The Effect of Aeration Rate and Free-Floating Carrier Media on the Emission of \u3ci\u3eBacillus globigii\u3c/i\u3e in Bioaerosols

Aerosols produced by turbulent mechanical mixing and bubble aeration at Waste Water Treatment Plants (WWTPs) become bioaerosols with the entrainment of biological materials. Bioaerosols become a public health risk when human pathogens are present. This study evaluated bioaerosols containing Bacillus globigii (BG) spores, and the effects that aeration rate and the addition of Free-Floating Carrier Media (FFCM) had on the amount of BG spores collected following aerosolization. A series of laboratory-scale experiments investigated two different sizes of floating polystyrene spheres as FFCM and four different aeration rates. When the differences in compared aeration rates were sufficiently large, a positive correlation was observed between increasing aeration rate and increasing bioaerosol production. The maximum increase from 0.50 to 1.00 L/min resulted in a 97.58% increase in the percent of starting BG spores captured after aerosolization. The addition of FFCM of both sizes reduced the amount of BG spores captured when compared to the control. Smaller spheres (0.42 cm diameter) consistently attenuated BG bioaerosol emissions more effectively than those with larger (1.91 cm) diameters, with a mean control efficiency of 93.03% compared to 83.95%. Statistical analysis showed a significant increase in the ability of smaller diameter FFCM to attenuate bioaerosol production at the two higher investigated aeration rates. This study was the first, to the author’s knowledge, to investigate multiple effects on bioaerosol production where the aerosol contained strictly bacterial endospores. As a part of a larger investigation including laboratory scale and pilot-scale WWTP research, this study is the first in a series of studies intended to investigate the effect of experimental scale on bioaerosol production. Results related to effects due to scale can be applied to better predict bioaerosol behaviors in operating treatment plants

Evaluating the Role of Anharmonic Vibrations in Zeolite β Materials

The characterization of zeolitic materials is often facilitated by spectroscopic analysis of vibrations, which informs about the bonding character of the substrate and any adsorbents. Computational simulations aid the interpretation of the spectra but often ignore anharmonic effects that can affect the spectral characteristics significantly. Here, the impact of anharmonicity is demonstrated with a combination of dynamical and static simulations applied to the structures formed during the synthesis of Sn-BEA via solid-state incorporation (SSI): the initial siliceous BEA (Si-β), aluminosilicate BEA (H-β), dealuminated BEA (deAl-β), and Sn-BEA (Sn-β). Heteroatom and defect-containing BEA are shown to have strong anharmonic vibrational contributions, with atomic and elemental resolution highlighting particularly the prevalence for H atoms (H-β, deAl-β) as well as localization to heteroatoms at defect sites. We simulate the vibrational spectra of BEA accounting for anharmonic contributions and observe an improved agreement with experimental data compared to harmonic methods, particularly at wavenumbers below 1500 cm–1. The results demonstrate the importance of incorporating anharmonic effects in simulations of vibrational spectra, with consequences toward future characterization and application of zeolitic materials

Aberrant Development of Thymocytes in Mice Lacking Laminin-2

In previous in vitro studies, we proposed a role for the extracellular matrix component, laminin- 2, and its integrin receptor, VLA-6, in thymocyte development. The characterization of two dystrophic mouse strains with different defects in laminin-2 allowed us to examine this proposal in vivo. Mice deficient in laminin-2, dy/dy, show a significant reduction in thymus size and number of thymocytes compared to normal littermates. These mice also exhibited apparent alterations of thymic architecture. Examination of the CD4/CD8 populations in dy/dy thymi showed large relative increases in the DN (CD4-CD8-) and SP (CD4+CD8-, CD4-CD8+) populations and a significant decrease in the DP (CD4+CD8+) population. Further examination of the DN population for CD44 and CD25 expression showed a remarkable decrease in the more mature pre-T cell populations. Analysis of apoptosis in situ, and by flow cytometry, in dy/dy thymi revealed a significant increase in apoptotic DN thymocytes in the capsule and subcapsular regions. Interestingly, thymocyte development appeared to proceed normally in dystrophic mice expressing a mutant form of laminin-2, dy2J, as well as, in fetal and neonatal dy/dy mice. We propose that laminin-2 plays an active role in thymocyte development by delivering cell survival and differentiation signals at specific stages of development in young adult mice

Circulation changes and teleconnections between glacial advances on the west coast of New Zealand and extended spells of drought years in South Africa

Twentieth century changes in the terminal position of the Franz Josef Glacier on the west coast of New Zealand are compared with an area‐averaged mean annual rainfall series for the summer rainfall region of South Africa. Distinctive teleconnections are evident in an out‐of‐phase relationship between the two series, each of which exhibits an oscillation of 18–20 years. Periods of glacial advance are shown to coincide with extended dry spells in South Africa, when drought years are prevalent. Reconstructed pressure anomaly fields are presented for periods of advance and recession of the glacier and for the inter‐decadal wet and dry spells in South Africa. In both cases major regional atmospheric circulation adjustments take place in a quasi‐regular fashion over time to produce an enhancement in westerly airflow during the periods of drought in Africa and glacial advance on the west coast of New Zealand. Extended wet periods and glacial recession are likewise shown to be associated with an enhancement of easterly components of the circulation. Changes in precipitation, temperature and moisture transport are examined and associations with the Southern Oscillation Index are investigated. Franz Josef glacial advances are shown to occur 4–5 years after the onset of enhanced south‐westerly airflow on to the west coast of New Zealand. Advances occur on average 4 years after the onset of extended dry spells in South Africa. Similar atmospheric circulation anomalies in the respective sectors of the Southern Hemisphere and adjustments in the locations of the positions of the ridges in standing wave three are responsible for this correspondence

Mindfulness training: success in reducing first year health professional students' study and exam related stress

Purpose: Students enrolling in high stakes, undergraduate entry, professional programs like medicine, dentistry and pharmacy may struggle to effectively achieve the transition from high school. This often results in high levels of mental distress. Method: The College of Medicine and Dentistry at James Cook University have implemented a health professional self-care program (HPSC) with an aim of helping students recognize stressors and develop coping strategies. The HPSC program has been running for three years in the first year of each of the three courses. The HPSC program was delivered as a series of eight sessions focusing on evidenced based theory with some time for practicing coping strategies. Five-point Likert scale surveys were administered prior to commencing the program and after completion. Results: Across the College, students reported significantly improved abilities to reduce study and exam related stress and develop effective coping skills. These results were more pronounced in students that practiced techniques of mindfulness. Discussion: The HPSC program changed student perceptions in being able to improve their own self-care and reduced study and exam related stress

Emotional orienting during interoceptive threat in orthostatic intolerance: dysautonomic contributions to psychological symptomatology in the postural tachycardia syndrome and vasovagal syncope

Cognitive and emotional processes are influenced by interoception (homeostatic somatic feedback), particularly when physiological arousal is unexpected and discrepancies between predicted and experienced interoceptive signals may engender anxiety. Due to the vulnerability for comorbid psychological symptoms in forms of orthostatic intolerance (OI), this study investigated psychophysiological contributions to emotional symptomatology in 20 healthy control participants (13 females, mean age 36 ± 8 years), 20 postural tachycardia syndrome (PoTS) patients (18 females, mean age 38 ± 13 years) and 20 vasovagal syncope (VVS) patients (15 females, mean age 39 ± 12 years). We investigated indices of emotional orienting responses (OR) to randomly presented neutral, pleasant and unpleasant images in the supine position and during the induced interoceptive threat of symptom provocation of head-up tilt (HUT). PoTS and VVS patients produced greater indices of emotional responsivity to unpleasant images and, to a lesser degree, pleasant images, during interoceptive threat. Our findings are consistent with biased deployment of response-focused emotion regulation (ER) while patients are symptomatic, providing a mechanistic underpinning of how pathological autonomic overexcitation predisposes to anxiogenic traits in PoTS and VVS patients. This hypothesis may improve our understanding of why orthostasis exacerbates cognitive symptoms despite apparently normal cerebral autoregulation, and offer novel therapeutic targets for behavioural interventions aimed at reducing comorbid cognitive-affective symptoms in PoTS and VVS

Mixed farming diversification may be costly: southern Queensland case study

Many farmers in Australia and in other countries have a choice of crop or livestock production, and many choose a mixture of both, based on risk preference, personal interests, markets, land resources and local climate. Mixed farming can be a risk-spreading strategy, especially in highly variable climates, but the right scales of each enterprise within the mix may be critical to farm profitability.To investigate expected farm profits, the probability of breaking even, as well as the worst and best case scenarios, we used farm data and APSIM (Agricultural Production Systems Simulator) to simulate the production of a typical, semi-arid, mixed-farm in southern Queensland. Three farming system scenarios were investigated: I, livestock and more intensive cropping; II, current production system of livestock and minimal cropping; and III, livestock only. We found that the expected profits were in the order system I > system III > system II. The key reason for the lower profits of system II was the high overhead cost of capital to continue some cropping, with low annual cropping income. Under the worst case scenario, in years with low rainfall, system I had the greatest downside risk with far greater financial losses. Systems I and III had similar probabilities of breaking even, and higher than system II, which incurs cropping overheads and limited cropping returns. Therefore, system II was less desirable than either system I or III. This case study helps farmers and advisors of semi-arid mixed farming enterprises to be better informed when making decisions at the paddock and whole-farm level, in both the short and long term, with respect to profit and risk. The method used in this paper can be applied to other mixed farms, in Australia and elsewhere

Absence of FMLP Receptors on Rat Macrophages

Although rat peritoneal neutrophils in the presence of cytochalasin B demonstrate superoxide (O2‐) responses to the chemotactic peptide N’‐formyl‐met‐leu‐phe (FMLP), neither elicited rat peritoneal macrophages nor rat alveolar macrophages show an O2‐response to FMLP (in the presence or absence of cytochalasin B), although a good O2‐response to opsonized zymosan is demonstrated by both types of macrophages. Using Fura‐2 loaded cells, peritoneal macrophages failed to show an increase in intracellular calcium after exposure to FMLP, f‐nor‐leu‐phe, F‐met‐met‐met, or F‐norleu‐leu‐phe‐norleu‐lys. FMLP also failed to induce elevations in intracellular calcium in alveolar macrophages. In 3H‐FMLP binding studies, the lack of responsiveness of peritoneal and alveolar macrophages was associated with the lack of FMLP receptors on these cell types, in striking contrast to the presence of functional receptors on rat neutrophils.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141351/1/jlb0600.pd

Novel low energy hydrogen–deuterium isotope breakthrough separation using a trapdoor zeolite

AbstractCs-chabazite, a type of zeolite with caesium counter-cations, possesses interesting gas separation properties due to a highly selective molecular “trapdoor” effect. Herein the use of this material for H2/D2 isotope separation is demonstrated. Isotope separation was achieved using breakthrough separation with a single pass through a packed bed at moderate temperatures (293K) and pressures (0.17MPa) when one species was in a sufficiently low concentration. The breakthrough separation curves were successfully modelled using the Thomas kinetic breakthrough model and the Yoon and Nelson kinetic breakthrough model, where working transferable kinetic rate constants were developed. Use of this material for hydrogen isotope separation would significantly lower the total energy demand compared with current hydrogen isotope separation techniques such as cryogenic distillation and is applicable to separating out low concentrations of D2 (0.0156%) present in standard grade H2