Adapting wheat sowing dates to projected climate change in the Australian subtropics: analysis of crop water use and yield

Projected increases in atmospheric carbon dioxide concentration ([CO2]) and air temperature associated with future climate change are expected to affect crop development, crop yield, and, consequently, global food supplies. They are also likely to change agricultural production practices, especially those related to agricultural water management and sowing date. The magnitude of these changes and their implications to local production systems are mostly unknown. The objectives of this study were to: (i) simulate the effect of projected climate change on spring wheat (Triticum aestivum L. cv. Lang) yield and water use for the subtropical environment of the Darling Downs, Queensland, Australia; and (ii) investigate the impact of changing sowing date, as an adaptation strategy to future climate change scenarios, on wheat yield and water use. The multimodel climate projections from the IPCC Coupled Model Intercomparison Project (CMIP3) for the period 2030–2070 were used in this study. Climate scenarios included combinations of four changes in air temperature (08C, 18C, 28C, and 38C), three [CO2] levels (380 ppm, 500 ppm, and 600 ppm), and three changes in rainfall (–30%, 0%, and +20%), which were superimposed on observed station data. Crop management scenarios included a combination of six sowing dates (1 May, 10 May, 20 May, 1 June, 10 June, and 20 June) and three irrigation regimes (no irrigation (NI), deficit irrigation (DI), and full irrigation (FI)). Simulations were performed with the model DSSAT4.5, using 50 years of daily weather data.Wefound that: (1) grain yield and water-use efficiency (yield/evapotranspiration) increased linearly with [CO2]; (2) increases in [CO2] had minimal impact on evapotranspiration; (3) yield increased with increasing temperature for the irrigated scenarios (DI and FI), but decreased for the NI scenario; (4) yield increased with earlier sowing dates; and (5) changes in rainfall had a small impact on yield for DI and FI, but a high impact for the NI scenario.

Transcriptome analysis of neutrophils after endurance exercise reveals novel signaling mechanisms in the immune response to physiological stress

Neutrophils serve as an intriguing model for the study of innate immune cellular activity induced by physiological stress. We measured changes in the transcriptome of circulating neutrophils following an experimental exercise trial (EXTRI) consisting of 1 h of intense cycling immediately followed by 1 h of intense running. Blood samples were taken at baseline, 3 h, 48 h, and 96 h post-EXTRI from eight healthy, endurance-trained, male subjects. RNA was extracted from isolated neutrophils. Differential gene expression was evaluated using Illumina microarrays and validated with quantitative PCR. Gene set enrichment analysis identified enriched molecular signatures chosen from the Molecular Signatures Database. Blood concentrations of muscle damage indexes, neutrophils, interleukin (IL)-6 and IL-10 were increased (P < 0.05) 3 h post-EXTRI. Upregulated groups of functionally related genes 3 h post-EXTRI included gene sets associated with the recognition of tissue damage, the IL-1 receptor, and Toll-like receptor (TLR) pathways (familywise error rate, P value < 0.05). The core enrichment for these pathways included TLRs, low-affinity immunoglobulin receptors, S100 calcium binding protein A12, and negative regulators of innate immunity, e.g., IL-1 receptor antagonist, and IL-1 receptor associated kinase-3. Plasma myoglobin changes correlated with neutrophil TLR4 gene expression (r = 0.74; P < 0.05). Neutrophils had returned to their nonactivated state 48 h post-EXTRI, indicating that their initial proinflammatory response was transient and rapidly counterregulated. This study provides novel insight into the signaling mechanisms underlying the neutrophil responses to endurance exercise, suggesting that their transcriptional activity was particularly induced by damage-associated molecule patterns, hypothetically originating from the leakage of muscle components into the circulation.

Stress effects caused by the expression of a mutant cellobiohydrolase I and proteasome inhibition in Trichoderma reesei Rut-C30

Trichoderma reesei Rut-C30 is used widely as an expression host for various gene products. We have explored cellular effects caused by the expression of a mutant form of cellobiohydrolase I (CBHI), the major secreted protein of T. reesei using biochemical and transcriptomic analyses and confocal laser scanning microscopy. The mutated CBHI was tagged fluorescently with Venus to establish the subcellular location of the fusion protein and its potential association with the proteasome, an organelle assigned for the disposal of misfolded proteins. Expression of the mutant CBHI in the high protein-secreting host Rut-C30 caused physiological changes in the fungal hyphae, affected protein secretion and elicited ER stress. A massive upregulation of UPR- and ERAD-related genes sec61, der1, uba1, bip1, pdi1, prp1, cxl1 and lhs1 was observed by qRT-PCR in the CBHIΔ4-Venus strain with four mutations introduced in the DNA encoding the core domain of CBHI. Further stress was applied to this strain by inhibiting function of the proteasome with MG132 (N-benzoylcarbonyl(Cbz)-Leu-Leu-leucinal). The effect of MG132 was found to be specific to the proteasome-associated genes. There are no earlier reports on the effect of proteasome inhibition on protein quality control in filamentous fungi. Confocal fluorescence microscopy studies suggested that the mutant CBHI accumulated in the ER and colocalized with the fungal proteasome. These results provide an indication that there is a limit to how far T. reesei Rut-C30, already under secretion stress, can be pressed to produce higher protein yields.

Atmospheric gas plasma–induced ROS production activates TNF-ASK1 pathway for the induction of melanoma cancer cell apoptosis

Atmospheric gas plasmas (AGPs) are able to selectively induce apoptosis in cancer cells, offering a promising alternative to conventional therapies that have unwanted side effects such as drug resistance and toxicity. However, the mechanism of AGP-induced cancer cell death is unknown. In this study, AGP is shown to up-regulate intracellular reactive oxygen species (ROS) levels and induce apoptosis in melanoma but not normal melanocyte cells. By screening genes involved in apoptosis, we identify tumor necrosis factor (TNF)-family members as the most differentially expressed cellular genes upon AGP treatment of melanoma cells. TNF receptor 1 (TNFR1) antagonist-neutralizing antibody specifically inhibits AGP-induced apoptosis signal, regulating apoptosis signal-regulating kinase 1 (ASK1) activity and subsequent ASK1-dependent apoptosis. Treatment of cells with intracellular ROS scavenger N-acetyl-l-cysteine also inhibits AGP-induced activation of ASK1, as well as apoptosis. Moreover, depletion of intracellular ASK1 reduces the level of AGP-induced oxidative stress and apoptosis. The evidence for TNF-signaling dependence of ASK1-mediated apoptosis suggests possible mechanisms for AGP activation and regulation of apoptosis-signaling pathways in tumor cells.

Stress and Resilience in Combat-Related PTSD: Integration of Psychological Theory and Biological Mechanisms

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric disorder that has a major impact on the ability to function effectively in daily life. PTSD may develop as a response to exposure to an event or events perceived as potentially harmful or life-threatening. It has high prevalence rates in the community, especially among vulnerable groups such as military personnel or those in emergency services. Despite extensive research in this field, the underlying mechanisms of the disorder remain largely unknown. The identification of risk factors for PTSD has posed a particular challenge as there can be delays in onset of the disorder, and most people who are exposed to traumatic events will not meet diagnostic criteria for PTSD. With the advent of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM V), the classification for PTSD has changed from an anxiety disorder into the category of stress- and trauma-related disorders. This has the potential to refocus PTSD research on the nature of stress and the stress response relationship. This review focuses on some of the important findings from psychological and biological research based on early models of stress and resilience. Improving our understanding of PTSD by investigating both genetic and psychological risk and coping factors that influence stress response, as well as their interaction, may provide a basis for more effective and earlier intervention.

The genetic basis of human height : the role of estrogen

Height is a complex physical trait that displays strong heritability. Adult height is related to length of the long bones, which is determined by growth at the epiphyseal growth plate. Longitudinal bone growth occurs via the process of endochondral ossification, where bone forms over the differentiating cartilage template at the growth plate. Estrogen plays a major role in regulating longitudinal bone growth and is responsible for inducing the pubertal growth spurt and fusion of the epiphyseal growth plate. However, the mechanism by which estrogen promotes epiphyseal fusion is poorly understood. It has been hypothesised that estrogen functions to regulate growth plate fusion by stimulating chondrocyte apoptosis, angiogenesis and bone cell invasion in the growth plate. Another theory has suggested that estrogen exposure exhausts the proliferative capacity of growth plate chondrocytes, which accelerates the process of chondrocyte senescence, leading to growth plate fusion. The overall objective of this study was to gain a greater understanding of the molecular mechanisms behind estrogen-mediated growth and height attainment by examining gene regulation in chondrocytes and the role of some of these genes in normal height inheritance. With the heritability of height so well established, the initial hypothesis was that genetic variation in candidate genes associated with longitudinal bone growth would be involved in normal adult height variation. The height-related genes FGFR3, CBFA1, ER and CBFA1 were screened for novel polymorphisms using denaturing HPLC and RFLP analysis. In total, 24 polymorphisms were identified. Two SNPs in ER (rs3757323 C>T and rs1801132 G>C) were strongly associated with adult male height and displayed an 8 cm and 9 cm height difference between homozygous genotypes, respectively. The TC haplotype of these SNPs was associated with a 6 cm decrease in height and remarkably, no homozygous carriers of the TC haplotype were identified in tall subjects. No significant associations with height were found for polymorphisms in the FGFR3, CBFA1 or VDR genes. In the epiphyseal growth plate, chondrocyte proliferation, matrix synthesis and chondrocyte hypertrophy are all major contributors to long bone growth. As estrogen plays such a significant role in both growth and final height attainment, another hypothesis of this study was that estrogen exerted its effects in the growth plate by influencing chondrocyte proliferation and mediating the expression of chondrocyte marker genes. The examination of genes regulated by estrogen in chondrocyte-like cells aimed to identify potential regulators of growth plate fusion, which may further elucidate mechanisms involved in the cessation of linear growth. While estrogen did not dramatically alter the proliferation of the SW1353 cell line, gene expression experiments identified several estrogen regulated genes. Sixteen chondrocyte marker genes were examined in response to estrogen concentrations ranging from 10-12 M to 10-8 M over varying time points. Of the genes analysed, IHH, FGFR3, collagen II and collagen X were not readily detectable and PTHrP, GHR, ER, BMP6, SOX9 and TGF1 mRNAs showed no significant response to estrogen treatments. However, the expression of MMP13, CBFA1, BCL-2 and BAX genes were significantly decreased. Interestingly, the majority of estrogen regulated genes in SW1353 cells are expressed in the hypertrophic zone of the growth plate. Estrogen is also known to regulate systemic GH secretion and local GH action. At the molecular level, estrogen functions to inhibit GH action by negatively regulating GH signalling. GH treated SW1353 cells displayed increases in MMP9 mRNA expression (4.4-fold) and MMP13 mRNA expression (64-fold) in SW1353 cells. Increases were also detected in their respective proteins. Treatment with AG490, an established JAK2 inhibitor, blocked the GH mediated stimulation of both MMP9 and MMP13 mRNA expression. The application of estrogen and GH to SW1353 cells attenuated GH-stimulated MMP13 levels, but did not affect MMP9 levels. Investigation of GH signalling revealed that SW1353 cells have high levels of activated JAK2 and exposure to GH, estrogen, AG490 and other signalling inhibitors did not affect JAK2 phosphorylation. Interestingly, AG490 treatment dramatically decreased ERK2 signalling, although GH did stimulate ERK2 phosphorylation above control levels. AG490 also decreased CBFA1 expression, a transcription factor known to activate MMP9 and MMP13. Finally, GH and estrogen treatment increased expression of SOCS3 mRNA, suggesting that SOCS3 may regulate JAK/STAT signalling in SW1353 cells. The modulation of GH-mediated MMP expression by estrogen in SW1353 cells represents a potentially novel mechanism by which estrogen may regulate longitudinal bone growth. However, further investigation is required in order to elucidate the precise mechanisms behind estrogen and GH regulation of MMP13 expression in SW1353 cells. This study has provided additional evidence that estrogen and the ER gene are major factors in the regulation of growth and the determination of adult height. Newly identified polymorphisms in the ER gene not only contribute to our understanding of the genetic basis of human height, but may also be useful in association studies examining other complex traits. This study also identified several estrogen regulated genes and indicated that estrogen modifies the expression of genes which are primarily expressed in the hypertrophic region of the epiphyseal growth plate. Furthermore, synergistic studies incorporating GH and estrogen have revealed the ability of estrogen to attenuate the effects of GH on MMP13 expression, revealing potential pathways by which estrogen may modulate growth plate fusion, longitudinal bone growth and even arthritis.

Porphyromonas gingivalis lipopolysaccharide alters atherosclerotic-related gene expression in oxidized low-density-lipoprotein-induced macrophages and foam cells

The molecular mechanism between atherosclerosis formation and periodontal pathogens is not clear although positive correlation between periodontal infections and cardiovascular diseases has been reported. Objective: To determine if atherosclerosis related genes were affected in foam cells during and after its formation by P. gingivalis lipopolysaccharide (LPS) stimulation. Methods: Macrophages from human THP-1 monocytes were treated with oxidized low density lipoprotein (oxLDL) to induce the formation of foam cells. P. gingivalis LPS was added to cultures of either oxLDL-induced macrophages or foam cells. The expression of atherosclerosis related genes was assayed by quantitative real time PCR and the protein production of granulocyte-macrophage colony-stimulating factor（GM-CSF）, monocyte chemotactic protein-1 (MCP-1), IL-1β, IL-10 and IL-12 was determined by ELISA. Nuclear translocation of NF-κB P65 was detected by immunocytochemistry and western blot was used to evaluate IKB-α degradation to confirm the NF-κB pathway activation. Results: P. gingivalis LPS stimulated atherosclerosis related gene expression in foam cells and increased oxLDL induced expression of chemokines, adhesion molecules, growth factors, apoptotic genes, and nuclear receptors in macrophages. Transcription of the pro-inflammatory cytokines IL-1β and IL-12 was elevated in response to LPS in both macrophages and foam cells, whereas the anti-inflammatory cytokine IL-10 was not affected. Increased NF-κB pathway activation was also observed in LPS and oxLDL co-stimulated macrophages. Conclusion: P. gingivalis LPS appears to be an important factor in the development of atherosclerosis by stimulation of atherosclerosis related gene expression in both macrophages and foam cells via activation of the NF-κB pathway.

SECIS-binding protein 2 promotes cell survival by protecting against oxidative stress

Reactive oxygen species (ROS) are a primary cause of cellular damage that leads to cell death. In cells, protection from ROS-induced damage and maintenance of the redox balance is mediated to a large extent by selenoproteins, a distinct family of proteins that contain selenium in form of selenocysteine (Sec) within their active site. Incorporation of Sec requires the Sec-insertion sequence element (SECIS) in the 3'-untranslated region of selenoproteins mRNAs and the SECIS-binding protein 2 (SBP2). Previous studies have shown that SBP2 is required for the Sec-incorporation mechanism; however, additional roles of SBP2 in the cell have remained undefined. We herein show that depletion of SBP2 by using antisense oligonucleotides (ASOs) causes oxidative stress and induction of caspase- and cytochrome c-dependent apoptosis. Cells depleted of SBP2 have increased levels of ROS, which lead to cellular stress manifested as 8-oxo-7,8-dihydroguanine (8-oxo-dG) DNA lesions, stress granules, and lipid peroxidation. Small-molecule antioxidants N-acetylcysteine, glutathione, and α-tocopherol only marginally reduced ROS and were unable to rescue cells fully from apoptosis, indicating that apoptosis might be directly mediated by selenoproteins. Our results demonstrate that SBP2 is required for protection against ROS-induced cellular damage and cell survival. Antioxid. Redox Signal. 12, 797–808.

Genes and growth performance in crustacean species : a review of relevant genomic studies in crustaceans and other taxa

Global aquaculture has expanded rapidly to address the increasing demand for aquatic protein needs and an uncertain future for wild fisheries. To date, however, most farmed aquatic stocks are essentially wild and little is known about their genomes or the genes that affect important economic traits in culture. Biologists have recognized that recent technological advances including next generation sequencing (NGS) have opened up the possibility of generating genome wide sequence data sets rapidly from non-model organisms at a reasonable cost. In an era when virtually any study organism can 'go genomic', understanding gene function and genetic effects on expressed quantitative trait locus phenotypes will be fundamental to future knowledge development. Many factors can influence the individual growth rate in target species but of particular importance in agriculture and aquaculture will be the identification and characterization of the specific gene loci that contribute important phenotypic variation to growth because the information can be applied to speed up genetic improvement programmes and to increase productivity via marker-assisted selection (MAS). While currently there is only limited genomic information available for any crustacean species, a number of putative candidate genes have been identified or implicated in growth and muscle development in some species. In an effort to stimulate increased research on the identification of growth-related genes in crustacean species, here we review the available information on: (i) associations between genes and growth reported in crustaceans, (ii) growth-related genes involved with moulting, (iii) muscle development and degradation genes involved in moulting, and; (iv) correlations between DNA sequences that have confirmed growth trait effects in farmed animal species used in terrestrial agriculture and related sequences in crustacean species. The information in concert can provide a foundation for increasing the rate at which knowledge about key genes affecting growth traits in crustacean species is gained.

Stress, lifestyle and quality of life in midlife and older Australian women : results from the stress and the health of women study

Background Chronic psychological stress may pose a serious threat to health, although the mechanisms are not fully understood. This study examines the impact of stress on modifiable lifestyle factors, depressive symptoms, health-related quality of life (HRQOL) and chronic illness in older Australian women. Methods Cross-sectional data were collected from a random sample of 181 older adults aged 60-70 years from rural and urban areas of South-East Queensland, Australia. We used structural equation modelling to examine associations between stress, modifiable lifestyle factors, HRQoL, and chronic illness. Findings Parameter estimates show that older women who reported life stressors where they felt helpless and feared for their life (high magnitude stressors) also reported higher body mass index (p = 0.03) and more chronic illness (p <0.01). In contrast, duration of exposure to life stressors was associated with higher depressive symptom scores (CES-D, p = 0.02) and sleep disturbance scores (p <0.01). Conclusions Our findings support the link between traumatic personal histories (exposure to high magnitude stressors) and unhealthy lifestyle factors. Findings highlight the need for more research on how stress reduction healthy lifestyle and positive coping strategies can be used to reduce the effects of high magnitude stress on health-related quality of life and chronic illness.

Genomic organisation, activity and distribution analysis of the microbial putrescine oxidase degradation pathway

The catalytic action of putrescine specific amine oxidases acting in tandem with 4-aminobutyraldehyde dehydrogenase is explored as a degradative pathway in Rhodococcus opacus. By limiting the nitrogen source, increased catalytic activity was induced leading to a coordinated response in the oxidative deamination of putrescine to 4-aminobutyraldehyde and subsequent dehydrogenation to 4-aminobutyrate. Isolating the dehydrogenase by ion exchange chromatography and gel filtration revealed that the enzyme acts principally on linear aliphatic aldehydes possessing an amino moiety. Michaelis-Menten kinetic analysis delivered a Michaelis constant (KM=0.014mM) and maximum rate (Vmax=11.2μmol/min/mg) for the conversion of 4-aminobutyraldehyde to 4-aminobutyrate. The dehydrogenase identified by MALDI-TOF mass spectrometric analysis (E value=0.031, 23% coverage) belongs to a functionally related genomic cluster that includes the amine oxidase, suggesting their association in a directed cell response. Key regulatory, stress and transport encoding genes have been identified, along with candidate dehydrogenases and transaminases for the further conversion of 4-aminobutyrate to succinate. Genomic analysis has revealed highly similar metabolic gene clustering among members of Actinobacteria, providing insight into putrescine degradation notably among Micrococcaceae, Rhodococci and Corynebacterium by a pathway that was previously uncharacterised in bacteria.

Environmental regulation of leaf colour in red 35S : PAP1 Arabidopsis thaliana

High-temperature, low-light (HTLL) treatment of 35S:PAP1 Arabidopsis thaliana over-expressing the PAP1 (Production of Anthocyanin Pigment 1) gene results in reversible reduction of red colouration, suggesting the action of additional anthocyanin regulators. High-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LCMS) and Affimetrix®-based microarrays were used to measure changes in anthocyanin, flavonoids, and gene expression in response to HTLL. HTLL treatment of control and 35S:PAP1 A. thaliana resulted in a reversible reduction in the concentrations of major anthocyanins despite ongoing over-expression of the PAP1 MYB transcription factor. Twenty-one anthocyanins including eight cis-coumaryl esters were identified by LCMS. The concentrations of nine anthocyanins were reduced and those of three were increased, consistent with a sequential process of anthocyanin degradation. Analysis of gene expression showed down-regulation of flavonol and anthocyanin biosynthesis and of transport-related genes within 24 h of HTLL treatment. No catabolic genes up-regulated by HTLL were found. Reductions in the concentrations of anthocyanins and down-regulation of the genes of anthocyanin biosynthesis were achieved by environmental manipulation, despite ongoing over-expression of PAP1. Quantitative PCR showed reduced expression of three genes (TT8, TTG1 and EGL3) of the PAP1 transcriptional complex, and increased expression of the potential transcriptional repressors AtMYB3, AtMYB6 and AtMYBL2 coincided with HTLL-induced down-regulation of anthocyanin biosynthesis. HTLL treatment offers a model system with which to explore anthocyanin catabolism and to discover novel genes involved in the environmental control of anthocyanins.

Staurosporine augments EGF-mediated EMT in PMC42-LA cells through actin depolymerisation, focal contact size reduction and Snail1 induction : a model for cross-modulation

Background A feature of epithelial to mesenchymal transition (EMT) relevant to tumour dissemination is the reorganization of actin cytoskeleton/focal contacts, influencing cellular ECM adherence and motility. This is coupled with the transcriptional repression of E-cadherin, often mediated by Snail1, Snail2 and Zeb1/δEF1. These genes, overexpressed in breast carcinomas, are known targets of growth factor-initiated pathways, however it is less clear how alterations in ECM attachment cross-modulate to regulate these pathways. EGF induces EMT in the breast cancer cell line PMC42-LA and the kinase inhibitor staurosporine (ST) induces EMT in embryonic neural epithelial cells, with F-actin de-bundling and disruption of cell-cell adhesion, via inhibition of aPKC. Methods PMC42-LA cells were treated for 72 h with 10 ng/ml EGF, 40 nM ST, or both, and assessed for expression of E-cadherin repressor genes (Snail1, Snail2, Zeb1/δEF1) and EMT-related genes by QRT-PCR, multiplex tandem PCR (MT-PCR) and immunofluorescence +/- cycloheximide. Actin and focal contacts (paxillin) were visualized by confocal microscopy. A public database of human breast cancers was assessed for expression of Snail1 and Snail2 in relation to outcome. Results When PMC42-LA were treated with EGF, Snail2 was the principal E-cadherin repressor induced. With ST or ST+EGF this shifted to Snail1, with more extreme EMT and Zeb1/δEF1 induction seen with ST+EGF. ST reduced stress fibres and focal contact size rapidly and independently of gene transcription. Gene expression analysis by MT-PCR indicated that ST repressed many genes which were induced by EGF (EGFR, CAV1, CTGF, CYR61, CD44, S100A4) and induced genes which alter the actin cytoskeleton (NLF1, NLF2, EPHB4). Examination of the public database of breast cancers revealed tumours exhibiting higher Snail1 expression have an increased risk of disease-recurrence. This was not seen for Snail2, and Zeb1/δEF1 showed a reverse correlation with lower expression values being predictive of increased risk. Conclusion ST in combination with EGF directed a greater EMT via actin depolymerisation and focal contact size reduction, resulting in a loosening of cell-ECM attachment along with Snail1-Zeb1/δEF1 induction. This appeared fundamentally different to the EGF-induced EMT, highlighting the multiple pathways which can regulate EMT. Our findings add support for a functional role for Snail1 in invasive breast cancer.

Phosphorylation of caveolin-1 is anti-apoptotic and promotes cell attachment during oxidative stress of kidney cells

Aims: Caveolin-1 (cav1) is reported to have both cell survival and pro-apoptotic characteristics. This may be explained by its localisation or phosphorylation in injured cells. This study investigated the role of cav1 in kidney cells of different nephron origin and developmental state after oxidative stress. Methods: Renal MCDK distal tubular, HK2 proximal tubular epithelial cells and HEK293T renal embryonic cells were treated with 1mM hydrogen peroxide. Apoptosis, loss of cell adhesion, and cell survival were compared with expression of cav1 in its non-phosphorylated and phosphorylated (p-cav1) forms. Cav1 was transfected into the HEK293T cells, or caveolae were disrupted with filipin or nystatin in HK2 cells, to investigate functions of cav1 and p-cav1. Results: Oxidative stress induced more apoptosis in HK2s than MDCKs (p<0.05). HK2s had lower endogenous cav1 and p-cav1 than MDCKs (p<0.05). Both cell lines had increased p-cav1, but not cav1, with oxidative stress. This increase was greatest in MDCKs (p<0.01). Cav1 was located mainly in the plasma membrane of untreated cells and translocated to the cytoplasm with oxidative stress in both cell lines, more so in MDCKs. Disruption of caveolae caused cytoplasmic translocation of cav1 in HK2s, but did not alter high levels of oxidative stress-induced apoptosis. When HEK293Ts lacking endogenous cav1 were transfected with cav1, oxidant-induced apoptosis and loss of cell adhesion was decreased (p<0.01), and p-cav1 was induced by treatment. Conclusion: Cav1 expression and localisation in kidney cells is not anti-apoptotic, but increased expression of p-cav1 may promote cell survival after oxidative stress. © 2008 Royal College of Pathologists of Australasia.

4D GPR tracking of water infiltration in fractured high-porosity limestone

Three thousand liters of water were infiltrated from a 4 m diameter pond to track flow and transport inside fractured carbonates with 20-40 % porosity. Sixteen time-lapse 3D Ground Penetrating Radar (GPR) surveys with repetition intervals between 2 hrs and 5 days monitored the spreading of the water bulb in the subsurface. Based on local travel time shifts between repeated GPR survey pairs, localized changes of volumetric water content can be related to the processes of wetting, saturation and drainage. Deformation bands consisting of thin sub vertical sheets of crushed grains reduce the magnitude of water content changes but enhance flow in sheet parallel direction. This causes an earlier break through across a stratigraphic boundary compared to porous limestone without deformation bands. This experiment shows how time-lapse 3D GPR or 4D GPR can non-invasively track ongoing flow processes in rock-volumes of over 100 m3.