Population divergence in maternal investment and embryo energy use and allocation suggests adaptive responses to cool climates

The thermal sensitivity of early life stages can play a fundamental role in constraining species distributions. For egg-laying ectotherms, cool temperatures often extend development time and exacerbate developmental energy cost. Despite these costs, egg laying is still observed at high latitudes and altitudes. How embryos overcome the developmental constraints posed by cool climates is crucial knowledge for explaining the persistence of oviparous species in such environments and for understanding thermal adaptation more broadly. Here, we studied maternal investment and embryo energy use and allocation in wall lizards spanning altitudinal regions, as potential mechanisms that enable successful development to hatching in cool climates. Specifically, we compared population-level differences in (1) investment from mothers (egg mass, embryo retention and thyroid yolk hormone concentration), (2) embryo energy expenditure during development, and (3) embryo energy allocation from yolk towards tissue. We found evidence that energy expenditure was greater under cool compared with warm incubation temperatures. Females from relatively cool regions did not compensate for this energetic cost of development by producing larger eggs or increasing thyroid hormone concentration in yolk. Instead, embryos from the high-altitude region used less energy to complete development, that is, they developed faster without a concomitant increase in metabolic rate, compared with those from the low-altitude region. Embryos from high altitudes also allocated relatively more energy towards tissue production, hatching with lower residual yolk: tissue ratios than low-altitude region embryos. These results are consistent with local adaptation to cool climate and suggest that this is underpinned by mechanisms that regulate embryonic utilisation of yolk reserves and its allocation towards tissue, rather than shifts in maternal investment of yolk content or composition.

Individual telomere dynamics and their links to life history in a viviparous lizard

Emerging patterns suggest telomere dynamics and life history are fundamentally linked in endotherms through life-history traits that mediate the processes underlying telomere attrition. Unlike endotherms, ectotherms maintain the ability to lengthen somatic telomeres throughout life and the link between life-history strategies and ectotherm telomere dynamics is unknown. In a well-characterized model system (Niveoscincus ocellatus), we used long-term longitudinal data to study telomere dynamics across climatically divergent populations. We found longer telomeres in individuals from the cool highlands than those from the warm lowlands at birth and as adults. The key determinant of adult telomere length across populations was telomere length at birth, with population-specific effects of age and growth on adult telomere length. The reproductive effort had no proximate effect on telomere length in either population. Maternal factors influenced telomere length at birth in the warm lowlands but not the cool highlands. Our results demonstrate that life-history traits can have pervasive and context-dependent effects on telomere dynamics in ectotherms both within and between populations. We argue that these telomere dynamics may reflect the populations' different life histories, with the slow-growing cool highland population investing more into telomere lengthening compared to the earlier-maturing warm lowland population.

Temperature and telomeres: thermal treatment influences telomere dynamics through a complex interplay of cellular processes in a cold-climate skink

Telomere dynamics vary fundamentally between endothermic populations and species as a result of differences in life history, yet we know little about these patterns in ectotherms. In ectotherms, the relationships between climate, metabolism and life history suggest that telomere attrition should be higher at relatively high environmental temperatures compared to relatively low environmental temperatures, but these effects may vary between populations due to local adaptation. To address this hypothesis, we sampled reactive oxygen species (ROS) and telomere length of lizards from warm lowland and cool highland populations of a climatically widespread lizard species that we exposed to hot or cold basking treatments. The hot treatment increased relative telomere length compared to the cold treatment independent of climatic origin or ROS levels. Lizards from the cool highland region had lower ROS levels than those from the warm lowland region. Within the highland lizards, ROS increased more in the cold basking treatment than the hot basking treatment. These results are in the opposite direction to those predicted, suggesting that the relationships between temperature, metabolism, ROS and telomere dynamics are not straightforward. Future work incorporating detailed understanding of the thermal reaction norms of these and other linked traits is needed to fully understand these processes.

Tail loss and telomeres: consequences of large-scale tissue regeneration in a terrestrial ectotherm

Large-scale tissue regeneration has potential consequences for telomere length through increases in cell division and changes in metabolism which increase the potential for oxidative stress damage to telomeres. The effects of regeneration on telomere dynamics have been studied in fish and marine invertebrates, but the literature is scarce for terrestrial species. We experimentally induced tail autotomy in a lizard ( Niveoscincus ocellatus) and assessed relative telomere length (RTL) in blood samples before and after partial tail regeneration while concurrently measuring reactive oxygen species (ROS) levels. The change in ROS levels was a significant explanatory variable for the change in RTL over the 60-day experiment. At the average value of ROS change, the mean RTL increased significantly in the control group (intact tails), but there was no such evidence in the regenerating group. By contrast, ROS levels decreased significantly in the regenerating group, but there was no such evidence in the control group. Combined, these results suggest that tail regeneration following autotomy involves a response to oxidative stress and this potentially comes at a cost to telomere repair. This change in telomere maintenance demonstrates a potential long-term cost of tail regeneration beyond the regrowth of tissue itself.

Structure and solution equilibria of D-glucose and D-mannose sulfite adducts

An X-ray crystallographic study has confirmed that the potassium bisulfite adducts of D-glucose and D-mannose have open-chain structures with R and S configurations respectively at C-1. NMR studies have shown that each sugar gives rise to two bisulfite compounds, and solution-state structures and conformations of these isomers have been deduced from analysis of (1)H NMR spectra. (13)C NMR data for the four adducts are given. Furanose forms of the D-glucose and D-mannose have been detected in the equilibrium solutions.

Pressurised fluid extraction of bupirimate and ethirimol from aged soils

This paper assesses the effect of pressurised fluid extraction (PFE) on the recovery of bupirimate and its degradation product, ethirimol from a range of soil types. The analytes were extracted under standard conditions (pressure, 2000 p.s.i.; temperature, 100 degrees C; and, three static flush cycles of 5 min static extraction time each) using a variety of individual and combined solvents. It was found that the recovery of bupirimate was dependent upon the organic matter content of soil.

Influence of solvent and soil type on the pressurised fluid extraction of PAHs

Pressurised fluid extraction (PFE) of polycyclic aromatic hydrocarbons (PAHs) from a certified reference material (CRM) 524 has been firstly optimised following a central composite design. The instrumental parameters of the PFE (pressure, temperature, extraction time and number of solvent cycles) were studied in order to obtain maximum extraction yields. Neither pressure nor extraction time or temperature seemed to have any significant effect on the extraction yield, therefore one extraction cycle was enough to exhaustively extract all the PAHs from CRM 524. Once the instrumental conditions were established, the extraction yields obtained with eight different solvents or solvent mixtures [acetone, dichloromethane, acetonitrile, acetone-dichloromethane (1 + 1 v/v), acetone-isohexane (1 + 1 v/v), isohexane, methanol and toluene] from the CRM 524 were compared and showed that the best recoveries were obtained with acetone-isohexane (1 + 1 v/v). Finally, the effect of sand, silt, clay and the organic matter content of soil was investigated with respect to recovery of PAHs by PFE with different solvents or solvent mixtures for aged soil samples. In this case, eight soils with different sand, silt, clay and organic matter contents were slurry spiked with PAHs and aged for 19 days. Three aliquots of each slurry spiked soil were extracted with the previously mentioned solvents and the results were studied by means of principal component analysis (PCA) of the whole data set (soil composition, solubility parameter of the solvent and recoveries of all PAHs) and partial least squares (PLS). Clay and organic matter content and the squared solubility parameter have the highest correlation with the recovery of PAHs from soil samples.

Extraction of DDT [1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane] and its metabolites DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene] and DDD [1,1-dichloro-2,2-bis(p-chlorophenyl)-ethane]) from aged contaminated soil

Pressurised liquid extraction (PLE) was used to extract DDT [1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane] and its metabolites, DDD [1,1-dichloro-2,2-bis(p-chlorophenyl)ethane] and DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] from an aged, contaminated soil. Using three sequential static phases, PLE removed an equivalent quantity of DDT and its metabolites as Soxhlet extraction, in less time and with less solvent. Recovery was almost quantitative, implying appropriate sample work-up and manipulation.

Pressurised liquid extraction of pentachlorophenol from dyestuffs and cotton

Pressurised liquid extraction (PLE) was used to extract pentachlorophenol from cotton and dyestuffs. Five dyes and one dyed cotton were investigated for pentachlorophenol. The dyed cotton was found to have between 5.3 and 5.9 microg g(-1) pentachlorophenol, while the dyes were found to have between 42 and 2569 microg g(-1) pentachlorophenol present. The latter were found to be dye and manufacturing site dependant. Recovery experiments, in all cases, were found to be quantitative indicating appropriate sample work-up and manipulations.

Thiophene systems. 14. Synthesis and antihypertensive activity of novel 7-(cyclic amido)-6-hydroxythieno[3,2-b]pyrans and related compounds as new potassium channel activators

The synthesis and antihypertensive activity of novel 7-(cyclic amido)-6-hydroxy-5,5-dimethylthieno[3,2-b]pyrans and related compounds are described. The compounds were tested for oral antihypertensive activity in spontaneously hypertensive rats (SHR) and selected compounds were evaluated in vitro for increases in 86Rb efflux in rabbit isolated mesenteric arteries. The effects on activity in SHR of lactam ring size, the presence of heteroatoms in the lactam ring, the relative stereochemistry at C-6 and C-7, and the substituents on the thiophene ring are examined. The best racemic compound in this series is 32, trans-5,6-dihydro-6-hydroxy-5,5-dimethyl-2-nitro-7-(2-oxopiperidin -1-yl)-5H- thieno[3,2-b]pyran, which is 10-fold more potent than cromakalim with an ED30 = 0.015 mg/kg in SHR. Compound 32 could be resolved and the antihypertensive activity determined to reside primarily in the (6S,7S)-(-)-enantiomer 41. Surprisingly, the elimination of water to give the enamides 50-52, thiophene isosteres of bimakalim, diminishes activity significantly.

Predicting recidivism among first admissions at Tennessee's state psychiatric hospitals

Using data from computerized patient records, the authors attempted to identify characteristics of first admissions to state psychiatric facilities who would later become recidivists. In an examination of 22,062 first admissions to all state hospitals in Tennessee, they found six variables with significant ability to predict recidivism: age, delusional beliefs, assaultive acts, out-of-state residence, indigence, and living with parents. A risk profile that predicted future recidivism with statistical significance at all five Tennessee state hospitals was subsequently developed, but the predictive accuracy was too low for the profile to be clinically useful. The authors believe the benefits of early identification of patients at risk justify further research.

Light-induced electron-transfer reactions involving the Tris(2,2'-bipyridine)ruthenium dication and related complexes. II. Effect of the 2-(Thiazol-2'-yl)pyridine ligand

The complexes [Ru(bpy)n(thpy)3-n ]2+ [where bpy = 2,2'-bipyridine, thpy = 2-(thiazol-2'-yl)pyridine, and n = 2, 1 or 0] sensitize the photo reduction of water and inhibit the hydrogenation of methylviologen. Compared with Ru(bpy)32+, the turnover numbers of methylviologen are increased but the rates of formation and yields of hydrogen are lowered. Photophysical and kinetic data have been used to explain the observed effects.