Status of mammals on Groote Eylandt: Safe haven or slow burn?

Native mammals across northern Australia have suffered severe decline, with feral cats (Felis catus), introduced herbivores and changed fire regimes being implicated as drivers. However, uncertainty surrounding the relative contribution of each of these threats, and the interactions between them, is limiting the development of effective management strategies. The absence of introduced herbivores and cane toads (Rhinella marina) on Groote Eylandt, Northern Territory, provides an opportunity to evaluate some hypothesised threats in isolation of others. We used camera traps to investigate the correlates of native mammal distribution and abundance at 112 lowland savanna sites across Groote Eylandt. Two large grids of camera traps were also deployed to obtain estimates of feral cat density. We hypothesised that native mammal populations would be negatively associated with feral cat occupancy as well as frequent, large fires. Native mammal site‐occupancy on Groote Eylandt was generally higher compared to mainland Northern Territory. Feral cats were infrequently detected, precluding both an estimate of feral cat density and an evaluation of the relationship between feral cats and native mammals. We found no evidence that native mammal site‐occupancy or relative abundance is negatively associated with frequent, large fires. The relatively healthy state of native mammal populations on Groote Eylandt is likely due to the low density of feral cats, the benign fire regime and the absence of large introduced herbivores and cane toads. However, due to a lack of historical data, the current state of mammals should not be taken as evidence that these populations are safe from decline. This study highlights that the apparent resilience of mammal populations is a result of complex interactions between factors that vary substantially across the landscape. Caution is therefore required when making broad inferences about the drivers of mammal decline from studies that are spatially and temporally limited.     

Mechanics in embryogenesis and embryonics: prime mover or epiphenomenon?

Mechanics is shown to be an important, perhaps central component to the differentiation and development of embryos. Mechanics of the nucleus may also be involved in determining which genes are expressed in a given cell. There are two major approaches at present to the mechanics of differentiation in embryos: morphomechanics and differentiation waves. These are compared in detail, to provide a starting point for future experimental work to bring them into one conceptual framework. This may rationalize the present cookbookery of stem cell production by placing it in the context of differentiation waves and the differentiation code. Embryonics, the realization of concepts from embryology in computer hardware and software, might be considerably enhanced by incorporating mechanical concepts of embryogenesis. Segmented robots, modular robotics, cellular microrobotics, flexible electronics, wearable computers, diatom nanotechnology and waves in active media point to a synthesis that we could call embryonic robotics.     

Autism: not interested or not 'tuned-in'?

Recent studies of perceptual adaptation to faces have revolutionised our understanding of neural mechanisms that support face recognition. A new study has applied this approach to autistic spectrum disorders, revealing severe deficits in such adaptation.     

Protected areas for kiwi in mainland forests of New Zealand: how large should they be?

This paper examines, theoretically, how dispersal affects the viability of brown kiwi populations in protected areas of different size. Brown kiwi are threatened by introduced mammalian predators in mainland forests and are likely to persist only in managed forests where predators are controlled. In each protected area, the kiwi population will function as a net source, with an outflow of juveniles into the adjoining forest and minimal backflow into the reserve. Computer simulations show the minimum area of forest required for population viability increases non-linearly as the mean dispersal distance of juveniles increases. Preliminary measurements of the mean dispersal distance of brown kiwi in the wild suggest kiwi populations are unlikely to be viable in protected areas of less than 10 000 ha. Our estimate of the forest area requirement for viable populations of brown kiwi agrees with those derived by earlier workers using biogeographic techniques.     

DNA vaccines: ready for prime time?

Since the discovery, over a decade and a half ago, that genetically engineered DNA can be delivered in vaccine form and elicit an immune response, there has been much progress in understanding the basic biology of this platform. A large amount of data has been generated in preclinical model systems, and more sustained cellular responses and more consistent antibody responses are being observed in the clinic. Four DNA vaccine products have recently been approved, all in the area of veterinary medicine. These results suggest a productive future for this technology as more optimized constructs, better trial designs and improved platforms are being brought into the clinic.     

To trade or not to trade? Criteria for applying cap and trade

The use of emissions trading (cap and trade) is gaining worldwide recognition as an extremely effective policy tool. The U.S. Sulfur Dioxide (SO2) Emissions Trading Program has achieved an unprecedented level of environmental protection in a cost-effective manner. The successful results of the program have led domestic and foreign governments to consider the application of cap and trade to address other air quality issues. Certain analyses are particularly important in determining whether or not cap and trade is an appropriate policy tool. This paper offers a set of questions that can be used as criteria for determining whether or not cap and trade is the preferred policy approach to an environmental problem.     

Dream relevance and the continuity hypothesis: Believe it or not?

The dream-related beliefs of two university samples were surveyed and analyzed: (a) the belief that dreams contain important information; and (b) the belief that dreams reflect aspects of waking life. In addition, this study investigated the relationships between dream-related beliefs and both dream content and waking life measures of health, mood, and self-construal. The majority of participants maintained the belief that dreams contain important information, and participants were most likely to believe that dreams reflect relationships and decisions being made. Those believing that dreams reflect their spirituality scored higher on metapersonal self-construal and reported fewer deaths in their dreams. In contrast, those maintaining the belief that dreams reflect physical health scored lower on physical functioning and reported more body parts in their dreams. Within this demographic, findings suggest a common belief in dream relevance and waking-dreaming continuity. Further research is needed in order to fully account for possible sources of these beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The chlamydial protease CPAF: important or not,important for what?

The protease CPAF is only found in Chlamydiales and in at least most bacteria that share with Chlamydia the biphasic life-style in a cytosolic inclusion. CPAF is intriguing: it appears to be secreted from the inclusion across the inclusion membrane into the cytosol. A bacterial protease ravaging in the cytosol of a human cell may cause a plethora of effects. Curiously, very few are known. The current discussion is bogged down by a focus on experimental artifact, while proposed functions of CPAF remain speculative. I here make the attempt to summarize what we know about CPAF.     

Summer mastitis: vector transmission or not?

Summer mastitis is on acute, suppurative infection of cattle with considerable importance to European agriculture. The causative bacteria are thought to be transmitted by the fly Hydrotaea irritans (L.) but evidence for this remains circumstantial. In this article, Eric Hillerton presents a working hypothesis to explain the transmission mechanism.     

FSH and bone – important physiology or not?

For many years, osteoporosis in women was equated with estrogen deficiency. The recent articles by Zaidi and colleagues offer a new challenge to the estrogen-deficiency-osteoporosis hypothesis by showing that follicle-stimulating hormone (FSH) stimulates osteoclastic bone resorption perhaps through tumor necrosis factor-alpha (TNF-alpha). These authors, however, neglected to mention bone abnormalities and high testosterone levels that were previously shown in FSH-receptor knockout and other modified mice. It is also possible that they have overemphasized potential relationships of these new data with human bone loss. Despite these fascinating data, the paradigm of FSH causing hypogonadal bone loss is not yet ready to displace the estrogen-deficiency-osteoporosis paradigm, although that model already faces considerable challenge.