Diagnosis of an anaerobic pond treating temperate domestic wastewater: An alternative sludge strategy for small works

An anaerobic pond (AP) for treatment of temperate domestic wastewater has been studied as a small works sludge management strategy to challenge existing practice which comprises solids separation followed by open sludge storage, for up to 90 days. During the study, effluent temperature ranged between 0.1 °C and 21.1 °C. Soluble COD production was noted in the AP at effluent temperatures typically greater than 10 °C and was coincident with an increase in effluent volatile fatty acids (VFA) concentration, which is indicative of anaerobic degradation. Analysis from ports sited along the AP's length, demonstrated VFA to be primarily formed nearest the inlet where most solids deposition initially incurred, and confirmed the anaerobic reduction of sludge within this chamber. Importantly, the sludge accumulation rate was 0.06 m3 capita−1 y−1 which is in the range of APs operated at higher temperatures and suggests a de-sludge interval of 2.3–3.8 years, up to 10 times longer than current practice for small works. Coincident with the solids deposition profile, biogas production was predominantly noted in the initial AP section, though biogas production increased further along the AP's length following start-up. A statistically significant increase in mean biogas production of greater than an order of magnitude was measured between winters (t(n=19) = 5.52, P < 0.001) demonstrating continued acclimation. The maximum methane yield recorded was 2630 mgCH4 PE−1 d−1, approximately fifty times greater than estimated from sludge storage (57 mgCH4 PE−1 d−1). Anaerobic ponds at small works can therefore enable sludge reduction and longer sludge holding times than present thus offsetting tanker demand whilst reducing fugitive methane emissions currently associated with sludge storage, and based on the enhanced yield noted, could provide a viable opportunity for local energy generation

Antioxidant therapy mitigates summer-induced DNA damage in boar spermatozoa

Introduction: While pork is the most widely eaten meat in the world, pig production is continually threatened by changing climate conditions resulting in poor reproductive performance, particularly in the tropics. The boar's inefficient capacity to sweat; non-pendulous scrotum and high susceptibility of boar sperm to temperature shock makes this species particularly vulnerable to the effects of heat stress. While DNA-damaged sperm may fertilize normally, key genes involved in early embryo development may be severely affected inducing early embryo loss as shown in the mice. Our study demonstrates that tropical summer significantly increases DNA damage in populations of sperm within the ejaculate without necessarily affecting sperm motility. Moreover, supplementing boars with antioxidants during summer could potentially reduce the negative impact of heat stress on sperm DNA integrity. Materials and Methods: Five mature Large White boars were housed individually in open gable pens at JCU in the dry tropics of Townsville, Queensland, Australia. Semen was collected by the gloved-hand technique using a dummy sow during spring (Oct 2014), summer (Feb 2015) & early winter (end May 2015) and diluted 1:3 in BTS media. Boar feed was supplemented with 100g/boar/day custom-made antioxidant formulation during summer (Jan - Apr 2016) and semen was collected after 42 & 84 days treatment. Sperm concentration was determined by haemocytometer and motility of 20 x 106 sperm/ml at 38°C was analyzed using CASA (Hamilton Thorne). Sperm DNA damage in 20,000 Percoll-purified sperm per boar per treatment was evaluated using TUNEL (Roche) & flow cytometry (Dako Cytomation; Fig. 1). Results: Sperm motility was similar in summer to winter & spring (P > 0.05) but total motility was lower in spring than winter (P ≤ 0.05). Antioxidant supplementation for 42 & 84 days during summer did not affect motility of spermatozoa (P > 0.05). Sperm DNA damage was more than 16-fold higher in summer than winter & nearly 9-fold higher than spring (P ≤ 0.05; Fig. 2). Antioxidant supplementation during summer reduced sperm DNA damage after 42 & 84 days antioxidant treatment (P ≤ 0.05; Fig. 3). Conclusions and discussion: Sperm DNA integrity is compromised in boars during summer, suggesting boar factors may contribute to embryo loss in sows. Moreover, such damage appears undetectable using traditional measures of sperm motility. Antioxidant therapy during summer appears to significantly alleviate heat stress-induced DNA damage in boar sperm, which may provide one solution to the problem of summer infertility in the pig

Evidence for quantum confinement in the photoluminescence of porous Si and SiGe

We have used anodization techniques to process porous surface regions in p-type Czochralski Si and in p-type Si0.85Ge0.15 epitaxial layers grown by molecular beam epitaxy. The SiGe layers were unrelaxed before processing. We have observed strong near-infrared and visible light emission from both systems. Analysis of the radiative and nonradiative recombination processes indicate that the emission is consistent with the decay of excitons localized in structures of one or zero dimensions

Tropical summer induces sperm DNA damage in boars which can be mitigated by antioxidant therapy

Summer infertility due to heat stress grossly affects reproductive performance in pigs, particularly in the tropics, and causes over $300 million in annual losses to the US swine industry. Boar's inefficient capacity to sweat; non-pendulous scrotum and the high susceptibility of boar sperm to temperature shock makes this species particularly vulnerable to heat stress. While traditionally considered a sow problem, recent studies demonstrate that heat stress-induced sperm DNA damage can result in early embryo loss in mice. Our study aimed to demonstrate higher sperm DNA damage during summer in boars and trial antioxidant therapy to alleviate the problem. Motility of sperm obtained from n=5 Large White boars housed in the dry tropics of Townsville, North Queensland, Australia was characterized by Computer-Assisted Sperm Analysis (CASA), but did not differ between spring, summer and winter (total motility: 70.8 ± 5.5% vs. 71.3 ± 8.1% vs. 90.2 ± 4.2%; progressive motility: 41.7 ± 2.8% vs. 35.4 ± 7.0% vs. 46.6 ± 4.0% respectively, both P ≥ 0.05). However, sperm DNA integrity in twenty-thousand spermatozoa per boar per treatment, evaluated using TUNEL staining and flow cytometry, revealed nearly 9-fold higher DNA damage in summer than spring and winter (16.1 ± 4.8% vs. 1.8 ± 0.5% vs 1.1 ± 0.2% respectively; P ≤ 0.05). However, boar feed supplemented with antioxidants during summer significantly reduced sperm DNA damage to 9.9 ± 4.5% and 7.2 ± 1.6% (P ≤ 0.05) after 42 and 84 days treatment respectively. Total and progressive motility were not altered by the supplement. Our results show sperm DNA integrity is compromised in boars during summer, suggesting boar factors may contribute to embryo loss in sows. Moreover, such damage may go undetected using traditional measures of sperm motility. Antioxidant supplementation during summer alleviates the negative impact of heat stress on sperm DNA integrity

Boar sperm DNA damage induced by tropical heat stress can be alleviated using antioxidants

Seasonal heat stress is known to significantly diminish reproductive performance in pigs, particularly in the tropics, costing the industry millions in annual loses. The boar's reduced capacity to sweat, non-pendulous scrotum, and widespread use of European breeds in the tropics, makes this species particularly vulnerable to heat stress. While traditionally considered a sow problem, recent mouse studies demonstrate that heat stress-induced sperm DNA damage can result in arrested development and loss of early embryos. Our study investigated the impact of tropical summer heat stress on the quality and DNA integrity of boar sperm, and trialled antioxidant supplementation to alleviate the problem. Motility of sperm obtained from n = 5 Large White boars housed in the dry tropics of Townsville, North Queensland, Australia was characterized by Computer-Assisted Sperm Analysis but did not differ between summer, winter or spring (total motility: 71.3 ± 8.1 vs. 90.2 ± 4.2 vs. 70.8 ± 5.5% respectively, P > 0.05; progressive motility: 35.4 ± 7.0 vs. 46.6 ± 4.0 vs. 41.7 ± 2.8% respectively, P > 0.05). Sperm DNA integrity in 20,000 sperm/boar/season, evaluated using TUNEL and flow cytometry, revealed 16-fold more DNA damaged sperm in summer than winter, and nearly 9-fold more than spring (16.1 ± 4.8 vs. 1.0 ± 0.2 vs. 1.9 ± 0.5% respectively, P ≤ 0.05). However, boar feed supplemented with 100g/boar/day of proprietary custom-made antioxidants during summer significantly reduced sperm DNA damage to 9.9 ± 4.5% and 7.2 ± 1.6% (P ≤ 0.05) after 42 and 84 days treatment respectively. Total and progressive motility were not altered by the supplement. In summary, sperm DNA integrity is compromised in boars during summer, suggesting boar factors may contribute to seasonal embryo loss in sows. Moreover, such damage appears undetectable using traditional measures of sperm motility. Antioxidant supplementation during summer appears to mitigate the negative impact of heat stress on sperm DNA integrity

FIRE Cirrus on October 28, 1986: LANDSAT; ER-2; King Air; theory

A simultaneous examination was conducted of cirrus clouds in the FIRE Cirrus IFO-I on 10/28/86 using a multitude of remote sensing and in-situ measurements. The focus is cirrus cloud radiative properties and their relationship to cloud microphysics. A key element is the comparison of radiative transfer model calculations and varying measured cirrus radiative properties (emissivity, reflectance vs. wavelength, reflectance vs. viewing angle). As the number of simultaneously measured cloud radiative properties and physical properties increases, more sharply focused tests of theoretical models are possible

The 27-28 October 1986 FIRE IFO cirrus case study: Comparison of satellite and aircraft derived particle size

Theoretical calculations predict that cloud reflectance in near infrared windows such as those at 1.6 and 2.2 microns should give lower reflectances than at visible wavelengths. The reason for this difference is that ice and liquid water show significant absorption at those wavelengths, in contrast to the nearly conservative scattering at wavelengths shorter than 1 micron. In addition, because the amount of absorption scales with the path length of radiation through the particle, increasing cloud particle size should lead to decreasing reflectances at 1.6 and 2.2 microns. Measurements at these wavelengths to date, however, have often given unpredicted results. Twomey and Cocks found unexpectedly high absorption (factors of 3 to 5) in optically thick liquid water clouds. Curran and Wu found expectedly low absorption in optically thick high clouds, and postulated the existence of supercooled small water droplets in place of the expected large ice particles. The implications of the FIRE data for optically thin cirrus are examined

Solar Flare Intermittency and the Earth's Temperature Anomalies

We argue that earth's short-term temperature anomalies and the solar flare intermittency are linked. The analysis is based upon the study of the scaling of both the spreading and the entropy of the diffusion generated by the fluctuations of the temperature time series. The joint use of these two methods evidences the presence of a L\'{e}vy component in the temporal persistence of the temperature data sets that corresponds to the one that would be induced by the solar flare intermittency. The mean monthly temperature datasets cover the period from 1856 to 2002.Comment: 4 pages, 5 figure