Contemplating the future: Acting now on long‐term monitoring to answer 2050's questions

In 2050, which aspects of ecosystem change will we regret not having measured? Long‐term monitoring plays a crucial part in managing Australia's natural environment because time is a key factor underpinning changes in ecosystems. It is critical to start measuring key attributes of ecosystems – and the human and natural process affecting them – now, so that we can track the trajectory of change over time. This will facilitate informed choices about how to manage ecological changes (including interventions where they are required) and promote better understanding by 2050 of how particular ecosystems have been shaped over time. There will be considerable value in building on existing long‐term monitoring programmes because this can add significantly to the temporal depth of information. The economic and social processes driving change in ecosystems are not identical in all ecosystems, so much of what is monitored (and the means by which it is monitored) will most likely target specific ecosystems or groups of ecosystems. To best understand the effects of ecosystem‐specific threats and drivers, monitoring also will need to address the economic and social factors underpinning ecosystem‐specific change. Therefore, robust assessments of the state of Australia's environment will be best achieved by reporting on the ecological performance of a representative sample of ecosystems over time. Political, policy and financial support to implement appropriate ecosystem‐specific monitoring is a perennial problem. We suggest that the value of ecological monitoring will be demonstrable, when plot‐based monitoring data make a unique and crucial contribution to Australia's ability to produce environmental accounts, environmental reports (e.g. the State of the Environment, State of the Forests) and to fulfilling reporting obligations under international agreements, such as the Convention on Biological Diversity. This paper suggests what must be done to meet Australia's ecological information needs by 2050.     

An emerging role for TOR signaling in mammalian tissue and stem cell physiology

The mammalian target of rapamycin (mTOR) is a kinase that responds to a myriad of signals, ranging from nutrient availability and energy status, to cellular stressors, oxygen sensors and growth factors. The finely tuned response of mTOR to these stimuli results in alterations to cell metabolism and cell growth. Recent studies of conditional knockouts of mTOR pathway components in mice have affirmed the role of mTOR signaling in energy balance, both at the cell and whole organism levels. Such studies have also highlighted a role for mTOR in stem cell homeostasis and lifespan determination. Here, we discuss the molecular mechanisms of TOR signaling and review recent in vitro and in vivo studies of mTOR tissue-specific activities in mammals.     

Electrospun gold nanofiber electrodes for biosensors

A new form of high surface area bioelectrode, based on nanofibers of electrospun gold with immobilized fructose dehydrogenase, was developed. The gold fibers were prepared by electroless deposition of gold nanoparticles on an electrospun poly(acrylonitrile)-HAuCl(4) fiber. The material was characterized using electron microscopy, XRD and BET, as well as cyclic voltammetry and biochemical assay of the immobilized enzyme. The electrochemical surface area of the gold microfibers was 0.32 ± 0.04 m(2)/g. Fructose dehydrogenase was covalently coupled to the gold surface through glutaraldehyde crosslinks to a cystamine monolayer. The enzyme exhibited mediated electron transfer directly to the gold electrode and catalytic currents characteristic of fructose oxidation in the presence of a ferrocene methanol mediator were observed. The limit of detection of fructose was 11.7 μM and the K(M) of the immobilized enzyme was 5mM. The microfiber electrode was stable over 20 cycles with a 3.05% standard deviation. The response time of the sensor was less than 2.2s and reached half maximum value within 3.6s. The sensor was proven to be accurate and precise in both serum and popular beverages sweetened with high fructose corn syrup. The addition of glucose isomerase enabled the sensor to perform with glucose, thus expanding the available analyte selection for the sensor.     

The power of correlative microscopy: multi-modal, multi-scale, multi-dimensional

Correlative microscopy is a sophisticated approach that combines the capabilities of typically separate, but powerful microscopy platforms: often including, but not limited, to conventional light, confocal and super-resolution microscopy, atomic force microscopy, transmission and scanning electron microscopy, magnetic resonance imaging and micro/nano CT (computed tomography). When targeting rare or specific events within large populations or tissues, correlative microscopy is increasingly being recognized as the method of choice. Furthermore, this multi-modal assimilation of technologies provides complementary and often unique information, such as internal and external spatial, structural, biochemical and biophysical details from the same targeted sample. The development of a continuous stream of cutting-edge applications, probes, preparation methodologies, hardware and software developments will enable realization of the full potential of correlative microscopy.     

A metabolomic comparison of mouse models of the Neuronal Ceroid Lipofuscinoses

The Neuronal Ceroid Lipofuscinoses (NCL) are a group of fatal inherited neurodegenerative diseases in humans distinguished by a common clinical pathology, characterized by the accumulation of storage body material in cells and gross brain atrophy. In this study, metabolic changes in three NCL mouse models were examined looking for pathways correlated with neurodegeneration. Two mouse models; motor neuron degeneration (mnd) mouse and a variant model of late infantile NCL, termed the neuronal ceroid lipofuscinosis (nclf) mouse were investigated experimentally. Both models exhibit a characteristic accumulation of autofluorescent lipopigment in neuronal and non neuronal cells. The NMR profiles derived from extracts of the cortex and cerebellum from mnd and nclf mice were distinguished according to disease/wildtype status. In particular, a perturbation in glutamine and glutamate metabolism, and a decrease in γ-amino butyric acid (GABA) in the cerebellum and cortices of mnd (adolescent mice) and nclf mice relative to wildtype at all ages were detected. Our results were compared to the Cln3 mouse model of NCL. The metabolism of mnd mice resembled older (6?month) Cln3 mice, where the disease is relatively advanced, while the metabolism of nclf mice was more akin to younger (1-2?months) Cln3 mice, where the disease is in its early stages of progression. Overall, our results allowed the identification of metabolic traits common to all NCL subtypes for the three animal models.     

The price of insulation: costs and benefits of feather delivery to nests for male tree swallows Tachycineta bicolor

Many species of birds line their nests with feathers, and it has been hypothesized that this functions to provide a thermally stable microenvironment for the development of eggs and nestlings. Feathers in the nest may also function as a mechanism for parasite control, providing a physical barrier that protects nestlings from ectoparasites. We tested these hypotheses by performing a feather removal and addition experiment in tree swallows Tachycineta bicolor, a species well‐known for lining their nests with feathers. While we found no evidence that quantity of feathers in nests influenced the ability of females to produce and incubate eggs, offspring in well‐feathered nests had longer flight feathers and were structurally larger just prior to fledging that those in nests with fewer feathers. Furthermore, we also demonstrated a positive correlation between feathers and the abundance of larval blow flies Protocalliphora spp. in nests, a result opposite to that predicted by the anti‐parasite hypothesis. While our study provides strong support for the insulation hypothesis, we also discuss the possibility that devoting time to feather gathering may result in males losing paternity in their nests, although manipulative studies will be necessary to fully evaluate this idea.     

Smoking and COPD increase sputum levels of extracellular superoxide dismutase

Extracellular superoxide dismutase (ECSOD) is the major superoxide-scavenging enzyme in the lung. Certain ECSOD polymorphisms are protective against COPD. We postulated that smokers and COPD subjects would have altered levels of ECSOD in the lung, airway secretions, and/or plasma. Lung tissue ECSOD was evaluated from nonsmokers, smokers, and subjects with mild to very severe COPD by Western blot, immunohistochemistry, and ELISA. ECSOD levels in plasma, bronchoalveolar lavage fluid (BALF), and induced-sputum supernatants were analyzed by ELISA and correlated with smoking history and disease status. Immunohistochemistry identified ECSOD in extracellular matrix around bronchioles, arteries, and alveolar walls, with decreases seen in the interstitium and vessels of severe COPD subjects using digital image analysis. Plasma ECSOD did not differ between COPD subjects and controls nor based on smoking status. ECSOD levels in induced sputum supernatants were elevated in current smokers and especially in COPD subjects compared to nonsmokers, whereas corresponding changes could not be seen in the BALF. ECSOD expression was reduced around vessels and bronchioles in COPD lungs. Substantial increases in sputum ECSOD in smokers and COPD is interpreted as an adaptive response to increased oxidative stress and may be a useful biomarker of disease activity in COPD.