bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations on the formation, development, and structure of the tuber of Testudinaria elephantipes, and on the origin of the vegetative shoot
Authors: Sparshott E. N. 
Published: May 2008

SummaryThe young plants used for these observations were grown from seed collected in the Southern Karroo.The tuber of Testudinaria elephantipes is at first small, white, and spherical. Later it turns brown and develops a flattened or concave base and a thin continuous periderm.In the older, massive, semi-globular condition the tuber has a thick, deeply fissured, corky crust. Towards the base of the tuber the cork forms a thinner layer, broken only by the protrusion of roots. Various developmental stages are figured.There is no cork over a small area at the apex of the tuber. The growing point of the vegetative shoot is in this region, and is enclosed within a number of persistent scale leaves.The seed contains a small embryo embedded in considerable endosperm. There is no suggestion of tuberisation in the embryo.The development of the seedling is described and figured. A longitudinal section suggests that the plumular axis consists at first of little more than a stem apex and one leaf.Lack of opportunity for translocation of food synthesised is probably the cause of tuberisation. An explanation of the lack of symmetry is suggested. Tuberisation is not due to fungal infection.The anatomy of seedlings at different stages of development is described. The initial thickening of the hypocotyl results partly from cell division and partly from hypertrophy of the cortical parenchyma cells. Tuberisation is finally due to secondary growth originating in the pericycle.The early development of the cork crust and the growth zone is described.The structure of a three-year old tuber is dealt with in some detail. In general, the growth zone is hemispherical. Beneath the apex and just above the base no continuous meristem appears, though local growth zones may be found over the base. Vascular strands and medullary parenchyma are cut off towards the inside of the meristem, and secondary parenchyma towards the outside.The vascular tissue forms a small flat network under the apex and a larger network over the base, and these plates are connected by a complex system of anastomosing vascular strands running down the side of the tuber towards the inside of the growth zone. These vascular systems form growth rings. The bulk of the tissue cut off from the growth zone is parenchymatous.Fissures abutting on the medullary rays appear in the cork. The exposed parenchyma within the cork becomes suberised and a new band of cork is formed. Over the base of the tuber the original cork layer persists.An explanation is given for the origin of adventitious shoots.The sympodial origin of the seasonal vegetative shoots formed at the apex of the tuber is described and figured.The tuber is held to consist of a secondarily thickened hypocotyl and a very short epicotyl.
Phase I and pharmacokinetic study of sorafenib, an oral multikinase inhibitor, in Japanese patients with advanced refractory solid tumors
Authors: Minami Hironobu , Kawada Kenji , Ebi Hiromichi , Kitagawa Koichi , Kim Yon‐il , Araki Kazuhiro , Mukai Hirofumi , Tahara Makoto , Nakajima Hikaru , Nakajima Keiko 
Published: May 2008

Sorafenib is a novel oral multikinase inhibitor that targets Raf serine/threonine and receptor tyrosine kinases, and inhibits tumor cell proliferation and angiogenesis. We have conducted a phase I study of sorafenib to determine the safety, tolerability, pharmacokinetics, and potential efficacy of this agent in 31 Japanese patients with advanced refractory solid tumors. Sorafenib (100–600 mg) was given as a single dose followed by a 7‐day wash‐out period, and then administrated twice daily (bid). The most frequent drug‐related adverse events were rash/desquamation (61%), hand–foot skin reactions (39%), diarrhea (36%), and elevations of serum lipase (36%) and amylase (26%) levels. Dose‐limiting toxicities (DLTs) were grade 3 diarrhea at 200 mg bid and grade 3 fatigue at 600 mg bid. Grade 3 and 4 pancreatic enzyme elevations were observed at 200–600 mg bid, but they were not deemed dose‐limiting because they were asymptomatic and were not associated with pancreatitis or chronic damage to the pancreas. The AUC and Cmax of sorafenib increased linearly with dose up to 400 mg bid. Partial responses were observed in one of 10 patients with non‐small cell lung cancer and one of three patients with renal cell carcinoma. In conclusion, sorafenib 400 mg bid was well tolerated in Japanese patients with advanced refractory solid tumors. The recommended dose for future clinical trials is 400 mg bid. (Cancer Sci 2008; 99: 1492–1498)
Occurrence of Francisella piscicida in farmed and wild Atlantic cod, Gadus morhua L., in Norway
Authors: Ottem K F , Nylund A , Isaksen T E , Karlsbakk E , Bergh Ø 
Published: May 2008

AbstractFrancisellosis, caused by the bacterium Francisella piscicida, has become one of the most serious diseases in Atlantic cod production in Norway. The major aim of this study was to determine the distribution of F. piscicida in farmed and wild fish in areas with cod farming along the Norwegian coast, and its occurrence in cod from areas without cod farming. Two real‐time PCR assays, targeting the 16S rRNA gene and the FopA gene of F. piscicida, were developed since sensitive and specific diagnostic tools are required for detecting asymptomatic carriers of the bacterium. A total of 422 wild cod from 13 sampling areas and 955 farmed cod from 10 areas along the coast of Norway were examined. Using the real‐time polymerase chain reaction (PCR) assays, F. piscicida was detected in wild populations of cod from all counties examined south of Sogn og Fjordane in southern Norway (overall prevalence 13%, n = 221). Wild cod north of Sogn og Fjordane were negative for the bacterium (n = 201). Farmed cod from most parts of Norway were F. piscicida positive. The apparent absence of the bacterium in wild populations of cod in the northern parts of Norway and its widespread occurrence in wild cod from southern parts of Norway is believed to relate to differences in seawater temperatures.
Electroencephalogram asymmetry and spectral power during sleep in the northern fur seal
Authors: LYAMIN OLEG I. , LAPIERRE JENNIFER L. , KOSENKO PETER O. , MUKHAMETOV LEV M. , SIEGEL JEROME M. 
Published: May 2008

SummaryThe fur seal (Callorhinus ursinus), a member of the Pinniped family, displays a highly expressed electroencephalogram (EEG) asymmetry during slow wave sleep (SWS), which is comparable with the unihemispheric sleep in cetaceans. In this study, we investigated the EEG asymmetry in the fur seal using spectral analysis. Four young (2–3 years old) seals were implanted with EEG electrodes for polygraphic sleep recording. In each animal, EEG spectral power in the frequency range of 1.2–16 Hz was computed in symmetrical cortical recordings over two consecutive nights. The degree of EEG asymmetry was measured by using the asymmetry index [AI = (L − R)/(L + R), where L and R are the spectral powers in the left and right hemispheres, respectively]. In fur seals, EEG asymmetry, as measured by the percent of 20‐s epochs with absolute AI > 0.3 and >0.6, was expressed in the entire frequency range (1.2–16 Hz). The asymmetry was significantly greater during SWS (25.6–44.2% of all SWS epochs had an absolute AI > 0.3 and 2.1–12.2% of all epochs had AI > 0.6) than during quiet waking (11.0–20.3% and 0–1.9% of all waking epochs, respectively) and REM sleep (4.2–8.9% of all REM sleep epochs and no epochs, respectively). EEG asymmetry was recorded during both low‐ and high‐voltage SWS, and was maximal in the range of 1.2–4 and 12–16 Hz. As shown in this study, the degree of EEG asymmetry and the frequency range in which it is expressed during SWS in fur seals are profoundly different from those of terrestrial mammals and birds.
Alertness, mood and performance rhythm disturbances associated with circadian sleep disorders in the blind
Authors: LOCKLEY STEVEN W. , DIJK DERK‐JAN , KOSTI OURANIA , SKENE DEBRA J. , ARENDT JOSEPHINE 
Published: May 2008

SummaryBlind people report disturbances in alertness, mood and performance. In laboratory studies, these waking functions can only be maintained when the wake‐dependent deterioration is opposed by appropriately‐timed endogenous circadian rhythms. We aimed to quantify whether variations in waking function experienced by blind people living in society were dependent on the phase relationship between the sleep‐wake cycle and the circadian pacemaker. The time course of alertness, mood and performance was assessed in 52 blind subjects with and without circadian rhythm disorders every 2 h for 2 days per week for 4 weeks. Sleep‐wake timing and circadian phase were assessed from diaries and weekly measurements of urinary 6‐sulphatoxymelatonin rhythms, respectively. In those subjects who woke at either a normal circadian phase (n = 26) or abnormally early (n = 5), alertness, mood and performance deteriorated significantly with increased time awake (P < 0.05). In 17 non‐entrained (‘free‐running’) subjects, waking function varied significantly with circadian phase such that subjects rated themselves most sleepy (P = 0.03) and most miserable (P = 0.02) when they were awake during the time of peak melatonin production. The internal phase relationship between sleep‐wake behaviour and the circadian melatonin rhythm in entrained subjects contributed to predictable differences in the daily profile of alertness, mood and performance. Disruption of this phase relationship in non‐entrained blind individuals with circadian rhythm sleep disorders resulted in impaired waking function during the day equivalent to that usually only experienced when awake during the night. Treatment for circadian rhythm disorders should be targeted in normalizing these phase relationships.
Cold exposure impairs dark‐pulse capacity to induce REM sleep in the albino rat
Authors: BARACCHI FRANCESCA , ZAMBONI GIOVANNI , CERRI MATTEO , SINDACO ELIDE DEL , DENTICO DANIELA , JONES CHRISTINE ANN , LUPPI MARCO , PEREZ EMANUELE , AMICI ROBERTO 
Published: May 2008

SummaryIn the albino rat, a REM sleep (REMS) onset can be induced with a high probability and a short latency when the light is suddenly turned off (dark pulse, DP) during non‐REM sleep (NREMS). The aim of this study was to investigate to what extent DP delivery could overcome the integrative thermoregulatory mechanisms that depress REMS occurrence during exposure to low ambient temperature (Ta). To this aim, the efficiency of a non‐rhythmical repetitive DP (3 min each) delivery during the first 6‐h light period of a 12 h : 12 h light–dark cycle in inducing REMS was studied in the rat, through the analysis of electroencephalogram, electrocardiogram, hypothalamic temperature and motor activity at different Tas. The results showed that DP delivery triggers a transition from NREMS to REMS comparable to that which occurs spontaneously. However, the efficiency of DP delivery in inducing REMS was reduced during cold exposure to an extent comparable with that observed in spontaneous REMS occurrence. Such impairment was associated with low Delta activity and high sympathetic tone when DPs were delivered. Repetitive DP administration increased REMS amount during the delivery period and a subsequent negative REMS rebound was observed. In conclusion, DP delivery did not overcome the integrative thermoregulatory mechanisms that depress REMS in the cold. These results underline the crucial physiological meaning of the mutual exclusion of thermoregulatory activation and REMS occurrence, and support the hypothesis that the suspension of the central control of body temperature is a prerequisite for REMS occurrence.
Natural selection in avian protein‐coding genes expressed in brain
Authors: AXELSSON ERIK , HULTIN‐ROSENBERG LINA , BRANDSTRÖM MIKAEL , ZWAHLÉN MARTIN , CLAYTON DAVID F. , ELLEGREN HANS 
Published: May 2008

AbstractThe evolution of birds from theropod dinosaurs took place approximately 150 million years ago, and was associated with a number of specific adaptations that are still evident among extant birds, including feathers, song and extravagant secondary sexual characteristics. Knowledge about the molecular evolutionary background to such adaptations is lacking. Here, we analyse the evolution of > 5000 protein‐coding gene sequences expressed in zebra finch brain by comparison to orthologous sequences in chicken. Mean dN/dS is 0.085 and genes with their maximal expression in the eye and central nervous system have the lowest mean dN/dS value, while those expressed in digestive and reproductive tissues exhibit the highest. We find that fast‐evolving genes (those which have higher than expected rate of nonsynonymous substitution, indicative of adaptive evolution) are enriched for biological functions such as fertilization, muscle contraction, defence response, response to stress, wounding and endogenous stimulus, and cell death. After alignment to mammalian orthologues, we identify a catalogue of 228 genes that show a significantly higher rate of protein evolution in the two bird lineages than in mammals. These accelerated bird genes, representing candidates for avian‐specific adaptations, include genes implicated in vocal learning and other cognitive processes. Moreover, colouration genes evolve faster in birds than in mammals, which may have been driven by sexual selection for extravagant plumage characteristics.
Gene flow and population subdivision in a pantropical plant with sea‐drifted seeds Hibiscus tiliaceus and its allied species: evidence from microsatellite analyses
Authors: TAKAYAMA KOJI , TATEISHI YOICHI , MURATA JIN , KAJITA TADASHI 
Published: May 2008

AbstractThe genetic differentiation and structure of Hibiscus tiliaceus, a pantropical plant with sea‐drifted seeds, and four allied species were studied using six microsatellite markers. A low level of genetic differentiation was observed among H. tiliaceus populations in the Pacific and Indian Ocean regions, similar to the results of a previous chloroplast DNA (cpDNA) study. Frequent gene flow by long‐distance seed dispersal is responsible for species integration of H. tiliaceus in the wide distribution range. On the other hand, highly differentiated populations of H. tiliaceus were detected in West Africa, as well as of Hibiscus pernambucensis in southern Brazil. In the former populations, the African continent may be a geographical barrier that prevents gene flow by sea‐drifted seeds. In the latter populations, although there are no known land barriers, the bifurcating South Equatorial Current at the north‐eastern horn of Brazil can be a potential barrier to gene flow and may promote the genetic differentiation of these populations. Our results also suggest clear species segregation between H. tiliaceus and H. pernambucensis, which confirms the introgression scenario between these two species that was suggested by a previous cpDNA study. Our results also provide good evidence for recent transatlantic long‐distance seed dispersal by sea current. Despite the distinct geographical structure observed in the cpDNA haplotypes, a low level of genetic differentiation was found between Pacific and Atlantic populations of H. pernambucensis, which could be caused by transisthmian gene flow.
Zooplankton Grazing during Dinoflagel‐late Blooms in a Cape Cod Embayment, with Observations of Predation upon Tin‐tinnids by Copepods
Authors: Turner Jefferson T. , Anderson Donald M. 
Published: May 2008

Abstract. The patterns and rates of feeding by the copepod Acartia hudsonica and larvae of the polychaete Polydora sp. were investigated during the spring in an estuarine embayment. These dominant macrozooplankters fed upon the natural particulate assemblages (predominantly dino‐flagellates) spiked with the toxic dinoflagellate Gonyaulax tamarensis. G. tamarensis was ingested by both zooplankters, as was Heterocapsa triquetra, the most abundant alternative food item. Ingestion rates generally increased as dinoflagellate concentrations increased, resulting in a relatively constant (and low) filtration rate for each grazer. Dinophysis acuminata, another dominant dinoflagellate, was essentially ungrazed. Thus, the zooplankters did not ingest one dinoflagellate and consumed others in proportion to their availability but at low rates. Based on these low rates and the small number of A. hudsonica observed during the spring, we infer minima! grazing impact on a 1980 G. tamarensis bloom. In contrast, the impact of polychaete larvae may have been substantial, since their extreme numerical abundance more than compensated for low filtration rates.In one instance, the tintinnid Eutintinnus pectinis was accidentally included in a grazing experiment. Our ingestion data demonstrate that A. hudsonica, when presented with a combination of tintinnids and several species of phytoplankton (G. tamarensis and D. acuminata) ingested the tintinnids at high rates, in proportion to their high abundance. Since the nanoflagellate Chroomonas amphioxea was found within the loricae of many of the surviving tintinnids, this also provided a qualitative demonstration of the often‐hypothesized nanoplankton to tintinnid to copepod link in a marine food chain.
Seasonality of Plankton Assemblages in a Temperate Estuary
Authors: Turner Jefferson T. , Bruno Stephen F. , Larson Ralph J. , Staker Robert D. , Sharma Gurdial M. 
Published: May 2008

Abstract. Synoptic measurements of temperature, salinity, nutrients, primary productivity, chlorophyll a, and abundance and composition of phytoplankton, zooplankton, and ichthyoplank‐ton were made over an annual cycle on the Peconic Bay estuary (Long Island, New York, USA).There were pronounced seasonal fluctuations in all variables measured. During the warmer season, the plankton was dominated by nanophytoplankton (athecate microflagellates and chlorophytes, short chains of diatoms), small zooplankton (copepod nauplii, copepodites, and adults of small copepod species) and gelatinous carnivores (ctenophores and medusae). During the colder season, the plankton was dominated (in terms of primary productivity and chlorophyll a) by netplankton, larger zooplankton (adult copepods) and fish larvae. The winter bloom of apparent netplankton (> 20 μm fraction) was largely an artifact of the screening method employed, in that long chains of a diatom with small individual cell size (Skeletonema costatum) comprised 84.4–97.8% of the phytoplankton present. There was a significant negative relationship over the year between length of diatom chains and number of smaller zooplankton. For this reason, as well as initiation of the winter bloom during a period of declining levels of both light and zooplankton, inception of the bloom appeared more related to release of zooplankton grazing pressure than to illumination. Temporally offset pulses of ctenophores and other zooplankton during the warmer season suggest substantial predation by ctenophores. Apparent decimation of copepod populations by ctenophore predation in late summer and fall immediately preceeded inception of the winter diatom bloom. Larval Ammodytes americanus were the dominant ichthyoplankton, and these co‐occurred in winter with increased abundances of larger adult copepods of species upon which A. americanus is known to feed. With certain modifications the patterns recorded for Peconic Bay corresponded to both of two generalized trophic pathways proposed by Greve & Parsons (1977) for temperate waters: nanoplankton → small zooplankton → gelatinous zooplankton carnivores ornetplankton → larger zooplankton → young fish.The former pattern characterized the warmer season, and the latter the colder season. Comparison of patterns in Peconic Bay with those in some other temperate estuarine and coastal waters suggests similarity, particularly for estuaries of the northeastern United States.
A Study in Ultra‐Ecology: Microorganisms on the Seagrass Posidonia oceanica (L.) DELILE
Authors: Novak Rudolf 
Published: May 2008

Abstract. Microbial colonization on the leaves of a shoot of the mediterranean seagrass Posidonia oceanica (L.) DELILE was studied using Scanning Electron Microscopy. Methods of field ecology such as transect, random plot and stratified sampling survey were applied to the microbial niveau to gain both qualitative and quantitative information on the microbial assemblage.While macro‐epiphytic growth was significantly greater on the outer leaf sides, microbial colonization density was significantly higher on the inner leaf sides, both on leaf surface and epiphyte surface. Diatoms colonized the surface of incrusting algae and epiphytic animals in significantly lower numbers than the Posidonia leaf surface and were absent on erect epiphytic algae. Bacterial densities on epiphyte surfaces even exceeded values of the corresponding leaf surfaces on algal thalli near the leaf tips and on old leaves. Diatoms reach highest mean density on mature leaves and close to the leaf tips, while bacteria reach their greatest density on the oldest leaf and closer to the leaf base. Diatom density in general increases with exposure time of plant surface, while greatest bacterial density was observed at 7–10 weeks exposure. Basal leaf parts on younger leaves were dominated by rod‐shaped bacteria, while distal leaf parts and old leaves were dominated by small coccoid bacteria. Surfaces of epiphytic algae were always distinctly dominated by small coccoid bacteria, and edges of thalli attracted high microbial densities. Microbial biomass (calculated from cell volumes using standard conversion factors) amounts to 2.3 g dry weight m‐2 in the Posidonia stand where the shoot was sampled.The observed patterns of epiphytic colonization are interpreted as the result of a complex, dynamically changing system of interactions both within the epiphytic community and between the epiphytic community, the host plant, and it's environment. A model of the organization of the epiphytic community on Posidonia leaves is presented. “Ultra‐ecology” is a term introduced to denote a type of SEM research in the micro‐environment which is analogous to in situ investigation in “macroscopic” ecological work.