRL emerging player development squad (n = 34) was observed from the beginning of pre-season until the finish of competition. Time-loss injury was defined as any physical pain or impairment sustained that resulted in players missing a match. Injuries were categorised according to circumstance, incidence, characteristics, playing position and competition level. Of a total of 196 injuries that were recorded, 45 were time-loss and 151 were transient. The total injury incidence was 7.9/1,000 playing hours. The most common sites for time-loss injuries were the shoulder, ankle/foot and knee. Ligament injuries accounted for the highest number of injuries by type. Forwards sustained the greatest number of injuries. However, backs suffered the greatest injury cost. The majority of time-loss injuries were sustained during competition matches. Injuries sustained during open age matches resulted in significantly higher injury cost to those received at NYC matches. NRL development and emerging rugby league players are exposed to high risk of injury. Lower limb and shoulder injuries to bone or connective tissue are prevalent as a result of contact during match play. Players at this developmental level feed into several different playing squads where disparities in physical development, maturation, playing intensity and training regimes are evident. This presents a challenge in matching physiological capabilities with playing demands for NRL development squads. [ABSTRACT FROM AUTHOR]

Background: Current interventions against malaria have significantly reduced the number of people infected and the number of deaths. Concerns about emerging resistance of both mosquitoes and parasites to intervention have been raised, and questions remain about how best to generate wider knowledge of the underlying evolutionary processes. The pedagogical and research principles of evolutionary medicine may provide an answer to this problem. Methods: Eight programme managers and five academic researchers were interviewed by telephone or videoconference to elicit their first-hand views and experiences of malaria control given that evolution is a constant threat to sustainable control. Interviewees were asked about their views on the relationship between practit groups and academics and for their thoughts on whether or not evolutionary medicine may provide a solution to reported tensions. Results: There was broad agreement that evolution of both parasites and vectors presents an obstacle to sustainable control. It was also widely agreed that through more efficient monitoring, evolution could be widely monitored. Interviewees also expressed the view that even well planned interventions may fail if the evolutionary biology of the disease is not considered, potentially making current tools redundant. Conclusions: This scoping study suggests that it is important to make research, including evolutionary principles, available and easily applicable for programme managers and key decision-makers, including donors and politicians. The main conclusion is that sharing knowledge through the educational and research processes embedded within evolutionary medicine has potential to relieve tensions and facilitate sustainable control of malaria and other parasitic infections. [ABSTRACT FROM AUTHOR]

Debris discs, the tenuous rocky and icy remnants of planet formation, are believed to be evidence for planetary systems around other stars. The JCMT/SCUBA-2 debris disc legacy survey 'SCUBA-2 Observations of Nearby Stars' (SONS) observed 100 nearby stars, amongst them HD 76582, for evidence of such material. Here, we present imaging observations by JCMT/SCUBA-2 and Herschel/PACS at sub-millimetre and far-infrared wavelengths, respectively. We simultaneously model the ensemble of photometric and imaging data, spanning optical to sub-millimetre wavelengths, in a self-consistent manner. At far-infrared wavelengths, we find extended emission from the circumstellar disc providing a strong constraint on the dust spatial location in the outer system, although the angular resolution is too poor to constrain the interior of the system. In the sub-millimetre, photometry at 450 and 850 μm reveals a steep fall-off that we interpret as a disc dominated by moderately sized dust grains (amin = 36 μm), perhaps indicative of a non-steady-state collisional cascade within the disc. A disc architecture of three distinct annuli, comprising an unresolved component at 20 au and outer components at 80 and 270 au, along with a very steep particle size distribution (γ = 5), is proposed to match the observations. [ABSTRACT FROM AUTHOR]

A 5 week experiment was carried out with juvenile yellowtail kingfish Seriola lalandi to investigate the interactive effects of water temperature (21, 24, or 27°C) and dissolved oxygen regime (normoxic vs. hypoxic) on the growth rate, feed intake and digestive enzyme activity of this species. Specific growth rate ( SGR) was highest at 24°C, regardless of oxygen regime, but the SGRs of the fish exposed to hypoxia at 21, 24 and 27°C were 13%, 20% and 17% lower, respectively, than the SGRs recorded for the fish reared under normoxic conditions. The digestive enzyme activities (i.e. trypsin, lipase and α-amylase) were influenced by temperature but did not appear to be affected by dissolved oxygen concentration. Information about the effects of water temperature and dissolved oxygen on feeding, growth and digestive capacity of juvenile yellowtail kingfish could contribute to improving feed management decisions for production of this fish species under different environmental conditions. [ABSTRACT FROM AUTHOR]

The Essential Amino Acid (EAA) requirements of many cultured species remains unknown and therefore aquafeeds used in new industries are often based on the requirements of similar species or those from a similar trophic level. One such example is the formulation of aquafeeds for Australian Yellowtail Kingfish Seriola lalandi (YTK), which are historically based on the published EAA requirements of Japanese Yellowtail Seriola quinqueradiata. The requirements of YTK for sulphur-amino acids as well as taurine have recently been quantified. These studies indicated that cultured YTK may have different EAA requirements to Japanese Yellowtail which has raised doubts about the adequacy of other EAAs in commercial feeds for YTK. Of these, the adequacy of histidine was considered particularly important due to concerns about cataract formation and poor growth. Therefore, the digestible histidine requirement of YTK was quantified using a dose-response design that employed a fishmeal-free basal diet containing 0.61% digestible histidine. Supplemental crystalline L-histidine was added to the basal formulation in 0.5% increments resulting in four additional diets with a digestible histidine content of 0.96, 1.32, 1.61 and 2.0%, respectively. Each dietary treatment was assigned to triplicate saltwater tanks containing 10 × 80 g YTK which were fed to apparent satiation for seven weeks at a temperature of 20 °C. Despite the incremental addition of histidine there were no differences in growth rate, feed intake, condition factor and feed conversion ratio of YTK in response to dietary treatment. In contrast, evaluation of whole carcass revealed histidine deposition rate increased in response to digestible histidine content before declining at the highest dietary level (i.e. >1.61%), suggesting YTK had reached their maximum rate of histidine deposition under our experimental conditions. A factorial analysis of the retention data from the current study was compared to and combined with previous factorial models on histidine utilisation by YTK. The combined model indicated that while the maintenance demand for histidine varied with experimental conditions, the unit cost of histidine deposition in YTK was constant at 1.99. A conservative estimate of the variable digestible histidine requirement for maintenance at temperatures between 15 and 24 °C was found to be 64.2 mg kgBW-0.7d−1. Feed ration models generated from the factorial data sets indicate YTK should be fed diets that contain between 1.6 and 2.0% digestible histidine in order to meet their daily histidine requirement. These amounts are slightly higher than generally recommended for Japanese Yellowtail. • The unit cost of histidine deposition in Yellowtail Kingfish is 1.99:1, and constant. • The maintenance histidine requirement of Yellowtail Kingfish is approximately 64 mg kgBW-0.7d−1. • Yellowtail Kingfish should be fed diets that contain between 1.6 and 2.0% digestible histidine • Yellowtail Kingfish grow well on zero fishmeal diets containing brewer's yeast and krill meal. [ABSTRACT FROM AUTHOR]

The Essential Amino Acid (EAA) requirements of many cultured species remains unknown and therefore aquafeeds used in new industries are often based on the requirements of similar species or those from a similar trophic level. One such example is the formulation of aquafeeds for Australian Yellowtail Kingfish Seriola lalandi (YTK), which are historically based on the published EAA requirements of Japanese Yellowtail Seriola quinqueradiata. The requirements of YTK for sulphur-amino acids as well as taurine have recently been quantified. These studies indicated that cultured YTK may have different EAA requirements to Japanese Yellowtail which has raised doubts about the adequacy of other EAAs in commercial feeds for YTK. Of these, the adequacy of histidine was considered particularly important due to concerns about cataract formation and poor growth. Therefore, the digestible histidine requirement of YTK was quantified using a dose-response design that employed a fishmeal-free basal diet containing 0.61% digestible histidine. Supplemental crystalline L-histidine was added to the basal formulation in 0.5% increments resulting in four additional diets with a digestible histidine content of 0.96, 1.32, 1.61 and 2.0%, respectively. Each dietary treatment was assigned to triplicate saltwater tanks containing 10 × 80 g YTK which were fed to apparent satiation for seven weeks at a temperature of 20 °C. Despite the incremental addition of histidine there were no differences in growth rate, feed intake, condition factor and feed conversion ratio of YTK in response to dietary treatment. In contrast, evaluation of whole carcass revealed histidine deposition rate increased in response to digestible histidine content before declining at the highest dietary level (i.e. >1.61%), suggesting YTK had reached their maximum rate of histidine deposition under our experimental conditions. A factorial analysis of the retention data from the current study was compared to and combined with previous factorial models on histidine utilisation by YTK. The combined model indicated that while the maintenance demand for histidine varied with experimental conditions, the unit cost of histidine deposition in YTK was constant at 1.99. A conservative estimate of the variable digestible histidine requirement for maintenance at temperatures between 15 and 24 °C was found to be 64.2 mg kgBW-0.7d−1. Feed ration models generated from the factorial data sets indicate YTK should be fed diets that contain between 1.6 and 2.0% digestible histidine in order to meet their daily histidine requirement. These amounts are slightly higher than generally recommended for Japanese Yellowtail. • The unit cost of histidine deposition in Yellowtail Kingfish is 1.99:1, and constant. • The maintenance histidine requirement of Yellowtail Kingfish is approximately 64 mg kgBW-0.7d−1. • Yellowtail Kingfish should be fed diets that contain between 1.6 and 2.0% digestible histidine • Yellowtail Kingfish grow well on zero fishmeal diets containing brewer's yeast and krill meal. [ABSTRACT FROM AUTHOR]

Introduction: There is increasing interest in the control and elimination of schistosomiasis. Little is known, however, about the likely effects of increasing water-body temperatures on transmission. Methods: We have developed an agent-based model of the temperature-sensitive stages of the Schistosoma and intermediate host snail life-cycles, parameterised using data from S. mansoni and Biomphalaria pfeifferi laboratory and field-based observations. Infection risk is calculated as the number of cercariae in the model, adjusted for their probability of causing infection. Results: The number of snails in the model is approximately constant between 15–31°C. Outside this range, snail numbers drop sharply, and the snail population cannot survive outside the range 14–32°C. Mean snail generation time decreases with increasing temperature from 176 days at 14°C to 46 days at 26°C. Human infection risk is highest between 16–18°C and 1pm and 6–10pm in calm water, and 20–25°C and 12–4pm in flowing water. Infection risk increases sharply when temperatures increase above the minimum necessary for sustained transmission. Conclusions: The model suggests that, in areas where S. mansoni is already endemic, warming of the water at transmission sites will have differential effects on both snails and parasites depending on abiotic properties of the water-body. Snail generation times will decrease in most areas, meaning that snail populations will recover faster from natural population reductions and from snail-control efforts. We suggest a link between the ecological properties of transmission sites and infection risk which could significantly affect the outcomes of interventions designed to alter water contact behaviour – proposing that such interventions are more likely to reduce infection levels at river locations than lakes, where infection risk remains high for longer. In cooler areas where snails are currently found, increasing temperatures may significantly increase infection risk, potentially leading to new, high-intensity foci of infection. [ABSTRACT FROM AUTHOR]

Introduction: A number of studies have attempted to predict the effects of climate change on schistosomiasis risk. The importance of considering different species of intermediate host snails separately has never previously been explored. Methods: An agent-based model of water temperature and Biomphalaria pfeifferi population dynamics and Schistosoma mansoni transmission was parameterised to two additional species of snail: B. glabrata and B. alexandrina. Results: Simulated B. alexandrina populations had lower minimum and maximum temperatures for survival than B. pfeifferi populations (12.5–29.5°C vs. 14.0–31.5°C). B. glabrata populations survived over a smaller range of temperatures than either B. pfeifferi or B. alexandrina (17.0°C–29.5°C). Infection risk peaked at 16.5°C, 25.0°C and 19.0°C respectively when B. pfeifferi, B. glabrata and B. alexandrina were simulated. For all species, infection risk increased sharply once a minimum temperature was reached. Conclusions: The results from all three species suggest that infection risk may increase dramatically with small increases in temperature in areas at or near the currents limits of schistosome transmission. The effect of small increases in temperature in areas where schistosomiasis is currently found will depend both on current temperatures and on the species of snail acting as intermediate host(s) in the area. In most areas where B. pfeifferi is the host, infection risk is likely to decrease. In cooler areas where B. glabrata is the host, infection risk may increase slightly. In cooler areas where B. alexandrina is the host, infection risk may more than double with only 2°C increase in temperature. Our results show that it is crucial to consider the species of intermediate host when attempting to predict the effects of climate change on schistosomiasis. [ABSTRACT FROM AUTHOR]

Highlights: [ • ] Climate change is an important potential modifier of schistosomiasis control plans. [ • ] We highlight important knowledge gaps in predictive mathematical models. [ • ] We stress the need to consider the impact of changes in rainfall and extreme weather events. [•] We suggest observations and experiments needed to support modelling efforts. [ABSTRACT FROM AUTHOR]

Feeding regimes on fish farms are often disrupted for logistical reasons or adverse environmental conditions. Issues such as these are commonplace with respect to the sea pen culture of Yellowtail Kingfish Seriola lalandi (YTK) in Australia. These disruptions represent periods of feed restriction which lead to reduced productivity. However, production losses may be ameliorated using different feeding strategies or the use of nutrient dense aquafeeds. To examine the potential of these options we conducted an eight-week experiment with sub-adult YTK (stocking weight ~ 0.80 kg) investigating three feeding regimes crossed with two dietary specifications. The feeding regimes were selected following industry consultation; feeding once daily 7 days per week (control), once daily Monday to Friday (economic) or once daily on randomly selected days of the week (random). Regardless of regime all feed was offered to apparent satiation. A standard specification (Std-Spec; 386 g DP kg−1, 15.1 MJ DE kg−1) and high specification diet (High-Spec; 460 g DP kg−1 and 19.2 MJ DE kg−1) were formulated using a similar suite of ingredients. Each of the 6 treatment combinations was fed to three replicate tanks of fish and results were examined using two-way ANOVA. There was a general absence of interaction between the main effects for most production indices. Specific growth rate (SGR) and relative feed intake (RFI) were significantly better in YTK fed 7 days per week than in YTK fed under more restricted regimes, but feeding regime did not affect FCR. The SGR, FCR and condition factor of YTK were significantly better when fed the High-Spec diet than in YTK fed the Std-Spec diet. The RFI of fish fed under restricted regimes was significantly lower than YTK fed 7 days per week, irrespective of diet specification, indicating YTK were not capable of hyperphagia. However, the RFI of YTK fed the Std-Spec diet was significantly higher than YTK fed the High-Spec diet, confirming nutrient or energy density was likely controlling feed intake. Examination of data on digestible protein, fat and energy intake indicated YTK were eating primarily to satisfy their protein requirement and sub-optimal energy intake was indirectly limiting growth. Our results demonstrate YTK have a limited capacity to increase their feed intake as a means of overcoming moderate feed restriction in order to meet nutrient and energy demands. We recommend feeding YTK of this size a high specification diet to apparent satiation once per day 7 days a week in order to maximize their growth, feed efficiency and physical condition. • Production performance of Yellowtail Kingfish is better using a high specification diet. • Feed intake in Yellowtail Kingfish is governed by their digestible protein requirement. • The production performance of YTK is extremely sensitive to the nutrient and energy composition of aquafeeds. [ABSTRACT FROM AUTHOR]

The majority of debris discs discovered so far have only been detected through infrared excess emission above stellar photospheres. While disc properties can be inferred from unresolved photometry alone under various assumptions for the physical properties of dust grains, there is a degeneracy between disc radius and dust temperature that depends on the grain size distribution and optical properties. By resolving the disc we can measure the actual location of the dust. The launch of Herschel, with an angular resolution superior to previous far-infrared telescopes, allows us to spatially resolve more discs and locate the dust directly. Here we present the nine resolved discs around A stars between 20 and 40 pc observed by the Disc Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre (DEBRIS) survey. We use these data to investigate the disc radii by fitting narrow ring models to images at 70, 100 and 160 μm and by fitting blackbodies to full spectral energy distributions. We do this with the aim of finding an improved way of estimating disc radii for unresolved systems. The ratio between the resolved and blackbody radii varies between 1 and 2.5. This ratio is inversely correlated with luminosity and any remaining discrepancies are most likely explained by differences to the minimum size of grain in the size distribution or differences in composition. We find that three of the systems are well fit by a narrow ring, two systems are borderline cases and the other four likely require wider or multiple rings to fully explain the observations, reflecting the diversity of planetary systems. [ABSTRACT FROM PUBLISHER]

Abstract: Polarization-sensitive quantum optical coherence tomography (PS-QOCT) makes use of a Type-II twin-photon light source for carrying out optical sectioning with polarization sensitivity. A BBO nonlinear optical crystal pumped by a Ti:sapphire psec-pulsed laser is used to confirm the theoretical underpinnings of this imaging paradigm. PS-QOCT offers even-order dispersion cancellation with simultaneous access to the group-velocity dispersion characteristics of the interstitial medium between the reflecting surfaces of the sample. [Copyright &y& Elsevier]

Abstract: This study used a factorial approach to estimate the digestible protein (DP) and energy (DE) requirements of yellowtail kingfish Seriola lalandi weighing between 50 to 2000g and reared at 20–25°C. The factorial model was subsequently used to calculate theoretical changes in the optimum ratio of DP:DE (g DP MJ DE−1) and estimate changes in the theoretical feed conversion ratio (FCR) or feed intake with increasing fish size. Growth of S. lalandi was described by the function; growth (g fish−1 d−1)=0.268±0.33 BW (g)0.52±0.2. Body weight exponents for protein or energy loss in S. lalandi were found to be statistically similar to 0.7 or 0.8, respectively. Maintenance requirements for DP were found to be 1.70g DP BW (kg)−0.7 d−1 while those for DE were found to be 87.44kJ BW (kg)−0.8 d−1. Utilisation coefficients for DP or DE estimated from linear regressions which incorporated data above and below maintenance ration were 0.51 and 0.65, respectively. However, regressions which excluded data below maintenance ration returned coefficients of 0.41 (DP) and 0.55 (DE). The partial energetic efficiencies of protein (K P ) and lipid (K L ) deposition as estimated by multiple linear regression were 0.61 and 0.83, respectively. Piecewise linear regression analysis was applied to the curvilinear response of DP:DE on increasing fish weight in order to differentiate key growth stages in the production of S. lalandi. Three stages were identified; a juvenile stage≤200g, an intermediate stage between 200 and 1000g and a stage for fish≥1000g. These stages corresponded to DP:DE requirements of 38, 31 and 24g DP MJ DE−1, respectively. Practical diet formulations that would best meet the DP:DE criteria for fish≤200g are those which contain approximately 456g DP kg−1 and 12MJ DE kg−1. For fish growing between 200 and 1000g a diet containing 465g DP kg−1 and 15MJ DE kg−1 would be suitable while a diet containing 432g DP kg−1 and 18MJ DE kg−1 would be appropriate for fish≥1000g. Further evaluation of growth potential and nutrient requirements at different water temperatures will assist in improving the utility of this model. [Copyright &y& Elsevier]

Abstract: This study applied a factorial approach to predicting the requirements for digestible protein (DP) and digestible energy (DE) for mulloway throughout the production range. Published data relating to protein and energy utilisation and protein and energy requirements for maintenance and growth of this species were consolidated with quantitative descriptions of proximate whole body composition and an assessment of growth potential undertaken over a range of temperature and fish sizes. Factorial modelling of the data provided estimations of the decreasing requirement of the ratio of DP:DE for mulloway with increasing body size up to 2kg. Piecewise regression analyses identified significant changes in the requirement for DP:DE at key growth stages. From this information diet specifications and suggested daily feed intake were iteratively derived applicable for the different dietary requirements dependant on body size. Four growth stages with corresponding dietary requirement for DP:DE are suggested; 10–100g=31.3g DP MJ DE−1 , 100–500g=24.8g DP MJ DE−1, 500–1100g=20.8g DP MJ DE−1, 1100–2000g=19.1g DP MJ DE−1. Sensitivity analyses was used to test the response of the factorial model to small perturbations of individual parameter values on the predicted optimal ratio of DP:DE. Protein and energy utilisation coefficients and the whole body composition coefficients for protein and energy were identified to have the greatest influence on the predicted requirement for DP:DE while the growth model exponent value becomes increasingly influential for fish >200g. [Copyright &y& Elsevier]

The article presents a reprint of an auction catalog of the sale of photographer Camille Silvy’s studio located at 38 Porchester Terrace, Bayswater in London, England. The sale was held on March 23-24, 1869 by Lomax & Flexman of 8 Orchard Street, Portman Square, London. A list of the contents of the photographic laboratory, printing frames, backdrops, cameras, lenses, and furniture is provided.

The Nice model of Gomes et al. suggests that the migration of the giant planets caused a planetesimal clearing event, which led to the late heavy bombardment (LHB) at 880 Myr. Here, we investigate the infrared emission from the Kuiper belt during the history of the Solar system as described by the Nice model. We describe a method for easily converting the results of N-body planetesimal simulations into observational properties (assuming blackbody grains and a single size distribution) and further modify this method to improve its realism (using realistic grain properties and a three-phase size distribution). We compare our results with observed debris discs and evaluate the plausibility of detecting an LHB-like process in extrasolar systems. Recent surveys have shown that 4 per cent of stars exhibit 24 μm excess and 16 per cent exhibit 70 μm excess. We show that the Solar system would have been amongst the brightest of these systems before the LHB at both 24 and 70 μm. We find a significant increase in 24 μm emission during the LHB, which rapidly drops off and becomes undetectable within 30 Myr, whereas the 70 μm emission remains detectable until 360 Myr after the LHB. Comparison with the statistics of debris disc evolution shows that such depletion events must be rare occurring around less than 12 per cent of Sun-like stars and with this level of incidence we would expect approximately one of the 413 Sun-like field stars so far detected to have a 24 μm excess to be currently going through an LHB. We also find that collisional processes are important in the Solar system before the LHB and that parameters for weak Kuiper belt objects are inconsistent with the Nice model interpretation of the LHB. [ABSTRACT FROM AUTHOR]

Abstract: Specific dynamic action (SDA) is the energy expended on the physiological processes associated with meal digestion and is strongly influenced by the characteristics of the meal and the body weight (BW) and temperature of the organism. This study assessed the effects of temperature and body weight on the routine metabolic rate (RMR) and postprandial metabolic response in mulloway, Argyrosomus japonicus. RMR and SDA were established at 3 temperatures (14, 20 and 26 °C). 5 size classes of mulloway ranging from 60 g to 1.14 kg were used to establish RMR with 3 of the 5 size classes (60, 120 and 240 g) used to establish SDA. The effect of body size on the mass-specific RMR (mg O2 kg−1 h−1) varied significantly depending on the temperature; there was a greater relative increase in the mass-specific RMR for smaller mulloway with increasing temperature. No statistical differences were found between the mass exponent (b) values at each temperature when tested against H 0: b =0.8. The gross RMR of mulloway (mg O2 fish−1 h−1) can be described as function of temperature (T; 14–26 °C) as: (0.0195T–0.0454)BW(g)0.8 and the mass-specific RMR (mg O2 kg−1 h−1) can be described as: (21.042T–74.867)BW(g)−0.2. Both SDA duration and time to peak SDA were influenced by temperature and body weight; SDA duration occurred within 41–89 h and peak time occurred within 17–38 h of feeding. The effect of body size on peak metabolic rate varied significantly depending on temperature, generally increasing with temperature and decreasing with increasing body size. Peak gross oxygen consumption (MO2: mg O2 fish−1 h−1) scaled allometrically with BW. Temperature, but not body size, significantly affected SDA scope, although the difference was numerically small. There was a trend for MO2 above RMR over the SDA period to increase with temperature; however, this was not statistically significant. The average proportion of energy expended over the SDA period (SDA coefficient) ranged from approximately 7–13% of the total DE intake while the proportion of total energy expended on SDA above RMR ranged from approximately 16–27%. [Copyright &y& Elsevier]

Abstract: This study compared the mass-specific routine metabolic rate (RMR) of similar sized mulloway (Argyrosomus japonicus), a sedentary species, and yellowtail kingfish (Seriola lalandi), a highly active species, acclimated at one of several temperatures ranging from 10–35 °C. Respirometry was carried out in an open-top static system and RMR corrected for seawater–atmosphere O2 exchange using mass-balance equations. For both species RMR increased linearly with increasing temperature (T). RMR for mulloway was 5.78T −29.0 mg O2 kg−0.8 h−1 and for yellowtail kingfish was 12.11T −39.40 mg O2 kg−0.8 h−1. The factorial difference in RMR between mulloway and yellowtail kingfish ranged from 2.8 to 2.2 depending on temperature. The energetic cost of routine activity can be described as a function of temperature for mulloway as 1.93T −9.68 kJ kg−0.8 day−1 and for yellowtail kingfish as 4.04T −13.14 kJ kg−0.8 day−1. Over the full range of temperatures tested Q 10 values were approximately 2 for both species while Q 10 responses at each temperature increment varied considerably with mulloway and yellowtail kingfish displaying thermosensitivities indicative of each species respective niche habitat. RMR for mulloway was least thermally dependent at 28.5 °C and for yellowtail kingfish at 22.8 °C. Activation energies (E a) calculated from Arrhenius plots were not significantly different between mulloway (47.6 kJ mol−1) and yellowtail kingfish (44.1 kJ mol−1). [Copyright &y& Elsevier]

A two-factor experiment was carried out to investigate the change in skin colour and plasma cortisol response of cultured Australian snapper Pagrus auratus to a change in background colour. Snapper (mean weight=437 g) were held in black or white tanks and fed diets containing 39 mg unesterified astaxanthin kg−1 for 49 days before being transferred from white tanks to black cages (WB) or black tanks to white cages (BW). Skin colour values [ L* (lightness), a* (redness) and b* (yellowness)] of all snapper were measured at stocking ( t=0 days) and from cages of fish randomly assigned to each sampling time at 0.25, 0.5, 1, 2, 3, 5 and 7 days. Plasma cortisol was measured in anaesthetized snapper following colour measurements at 0, 1 and 7 days. Fish from additional black-to-black (BB) and white-to-white (WW) control treatments were also sampled for colour and cortisol at those times. Rapid changes occurred in skin lightness ( L* values) after altering background colour with maximum change in L* values for BW and WB treatments occurring within 1 day. Skin redness ( a*) of BW snapper continued to steadily decrease over the 7 days ( a*=7.93 × e−0.051 × time). Plasma cortisol concentrations were highest at stocking when fish were held at greater densities and were not affected by cage colour. The results of this study suggest that transferring dark coloured snapper to white cages for 1 day is sufficient to affect the greatest benefit in terms of producing light coloured fish while minimizing the reduction in favourable red skin colouration. [ABSTRACT FROM AUTHOR]

A single-factor experiment was conducted to investigate the effects of dietary astaxanthin concentration on the skin colour of snapper. Snapper (mean weight=129 g) were held in white cages and fed one of seven dietary levels of unesterified astaxanthin (0, 13, 26, 39, 52, 65 or 78 mg astaxanthin kg−1) for 63 days. Treatments comprised four replicate cages, each containing five fish. The skin colour of all fish was quantified using the CIE L*, a*, b* colour scale after 21, 42 and 63 days. In addition, total carotenoid concentrations of the skin of two fish cage−1 were determined after 63 days. Supplementing diets with astaxanthin strongly affected redness ( a*) and yellowness ( b*) values of the skin at all sampling times. After 21 days, the a* values increased linearly as the dietary astaxanthin concentration was increased before a plateau was attained between 39 and 78 mg kg−1. The b* values similarly increased above basal levels in all astaxanthin diets. By 42 days, a* and b* values increased in magnitude while a plateau remained between 39 and 78 mg kg−1. After 63 days, there were no further increases in measured colour values, suggesting that maximum pigmentation was imparted in the skin of snapper fed diets >39 mg kg−1 after 42 days. Similarly, there were no differences in total carotenoid concentrations of the skin of snapper fed diets >39 mg kg−1 after 63 days. The plateaus that occurred in a* and b* values, while still increasing in magnitude between 21 and 42 days, indicate that the rate of astaxanthin deposition in snapper is limited and astaxanthin in diets containing >39 mg astaxanthin kg−1 is not efficiently utilized. Astaxanthin retention after 63 days was greatest from the 13 mg kg−1 diet; however, skin pigmentation was not adequate. An astaxanthin concentration of 39 mg kg−1 provided the second greatest retention in the skin while obtaining maximum pigmentation. To efficiently maximize skin pigmentation, snapper growers should commence feeding diets containing a minimum of 39 mg unesterified astaxanthin kg−1 at least 42 days before sale. [ABSTRACT FROM AUTHOR]

Background. Helminth infections and malaria are widespread in the tropics. Recent studies suggest helminth infections may increase susceptibility to Plasmodium falciparum infection. If confirmed, this increased susceptibility could be particularly important during pregnancy-induced immunosuppression. Objective. To evaluate the geographical distribution of P. falciparum-helminth coinfection and the associations between P. falciparum infection and infection with various parasite species in pregnant women in Entebbe, Uganda. Methods. A cross-sectional study was conducted at baseline during a trial of antihelminthic drugs during pregnancy. Helminth and P. falciparum infections were quantified in 2507 asymptomatic women. Subjects' socioeconomic and demographic characteristics and geographical details were recorded. Results. Hookworm and Mansonella perstans infections were associated with P. falciparum infection, but the effect of hookworm infection was seen only in the absence of M. perstans infection. The odds ratio [OR] for P. falciparum infection, adjusted for age, tribe, socioeconomic status, HIV infection status, and location was as follows: for individuals infected with hookworm but not M. perstans, 1.53 (95% confidence interval [CI], 1.09 -2.14); for individuals infected with M. perstans but not hookworm, 2.33 (95% CI, 1.47-3.69); for individuals infected with both hookworm and M. perstans, 1.85 (CI, 1.24 -2.76). No association was observed between infection with Schistosoma mansoni, Trichuris, or Strongyloides species and P. falciparum infection. Conclusions. Hookworm-P. falciparum coinfection and M. perstans-P. falciparum coinfection among pregnant women in Entebbe is more common than would be expected by chance. Further studies are needed to elucidate the mechanism of this association. A helminth-induced increase in susceptibility to P. falciparum could have important consequences for pregnancy outcome and responses to P. falciparum infection in infancy. [ABSTRACT FROM AUTHOR]

Consensus is growing that long-term care delivery, regulation, and financing are no longer viable, a concern that will grow more salient as the population ages. To better understand these prevailing challenges, the authors interviewed experts regarding the current state of long-term care in the United States, the attributes of an ideal long-term care system, and potential areas for reform. The findings highlight the problem of maintaining an adequate workforce despite changing demographics. They also identify commonly agreed upon attributes of an ideal system—person centered, professionally rewarding, integrated, affordable, accountable, community based, and consumer directed—in addition to less commonly identified attributes—supportive, comprehensive, dignified, culturally appropriate, innovative, responsible, and safe and secure. Areas for reform include workforce recruitment and retention, financing and insurance, quality improvement and regulation, health information technology, and organizational change and innovation. The challenges facing long-term care must be addressed by both government and private citizens alike if long-term care recipients' lives are to improve and the increased demand for services is to be met. [ABSTRACT FROM AUTHOR]

There are several innovative service delivery models in the United States (US) relevant to long-term care policy development and implementation in New Zealand. An especially fruitful source of innovation has been the culture change movement, which originated in the US but has begun to spread to New Zealand and other OECD countries. The culture change philosophy requires that providers respond to the values, preferences, and needs of care recipients. It also requires devolving authority to direct care workers who know their clients best, in addition to transitioning from sterile 'clinical' settings to more homelike environments. New Zealand has a more favourable policy context for improving long-term care than the US. Thus, it is critical that it build upon these short term advantages to promote further dissemination of the culture change ethos, thereby placing caregivers in a better position to meet current care challenges, not to mention those posed by growth in the elderly population ahead. [ABSTRACT FROM AUTHOR]

The USA and New Zealand have different health and social care systems, but both share a desire for high-quality, affordable, long-term care for elders. In the USA moves have been made to integrate long-term care services within single capitated providers to provide clients with a seamless, easy-to-use service. Other initiatives seek to improve consumer direction by giving clients control of funding their own long-term care services. Such initiatives use different incentives to balance the need for high-quality care with affordability at both an individual and societal level. Initial analysis suggests that satisfaction and outcomes improve under these schemes. The integration models provide an interesting comparison for New Zealand as primary health care changes are further developed. [ABSTRACT FROM AUTHOR]

A two-factor experiment was performed to evaluate the effects of cage colour (black or white 0.5 m3 experiment cages) and light environment (natural sunlight or reduced level of natural sunlight) on the skin colour of darkened Australian snapper. Each treatment was replicated four times and each replicate cage was stocked with five snapper (mean weight=351 g). Snapper exposed to natural sunlight were held in experimental cages located in outdoor tanks. An approximately 70% reduction in natural sunlight (measured as PAR) was established by holding snapper in experimental cages that were housed inside a ‘shade-house’ enclosure. The skin colour of anaesthetized fish was measured at stocking and after a 2-, 7- and 14-day exposure using a digital chroma-meter (Minolta CR-10) that quantified skin colour according to the L* a* b* colour space. At the conclusion of the experiment, fish were killed in salt water ice slurry and post-mortem skin colour was quantified after 0.75, 6 and 22 h respectively. In addition to these trials, an ad hoc market appraisal of chilled snapper (mean weight=409 g) that had been held in either white or in black cages was conducted at two local fish markets. Irrespective of the sampling time, skin lightness ( L*) was significantly affected by cage colour ( P<0.05), with fish in white cages having much higher L* values ( L*≈64) than fish held in black cages ( L*≈49). However, the value of L* was not significantly affected by the light environment or the interaction between cage colour and the light environment. In general, the L* values of anaesthetized snapper were sustained post mortem, but there were linear reductions in the a* (red) and b* (yellow) skin colour values of chilled snapper over time. According to the commercial buyers interviewed, chilled snapper that had been reared for a short period of time in white cages could demand a premium of 10–50% above the prices paid for similar-sized snapper reared in black cages. Our results demonstrate that short-term use of white cages can reduce the dark skin colour of farmed snapper, potentially improving the profitability of snapper farming. [ABSTRACT FROM AUTHOR]

This study used a curvilinear model to investigate the effects of different digestible energy (DE) levels on the digestible protein (DP) requirements of juvenile snapper Pagrus auratus. For each DE level (15, 18 or 21 MJ kg−1), DP content was increased from about 210–560 g kg−1 in seven evenly spaced increments by formulating a summit diet (highest DP content) and a diluent diet (lowest DP content) at the desired DE level and combining the summit and diluent diets in various ratios to achieve the desired DP content. This ensured the DE level remained relatively stable. Each of the 21 dietary treatments was fed to three replicate groups of snapper twice daily to apparent satiation for 57 days. At the completion of the trial, fish were weighed and killed for chemical analysis. Results indicated that the rapid growth of snapper weighing 30–90 g was highly dependent on the ratio of DP to DE and that optimum protein deposition did not occur until snapper were offered feeds with at least 350 g DPkg−1, irrespective of DE level. According to the fitted models, diets formulated for snapper reared at temperatures from 20–25°C should contain approximately 23 g DP MJ DE−1 to promote optimal weight gain and protein deposition. Based on the feeding regime used in this study, this could be achieved with practical diets containing a DP:DE ratio of 460:20, 420:18 or 350:15. [ABSTRACT FROM AUTHOR]

Background: Amongst school-aged children living in malaria endemic areas, chronic morbidity and exacerbation of morbidity associated with other infections are often not coincident with the presence or levels of Plasmodium parasitaemia, but may result from long-term exposure to the parasite. Studies of hepatosplenomegaly associated with Schistosoma mansoni infection and exposure to Plasmodium infection indicate that differences that occur over 1-2 km in levels of Plasmodium transmission are related to the degree of exacerbation of hepatosplenomegaly and that Plasmodium falciparum schizont antigen (Pfs)-IgG3 levels may be a marker for the differing levels of exposure. Methods: To investigate the validity of Pfs-IgG3 measurements as a tool to assess these comparative exposure levels on a microgeographical scale, cross-sectional community surveys were conducted over a 10 x 6 km study site in Makueni District, Kenya, during low and high malaria transmission seasons. During both high and low malaria transmission seasons, thick blood smears were examined microscopically and circulating Pfs-IgG3 levels measured from dried blood spot elute. GIS techniques were used to map prevalence of parasitaemia and Pfs-IgG3 levels. Results: Microgeographical variations in prevalence of parasitaemia were observed during the high but not the low transmission season. Pfs-IgG3 levels were stable between high and low transmission seasons, but increased with age throughout childhood before reaching a plateau in adults. Adjusting Pfs-IgG3 levels of school-aged children for age prior to mapping resulted in spatial patterns that reflected the microgeographical variations observed for high season prevalence of parasitaemia, however, Pfs-IgG3 levels of adults did not. The distances over which age-adjusted Pfs-IgG3 of school-aged children fluctuated were comparable with those distances over which chronic morbidity has previous been shown to vary. Conclusion: Age-adjusted Pfs-IgG3 levels of school-aged children are stable and when mapped can provide a tool sensitive enough to detect microgeographical variations in malaria exposure, that would be useful for studying the aetiology of morbidities associated with long-term exposure and co-infections. [ABSTRACT FROM AUTHOR]

Abstract: An experiment was done to investigate the interactive effects of photoperiod (12L:12D or 18L:6D) and feeding frequency on the growth of newly weaned Australian snapper (mean weight=0.14 g fish−1). Feeding frequency was investigated over 4 levels with 2 feeds delivered during the first half of the daylight period (2FE), 2 feeds during the latter half of the daylight period (2FL), 4 (4F) or 8 (8F) evenly spaced feeds per daylight period. Each treatment combination was replicated in 6 tanks and each tank was stocked with a biomass of 15 g tank−1 (i.e. approximately 108 fish tank−1). Snapper were fed a constant ration of 10% BW day−1 for 32 days, which was adjusted during the experiment according to frequent weight check procedures. Fish that died were counted but not replaced. Photoperiod, feeding frequency and the interaction of these factors significantly affected the individual harvest weight and thermal growth coefficient (TGC) of snapper. Interactions were driven by an increase in the magnitude of individual weight and TGC in snapper fed the 4F and 8F treatments and reared under the 18L:6D photoperiod, compared to snapper fed at the same frequencies but reared under the 12L:12D regime. Weight gain and TGC were best in snapper reared under a 18L:6D photoperiod regime and fed 8 feeds day−1, however, weight gain did not plateau, suggesting further increases in weight gain may be possible if feeding frequencies greater then 8F are employed. Survival and apparent feed conversion ratio (AFCR) were significantly affected by feeding frequency alone, with significant improvements in snapper fed more frequently and in snapper fed twice daily but later in the same photoperiod (2FE<2FL<4F<8F). Size heterogeneity (measured by the coefficient of variation for individual harvest weight, CVhw) was affected by photoperiod, and decreased significantly in snapper reared under the 18L:6D regime. Size heterogeneity was also affected by feeding frequency, however, only the CVhw for snapper reared under the 8F feeding frequency was significantly lower than snapper fed at other rates (i.e. 2FE=2FL=4F<8F). Snapper fed later in a photoperiod regime generally performed better than snapper fed earlier. Results from this study indicate that in order to maximize weight gain, survival and AFCR and to reduce size heterogeneity, newly weaned snapper should be reared under a 18L:6D photoperiod and, for fish fed 10% BW day−1, fed 8 times day−1. [Copyright &y& Elsevier]

Conflicting opinions on the nature of malaria and helminth coinfections in humans have highlighted the need for a rational approach to study the effects of coinfections on morbidity. Here, it is argued that a variety of factors have led to this confusion but that many problems might be helped by more deliberate consideration of residential location and spatial aspects of exposure in parasitological surveys. [Copyright &y& Elsevier]

Two experiments were performed to investigate the digestibility and utilization of carbohydrate sources by Australian snapper Pagrus auratus. In the first experiment, snapper of two different size classes (110 and 375 g) were fed a reference diet containing no starch (REF) or diets containing 150 (PN15), 250 (PN25), 350 (PN35) or 450 g kg−1 (PN45) of 100% gelatinized wheat starch to investigate the interactive effects of fish size and starch inclusion level on apparent organic matter (OM) or gross energy (GE) digestibility (ADC), post-prandial plasma glucose concentration, hepatosomatic index (HSI) and liver or tissue glycogen content. A second experiment used a 72 h time course study to investigate the ability of larger snapper (300–481 g) to clear an intra-peritoneal injection of 1 g d-glucose kg−1 body weight (BW). Organic matter and GE ADCs declined significantly in both fish sizes as the level of starch increased (PN45

Two experiments were carried out to determine the apparent crude protein (CP), organic matter (OM), fat and gross energy (GE) digestibility coefficients (ADCs) of several protein and energy sources (ingredients) for Australian snapper using the indirect method of determination and collection of faeces by passive settlement. The first experiment determined ADCs for one level of fishmeal (500 g kg−1 diet), three levels of extruded wheat (200, 300 or 400 g kg−1 diet) and two levels of fish oil (150 or 250 g kg−1 diet). The second experiment determined ADCs for two levels each of meat meal or poultry meal (300 or 500 g kg−1 diet), one level each of haemoglobin powder or blood meal (150 g kg−1 diet) and one level each of solvent extracted soybean meal or a low-allergenic, cold-pressed soybean meal (300 g kg−1 diet). Similar ingredients and where appropriate, different inclusion levels were compared using one- or two-way analysis of variance (anova). Fishmeal was almost completely digested and ADC values ranged between 94.3% and 99.2%. Fish oil was also well digested, with ADC values ranging between 97.6% and 106.0% and was not significantly affected by inclusion level. Linear regression analysis indicated that there was no relationship between the inclusion level of extruded wheat and either CP (ADCs ranged from 100.1% to 105.4%) or fat digestibility (ADCs ranged from 89.1% to 104.4%). However, there was a significant negative linear relationship between the inclusion level of extruded wheat and GE digestibility (GEADC=86.51−0.031× inclusion level;R2=0.49). Two-wayanovaindicated that CP, OM and GE ADCs of poultry meal (i.e. 85.9%, 89.7% and 91.3% respectively) were significantly higher than those determined for meat meal (i.e. 63.8%, 63.4% and 71.3% respectively), but ADCs were not affected by inclusion level or the interaction between inclusion level and ingredient type. The fat digestibility coefficients of meat and poultry meal were not significantly different (ADCs ranged from 92.3% to 95.0%). The CP digestibility of haemoglobin powder (95.1%) was significantly higher than that of ring-dried blood meal (81.6%), but there was no difference between the digestibility of OM (77.0%) or GE (80.4%) from these products. There was no difference between the CP (88.9%), OM (56.9%) and GE (65.6%) digestibility of the solvent extracted soybean meal and the low-allergenic, cold-pressed soybean meal. These coefficients will be useful in formulating both practical and research-based diets for this species. [ABSTRACT FROM AUTHOR]

Focuses on spatial awareness in parasite immunoepidemiology. Demographic and environmental factors that affect infection patterns, morbidity and immune responses; Contributions that co-infections have on the response to specific pathogens; Procedures for identifying and analyzing variables with spatial structure.

Two experiments were conducted to investigate effects of processing on apparent digestibility coefficients (ADCs) of legumes and oilseeds for juvenile silver perch, Bidyanus bidyanus (∼49 g). The first experiment evaluated interactive effects of ingredients (lupins or field peas), processing (whole seed; hulls on or hulls off) and extrusion cooking (raw or extruded) on ADCs for juvenile silver perch (∼4 g fish−1). The second experiment was a three-fixed-factor anova designed to evaluate interactive effects of ingredients (soybean meal or canola meal), extrusion cooking (raw or extruded) and inclusion content (30% or 50% of the diet) on ADCs for juvenile silver perch (∼4 g fish−1). Lupin protein was more digestible than that of peas (ADC for crude protein 91% vs. 85% for peas) but the organic matter was less digestible (ADC for organic matter 50% vs. 67% for peas). Dehulling lupins significantly improved ADCs for all indices (dry matter, organic matter, energy and crude protein), but extrusion had no effect because lupins do not contain starch or heat-labile anti-nutrients. Conversely, for starch-rich peas that contain heat-labile trypsin inhibitors, both dehulling and extrusion significantly improved ADCs. Digestibility of soybean meal was much higher than that of canola meal. For soybean meal, neither processing, content nor their interaction affected digestibility but extrusion improved ADCs for dry matter, organic matter and energy but there was an interaction with content. Although higher overall, digestibility for these indices declined with increasing content for extruded product while there were only minor effects of inclusion for raw product. Benefits of extrusion were attributed to reductions in anti-nutrients, including phytic acid. For canola, there were no interactions between extrusion and content for any ADC. Increasing content reduced ADCs for crude protein, dry matter and organic matter but did not effect energy. Surprisingly, extrusion of canola also reduced digestibility for all ADCs. Dehulling improved both lupins and peas. Crude protein for all ingredients was well digested with ingredients ranked: lupins>soybean meal>peas>canola meal. Energy digestibility was best for soybean meal and worst for lupins. Extrusion greatly improved digestibility of peas and to a lesser extent soybean meal, gave no benefits to lupins and was detrimental for canola. [ABSTRACT FROM AUTHOR]

Effects of varying dietary digestible protein (DP) and digestible energy (DE) on protein retention efficiency (PRE), weight gain, protein deposition and carcass composition for silver perch ( Bidyanus bidyanus, Mitchell) were studied. Using digestibility data for silver perch, we formulated three series of diets with different DE contents (13, 15 or 17 MJ DE kg−1). For each series, a ‘summit’ diet containing an excess of protein for silver perch (based on previous research) and a ‘diluent’ diet with only 10–13% DP were formulated. By blending the summit and diluent diets together in different ratios, five diets with different DP contents were produced for each DE series. A commercial diet was also included to give 16 experimental diets in total. Eight juvenile fish (mean initial weight 1.2 g) were stocked into each of 64 × 70-L acrylic aquaria and then each of the 16 diets was randomly allocated to four replicate aquaria. Tanks were supplied with partially recirculated water (75%) at 25–27°C. Fish were fed restrictively, twice per day, based initially on 3.5% body weight day−1 with 40% of the ration given at 08:30 hours and 60% given at 15:00 hours for 59 days. Quadratic functions were fitted to each energy series to describe the relationship between DP content of diets and PRE (the asymptote of these functions were used to predict maximum PRE). For low DE (13 MJ kg−1), mid-DE (15 MJ kg−1) and high DE (17 MJ kg−1), the dietary DP contents to give maximum PRE were 24.7%, 26.1% and 30.1% respectively. Carcass fat decreased with increasing DP and increasing DP:DE ratio. Varying the dietary protein and DE also influenced other indices of fish performance. ‘Optimum’ dietary protein therefore depends on several factors. For fish fed, restrictively, the protein content needed to maximize PRE is lower than the content needed to maximize weight gain or minimize carcass fat. For fish fed to satiation, the lowest protein content for maximum weight gain is lower than for fish fed restrictively. [ABSTRACT FROM AUTHOR]

Two experiments were conducted with Australian snapper Pagrus auratus (Bloch and Schneider, 1801). The first was aimed at determining the dietary level of astaxanthin that improved skin redness (CIE a*values) of farm-reared snapper. Farmed snapper (ca. 600 g) fed a commercial diet without carotenoids were moved to indoor tanks and fed the same diet supplemented with 0, 36 or 72 mg astaxanthin kg−1 (unesterified form as Carophyll Pink™) for nine weeks. Skin redness (CIE a* values) continued to decrease over time in fish fed the diet without astaxanthin. Snapper fed the diet containing 72 mg astaxanthin kg−1 were significantly more red than fish fed the diet with 36 mg astaxanthin kg−1 three weeks after feeding, but skin redness was similar in both groups of fish after 6 and 9 weeks. The second experiment was designed to investigate the interactive effects of dietary astaxanthin source (unesterified form as Carophyll Pink™ or esterified form as NatuRose™; 60 mg astaxanthin kg−1) and degree of shading (0%, 50% and 95% shading from incident radiation) on skin colour (CIE L* a* b*) and skin and fillet astaxanthin content of farmed snapper (ca. 800 g) held in 1 m3 floating cages. After 116 days, there were no significant interactions between dietary treatment and degree of shading for L*, a* or b* skin colour values or the concentration of astaxanthin in the skin. Negligible amounts of astaxanthin were recovered from fillet samples. The addition of shade covers significantly increased skin lightness ( L*), possibly by reducing the effect of melanism in the skin, but there was no difference between the lightness of fish held under either 50% or 95% shade cover ( P>0.05). [ABSTRACT FROM AUTHOR]

Background: Schistosoma mansoni and malaria infections are often endemic in the same communities in sub-Saharan Africa, and both have pathological effects on the liver and the spleen. Hepatosplenomegaly associated with S. mansoni is exacerbated in children with relatively high exposure to malaria. Treatment with praziquantel reduces the degree of hepatosplenomegaly, but the condition does not completely resolve in some cases. The present analysis focused on the possibility that exposure to malaria infection may have limited the resolution of hepatosplenomegaly in a cohort of Kenyan schoolchildren. Methods: Ninety-six children aged 6-16, from one community in Makueni district, Kenya, were treated with praziquantel. At baseline, all children had hepatomegaly and most had splenomegaly. The source of S. mansoni infection, a river, was molluscicided regularly over the following three years to limit S. mansoni re-infection, whereas malaria exposure was uninterrupted. Hepatic and splenic enlargement was assessed annually outside the malaria transmission season. Results: Children living in an area of relatively high exposure to both infections presented with the largest spleens before treatment and at each follow-up. Spleens of firm consistency were associated with proximity to the river. The regression of hepatomegaly was also affected by location, being minimal in an area with relatively low S. mansoni exposure but high exposure to malaria, and maximal in an area with relatively low exposure to both infections. Conclusions: The outcome of treating cases of hepatosplenomegaly with praziquantel in this cohort of Kenyan children depended strongly on their level of exposure to malaria infection. Furthermore, a residual burden of hepatosplenic morbidity was observed, which was possibly attributable to the level of exposure to malaria. The results suggest that exposure to malaria infection may be a significant factor affecting the outcome of praziquantel treatment to reduce the level of hepatosplenic morbidity. [ABSTRACT FROM AUTHOR]

Background: Schistosoma mansoni and Plasmodium falciparum are common infections of school aged children in Kenya. They both cause enlargement of the spleen, but their relative contribution to the condition of splenomegaly remains unknown in areas where both infections are endemic. Here, we have investigated whether relatively high exposure to both infections has a clinically measurable effect on this condition. Methods: 96 children aged 6-16 years living along a ten kilometre stretch and within 4 km south of a river that is a source of both S. mansoni and malaria infections were examined clinically for splenomegaly along the mid clavicular line (MCL) and mid axillary line (MAL). The survey was conducted outside the malaria transmission season. The consistency of the organ was recorded as soft, firm or hard. Mapping of the locations of houses and the course of the river was undertaken. Egg counts were mapped at the household level, as were IgG3 responses to Plasmodium falciparum schizont antigen (anti-Pfs IgG3), in order to identify areas with relatively high exposure to both infections, either infection or neither infection. ANOVA was used to test for differences in egg counts, IgG3 levels and the magnitude of spleen enlargement between these areas. Results: 4 contiguous sectors were identified, one where anti-Pfs IgG3 responses and S. mansoni egg counts were both high, one where only anti-Pfs IgG3 responses were high, one where only egg counts were high, and one where both anti-Pfs IgG3 responses and egg counts were low. Spleen MAL and MCL values were significantly higher amongst children from the sector with highest IgG3 levels and highest egg counts but similar amongst children from elsewhere. Both egg counts and anti-Pfs IgG3 responses were significantly higher in children with MAL values >=4 cm. Hardening of spleens was associated with proximity of domicile to the river. Conclusions: Micro-geographical variation in exposure to S. mansoni and malaria infections can be exploited to investigate the chronic impact of these two infections. These results provide firm evidence that relatively high exposure to both infections exacerbates splenomegaly even outside the malaria transmission season. Major implications include assessing the burden of infection in school age-children. [ABSTRACT FROM AUTHOR]

In schistosomiasis endemic areas, antibody isotype responses against Schistosoma mansoni antigens vary with host age, sex and duration or intensity of infection, and are associated with susceptibility or resistance to infection. Identifying the quality and quantity of these responses is important to our understanding of the host-parasite relationship; however, the various host and parasite factors have a strong tendency to confound each other. We investigated the relationships and interactions between age, sex, faecal egg-counts and specific antibody isotype (IgA, IgG1, IgG2, IgG3, IgG4, IgE, IgM) responses to S. mansoni worm (SWA) and egg (SEA) antigens, amongst 380 individuals aged 5-59 from a fishing community from Uganda. This community was characterized by high levels of exposure, and high infection intensities, with higher infection intensities in males than in females. Multivariate anova was conducted with interaction terms between the three categorized explanatory variables. Most anti-SWA responses increased with age, whereas anti-SEA responses tended to decline with age, especially after puberty. IgG1-SWA, IgG4-SWA, IgG4-SEA, IgE-SWA responses increased with egg count, whereas IgG2-SEA decreased with egg count. IgG1-SWA, IgG4-SWA, IgE-SWA and IgG4-SEA responses were independently higher in males, whereas IgG2-SEA responses were independently higher in females. The significant effects of sex on isotype responses to adult worm antigens may be partly because of different levels of cumulative exposure. IgG4-SEA and IgG4-SWA were both strongly correlated with egg count. Patterns of IgE-SWA responses were qualitatively different to IgG4 responses, suggesting independent pathways of regulation. [ABSTRACT FROM AUTHOR]

The dietary methionine and cysteine requirements of Yellowtail Kingfish (YTK) are unknown. Methionine, an essential sulfur-containing amino acid, acts as a sulfur and methyl donor for key metabolites, such as cysteine and taurine. Cysteine, a conditionally essential sulfur-containing amino acid, can spare significant amounts of methionine in the total sulfur amino acid (TSAA) requirement. Both methionine and cysteine are an integral part of YTK aquafeeds, in which methionine supplementation levels are based on the requirements of the closely related Japanese Yellowtail (Seriola quinqueradiata) at approximately 11.1 g kg−1 diet. However, recent research has demonstrated better growth and feed efficiency in YTK fed diets containing more than 11 g methionine kg−1, although the precise methionine requirement and potential interactions with cysteine remain unknown. Therefore, the present study was designed to (1) elucidate the methionine requirement of YTK at low and high dietary cysteine contents and to (2) quantify cysteine's sparing capacity for methionine in the TSAA requirement. These requirements and relationships were established by feeding ten isonitrogenous and isoenergetic diets, made from common feed ingredients, to triplicate groups of 12 fish (initial 52.6 ± 1.0 g fish−1) over 54 days. The orthogonal design consisted of two levels of dietary cysteine (5.6 & 13.9 g kg−1), crossed with five levels of dietary methionine, increasing from 7.9 to 25.2 g kg−1. Non-linear regression analysis indicated an average digestible TSAA requirement of 0.70 g kgBW−1 d−1 (0.56 g Met kgBW−1 d−1 & 0.14 g Cys kgBW−1 d−1) based on feed conversion ratio, specific growth rate, and protein retention efficiency. This approximates to an average dietary sulfur amino acid specification of 24.5 g kg−1 (18.9 g Met kg−1 & 5.6 g Cys kg−1). Cysteine spared 40.4–49.2% of methionine in the TSAA requirement on an equimolar sulfur basis. Sub- and supra-optimal levels of dietary methionine and cysteine induced inferior growth and feed efficiency. Additionally, fish fed the diet lowest in dietary methionine and cysteine indicated early stages of cataract. This study provides quantitative data on the sulfur amino acid requirements of juvenile YTK and will facilitate the formulation of better diets for this species. • The total sulfur amino acid (Met+Cys) requirement was met at an average 24.5 g kg−1 diet (18.9 g Met kg−1 & 5.6 g Cys kg−1) • The minimum obligatory methionine requirement in Yellowtail Kingfish was met at an average of 14.3 g kg−1 diet • A diet with relatively low dietary methionine (8.8 g kg−1) and cysteine (5.8 g kg−1) induced cataracts • Levels above the total sulfur amino acid requirement (23.4–26.1 g kg−1) induced inferior FCR, SGR, and PRE [ABSTRACT FROM AUTHOR]