The role of floods and droughts on riverine ecosystems under a changing climate

Floods and droughts are key driving forces shaping aquatic ecosystems. Climate change may alter key attributes of these events and consequently health and distribution of aquatic species. Improved knowledge of biological responses to different types of floods and droughts in rivers should allow the better prediction of the ecological consequences of climate change‐induced flow alterations. This review highlights that in unmodified ecosystems, the intensity and direction of biological impacts of floods and droughts vary, but the overall consequence is an increase in biological diversity and ecosystem health. To predict the impact of climate change, metrics that allow the quantitative linking of physical disturbance attributes to the directions and intensities of biological impacts are needed. The link between habitat change and the character of biological response is provided by the frequency of occurrence of the river wave characteristic—that is the event's predictability. The severity of impacts of floods is largely related to the river wave amplitude (flood magnitude), while the impact of droughts is related to river wavelength (drought duration).     

Inter-individual variation in provisioning rate,prey size and number,and links to total prey biomass delivered to nestlings in the Collared Flycatcher (Ficedula albicollis)

Background: In bird species where offspring growth and survival rely on parents' food provisioning, parents can maximise their fitness by increasing the quantit...     

Fatigue of structural plywood under cyclic shear through thickness II: a new method for fatigue life prediction

For plywood specimens under shear through the thickness, a fatigue life prediction method based on strain energy has been newly developed with the fatigue process and failure criterion applicable to various loading conditions. Once the fatigue process and failure criterion of the plywood specimen were determined by the fatigue data measured under a loading condition other than the square loading waveform, the fatigue life of a specimen under various loading conditions could be predicted easily and accurately by the first cycle loading test. The relationship between stress level and the predicted fatigue life was also similar to that between stress level and the experimentally determined fatigue life. The fatigue life prediction method proposed may be widely applicable to the prediction of the fatigue life of solid wood and wood composites.     

Biological roles of monoterpene volatiles derived from rough lemon (<Emphasis Type="Italic">Citrus jambhiri</Emphasis> Lush) in citrus defense

Volatile compounds of plants, including monoterpenes, are a possible source of signal molecules that induce defense systems to protect plants from tissue damage. Volatile compounds from rough lemon leaves were trapped by solid-phase microextraction fibers in sealed vials, and subsequent gas chromatography–mass spectrometry and gas chromatography analyses identified the profile of the major components, mainly various monoterpenes. Among several monoterpenes examined, citral, citronellal, and linalool significantly inhibited the spore germination and hyphal growth of Alternaria alternata. The effect of linalool was fungistatic, while the effects of citral and citronellal were partially fungicidal. Wounding of rough lemon leaves induced a significant increase in release of monoterpenes. The release of linalool was the most abundant and was 14.5 times that of unwounded rough lemon leaves. Unlike the wounding treatment, microbe attack did not significantly change monoterpene releases, and there was statistically no difference found in the peak areas from microbe-treated and untreated leaves. Linalool, limonene, and β-pinene also had insect-repellant effects on wild-type Drosophila melanogaster. Expression patterns of defense-related genes in rough lemon and rice significantly changed after treatment with vapors of monoterpene volatiles. Taking these results together, monoterpene volatiles are likely to play roles in the defense of rough lemon against microbe and insect pathogens.     

GM2-gangliosidosis variant 0 (Sandhoff-like disease) in a family of Japanese domestic cats

A five-month-old, female Japanese domestic shorthair cat with proportionate dwarfism developed neurological disorders, including ataxia, decreased postural responses and generalised body and head tremors, at between two and five months of age. Leucocytosis due to lymphocytosis with abnormal cytoplasmic vacuolations was observed. The concentration of G(M2)-ganglioside in its cerebrospinal fluid was markedly higher than in normal cats, and the activities of beta-hexosaminidases A and B in its leucocytes were markedly reduced. On the basis of these biochemical data, the cat was diagnosed antemortem with G(M2)-gangliosidosis variant 0 (Sandhoff-like disease). The neurological signs became more severe and the cat died at 10 months of age. Histopathologically, neurons throughout the central nervous system were distended, and an ultrastructural study revealed membranous cytoplasmic bodies in these distended neurons. The compound which accumulated in the brain was identified as G(M2)-ganglioside, confirming G(M2)-gangliosidosis. A family study revealed that there were probable heterozygous carriers in which the activities of leucocyte beta-hexosaminidases A and B were less than half the normal value. The Sandhoff-like disease observed in this family of Japanese domestic cats is the first occurrence reported in Japan.     

Investigating the in situ degradation of atrazine in groundwater

This study focused on whether or not atrazine could be degraded by indigenous groundwater bacteria as part of an in situ remediation approach. Groundwater was taken from an unconfined middle upper chalk site where concentrations of atrazine and nitrate were typically in the ranges 0.02-0.2 microg litre-1 and 11.6-25.1 mg NO3-N litre-1 respectively. Sacrificial batch studies were performed using this groundwater spiked with atrazine at a concentration of 10 microg litre-1 in conjunction with a minimal mineral salts liquid (Glu-MMSL) medium which contained glucose as the sole carbon source. Treatments comprised either the Glu-MMSL groundwater cultured bacteria or Pseudomonas sp. strain ADP. Results from sacrificial batches indicated the occurrence of bacterial growth and denitrification as monitored by optical density (absorbance at 600 nm) and NO3-N content. Analysis of atrazine content by solid phase extraction coupled with high-performance liquid chromatography showed no degradation of atrazine over a period of 103 days in either treatment. These results indicated that no acclimatised bacterial community featuring positive degraders to the herbicide atrazine had become established within this chalk aquifer in response to the trace levels encountered.     

The Norwegian Healthier Goats programme – A financial cost–benefit analysis

The aim of this study was to evaluate the profitability to dairy goat farmers of participating in the Healthier Goats disease control and eradication programme (HG), which was initiated in 2001 and is still running. HG includes the control and eradication of caprine arthritis encephalitis (CAE), caseous lymphadenitis (CLA) and paratuberculosis (Johne's disease) in Norwegian goat herds.     

Cloning and expression of the human interleukin-6 (BSF-2/IFN beta 2) receptor

Interleukin-6 (IL-6/BSF-2/IFN beta 2) is a multifunctional cytokine that regulates the growth and differentiation of various tissues, and is known particularly for its role in the immune response and acute phase reactions. A complementary DNA encoding the human IL-6 receptor (IL-6-R) has now been isolated. The IL-6-R consists of 468 amino acids, including a signal peptide of approximately 19 amino acids and a domain of approximately 90 amino acids that is similar to a domain in the immunoglobulin (Ig) superfamily. The cytoplasmic domain of approximately 82 amino acids lacks a tyrosine/kinase domain, unlike other growth factor receptors.     

Coastal ecosystem-based management with nonlinear ecological functions and values

A common assumption is that ecosystem services respond linearly to changes in habitat size. This assumption leads frequently to an "all or none" choice of either preserving coastal habitats or converting them to human use. However, our survey of wave attenuation data from field studies of mangroves, salt marshes, seagrass beds, nearshore coral reefs, and sand dunes reveals that these relationships are rarely linear. By incorporating nonlinear wave attenuation in estimating coastal protection values of mangroves in Thailand, we show that the optimal land use option may instead be the integration of development and conservation consistent with ecosystem-based management goals. This result suggests that reconciling competing demands on coastal habitats should not always result in stark preservation-versus-conversion choices.