We integrated information from satellite transmitters, GPS loggers and wet/dry activity loggers to compare the at-sea behaviour of 4 sympatric albatross species by night and day: wandering Diomedea exulans, grey-headed Thalassarche chrysostoma, black-browed T. melanophrys and light-mantled sooty Phoebetria palpebrata (in total, 350 foraging trips by 101 individuals). Trip duration, distance and maximum range varied more within species between stages (incubation, broodguard and post-brood) than between species at the same stage, implying that reproductive constraints are more important than interspecific competition in shaping foraging behaviour. Wandering albatrosses spent more time on the water in fewer, longer bouts than other species. The proportion of time spent on the water was similar among the 3 smaller species. The partitioning of foraging activity between day and night varied little between species: all landed and took off more often, but spent less time overall on the water during the day than at night. This supports observations that albatrosses forage most actively during daylight, even though many of their fish and squid prey approach the surface only at night. Albatrosses were more active on bright moonlit nights, seem to have no fixed daily requirement for sleep, rest or digestion time on the water, can navigate in darkness, and are probably unhindered by the slight reduction in mean wind strength at night. They are probably less active at night because their ability to see and capture prey from the air is reduced and it is then more energy-efficient for them to rest or to catch prey using a 'sit-and-wait' foraging strategy.
As a consequence of warming temperatures around the world, spring and autumn phenologies have been shifting, with corresponding changes in the length of the growing season. Our understanding of the spatial and interspecific variation of these changes, however, is limited. Not all species are responding similarly, and there is significant spatial variation in responses even within species. This spatial and interspecific variation complicates efforts to predict phenological responses to ongoing climate change, but must be incorporated in order to build reliable forecasts. Here, we use a long-term dataset (1953 -2005) of plant phenological events in spring (flowering and leaf out) and autumn (leaf colouring and leaf fall) throughout Japan and South Korea to build forecasts that account for these sources of variability. Specifically, we used hierarchical models to incorporate the spatial variability in phenological responses to temperature to then forecast species' overall and site-specific responses to global warming. We found that for most species, spring phenology is advancing and autumn phenology is getting later, with the timing of events changing more quickly in autumn compared with the spring. Temporal trends and phenological responses to temperature in East Asia contrasted with results from comparable studies in Europe, where spring events are changing more rapidly than are autumn events. Our results emphasize the need to study multiple species at many sites to understand and forecast regional changes in phenology.
Structural analysis of 70Li2S–30P2S5 glass ceramic by 31P MAS NMR revealed a strong correlation between the degree of crystallisation and the lithium ionic conductivity.
A series of new quinodimethane-substituted terthiophene and quaterthiophene oligomers has been investigated for comparison with a previously studied quinoid oligothiophene that has demonstrated high mobilities and ambipolar transport behavior in thin-film transistor devices. Each new quinoidal thiophene derivative shows a reversible one-electron oxidation between 0.85 and 1.32 V, a quasi-reversible one-electron second oxidation between 1.37 and 1.96 V, and a reversible two-electron reduction between -0.05 and -0.23 V. The solution UV-vis-NIR spectrum of each compound is dominated by an intense (epsilon congruent with 100 000 M(-1) cm(-1)) low energy pi-pi transition that has a lambda(max) ranging between 648 and 790 nm. All X-ray crystal structures exhibit very planar quinoidal backbones and short intermolecular pi-stacking distances (3.335-3.492 A). Structures exhibit a single pi-stacking distance with parallel cofacial stacking (sulfur atoms of equivalent rings pointed in the same direction) or with alternating distances and antiparallel cofacial stacking (sulfur atoms of equivalent rings pointed in the opposite direction). Examples of the layered and herringbone-packing motifs are observed for both the parallel and the antiparallel cofacial stacking. Analysis of the X-ray structures and molecular orbital calculations indicates that all of these compounds have one-dimensional electronic band structures as a result of the pi-stacking. For structures with a unique pi-stacking distance, a simple geometric overlap parameter calculated from the shape of the molecule and the slip from perfect registry in the pi-stack correlates well with the transfer integrals (t) calculated using molecular orbital theory. The calculated valence (633 meV) and conduction (834 meV) bandwidths for a quinoid quaterthiophene structure are similar to those calculated for the benchmark pentacene and indicate that both hole and electron mobilities could be significant.
The purpose of this study was to examine the validity of the quantitative measurement of muscle oxidative metabolism in exercise by near-infrared continuous-wave spectroscopy (NIRcws). Twelve male subjects performed two bouts of dynamic handgrip exercise, once for the NIRcws measurement and once for the (31)P-magnetic resonance spectroscopy (MRS) measurement as a standard measure. The resting muscle metabolic rate (RMRmus) was independently measured by (31)P-MRS during 15 min of arterial occlusion at rest. During the first exercise bout, the quantitative value of muscle oxidative metabolic rate at 30 s postexercise was evaluated from the ratio of the rate of oxyhemoglobin/myoglobin decline measured by NIRcws during arterial occlusion 30 s after exercise and the rate at rest. Therefore, the absolute values of muscle oxidative metabolic rate at 30 s after exercise [VO(2NIR(30))] was calculated from this ratio multiplied by RMRmus. During the second exercise bout, creatine phosphate (PCr) resynthesis rate was measured by (31)P-MRS at 30 s postexercise [Q((30))] under the same conditions but without arterial occlusion postexercise. To determine the validity of NIRcws, VO(2NIR(30)) was compared with Q((30)). There was a significant correlation between VO(2NIR(30)), which ranged between 0.018 and 0. 187 mM ATP/s, and Q((30)), which ranged between 0.041 and 0.209 mM ATP/s (r = 0.965, P < 0.001). This result supports the application of NIRcws to quantitatively evaluate muscle oxidative metabolic rate in exercise.
The great tit complex is divided into four groups, each containing several subspecies. Even though the groups are known to differ markedly on morphological, vocal and behavioural characters, some hybridization occurs in the regions where they meet. The great tit has often been referred to as an example of a ring species, although this has later been questioned. Here, we have studied the genetic structure and phylogenetic relationships of the subspecies groups to clarify the evolutionary history of the complex using control region sequences of the mitochondrial DNA. The subspecies groups were found to be monophyletic and clearly distinct in mitochondrial haplotypes, and therefore must have had long-independent evolutionary histories. This conflicts with the ring species assignment and supports the formation of secondary contact zones of previously temporarily isolated groups. According to the phylogenetic species concept, all the subspecies groups could be considered as separate species, but if the definition of the biological species concept is followed, none of the subspecies groups is a true species because hybridization still occurs.
Climate change is affecting plant phenology worldwide. Phenological responses vary among species, but it is not clear how responses differ among closely related species. We examined a 25-yr record (1981-2005) of flowering times for 97 trees, representing 17 species and hybrids of cherry (Cerasus sp. or Prunus sp.) grown at Mt. Takao, in Tokyo, Japan. The cherry trees flowered earlier over time, by an average of 5.5 d over the 25-yr study. Earlier flowering was explained largely by a 1.8°C increase in February-March mean monthly temperatures. Most species and hybrids flowered 3-5 d earlier for each 1°C increase in temperature, but early-flowering taxa flowered as much as 9 d earlier for each 1°C increase in temperature. Flowering durations and differences in flowering times among species were greater in warm years than in cold years. Species and individual trees also flowered longer in warm years. These results show that the flowering times of closely related species may change similarly in response to climate change, but that early-flowering species may diverge from the overall trend in a predictable way. Such changes in flowering may affect gene flow and pollination as the length of the flowering season increases.
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