Food safety

Illness induced by unsafe food is a problem of great public health significance. This study relates exclusively to the occurrence of chemical agents which will result in food unsafe for human consumption since the matter of food safety is of paramount importance in the mission and operation of the manned spacecraft program of the National Aeronautics and Space Administration

THE IMPACT OF AGING AND MECHANICAL INJURY ON ALVEOLAR EPITHELIAL AND MACROPHAGE RESPONSES IN ACUTE LUNG INJURY AND INFLAMMATION

Patients with severe lung pathologies, such as Acute Respiratory Distress Syndrome (ARDS), often require mechanical ventilation as a clinical intervention; however, this procedure frequently exacerbates the original pulmonary issue and produces an exaggerated inflammatory response that potentially leads to sepsis, multisystem organ failure, and mortality. This acute lung injury (ALI) condition has been termed Ventilator-Induced Lung Injury (VILI). Alveolar overdistension, cyclic atelectasis, and biotrauma are the primary injury mechanisms in VILI that lead to the loss of alveolar barrier integrity and pulmonary inflammation. Stress and strains during mechanical ventilation are believed to initiate alveolar epithelial mechanotransduction signaling mechanisms that contribute to injury and repair responses and lead to the direct activation of resident lung and recruited macrophages. These types of cells, alveolar and interstitial macrophages, have various polarization states, such as M1 and M2, which are believed to play significant roles in tissue homeostasis and inflammatory regulation. Epidemiology studies have also suggested that age influences lung function and is a predictive factor in the severity of VILI; however, the mechanisms of aging that influence the progression or increased susceptibility of VILI in the elderly are still unknown. Aging also critically impacts immune system function and may increase inflammation in healthy individuals, which is known as inflammaging. Disruption to Endoplasmic Reticulum (ER) homeostasis results in a condition known as ER stress that leads to disruption of cellular homeostasis, apoptosis, and inflammation. ER stress is increased with aging and other pathological stimuli. We hypothesized that age and mechanical stretch increase alveolar epithelial cells’ pro-inflammatory responses that are mediated by ER stress. Furthermore, we hypothesized that inhibition of this upstream mechanism with 4PBA, an ER stress reducer, alleviates subsequent inflammation and monocyte recruitment. Type II alveolar epithelial cells (ATII) were harvested from C57Bl6/J mice 2 months (young) and 20 months (old) of age. The cells were cyclically stretched at 15% change in surface area for up to 24 hours. Prior to stretch, groups were administered 4PBA or vehicle as a control. Mechanical stretch and age upregulated ER stress and proinflammatory signaling expression in ATIIs. Age increases susceptibility to stretch-induced ER stress and downstream inflammatory gene expression in a primary ATII epithelial cell model. Administration of 4PBA attenuated the increased ER stress and proinflammatory responses from stretch and/or age and significantly reduced monocyte migration to ATII conditioned media. Recent studies also suggest a critical, protective role for the bioactive sphingolipid mediator sphingosine-1-phosphate (S1P) signaling in several lung pathologies and macrophage differentiation and function. It is unknown whether aging alters S1P signaling that appears involved in lung inflammation, injury, and apoptosis. We postulated that aging and injurious mechanical ventilation synergistically impair macrophage polarization in the lung that is associated with dysfunctional S1P signaling and produces amplified alveolar barrier damage and diminished pulmonary function. Young (2-3mo) and old (20-25mo) C57BL/6 mice were mechanically ventilated for 2 hours using pressure-controlled mechanical ventilation (PCMV). We assessed tissue mechanics, lung injury/repair responses, macrophage polarization, and S1P/S1PL lung activity. PCMV exacerbated lung injury in old mice. CD80 and CD206, classical and alternative macrophage markers, were both elevated in old alveolar and interstitial macrophages that also further increased due to PCMV. S1P lung levels were elevated in the young ventilated mice compared to the control group, which was not observed with the old mice. S1P lyase expression increased in the young and old ventilated mice and the old nonventilated group. 2-Acetyl-4- tetrahydroxybutyl Imidazole (THI) administration reduced indications of ALI in both young and old mice and altered macrophage polarization. The structural and cellular implications in injury responses of an aging lung more accurately represent clinical conditions and warrant further study at a cellular level. We found that aging significantly impacts alveolar epithelial and lung macrophage signaling and polarization; moreover, these aging disparities may result from elevated ER stress and/or a loss of protective S1P signaling in response to mechanical stretch that further contribute to the age-associated susceptibility and alveolar barrier dysfunction. Furthermore, administration of 4PBA, an ER stress inhibitor, and THI, an S1PL inhibitor, attenuated ER stress and S1PL activity, respectively, as well as several indications of ALI

Natural history, science and conservation: the 70 year legacy of the North Queensland Naturalist 1933-2002

This paper presents an over-view of the original journal based on a review of the collection held by the Cairns Historical Society. It focusses on the scope of material covered, examples of subjects and some of the many significant authors who published their observations over the period

An observation of Black-necked Stork hunting and eating an Australasian Grebe

In October 2015 a male Black-necked Stork (Ephippiorhynchus asiaticus australis) was seen stalking, catching, killing and eating an Australasian Grebe (Tachybaptus novaehollandiae) at Hasties Swamp National Park, northern Queensland. This appears to be only the third record in Australia and the first in Queensland of predation on a waterbird. Detailed photographs are included

A new southern record of the Golden Jezebel (Delias aruna) on Cape York Peninsula

The Golden Jezebel (Delias aruna) is a large pierid butterfly known in Australia from Torres Strait and from Cape York to the McIlwraith Range, with most sightings in the Iron Range area. This paper records a new southern record, and thus a possible extension of range, in Rinyirru (Lakefield) National Park some 100 km south-east of previous records and in quite different habit at to normal

Susceptibility in vitro of canine methicillin-resistant and -susceptible staphylococcal isolates to fusidic acid, chlorhexidine and miconazole: opportunities for topical therapy of canine superficial pyoderma

OBJECTIVES: Increasing multidrug resistance amongst canine pathogenic staphylococci has renewed interest in topical antibacterial therapy for skin infections in the context of responsible veterinary prescribing. We therefore determined the activity in vitro of three clinically relevant topical agents and synergism between two of them against Staphylococcus pseudintermedius and Staphylococcus aureus. METHODS: The MICs of fusidic acid (n = 199), chlorhexidine (n = 198), miconazole (n = 198) and a 1:1 combination of miconazole/chlorhexidine (n = 198) were determined for canine isolates [50 MRSA and 49 methicillin-resistant S. pseudintermedius (MRSP), 50 MSSA and 50 methicillin-susceptible S. pseudintermedius (MSSP)] collected from the UK and Germany using an agar dilution method (CLSI VET01-A4). Fractional inhibitory concentration (FIC) indices were calculated to assess the interaction of miconazole with chlorhexidine. RESULTS: MICs of each drug/combination were significantly (P < 0.0005) higher for S. aureus when compared with S. pseudintermedius. Most strains (n = 172) had an MIC of fusidic acid of ≤0.03 mg/L (MIC ≥64 mg/L, n = 5 MRSA). All strains had MICs of chlorhexidine of 0.5–4 mg/L, except for one MRSA (MIC = 8 mg/L). All but four strains had MICs of miconazole of 1–4 mg/L (MIC = 16 mg/L, n = 3; MIC = 256 mg/L, n = 1). Miconazole/chlorhexidine (1:1 ratio) had a synergistic effect against 49/50 MRSA, 31/50 MSSA, 12/49 MRSP and 23/49 MSSP. CONCLUSIONS: Since the majority of these staphylococci, including methicillin-resistant isolates, had MICs that should be readily exceeded by topical skin application of these agents, their therapeutic efficacy for canine superficial pyoderma should be assessed. The synergistic interaction shown in vitro supports further clinical evaluation of miconazole/chlorhexidine combination therapy for staphylococcal infection

Time resolved spectroscopy of photoinduced absorption in glow-discharge a-Si:H

Journal ArticleThe time and temperature dependence of the photoinduced absorption spectra was measured in glow-discharge a-Si:H in the energy range 0.7 to 1.4 eV, temperature interval 10 to 306K and time domain 2 ys to 2 ms. The results are consistent with a model based on thermalization of excess carriers in trap states

Relaxation of photoinduced sub-bandgap absorption in a-Si:H

Journal ArticleThe decay of photoinduced sub-bandgap absorption (PA) following pulsed excitation was studied in the temperature range 80 - 305K, in a-Si:H samples prepared by glow discharge and sputtering. The decay was interpreted in terms of bimolecular diffusion limited recombination involving dispersive transport of electrons and was used for the determination of the dispersion parameter a. It was found to be a linear function of T in the glow-discharge sample while it was weakly T-dependent in the sputtered sample. In addition, a first measurement of the time evolution of the PA spectrum is reported